starpower: the u.s. and the international quest for fusion

Starpower: The U.S. and the InternationalQuest for Fusion Energy

October 1987

NTIS order #PB88-128731

Recommended Citation:U.S. Congress, Office of Technology Assessment, Starpower: The U.S. and the Internna-tional Quest for Fusion Energy, OTA-E-338 (Washington, DC: U.S. Government PrintingOffice, October 1987).

Library of Congress Catalog Card Number 87-619854

For sale by the Superintendent of DocumentsU.S. Government Printing Office, Washington, DC 20402-9325

(order form can be found in the back of this report)

.

ForewordFusion research, offering the hope of an energy technology with an essentially un-

limited supply of fuel and relatively attractive environmental impacts, has been con-ducted worldwide for over three decades. In the United States, increased budgetarypressures, along with a decreased sense of urgency, have sharpened the competitionfor funding between one research program and another and between energy researchprograms and other components of the Federal budget. This report, requested by theHouse Committee on Science, Space, and Technology and endorsed by the SenateCommittee on Energy and Natural Resources, reviews the status of magnetic confine-ment fusion research and compares its progress with the requirements for develop-ment of a usefuI energy technology. The report does not analyze inertial confinementfusion research, which is overseen by the House and Senate Armed Services Committees.

OTA analyzed the magnetic fusion research program in three ways: (1) as an energyprogram, by identifying important features of the technology and discussing its possi-ble role in the energy supply mix; (2) as a research program, by discussing its role intraining scientists and developing new fields of science and technology; and (3) as aninternational program, by reviewing its history of international cooperation and itsprospects for even more extensive collaboration in the future.

OTA could not have conducted this work without the valuable assistance it re-ceived from many organizations and individuals. I n particular, we would like to thankthe advisory panel members, workshop participants, and outside reviewers, who pro-vided guidance and extensive critical reviews to ensure the accuracy of the report.Responsibility for the final report, however, rests solely with the Office of TechnologyAssessment.

Magnetic Fusion Research Advisory PanelWilliam Carey, Panel Chair

Executive Officer, American Association for the Advancement of Science

Ellen BermanExecutive DirectorConsumer Energy Council of America

Linda CohenAssistant Visiting Professor of EconomicsUniversity of Washington

Paul Craigprofessor of PhysicsDepartment of Applied ScienceUniversity of California, Davis

Betty JensenNuclear and Environmental Program ManagerResearch and DevelopmentPublic Service Electric & Gas Co.

Hans LandsbergSenior Fellow EmeritusResources for the Future

Lawrence LidskyProfessor of Nuclear EngineeringMassachusetts Institute of Technology

Harold Forsen Irving MintzerManger of Research and Development Senior AssociateBechtel National, Inc. World Resources Institute

T. Kenneth Fowler Robert parkAssociate Director Executive DirectorMagnetic Fusion Energy Office of Public AffairsLawrence Livermore National Laboratory American Physical Society

Melvin GottliebDirector EmeritusPrinceton Plasma Physics Laboratory

L. Charles HebelManager, Research PlanningCorporate Research Technical StaffXerox Corp.

Robert HirschVice PresidentArco Oil & Gas Co.

Leonard HymanVice PresidentMerrill Lynch Capital Markets

Murray RosenthalAssociate Laboratory Director for Advanced

Energy SystemsOak Ridge National Laboratory

Eugene SkolnikoffDirectorCenter for International StudiesMassachusetts Institute of Technology

Herbert WoodsonDirectorCenter for Energy StudiesUniversity of Texas, Austin

NOTE: OTA appreciates and is grateful for the valuable assistance and thoughtful critiques provided by the advisory panelmembers. The panel does not, however, necessarily approve, disapprove, or endorse this report. OTA assumes fullresponsibility for the report and the accuracy of its contents.

iv

OTA Project Staff on Magnetic Fusion Research

Lionel S. Johns, Assistant Director, OTAEnergy, Materials, and International Security Division

Peter D. Blair, Energy and Materials

Gerald L. Epstein, Project

Program Manager

Di rector

Dina K. Washburn

Contractors

Wilfrid K o h l Leonard Lynn

Paul Josephson Lynn Powers

Fusion Power Associates

Battelle Pacific Northwest Laboratories

Administrative Staff

Lillian Chapman Linda Long Barbara J. Carter

Workshop Participants and Other Outside Reviewers

Workshop 1: Fusion Research

Panelists

Robert Seamans, Workshop ChairSenior LecturerAeronautics and Astronautics

DepartmentMassachusetts Institute of

Technology

Sibley BurnettGeneral ManagerApplied Superconetics DivisionGA Technologies

Ronald DavidsonDirectorPlasma Fusion CenterMassachusetts Institute of

Technology

Stephen DeanPresidentFusion Power Associates

Harold ForsenManager of Research and

DevelopmentBechtel National, Inc.

T. Kenneth FowlerAssociate DirectorMagnetic Fusion EnergyLawrence Livermore National

Laboratory

Harold FurthDirectorPrinceton Plasma Physics

Laboratory

Melvin GottliebDirector EmeritusPrinceton Plasma Physics

Laboratory

Robert HirschVice PresidentArco Oil & Gas Co.

Robert KrakowskiGroup LeaderSystems Study GroupLos Alamos National Laboratory

Lawrence LidskyProfessor of Nuclear EngineeringMassachusetts Institute of

Technology

Chuan Sheng LiuChairmanDepartment of Physics and

AstronomyUniversity of Maryland, College

Park

Thomas RatchfordAssociate Executive OfficerAmerican Association for the

Advancement of Science

John SheffieldAssociate Director for

ConfinementFusion Energy DivisionOak Ridge National Laboratory

Herbert WoodsonDirectorCenter for Energy StudiesUniversity of Texas, Austin

Contributor

N. Anne DaviesAssistant DirectorOffice of Fusion EnergyU.S. Department of Energy

Workshop II: InternationalCooperation

Eugene Skolnikoff, WorkshopChair

DirectorCenter for International StudiesMassachusetts Institute of

Technology

Harold BenglesdorfVice PresidentInternational GroupInternational Energy Associates

Limited

Diana BieliauskasProgram OfficerOffice of Soviet and East European

AffairsNational Academy of Sciences

Justin BloomPresidentTechnology International, Inc.

Judy BostockOperations Research AnalystU.S. Office of Management and

Budget

Melvin GottliebDirector EmeritusPrinceton Plasma Physics

Laboratory

Paul HuraySenior Policy AnalystGeneral ScienceU.S. Office of Science and

Technology Policy

Paul JosephsonProgram in Science, Technology

and SocietyMassachusetts Institute of

Technology

Wilfrid KohlDirectorInternational Energy ProgramJohns Hopkins School of

Advanced International Studies

Linda LubranoProfessorSchool of International ServiceThe American University

Leonard LynnAssistant ProfessorDepartment of Social and

Decision SciencesCarnegie-Mellon University

Charles NewsteadForeign Affairs OfficerBureau of Oceans and

International Environmental andScientific Affairs

U.S. Department of State

Douglas R. NortonChief of International Planning

and Program OfficeU.S. National Aeronautics and

Space Administration

Herman PollackResearch ProfessorDepartment of International AffairsGeorge Washington University

vi

Michael RobertsDirectorInternational ProgramsOffice of Fusion EnergyU.S. Department of Energy

Richard SamuelsProfessor of Political ScienceMassachusetts Institute of

Technology

U. John SakssChief of International Program

Support OfficeU.S. National Aeronautics and


Workshop Ill: Energy Context

Robert Fri, Workshop ChairPresidentResources for the Future

Truman AndersonDirectorProgram Planning and AnalysisOak Ridge National Laboratory

Charles BackusAssistant DeanCollege of Engineering and

Applied ScienceArizona State University

Charles BergProfessor and Head of DepartmentDepartment of Mechanical

EngineeringNortheastern University

Jan BeyeaVice President of ScienceNational Audubon Society

Paul CraigProfessor of PhysicsDepartment of Applied ScienceUniversity of California, Davis

Daniel DreyfusVice PresidentStrategic Analysis and Energy

ForecastingGas Research Institute

James A. EdmondsSenior Research EconomistBattelle Pacific Northwest

Laboratories

Harold FeivesonCenter for Energy and

Environmental StudiesPrinceton University

Bill KeepinSchool of Engineering and Applied

SciencePrinceton University

Carlo La PortaDirector of ResearchSolar Energy Industries Association

René MaIèsSenior Vice President and

PrincipalDecision Focus, Inc.

Michael MauelAssistant ProfessorDepartment of Applied Physics

and Nuclear EngineeringColumbia University

Irving MintzerSenior AssociateWorld Resources Institute

Eric ReichlRetired, Conoco Coal Corp.

Arthur RosenfeldDirectorCenter for Building ScienceLawrence Berkeley Laboratory

John SiegelVice PresidentAtomic Industrial Forum

Don SteinerInstitute ProfessorDepartment of Nuclear

Engineering and EngineeringPhysics

Rensselaer Polytechnic Institute

Other Outside Reviewers

Mohamed AbdouUniversity of California, Los

Angeles

Charles BakerArgonne National Laboratory

David BaldwinLawrence Livermore National

Laboratory

Richard BarnesU.S. National Aeronautics and


Lee BerryOak Ridge National Laboratory

Joan Lisa BrombergLaser History Project

Daniel ChavardesEmbassy of France

Daniel CohnMassachusetts Institute of

Technology

Donald L. CookSandia National Laboratories

Tony CoxEmbassy of the United Kingdom

John DeutchMassachusetts Institute of

Technology

Thomas J. FessendenLawrence Berkeley Laboratory

Thomas G. FinnU.S. Department of Energy

William HoganLawrence Livermore National

Laboratory

John HoldrenUniversity of California, Berkeley

Paul KolocPhaser Corp.

Dennis MahlumBattelle Pacific Northwest

Laboratories

George MileyUniversity Fusion Associates

David OverskeiGA Technologies

John RichardsonNational Research Council

Marshall RosenbluthUniversity of Texas, Austin

Richard RowbergCongressional Research Service

Mike SaltmarshOak Ridge National Laboratory

vii

John Santarius F. Robert Scott Albert TeichUniversity of Wisconsin, Madison Retired, Electric Power Research American Association for the

Institute Advancement of ScienceWinfried SchmidtKarlsruhe Nuclear Research Center

Richard Siemons Robert W. TurnerLos Alamos National Laboratory U.S. Department of Defense

Ken Schultz Joel Snow Wim Van DeelenGA Technologies U.S. Department of Energy European Communities Delegation

viii

.

ContentsChapter Page

I, Executive Summary. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

2. Introduction and Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

3. History of Fusion Research . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

4. Fusion

5. Fusion

6. Fusion

7. Fusion

8. Future

Appendixes

A.

B.

c.D.

Science and Technology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

as

as

as

an Energy Program. . . . . . . . . . . . . . . . . . . . . . . . . , . . . . . . . . . . . . . . . . . .105

a Research Program . . . . . . . , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .131

an International Program . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . , . , .155

Magnetic Fusion Program . . . . . . . . . . . ..................189

Page

Non-Electric Applications for Fusion . . . . . . . . . . . . . . . . . . . . . ................201

Other Approaches to

Data for Figures . . . .

List of Acronyms and

Fusion. .

. . . . . . . .

Glossary

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 205

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 209

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213

Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .........227

ix

Chapter 1

Executive Summary

CONTENTS

Page

Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Potential Role of Fusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .The Policy Context . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Findings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

A Quick Fusion Primer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .The Fusion Reaction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .The Feasibility of Fusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Probability of Success . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

History of Magnetic Confinement Fusion Research . . . . . . . . . . . . . . . . . . . . . . . .1950s and 1960s . . . . . . . . . . .1970s and 1980s . . . . . . . . . . .

Fusion Science and TechnologyConfinement Concepts . . . . . .Reactor Development . . . . . . .Future Plans and Facilities . . .Schedules and Budgets . . . . . .Status of the World Programs.

Fusion as an Energy Program . . .Safety . . . . . . . . . . . . . . . . . . . .Environmental Characteristics.Nuclear Proliferation PotentialResource Supplies . . . . . . . . . .cost. . . . . . . . . . . . . . . . . . . . . .Fusion’s Energy Context . . . . .

Fusion as a Research Program . .Near-Term Benefits . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Near-Term Financial and Personnel Needs . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Participation in the Magnetic Fusion Program , . . . . . . . . . . . . . . . . . . . . . . . . .

Fusion as an International Program. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Opportunities for Increased Collaboration ., . . . . . . . . . . . . . . . . . . . . . . . . . . .Benefits and Liabilities of Cooperation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Obstacles to International Cooperation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .The International Thermonuclear Experimental Reactor . . . . . . . . . . . . . . . . . .

Figures

33346688889

11111212151616171818191919202021212424252526

Figure No. Page

l-1. Historical Magnetic Fusion R&D Funding, 1951-87 (in 1986 dollars) . . . . . . 41-2, Historical Magnetic Fusion R&D Funding, 1951-87 (in current dollars) . . . . 51-3.The D-T Fusion Reaction and a Fission Reaction . . . . .1-4. Systems in a Fusion Electric Generating Station . . . . . .1-5. Systems in the Fusion Power Core. . . . . . . . .l-6. Annual Appropriations of DOE Civilian R&D

TableTable No.

l-1.Classification of Confinement Concepts. . . . .

. . . . . . . .Programs

. . . . . . . .

. . . . . . . . . . . . . . . . . 7

. . . . . . . . . . . . . . . . . 13

. . . . . . . . . . . . . . . . . 14

. . . . . . . . . . . . . . . . . 22

Page

. . . . . . . . . . . . . . . . . 12

Chapter 1

Executive Summary

OVERVIEW

Potential Role of Fusion

If successfully developed, nuclear fusion couldprovide humanity with an effectively unlimitedsource of electricity that has environmental andsafety advantages over other electric energy tech-nologies. However, it is too early to tell whetherthese advantages, which could be significant, canbe economically realized. Research aimed at de-veloping fusion as an energy source has beenvigorously pursued since the 1950S, and, despiteconsiderable progress in recent years, it appearsthat at least three decades of additional researcharid development will be required before a pro-totype commercial fusion reactor can be dem-onstrated.

The Policy Context

The budget for fusion research increased morethan tenfold in the 1970s, due largely to grow-ing public concern about environmental protec-tion and uncertainty in long-range energy sup-ply. However, a much-reduced sense of publicurgency in the 1980s, coupled with the mount-ing Federal budget deficit, halted and thenreversed the growth of the fusion budget. Today,the fusion program is being funded (in 1986 dol-lars) at about half of its peak level of a decadeago (see figures 1-1 and 1-2).

The change in the fusion program’s status overthe past 10 years has not resulted from poor tech-nical performance or a more pessimistic evalua-tion of fusion’s prospects. On the contrary, theprogram has made substantial progress. How-ever, the disappearance of a perceived need fornear-term commercialization has reduced theimpetus to develop commercial fusion energyand has tightened pressure on fusion researchbudgets. Over the past decade, the fusion pro-gram has been unable to maintain a constantfunding level, much less command the substan-

tial funding increases required for next-generationfacilities. In fact, due to funding constraints, theprogram has been unable to complete and oper-ate some of its existing facilities.

The Department of Energy (DOE) manages theU.S. fusion program, and its goal is to evaluatefusion’s technological feasibility–to determinewhether or not a fusion reactor can be designedand built—early in the 21st century. A positiveevaluation would enable a decision to be madeat that time to construct a prototype commercialreactor. However, this schedule cannot be metunder existing U.S. fusion budgets. The DOEplan requires either that U.S. budgets be in-creased substantially or that the world fusionprograms collaborate much more closely on fu-sion research.

Choices made over the next several years canplace the U.S. fusion program on one of four fun-damentally different paths, which are discussedmore thoroughly in chapter 8 of this report:

1

2.

3.

With substantial funding increases, the fu-sion program could complete its currentlymapped-out research effort domestically, per-mitting decisions to be made early in thenext century concerning fusion’s potentialfor commercialization.At only moderate increases in U.S. fundinglevels, the same results as above might beattainable—although possibly somewhatdelayed–if the United States can work withsome or all of the world’s other major fu-sion programs (Western Europe, Japan, andthe Soviet Union) at an unprecedented levelof collaboration.Decreased funding levels, or current fund-ing levels in the absence of extensive col-laboration, would require modification ofthe program’s overall goals. At these con-strained funding levels, U.S. evaluation offusion as an energy technology would bedelayed.

3

4 ● Starpower: The u.s. and the International Quest for Fusion Energy

Figure 1-1 .—Historical Magnetic Fusion R&D Funding, 1951087 (in 1986 dollars)

1955 1960 1965 1970 1975 1980 1985

YearSOURCE: U.S. Department of Energy, Office of Energy Research, letter to OTA project staff, Aug. 15, 1986.

4. If fusion research ceased in the UnitedStates, the possibility of domestically devel-oping fusion as an energy technology wouldbe foreclosed unless and until funding wererestored. Work would probably continueabroad, although possibly at a reduced pace; ●

resumption of research at a later time in theUnited States would be possible but difficult.

Findings

Here are some of the overall findings fromOTA’s analysis:

● Experiments now built or proposed should, ●

over the next few years, resolve most of themajor remaining scientific uncertainties re-garding the fusion process. If those experi-

ments do not uncover major surprises, it islikely–although by no means certain–thatthe engineering work necessary to build anelectricity-producing fusion reactor can becompleted successfully.Additional scientific understanding and tech-nological development is required before fu-sion’s potential can be assessed. It will takeat least 20 years, under the best circum-stances, to determine whether constructionof a prototype commercial fusion reactor willbe possible or desirable; additional time be-yond then will be required to build, oper-ate, and evaluate such a device.It is now too early to tell whether fusion re-actors, once developed, can be economi-cally competitive with other energy tech-nologies.

C/7. I.—Executive Summary “ 5

150

100

50

0

Figure 1-2.—Historical Magnetic Fusion R&D Funding, 1951-87 (In current dollars)

1955 1960 1965 1970 1975


1980 1985

● Demonstration and commercialization of fu-sion power will take several decades aftercompletion of the research program. Even ●

under the most favorable circumstances, itdoes not appear likely that fusion will be ableto satisfy a significant fraction of the Nation’selectricity demand before the middle of the21st century.

• With appropriate design, fusion reactorscould be environmentally superior to other ●

nuclear and fossil energy production tech-nologies. Unlike fossil fuel combustion, fu-sion reactors do not produce carbon dioxidegas, whose accumulation in the atmospherecould affect world climate. Unlike nuclearfission–the process utilized in existing nu-clear powerplants—fusion reactors should

not produce high-level, long-lived radio-active wastes.One of the most attractive features of fusionis its essentially unlimited fuel supply. Theonly resources possibly constraining fusion’sdevelopment might be the materials neededto build fusion reactors. At this stage of de-velopment, it is impossible to determinewhat materials will eventually be developedand selected for fusion reactor construction.If fusion technology is developed success-fully, it should be possible to design fusionreactors with a higher degree of safety as-surance than fission reactors. It may be possi-ble to design fusion reactors that are incapa-ble of causing any immediate off-site fatalitiesin the event of malfunction, natural disaster,or operator error.

6 ● Starpower : The us and the Intemational Quest for fusion Energy

●

●

●

●

potential problems with other major sourcesof electricity—fossil fuels and nuclearfission–provide incentives to develop alter-nate energy technologies as well as to sub-stantially improve the efficiency of energyuse. Fusion is one of several technologies be-ing explored.It is unlikely that major, irreversible energyshortages will occur early in the next cen-tury that could only be ameliorated by thecrash development of fusion power. Thereis little to be gained—and a great deal to belost–by introducing fusion before its poten-tial economic, environmental, and safety ca-pabilities are attained. Even if difficulties withother energy technologies are encounteredthat call for the urgent development of analternative source of energy supply, thatalternative must be preferable in order to beaccepted. It would be unwise to emphasizeone fusion feature—economics or safety orenvironmental advantages—over the othersbefore we know which aspect will be mostimportant for fusion’s eventual acceptance.Due to the high risk and the long time be-fore any return can be expected, private in-dustry has not invested appreciably in fusionresearch and cannot be expected to do soin the near future. But, unless the govern-ment decides to own and operate fusiongenerating stations, the responsibility for fu-sion research, development, and commer-cialization must be transferred to private in-dustry at some stage. The nature and timingof this transition are highly controversial.Fusion research has provided a number of

●

●

●

A QUICK FUSION

near-term benefits such as development ofplasma physics, education of trained re-searchers, contribution to “spin-off” tech-nologies, and support of the scientific stat-ure of the United States. However, fusion’scontributions to these areas do not imply thatdevoting the same resources to other fieldsof study would not produce equivalent ben-efits. Therefore, while near-term benefits doprovide additional justification for conduct-ing research, it is difficult to use them tojustify one field of study over another.Fusion research has a long history of success-ful and mutually beneficial international co-operation, If this tradition can be extrapo-lated in the future to an unprecedented levelof collaboration, much of the remaining costof developing fusion power can be sharedamong the world’s major fusion programs.International collaboration cannot substitutefor a strong domestic research program. Ifthe domestic program is sacrificed to sup-port international projects, the rationale forcollaboration will be lost and the ability toconduct it successfully will be compromised.Agreeing to collaborate on fusion research,both within the U.S. Government and be-tween the U.S. Government and potentialpartners, will require sustained support at thehighest levels of government. A variety of po-tential difficulties associated with large-scalecollaborative projects will have to be re-solved, and presidential support will be re-quired. If these difficulties can be resolved,the benefits of successful collaboration aresubstantial.

The Fusion Reaction isotopes; two of them—deuterium (D) and tritium(T)–in combination work the best in fusion re-

in a fusion reaction, the nuclei–or central actions. The kinetic energy released in the D-Tcores—of light atoms combine or fuse together;. . reaction can be converted to heat, which in turnwhen they do, energy is released. In a sense, tu- can be used to make steam to drive a turbine tosion is the opposite of fission, the process utilized generate electricity.in existing nuclear powerplants (see figure 1 -3),in which energy is released when a heavy nucleus

But a fusion reaction cannot happen unless cer-splits into smaller pieces. tain conditions are met. To fuse hydrogen nucleiThe lightest atom, hydrogen, is the easiest one together, the nuclei must be heated to approxi-

to use for fusion. Hydrogen has three forms, or mately 100 million degrees Celsius (C). At these

.

Ch. I.—Executive Summary ● 7

Figure 1-3. —The D-T Fusion Reaction and a Fission Reaction

I). T fusion reaction

Tritium

Deuterium

Fuel

Neutron

FIssion fuel nUcleus

e Proton Kev: o Neutron

MeV: million electron volts

Reaction conditions (density, temperature, time)

Neutron 14.1 MeV

r. +

" Helium 3.5 MeV

ProdUCIS'

0--'" Neutron

Neutron

;~ ,':,:,I!~lUM L·~~t 2 *;,:'! -;''''_ ~ V-tP'~J nucleus

r

SOURCE: Adapted from Princeton Plasma Physics Laboratory, Information Bulletin NT·1: Fusion Power, 1984, p. 2; Office of Technology Assessment (fission), 1987.

8 ● Starpower: The U.S. and the International Quest for Fusion Energy

temperatures, matter exists as plasrna, a state inwhich atoms are broken down into electrons andnuclei. Keeping a plasma hot enough for a longenough period of time, and effectively confiningit, are crucial for generating fusion power.

While no solid container can withstand theheat of a plasma, magnetic fields may be able toconfine a plasma successfully. This assessmentdiscusses magnetic confinement research and thevarious magnetic field configurations that lookpromising for producing fusion power.

More detail on the basics of fusion power canbe found in chapter 2.

The Feasibility of Fusion

Before fusion powerplants can generate elec-tricity, fusion must be proven technologically andcommercially feasible.

Technological feasibility will require that bothscientific feasibility and engineering feasibility beshown. Scientists must bring fusion reactions tobreakeven, the point at which at least as muchenergy is produced as must be input to maintainthe reaction. Existing experiments are expectedto reach this long-elusive milestone by 1990. Be-yond breakeven, scientists have an even harderbut more important task of creating high energygain–energy output that is many times higherthan the energy input. Only when high-gain re-actions are produced will the scientific feasibilityof the fusion process be demonstrated. If a high-gain reaction reaches ignition, it will sustain it-self even when the external heat is turned off.

Once scientific feasibility of fusion as a poten-tial energy source is established, the engineer-ing development necessary to develop fusion re-actors must be completed. Engineering feasibilitydenotes the successful development of reliablecomponents, systems, and subsystems for oper-ating fusion reactors.

Scientific and engineering feasibility, althoughinvolving different issues, are interdependent.Demonstrating either one will require advancesto be made in basic scientific understanding aswell as in technological capability.

The goal of fusion research is to prove fusion’stechnological feasibility so that its commercialfeasibility is likely. To be marketable, fusion pow-er must be socially and environmentally accept-able and economically attractive compared to itscompetitors, and it must meet regulatory andlicensing requirements.

Probability of Success

Experiments now existing or proposed to bebuilt should be sufficient, within the next fewyears, to demonstrate fusion’s scientific feasibil-ity. If these experiments do not uncover unfavora-ble surprises, it appears likely–although not cer-tain—that fusion’s engineering feasibility can besubsequently established. Most of the technologi-cal and engineering challenges to designing andbuilding a reactor have been identified. How-ever, it cannot yet be determined whether or nota fusion reactor will be commercially attractive.

HISTORY OF MAGNETIC CONFINEMENT FUSION RESEARCH

1950s and 1960s

From 1951 until 1958, fusion research was con-ducted by the U.S. Atomic Energy Commission(AEC) in a secret program code-named “ProjectSherwood.” Many different magnetic confine-ment concepts were explored during the early1950s. Although researchers were careful to notethat practical applications lay at least 10 to 20years in the future, the devices being studied

were thought to be capable of leading directlyto a commercial reactor.

In reality, however, very little was known aboutthe behavior of plasma in experiments and evenless about how it would act under the conditionsrequired for fusion reactors. Experimental resultswere often ambiguous or misinterpreted, and thetheoretical understanding underlying the researchwas not well established. By 1958—as people

Ch. I.—Executive Summary ● 9

Photo credtt: Los Alamos National Laboratory

Perhapsatron, built and operated in the 1950s at LosAlamos Scientific Laboratory.

realized that harnessing magnetic fusion was go-ing to be difficuIt and that national security con-siderations were less immediate—the researchwas declassified. This action made widespreadinternational cooperation in fusion research pos-sible, particularly since the countries involvedrealized that the state of their research programswas more or less equivalent.

With the optimism of the 1950s tempered, fu-sion researchers in the United States proceededat a steady pace throughout the 1960s. In 1968,Soviet scientists announced a major breakthroughin plasma confinement in a device called a “toka-mak. ” After verifying Soviet results, the otherworld fusion programs redirected their effortstoward development of the tokamak.

1970s and 1980s

With the identification of the tokamak as a con-finement concept likely to reach reactor-levelconditions, the U.S. fusion program grew rapidly.Between 1972 and 1979, the fusion program’sbudget increased more than tenfold. This growthwas due in part to uncertainty in the early 1970sconcerning long-range energy supply; fusionenergy, with its potentially inexhaustible fuel sup-ply, appeared to be an attractive alternative toexhaustible resources such as oil and gas. In addi-

tion, the growth of the environmental movementand increasing opposition to nuclear fission tech-nology drew public support to fusion as an energytechnology that might prove more environmen-tally acceptable than other energy technologies.

The fusion program capitalized on this publicsupport; program leadership placed a high pri-ority on developing a research plan that couldlead to a demonstration reactor. Planning beganfor the Tokamak Fusion Test Reactor, a new ex-periment using D-T fuel that would reachbreakeven. By 1974, the funding increases nec-essary to pursue accelerated development of fu-sion were appropriated.

Program organization changed twice during the1970s. In 1974, Congress abolished the AEC andtransferred its energy research programs to thenewly created Energy Research and Develop-ment Administration (ERDA). ERDA assumedmanagement of the AEC’s nuclear fission and fu-sion programs, as well as programs in solar andrenewable technologies, fossil fuels, and conser-vation. Three years later, President Carter incor-porated the functions of ERDA into a new agency,the Department of Energy (DOE).

Under DOE, the fusion program did not havethe same sense of urgency. Fusion could not mit-igate the short-term oil and gas crisis facing theUnited States. Furthermore, as a potentially in-exhaustible energy source (along with solar energyand the fission breeder reactor), fusion was notexpected to be needed until well into the nextcentury. Therefore, there appeared to be no com-pelling reasons to rapidly develop a fusion dem-onstration plant.

Nevertheless, the Magnetic Fusion Energy Engi-neering Act of 1980 urged acceleration of the na-tional effort in magnetic fusion research, devel-opment, and demonstration activities. The actrecommended that funding levels for magneticfusion double (in constant dollars) within 7 years.However, Congress did not appropriate these in-creases, and there was no follow-up. Actual ap-propriations in the 1980s have not grown at thelevels specified in the act; in fact, since 1977, theyhave continued to drop in constant dollars.


Photo credit: Princeton Plasrna Physics Laboratory

Model C Stellarator at Princeton Plasma Physics Laboratory. Designed and built in the late 1950s, the Model C wasconverted into the United States’ first tokamak in 1970.

Despite constrained funding, the U.S. fusionprogram has made significant advances in plasmaphysics and fusion technology throughout the1980s. However, DOE has had to adjust its long-range planning to the new fiscal situation. In1985, it issued the Magnetic Fusion Program Plan(MFPP), which states that the goal of the fusionprogram is to establish the scientific and techno-logical base required for fusion energy. This planexplicitly recognizes that:

. . . although the need for and desirability of anenergy supply system based on the nuclear fu-

sion principle have not diminished, there is lessurgency to develop such a system. ’

The plan emphasizes the importance of interna-tional collaboration if the United States is to estab-lish fusion’s technological feasibility during theearly 21st century.

The history of U.S. magnetic confinement fu-sion research is discussed in chapter 3 of thisreport.

U.S. Department of Energy, Office of Energy Research, Magnetic Program P/an, DOE/ER-0214, February 1985, preface.

Ch. 1.—Executive Summary ● 11

FUSION SCIENCE

Great scientific progress has been made in thefield of fusion research over the past 35 years.The fusion program appears to be within a fewyears of demonstrating breakeven, an event thatwill show an impressive degree of understand-ing and technical capability. Nevertheless, manyscientific and technological issues must be re-solved before fusion reactors can be designed andbuilt. The principal scientific uncertainties involvewhat happens to a plasma when it generates ap-preciable amounts of fusion power. Because noexisting devices can produce significant amountsof power, this uncertainty currently cannot be ex-plored. Simply reaching breakeven will not re-solve the uncertainties, since the effects of inter-nally generating fusion power will not be fully

AND TECHNOLOGYrealized under breakeven conditions. An ignitedplasma, or at least one with high energy gain,must be studied. Issues to be resolved before fu-sion’s technological feasibility can be establishedare discussed more fully in chapter 4.

Confinement Concepts

Besides the behavior of ignited plasmas, thecharacteristics, advantages, and disadvantages ofvarious confinement concepts need further study.Several different concepts, utilizing different con-figurations of magnetic fields and different meth-ods of generating the fields, are being studied(table l-l).

Photo credit: Princeton Plasma Physics Laboratory

The Tokamak Fusion Test Reactor at Princeton Plasma Physics Laboratory,where breakeven experiments are scheduled for 1990.

12 ● Starpower The U.S. and the International Quest for Fusion Energy

Table 1-1.—Classification of Confinement Concepts

Well-developed Moderately developed Developingknowledge base knowledge base knowledge base

Conventional Tokamak Advanced Tokamak SpheromakTandem Mirror Field-Reversed ConfigurationStellarator Dense Z-PinchReversed-Field Pinch

SOURCE: Adapted from Argonne National Laboratory, Fusion Power Program, Technical Planning Activity: Final Report, com-missioned by the U.S. Department of Energy, Office of Fusion Energy, ANL/FPP-87-1, 1987, p. 15.

At this stage of the research program, it is notknown which confinement concepts can formthe basis of an attractive fusion reactor. The toka-mak is the most developed concept, and it hasattained plasma conditions closest to those re-quired in a fusion reactor. Its experimental per-formance has been encouraging, and it providesa standard for comparison to other concepts.Studies of reactor-like plasmas must be done intokamaks because no other concept has yet dem-onstrated the potential to reach reactor condi-tions. Most fusion technology development takesplace in tokamaks as well. Although tokamak be-havior has not yet been fully explained theoreti-cally, it may well be possible to design reactor-scale tokamaks on the basis of experimental per-formance in smaller tokamaks.

Research on alternatives to the tokamak con-tinues because it is not clear that the tokamakwill result in the most attractive or acceptable fu-sion reactor. Moreover, research conducted ondifferent concepts provides important insightsinto the fusion process. It remains to be seenwhich alternate concepts will be able to reachthe level of performance already attained by thetokamak, whether their relative strengths will bepreserved in the development process, and whatthe costs of developing these concepts to reactorscale will be. Nor is it known what the ultimatecapability of the tokamak concept will be.

Reactor Development

Just as an automobile is much more than sparkplugs and cylinders, a fusion reactor will containmany systems besides those that heat and con-fine the plasma. Fusion’s overall feasibility willdepend on all of the “engineering details” thatsupport the fusion reaction, convert the powerreleased in the reaction into usable energy, and

ensure safe, environmentally acceptable opera-tion. Developing and building these associatedsystems and integrating them into a reactor willrequire a technological development effort atleast as impressive as the scientific challenge ofunderstanding and confining fusion plasmas.

The overall fusion generating station (figure 1-4)consists of a fusion power core, which containsthe systems that support and recover energy fromthe fusion reaction, and the balance of p/ant,which converts this energy to electricity. Fusionreactor conceptual designs typically have balanceof plant systems similar to those found in exist-ing electricity generating stations. However, fusiontechnology may permit more advanced systemsto generate electricity in a manner that is qualita-tively different from the methods in use today.

The fusion power core, shown schematicallyin figure 1-5, is the heart of a fusion generatingstation. The systems in the core create and main-tain the plasma conditions required for fusion re-actions to occur. These technologies confine theplasma, heat and fuel it, remove wastes and im-purities, and, in some cases, drive electric cur-rents within the plasma. Other systems in the fu-sion power core recover heat from the fusionreactions, breed fuel, and provide shielding. Oneof the key requirements for many of these fusionpower core systems is the development of suit-able materials that are resistant to the intense neu-tron radiation generated by the plasma. The envi-ronmental and safety aspects of fusion reactorsdepend significantly on materials choice.

Future Plans and Facilities

Many additional experiments and facilities willbe required to investigate both scientific and tech-nological aspects of fusion. Preliminary experi-ments that investigate the basic characteristics of

Ch. I.—Executive Summary c 13

In

Figure 1=4.—Systems in a Fusion Electric Generating Station

Rejectedheat

new confinement concepts can be done for a fewmiIlion dollars or less. As concepts approach re-actor capability, successively larger facilities arerequired, with reactor-scale experiments costinghundreds of millions of dollars each. Obviously,the U.S. fusion program cannot afford to inves-tigate every confinement concept at the reactorscale; choices must be made on the basis of in-formation gathered at earlier stages.

Additional facilities will be required to resolvegeneral issues not identified with specific confine-ment concepts. In particular, facilities will beneeded to address the scientific issues associatedwith ignited plasmas. Many physical processesassociated with ignition can be studied in ignitedplasmas that only last for a few seconds; otheraspects, such as fueling and removal of reactionproducts, will require a facility that can produceignited plasmas lasting hundreds of seconds.Short- and long-burn ignition questions can bestudied either in a single device or in two sepa-rate devices. DOE has chosen to separate them,

Electric powerout to grid

and it has requested funds in its 1988 budget tobuild a short-pulse ignition facility, called theCompact Ignition Tokamak (CIT). Total costs forthis device are estimated at about $360 million.

CIT cannot satisfy the requirements for longpulses, materials studies, or nuclear technologytesting. These needs could be addressed in sep-arate facilities and later combined (except for ma-terials testing) in a device that would integrateall the systems for the first time. Alternatively,many of these issues could be addressed and in-tegrated simultaneously in a next-generation engi-neering test reactor. Satisfying a number of pur-poses simultaneously would complicate anengineering test reactor’s design and could forcetrade-offs between the different objectives. More-over, it is likely that each additional requirementwill increase the price of the machine. Even so,a general-purpose engineering test reactor wouldpresumably cost less than the combination of sev-eral single-purpose facilities and a subsequentsystem-integration device.


SOURCE: Modified from “The Engineering of Magnetic Fusion Reactors, ” by Robert W. Corm. Copyright © 1983 by ScientificAmerican, Inc. All rights reserved

DOE has not yet determined the features to be Thermonuclear Experimental Reactor (ITER), beincluded in an engineering test reactor. It is com- undertaken.mitted to investigating the possibility for interna-tional cooperation on the device; the U.S. Gov- Materials testing will require a dedicated de-ernment has proposed to the other major world vice even if a general-purpose engineering testfusion programs that collaborative conceptual de- reactor is built. To complete lifetime irradiationsign of such a device, called the International testing of reactor materials in a reasonable

Ch. I.—Executive Summary “ 75

Photo credit” GA Technologies

View inside vacuum vessel of D II I-D fusion device at GA Technologies, San Diego, CA.The plasma is contained within this vessel.

amount of time, a source of fusion neutrons sev-eral times more intense than expected from acommercial reactor is required. While an engi-neering test reactor wouId duplicate conditionsexpected in a reactor, it would not be able to con-duct accelerated materials tests at several timesthe radiation levels to be found in a reactor.

Schedules and Budgets

A major fusion-communitywide study has iden-tified the technical tasks and facilities requiredto establish fusion’s technological feasibility andenable a decision to be made early in the nextcentury to start the commercialization process,2

2Argon ne National Laboratory, Fusion Power Program,

f’/anning Activity: Report, commissioned by DOE, Office

of Fusion Energy AN L/FPP-87-l, 1987,

The study estimated that the worldwide cost ofthis research effort would be about $20 billion.As mentioned earlier, developing fusion on thisschedule will require either substantially in-creased U.S. funding or wide-scale collaborationamong the world fusion programs.

The requirements and schedule for establish-ing fusion’s subsequent commercial feasibility aremore difficult to project, and they depend on fac-tors other than fusion research funding. Conceiv-ably, if the research program provides the infor-mation necessary to design and build a reactorprototype, such a device could be started earlyin the next century. After several years of con-struction and several more years of qualificationand operation, a base of operating experiencecould be acquired that would be sufficient for thedesign and construction of commercial devices.

16 ● S t a r p o w e r: The us. and the Internat jonal Quest for Fusion Energy

If the regulatory and licensing process proceededconcurrently, vendors and users could begin toconsider manufacture and sale of commercial fu-sion reactors sometime during the middle of thefirst half of the next century. From that point, itwill take decades for fusion to penetrate energymarkets. Even under the most favorable circum-stances, it does not appear likely that fusion willbe able to satisfy a significant fraction of the Na-tion’s electricity demand before the middle ofthe 21st century.

This schedule for demonstrating technologicaland commercial feasibility requires a number ofassumptions. Sufficient financial support or inter-national coordination must be attained so thatthe research needed to establish technologicalfeasibility can be completed early in the next cen-tury. Research must proceed without major dif-ficulty and must lead to a decision to build a re-actor prototype. The prototype must operate asexpected and prove convincingly that fusion isboth feasible and preferable to its alternatives.

Status of the World Programs

The United States, Western Europe, Japan, andthe Soviet Union all have major programs in fu-sion research that are at similar stages of devel-opment. Each program has built or is building amajor tokamak experiment. The U.S. TokamakFusion Test Reactor and the European Commu-nity’s Joint European Torus are operating and areultimately intended to reach breakeven condi-tions with D-T fuel. Japan’s JT-60 tokamak, alsooperational, will not use tritium fuel; it is intendedto generate a “breakeven-equivalent” plasmausing ordinary hydrogen and deuterium. The So-viet Union’s T-1 5 experiment is under construc-

Photo credit: JET Joint Undertaking

The Joint European Torus, located in Abingdon,United Kingdom.

tion. In addition to these major devices, each ofthe programs operates several smaller fusion ex-periments that explore the tokamak and otherconfinement concepts. Each program is also de-veloping other aspects of fusion technology.

FUSION AS AN ENERGY PROGRAMThe long-term goal of the fusion program in the oriented towards producing fuel for fission re-

United States is to produce electricity. Fusion reactors .)3actors can also produce fuel for fission reactorsby irradiating suitable materials with neutrons, 3A fusion reactor that produces fissionable fuel, or one that gen -

but this ability is not seen as fusion’s primary ap- erates part of its energy from fission reactions that are induced by

plication in the United States, Western Europe, fusion-generated neutrons, is called a reactor.Although the applications and characteristics of hybrid reactors are

or Japan. (The Soviet fusion effort does appear different from those of “pure fusion” reactors that do use or

Ch. I.—Executive Summary . 17

Photo credit; Japanese Atomic Energy Research Institule

The JT-60 tokamak, located in Naki-machi, Japan.

for fusion reactors thatbeen studied for a num-research program is far

Hypothetical designsproduce electricity havebet of years. Since thefrom complete, however, current systems studiesare necessarily tentative. Although these studieshave been especially valuable in identifying im-provements in fusion physics or technology thatappear to have the greatest potential for makingfusion reactors attractive and competitive, theycannot provide a firm basis for assessing fusion’spotential as a future energy source. Nevertheless,the studies do provide a basis for projecting the

produce fissionable materials, there is l i tt le difference at present

I n the research requ I red to develop the two. Differences wil I ariseat subsequent stages of research and development.

This assessment focuses on pure fusion reactors; hybrid reactorsare discussed briefly in app. A of the full report,

possible characteristics of fusion reactors. Theseprojections will improve as additional knowledgeand understanding enable scientists and engi-neers to better model the reactor systems. Chap-ter 5 of this report discusses projected charac-teristics of fusion reactors, along with the factorsthat will determine the degree to which fusionis accepted in the energy marketplace.

Safety

If fusion development is successful, it maybepossible to ensure that accidents due to mal-functions, operator error, or natural disasterscould not result in immediate public fatalities.This safety would depend on passive systems oron materials properties, rather than on active sys-tems that could fail or be overridden. A number

18 . Starpower: The U.S. and the International Quest for Fusion Energy

of attributes of the fusion process should makesafety assurance easier for fusion reactors thanfor fission reactors:

●

●

●

●

Fusion reactions cannot run away. Fuel willbe continuously injected, and the amountcontained inside the reactor chamber willonly operate the reactor for a short periodof time. Energy stored in the plasma at anygiven time can be dissipated by the vacuumchamber in which the fusion reactions takeplace.With appropriate choice of materials, theamount of heat produced by the decay ofradioactive materials in the reactor after thereactor has been shut down should be lessfor fusion reactors than for fission reactors.Fusion reactors should therefore require sim-pler post-shutdown or emergency coolingsystems, if any such systems are required atall.The radioactive inventory of a fusion reactor—in terms of both the total amount presentin the reactor and the fraction that would belikely to be released in an accident–shouldbe smaller than that of a fission reactor. Fu-sion will not generate long-lived wastes suchas those produced by fission reactors. Exceptfor tritium gas, the radioactive substancespresent in fusion reactors will generally bebound as metallic structural elements.in the event of accidental release, fusion re-actors should not contain radioactive elements—except tritium —that would tend to be ab-sorbed in biological systems. Tritium is aninherent potential hazard, but the risk itposes is much smaller than that of the gase-ous or volatile radioactive byproducts pres-ent in fission reactors, Active tritium inven-tories in current fusion reactor designs aresmall enough that even their complete re-lease should not produce any prompt fatal-ities off-site. Moreover, fusion reactors oper-ating on advanced fuel cycles would notneed tritium.

This discussion does not imply that fission re-actors are unsafe. Indeed, efforts are underwayto develop fission reactors whose safety does notdepend on active safety systems. However, thepotentially hazardous materials in fission reactors

include fuels and byproducts that are inherentto the technology. While the tritium fuel requiredby a D-T fusion reactor is a potential hazard, thebyproducts of fusion are not in themselves haz-ardous, Since there is much greater freedom tochoose materials that minimize safety hazards forfusion reactors than there is in fission reactor de-sign, a higher degree of safety assurance shouldbe attainable with fusion.

Environmental Characteristics

Fusion reactors will not be free of radioactivewastes, although the wastes that they produceshould be easier to dispose of than fissionwastes. Fusion reactors will not generate the long-Iived and highly radioactive wastes contained inthe spent fuel rods of fission reactors. Fusionwastes may have a greater physical volume thanfission wastes, but they should be substantiallyless radioactive and orders of magnitude lessharmful. The amount of radioactive waste antic-ipated from different fusion designs ranges overseveral orders of magnitude because it dependson the choice of materials with which the reactoris made. Special materials that do not generateintense or long-lived radioactive wastes may bedeveloped that would make it possible to sub-stantially reduce the radioactive waste producedby a fusion reactor.

Nuclear Proliferation Potential

The ability of a fusion reactor to breed fission-able fuel could increase the risk of nuclearproliferation. Proliferation concerns relate to thepossibility of constructing fission-based or atomicweapons. Although fusion reactors contain tritium,a material that could be used in principle to makethermonuclear weapons such as the hydrogenbomb, such weapons cannot be built by partieswho do not already possess fission weapons.

A reactor deriving all its energy from fusion andproducing only electricity would not contain ma-terials usable in fission-based nuclear weapons,and it would be impossible to produce such ma-terials by manipulating the reactor’s normal fuelcycle. However, material usable in fission weap-ons could be produced by placing other materi-

Ch. I.—Executive Summary “ 1 9

als inside the reactor and irradiating them withfusion neutrons. This procedure, in effect, wouldconvert a pure fusion reactor into a fission/fusionhybrid reactor (see note 3, above). If such modifi-cations to the reactor structure were easily de-tected or were extremely difficult and expensive,pure fusion reactors would be easier to safeguardagainst surreptitious production of nuclear weap-ons material than existing fission reactors, and fu-sion reactors would therefore pose less of aproliferation risk.

Resource Supplies

Shortage of fuels will not constrain fusion’sprospects for the foreseeable future. Enoughdeuterium is contained in the earth’s waters tosatisfy energy needs through fusion for billionsof years at present consumption rates. Domes-tic lithium supplies should offer thousands ofyears worth of fuel, with vastly greater amountsof potentially recoverable lithium contained inthe oceans.

Materials required to build fusion reactors maypose more of a constraint on fusion’s develop-ment than fuel supply, but at this stage of researchit is impossible to determine what materials willeventually be developed and selected for fusionreactor construction. No particular materialsother than the fuels appear at present to be in-dispensable for fusion reactors.

cost

It is currently impossible to determinewhether a fusion reactor, once developed, willbe economically competitive with other energytechnologies. The competitiveness of fusionpower will depend not only on successful com-pletion of the remaining research program butalso on additional factors that are impossible topredict—e.g., plant licensability, constructiontime, and reliability, not to mention factors lessdirectly related to fusion technology such as in-terest rates. Fusion’s competitiveness will also de-pend on technical progress made with otherenergy technologies.

Fusion’s Energy Context

The factors that influence how successfullyfusion technology will compete against otherenergy technologies include how well its char-acteristics meet the requirements of potential cus-tomers (most likely electric utilities) and how wellfusion compares to alternate electricity-generatingtechnologies. A more detailed look at these fac-tors

●

●

●

makes a number of points clear:

The overall size and composition of elec-tricity demand, by itself, should neither re-quire nor eliminate fusion as a supply op-tion. Supplies of both coal and uraniumappear adequate at reasonable prices tomeet high future demand in the absence offusion.4 It will be overall economics andacceptability, rather than total demand orfuel availability, which will determine themix of energy technologies.It is unlikely that any one technology willtake over the electricity supply market, bar-ring major difficulties with the others.Potential problems with currently foreseenfuture sources of electricity provide incen-tives to develop alternate energy technol-ogies and/or substantially improve the effi-ciency of energy use. Combustion of coalreleases carbon dioxide, whose accumula-tion in the atmosphere may affect world cli-mate; this problem may make increased reli-ance on coal undesirable. Safety, nuclearwaste, or nuclear proliferation concerns maycontinue to impair expansion of the nuclearfission option. The urgency for developingfusion, therefore, depends on assumptionsof the likelihood that existing energy tech-nologies will prove undesirable in thefuture.

4Coal supplies are adequate to provide power for centuries atcurrent rates of use. Uranium supplies should be available at a rea-sonable price until well into the next century without requiring ei-ther breeder reactors or reprocessing. Advanced, more efficient fis-sion reactors could delay the need for breeders or reprocessingstill further. With the use of breeders, uranium depos}ts becomeadequate for centuries.


● There is little to be gained and a great deal supply, that alternative must be preferableto be lost if fusion is prematurely intro- in order to be accepted, It would be unwiseduced without attaining its potential eco- to emphasize one fusion feature—economicsnomic, environmental, and safety capabil- or safety or environmental advantages—overities. Even in a situation where problems the others before we know which aspect willwith other energy technologies urgently call be most important for fusion’s eventualfor development of an alternative source of acceptance.

FUSION AS A RESEARCH PROGRAMThe ultimate objective of fusion research is to

produce a commercially viable energy source.Yet, because the research program is exploringnew realms of science and technology, it also pro-vides near-term, non-energy benefits. These ben-efits fall in four major categories.

Near-Term Benefits

1. Development of Plasma Physics

Plasma physics as a branch of science beganin the 1950s, driven by the needs of scientistsworking on controlled thermonuclear fusion and,later, by the needs of space science and expir-ation. The field of plasma physics has developedrapidly and has synthesized many areas of physicspreviously considered distinct disciplines. Mag-netic fusion research funding is crucial to the con-tinuation of plasma physics research; over halfof all Federal plasma physics research is fundedby the magnetic fusion program.

2. Educating Scientists

Educating scientists and engineers is one of themost widely acknowledged benefits of the fusionprogram. Over the last decade, DOE’s magneticfusion energy program has financed the educa-tion of most of the plasma physicists producedin the United States. DOE, through its magneticfusion program, directly supports university fu-sion programs and provides 37 fusion fellowshipsannually to qualified doctoral students. Trainingin plasma physics enables these scientists to con-tribute to defense applications, space and as-trophysical plasma physics, materials science, ap-

plied mathematics, computer science, and otherfields.

3. Advancing Science and Technology

Many high-technology research and develop-ment (R&D) programs produce secondary ben-efits or “spin -offs.” Over the years, the magneticfusion energy program has contributed to a va-riety of spin-off technologies with wide-rangingapplications in other fields. Among them are su-perconducting magnet technology, high-qualityvacuums, high-temperature materials, high-frequency and high-power radiofrequency waves,electronics, diagnostics and tools for scientificanalysis, high-speed mainframe computers, andparticle beams. Although spin-offs may benefitsociety, they are unanticipated results of researchand should not be viewed as a rationale for con-tinuing or modifying high-technology researchprograms. It is impossible to predict before-the-fact which research investments will have thegreatest spin-off return.

4. Stature

The stature of the United States abroad bene-fits from conducting high-technology research.The United States has been at the forefront of fu-sion R&D since the program began in the 1950s.Maintaining a first-rate fusion program has placedthe United States in a strong bargaining positionwhen arranging international projects, has at-tracted top scientists from other fusion programsto the United States, and has enhanced the repu-tation of the United States in scientific and tech-nical programs other than magnetic fusion.

Ch. I.—Executive Summary ● 2 1

Near-Term Financial andPersonnel Needs

Financial Resources

The Federal R&D budget has grown steadily inthe 1980s. The bulk of this growth has beendriven by increases in defense spending, but non-defense R&D has also grown. The fraction of theFederal R&D budget devoted to energy, however,has been steadily declining during the 1980s. Infiscal year 1987, energy R&D is estimated to ac-count for less than 4 percent of the Federal R&Dbudget.

virtually all fusion research is funded by theFederal Government; due to fusion’s long-term,high-risk nature, there is little private sector in-vestment. Even though the fusion budget hasfallen, in constant dollars, to less than half of its1977 peak, magnetic fusion has fared better thanmany other energy programs. DOE’s energy pro-grams in nuclear fission, fossil fuels, conservation,and renewable energy technologies have lostproportionately more of their Federal support be-cause it is believed that private sector financingis more appropriate in these cases. Figure 1-6shows the budgets of DOE’s larger energy R&Dprograms during the 1980s.

Personnel Resources

The fusion program currently supports approx-imately 850 scientists, 700 engineers, and 770technicians. s These researchers work primarilyat national laboratories and in university and col-lege fusion programs. According to estimates byDOE, the number of Ph.D. staff positions in thefusion program has declined by almost 20 per-cent since 1983. Most of the fusion researcherswho have left the fusion program have foundwork in other research programs within DOE andthe Department of Defense. Many former fusionresearchers, for example, are working on Strate-gic Defense Initiative projects,

SThOnlas G. Finn, Department of Energy, Office of Fusion Energy,letter to the Office of Technology Assessment, Mar. 12, 1987. Thenumber of technicians represents only full-time staff associated withexperiments; shop people and administrative staff are not included.Figures for scientists and engineers include university professorsand post-doctoral appointments; graduate student employees arenot included.

Participation in the MagneticFusion Program

The Department of Energy’s Office of FusionEnergy (OFE) conducts research through threedifferent groups: national laboratories, collegesand universities, and private industry. Each ofthese groups has different characteristics, andeach plays a unique role in the fusion program.

National Laboratories

It is estimated that national laboratories willconduct over 70 percent of the magnetic fusionR&D effort in fiscal year 1987. According to DOE,the laboratories are “a unique tool that the UnitedStates has available to carry on the kind of largescience that is required to address certain prob-lems in fusion.” G Four laboratories conduct thebulk of the Nation’s fusion research: LawrenceLivermore National Laboratory in Livermore, CA;Los Alamos National Laboratory in Los Alamos,NM; Oak Ridge National Laboratory in Oak Ridge,TN; and Princeton Plasma Physics Laboratory inPrinceton, NJ.

Universities and Colleges

Within the fusion program, universities and col-leges provide education and training and histori-cally have been a major source of innovativeideas as well as scientific and technical advances.It is estimated that the university and college pro-grams will receive about 11 percent of the Fed-eral fusion budget directly in fiscal year 1987. I naddition, they will probably receive another 2 or3 percent through the national laboratories.

Recent budget cuts have seriously affecteduniversity and college fusion programs. Over 80percent of these programs have budgets of lessthan $1 million, and there are no other sourcesof Federal funding for fusion research to replaceDOE appropriations. Since 1983, two-thirds of theuniversity and college fusion programs have re-duced or eliminated their programs. The Univer-sity Fusion Associates, an informal grouping ofindividual researchers from universities and col-

bJOhn F. clarke, Director of the DOE Office of Fusion Energy,“Planning for the Future, ” Journal of Fusion Energy, vol. 4, Nos.2/3, June 1985, p. 202.

22 ● Starpower: The U.S. and the international Quest for Fusion Energy

Figure l-6.—Annual Appropriations of DOE Civilian R&D Programs (in currant dollars)

3.2

3.0

Ieges, anticipates that as many as half of the in-stitutions represented by its members will elimi-nate their fusion programs between 1986 and1989 if the university fusion budgets are not main-tained. DOE, however, disputes this claim andprojects constant budgets (corrected for inflation)for the university programs.

Private Industry

private industry can take a variety of differentroles in fusion research, depending on its levelof interest in the program and the status of fu-sion development. At the lowest level, industrycan serve as an advisor to DOE and the national

laboratories. As the research approaches the engi-neering stage, industry can begin to participatedirectly by supplying components or contractingwith DOE. Ultimately, it is anticipated that in-dustry will sponsor research and developmentactivities.

To date, industry and utility involvement inmagnetic fusion R&D has been advisory, withlimited cases of direct participation. This is duelargely to fusion’s long time horizon and the lackof predictable, easily commercializable “spin-off”technologies. Most current industrial participa-tion is facilitated through subcontracts from na-tional laboratories.

Ch. I.—Executive Summary ● 2 3

Photo credit: Plasma Fusion Center, MIT

The Alcator C tokamak at the Massachusetts Institute of Technology.

The transition of responsibility for fusion re-search and development from government to in-dustry is a significant hurdle to be cleared beforefusion can be commercialized. Current DOE pol-icy calls for any demonstration fusion reactor tobe built and operated by the private sector. In-dustries and utilities, on the other hand, may beunwilling to risk a major investment in a new andunproven technology.

There is considerable controversy over theappropriate time for the private sector to be-come more involved in the research program.Some argue that the willingness of industry to in-vest in fusion technology should not be used asa criterion for determining its appropriate degreeof involvement. They maintain that early involve-

ment of industry in fusion research is necessaryto ensure that the technology will be attractiveto its eventual users and marketable by the pri-vate sector. Others counter that, given presentand foreseeable future research budgets, thereare not enough opportunities for the private sec-tor to develop and maintain a standing capabil-ity in fusion. These individuals believe that indus-try’s limited participation in fusion research in thenear-term will not preclude its eventual role indemonstration and commercialization.

Chapter 6 of this report describes characteris-tics of fusion as a near-term research program—itsnear-term benefits, its financial and personnelneeds, and its principal participants.

24 ● Starpower: The U.S.. and the International Quest for Fusion Energy

Photo credit: GA Technologies

The Ohmically Heated Toroidal Experiment at GA Technologies, Inc., which is the only major fusion experiment constructedand operated largely with private funds.

FUSION AS AN INTERNATIONAL PROGRAMThe field of magnetic fusion research has a 30-

year history of international cooperation. Theleaders of the U.S. fusion community continueto support cooperation, as does DOE. In the past,the United States cooperated internationally ina variety of exchanges that have produced use-ful information without seriously jeopardizing theautonomy of the domestic fusion program. In re-cent years, in response to budgetary constraintsand the technical and scientific benefits of co-operation, DOE has begun cooperating more in-tensively in fusion, and the major fusion programshave become more interdependent. For the fu-ture, DOE proposes undertaking cooperative proj-ects that will require the participating fusion pro-

grams to become significantly interdependent:indeed, DOE now sees more extensive interna-tional cooperation as a financial necessity.

Opportunities for IncreasedCollaboration

Cooperation among the major world fusionprograms can be expected to continue at its cur-rent level, at the least, as long as each of the ma-jor fusion programs maintains a level of effortsufficient to make it an attractive partner to theothers. In the future, it is also possible that a sub-stantially expanded degree of collaboration maytake place. Such collaboration may take two forms:

Ch. I.—Executive Summary s 25

joint construction and operation of major facil-ities on a scale not yet attempted among the fourprograms, and substantial additional joint plan-ning among the world programs to minimize redun-dant research and to maximize the transfer of in-formation and expertise among the programs.

Those who favor increased levels of collabo-ration believe that there will be important oppor-tunities over the next decade. At the same timethat similarities in the status and goals of the ma-jor international fusion programs provide a tech-nical basis for expanded cooperation, the com-parable levels of achievement ensure that eachprogram can contribute to and benefit from col-laboration. Moreover, commercial applicationsof fusion technology are sufficiently far off thatcompetitive concerns should be minimal. Sincethe programs may not remain comparable overthe long term, these pro-collaboration observersmaintain that the timing may not be as advanta-geous for collaboration in the future as it is now.In particular, they worry that if recent fundingtrends continue, the U.S. fusion program may fallbehind the other programs and might no longerbe viewed as a desirable partner.

Benefits and Liabilitiesof Cooperation

International collaboration introduces a num-ber of potential benefits and liabilities to the par-ticipants. Observers will weigh these featuresdifferently, arriving at different conclusions aboutthe value of collaboration:

● Knowledge Sharing. All forms of coopera-tion involve sharing knowledge. Research-ers can take advantage of one another’s ex-perience, greatly aiding their own progress.Some observers, however, are concernedthat collaboration could lead to exchange ofinformation that has adverse implications fornational security or technological competi-tiveness.

● Cost Sharing. Cooperation can save the part-ners money by spreading out the costs of ex-periments among the participants and avoid-ing duplication of effort. Some additionalcosts may be added as a result of increasedadministrative complexity, but barring un-

●

●

●

usual circumstances each partner shouldspend less through collaboration than itwould to duplicate the research by itself.Risk Sharing. The financial and program-matic costs of a collaborative project arespread among a number of participants, min-imizing the exposure of any one of them inthe event of failure. On the other hand,through collaboration, each party opens it-self up to the risk that withdrawal of any ofthe other partners may jeopardize the suc-cess of the entire project. A partner may alsobecome dependent on others for the con-tinuation of its own program. Finally, someobservers feel that the absence of competi-tion and duplication among experimental fa-cilities may increase the risk of technicalfailure.Diplomatic and Political Implications. Col-laboration can be diplomatically motivated,because it may improve relations and in-crease familiarity between the partners.Some analysts welcome this additional as-pect of collaboration; others fear that diplo-matic motivations may override technicalones, causing a project to be undertaken thatmight not be judged attractive on its techni-cal merits alone.Domestic Implications. If the domestic pro-gram is neglected in order to support the col-laboration, both the ability of the partner tocollaborate and the value of collaborationto that partner may be compromised. Evenif the domestic program is not damaged, itwill be influenced by participation in col-laboration. Becoming dependent on collabo-ration lessens the flexibility of the partnersto change research direction and emphasis.On the other hand, collaboration can stabi-lize domestic efforts; the additional commit-ment given to a collaborative effort makesit more difficult for domestic contributionsto that effort to be cut back.

Obstacles to InternationalCooperation

The process of organizing and executing large-scale collaboration presents challenges that mustbe overcome by each of the partners. Among the


challenges will be siting the facility, resolving thetechnology transfer concerns of the parties andmaking them compatible with an open exchangeof research results, resolving technical differencesamong the parties, and overcoming a variety ofadministrative obstacles including different in-stitutional frameworks, different budget cycles,different legal systems, and personnel needs.

Negotiating and executing workable agree-ments for international collaboration will un-doubtedly be a difficult and time-consumingprocess. Legal and institutional frameworks mustbe devised that address the issues in a manneracceptable to participants in the project.

The International ThermonuclearExperimental Reactor

Currently, most of the effort in international col-laboration is focused on a proposal to developa conceptual design for an international engineer-ing test reactor, called the International Thermo-nuclear Experimental Reactor (ITER). Estimates in-dicate that building an engineering test reactorwill cost well over $1 billion and possibly sev-eral times this amount, which is far more thanthe U.S. fusion program has spent on any onefacility in the past and is too expensive for theUnited States to undertake alone without substan-tial increases in fusion funding. Therefore, DOEis involved in discussions with the other world-wide fusion programs to jointly design, construct,and operate ITER.

At this stage, only the conceptual design of ITERis being considered by the potential collabora-tors; the U.S. Government recently issued a pro-posal to begin a joint planning activity on a con-ceptual design for the experiment, along withsupporting R&D. It is anticipated that the con-ceptual design phase of ITER will occur between1988 and 1990 at a total estimated cost rangingfrom $150 million to $200 million. The U.S. costof the undertaking is projected to be between $15

million and $20 million annually over the 3-yearprogram.

Since the U.S. Government proposal addressesonly the conceptual design phase of ITER, itmakes no commitment to future construction ofa collaborative experiment. Therefore, currentnegotiations will not address the obstacles to in-ternational collaboration that would arise if andwhen the decision were made to jointly constructand operate the device. At the completion of theconceptual design phase, interested partieswould be in a position to begin negotiations onwhether or not to proceed with construction. Theexistence of a conceptual design would make iteasier to resolve many of the questions that wouldarise should a subsequent decision be made tobuild and operate ITER. In particular, it shouldbe possible to analyze concerns about technol-ogy transfer specificalIy and determine their im-plications for national security or industrial com-petitiveness.

International cooperation on the scale re-quired for ITER is unprecedented for the UnitedStates. Reaching agreement within the U.S. Gov-ernment to initiate and maintain support for ITERover the lifetime of the project will probably re-quire a presidential decision. Even that, by itself,is insufficient to guarantee the viability of a projectinvolving all branches of the U.S. Governmentand extending over several presidential admin-istrations.

At this time, DOE considers international col-laboration on the scale of ITER to be crucial.Given the seriousness of the obstacles, however,it is possible that such collaboration may not oc-cur, In the event that no major collaborationtakes place, either the U.S. fusion program willhave to be funded at a higher level or its sched-ule will have to be slowed down and revised.

International issues are discussed in chapter7 of this report.

Chapter 2

Introduction and Overview

Chapter 2

Introduction and Overview

FUSION POWER

To geologists and physicists at the turn of thecentury, the term “energy problem” referred notto finding sources of energy for society, but toidentifying the one used by the sun. Most physi-cists believed that the source of the sun’s energywas heat released as the sun slowly shrank un-der its own gravity, a process that would burnout no more than 20 million years after the sunwas formed. Geologists, however, argued thatgeological and fossil evidence showed that theearth-assumed to be no older than the sun—was in fact many times more than 20 million yearsold.

Although many hypotheses were developed toreconcile the two positions, it was not until 1938that one explanation received virtually instantane-ous and universal acclaim: the sun’s “energyproblem” was solved when nuclear fusion wasidentified as its energy source. Through fusion,the sun has been able to shine for nearly 5 bil-lion years using only about half of its original fuel.

Nuclear fusion is the process by which thenuclei—or central cores—of two atoms combineor fuse together. The total mass of the final prod-ucts is slightly less than the total mass of the origi-nal nuclei, and the difference—less than 1 per-cent of the original mass—is released as energy.Nuclear fusion, in a sense, is the opposite of nu-clear fission, the process utilized in existing nu-clear powerplants. In a fission reaction, energyis released when a heavy nuclei splits into smallerpieces whose total mass is slightly less than thatof the original nucleus.

Nuclear fusion may be applicable to the energyneeds of humans. If the fusion process can beutilized economically, it has the potential to pro-vide society with an essentially unlimited sourceof electricity. It may also offer significant environ-mental and safety advantages over other energytechnologies, characteristics that are particularlyappealing in a world where no energy technol-

ogy is perfect. Since the 1950s, the potential pay-off of fusion energy has motivated a worldwideresearch effort.

The previous decades of research have shownthat fusion energy is extremely difficult to pro-duce. Experiments planned for the next few yearsshouId be able to assess fusion’s scientific feasi-bility as an energy source, but several decadesof additional research and development, and bil-lions of additional dollars, will be needed to seewhether a marketable fusion reactor can be de-veloped. Researchers in the United States, West-ern Europe, Japan, and the Soviet Union gener-ally agree on the technical tasks yet to be doneto evaluate fusion’s potential. Policy makers inthese nations must now decide if, when, and howto allocate the resources necessary to accomplishthese tasks.

The Allure

In the future, fusion power could bean attrac-tive source of energy because it might offer acombination of benefits unmatched by otherfuels. Compared to other energy technologies,fusion could be:

Unlimited. A form of hydrogen found natu-rally in water is a potential fusion fuel, andevery gallon of water on earth contains thefusion energy equivalent of 300 gallons ofgasoline.Clean. Using fusion reactions to generatepower may be significantly cleaner than ei-ther fossil fuels or nuclear fission. Fusion,unlike coal combustion, does not producecarbon dioxide whose accumulation in theatmosphere may affect world climate. More-over, fusion will not contribute to acid rainor other potential environmental damageassociated with fossiI fuels. Although fusionreactors themselves will become radioactive,the products of the fusion reaction are notradioactive. With appropriate choice of struc-

29

—


●

tural materials, fusion reactors will producefar less radioactive waste than fission re-actors.Safe. It may be possible to design fusion re-actors in which “safe operation is assured byphysical properties, rather than by activesafety systems that might fail due to malfunc-tion, operator error, or natural disaster.

Substantial further scientific and technological de-velopment is required to see whether these ben-efits can be attained,

Establishing Fusion’s Feasibility

Two requirements must be met before fusioncan be an attractive source of energy. First, fu-sion’s technological feasibility must be demon-strated by establishing the scientific and engineer-ing understanding necessary to build an operatingfusion reactor. Second, fusion’s commercial fea-sibility must be demonstrated.

Technological feasibility is usually consideredin two stages: scientific feasibility and engineer-ing feasibility. Scientific feasibility requires gen-erating a fusion reaction that produces at leastas much energy as must be input into the plasmato maintain the reaction. This milestone, calledbreakeven, has not yet been reached, but it isexpected that breakeven will be accomplishedin existing machines by 1990.

Simply breaking even, however, does not showthat fusion can serve as a useful source of energy.in addition, a fusion reaction must be created thathas high energy gain, producing an energy out-put many times higher than its energy input. Noexisting experiment has the capability to producesuch a reaction, a task that is more significant andmore difficult to achieve than breakeven. How-ever, the Department of Energy (DOE) has re-quested funds in its fiscal year 1988 budget to be-gin construction of an experiment to generate areaction with such high-gain that it should be-come self-sustaining, or ignited. At ignition, re-actions will generate enough power to sustain thefusion process even after external heating powerhas been shut off.

After high gain or ignition has shown fusion’sscientific feasibility, its engineering feasibility must

be demonstrated. This accomplishment will en-tail developing future reactor systems, subsystems,and components that can function reliably un-der reactor operating conditions. Demonstratingengineering feasibility will require an extensiveamount of research and development, and it willbe a technical achievement at least as impressiveas the scientific accomplishment of harnessingcontrolled fusion reactions.

Although scientific feasibility and engineeringfeasibility involve different issues, fusion scienceand fusion engineering are interdependent: ad-vancing scientific understanding of the fusionprocess requires improved technological capa-bilities in experimental facilities, just as solvingthe engineering problems posed by fusion reactordesign requires additional basic understanding ina number of areas. Demonstrating both the sci-entific and engineering feasibility of fusion powerrequires advances to be made in basic scientificunderstanding as well as in technological capa-bility.

The goal of fusion research is to establish fu-sion’s technological feasibility in a manner thatmakes commercial feasibility likely. If and whenit becomes clear that generating electricity in afusion reactor is possible, such a reactor mustprove socially and environmentally acceptableand economically attractive compared to its alter-natives. Although dependent on the technical re-sults of fusion research, fusion’s commercial fea-sibility also involves factors unrelated to thetechnology itself, such as the status of otherenergy technologies and the regulatory and li-censing structure. Commercial feasibility ulti-mately will be determined by individuals and in-stitutions that are not involved directly in fusionresearch.

The Fusion Reaction

Only light elements can release energy throughfusion. While many different fusion reactions takeplace in the stars, the one that can be used mosteasily to generate power on earth involves hydro-gen (H), the lightest element. Three forms, or iso-topes, of hydrogen exist: protium, which is usu-ally referred to simply as hydrogen, deuterium(D), and tritium (T). The nuclei of these isotopes

Ch. 2.—Introduction and Overview “ 31

consist of a single proton and zero, one, or twoneutrons, respectively. Over 99.98 percent of allhydrogen found in nature is the protium isotope.Less than 0.02 percent (one part in 6,700) is com-posed of deuterium. Tritium is radioactive, witha half-life of 121/4 years;1 it is practically nonexist-ent in nature, but it can be manufactured.2

The easiest fusion reaction to initiate combinesdeuterium and tritium to form helium and a freeneutron, as shown in figure 2-1; a fission reactionis also shown for comparison. The fusion reactionshown—called a D-T reaction—liberates 17.6 mil-lion electron volts3 of energy. By way of compar-ison, burning a single atom of carbon (the com-bustible material in coal) releases only about 4electron volts. Therefore, a single D-T fusion re-action is over 4 million times more energetic.

Four-fifths of the energy released in a D-T fu-sion reaction is carried off by the neutron as ki-netic energy. I n a fusion reactor, it is anticipatedthat neutrons would be captured in the materialsurrounding the reaction chamber, where theirkinetic energy would be converted into heat.One-fifth of the reaction energy, carried off bythe helium nucleus, would remain inside the re-action chamber, heating up the fuel and makingadditional reactions possible.

The primary application of fusion will probablybe for electric power generation, using heat fromthe fusion reaction to boil water to drive a steamturbine that generates electricity. Advanced sys-tems for converting fusion energy more directlyinto electricity may also be possible. Other ap-plications of fusion might use the neutrons them-selves for various purposes, rather than just ex-tracting their energy. It is also possible that, asfusion development progresses, additional usesof the technology might be found. The potential

I Radioactive materials decay over time as the nuclei of radioactiveatoms emit radiation and transform into other nuclei. The decayrate is measured by the substance’s ha/f-/ife, which is the time re-quired for half of the nuclei to be transformed.

2Trace amounts of tritium are continually produced by cosmicrays in the upper atmosphere. Most of the tritium now in the envi-ronment, however, was produced by atmospheric nuclear weap-ons tests In the 1950s.

30ne electron volt (eV) is the energy that a single electron canpick up from a 1 -volt battery. It is equal to 1.6 X 10-’9 joules, 1.52x 10”22 Btu, or 4.45 x 10-26 kilowatt-hours. One thousand elec-tron volts is called a kiloelectron volt, or keV.

characteristics of fusion reactors used to produceelectricity are discussed in chapter 5; other pos-sible applications of fusion are discussed in ap-pendix A.

The D-T reaction is not the only one that cangenerate fusion energy. One deuterium nucleuscan fuse with another in a D-D reaction. It is alsopossible to use other light elements besides hy-drogen as fuel. However, it is much harder to ini-tiate fusion reactions with fuels other than deu-terium and tritium, and many of these alternatefuels produce less power for a given amount offuel than the D-T reaction does. Reactors usingalternate fuels would be more difficult to designand build than D-T reactors producing the sameamount of energy. On the other hand, these alter-nate reactions may not require tritium produc-tion and/or may not generate as many neutronsas the D-T reaction. Both tritium production andneutron generation increase the amount of radio-active material contained in a reactor, a situationthat complicates the reactor’s design and canraise environmental and safety issues.

Requirements for Fusion Reactions

Fusion reactions can only occur when the re-quirements of temperature, confinement time,and density are simultaneously met. The mini-mum temperatures, confinement times, and den-sities needed to produce fusion power have beenknown for decades. Achieving these conditionsin experiments, however, has proven extremelydifficult.

Temperature

Because the nuclei that must fuse have thesame electrical charge, they must be heated toextremely high temperatures to overcome theirnatural repulsion. Temperatures on the order of100 million degrees Celsius (C) are required. Nomatter exists in solid form at these temperatures;individual atoms are broken down—ionized—into their constituent electrons and nuclei. Withtheir outside electrons missing, the nuclei havea positive electric charge and are called ions.

Matter in this state is called plasrna (figure 2-2). Plasma is considered a fourth state of matter


Figure 2-1 .—The D-T Fusion Reaction and a Fission Reaction

● Proton

Key:

o Neutron

MeV: million electron volts

SOURCE: Adapted from Princeton Plasma Physics Laboratory, Information Bulletin NT-1: Fusion Power, 1984, p. 2 (fusion); Office of Technology Assessment (fission), 1987,


Figure 2-2.— Gas and Plasma

because it has properties unlike solids, liquids,or gases. Fusion research, critically dependent onunderstanding plasmas, has led to the develop-ment of a new field of science called plasrnaphysics.

The temperature of a plasma is a measure ofthe average energy of the plasma particles andis usually expressed in units of electron volts. Aplasma temperature of 1 electron volt, which isabout 11 ,600° C, corresponds roughly to eachparticle in the plasma having an average energyof 1 electron volt. In a plasma, the ions and theelectrons can have different temperatures; iontemperature is most important and must exceedabout 10,000 electron volts for enough of the ionsto overcome their mutual repulsion to produceappreciable amounts of fusion power.

Confinement Time

The goal of fusion research is not only to cre-ate a hot plasma but also to keep it hot longenough to produce fusion power. [t is not suffi-cient simply to heat the fuel, because any sub-stance that is hotter than its surroundings will cooloff. The rate at which the substance cools de-pends on its physical characteristics, its surround-

ings, and the temperature difference between thetwo. The ability of a plasma to stay hot is repre-sented by its confinement time, which is a meas-ure of the time it would take to cool down to acertain fraction of its initial temperature if no ad-ditional heat were added.

With an insufficient confinement time, it is im-possible to reach breakeven or ignition. Even ifthe plasma is heated hot enough for fusion re-actions to start, heat would be lost faster than itwould be generated in those reactions, and thereactions would not produce any net power.Confinement times on the order of one secondare generally considered necessary for an ignitedplasma.

Density

The exact confinement time requirement de-pends on plasma density. The fusion reactionrate, and therefore the amount of fusion powerproduced by the plasma, goes down rapidly asdensity drops. A plasma that is not dense enoughwill not be able to generate power even if it isvery hot and retains its heat very well. The den-sity required to reach breakeven or ignition in-creases as confinement time decreases. The prod-

—


uct of density and confinement time (called theLawson parameter) must exceed a minimumthreshold in order for a fusion plasma to ignite.4

Confining Fusion Plasmas

A fusion plasma cannot be contained in an or-dinary vessel no matter how hot the vessel isheated, because the plasma will be instantlycooled far below the minimum temperature re-quired for fusion whenever it comes into contactwith the vessel walls. There are three primaryways to hold a plasma that avoid this obstacle.Only one of these–magnetic confinement-isdiscussed to any appreciable extent in this report.

Magnetic Confinement

Magnetic confinement relies on the fact thatbecause individual particles in a plasma are elec-trically charged, their motion is strongly affected

4The minimum threshold for ignition, as defined by the Lawsonparameter, is 3 X 10~4 second-particles per cubic centimeter. Thismeans that a plasma with a density of 3 X 10’4 particles per cubiccentimeter must be confined for one second in order to ignite. Asmentioned above, if the density were increased to 3 x 1015 parti-cles per cubic centimeter, then the confinement time requirementwould decrease to one-tenth (O. 1 ) of a second.

by magnetic fields. A charged particle moving ina magnetic field will be bent at right angles toboth the direction of the field and its directionof motion, with the result that the energetic par-ticles making up a fusion plasma will trace spiralorbits around magnetic field lines (figure 2-3).Magnetically confined plasmas will tend to flowalong field lines but not across them, and a suit-able configuration of magnetic fields can there-fore confine a plasma. Many different kinds ofmagnetic-confinement configurations are u riderinvestigation, as described in chapter 4. In thisreport, the word fusion refers to magnetic confine-ment fusion unless specifically noted otherwise.

Gravitational Confinement

A sufficiently large plasma can produce fusionpower while holding itself together with its owngravitational field. This process, called gravita-tional confinement, permits fusion to take placein the sun and other stars. It is impossible, how-ever, to utilize gravitational confinement for fu-sion processes on earth. Even the planet Jupiter,which is over 300 times more massive than earth,does not have sufficient mass to produce gravita-tionally confined fusion.

SOURCE: Princeton Plasma Physics Laboratory, Information Bulletin NT-1: Fusion Power, 1984, p. 3,


Inertial Confinement

In a hydrogen bomb, fusion fuel is heated andcompressed to such high densities that it needbe confined only for a very short time in orderto generate fusion power. The fuel’s own inertiakeeps it confined long enough for fusion reactionsto occur. A research effort is now underway tostudy this inertial confinement process i n a con-trolled manner on a laboratory scale. This pro-gram has near-term military applications, due to

its close connection with weapons physics, andmay have longer term energy applications as well.The energy applications of inertial confinementfusion are generally considered less developedthan those of the magnetic confinement process.Because of the direct links between this approachand hydrogen bomb design, much of the researchin inertial confinement fusion is classified. Theinertial confinement approach is discussed in ap-pendix B.

THE PURPOSE OF THIS STUDY

Increasing budgetary pressures, along with adecreasing sense of urgency regarding energysupply, have sharpened the competition for fund-ing between one research program and anotherand, perhaps more significantly, between energyresearch programs and other components of theFederal budget. At the same time, issues such asthe implications of increased fossil fuel usage onthe global climate and the long-term acceptabil-ity of nuclear power have raised serious concernsabout future energy supply.

In balancing the long-term potential of fusionenergy against shorter term, more immediatepressures, the congressional committees withjurisdiction over DOE’s magnetic fusion programrequested this study. In 1986, the House Com-mittee on Science and Technology requested thatOTA review the magnetic fusion energy program,citing that “. . . a number of factors have servedto decrease the sense of urgency with which theDOE management and many members of theCongress view the development of fusion power.”Shortly afterward, the Senate Committee onEnergy and Natural Resources endorsed this re-quest. These committees are faced with settingpolicy for the fusion program, and they were in-terested in an independent analysis of the fusionprogram as input to their budget authorizationdeliberations.

in response, OTA undertook this assessmentof the magnetic fusion research and developmentprogram in March 1986. The assessment exam-ines the technical and scientific achievements andobjectives of the fusion program. It also analyzes

the program from three different, but related, per-spectives:

1.

2.

3.

It considers the issues related to fusion’s roleas an energy research and development pro-gram, in particular those related to develop-ing an attractive energy supply technology.It analyzes the near-term, non-energy ben-efits of the fusion program and the financialand personnel resources necessary to sup-port the program.It examines the increasing role of interna-tional collaboration in magnetic fusion re-search.

OTA’s assessment was carried out with theassistance of a large number of experts reflect-ing different perspectives on the fusion program–fusion scientists and engineers, nuclear engi-neers, environmental scientists, international re-lations experts, industry and utility executives,consumer groups, economists, financial planners,and energy policy analysts. As with all OTA studies,an advisory panel representing these interests andfields of expertise met periodically throughout thecourse of the assessment to review and critiqueinterim products and proposals, to discuss fun-damental issues affecting the analyses, and to re-view drafts of the report. Contractors and con-sultants also provided material in support of theassessment.5

5Advlsory panel members, workshop participants, contractors,and other contributors to this assessment are listed in the front ofthis report.


Finally, OTA convened three workshops toclarify important issues considered in the assess-ment and to review and expand upon contrac-tors’ analysis. The first workshop dealt with gen-eral issues involved in fusion research. It focusedon the nature of the fusion research program, theimplications of current funding cuts on the pro-gram, and the main issues involved in decisionsabout future courses of action.

The second workshop addressed issues in in-ternational collaboration in fusion research. Threecontractor reports, detailing the characteristics ofthe major non-U.S. fusion programs and theirviews of collaboration, were reviewed at theworkshop. The principal issues addressed werethe motivations and goals of foreign fusion pro-grams, national security and competitiveness risksof technology transfer through collaboration, andother potential obstacles to collaboration,

The final workshop addressed fusion’s energycontext. Projections of electricity demand in the21st century and their relevance to fusion werepresented by OTA consultants and reviewed. Inaddition, the uncertainties inherent in forecast-ing supply and demand over times relevant to fu-sion were discussed. Alternative energy supplytechnologies that might compete with fusionwere addressed, as were the implications of po-tential difficulties such as global climate changeand nuclear fission safety or environmental issues.

The material in this report is based on OTA staffresearch, site visits, workshop discussions, advi-sory panel recommendations, and contractor andconsultant reports. The report is organized asfollows:

● Chapter 3 provides a brief history of the U.S.fusion program, which, since its inceptionin the 195os, has been almost entirely fundedby the U.S. Government.

●

●

●

●

●

Chapter 4 explains the technical underpin-nings of fusion research and sets out the re-quirements for demonstrating fusion’s tech-nological feasibility. Fusion research is oneof the Federal Government’s most futuristicand technically complex undertakings. Phys-ical theory and experimentation must ad-vance the present state of the art if the goalis to be reached; forefront technology mustbe developed not only in the long-run, toharness fusion, but in the short-run to con-struct each successive experiment.Chapter 5 addresses the long-range energyapplications of fusion research. The antici-pated characteristics of future fusion reactorsare discussed, including projected plant eco-nomic, safety, and environmental features.Issues involved in commercializing the tech-nology are also examined. In addition, fac-tors that will be important in determiningwhether and when fusion will penetrateenergy markets as a source of electricity arediscussed.Chapter 6 discusses the character of currentfusion research and analyzes the value of thefusion program in terms of its near-term,non-energy benefits. Data on program par-ticipants, funding levels, and personnel levelsare summarized.Chapter 7 examines the extremely importantrole that international cooperation in fusionresearch has had in the past and may havein the future. Motivations for and obstaclesto future large-scale collaboration are assessed,as well as possible models for such collabo-ration.Finally, chapter 8 summarizes the critical is-sues facing the fusion program and presentsa series of policy paths for Congress to con-sider as it makes decisions on funding fusionresearch. The implications of pursuing thedifferent paths are discussed.

Chapter 3

Fusion Research

CONTENTS

PageResearch Beginnings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

Nuclear Physics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39Plasma Physics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39Early Fusion Research . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

The U.S. Fusion Program Through the Decades . . . . . . . . . . . . . . . . . . . . . . . . . . 40The 1950s: Era of Optimism and Disillusionment. . . . . . . . . . . . . . . . . . . . . . . . 40The 1960s:A Plateau . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44The 1970s: Rapid Growth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46The 1980s: Leveling Off . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

FiguresFigure No. Page

3-1. Historical Magnetic Fusion R&D Funding, 1951-87 (in 1986 dollars) . . . . . . 413-2. Historical Magnetic Fusion R&D Funding, 1951-87 (in current dollars) .,.. 42

Chapter 3

History of Fusion Research

RESEARCH BEGINNINGS

Fusion research draws on two independentbranches of physics–nuclear physics and plasmaphysics. Studying the fusion reaction itself is thedomain of nuclear physics. Studying the behaviorof matter u rider conditions necessary for fusionreactions to take place is the focus of plasmaphysics.

Nuclear Physics

Early in this century, the search for the causesof radioactivity revealed that vast amounts ofenergy were stored in an atom’s nucleus. As earlyas 1920, this energy was hypothesized to be theheat source that powered the sun and other stars.With the discovery of the neutron in 1932 thesenuclear processes began to be understood, andby the time efforts to control fusion reactions inthe laboratory began in the 195os, the nuclearphysics underlying laboratory fusion reactionswere well known. “Then, as now, ” noted a re-cent National Academy of Sciences panel review-ing physics research, “the obstacles to achiev-ing controlled fusion lay not in our ignorance ofnuclear physics, but of plasma physics. ”2

I Most of the historical material in this chapter is based on Fu-sion: Science, Politics, and the Invention of a New Energy Source(Cambridge, MA: MIT Press, 1982), a comprehensive and exten-sively documented history of the U.S. fusion program written byJoan Lisa Bromberg under contract with the U.S. Department ofEnergy. The book is restricted almost entirely to magnetic confine-ment fusion and covers a period ending in 1978. While Brombergwas given access to unclassified and declassified DOE and nationallaboratory records, the book does not represent the official posi-tion of DOE.

A more popularized history of the fusion program, covering in-ertial fusion as well as magnetic fusion and extending until 1983,is found i n T.A. Heppenheimer, The Man-Made Sun: Hre Questfor Fusion Power (Boston, MA: Little, Brown & Co., 1984),

2Natlonal Research Council, Panel on the Physics of Plasmas and

Fluids, Physics Survey Committee, Physics Through the 1990s:P/asrnas and F/uids (Washington, DC: National Academy Press,1986), p. 4,

Plasma Physics

Plasma physics, according to the same NationalAcademy review panel, is “the only major branchof physics to come largely into being in the pastgeneration.”3 Its development drew upon a num-ber of previously distinct and independent dis-ciplines, pulling them together into a unifiedmethodology for the study of the plasma state.

Explaining plasmas could not begin until thediscovery of the electron in 1895 and the devel-opment of the atomic theory of matter. Between1930 and 1950, the foundations of plasma physicswere laid, largely as a byproduct of investigationson topics such as the earth’s outer atmosphere,the sun, and various astrophysical phenomena.The advent of space exploration and controlledfusion research–the two major experimentalarenas for modern plasma physics—firmly estab-lished the field.

Early Fusion Research

The first probe into harnessing fusion powertook place during the Manhattan Project, the ef-fort during World War II dedicated to develop-ing an atomic bomb. Some physicists working onthe Manhattan Project in Los Alamos, New Mex-ico, began to consider whether the fusion proc-ess could be utilized in nuclear weapons. Suchinvestigations were not a high priority during thewar, however, because the national effort wasfocused on developing weapons that utilized themore immediately promising fission process.

In 1949, largely in response to the first Sovietnuclear detonation, senior U.S. scientists and pol-icymakers conducted an extensive, classified(secret) debate about whether hydrogen bombs–weapons that use the fusion process instead ofthe fission process—could and should be devel-oped. In 19s0, the debate ended when presidentTruman approved a crash program to build such

jlbid., p, 6.

39

72-678 0 - 87 - 2


a weapon. The United States detonated its firstH-bomb in 1952.4

In the beginning, most research in thermo-nuclear fusion was weapons-related and classi-fied. This research fell under the constraints ofthe Atomic Energy Act of 1954, which mandatedthat data concerning the “design, manufacture,or utilization of atomic weapons, ” as well as “theproduction of special nuclear material” and the

4Herbert York, “The Debate Over the Hydrogen Bomb, ” Scien-tific American, October 1975. There are many names for bombsthat use the fusion process: hydrogen bombs, H-bombs, and ther-monuclear or hydrogen weapons. Such weapons can have manytimes the explosive power of fission weapons.

“use of special nuclear material in the produc-tion of energy,” remain classified indefinitely un-less specific action was taken to declassify its

Over the years, some of the emphasis in fusionresearch shifted from weapons to reactors. Fu-sion reactors were sought not only to produce“special nuclear materials’’—tritium and pluto-nium—needed for nuclear weapons, but also toproduce electricity. At the time, both energy pro-duction and materials production fell under therestrictions of the Atomic Energy Act that man-dated continued classification.

“’Special nuclear material,” as defined in the Atomic Energy Actof 1954, is material capable of undergoing nuclear explosions.

THE U.S. FUSION PROGRAM THROUGH THE DECADES

The nature of the U.S. fusion research programthrough each decade from its conception to thepresent is summarized below. The funding pro-file for U.S. fusion research, both in constant andcurrent dollars, is shown in figures 3-1 and 3-2.Data for these figures is provided in appendix C;for more information on funding for magnetic fu-sion research, see chapter 6.

The U.S. Atomic Energy Commission (AEC) wasresponsible for magnetic fusion research from1951, when the program was formally under-taken, until 1974, when the AEC was disbandedand replaced by the Energy Research and Devel-opment Administration (ERDA). In 1977, ERDAin turn was disbanded and its responsibilitiestransferred to the new Department of Energy(DOE). Since 1977, DOE has managed the mag-netic fusion research program.

The 1950s: Era of Optimismand Disillusionment

Project Sherwood

From 1951 until 1958, fusion research was clas-sified; during these years, the program was con-ducted under the code name “Project Sherwood.”At the outset of Project Sherwood, both field sci-entists and program managers at the AEC believedthat fusion could yield an important technology

to supply future electricity needs. In pursuing fu-sion, scientists and AEC commissioners sought tomaintain U.S. scientific supremacy; there couldbe significant political and economic advantageshould fusion lead to a commercially competi-tive new energy technology. Fusion researchwould also support the U.S. weapons program.The potential use of fusion reactors for generat-ing weapons materials, as well as the possibilityof other military applications, was important tothe AEC; thus, during the early 1950s, fusion re-search grew along with military atomic research.

project Sherwood began optimistically in 1951.At that time, it was estimated that spending about$1 million over a period of 3 to 4 years wouldbe sufficient to learn whether a high-temperatureplasma could be confined by a magnetic field.About that amount was budgeted for fusion re-search from 1951 to 1953. However, the prob-lem proved harder than originally anticipated,and in 1953 the fusion research program ex-panded. The personnel level increased from 8 in1952 to 110 in 1955 and rose to over 200 peo-ple in 1956. Annual budgets increased from under$1 million to $7 million over the same period.6

The United States established several fusion re-search centers. Federally funded efforts were con-

6Bromberg, Fusion, Op. Cit., P. 30.

Ch. 3.—History of Fusion Research ● 4 1

Figure 3-1 .—Historical Magnetic Fusion R&D Funding, 1951-87 (in 1988 dollars)

1955 1960 1965 1970

Year

ducted at Oak Ridge National Laboratory in Ten-nessee, Los Alamos Scientific Laboratory in NewMexico, Lawrence Livermore Laboratory in Cali-fornia, and a number of universities, includinga major plasma physics laboratory at PrincetonUniversity in New Jersey established primarily toconduct fusion research. Private or corporate-sponsored research began in 1956 at the Gen-eral Electric Co. (GE) in New York and at thenewly created General Atomic Corp. in Califor-nia. Several other companies dedicated a few staffmembers to monitor the field.

Many different confinement schemes were ex-plored during the early 1950s. Although propo-nents of the various schemes were careful to notethat practical applications lay at least 10 or 20years in the future, the devices under study were

1975 1980

m

.

1985.

SOURCE: U.S. Department of Energy, Office of Energy Research, letter to OTA project staff, Aug. 15, 1986.

thought to be capable of leading, in a straight-forward process of extrapolation, to a commer-cial reactor. One report concluded in 1958:

With ingenuity, hard work, and a sprinkling ofgood luck, it even seems reasonable to hope thata full-scale power-producing thermonuclear de-vice may be built within the next decade or two.7

In reality, very little was known about the be-havior of matter under the conditions being stud-ied, much less under reactor-like conditions. Ex-periments were trial-and-error operations, andeach one charted new ground. Results were often

7Amasa S. Bishop, Project Sherwood.” The U.S. Program (Reading, MA: Addison-Wesley Publishing Co., Inc.,

1958), p. 170. Bishop managed the AEC fusion program from 1953to 1956 and again from 1965 to 1970.


Figure 3-2.—Historical Magnetic Fusion R&D Funding, 1951-87 (in currant dollars)

50

0 L1955 1980 1985 1970 1975 1980 1985


ambiguous or misinterpreted, and the theoreti-cal underpinnings of the research were not wellestablished. All devices investigated showed evi-dence of “instabilities,” or disturbances that grewto the point where the plasma escaped confine-ment faster than expected. The devices studiedin the 1950s could not attain Lawson parametershigher than about 1010 second-particles per cu-bic centimeter, a factor of about 10,000 less thanthe minimum required to make net fusion power.8

‘The Lawson parameter is the product of density and confine-ment time (see 2, note 4). The units in which the Lawson pa-rameter is expressed represent a density (particles per cubic centi-meter) multiplied by a time (seconds), and have no immediatephysical significance. A product of 3 X second-particles percubic centimeter is considered the minimum for ignition in a D-Treaction. (See discussion of “energy gain” in 4, pp. 67-68. )

Temperatures attained were about 100 electronvolts, in comparison to the minimum requirementof 10,000 electron volts.9

Declassification

By the mid to late 1950s, the advantages ofdeclassifying Project Sherwood were recognized,both within the AEC and among scientists in thefield. Some U.S. scientists had sought to delaydeclassification of fusion research because theywere optimistic about harnessing controlled fu-sion reactions in the near future, and they rea-

9An electron volt is a unit of energy. It is also used as a measureof temperature, representing that temperature at which the aver-age energy of plasma particles is roughly electron volt. (See 2, note 3.)

H ry R

P 9 A m S

d h d o wo dh mo m p g on pow w db m p me w h 0 eme 0 h ph o ope mm d wo do he u e pod one he mon h g m d po b b d

e 0 Mo e he how e A he h d ed h o d h

me m og g 0 on

h h d ed b bo gob h h d h m m 0 w go m

p rt New upp d h d 0 m w p g p pp w d d Mo 0 AEC omm m b h d h wh h d b d g

g p m d m w p w b gd d dd m


sense to classify fusion research, whose applica-tion in producing weapons material was stillhypothetical, after fission technology that was ac-tually being used for that purpose was declassi-fied.11

U.S. magnetic fusion research was declassifiedin 1958 at the Second Geneva Conference on thePeaceful Uses of Atomic Energy. Following declas-sification, it was apparent that the American, Brit-ish, and Soviet programs were at more or less thesame level and were pursuing similar approachestoward confining plasmas. Declassification openedthe door to widespread international cooperationin fusion.

The 1960s: A Plateau

Fusion research in the United States proceededat a steady pace throughout the 1960s. The theo-retical framework advanced, but discrepanciesbetween theoretical predictions and experimentalresults were common. By the mid-1960s, Con-gress became impatient. In the late 1950s, mem-bers of Congress had believed that the Federalprogram would beat the reactor prototype levelin 5 or 6 years. Since that time, fusion research-ers realized that they had seriously underesti-mated the complexity of the problem. Therefore,the researchers concentrated on studying plasmabehavior rather than on building reactor proto-types. Congress, however, worried that the re-searchers were building an array of different ex-periments that did not appear to be leading toan attractive reactor.12 Thus, in 1963, the HouseAppropriations Committee recommended a 16percent cut in the program’s operating budget.Much of the cut was restored, but the programended up with a budget of 7 percent less thanrequested.

Enthusiasm for the fusion program cooled out-side of Congress as well. While remaining sup-portive of fusion, AEC commissioners were moreinterested in expanding the fission breeder re-actor program .13 GE reviewed its corporate in-volvement in fusion in 1965 and concluded that“the likelihood of an economically successful fu-

1 I Ibid., pp. 69, 72-73.Izlbid., pp. 118-119.IJlbid., p. 136.

sion electricity station being developed in theforeseeable future is small.”14 GE proposed thatthe AEC finance its research through a joint ef-fort, but the AEC refused and GE phased out itsfusion program. While GE was reconsidering itsfusion program, the consortium of Texas utilitiesthat funded fusion research at General Atomicin California withdrew its support.15 The AEC re-sponded to this decision by funding much ofGeneral Atomic’s fusion research itself in orderto preserve the expertise assembled there. In ef-fect, this response created an additional nationallaboratory.

In 1965, a prestigious outside review commit-tee evaluated the fusion program. The commit-tee found that the magnetic fusion program hadmade significant progress, that the United Statesneeded to support research in order to developthe technology, and that the program produced“spin-off” technologies that could benefit theeconomy. Moreover, the committee stated thatthe United States would suffer a great loss of in-ternational stature if another country demon-strated the feasibility of fusion first. The commit-tee recommended that the fusion budget increaseby 15 percent annually and that a new genera-tion of experiments be funded to replace obso-lete ones.16 After considerable deliberation withinthe AEC and the Bureau of the Budget, an in-crease in funding was recommended, though notof the magnitude suggested by the committee.

The Tokamak

By 1968, the highest temperatures that hadbeen achieved in a magnetic confinement fusiondevice were only about 100 electron volts–notappreciably higher than they were in the 1950s.The quality of confinement, as measured by theLawson parameter, had increased by an order ofmagnitude (factor of 10) to about 1011 second-particles per cubic centimeter. In 1968, however,Soviet scientists announced that they had ex-ceeded the previous best values of each of theseparameters by an additional order of magnitude.

“1bid., p. 137.I tThis consortium has continued to fund a modest level of fu-

sion research at the University of Texas.lbBromberg, Fusion, op. cit., pp. 138-139.

Ch. 3.—History of Fusion Research w 45


Model C Stellarator at Princeton Plasma Physics Laboratory. Designed and built in the late 1950s, the Model C wasconverted into the United States’ first tokamak in 1970.

Using a device named the “tokamak,” a Russianacronym taken from the words for “toroidalchamber with magnetic coil,” the Soviets claimedto have generated ion temperatures of 500 elec-tron volts, electron temperatures of twice that,and a Lawson parameter of 1012 second-particlesper cubic centimeter.

The Soviet announcement both excited andtroubled the U.S. fusion community. U.S. pro-gram administrators worried that the SovietUnion would beat the United States to demon-

strating fusion’s feasibility. Some U.S. scientistssubmitted proposals to build tokamaks in theUnited States, while others argued that previousplans to upgrade existing devices were more im-portant. Many scientists were skeptical of Sovietdata, contending that it was ambiguous and notsufficiently compelling to change the emphasisof the U.S. program.

Early in 1969, the director of the Soviet fusioneffort invited a British team of scientists to bringits own diagnostic equipment to Moscow to verify

—

46 . Starpower: The us. and the International Quest for Fusion Energy

Soviet research results. During the summer of1969, the British team in Moscow announced itspreliminary findings: the Soviet results were gen-uine, and, in fact, the tokamak performed evenbetter than the Soviets had claimed. This announce-ment came shortly after the American scientificcommunity had decided to convert the premierPrinceton machine, the Model C stellarator, intoa tokamak. In addition, funds had been allocatedfor the development of another tokamak at OakRidge National Laboratory. After publicationthe British findings, the U.S. program Iauncthree more experimental tokamaks.

The 1970s: Rapid Growth

With the identification of the tokamak as

ofed

theconfinement concept most likely to reach reactor-Ievel conditions, the U.S. fusion program grewrapidly. Between 1972 and 1979, the fusion pro-gram’s budget increased more than tenfold.Three forces spurred this growth. First, uncer-tainty over long-range energy supply mobilizedpublic concern for finding new energy technol-ogies. Second, fusion energy, with its potentiallyinexhaustible fuel supply, looked especially at-tractive. Third, the growth of the environmentalmovement and increasing opposition to nuclearfission technology drew public attention to fusionas an energy technology that might prove moreenvironmentally acceptable. The fusion programcapitalized on this public support; program leader-ship placed a very high priority on developinga research plan that could lead to a demonstra-tion reactor.

From Research to Development?

The emphasis on building a demonstration re-actor dramatically changed the fusion program.Previous fusion program plans had called for“breakeven-equivalent” to be demonstrated ina device containing only deuterium, to avoid thecomplications introduced by use of tritium.17 Thenew plans called for an experiment fueled withdeuterium and tritium (D-T), which would reachbreakeven by actually generating fusion power.

1 ~ritiu m is radioactive and difficu It to work with. More signifi-cantly, its use in fusion experiments generates neutrons that makematerials in the device radioactive.

During much of the 1970s, the director of thefusion program was largely responsible for re-orienting the program toward the use of tritiumin an experimental device. He sought to attainbreakeven with tritium for a number of reasons:18

●

●

●

●

Physics. The energy released in actual fusionreactions involving tritium introduced a newcomplication in device operation that couldsignificantly affect experimental behavior.The director thought it was essential to studythe physical consequences of releasing fu-sion energy in a plasma.Psychology. He also believed that too manyfusion scientists were interested in plasmaphysics as a research enterprise, not as anenergy technology. Burning D-T, he thought,wouId force them to come to grips with therealities of fusion power instead of the ab-stractions of plasma physics.Engineering. A D-T experiment would in-crease the amount of attention given to theengineering aspects of a fusion reactor, de-parting from the near-total emphasis onplasma physics in fusion research to date.Politics. A D-T experiment would generateactual fusion power for the first time. Thisdemonstration would dramatize to the pub-lic the capabilities of fusion in a more directway than simply achieving “breakeven-equiv-alent” conditions.19 Moreover, this demon-stration had to take place soon enough sothat the fission breeder reactor would not be-come established as the long-run energy op-tion of choice.

Many members of the fusion community op-posed a D-T machine. They questioned whetherthe scientific principles underlying tokamak oper-ation were sufficiently known to take such a ma-jor step. Moreover, many felt that it was not nec-essary to construct an experiment at this pointin the research program that would involve radio-activity and thus more complications and moreexpense.

18 Bromberg, Fusion, op. cit., PP. 204-205.

19’’Breakeven-equivaIent” is the attainment of plasma conditionsin a deuterium-only plasma equivalent to those that, in a D-Tplasma, would produce breakeven. Breakeven-equivalent does notrequire use of radioactive tritium and does not produce the neu-tron radiation generated in a breakeven D-T plasma.

Ch. 3.—History of Fusion Research ● 4 7


The Tokamak Fusion Test Reactor at Princeton Plasma Physics Laboratory.

In mid-1 973, senior fusion researchers, fusionprogram managers, and outside observers evalu-ated the plans to accelerate building a D-T ma-chine. They concluded: 1 ) that scientific questionsshould be answered in deuterium experiments,which would be simpler and cheaper to buildthan machines using tritium, but 2) that a burning experiment should be conducted on anaccelerated schedule.

During this period, congressional and publicconcern about energy supply was increasing,and, in June 1973, president Nixon announcedhis intention to nearly double the budget pro-posed for energy research over the next 5 years.By June 1974, the funding increases necessary topursue accelerated development of fusion wereappropriated. Planning began for a D-T burning

breakeven experiment, the Tokamak Fusion TestReactor (TFTR), to be constructed at the Prince-ton Plasma Physics Laboratory.

program organization also changed when Con-gress abolished the AEC in 1974 and transferredits energy research programs to the Energy Re-search and Development Administration. ERDAwas a new agency with a broad mission in energyresearch. It assumed management of AEC’s nu-clear fission and fusion programs, as well as pro-grams in solar and renewable technologies, fos-sil fuels, and conservation.

Concept Competition

The expansion of the tokamak program in-creased competition for funds among proponents


of alternate confinement concepts. Most fusioncommunity leaders believed that the fusion pro-gram could not command the budget requiredto construct more than one additional TFTR-classexperiment. Thus, there was some concern aboutthe role of the three remaining major fusion lab-oratories. Oak Ridge National Laboratory, whichhad competed unsuccessfully with Princeton toconstruct the tokamak breakeven experiment,had tokamak experience that would be neededto support the Princeton experiment. The futurewas more uncertain for the non-tokamak re-search programs at Los Alamos and LawrenceLivermore national laboratories.

Between the major concepts investigated atthese two labs, the “magnetic mirror” at Liver-more was selected over the “theta pinch” at LosAlamos to become the principal alternative to thetokamak. Livermore had constructed a series ofmirror devices during the 1960s and 1970s, and,in 1976, its proposal to build a greatly scaled-upMirror Fusion Test Facility (MFTF) was approved.After design and construction of MFTF wereunderway, researchers developed a design inno-vation that could improve the performance of themirror concept. This idea was tested by buildingthe Tandem Mirror Experiment (TMX) and foundto be valid. Even so, the improvement was toosmall to justify changing the MFTF design, so con-struction proceeded as originally planned.

Livermore scientists then proposed another in-novation that seemed to have the potential tomake a mirror reactor a viable competitor to atokamak reactor. This time, the gain appearedto be sufficiently great to warrant modifying theMFTF design, more than tripling its size. More-over, Livermore scientists had so much confi-dence in the theory that they proposed to startmodifications to MFTF before testing the newconcept experimentally. In 1979, they proposedto modify both TMX and MFTF in parallel, withthe smaller TMX-Upgrade (TMX-U) to be com-pleted and operated to verify the new conceptat a time when substantial work still remained tobe done on the revised MFTF (now called MFTF-B). In this way, any changes found to be neces-sary as a result of tests on TMX-U could be in-corporated directly into MFTF-B during its con-struction. Construction of MFTF-B began in 1981.

Systems Studies

In addition to experiments on confinementconcepts, fusion program managers in the 1970sbegan to consider design attributes of fusion re-actors in a systematic way. Scientists and engi-neers began to address the engineering problemsthat various confinement methods posed for re-actor design, and “reactor relevance” soon be-came a driving force for additional research. Sus-tained and serious interest in these design studies,also called systems studies, attracted the atten-tion of people outside the fusion community.Several individuals in electric utilities began tofollow fusion closely, and the utility research con-sortium, the Electric Power Research Institute(EPRI), established a Fusion Advisory Committee.

World Effort

During the 1970s, the U.S. fusion program ledthe world. It had the greatest breadth and depthof confinement concepts under investigation, andits attention to fusion systems and technology wasunmatched. However, programs in the SovietUnion, Japan, and Western Europe grew duringthe 1970s. Each program made plans to build aTFTR-class tokamak to reach breakeven-equiva-Ient conditions: the Joint European Torus (JET) inEurope, JT-60 in Japan, and the T-15 tokamak inthe Soviet Union. All of these machines exceptthe T-1 5 are now operational. The internationalaspects of fusion research are discussed morefully in chapter 7.

Program Reorientation

In 1977, president Carter incorporated the func-tions of ERDA, including the fusion program, intoa new agency, the Department of Energy. DOEreemphasized support for nuclear fission, primar-ily due to concern over the proliferation aspectsof breeder reactors, and it increased support forsolar energy, conversion from oil and gas to coal,and conservation .*0

The first director of the DOE Office of EnergyResearch believed that the budget for the fusionprogram was too large for fusion’s uncertain pros-pects. In his capacity as scientific advisor to the

2oBrom&rg, Fusion, op. cit., P. 235.

Ch. 3.—History of Fusion Research . 49

Photo credit: Lawrence Livermore National Laboratory

Installation of one of the end cell magnets for MFTF-B. Another view of this magnet is shown on p. 87.

Secretary of Energy, he commissioned a high-Ievel outside review of the program, a review thathe expected would recommend cutting the bud-get and relaxing the program’s emphasis on anearly demonstration reactor.21 On the contrary,the review panel praised the management andscientific achievements of the fusion program anddid not recommend budget cuts. Mostly as a re-

Z’ Ibid., p. 236.

suit of the panel’s findings, the Secretary of Energysubsequently reaffirmed the near-term planningof the fusion program. With few modifications,DOE management supported maintaining currentbudget levels, pushing towards early completionand operation of TFTR, maintaining ongoing fu-sion system studies, and accelerating fusion tech-nology development.

Although the short-term fusion program planscontinued much as before, the long-term strat-


egy under DOE in the late 1970s differed fromthe ERDA strategy earlier in the decade. The re-view panel stated in its report that “the first ob-jective of the program must be to determine thehighest potential of fusion as a practical sourceof energy.” This meant not proceeding with con-struction of a tokamak device to succeed TFTRuntil “a convincing case should be made thatTokamaks can be engineered into attractive energyproducers.” 22 In effect, the committee recom-mended that the tokamak program be held upat the TFTR stage until other devices, such as themirror, could be compared to it at relativelyequivalent stages of development.

Under DOE, the fusion program did not havethe sense of urgency that was so important earlierin the decade. Fusion could not mitigate theshort-term oil and gas crisis facing the UnitedStates. Furthermore, as a potentially inexhausti-ble long-range energy source (along with solarenergy and the fission breeder reactor), fusionwas not thought needed until well into the nextcentury. Therefore, there appeared to be no com-pelling reasons to develop a fusion demonstra-tion plant rapidly .23

The 1980s: Leveling Off

The fusion program has continued to makesubstantial technical progress during the 1980s.Several world machines have the potential toachieve breakeven, or breakeven-equivalent con-ditions, within the decade; in addition, significantadvances in plasma physics and fusion technol-ogy continue.24

ERAB Review of the Fusion Program,1980

In 1980, the Energy Research Advisory Board(ERAB), a standing committee that advises theSecretary of Energy, established a committee toreview DOE’s fusion program. The committee’sreport evaluated technical progress in the fusion

zzFOster Committee, Final Report (DOE/ER-OO08, June 1978).

Quoted in T,A. Heppenheimer, The Man-Made Sun, op. cit., pp.201-202.

zjBromberg, Fusion, op. cit., p. 247.24ManY of the technica[ accomplishments in the fusion program

and the tasks still to be done are discussed in ch. 4 of this assessment.

program over the previous few years and foundmany accomplishments that justified the panel’sconfidence that breakeven was near. The panelconcluded that:

. . . the United States is now ready to embark onthe next step toward the goal of achieving eco-nomic fusion power: Exploration of the engineer-ing feasibility of fusion .25

The panel proposed that the program beginplanning a Fusion Engineering Device (FED),which would provide a focus for developmentof reactor-relevant technologies and components,enable researchers to evaluate safety issues asso-ciated with fusion power, and facilitate investi-gation of additional plasma physics issues. Thisdevice would be built and operated as part of abroad program of engineering experimentationand analysis to be conducted by a new fusionengineering center. The ERAB panel recognizedthat planning and constructing FED would requirea doubling of the fusion budget over the next 5to 7 years, and it recommended this budget in-crease.

The Magnetic Fusion EnergyEngineering Act, 1980

Many of the recommendations of the ERABpanel were incorporated into the Magnetic Fu-sion Energy Engineering Act (MFEE Act), passedby Congress in September 1980.26 Passage of theMFEE Act was largely a result of RepresentativeMike McCormack’s (D-Washington) efforts. Iturged acceleration of the national effort in mag-netic fusion research, development, and demon-stration activities. Like the ERAB report, the actrecommended creation of a Magnetic FusionEngineering Center to coordinate major magneticfusion engineering devices.

The MFEE Act recommended that funding lev-els for magnetic fusion be doubled (in constantdollars) within 7 years. However, it did not ap-

2t’’Report on the Department of Energy’s Magnetic Fusion Pro-gram,” prepared by the Fusion Review Panel of the Energy ResearchAdvisory Board, August 1980, as quoted in Fusion Energy: An Over-view of the Magnetic Confinement Approach, /ts Objectives, andPace, a report prepared for the Subcommittee on Energy Researchand Production, House Committee on Science and Technology,96th Cong., 2d sess., Serial GGG, December 1980, p. 133.

Zbpublic Law 96-386, signed into law on OCt. 7, 1980.

Ch. 3.—History of fusion Research ● 5 1

propriate these increases, and there was no fol-low-up. in effect, the act indicated that Congressconsidered the fusion program worthwhile anddeserving of support but was unable or unwillingto make a long-term commitment to substantiallyincrease expenditures. Actual appropriations inthe 1980s did not grow at the level specified inthe act and in fact continued the drop in con-stant dollar funding that began in 1977.

Reagan Administration Budgetsand Philosophy

Energy R&D budgets underwent radical cuts in1981 at the beginning of the Reagan Administra-tion. The Reagan Administration stated that de-velopment activity belonged in the private sec-tor and that the government could encourage thisactivity most effectively by staying out of it. Ac-cordingly, DOE research budgets for solar energy,fossil fuel technology, fission technology, andenergy conservation—those energy areas mostheavily weighted towards development or dem-onstration, as opposed to research—were sub-stantially reduced. In contrast, the Reagan Ad-ministration continued to support governmentfunding for long-term, high-risk programs–e.g.,fusion research–that would not attract privateinvestment. Therefore, although the fusion re-search budget has decreased in the 1980s, it hasnot been cut as severely as some of DOE’s otherenergy R&D programs.

With annual budget appropriations falling, theambitious plans of the 1970s, which culminatedin the MFEE Act of 1980, could not be imple-mented. Thus, the fusion program has had tomodify its program strategy; subsequent plans at-tempted to identify the most important aspectsof the fusion program to pursue.

The Comprehensive ProgramManagement Plan, 1983

The MFEE Act required that the Secretary ofEnergy prepare a Comprehensive Program Man-agement Plan (CPMP) outlining the fusion pro-gram’s strategy and schedule. This plan was com-pleted by DOE and transmitted to Congress in1983.27 The CPMP attempted to satisfy the em-

phases of the MFEE Act within the fiscal con-straints imposed by the Reagan Administration.The plan also sought to preserve the role of in-ternational leadership in fusion for the UnitedStates.

The CPMP had a clear reactor emphasis, butit was also consistent with Reagan Administrationphilosophy towards development. The plan ex-plicitly ruled out government construction of ademonstration reactor, stating that:

The primary objectives of the [fusion] programare designed to provide a technical basis for de-cisions by the private sector on whether to pro-ceed with the commercial development of fusionenergy. Proceeding with a Federally funded dem-onstration plant is not part of this plan .28

The CPMP stated that within the next decade,the fusion program would select a plasma con-finement concept to undergo further develop-ment as a power reactor core. The plan definedtwo stages that would permit a decision to bemade to build a demonstration reactor by theyear 2000.


An additional provision of the MFEE Act estab-lished a technical panel on magnetic fusion asan ERAB subcommittee. The subcommittee wasmandated to conduct a triennial review of thefusion program, with the first such review to beconducted in 1983.

The subcommittee’s report29 recognized thatbudgetary constraints had made it impossible toaccomplish the goals of the MFEE Act on the time-scale envisioned. The panel recommended thatDOE abandon the CPMP, stating that it wouldforce the program to make a choice between tan-

z7Compreben5;ve Program Management Plan (CPMP) for Mag-netic Fusion Energy, June 1983. Submitted to the House Scienceand Technology Committee by the Secretary of Energy pursuantto the Magnetic Fusion Energy Engineering Act.

Zslbid., p. 2.29 Energy Research Advisory Board, Magnetic Fusion Energy Re-

search and ~eve/opment, Final Report prepared by the TechnicalPanel on Magnetic Fusion of the Energy Research Advisory Board,DOE/S-0026, January 1984.


dem mirror and tokamak confinement conceptsbefore constructing another major device, a choicethat in turn would require delaying progress onthe tokamak. The paneI also noted that the CPMP’sschedule called for construction of a next-gen-eration engineering test reactor—a major facilityintended to explore engineering aspects of fusion–before necessary technology developmentcould be completed.

As a revised program strategy, the ERAB panelrecommended that a tokamak follow-up deviceto TFTR be built to study scientific issues. Thepanel recommended that the reactor engineer-ing efforts be postponed until additional resourceswere available, and that a strong and innovativebase program be maintained in plasma physics,technology development, and alternative con-finement concepts.

The Magnetic Fusion Program Plan, 1985

DOE revised its program plan in response tothe criticisms of the ERAB subcommittee. In 1985,DOE issued the Magnetic Fusion Program Plan(MFPP), which stated that “the goal of the mag-netic fusion program is to establish the scientificand technological base required for fusionenergy. ”3° Unlike the CPMP, however, the MFPPlessened the reactor emphasis, concentratedmore on the science and engineering require-ments, and relaxed the schedule for fusion de-velopment:

The schedule for completing magnetic fusiondevelopment is directly related to the technical,economic, and political uncertainties associatedwith energy supply, which are likely to exist forseveral decades. The Magnetic Fusion ProgramPlan is a strategy for solving fusion’s technicalproblems within a time frame keyed to resolutionof other areas of energy development.31

Like the CPMP, the MFPP did not extend toconstruction of a fusion demonstration reactor.The plan laid out key technical issues that mustbe resolved by the fusion program and set outa goal of international collaboration, rather than

30U. S. Department of Energy, Office of Energy Research, A4ag-rretic Fusion Program Han, DOE/ER-0214, February 1985, Execu-tive Summary.

311 bid .

international leadership, for the U.S. fusionprogram.


The second triennial review of the magnetic fu-sion program was completed by the ERAB sub-committee on magnetic fusion in November1986. 32 The subcommittee endorsed the fusionprogram’s direction, strategy, and plan and re-affirmed the need to investigate fusion energy as“an attractive energy source of great potential forthe future.” The panel specifically considered twoissues of great importance to the future directionof the program: 1 ) the construction of a CompactIgnition Tokamak (CIT) as an experiment thatwould extend scientific understanding beyondthat obtainable in TFTR; and 2) the role of inter-national collaboration in an engineering test re-actor project.

The Compact Ignition Tokamak.–Severalyears of TFTR operation have shown continuedprogress both in understanding and in achievingconfinement. TFTR has attained Lawson param-eters above 1014 second-particles per cubic centi-meter (a factor of 10,000 improvement over1950’s results) and ion temperatures of 20,000electron volts (a factor of 200 improvement). At-tainment of actual breakeven when tritium is in-troduced seems highly probable, and the fusioncommunity has been actively exploring optionsfor a next step beyond TFTR. This has led to DOErecommendations for CIT construction.

CIT will explore the physics associated with ig-nited plasmas. The ERAB subcommittee concludedthat CIT is “an essential and timely project,”33

both because it will address a fundamental physicsissue and because it will provide technical infor-mation and experience valuable to the engineer-ing test reactor. ERAB recommended providingan increment to the magnetic fusion programbudget to prevent funding for CIT from beingtaken from other program areas. The construc-tion cost of CIT, in 1986 dollars, has been esti-

32 Energy Research Advisory Board, Repofl of the Technical pane/on Magnetic Fusion of the Energy Research Advisory Board, pre-pared for the U.S. Department of Energy, November 1986.

JJlbid,, p. 1.

Ch. 3.—History of Fusion Research . 53

mated at $300 million for the facility, plus about$60 million for diagnostic equipment and asso-ciated R&D. This estimate assumes that the fa-cility will be located at Princeton Plasma PhysicsLaboratory, where, according to DOE, site creditswill save about $200 million.34

The Role of International Collaboration.–Thesubcommittee endorsed current DOE efforts ininternational collaboration. In particular, thepanel supported the idea of constructing an inter-national engineering test reactor. As envisioned,this device—called the International Thermonu-clear Experimental Reactor (lTER)—will be a large

ldlbid., p. 11, site credits refer to the savings that result from con-

structing the project at a location that already has some of theneeded equipment in place. By constructing CIT at Princeton, theexperiment will be able to take advantage of the existing T~R powersupplles and other equipment.

experimental facility designed to explore engi-neering and technological issues relevant to fu-sion reactors. The ERAB subcommittee stated that“the United States should consider reaching outto other nations to establish a multinational struc-ture for fusion relationships. ”35 However, ERABalso recognized the inherent complexity and un-certainty of major international collaborations,pointing out that “some realistic considerationmust be given to the possibility that internationalcollaboration on a large scale may not comeabout.” 36 At present, DOE is investigating the po-tential of undertaking a joint planning activitywith the other major fusion powers on a concep-tual design for ITER, along with supporting R&D.

Jslbid., p. 14.JGlbid,, p. 1 T. A detailed discussion of international collabora-

tion on ITER and other projects can be found in ch. 7 of thisassessment.

Chapter 4

Fusion Science and Technology

Chapter 4

Fusion Science and Technology

Great progress has been made over the past35 years of fusion research. Nevertheless, manyscientific and technological issues have yet to beresolved before fusion reactors can be designedand built. Fundamental questions in plasma sci-ence remain, especially involving the behaviorof plasmas that actually produce fusion power.Other plasma science questions involve the be-havior and operation of the various confinementconcepts that might be used to hold fusionplasmas.

To date, engineering issues have not been stud-ied as extensively as plasma science issues. Formany years, engineering studies were deferred

for lack of funds; science had a higher fundingpriority. In addition, fusion technologies that re-quire a source of fusion power to be tested anddeveloped have had to await a device that couldsupply the power. Until recently, the fusion sci-ence database has not been sufficient to permitsuch a device to be designed with confidence.

This chapter discusses the various confinementconcepts under study, the systems required in afusion reactor, and the issues that must be re-solved before such systems can be built. It thenoutlines the research plan required to resolvethese issues and estimates the amount of time andmoney that such a research plan will take.

CONFINEMENT CONCEPTS’

Most of the fusion program’s research has fo-cused on different magnetic confinement con-cepts that can be used to create, confine, andunderstand the behavior of plasmas. In all ofthese concepts, magnetic fields are used to con-fine the plasma; the concepts differ in the shapeof the fields and the manner in which they aregenerated. These differences have implicationsfor the requirements, complexity, and cost of theengineering systems that surround the plasma.

1 Th is chapter d Iscusses on Iy magnetic confinement approaches.Other approaches to fusion are discussed In app. B. The conceptsmentioned In this section are described in greater detail in pp. 156-204 ot’ Physics Through the 19905: P/asmas and F/uids, by the Na-tional Research Council (Wa~hington, DC: National Academy Press,1 986).

Table 4-1 .—Classification of

Table 4-1 lists the principal confinement schemespresently under investigation in the United Statesand classifies them according to their level of de-velopment. The concepts are described in the fol-lowing section.

At this stage of the research program, it is notknown which confinement concept can bestform the basis of a fusion reactor. The tokamakis much more developed than the others, andtokamaks are expected to demonstrate the basicscientific requirements for fusion within a fewyears. However, several alternate concepts areunder investigation in order to gain a better un-derstanding of the confinement process and toexplore possibilities for improving reactor per-formance.

Confinement Concepts

Well-developed Moderately developed Developingknowledge base knowledge base knowledge base

Conventional tokamak Advanced tokamak SpheromakTandem mirror Field-reversed configurationStellarator Dense Z-pinchReversed-field pinch

SOURCE Adapted from Argonne National Laboratory, Fusion Power Program, Technical Planning Activity Final Report,commissioned by the U S Department of Energy, Off Ice of Fusion Energy, AN UFPP-87-1, January 1987, p 15

57


The major scientific questions to be answeredfor each confinement approach are whether andwith what confidence the conditions necessaryfor a sustained, power-producing fusion reactioncan be simultaneously satisfied in a commercial-scale reactor. Much of the experimental andtheoretical work in confinement studies involvesthe identification and testing of scaling relation-ships that predict the performance of future de-vices from the results of previous experiments.ideally, such scaling models should be derivablefrom the basic laws of physics. However, the be-havior of plasmas confined in magnetic fields isso complicated that a general theory has not yetbeen found. With some simplifying assumptions,limited theoretical models have been developed,but they are not broad enough to extrapolate thebehavior of a concept to an unexplored range.Without a sound theoretical base, the risk of tak-ing too large a step is great. A series of interme-diate-scale experiments is needed to bridge thegap between concept development and a full-scale reactor.

Even with the tokamak—the most studied con-finement concept–scaling properties are not fullyunderstood. Although tokamaks have attainedby far the best experimental performance of anyconfinement concept, no proven theoretical ex-planation of how that performance scales withparameters such as size, magnetic field, andplasma current has yet been derived. Withouta complete theoretical basis, “empirical” scalingrelationships deduced from past observationsmust be used. Such empirical relationships maywell prove sufficient for designing a machine ca-pable of forming reactor-scale plasmas before afundamental theoretical understanding of toka-mak behavior is reached.

“Closed” Concepts

In “closed” magnetic confinement configura-tions, the plasma is contained by magnetic linesof force that do not lead out of the device. Closedconfigurations all have the basic shape of a dough-nut or inner tube, which is called a “torus. ” Amagnetic field can encircle a torus in two differ-ent directions (figure 4-1 ). A field running the longway around the torus, in the direction that thetread runs around a tire, is called a “toroidal”

Figure 4-1 .—Tokamak Magnetic Fields

SOURCE: Princeton Plasma Physics Laboratory Information Bulletin NT-1: Fu-sion Power, 1984, p. 4.

field. This field is generally created by externalmagnet coils, called toroidal field coils, throughwhich the plasma torus passes. A magnetic fieldperpendicular to the toroidal field, encircling thetorus the short way, is called a “poloidal” field.This field is generated by electrical currents in-duced to flow within the plasma itself. Together,toroidal and poloidal magnetic fields form the to-tal magnetic field that confines the plasma.

Ch. 4.—Fusion Science and Technology ● 5 9

Conventional Tokamak

In a tokamak, the principal confining magneticfield is toroidal, and it is generated by large ex-ternal magnets encircling the plasma. This fieldalone, however, is not sufficient to confine theplasma. A secondary poloidal field, generated byplasma currents, is also required. The combina-tion of poloidal and toroidal fields produces a to-tal field that twists around the torus and is ableto confine the plasma (figure 4-1).

The tokamak concept was developed in the So-viet Union, and, since the Iate 1960s, it has beenthe primary confinement concept in all four ofthe world’s major fusion research programs. Ithas also served as the principal workhorse fordeveloping plasma technology. The scientificprogress of the tokamak is far ahead of any otherconcept. Major world tokamaks are listed in ta-ble 4-2.

Advanced Tokamak

Various features now under investigation maysubstantially improve tokamak performance. Mod-ifying the shape of the plasma cross-section canincrease the maximum plasma pressure that canbe confined with a given magnetic field. TheDoublet II I-D (D III-D) tokamak at GA Technol-ogies and the Princeton Beta Experiment Modifi-cation (PBX-M) tokamak at Princeton PlasmaPhysics Laboratory are being used to investigate

shaped plasmas according to this principle, Othervariants on tokamak design would permit morecompact fusion cores to be constructed, whichcould lead to less expensive reactors; these im-provements are under study.

Still other improvements would permit toka-maks to run continuously. The technique typi-cally used today to drive the plasma current ina tokamak can be run only in pulses. Technol-ogies for driving continuous, or steady-state,plasma currents are being investigated at a num-ber of different experimental facilities.

Stellarator

The stellarator is a toroidal device in whichboth the toroidal and poloidal confining fields aregenerated by external magnets and do not de-pend on electric currents within the plasma. Theexternal magnets are consequently more com-plicated than those of a tokamak (figure 4-2).However, the absence of plasma current in a stel-Iarator enables steady-state operation to beachieved more directly without the need for cur-rent drive.

The stellarator concept was invented in theUnited States. After the discovery of the tokamakin the late 1960s, however, the United States con-verted its stellarators into tokamaks. The stella-rator concept was kept alive primarily by research

Table 4-2.—Major World Tokamaksa

Device Location Status

JET . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . European Community (United Kingdom) OperatingD III-D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . United States (GA Technologies) OperatingAlcator C-Mod . . . . . . . . . i . . . . . . . . . . . . . . . . . . . . . . . United States (MIT) Under constructionT-14 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . U.S.S.R. (Kurchatov) Under constructionTFTR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . United States (PPPL) OperatingJT-60 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Japan (Naka-machi) OperatingT-15 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . U.S.S.R. (Kurchatov) Under constructionASDEX-Upgrade . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Federal Republic of Germany (Garching) Under constructionTore Supra. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . France (Cadarache) Under constructionFrascati Tokamak Upgrade . . . . . . . . . . . . . . . . . . . . . . Italy (Frascati) Under constructionPBX-M . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . United States (PPPL) Under constructionTEXTOR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Federal Republic of Germany (Julich) OperatingaListed in decreaing order of plasma current, one of the many parameters that determines tokamak capability. NO single factor by itself measures capability well;

current is used here only to give a rough distinction between those devices at the top of the list and those at the bottom. Ranking by size, magnetic field, or otherparameter would rearrange the list somewhat.

NOTE: This table includes only the largest tokamaks. The World Survey of Activities in Corrtrolled Fusion Research, 1986 Edition (published in Nuclear Fusion, SpecialSupplement 1966) lists a total of 77 existing and proposed tokamaks at 54 sites in 26 countries.

SOURCE Office of Technology Assessment, 1987


Figure 4-2. —Magnet Coils for the Advanced Toroidal Facility, A Stellarator

SOURCE Oak Ridge National Laboratory

in the Soviet Union, Europe, and Japan, and, dueto good results, the United States has recently re-vived its stellarator effort. Stellarators today per-form as well as comparably sized tokamaks.

Major world stellarator facilities that are oper-ating or under construction are listed in table 4-3.Not shown on the table is the Large Helical Sys-tem proposed to be built in Japan at a cost sev-eral times that of the largest stellarator machinenow u

the new Japanese device would be the largestoperational non-tokamak fusion experiment,

Reversed-Field Pinch

In a reversed-field pinch, the toroidal magneticfield is generated primarily by external magnetsand the poloidal field primarily by plasma cur-rents. The toroidal and poloidal fields are com-parable in strength, and the toroidal field reversesdirection near the outside of the plasma, givingnder construction; if built and operated,

Table 4-3.—Major World Stellarators a

Device Location StatusATF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . United States (ORNL) Under constructionWendelstein VII-AS . . . . . . . . . . . . . . . . . . . . . . . . . . . . Federal Republic of Germany (Garching) Under constructionURAGAN-2M . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . U.S.S.R. (Kharkov) Under constructionHeliotron-E. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Japan (Kyoto University) OperatingURAGAN-3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . U.S.S.R. (Kharkov) OperatingCHS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Japan (Nagoya University) Under constructionL-2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . U.S.S.R. (Lebedev) OperatingH-1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Australia (Canberra) Under constructionaListed in order of decreasing stored magnetic energy, a parameter which in turn depends both on magnetic field strength and plasma

SOURCE Office of Technology Assessment, 1987; from data provided by Oak Ridge National Laboratory,

Ch. 4.—Fusion Science and Technology “ 61

Figure 4-3.— Reversed. Field Pinch

Toroidal fieldwindings

SOURCE: Adapted from National Research Council, Physics Through the 1990s:Plasmas and FluIds (Washington, DC: National Academy Press, 1988).

the concept its name (see figure 4-3). In a toka-mak, the toroidal field dominates and points inthe same direction throughout the plasma.

The reversed-field pinch generates more of itsmagnetic field from plasma currents and less fromexternal magnets, permitting its external magnetsto be smaller than those of a comparably per-forming tokamak. The nature of the magneticfields in a reversed-field pinch may also permitsteady-state plasma currents to be driven in amuch simpler manner than is applicable in a toka-mak. Moreover, a reversed-field pinch plasmamay be able to heat itself to reactor temperatures

without the complex and costly external heatingsystems required by tokamaks.

Los AIamos National Laboratory in New Mex-ico is the center of U.S. reversed-field pinch re-search. The Confinement Physics Research Fa-cility (CPRF) to be built there will hold the largestreversed-field pinch device in the United States.A variant of the reversed-field pinch, the Ohmi-cally Heated Toroidal Experiment, or OHTE, wasbuilt at GA Technologies in San Diego, Califor-nia. Reversed-field pinch research is also con-ducted in both Europe and Japan. Table 4-4 liststhe major world reversed-field pinches.

Spheromak

The spheromak is one of a class of less devel-oped confinement concepts called “compacttoroids,” which do not have toroidal field coilslinking the plasma loop and therefore avoid theengineering problem of constructing rings lockedwithin rings. Conceptually, if the torodial fieldcoils and inner walls of a reversed-field pinchwere removed and the central hole were shrunkto nothing, the resultant plasma would be thatof the spheromak. Its overall shape is spherical;although the internal magnetic field has bothtoroidal and poloidal components, the device hasno central hole or external field coil linking theplasma (figure 4-4). The plasma chamber lies en-tirely within the external magnets. If the sphero-mak can progress to reactor scale, its small sizeand simplicity may lead to considerable engineer-ing advantages. However, the present state ofknowledge of spheromak physics is rudimentary.

Table 4.4.—Major World Reversed-Field Pinches a


CPRF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . United States (LANL) Under constructionRFX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Italy (Padua) Under constructionOHTE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . United States (GA Technologies) OperatingHBTX 1-B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . United Kingdom (Culham) OperatingZT-40M . . . ! . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . United States (LANL) OperatingMST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . United States (University of Wisconsin) Under constructionETA BETA 11 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ., Italy (Padua) OperatingRepute I. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Japan (Tokyo University) OperatingTPE-1RM(15) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Japan (Tsukuba University) OperatingSTP-3M . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Japan (Nagoya University) OperatingaListed in order of decreasing plasma current, a rough measure of reversed-field pinch performance.

SOURCE: Office of Technology Assessment, 1987; from data supplied by the Los Alamos National Laboratory.

62 “ Starpower: The U.S. and the International Quest for Fusion Energy

Figure 4-4.—Spheromak

Spheromak research at Los Alamos NationalLaboratory was terminated in 1987 due to fiscalconstraints, and another major U.S. device atPrinceton Plasma Physics Laboratory is to be ter-minated in fiscal year 1988. The remaining U.S.

spheromak research effort takes place at the Uni-versity of Maryland. Spheromaks also are beingstudied in Japan and the United Kingdom. Ma-jor world spheromak devices are listed in table4-5.

Field= Reversed Configuration

The field-reversed configuration (FRC) is anotherform of compact toroid. Despite the similar name,it does not resemble the reversed-field pinch. Itis unusual among closed magnetic confinementconcepts in providing confinement with onlypoloidal fields; the FRC has no toroidal field. Theplasma is greatly elongated in the poloidal direc-tion and from the outside has a cylindrical shape(figure 4-5).

Like the spheromak, the FRC does not have ex-ternal magnets penetrating a hole in its center;all the magnets are located outside the cylindri-cal plasma. The FRC also has the particular vir-tue of providing extremely high plasma pressurefor a given amount of magnetic field strength. ifits confining field is increased in strength, the FRCplasma will be compressed and heated. Suchheating may be sufficient to reach reactor con-ditions, eliminating the need for external heat-ing. Existing FRC plasmas are stable, but whetherstability can be achieved in reactor-sized FRCplasmas is uncertain. A new facility, LSX, is underconstruction at Spectra Technologies in Bellevue,Washington, to investigate the stability of largerplasmas.

U.S. FRC research started at the Naval ResearchLaboratory in Washington, D. C., in the late 1960s.Increased effort in the United States in the late1970s, centered at Los Alamos, was undertakenlargely in response to experimental results ob-tained earlier in the decade from the Soviet Union

Table 4-5.—Major World Spheromaks a



Figure 4-5.— Field-Reversed Configuration

SOURCE: National Research Council, Physics Through the 1990s: Plasmas andFluids (Washington, DC National Academy Press, 1988),

and the Federal Republic of Germany. Soviet re-search has continued, but German and British re-search programs have stopped. Meanwhile, aprogram in Japan has begun. Major field-reversedconfiguration experiments around the world arelisted in table 4-6.

"Open” Concepts

plasmas in open magnetic confinement devicesare confined by magnetic fields that do not closeback on themselves within the device but ratherextend well outside the device. Since plasma par-ticles can easily travel along magnetic field lines,some additional mechanism is required to reducethe rate at which plasma escapes out the endsof an open confinement device.

Magnetic Mirrors

Fusion plasmas can be confined in an open-ended tube by strengthening, and thereby com-pressing, the magnetic fields near the ends .Strengthening the magnetic field near the ends“reflects” plasma particles back into the centermuch as narrowing the ends of a sausage helpskeep in the meat. However, the ends of a sim-p/e magnetic mirror (figure 4-6a) are not other-wise sealed. Just as the meat eventually forces itsway out of an unsealed sausage when squeezed,a simple magnetic mirror cannot confine a plasmawell enough to generate fusion power. In addi-tion, simple mirrors are usually unstable, with theplasma as a whole tending to slip out sideways.

A variation of the simple mirror is the mini-mum-B mirror (figure 4-6 b), one version of whichuses a coil shaped like the seam on a baseballto create a magnetic field that is lowest in strengthat the center and increases in strength towardsthe outside. Particles leaving the center tend tobe reflected back by the increasing magnetic fieldat the outside, just as particles leaving the sim-ple mirror tend to be reflected back at the ends.This configuration is stable, and there is no ten-dency for the plasma as a whole to escape. How-ever, despite these improvements, the minimum-B mirror cannot confine a plasma well enoughto generate net fusion power.

The tandem mirror (figure 4-6c) improves thesimple magnetic mirror by utilizing additionalmirrors to improve the plugging at each end.These plugs, called end cells, are themselves mag-netic mirrors. Rather than trapping the mainplasma, the end cells hold particles that gener-ate an electric field. This electric field, in turn,keeps the plasma in the central cell from escap-

able 4.6.—Major World Field-Reversed Configurationse


LSX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . United States (Spectra Technologies) Under constructionFRX-C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . United States (LANL) OperatingBN, TOR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . U.S.S.R. (Kurchatov) OperatingTRX-2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . United States (Spectra Technologies) OperatingOCT, PIACE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Japan (Osaka University) OperatingNUCTE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Japan (Nihon University) OperatingaListed approximately by decreasing order of size; similarly sized devices at the same institution are listed together.

SOURCE Office of Technology Assessment, 1987; from information supplied by the Los Alamos National Laboratory.


Figure 4-6.—Magnetic Mirrors

(a) Simple mirror (b) Minimum-B mirror

Plasma

/

SOURCE: Lawrence Livermore National Laboratory, “Evolution of the Tandem Mirror,” Energy and Technology Review, November1986

ing. While particle losses from the end cells arehigh, these losses can be compensated by inject-ing new particles.

The tandem mirror concept was developedsimultaneously in the United States and the So-viet Union in the late 1970s. The Mirror FusionTest Facility B (MFTF-B), located at LawrenceLivermore National Laboratory in California, isthe largest mirror device in the world and thelargest non-tokamak magnetic confinement fu-sion experiment. Budget cuts, however, forcedMFTF-B to be moth balled before it could be usedexperimentally. The Tandem Mirror ExperimentUpgrade (TMX-U) at Livermore, a smaller versionof MFTF-B, was terminated as well, and the TARAdevice at the Massachusetts Institute of Technol-ogy will be shut down in 1988. At that point,Phaedrus at the University of Wisconsin will bethe only operational U.S. mirror machine. Mir-ror research is still conducted in the Soviet Unionand Japan. Table 4-7 presents a list of major worldtandem mirror facilities.

Dense Z= Pinch

In this concept, a fiber of frozen deuterium-tritium fuel is suddenly vaporized and turned intoplasma by passing a strong electric current throughit. This current heats the plasma while simultane-ously generating a strong magnetic field encirclingthe plasma column (figure 4-7), “pinching” it longenough for fusion reactions to occur. Many de-vices investigated in the earliest days of fusionresearch in the 1950s operated in a similar man-ner, but they were abandoned because theirplasmas had severe instabilities and were una-ble to approach the confinement times neededto generate fusion power.

The dense z-pinch differs from the 1950s pinchesin several important aspects that, as calcuIationsand experiments have shown, improve stability.Crucial to the modern experiments are preciselycontrolled, highly capable power supplies thatwould have been impossible to build with 195ostechnology, and the use of solid, rather than gase-

—


Table 4-7.—Major World Tandem Mirrorsa


MFTF-B . . . . . . United States (LLNL) Moth balledTMX-U . . . . . . . United States (LLNL) MothballedGamma-10 . . . .Japan (Tsukuba University) OperatingTARA . . . . . . . . United States (MIT) To be terminated, fiscal year 1988Phaedrus . . . . . United States (University of Wisconsin) OperatingAmbal M . . . . . USSR (Novosibirsk) Under constructionaListed in decreasing order of size.

SOURCE: Office of Technology Assessment, 1987; from data supplied by the Lawrence Livermore National Laboratory.

Figure 4-7. —Dense Z-Pinch

SOURCE: Office of Technology Assessment, 1987

OUS, fuel to initiate the discharge. However, it ismuch too early to tell whether this concept canbe developed successfully. If the concept can bedeveloped, the device has the potential to be farsmaller and far less expensive than devices basedon other concepts. External magnets are notneeded since the plasma current supplies the en-tire confining field. Dense z-pinch research is tak-ing place in the United States at two facilities: theNaval Research Laboratory and Los Alamos Na-tional Laboratory.

Conclusions ConcerningConfinement Approaches

A number of general conclusions can be drawnfrom studies of the confinement concepts thathave evolved over the past 10 to 15 years:

●

●

●

Many fusion concepts are under study be-cause the frontrunner tokamak, while likelyto be scientifically feasible, may yet be foundweak in some critical area or less economi-cally attractive than alternatives. Featuresbeing studied in alternate concepts includeeased conditions for steady-state operation,reduced external magnet complexity andcost, and improved use of the magnetic field.Searching for optimum reactor configura-tions and developing further understandingof the fusion process mandate that the rangeof concepts under investigation not beprematurely narrowed.

The tokamak concept is by far the mostdeveloped, and it has attained plasma con-ditions closest to those needed in a fusionreactor. At present and for the next severalyears, studies of reactor-like plasmas will bedone with tokamaks because no other con-cept has yet proven that it can reach reactorconditions. A number of other confinementconcepts have features that might makethem preferable to the tokamak if they arecapable of progressing to an equivalent stageof performance. It remains to be seen whichof these concepts will attain that perform-ance level, what their development will cost,and to what degree the tokamak concept it-self will further improve.Different confinement studies complementeach other. Knowledge obtained through re-search on a specific concept often can begeneralized. Throughout the history of fusionresearch, plasma science issues originally in-vestigated because of their relevance to aparticular concept have become importantto studies of other concepts as well.A great deal of progress in understandingfusion plasmas and confinement conceptshas been made to date. Many concepts

66 ● Starpower : The U.S. and the In te rna t iona l Quest for F u s i o n E n e r g y

●

●

studied earlier, such as the simple magneticmirror, are no longer studied today becausethey cannot compare attractively to improvedor alternate concepts. At the same time, asin the case of the dense z-pinch, problemsonce considered intractable may be solvedwith additional scientific understanding andmore advanced technology.Research on all confinement concepts hasbenefited from international cooperation.Studies undertaken by different groups indifferent countries enhance each other sig-nificantly. Furthermore, advances by oneprogram have frequently stimulated addi- ●

tional progress in other programs. interna-tional cooperation in fusion research is dis-cussed further in chapter 7.Not all confinement concepts can be devel-

require study at greater levels of capabilitybefore their potential as reactor candidatescan be assessed. Moreover, since this haslargely been an empirical program, advancedstudies will require larger and increasinglymore expensive facilities. Fiscal constraintswill almost certainly require that not all ofthe concepts be “promoted” to subsequentstages of development. Criteria such as de-velopment cost, characteristics of the endproduct, and likelihood of success must bedeveloped for selecting which concepts areto be pursued further.progress in fusion science depends on prog-ress in fusion technology. Time after time,the exploration of new ranges of plasma be-havior has been made possible by the devel-opment of new heating, fueling, and plasma

oped to reactor scale. Promising concepts shaping technologies.

SCIENTIFIC PROGRESS AND REACTOR DESIGNDifferent Dimensions of Progress

To form the basis of a viable fusion reactor, aconfinement concept must meet two objectives.First, it must satisfy scientific performance require-ments—temperature, density, and confinementtime—necessary for a plasma to produce fusionpower. progress towards those requirements iseasy to measure.

Second, a confinement concept must demon-strate “reactor potential. ” Unlike scientific per-formance, reactor potential is difficult to meas-ure. A viable reactor must be built, operated, andmaintained reliably, and it must be economically,environmentally, and socially acceptable. Whilefusion’s acceptability in these respects dependson factors external to fusion technology, it alsodepends on the choice of confinement concept.

Each concept may have different advantages,and, in the absence of quantitative measures, theprocess of i dentifying the concepts t hat offer t hemost attractive reactors depends in large part onthe innovation and technological optimism of thereactor designer. Also, attributes of an attractivereactor can be identified today, but the relativeimportance of these attributes may change as our

understanding of fusion technology and futuresocietal needs improves.

No matter how it is evaluated, reactor poten-tial is a requirement that, along with scientific per-formance, must be satisfied by at least one con-finement concept before fusion power can berealized. Figure 4-8 shows two different paths bywhich a concept can develop toward commer-cial use. Along the “performance-driven” path,a concept first demonstrates the ability to attainplasma parameters near those required to pro-duce fusion power; subsequently, innovations orsuccessive refinements show that the concept’sscientific capabilities can be used in a viable re-actor design. Alternatively, along the “concept-improvement-driven” path, features that are at-tractive in a fusion reactor—e.g., compact size,ease of maintenance, simple construction, andreliable operation—are apparent before the sci-entific performance necessary to produce fusionpower is demonstrated.

The actual development of any given confine-ment concept will fall somewhere between theseextremes. Development of the tokamak appearsto be closer to the performance-driven curve. Itsscientific performance, along with its use in de-


Figure 4-8.—Alternate Paths for Concept Development

SOURCE Adapted from Argonne National Laboratory, Technical Planning Activity: Final Report, commissioned by the U.S. Department of Energy, Office of EnergyResearch, AN L/FPP-87-1, January 1987, figure 1.5, p. 56.

veloping plasma technology and diagnostics, hasbeen the primary motivation for study to date;improvements to the basic tokamak concept arecurrently focused on improving reactor poten-tial. Other concepts are more concept-improve-ment-driven in that their features might makethem preferable to the tokamak if they can reachreactor scale. However, the ability of other con-cepts to attain the necessary plasma conditionsis much less certain because their experimentaldatabases are less developed.

Scientific Progress

Energy Gain

An important measure of scientific progresstowards attaining reactor-relevant conditions isenergy gain, denoted as “Q. ” Energy gain is theratio of the fusion power output that a device gen-erates to the input power injected into the plasma.

Input and output power are measured at someinstant after the plasma has reached its operat-ing density and temperature. In experimentalplasmas that do not contain tritium and thereforedo not produce significant amounts of fusionpower, an “equivalent Q“ is measured. It is de-fined as the Q that would be produced by theplasma if it were fueled equally by both deu-terium and tritium (D-T) and if it had attained thesame plasma parameters. z

The numerator of the Q ratio includes all thefusion power produced by the plasma, eventhough most of the output power (80 percent)

“’Equivalent Q“ is either calculated from the measured plasmadensity and temperature or derived from actual measurements ofdeuterium-deuterium (D-D) fusion reactions. Since the ratio be-tween the D-T reaction rate and the D-D reaction rate under thesame conditions IS believed known, a measurement of D-D re-actions can be used to infer what the D-T fusion yield would beunder the same conditions.


immediately escapes from the plasma via ener-getic neutrons. The denominator of the ratio–the power used to heat the plasma—greatly un-derestimates the amount of power actually con-sumed. Losses incurred in generating heatingpower and delivering it to the plasma are not in-cluded, nor is the power needed for the confin-ing magnets, vacuum system, and other supportsystems. In present-generation experiments, thepower excluded from the definition of Q is asmuch as 35 times greater than the power ac-counted for in this ratio.3

Q excludes most of the power drawn by a fu-sion experiment because it is a scientific meas-ure that is not intended to gauge engineeringprogress. Present experiments, needing only tooperate for short pulses, have not been designedto minimize consumed power; to lessen construc-tion cost, they use magnets that are far less effi-cient than those likely to be used in future re-actors. Similarly, the inefficiencies in generatingthe externally applied plasma heating power arenot included because auxiliary heat is not re-quired once a plasma generates enough fusionpower to become self-sustaining. Even so, someexternal power will be required in any steady-state plasma device except the stellarator to main-tain electrical currents within the plasma.

Figure 4-9 shows the plasma temperatures andconfinement parameters needed to obtain Qs ofat least 1, a condition known as “breakeven. ”The plasma temperatures and confinement pa-rameters that have been attained experimentallyby various confinement configurations are alsoshown. No device has yet reached breakeven,although tokamak experiments have clearly comethe closest.

Ignition

The most significant region in figure 4-9 is ig-nition in the top right corner. An ignited D-Tplasma not only generates net fusion power butalso retains enough heat to continue producingfusion reactions without external heat. The Q ofan ignited plasma is infinite, since the plasma gen-

Jsee specifications for the Tokamak Fusion Test Reactor at the

Princeton Plasma Physics Laboratory, footnote 4 below.

crates output power without auxiliary input powerfrom external sources. (Power to drive currentsin the plasma and to cool the magnets to theiroperating temperature will be required even forignited plasmas, but, as stated above, this poweris not included in Q.)

Successfully reaching ignition—or at least suc-cessfully generating a plasma that produces manytimes more power than is input into it—will bea major milestone in determining fusion’s tech-nological feasibility. The energy and the reactionproducts generated in a plasma producing apprecia-ble amounts of fusion power will significantlyaffect the plasma’s behavior. Understanding theseeffects may be crucial to utilizing self-sustainingfusion reactions in reactors, and these effects can-not be studied under breakeven conditions alone.

Breakeven

The breakeven curve in figure 4-9 shows theconditions under which a plasma generates asmuch power through fusion reactions as is in-jected into it to maintain the reactions. Althoughreaching breakeven will be a major accomplish-ment, it will not have the technical significanceof reaching ignition. Due to the way that energygain is defined, the breakeven threshold in somerespects is arbitrary, and it depends significantlyon the manner in which the plasma is heated.Crossing the threshold does not cause a signifi-cant change in plasma behavior and in no wayindicates that the experiment is able to power it-self. Problems that are not fully evident underbreakeven conditions may yet be encounteredon the way to ignition.

The breakeven curve in figure 4-9 is calculatedfor plasmas that are uniformly heated. If theplasma is heated in such a way that a small frac-tion of the plasma particles become much hot-ter than the rest, this fraction will produce a dis-proportionate amount of fusion power and thebreakeven requirements can be substantially lo-wered. For this reason, plasmas heated with neu-tral beams can reach breakeven under conditionsthat would not be sufficient without the use ofneutral beams.

Neutral beams are extremely hot jets of neu-tral atoms that can penetrate the confining mag-


10

1

0.1

Figure 4-9.— Plasma Parameters Achieved by Various Confinement Concepts

Confinement parameter (particle –see cm-3)KEY: S-1: Spheromak-1; Princeton Plasma Physics Laboratory, Princeton, NJ.

TMX-U: Tandem Mirror Experiment Upgrade; Lawrence Livermore National Laboratory, Livermore, CA.ZT-40M: Toroidal Z-pinch, -40, Modified; Los Alamos National Laboratory, Los Alamos, NM.FRX-C: Field-Reversed Experiment C; Los Alamos National Laboratory, Los Alamos, NM.OHTE: Ohmically Heated Toroidal Experiment; GA Technologies, Inc., San Diego, CA.Gamma-IO: University of Tsukuba, Ibaraki, Japan.WVII-A: Wendelstein VII-A; Institute for Plasma Physics, Garching, Federal Republic of Germany.HEL-E: Heliotron-E; Kyoto University, Kyoto, Japan.D Ill: Doublet Ill; GA Technologies, Inc., San Diego, CA.JET: Joint European Torus; JET Joint Undertaking, Abingdon, United Kingdom.TFTR: Tokamak Fusion Test Reactor; Princeton Plasma Physics Laboratory, Princeton, NJ.ALC-C: Alcator C; Massachusetts Institute of Technology, Cambridge, MA.

SOURCE Office of Technology Assessment, 1987.

netic fields to enter the plasma. Beam atoms col-lide with particles inside the plasma and becomeelectrically charged, thereby becoming trappedby the magnetic field. Through collisions, muchof the energy carried by the beams is transferredto the “target” plasma, heating it up. In the proc-ess, the beam particles themselves cool down.

However, it will take many collisions for thebeam particles to cool down to the temperatureof the target plasma. As long as the beams areon, the most recently injected beam particles are

significantly hotter than the original plasma par-ticles. (Once the beams are turned off, the in-jected particles cool down to the temperature ofthe remaining plasma.) Since the fusion reactionrate increases very rapidly with temperature, thehotter particles from the neutral beam have amuch higher probability of generating fusion re-actions than other particles in the plasma. in thismanner, a beam-heated plasma can achievebreakeven with plasma parameters up to a fac-tor of 10 lower than those needed for plasmasheated by other mechanisms. However, since the


beams themselves require so much power tooperate, it is not expected that beam-heatedplasmas will be used in reactors. Therefore, thelower breakeven threshold for beam-heatedplasmas may not translate into lower require-ments for a practical reactor.

The Tokamak Fusion Test Reactor (TFTR) atPrinceton Plasma Physics Laboratory was de-signed to take advantage of beam heating. It isexpected that breakeven-equivalent (breakevenconditions in a plasma not containing tritium) willbe obtained sometime between fall 1987 andspring 1988. Experiments to realize true break-even using tritium are scheduled for the end of1990. These achievements will be important be-cause, for the first time, a significant amount ofheat from fusion power will be produced in amagnetic fusion device. Moreover, successful D-Toperation of TFTR will provide important tritium-handling experience necessary for future reactoroperation.

Nevertheless, TFTR–not being an engineeringfacility–does not address most of the technologi-cal issues that must be resolved before a fusionreactor can be built. Moreover, it will not reachignition, and the advantage it derives from usingneutral beams will probably not translate into aworkable reactor. It does not incorporate ad-vanced physics aspects that have been identifiedsince its design in the 1970s. TFTR will not—andnever was intended to—have the capability togenerate electricity from the fusion power it willproduce. Even on attaining breakeven, the TFTRexperiment as a whole—as opposed to the TFTRplasma alone—will produce less than 3 percentof the power it will consume.4

State of the Art

Temperature and Confinement.–Figure 4-9shows results that have been attained by each

4TFTR is being upgraded to deliver up to 27 megawatts of neu-tral beam power to the plasma. To reach breakeven, where thefusion power generated equals the external power injected intothe plasma, 27 megawatts of fusion power would have to be gen-erated in the plasma. If reaching breakeven were to require TFTRto draw near the maximum amount of power available from its elec-trical supply, it could consume close to 1,000 megawatts of elec-tricity. This amount IS 37 times greater than the fusion power tobe produced at breakeven.

of the confinement concepts to date. Tokamakexperiments have clearly made the most progressin terms of coming the closest to the ignitionregion.

TFTR, in particular, has reached the highesttemperature and confinement parameters of anymagnetic fusion experiment. In 1986, TFTR at-tained ion temperatures of 20 kiloelectron volts(kev) or more than 200 million degrees C, wellover the temperature needed for breakeven orignition. However, these high-temperature resultswere obtained in a relatively low-density plasmahaving a confinement parameter of 1013 second-particles per cubic centimeter, which is about halfof the confinement parameter needed to reachbreakeven at that temperature. The equivalentQ actually attained by the plasma was 0.23. Useof neutral beam heating under these conditionsreduces the breakeven threshold by almost a fac-tor of four; a plasma heated to 20 keV withoutthe use of neutral beams would need a confine-ment parameter 7.5 times higher than was at-tained to reach equivalent breakeven.

In a separate experiment at a lower tempera-ture of 1.5 keV, TFTR reached a confinement pa-rameter of 1.5 X 1014 second-particles per cubiccentimeter. Had this confinement been attainedat a temperature of 20 keV, TFTR would havebeen well above equivalent breakeven, comingclose to meeting the equivalent ignition condi-tion. However, in practice, TFTR will not be ableto attain temperature and confinement values thishigh simultaneously. Temperature can be raisedat the expense of confinement, and vice versa,but the product of the two–which determinesequivalent Q—is difficult to increase. With addi-tional neutral beam power and other improve-ments, TFTR may well be able to raise its equiva-lent Q from 0.23 to 1 and reach equivalentbreakeven. However, it is extremely unlikely thatequivalent Qs much greater than 1 are attaina-ble in TFTR.

Beta.–The beta parameter, also called the“magnetic field utilization factor, ” measures theefficiency with which the energy of the magneticfield is used to confine the energy of the plasma.Beta is defined as the ratio of the plasma pres-

Ch. 4.—Fusion Science and Technology c 71


The PBX tokamak at Princeton Plasma PhysicsLaboratory.

sure to the magnetic field pressures Record toka-mak values for beta of 5 percent, in the PBX ex-periment at Princeton Plasma Physics Laboratory,and 6 percent, in the D II I-D experiment at GATechnologies, have been attained. These resultsare especially important in that they generallyvalidate theoretical models that predict how fur-ther improvements in beta can be obtained.

In a fusion reactor, the fusion power output perunit volume of the plasma would be proportionalto beta squared times the magnetic field strengthto the fourth power. Since tokamaks have rela-tively low betas compared to many of the otherconfinement concepts currently studied, improv-ing the beta of tokamaks can be useful. Betasgreater than 8 percent are indicated in some sys-tem studies as being necessary for economicalperformance,6 and values considerably exceed-

~plasma pressure IS equal to plasma temperature times density

and is proportional to the plasma energy per unit volume; mag-netic field pressure, which is proportional to the square of the mag-netic field strength, is a measure of the energy stored in the mag-netic field per unit volume.

Typical reactor studies indicate that the plasma in an operatingfusion reactor WIII have a pressure several times that of the earth’satmosphere at sea level, The plasma density, however, will onlybe about 1/1 00,000 the density of’ the atmosphere at sea level That

so tew par-t lcles can exert such a h lgh pressure IS a measure ot thel r

extreme tern peratu re about 10,000 electron volts, or more than

100 mil l ion degrees C.6For ~xam Pie, J, Sheff ield, et a[., Cost Assewnent of.? ~eflerlc

Magnet/c Fus/orr Rex-tor, oak Rlcige N a t i o n a l L a b o r a t o r y ,

(3RNLKM-931 1 , March 1986, p . 5.

ing that have been obtained by certain other con-finement concepts (albeit to date at much poorertemperatures and confinement parameters). How-ever, physical phenomena in the plasma preventbeta values from being increased indefinitely.These phenomena, which differ from concept toconcept, are not completely understood; gain-ing additional understanding in this area is a highpriority.

Low beta values can also be compensated byraising the magnetic field strength. Whereas rais-ing beta primarily involves plasma physics issues,the issues involved in raising the magnetic fieldstrength are primarily engineering-related: strongermagnetic fields are more difficuIt and expensiveto generate and place greater stress on the magnetstructures. At some field strength, the advantagesof stronger magnetic fields will be outweighedby the additional expense of the magnets.

Scaling.–Understanding how tokamak per-formance can be expected to improve is crucialto evaluating the tokamak’s potential for futurereactors as well as to designing next-generationtokamak experiments. As mentioned earlier, thecomplete theoretical mechanism determiningtokamak scaling has yet to be understood. Ob-servationally, plasma confinement has been foundto improve with increased plasma size. Empiri-cal data also show that tokamak confinement im-proves when plasma density is increased, but thatthis behavior holds only for ohmically heatedplasmas. Non-ohmically heated plasmas followwhat has come to be known as “L (Low) -mode”scaling, in which confinement degrades as in-creasing amounts of external power are injected.

A few years ago, experiments on the GermanAxisymmetric Divertor Experiment (ASDEX) dis-covered a mode of tokamak behavior describedby a more favorable scaling, labeled “H (High)-mode. ” In this mode, performance even withauxiliary heating behaved more like the original,ohmically heated plasmas. However, H-modescaling could be achieved only with a particuIarcombination of device hardware and operatingconditions. Subsequently, additional work atother tokamaks has broadened the range of con-ditions under which this more favorable behaviorcan be found. The challenge to tokamak re-searchers is to obtain H-mode scaling in config-u rations and operating regimes that are also con-


Photo credit: Commission of the European Communities

The ASDEX tokamak at the Max-Planck Institute forPlasma Physics, Garching, Federal Republic

of Germany.

ducive to attaining reactor-like temperatures anddensities.

Reactor Design

Just as an automobile is much more than sparkplugs and cylinders, a fusion reactor will contain

In

many systems besides those that heat and con-fine the plasma. Fusion’s overall engineering fea-sibility will depend on supporting the fusion re-action, converting the power released into a moreusable form of energy, and ensuring operationin a safe and environmentally acceptable man-ner. Developing and building these associatedsystems and integrating them into a functionalwhole will require a technological developmenteffort at least as impressive as the scientificchallenge of creating and understanding fusionplasmas.

The following section describes the systems ina fusion reactor. Since the tokamak confinementconcept and the D-T reaction are the most ex-tensively studied, a tokamak-based reactor fueledwith D-T is used as an example. However, mostof the systems described here would be found,in some form, in reactors based on other con-cepts as well.

The overall fusion generating station (figure 4-10) consists of a fusion power core, containingthe systems that support and recover energy fromthe fusion reaction, and the balance of plant thatconverts this energy to electricity using equip-

Figure 4-10.—Systems in a Fusion Electric Generating Station

Rejectedheat

Fusion power coreinside

Balance ofplant -

Electric powerout to grid


ment similar to that found in present electricitygenerating stations. Features that might convertfusion power to electricity more directly in ad-vanced fusion reactors are described in a subse-quent section.

Fusion Power Core

The fusion power core, shown schematicallyin figure 4-11, is the heart of a fusion generating

station. It consists of the plasma chamber, the sur-rounding blanket and first wall systems that re-cover the fusion energy and breed tritium fuel,the magnet coils generating the necessary mag-netic fields, shields for the magnets, and the fuel-ing, heating, and impurity control systems. Be-fore an acceptable design for a fusion power corecan be developed, the behavior of fusion plasmasmust be understood under all conditions thatmight be encountered. Furthermore, significant

Figure 4-11.—Systems in the Fusion Power Core

Electromagneticradiation

Neutrons

SOURCE.


advances must be made in plasrna technologies,which confine and maintain the plasma, and nu-c/ear technologies, which recover heat from theplasma, breed fuel, and ensure safe operation.

Balance of Plant

Balance of plant generally describes the systemsof a fusion generating station outside of the fu-sion power core. In the example shown in fig-ure 4-11, the balance-of-plant resembles systemsfound in other types of electric generating sta-

tions. These systems use heat provided by the fu-sion core to produce steam that drives turbinesand generates electricity. The steam is cooled bypassing through the turbines, and the remainingheat in the steam is exhausted through coolingtowers or similar mechanisms.

More advanced systems that convert plasmaenergy directly into electricity also may be pos-sible. Fusion reactors incorporating such systemscould be made more efficient than those usingsteam generators and turbines.

FUSION POWER CORE SYSTEMS

The Fusion Plasma

At the center of a fusion reactor, literally andfiguratively, is the fusion plasma. A number ofsupporting technology systems create and main-tain the plasma conditions required for fusion re-actions to occur. These technologies confine theplasma, heat and fuel it, remove wastes and im-purities, and, in some cases, drive electric cur-rents within the plasma. They also recover heat,breed fuel, and provide shielding.

Further development of many of these plasmatechnologies is required before they will be ca-pable of producing a reactor-scale plasma. Fur-thermore, each of these supporting systems af-fects plasma behavior, and the interactions areincompletely understood. progress in both plasmatechnology and plasma science is thereforeneeded before reactor-scale fusion pbe created.

Heating

Description.–Some heat loss from

lasmas can

I a plasmais inevitable (see box 4-A), but, with good con-finement, the losses can be made up by externalheating and/or by fusion self-heating. Differentmechanisms for heating the plasma, illustratedin figure 4-12, are listed below.

Ohmic Heating. -Like an electric heater, aplasma will heat up when an electrical currentis passed through it. However, the hotter aplasma gets, the better it conducts electricity andtherefore the harder it is to heat further. As a re-

sult, ohmic heating is not sufficient to reach ig-nition in many configurations.

Neutral Beam Heating. –Energetic charged orneutral particles can be used to heat fusionplasmas. However, the same magnetic fields thatprevent the plasma from escaping also preventcharged particles on the outside from easily get-ting in. Therefore, beams of energetic neutral (un-charged) particles that can cross the field linesare usually preferred for heating the plasma.

Radiofrequency Heating. -Electromagnetic ra-diation at specific frequencies can heat a plasmalike a microwave oven heats food. Radiofrequencyor microwave power beamed into a plasma atthe proper frequency is absorbed by particles inthe plasma. These particles transfer energy to therest of the plasma through collisions.

Compression Heating. –Increasing the confin-ing magnetic fields can heat a plasma by com-pressing it. This technique has been used in toka-mak devices and is one reason for studying thefield-reversed configuration confinement ap-proach. As stated earlier, there is hope that com-pression may be sufficient to heat an FRC plasmato ignition.

Fusion Self-Heating.–The products of a D-T fu-sion reaction are a helium nucleus—an alphaparticle–and a neutron. The neutron, carryingmost of the reaction energy, is electrically un-charged and escapes from the plasma without re-acting further. The alpha particle, carrying the restof the energy from the fusion reaction, is chargedand remains trapped within the confining mag-


Photo credit: GA Technologies Inc

View inside vacuum vessel of the D II I-D tokamak at GA Technologies, San Diego, California.The plasma is contained within this vessel.

netic fields. Hundreds of times hotter than the gigahertz (billions of cycles per second), are un-surrounding plasma, the alpha particle heats der study. Each frequency range involves differ-other plasma particles through collisions. ent technologies for generation and transmission.

Status.– Recent system studies show that radio-frequency (RF) heating offers significant advan-tages over neutral beam heating. Consequently,the U.S. neutral beam research program has beenreduced while the RF heating program has grown.Various types of RF heating, using different fre-quencies of radiation from tens of megahertz (mil-lions of cycles per second) to over a hundred

Issues.—Additional research and development(R&D) in heating technologies is essential to meetthe needs of future experiments and reactors. Keytechnical issues in RF heating are the develop-ment of sufficiently powerful sources of radiofre-quency power (tens of megawatts), particularlyat higher frequencies, and the development oflaunchers or antennas to transmit this power into

the plasma, particularly at lower frequencies.Resolution of these issues will require technologi-cal development as well as improved understand-ing of the interaction between radio waves andplasmas.

Since no ignited plasma has yet been produced,the effects of fusion self-heating on plasma con-finement and other plasma properties are notexperimentally known. Confinement could de-grade, just as it does with other forms of auxiliaryheating. Although self-heating can be simulatedin some ways in non-ignited plasmas, its effectscan be fully studied only upon reaching highenergy gain or ignition. The ignition milestone,therefore, is crucial to the fusion program, andunderstanding the behavior of ignited plasmas isone of the program’s highest scientific priorities.

Fueling

Description. –Any fusion reactor that operatesin pulses exceeding a few seconds in length mustbe fueled to replace particles that escape theplasma and, to a lesser extent, those that are con-sumed by fusion reactions. Firing pellets of fro-zen deuterium and tritium into the plasma cur-rently appears to be the best approach for fueling.Both pneumatic (compressed gas) and centrifugal(sling) injectors have been used (figure 4-13).Neutral beam fueling has been used in experi-ments, but fueling reactors in this way would takeexcessive amounts of power.

Status.–Pellets up to 4 millimeters in diameterhave been fired into experimental plasmas atspeeds of up to 2 kilometers per second and at

Ch. 4.—Fusion Science and Technology . 77

Figure 4-12.—Plasma Heating Mechanisms

Radiofrequencyheating

hydrogen atoms Magnetic deflector/ /

Hydrogenion

Neutralizer source

Neutral injection Acceleratorheating

SOURCE. Oak Ridge National Laboratory

repetition rates ofs to 40 pellets per second. U.S.development of pellet fueling technology, cen-tered at Oak Ridge National Laboratory, is wellahead of fueling technology development else-where in the world. By building state-of-the-artpellet injectors for use on foreign experiments,the United States is able in return to gain accessto foreign experimental facilities.

Issues.—Reactor-scale plasmas will be denser,hotter, and perhaps bigger than the plasmas madeo date in fusion experiments; moreover, reactorpIasmas will contain energetic alpha particles. Allthese factors will make it much more difficult forpellets to penetrate reactor plasmas than plasmas


made in present-day facilities. Penetration to thecenter of the plasma, most desirable from a theo-retical point of view, probably will be extremely

Princeton Large Torus at PPPL, showing waveguides diff icult in reactor plasmas. Experiments are nowfor the RF heating system. u n d e r w a y t o u n d e r s t a n d h o w d e e p l y a p e l l e t


Figure 4-13.—Centrifugal Pellet Injection

SOURCE: Oak Ridge National Laboratory

must penetrate. Tokamaks, for example, appearto have a mechanism, not yet understood, thattransports fuel to the center of the plasma. Fuelmight be brought into the center more effectivelyin some of the alternate confinement conceptswith turbulent plasmas, such as the reversed-fieldpinch or the spheromak.

If deeper penetration is required than can nowbe attained, either larger pellets or higher injec-tion speeds will be needed. Larger pellets are not

difficult to produce, but they may disturb theplasma too much; additional work needs to bedone to determine how fuel pellets affect plasmabehavior, If larger pellets cannot be used, higherinjection speed will be required, which is tech-nologically much more difficult. Improving pres-ent techniques is unlikely to increase injectionspeeds by more than about a factor of 2. Newtechniques capable of producing much higher in-jection speeds are being investigated, but thepellets themselves may not survive injection at


these speeds due to fundamental limitations intheir mechanical properties.7

Current Drive

Description.–Several confinement concepts,including the tokamak, require generation of anelectric current inside the plasma. In most presentexperiments, this current is generated by a trans-former. In a transformer, varying the electric cur-rent in one coil of wire generates a magnetic fieldthat changes with time. This field passes througha nearby second coil of wire—or in this case theconducting plasma—and generates an electriccurrent in that coil or plasma. Varying the mag-netic field is essential; a constant magnetic fieldcannot generate current.

in tokamak experiments, a coil located in the“doughnut hole” in the center of the plasmachamber serves as one coil of the transformer.Passing a steadily increasing current through thiscoil creates an increasing magnetic field, whichgenerates current in the plasma. When the cur-rent in the first coil levels off at its maximumvalue, its magnetic field becomes constant, andthe current in the plasma peaks and then startsto decay. If the fusion plasma requires a plasmacurrent, its pulse length is limited by the maxi-mum magnetic field of the first coil and the lengthof time taken for the plasma current to decay.8

Status.–Techniques are now being studied forgenerating continuous plasma currents, ratherthan pulsed ones, because steady-state reactorsare preferable to ones that operate i n puIses. g In-jecting radiofrequency power or neutral beamsinto the plasma might be able to generate suchsteady-state currents in tokamaks. The injectedpower or beams generate currents either by

7Argon ne National Laboratory, Fusion Power Program, Techni-ca/ Planning Activity: Find/ Report, commissioned by the U.S. De-partment of Energy, Office of Fusion Energy, AN L/FPP-87-l, janu-ary 1987, p. 189.

81n tokamaks, this decay time can be thousands of seconds. Forconfinement concepts with plasmas that are more resistive to elec-tric currents, the decay time is shorter, on the order of hundredsof seconds. Operating for periods of time longer than the decaytime requires non-transformer current drive mechanisms.

9Components in pulsed systems undergo periodic stresses notexperienced in steady-state systems. Pulsed reactors also requiresome form of energy storage to ellminate variations in their elec-trical output.

“pushing” directly on electrons in the plasma orby selectively heating particles traveling in onedirection. Experiments have confirmed the the-ory of radiofrequency current drive and have suc-ceeded in sustaining tokamak current pulses forseveral seconds.

Some other confinement concepts, such as thereversed-field pinch or the spheromak, can gen-erate plasma currents with small, periodic varia-tions in the external magnetic fields. Such current-drive technologies do not involve complex ex-ternal systems.

Issues.–The principal issues involving steady-state current drive are cost and efficiency, espe-cially under reactor conditions. I n particular, theradiofrequency technique becomes less efficientas the plasma density increases. This inefficiencycould pose problems because reactors will prob-ably operate at higher densities to maximize gen-erated power. At this time, it is not known whetherthe efficiency of continuous current drive canbe increased to the point where it could replacethe pulsed transformers now used in tokamaks.However, radiofrequency current drive mightalso be used to augment the puIsed transformerby starting up the plasma current in a period oflow-density operation. Once the plasma currentwas started, the density could be raised and thetransformer used to sustain the current. The ra-diofrequency current drive together with thetransformer would be able to generate longer last-ing pulses than the transformer alone.

Reaction Product and Impurity Control

Description .–Alpha particles, which build upas reaction products in steady-state or very long-pulse fusion reactors, will have to be removedso that they do not lessen the output power bydiluting the fuel and increasing energy loss by ra-diation, Devices that collect ions at the plasmaedge can be used to remove alpha particles fromthe plasma. Alpha particles, when combined withelectrons that are also collected at the plasmaedge, form helium gas that can be harmIessly re-leased. Unburned fuel ions also will be collected;these will be converted to deuterium and tritiumgas, which will have to be separated from thehelium and reinfected into the plasma.


The same devices that collect ions at the plasmaedge help prevent impurities from entering theplasma. Even small amounts of impurities cancool the plasma by greatly accelerating the rateat which energy is radiated away.

Status.–Two types of devices are being con-sidered for these tasks: pumped limiters anddiverter-s. A limiter is a block of heat-resistant ma-terial that, when placed inside the reaction cham-ber, defines the plasma boundary by intercept-ing particles at the plasma edge. A variant, thepumped limiter, combines a limiter with a vacuumpump to remove the material collected by thelimiter. A divertor generates a particular magneticfield configuration in which ions diffusing out ofthe fusion plasma, as well as those knocked outof the vessel walls and drifting towards theplasma, are diverted away and collected by ex-ternal plates.

Both limiters and diverters are in direct con-tact with the plasma edge. Although temperaturesat the edge are far below the 100-million-degreeC temperatures found in the plasma center, thesecomponents will nevertheless get very hot. Allthe energy injected into or produced by theplasma that is not carried away by neutrons orradiated away as electromagnetic energy is even-tually deposited on the limiter or divertor platesby electrons and ions. Therefore, these devicesmust withstand high heat loads under energeticion and neutral particle bombardment while be-ing exposed to intense neutron radiation. In a fu-sion environment, they will become radioactivedue to neutron-induced reactions and, to a muchlesser extent, to permeation with tritium. Theirreliability must be high since they will be locateddeep within the reactor, inside the vacuum ves-sel, where maintenance will be difficult.

issues.–A key issue for reaction product andimpurity control will be the choice betweenpumped limiters and diverters. The devices notonly have different efficiencies but have differ-ent effects on plasma confinement. Limiters aresimpler, but diverters may have operational ad-vantages. 10 More R&D is necessary to investigate

issues such as the conditioning and cleaning ofsurfaces in contact with the plasma, the erosionof these surfaces and redeposition of their mate-rials elsewhere in the plasma chamber, the ef-fects of high heat loads, the development of cool-ing systems, and the degree and effects of tritiumpermeation.

Burn Control

Description. —When a fusion reactor plasmais ignited, it provides its own heat and no longerdepends on external heating. Two opposing ten-dencies make it difficult to determine how sta-ble, or self-regulating, an ignited plasma will be.An ignited plasma may be inherently unstabledue to the strong temperature dependence of thefusion reaction rate. If, for whatever reason, a hotspot forms in the plasma, the fusion reaction ratethere will go up. As a result, more fusion powerwill be generated in that area, heating it furtherand compounding the original problem.

If the plasma particles mix with sufficient speed,hot spots that form will not persist long enoughto grow. If, on the other hand, the mixing is slow,this thermal instability might make it very diffi-cult to maintain a steady reaction. Formation andgrowth of hot spots could cause output powerlevels to fluctuate considerably, and in the worstcase these hot spots could grow until much ofthe fuel present in the reaction chamber was con-sumed. The amount of fuel would not be large—at most a few seconds’ worth-making this proc-ess more of an operational problem than a safetyone. The reactor would have to be designed sothat it could not be damaged, and its contentsnot be released, by the maximum amount ofenergy that could be produced in this way.

Countering this possible instability is a self-regulating mechanism that limits the maximumattainable value of the beta parameter. Any in-stability that heated the plasma would increasethe plasma beta, which is proportional to tem-perature. However, since the power generatedby a fusion reactor is proportional to beta squared,a reactor would probably already be operating

IOThe H.mode of tokamak operation, in which confinement prop-

erties are significantly improved, is seen in tokamaks with diver-ters. This mode, now thought to depend on processes occurringat the plasma edge, may be difficult to reproduce with Iim iters.


at the highest value of beta consistent with goodperformance. Further increases in beta would de-grade plasma confinement and increase energyloss. These increased losses would cool theplasma back down, counteracting the initial in-stabiIity.

These beta-limiting processes could maintaina steady reactor power level. The plasma wouldtend to operate just under the limiting beta value,and, by adjusting the magnetic field or the plasmadensity, the power level corresponding to thelimiting beta value could be controlled.

Status and Issues.– It is impossible, withoutcreating and studying an ignited plasma, to de-termine how a plasma will behave in the face ofthe two opposing tendencies described above.Neither the causes of beta-limiting processes northeir effects on the plasma are fully understoodin general. More research is necessary before theability of these processes to stabilize a fusionplasma can be determined.

The processes that control the reaction rate andburn stability of an ignited plasma are probablythe most device-dependent and least understoodof any aspect of burning plasma behavior. 11 Evenfor tokamaks, the properties that determine sta-bility have been studied only under conditionswell short of ignition; still less is known about theproperties of other confinement concepts. If theseissues are indeed concept-specific, only limitedinformation from a burning plasma experimentusing one confinement concept can be used topredict the behavior of another.

The Fusion Blanket and First Wall

The region immediately surrounding the fusionplasma in a reactor is called the blanket; the partof the blanket immediately facing the plasma iscalled the first wall. In some designs, the first wallis a separate structure; most often, however, thefirst wall refers to the front portion of the blan-ket that may contain special cooling channels.

The blanket serves several functions. Coolingsystems in the blanket remove the heat gener-

ated by fusion reactions and transfer it to otherparts of the facility to generate electricity. De-pending on plant design and materials selection,these cooling systems also might be needed toremove afterheat from the radioactive decay ofmaterials in the blanket after a plant shutdown.In addition, the tritium fuel required by the re-actor is produced, or “bred,” in the blanket. Fur-thermore, the blanket must support itself and anyother structures that are mounted on it.

The safety of the plant will be greatly influencedby the blanket breeder, coolant, and other sub-systems. Since the blanket will perform multiplefunctions, its development will require an in-tegrated R&D program. This program must havetwo primary aspects: it must develop the capa-bility to predict the behavior of blanket compo-nents and systems under actual reactor usage,and it must develop technologies that can pro-duce fuel and recover energy in the blanket whilemaintaining attractive economic, safety, and envi-ronmental features.

Intense irradiation by neutrons produced in thefusion plasma will make blanket componentsradioactive, with the level of induced radioactivitydepending on the materials with which thesecomponents are made. Tritium bred within theblanket will add to the blanket’s total radioactiveinventory. As the largest repository of radioactivematerials in a fusion plant, the blanket will be thefocus of environmental and safety concerns.12

The discussion below focuses on blankets thatwould be used in fusion reactors that generateelectricity. Reactors used for other purposes,some of which are discussed in appendix A,would have different blanket designs.

Description

Energy Conversion.–The first wall is heatedby radiation from the plasma as well as by energycarried by particles leaking out of the plasma.Energetic neutrons produced in the plasma pene-trate the blanket, where they slow down and con-vert their kinetic energy into heat. coolant cir-cuIating within the blanket and first wall transfersthis heat to other areas of the plant, where it is

I I Argonne Nat I. na I La t)orato ry, Technic,;/ P/arming ActI\It)’: F;-na/ Report, op. cit., p. 155. I J plant safety characterlst ICS are d ISCU JSed tu rther I n ch. J

82 . Starpower: The U.S.. and the International Quest for Fusion Energy

used to generate electricity. The coolant also pre-vents blanket and first wall components fromoverheating during reactor operation; depend-ing on plant design, coolant also may be neededto prevent overheating after plant shutdown,whether scheduled or emergency. Depending onthe level of radioactivity within the blanket andcoolant, secondary heat exchangers like thosenow used in nuclear fission plants may be re-quired to isolate the coolant.

Fusion neutrons slow down by colliding withthe nuclei of blanket materials, transferring energyto the blanket in the process. Additional heat isalso generated in reactions that occur when theneutrons are captured by materials in the blan-ket. Depending on their energy, the neutronstravel up to several centimeters between colli-sions. Collisions change the neutrons’ directions,and a blanket thickness of from one-half meterto one meter is enough to capture most of theneutron energy.

Tritium Breeding.–Through reactions with fu-sion neutrons, the nuclei in the blanket can bechanged into other nuclei that are either stableor radioactive. In particular, if a fusion neutronis captured by a lithium nucleus, it will inducea reaction that produces tritium (see box 4-B).13Therefore, the presence of lithium in the blan-ket is necessary for tritium breeding.

The number of tritium nuclei produced in thefusion blanket per tritium nucleus consumed inthe fusion plasma, called the breeding ratio, mustbe at least 1 for the reactor to be self-sufficientin tritium supply. Accounting for losses and im-perfections in the blanket, as well as uncertain-ties in the data used to calculate tritium breed-ing rates, this ratio probably should be in therange of 1.1 to 1.2.

Lithium can be contained in the blanket in ei-ther solid or liquid form. Lithium metal has a lowmelting point (186 o C) and excellent heat trans-fer properties, making it attractive as a coolantin addition to its use in breeding tritium. How-ever, in its pure form, liquid lithium can be highly

1 JLithium is a reactive metal that does not occur in its pure form

in nature. However, chemical compounds containing lithium arefound in many minerals and in the waters of many mineral springs.Fuel resources for fusion are discussed in ch. 5.

reactive and may pose safety problems i n fusionreactors. Liquid lithium’s reactivity can be les-sened by alloying it with molten lead, but theaddition of lead substantially increases the pro-duction of undesired radioactive materials in theblanket.

Liquid metal coolants can be avoided by sep-arating the function of cooling the blanket fromthat of breeding tritium. A non-lithium-containingfluid can be used as the coolant, and solid lith-ium-containing compounds can be used to pro-duce tritium. However, solid lithium compoundscontain other elements, such as oxygen and alu-minum, that would capture some of the fusionneutrons and lower the breeding ratio. To com-


pensate for the lost neutrons, substances calledneutron rnultipliers can be added to the blanket.Neutron multipliers convert one very fast fusionneutron to two or more slower neutrons bymeans of a nuclear reaction.

Recovering the tritium from solid breeder ma-terials is more difficult than from liquid breeders.When tritium is bred in a liquid coolant, the cool-ant carries the tritium directly outside the blan-ket where it can be extracted. Tritium producedin solid lithium-containing compounds, on theother hand, must first diffuse out of those com-pounds before it can be collected and flushedout of the blanket by a circulating stream ofhelium gas.

Blanket Structure.—The heat loads, neutronfluxes, and radiation levels found in the blanketplace stringent requirements on the materialswith which the blanket is made. Conditions aremost severe at the first wall, which is bombardedby neutron and electromagnetic radiation fromthe plasma, by neutral particles, and by plasmaelectrons and ions that escape confinement. Firstwall issues are similar to many of the issues asso-ciated with limiters and diverters (discussed pre-viously in the section on “The Fusion Plasma, ”under the heading “Reaction Products and im-purity Control”), which undergo even higher heatand particle fluxes than the first wall.

Neutron irradiation introduces two major prob-lems in the blanket materials. First, irradiation canlead to brittleness, swelling, and deformation ofthe reactor structural materials. During the serv-ice lives of first wall and blanket components,each atom in those components will be displacedseveral hundred times by collisions with fusionneutrons. The amount of radiation damage thatthe blanket materials can withstand determinescomponent lifetimes and also places an upperlimit on reactor power for a blanket of a givensize.

Second, neutron irradiation makes the blanketradioactive. Not all the neutrons penetrating theblanket will be captured in lithium to breedtritium, Some will be absorbed by other blanketmaterials, making those materials radioactive.

I J Beryl I I u m ~ ncj lead are common Iy used I n rea~to r stud I es Js

neutron mu Itlpliers,

Other fusion neutrons will penetrate the blanketto make reactor structures outside the blanketradioactive. Since the degree of radioactivity gen-erated within the reactor structure strongly de-pends on the reactor’s composition, develop-ment and use of /ow-activation materials that donot generate long-lived radioactive productsunder neutron bombardment will greatly lesseninduced radioactivity,

Due to radiation damage, blanket and first wallcomponents in a fusion reactor wil I require peri-odic replacement. After their removal, the oldcomponents will constitute a source of radio-active waste. ’ 5

Impact on Fusion Reactor Design .–Althoughthe blanket and first wall components themselvesmay not represent a large fraction of the cost ofa fusion reactor, blanket design has a substan-tial influence on total reactor cost. The blanketthickness (along with that of the shield, describedbelow) determines the size and cost of the mag-nets, which are substantially more expensive thanthe blanket. The blanket coolant temperature de-termines the overall efficiency with which theplant converts fusion power into electricity, di-rectly affecting the cost of electricity. The selec-tion of materials in the blanket determines theamount of long-term radioactive waste and theamount of heat produced by radioactive decayin the blanket after plant shutdown; both thewaste and the heat affect the reactor’s environ-mental and safety aspects. Finally, the ability ofthe blanket materials to withstand heat loads andneutron irradiation levels determines the amountof fusion power that can be generated in a plantof a given physical size, which has a significanteffect on reactor size and cost and on its behaviorduring accidents.

Status and Issues

A wide variety of designs have been proposedfor the blanket and first wall. However, since the

1 sAccord ! ng to Argonne National Laboratory, Technical P/.lnn/nL~

Acti\ity: F/na/ Repor?, op. cit., p. 283, the amount ot long-l{~ed(more than 5 years) radioactive waste depends primarily on theamounts of copper, molybcien u m, nitrogen, niobium, and nickelused In the blanket. Radioacti\lty levels, radioactive wastes fromfusion reactors, and Iow-activation materials are discussed tu rtherIn ch. 5.


fusion research program has concentrated to dateprimarily on plasma science issues, relatively lit-tle experimental work has been done on blan-ket design or fusion nuclear technologies in gen-eral. As the program moves from establishingscientific feasibility to demonstrating engineeringfeasibility, engineering issues will become muchmore important.

Tritium Self-Sufficiency .-Engineering designsmust be developed to produce tritium at a rateequal to the rate of consumption in the plasmaplus an additional margin, The extra tritium, 10to 20 percent of the amount consumed in theplasma, is needed to compensate for losses dueto radioactive decay and to provide the initial in-ventory to start up new reactors. Improvementsin calculating neutron flow through the reactorstructure and in collecting additional basic nu-clear data such as reaction rates are necessaryto develop adequate engineering designs. Exper-imental verification of the calculation methodsand data is also required to demonstrate tritiumself-sufficiency.

Structural Materials.–Structural materials inthe first wall and deeper in the blanket must bedeveloped that can withstand neutron-inducedeffects such as swelling, brittleness, and defor-mation. Stainless steel alloys already have beenidentified that appear to show adequate perform-ance under neutron fluxes at the low end of thoseexpected in a reactor. However, these materialsproduce more radioactive products than may bedesirable for commercial reactors. Developinglow-activation materials that also have acceptablephysical properties under irradiation remains asignificant challenge. The task will require furtherbasic research in materials science as well asprogress in materials technology.

Non-Structural Blanket Materials.–The tritium-breeding properties of various lithium-containingmaterials must be studied and compared. Thechoice between solid and liquid breeder mate-rials, in particular, will greatly affect overall blan-ket design. in addition to lithium, other materi-als may be required in the blanket such asneutron multipliers and moderators (which slowdown neutrons to make them more easily ab-sorbed in the blanket). Insulators, or materials thatdo not conduct electricity, also maybe required

for high radiation areas inside the reactor. Sincea typical effect of radiation damage on insulatorsis to increase electrical conductivity, developingmaterials that will remain insulators under highradiation fluxes is a challenging task.

Special Materials.–Other materials require-ments for a fusion reactor may include specialmaterials to coat plasma-facing surfaces to mini-mize their effect on the plasma, coatings or clad-dings used to form barriers to contain tritium, andadvanced superconducting magnet materials (de-scribed in the section on magnets, below). Manyof the specific requirements for these materialshave not yet been determined.

Compatibility.–Certain combinations of ma-terials, each suitable for a particular task, may incombination prove unacceptable in a reactor de-sign. For example, liquid lithium reacts violentlywith water, so a liquid lithium-cooled blanket de-sign would probably prohibit use of water as anadditional coolant.

Tritium Permeation and Recovery.–Once pro-duced inside the blanket, tritium must be recov-ered and removed. However, tritium will perme-ate many materials that are continuously exposedto it. Its interactions with blanket materials un-der the conditions inside a fusion reactor willhave to be understood. In particular, tritium maybe difficult to collect from solid breeder materials.

Liquid Metal Flow.—Liquid metal coolants ina fusion reactor will be subject to strong magneticfields created both by the plasma and by exter-nal magnets. Liquid metals are conductors ofelectricity; when electrical conductors movethrough magnetic fields, voltages and currents aregenerated.16 The currents induced in the cool-ant, in turn, are subject to forces from the mag-netic field that oppose the motion of the cool-ant, increasing coolant pressure and adding tothe power required for pumping.

The Shield

Description and Status

Since many neutrons will penetrate all the waythrough the blanket during fusion reactor oper-

IGThis process IS the basis of electrical generators.


ation, a shield may be required between the blan-ket and the magnet coils.17 The shield may becomposed of materials such as steel and water,will probably contain a circulating coolant, andwould have a thickness from tens of centimetersto over a meter. The shield would provide extraprotection to the magnets and could reflect es-caping neutrons back into the blanket to improvethe efficiency of tritium breeding. Additionalshielding wouId probably surround the entire re-actor core, perhaps in the form of thick walls forthe enclosing building.

Most existing fusion experiments have not beendesigned to use tritium and are incapable of gen-erating significant amounts of fusion power. Con-sequently, shielding has generally not been animportant issue for the research program. It has,however, been a factor in the design of devicessuch as TFTR and the Joint European Torus thatare intended to use tritium. As future machinesare designed that will generate appreciable amountsof fusion power, shielding will become more im-portant.

Issues

The intensity of the incident neutron radiation;the size, shape, and effectiveness of the shield;and the permissible levels of neutron irradiationpenetrating the shield must all be determined toevaluate shielding requirements. As improvedmagnet materials are developed that are less sen-sitive to neutron radiation, shielding requirementsfor plant components will lessen. However, pro-tection of plant personnel alone will require sub-stantial shielding.

The Magnets

Description

The external confining magnetic fields in a fu-sion reactor are generated by large electric cur-rents flowing through magnet coils surroundingthe plasma. These magnets must withstand tremen-dous mechanical forces,

.. —-—-—. .I Plf the magnets are superconducting, the shield will be requl red.

If they are made of copper, the shield may not be necessary. How-ever, without a shield, the coils would require periodic replace-ment. See the following section on magnets.

The most important choice concerning designof the magnets is whether they will be made ofsuperconducting materials or of conventionalconductors such as copper. Copper is an excel-lent conductor of electricity but nevertheless hassufficient resistance to electric currents that agreat deal of power is wasted as heat when themagnet is running. This heat must be removedby cooling systems. Superconducting coils loseall resistance to electricity when cooled suffi-ciently; below a temperature called the criticaltemperature, their magnetic fields can be sus-tained without any additional power. However,power is required to establish the fields initially,and a small amount of refrigeration power is re-quired to keep superconducting magnets at theiroperating temperature. No heat is generated in-side a superconducting magnet, but heat thatleaks in from the outside must be removed.

Although recent discoveries could revolution-ize the field (see “issues” section below), all su-perconducting materials that have so far beenused in large magnets have critical temperatureswithin about 20° K of absolute zero. The onlysubstance that does not freeze solid at these tem-peratures is helium, and the only way to cool su-perconducting magnets to these temperatures isto circulate liquid helium through them. Use ofliquid helium makes superconducting magnetsmore complicated and expensive to build thancopper magnets; superconducting magnets alsorequire thicker shields. However, superconduct-ing magnets require much less electricity to run,substantially lowering their operating costs.

Conceptual design studies typically have shownthat the operational savings from using supercon-ducting magnets in commercial fusion reactorswould more than compensate for their higher ini-tial cost. However, there may be exceptions,especially for confinement concepts with higherbeta values that are able to confine fusion plasmasat lower magnetic field strengths. At lower fieldstrengths, copper magnets, which do not requireas much shielding as superconducting magnets,can be made to fit more closely around theplasma chamber. The resultant reduction in sizeof the magnet/shield combination might reduceits cost enough to outweigh the operational in-efficiencies of copper magnets.


Whereas the magnets in future fusion reactorswill operate for long pulses, if not continuously,magnets in present-day fusion experimental fa-cilities generally operate only for several secondsat a time. For pulses this short, the cost of elec-tricity is less of a factor in determining magnetdesign, making the simpler construction of cop-per magnets preferable in most cases. A notableexception is the MFTF-B device at Lawrence Liv-ermore National Laboratory, which was built withsuperconducting magnets because copper coilswould have been prohibitively expensive to oper-ate even for 30-second puIses.

Status

The first fusion device built with superconduct-ing magnets was the Soviet T-7 tokamak, com-pleted 7 years before any Western fusion deviceusing superconducting magnets. The Soviets arenow building T-1 5, a much larger superconduct-ing tokamak. Difficulties with the T-1 5 magnetshave been among the reasons that the project’scompletion has been delayed for several years;however, these difficulties apparently have beenresolved. The Tore Supra tokamak being built inFrance will also use superconducting magnetsand will probably exceed the parameters of T-15.18 In the United States, MFTF-B was completedin 1986; its superconducting magnets have beensuccessfuIly tested at their operating conditions.Overall, DOE considers U.S. magnet develop-ment to be comparable to that in Europe and Ja-pan and ahead of that in the Soviet Union.19

Generally, magnet development has been asso-ciated with individual fusion confinement exper-iments rather than with facilities dedicated specifi-cally to magnet development. A major exceptionis the Large Coil Task, an international programto build and test superconducting magnets. Mag-nets developed through the Large Coil Task have

161 nformation on Soviet tokamak development IS from an oral

presentation on “Assessment of Soviet Magnetic Fusion Research”by Ronald C. Davidson, Director of the Plasma Fusion Center, Mas-sachusetts Institute of Technology, to the Magnetic Fusion Advi-sory Committee, Princeton, Nj, May 19, 1987.

l~lnternational comparisons are from a presentation by R.J. Dowl-ing, Director of the Division of Development and Technology, Of-fice of Fusion Energy, U.S. Department of Energy, to the EnergyResearch Advisory Board, Sub-Panel on Magnetic Fusion, Wash-ington, DC, May 29, 1986.

worked very well and have exceeded their origi-nal design specifications. 20

Issues

Recent discovery of new superconducting ma-terials with critical temperatures far above thoseof previously known materials, and possibly withthe capability to reach very high magnetic fieldstrengths, will have a profound impact on a greatmany fields, including fusion. Materials have beenidentified with critical temperatures higher thanthe 77 Kelvin (–196° C) threshold that wouldpermit use of liquid nitrogen as a refrigerant. Liq-uid nitrogen is cheaper and easier to handle thanliquid helium, and its use could reduce the costand complexity of superconducting magnets.

However, the discovery of these “high-temper-ature’ superconductors does not necessarilymean that they can soon be utilized in fusion ap-plications. Little is known about the physicalprocesses underlying superconductivity in thesematerials, and they present great engineeringchallenges. They are difficult to fabricate intomagnet coils, and they may not be able to with-stand the forces exerted in fusion magnets. Al-though their current-carrying capability is improv-ing, they may not be able to carry high enoughcurrents under high magnetic fields to be usefulin large-scale magnets. Moreover, their responseto neutron irradiation is not known. If these ma-terials are highly susceptible to radiation damage,their use in fusion magnets could be difficult.Conversely, if they proved more resistant to ra-diation effects than previous superconductingmaterials, thinner shields and correspondinglysmaller magnets could be used.

Further research is required to see whether thenew superconducting materials can be used inpractical applications. The great economic advan-tage that they would have in numerous applica-tions ensures that much of this research will beundertaken independently of the fusion program.However, fusion does have particular require-ments for large, high-field magnets that may nototherwise be investigated.

zOThe Large Coi I Task is discussed further in ch. 7.


- . 3

Photo credit: Lawrence LIvermore National Labora/ory

375-ton superconducting magnet being moved to the east end cell of MFTF-8 for installation. This magnet's location within MFTF-8 is shown at top.

72-078 0 87


Issues for superconducting fusion magnet ma-terials include further development and investi-gation of the new high-temperature materials. Ifthese new materials prove unacceptable for fu-sion, improvements in the strength, workability,and maximum current capacity of the previouslyknown superconductors will be important. Issuesfor copper magnets include fully exploiting cop-per’s strength and developing joints (needed toassemble and maintain the magnet) that can carrylarge electric currents.

Fuel Processing

Description

Tritium fuel contained in the exhaust from theplasma, or generated in the reactor blanket, mustbe extracted, purified, and supplied back to thefueling systems for injection into the plasma. Con-siderable experience has been developed in han-dling tritium, particularly within the nuclear weap-ons program, making tritium technology morehighly developed than many of the other nucleartechnologies required for fusion. However, thisexperience is applicable primarily to handling the

tritium in a fusion reactor once it has beenproduced and separated. The task of extractingtritium from a blanket under reactor conditionswhile at the same time generating electric powerwith high efficiency has yet to be done.

Status

To acquire experience with tritium handling forfusion applications, DOE has built and is operat-ing the Tritium Systems Test Assembly (TSTA) atLos Alamos National Laboratory. A prototype ofthe tritium processing and handling facilitiesneeded for a full-scale fusion reactor, TSTA in-cludes plant safety equipment such as a roomatmosphere detritiation system. TSTA operatorshave developed system maintenance proceduresthat minimize or eliminate tritium release. Thissystem, however, does not duplicate the produc-tion or extraction of tritium from a fusion blanket.

Issues

Specific issues involved with tritium process-ing include monitoring, accountability, and safety.Being radioactive, tritium cannot be allowed todiffuse out of the reactor structure. if tritium col-lects on inaccessible surfaces within the reactor,it cannot be completely recovered, and it willmake those surfaces radioactive. Developing trit-ium processing systems will require additional re-search in measuring basic tritium properties suchas diffusivity, volubility, and oxidation chemistry.Safety needs include developing and maintain-ing the capability to contain and recover tritiumfrom air and from water coolants (if any) in theevent of tritium contamination.

Remote Maintenance

Due to their inventory of radioactive tritiumand the activation of their structural components,the interior of all subsequent fusion experimentsthat burn D-T will become too radioactive forhands-on maintenance. Therefore, remote main-tenance is a key issue not only for future powerreactors, but also for near-term D-T experiments.Nearly all aspects of the research program, fromdesign of experiments to operation and mainte-nance to decommissioning, will be affected bythe need for remote maintenance.

Ch. 4.–Fusion Science and Technology “ 89

Photo credit Oak Ridge National Laboratory

The Swiss superconducting magnet coil being installed in the International Fusion Superconducting Magnet Test Facility(Large Coil Task) at Oak Ridge National Laboratory.

The fusion program at present is relying on tenance requirements for fusion facilities will in-

activities outside the fusion community for gen- clude transporters able to move heavy loads (overeral development of remote maintenance equip- 100 tons) with precision alignment; manipulatorsment. Much work in remote manipulation and made of nonmagnetic material that can operateremote maintenance has been done, but some under high vacuum conditions; and rapid andapplications are likely to be unique to fusion and precise remote cutting, welding, and leak detec-will require special development. Remote main- tion equipment. The first challenge in this field


Photo credit: Los Alamos National Laboratory

The Tritium Systems Test Assembly at Los Alamos National Laboratory

will be identification of the remote maintenance quently, needs for test facilities and reactors mustrequirements for near-term facilities and the de- be identified and assessed.velopment of any necessary equipment. Subse-

ADVANCED FUEL AND ENERGY CONVERSION CONCEPTSEven though the fusion power core systems de-

scribed in the previous section have not yet beendeveloped, researchers already are designing re-actors using more advanced concepts. Improve-ments described below are not mere refinementsof the systems already described; they are qualita-tively new features that may be much more at-tractive. In general, these improvements involveuse of either advanced fuels or advanced meth-ods of converting fusion energy into useful forms.

Advanced Fuels

The fusion power core described in the previ-ous section uses D-T fuel because it is by far themost reactive of all potential fusion fuels. Thisreactivity can be increased still further by align-ing the internal spins of the deuterium and tritiumnuclei, a technique known as spin polarization.If the spins can be aligned initially, the magneticfield of the fusion reactor will tend to keep them


in alignment. Therefore, research is ongoing atPrinceton Plasma Physics Laboratory to developintense sources of spin-polarized fuel.

The principal disadvantage of D-T fuel is thatthe D-T reaction produces energetic neutrons thatcause radiation damage and induce radioactiv-ity in reactor structures. Moreover, reactors usingD-T must breed their own tritium, substantiallyadding to reactor complexity and radioactivitylevels. For these reasons, the possibility of usingother fuels in fusion reactors is being investigated.

Fuels other than D-T require higher tempera-tures and Lawson confinement parameters toreach ignition and higher beta values to performeconomically. Achieving these parameters will re-quire stronger magnetic fields, higher plasma cur-rents, and substantial improvements in otherplasma technologies beyond those needed toreach ignition with D-T fuel—a task that in itselfhas not yet been accomplished. However, re-actions that use advanced fuels would have anumber of advantages:

c They wouId require little to no tritium, re-ducing or eliminating the need for the blan-ket to breed tritium and permitting a muchwider range of blanket designs. Tritium in-ventories would be smaller and the conse-quent radioactivity levels would be lower.

● They would generate fewer and lower energyneutrons, alleviating radiation damage andminimizing radioactive wastes.

● They might permit the use of more efficientmethods to generate electricity from fusionenergy. I n advanced fuel fusion reactions,more energy is released i n the form of ener-getic charged particles, such as protons oralpha particles, than is the case in the D-Treaction. Therefore, these advanced fuelsmay be amenable to various techniques thatgenerate electricity directly from the fusionplasma or from plasma-generated radiationwithout having to first convert the energyinto heat. (See the following section on “Ad-vanced Energy Conversion.”)

Table 4-8 presents five fusion fuel cycles, in-cluding the “baseline” D-T cycle and four pos-sibilities for advanced fuel cycles. Of the advancedcycles, the D-3He cycle is currently drawing themost attention within the fusion community. Theprimary reaction produces no neutrons, and neu-trons resulting from corollary D-D reactions canbe minimized by using a mixture consisting mostlyof 3He or by using spin-polarization. 21

ZI Deuterium, being relatively scarce i n a 3He -rich mixture, would

be much more likely to react with a 3He nucleus than with anotherdeuterium nucleus, making D-D reactions relatively rare. However,one consequence of this mode ot operation, in addition to mini-mizing neutron generation, wou Id be the lessening of output powersince most of the 3He nuclei would be unable to find D nuclel withwhich to react. Increasing the ratio of D to ‘He to more nearly equalproportions, theretore, would increase both the output power andthe neutron generation.

Spin polarization suppresses the D-D reaction rate because, un-like the D-T reaction, two deuterium nuclel whose spins are allgnedare Jess likely to react with each other,

Table 4-8.—Fusion Fuel Cyclesa


However, the D-3He reaction is much more dif-ficult to start than the D-T reaction. The minimumtemperature required to ignite D-3He is severaltimes higher than that needed for D-T; the mini-mum confinement parameter is about 10 timeshigher. Given that the requirements for ignitingD-T have not yet been experimentally achieved,attaining conditions sufficient to ignite D-3He isconsiderably farther off. On top of its technologi-cal requirements,

3H e i s s c a r c e . I t i s a n i s o t o p e

of helium with one fewer neutron than naturalhelium (4He), and it occurs on earth only as theend-product of tritium decay. The only way tocollect 3He is to make tritium and wait for it todecay or to breed 3He as the product of anotheradvanced fuel fusion reaction, the D-D reaction.Due to the scarcity of 3He, the D-3He reactionhas been considered primarily an academic curi-osity until recently.

Today, a resurgence of excitement about 3Hecomes with the discovery that it is found in sub-stantial amounts in the uppermost layers of soilon the moon. Analysis of moon rocks broughtback by the Apollo missions shows that 3H e ,which is constantly emitted by the sun and car-ried by the solar wind, is deposited and retainedin the lunar surface. In principle, a rocket withthe cargo volume of the space shuttle could carryback enough liquid 3He to generate all the elec-tricity now used in the United States in one year.Of course, the technology to recover 3He fromthe moon would not be available for decades,and the energy and capital investment requiredto mine, refine, liquefy, and transport the 3H ehave yet to be evaluated.22

Advanced Energy Conversion

Despite the very high-level technology in thefusion core, a baseline fusion reactor would gen-erate electricity in much the same way that pres-ent-day fossil fuel and nuclear fission powerplantsdo. Heat produced in the reactor would be usedto boil water into steam, which would pass throughturbines to drive generators. Through this proc-ess, about 35 to 40 percent of the energy pro-duced in the fusion reaction would be converted

————~~Use of lunar ‘He is discussed in “Lunar Source ot ‘He for Com-

mercial Fusion Power, ” by L.J. Wittenberg, J.F, Santarius, and G.LKulclnski, Fus/on Technology 10(2): 167, 1986.

into electricity, with the remainder discharged aswaste heat. This efficiency, roughly the same asthat of fossil fuel and nuclear fission generatingstations, is determined primarily by the processof generating electricity from the energy in thesteam. Efficiency could be raised if advanced,high temperature materials in the blanket and firstwall of a fusion reactor permitted higher coolanttemperatures to be used.

If the intermediate step of heating steam couldbe bypassed, a higher percentage of the energyreleased in fusion reactions couId be convertedinto electricity. Several techniques to integrategeneration of electricity directly into the fusionpower core have been conceived. One of these,applicable to D-T reactors as well as to advancedfuel reactors, would convert energy carried offby escaping charged particles directly to electri-city by collecting the particles on plates. Thistechnique is most applicable to open confine-ment concepts, in which charged particles canbe allowed to escape along magnetic field lines.

Other techniques, which can work with closedconfinement concepts, require plasma temper-atures significantly higher than the 10- to 15-kiloelectron-volt D-T ignition temperatures. Veryhot plasmas radiate more energy away in the formof microwave radiation than cooler plasmas do,23

and it appears that this radiation could be cap-tured at the first wall or in the blanket and con-verted directly into electricity. These “direct con-version” techniques would be better suited toadvanced fuels, which not only burn at highertemperatures than D-T but also produce most oftheir energy in the form of energetic charged par-ticles. Unlike neutrons, which escape from theplasma without heating it, charged particles areretained within the plasma. The D-T reaction, inwhich only 20 percent of the energy is given tocharged particles, is less suitable for techniquesthat recover energy directly from the plasma.

Several direct conversion techniques that mayconvert well over 35 percent of the fusion energyto electricity have been identified. Until they canbe tested experimentally under conditions simi-lar to those in an advanced fusion reactor, theymust be considered speculative. Nevertheless,they provide a tantalizing goal.

J ‘See Item 2 In box 4-A, ‘ ‘Plasma Energy Lo\s Mec hanisnl~ ‘‘


RESEARCH PROGRESS AND FUTURE DIRECTIONS

In 35 years of fusion research, the technologi-cal requirements for designing a fusion reactorhave become clearer, and considerable progresshas been made towards meeting them. Improvedunderstanding, based on both experiments andincreased computational ability, is providingmuch of the predictive capability needed to de-sign, and eventually to optimize, future plasmaexperiments and fusion reactors.

Major advances in plasma research have beenmade possible by progress in tokamak plasmatechnologies:

. By the 1960s, experiments demonstrated thecrucial importance of attaining high vacuumand low impurity levels in the plasma toachieve high densities, temperatures, andconfinement times.

● In the mid-197os, neutral beam technologywas first used to heat plasmas to tempera-tures several times higher than those previ-ously attained. High-performance, high-fieldcopper magnets were used to obtain highLawson confinement parameters in compacttokamak plasmas.

● The development in the late 1970s of pelletinjectors to fuel plasma discharges led to fur-ther advances in plasma density and confine-ment. Development of the poloidal divertorat about the same time led to the discoveryof the “H-mode,” a mode of tokamak be-havior that was not subject to degraded con-finement when auxiliary heating was used.

● I n the early 1980s, advances in high-powerradiofrequency technology gave experimentersnew tools to modify the temperature, cur-rent, and density distributions within theplasma. Much of this new capability has yetto be exploited.

These accomplishments have contributed tothe steady progress in plasma parameters plot-ted in figure 4-14. Figure 4-14(a) shows the prod-uct of the temperature, density, and confinementtime that has been achieved simultaneously invarious experiments over the last 20 years. Sinceall three of these parameters must be high simul-taneously for the product to be high, this prod-

uct provides a rough measure of how well thesethree requirements have been simultaneouslyachieved.

The next figure, 4-1 4(b), plots the temperaturealone and compares it to the minimum temper-ature below which neither breakeven nor igni-tion can occur no matter how high the densityand confinement time. The TFTR point showstemperatures well into the reactor regime and farabove that needed for ignition. However, the factthat the corresponding TFTR point in figure 4-14(a) is below the ignition threshold indicates thathigh temperature is not sufficient; the product ofdensity and confinement time must also be highfor ignition.

Figure 4-1 4(c) shows progress in the parame-ter beta, the ratio of plasma pressure to magneticfield pressure. Note that devices that have achievedhigh values on one of the three plots often havenot been the ones that have gotten the highestvalues in others. Future devices will have toachieve high values in all areas simultaneously.

The Technical Planning Activity

The technological issues to be resolved betorefusion’s potential as a power producer can beassessed have been examined in detail in theTechnical Planning Activity (TPA), an analysiscommissioned by DOE’s Office of Fusion Energyand coordinated by Argonne National Labora-tory. 24 Over 50 scientists and engineers from thefusion community identified and analyzed thetasks and milestones that constitute the researchneeded to reach the goal of the DOE fusion pro-gram: the establishment of the “scientific andtechnological base required to carry out an assess-ment of the economic and environmental aspectsof fusion energy. ”25 According to DOE’s assign-ment to TPA, the assessment of fusion wouId beculminated by the construction and operation of“one or more integrated fusion faciIities . . . inthe post 2000 period. ”26

24 Argon “e N~tl~nc~ I L~bratc)ry, ~6Thf7;cd/ P/JfJfllf7~ Acfll 1~)”” ‘/-nc7/ Report, op. cit.

251 bid., “Technical Pl~nnlng Acti\ @ Mlsslon Statement, ” p. 348‘blblci.


A)

Figure 4-14.-Progress in Tokamak Parameters

20

10

5

0.5

0.2

0.1

B)

6

1965 1970 1975 1980 1985 1990 1965 1970 1975 1980 1985 1990

Year

5

2

1970 1975 1980 1985 1990

The nature of an integrated fusion facility is notspecified by either DOE or TPA. The TPA reportdescribes it only as “the beginning of the com-mercialization phase of fusion” that could “per-haps” take the form of a demonstration powerreactor. 27 The decision to proceed with an in-tegrated facility is scheduled in the TPA reportin the year 2005.

Key Technical Issues and Facilities

DOE defines four “key technical issues” thatmust be resolved: magnetic confinement systems,

zTlbid., p. 26. On p. 11 of the TPA report, table S.2 provides “rep-resentative goals” for an integrated fusion facility (IFF) and for acommercial power reactor. Comparing the two sets of goals showsthat the IFF falls well short of commercial performance. h wouldonly produce from one-sixth to one-third the heat generated bya commercial-scale reactor, and it would have considerably loweravailability and shorter lifetime than a commercial plant. The IFFdescribed by these parameters, therefore, could not be consideredto be a “demonstration” power reactor.

properties of burning plasmas, fusion materials,and fusion nuclear technology .18 For each ofthese issues, TPA set technical goals and deter-mined requirements for facilities that could reachthese goals.

Magnetic Confinement Systems

The key issue in confinement systems is the de-velopment of confinement concepts that wouldbe suitable for commercial fusion reactors. Prog-ress here will require that a series of facilities bebuilt for whichever concepts are judged worthyof further development. A preliminary experi-ment that investigates basic characteristics of anew concept can be done for a few million dol-lars or less. An experiment that looks promisingcan be followed up by a larger “proof-of-con-

w .s. @partrnent of Energy, Office of Energy Research, Mag-netic Fusion Program P/an, DOE/ER-0214, February 1985, p. 6.


cept” experiment, costing up to tens of millionsof dollars; such a device would explore the scal-ing properties of the concept and determinewhether it offers the potential for extrapolationto a reactor.

If the results are promising, a “proof-of-prin-ciple” experiment would then be required to pro-vide confidence that the concept could be scaledup to reactor-level conditions. The JET, TFTR, andJT-60 tokamaks are in this category. They are notthemselves reactor-level devices, but they will en-able decisions to be made about whether to pro-ceed to the final stage of concept development:demonstration of reactor-level plasma conditions,including fueling, burn control, ash removal, andother functions necessary for reactor operation.No reactor-level devices have yet been built forany concept, including the tokamak.

Cost is very difficult to estimate for a futureproof-of-principle or reactor-level device. TheTPA report estimates costs ranging from 100 mii-Iion to several hundred million dollars or more.29

The costs of the existing JET, TFTR, and JT-60 de-vices range between $600 million and $950 mil-lion dollars,30 but these devices perform manyfunctions in addition to proof-of-principle for thetokamak concept. There is no reason to think thatproof-of-principle devices for other confinementconcepts would be as expensive. A reactor-scaledevice for a particular concept would have morestringent technical requirements than its proof-of-principle device and presumably would bemore expensive. However, the cost of a reactor-Ievel device depends on whether it would serveother functions such as the long-pulse burn, nu-clear technology demonstration, or system in-tegration functions discussed below.

In addition to generic device requirements forselected alternate confinement concepts, TPAalso set a requirement for additional tokamaksto investigate features such as shaped plasmas (to

29 Argonne National Laboratory, Technical P/arming Activ;tY: Fi-

nal Report, op. cit., table S. 12, p. 44 and table S. 16, p. 48.JOU .s, Congress, House Committee on Science and Technology,

Task Force on Science Policy, Science Policy Study BackgroundReport No. 4: World Inventory of “Big Science” Research lnstru-rnents and Facilities, Serial DD, prepared by the Congressional Re-search Service, Library of Congress, 99th Cong., 2d sess., Decem-ber 1986, pp. 111, 121, and 127.

follow up on the PBX-M and D II I-D results dis-cussed in the earlier sections “Advanced Toka-mak, ” p. 59, and “Beta,” p. 70), steady-statetokamak operation, and high-magnetic-field ap-proaches to tokamak confinement.31

Properties of Burning Plasmas

Some of the most critical scientific issues yetto be resolved in the fusion program involve thebehavior of ignited, or burning, plasmas. Theseissues include the effects of self-heating on con-finement and the effects of energetic alpha parti-cles on plasma stability, burn control, and fueling.Effects such as these, which existing experimentscannot yet address, can profoundly influence fu-sion’s feasibility. TFTR may be able to providesome information about the effects of alpha par-ticle generation if it attains near-breakeven con-ditions in D-T operation. However, TFTR doesnot have the capability to reach ignition andtherefore will not be able to resolve burningplasma issues definitively. The European JET de-vice should also have the capability to reach andperhaps exceed breakeven, but it too will not beable to resolve many of the burning plasmaissues.

According to TPA, two different tasks are re-quired to study burning plasma issues fully. Oneis a short-pulse ignition demonstration to createa self-sustaining fusion reaction. The second isa long-burn demonstration to maintain a self-sus-taining fusion reaction long enough to study ef-fects such as the evolution of the plasma understeady-state burn and the buildup of reactionproducts. These two tasks could be done in sep-arate facilities or in the same facility.

For fiscal year 1988, DOE has requested fundsto start building a Compact Ignition Tokamak(CIT) to study short-pulse ignition issues (figure4-15). This device, to be located immediately ad-jacent to TFTR at Princeton Plasma Physics Lab-oratory, is anticipated to cost about $360 million(including diagnostic equipment and associatedR&D) and will take advantage of existing equip-ment at the site. Operation is scheduled to be-

31 Argonne National Laboratory, Technical P/arming Act;v;~y: Fi-

na/ Report, op. cit., p. 79.


S H I E L D

Figure Preliminary Design

SOURCE: Princeton Plasma Physics Laboratory, 1987.

gin in 1993, and annual operating cost is esti-mated at about $75 million. According to a reviewby a panel of the Magnetic Fusion Advisory Com-mittee (M FAC)32, CIT will be able to study mostof the effects that generation of alpha particlesmight have in a fusion plasma.

Ever since TFTR was designed in the mid- 1970s,the design for a successor device has been a topicof active interest in the fusion community. As far

Committee is a committee

of scientists and engineers from academia, national labora-tories, and industry that advises DOE on technical matters

fusion research. An (Panel XIV, chaired by DaleMeade of Princeton Plasma Physics Laboratory) reviewed plans for

in the Report on Assessment Phenomena Feb. 10, 1986. The re-

port was reviewed by the full in AdvisoryCommittee on Compact Experiments (Charge XIV),submitted to Dr. Alvin Director, Off Ice of Energy Re-search, Department Energy, Washington, DC, February 1986.

back as 1977, proposals were made for compact,high-magnetic-field tokamak devices using high-performance copper magnets; this is the approachthat was selected for CIT. Other proposals, whichwere ultimately not adopted, called for long-pulsetokamaks using superconducting magnets andcosting well over over $1 billion. The CIT designis intended to focus on scientific aspects of thefusion process, and it will not necessarily formthe engineering basis for future fusion reactors:ClT’s copper magnets consume amounts of elec-tricity that would be prohibitive for commercialpurposes, they cannot operate for longer than afew seconds at a time without overheating, andtheir compact size does not provide enoughroom for a blanket to recover fusion energy orbreed tritium. But CIT will have the ability to re-solve critical physics uncertainties sooner and atlower cost than an experiment having more of


the engineering features that a reactor wouId re-quire. Moreover, although specifics of the CIT de-sign may not be applicable to future reactors, theoverall approach of high-field, high-performancemagnets in fact may be relevant if such magnetscan be made with superconducting technology.

CIT is being designed through a national effortwith wide-based technical support, and the proj-ect has been endorsed by MFAC as a “cost-ef-fective means for resolving the technical issuesof ignited tokamak plasmas.”33 MFAC determinedthat the “existing tokamak data base is adequate,with credible extrapolation, to proceed with thedesign of the ClT,” and that by fiscal year 1988“we shouId have acquired sufficient informationfrom present large machines to support proceed-ing with the construction of the CIT.”34 M F A Calso stated that CIT “should be part of a balancedoverall fusion program, “ implying that it shouldnot drain funds away from “other essential ele-ments . . . in the DOE Magnetic Fusion ProgramP lan .”35

Long-term burn issues, which cannot be ad-dressed by CIT, will require another device in thefuture. Even if constructed solely to study physicsissues, such a device would probably cost at least$1 billion. If other functions such as nuclear tech-nology testing were incorporated, the cost wouldbe even higher.

Fusion Materials

According to TPA, “the ultimate economicsand acceptability of fusion energy, as with mostother energy sources, will depend to a large ex-tent on the limitations of materials for the vari-ous components.”36 Addressing the specific ma-terial issues identified earlier in the chapterrequires faciIities for testing and evaluating can-didate materials. Some of this testing can be doneby exposing materials to neutrons in fission re-actors. Fission-generated neutrons, however, dif-

33Magnefic Fusion Advisory Committee Report on compact ig-

nition Experiments (Charge X/V), letter from MFAC chair Fred L.Rlbe to Dr. Alvin Trlvelpiece, Director, Office of Energy Research,Department of Energy, Feb. 24, 1986.

]~1 bid,

3jlbid.1 6 A r g o n n e N~tlona [ Laboratory, Techrr/ca/ ~/.3flfl;~g Act/~;ty: FI-

rra/ Report, op. cit., p, 259,

fer in energy and effects from fusion-generatedneutrons; tests of materials in fission reactors haveto be carefully arranged in order to providemeaningful data on fusion neutron effects.

Eventually, a high-intensity source of 14-million-electron-volt (14-MeV) neutrons will be requiredto evaluate the lifetime potential of most materi-als. To accelerate the effects of aging, the test fa-cility must generate neutron irradiation levels sig-nificantly higher than those expected in a reactor.Such levels could be provided by a device suchas a driven fusion reactor, which would gener-ate fusion neutrons but consume more powerthan it generated. Such a device would be com-pletely impractical as an energy source, but couldbean effective method of generating high fusionneutron intensity over a small volume (1 O to1,000 cubic centimeters).

TPA estimates that a materials irradiation testfacility would cost from $150 million to $250 mil-lion and would take about 4 years to build. Ma-terials testing would also require several addi-tional facilities each costing $10 million or less.

Fusion Nuclear Technology

Fusion nuclear technologies are those involvedwith the recovery of energy from the fusion re-action and the breeding and recovery of tritiumneeded to replace the tritium consumed in thereaction. Most of the nuclear technology func-tions of a fusion reactor are incorporated in thefirst wall, blanket, and shield.

The first wall/blanket test program is currentlyat a very early stage. However, the characteris-tics of the required experiments have been de-fined in the FINESSE study .37 A number of exper-iments, each costing about $5 million, will beimportant for guiding the future of the program.Several larger experiments will be needed to fol-low upon the earlier ones; each of these will costup to tens of millions of dollars to build and $1million or more a year to operate .38

j~he FINESSE study IS a 3-year study done to r DOE Ink o I \ I ngorganizations and scientists from the U n ited States, ELI rope a nciJapan. The study produced many pub]lcatlons; one example IS ‘AStudy of the Issues and Experiments (or Fusion Nuclear Technol-ogy,” by M. A. Abdou, et al., Fwon Technology 8, November 1985.

IBArgonne Nationa I Laboratory, Technic a/ f’/.? nngng Ac~l~’lty. FI -

na/ Reporf, op. cit., table 4.13, pp. 234-236.


After individual facilities enable blanket con-cepts and components to be designed and thenumber of options to be reduced, a large-scalenuclear technology demonstration facility will berequired to integrate these components and testthem under fusion reactor conditions. Such alarge-scale device must not only produce enoughfusion power to provide a realistic environmentfor nuclear technology testing, but it must alsoincorporate development and construction of theindividual nuclear technology systems themselves.If this device is also intended to address thephysics issues associated with long-term fusionburns, it will become still more complex and ex-pensive.

One possibility, identified by the FINESSE studyand reviewed and adopted by TPA, is buildinga nuclear technology demonstration facility thatdoes not simultaneously serve as the long-burnphysics test facility. A device built solely to studynuclear technologies would need a source offusion-generated 14-MeV neutrons, but this sourcewould not need to be an ignited plasma. Sucha device could test scaled-down versions of nu-clear technology components, provided thatthese results could be applied with confidenceto reactor-sized versions. TPA estimated that sucha nuclear-technology-only device would costabout $1 billion and would take 5 to 6 years tobuild. TPA did not estimate operating costs forthis device.

TPA identified as a second possibility an engi-neering test reactor (ETR) that would include bothlong-term burn physics and nuclear technologystudies. Such a device would require an ignitedor near-ignited plasma, making it big enough toaccommodate full-size nuclear technology com-ponents. Both the more stringent physics require-ments and the need for full-scale nuclear tech-nology components would make an ETR muchmore expensive than a nuclear-technology-onIyfacility. TPA estimated the cost to build an ETRat about $3 billion. It did not estimate operatingcosts but said that the experience with TFTRwould suggest $150 million annually.39

WIt is not clear how this estimate of $150 million is obtained; itis not computed merely by assuming the annual operating expenseof a device to be a specific fraction of its capital cost. Were theestimate made in this manner, it would be considerably higher.

If a nuclear-technology-only device is built in-stead of an ETR, an additional device would berequired specifically to study long-term burn. Thisadditional experiment would probably cost morethan $1 billion. Further expense would come laterwhen the tested nuclear technology systems werescaled to reactor-level and integrated with areactor-sized plasma. Thus, the cost of an ETRcannot be compared only to the cost of a nucleartechnology device plus a long-term burn device.

Although DOE recognizes the need for an ETRor equivalent, it has no plans to build one. TheJapanese and European programs each haveplans to design such a device independently, butneither has yet committed to its construction. TheSoviet and the U.S. fusion programs, on the otherhand, appear to prefer international collabora-tion on such a facility. The U.S. Government hasproposed to the other major fusion programs thatconceptual design of an international engineer-ing test reactor, called the International Ther-monuclear Experimental Reactor (ITER), be jointlyundertaken. The U.S. proposal does not extendto multinational construction of such a device.However, at the conclusion of the conceptual de-sign effort, the parties could decide whether theywanted to proceed with construction, either in-dependently or jointly. Possible avenues of fu-ture international collaboration in fusion researchare discussed in chapter 7.

Resource Requirements

Schedule

TPA identified six major decision points that de-termine the course and schedule of future fusionresearch, leading up to the overall assessment offusion’s potential. In figure 4-16, each decisionis pegged to a key technical issue and to a year.

The ratio of annual operating expense to capital expense for TFTRis about 15 percent, and that projected for CIT is about the sameif the value of existing facilities at Princeton Plasma Physics Lab-oratory is included in ClT’s capital cost. Applying this 15 percentratio to an engineering test reactor would predict annual operat-ing expenses of close to $500 million.

However, fusion scientists argue that there is no reason to be-lieve the ratio of operating expense to capital expense to be thesame for an ETR as it is for significantly smaller devices. They agreethat the more a device costs to build, the more it will cost to oper-ate. However, they maintain that there is no reason to expect cap-ital and operating costs to increase at the same rate,


Figure 4-16.-Top Level Decision Points in the Magnetic Fusion Program

SOURCE: Argonne National Laboratory, Technical Planning Activity: Final Report, commissioned by the U.S. Department of Energy, Office of Fusion Energy, ANL/FPP-87-1,January 1987, figure S.8, p. 23.

TPA did not examine all the possible scenariosresulting from different timings and outcomes forthese decisions but instead adopted a “referencescenario” believed to reflect current DOE plan-ning. The years in figure 4-16 are taken from thereference scenario, which is shown in greater de-tail in figure 4-17.

In the reference scenario, the decision to pro-ceed with CIT as the short-term burn experimentis made in 1987. By about 1990, the decision ismade to combine nuclear technology studies andlong-term burn physics issues in a single engineer-ing test reactor, possibly ITER. At about the sametime, decisions are made concerning the natureof a materials testing facility and the selection ofconfinement concepts to be tested at the proof-of-principle scale. By 1997, certain alternate con-finement concepts successfully showing proof-of-principle are selected for reactor-scale dem-onstration, and the overall assessment of fusionis targeted for 2005. TPA does not conclude thatthe reference scenario is fastest, cheapest, or most

assured of success. Rather, it shows that an ex-haustive process of technical review has not un-covered any inconsistencies.

cost

TPA estimates that the worldwide research re-quired between 1987 and 2005 under the refer-ence scenario will cost in the range of $20 bil-lion. This cost does not include an integratedfusion facility, demonstration reactor, or anyother facility constructed after the assessment offusion in 2005. Total operating cost worldwideis judged to be relatively constant at about $800million annually, and total yearly funding for fu-sion research increases to about $1.5 billion inthe mid-1990s when construction cost is added.The total construction budget is estimated atabout $6 billion, half of which is required for anengineering test reactor.

TPA acknowledges that the ground rules usedfor cost projection could have been applied more

January 1987, figure S.1O, p. 27.

uniformly, that no iterative review of the cost esti-mates was undertaken, and that no effort wasmade to estimate the resources required for alter-nate research scenarios. Nevertheless, the reportstates that the information gathered is sufficientto present “a broad view of the resources re-quired for a full assessment of the commercialpotential of fusion.”40

Some critics of TPA’s cost estimates argue that,since TPA was not charged with designing, man-aging, and executing an actual research strategy—indeed, TPA was forbidden from performing suchprogrammatic planning, which is strictly DOE’sdomain–the total cost represents a sum of “wishlists” rather than a realistic budget. According tothese critics, without the requirement to conductthe politically difficult task of eliminating researchthat, although useful, may not be necessary, the

Laboratory,

Report, op. cit., p. 28.

estimated total cost is higher than an actual man-ager would spend when faced with fiscal con-straints. Similarly, these critics complain that anystudy done by experts from a single field has aninherent bias towards overestimating that field’sresearch requirements. Researchers in a field arepresumed to have an interest in maintaining orincreasing their field’s funding, these critics ar-gue, and the researchers would not have any in-centive to prepare a study underestimating thecost of research if such a study might be used asjustification for cutting the field’s research budget.

Other critics, however, feel that any bias inTPA’s estimated total is likely to be in the direc-tion of underestimating the total rather than in-flating it. Since each technical aspect of the studywas analyzed by experts in the field, some de-gree of technical optimism is probably inherentat each stage; unanticipated difficulties woulddrive the cost of the research program aboveTPA’s estimates. Moreover, these critics suggest,

Ch. 4.—Fusion Science and Technology ● 101

it would not be in the collective interest of thefusion community to estimate a higher total costthan necessary, since continued support of thefusion program depends on perceptions that itsbenefits are worth its cost. Overestimating the to-tal cost could threaten the program’s support.

The process by which TPA estimated the to-tal cost of future fusion research involved a widedegree of fusion community participation, andOTA can find no evidence that the estimate isflawed. However, OTA also recognizes that whilethe researchers in any technical field are themost qualified to estimate costs of experimentsin that field, they are also the beneficiaries ofsupport given to the field. Therefore, their esti-mates may be influenced by non-technical fac-tors, although it is not clear whether the esti-mate would be too high or too low as a result.

Summary

Probability of Success

It seems likely that at the conclusion of the re-search program, fusion’s technological feasibil-ity—the ability to use fusion power to generateelectricity—can be shown. The fusion programhas made steady progress over the last 35 yearson the key technical issues. It is still possible thatfusion’s scientific feasibility will be impossible todemonstrate, due to surprises in the behavior ofa plasma that generates substantial amounts offusion power. However, successfully attaining ig-nition in CIT will resolve most of the scientific un-certainties.

Most of the subsequent scientific and engineer-ing challenges in designing and building a reactorhave been identified. Once scientific feasibilityis established, a concerted and well-funded re-search effort should be able to develop a reactorthat produces fusion power. However, it can-not yet be determined whether or not such afusion reactor will be commercially attractive.

Characteristics and prospects of fusion as a com-mercial energy source are discussed in chapter 5.

Findings

Estimates of the annual worldwide funding re-quired to evaluate fusion’s potential early in thenext century are several times today’s annual U.S.fusion research budget. The estimated annualworldwide funding is, however, on the order ofthe amount now spent each year by all the world’smajor fusion programs put together. The fund-ing estimates suggest three possibilities to U.S.policy makers for continuing the U.S. fusion re-search program:

1. With funding levels several times their pres-ent level and with a significant measure oftechnical success, the U.S. fusion programcan decide on its own whether or not to be-gin the demonstration and commercializa-tion of fusion power in the early part of thenext century.

2. If the major world fusion programs can col-laborate and plan their research efforts tocomplement each other and eliminate dupli-cation, and if the effort has a significantmeasure of technical success, a collectiveassessment to proceed with fusion’s devel-opment could be made early in the 21st cen-tury. In this case, only modest increases infunding would be required for each of theworld’s fusion programs, with the exactamount of the increases depending on howwell the programs were able to avoid dupli-cation of research.

3. If major international collaboration is not at-tained, and if the U.S. fusion budget is notincreased to the point where the necessaryresearch can be carried out domestically, theUnited States cannot assess fusion’s poten-tial until later in the next century.

These possibilities form the basis of the policyoptions discussed in greater detail in chapter 8,

Chapter 5

Fusion as an Energy Program

CONTENTS

PageCharacteristics of Fusion Electric Generating Stations. . . . . . . . . . . . . . . . . . . . . . . 105

Risk and Severity of Accident . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..106Occupational Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ............108Environmental Effects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .............109Nuclear Proliferation Potential . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ......112Resource Supplies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ................113cost. . . . . . . . . . . . ● * * *, . . * ***..*... 6.**.....*...*.*. . ..............113

The Supply of and Demand for Fusion Power . . . . . . . . . . . .................116The Availability of Fusion Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .......116The Desirabitity of Fusion Power.... . . . . . . . . . . . . . . . . . . . . . . . . . .Comparisons of Long-Term Electricity Generating Technologies. . . . .Fusion’s Energy Context . . . . . . . . . . . . . . . . . . .:....

Conclusions . . . . .. .. .. .. .. .. .. .. .. ... ... ... ..$..Characteristics of Fusion Reactors . . . . . . . . . . . . . . . .Timetable for Fusion Power . . . . . . . . . . . . . . . . . . . . .

Figure No.

5-1. Post-Shutdown Radioactivity Levels . . . . . . . . . . . . .5-2. Post-Shutdown Afterheat Level s . . . . . . . . . . . . . . .5-3. Projections of Global Primary Energy Consumption

—. . . . . . . . . . . . .. . . . . . . . . . . . .. . . . . . . . . . . . .. . . . . . . . . . . . .

.**.... . . . . . .

. . . . . . . . . . . . .to 2050. . . . . .

Table No.

5-1. Principal Locations of Potential Hazardous Agentsin D-T Fusion Reactors . . . . . . . . . . . . . . . . . . . . . . .

5-2. Utility Requirements Summary . . . . . . . . . . . . . . . . .5-3. Comparison of Prospective Long-Range Electricity Supply Options

. . . . . . . . . . . . .

. . . . . . ● ✎ ✎ ✎ ✎ ✎ ✎

. . . . . . . 117

. . . . . . . 119

....*O . 123

. . . . . . . 127

. . . . . . . 127

. . . . . . . 127

Page. . . . . . . 110● . . . . . . 111. . . . . . . 126

Page

. . . . . . . 109

. . . . . . . 118

. . . . . . . 124

Chapter 5

Fusion as an Energy Program

The primary long-term goal of U.S. fusion re-search is to develop a fusion reactor that is anattractive source of electricity. ’ The overall rolethat fusion might play in the future energy sup-ply of the United States depends on the charac-

] Fusion a I so may be \a I uable I n a n u m her cd non-electric appl I-catlons, descrl bed i n ap~). A.

teristics of such a fusion reactor and on the char-acteristics of other energy technologies withwhich fusion will compete. It is too early to evalu-ate either of these characteristics: fusion’s com-mercial prospects are not yet known and neitherare the prospects of developments i n other tech-nologies. However, preliminary analyses can beperformed on the basis of fusion system studiesconducted to date.

CHARACTERISTICS OF FUSION ELECTRIC GENERATING STATIONS

Pre-conceptual designs and feasibility studiesfor fusion generating stations were developed aslong ago as 1954.2 However, it was not until theearly 1970s that studies began to simultaneouslyaddress the plasma physics, structural materials,operating characteristics, economics, and envi-ronmental implications of fusion reactors.3 Dur-ing the late 1970s and early 1980s, comprehen-sive system studies and comparative models weredeveloped to evaluate the interdependence of fu-sion reactor performance and various scientificand technological parameters.

These studies represent a mix of technologicaloptimism and conservatism. They optimisticallyassume that the research and development (R&D)effort mapped out in chapter 4 of this assessmentwill be successfully completed and that it willpermit a fusion reactor to be designed and built.At the same time, studies are inherently conserv-ative in that they cannot account for as-yet-unforeseen developments and innovations i n fu-sion and competing technologies.

The studies have been especially valuable inidentifying improvements in fusion physics ortechnology that appear to have the greatest po-

2L. Spitzer, Jr., et al., Problems of the Stellarator as a Usefu/ PowerSource, NYO 6047 (Princeton, NJ: Princeton University, 1954),

‘The evol ut Ion of fusion reactor stud Ies 15 d i scussed I n FujIorJ Re-actor Desgn: On the RoJd to Comrnercl.]/iz~ tlon, by G. L Ku ICI n-skl, Fusion Engineering Program, NUC Iear En~lneerlng Department,Unwerslty of Wlsconsln, LJWFDM-5.29, Nlachson, \Vl, May 31, 1983,p. 3.

tential for making fusion reactors attractive andcompetitive. Their value to the fusion programnotwithstanding, system studies should not beconsidered definitive assessments of future fusionreactors. Given that the scientific and technologi-cal base for fusion has not yet been established,fusion system studies are inherently based on in-complete information, and the values calculatedfor reactor parameters such as capital cost andcost-of-electricity must be considered highIy un-certain. As a result of the technical progress madein fusion research, system studies today describereactors that are very different from those envi-sioned 30 years ago. It is likely that the fusion re-actor that eventually enters the marketplace willmake today’s designs appear just as dated.

The discussion that follows identifies genericfeatures of future fusion reactors as well as fac-tors that depend on particular design choices. Thefocus is on reactors that produce electricity fromfusion alone, called pure fusion reactors, as dis-tinguished from fusion reactors that draw part oftheir energy from fission or that are used to makefissionable fuel.4 Much of the discussion drawson comparisons of fusion technology to present-generation light-water reactor fission technology,the closest analog to fusion for which significantoperational data exists. Fusion and fission plants

105


are comparable because both are nuclear tech-nologies suited for central-station power gener-ation, and because they share some of the sameenvironmental and safety concerns. However,the further that a technology is extrapolated be-yond present experience, the less certain any ofits features become. As a resuIt, all characteriza-tions of future systems—including the ones in thischapter—should be treated with extreme caution.

Risk and Severity of Accident

The D-T fusion process has several advantagesover fission that should make it easier to assurethe safety of a fusion reactor than of a fission re-actor. This statement does not imply that exist-ing fission reactors are unsafe, or that fission tech-nology will not continue to develop and improve.However, assuring public safety with fusion tech-nology should be easier for the following reasons:

● Fusion reactors cannot sustain runaway re-actions. Fuel will be continuously injected,and the amount contained inside the reactorvessel at any given time would only oper-ate the reactor for a short period (probablyseconds or less). A fission reactor, on theother hand, contains several years of fuel inits core—a far greater amount of stored energypotentially available for release. Moreover,the conditions necessary to sustain a fusionreaction are difficult to maintain; any signif-icant system malfunction would stop the re-action.

● Fusion reactors should require simpler post-shutdown or emergency cooling systemsthan fission reactors, if such systems areneeded at all. Due to the decay of radio-active materials in the reactor, both fusionand fission reactors will continue to gener-ate heat at a small fraction of the full powerrate after they have been shut down. I n afission reactor, this decay heat, or afterheat,

is largely due to fission byproducts that ac-cumulate in the spent fuel rods. In a fusionreactor, afterheat results mostly from radio-activity induced in the reactor structural ma-terials, and the afterheat level is highly de-pendent on the choice of those materials.

With appropriate materials choices, afterheatfrom fusion reactors should be much lessthan from fission reactors.potential accidents that could occur in fu-sion reactors should be less serious thanthose that could take place in fission reactors.With suitable materials choices, the radio-active inventory of a fusion reactor shouldbe considerably less hazardous than that ofa fission reactor. Fusion reactors would notcontain biologically active fission productssuch as strontium and iodine. Moreover, theradioactive materials in a fusion reactorwould generally be less likely to be releasedin an accident than wouId those in a fissionreactor, since they would largely be boundas metallic structural elements. The onlyvolatile or biologically active radioactivecomponent in a fusion reactor would be theactive tritium inventory; gaseous and vola-tile radioactive products in a fission reactorwould be present in amounts orders of mag-nitude greater.

recent study of fusion’s environmental, safety,and economic attributes quantitatively comparesthe safety of fusion and fission designs. s Th isstudy, referred to here as the ESECOM report,sorts various fission and fusion reactor designsinto four categories according to the means bywhich prompt off-site fatalities are prevented inthe event of an accident. Some of the designsstudied depend on active safety systems to pre-vent off-site fatalities. These reactors can be safe,but demonstrating their safety involves certifyingthat the safety systems will work as expected dur-ing all conceivable accidents. In other designs,

Jjohn Holdren, et al., Exp/oring the Cornpetiti~7e Pofentia/ ofMa~-netic Fusion Energy: The Interaction ot’fconomics With Safety andEnvironmental Characteristics, excerpts from the Report of the Sen-ior Committee on Economic, Safety, and Environmental Aspectsof Magnetic Fusion Energy (ESECOM). Interim results from this studywere presented to the Magnetic Fusion Advisory Committee inPrinceton, NJ, on May 19, 1987; the full report should be publishedas a Lawrence Livermore National Laboratory report in Septem-ber 1987. This study will be cited hereinafter as the ESECOM report.

ESECOM analyzed and compared the environmental, safety, andeconomic aspects of eight pure fusion reactor designs, two fission/fu-sion hybrids, and four types of fission reactor. Of the pure fusionreactors, six were tokamaks and two were reversed-tield pinches;both the hybrid reactors were tokamak-based.

Ch. 5.—Fusion as an Energy Program ● 107

and the safety of these systems is much easier todemonstrate. 6

The levels of safety assurance derived byESECOM, ordered by increasing ease of demon-strability, are:

● Level 4: Active Protection. This level of pro-tection depends on the proper operation ofactive safety systems to ensure safety.7 It isextremely difficult to certify that such systemswill indeed work as expected in case of ac-cident. These systems must be designed torespond to particular contingencies, anddeciding which accident scenarios should becovered is not easy. Furthermore, as the1986 Chernobyl accident in the Soviet Unionshowed, active safety systems can be discon-nected. At this level of protection, it is im-possible to eliminate the risk of operatorerror.

● Level 3: Small-Scale Passive Protection. Atthis level, safety does not depend on activesafety systems. Moreover, failure of compo-

bThe analysis in this study computes ‘‘worst-case” radiation ex-posures to members of the public by calculating the maximum ra-diation dose deliverable to an individual at the worst possible loca-tion at the plant boundary, under weather conditions that keepthe radiation from dispersing. Effects that would serve to mitigatethe delivered dose, such as buildings, rain, or fallout, were not in-cluded (except that the effect of buildings on the wind pattern wasincluded). Absence of prompt fatalities corresponds to limiting the‘‘worst-case” dose to under 200 reins, an amount of radiation ex-posure generally accepted to be the minimum capable of causinga prompt fatality in the absence of medical treatment. This radia-tion dose is about 2,000 times the total dosage typically receivedin one year due to cosmic rays and other naturally occurring sourcesof radiation.

In addition to prompt radiation dose, the study also consideredthe long-term dose from ground contamination due to an accident.However, these long-term dosages were not used to define the cat-egories of safety assurance. Long-term effects of radiation releaseare more difficult to determine than prompt effects because theeffects of long-term, low-level exposure to radiation are highly con-troversial. Estimates of the cancer fatalities resulting from a givenlong-term, low-level exposure vary by more than a factor of 10.

7U rider the ESECOM analysis, any system such as an emergencycooling system that would have to be activated or powered at thetime of an accident, or any system that would have to be activelyturned off, is considered an active system. A containment build-ing is considered an active system under this definition since pene-trations such as airlocks, ventilation systems, and plumbing are man-aged by active systems. Therefore, designs relying significantly oncontainment buildings to prevent escape of radiation could notachieve a rating higher than Level 4.

nents such as relief valves and pump seals—in conjunction with the failure of any activesystems—could be tolerated without riskingoff-site fatalities. However, ensuring safetyat this level requires assuming the integrityof key systems such as coolant loops, as wellas maintaining the large-scale physical integ-rity of the overall structure. It would haveto be proven that passive design featuresalone could keep these critical componentsor systems from being damaged under credi-ble accident scenarios.Level 2: Large-Scale Passive Protection. Alarge-scale passively protected reactor wouldbe able to prevent the release of dangerousamounts of hazardous materials as long ascertain large-scale structures remained intact.Such a system would not rely on active safetysystems and would be able to withstand anycombination of small-scale component orsystem failures. Demonstrating the safety ofsuch a reactor wouId only require showingthat no credible accident could destroy thelarge-scale geometry of the device.Level 1: Inherent Safety. A reactor with thisdegree of safety assurance could be shownto be incapable of causing an immediate, off-site fatality in the event of any conceivablefailure, including total system reconfiguration(e.g., it would remain safe even if the entirereactor were somehow crumpled up into aball). This level of protection is assured bythe properties of the reactor materials in oneof two ways: either the radioactive inventorymust be so small that, if totally released, itcould not constitute a lethal dose to the pub-lic, or the inventory must consist of materi-als that could not be melted, converted intovolatile oxides, or otherwise dispersed by thesudden release (in an explosion, fire, orpower surge) of all the plant’s stored energy.

According to the ESECOM report, attributesof the fusion process show that fusion reactorsshould be able to achieve greater degrees ofsafety assurance than fission reactors. Of theeight fusion designs that ESECOM evaluated, onewas a Level 1 system, three were Level 2, one


was Level 3, and three were Level 4. Designchanges were identified for several of the Level3 or 4 fusion systems that could raise them toLevels 2 or 3, respectively. ESECOM found thatpresent-generation commercial light-water fissionreactors are Level 4 systems, and that two “in-herently safe” fission reactor designs now underinvestigation should be capable of reaching Level3 on this scale.

Different fusion designs varied significantly interms of the maximum radiation dose that couldbe delivered to the public in an accident. Designsusing low-activation materials, which do not gen-erate long-lived radioactive byproducts underneutron irradiation, and designs operating on ad-vanced fuel cycles were calculated to have ahigher degree of safety assurance than the “refer-ence” design, an updated version of a tokamakreactor study originally published in 1980.8 How-ever, materials selections and design choices arealso possible that yield fusion reactors that requireactive safety systems.

ESECOM concluded that Level 2 fusion reactorsshould be possible to design, and that Level 1designs–although more difficult due to limitedmaterials choices—should also be possible. Noneof the fission designs ESECOM analyzed could at-tain these levels of safety assurance. Although fis-sion designs are being developed that appear tohave greater degrees of safety assurance than ex-isting fission reactors, fusion appears to havesome fundamental advantages. Many of the po-tentially dangerous substances present in fissionreactors are either fuels or fission byproducts thatare inherent to the fission reaction. The productsof the fusion reaction, on the other hand, are notin themselves hazardous. Tritium fuel does posea potential hazard, but according to the ESECOM

BCharles C. Baker, et al., STARFIRE—A Commercial TokamakPower P/an( Study, AN L/FPP-80-l, Argonne National Laboratory,1980. The STARFIRE study, conducted by a team of 70 research-ers, is one of the most comprehensive fusion reactor design studiescompleted to date. It presents a conceptual design of a full fusionpowerplant, including descriptions of the tokamak reactor as wellas all the associated subsystems in the remainder of the facility.

The STARFIRE study has been extensively drawn upon by, andprovides a base of comparison for, many subsequent analyses otfusion reactors and system designs. The ESECOM report chose theSTARFIRE design, updated with lower activation materials and amore recent blanket design, as its ‘‘point-of-departure’ referencecase.

report even the complete release of the activetritium inventory of current reactor designs un-der adverse meteorological conditions would notproduce any prompt fatalities off-site.9 There ismuch greater freedom to choose appropriate ma-terials that minimize safety hazards in fusion re-actors than in fission reactors. Therefore, a higherdegree of safety assurance should be attainablewith fusion.

Occupational Safety

Most of the occupational hazards a workermight encounter at a fusion reactor site are al-ready familiar from other occupations. Table 5-1shows the locations of potential hazards duringthe operation and maintenance of a D-T fusionreactor.

Of the potential hazards listed, the least isknown about the effects of magnetic fields. Thereis no reason to suppose that the steady or slowlyvarying magnetic fields associated with fusion re-actors could cause adverse health effects. How-ever, little is known definitively about the bio-logical effects of such fields; after many years ofresearch, the technical literature is “extensive andoften contradictory. ” 10 The U.S. Department ofEnergy (DOE) established interim occupationalmagnetic field exposure guidelines on an ad hocbasis in 1979, although the committee that de-veloped these guidelines expressed “strong con-cerns about the lack of data upon which one canconstruct appropriate exposure criteria,”11

9joh n Hold ren, et al., ESECOM Report, op cit. Larger “inactive”tritium supplies would be stored in the plant in addition to the ac-tive working inventory, but these could be divided up and extremelywell protected.

10J, B, cannon (ed .), Background Information and Technical Ba-sis for Assessment of Environmental Implications of Magnetic Fu-sion Energy, DOE/ER-01 70, prepared by the Oak Ridge NationalLaboratory for the U.S. Department of Energy, Office of FusionEnergy, Division of Development and Technology, August 1983,p. 6-2.

This document, hereinafter referred to as Background /format-ion, served as the principal reference for a generic EnvironmentalImpact Statement that was prepared for the magnetic fusion pro-gram. The generic statement, although completed, has not beenreviewed and approved by DOE. DOE has chosen not to file ageneric impact statement for the program as a whole but ratherto prepare specific statements for individual fusion facilities asneeded.

I I Letter from Dr. Edward Alpen, Director of the Dormer Labora-tory, Unwerslty of California at Berkeley, and Chairman of the com-mittee established to set interim magnetic field exposure standards,to Dr. Kenneth Baker, U.S. Department of Energy, July 23, 1979.

Ch. 5.—Fusion as an Energy Program w 109

Table 5-1 .—Principal Locations of Potential Hazardous Agents in D-T Fusion Reactors

Locations of possible exposure Locations of possible exposureHazard during operation during maintenance

Radiation from tritium. . . . . . . . . . . . . . . ●

●

Radiation from activation products. . . . ●

Radiation from neutrons . . . . . . . . . . . . . ●

Non-radioactive toxic materials . . . . . . . ●

Radiofrequency (RF) fields . . . . . . . . . . . ●

●

Magnetic fields. . . . . . . . . . . . . . . . . . . . . .

Tritium recovery systems ●

Coolant loops ●

●

Coolant loops ●

●

●

Not present in accessible areas ●

Possibly in auxiliary reactor systems ●

Near power sources ●

Along waveguides

Environment of reactor hall ●

Reactor hall and structureBlanket processingFuel recycling

Reactor hall and structureBlanket processingSteam generator

Not present

Chemical processing

Not present unless RF componentsare being tested

Not present unless magnets arebeing tested

aHazards are only listed for areas where personnel will be permitted, personnel will not be permitted in the reactor hall during reactor operation, so activation products

and neutron radiation present there are not considered occupational hazards in this table.

SOURCE Adapted from J B. Cannon (ed), Backrground Information and Technical Basis for Assessment of Environmental Implications of Magnetic fusion Energy,DOE/ER-0170, prepared by Oak Ridge National Laboratory for the U.S. Department of Energy, Office of Fusion Energy, Division of Development and Technol-ogy, August 1983, table 6.1, P 6-2

These standards are still being used on a trialbasis; although researchers analyzing this issuehave flagged uncertainties that call for further re-search, they have still not found many well-docu-mented studies that show detrimental biologicaleffects of static (non-varying) or slowly varyingmagnetic fields such as those to be found in fu-sion reactors. The National Committee on Radi-ation Protection and Measurement has estab-lished a subcommittee on Biological Effects ofMagnetic Fields to recommend limits on magneticfield exposure; this subcommittee is in its finalstages of document preparation prior to submis-sion to the full committee. ’ 2

Significant exposure to magnetic fields in ornear a fusion reactor probably would be limitedto plant workers because magnetic fields extend-ing beyond the site boundary are not expectedto be stronger than the earth’s field. The interimstandards established by DOE were for occupa-tional exposure only, and the committee that de-veloped them stated that it was “not preparedto offer an exposure criteria for general popula-tion exposure." 13

Environmental Effects

Radioactive Waste

The main environmental problem with fusionreactors is expected to be radioactive waste. Al-though the reaction products of the D-T fusionreaction are not radioactive, the fusion reactoritself—particularly the first wall, blanket, shield,and coils—will be. The first wall will be the mostseverely affected; the cumulative effects of radi-ation damage will require that the first wall bereplaced every 5 to 10 years and disposed of asradioactive waste.

The type and amount of radioactive waste gen-erated by a fusion reactor is highly dependenton the choice of materials. With appropriate ma-terials, fusion reactors can avoid producing thelong-lived, intense, and biologically active wastesinherently produced by fission reactors. Accord-ing to the ESECOM report, although fusion wastesmay have greater volume than fission wastes, theywill be of shorter half-life and intensity and shouldbe orders of magnitude less hazardous. ” Thewastes from fusion reactors operating with ad-

I ZI nformation provided to OTA staff by Dr. Donald ROSS, Acting

Director, Occupational Safety and Health Division, Office of Oper-ational Safety, U ,S. Department of Energy, Apr. 22, 1987; and by

Dr. Dennis Mahlum, chairman ot’ the National Committee on Ra-dlatlon ProtectIon and Measurement Scientific Committee 67 onBiological Effects of Magnetic Fields, Apr. 28, 1987.

13 Letter from A I pen to Baker, note 1 1 above.

14ESECOM measured racjioactive waste hazard by calcu Iating the

dosages that future “intruders” could acquire by excavating or farm-ing a radioactive waste site hundreds of years from now. Radio-active waste produced by the fusion designs ESECOM studied wereorders of magnitude less hazardous than those produced by tls-sion designs by this measure.


vanced, non-tritium-based fuel cycles would beeven less radioactive than those from D-T fusionreactors.

ESECOM’s estimates of radioactive waste haz-ards also indicate that fusion designs differamong themselves by several orders of magni-tude. The study found that advanced “low-activation” fusion designs could be tens to hun-dreds of times better than the fusion referencedesign, and that other designs could be hundredsor thousands of times worse if the wrong mate-rials are chosen. ESECOM concluded that withproper materials selection, radioactive waste fromall of the fusion designs could qualify as low-levelwaste under existing Nuclear Regulatory Com-mission regulations.15

Figure 5-1 shows the dependence of fusion re-actor radioactivity levels on materials selection.Figure 5-2 shows the corresponding dependencefor afterheat produced by radioactive decay. Forthe top curve in each figure, the reactor first walland blanket are assumed to be made out of a typeof steel. The lower curve, having radioactivity andafterheat levels thousands to millions of timeslower, assumes that low-activation materials areused in the blanket and first wall.16

These figures represent the potential of low-activation materials to reduce radioactive wastesbut do not necessarily address the feasibility ofusing these materials. The source for figures 5- Iand 5-2 was a preliminary conceptual designstudy that attempted to design credible replace-ments using low-activation ceramic materials forall reactor structures in the high neutron flux zoneof the STARFIRE reactor (footnote 8, above). Engi-neering feasibility of these materials was consid-ered, and at an initial level of analysis the designswere found to be achievable. However, using

al., induced radioactivity intrinsic to the low-activation mate-

rials themselves is extremely small; the majority of the radioactiv-ity shown by the “low-activation” curve more than one day aftershutdown is due to iron impurities. According to Cannon, Back-ground op. cit., p. 3-41, realizing impurity levels aslow as those assumed in this figure is a “difficult and expensivetask at the present time, and may or may not be achievable at thetime rity structural materials are requiredin a fusion reactor economy. ”

Figure 5-1 .—Post-Shutdown Radioactivity Levelsfor Fission Breeder Reactor, Reference STARFIRE

Fusion Reactor, and Low-Activation FusionReactor Design

10’

10°

ceramics for these components poses engineer-ing issues quite different from those encounteredwith the metals typically used in engineering ap-plications today. Substantial development of ma-terials and fabrication techniques would be re-quired to use ceramics in a fusion reactor.


Figure 5-2.— Post-Shutdown Afterheat Levelsfor Fission Breeder Reactor, Reference STARFIRE

Fusion Reactor, and Low-Activation FusionReactor Design

Routine Radioactive Emissions

The total estimated radiation dosages attrib-utable to routine releases from fusion reactorswould be a very small fraction of the radiationdose due to naturally occurring background ra-

diation. 17 Two types of radioactive substancesmay be emitted by fusion reactors: activationproducts, which are substances made radioactiveby neutron irradiation, and tritium, which isproduced in the reactor blanket and used as fuel.Activation products would be released eitherthrough liquid waste processing systems or plantventilation systems; most of the tritium releaseswould be to the atmosphere.

Activation products released by fusion reactorsshould be no more hazardous than those routinelyreleased by fission reactors. Tritium dischargesfrom fusion reactors, in terms of radioactivitylevels, would be much larger than activationproduct emissions. However, since tritium differssignificantly from activation products in the typeof radiation emitted and the method of absorp-tion in the body, the total radiation dosages dueto tritium releases would not be correspondinglylarge.

Very preliminary estimates of tritium emissionsfrom fusion reactors are on the order of 5,000to 10,000 curies per year from a 1,000-megawattplant.18 Most of these emissions would occur dur-ing major system maintenance, and they mightbe removable by an atmospheric detritiation sys-tem before release to the environment. Tritiumreleases of this amount are well within the rangeof routine tritium releases from some existingDOE facilities. By comparison, tritium emissionsfrom an equivalently sized pressurized-water fis-sion reactor—the predominant type of commer-cial nuclear fission reactor—would be about

background radiation is due primarily

cosmic and to radioactive elements contained rocks andsoils. In the United States, the dosages due to these sources varyby factors of 2 to 4 depending on location; the typical contribu-tions of the two sources are comparable.

Medical X-rays and provide, on average,a radiation dosage about equal to the natural background. A sub-stantially smaller contribution comes from the sum of other man-made sources such as atmospheric nuclear weapons tests, occupa-tional radiation exposure, nuclear powerplant emissions, and con-sumer products.

of a substance is the amount needed to

have 3.7 X radioactive disintegrations per second. Ten thou-sand curies have a mass of about one gram.

—


1,400 curies per year.19 It is estimated that thetotal dose to the population within 80 kilometers(50 miles) of a routinely operating fusion reactorshould be less than 0.01 percent of the dose fromnatural background sources .20

Routine Nonradioactive Emissions

The energy generated in a fusion reactor thatis not converted into electricity would be dis-charged as heat, primarily into the atmosphere.In this respect, a fusion reactor would resemblefossil fuel and nuclear fission generating stations.Like a fission plant, but unlike a plant that burnsfossil fuels, a fusion plant would not emit com-bustion products such as carbon dioxide into theatmosphere. Since carbon dioxide emissions maypotentially affect world climate, this aspect of fu-sion (and fission) technology could prove to bevery advantageous. Carbon dioxide emissions arediscussed later in this chapter under “Compari-sons of Long-Term Electricity Generating Tech-nologies. ”

Nuclear Proliferation Potential

A fusion reactor’s ability to breed fissionablematerials such as uranium or plutonium couldpossibly increase the risk of nuclear weaponsproliferation. A pure fusion reactor would notcontain fissionable materials usable in nuclearweapons, and it would be impossible to producesuch materials by manipulating the reactor’s nor-mal fuel cycle. Therefore, normal operation ofa pure fusion reactor poses negligible prolifera-

lgFusion reactor radioactive discharge and radiation dosage esti-mates are from Cannon, Background /nforrnation, op. cit., chs. 4and 8, particularly tables 4.19, 8.8, and 8.9. Pressurized water re-actor emissions are from Nuclear Regulatory Commission, Ca/cu-Iation of Releases of Radioactive Materials in Gaseous and LiquidEff/uents From Pressurized Water Reactors, NUREG-0017, Rev. 1,1985, p. 2-70.

ZODOSageS estin-rated from tritium releases assume that all the

tritium is in the form of tritium oxide, or tritiated water. Tritiatedwater is water in which one or both of the hydrogen atoms arereplaced by tritium atoms, and it is absorbed by and dischargedfrom the human body like ordinary water. These dosages repre-sent conservative upper bounds, and are tens of thousands of timeshigher than the dosages that would result if the tritium were re-leased in the form of tritium gas. Tritium gas is not readily absorbedby the body.

tion risk.zl However, if the blanket of a pure fu-sion reactor were appropriately modified, fission-able fuel could be bred there. To ensure thatfissionable materials were not surreptitiouslyproduced, changes to the reactor blanket wouldhave to be prevented. The difficulty of detectingsuch changes would depend on the design of thereactor; it is plausible that reactor designs couldbe developed that would make undesirable modifi-cations easy (or difficult) to monitor.22

Proliferation concerns are not unique to fusionreactors; fission reactors also pose this risk. De-pending on the fuel cycle used, the proliferationpotential of fission can be much greater than thatof a pure fusion reactor. After being irradiatedin the core of a fission reactor, uranium fuel willbe converted into plutonium, which can be ex-tracted from the uranium and other byproductsby chemical reprocessing, Alternatively, pluto-nium can be produced in breeder reactors (purefission or fission/fusion hybrid) designed explicitlyfor plutonium production. If either reprocessingor breeder reactors become used on a wide scale,it is possible that material usable for nuclearweapons could be produced and extracted dur-ing the production, processing, and transporta-tion of fissionable fuel.23

ZI Pure fusion reactors do contain tritium, which could be used

in thermonuclear weapons such as the hydrogen bomb. However,such weapons cannot be built by parties who do not already pos-sess fission weapons, and possession of tritium will not provide anyassistance to a party that is trying to develop fission weapons.

22A fission/fusion hybrid reactor would incorporate a blanket de-

signed specifically to breed (and/or utilize) fissionable fuel. Prolifer-ation concerns for hybrids are therefore considerably more seri-ous than those for pure fusion reactors.

zjThe Plutonium procfuced in a fission reactor consists Of a m iX-

ture of different isotopes whose relative proportions depend on howlong the original uranium is irradiated. Any mixture of plutoniumisotopes can be used to make a nuclear explosive, but weaponsdesigners prefer to minimize the percentage of the heavier isotopesthat are produced when the fuel is irradiated for longer periodsof time. Therefore, short fueling cycles are preferable—but notrequired—for producing plutonium usable in nuclear weapons.Since plutonium can be produced in this manner in existing tis-sion reactors, the International Atomic Energy Agency operates asafeguards program to assure that production and diversion of fis-sionable fuel would be detected, minimizing the possibility of covertproduction of nuclear weapons.

Resource Supplies

Much of fusion’s allure stems from the essen-tially unlimited supply of fuel. D-T fusion reactorswill require two elements—deuterium and lithium–for fueling. Deuterium will be used as fueldirectly in the reaction chamber and lithium willbe used in the blanket to breed tritium fuel. Ad-vanced fuel cycles discussed in chapter 4 that donot use tritium wouId not require lithium.

It appears that domestic supplies of fusionfuel will not constrain the development and useof fusion power. Deuterium contained in wateris readily extractable, with each gallon of waterhaving the energy equivalent of 300 gallons ofgasoline. This supply offers billions of years’ worthof energy at present consumption rates. Similarly,domestic lithium supplies probably offer thou-sands of years’ worth of fuel with vastly greaterquantities of lithium contained in the oceans. Al-though recovering lithium from seawater is notcurrently economical, it could be in the future;fuel costs are such a small part of the cost of fu-sion power that lithium could become manytimes more expensive without substantially affect-ing the cost of fusion electricity. According to astudy of fuel resources for fusion, it appears “un-likely that an absolute shortage of lithium couldconstrain the prospects of D-T fusion in any timeof practical interest.”24

Preliminary studies of the materials required tobuild fusion reactors also do not foresee any im-portant materials constraints, although the pre-liminary nature of fusion reactor designs makesfirm conclusions impossible. In 1983, Oak RidgeNational Laboratory conducted a study that esti-mated a “per reactor” materials demand froma set of fusion reactor design studies completedin the 1970s. These estimates were converted intoannual fusion demands by assuming that in thelong run, close to 40 fusion reactors would bebuilt per year.25

24w. Hafele, j. F. Hold ren, and G. L. Kulcinski, ‘‘The Problem of

Fuel Resources, ” Fusion and Fast Breeder Reactors (Laxenburg, Aus-tria: International Institute for Applied Systems Analysis, 1977), p. 32,

2jCannon, Background /nformat)on, op. cit., ch. 9. The study as-sumed a worldwide installed electric generating capacity of 1,500gigawatts, or about 2.4 times the 1986 U.S. installed capacity [givenby the North American Electrlc Reliability Council, “ 1986 Electri-city Supply and Demand, ” figure 8, p. 25]. Assuming this capacity

Ch. 5.—Fusion as an Energy Program “ 113

The study compared these estimates to non-fusion demand projections, based on U.S. Bureauof Mines estimates, which were extrapolated overa time span comparable to that assumed for thefusion estimates. The study also compared de-mand estimates to estimated world supplies.

The study did not find any materials for whichtotal fusion demands exceeded non-fusion de-mands. Therefore, in those cases for which totaldemand appeared to exceed available supplywhen projected over many decades, overall scar-city would not be due solely to fusion. TherewouId be ample motivation other than fusion foreither identifying substitutes or finding new sourcesof Supply. 26

At this stage of fusion reactor design, substitutescan be found for any of the materials that mightbe in short supply. However, replacing severalmaterials simultaneously, such as all those thatwouId be in short supply if foreign sources werenot available, would be much more difficult thanfinding substitutes for any one material. If re-source constraints affect fusion reactors, theywill concern materials for reactor constructionrather than fuel supply.

cost

Estimating the costs of fusion reactors that can-not yet be designed in detail is difficult. The taskis considerably complicated by the fact that eco-nomic projections, more than many other fea-tures discussed so far, depend critically on pa-rameters that can be little more than guessed at

to be supplied by generating stations averaging 1 gigawatt each andhaving an average l i fet ime of 40 years, an average of1,500+-40= 37.5 plants would have to be replaced per year. Thestudy assumed that all replacements would eventually be made withfusion reactors.

zGlbid, table 9.24, p. 9-36. Although fusion materials demand did

not constitute the majority of the total (fusion plus non-fusion) de-mand for any of the materials studied, fusion requirements con-stituted between 10 and 50 percent of the total demand for fwematerials: beryllium, lithium, helium, tungsten, and vanadium. Allof these except tungsten were found to be in ample supply.

Fusion demands were calculated from an ensemble of 10 dJffer-ent reactor designs. Such an ensemble represented a diversity ofreactor concepts, and using the ensemble kept the analysis frombeing too dependent on a single design. Any individual reactor de-sign, however, may have materials requirements significantly differ-ent from the ensemble average.

today. Many non-technical factors such as inter-est rates, construction time, and the licensing andregulatory process will have a profound and un-predictable impact on ultimate cost.

Fusion will be a capital-intensive technology.Existing system studies show that most of the costof electricity will come from building the power-plant. Costs for the deuterium and lithium re-quired to fuel fusion reactors will be a negligiblefraction of the total cost. More significant as aneffective “fuel” cost will be the expense of peri-odically replacing the blanket components asthey exceed their service lifetimes. Even includ-ing these replacements, however, total opera-tional and maintenance expense is projected toconstitute less than half of the total cost of fusion-generated electricity.27

In analyzing how the costs of fusion electricitydepend on various physics and technology pa-rameters, system designers can determine impor-tant cost drivers and identify high-payoff areas forfurther research. Because of overall uncertainties,however, the actual costs estimated in systemstudies are less dependable than their variationas design assumptions are changed. A NationalResearch Council report on fission/fusion hybridreactors 28 identifies many sources of uncertaintyin present cost estimates, including:

●

●

●

●

●

incomplete design information;limited understanding of the required fusiontechnologies, methods of fabrication, mate-rials, and support systems, including in par-ticular incomplete knowledge of the effectsof high-energy neutron irradiation;complex requirements for tritium recoveryand handling, and the need for remote han-dling and storage of large, radioactive com-ponents;the degree of containment facility that willbe required for the reactor and for associ-ated tritium handling systems;the approach taken towards licensing, in-cluding the need for in-service inspection,

27J. Sheffield, et al,, Cost Assessment of a Generic Magnetic Fu-sion Reactor, Oak Ridge National Laboratory, ORNL/TM-931 1,March 1986, table 1.2, p. 7.

28NatiOnal Re5earch council, ~u[/oO& (or ~he Fusjort Hybrid and

Tritiurn-Breedirtg Fusion Reactors (Washington, DC: National Acad-emy Press, 1987), p. 90.

●

●

seismic qualification, redundancy and di-versity;the costs of waste disposal and decommis-sioning; andthe life expectancies and failure modes ofplant components, which depend on thecombined effects of neutron irradiation,magnetic fields, high temperatures, and cor-rosion.

Existing information on the costs of fusion ex-perimental facilities does not necessarily providemuch guidance for estimating the future costsof commercial reactors. No experiment to datecomes close to integrating the various systemsthat would be required in an operating reactor.Many individuals argue that the proposed costsof future experimental facilities—an engineeringtest reactor, for example, which will cost at least$1 billion and very possibly several times thatmuch—do not bode well for inexpensive power-plants. However, experimental facilities and com-mercial devices have very different missions anddesign constraints.

A number of factors would tend to make com-mercial facilities less expensive than experimentaldevices that produce comparable amounts ofpower. Experiments are necessarily based on in-complete knowledge—otherwise there would beno need for them—and their designs must be con-servative to ensure that their objectives can befulfilled. Experiments must be flexible; they musthave the ability to operate under a wide rangeof conditions, since the operating parameters thatwill be of most interest for future commercial re-actors are not yet known. They must be exten-sively instrumented with diagnostic equipment,since their primary objective would be to pro-duce information, not electricity. The result of thisinformation and the experience with the technol-ogy acquired through the research program shouldmake it possible to reduce the cost of subsequentfacilities, including commercial ones.

On the other hand, a different set of factorswould tend to increase the cost of commercialfacilities over that of their experimental counter-parts. Expenses may be incurred in ensuring longlife, reliability, ease of maintenance, and ease ofoperation, qualities that are crucial for commer-


cial facilities but that may not be so importantfor experimental devices. Many of the design fea-tures and requirements introduced in the proc-ess of licensing, optimizing, and commercializ-ing fusion reactors will also tend to add to theexpense of commercial facilities. It is thereforevery difficuIt to draw conclusions about reactorcost from existing experience or from the cost ofproposed experiments.

ESECOM has conducted the most extensiveanalysis to date comparing costs of various fusiondesigns to one another and to fission reactors.In the ESECOM report, construction cost estimatesvaried by about a factor of 2 among the fusiondesigns, and the pure fission costs were similarto or below the low fusion estimates. “Cost-of-electricity’ estimates varied over a somewhatsmalIer range, and the fission designs again wereat the low end.

The lowest operating cost of any of the reactorsexamined by ESECOM was for the “best experi-ence” light-water reactor, representing the lowestcost fission reactors now operating. The highestoperating cost of all designs was for the “medianexperience’ light-water reactor, representing across-section of present light-water reactor experi-ence. Estimated operating costs for all the fusiondesigns fell in between these cases. Constructioncost (as opposed to operating cost) estimates var-ied similarly, with some of the pure fusion de-sign construction costs exceeding that of the “me-dian experience” light-water reactor.

One feature of fusion reactor design that couldsignificantly affect economics is its level of safetyassurance. The easier it is to demonstrate thesafety of a fusion reactor, the easier that reactorwill be to license and site. in particular, if thelicensing process does not depend on complexand controversial calculations concerning theperformance of active safety systems, it might pro-ceed more quickly and with greater consensus.If in turn the construction process were sped up,considerable cost savings could result.

Higher degrees of safety assurance could alsohave a more direct effect in reducing construc-tion cost. Because safe operation of commercialnuclear reactors today depends on active safetysystems, those systems must meet exacting quality

assurance standards. Components and systemsbuilt to meet these “nuclear-grade” standards areconsiderably more expensive than similar com-ponents in less critical applications. Since thesafety of reactor designs with higher levels ofsafety assurance would not be as dependent onparticular components or systems, fewer “nu-clear-grade” components would be required. TheESECOM report estimated that up to 30 percentof the “overnight” construction costs (e. g., thetotal cost if construction could be completed in-stantaneously, not including interest charges orinflation) could be avoided if nuclear-grade con-struction were not required. Such a decrease inconstruction cost would lower the cost of elec-tricity by about 25 percent. This savings is over-estimated in that no fusion system is likely to beable to avoid nuclear-grade construction entirely;tritium-handling systems, for example, will alwayshave the potential to release some radioactivityin the event of sufficient component failures.Nevertheless, the ability to relax constructionstandards through higher levels of safety assur-ance could lead to cost savings.

Possibly mitigating these cost savings is theprice of achieving increased safety assurance inthe first place. In the ESECOM report, the costsof the pure fusion designs (before any savings dueto safety assurance were taken into account)tended to be higher for those designs with higherlevels of safety assurance. The net effect of safetyassurance on reactor cost, therefore, depends onwhether savings can outweigh the price of addi-tional design constraints.

Future technological developments could alsodecrease the cost of fusion power. For example,the recent discovery of new superconducting ma-terials that do not require liquid helium temper-atures could affect fusion design and economicsif these materials can be used in fusion magnets.Cheaper magnets, by themselves, will not dra-matically alter the price of a fusion reactor. Evenif the magnets in the STARFIRE design were free,the total capital cost would only be reduced byabout 12 percent .29 However, if new magnet ca-pabilities in turn make possible the use of sign if-

‘9J. Sheffield, et al,, Cost Assessment ofa Generic Magrtetlc Fu-sion Reactor, op. cit., tables A,4. 1 and A.4.2, pp. 84-85,


icantly different designs—e.g., the use of substan-tially higher magnetic fields, which could easethe requirements on other systems or permit theuse of advanced fuels—then significantly differ-ent economic estimates might result. JO

If reactors running on advanced fuel cycleswere developed that had substantially lowerlevels of neutron irradiation, blanket componentswould not have to be changed as often, reduc-ing operating costs, However, in the case of theD -3He cycle, the costs of the actual fuel would

no longer be negligible due to the expense ofgenerating or recovering 3He, which is not foundin nature. Capital cost for the fusion core of a re-actor using advanced fuels might be higher than

lopossible appl icatic3ns of high field superconducting magnets to

fusion reactor design are discussed in Tokarnak Reactor ConceptsUsing High Temperature, High Field Superconductors, by D.R.Cohn, et al., Massachusetts Institute of Technology Plasma FusionCenter, PFC/RR-87-5, Apr. 14, 1987.

that of a D-T reactor since the advanced reactortechnology would be considerably more chal-lenging. On the other hand, if an advanced re-actor were able to generate electricity directly,without the use of steam generators and turbines,it might be able to bypass some of the balance-of-plant costs.

Given all the uncertainties, OTA finds that theeconomic evidence to date concerning fusion’scost-effectiveness is inconclusive. No factors yetidentified in the fusion research program conclu-sively demonstrate that fusion will be either muchmore or much less expensive than possible com-petitors, including nuclear fission. Fusion appearsto have the potential to be economically com-petitive, but making reliable cost comparisons willrequire additional technical research and a bet-ter understanding of non-technical factors, suchas ease of licensing and construction, that canhave a profound influence on the bottom line.

THE SUPPLY OF AND DEMAND FOR FUSION POWER

The factors that influence how successfully fu-sion technology will serve as a source of energyinclude how well fusion’s characteristics meet therequirements of potential customers and howwell fusion compares to alternate electricity-gen-erating technologies. How well fusion will meetthe needs of its users, primarily electric utilities,depends in turn both on when it can becomecommercially available and on what its userswant. These issues are discussed first below. Nextis a brief summary of competing energy supplytechnologies that provides some context for fu-sion power. Finally, the implications of estimatesof future electricity demand are analyzed.

The Availability of Fusion Power

Financial resources permitting, the researchprogram outlined by the Technical Planning Ac-tivity (TPA)31 and described in chapter 4 is tar-

llThe TeChniCal plarln~ng Activity was a fusion communitywideeffort to identify the technical issues, tasks, and milestones that char-acterize the remaining fusion research effort. Its primary output wasTechnical Planning Activity: Final Repofl, prepared by the ArgonneNational Laboratory, Fusion Power Program, for the U.S. Depart-

geted toward enabling a decision on fusion’soverall potential to be made by 2005. Accord-ing to TPA, if the decision is made to proceedwith fusion at that time, an “Integrated FusionFacility” (IFF) based on “commercially relevantfusion technology” could be built that wouldmark the “beginning of the commercializationphase of fusion.”32 TPA did not specify the na-ture of the IFF. It could be a demonstration orprototype reactor, although the IFF parametersTPA presented in an example show it to be wellshort of commercial performance (see ch. 4, foot-note 28). Thus, the technical steps that might fol-low the research phase, in terms of the neces-sary facilities that would lead to a prototypecommercial fusion reactor, have not yet been de-termined.

The institutional process by which any dem-onstration fusion reactor might be built and oper-ated is also highly uncertain. Under present Fed-

ment of Energy, Office of Energy Research, AN L/FPP-87- 1, Janu-ary 1987. The Technical Planning Activity is described in the sec-tion of ch. 4 titled “The Technical Planning Activity. ”

lzTechnica/ planning Activity: Final Report, op. c!t., PP. ~ and 26.


eral policy, building and operating a demonstrationreactor is the responsibility of the private sector,which has certainly proven capable of demon-strating major new technologies in the past. How-ever, involving the private sector in an effort ofthis scale may not be straightforward. Accordingto one utility executive:

. . . there is a certain level of concern for theenormous gap in perception that exists betweenindustry and government concerning private sec-tor commercialization. It may be unrealistic to as-sume that once a scientific and related technol-ogy data base is established in the program, thestage will be set for private sector commerciali-zation of attractive fusion energy sources.33

Unless the Federal Government becomes re-sponsible for owning and operating fusion gen-erating stations—a change whose ramificationswould extend far beyond fusion’s development—some mechanism for easing the transition fromgovernment to private responsibility will be re-quired. 34

The timing of the commercialization processis difficult to predict for both technical and in-stitutional reasons. Conceivably, if the researchprogram provides the information necessary todesign and build a reactor prototype, such a de-vice couId be started early in the next century.After several years of construction and severalmore years of qualification and operation, a baseof operating experience could be acquired thatwouId be sufficient for the design and construc-tion of subsequent reactors. If the regulatory andlicensing processes proceeded concurrently, ven-dors could begin to consider the manufactureand sale, and utilities could consider the pur-chase, of commercial fusion reactors midwaythrough the first half of the next century.

The subsequent penetration of fusion reactorsinto the energy market wouId take time because

~jKenneth L. Matson, Vice President, PSE&G [Public Service Elec-

tric & Gas Co.] Research Corp., Newark, NJ; quoted in “Panel Dis-cussion on Industry and Utility Perspectives on Future Directionsin Fusion Energy Development, ” Journa/ of Fusion Energy, vol. 5,No. 2, June 1986, pp. 144-145. This issue of the Journa/ of FusiorIEnergy presents an edited transcript of a symposium sponsored byFusion Power Associates titled “The Search for Attractive FusionConcepts. ”

jqFor more discussion of the role of the private sector in fUsiOn’s

development, see the section in ch. 6 on “Private Industry. ”

existing electrical generating capacity will not bereplaced overnight. If early fusion plants can bebuilt and operated without undue delays or sur-prises, they may begin to develop a satisfactorytrack record that will stimulate further construc-tion; if early plants show unfavorable operatingexperience, commercialization will be delayed.At any rate, it will take decades from their firstsuccessful demonstration for fusion reactors togenerate a considerable fraction of the Nation’selectricity. Even under the most favorable cir-cumstances it does not appear likely that fusionwill be able to satisfy a significant fraction ofthe Nation’s electricity demand before the mid-dle of the 21st century.

The Desirability of Fusion Power

Ultimately, fusion’s commercial potential willbe determined by its ability to meet societal needsmore effectively than its alternatives. This deter-mination will be made by the eventual purchasersof fusion technology, most likely electric utilities.However, given the long-term nature of the fu-sion program, it is difficult to predict what char-acteristics will be important to future customers.The best that can be done is to identify those at-tributes that are important to utilities today, rec-ognizing that utilities and their requirements mayevolve with time.

Certainly one of the most important factors willbe the capital cost of fusion plants and the costof fusion-generated electricity. Although fusionmay be economically competitive with otherenergy technologies, it is not likely to be substan-tially less expensive. Nevertheless, without ademonstrable economic advantage, it might bedifficult to convince potential purchasers to risksubstantial investments in what wouId be an un-known and unproven technology.

Even if fusion cannot beat its competitors eco-nomically, it still may be judged preferable onenvironmental, safety, and resource securitygrounds. If the potential of fusion technology inthese areas is achieved, and if these attributes areimportant enough to compensate for an eco-nomic penalty, explicit policy decisions could bemade to promote fusion through legislation orregulation. Barring such direct intervention, how-


ever, the primary determinant of fusion’s marketpenetration probably will be cost.

In addition to purely economic factors, a num-ber of additional factors–most of them indirectlyinfluencing the cost of energy—are also impor-tant to present utilities. The Electric Power Re-search Institute (EPRI) surveyed a number of elec-tric utilities in 1981 to determine how importantfactors other than the cost of energy would beto their acceptance of fusion. The results of thesurvey are shown in table 5-2.

EPRI found that utilities identified four factorsas “vital” and ten as “very important” for futurefusion reactors. Although it is too early to evalu-ate how well fusion will be able to satisfy theserequirements, the potential of the technology i n

Table 5-2.—Utility Requirements Summary(in addition to cost of energy)

Requirement Weighting

A. Utility planning and finance1. Plant capital cost ., Vital2. Plant O&Ma and fuel cost Important3. Outage rates Very important4 . P l a n t l i f e Important5 . P l a n t c o n s t r u c t i o n t i m e Very important6. Financial liability , . . Vital7. Unit rating ~ ~ Moderately important

B. Safety, siting, and licensing1 , P l a n t s a f e t y Vital2. Flexibility of siting ~ ~ Very important3. Waste handl ing and disposal .Very important4. Decommissioning ., Important5. Licensability. Vital6. Weapons proliferation Important

C. Utility operations1. Plant operating requirements Very important2. Plant maintenance requirements Very important3. Electrical performance . Very important4. Capability for load change Moderately important5. Part load efficiency . . Moderately important6. Minimum load . . . Moderately important7. Startup power requirements Important

D. Manufacturing and resources1, Hardware materials availability Very Important2. Industrial base. . . . . Very Important3. Fuel and fertile material availability Very important

Order of significance1. Vital2. Very important3. Important4. Moderately important

No factors were judged ‘‘slightly important’; factors judged‘‘unimportant’ have been deleted from the list. )

aOperations and maintenance

SOURCE Electric Power Research Institute Utility Requirements for Fusion EPRI AP-2254 February1982 table 2-1 p 2-3

some areas can be noted. For example, success-fully designing fusion reactors with high levels ofsafety assurance could satisfy plant safety require-ments, lessen f inancial l iabil ity 3 5, and improveplant licensability. In addition, if fusion reactorscould be convincingly demonstrated to be safe,siting flexibility might be increased; reactors couldbe located close to population centers on sitesthat would not be considered for fission reactors.

potential advantages for fusion reactors alsoemerge with respect to other utility requirements.Due to its virtually limitless fuel supply, fusionshould be able to satisfy the fuel availability cri-teria. Moreover, it appears that the waste han-

dling and disposal should be better addressed byfusion than by fission.

A number of uncertainties remain for other fac-tors of importance to utilities. At present, thereis virtually no industrial base for fusion, althoughexisting fission, aerospace, and materials indus-tries all have capabilities relevant to fusion’sneeds. Developing fusion’s industrial base is es-sential if the commercialization process is to suc-ceed. Moreover, due to uncertainties in eco-nomic studies, how well fusion will be able tominimize plant capital cost cannot yet be deter-mined. In addition to affecting the cost of energythrough life-cycle capital amortization, large cap-ital expenditures can complicate corporate finan-cial management in areas such as debt-to-equityratios and capital flexibility. It is clear that fusionreactors will be capital-intensive, but at this stageof development their costs cannot be accuratelydetermined.

Hardware availabil i ty, which measu res thecost, scarcity, and supply dependability of ma-terials required for plant construction, cannot bedetermined at this stage of design. Factors suchas outage ra tes, p lant const ruct ion t imes, p lant

o p e r a t i n g r e q u i r e m e n t s , p l a n t m a i n t e n a n c e r e -

q u i r e m e n t s , a n d e l e c t r i c a l p e r f o r m a n c e , a l s oviewed as very important by utilities, probablycannot be evaluated until fusion reactors are wellinto the commercialization process. Experience

JJFinancial Ilability measures the maximum potential flnanClal

losses due to death, injury, property damage, loss of revenue, andother costs in the event of an accident.


with construction, operation, and maintenanceof the reactors will be necessary to fully under-stand these aspects of fusion technology.

A factor that is interesting due to its relativelylow weighting is unit rating, or the electrical ca-pacity of a particular generating station. In theearly 1970s, fusion reactor conceptual designshad electrical outputs considerably higher thanthose of existing generating stations. Subsequentdesigns have lowered electrical capacities to1,000 megawatts of electricity or less, more in linewith existing stations; some recent studies haveeven considered fusion plants generating as lit-tle as 300 megawatts of electricity, although ata higher projected cost of electricity.36 Now thatfusion reactor designs are sized within the rangeof utility experience—together with the relativeunimportance of this parameter —fusion reactorsshould have little trouble meeting unit rating re-quirements.

Comparisons of Long-Term ElectricityGenerating Technologies

This section summarizes the long-range poten-tial of various electricity generating technologiesin the 21st century and discusses possible prob-lems associated with their use and/or further de-velopment. A detailed examination of the char-acteristics of these energy technologies, however,is beyond the scope of this report .1’

The role of demand modification, such as con-servation and improvement in the efficiency ofenergy use, is critical in determining future energyrequirements. However, as shown in the follow-ing section on “Fusion’s Energy Context, ” thelevel of electricity demand does not strongly af-fect the relative demand for fusion power com-

Jbone study presenting cost of electricity as a fu nCtiOn Of electri-cal output is J. Sheffield, et al., Cost Assessment ofa Generic Mag-netic Fusion Reactor, op. cit., figure 4.17, p. 48.

Jzselected OTA studies that have examined other energy tech-nologies i n more detail include New .E/ectric Power Technologies:Problems and Prospects i’or the 1990s, OTA-E-246 (Washington,DC: U.S. Government Printing Office, July 1985); Nuc/ear Powerin an Age of Uncertainty, OTA-E-216 (Washington, DC: U.S. Gov-ernment Printing Office, February 1984); and /ndustria/ and Com-rnercia/ Cogeneration, OTA-E-192 (Springfield, VA: National Tech-nical Information Service, February 1983).

pared to its alternatives. Therefore, improved effi-ciency of energy use is not specifically discussedhere as a generating technology.

Fossil Fuel Technologies

Coal.–Coal is the most abundant energy sourcein the United States and is currently used to gen-erate over half of the Nation’s electricity .38 Ac-cording to the Energy Research Advisory Board:

Coal supply for the 1985-2020 period does notseem to require any special attention at this time. . . It has been the conventional wisdom that theU.S. coal resource base is of such magnitude thatit can be safely relied upon to supply any demandfor the foreseeable future. This would be trueeven if nuclear generation does not grow and ifa major demand for coal-based synthetics shouldarise,39

Many coal technologies are highly developedand well understood, and they are economicallyattractive. Proven domestic reserves of coal areadequate to maintain present rates of use for sev-eral hundred years. However, there are seriousenvironmental impacts associated with or antic-ipated from the combustion of coal. Mitigatingthese adverse environmental impacts increasesthe cost of coal combustion and may reduce theefficiency of conversion to electricity. Further-more, coal combustion inherently produces car-bon dioxide gas, which may affect world climateand make the use of coal undesirable.

The main near-term problem associated withthe use of coal appears to be emissions of com-bustion byproducts such as sulfur and nitrogenoxides and particulate. These emissions are amajor contributing factor to acid deposition, alsocalled “acid rain. ” Air pollution from coal andother fossil fuel combustion can harm natural

jBln 1985, coal generated 1,401 billion of the 2,469 billion

kilowatt-hours of electricity generated in the United States, accord-ing to Annua/ Energy Review 1985, published by the U.S. Depart-ment of Energy, Energy Information Administration, DOE/EIA-0384(85), table 81, p. 185.

jqEnergy Research Advisory Board, “Appendix D: Coal Researchand Development, ” by Eric H. Reichl, Cuide/ines for DOf LongTerm Civilian Research and Development, vol. VI( Report of ERABSupply Subpanel, Long-Range Energy Research and DevelopmentStrategy Study, A Report of the Energy Research Advisory Boardto the U.S. Department of Energy, DOE/S-9944, December 1985,p. 65.


ecosystems, damage economically important ma-terials, impair visibility, and may affect humanhealth.@

The near-term environmental problems asso-ciated with coal and fossil fuel combustion,though serious, can be controlled. The releaseof combustion byproducts can be mitigated byusing cleaner fuels, attaining more complete com-bustion, or cleaning (“scrubbing”) the combus-tion exhaust. Several technologies to reduce un-desirable combustion byproducts are currentlyavailable, and more are being developed.41 Suchpollution abatement systems make coal-firedelectricity somewhat more expensive, but theydo not eliminate coal as a major source of futureelectricity supply. With the exception of carbondioxide buildup, discussed below, issues con-cerning the environmental acceptability of coalcombustion are resolvable by burning cleanerfuels or by using “clean coal” technologies.

Oil and Gas.–Oil and gas today generate sub-stantially less electricity in the United States thancoal. 42 The domestic resource bases for oil andgas are considerably smaller than coal’s, and forthis reason oil and gas technologies are not gen-erally included in discussions of long-range elec-tricity supply over the periods in which fusionmay make a major contribution.

In the nearer term, however, these fuels—par-ticularly gas—may have an increasing role in elec-tricity generation and may very well form part ofthe mix of generating technologies at the time thatfusion reactors are first introduced. Advanced gasturbines now under development may be highlyefficient sources of electricity emitting far lesscombustion byproducts than current coal plants.Furthermore, such turbines would produce onlyabout one-third as much carbon dioxide per kilo-watt-hour as a coal generation plant, reducing(but not eliminating) carbon dioxide emissions

40u .s. Congres5, Office of Technology Assessment, Ac;d Rain andTranspotied Air Pollutants: Implications for Public Policy, OTA-O-204 (Washington, DC: U.S. Government Printing Office, June 1984),pp. 9-13.

41 Ibid., Appendix A.z: “control Technologies for Reducing SUI -

fur and Nitrogen Oxide Emissions, ” p, 152.AZTotal use of oil and gas, however, including uses other than

electricity generation, is greater than that of coal.

as well.43 Near-term electricity generating tech-nologies are discussed in a separate OTA assess-ment .44

Carbon Dioxide Buildup.–Carbon dioxide(C02) is formed as a byproduct of the combus-tion of fossil fuels–coal, oil, and gas. in the pastseveral decades, the amount of CO2 in the atmos-phere has increased about 10 percent, largely asa result of fossil fuel combustion. Atmosphericcarbon dioxide gas can trap some of the heat radi-ated from the earth instead of allowing it to es-cape into space. Therefore, the buildup of C02

is associated with a global warming effect, some-times called the “greenhouse effect. ”

Increased use of fossil fuels is only one poten-tial contributor to global warming. Other gasesreleased into the atmosphere, such as methane,nitrous oxide, and chlorofluorocarbons, havesimilar heat-retaining properties and may, in ag-gregate, contribute as much as C02 to globalwarming. Moreover, the connection between fos-sil fuel use and global warming is influenced byfactors such as the production and use of CO,by green plants, its absorption by the oceans, andvegetative decomposition. Global warming is po-tentially a very serious problem, and the con-sensus within the scientific community studyingthe issue is that such a warming appears inevita-ble if emission of C02 and other “greenhousegases” continues to increase. However, there isno certainty to date about the timing and mag-nitude of the effect, nor about what its climaticimplications might be.

The use of fossil fuels will always produce CO2;there is no way to eliminate C02 as a productof the combustion process. As noted above, how-ever, different fossil fuels and combustion tech-nologies produce different amounts of CO2 perunit of generated energy. Techniques to capturethe C02 from fossil fuel combustion emissionshave been proposed, but they are generally con-sidered to be impractical for either economic ortechnological reasons. Neither is there a practi-cal way to recover C02 and other greenhouse

qJPa~ of the reduction IS due to the higher etficlency Of these

turbines; part is due to the lower carbon content of the fuel.AANew E/ectric power Technologies: Problems and Prospect> for

the 1990s, op. cit., chs. 4 and 5.


gases that are already in the atmosphere. The onlyway to reduce CO 2 emissions from fossil fuelcombustion is to curtail the combustion of fossilfuels.

Limiting the use of fossil fuels will not be easy.The simplest way, up to a point, would be to in-crease the efficiency of energy use, lessening thegrowth of energy demand. Displacing fossil fuelusage with other energy technologies will bemore difficult. Coal will continue to be a majorsource of electricity for the early 21st century, anddeemphasizing its use would foreclose a substan-tial resource base. Oil and gas currently gener-ate more C02 annually than coal due to theirheavier use; much of their use is in decentralizedapplications such as transportation and spaceheating where they will be difficult and expen-sive to replace.

Without government intervention, technologiesdeveloped to reduce fossil fuel usage must beeconomically preferable to succeed. BecauseC O2 buildup would be a global problem, fossilfuel combustion would have to be reduced ona global scale. It is not clear that developing na-tions would be willing or able to shift from fossilfuels to other energy sources if doing so wouldimpose serious economic hardship. Furthermore,those regions of the world that might benefit fromCO2-induced climatic change would have no in-centive to reduce CO2 emissions unless they wereotherwise compensated.

Possible global warming due to carbon dioxidebuildup is a complex problem with a number ofcontributing causes. It provides an incentive todevelop new technologies that can substitute foror otherwise curtail the use of fossil fuels. How-ever, the degree to which these new technologiesreduce fossil fuel use will depend heavily on theireconomic advantages, and any reductions theycontribute to fossil fuel use will occur gradually.

Nuclear Fission Technologies

Nuclear fission currently appears to be the mainalternative to the widespread future use of coal.The technology is well developed and relativelywell understood, and it is supported by a sub-stantial research and development infrastructure.In 1985, 95 nuclear powerplants produced 16

percent of U.S. electricity supply,45 and nuclearpower is likely to remain the second largestsource of domestic electricity generation (aftercoal) into the 21st century. Nuclear fission maybecome a more important source of electricityif CO2 or other environmental problems requireconstraint of coal combustion. The main impedi-ments to increased use of nuclear fission appearto be its unfavorable economics and concernabout health and safety. I n the long run, manydecades from now, fuel constraints may affect thepotential of nuclear fission unless more efficienttechnology, fuel reprocessing, or fuel breedingis instituted.

Public Acceptance.–The long-term feasibilityof nuclear fission technologies will require reso-lution of health and safety concerns. Nuclearpower is currently the target of widespread oppo-sition for several reasons. Members of the publicfeel that mechanisms to dispose of radioactivewastes are inadequate to prevent the uItimate re-lease of dangerous radioactive effluents. More-over, there is concern about the safety of nuclearreactors, particularly in the aftermath of the ThreeMile Island (U. S.) and Chernobyl (U. S. S. R.) ac-cidents. The potential for mechanical failure andoperator error casts doubt on the integrity of re-actor safety systems.

Economics.–The economics of nuclear powerare currently uncertain for several reasons, notall of which are related to characteristics of thetechnology. The technology is complex and de-mands strict quality control; nuclear plant con-struction requires longer lead times and greatercapital investment than coal plants. Changing reg-ulations, inadequate management at some plants,and time-consuming litigation add to its cost. Thecombination of these factors with the soaring in-terest rates of the late 1970s resulted in costsmuch higher than expected. Although someplants–even in recent years–have been built onschedule and within budget, the more commonexperience has been so traumatic that utilities willcontinue to be extremely cautious about under-taking new nuclear construction. Furthermore,large-scale plants–the only type available atpresent for nuclear fission–are unattractive in the

122 . Starpower: The U.S. and the lnternational Quest for Fusion Energy

situation of uncertain demand growth that utili-ties now face. Smaller scale, modular plants thattrack load growth more flexibly are preferred inthese circumstances.

Fuel.–The light-water reactor technology cur-rently used in fission reactors is capable of ex-tracting only a small fraction of the energy po-tentially available from uranium fuel rods. In the“once-through” fuel cycle currently in use, thefuel rods are withdrawn from the reactor andstored or disposed of once they become unusable.With greatly expanded use of fission reactors ofthis type, the demand for uranium would increaseand the supply of inexpensive uranium wouldeventually be depleted. At some point, the priceof uranium would rise high enough to make light-water reactor technology economically prohibi-tive, although current projections indicate thatsuch a point is not likely to be reached beforethe middle of the next century. Advanced con-vertor reactors, which extract much more energyfrom the uranium fuel, are being developed andcould extend uranium supply still further.

If the price of uranium rises too high for evenadvanced convertor reactors to be economicalon a once-through fuel cycle, other fuel cyclesmay be possible. These fuel cycles are sufficientto give fission technology a very long-term re-source base. However, since these cycles involvethe production, separation, and transportation offissionable fuel, they could increase the risk ofnuclear proliferation over that of a once-throughfission economy. (See the discussion of “NuclearProliferation Potential” earlier in this chapter).

Research and Development.– It does not ap-pear that nuclear fission technology is unusableor necessarily uneconomical. Extensive researchis currently directed at developing advanced fis-sion reactors that will be more acceptable to thepublic and more attractive to utilities; the intentof this research is to demonstrate that future nu-clear fission reactors with very different charac-teristics than current plants can be a viable sourceof electricity. in particular, the nuclear industryis attempting to develop passively safe reactorsthat could not release large amounts of radioac-tivity due to operator error or mechanical mal-

function. 46 Research and development are alsofocusing on making modular reactor systems,which could be constructed with shorter lead-times and less financial risk to the utilities, andon developing systems that use fuel more effi-ciently.

The nuclear industry appears to have the po-tential to develop a superior advanced reactor,and a number of designs for such powerplantsexist. However, it is less certain that public con-fidence in the nuclear industry will improve sig-nificantly, particularly in the near term. Withoutrestoring public confidence, the long-term nu-clear option may be unattainable.

Renewable Energy Technologies

In addition to coal-fired and nuclear fissionpowerplants, there are several renewable energytechnologies. Two well-developed renewabletechnologies currently contribute significantly toworld energy supply: hydroelectric power andconventional biomass (wood), although only theformer is used significantly to generate electricity,Several other technologies, such as wind, uncon-ventional biofuels, solar photovoltaics, geother-mal, solar thermal, and ocean energy, may offersignificant contributions during the 21st century.47

Renewable energy sources are attractive be-cause many of them do not require constructionof large facilities for optimal economic operationand because their fuel supplies are continuallyreplenished. Other attractive features of some,but not all, of these technologies, according toan OTA report, “include fewer siting and regu-latory barriers, reduced environmental impact,and increased fuel flexibility and diversity.”48

qbsuch designs have been called “inherently safe. ’ However, in-

herent safety in this sense differs from the usage adopted by theESECOM report and discussed earlier in this chapter in the sectionon “Risk and Severity of Accident” under “Characteristics of Fu-sion Electric Generating Station s.” The ESECOM report found thatpassively safe fission reactors–although having greater safety as-surance than existing nuclear plants—would not attain the highestlevels of safety assurance, including the level ESECOM labeled “in-herent safety. ”

47 Energy Research Advisory Board, “Appendix D,” op. cit., P. 11.daNew Electric Power Technologies, Op. cit., P. 19.


Problems associated with renewable energysources, however, may limit their role as majorsources of electricity. Few of the technologies arecurrently economically competitive in other thanhighly specialized applications. Many renewableresources are only available intermittently, andtheir availability depends on factors like theweather and the time of day. Moreover, the avail-ability of renewable technologies depends ongeography and climate. The average amount ofavaiIable solar energy varies significantly acrossthe United States, largely as a result of differingweather conditions. Wind energy is most effec-tively recovered in California and Hawaii. Finally,most renewable energy sources are diffuse, re-quiring central-station powerplants to occupymore land than those using technologies such ascoal and fission. On the other hand, the diffusenature of renewable also makes them well-suitedfor decentralized applications, which may offsetthe need for large centralized facilities.

In general, both technical and economic im-provements are needed to make renewableenergy technologies competitive i n the 21st cen-tury. Research is being conducted on a wide va-riety of approaches for harnessing these energysources, and significant improvements are likely.Nevertheless, it is not expected that renewabletechnologies will eliminate the need for central-station generating technologies such as coal andnuclear fission.

Nuclear Fusion Technology

Unlike the other supply options, nuclear fusionis still in a pre-development stage. Much of thetechnology required for generating electricityfrom magnetic fusion has not been demonstrated,and the commercial potential of fusion cannotyet be determined.

Nuclear fusion appears to have attractive fea-tures. First, it could have significant environ-mental advantages with respect to other central-station generating technologies. The fusion proc-ess does not produce CO2, nor—with appropri-ate choice of materials—does it appear that radio-active waste will be as high-level or as biologicallyhazardous as waste produced by nuclear fission.

Second, it appears possible to design fusion re-actors that will not depend on active safety sys-tems to prevent serious accidents; such reactorscould have a higher degree of safety assurancethan fission reactors. Finally, high levels of safetyassurance, environmental advantages, and inde-pendence from geographical constraints couldmake siting a nuclear fusion powerplant consider-ably easier than siting a plant based on anotherenergy technology.

The ultimate feasibility of nuclear fusion willnot be known until the technology is developedand can be compared with the other energy op-tions that exist at that time. At this point, it is onlypossible to make projections based on the char-acteristics of the technology and the research nec-essary to overcome problems identified to date.

Table 5-3 compares various future electricitysupply options, based on extrapolations of cur-rent technologies. On this basis, magnetic fusionhas the potential to be a very attractive energysource. Obviously, unanticipated developmentsin any of the technologies described in this ta-ble could significantly alter their future role.

Fusion’s Energy Context

The anticipated need for energy over the periodin which fusion wouId undergo commercializa-tion will influence the urgency of fusion researchand the pace of its entry into the energy supplymarketplace. OTA convened a workshop in No-vember 1986 to examine the factors that woulddetermine demand for electricity in general andfusion in particular. Several points became clearduring the discussion:49

● The overall size and composition of elec-tricity demand, by itself, should neither re-quire nor eliminate fusion as a supply op-tion. Economics and acceptability, ratherthan total demand, will determine the mixof energy technologies. If fusion technologyis preferable to its alternatives, it will be used

AqFusion Energy Context Workshop, Office of “[ethnology Assess-ment, Washington, DC, Nov. 20, 1986. A list of participants is givenat the front of this report.


Table 5-3.—Comparison of Prospective Long-Range Electricity Supply Options

Energy source Advantages Disadvantages and research needs

Coal ●

Oil and gas ●

●

●

Fission ●

●

●

●

R e n e w a b l e “●

●

●

Fusion

●

●

PlentifulTechnology exists todaySafe

Technology exists todayFewer combustion byproducts emitted thancoalLess CO2 emitted per unit energy than coal

PlentifulNo emission of CO2

No emission of combustion byproductsTechnology exists today

Unlimited fuel supplyNo net CO2 emissionTechnologically simpleModular design

Unlimited fuel supplyPotential for higher degree of safety assur-ance than fissionNo CO2 production or combustionbyproduct emissionSubstantially less hazardous nuclear waste

●

●

●

●

●

●

●

●

●

●

●

●

Near-term environmental implications require de-velopment of “clean coal technologies” or fuel sub-stitutions that may increase the cost of energyC O2 buildup may make increased dependence on fos-sil fuels undesirable

Questionable long-term resource baseDoes not avoid CO2 emission

Unfavorable economics and safety concerns suggestdevelopment of advanced reactor designs that aresmaller and passively safeNuclear waste disposal not yet resolvedPublic confidence must be improved and may or maynot result from technical improvements

Uncertain economics and technical problems requiremore R&DIntermittence and diffuseness may make renewableinadequate substitute for central-station power gener-ation in arbitrary locations

Significant R&D effort required to establish technicalfeasibilityEnvironmental and safety potential highly dependenton design, especially on materials choiceEconomic potential unknown

than fission”SOURCE” Office of Technology Assessment, 1987.

●

to replace retired generating capacity evenif overall demand is low. If fusion proves in-ferior to its competitors, it may not be usedeven at very high demand levels. Fuel sup-plies for both coal and nuclear fission areadequate to meet high levels of demand forat least a few hundred years without fusion.However, late in the next century, fissionmay require the use of breeder reactors.

Should fusion technology prove favorable,rapid growth in demand would facilitate itsintroduction because the opportunities fornew powerplant construction would begreater. Nevertheless, demand alone cannotturn an unattractive technology into an at-tractive one.It is unlikely that any one technology willtake over the electricity supply market, bar-ring major difficulties with the others. Atpresent, a number of supply technologieshave roughly equivalent marginal costs ofproduction, and all participate in the supplymix.

● Given that technologies such as coal com-bustion and nuclear fission are alreadycommercialized, fusion will have to provebetter-not only comparable—before it canstart to displace them. The criteria on whichfusion will be judged include economic,safety and environmental issues as well asresource security. Advantages in one areamay, but will not necessarily, compensatefor shortcomings in another.

● Potential problems with the major technol-ogies currently viewed as supplying electri-city in the future provide incentives to de-velop alternate energy technologies and/orsubstantially improve the efficiency of en-ergy use. Considerable expansion of coal usemay prove undesirable due to the “green-house effect”; safety or proliferation con-cerns may similarly impair expansion of thenuclear fission option. Over the long run, fu-sion could provide a substitute for thesetechnologies. The urgency for developing fu-sion, therefore, depends on assumptions of


the likelihood that existing energy technol-ogies will prove undesirable in the future.

● There is little to be gained and a great dealto be lost if fusion is prematurely intro-duced without attaining its potential eco-nomic, environmental, and safety capabil-ities. Even in a situation where problemswith other energy technologies urgently callfor development of an alternative source ofsupply, that alternative must be preferablein order to be accepted. It would be unwiseto emphasize one fusion feature—economicsor safety or environmental advantages—overthe others before we know which aspect willbe most important for fusion’s eventualacceptance.

● New energy technologies take a long timeto develop and gain wide use. It currentlyappears that it will be many decades beforefusion will be able to supply a significant frac-tion of U.S. electricity even under optimis-tic assumptions concerning its technologicaldevelopment.

With respect to global energy demand, in par-ticular, as a motivation for fusion, workshop par-ticipants discussed various estimates of futureenergy demand. Models attempting to chart theevolution of global energy demand over manydecades have been developed in the last fewyears. Because the time periods of interest aremuch too long for projections of recent experi-ence to be valid, these models must instead simu-late the future world economy and use of energy.These models start with a number of assumptionsconcerning world economic and populationgrowth; the relationship between economicgrowth, technological development, and energyuse; and the resource bases and costs of variousenergy technologies. The models calculate theevolution of those parameters assumed to be de-terminants of energy use and then determinedesired outputs such as the supply and price ofvarious types of energy.

These models are most useful for parametricanalysis: What might be the consequences ofsome set of actions? Which parameters appearto be the most sensitive determinants of futuredemand? The models are, however, much lessable to project future behavior in any absolute

sense. They are inherently simplified, and evenif they accurately reflect the behavior of the sys-tem they represent, the input data they act onare in many cases highly uncertain.

A recent review of a number of world energymodels discusses their respective methodologiesand compares some of their results, finding thatthere is more than an order of magnitude varia-tion in their respective estimates for energy de-mand in the year 2050 (figure 5-3).50 The variationresuIts largely from differing input assumptions,as is shown by the fact that, for several of themodels, a number of different projections areplotted based on different assumptions or differ-ent sets of input data. Nevertheless, unless it isknown which assumptions are correct, even amodel known to be valid cannot produce validpredictions.

The relative contributions of different forms ofenergy supply are no better determined than thetotal energy demands calculated by these models.The costs of different supply technologies can-not be known over the periods of interest andmust be assumed. The mix of supply technologiescomputed by these models therefore dependsprimarily on the corresponding input assump-tions. Furthermore, a detailed sensitivity analy-sis using one global energy model shows thatoverall energy consumption figures appear to bemuch more sensitive to parameters relating todemand–e.g., relative rates of economic devel-opment and productivity growth-than to param-eters describing supply technologies and costs. 5

1

This finding further reinforces the conclusionthat predictions of future energy use provide lit-tle information about the demand for any par-ticular supply technology. The urgency for de-veloping fusion technology, therefore, dependson one’s assumptions as to the likelihood thatexisting sources of energy supply cannot becounted on in the future. Little justification canbe provided from demand estimates alone.

SoBill Keepin, “Review of Global Energy and Carbon DIo\Kle l+)-

jections, ” Annua/ Review of Energy, Jack Hollander, I+art m Brooks,and David Stern llght (eds. ), vol. 11 (Palo Alto, CA: Annual Rejleih<Inc., 1986), p. 357.

5 I j .M. Rei I!y, j .A. Ed mods, R. H. Gardner, and A. L. B ren ken, ‘‘~’ n-

certalnty Analysis ot the I EA/ORAU CO1 Emlsslons Model ‘‘ Energ}f)ourna/, vol. 8, No. 3, July 1987, pp. 1-30.

126 ● Starpower: The U.S. and the /international Quest for Fusion Energy

Figure 5-3.—Projections of Global Primary EnergyConsumption to 2050

Edmonds 85 (z 95th)

55 NY (high). • • Edmonds 84 (high)

50

o :!:.. 40 c:: o ~ E 35 ::J IJ:l c::

8 30 >-e> Q)

tfi 25 ~ to

.§ 20 a. C:;j .c o 15 B

10

I~U 2UUU 2020 2040

Year '~T: IIA;:'A: International Institute for Applied Systems Analysis, Energy

in a Finite World: A Global Systems Analysis (Cambridge, MA: Ballinger, 1981).

_OVtns: Lovins, A.B., Lovins, LH., Krause, F., and Bach, W., Least Cost Energy: Solving the CO. Problem (Andover, MA: Brick House, 1982).

rvt:v ..vorld Energy Conference, Energy 2O(J()-2020: World Prospects gnd Regions Stresses, J.R Frisch (ed.), World Energy Con· ference Conservation Commission (London: Graham & Trot· 'TIan, 1983).

~ T: Nordhaus, W.O., and Yohe, G., "Future Paths of Energy and :;arbon Dioxide Emissions, Changing Climate (Washington, JC: National Academy of Sciences, 1983).

1111 tL: ~ose, D.J., Miller, M.M., and Agnew, C., Global Energy Futures ind CO,-Induced Climate Change, MITEL 83'()15 (Cambridge, \4A: MIT Energy Laboratory, 1983). J.S. Environmental Protection Agency, Warning: Can We ')elaya Greenhouse Warming? S. Seidel and D. Keyes (eds.) Washington, DC: U.S. Environmental Protection Agency, 1983). :dmonds, J., and Reilly, J., "Global Energy and CO. to the fear 2050," Energy Journal 4(3):21-27, 1983.

:dmonds 84: Edmonds, J., Reilly, J., Trabalka, J.R, and Reichle, D.E., An Analysis of Possible Future Atmospheric Retention of Fos· sll Fuel CO" Report No. DOElORI21400-1 (Washington, DC: U.S. Department of Energy, 1984).

:dmonds 85: Edmonds, J., Reilly, J., Gardner, R, and Brenkert, A., Uncertainty In Carbon Emissions, 1975-2075, Report of the Carbon Dioxide Emissions Project (Oak Ridge, TN: Institute for Energy AnalySis. 1985).

20ldemberg: Goldemberg. J., Johansson, T.B., Reddy, A.K.N., and Williams, RH., "An End-Use Oriented Global Energy Strategy," Annual levlew of Energy, Jack Hollander, Harvey Brooks, and David iternlight (eds.), vol. 10 (Palo Alto, CA: Annual Reviews Inc., 985), pp. 613·88.

iQURGE: Bill Keepin, "Review of Global Energy and Carbon Dioxide Projections," Annual Review of Energy, vol. 11, 1986, figure 2, p. 364. Data points are keyed to different models analyzed in that paper.


CONCLUSIONS

Characteristics of Fusion Reactors

Fusion reactors appear to have the potential,using only passive systems, to assure safe opera-tion and shutdown in the event of accident, mal-function, or operator error. If this potential fora high degree of safety assurance is realized, afusion reactor would be easier to certify as safethan a reactor that depends on active safety sys-tems, such as today’s fission reactors. Moreover,fusion reactors do not appear likely to pose newtypes of occupational hazards.

With proper choice of materials, the environ-mental characteristics of fusion reactors wouldlikely be preferable to other energy technologies.Unlike fossil fuel combustion, fusion does notproduce carbon dioxide that could contribute tooverall global warming. Fusion reactors will pro-duce radioactive waste, but these wastes shouldbe less radioactive, less hazardous, and easier todispose of than those from nuclear fission re-actors. However, fusion reactor designs can dif-fer by orders of magnitude in the amount of radio-active waste to be generated. In principle, wastegeneration can be greatly minimized by the useof materials that would not generate long-livedradioactive isotopes inside a fusion reactor; suchmaterials must still be developed and tested. Rou-tine radioactive emissions from fusion reactorsare expected to be insignificant.

One of the most attractive features of fusionis its essentially unlimited fuel supply. Sufficientdeuterium is available and recoverable at lowcost from water to provide energy for billions ofyears at present rates of use. The lithium neededto breed tritium in D-T reactors is not as plenti-ful as deuterium, but it is nevertheless present insufficient quantity that supply of adequately pricedfuel is very unlikely to constrain the prospects ofD-T fusion over any time of conceivable inter-est. Pending detailed fusion reactor designs, otherresource requirements are harder to estimate;however, there is no reason to believe that otherresource requirements will constrain fusion’s de-velopment.

Projections of the economics of fusion reactorsare inconclusive at this stage of fusion’s devel-

opment. Existing studies tend to show the costof electricity from present fusion designs wouldbe somewhat more expensive than that of exist-ing energy supplies. However, these studies can-not be considered definitive for a number of rea-sons. First, any comparisons between prospectivetechnologies and existing ones are highly uncer-tain, considering the disparate levels of develop-ment. Second, fusion’s costs are difficult to estimatebecause substantial research and developmentremains to be done. Technical features that maylead to decreased fusion costs are being explored,and the ultimate success of these features is un-

certain. Alternatively, technical problems thatdrive up the cost maybe encountered. More sig-nificantly, fusion’s economics will be profoundlyaffected by non-technical factors— e.g., the easeand length of the construction and licensing proc-esses—whose impact on fusion costs is not wellunderstood at present. Finally, the costs for fu-sion’s potential competitors are uncertain.

Timetable for Fusion Power

Considering the remaining technical researchto be done and the time period needed for thecommercialization process to result in substan-tial market penetration, it does not appear likelythat fusion will be able to satisfy a significant frac-tion of the Nation’s electricity demand before themiddle of the 21st century. The degree to whichfusion is indeed able to penetrate the energy mar-ket depends on how effectively it meets the needsof its customers in comparison with other energytechnologies. Although the needs of 21st centuryutilities cannot be predicted with confidence, anumber of features desirable to utilities today canbe identified. Economic competitiveness is cer-tainly one of the most important; other cruciallyimportant attributes are plant capital cost, safety,licensability, and maximum financial liability incase of accident. Developing fusion reactors withhigh degrees of safety assurance would make fu-sion attractive in many of these respects.

Competitors with fusion have the potential tosupply most or all of the electricity required bythe United States in the first half of the next cen-


tury; the overall size of future electricity demand suppliers of electricity that could make fusion theshould neither require nor eliminate fusion as a technology of choice. The degree to which fu-supply option. However, there are potentially sion will replace its competitors is impossible tofundamental problems involving the alternate predict today.

Chapter 6

Fusion as a Research Program

.

Page

Near-Term Benefits. . . . . . . . . . . . . . . . . . . . . + . . . . . . . . . . . . . . , .............131Development of Plasma Physics . . . . . . . . . . . . . . . . . ...+..... . ...........131Educating Plasma Physicists . . . . . . . . .....+... . .......................132Advancing Science and Technology . . . . . . . . . . . . . . . . . . . . . . . . . . ........132Stature ● **..****.*.***** . ***.************ .. *******~*****.. . ......133

Near-Term Benefits. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ........= ...134Magnetic Fusion Funding . . . . . . . . . . . . . . . . . ..........................134Magnetic Fusion Personnel. . . . . . . . . . . . . . . . . . . . . . . . . . .... ............139

Participation in Magnetic Fusion Research.. . . . . . . . . . . . . . . . . . .. ... + ......140‘Department of Energy National Laboratories . . . m +.. . . . . . . . . . . . . . . . . . . . . 140Universities and Colleges . . . . . . . . . . . . . . . . . . . . . . . + .+....... . .......143Private Industry . . . . . . . . . . . . . . . . . .S. ... ... .O. ....O . ........0.0...0.147

summary and Conclusions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ... .+ ......151

FiguresFigure No. Page

6-1. Federal Funding of Plasma Physics in 1984. . . . . . . . . . . . . . . . . ., ........13262. Defense and Civilian Federal R&D Expenditures . ....................1346-3. Major Components in Federally Funded R&O in Fiscal Year 1987. . ......13564. Historical Component Funding Levels of Federal R&D Programs... .. ....136

6-6 MajorDOE Civilian R&D Funding at National Laboratories inFiscal Year1987 .**.+** ● . . . . . . . ● ****4** ● ***.... .*.**B** .***.*.. . . 141

Page

* . . . . * . ● ✎ ☞ ☛ ✎ ✎ ✎ ✎ 137. * + * * . * * ● . * . * . . 139. * * * * * * . * * * . . . . 141

.*+**.. . . . . . . . . 145, . . . . , ● * , * . . . ● o 147

Chapter 6

Fusion as a Research Program

The ultimate objective of fusion research is to A complete analysis of the fusion energy programproduce a commercially viable energy source. must include the immediate, indirect benefits andYet, because the research program is exploring costs of the ongoing research effort, in additionnew realms of science and technology, it also pro- to its progress in reaching its long-term goal.vides a weal h of near-term, non-energy benefits.

NEAR-TERM BENEFITS

Fusion research has provided four major near-term, non-energy benefits. It has been a drivingforce behind the development of plasma physics.It educates plasma physicists who contribute tofusion and other fields. It produces technologieswith valuable applications elsewhere, and it hasput the United States in a strong position in theworld scientific community.

Development of Plasma Physics

The development of the field of plasma physicswas driven by the needs of scientists working oncontrolled thermonuclear fusion and space scienceand exploration. In the case of fusion energy,

The simultaneous achievement of high temper-atures, densities, and confinement times [neededfor a plasma to generate fusion power] requiredsignificant improvements in forming and under-standing plasmas confined by magnetic fields orby inertial techniques.l

Thus, research conducted on the prospects of fu-sion energy necessitated concurrent advances inthe area of plasma physics, and, in fact:

The international effort to achieve controlledthermonuclear fusion has been the primary stimu-lus to the development of laboratory plasmaphysics. 2

The field of plasma physics has synthesizedmany areas of physics previously considered dis-tinct disciplines: mechanics, electromagnetism,thermodynamics, kinetic theory, atomic physics,

1 National Research Council, Physics Through the 1990s: F%srnasand F/uids (Washington, DC: National Academy Press, 1986), p. 5.

~lbid.

and fluid dynamics. Today, plasma physics goesbeyond fusion research. Since most known mat-ter in the universe is in the plasma state, plasmaphysics is central to our understanding of natureand to the fields of space science and astrophysics.Theories and techniques developed in plasmaphysics are providing fundamental new insightsinto classical physics and are opening up newareas of research.

The field of plasma physics has grown rapidlysince the 1950s. When the American Physical So-ciety formed the Division of Plasma Physics in1958, for example, the division had less than 200members. Today, the Division of Plasma Physicsis one of the society’s biggest groups, with almost3,400 members. The careers of most of thesemembers originated in magnetic fusion-relatedwork. In addition, over 40 American universitiesnow have major graduate programs in plasmaphysics and/or fusion technology. Graduate levelplasma physics courses are also taught in appliedmathematics and in electrical, nuclear, aeronau-tical, mechanical, and chemical engineering de-partments.

As shown in figure 6-1, the Department ofEnergy (DOE) has played a major role in plasmaphysics research, funding over three-quarters offederally sponsored plasma physics research infiscal year (FY) 1984. Virtually all DOE supportwas directed at fusion applications; 72 percentof DOE’s funding was dedicated to the magneticfusion program, 26 percent funded the inertialconfinement fusion program, and only 2 percent($3 million, in 1984 dollars) was directed at gen-eral plasma physics. Outside of the fusion ap-plications, Federal funding for plasma physics

131


Figure 6-l.— Federal Funding of Plasma Physicsin 1984

NOAA (0.2°/0)

research is very limited. A National ResearchCouncil report concluded that “support for basicplasma physics research has practically vanishedin the United States, ” with only the National Sci-ence Foundation providing funds “clearly for thispurpose.” 3

Educating Plasma Physicists

Educating plasma physicists, as well as otherscientists and engineers, is one of the most widelyacknowledged benefits of the fusion program.Over the last decade, DOE’s magnetic fusionprogram has supported the education of almostall of the plasma physicists trained in the UnitedStates. 4 This achievement is due largely to DOE’scommitment to maintaining university fusion pro-grams during a period when budget reductionshave forced other agencies to curtail their fund-ing of plasma physics research. In addition, DOEprovides 37 fusion fellowships annually to qual-ified doctoral students.

Jlbid., p. 97.4John F. Clarke, Director, DOE Office of Fusion Energy, P/asrna

Physics Within DOE and the Academy Report-Physics Throughthe 1990s, Department of Energy, Office of Fusion Energy, July 1986,p. 5.

Although DOE supports the education of mostof the Nation’s plasma physics graduates, the de-partment does not have the resources to employmany of these people. A large fraction of the Na-tion’s plasma physicists are engaged in defense-related work; 5 plasma physicists also work inuniversities, private industry, and the NationalAeronautics and Space Administration (NASA)space science program. Education in plasmaphysics and fusion research enables these scien-tists to “make major contributions to defenseapplications, space and astrophysical plasmaphysics, materials science, applied mathematics,computer science, and other fields."6

Advancing Science and Technology

Many high-technology R&D programs producesecondary benefits or “spin -offs.” Spin-offs arenot unique to particular fields of research, sinceextending the frontiers of practically any technol-ogy can lead to external applications. Althoughspin-offs may benefit society, they are unantici-pated results of research and should not be viewedas a rationale for continuing or modifying high-technology research programs. Spin-offs may notbe efficient mechanisms of developing new oruseful technologies, compared to programs dedi-cated specifically to those purposes. Moreover,applications of new technologies are often drawnfrom several fields and may not be attributableto any particular one.

Over the years, fusion research has contributedto a variety of spin-offs in other fields. While theprogram cannot claim sole credit, each of the in-novations listed below has at least one key ele-ment that came from the fusion program.7

‘Energy Research Advisory Board, Review of the National Re-search Council Report: Physics Through the 1990s, prepared bythe Physics Review Board for the U.S. Department of Energy, Feb-ruary 1987, p. 44.

‘Ronald C. Davidson, “Overview of Magnetic Fusion AdvisoryCommittee Findings and Recommendations, ” presentation toEnergy Research Advisory Board Fusion Panel, Washington, DC,June 25, 1986.

This list is drawn from three reports: U.S. Department of Energy,Office of Energy Research, Technology Spin-offs From the Magnet\cFusion Energy Program, DOE/ER-01 32, May 1982; U.S. Departmentof Energy, Office of Fusion Energy, Technology Spinoffs From theMagnetic Fusion Energy Program, DOE/ER-01 32-1, February 1984;and U.S. Department of Energy, Office of Energy Research, TheFusion Connection, DOE/ER-0250, October 1985. For more infor-mation about the role of these technologies and others in magneticfusion research, see ch. 4.

Ch. 6.—Fusion as a Research Program . 133

Contributions to Industry

Certain phenomena associated with fusion re-search have proven particularly applicable to thedevelopment of electronic systems and industrialmanufacturing processes. Plasma etching is animportant process in the semiconductor indus-try. Fusion research has provided informationnecessary to characterize and understand theprocess more completely and also has contrib-uted plasma diagnostics that can be used to mon-itor the etching process.

Microwave electronics is another fusion con-tribution that has both civilian and military ap-plications. Microwave tubes and plasmas sharecertain physical principles of operation, and ad-vances in the understanding of basic plasmaphysics have contributed to improvements inmicrowave technology. The fusion program hasalso fostered development of the microwave in-dustry through its requirements for high-frequency,high-power microwave sources, such as the gy-rotron. Typical applications of microwave tech-nology include high-power radar stations, tele-vision broadcasting, satellite communications,and microwave ovens.

Plasma physics phenomena studied in the fu-sion program also have significant applicationsi n the plasma coating and surface modificationof industrial materials. Plasma coating is impor-tant to the manufacturing industry because it mayenable materials to better resist wear and corro-sion. Finally, fusion experimental facilities use so-phisticated power-handling technologies; electricutilities are interested in the near-term applica-tions of these technologies.

Contributions to National Defense

Although magnetic fusion research has no di-rect application to military uses, the fusion pro-gram has contributed to the national defense. Themost valuable contributions are in the backgroundplasma physics research conducted by the fusionprogram and the education of scientists that laterare hired by defense programs. in addition, manyscientific ideas and technological developmentsbeing investigated under the Strategic DefenseInitiative (SDI) grew out of research in the fusionprogram. For example, contributions made by the

magnetic fusion program in the development ofneutral beams and accelerators for free electronlasers have been instrumental to the developmentof directed-energy weapons necessary for SDI ap-plications.

Contributions to Basic Science

Plasma physics is by now considered one ofthe core areas of physics research. Advancesmade in the fusion program in the understand-ing of plasma phenomena have been used byNASA, the Department of Defense (DoD), andothers. Moreover, the fusion program has sup-ported basic atomic physics research for morethan two decades in order to develop detailedknowledge of fundamental atomic and molecu-lar processes influencing plasma behavior.

Magnetic fusion research requires computa-tional methods and facilities that are not avail-able in other disciplines. Thus, the magnetic fu-sion program leads the way in the acquisition anduse of state-of-the-art computers. The MagneticFusion Energy Computing Center’s (MFECC) sys-tem of Cray computers and the satellite networksystem installed for these computers are impor-tant advances in computer technology. In addi-tion, the fusion program has developed advancedcomputational methods in order to model andanalyze plasma behavior.

Finally, fusion research has contributed to thedevelopment of plasma diagnostic technologiesthat have commercial, scientific, and defense ap-plications. The demands of fusion research ondiagnostic instrumentation are extremely exact-ing. Not only are plasmas very complex phe-nomena, but measurements of their characteris-tics must be made from the outside of the plasmaso as not to affect it. Therefore, considerable de-velopment of sophisticated instrumentation hasbeen required throughout the history of fusionresearch.

Stature

The stature of the United States abroad bene-fits from conducting high-technology research.The United States has been at the forefront of fu-sion R&D since the program was initiated in the


1950s. Maintaining a first-rate fusion program has grams to the United States, and has enhanced the

placed the United States in a strong bargaining reputation of the United States in scientific andposition when arranging international projects, technical programs other than magnetic fusion.has attracted top scientists from other fusion pro-

NEAR-TERM COSTS

Magnetic Fusion Funding Comparing Fusion toOther Government R&D

The fusion program utilizes both financial and The Federal budget for R&D has grown stead-personnel resources. This section analyzes the ily during the 1980s, in real terms. The bulk ofmonetary cost of fusion research by providing a this growth has been driven by increases in de-sense of context for fusion expenditures. Fusion fense R&D spending, which almost doubled be-expenditures are compared to other government tween 1982 and 1987. Non-defense R&D has alsoR&D programs and to energy R&D programs in grown, though only 15 percent over the sameparticular. period (see figure 6-2).

Figure 6-2.-Defense and Civilian Federal R&D Expenditures (in current dollars)

1982 1983 1984 1985 1986 1987(estimate)

1988(request)

Year

■ Defense ❑ Civilian

Ch. 6.—Fusion as a Research Program ● 135

Figure 6-3.–Major Components in FederallyFunded R&D in Fiscal Year 1987

The next largest identifiable blocks of FederalR&D funding, each of approximately equal size,are space, health, energy, and general scienceresearch. Space activities are conducted by NASA.Most health-related research is conducted by theDepartment of Health and Human Services,through the National Institutes of Health (NIH).Most general science research is carried out bythe National Science Foundation (NSF) and DOE’s

high energy physics and nuclear physics pro-grams. DOE conducts most Federal energy R&D;the Nuclear Regulatory Commission and the Envi-ronmental Protection Agency also conduct lim-ited energy research.

Those Federal R&D programs with budget au-thority estimated at over $200 million in FY 1987are listed in table 6-1.8 The intent of this table isto provide a context for the fusion program bydepicting its relative funding commitment. Thetable is not intended to compare the magneticfusion program to other programs, because theprograms listed are not directly comparable.Some are near-term efforts; others—like fusion—are very long-term. Some, also like magnetic fu-sion, are focused on a single primary application;others, like the cancer research conducted byNIH, encompass a wide range of smaller subpro-grams. The balance between research and de-velopment varies considerably as well. DoD’slarge research, development, and testing pro-grams include a small amount of research anda great deal of development and testing, whereasNSF’s programs, for example, are almost entirelypure research.

As the table shows, the largest Federal R&Dprograms are defense-related. Magnetic fusion isDOE’s fifth largest R&D program, following weap-ons R&D and testing, naval reactor development,high energy physics, and basic energy sciences.

Although table 6-1 provides a sense of scale be-tween magnetic fusion research and other Fed-eral R&D programs, it cannot be used to com-pare the programs themselves or the decisionsby which these programs are funded. The criteriaby which funding decisions are made in differ-ent agencies and departments are not consistent,and the degree of competition for funds betweenprograms–either within a specific office or be-tween offices, agencies, or departments—is dif-ficult to measure. The budgets of different pro-grams are prepared separately within the executivebranch and considered separately in Congress.

8A distinction is made between Budget Authority and Budget Out-

lay. Budget authority denotes how much a program could spend.In some cases, however, actual budget outlays (what the programdid spend) will differ from the budget authority. A program mayspend less than its budget authority, or more if it has accrued sawings from previous years.


Figure 6=4.—Historical Component Funding Levels of Federal R&D Programs (in currant dollars)

Energy Space Health

Overall comparisons of one program to anotherare typically made only at the highest levels ofaggregation, if at all.

In addition, this table does not represent a com-plete picture of all research undertaken by theU.S. economy. It only measures Federal invest-ments, and in many programs there is substantialprivate sector involvement. Total private sectorinvestment in R&D activities for 1987 is estimatedat $60 billion, about the same as Federal R&Dinvestment for that year. g

gNational Science Foundation, Division of Science Resources

Studies, Science and Technology Data Book 1987 (Washington,DC: National Science Foundation, 1986), NSF-86-31 1, figure 1, p. 3.

Comparing Fusion to Energy R&D

Since 1980, significant shifts in the emphasisof DOE appropriations have occurred. The de-partment has focused more heavily than it didpreviously on atomic energy defense activitiesand less heavily on activities conducted by civil-ian programs, while overall DOE appropriationshave decreased. Thus, civilian programs havecompeted for a smaller piece of a shrinking pie,resulting in serious financial pressure on civilianenergy R&D. This shrinkage is in large part dueto the Reagan Administration policy that devel-opment of near-term technology for civilian ap-plications is better left to the private sector.


Table 6-1 .—Federally Funded R&D Programs With Budget Authority Over $200 Million in Fiscal Year 1987

Fiscal year 1987 Fiscal year 1987Research and development budget estimatea Research and development budget estimatea

program name ‘ (millions) program name (millions)

Department of Defense . . . . . . . . . . . . . .Army . . . . . . . . . . . . . . . . . . . . . . . . . . . .Navy . . . . . . . . . . . . . . . . . . . . . . . . . . . .Air Force . . . . . . . . . . . . . . . . . . . . . . . .Defense agencies . . . . . . . . . . . . . . . . .Strategic Defense Initiative. . . . . . . . .

Defense Advanced ResearchProjects Agency . . . . . . . . . . . . . . .

Office, Secretary of Defense. . . . . .Defense Nuclear Agency . . . . . . . . .

National Aeronautic and SpaceAdministration . . . . . . . . . . . . . . . .

Space Station . . . . . . . . . . . . . . . . . . . .Space Transportation Capability

Development . . . . . . . . . . . . . . . . . .Space Science and Applications . . . .

Physics and Astronomy . . . . . . . . . .Planetary Exploration ., . . . . . . . . . .Environmental Observations . . . ., .

Aeronautics and SpaceTechnology . . . . . . . . . . . . . . . . . .

Aeronautical research andtechnology . . . . . . . . . . . . . . . . . . .

Department of Energy . . . . . . . . . . . . . . .Energy Supply R&D . . . . . . . . . . . . . . .

Basic Energy Sciences . . . . . . . . . .Magnetic Fusion . . . . . . . . . . . . . . . .Nuclear Energy . . . . . . . . . . . . . . . . .

General Science and Research . . . . .High Energy Physics . . . . . . . . . . . .Nuclear Physics . . . . . . . . . . . . . . . .

Atomic Energy Defense Activities . . .Weapons R&D and Testing . . . . . . .Naval Reactors Development . . . . .

$ 38,374.5($ 4,754.6)($ 9,381.9)($ 15,416.8)($ 7,185.5)[$ 3,743.4]

[$ 785.2][$ 569.1][$ 306.0]

$ 3,127.7($ 420.0)

($ 495.5)$ 1,552.6)

552.8][$ 358.4][$ 320.9]

($ 592.0)

[$ 376.0]

$ 5,561.1($ 1,498.6)[$ 470.6][$ 345.3][$ 325.9]($ 716.8)[$ 499.7][$ 217.1]($ 2,785.7)[$ 1,882.2][$ 563.8]

Department of Health and HumanServices . . . . . . . . . . . . . . . . . . . . . .

Alcohol, Drug Abuse and MentalHealth Administration . . . . . . . . . .

General Mental Health . . . . . . . . . . .National Institutes of Health . . . . . . .

Cancer . . . . . . . . . . . . . . . . . . . . . . . .Heart, Lung, and Blood . . . . . . . . . .Allergy and Infectious Diseases. . .Diabetes, Digestive and Kidney

Diseases . . . . . . . . . . . . . . . . . . . . .Neurological and Communicative

Diseases and Stroke . . . . . . . . . . .Child Health and Human

Development . . . . . . . . . . . . . . . . . .Eye . . . . . . . . . . . . . . . . . . . . . . . . . . .Environmental Health Sciences . . .

National Science Foundation . . . . . . . . .Mathematical and Physical

Sciences. , . . . . . . . . . . . . . . . . . . .Biological, Behavioral, and Social

Sciences . . . . . . . . . . . . . . . . . . . . .Geosciences . . . . . . . . . . . . . . . . . . . . .

Department of Agriculture. . . . . . . . . . . .Agricultural Research Service . . . . . .Cooperative State Research Service .

Department of Interior . . . . . . . . . . . . . . .Geological Survey. . . . . . . . . . . . . . . . .

Department of Transportation . . . . . . . .Department of Commerce . . . . . . . . . . . .

National Oceanic and AtmosphericAdministration . . . . . . . . . . . . . . . .

Environmental Protection Agency . . . . .Veterans Administration . . . . . . . . . . . . .Agency for International

Development . . . . . . . . . . . . . . . . .

$

($[$($[$[$[$

[$

[$

[$[$[$$

($

($($

(:($

(:$$

($$$

$

6,709,8

569.4)307.5]

5,853.2) b

1,371 .5]891 .2]535.6]

488.2]

476.5]

352.5]211 .1]200.4]

1,520.3

463.4)

257.7)284.6)

1,027.5523.3)300,3)362.2

208.6)285.2401.6

287.5)343.4225.3

224.2aValues denoted with "( )" comprise programs included within the preceding department total. and values denoted with “[ ]“ comprise subprograms included withinthe preceding program total Only departments, programs, and subprograms with an annual budget over $200 million are listed; therefore, the listed program andsubprogram budgets may not total the preceding departmental or program budget

bTotal program budget given for the National Institutes of Health Includes an overall reduction of $67.1 million, which has not been allocated among individual Institute

subprogram budgets in these figures

SOURCE American Association for the Advancement of Science, Intersociety Working Group, AAAS Report Xll: Research and Development FY 1988 (Washington, DCAmerican Association for the Advancement of Science, 1987)

Though magnetic fusion has fared better thanmany other energy programs, its budget hasfallen significantly in recent years. From a peakof $659.7 million in FY 1977 (in 1986 dollars),funding for the fusion program has declined byover half, to a level of $319.1 million in FY 1987(in 1986 dollars) .10 Figure 6-5 illustrates the recentbudgets of DOE’s larger energy R&D programs.—..—

I t)gud~et \ alues and I nflatlon i nd Ices were pro~lded by J. Ronald

Young, Director of the Ot’t’lce ot Management, U.S. Department

Unlike short-term energy development, thelong-term, high-risk nature of the fusion energyprogram satisfies the criteria of the Reagan Ad-ministration’s science and technology policy.Long-term, research-oriented programs like fu-sion have been able to maintain Federal budget-ary support because, although there is a poten-tially high payoff, there is currently little incentive— - — . .of Energy, Off Ice of Energy Research, letter to the Office of Tech-nology Assessment, Aug. 15, 1986.


Figure 6-5.—Annual Appropriations of DOE Civilian R&D Programs (in current dollars)

3.2I

0.6

0.4

0.2

0

for industrial involvement. Even if the risks were The most expensive fusion projects to date arenot high, the benefits are so far off that theirpresent value is not sufficient to interest privateinvestors today. Virtually all fusion research isfunded by the Federal Government. DOE’s pro-grams in nuclear energy, fossil fuels, conserva-tion, and renewable energy, on the other hand,have lost much of their Federal support becauseit is believed that industry financing is appropri-ate in these cases.

Costs of Fusion Facilities

Table 6-2 lists the total construction costs ofsome representative fusion program experiments.11

I I For information about the technical details of many of theseprojects, see ch. 4.

the Tokamak Fusion Test Reactor (TFTR) and theMirror Fusion Test Facility (MFTF-B), which arean order of magnitude more expensive than otherconfinement experiments. In part, TFTR andMFTF-B were more expensive than other exper-iments because they required development of anextensive supporting infrastructure as well as con-struction of the actual device. In addition, thesefacilities are more advanced and much largerthan the experiments constructed on alternativeconcepts.

The next facility the U.S. fusion program plansto construct, the Compact Ignition Tokamak(ClT), has an estimated cost of $360 million. Itis proposed to be built at Princeton Plasma Physics


Table 6-2.—Cost of Representative Fusion Experiments

Construction costExperiment Location Type (millions of 1987 dollars)

Tokamak Facility Test Reactor. . . . . . . . . . . . . . . . . . . . . . . . . . . PPPL Tokamak $562Mirror Fusion Test Facility-B . . . . . . . . . . . . . . . . . . . . . . . . . . . . LLNL Tandem Mirror $330Doublet Ill . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .GA Tokamak $ 56a

Doublet III-D (Upgrade) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .GA Tokamak $ 36a

International Fusion Superconducting Magnet Test Facility . . .ORNL Magnet Testb $ 36C

Poloidal Divertor Experiment , . . . . . . . . . . . . . . . . . . . . . . . . . . . PPPL Tokamak $ 5 4Princeton Large Torus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . PPPL Tokamak $ 4 3Tritium Systems Test Assembly . . . . . . . . . . . . . . . . ... ... ...LANL Tritium Testb $ 2 6Tandem Mirror Experiment . . . . . . . . . . . . . . . .. .. .. ... ... ...LLNL Tandem Mirror $ 24Tandem Mirror Experiment Upgrade . . . . . . . . . . . . . . . ... ... .LLNL Tandem Mirror $ 2 3Texas Experimental Tokamak . . . . . . . . . . . . . . . . . . . . ... .....UT Tokamak $ 21Advanced Toroidal Facility . . . . . . . . . . . . . . . . .. .. ... ... ... .ORNL Stellarator $ 21TARA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ... .., ..MIT Tandem Mirror $ 19ZT-40 . . . . . . . . . . . . . . . . . . . . . . . . .. .. .. .. .. .. .. ... ... ... .LANL Reversed-Field Pinch $ 1 7Alcator C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. .. ... ... ... ..MIT Tokamak $ 15Rotating Target Neutron Source . . . . . . . . . . . . . . . ... ... ... .LLNL Materials Testb $ 1 1Impurity Studies Experiment-B . . . . . . . . . . .. .. .. .. ... ... ...ORNL Tokamak $ 5Field Reversed Experiment-C . . . . . . . . . . .. .. .. .. ... ... ... .LANL Field-Reversed $ 3

ConfigurationPhaedrus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ....UW Tandem Mirror $ 1.8Macrotor. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ... ... ... .UCLA Tokamak $ 1.5IMS . . . . . . . . . . . . . . . . . . . . . . . . . . .. .. .. .. .. .. ... ... .....UW Stellarator $ 1.4Tokapole . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ... .....UW Tokamak $ 0.6KEY PPPL—Princeton Plasma Physics Laboratory, Princeton, New Jersey

LLNL—Lawrence Livermore National Laboratory, Livermore, CaliforniaORNL—Oak Ridge National Laboratory, Oak Ridge, TennesseeGA—GA Technologies, Inc. San Diego, CaliforniaLANL—Los Alamos National Laboratory, Los Alamos, New MexicoUT—University of Texas, Austin, TexasMlT—Massachusetts Institute of Technology, Cambridge, MassachusettsUW—University of Wisconsin, Madison, WisconsinUCLA—University of California, Los Angeles, California

aValues shown for the combined Doublet III facility and upgrade do not Include an additional $54 million (in current dollars) of hardware provided by the governmentof Japan or $36 million (in 1987 dollars) for a neutral beam addition

bThese facilities are fusion technology facilities; all others on the table are confinement physics experiments.CThe cost of this facility does not include the cost of the six magnet coils that are being tested there. It is estimated that the magnet coils cost between $12 million

and $15 million each (in current dollars)

SOURCE US Department of Energy, Office of Fusion Energy, 1987

Laboratory, where it can take advantage of theIab’s existing infrastructure. With initial construc-tion funds requested in the FY 1988 DOE bud-get, CIT will be the largest fusion project under-taken in recent years.

Looking beyond CIT, the U.S. fusion programsees a next-generation engineering test reactoras necessary during the 1990s. Funding for thisdevice, which is projected to cost well overabil-Iion dollars, has not been requested by or appro-priated to DOE. A recent DOE proposal to un-dertake international conceptual design andsupporting R&D is currently being considered.lf successful international construction and oper-ation of the device couId follow the design phaseof the project (see ch. 7).

Magnetic Fusion Personnel

The fusion program currently supports approx-imately 850 scientists (almost all Ph.D.s), 700engineers, and 770 technicians.12 These research-ers work primarily at the national laboratories andin the university and college fusion programs. Be-cause the size of the labor pool responds to shiftsin the demand for labor, and because the long-term value of having a person work on one pro-

I ZThOrna5 G. Finn, u. S. Ckpa rtment of Energy, Office Of Fu SiO n

Energy, letter to the Office of Technology Assessment, Mar. 12,1987. The number of technicians represents only full-time staff asso-ciated with experiments; shop people and administrative staff arenot included. Figures for scientists and engineers include u n ive r-sity professors and post-doctoral appointments; graduate studentemployees are not included.


gram as opposed to any other is difficult to meas-ure, it is hard to quantify the implications ofdedicating scientific and engineering manpowerto the fusion program. The value of the fusionprogram for training plasma physicists, however,cannot be denied. The fusion program trains farmore people than it employs, and these peoplemake valuable contributions in a variety of fieldsother than fusion.

According to DOE, since 1983 the number ofPh.D. staff positions at the major national fusionresearch centers has declined by almost 20 per-cent. Personnel levels among individuals with-

out Ph.D.s, and the staffs of smaller fusion re-search centers, have also declined substantially.A recent study for the National Academy of Sci-ences predicts that if recent funding trends con-tinue, the fusion program could lose 345 Ph.D.sbetween 1985 and 1991. Most fusion research-ers who have left the fusion program have foundwork easily in other research programs withinDOE and DoD. Many former fusion researchersare working on SDI. As the mobility of fusion re-searchers shows, these individuals have skills thatare in demand in many areas.

PARTICIPATION IN MAGNETIC FUSION RESEARCH

DOE’s Office of Fusion Energy (OFE) funds re-search conducted by three different groups: na-tional laboratories, colleges and universities, andprivate industry. Each of these groups has differ-ent characteristics, and each plays a unique rolein the fusion program.

Department of Energy NationalLaboratories

DOE’s national laboratories play an importantrole both in the fusion program and in the de-partment’s general energy R&D. Figure 6-6 depictsDOE’s distribution of laboratory funding amongvarious subject areas. A list of DOE’s major na-tional laboratories, showing the extent of theirfusion participation, is shown in table 6-3.

National laboratories are generally government-owned, contractor-operated facilities. Most ofthem were created during or shortly after WorldWar II to conduct research in nuclear weaponsand nuclear power development. Four DOE na-tional laboratories have major research programsin magnetic fusion. It is estimated that these lab-oratories will conduct over 70 percent of the mag-netic fusion R&D effort in FY 1987. According toDOE, the laboratories “are a unique tool that theUnited States has available to carry on the kindof large science that is required to address cer-tain problems in fusion. ” It is expected that the

13john F, Clarke, Director, DOE Off Ice of Fusion Energy, ‘ ‘plan-

ning for the Future, ’ /ourna/ of Fuwon Energy, vol. 4, nos. 2/3, June1985, p, 202.

involvement of the national laboratories in theresearch program will remain important at leastuntil the technology is transferred to the privatesector for commercialization. The four major fu-sion laboratories are described below, in decreas-ing order of their share of the FY 1987 fusionbudget.

Princeton Plasma Physics Laboratory

The Princeton Plasma Physics Laboratory (PPPL),located in Princeton, New Jersey, is one of thefusion program’s oldest and most important fa-cilities. It is located on Princeton University’sJames Forrestal Campus, and, in FY 1987, PPPLis estimated to receive the largest share of DOE’smagnetic fusion budget of any single institution(27 percent).14 PPPL is a program-dedicated lab-oratory, which means that virtually all of its re-search involves magnetic fusion. The bulk ofPPPL’s budget is used to operate TFTR, the largestU.S. tokamak experiment. TFTR is one of twooperational experiments in the world designedto burn D-T fusion fuel, the other being the Euro-pean Community’s Joint European Torus.15 I naddition to TFTR, PPPL operates other smallertokamak experiments.

laBased on U.S. Depaflment of Energy, FY 1988 Congression Bud-

get Estimates for Lab/Plant, January 1987.Is prl nceton plasma physics Laboratory, A n Overview. Princeton

P/asrna Physics Laboratory, April 1985, p. 5. For more informationon TFTR and other experiments, see ch. 4.

Ch. 6.—Fusion as a Research Program c 141

Figure 6-6.—Major DOE Civilian R&D Funding atNational Laboratories in Fiscal Year 1987

Lawrence Livermore National Laboratory

In FY 1987, it is estimated that Lawrence Liver-more National Laboratory (LLNL), located inLivermore, California, will receive 15 percent of

Table 6.3.—DOE’S Major

DOE’s magnetic fusion energy budget.16 LLNL hasconcentrated on tandem-mirror systems, andmost of the experimental facilities at the labora-tory have explored the capabilities of this con-finement scheme.17 The major magnetic fusionfacility at LLNL is MFTF-B, a project that wasmoth balled in 1986, due to budget cuts, justweeks after construction was completed; MFTF-B has never operated. In addition to MFTF-B,there is another significant tandem-mirror facil-ity at LLNL—the Tandem Mirror Experiment Up-grade (TMX-U), which has also been terminated.LLNL is now installing a small tokamak experi-ment and has been given responsibility for thedesign of the next-generation engineering test re-actor. LLNL also operates the Magnetic FusionEnergy Computing Center for DOE. Moreover,LLNL conducts the largest component of the Na-tion’s inertial confinement fusion research pro-grams (see app. B).

IGBased on U.S. Department of Energy, FY 1988 congressional

Budget Estimates, op. cit.1 TFor technical information on the tandem m i rror configuration,

see ch. 4.

National Laboratories

Laboratory Location

Ames Laboratory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Ames, IAArgonne National Laboratory. . . . . . . . . . . . . . . . . . . . . . .Argonne, ILBettis Atomic Power Laboratory . . . . . . . . . . . . . . . . . . . .West Mifflin, PABrookhaven National Laboratory. . . . . . . . . . . . . . . . . . . .Upton, NYFermi National Accelerator Laboratory . . . . . . . . . . . . . . Batavia, ILHanford Engineering Development Laboratory. . . . . . . . Richland, WAIdaho National Engineering Laboratory . . . . . . . . . . . . . . Idaho Falls, IDKnolls Atomic Power Laboratory . . . . . . . . . . . . . . . . . . .Schenectady, NYLawrence Berkeley Laboratory . . . . . . . . . . . . . . . . . . . . . Berkeley, CALawrence Livermore National Laboratory . . . . . . . . . . . . Livermore, CALos Alamos National Laboratory. . . . . . . . . . . . . . . . . . . . LOS Alamos, NMMound Laboratory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Miamisburg, OHNevada Test Site . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Mercury, NVOak Ridge National Laboratory . . . . . . . . . . . . . . . . . . . . . Oak Ridge, TNPacific Northwest Laboratory . . . . . . . . . . . . . . . . . . . . . . Richland, WAPaducah Gaseous Diffusion Plant . . . . . . . . . . . . . . . . . . Paducah, KYPinellas Plant . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .St. Petersburg,Portsmouth Gaseous Diffusion Plant. . . . . . . . . . . . . . . . Piketon, OHPrinceton Plasma Physics Laboratory . . . . . . . . . . . . . . . Princeton, NJRocky Flats Plant . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Golden, COSandia National Laboratory . . . . . . . . . . . . . . . . . . . . . . . .Albuquerque, NMSavannah River Plant . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Aiken, SCStanford Linear Accelerator Laboratory . . . . . . . . . . . . . .Stanford, CAKEY: None - No magnetic fusion funding.

Minor - Fusion funding is less than $10 million in fiscal year 1987.Major - Fusion funding is more than $10 million in fiscal year 1987.

SOURCE: Office of Technology Assessment, 1987.

Magneticfusion research

NoneMinorNoneNoneNoneMinorMinorNoneMinorMajorMajorNoneNoneMajorMinorNoneNoneNoneMajorNoneMinorNoneNone

Oak Ridge National Laboratory

Oak Ridge National Laboratory (ORNL), locatedin Oak Ridge, Tennessee, conducts researchacross the full range of magnetic fusion programactivities and is actively involved with nationaland international cooperation in virtually everyarea. The Advanced Toroidal Facility (ATF), whencomplete, will be ORNL’s main experiment intoroidal confinement. It is anticipated that ATF,a stellarator, will make important contributionsto the improvement of toroidal systems by in-creasing the understanding of fundamental con-finement physics.18 Contributing to this under-standing are other ORNL programs in theory,diagnostics, and atomic physics The ORNL tech-nology program is fusion’s largest, and it includesplasma heating and fueling, superconductingmagnets, materials, and environmental assess-

— — ..-. description the confine-

concept.

ment programs. In addition, ORNL is the host forthe Fusion Engineering Design Center, which sup-ports both reactor and next-generation devicestudies throughout the program. It is estimatedthat ORNL will receive about 15 percent of themagnetic fusion energy program’s budget in FY1987.19

Los Alamos National Laboratory

Los Alamos National Laboratory (LANL) is lo-cated in Los Alamos, New Mexico, and it contrib-utes to DOE’s fusion energy program in severalways. LAN L has focused on alternative concepts.These concepts, not as far developed as the toka-mak or mirror, are studied in several experimentsat Los Alamos that are smaller and therefore lessexpensive than the large tokamak and mirror ma-

of Energy, 1988

mates, op. cit.

Ch. 6.—Fusion as a Research Program “ 143

Photo credit: Oak Ridge National Laboratory

Assembly of The Advanced Toroidal Facility at Oak Ridge National Laboratory.

chines. 20 In addition, LANL conducts research infusion technology and materials, studies reactorsystems, and operates the Tritium Systems TestAssembly (TSTA)—a prototype of the tritium-handling apparatus necessary to fuel a D-T fusionreactor. In FY 1987, LANL will receive about 7percent of the magnetic fusion energy program’sbudget .21

t. h. 4 tech n information o n a Iterative CO

ment concepts. Congressional Budget

mates, op. cit.

Universities and Colleges

Role in the Research Program

Universities and colleges contribute to manyareas of energy research, including magnetic fu-sion. The role of these programs in fusion R&Dactivities differs significantly from the role of thenational laboratories. Universities and collegesprovide education and training and have beenhistorically a major source of innovative ideas aswell as scientific and technical advances. Theseprograms could not replace the national labora-

s w s Q En rg

m m N ry

b d m Am g h 0 b 0 hp g m d p h h d pm h h gh d k m k p

g p m d h d d b p h h w b d C h d om h mp h p m pm p g d h d opm

b h o How d g d g 0 h 0 g dd p g m h m d q d mp rt p g m h m d mp

b h h b m

Ch. 6.—Fusion as a Research Program c 145

cepts. Overall, the Magnetic Fusion Advisory University and college fusion programs also edu-Committee (MFAC) Panel V found: cate the young researchers in the field.

The contributions from university-based exper- table 6-4 lists the university and college fusionimental programs over the past decade have been programs. It is estimated that these programs col-significant, obviously cost-effective and have had Iectively will receive over 14 percent of the mag-a major impact on the development of fusion netic fusion budget in FY 1987 directly from DOE.energy in general, and the large-scale or “main- In addition, university and college fusion pro-Iine” experiments at the national laboratories inparticular. 22 grams could receive another 2 to 3 percent of

zzMagnetic Fusion Advisory Committee Panel V, Princi~a/ Find- the Fusion Program, July 1983, p. 18. The Magnetic Fusion Advi-ings and Recommendations of the Magnetic Fusion Advisory Com- sory Committee is a committee of fusion scientists and engineersmittee Subpanel Evaluating the Long-Term Role of (Universities in that provide technical advice to DOE’s Office of Fusion Energy.

Table 6-4.—Universities and Colleges Conducting Fusion Researchin Fiscal Years 1983 and 1986 (in 1986 dollars)

Fiscal year 1983 Fiscal year 1986University or college budget authority budget authority

--- - . . . .Massachusetts Institute of Technology . . . . . . . .University of Texas . . . . . . . . . . . . . . . . . . . . . . . . . .University of California—Los Angeles . . . . . . . . .University of Wisconsin . . . . . . . . . . . . . . . . . . . . . .University of Maryland . . . . . . . . . . . . . . . . . . . . . . .New York University . . . . . . . . . . . . . . . . . . . . . . . . .Columbia University . . . . . . . . . . . . . . . . . . . . . . . . .University of Washington . . . . . . . . . . . . . . . . . . . .Cornell University . . . . . . . . . . . . . . . . . . . . . . . . . . .University of California—Berkeley . . . . . . . . . . . . .Johns Hopkins University . . . . . . . . . . . . . . . . . . . .University of California—Irvine. . . . . . . . . . . . . . . .Rensselaer Polytechnic Institute . . . . . . . . . . . . . .California Institute of Technology . . . . . . . . . . . . .Georgia Institute of Technology. . . . . . . . . . . . . . .Pennsylvania State University. . . . . . . . . . . . . . . . .University of California—Santa Barbara . . . . . . . .University of Illinois . . . . . . . . . . . . . . . . . . . . . . . . .Auburn University . . . . . . . . . . . . . . . . . . . . . . . . . . .University of Missouri . . . . . . . . . . . . . . . . . . . . . . .University of California—San Diego . . . . . . . . . . .Yale University. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .University of Arizona . . . . . . . . . . . . . . . . . . . . . . . .College of William and Mary. . . . . . . . . . . . . . . . . .University of Connecticut . . . . . . . . . . . . . . . . . . . .Western Ontario University . . . . . . . . . . . . . . . . . . .University of Michigan . . . . . . . . . . . . . . . . . . . . . . .Wesleyan University . . . . . . . . . . . . . . . . . . . . . . . . .Stanford University . . . . . . . . . . . . . . . . . . . . . . . . . .University of lowa . . . . . . . . . . . . . . . . . . . . . . . . . . .University of Virginia . . . . . . . . . . . . . . . . . . . . . . . .State University of New York—Buffalo . . . . . . . . .Dartmouth College . . . . . . . . . . . . . . . . . . . . . . . . . .University of Colorado . . . . . . . . . . . . . . . . . . . . . . .North Carolina State University . . . . . . . . . . . . . . .Stevens Institute of Technology. . . . . . . . . . . . . . .Syracuse University . . . . . . . . . . . . . . . . . . . . . . . . .University of New York City . . . . . . . . . . . . . . . . . .

Total university and college budget . . . . . . . . .

$26.6 million$ 6.9 million$ 4.1 million

, $ 4.1 million$ 1.9 million$ 1.3 million$ 1.1 million$ 776,000$ 760,000$ 6 1 8 , 0 0 0$ 483,000$ 481,000$ 353,000$ 351,000$ 271,000$ 263,000$ 241,000$ 226,000$ 212,000$ 201,000$ 175,000$ 123,000$ 115,000$ 95,000$ 90,000$ 78,000$ 66,000$ 63,000$ 60,000$ 30,000$ 30,000$ 24,000$ 14,000

—————

$24.6 million$ 5.4 million$ 6.2 million$ 4.8 million$ 983,000$ 1.1 million$ 1.2 million$ 708,000$ 535,000$ 438,000$ 340,000$ 147,000$ 392,000$ 503,000$ 115,000$ 97,000

$ 335,000$ 372,000$ 239,000$ 240,000$ 50,000$ 13,000$ 18,000$ 80,000

—

$ 50 ,000$ 13,000

——

$ 60,000$ 60,000

$ 15,000$ 101,000$ 25,000

$52,322,000 $49,301,000(33 programs) (30 programs)

SOURCE: Fiscal year 1983 budgets from Magnetic Fusion Advisory Committee Panel V, Principal Findings and Recommenda-tions of the MFAC Subpanel Evaluating the Long-Term Role of Universities in the Fusion Program, July 1983, p.9 Fiscal year 1986 budgets provided by DOE’s Office of Fusion Energy, FY 1988 Congressional Budget ContractorSummary, Jan 16, 1987


the fusion budget indirectly through subcontractsfrom the national laboratories. The programs con-ducted by the universities in fusion are diverse,varying in funding level and research area. Over80 percent of the university programs receivedless than $1 million each from DOE in FY 1986.

Recent budget cuts have seriously affected uni-versity and college fusion programs, which havesuffered larger percentage budget reductions thanthe fusion program as a whole. University fund-ing was $49.3 million in FY 1986, is estimated at$44.7 million in FY 1987, and is requested to be$41.7 million in FY 1988, in current dollars. Thelast two figures represent percentage decreasesof 9 and 7 percent, respectively. 23 The cor-responding decreases for the overall fusion bud-get ($361.5 million in FY 1986, an estimated

$341.4 mill ion in FY 1987, and a requested$345.6 million in FY 1988, in current dollars) are6 percent and – 1 percent.

For university and college fusion programs,DOE is the only source of financial support. NSF,the other likely Federal support agency, does notfund fusion research because it is considered ap-plied, as opposed to basic, research and becauseit is believed to be DOE’s area. Thus, given re-cent budget cuts, two-thirds of the university andcollege programs have either reduced or elimi-nated their programs since 1983. Seven collegeshave eliminated their fusion programs, while fivenew programs have been added. It is anticipatedby University Fusion Associates (UFA), an infor-mal grouping of individual fusion researchersfrom universities and colleges, that if currentfunding trends continue, as many as half of thecolleges and universities will eliminate their fu-sion research programs between 1986 and 1989.24DOE has stated that it intends to maintain theuniversity fusion budget at a constant level (cor-rected for inflation) and does not foresee anyneed for additional programs to drop out. In any

z~lf the Massachusetts Institute of Technology (MIT), the largestuniversity fusion program, is not included, the university fusion bud-get decreases in FY 1987 and FY 1988 are 7 and 2 percent, respec-tively.

~qGeorge H. Mi Icy, testimony on Fisca/ Year 1987 DeParOnefrtof Energy Authorization (Magnetic Fusion Energy), Hearings beforethe Subcommittee on Energy Research and Production, House Sci-ence and Technology Committee, 99th Cong., 2d sess., vol. 5, Feb.26, 1986, p. 103.

case, continued tight budgets and the loss of uni-versity programs reduces the ability of the fusionprogram to attract and educate new researchers.

In response to the funding cuts and the nar-rowing of the fusion program’s scope, UFA hasrecommended that “approximately 3 to 5 per-cent additional funding should be added backinto the fusion budget to support innovative andnew ideas.”25 According to UFA, one of the mosturgent uses of this money would be to provideseed money to innovative research proposed byuniversities, national laboratories, and private in-dustry. UFA contends that this funding wouldhelp preserve some of the small university pro-grams endangered by budget cuts, as well as cre-ate the atmosphere of excitement necessary toattract top students to the field. This idea has beenendorsed by other members of the fusion com-munity.

Given recent budgets, university and collegefusion programs are concerned about the futuredirection of DOE’s fusion program. In particular,representatives of UFA worry that the role of uni-versity fusion programs may be difficult to pre-serve if the Federal fusion program becomesmore dependent on international cooperativeprojects. The international activities of collegeand university fusion programs are generallysmall-scale, and it is not clear how these activi-ties could fit in a collaborative engineering testreactor effort.

University and College Activities

Universities and colleges have made contribu-tions to fusion research in a variety of areas. Intokamak development, university fusion pro-grams have worked on radiofrequency heatingand current drive, boundary physics, high betastability, and transport of heat and particles in fu-sion plasmas.26 The largest university tokamak ex-periments are MIT’s Alcator project, the TexasExperimental Tokamak (TEXT) experiment at theUniversity of Texas, and Macrotor at the Univer-sity of California at Los Angeles (UCLA).

*sIbid., p. 100.*b For more information on the tech n ica I aspects Of these cent ri

butions, see ch. 4.


Photo credit: Plasma Fusion Center, MIT

The Alcator C tokamak at the Massachusetts Instituteof Technology.

In addition to tokamak research, a small groupof universities is exploring the mirror confinementconcept. The TARA facility at MIT and Phaedrusat the University of Wisconsin are the majoruniversity mirror experiments and, since themoth balling of the mirror machines at LLNL, havebecome the only U.S. mirror experiments. Sup-port for university mirror programs has decreased,however. In fact, in the budget for FY 1987, DOEproposed elimination of funding for these univer-sity-based mirror projects. Congress has made ad-ditional funds available to keep both operationalthroughout FY 1987, and it appears that Phaedruswill remain operational throughout FY 1988 aswelI.

Several universities also study other confine-ment concepts for fusion reactors, including thestellarator, compact toroid, and reversed-fieldpinch. Work in these concepts is conducted atthe University of California at Irvine, UCLA, Cor-nell University, University of Maryland, Pennsyl-vania State University, University of I l l inois,University of Washington, and University of Wis-consin.

Finally, several university programs are explor-ing technology development and atomic physics.

Programs at the University of Arizona, AuburnUniversity, University of California at Santa Bar-bara, UCLA, Georgia Institute of Technology,University of Illinois, MIT, University of Michi-gan, Rensselaer Polytechnic Institute, Universityof Washington, and University of Wisconsin fo-cus on reactor systems, materials, surface effects,and superconducting magnets.

Private Industry

Role in the Research Program

Private industry can take a variety of differentroles in fusion research, depending on its levelof interest and the stage of development. Themost useful roles fall into three main categories.27

These categories, along with the principal func-tions performed in each category, are listed intable 6-5.

Industry as Advisor.–The advisory role of pri-vate industry is filled frequently by corporate ex-ecutives who are asked to help assess variousstages of program development. The principalbenefit of the advisory role is the developmentof appropriate program goals. As a support serv-ices contractor, industry assigns individuals orsmalI groups to work i n direct support of a man-ager at DOE or at a national laboratory. Privateindustry also provides members of its technicalstaffs to serve on technical committees, such as

27 Argonne National Laboratory, Fusion pOw’er program, T~chnl-

ca/ F%nning Acti\ ;ty: FirIa/ Report, commissioned by the U.S. De-partment of Energy, Office of Fusion Energy, AN L/FPP-87- 1, 1987pp. 340-343.

Table 6-5.—lndustrial Roles and Functions

Roles Functions

Advisor . . . . . . . . . . . . Support services contractorAdvisory committee

Direct participant . . . Materials supplierComponent supplier and

manufacturerSubsystems contractorPrime contractor, project managerFacilities operatorCustomer

Sponsor . . . . . . . . . . . Research and developmentSOURCE: Argonne National Laboratory, Fusion Power Program, Technical

Planning Activity: Final report, commissioned by the U S. Departmentof Energy, Office of Fusion Energy, ANL/FPP-87-1, 1987, table 7-4, p340

748 c Starpower: The U.S. and the International Quest for Fusion Energy

the Magnetic Fusion Advisory Committee (MFAC)or the Energy Research Advisory Board (ERAB).Through advisory arrangements, DOE gains in-dustry’s expertise and skills, and industry gainsknowledge, contacts, and income. However,there is no commitment in this type of advisoryrelationship that the advice will be used by DOEor the national laboratories.

Industry as Direct Participant. -To becomemajor participants in the fusion program, indus-try executives must understand near-term pro-gram objectives and be willing and able to con-tribute to the achievement of these objectives.Industry’s direct participation will be particularlyimportant during the engineering phase of the re-search program, when information and expertisemust be transferred to industry from the nationallaboratories and universities.

As a direct participant, industry can serve avariety of functions. It can supply off-the-shelfcomponents, as well as design and manufacturecomponents made to customer-supplied speci-fications. One form of direct participation, whichindustry sees as most valuable, allows the cus-tomer (e.g., DOE, a national laboratory, or even-tually an electric utility) to define a project andto assign responsibility for the task to a company.Industry can also act as a prime contractor orproject manager; in this case, industry is directlyresponsible to a customer for defined aspects ofmanagement, engineering, fabrication, and instal-lation of a product, such as a fusion device orpower reactor.

Industry as Sponsor.—The most extensivelevel of industrial involvement will be the spon-sorship of private R&D activities. Sponsorship in-cludes the contribution of direct funds, labor, orboth. As a sponsor, industry finances its own re-search program independently, whereas as a di-rect participant industry’s activities are largelyfinanced by the Federal Government. Sponsor-ing privately funded R&D requires confidence inthe eventual profitability of the technology.

Current Industrial Activities

To date, industrial involvement in fusion re-search primarily has been advisory, with limited

cases of direct participation. Industry represent-atives serve on the Energy Research AdvisoryBoard and the Magnetic Fusion Advisory Com-mittee, both of which advise DOE on the fusionprogram. Other industrial participation is facili-tated through sub-contracts from national labora-tories.

Only one private company, GA Technologiesof San Diego, California, participates significantlyin fusion research. GA Technologies is a privatefirm that conducts fusion research under Federalcontract. In this sense, GA has been comparedto a national laboratory in the field of fusion re-search. The company became involved in fusionresearch during the 1950s, when the energy ap-plications of fusion were thought to be closer.Because GA Technologies (then called GeneralAtomic Corp.) was able to assemble a high-qualityteam of fusion scientists and engineers, the Fed-eral Government has funded the bulk of its fu-sion research since 1967, when GA lost its pri-mary source of private fusion support. In FY 1987,GA Technologies received 10 percent of DOE’sfusion budget.

The fusion program at GA Technologies con-sists primarily of tokamak confinement research;GA operates the Doublet II I-D (D III-D) tokamak,which is the second largest tokamak in the UnitedStates. 28 D II I-D is also the largest U.S. interna-tional project. Japan and the United States,through GA Technologies, have jointly financedand operated the D II I-D facility since 1979.29

In addition, GA Technologies and Phillips Pe-troleum Co. invested over $30 million in invent-ing, fabricating, developing, and operating theOhmically Heated Toroidal Experiment (OHTE)at GA. OHTE is the only major fusion experimentconstructed and operated largely with privatefunds. OHTE was completed in 1982 and oper-ated until 1985. In 1985, GA and Phillips re-quested financial support from DOE for furtherdevelopment of the concept. However, DOEwould not fund this additional work, initiating acomparable program at LAN L instead. Without

Z8The Tokamak Fusion Test Reactor (TFTR) at Pri fK@On pbSma

Physics Laboratory is about twice as large as D III-D.zgFor more information on the international cooperation aSpeCtS

of GA’s D II I-D experiment, see ch. 7, pp. 162-163.

Ch. 6.—Fusion as a Research Program s 149

Photo credit: GA Technologies

OHTE fusion device at GA Technologies, San Diego,California.

Federal financial support, OHTE was discon-tinued. In mid-1986, DOE agreed to provide GAwith a grant to operate OHTE, and the experi-ment was restarted. Recently, DOE decided notto renew GA’s operating grant for OHTE after FY1987; it is anticipated that the experiment will bepermanently mothballed.

At this stage in the research program, other pri-vate companies have found no compelling rea-son to sponsor fusion research. Even GA Tech-nologies’ involvement would be severely limitedwere it not for extensive Federal funding. Nei-ther are electric utilities currently conducting fu-sion research. By 1986, the Electric Power Re-search Institute (EPRI), a utility-funded researchorganization, had phased out what had been a$4 million per year program. According to theformer EPRI fusion manager, EPRI is unwilling tospend money on fusion because the energy ap-plications are so long-range.30 Individual utilities

Robert Scott, “Industry and Perspectives on FutureDirections in Fusion Energy Development, ” Energy, vol. 5, No. 2, June 1986, p. 138.

are not conducting fusion research either, be-cause of the large investment required and thedifficulty of convincing regulatory agencies to al-low research costs to be transferred to ratepayers.

An MFAC panel on industrial participation infusion noted that:

fusion commercialization is sufficiently far in. . .the future and fusion technology sufficiently spe-cialized so that significant cost sharing [betweenthe Federal Government and the private sector]should not be expected. The government and itsnational laboratories are the immediate custom-ers and should pay the full cost of received prod-ucts and services. Jl

The position of industry, at least until commer-cialization is closer, appears to be a subordinaterole supporting the national laboratories and uni-versities.

The role of industry in the U.S. fusion programis completely different from its role in the Japa-nese program, where mechanisms for technol-ogy transfer from government to industry havebeen institutionalized. In Japan, the Japan AtomicEnergy Research Institute (JAERI) and various na-tional laboratories and universities conducting fu-sion research contract with industry to do all thedesign, research, and development that is nec-essary. As in the United States, the financial con-tribution of Japanese industry to fusion researchis small. However, its role is critical; accordingto one JAERl official, the Japanese Government’srole is limited to “resolving what type of machineis needed and designing it, ” and even this taskis “shared” with industry.32 Thus, Toshiba, Hitachi,and Mitsubishi are intimately involved in fusionresearch.

In the United States, in contrast, fusion is pri-marily a government research program. The na-tional laboratories maintain large engineeringstaffs and have strong manufacturing capabilities.

Fusion Advisory Committee Panel VI Report on Participation in Fusion Energy Development, May 1984,

5-2 to 5-3, official, quoted in H.

national in Magnetic Fusion Energy: The IndustrialRole. A Strategy for Industry Participation in an International Engi-neering Test Reactor Project, prepared for the U.S. Department ofEnergy, Office of Fusion Energy, August p. 15.


DOE has only a limited role at present for involv-ing industry in fusion research; industrial partici-pation is typically ad hoc. Due to the budget cutsin recent years, the role of industry has beenadditionally limited, both because of the few ma-jor new projects undertaken and because con-stricted budgets have made the national labora-tories reluctant to subcontract to industry. Therole of industry in the U.S. fusion program is notinstitutionalized.

Establishing an Industrial Basefor Fusion

Under current administration policy, the pri-vate sector will be responsible for the demonstra-tion and commercialization of fusion technology.As discussed in chapter 5, it is important to estab-lish an industrial capacity on which the privatesector can base its development efforts. An MFACpanel on industrial participation in fusion re-search concluded that:

. . . if a utility is to invest capital to build a fusionprototype or power plant, it must have confi-dence in its suppliers. This confidence can beestablished only if the suppliers have been qual-ified through active participation in the fusionprogram and have a record of furnishing qualitygoods and services.33

Currently, there is controversy over how to pre-pare the industrial base. In particular, there is ex-tensive disagreement over the timing of indus-trial participation in the research program priorto the demonstration and commercializationstages.

For the research phase of fusion development,many fusion scientists contend that industryshould be an advisor or low-level direct partici-pant supporting national laboratories and univer-sities. Given the current budget situation and thenature of the research to be completed beforedemonstration and commercialization, these in-dividuals believe that there are not enough op-portunities appropriate for industry to developand maintain a standing capability in fusion.Moreover, since the private sector is reluctant toinvest its own funds, proponents of this position

JsMagnetic Fusion Adviso~ Committee panel Vll, op. cit., pp. 2-4.

maintain that it is too early in the program to en-courage substantial industrial participation. Theypredict that as demonstration and commerciali-zation approach, industry will naturally becomemore interested in the applications of fusion tech-nology, hopefully to the point where they arewilling to invest money to explore the technol-ogy’s potential. These individuals believe thatlimiting industry’s participation in the near-termwill not preclude its eventual role in demonstra-tion or commercialization; they believe prema-ture industrial involvement could be detrimental.

Others argue that it is essential to involve in-dustry in the research effort before the demon-stration stage. The proponents of early industrialinvolvement stress that technology transfer shouIdoccur from the national laboratories and univer-sities to private industry at all stages of the re-search program, and that such transfer cannot beeffective without active industrial participation.The willingness of industry to invest in the tech-nology should not be used as a criteria for de-termining the appropriate degree of involvement,these people argue, because industry needs in-formation and expertise to accurately assess thevalue of the technology.

According to these individuals, early involve-ment of industry and utilities ensures that thetechnology developed will be marketable by ven-dors and attractive to its eventual users. Technol-ogy transfer will take time; if this transfer is notstarted until after completion of the research pro-gram, fusion’s overall development could be de-layed. In addition, proponents of this position citea variety of near-term benefits of industrial par-ticipation, including increasing support for the fu-sion program, facilitating spin-offs from fusion toother technologies, and transferring skills ac-quired by industries involved in fusion to otherareas of high-technology such as aerospace anddefense.

The impact of various levels of industrial par-ticipation in the research program on the success-ful commercialization of fusion technology can-not be determined now. Since the mechanismsfor transferring responsibility for fusion’s devel-opment from the Federal Government to the pri-vate sector are not yet known, the impact of early


industrial participation on the pace and effective- commercialize fusion technology. If the indus-ness of this transfer is unclear. However, even trial base is insufficient, it will not only be diffi-without linking near-term industrial participation cult for industry to construct and operate a dem-in research to the success of future development, onstration reactor, but the customers (probablya well-established industrial base must be in place electric utilities) will be reluctant to purchase fu-before the private sector can demonstrate and sion reactors.

SUMMARY AND CONCLUSIONS

Fusion research has provided a number of near-term benefits such as development of plasmaphysics, education of trained researchers, con-tribution to “spin-off” technologies, and supportof the scientific stature of the United States. How-ever, fusion’s contributions to these areas doesnot imply that devoting the same resources toother fields of study would not produce equiva-lent benefits. Therefore, while near-term bene-fits do provide additional justification for conduct-ing research, it is hard to use them to justify onefield of study over another.

Virtually all of the money spent on fusion re-search in the United States comes from the Fed-eral Government. The fusion program is DOE’sfifth largest research program, and in recent yearsthe program has been relatively well-funded com-pared to DOE’s other energy R&D programs.Nevertheless, the budget for magnetic fusionR&D has fallen by about a factor of 2 since 1977(in constant dollars). These budget decreaseshave severely constrained program activities.

Funding limitations have affected the activitiesof all three major groups that conduct fusion re-search: national laboratories, universities and col-leges, and private industry. Few new construc-tion projects have been initiated in recent years,and research in some areas (particularly mirrorfusion) has been curtailed or eliminated. More-

over, many researchers have left fusion. Budgetcuts have also interfered with the attainment ofthe program’s near-term goals. In particular, theability of the fusion program to attract new re-searchers to its university programs and to trainthem has suffered. Constrained budgets also limitthe participation of industry in fusion research.In addition, the United States is no longer the un-disputed leader in fusion research; the Japaneseand European fusion programs have caught upwith—and may have even surpassed—the U.S.effort.

OTA has not evaluated whether Federal fusionresearch funds are being spent in the most effec-tive and efficient manner. Neither has it evalu-ated the appropriate priority to be given to fu-sion research as compared to other researchprograms. Comparisons among R&D programsare difficuIt to make and are typically not madeexplicitly during the budgetary process. There-fore, comparative funding levels do not neces-sarily provide an indication of relative priority.The appropriate funding level given to fusion re-search depends on the motivations and goals ofthe program. It also depends on where themoney will come from—whether from cuttingother programs or from additional sources ofrevenue—and the impacts of these funding choicesreach far beyond the program itself.

Chapter 7

Fusion as an International Program

'CONTENTS

Page Inttoduction .......................................................... 155

Why Cooperation Is Attractive .............•......................... 155 Forms of Cooperation • . . . • . . . . . . . . . . .. : . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156

Major International Agreements .. , .................................... 158 Multi lateral Activities . . . . . . . . . . . . . . • . . . . . . . . . . . . . . . . . . . . . . . ... , .... , 158 , 8ilateral, Activities .....................,....,...................... 161

EvaluatIOn of Collaboration ... .-, .....•..... , .. ,. . . . . . . . . . . . . . . . . . , .... 164 8!enefits~ and Risks " • • • . . . • . • . . . . , . . . . . • . . . . . . . . . . . . . . . . . . . . . . . . .... 164 :.<;lbstaCres • • • • ':.; ;:. ; • :. 1;' !! • ,~ • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • , • • • • • • 166

,:~;:-" flalement ApproacMs ........................................... 170 ~arison of International Fusion Programs ... , ...•................ , ... 174 , QiJfrafative :Comparisons , ............................. , . . . . . . . . . . . . . 174

Quantitative Comparisons ........... , ......... , .... , ................ 174 Potential Partners ., .. "............ .......•........ , ...... ,........, 179

The Unked States ......... , ..... ,., ..... , ... , .. ,., ........... ,', .. 179 The European Community .......................................... 180 The Soviet Union .....••........................................... 180 japan .•........... ' ~ •............................................. 161

ProsPects for International Cooperation ................................. 182 U.S. Plans for Futu re Cooperation ................... , ............... , 182 Analysis of U.S. Proposal for ITER .......•..•......................... 185

Summary and Conclusions ..•••............................. , ......... 185

Fllure. Figure No. . Page "·1; Emphases of Major Programs on Confinement Concepts, 1986 .......... 175 7.:.2. Emphases of Major Programs on Technology Development, 1986 ........ 175 1·3. Cornparison of International fusion, Budgets .......................... 176 i .... ~ ~Compartson of intemational Equivalent Person-Years .................. 177 7-5. C()fhparison of International Fusion Budgets by Percentage of Gross

National Product . . . . . . . . . . . . . • . . . . . . . . . . . . . . . . . . . ............... 178

Tabl •• Tlble No. Page 7·1. C9rnparison of Type of Cooperation and Level of Agreement ........... 157 '.2. Principal International Fusion Activities •............................. 158 7~3. Applicability of Existing Projects to Future fusion Collaboration ......... 173 7-4. Pro8ram Goals of Major fusion Programs ............................ 174

Chapter 7

Fusion as an International Program

INTRODUCTION

Many nations of the world have cooperated onmagnetic fusion research for almost 30 years.Since U.S. magnetic fusion research was declas-sified in 1958, the major international programshave engaged in regular information and person-nel exchanges, meetings, joint planning efforts,and jointly conducted experiments. ’

The leaders of the U.S. fusion community con-tinue to support international cooperation, asdoes the U.S. Department of Energy (DOE). Inthe past, the United States cooperated interna-tionally on a variety of exchanges that have pro-duced useful information without seriously jeop-ardizing the autonomy of the domestic fusionprogram. In recent years, in response to budget-ary constraints and the technical and scientificbenefits of cooperation, DOE has begun coop-erating more intensively i n fusion, and the majorfusion programs have become more interdepen-dent, For the future, DOE proposes undertak-ing cooperative projects that will require theparticipating fusion programs to become signif-icantly interdependent; indeed, DOE now seesmore intensive international collaboration as afinancial necessity.

Why Cooperation Is Attractive

Without exception, all of the major fusion pro-grams participate in international activities andlook favorably on more intensive future activi-ties. There are several reasons for this widespreadinterest. 2

‘Major fusion programs are currently active in the United States,Japan, the European Community (EC), and the Soviet Union. Pri-mary contributors to the European Community’s fusion programare the Federal Republic of Germany, France, Italy, and the UnitedKingdom, although other member nations are also involved.

ZThe reasons that follow were based i n part on a discussion ofIncentives to collaborate found in: Energy Research Advisory Board,International Co//~? boration in the U.S. DOE’s Research and De-ve/oprrrent Programs, report to the U.S. Department of Energy, pre-pared by the ERAB International Research and Development Panel,D(lE/S-0047, December 1985, p, 11,

Fusion Research Is Expensive

The high cost of fusion research is a practicalincentive for nations to cooperate. The next-gen-eration engineering test reactor, for example, isexpected to cost well over $1 billion and possi-bly several times that much, requiring a substan-tial increase in U.S. annual fusion budgets if itwere to be built domestically. It is not clearwhether or not the governments of any of the ma-jor fusion powers would be willing to constructsuch an expensive experiment alone. Given theexpense and considering the similarity in next-step program goals, the major fusion programshave agreed in principle that the world does notneed four engineering test reactors of the samekind. Limited funding can be allocated more effi-ciently if nations are willing to collaborate on onemajor experimental facility.

Fusion Programs Areat Comparable Levels

The comparable levels of progress among themajor fusion programs make higher levels of co-operation attractive, particularly over the nextdecade. While there are differences in empha-sis and achievement, the programs have com-parable scientific and technical capabilities andrecognize the need for similar next-generation ex-periments. Cooperative projects are easier to im-plement in complementary programs because thebenefits can be distributed equitably and becauseall participants stand to gain from their partners’expertise.

Fusion Can Advance More Effectively

International collaboration in fusion researchis attractive because it provides a forum for sci-entists and engineers to interact. If the major pro-grams can coordinate their activities, the intel-Iectual resources available to address pressingissues in fusion research and development (R&D)can increase dramatically.

155

— — .


Forms of Cooperation

International cooperative efforts range fromsimply exchanging information in internationalmeetings through the joint construction and oper-ation of experimental devices to complete in-tegration of research efforts.3 Various types ofcooperation entail different levels of program in-tegration, information transfer, and trust. The po-tential risks and benefits of the programs vary cor-respondingly.

It is necessary to make a distinction betweenthe terms “cooperation” and “collaboration. ”This report will adopt the usage of a recent Na-tional Research Council report on cooperationin fusion research.4 Throughout this OTA assess-ment, “cooperation” will refer to all activities in-volving nations, or individuals from different na-tions, working together. “Collaboration,” a moreintensive type of cooperation, will describe activ-ities involving a substantial degree of program in-tegration, funding commitment, and joint man-agement.

Types of Cooperation and Collaboration

●

●

�

Information Exchange. Information exchangeis the most common form of international co-operation. Information on achievements andadvances, as well as technical approaches andexperimental data, is exchanged through sev-eral channels, including meetings, conferences,symposia, workshops, and publication in tech-nical journals.

Personnel Exchange. Personnel exchanges–visits and assignments—also are widely used.During a typical visit, research scientists tourone or more of the host program’s facilities for1 or 2 weeks. Assignments are extended staysin which the guest participant actually workson an experiment and contributes to the hostprogram’s research effort. For the duration ofthe assignment, the guest participant is a full-fledged member of the experimental or theo-

3A discussion of proposals for tutu re cooperation and collabora-tion now under consideration can be found later in this chapterunder “Prospects for International Cooperation. ”

‘National Research Council, Cooperation and Competition onthe Path to Fusion Energy (Washington, DC: National AcademyPress, 1984), p. 5.

●

●

●

retical team. Assignments are one of the mosteffective ways to transfer expertise.

Joint Planning. Joint planning includes activi-ties to identify areas for future cooperative re-search, to provide a forum for coordinating ex-perimental and theoretical programs on largeexperimental devices, and to avoid unneces-sary duplication of effort while still ensuringverification of important experimental or theo-retical results.

Joint Research. Through joint research, ma-jor facilities are made available for researchprojects of other programs. The facility is fi-nanced and constructed primarily by the hostprogram, with other participating programs ei-ther providing a percentage of constructionand operation costs or contributing equipment.In exchange for their contributions, participat-ing programs are granted access to the ma-chine and experimental data. Frequently, con-tributions of the participants enable an existingmachine to be upgraded; in some cases thesecontributions are essential to the constructionof the machine in the first place. Activities in-volving joint research are becoming increas-ingly common.

Joint Construction and Operation. Joint con-struction and operation of major experimentsand facilities are the most intensive forms ofinternational cooperation; this form of coop-eration is referred to as collaboration. Partici-pating programs agree to pool their resourcesand construct a commonly owned and oper-ated facility. There is no “host” program in thiscase; the facility is operated by a managementteam comprised of representatives from eachprogram.

Plans for future U.S. participation in interna-tional fusion activities include collaborative proj-ects in addition to the other levels of coopera-tion. The largest scale example of a collaborativeproject under discussion today would be a jointlyconstructed and operated engineering test re-actor. The current proposal for this experiment,called the International Thermonuclear Experi-mental Reactor (ITER), involves only conceptualdesign and supporting R&D for the project. If thisphase of the project is arranged and proves work-

Ch. 7.—Fusion as an International Program . 157

able, more extensive collaboration on construc-tion and operation could be considered.

If successfully negotiated, ITER probably willbe the world’s largest, most expensive, and mostvisible cooperative project. Therefore, this chap-ter primarily focuses on it. The full scope of DOE’splans for future cooperative activity includes avariety of additional, lesser facilities in areas suchas materials research and technology develop-ment. DOE plans to investigate more intensiveforms of cooperation–including joint research,planning, and possibly even joint constructionand operation of facilities—on these other proj-ects as well. The U.S. plans for future coopera-tion are analyzed in this chapter under “Prospectsfor International Cooperation.”

Types of Agreements

Different levels of international agreementscould be used to facilitate cooperation. Theseagreements can range from formal treaties downto informal workshops and publications:

● Treaty. A treaty between governments is themost binding and formal agreement that canbe established. Ratification signifies commit-ment to the substance of the agreement;obligations incurred under a treaty can beabrogated, but such action is not taken lightlyor often. However, a treaty is the most diffi-cult type of agreement to implement. Thereis a greater risk of negotiations breakingdown during the development of a treaty,and more issues must be resolved in orderfor a treaty to be ratified. Moreover, the ratifi-cation process for a treaty is time-consuming;a treaty may be obsolete by the time it is fi-nally ratified. In the United States, a treatymust be signed by the President and ratifiedby a two-thirds majority of the Senate.

● Heads-of-State Agreement. A heads-of-stateagreement is less formal than a treaty but isconsidered binding by most governments.Such an agreement carries the full weight ofthe government in power, and abrogationby a signatory head of state would bean un-usual, though not impossible, act. When thesubject of the agreement has a strong baseof support among many different groups, the

●

●

D

risk that the signing head of state, or a suc-ceeding one, would disavow the agreementis small.Ministerial-level Agreement. A ministerialagreement is arranged between ministries ofthe participating governments, and it is lessformal than either a treaty or a heads-of-stateagreement. It requires less review and ap-proval than the more formal agreements andis affected more directly by changes in bud-getary constraints and political objectives.However, it still carries the full weight of thegovernment. In the United States, ministerial-Ievel agreements in fusion research are ne-gotiated with participation of the Depart-ments of Energy and State.Informal Arrangement. An informal arrange-ment can be undertaken between govern-ments, laboratories, and individuals. It canprovide an excellent means of transferringinformation among scientists, but it does notprovide a basis for programmatic or interna-tional planning. This arrangement is typicallyinstituted on an ad hoc basis, in response toparticular needs and objectives of the par-ticipants.

ifferent types of agreements are appropriatefor the various forms of cooperation that occurin fusion and in other areas (see table 7-1).

Most cooperative efforts occur u rider a generalarrangement called an umbrella agreement. A n

Table 7-1.—Comparison of Type of Cooperationand Level of Agreement

Type of cooperation Level of agreement

Information exchange . . . . . . . Informal ArrangementMinisterial AgreementHeads-of-State Agreement

Personnel exchange . . . . . . . . . Informal arrangementMinisterial AgreementHeads-of-State Agreement

Joint planning . . . . . . . . . . . . . Ministerial AgreementHeads-of-State Agreement

Joint research . . . . . . . . . . . . . . Ministerial AgreementHeads-of-State Agreement

Joint construction andoperation . . . . . . . . . . . . . . . . Ministerial Agreement

Heads-of-State AgreementTreaty

SOURCE Office of Technology Assessment, 1987


umbrella agreement usually is established as partof a ministerial agreement before any specific co-operative agreement is instituted. It defines theprinciples of cooperation and provides a frame-work for developing future cooperative agree-ments. It is undertaken when governments areinterested in cooperation and want to formalizethe intent to cooperate. An umbrella agreementtypically states that the participating governmentssupport cooperation and are ready to begin ne-gotiating specific cooperative projects.

ogy, sets up joint planning and negotiation efforts,and provides a forum for exploring the potentialof future cooperation on medium- and long-termprojects. An umbrella agreement is not a finalagreement. It is not intended to address the sub-stantive issues involved in decisions to undertakespecific cooperative projects. It is a useful device,however, for defining areas of potential cooper-ation and for creating a framework for negotiat-ing future agreements.

Frequently, an umbrella agreement authorizestransfer of preliminary information and technol-

MAJOR INTERNATIONAL AGREEMENTS

Under current arrangements, the United Statesparticipates in cooperative fusion activities at alllevels except that of joint construction and oper-ation. To date, only one international fusion proj-ect has been collaborative in this sense: the jointEuropean Torus project of the European Com-munity (EC). Table 7-2 summarizes the principalexisting international fusion arrangements; theorganizations and agreements mentioned in thetable are described below.

Multilateral Activities

International Atomic Energy Agency

The International Atomic Energy Agency (IAEA)has been one of the most important facilitatorsof fusion cooperation. The IAEA is an independ-ent intergovernmental organization within theUnited Nations system, and its mission is to pro-mote and ensure the peaceful use of atomic

Table 7-2.—Principal International Fusion Activities

Type of cooperation Representative project Agreement

Information exchange. . . . . Large Tokamak AgreementNuclear Fusion journalConferences

Personnel exchange . . . . . . Large Tokamak Agreement50 transfers each waySix transfers each wayTo be determined

Joint research . . . . . . . . . . . ASDEX UpgradeLarge Coil TaskDoublet III-D UpgradeTore Supra

Joint planning . . . . . . . . . . . INTORLarge Tokamak AgreementJoint Institute for Fusion TheoryTo be determined

Joint construction andoperation . . . . . . . . . . . . . . Joint European Torus

SOURCE: Office of Technology Assessment, 1987.

IEAIAEAIAEA

IEAU.S.-Japan BilateralU.S.-USSR BilateralU.S.-EC Bilateral

IEAIEAU.S.-Japan BilateralU.S.-EC Bilateral

IAEAIEAU.S.-Japan BilateralU.S.-EC Bilateral

European Community

Ch. 7.—Fusion as an International Program “ 159

energy. The headquarters of the IAEA are locatedin Vienna, Austria. All countries currently doingfusion research are members of the IAEA. It hasfacilitated two different types of cooperative activ-ity: information exchanges and joint planningefforts.

Major informational activities conducted by theIAEA in the area of fusion research include host-ing biennial meetings and arranging topical meet-ings and workshops on areas of special interestor concern. In addition, the IAEA publishes atechnical journal, Nuclear Fusion, in which fu-sion researchers can share their findings.

The IAEA also facilitates a joint planning activ-ity, called the International Tokamak Reactor (l N-TOR) design study. INTOR began in 1978, andit involves the European Community, Japan, theSoviet Union, and the United States. The goal ofINTOR is to define concepts and designs for aconceivable next-generation fusion experiment.It is a forum where Western fusion scientists haveregular contact with their Soviet counterparts. Na-tional teams work on parallel tasks and meet twoor three times a year for several weeks to com-pare results and plan future work. Most analystsagree that INTOR discussions have successfullyidentified critical issues in both physics and tech-nology.

International Energy Agency

The International Energy Agency (IEA) was cre-ated by 21 Western oil-importing nations in 1974in response to the OPEC oil embargo. IEA’s maintask is to plan for crisis response to future oil em-bargoes. In addition, the IEA also promotes in-ternational cooperation in research and devel-opment of energy technologies that have thepotential to decrease the West’s dependence onoil imports, The European Community, Japan,and the United States participate in IEA’s coop-erative projects. Magnetic fusion research is oneof many areas IEA promotes, largely by facilitat-ing joint research efforts. The IEA is headquar-tered in Paris, France.

In 1977, the Large Coil Task (LCT) was orga-nized u rider the auspices of the I EA. As part ofthe LCT, the U.S. fusion program constructed theInternational Fusion Superconducting Magnet

Test Facility at Oak Ridge National Laboratory inTennessee at a cost of about $40 million. This fa-cility is designed to test superconducting magnetcoils. s It holds six large coils, one each con-structed by the European Atomic Energy Com-munity, the Japan Atomic Energy Research Insti-tute, and the Swiss Institute for Nuclear Researchand three constructed by U.S. manufacturers.6

Each coil cost between $12 million and $15 mil-lion to construct. international involvement in theLCT has distributed the costs of the project amongseveral nations, and it has also enabled differenttypes of coils to be tested in a common facility,allowing direct comparison. Moreover, the LCTis the major instance in the fusion area that in-volved industry in international cooperation.

Several other cooperative projects also occurunder IEA auspices. The European Communityand the United States participate in joint plan-ning on next-generation stellarator experimentsto coordinate their research efforts. It appears thatJapan will soon be joining this project. Throughthe IEA, the United States and the European Com-munity are also conducting joint research on theAxisymmetric Divertor Experiment (ASDEX) andits upgrade (ASDEX-U). These facilities are locatedat the Institute for Plasma Physics at Garching,Federal Republic of Germany, and U.S. partici-pation in this research has made it unnecessaryfor the United States to construct similar facilities.The IEA provides no funding for any of theseprojects, only an umbrella framework and minorsecretariat functions.

The most recent IEA agreement, signed in Jan-uary 1986, provides for cooperation among thethree large operational tokamak experiments (jT-60 in Japan, the joint European Torus (JET) in theEuropean Community, and the Tokamak FusionTest Reactor (TFTR) in the United States). Underthis agreement, the three programs conduct per-sonnel and information exchanges for tokamakexperiments. An executive committee, consist-ing of two members from each fusion program,

5For a discussion of the role of superconducting magnets in a fLJ -

sion reactor, see the section of ch. 4 titled “The Magnets” under“Fusion Power Core Systems. ”

W .S. Department of Energy, Office of Energy Research, ,14agnefrcFusion Energy Research: A Summary of Accomp/ishmerrts, DOE/ER-0297, December 1986, p. 19.


Photo credit: Oak Ridge National Laboratory

The International Fusion Superconducting Magnet Test Facility at Oak Ridge National Laboratory, containing the sixsuperconducting magnets.

will meet at least once a year to coordinate re-search. The agreement is in effect from 1986 to1991. This agreement has the potential to evolveinto joint planning and program coordination.

Joint European Torus

The joint European Torus is Europe’s most im-portant experimental fusion facility and the world’slargest tokamak. JET is a joint undertaking of themember nations of the European Community; ithas been designed, constructed, and operatedby the EC. The JET Working Group was createdto explore the project in 1971; the device wasapproved by the EC Council of Ministers in 1978,

following a political wrangle of 21/2 years overproject location.

The JET experiment is located adjacent to theCulham Laboratory, in Abingdon, United King-dom. The land on which JET is constructed is tem-porarily leased from the United Kingdom; at thecompletion of the project the land will be returned.Construction of JET began in 1977, and the facil-ity began operating in 1983; current plans callfor JET to operate until about 1992.7

of design phase and the political negotia-

tions concerning JET, see Denis A European Experiment: Launching of Project (Bristol, U. K.: Adam Ltd.,

1981 ).

Ch. 7.—Fusion as an International Program ● 161

Photo credit: JET Joint Undertaking

The Joint European Torus, located in Abingdon,United Kingdom.

Legally, JET is an independent international en-tity; it is not a national project. The JET adminis-trative structure is multinational. The project ismanaged by a project director on site, but all im-portant strategic decisions must be presented toand approved by the JET Council, which is com-prised of two members from each participatingnation, one of which is a scientist. When theproject is completed, the administrative structurewill be dismantled.

JET is staffed by two distinct and roughly equal-ized groups: the multinational staff supported bythe EC and a local staff supported by the UnitedKingdom Atomic Energy Agency. Provisions havebeen made for staff to return to their national fu-sion programs after completion of their appoint-ments at JET.

The EC pays 80 percent of the costs of JETthrough the contributions of member nations. inaddition to their contributions through the EC,the national programs also contribute directly tothe project. Direct national contributions repre-sent 10 percent of the costs. The final 10 percentis a site premium paid by the United Kingdom.This premium offsets the financial benefits thatthe host country receives from the project. In thelast 5-year budget plan, approved in 1985, fund-ing for the overall EC fusion program for 1985-89 was set at 690 million European CurrencyUnits (worth at that time about $766 million). Ofthis amount, roughly half will go to JET.

The JET model has been effective and efficient.Through cooperating on the project, national pro-grams have saved money, have had access to aworld-class experiment, and have advanced thestate of European scientific research.

Bilateral Activities

United States-Japan Bilateral Agreement

In 1979, a ministerial-level agreement was signedcommitting the United States and Japan to co-operate on general energy research and, morespecifically, to develop commercial fusion powerfor the 21st century. Within the framework of thisumbrella agreement, the United States and Japanhave negotiated several specific cooperativeagreements. The U.S.-Japan cooperation is themost extensive international cooperation in fu-sion research in which the United States partici-pates. Information and personnel exchanges,joint research activities, and joint planning activ-ities all occur within the context of the umbrellaagreement.

About 50 formal personnel exchanges occureach way annually between the United States andJapan. 8 There are also a few (usually under 10)personnel exchanges arranged yearly on an adhoc basis; these informal exchanges enable thepartners to accommodate unique program needs.

‘Michael Roberts, rector I Programs, U Energy, Fusion Energy, letter to the

Technology Aug. 1986.


Photo credit: GA Technologies, Inc.

D II I-D fusion device at GA Technologies, San Diego, California, showing neutral beam injection systems.

Under the umbrella agreement, a specific agree-ment to conduct a major joint research projectwas also signed in 1979. Through this agreement,Japanese involvement in the upgrade of the U.S.Doublet Ill (D Ill) tokamak was formalized.9 T h eJapanese and the Americans shared machine timeon the experiment equally, and both have hadaccess to all data generated in the experimentsrun on the machine.

“U.S. of Energy, Magnetic fusion Energy Research,op. cit., p. 20.

The United States hosts the Doublet project,which is located at GA Technologies’ laboratoryin California. Since 1979 the project has had jointfunding and a joint management team. Between1979 and 1984, the United States contributed$104 million and the Japanese contributed $62million to finance an upgrade in the D Ill facility(after the upgrade the name was changed to D III-D). In 1983, the agreement was extended until1988, and additional upgrades were undertakenfor which the United States is contributing $37.8million and Japan $8.5 million. Currently, discus-


sions are underway to extend cooperation until1992. 10

The Doublet cooperation has provided bothparties with access to a state-of-the-art tokamakfor much less than the cost of independently con-structing and operating the experiment. In fact,it is unlikely that the D Ill upgrades would havebeen possible without Japanese funding contri-butions. In addition, Japanese and U.S. scientistsboth have made valuable technical contributionsto the experiment that have improved the scien-tific quality of the project.

Within the context of the U.S.-Japan umbrellaagreement, the countries also have undertakenjoint planning activities. The United States andJapan have created a joint Institute for FusionTheory (JlFT) and designated two theory centers,one at the University of Texas at Austin and theother at Hiroshima University in Hiroshima, Japan.Each fusion center has continued to operate in-dependently, and a coordinating committee hasbeen created to oversee and guide cooperativeactivities.

United States-U.S.S.R.Bilateral Agreement

The Soviet Union has cooperated extensivelywith the United States and has made substantialcontributions to the U.S. fusion program (see thehistory of tokamak development in ch. 3). TheUnited States and the Soviet Union have had aformal agreement to cooperate in fusion researchsince 1958. In 1973, this agreement was strength-ened, under the Nixon-Brezhnev Accord, to ex-tend and broaden cooperation in fusion research.Most of the detailed information that the U.S. fu-sion program has about the Soviet program comesfrom the U.S.-Soviet exchange activities.11

Under the terms of the Nixon-Brezhnev Ac-cord, 12 personnel exchanges occur between theUnited States and the Soviet Union annually, six

——. .—10Test;mony of Dr. David Oversket, Senior Vice President at GA

Technologies, Inc., before the House Science, Space, and Tech-nology Committee, Energy Research and Production Subcommit-tee on the Fiscal Year 1988 Magnetic Fusion Energy Budget, Feb.24, 1987, p. 4.

11 u .s, Depa~rnent of Energy , Of f i ce of Fusion Energy, ~Va/Ua-

tion of Benefits of Cooperation on Magnetic Fusion Energy Betweenthe United States and the Soviet Union for the period 1983 to 1985,November 1985.

in each direction. These exchanges are limitedby the United States to fusion science issues, suchas experiments and theory, with no regular in-teraction on technology development .12 Most ofthe personnel exchanges are visits; some are as-signments, however, which have given Soviet sci-entists an opportunity to work with U.S. scien-tists on research projects, and vice versa,

The U.S.-U.S.S.R. bilateral agreement is vulner-able to the political situation between the twocountries. For example, no exchanges occurredduring 1980 or 1981, the years following the So-viet invasion of Afghanistan. However, since the1985 U.S.-U.S.S.R. summit meeting in Geneva,bilateral activity between the nations has progressedto a point where collaboration with the SovietUnion on the conceptual design and supportingR&D of a major fusion experiment is being con-sidered. 13

United States= European CommunityBilateral Agreement

The United States and the European Commu-nity have cooperated extensively for more than30 years without a formal bilateral agreement.Until recently, most cooperation involving the ECand its member states was conducted indirectlythrough the I EA. While this cooperation was re-warding, many tasks were not easy to arrangeunder the existing arrangements.

A ministerial agreement was signed betweenthe United States and the EC in December 1986.Because the agreement was signed so recently,details for all of the activities that will occur withinits framework have not yet been formalized. Ar-rangements have been made for joint researchat the JET facility in the United Kingdom and atthe Tore Supra facility in France. The agreementwill provide an annual forum for managementdiscussions about bilateral cooperation issues andwill establish a legal basis that can simplify theexchange of hardware and the initiation of somecooperative endeavors. It also will increase themobility of European scientists; within the EC, aformal agreement helps facilitate personnel ex-changes.

I Zlbid., app. A.1 IThe Geneva summit meeting and the SU bseq uent proposal for

a major fusion collaboration involving the Soviet Union are dis-cussed on p. 184.

.


EVALUATION OF COLLABORATION

Benefits and Risks

Knowledge Sharing

All forms of international cooperation involveinformation transfer. Throughout the history offusion research, access to information–includingtechnical know-how, experimental data, and newtheoretical ideas—has enabled fusion scientiststo learn from each other. Innovative ideas anda wider variety of approaches to projects aremore likely to arise in an international versus apurely domestic program .14 Researchers can com-pare their experimental results with those of otherprograms, making it possible to verify results,identify anomalous data, and distinguish experi-mental results based on fundamental character-istics from results based on special features orflaws in a particular experimental device. Thus,scientific progress can occur more rapidly throughcooperation.

On the other hand, some observers feel thatextensive knowledge sharing between nationalfusion programs should be discouraged in the in-terests of national security and national competi-tiveness. These individuals believe that the ad-vantages of information transfer, in terms ofimproved scientific research, do not outweigh thedisadvantages of participating in extensive coop-erative projects.

Cost Sharing

One advantage of international cooperation isthat it potentially can save significant amounts ofmoney. Information and personnel exchangesenable independent programs to learn, at lowcost, about the research activities of other pro-grams. joint planning activities enable fusion pro-grams to coordinate activities to avoid duplica-tion of effort and to conduct mutually beneficialresearch. Most dramatically, joint research andjoint construction and operation of projects dis-tribute the costs of major experimental facilities,while still providing the experimental results toall participants.

lqsee U.S. Departrnerrt ot Energy, Office of Energy Research, /fJ-

ternational Program Activities in Magnetic Fusion Energy, DOE/ER-0258, March 1986, p. 5; or National Research Council, Coopera-tion and Competition, op. cit., p. 19.

The full extent of the cost savings is unclear,however. As the National Research Council re-port pointed out, because cooperation requiresextensive negotiation and more formal manage-ment structures, the total administrative costs ofconstructing and operating a cooperative projectare higher than if the same project were con-structed independently.15 Moreover, there areadditional costs if the facility is not sited in theUnited States, such as lost domestic contracts,employment, and support facilities.16 Althoughthese added costs temper the financial benefitsof international cooperation, it is expected thatthe contribution of any one partner will be lessthan the cost of that partner proceeding inde-pendently with an identical project.

Risk Sharing

International cooperation on majormental facilities can mitigate the risk of

experi -project

failure by spreading the financial and program-matic costs over all participants. Constructing andoperating large experimental facilities is expen-sive; the cost of failure, both monetarily and ona program’s morale and future plans, can be high.Through sharing knowledge between major fu-sion programs, there is a greater probability ofscientific or technical success, In addition, the for-mal agreements required to negotiate an inter-national project and the political implications ofabandoning such an undertaking may serve tostabilize national commitments to the project.

On the other hand, some scientists feel that theabsence of competition and duplication among

I JNationa[ Research Counci 1, Cooperation c?nd competition, op.

cit., p. 31. Actual statistics are difficult to collect; however, one su r-vey of technical personnel involved in the I NTOR workshop indi-cated that constructing INTOR as an international project wouldincrease total costs by about 70 percent, staffing requirements by15 percent, and require 2 years longer to complete. It is not clearthat these projections are generally applicable; cooperative con-struction of JET probably did not inflate costs this much. However,no matter to what degree, collaboration will tend to increase con-struction times and project costs.

IGTesti mony of Dr. Walter A. McDougall, Associate ?rOfeSSOr of

History at the University of California–Berkeley, Science Po/icyStudy Vo/ume 7: /nternationa/ Cooperation in Science, Hearing be-fore the Task Force on Science Policy of the Committee on Sci-ence and Technology, House of Representatives, 99th Cong., 1stsess., June 18-20 and 27, 1985, p. 70.


experimental facilities may increase technical riskand that extensive cooperation may increase therisk of abandonment before project completion.Some members of the fusion community pointout that coordinating research to the point ofjointIy constructing a single international facility,as opposed to comparable national facilities,would eliminate the potential for validating ex-perimental results through comparisons betweendifferent machines of similar size and purpose.With more than one machine, a number of differ-ent scientific and technical approaches could beexplored, and experimental results among ma-chines could be compared. In addition, some feelthat the absence of competition among facilitieswill lead to more conservatism in design andoperation, which can limit progress. Finally, allparticipants must fulfill their financial and person-nel obligations if the project is to succeed, espe-cially with larger, more complex projects that ex-tend over several years. The entire project canbe jeopardized if even one nation abrogates theagreement, and cancellation can have implicationsfar broader than just one abandoned project.17

Diplomatic and Political Implications

A large cooperative experiment will clearlyhave significant diplomatic and political implica-tions. Many proponents of international cooper-ation believe the diplomatic and political conse-quences can be positive. The commitment tocooperate on an experimental fusion device isnot trivial; a commitment represents confidencein the reliability of the other participants and faiththat they can work together to the benefit of allinvolved. Through the negotiating process, differ-ences between partners can be reconciled and acommitment to a common goal can be affirmed.

In addition, the diplomatic value of a decisionto cooperate could be used to further U.S. ob-jectives and improve U.S. relations in areas other-wise unrelated to fusion, For example, an agree-ment to cooperate on magnetic fusion could bereached as part of a larger non-technical diplo-matic initiative. Some observers argue that suchdiplomatic benefits have been particularly valu-

I TNationa] Research COU ncil, Cooperation and Competition, op.

cit., p. 23.

able in the case of U.S.-Soviet cooperation, andthat more intensive cooperation with the Sovietsshould be pursued.

Some people consider these non-technical dip-lomatic benefits a positive feature of large-scalecooperative projects. Others, however, fear thatthe diplomatic implications of collaboration couldresult in the subordination of technical objectivesto non-technical goals, which would be undesira-ble. Moreover, some observers fear that interna-tional projects should be viewed cautiously be-cause broken cooperative agreements couldcomplicate international relations. If a nationabandoned its commitment in the course of a co-operative undertaking, there could be importantpolitical consequences. The fear of these conse-quences might even cause reluctance to ter-minate a technically undesirable project.

Domestic Implications

In addition to its technical benefits, manyproponents of cooperation support it as a methodof preserving the U.S. fusion program. These in-dividuals are concerned, at least in part, that cur-rent budgets are insufficient to maintain a viabledomestic fusion effort. At current funding levelsand as currently structured, the U.S. fusion pro-gram cannot construct and operate essential ex-perimental facilities on its own without dramaticcurtailment of other necessary aspects of the fu-sion effort. Collaboration proponents thereforesee intensive international cooperation as criti-cal for a challenging, growing U.S. research pro-gram. This point is made in the National ResearchCouncil report:

For the United States at this time, large-scaleinternational collaboration is preferable to amainly domestic program which wouId have tocommand substantial additional resources for thecompetitive pursuit of fusion energy developmentor run the risk of forfeiture of equality with otherworld programs.18

Increased international cooperation in fusionenergy research can also stabilize the commit-ment of the U..S Government to the magnetic fu-sion program.19 Moreover, international projects

‘81 bid., p. 11.‘g Ibid., p. 22.


often have more visibility than domestic under-takings and therefore can better mobilize publicsupport.

However, incentives for future collaboration onbig fusion projects must be traded off against avariety of other domestic concerns. Some mem-bers of the fusion community, for example, worrythat the United States might link the continuedviability of its fusion program to internationalactivities that it cannot adequately influence. *0Others are concerned that U.S. policy makersmight sacrifice the Nation’s domestic fusion pro-gram in order to promote international cooper-ation,21 particularly if domestic budgets were notincreased sufficiently to cover the additional costof an expensive cooperative project. In addition,some individuals are concerned that undesirablechanges in the direction of fusion research mightbe made to facilitate increased cooperation. Fi-nally, there is concern that the participation ofdomestic universities and industry in fusion re-search could be limited if the program empha-sizes international cooperation.

Obstacles22

A number of potential obstacles must be ad-dressed through negotiation before the UnitedStates can participate in large-scale cooperativeprojects in fusion research.

Technology Transfer

Transferring high technology to our partnerscould be the most serious political obstacle tomore intensive international cooperation. Manycritics worry that militarily significant technologycould be transferred, either directly or indirectly,to the Soviet Union through fusion cooperation,especially through joint construction and oper-

— ———,?ol bld ,

21 Ibid., p. 23.zzThe information in this section is based on a workshop on is-

sues in International Cooperation held by the Office of Technol-ogy Assessment, Washington, DC, on Oct. 14, 1986 (list of panelistspresented in front of this report); on reports done under contractto OTA by specialists in Japan, Europe, and the Soviet Union; ondiscussions and interviews conducted with members of the fusioncommunity; and on the National Research Counci I report Coop-eration and Competition, op. cit.

ation projects. Some analysts are also concernedthat cooperation in fusion could jeopardize U.S.competitiveness in international markets.

National Security .–Some of the technologiesdeveloped for use in fusion experiments–e.g.,high-power neutral beams, high-power micro-wave technology, and plasma diagnostics—can,with varying degrees of modification, have mili-tary applications. Various individuals and govern-ment agencies contend that the Soviet Union willbe able to utilize technology transferred throughmore extensive fusion cooperation for military ap-plications. According to Richard Perle, former As-sistant Secretary of Defense for InternationalSecurity Policy, “Soviet officials and agents havesuccessfully exploited the openness of the U.S.and European scientific communities to gathermilitarily useful technical information.”23 Oppo-nents of extensive cooperation with the Sovietscontend that it wouId be difficult, if not impossi-ble, to control the transfer of militarily sensitivetechnology in an experimental facility such asITER. In particular, opponents contend that long-term association with Western scientists will pro-vide disproportionate benefits to the Soviets. Op-ponents say that through the ITER project, Sovietscientists will be able to acquire Western know-how, technology, and experience in leading-edgetechnologies.

Supporters of cooperation do not claim thatmilitary applications of fusion-related technol-ogies are irrelevant, but they believe that manyof the concerns raised by opponents are over-stated. When examined in detail, proponents ar-gue, most of the objections disappear, and thosethat remain can be addressed on a case-by-casebasis. As the Director of the Office of Energy Re-search at DOE has stated:

It is my opinion . . . that a device of the sort weare talking about could be built and that the nec-essary computer activities associated with it couldbe carried out in a manner that did not involveany violation to COCOM regulations.24

zjRichard perle, Assistant Secretary of Defense for I nternatlona I

Security Policy, “Technology Security, National Security, and U.S.Competitiveness, ” /ssues in Science and Technology, fall 1986, vol.[II, No. 1, p. 112.

~aTestlmony of AIvin W. Trivelpiece, Director Of the office of

Energy Research, U.S. Department of Energy, Fisc~?/ Year /987’ De-


Proponents point out that, generally, fusiontechnologies are not directly applicable to mili-tary needs; those technologies that do have de-fense applications must undergo substantial modifi-cation and redesign before reaching militarysignificance. For example, although many of thetechnologies currently being investigated in theStrategic Defense Initiative were first developedfor or used by the magnetic or inertial fusion pro-grams, U.S. scientists are nevertheless spendingbillions of dollars to apply these technologies toweapons systems. Applying fusion technologiesto military uses may require as much indigenoustechnical capability as developing the technol-ogies in the first place.

Furthermore, supporters of U.S.-Soviet fusioncollaboration argue that those technologies pos-ing true risks can be identified through carefulreview procedures and that problems can be han-dled on a case-by-case basis. If, for example, aparticular component poses a significant technol-ogy transfer risk, the Soviets couId be asked toprovide it, its use could be restricted, or the ex-periment could be redesigned to eliminate it.

Proponents of increased cooperation insist thatthere are significant benefits to the United Statesfrom collaborating with the Soviet Union thatmust be weighed against the risks. Magnetic fu-sion research is not classified; information aboutexperiments, techniques, and methodologies areavailable in international publications. Moreover,as the Associate Director of Confinement at OakRidge National Laboratory noted:

Everything in the world is not done here. Inmany areas we are not ahead . . . We got the factthat you could make a gyrotron [a high-powermicrowave generator] from the Russians. All sortsof things came out of the Russian program .25

—.— .——partment of Energy Authorization: Magnetic Fusion Energy, Hear-ings before the Subcommittee on Energy Research and Production,Committee on Science and Technology, House of Representatives,99th Cong., 2d sess., Feb. 25-26, 1986, p. 24.

COCOM IS the acronym of the Coordinating Committee, an in-formal, voluntary, cooperative alliance through which the UnitedStates and its allies seek to control the export of strategic goodsand technology to the Eastern bloc, It is an intergovernmental com -m ittee, and 15 nations participate i n it—the NATO countries (ex-cept for Iceland and Spain) and Japan. Members of COCOM haveagreed to restrict export of certain specified items to Communistcou ntrles for strategic reasons.

25Mark Crawford, “Soviet-U.S. Fusion Pact Divides Administra-tion, ” Science, May 23, 1986, p. 926, quoting John Shefflelci, Asso-ciate Director of Conti nement at Oak Ridge National Laboratory.

72-678 () - 87 _ 5

Over the years, the Soviet Union has made val-uable contributions to fusion research, and itsparticipation in a major project would improvethe quality of the undertaking.

Undoubtedly, measures taken to resolve tech-nology transfer concerns will constrain the freeflow of information and technology between thepartners in collaboration. Such constraints maypose an obstacle to collaboration in their ownright: it is possible that after compromises havebeen made to satisfy technology transfer con-cerns, the proposed collaborative project mightnot satisfy the needs of the parties in the activ-ity, including the U.S. fusion community. If, forexample, it was decided that the use of old tech-nology would avoid the risk of transferring state-of-the-art technology, the overall capabilities ofthe device could be reduced, and as a result theproject could become less attractive.

The national security debate is not easily re-solved, and it involves underlying motivationsand assumptions concerning the U.S.-Soviet rela-tionship that go far beyond the details of any spe-cific technical exchange. Given the depth of thedebate within the U.S. Government, it appearsthat the United States will not be able to partici-pate in a major joint undertaking with the SovietUnion until these issues are settled. Many ob-servers contend that resolving the national secu-rity questions ultimately will require a presiden-tial decision.

U.S. Competitiveness.–Many analysts are con-cerned about the competitiveness of Americanindustry in international markets, and some arehesitant, in particular, about the long-term im-plications of intensive cooperation with the Jap-anese and the Europeans i n fusion.26 At present,U.S. industry is only minimally involved in thefusion program. If no provisions are made todirectly involve U.S. industry in future collabora-tive projects such as ITER, some observers fearthat U.S. industry could fall farther behind Japa-nese industry—particularly since Japanese indus-try is more directly involved in fusion research.27

jGThe General Accounting Office documents th IS concern in Its

report The Impact ot International Cooperation in DOE’s MagneticConfinement Fusion Program, report to the Honorable Fortney H.Stark, Jr., House of Representatives, GAO/RCED-84-74, February1984, pp. 13-14.

jTFor a more detai led d Iscussion of i nd ustria I participation I n the

U.S. fusion program, see the section in ch. 6 titled “Prl\ate in-dustry. ”


DOE does not consider U.S. competitivenessissues to pose a serious obstacle to increased co-operation in fusion. As DOE points out, magneticfusion is currently in a pre-competitive stage. Be-cause there are few commercial applications ofthe technology, there are no substantial risks fromsharing the technology internationally, Accord-ing to DOE, there appears to be little risk that theUnited States would sacrifice its future competi-tive position through near-term cooperative en-deavors.

Technical Differences

Successful cooperation on a major device likeITER requires that the partners agree on a com-mon set of goals and objectives, that their fusionprograms beat comparable levels, and that theybe moving in compatible directions. Differencesbetween the long-term objectives of the partners’fusion programs or research plans must be ac-commodated or resolved.

At present, all the major world fusion programsagree on the need for an experiment such as ITERand welcome it as an opportunity for more in-tensive cooperation. However, given the differ-ences in detailed technical objectives among theprograms, designing an experiment that satisfieseach program’s goals simultaneously will involvea great deal of negotiation and compromise.

Project Location

Siting major projects, whether domestically orinternationally, is traditionally time-consumingand politically sensitive. According to the Na-tional Research Council, selecting a project siteis a “frequent sticking point in large internationalprojects.” 28 Intense competition for the site of amajor international fusion project can be expected,since such a facility will be beneficial to local in-stitutions, may provide some advantage to localindustry, and will carry a great deal of prestige.

Most analysts believe it is unlikely that the fa-cility will be located in either the United Statesor the Soviet Union. It is not expected that ei-ther nation would participate if the project were

28National Research council, cOOpHdtbJ dfld cO~pe~ifiO~, op.cit., p. 57.

located within the other’s borders. In addition,with both the Western Europeans and the Japa-nese sensitive about superpower dominance,they too might be reluctant to site the project ineither the United States or the Soviet Union.

Even after the competition is narrowed downto one nation or region, internal competition forthe site will be intense. In the case of the JETproject, for example, the siting negotiations tookover 21/2 years to resolve and almost caused theabandonment of the project.29 The siting deci-sion for ITER probably will be even more diffi-cult, since it will be a larger facility and more na-tions will be involved. Collaboration on ITERrequires that the project have value to all partici-pants, including those that do not host it.

U.S. Commitment

Another difficulty for U.S. participation in a ma-jor international joint undertaking is the degreeof commitment by the U.S. Government to thefusion program. The U.S. fusion program hasfaced decreasing budgets, in real terms, for 9 ofthe last 10 years, and, given this recent history,international partners could reasonably questionU.S. commitment to the development of fusionenergy, Moreover, many nations already believethat cooperating with the United States is risky.A recent Energy Research Advisory Board panelon DOE’s international research and develop-ment activities concluded:

. . . the Department [of Energy] has a poor repu-tation abroad for long-term commitment to inter-national collaborative programs. This poor repu-tation will make it extremely difficult for DOE toattract foreign countries into significant new part-nerships . . . the responsibility lies with DOE toimprove its own image abroad.30

The United States needs to establish a strong andstable commitment to its domestic fusion pro-gram as well as to international projects in orderto win the confidence of potential partners.

zgDenis Wlllson, A European Experiment: The Launching of the

JET Project, op. cit.JoEnergy Research Advisory Board, International Collaboration

in the U.S. Department of Energy’s Research and Development Pro-grams, op. cit., p. 2.


Equitable Allocation of Benefits

Negotiating an agreement in which the bene-fits of the project are distributed equitably in re-lation to the investment of the participants willbe complex. Among the benefits are the distri-bution of available staff positions, the amount ofdesign and equipment fabrication work to bedone by contractors, and the access or rights toinformation and technical know-how generatedby the project. Benefits associated with hostingthe site of the experiment also must be accountedfor, a task that has frequently resulted in requir-ing the host to contribute more to the project’scosts. I n the JET project, for example, the UnitedKingdom contributes 10 percent of project costsas a site premium, over and above its contribu-tion as a participant.

Administration

For cooperation to be successful, it will be nec-essary to resolve a variety of administrative issuesfaced in all cooperative programs.

Different Institutional Frameworks.–Each na-tional agency involved in negotiations operatesunder different ruIes and procedures. In addition,the negotiating agencies generally have varyingdegrees of autonomy, flexibility, and decision-making power.

Decentralization of the U.S. Government.—The decentralized character of the U.S. Govern-ment poses a challenge to developing major in-ternational agreements. Each executive branchagency has different concerns, making it difficultfor the U.S. Government to reach the consensusneeded to “speak with one voice. ” Therefore,negotiators will have to ensure either that thereis widespread commitment to the project withinthe U.S. Government or that the project has sup-port at levels of government high enough to as-sure such a commitment.

Different Budget Cycles.–Agreements willhave to reconcile differences in national budget-setting procedures in order to finance a majorcooperative undertaking. The European Commu-nity, for example, has a multi-year budget cycle,whereas both the United States and Japan haveannual budget cycles. Even these annual budget

processes are quite different. Whereas the Japa-nese budget process is very incremental, with ma-jor changes in program funding levels being un-usual, in the United States the budget cycle is lessstable and less predictable. Funding choices arereevaluated annually in the United States, andchanges in priorities are common. Thus, there issome concern that the United States might makea commitment to begin a long-term project andthen change its mind.

It has been suggested that the United Statesadopt a multi-year budget cycle or take major in-ternational projects “off-budget.” While such ac-tions certainly would reduce the budgetary ob-stacles to cooperation, the chance of such achange is slim, because the ramifications of sucha decision wouId extend far beyond any particu-lar project.

Different Currencies and Economic Systems.– Itis generally considered easier if international proj-ect management minimizes currency transfers be-tween nations. Different budget cycles, fluctuat-ing exchange rates, and different economic systems—particularly with regard to the Soviet Union—make limiting the exchange of currency an attrac-tive goal. Therefore, having participants contrib-ute components and services is preferable tohaving them contribute funds to a central man-agement agency that contracts for constructionof necessary components.

Different Legal Systems.–Nations also havedifferent legal systems that can complicate nego-tiations. Defining legal ownership of the experi-mental facility and of the information generatedthere is a critical facet of a workable agreement.

Personnel Needs.–The staff of a joint under-taking will include participants from all programsinvolved in the project, and administrative ar-rangements will have to accommodate their needs,Currently, relationships between staff and theirrespective governments differ over such issues asthe ability to sign contracts, intellectual propertyrights, and compensation.

Staff for the project would come to a centrallocation from many countries and would in mostcases bring their families. They wouId expect,without undue difficuIty, to find housing with ac-cess to shopping facilities and other amenities.


In particular, they would want an international,rather than national, educational system for theirchildren. Moreover, most staff will return to theirhome fusion programs after completion of theirassignments at the joint facility, and they will needto be assured that their positions at home will re-main available to them.

Management Approaches

If the conceptual design phase of the ITER proj-ect is successful, it could be followed by a deci-sion to jointly construct and operate a major fusionexperiment. The prospects for such an activityare being investigated by the major fusion pro-grams. Any agreement to undertake such a proj-ect would be complex, and a variety of manage-ment and organizational issues could arise inproject negotiation and implementation. This sec-tion explores the applicability of managementstructures developed for existing internationalprojects, both in fusion and in other areas, to thepotential collaborative fusion endeavor.

The organizational structure of a large-scale in-ternational project such as ITER depends on itsoverall goals and objectives, which will be de-termined through negotiation. The main require-ment for the organizational structure is that it de-fine each participants’ degree of control over theproject by establishing such things as the project’stechnical and political decisionmaking proce-dures, the allocation of contributions and bene-fits among the partners, the degree of autonomybetween the collaborative project and the sup-porting domestic fusion programs, the arrange-ments for staff and contractors, and the routineoperation and long-range planning of the en-terprise.

The degree of control that any participant ex-erts over the direction of the project can vary sig-nificantly, from minor technical influence to over-sight of the entire project. Generally, however,the amount of control a partner exercises is pro-portional to the amount of financial support itprovides. In the case of ITER, it appears likelythat financial support will be fairly evenly dividedamong partners; thus, project control probablywill be shared by the partners.

The management structures of the existing co-operative projects examined below offer someinsight into how—or how not—to organize fusioncollaboration. Since each project’s goals are dif-ferent, it is unlikely that any of these existing ar-rangements will be applicable as is for future fu-sion collaboration. Each project weighs its goalsand requirements independently, and, throughnegotiation, unique trade-offs among competinggoals are made. Studying the organizational struc-tures of existing international projects, however,can be useful in exploring future projects suchas ITER.

International Tokamak Workshop (INTOR)31

Conducted under IAEA auspices, the INTORdesign study for a next-generation fusion exper-iment has features that may be useful for futurecollaborative projects. INTOR has successfully en-abled the international fusion programs to co-operatively develop a design for and explore thetechnical characteristics of a next-generation ma-chine. Moreover, the INTOR process was devel-oped without causing concerns about nationalsecurity and is the most extensive cooperative fu-sion activity involving the Soviet Union. SinceINTOR is strictly a design effort, however, it pro-vides no guidance for the construction and oper-ation of future fusion collaborative experiments.

Joint European Torus (JET)32

The JET management structure is another ap-proach for major collaborative projects. The JETfacility was designed and built by multinationalteams, is financed by the EC and the participat-ing national fusion programs, and is managed bya multinational council. The project has been suc-cessful, and the EC currently is exploring the pos-sibility of using the same approach to manage anext-generation experiment (the Next EuropeanTorus or NET).

Though the JET approach has proven success-ful for European fusion collaboration, it is notdirectly applicable as a model for ITER. First, the

JIThe I NTOR project is discussed in more detail on p. 159Jzsee pp. 160-161 for a detailed description of JET.

Ch. 7. —Fusion as an /international Program s 171

JET agreement was negotiated within the exist-ing umbrella structure of the European Commu-nity in which most of the administrative obsta-cles to international collaboration were alreadyresolved. Negotiating a major fusion cooperationthat included parties outside of the EC would besignificantly more complex because there is nopreviously negotiated legal framework.

In addition, the JET approach was not designedto provide a mechanism for limiting the transferof potentially sensitive technologies. Within theJET framework, all participants have access to theinformation and technology used or developedin the project. Finally, the JET structure operatesthrough the cash contributions of participatingprograms to its central management agency.Hard currency transfers among the participantsin an ITER-type project would be more difficultto arrange.

Large Coil Task (LCT)33

The Large Coil Task is a superconducting mag-net testing project that has been conducted un-der the auspices of the IEA. The United States hastaken the lead on the project, financing construc-tion of the magnet testing facility and three of thesix test magnets. The facility was designed jointly,and three magnets were designed, constructed,and financed by foreign participants in theproject. All information and non-proprietary tech-nology used in construction of the test magnetsand all data generated through the experimentare available to participating programs.

Although the LCT was not designed to precludeinformation and technology transfer, its structurecould be slightly modified and used if limitingsuch transfer was an objective. If a given taskwere broken down into distinct components,each subtask could be assigned to a partner whowould be responsible both financially and tech-nically for its contribution. Provided that the “in-dependent development” met technical speci-fications, each partner’s contribution could beintegrated into the overall machine, minimizingexchange of information.

~lThe Large Coil Task IS described in more detail on p. 159.

This approach might resolve technology trans-fer concerns, but it could also introduce consid-erable difficulties into project management. Sincea primary goal of collaborating on a next-gen-eration fusion experiment would be to make ex-perimental techniques and results available to allthe cooperating parties, the independent devel-opment approach probably would not be accept-able in ITER. In addition, it would be difficuIt todivide a major fusion project into isolated mod-ules connected at interfaces; ITER probably willbe a complex and interrelated assemblage of sys-tems and components. Moreover, coordinatinga project in which data and access were restrictedwould require an extremely effective manage-ment team.

Another problem with applying the LCT modelto a future collaboration like ITER is control ofthe project. In the LCT, the United States con-tributed most of the financial support and as-sumed principal technical control. For ITER, onthe other hand, it appears unlikely that any part-ner will assume the responsibility of becomingproject leader and shouldering most of the cost.Thus, the management design of the LCT will notbe applicable to ITER.

Doublet Ill Project (D III)34

Doublet Ill is the most extensive cooperativefusion project in which the United States cur-rently is involved. The United States is the hostcountry for the Doublet project, and the Japa-nese have contributed over one-third of the fundsnecessary to support the project i n recent years.This direct contribution of currency distinguishesthe Doublet cooperation from other fusion activ-ities in which the United States participates. Theproject is jointly managed by a team of U.S. andJapanese scientists; machine time and experi-mental results are shared equally between thetwo nations. Doublet’s management structure hasdistributed control of the project and financialresponsibility effectively among the Japanese andAmerican participants.

Several factors, however, may complicate theuse of the Doublet approach for more intensive

~~FOr mo~e detai led cj Iscussion of Doublet-1 I I D project, ~ee PP

162-163.


future undertakings. The scope of the project,though extensive by U.S. standards, is quite lim-ited when compared with the scale of potentialfuture projects such as ITER. Only two nationsare involved, and the amount of currency trans-ferred is small compared to the projected costof ITER. Also, the original D I I I facility was an in-dependent U.S. project, and the Japanese did notbecome involved until the upgrades were under-taken. Thus, the Doublet project did not have toaddress facility design and construction issuesfrom the beginning, as a completely collabora-tive project would.

European Laboratory forNuclear Research (CERN)35

CERN was established in 1954 by several West-ern European nations. Its objective was to ad-vance knowledge in high energy physics, and ithas provided a framework for extensive cooper-ation in the design and construction of large-scaleexperimental facilities. It has enabled the Euro-pean nations to conduct physics research on ascale that would have been impossible for anyof them acting independently.

CERN is coordinated by a council consistingof two representatives—one administrative andone technical—from each participating nation.Participants make cash contributions to CERNbased on a percentage of each nation’s gross na-tional product (GNP). No nation can contributemore than 25 percent of CERN’s costs annually.There are no “national rights” within the CERNstructure. Participating nations are not guaran-teed particular positions for their representatives,specified shares of CERN’s procurements, or pri-ority for projects within CERN.

Many features of the CERN management struc-ture could be attractive in future fusion coopera-tion. For example, the practice of making decisionsbased on merit, not national rights or privileges,is considered by many analysts to be responsi-ble for CERN’s excellent technical record. In addi-tion, involving both technical and administrativepeople in decisionmaking has resulted in informed,comprehensive decisions.

~SThiS dlcusslon based on pp. 92-93 of the National ResearchCouncil report, Cooperation and Competition, op. cit.

Yet CERN, like JET, does not provide a com-plete model for a future ITER. First, CERN relieson cash contributions, which may not be appro-priate for ITER. Second, CERN does not havemechanisms in place for protecting sensitive tech-nologies. Third, some more formalized system of“national rights, ” at least with respect to imme-diate economic return and longer term researchand development return, may be necessary to al-locate the benefits of ITER among diverse econ-omies that are not already as interdependent asthe individual European Community economiesare.

Space Station

The space station, a proposed multi-billion dol-lar orbiting facility, is the only attempt by theUnited States to cooperate internationally on ascale financially comparable to future fusionplans. Under U.S. proposals for space station col-laboration, the United States would take the leadon the project and invite participation of others,particularly Japan, Canada, and the EuropeanSpace Agency. Currency exchanges would beminimal. Each of the programs would contributeits own hardware to the station, and these con-tributions would be joined together at carefullydefined interfaces. Each program would retain es-sential control over development of its own hard-ware, but the United States would bear overallresponsibility for program direction and coordi-nation, for overaIl systems engineering and in-tegration, and for development and implementa-tion of overall safety requirements. This approachis intended to ensure compatibility and cooper-ation without transferring technology that thepartners may wish to protect.

Some aspects of the space station project couldprovide a model for large-scale fusion collabo-ration. In particular, the space station may developa workable mechanism for limiting the undesira-ble transfer of technology among the participants.In addition, it is likely that administrative aspectsof the agreement might have relevance to futurejoint undertakings in fusion. Both the space sta-tion and a future fusion collaboration such as ITERwould have to address issues such as ownershipof equipment, intellectual property rights, disputesettlement, liability, selection and assignment of


personnel, and establishment and maintenanceof safety standards. If the space station can re-solve these issues successfully, it could providea model for ITER.

In many ways, however, it is difficult to applythe space station approach to future fusion col-laborations. The space station is designed to bemodular, with participants contributing independ-ently developed components. As noted earlier,the independent development approach wouldprobably be unacceptable and unworkable forITER. In addition, the United States is taking thelead on the space station, dividing tasks andshouldering much of the cost. It is not clear thatsuch an approach in a major fusion collabora-tion would be acceptable to either the UnitedStates or other participants. Moreover, it is notcertain that the United States would accept a

subordinate role in a fusion collaboration if anothernation were to assume leadership of the project.Fusion projects also have to address siting issues,which the space station avoids because it is notlocated on national territory. Finally, the spacestation project does not include the Soviet Union,and thereby avoids the additional security anddiplomatic concerns introduced by Soviet par-ticipation.

Summary of Potential ManagementApproaches

It is unlikely that any existing cooperativeproject will provide a model management struc-ture for a major international effort such asITER. The strengths and weaknesses of existingprojects, with respect to large-scale fusion col-laboration, are summarized in table 7-3.

Table 7-3.—Applicability of Existing Projects to Future Fusion Collaboration

Project Strengths Weaknesses

INTOR . . . . . . . . . . . . . .●

JET . . . . . . . . . . . . . . . ●

LCT . . . . . . . . . . . . . . . ●

●

Proven approach to project design phase ●

Most extensive fusion collaborationinvolving the Soviet Union

Successful design, construction, and ●

operation of world-class facility●

Successful joint research project ●

Could provide for control of technologytransfer ●

D Ill . . . . . . . . . . . . . . . ● Successful management structure

CERN . . . . . . . . . . . . . c

●

Space Station . . . . . . ●

Successful design, construction, andoperation of world-class high-energyphysics programNot bound by “national rights” system

Successful conclusion of negotiations willshow that large-scale, multi-year, andmulti-billion dollar collaborations can beestablished by the United States

●

●

●

●

●

●

●

●

●

●

Poorly suited for construction and operation

Negotiated within preexisting cooperativeframeworkMight not address technology transfer issuesadequately

United States was lead agency and boremajority of costs“Independent development” approach mightbe unworkable for ITERMight not ensure technical equality ofparticipants, depending on distribution oftasks

United States was lead agency and boremajority of costsSmall-scale project when compared withITERJoint project dealt only with upgrade ofpreviously constructed experimentInvolves hard currency transfer

Involves hard currency transferMight not address technology transfer issuesadequatelyLack of “national rights” system may limitequitable allocation of project benefits

Negotiations have not been finalizedIndependent developments approach mightbe unworkable for ITERDoes not address siting issuesProvides no experience with Sovietparticipation

SOURCE: Off Ice of Technology Assessment, 1987


COMPARISON OF INTERNATIONAL FUSION PROGRAMS

Comparing levels of effort among the interna-tional fusion programs is complex. Qualitativemeasures show that the programs are similar indirection and achievement, but these measuresare subjective. Quantitative measures are moreobjective, but they may be distorted. Moreover,different techniques give different results.

Qualitative Comparisons

Qualitative comparisons show that the four ma-jor fusion programs are comparable in levels ofeffort and accomplishment and in their near-termresearch objectives, although the stated long-termgoals and rationales for the programs differ (seetable 7-4). Three of the programs operate toka-mak experiments of similar capability and com-plexity, and the fourth (the Soviet Union) is inthe process of building a large tokamak of some-what similar capability; each program also studiesalternative confinement concepts. All of the pro-grams recognize the need for a next-generationexperiment during the mid-1990s to advance fu-sion technology and science.

Table 7-4.—Program Goals of theMajor Fusion Programs

ProgramGoal Rationale

U s .Demonstrate science and

technology base forfusion power

ECPrototype construction

JapanDemonstration plant

U.S.S.R.Fusion hybrid systema

Determine potential as anenergy option

Develop energy optionPromote industrial

capabilityStrengthen political unity

Develop energy optionFulfill national project

Support fission programMaintain international

activityaFusion hybrids are discussed in app. A.

SOURCE Michael Roberts, Director of International Programs, U.S. Departmentof Energy, Office of Fusion Energy, briefing on “lnternatlonal Discus.sions on Engineering Test Reactor, ” before the ETR Workshop, Rock-vine, MD, July 16, 1966

Figure 7-1 compares the programs’ researchand development emphases on confinement con-cepts, and figure 7-2 compares their technologydevelopment efforts.36 Variations among programsare influenced by differing program concentra-tion, funding levels, technological capabilities,and program history.

Quantitative Comparisons

There are a variety of ways to compare quan-titatively the levels of effort among the U. S., EC,and Japanese fusion programs, but each way hasflaws. (Data for the Soviet Union is not includedin this discussion; it is difficult to obtain reliableinformation on the size of the Soviet program,its funding level, and the number of people it em-ploys.) Figure 7-3 compares DOE’s estimates ofthe annual fusion budgets of the three programsconverted into dollars. According to this figure,the United States has had the highest level of ef-fort in fusion research. However, this conclusionis dependent on the exchange rates used in thecurrency conversion. The relative magnitude ofthe U.S. effort is due in part to the extraordinarystrength of the dollar in the mid-1980s with re-spect to European and Japanese currencies. Tothe extent that goods and services purchased withfusion research funds are not traded on interna-tional markets, fluctuations in exchange rates dis-tort the calculations of relative expenditures. Sud-den shifts in the value of the dollar have dramaticeffects on dollar-based comparisons of the fusionbudgets, but do not represent actual changes infusion work effort.

To correct for distortions from fluctuating ex-change rates, DOE has used another method tocompare fusion programs.37 In this method, the

}bThe discussion I n this and the following paragraph is based ondocumentation by Dr. Stephen 0, Dean, President of Fusion PowerAssociates and author of figures 7-1 and 7-2. His insights representa view commonly held by the fusion community regarding the rela-tive levels of effort among the major fusion programs. The techni-cal characteristics of the confinement concepts are explained inch. 4.

JTjohn Willis, U.S. Department of Energy, Office of Fusion Energy,Oc. 9, 1986, personal communication to OTA.

Program ● 1 7 5Ch. 7.—Fusion as an International

Figure 7-1.— Emphases of Major Programs on Confinement Concepts, 1986

us

JAPAN

USSR

EC

Figure 7.2.–Emphases of Major Programs on Technology Development, 1986

SOURCE Fusion Power Associates.

fusion budget of each program is divided by the This f igure does not l i terally represent the num-average annual manufactur ing wages preva i l ing ber of people employed by the respective fusionin the country or region, with both values meas- programs, but rather represents an arbitrary meansured in local currency. The resulting value is a of comparing relative levels of effort. Expendituresmeasure of the level of effort of each program on construction and operation of facilities arein units of “equivalent person-y ears.” Compari- converted, along with actual personnel costs, intosons are shown in figure 7-4. “person-years” of effort. The validity of this meas-


Figure 7-3.—Comparison of International Fusion Budgets (in current dollars)

1980 1981 1982

■ United States ❑ European CommunitySOURCE: U.S. Department of Energy, Office of Fusion Energy, 1986,

ure depends on how well the quoted manufac-turing wage rates reflect the wages relevant to thefusion program, on how similar the productivityof labor is between programs, and on how simi-lar the relative values of capital and labor expend-itures are among the three programs.

Figure 7-4 shows that by this measure, both theJapanese and the U.S. levels of effort droppedslightly from 1980 to 1986. In both programs, thefusion budget rose in real dollars. However, in-creases in the average industrial wage rate overthe same period resulted in a substantial drop in

1983

Year

❑ Japan

1984 1985 1986

“equivalent person-years."38 Unless the majorityof the costs incurred by the Japanese and U..S.fusion programs actually rose by the same amountas the wage rate, the conversion to “equivalentperson-years” overestimates the decline in thesefusion efforts.

programs, the average industrial wage 1980 to 1986 rose 38 percent in the United States, rose 76 percentin Japan, and fell 6 percent in the European Community. Over thesame period, the fusion budget rose only 4.6 percent in the UnitedStates, rose 24 percent in Japan, and rose 97 percent in the Euro-

pean Communi ty , in rea l do l lars .


32

30

28

26

24

22

20

18

16

14

12

10

8

6

4

2

0

Figure 7-4.—Comparison of International Equivalent Person-Years

1980 1981 1982

OTA used a third method of comparison toconstruct figure 7-5, which illustrates the fusionbudgets as a percentage of each program’s GNP.Under this method, the fusion budgets, as reportedby DOE, are divided by the national GNP.39 Al-though all values are converted to dollars, inac-curacies in the conversion process should not af-fect the final result since both GNP values andfusion budgets were adjusted. This approach,which shows that the Japanese devote the great-est proportion of their resources to fusion, meas-ures the relative level of effort of fusion research

European Community was calculated by adding

the GNPs the member

1983 1984 1985 1986

Year

J a p a n

compared to the rest of the economy of eachparty. It does not present a comparison of abso-lute levels of effort, but might be taken to indi-cate some measure of the commitment of eachnation to its fusion program. Of course, many ex-ternal factors that strongly influence each nation’sspending priorities cannot be shown in this fig-ure. For example, this figure does not show thegreat asymmetry in defense expenditures of thevarious nations.

An additional problem confounds all of thequantitative methods: the calculations are basedon program budgets that are not directly com-parable. Budget figures provided by the Japanese


0.004

0.002

01980 1981

■ United States ■ European CommunitySOURCE: Office of Technology Assessment, 1987

G o v e r n m e n t , f o r e x a m p l e , d o n o t i n c l u d e p e r -

sonnel costs. In the figures shown here, thesecosts were estimated by DOE for the Japaneseprogram and added to the Japanese figures. Inthe EC and the United States, distinctions mustbe made between budget authority (how muchthe program was authorized to spend) and bud-get outlay (how much the program actually did

spend), and these values can be substantiallydifferent.

Obviously, quantitative level-of-effort compar-isons based on budget levels may not be relia-ble. Each method of analysis discussed here sug-gests different results, and no conclusions can bedrawn.

Ch. 7.—Fusion as an /international Program . 179

POTENTIAL PARTNERS

Since DOE is investigating the possibility of in-creased levels of collaboration, an analysis of thegoals and incentives of the potential collabora-tive partners is important.

The United States

Program Goals

The stated goal of the U.S. fusion program isto establish the scientific and technological basenecessary to evaluate the potential for fusionenergy by early in the 21st century. In 1988, de-sign and construction of the next major facility,the Compact Ignition Tokamak (CIT), may begin,if approved by Congress. The United States rec-ognizes the need to have an engineering test re-actor by the mid-1990s to study technical issuesrelated to reactor design and operation, but, dueto funding limitations, DOE would like to con-struct such a reactor in collaboration with oneor more other fusion programs. In the concep-tual design and supporting R&D proposal cur-rently being negotiated, this project is called theInternational Thermonuclear Experimental Re-actor (ITER). The U.S. fusion program does notcurrently have plans to construct an engineeringtest reactor independently. Beyond a collabora-tive engineering test reactor, the U.S. programhas no plans to construct a demonstration re-actor. 40

Views on Collaboration

The United States is extremely interested in fu-ture international collaboration, particularly onconstruction and operation of ITER. A primaryincentive is financial; at present, the domestic fu-sion program is not able to command the finan-

cial resources necessary to construct experimentsof this scale by itself. Another incentive is DOE’sbelief that a well-developed scientific and tech-nological base for fusion will be easier to estab-lish if the major fusion programs share informa-tion and expertise.

At this point, the U.S. fusion program is con-sidering the possibility of collaborating on ITERwith any or all of the major fusion programs. Ofthe major programs, the United States has coop-erated most extensively with Japan. Formal tiesbetween the United States and the EuropeanCommunity are more recent, but the EC fusionprogram is highly advanced and would be an at-tractive partner. The U.S. fusion community alsohighly values input from its Soviet counterpart,which has made significant contributions to pastcooperative projects and which continues tomake technological advances. However, the pol-itics of the U.S.-Soviet relationship are more vola-tile than those between the United States and Ja-pan or the EC. This difference will make majorcollaboration with the Soviet Union the most dif-ficult to arrange.

Nevertheless, Soviet participation in a multi-lateral fusion project has been supported at thehighest levels of both governments. At the GenevaSummit of 1985, President Reagan and GeneralSecretary Gorbachev “advocated the widestpracticable development of international collabo-ration” in fusion research .4’ The United Statesexplicitly made this arrangement conditionalupon allied participation, and a strictly bilateralcollaboration between the two countries on ITERwould be very unlikely.

q~see the Section Ot ch, 4 titled ‘‘Research Progress and Future

Directions” for a more detailed cliscussion of the U.S. research plansand facility needs.

~1 From statement at the Reaga n-Gorbache\ Sum m It, November1985.

180 ● Starpower: The U.S. and the international Quest for Fusion Energy

The European Community42

Program Goals

The member countries of the European Com-munity are making a long-term investment in fu-sion for its possible value as a major new energysource that could contribute to Western Europe’sfuture energy security. Collaboration within theEC has been extremely successful; it has been asource of pride.

The joint European Torus (JET) is the EC’s mostimportant experimental fusion facility and theworld’s largest tokamak.43 Planning has begun fora second facility—the Next European Torus (NET)—which, like ITER, is intended to confirm the sci-entific feasibiIity of fusion and address the ques-tion of engineering feasibility. The current sched-ule for NET calls for a detailed design decisionin 1989 or 1990 and a decision on constructionin 1993. A third facility envisioned by the EC isa prototype fusion power reactor to demonstratethe economic feasibility of fusion. The timetablefor this prototype depends on the success of JETand NET. Construction is projected to begin be-tween 2010 and 2020.


The European Community is interested in in-ternational collaboration for a variety of reasons.In recent years, the EC has confronted tightbudgets and competing demands for funding,which increase the attractiveness of working withpartners outside of Europe. Like other nations,the EC recognizes the substantial benefits of costsavings and knowledge and risk sharing. More-over, through the JET project, the EC has hadpositive first-hand experience with the scientific,technical, and management aspects of collabo-ration. In addition, the EC fusion effort has co-operative relationships with the other programs,principally the United States for which it has con-siderable respect. It also respects the Soviet and

qzThi5 discussion is based in part on information provided by an

OTA contractor, Professor Wilfrid Kohl, in a report titled “The Po-litical Aspects of Fusion Research in Europe.” Kohl IS director ofthe International Energy Program at the Johns Hopkins UniversitySchool of Advanced International Studies.

JJThe j ET project is de5cribed I n cfeta i I i n ‘‘Mu ki Iaterat Activities.

Japanese fusion programs, but contact with themhas been less frequent.

Even without international collaboration, theEuropean Community’s program has establishedpolitical support and momentum through JET.The EC has a clear strategy for future fusion re-search, in which NET plays a vital role, and it ap-pears committed to carrying this program out.Nevertheless, the European Community is will-ing to investigate prospects for a large-scale col-laboration with the other major fusion programs.At the same time, the EC plans to continue work-ing independently on NET unless and until theITER effort offers convincing guarantees of suc-cess. The EC might not wish to participate in amajor project that is not located in Europe.

The Soviet Union44

Program Goals

The Soviet Union has an active fusion researchprogram, which is supported by a strong com-mitment to nuclear power for geographical andfuel cycle reasons.45 The breeder reactor is theprimary focus of the Soviet atomic energy pro-gram for the 199os, and the fusion reactor is thefocus of the next century. The Soviet Union isalso investigating the potential of fission-fusionhybrid reactors for its thermal and breeder reactorprogram .46

The Soviet Union is currently constructing amajor tokamak experiment, T-15, which is simi-lar in objective and capability to the large toka-maks currently being operated in the UnitedStates, EC, and Japan. Completion of T-15 was

441 nformation on the Soviet Union’s fusion program was providedto OTA by Dr. Paul Josephson, “The History and Politics of EnergyTechnology: Controlled Thermonuclear Synthesis Research in theUSSR. ” Josephson has studied Soviet science and technology pol-icy issues at the Massachusetts Institute of Technology’s Programin Science, Technology, and Society.

dsseventy percent of Soviet energy consumption and POPU Iatlon

is located in the European part of the country, but 90 percent of

the fuel resources are located in Siberia and Soviet Central Asia.

The cost of transporting the energy thousands of miles from east

to west, either in its primary form or as electricity, is high. There-

fore , the government is pursu ing the rap id commerc ia l iza t ion o f

nuclear energy near the western population centers.aGFission-fusion hybrid reactors use the neutrons generated in fu-

sion reactions to produce fissionable fuel. For more information,see app. A.


originally scheduled for 1982, but the project hasbeen delayed repeatedly due to engineeringproblems and is now expected to operate in1988. The Soviets are considering constructionof a device called the Operational Test Reactor(OTR) to succeed T-1 5.47 This device is believedto be analogous to the next-generation devicesplanned in other major national programs, ex-cept that it is also intended to verify how effec-tively fusion can be used to breed fuel for fissionreactors.


The Soviet Union has regularly made proposalsto enhance international cooperation in fusion.The INTOR project was initially proposed by theSoviets, as was the genesis of the current proposalfor an international next-generation experiment.The Soviet Union has made major contributionsto past international projects and has clearlyfound the activities rewarding.

It appears that budgetary constraints are put-ting pressure on the Soviet fusion program. Whileit is difficult to provide actual data on the sizeof the Soviet fusion budget, a review of Sovietjournals indicates that plasma physicists currentlyare more circumspect in their predictions for fu-sion power than they used to be, and that theyare fighting to retain their fusion budgets in theface of intense pressure from other energy re-search programs such as breeder reactors.48

There is high-level political support for collabo-ration in fusion, and General Secretary Gorbachevhas stressed repeatedly its importance. He raisedthe issue with President Reagan at the GenevaSummit in 1985 and again in a speech before theSupreme Soviet in 1986. On the latter occasion,he said:

On the initiative of the U. S. S. R., work involv-ing scientists from different countries has begunon the tokamak thermonuclear reactor project[lNTOR], which opens up an opportunity to rad-ically resolve the energy problem. According toscientists, it is possible to create as early as within

~7MlCha~l RO&rlS, U, S. Depar tment of Energy, (] ftlce Of Fusion

Ener~y, brlet’lng o n ‘‘International Dlscus\ions on ETR, ” Rock\ llle,

M D , jU]Y 16, 1 9 8 6 .

48P, Josephson, “H I$tory and Politics, ” op. cIt,, pp. 16-19.

this century a terrestrial sun . . . thermonuclearenergy. We note with satisfaction that it wasagreed in Geneva to carry on with that impor-tant work.49

In addition to incentives to collaborate, thereare also obstacles from the Soviet perspective.These include pressures within the U.S.S.R. toavoid technological reliance on the West andshortages of hard currency with which to partici-pate. Another obstacle is any unforeseen deteri-oration of the U.S.-U.S.S.R. relationship due topolitical developments unrelated to fusion; in1980, for example, the Soviet invasion of Af-ghanistan interrupted cooperative fusion workthat had been relatively stable until then.

It appears that the Soviets would be comforta-ble collaborating with any of the major fusionprograms on ITER, judging from the positive So-viet evaluation of INTOR. However, as yet nei-ther the Japanese nor the Europeans have soughtto build a machine with the Soviets.50 Because ofthe Soviet Union’s relatively long-term involve-ment with the United States in bilateral scien-tific agreements, the role of these scientific ex-changes in the pursuit of improving relations,the present international outlook of Soviet leaderstoward technology, and Soviet respect for Amer-ican science and technology, the Soviets appearinterested and willing to collaborate with theUnited States.

Japan51

Program Goals

Many Japanese see fusion as the ultimate so-lution to Japan’s energy problems. Japan is moredependent on imported energy than any othermajor economic power, and the Japanese areconcerned about how precarious this depen-dence makes their economy. Nuclear energy has

49M S. GOrbac hev, as cited I n Kadomtw\, ‘ ‘ T o k a m a k , SOL let

L/fe, August 1986, p. 13.50Mark Crawford, “Researchers’ Dreams Turn to Paper In U.S -

USSR Fusion Plan, ” Science, vol. 234, Nov. 7, 1986, p. 6675)Thls section IS ba~ed In par t on a repor t comple ted f o r O T A

by Dr. Leonard Lynn, “Politlcal Aspects of Fusion Research In ja-pan, ” Lynn IS a proiessor who analyzes Japanese science and tech-nology pollcy I n the Department oi Social and Decision Sciencesat Ca rnegle-Mel Ion U n[verslty.


helped the Japanese decrease their dependenceon oil, and Japanese policy makers favor the con-tinued use and development of nuclear power.Japan’s general long-range energy policy calls foran increased reliance on conventional nuclearenergy over the next 25 years. It is anticipatedthat this policy will be followed by a reliance onfast breeder reactors around 2010 and a transi-tion to fusion energy about 30 years later.

The largest experimental fusion facility in Ja-pan is JT-60. Japanese scientists have begun con-ceptual design studies for a next-generation toka-mak, the Fusion Experimental Reactor (FER),which is intended to succeed JT-60. FER, whichcould be built in the late 1990s, would resembleNET or ITER and probably would be designed toachieve ignition and demonstrate the technicalfeasibility of the nuclear fusion reactor.


International collaboration is attractive to theJapanese for many of the same reasons that it isattractive to other countries. The Japanese, likeothers, feel that the financial and human resourcesrequired to construct a next-generation fusion de-vice may be too great a burden to bear alone.Moreover, the Japanese have both contributedand received valuable technical information frompast fusion cooperative projects.

Although the Japanese are interested in col-laborating on fusion research, there maybe someobstacles to such collaboration. The Japaneseconfront a major debt burden that has grown rap-idly in the last few years and that has increasedgovernment pressure to cut spending.52 In addi-tion, the Japanese might be unwilling to partici-pate if the experiment is not sited in Japan.

The Japanese are willing to explore the possi-bility of multilateral collaboration on ITER, how-ever, and they are currently participating i n dis-cussions of the project with the United States, theEuropean Community, and the Soviet Union. Ofthe three, Japan appears most interested in col-laborating with the United States. In addition toextensive cooperative experience with the UnitedStates, the Japanese also have a bilateral arrange-ment with the EC that involves meetings of ex-perts and information exchange.53 However, theJapanese and European programs currently areless familiar with each other than either is withthe United States. The Japanese have the leastexperience cooperating with the Soviet Union.

Jzlbid,, ~p, 46.47 : public debt climbed from 2.2 trllllon Yen In 1976

(13 percent ot’ GNP) to 130 trillion yen in 1985 (42 percent of GNP),In 1986, the cost of servicing this debt accounted for more thdn20 percent of government expenditures. This compares to 14 per-cent of government expenditures going to service the U.S. nationaldebt in 1985.

5Jlbid., pp. 42-43.

PROSPECTS FOR INTERNATIONAL COOPERATION

U.S. Plans for Future Cooperation International collaboration in fusion researchand development has become a key factor in

DOE is interested in the prospects for more ex- DOE’S program planning.tensive international cooperation on future mag-netic fusion experiments. In fact, a recent DOE Possible Areas for Internationalreport on international activities in magnetic fu- Cooperationsion states:

There are several possible areas of cooperationThe objectives of U.S. international collabora- delineated in DOE’s report. 55 These areas are

tion are to share the many high priority tasks, to linked to the four key technical issues in the DOEreduce the total costs associated with the required Magnetic Fusion Program Plan (see the sectionmajor facilities and to combine intellectual forcesin pursuit of the most essential problems.54 in ch. 4 titled “Key Technical Issues and Facil-

ities” under “Research Progress and Future Direc-

J~U .s, Depaflnlent of Energy, Office of Fusion Energy, /nte~na -

fiorra/ Program Activities In Magnetic FusIorr Energy, op. cit., p. 1. ~Jl bid., Attachment 3, pp. 1-5.

tions”). In confinement systems, DOE states thatpossible initiatives include gaining long-term ac-cess to the JET experimental programs and pos-sibly those at JT-60, developing a coordinatedprogram to develop the reversed-field pinch con-cept, and using selected foreign facilities to con-tinue development of superconducting magnets.in burning plasmas, the United States would seekforeign participation in the planning and opera-tion of CIT. In nuclear technology for fusion sys-tems, DOE is investigating proposals to extendthe current cooperative activity in technology re-search and development and to coordinate ef-forts in development of tritium handling technol-ogy. In fusion materials, DOE further proposesto coordinate research with the other majorprograms.

Considerations of the InternationalThermonuclear Experimental Reactor

To date, DOE’s proposal to design ITER collabora-tively has drawn the most attention among themany cooperative efforts outlined in DOE’s report.Within the framework of the Versailles and Genevasummits, DOE has been involved in negotiationswith the other major fusion programs to developthe conceptual design and supporting R&D forITER. The proposal does not currently extend tojoint construction and operation of the experi-mental faciIity. At the conclusion of the concep-tual design effort, the parties would be free tobuild such a device, either alone or collectively.

The Versailles Economic Summit.—Several na-tions participate each year in an economic sum-


mit meeting.56 These nations began consideringthe implications of technology for economicgrowth and employment at the urging of FrenchPresident Mitterand in 1982 when the meetingwas held in Versailles, France, and a process forconsidering specific ideas on this topic was estab-lished. The prospect of international cooperationin magnetic fusion was one of 18 ideas specifi-cally investigated. Cooperative efforts in fusionresearch have been discussed since then, and agreat deal of effort has gone into developing plansfor a workable joint undertaking.57

Under the framework established at the Ver-sailles summit, the Fusion Working Group wascreated in 1983. The Fusion Working Group isinvolved in early joint planning efforts and dis-cussions aimed at identifying necessary major fa-cilities. in 1985, the Fusion Working Group cre-ated the Technical Working Party to considertechnical and research-related issues in interna-tional fusion projects. In late 1985, the Techni-cal Working Party endorsed the U.S. plan to con-struct CIT.

In 1986, the Fusion Working Group reacheda consensus on the desirability of future collabora-tive activities. Participants issued a joint statementthat an engineering test reactor (now called ITER)is a common midterm goal for the fusion pro-grams of the United States, Japan, and the Euro-pean Community.58

The Geneva Summit.–Fusion cooperation wasalso discussed by the United States and the So-viet Union at the Geneva summit in November1985. Prior to the summit, in an October 1985meeting between French president Mitterand andSoviet General Secretary Gorbachev, Gorbachevhad expressed interest in pursuing internationalcollaboration on a large next-generation fusionexperiment. The Geneva summit between Presi-dent Reagan and Gorbachev, held in Geneva,

Sbparticipants are the united States, Canada, the Federal f@ub-

Iic of Germany, France, Italy, Japan, and the United Kingdom. The

European Communi ty as a whole is a lso represented.SzMlchael Roberts, Director of International Programs, U.S. De-

partment of Energy, Office of Fusion Energy, briefing on “interna-tional Programs in Fusion, ” presented to ERAB Fusion Panel, Wash-ington, DC, May 29, 1986.

WSU mmlt Working Group on Controlled Thermonuclear Fusion,

Summary Conclusions, Schloss Ringberg, Jan. 17, 1986.

Switzerland, followed up on this point. At theconclusion of the meeting, President Reagan andGeneral Secretary Gorbachev issued a joint state-ment supporting fusion collaboration to the “widestdegree practicable.” The statement did not rec-ommend a specific proposal or approach.

Current Status of the ITER Project.–No for-mal agreement has been reached on the ITERproject. Recently, the United States proposed thatthe potential partners begin a 3-year joint plan-ning activity to do conceptual design and sup-porting R&D for the device. Areas of collabora-tion would include defining the scope of theproject, developing a conceptual design for thedevice, and coordinating the research needed tosupport the design effort.

Representatives from the United States, Japan,the European Community, and the Soviet Unionmet in March 1987, in Vienna, Austria, to discussthe conceptual design phase of such a project.This meeting, held under IAEA auspices, markedthe first time that all four parties met to discusscollaboration on ITER. The meeting producedgeneral agreement on the nature of the project

“and the necessary steps to formalize it. The IAEAstated at the end of the meeting:

The Parties were favorably disposed to the pro-posal for joint conduct of conceptual design andsupporting R&D for an international thermonu-clear experimental reactor. The Parties reachedan understanding that the proposal was a soundbasis for further discussion. The four Parties willeach identify their representative to a group ofexperts to make proposals for a common set ofdetailed technical objectives for the conceptualdesign and to prepare the basis for further con-sideration by the Parties .59

In some ways, the arrangement proposed bythe United States resembles the InternationalTokamak Reactor (lNTOR) study. The proposalis more extensive, however, than INTOR. First,ITER deliverables would have a defined sched-ule, whereas the INTOR schedule is indefinite.Second, the ITER project would receive higherlevel attention than INTOR. Third, under the ITER

WI nternational Atom ic Energy Agency, as quoted i n hecutiveNewsle t te r , Fus ion Power Assoc ia tes , Apr i l 1987, p . 4 .


project, there would be full-time design teamsworking in each program; the INTOR designteams are part-time. Finally, the ITER project, un-like INTOR, would include cooperation on sup-porting R&D.

DOE has proposed that there be a full-timegroup of managing directors to coordinate theplanning effort. According to DOE, this phase ofthe activity could utilize the International AtomicEnergy Agency as an umbrella organization to fa-cilitate the project. For simplicity, the coordinat-ing site could be located at the IAEA headquar-ters in Vienna, Austria. No other site agreementswould be necessary at this stage because all otherwork would be undertaken within the nationalprograms.

The total cost of the 3-year conceptual designphase of ITER is estimated to be between $150million and $200 million, which includes its sup-porting R&D. The U.S. cost of the undertakingis projected at between $15 million and $20 mil-lion annually. This annual budget representsabout a tripling of the amount the United Statescurrently spends on design studies.

DOE anticipates that the conceptual designphase of the ITER project will occur between1988 and 1990. At the completion of this phase,interested parties would be in a position to be-gin negotiations on whether or not to jointly con-struct and operate the device. Any party couldwithdraw at this point, decide to construct andoperate the experiment independently, or chooseto pursue the effort collaboratively.

Analysis of U.S. Proposal for ITER

The U.S. Government’s recent proposal marksthe first step toward a collaborative ITER. Noagreement has been reached; the details of theproposal will be modified during negotiationswith other fusion programs. Therefore, it is im-possible to assess the proposal completely.

The proposal is based on the INTOR model,which provides an example of successful, if lim-ited, cooperation on project design. Like INTOR,in which the Soviet Union participates withoutthreatening U.S. national security, this proposaldoes not raise technology transfer concerns be-cause it will include only common design, notcommon technology development.

The current proposal does not address theproblems that would be encountered in jointlyconstructing and operating ITER. These obsta-cles will still arise when and if the decision ismade to build and operate the device. The cur-rent proposal does provide a mechanism wherebythe conceptual design and supporting R&D canbe completed, enabling informed decisions aboutproceeding with collaboration to be made at alater date.

Completing the conceptual design phase ofITER may help resolve some of the obstacles tosubsequent collaboration. For example, the con-ceptual designs developed over the next 3 yearsmay enable concerns about technology transferto be analyzed specifically and their implicationsfor national security to be resolved definitively.Furthermore, issues such as siting the facility ordetermining a technically acceptable project de-sign may be settled, either through the initialphase of the project or through concurrent dis-cussions and negotiations. At the completion ofthe design phase, the major fusion programsshould be better situated to develop detailedplans for further collaboration.

The current ITER proposal begins conserva-tively, utilizing an already well-established coop-erative arrangement. Participants will be able towork on the project without making a firm com-mitment to future involvement in joint construc-tion and operation. Perhaps most importantly,U.S. Government agencies will have more timeand additional information with which to estab-lish clear policy guidelines.

SUMMARY AND CONCLUSIONS

Magnetic fusion has a long history of interna- costs, risk, and knowledge; they value the oppor-tional cooperation. For the future, the major fu- tunity to achieve collectively what no programsion programs recognize the benefits of sharing could afford to achieve alone. Any or all of the

——


major world fusion programs would be techni-cally attractive collaborative partners for theUnited States. Higher levels of cooperation havedrawbacks, however. Cooperation may actuallyincrease the total cost and risk associated withfusion projects, and the benefits of knowledgesharing may be cut short if technology threaten-ing national security or national competitivenessis transferred to the partners.

There are many successful examples of coop-eration in fusion research and other scientificareas. JET, for example, is a collaborative under-taking in which the major European fusion pro-grams have jointly constructed and operated aworld-class tokamak facility. CERN, a major non-fusion project, is an example of the European na-tions pooling their resources and developing astate-of-the-art high-energy physics program.

While future cooperation can build on the solidfoundation of the past, collaborative projects suchas ITER will have to resolve many new issues. Col-laboration on this scale involving countries out-side Europe is unprecedented. Negotiating andapproving the necessary international agreementswill be possible only if the parties involved arecommitted both to the collaborative project andto their domestic programs. International collabo-ration cannot substitute for a domestic fusion pro-gram. If the domestic program is sacrificed to sup-port an international project, the rationale forcollaboration will be lost and the ability to conductthe project successfully will be compromised.

The U.S. Government’s current ITER proposalappears to be a workable first step toward a ma-jor experimental facility. The proposal minimizesthe risks in the project’s early stages by decouplingdesign from construction and operation.

The proposal has far to go. Although successfulcompletion of the conceptual design and sup-porting R&D will be important for addressing theissues related to construction and operation, thedesign process alone will not resolve these issues.In the United States, at the moment, the most sig-nificant issue on joint construction and operationis the possible transfer of militarily relevant tech-nology. Agencies within the U.S. Governmentdisagree about the severity of this problem, andthe dispute must be settled internally before a ma-jor collaboration can proceed.

project location is another critical issue. Just assiting was a major problem for JET, it is likely thata decision on ITER location will not come eas-ily. What does seem clear is that it is unlikely thateither the United States or the Soviet Union willbe chosen as the site for ITER.

Ultimately, reaching an agreement to jointlyconstruct and operate an international experi-ment will require high-level government support.A clear presidential decision to support the under-taking will be required. Even that, by itself, is in-sufficient to guarantee the viability of a projectinvolving all branches of the U.S. Governmentand extending over several Presidential Admin-istrations. Moreover, the national programs willhave to formalize their support in an agreementthat will establish confidence in the managementand operation of the project.

DOE considers international collaboration onITER and other projects essential to the progressof the U.S. fusion program. If more extensive co-operation proves impossible or unacceptable,DOE’s program plans must be reevaluated: ei-ther the U.S. program will need more funding orits schedule will have to be slowed down andrevised.

Chapter 8

Future Paths for the Magnetic Fusion Program

CONTENTS

Key Issues Affecting theThe Independent Path .

Description. . . . . . . . .. . . . . .. . . . . .

Motivations and AssumptionsThe Collaborative Path . .“. . . . .

Description. . . . . . . . . . . . . . .Motivations and Assumptions

The Limited Path. . . . . . . . . . . .Description. . . . . . . . . . . . . . .Motivations and Assumptions

The Mothballed path . . . . . . . . .Description. . . . . . . . . . . . . . .Motivations and Assumptions

. .

. .

. .

. .

. .

. .

. .

. .

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Page

of Fusion Research . . . . . . . . . . . . . . . . . . . . .189. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 191. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 191. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 191. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 193. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 193. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 193. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 194. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 194. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 195. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 196● . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 196● . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 196

Chapter 8

Future Paths for theMagnetic Fusion Program

The likelihood that fusion will be developed asa future energy supply option is affected—althoughnot completely determined—by policy choicesmade today. A decision to accelerate fusion re-search does not ensure that fusion’s potential willbe successfully realized, any more than a deci-sion to terminate the current research programimplies that fusion will never be developed.Nevertheless, near-term decisions clearly influ-ence the pace of fusion’s development. Thesooner we wish to evaluate fusion as an energysupply technology, the more important our near-term decisions become. Over the next severaldecades, the fusion research program can evolvealong any of four largely distinct paths:

1. With substantial funding increases, the U.S.fusion program can complete its currentlymapped-out research plan independently.This plan is intended to permit decisionsconcerning fusion’s commercialization to bemade early in the next century. This approachis called the “Independent” path.

2. At only moderate increases in U.S. fundinglevels, the same results might be attainable–although possibly somewhat delayed—if theUnited States can work with some or all ofthe world’s other major fusion programs(Western Europe, Japan, and the Soviet

Union) at an unprecedented level of collabo-ration. This path is termed ‘‘Collaboratii’e.

3. In the absence of major collaboration, a flator declining funding profile wouId force sig-nificant changes to be made in the program’soverall goals, including a recognition that fu-sion’s commercialization would be delayedfrom current projections. This path is called“Limited,” indicating that progress in somecritical areas wouId be impossible withoutadditional resources.

4. Shutting down the fusion program wouldforeclose the possibility of developing fusionas an energy supply option unless and untilresearch were resumed. On this “ M o t h -

balled” path, progress towards fusion in theUnited States would halt. Work would prob-ably continue abroad, although possibly ata reduced pace; resumption of research inthe United States would be possible but dif-ficult.

Current Department of Energy long-rangeplans for the fusion program are aimed at the“Collaborative” path. If recent funding declinescontinue, however, or if the United States doesnot successfully arrange its participation in ma-jor collaborative activities, the U.S. fusion pro-gram will evolve along the “Limited” path.

KEY ISSUES AFFECTING THE EVOLUTION OF FUSION RESEARCH

The four paths are differentiated by the degreeof commitment and the level of funding providedby the U.S. Government for fusion research. Pathcharacteristics and the choices between them aredetermined by several factors, including: 1 ) thelikelihood of technical and commercial successin developing fusion technology; 2) the perceivedurgency with which a new supply of electricity

is needed; 3) the advantages and risks of large-scale international collaboration; 4) the implica-tions of requirements for expensive research fa-cilities; and 5) the value of the “auxiliary bene-fits” associated with fusion research such asscientific understanding, education, and techno-logical development. Another factor, the poten-tial for surprise inherent in any new technology,

189


may also be an important aspect of one’s choiceof research approach; however, such a factor isnot amenable to analysis.

Discussions earlier in this report have addressedmany of these factors, which are summarizedbelow:

●

●

Likelihood of Success: In evaluating the like-lihood of program success, technical successmust be differentiated from commercial suc-cess. According to chapter 4, the risk of tech-

nical failure appears small, particularly ifoperation of the Compact Ignition Tokamak(CIT) does not uncover serious problems.1

If CIT operates as anticipated, it seems likelythat a fusion device capable of producingelectricity can be developed.

However, the risk of commercial failure—

the development of a technology that doesnot interest potential users—is much harderto evaluate. The commercial attractivenessof fusion energy will depend not only on itscost, but also on conditions unrelated to fu-sion technology that cannot be estimated atpresent. Different opinions as to the likeli-hood of successful commercialization andthe attractiveness of fusion over other elec-tricity alternatives affect the priority given tofusion research.Perceived Urgency: Chapter 5 concludedthat estimates of future electricity demandneither require nor eliminate fusion as a pos-sible energy source. It appears that electri-city technologies other than fusion—principallycoal and nuclear fission—should be capableof supplying ample power at reasonableprices through at least the middle of the nextcentury. However, uncertainties as to thecontinued acceptability of fossil fuels and nu-clear fission provide incentives to explore thepotential of improved energy efficiency andto develop alternative energy sources. Differ-ent estimates of the future attractiveness ofcoal and nuclear fission, and different judg-ments of the ability of various alternatives to

ICIT is described in the section of ch. 4 titled “Key TechnicalIssues and Facilities. ”

●

●

replace coal and/or fission, affect one’s per-ception of the urgency of fusion research anddevelopment.

None of the research paths presented inthis chapter call for a crash program to de-velop fusion. It is very difficult to formulatea credible scenario of major, irreversibleelectricity shortages in the early 21st centurythat would require fusion’s development ona schedule faster than that discussed in chap-ter 4.Advantages and Risks of Large-Scale Inter-national Collaboration: It appears possiblethat large-scale international collaborationcould enable the United States to make prog-ress towards assessing fusion’s potential ata substantially lower cost than would be re-quired for the United States to proceed in-dependently. Chapter 7 discussed the advan-tages and risks of large-scale internationalcollaboration in future fusion projects. Differ-ent evaluations of the costs and benefits oflarge-scale collaboration, which were pre-sented in chapter 7, affect one’s willingnessto consider undertaking the next stages offusion research collaboratively. In addition,different assessments of the obstacles to in-ternational collaboration may affect one’s will-ingness to negotiate a collaborative agreement.Implications of the Need for Expensive Re-search Facilities: Chapter 4 identified severalmajor research facilities that may be requiredto evaluate fusion’s potential. The total world-wide cost of these facilities has been esti-mated at $6 billion, with a next-generationengineering test reactor alone expected tocost well over $1 billion. As long as multi-billion-dollar facilities are necessary to as-sess fusion’s potential, development of fu-sion power cannot proceed without strongfinancial support at the highest levels ofgovernment. The private sector will not bewilling to finance fusion research until fu-sion’s potential is clearer.

The need for major facilities, along withthe need to conduct a diverse array of sup-porting research, means that the fusion re-search program will not make progress towardsevaluating fusion’s energy potential if itsfunding is too low. With insufficient fund-

Ch. 8.—Future Paths for the Magnetic Fusion Program ● 191

ing, the program must either delay completeevaluation of fusion’s potential or await tech-nological developments (which may neverbe realized) that lower the cost of the re-search remaining to be done.

● Near-Term Benefits: Chapter 6 discussednear-term benefits of fusion research suchas increasing scientific understanding, edu-cating and training skilled technical person-nel, and developing technologies with eco-nomic and defense applications. Differentvalues assigned to these benefits, and differ-ent estimates of the benefits that would havebeen derived had the resources spent on fu-sion been allocated elsewhere, lead to differ-ent levels of emphasis on fusion research.

● Potential for Surprise: In many respects, fu-sion technology will be unlike any existingtechnology, and it may open up capabilitiesand applications that cannot be foreseentoday. Like other qualitatively new technol-ogies, fusion’s most significant impacts maybe totally different than those that were ex-pected prior to its introduction. Some ob-

servers might oppose fusion’s developmentbecause of this inherent potential for unan-ticipated consequences; others would eagerlysupport exploration of the technology pri-marily because of the new possibiIities it mayoffer. Since unforeseen capabiIities or con-sequences are by definition impossible topredict, this report cannot and does not ad-dress them.

The possible advantages and disadvantages ofeach of the four paths outlined at the beginningof this chapter are described below, along withthe assumptions that would lead to each’s selec-tion. The discussions of the paths are interdepen-dent; in many cases, the advantages of selectingone approach also describe the disadvantages ofselecting another. The paths are discussed in gen-eral terms, and the detailed structure of the fu-sion research program is not specified under anyof them. Extensive additional study would be re-quired to determine the best way to implementeach path.

THE INDEPENDENT PATH

Description

The goal of the Independent path would be toaggressively establish the scientific and techno-logical base necessary to evaluate fusion’s poten-tial and to decide by the early 21st century whetherto proceed with a demonstration reactor. All thefacilities required to establish this base would befunded and operated domestically under this ap-proach. The exact funding necessary for this pathcannot be determined without detailed additionalexamination, but considerably more supportwould be required than is currently available tothe fusion program. On average, between $500million and $1 billion per year probably wouldbe required over the next 20 years, with peak an-nual funding possibly exceeding $1 billion. Wide-spread international cooperation might continue,but it would fall well short of the shared decision-making and funding that would characterize theCollaborative approach. The Independent path

is similar to the one specified (but not funded)in the 1980 Magnetic Fusion Energy EngineeringAct. 2

Motivations and Assumptions

Choice of this path would be motivated by theassumption that evaluating fusion’s potential earlyin the next century is an important national goal.The probability of success and the need for de-veloping fusion would both be assumed highenough to justify considerably increasing the cur-rent U.S. investment in fusion research.

The benefits of conducting fusion researchwithout depending on the participation of othercountries would be assumed to outweigh the costsavings and other possible advantages of large-scale international collaboration. Although the

~Tht\ act IS d e s c r i b e d In the sec t ion ot ch. 3 t i t l ed “The 1980$:

Le\ elln~ Ot’t’ “


near-term domestic benefits of fusion researchprobably also would be highly valued, the pros-pects of developing a viable energy technologywould be the primary motivation for selecting thispath.

Advantages

Control Over Research and Development.–Under this approach, the United States would befully self-sufficient in acquiring the informationneeded to assess fusion’s potential. Decisionsmade in other countries or difficulties in large-scale international collaboration would not affectthe U.S. ability to evaluate fusion’s potential ona time scale of its own choosing. Under this ap-proach, the United States could attempt to re-gain a position of world leadership in fusion re-search, rather than accept the technologicalparity required for true collaboration and inter-dependence.

If the United States were to go on to make apositive assessment of fusion’s potential, and ifthe U.S. technological capability in the field wereunmatched by other international fusion programs,the United States would have the advantage ofleading the development and commercializationof fusion technology.

Energy Supply. —If the United States were tomake a positive evaluation of fusion’s potentialas a result of pursuing this approach and werethen able to develop and commercialize fusiontechnology, a new, potentially attractive sourceof energy would become available. Even if fusionwere not viewed as preferable to other energytechnologies, investment in the technology mightstill be justified since fusion would be availableas a hedge against unforeseen or underestimateddifficulties with other energy sources.

Manpower, Infrastructure, and TechnologyDevelopment.–Conducting fusion research in-dependently could have significant domestic ben-efits, in terms of training personnel, acquiring adomestic fusion infrastructure, and developingassociated technologies. Since more funds devotedto the fusion effort would be spent domesticallythan under any of the other research approaches,these domestic benefits would be realized to agreater extent under this approach. Moreover,the United States would not be dependent on ex-

ternally acquired information or technical ex-pertise.

International Stature. –Through this researchapproach, the United States would be able todemonstrate its technological capability and bol-ster its international stature. In addition to the po-tential economic returns, being in a position ofworld leadership could give the United States sig-nificant leverage in future cooperative projectsand couId make the United States a more desira-ble cooperative partner.

Disadvantages

Cost.–The principal disadvantage of this re-search approach is its cost, which is considera-bly higher than that of any other approach. Fusionis not guaranteed to succeed, and the investmentin fusion research may not “pay off” with an at-tractive energy technology. In this case, the in-vestment in fusion research might be consideredwasted. Benefits of the fusion program such asscientific return, training of personnel, techno-logical development, and international stature–hard as they are to measure–are unlikely tojustify the full cost of independently developingfusion technology.

Potential Overemphasis.–A sense of urgencyand direction is necessary in order for the fusionprogram to command the resources it would re-quire under the Independent path. However, therisks of program failure are increased if an exag-gerated sense of urgency pushes the research ef-fort faster than it can responsibly proceed andprematurely forces key decisions. A balance mustbe struck between proceeding with determina-tion and direction, which is necessary, and rush-ing into a “crash program, ” which can be coun-terproductive.

A more subtIe risk could arise if fusion wereemphasized at the expense of improving the ex-isting sources of energy supply, increasing the effi-ciency of energy use, or developing other energysupply alternatives. if U.S. long-term energy re-search concentrates heavily on fusion, the impli-cations of technical or commercial failure couldbe serious. Therefore, if concern over energy sup-ply motivates more intense fusion research, itshould also motivate energy research in non-fusion areas.

Ch. 8.—Future Paths for the Magnetic Fusion Program c 193

THE COLLABORATIVE PATH

Description

Ideally, the Collaborative path would accom-plish the same technical tasks as the independ-ent path on a similar time scale. However, theCollaborative path would use the combined re-sources of the world’s major fusion programs,making it possible for the individual contributionof any one program to be smaller than wouId beneeded to perform the same tasks alone.

With large-scale international collaboration, theU.S. fusion program would require only modestincreases in funding above current levels to evalu-ate fusion’s feasibiIity early i n the 21st century.Annual funding on the order of $400 million to$500 million probably would be necessary overthe next 20 years, with the total being highly de-pendent on the degree of cost-sharing attainablethrough collaboration.


Choice of this approach, like the Independentapproach, is based on the assumption that evalu-ating fusion’s potential in the early 21st centuryis an important national goal. The assumed prob-ability of success and the perceived need for fu-sion power wouId be high, as they would be un-der the Independent path. The major differencebetween this path and the Independent path isthat under this approach the benefits of large-scale international collaboration would be assumedto outweigh the disadvantages. The United StateswouId consider self-determination in fusion ei-ther impossible or not worth the price.

Activities under the Collaborative path couldtake the form of joint construction and operationof major facilities, in which several nations’ fu-sion programs would be simultaneously involved.Activities could also take the form of allocatingvarious research tasks to particular programs. Ifsuch an allocation were done, all programs wouldeventually need to obtain data (which is rathereasily shared) and expertise or “know-how”(which is harder to transfer) from the program thathad done a particular piece of research.

The near-term benefits of fusion research wouldnot be judged important enough u rider this ap-

proach to justify conducting all the necessary re-search domestically. Choice of the ColIaborativeapproach assumes that the parties involved wiIIbe able to develop a program whose cost andschedule is acceptable to all, that major experi-mental facilities can be collaboratively built andoperated, and that equitable allocation of re-search tasks and results can be arranged.

Advantages

Cost-Sharing.–The principal benefit of theCollaborative path is the cost-effective utilizationof the resources avaiIable to the major fusion pro-grams worldwide. Total funding now spent an-nually on fusion research throughout the worldis comparable, or greater than, the amount neededper year to evaluate fusion’s potential by the early21st century. If the major fusion programs canminimize duplication of effort, reaching that evalu-ation should not require substantial budgetary in-creases in any of the major programs. Whereaspursuit of the Independent path requires dou-bling or tripling annual U.S. fusion budgets, theCollaborative path may only require funding in-creases of 20 to 50 percent above current levels.

Energy Supply.– If successfully implemented,the Collaborative approach would permit theUnited States and the other major fusion pro-grams to evaluate fusion’s potential by the early21st century. The timing of this evaluation issimilar—although possibly somewhat delayed—from that in the Independent path. However, theresults of a Collaborative research effort wouldbe more effectively shared among the major fu-sion programs.

Improving the Technical Base.—Fusion re-search may proceed more effectively if the re-search efforts of the major programs are integratedto a greater degree. All of the major programshave technical capabilities and skilled personnelthat can contribute to the research and develop-ment effort. In addition, effective planning amongthe major fusion research programs can ensurethat more research approaches are investigated.Ifr through such efforts, research efforts can bemutualIy supportive rather than duplicative, thiswidened technological base will benefit fusionresearch worldwide.


Foreign Policy Benefits.–The United Statesmay wish to participate in a large-scale collabora-tive project for diplomatic reasons as well as tech-nical ones. Since there appear to be significanttechnical and financial benefits to the UnitedStates from successful collaboration in fusion,diplomatic motivations would not appear to bein opposition to programmatic ones.

Disadvantages

Shared Control and Loss of Flexibility.–Underthe Collaborative approach, the United Stateswould sacrifice some control over the researchprogram. International collaboration on the scalenecessary for this approach will require com-promise by all partners. In particular, some ma-jor experimental facilities, such as the interna-tional Experimental Thermonuclear Reactor,wouId probably not be sited in the United States.This approach could be less flexible than theothers, since decisions—which would be mademulti laterally—would be difficult to modify.Moreover, depending on how time-consumingthe negotiation process is, the Collaborative pathcould take longer than the Independent path todevelop fusion.

Obstacles to Large-Scale Collaboration.–If thepotential obstacles to large-scale collaboration de-scribed in chapter 7 prove insurmountable, theCollaborative approach would fail. In this case,

the United States would either have to makemore resources available for fusion research,changing to the Independent path, or extend theschedule for fusion development as discussed inthe Limited path (below).

Cost.–Although the cost of this approach issubstantially less than that of proceeding inde-pendently, increases in U.S. annual fusion fund-ing are nevertheless required to carry out this ap-proach. If fusion research does not lead to anattractive energy source, this investment mightbe considered wasted.

Adverse Impact on Domestic Development.–The Collaborative approach is motivated in part

by pressures to share costs and lessen researchexpenditures. However, if international collabo-ration is supported at the expense of maintain-ing a healthy domestic program, both the col-laborative projects and the domestic programcould be damaged. A viable domestic programis required to contribute to and be attractive forfuture collaboration.

The Collaborative approach may create tensionbetween undertaking domestic activities, on theone hand, and participating in joint research withforeign programs, on the other. Incentives to min-imize costs and avoid duplication will have to bebalanced against developing and maintainingsufficient domestic expertise to contribute to andassimilate the results of collaborative projects.

THE LIMITED PATH

Description Because there are so many different motiva-

Under the Limited path, fusion research wouldcontinue but would not be supported at the levelnecessary to evaluate fusion’s potential domes-tically in the early 21st century. The schedule fordeveloping fusion under this approach thereforewould be delayed compared with the independ-ent or the Collaborative approaches. With theLimited path, funding levels would not be suffi-cient to support a healthy base program simul-taneously with the construction of major facilities

tions for pursuing this approach, no single plan,strategy, or estimated funding level can ade-quately describe it. Clearly, the funding levelwould be less than that needed for the independ-ent path and more than that for the Moth balledpath (below). It probably would be less than thatneeded for the Collaborative path, although evena funding profile sufficient for the Collaborativepath would result in the Limited path if collabora-tion were found to be undesirable or unworkable.

required’ to make progress in critical research The Limited approach would attempt to retain

areas. a base program in fusion research at universities


and national laboratories. The program would belimited to scientific research, however, with fund-ing levels and/or program intent not enabling itto advance to engineering development anddemonstration. With the Limited path, fusion’sscientific feasibility probably could be deter-mined. It is unlikely, however, that engineeringfeasibility could be determined domestically, andcommercial feasibility would be impossible toevaluate without increased financial support.


With the Limited path, pursuit of fusion wouldnot be a high national priority. Many different as-sumptions could result in a lower priority for fu-sion research and lead to selection of the Limitedpath. The Limited path also might be pursued asa “second choice” if either the Independent orthe Collaborative approaches could not be sus-tained.

Assumptions that might lead to selection of theLimited approach include the judgment that fu-sion’s promise or urgency was not high enoughto justify the Independent approach but too highto warrant shutting the research program downentirely. Moreover, either the prospects or therewards of international collaboration could bejudged too low to pursue the Collaborative ap-proach.

Perhaps the construction of large experimentalfacilities would not be seen as warranted unlessor until further technological development—in oroutside of the fusion program—brought downcosts. Alternatively, it might be decided that whilethe near-term benefits of fusion research justifiedmaintaining a limited program, the energy ben-efits did not justify a more extensive research ef-fort. Delaying development of fusion’s energy po-tential need not necessarily reduce the scientific,educational, and technological benefits of fusionresearch.

Advantages

Cost.–The major benefit of the Limited pathis that the United States could maintain a limitedresearch capability while still retaining the abil-ity to accelerate fusion research at a later time.

It would be cheaper–and therefore politicallyeasier—to fund a Limited path program than thehigher cost Independent or Collaborative ap-proaches.

Flexibility.–In some ways, research with theLimited path may be more flexible than with ei-ther the Independent or Collaborative paths. Earlydesign selections for large and expensive researchfacilities that would tend to lock in a given lineof research emphasis would be avoided. Delay-ing these investments could make it possible tobuild them either at substantially lower cost orwith a higher probability of commercial success.

Risk Avoidance.–Under this approach, theUnited States could let the rest of the world shoul-der the expense and take the risk of determin-ing fusion’s feasibility. The United States wouldretain a base program in fusion research to pre-serve the expertise needed to evaluate and even-tually reproduce work done abroad. The UnitedStates, of course, would start out with a competi-tive disadvantage in this case and might or mightnot be able to catch up. However, it would alsobe able to evaluate whether or not the technol-ogy was attractive without the substantial invest-ments required to pursue the Independent or Col-laborative paths. The United States would be freeto attempt to develop an improved technologyat some later time.

Disadvantages

Delaying Energy Supply .–The fundamentaldisadvantage of the Limited path is that it delaysthe evaluation of fusion. At our current level ofunderstanding, experimental devices that are in-herently large and expensive are required to re-solve key uncertainties in the development of fu-sion power. Unless these facilities are funded,progress cannot be made and fusion’s potentialcannot be determined or developed,

Technical developments may ultimately de-crease the cost or eliminate the need for expen-sive experiments. However, it is not likely thatsuch developments will occur quickly enough forthe Limited approach to make fusion power avail-able on the same schedule as the Independentor Collaborative approaches. Moreover, signifi-


cant developments may be less likely to occuror be recognized in the absence of a more am-bitious research program.

Loss of Direction and Scope.—If the fusion re-search program is not targeted towards an evalu-ation of fusion’s prospects as an energy source,it might become more of a basic science/plasmaphysics research program than an energy pro-gram. Without the direction provided by a rela-tively near-term goal—evaluating fusion’s engi-neering feasibility—the program’s subsequentevolution might lead it away from those issuesthat must be resolved to develop fusion reactors.This drift would not only delay the developmentof fusion power but might also make its eventualdevelopment less likely.

Damage to Fusion Infrastructure.–Lim itedFederal funding of fusion research could adverselyaffect many participants in the fusion researchprogram. Industrial participation would be themost severely constrained; steady and predicta-ble funding is required for industry to developand maintain the capability to participate in fu-sion research. Depending on the funding level,national laboratories and universities might alsohave to cut back on fusion work.

Moreover, the field of fusion research in gen-eral and university programs in particular mightnot be able to attract the most talented students

if the program were perceived as having an un-certain future, In this event, a valuable source ofnew ideas and innovation would be lost.

Loss of Momentum and International Stature.–With the Limited path, the fusion program couldlose its momentum. Unless other countries alsolimited their programs, the United States wouldfall behind. If other countries successfully com-mercialized fusion technology, the United Statescould be at a competitive disadvantage, at leastinitially.

However, U.S. decisions and foreign decisionsare not independent. Given that fusion researchbudgets are set in all the major fusion programsthrough a political process that balances fusionagainst other priorities, U.S. action to lower thepriority of fusion research might weaken the po-sitions of fusion researchers in other programs.Foreign fusion programs might reduce their re-search efforts. However, the other world fusionprograms are clearly developing fusion for broaderreasons than simply keeping up with the UnitedStates, and none of them are likely to eliminatetheir programs.

Difficulty in Collaboration.– If foreign fusionprograms pursue research more aggressively thanthe United States, the United States may nolonger be seen as a desirable collaborativepartner.

THE MOTHBALLED PATH

Description energy supply technologies, to see whether thedecision to stop funding fusion research should

With the Moth balled path, the magnetic fusion be reviewed.research program would shut down. To capital-ize on the research investment to date, this path In practice, however, monitoring might be dif-

would ideally be implemented in a manner that ficult. Competing funding priorities, too, might

preserved the existing state of knowledge in the make it hard to acquire the resources needed to

field and eased the transition of people and fa- reevaluate a canceled program.

ciIities from fusion to other areas. To keep openthe option of restarting the fusion program in the Motivations and Assumptionsfuture, some resources would be desirable (ei-ther provided directly or through other programs) Choosing the mothballed approach implies thatto permit periodic reevaluation of fusion. Tech- development of fusion–even as a hedge–doesnical developments in other fields would have not merit appreciable investment now or in theto be monitored, along with progress in alternate near future. Proponents of this approach might


consider the current state of fusion technologyanalogous to that of computer technology in the19th century: although many of the fundamen-tal concepts were known, a century of techno-logical progress in widely disparate fields wasrequired before computers of any practical sig-nificance could be built.

Technological pessimism is not likely to be thedeciding factor in stopping the fusion program,since the operation of ClT—if successful—shouldconfirm the scientific feasibility of fusion. instead,the decision to cancel the program probablywouId be motivated by the belief that fusion re-search will not result in a commercially, socially,or environmentally attractive source of energy,or that finding out how useful fusion could beis too expensive. The near-term benefits of con-ducting fusion research would not be assumedto justify the program, and the expected payoffof fusion would be considered too low to makecost-sharing with other countries attractive.

Advantages

Saving Money .–The major advantage of thisapproach would be avoiding the costs of futurefusion research.

Disadvantages

Unavailabil ity of Possible Energy Supply.–The major risk of this approach is that fusion’spotential as an energy source would not be real-ized. ShouId future circumstances make reeval-uating fusion desirable, restarting the programwouId be expensive, difficuIt, and time-con-suming.

Destruction of Fusion Infrastructure.–Withthe Moth balled path, the people and facilities thatcurrently carry out fusion research would switch

to other programs; the associated benefits of fu-sion research such as personnel training, scien-tific research, and technological developmentwould not continue in their current form, Al-though scientific data and technological accom-plishments would not be lost, the “know-how”of individual researchers would be. Decades wouldbe required from whenever a decision weremade to resume the program until the earliesttime that it could lead to a usable product. Dis-mantling the existing technological base and per-sonnel pool does not irrevocably eliminate fusionas an option, but significant costs (in both timeand resources) would be required to rebuild fu-sion research capability.

Mitigating this disadvantage somewhat is thebreadth of plasma physics as a research discipline.Since plasma physics is intrinsic to many appli-cations outside of fusion, plasma physics researchand application would certainly persist throughnon-fusion-program sources, even if fusion re-search were discontinued. Although the areas ofplasma physics most relevant to fusion would suf-fer, general plasma physics research could pro-vide a core of expertise if a program restart wererequired.

Inhibiting Technical Development.–Withoutan extensive base of technical personnel trainedin and sensitive to problems relevant to fusion,discoveries that might make fusion easier toachieve could go unrecognized.

Elimination of International Stature in Fusion.–if it is not conducting domestic fusion research,the United States will be unable to collaboratewith other countries or benefit from the resultsof research done abroad. If fusion technologywere developed successfully abroad, it could takemany years for the United States to reproducethe technology.

Appendixes

Appendix A

Non-Electric Applications of Fusion1

The baseline D-T fusion reactor discussed in chap-ters 4 and 5 produces energetic neutrons as its imme-diate output. In an electric generating station, theenergy of these neutrons would be recovered as heatand used to generate electricity. Other possible ap-plications of D-T fusion technology might use the neu-trons themselves to produce fission or fusion fuels orto induce nuclear reactions that change one isotopeor material into another. Applications of fusion as aneutron source and other non-electric applications offusion energy are discussed below.

Fusion as a Neutron Source

Each D-T reaction in the plasma produces one neu-tron, which is needed to breed tritium to replace thatused in the reaction. However, additional neutronscan be generated by neutron multipliers i n the reactorblanket. 2 These “excess neutrons” are available tomake up for losses as well as for other purposes, suchas the production of materials in the reactor blanket.Therefore, fusion reactors could be used as neutronsources in addition to sources of electricity.

If it produced a sufficiently valuable product, a fu-sion neutron source would not need to generate netelectric power to be cost-effective. In practice, how-ever, few if any such products exist; system studiesshow that a fusion reactor serving as a neutron sourcewill probably also need to produce electric power tobe economically viable. (A possible exception, tritiumproduction, is discussed below.)

Fusion-reactor neutron sources could have signifi-cant advantages over fission reactors, the major ex-isting large-scale sources of neutrons. A suitably de-signed fusion reactor would generate only aboutone-sixth the heat of a fission reactor with the sameneutron output. Furthermore, the energy of the fusionneutrons is several times higher than the energy of fis-sion neutrons, thus permitting applications that are notpossible with fission.

Tritium Production

One application of a fusion-reactor neutron sourcewould be production of tritium beyond that neededto fuel the fusion reactor.3 As discussed in chapter4, tritium self-sufficiency is a key issue for a fusion elec-tric power reactor;4 it is especially difficuIt to designa power-producing reactor capable of producing sub-stantial amounts of excess tritium. However, tritiumproduction can be enhanced at the expense of elec-tricity generation.

Tritium has several industrial, medical, and militaryapplications; its largest user is the nuclear weaponsprogram. Tritium is radioactive, with 5.5 percent ofthe tritium stockpile decaying each year. Therefore,the tritium supply for nuclear weapons requires con-stant replenishment even if no additional weapons arebuilt. Four fission reactors are operated for the De-partment of Energy (DOE) in Savannah River, SouthCarolina, to produce tritium for nuclear weapons.These reactors are currently about 35 years old, andthey will soon need replacement.

A recent National Research Council study found thatalthough fusion reactors have promising features forbreeding tritium, fusion technology is not yet suffi-ciently advanced to expand or replace the SavannahRiver facilities.5 The engineering development andtesting needed to create reliable fusion tritium-breederscannot be completed by the time decisions must bemade concerning the Savannah River reactors. Never-theless, the study also concluded that fusion has po-tential for producing tritium, and that DOE should“undertake a program that analyzes and periodicallyreassesses the concept, including design studies, ex-perimentation, and evaluation, as fusion developmentproceeds.” 6

Fusion technology could be applied to tritium pro-duction without necessarily altering the technicalcourse of the civilian magnetic fusion research pro-gram. However, if use of fusion technology for tritiumproduction were to precede its commercial applica-tion as a civilian electricity generating technology, thefusion research program nevertheless could be pro-

T Much ot the material In this appendix is drawn from K. R, Schultz, B,A,Engholm R F Bourque, ET Cheng, M j, Schatfert dnd C . P,C, L%’ong, TheFusion ApplIc atwrrs and Market El .jluatlon - “FAME’ ’-. Study, bv GA Tech-

nologies, In{ San Diego, CA, 1986 This study was done under contractto the Department of Energy’s (Iflce of Fusion Energy

2Neutron multipliers are discussed In ch 4, box 4-B

‘Tntlum-produc i ng fusion breeders are dlscuiw>d I n N atI{Jn,I I Rt,w,l r{ hCouncil, Committee on Fusion Hybrid Reactors out/ooA for thf, Fuworr }{Lbrd and Trltlurn-Breeding Fusion Reactors (Washington D( N,l:l~)nal ,Ac ,IC{-emy Press, 1987), pp. 94-110. See the following wctlon ot t h I\ al~~wndlx fordetlnltlons and discussion ot’ (usIon hybrid reactors,

‘See the section “The Fusion Blanket and Flr~t \\’all’ In c h .I5Natlona I Research L-ou ncl 1, Out/ooA for (Iw Fuwon H},hrd ,]ncf Tritlurm

Breeding Fusion Reactor,, op clt , p 16.61bld

201


foundly affected. On one hand, the nuclear weaponsprogram would shoulder some of the developmentcosts and would provide a near-term motivation forsupporting fusion research. Furthermore, associatingfusion R&D with the nuclear weapons program wouldensure it a higher national priority.

On the other hand, associating fusion power withthe nuclear weapons program could also become asevere liability in terms of public acceptance. More-over, since the technical requirements for breedingtritium and producing electricity are different, featuresof the tritium-breeder design would not necessarilybe applicable in an electric power reactor. The institu-tional experience gained in developing, building, andoperating a military tritium-breeder may be even lesstransferable to a civilian power reactor than the tech-nical experience because, at present, regulatory mech-anisms for the two are so different.7 For all of thesereasons, adopting the technological or institutionalframework from a military tritium-breeder to the ci-vilian fusion program could seriously compromise thefuture acceptability of fusion power.

Fissionable Fuel Production or Use

In a fission/fusion hybrid reactor, excess fusion neu-trons are used to breed fissionable fuel or to inducefission reactions within the fusion reactor blanket.There are, correspondingly, two different types of fis-sion/fusion hybrid: one that uses fission reactions inits blanket to multiply the energy generated in the fu-sion core, and one that suppresses blanket fission re-actions to generate fissionable fuel for use i n pure fis-sion reactors. The former type, the “power-only”hybrid, does not produce fissionable fuel. The latter,or “fission-suppressed” hybrid, does not producemuch of its own power from fission reactions; instead,it transforms “fertile” materials that are not readily fis-sionable into fissionable fuels such as uranium orplutonium. In both types of hybrid, the total energyreleased (or made available) is much larger than thatavailable from fusion reactions alone. g

Since most of the energy generated in a power-onlyhybrid is due to fission reactions, the amount of fu-sion power generated by such a device need not belarge. Therefore, the fusion core of a power-only hy-

~Weapons-related DOE facilities are not now sub)ect to the same processot Nucledr Regulatory Comm!sslon and Natlona[ Envlronmenta[ Poi Icy Actreview that governs civilian nuclear facl I itles. However, publ IC pressure torIncreasing the regulation of mtlltary reactors IS growing.

aEnergy multiplication occurs because a fission reaction releases about 10times as much energy as a fusion reaction. Each excess neutron that Inducesa tlsslon reaction in the blanket releases many times more energy than Itoriginally carries. (The same energy multlpllcatlon occurs when flsstonablematerial produced In a tuslon reactor IS removed to fuel external reactors,except that the addltiona I energy IS released In the cxterna 1 reactors and notIn the fusion blanket. )

brid would not need to achieve as high a level of per-formance as the core of a pure fusion power reactorin terms of parameters such as energy gain. g

In combining the fusion process with fission, a hy-brid reactor could also combine their liabilities. Sincehybrid reactors involve the production and/or use offissionable fuels, their environmental, safety, andproliferation concerns are more serious than those ofpure fusion reactors; many of the environmental andsafety concerns of nuclear fission, both perceived andactual, could be transferred to the hybrid. Further-more, a complete evaluation of the fuel-producing hy-brid must include the client fission reactors. If the in-centive for pursuing fusion research is to provide anenergy alternative that is environmentally or sociallypreferable to nuclear fission, then combining fusionwith fission in a fission/fusion hybrid reactor mightnot accomplish that goal.

The economic justification for hybrid reactors isweak at present because the price of uranium fuel isso low. According to the National Research Councilhybrid study, uranium prices must rise by a factor ofbetween 6 and 20 for a fission/fusion hybrid to be eco-nomically attractive.l ” The study concluded that ac-celerated use of fission reactors in the United States,coupled with policy decisions requiring U.S. reactorsto be fueled with domestic uranium supplies, couldincrease the domestic price of uranium by a factor of10 by the year 2020. However, a more likely rate offission growth would cause prices to reach this levelsometime between 2020 and 2045, and relaxing theconstraint on domestic supply would delay such aprice increase for an additional 30 years. Therefore,the NRC study concluded that fission/fusion hybridswill probably not be economically justified in termsof increased uranium price before the middle of thenext century.

Several additional factors besides the price of ura-nium affect the economic viabiIity of fission/fusionbreeders. First, advanced-converter fission reactorsthat use uranium much more efficiently than presentlight-water reactors would be less sensitive than pres-ent reactors to the price of uranium. Development ofthese more efficient reactors would further delay thetime when breeders would become attractive. Sec-ond, any discussion of hybrid breeders must comparethem to pure fission breeders, which can also producefissionable fuel. Such a comparison is beyond thescope of this study.

9Energy gain IS discussed I n the section of ch. 4 titled ‘‘Sclentklc Progress. ’

1~Natlonal Research COU ncil, Out/ook fOf t/7e ~usfon HyLmd and Trmum-Breedlng Fumm Reactors, op. cit., p 8, The study esttmated fission/fusionbreeders to become economically viable when the price of uranium oxidere~che> trom $100 to $300 per pound; the price currently 15$17 per pound

App. A—Non-Electric Applications of Fusion ● 203

Other Isotope Production

With the possible exception of tritium and fission-able fuels, no materials have yet been identified thatwould justify building a fusion reactor for the solepurpose of producing them. To be economicallyworthwhile, high-value materials would have to beproduced from inexpensive ones through reactionswith fusion neutrons. In addition, extraction of thedesired isotope from the fusion blanket could not betoo expensive. Furthermore, the amount of the ma-terial produced in a fusion reactor must not be so largecompared to the demand that it would saturate themarket { driving down the price and destroying thevalue of the material.

it would be much easier to justify producing spe-cial materials or isotopes in a fusion reactor if electri-city were produced at the same time. A recent studyhas identified cobalt-60 (60Co) as an isotope that might

be economically produced in a fusion electric gener-ating station.11 However, demand for 60Co would haveto be much greater than it is now for this process tobe viable, since the amount of 60Co that could be pro-duced annually in a single fusion reactor is muchlarger than the present annual demand.

Cobalt-60 is an intensely radioactive material whoseprimary use is in sterilizing medical products, with sec-ondary uses in providing cancer radiation therapy andfood preservation via irradiation. Food preservation,in particuIar, couId be a rapidly growing application.Furthermore, 60Co also could be used to treat sewageby sterilizing it, although this application has yet tobe commercialized. It is possible, therefore, that 60Codemand might increase substantially.12

The worldwide demand for replenishing existing60C0 stocks is currently estimated to be about 11megacuries per year,

13 most of which is produced byAtomic Energy of Canada, Ltd. in the heavy-watermoderated CANDU reactors operated by OntarioHydro. A commercial fusion power reactor could pro-duce hundreds of megacuries of 60Co per year witha blanket optimized for 60Co production. Therefore,this application is viable only at greatly increased de-mand levels; depending on its increased use for food

I I B A, Engholm, E,T, Cheng, and K R, Schultz, ‘‘Radlolsotope Produc-tlon

In Fusion Reactors, ” GA Technologies Inc. San Diego, CA (undated) Thl~article was prepared as part ot’ the “ F u s i o n Appllcatlonf Studv” by K.RSchultz, et al., 1986.

lzlbld., p, 2.I lone Curie of any radioactive substance IS the amount that procluce~ ~ ~

X 101~ radloactl~e dtslntegratlons per second: 1 rnegacurle IS 1 mllllon ( urle~One curie ot pure ‘co would have a mass ot 0.88 mllllgram, and 11 rnegac wrles w ou Id have ~ mas; of 9 7 kl Iograms (2 1 pou rids) (Actual ‘{ICO \ou rce~do not consist ot pure bOCo In practice, less than 10 percent of the cobaltI n a boCo source consists of the b(]Co Isotope I I n 1984, the prlc e ot ‘IqCO w a~about !$ 1 00 per cu rle (Ibid , pp. 2-3 I

preservation, the annual growth in this demand overthe next several years has been estimated at 6 to 25percent.14

Radioactive (Fission) Waste Processing

In theory, the neutrons from a fusion reactor couldbe used to change radioactive fission wastes intoshorter lived materials that would decay more quickly,posing less long-term hazard. However, several studiesin the 1970s analyzed fusion’s capabilities to proc-ess radioactive waste from fission reactors, and theresults were not promising.15 These studies deter-mined that extremely high levels of fusion reactor per-formance and decades of neutron irradiation wouldbe required, along with advanced isotope and chem-ical separation processes. Even if these requirementswere met, it was unclear whether this approach of-fered a net advantage over waste burial. The benefitof reducing the long-term hazard associated with fis-sion wastes would have to be balanced against thetechnological difficulties associated with transformingthem, as well as the short-term risk of releasing thesewastes i n an accident at the processing faciIity.

Other Possible NonelectricApplications of Fusion

Synthetic Fuels

Currently, about two-thirds of all energy used in theUnited States is consumed directly by users in the formof fossiI fuel; only one-third is used to generate elec-tricity, Although the trend in future energy use istowards increasing electrification, many requirementsfor non-electric sources of energy such as liquid orgas fuels will likely remain.

It may be possible to take advantage of the high tem-peratures present in fusion reactors, along with theelectricity generated by them, to generate hydrogengas by decomposing water into hydrogen and oxygen.Hydrogen has applications either directly as a fuel orin the synthesis of liquid fuels. The GA fusion appli-cations study indicated that fusion might be an eco-nomically competitive source of hydrogen i n the longterm but did not demonstrate a clear advantage overhigh-temperature fission-based sources of hydrogenthat could also be available by the time fusion is com-mercialized.

I ~1 bid. , p 3) ‘For a rei icui ot thwe stuciles ~ee Schultz, et al , Fusion 4pp/IcaIIon\ S(ud)

Op Cit. pp Y-1 o


Process Heat

Another energy requirement currently satisfied bynon-electric sources of energy is process heat. Proc-ess heat is less transportable than electricity; it mustbe used at locations close to the generating site. More-over, although there are many users of process heat,few require more than a few hundred megawattseach. Essentially all of these users now use fossil fuels.Present fusion reactor designs would produce on theorder of 3,000 megawatts of heat (corresponding to1,000 to 1,200 megawatts of electricity at 35- to 40-percent conversion eff iciency), and there would belittle motivation to construct such a fusion plant dedi-

cated solely to the production of process heat. Theredoes not even appear to be significant economic ad-vantage associated with recovering waste heat pro-duced as a byproduct of electricity generation. Proc-ess heat does not appear to be an attractive use forfusion reactors as long as fossil fuels are available.This conclusion is supported by present-day experi-ence with nuclear fission powerplants, which are notused for process heat production in the United States.In the far future, if fossil fuels become too expensiveor too difficult to use in an environmentally soundmanner, fusion could become attractive as a sourceof process heat due to lack of an alternative.

Appendix B

Other Approaches to Fusion

The main body of this report has discussed magneticconfinement fusion, the approach to controlled fusionthat the worldwide programs emphasize most heav-ily. However, two other approaches to fusion are alsobeing investigated. All three approaches are based onthe same fundamental physical process, in which thenuclei of light isotopes, typically deuterium and tri-tium, release energy by fusing together to form heav-ier isotopes. Some of the technical issues are similaramong all the fusion approaches, such as mechanismsfor recovering energy and breeding tritium fuel. How-ever, compared to magnetic confinement, the two ap-proaches discussed below create the conditions nec-essary for fusion to occur in very different ways, andsome substantially different science and technologyissues emerge in each case.

Inertial Confinement Fusion1

The inertial confinement approach to fusion researchhas been studied for some two decades, and its cur-rent budget almost half that of the magnetic confine-ment program. In inertial confinement fusion, a pel-let of fusion fuel is compressed to a density many timesthat of lead, and then heated and converted to plasma,by bombarding it with laser or particle beams (see fig-ure B-1 ). At this density, about 10 billion times the den-sity of a magneticalIy confined plasma, the confine-ment time needed is so small (less than one-billionthof a second) that it shouId be possible to generate netfusion power before the pellet blows itself apart. Thepellet’s own inertia is sufficient to hold it together longenough to generate fusion power,

Inertial confinement already has been demonstratedon a very large scale in the hydrogen bomb, an iner-tially confined fusion reaction whose input energy isprovided by a fission (atomic) weapon. The challengeof laboratory-scale inertial confinement research is toreproduce this process on a much smaller scale, witha source of input energy other than a nuclear weapon.I n a hypo the t i ca l i ne r t i a l con f i nemen t reac to r , m ic ro -

exp los ions w i t h exp los i ve y i e l ds equ i va len t t o abou t

one-tenth of a ton of TNT would be generated by ir-radiating fusion pellets—called targets—with laser orparticle beams; these explosions would be repeatedseveral times a second.

‘The U S inertial con flnem[~nf tuilon rewarch program I\ rm Ie\\ ed I n ,]recent report by the Nat Ion,l I Rew,] rc h LOU nc I I Ret ~e~t of rhe Dep.] rfmentof f m’rqi s /neflI,I/ Conflnemenf Fu\lon Progr,]rn {Wf,]sh I ngton, DC Nattona IA( .I(l(>rm}, l)rf>~i I W() I

The issues addressed by inertial confinement fusionresearch in the United States concern the individualtargets containing the fusion fuel; the input energysources, called drivers, that heat and compress thesetargets; and the mechanism by which energy from thedriver is delivered–or coupled–into the target. Dueto the close relationship between inertial confinementfusion target design and thermonuclear weapon de-sign, inertial confinement fusion research is fundedby the nuclear weapons activities portion of the De-partment of Energy’s (DOE’s) budget. Inertial confine-ment research is conducted largely at nuclear weap-ons laboratories; its near-term goals are dedicatedlargely to military, rather than energy applications, anda substantial portion of this research is classified.

There are two near-term military applications of in-ertial confinement fusion—one actual and one not yetrealized. First, because the physical processes in a pel-let micro-detonation resemble those in a nuclearweapon, inertial confinement experiments now con-tribute to validating computer models of these proc-esses, to collecting fundamental data on the behaviorof materials in nuclear weapons, and to developingdiagnostic instruments for actual nuclear weaponstests. These activities can be conducted today with ex-isting high-energy inertial confinement drivers.

These applications could be greatly intensified, anda second set of applications would arise, if a labora-tory facility producing substantial pulses of inertiallyconfined fusion energy could be developed. No suchfacility yet exists. Such a facility could simulate theeffects, particularly the radiation effects, of nucleardetonations on systems and components. This appli-cation might be particularly important if a Compre-hensive Test Ban Treaty prohibited underground testsof nuclear weapons.

The near-term, military inertial confinement researcheffort also contributes information that would be es-sential to any longer term commercial applications.For example, both military and civilian applicationsof inertial confinement fusion (other than the com-puter program and diagnostic development activitiesthat are being conducted today) require that an iner-tial confinement target generate several times moreenergy than is input to it. Such an accomplishment,which would show the scientific feasibility of inertialfusion, is beyond the capability of any existing lab-oratory device. (Of course, thermonuclear weaponshave already demonstrated the scientific feasibility ofvery-large-scale inertial confinement fusion. )

205


Heating

Laser or particle beamsrapidly heat the surface

of the fusion target,forming a plasma

envelope.

Figure B-1.— Inertial Confinement Fusion Process

Compression

Fuel IS compressed byrocket-like blowoff ofthe surface material

Ignit ion

The fuel core reacheshigh density and ignites.

Burn

Thermonuclearburn spreads

rapidly through thecompressed fuel. yielding

many times theinput energy.

SOURCE Lawrence Livermore National Laboratory, “ICF Reaction, ” Energy and Technology Review, April-May 1986

The technical requirements for commercial appli-cations of inertial confinement fusion go considerablybeyond the requirements for weapons effect simula-tion and would require still further scientific and tech-nological development. Due to the relatively low ef-ficiencies (e.g., 10 to 25 percent) at which the driversoperate, each target explosion must generate severaltimes more energy than it is driven with to reachbreakeven. An additional factor of 4 to 10 is requiredbeyond breakeven to produce substantial net output.In a commercial reactor, therefore, as much as 100times as much energy must be released in a pellet ex-plosion as is required to heat and compress the pelletto the point where it can react. Furthermore, commer-cial energy production requires that pellets be deto-nated several times a second, far more frequently thanneeded for military applications. Finally, cost-effective-ness, reliabiIity, and high efficiency are much moreimportant for energy applications than miIitary ones;successful commercialization will depend on howwell the technology addresses the commercial require-ments discussed in chapter 5.

A significant potential advantage of inertial confine-ment over magnetic confinement is that the complexand expensive driver system can be located some dis-tance away from the reaction chamber. Because ra-diation, neutron-induced activation, and thermal stressdue to the microexplosions could be largely confined

to the reaction chamber, the driver would not haveto be designed to withstand this environment. In thecore of a magnetic confinement fusion reactor, on theother hand, systems both for supporting and maintain-ing the plasma and for recovering the energy andbreeding tritium fuel are located in high radiation, highneutron-flux environments. A second potential advan-tage of inertial confinement arises from the relativelyrelaxed vacuum requirements inside the reactionchamber, which would permit the use of neutron ab-sorbing materials such as liquid lithium inside the firststructural wall of the reactor. Use of such neutron ab-sorbers would lessen neutron irradiation levels in thereactor’s structural elements, increase the lifetimes ofthose elements, and lessen induced radioactivitylevels.

On the other hand, inertial confinement also hasdisadvantages compared to magnetic confinement. in-ertial confinement is inherently pulsed; the systemsneeded to recover energy and breed fuel in the re-action chamber have to withstand explosions equiva-lent to a few hundred pounds of TNT several timesa second. Inertial confinement reactors must focushigh-power driver beams precisely on target in thisenvironment. Furthermore, the energy gains neededfor these facilities must be much larger than those ofa magnetic confinement device to make up for driverinefficiencies.

App. B—Other Approaches to Fusion . 207

Four principal driver candidates are now being stud-ied in the U.S. inertial confinement research program.Two of them —solid-state or glass lasers and light-ion 2

accelerators—have by far the largest facilities; theother two principal candidates—gas lasers and heavyion accelerators—are in lesser stages of development.Major U.S. glass lasers are located at Lawrence Liver-more National Laboratory in California and the Uni-versity of Rochester Laboratory for Laser Energetic inNew York. The Livermore facility, the most powerfullaser in the world, does both classified and unclassi-fied inertial confinement research; the University ofRochester facility conducts only unclassified researchon a laser fusion approach that is not as relevant toweapons applications as is the approach pursued atLivermore. The largest light-ion accelerator in theworld is located at Sandia National Laboratory in NewMexico; like the Livermore facility, it conducts bothunclassified and classified research. The krypton-fluo-ride gas laser, the third driver candidate being stud-ied, is being developed at Los Alamos National Lab-oratory. Other contributors to the laser and light-ioninertial confinement programs are the Naval ResearchLaboratory and KMS Fusion, Inc., the only private cor-poration significantly involved.

A fourth driver candidate—the heavy-ion accelerator—is much less developed than the laser or light-iondrivers. Unlike light-ion and laser research, heavy-ionaccelerator research is a non-military program fundedby the Office of Energy Research, the same DOE of-fice that funds the magnetic confinement fusion pro-gram. 3 Heavy-ion experimental work is limited to ac-celerator technology, and in the United States it isconcentrated at Lawrence Berkeley Laboratory in Cali-fornia.

Other national fusion programs conduct inertialconfinement research, but at a significantly lower levelof effort than their magnetic fusion programs. Inter-national collaboration is much more restricted in in-ertial fusion than it is in magnetic fusion due to U.S.national security constraints. On balance, the iner-tial confinement program involves scientific andtechnological issues that are quite distinct from thoserelevant to magnetic fusion. A detailed comparisonof the relative status and prospects of inertial con-finement and magnetic confinement fusion is be-yond the scope of this assessment.

2Llght Ions are Ions of IIght elementj such a s Ilthlum‘The heav}-lorl research program IS f,] r smal Ier than the magnetic contl ne-

ment program and IS managed by a dltterent pafl ot the D(>E Offlce of EnergyResearch

Cold Fusion

Another approach to fusion, presently at an em-bryonic stage of development, is fundamentally differ-ent from either the magnetic or inertial confinementconcepts. This approach, called ‘‘cold fusion” or“muon-catalyzed fusion, ” might make it possible tobypass the requirement for extremely high tempera-tures that make the magnetic and inertial approachesso difficult.4

If it were possible to “shield” the electric chargeof one of the nuclei in a fusion reaction, one nucleuscould get very close to another nucleus without be-ing repelled. In this case, fusion reactions could oc-cur at far lower temperatures than wouId otherwisebe required, since the extreme temperatures neededto overcome the mutual repulsion of two electrically

charged nuclei would be unnecessary. Such shield-ing can in fact be provided by a subatomic particlecalled the muon. The muon—like the electron—hasa charge that cancels out the charge of a hydrogennucleus. But unlike the electron, the muon binds sotightly to the nucleus that the nuclear charge is shieldedeven down to the distances where fusion reactions cantake place. Therefore, once a muon becomes boundto a nucleus, the combination can approach a sec-ond nucleus closely enough to fuse without the needfor extreme temperature.

If the muon is freed in the subsequent fusion re-action, it can become captured by another hydrogennucleus to repeat the process. I n this way it serves asa catalyst, enabling fusion energy to be released with-out itself being consumed. However, since the muonis unstable, muon catalysis can be practical only ifeach muon generates more than enough energy dur-ing its 2.2-microsecond Iifetime to make its own re-placement.

Muon-catalyzed fusion reactions were actually ob-served in high-energy physics experiments in the1950s. However, the muons were rarely observed toinduce more than one fusion reaction each beforedecaying, compared to the hundreds of reactions permuon that would be necessary to make the processworthwhile. More recent experimental and theoreti-cal work has shown that the number of fusion reactionsthat can be catalyzed by a single muon depends onparameters such as the density and temperature of thedeuterium-tritium mixture into which the muon is in-jected. Experiments have shown that muons are ca-pable of catalyzing many more reactions during theirlifetime than had been thought many years ago.

4A d Iscusston of recent muon -cata lyzeci tuslon rewarc h IS gI\ en I n ‘C-ddNuclear Fusion, ” by Johann Ratelskl ~nd Ste\ en E Ionw In the july I ’18-Is+ue ot Sclerrt(fjc Arnerlcan pp 8 4 - 8 9


Whether this process can ever yield net energy pro- Iimits to how many fusion reactions can be inducedduction depends on increasing the number of fusion by a single muon. If muon-catalysis proves to be fea-reactions per muon, The number is not yet high enough sible in principle, a substantially increased level of ef-for the process to be scientifically feasible, and fun- fort and a more detailed comparison of its potentialdamental limits may prevent it from ever being so. benefits and liabilities to those of the other fusion ap-Muon-catalysis research, currently at a very prelimi- proaches may be warranted.nary stage, focuses primarily on understanding the

Appendix C

Data for Figures

Chapter Three

Data for Figure 3-1 .— Historical Fusion Funding, 1951-88 (millions of 1986 dollars)

Operating Capital equipment Construction

Budget Budget Budget Budget

1.11.86.17.411.629.228.933.730.024.825.522.623.123.123.926.629.734.332.233.339.757.4

118.2166.352.9

316.3332.4355.1350.3393.6451.2461.3468.4429.6361.5327.3320.1

1.11.84.76.610.718.427.031.029.023.024.221.021.321.822.424.726.527.728.331.037.052.997.9

131.142.6

195.0206.7211.3235.1258.3295.1373.8391.1369.6320.5302.2286.1

Year authority authority Index authority Index authority Index1951 -53 . . . . . . . . . 0.200 a a1954 . . . . . . . . . . . .1955 . . . . . . . . . . . .1956 . . . . . . . . . . . .1957 . . . . . . . . . . . .1958 . . . . . . . . . . . .1959. . . . . . . . . . . .1960. . . . . . . . . . . .1961 . . . . . . . . . . . .1962. . . . . . . . . . . .1963. . . . . . . . . . . .1964. . . . . . . . . . . .1965. . . . . . . . . . . .1966. . . . . . . . . . . .1967. . . . . . . . . . . .1968. . . . . . . . . . . .1969. . . . . . . . . . . .1970. . . . . . . . . . . .1971 . . . . . . . . . . . .1972. . . . . . . . . . . .1973. . . . . . . . . . . .1974. . . . . . . . . . . .1975. . . . . . . . . . . .1976. . . . . . . . . . . .TQb . . . . . . . . . . . .1977. . . . . . . . . . . .1978. . . . . . . . . . . .1979. . . . . . . . . . . .1980. . . . . . . . . . . .1981 . . . . . . . . . . . .1982. . . . . . . . . . . .1983. . . . . . . . . . . .1984. . . . . . . . . . . .1985. . . . . . . . . . . .1986. . . . . . . . . . . .1987 (estimate). .1988 (request). . .aNo expenditures occurred in this category during the warbThe start of the fiscal year was changed in 1976 from July 1 to October 1. TQ represents the budget for the transition quarter from July 1, 1976 to September 30, 1976

SOURCE U.S Department of Energy, Officeof Energy Research, letter to OTA project staff, Aug 15, 1966, updated by personal communication to OTA staff Sept 2,1987

0.2020.2030.2020.2050.2120.2180.2200.2240.2260.2280.2310.2340.2380.2430.2520.2630.2770.2910.3100.3200.3530.3820.4290.4290.4590.4930.5290.5880.6740.7660.8290.8920.9381.0001.0431.080

a

a

a

a

a

a

2.21.01.81.31.61.81.31.51.81.62.02.12.12.54.3

19.817.04.5

23.029.627.229.836.942.039.537.827.528.317.118.1

0.2600.2600.2610.2620.2630.2660.2690.2760.2850.2950.3050.3190.3270.3340.3510.3760.4890.4890.5180.5680.6190.6840.7770.8470.8930.9470.9541.0001.0511.088

a

1.40.80.9

10.81.90.5

a

a

a

a

a

a

a

0.11.64.61.80.20.20.20.5

18.25.8

98.396.1

116.685.498.5

114.148.039.532.512.78.0

15.9

0.1620.1670.1750.1820.1890.196

0.2470.2640.2840.3100.3440.3680.3930.4440.4840.4840.5160.5640.6130.6750.7460.8140.8650.8820.9341.0001.0251.060

209


Data for Figure 3-2.— Historical Fusion Funding, 1951-88 (millions of current dollars)

Presidential Total Presidential Totalbudget request budget authority budget request budget authority

Year budget authority (in millions) Year budget authority (in millions)

1951-53 . . . . . . . . . . . . . a 1.1 1972 . . . . . . . . . . . . . . . . a 33.31954 . . . . . . . . . . . . . . . . a 1.8 1973 . . . . . . . . . . . . . . . . a 39.71955 . . . . . . . . . . . . . . . . a 6.1 1974 . . . . . . . . . . . . . . . . a 57.41956 . . . . . . . . . . . . . . . . a 7.4 1975 . . . . . . . . . . . . . . . . 102.3 118.21957 . . . . . . . . . . . . . . . . a 11.6 1976 . . . . . . . . . . . . . . . . 144.2 166.31958 . . . . . . . . . . . . . . . . a 29.2 TQ b . . . . . . . . . . . . . . . . 44.4 52.91959 . . . . . . . . . . . . . . . . a 28.9 1977 . . . . . . . . . . . . . . . . 291.1 316.31960 . . . . . . . . . . . . . . . . a 33.7 1978 . . . . . . . . . . . . . . . . 370.9 332.41961 . . . . . . . . . . . . . . . . a 30.0 1979 . . . . . . . . . . . . . . . . 334.0 355.11962 . . . . . . . . . . . . . . . . a 24.8 1980 . . . . . . . . . . . . . . . . 364.1 350.31963 . . . . . . . . . . . . . . . . a 25.5 1981 . . . . . . . . . . . . . . . . 403.6 393.61964 . . . . . . . . . . . . . . . . a 22.6 1982 . . . . . . . . . . . . . . . . 460.0 451.21965 . . . . . . . . . . . . . . . . a 23.1 1983 . . . . . . . . . . . . . . . . 444.1 461.31966 . . . . . . . . . . . . . . . . a 23.1 1984 . . . . . . . . . . . . . . . . 467.0 468.41967 . . . . . . . . . . . . . . . . a 23.9 1985 . . . . . . . . . . . . . . . . 482.7 429.61968 . . . . . . . . . . . . . . . . a 26.6 1986 . . . . . . . . . . . . . . . . 390.0 361.51969 . . . . . . . . . . . . . . . . a 29.7 1987 (estimate). . . . . . . 333.0 341.41970 . . . . . . . . . . . . . . . . a 34.3 1988 (request) . . . . . . . 345.61971 . . . . . . . . . . . . . . . . a 32.2aPresidential budget requests before 1975 were not available from DOE.bThe start of the fiscal year was changed in 1976 from July 1 to October 1. TQ represents the budget for the transition quarter frorn July l, 1976 to September 30,1976,

SOURCE: US. Department of Energy, Office of Energy Research, letter to OTA project staff, Aug. 15, 1986.

Chapter Six

Data for Figure 6-1.— Federal Funding of Plasma Physics in 1984 (millions of 1984 dollars)

Plasma Physics Area DOE NSF DoD NASA NOAA Total

General Plasma Physics . . . . . . . . . . . 3 3 68 0 0 74Magnetic Conf. Fusion . . . . . . . . . . . . 471 0 0 0 0 471Inertial Conf. Fusion . . . . . . . . . . . . . . 170 0 0 0 0 170Space/Astrophysical Plasma . . . . . . . 2 30 5 100 2 139

Total . . . . . . . . . . . . . . . . . . . . . . . . . . 646 33 73 100 2 854DOE = Department of EnergyNSF = National Science FoundationDoD = Department of DefenseNASA = National Aeronautics and Space AdministrationNOAA = National Oceanic and Atmospheric Administration

SOURCE: National Research Council, Physics Through the 1990s: Plasmas and Fluids (Washington, DC: National Academy Press, 1986), p. 33

Data for Figure 6-2.— Defense and Civilian Federal Research andDevelopment Expenditures (billions occurrent dollars)

Year Defense Civilian Total

1982 . . . . . . . . . . . . . . . . . . . . . . . 22.9 15.8 38.71983 . . . . . . . . . . . . . . . . . . . . . . . 25.6 14.4 40.01984 . . . . . . . . . . . . . . . . . . . . . . . 30.5 15.5 46.01985. . . . . . . . . . . . . . . . . . . . . . . 34.7 17.0 51.71986. . . . . . . . . . . . . . . . . . . . . . . 37.6 17.0 54.61987 (estimate) . . . . . . . . . . . . . 41.2 18.6 59.81988 (request) . . . . . . . . . . . . . . 48.1 21.3 69.4

NOTE: Defense: includes Department of Defense along with Department of Energy atomic energy defenseactivities. civilian: Includes all Federal research and development not included in defense.

SOURCE: American Association for the Advancement of Science, AAAS Report XII Research and development FY 1988(Washington, DC: American Association for the Advancement of Science, 1987)

App, C—Data for Figures ● 211

Data forFigure 6-3.— Major Components in Federally Funded Research and Development (in 1987 dollars)

andFigure 6-4.— Historical Component Funding Levels for Federal Research and Development (billions of current dollars)

Year Defense Energy Space Health Science Other

1982 . . . . . . . . . . . . . . . . . . . . . . . 22.9 3.5 3.6 4.1 1.5 3.11983 . . . . . . . . . . . . . . . . . . . . . . . 25.6 2.9 1.7 4.5 1.6 3.71984. . . . . . . . . . . . . . . . . . . . . . . 30.5 2.6 2.0 5.1 1.9 3.91985. . . . . . . . . . . . . . . . . . . . . . . 34.7 2.5 2.4 5.8 2.1 4.21986. . . . . . . . . . . . . . . . . . . . . . . 37.6 2.4 1.9 5.9 2.1 4.71987 (estimate) . . . . . . . . . . . . . 41.2 2.2 2.4 7.0 2.2 4.81988 (request) . . . . . . . . . . . . . . 48.1 2.0 3.1 9.0 2.6 4.7NOTE Defense Includes Department of Defense along with Department of Energy atomic energy defense activites Energy Includes Department of Energy activites,

Iess general science and defense, Nuclear Regulatory Commission, and Environmental Protection Agency Space includes National Aeronautics and Space Ad.ministration less space applications and aeronautical research Health includes Department of Health and Human Services, Veterans Administration, Depart-ment of Education, and Environmental Protection Agency Science includes National Science Foundation and Department of Energy high energy physics andnuclear physics

SOURCE American Association for the Advancement of Science, AAAS Report X// Research and Development FY 1988 (Washington, DC American Association forthe Advancement of Science, 1987)

Data for Figure 6-5.— Annual Appropriations of DOE Civilian Research and Development Programs(millions of current dollars)

Year Solar/renewables a Fusion Fission Fossil Conservation

1980 . . . . . . . . . . . . . . . . . . . . . . .1981 . . . . . . . . . . . . . . . . . . . . . . .1982 . . . . . . . . . . . . . . . . . . . . . . .1983 . . . . . . . . . . . . . . . . . . . . . . .1984 . . . . . . . . . . . . . . . . . . . . . . .1985 . . . . . . . . . . . . . . . . . . . . . . .1986 (estimate) . . . . . . . . . . . . .1987 (estimate) . . . . . . . . . . . . .1988 (request) . . . . . . . . . . . . . .

731.4711.2341.1261.2211.9201.7173.6146.393.5

350.3393.6451.2461.3468.4429.6361.5341.4345.6

847.8817.0819.4701.7622.9412.6358.1329.3336.4

847.8821,3566.8310.9331.5349.4343.0451.0368.5

296.1292.5151.9133.5150.1175.5170.9160.780.1

aSolar/Renewables Includes Solar, Geothermal, and Hydroelectric programs.

SOURCE: Fusion—U S Department of Energy, Off Ice of Energy Research, letter to OTA project staff, Aug 15, 1986 Others –’’Analysis of Trends in Civilian R&D Ap-propriations for the U.S. Department of Energy, ” prepared by Argonne National Laboratory, August 1986, table B 3, p 49

Data for Figure 6-6.— Major DOE Civilian Research andDevelopment Funding at National Laboratories in

Fiscal Year 1987 (millions of 1987 dollars)

Solar and Other Renewable . . . . . . . . . . . . . . .Electric Systems . . . . . . . . . . . . . . . . . . . . . . . . .Environment . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Conservation . . . . . . . . . . . . . . . . . . . . . . . . . . . .Fossil Energy . . . . . . . . . . . . . . . . . . . . . . . . . . . .Supporting Research. . . . . . . . . . . . . . . . . . . . . .Nuclear Energy . . . . . . . . . . . . . . . . . . . . . . . . . .Magnetic Fusion . . . . . . . . . . . . . . . . . . . . . . . . .

$114.519.6

133.349.5

116.6360.0254.3245.6

SOURCE U S Department of Energy. FY 1988 Congresslonal Budget Estlmatesfor /laboratory/P/anf, January 1987


Chapter Seven

Data forFigure 7-1 .—Comparison of International Fusion Budgets (current dollars)

andFigure 7.2.—Comparison of International Equivalent Person-Years

United States:Fusion budget Average industrial hourly

Year (in millions $) wage ($) Person-years

1980 . . . . . . . . . . . . . . . . . . . . . . . 350.3 7.27 23,1651981 . . . . . . . . . . . . . . . . . . . . . . . 393.6 7.99 23,6831982 . . . . . . . . . . . . . . . . . . . . . . . 451.2 8.50 25,5201983 . . . . . . . . . . . . . . . . . . . . . . . 461.3 8.84 25,0881984. . . . . . . . . . . . . . . . . . . . . . . 468.4 9.16 24,5841985. . . . . . . . . . . . . . . . . . . . . . . 429.6 9.57 21,5821986. . . . . . . . . . . . . . . . . . . . . . . 361.5 10.04 17,310

Japan:Fusion budget Fusion budget Average industrial Average industrial

Year (yen) (in millions $) hourly wage (yen) hourly wage($) Person-years

1980 . . . . . . . . . . . . 52,256 230 1,293 5.70 19,4301981 . . . . . . . . . . . . 61,115 277 1,373 6.22 21,4001982 . . . . . . . . . . . . 72,025 289 1,225 5.72 24,3001983 . . . . . . . . . . . . 69,112 291 1,490 6.28 22,3001984 . . . . . . . . . . . . 60,392 251 1,561 6.50 18,6001985 . . . . . . . . . . . . 65,154 271 1,640 6.83 19,1001986 . . . . . . . . . . . . 64,861 381 1,704 10.02 18,300

European Community:Fusion budget Fusion budget Average industrial

Year (MECU) (in millions $) hourly wage($) Person-Years

1980 . . . . . . . . . . . . . . . . . 190 264 5.93 21,4041981 . . . . . . . . . . . . . . . . . 225 254 5.35 22,8151982 . . . . . . . . . . . . . . . . . 300 297 5.20 27,4571983 . . . . . . . . . . . . . . . . . 300 300 5.06 28,5321984 . . . . . . . . . . . . . . . . . 350 298 4.60 31,0861985 . . . . . . . . . . . . . . . . . 350 245 4.06 28,9771986 . . . . . . . . . . . . . . . . . 375 338 5.60 28,990

SOURCE: U.S. Department of Energy, Office of Energy Research, staff memorandum to file. Oct.9, 1986

Data for Figure 7-3.— Comparison of international Fusion Budgets by Percentage Gross National Producta

United States European Community Japan

Year GNP Fusion/GNP GNPb Fusion/GNP GNP Fusion/GNP

1980 . . . . . . . . . . . . . . . . . 2,632 0.0133 1,962 0.0135 899 0.02711981 . . . . . . . . . . . . . . . . . 2,958 0.0133 2,131 0.0119 964 0.02871982 . . . . . . . . . . . . . . . . . 3,069 0.0147 2,277 0.0130 1,060 0.02731983 . . . . . . . . . . . . . . . . . 3,305 0.0139 2,394 0.0125 1,138 0.02561984 . . . . . . . . . . . . . . . . . 3,363 0.0128 data unavailable data unavailableaAll Gross National Products are shown in billions of current dollarsbThe GNP for the European Community is computed by adding the GNP’s of the major EC countries (Belgium, France. Federal Republic of Germany, Greece, Italy,

Netherlands, and the United Kingdom)

SOURCE. Gross National Products found in Statistical Abstract, No 1742

Appendix D

List of Acronyms and Glossary

AECASDEX-U

ATF

CERN

CIT

COCOMCPMP

CPRF

D Ill

D II I-D

Acronyms

–Atomic Energy Commission–Axisymmetric Divertor Experiment

Upgrade; Garching, Federal Repub-lic of Germany

–Advanced Toroidal Facility; Oak RidgeNational Laboratory, Oak Ridge, Ten-nessee

–European Laboratory for Nuclear Re-search (after its original Frenchacronym)

–Compact Ignition Tokamak; proposedfor the Princeton Plasma Physics Lab-oratory, Princeton, New Jersey

–Coordinating Committee–Comprehensive Program Management

Plan–Confinement Physics Research Facil-

ity; under construction at Los AlamosNational Laboratory, Los Alamos, NewMexico

–Doublet ill; GA Technologies Inc.,San Diego, California

–Doublet Ill Upgrade; GA Technol-ogies, San Diego, California

D-D Reaction– Deuterium-deuterium fusion reaction(see Glossary)

D-T Reaction —Deuterium-tritium fusion reaction

DoDDOEdpaECECRH

EPRI

ERABERDA

ESECOM

ETReVFEDFER

FPA

(see Glossary)–U.S. Department of Defense–U.S. Department of Energy–displacements per atom–European Community—electron cyclotron resonance heating

(see Glossary)—Electric Power Research Institute;

Palo Alto, California–Energy Research Advisory Board–Energy Research and Development

Administration–Senior Committee on Economic, Safety,

and Environmental Aspects of Mag-netic Fusion Energy

—engineering test reactor (see Glossary)—electron volt (see Glossary)–Fusion Engineering Device–Fusion Experimental Reactor (proposed

Japanese engineering test reactor)—Fusion Power Associates; Gaithers-

burg, Maryland

FRC

GA

GNPIAEAICRH

IEAIFFINTORITER

JAERI

JETJIFT

JT-60LANL

LCT

LLNL

LMFBR

LWR

MFACMFECC

MFEE Act

MFPPMFTF-B

MIT

NASA

NET

NIHNRCNSFOER

–field-reversed configuration(see Glossary)

–GA Technologies Inc.; San Diego,California

–gross national product–International Atomic Energy Agency—ion cyclotron resonance heating

(see Glossary)–International Energy Agency–Integrated Fusion Facility—International Tokamak Reactor—International Thermonuclear Experi-

mental Reactor–Japan Atomic Energy Research in-

stitute–Joint European Torus; Abingdon, UK–Joint Institute for Fusion Theory; Uni-

versity of Texas at Austin, Texas, andNagoya University in Japan

–Japan Tokamak-60–Los Alamos National Laboratory; Los

Alamos, New Mexico–Large Coil Task; Oak Ridge National

Laboratory, Oak Ridge, Tennessee—Lawrence Livermore National Labora-

tory; Livermore, California–liquid metal fast breeder reactor

(fission–see Glossary)–light-water reactor

(fission–see Glossary)—Magnetic Fusion Advisory Committee–Magnetic Fusion Energy Computing

Center; Lawrence Livermore NationalLaboratory, Livermore, California

–Magnetic Fusion Energy EngineeringAct of 1980 (Public Law 96-386)

–Magnetic Fusion Program Plan–Mirror Fusion Test Facil ity B at

Lawrence Livermore National Labora-tory, Livermore, California

–Massachusetts Institute of Technol-ogy; Cambridge, Massachusetts

–U.S. National Aeronautics and SpaceAdministration

—Next European Torus (proposed Euro-pean engineering test reactor)

–U.S. National Institutes of Health–U.S. Nuclear Regulatory Commission–U.S. National Science Foundation–Office of Energy Research in the U.S.

Department of Energy

213


OFE

OHTE

ORNL

OTR

PBX-M

PPPL

QRFRFPTEXT

TEXTOR

T F T R

TMX

TMX-U

Tokamak

TPATSTA

UCLAUFAU K

–Office of Fusion Energy in the Officeof Energy Research, U.S. Departmentof Energy

–Ohmically Heated Toroidal Experi-ment; GA Technologies Inc., SanDiego, California

–Oak Ridge National Laboratory; OakRidge, Tennessee

–Operational Test Reactor (proposedSoviet engineering test reactor)

–Princeton Beta Experiment Modifica-tion; Princeton Plasma Physics Lab-oratory, Princeton, New Jersey

–Princeton Plasma Physics Laboratory;Princeton, New Jersey

–Energy Gain (see Glossary)—radiofrequency—reversed-field pinch (see Glossary)–Texas Experimental Tokamak; Uni-

versity of Texas Fusion Research Cen-ter in Austin, Texas

–Tokamak Experiment for TechnologyOriented Research; Julich, FederalRepublic of Germany

–Tokamak Fusion Test Reactor; Prince-ton Plasma Physics Laboratory, Prince-ton, New Jersey

—Tandem Mirror Experiment; LawrenceLivermore National Laboratory, Liver-more, California

–Tandem Mirror Experiment Upgrade;Lawrence Livermore National Labora-tory, Livermore, California

–Toroidal magnetic chamber, in Rus-sian (see Glossary)

–Technical Planning Activity–Tritium Systems Test Assembly; Los

Alamos National Laboratory, LosAlamos, New Mexico

–University of California at Los Angeles–University Fusion Associates–United Kingdom

Glossary

Acid deposition: A consequence of fossil fuel com-bustion in which combustion byproducts emittedas gases react in the atmosphere and are depos-ited on earth in the form of acidic substances. Alsocalled “acid rain. ”

Activation product: Material made radioactive throughexposure to neutrons in fission or fusion reactors.

Active protection: The condition in which the safetyof a nuclear reactor can be assured only through

the proper design and operation of active safety sys-tems. See “Passive protection. ”

Advanced tokamak: A tokamak incorporating featuressuch as steady-state current drive or shaping of theplasma in order to attain higher performance ormore efficient operation than the conventionaltokamak. See “Tokamak” or “conventionaltokamak.”

Afterheat: Heat produced by the continuing decayof radioactive atoms in a nuclear reactor after fis-sion or fusion reactions have stopped. Afterheat i na fission reactor originates primarily in the fuel rods;in a fusion reactor it would result mainly from in-duced radioactivity in the reactor structure.

Alpha particle: A positively charged particle, identi-cal to a helium-4 nucleus, composed of two pro-tons and two neutrons. An alpha particle is emit-ted in the radioactive decay of many naturallyoccurring radioisotopes such as uranium and tho-rium; it is also one of the products of the D-T fu-sion reaction.

Alternate confinement concept: A fusion magneticconfinement concept other than the tokamak.

Anomalous transport: Loss of energy from tokamakplasmas due to escaping electrons that occurs ata rate several times higher than that predicted bypresent theory.

Ash: The end-product of a fusion reaction. For the D-Tfusion reaction, the “ash” is helium gas.

Atom: A particle of matter indivisible by chemicalmeans that is the fundamental building block of achemical element. The dense inner core of theatom, called the nucleus, contains protons andneutrons and constitutes almost all the mass of theatom. The nucleus is surrounded by a cloud of or-biting electrons. Atoms contain equal numbers ofpositively charged protons and negatively chargedelectrons and as a whole are electrically neutral.An atom is a few billionths of an inch in diameter,and several sextillion (1 followed by 21 zeros)atoms are found i n an ordinary drop of water.

Atomic nucleus: See “Nucleus.”Auxiliary heating: External systems that heat Plasmas

to higher temperatures than can be reached fromthe heat generated by electric currents within theplasma. Neutral beam heating and radiofrequencyheating are both examples of auxiliary heatingsystems.

Axial: The direction in a cylinder parallel to the cen-tral axis of the cylinder.

Background radiation: Naturally occurring sources ofradiation. Primary sources are cosmic rays and nat-urally occurring radioactive isotopes that are foundin the earth or are produced in the atmosphere bycosmic rays.

App. D—List of Acronyms and Glossary ● 215

Balance of plant: Those systems in a fusion reactornot associated with producing or controlling the fu-sion reaction. Systems i n the balance of plant con-vert the heat produced by fusion reactions intoelectricity. See also “Fusion power core.”

Beta: The ratio of the outward pressure exerted by theplasma to the inward pressure that the magneticconfining field is capable of exerting. Beta is equiva-lent to the ratio of the energy density of particlesin the plasma to the energy density of the confin-ing magnetic fields.

Beta particle: A high-energy electron emitted in thedecay of certain radioactive isotopes.

Bilateral agreement: An agreement between twonations.

Biologically active: Substances that are absorbed byliving organisms and are utilized in biological proc-esses. Radioactive substances that are biologicallyactive (e. g., radioactive iodine or strontium iso-topes) become incorporated into living organisms.

Blanket: Structure surrounding the plasma in a fusionreactor within which the fusion-produced neutronsare slowed down, heat is transferred to a primarycoolant, and tritium is bred from lithium.

Breakeven: The point at which the fusion power gen-erated in a plasma equals the amount of heatingpower that must be added to the plasma to sustainits temperature.

Breakeven-equivalent: Attainment in a non-tritium-containing plasma of conditions (temperature, den-sity, and confinement time) that would result inbreakeven if the plasma contained tritium. Becauseplasmas not containing tritium are far less reactivethan those containing tritium, the actual amountof fusion power generated by a breakeven-equiva-Ient plasma will be far less than would be producedunder actual breakeven conditions.

Breeder reactor: A nuclear reactor that producesmore fissionable fuel than it consumes. Breedersproduce fissionable fuel by irradiating fertile ma-terials with neutrons. See “Fertile material.”

Breeding ratio: The number of tritium atoms pro-duced in the blanket of a fusion reactor for eachtritium atom consumed in the fusion plasma.

Burn control: The mechanism by which the powerlevel of a self-sustaining fusion reaction is regulated.

Capital-intensive: An energy-generating technologyin which most of the cost of energy is due to thefixed cost of the capital investment in the generat-ing station, as opposed to variable fuel or opera-tions and maintenance expenditures.

Carbon dioxide (C02): An inherent product of thecombustion of fossil fuels. Buildup of carbon di-oxide i n the earth’s atmosphere as a result of fossil

fuel use may affect global climate. See “Green-house effect.”

Central cell: In the tandem mirror confinement con-cept, the central cell is the region where most ofthe power-producing fusion reactions would occur.Plasma in the central cell is kept from escaping byelectric fields generated by the end cells. See “End

Centrifugal injector: Device that uses centrifugal forceto inject pellets of frozen fuel into fusion plasmas.

Chlorofluorocarbons: Manmade chemicals, used asrefrigerants, industrial solvents, and for other pur-poses, which have heat-retaining properties similar tocarbon dioxide when released into the atmosphere.

Cladding: In a fission reactor, the material that en-closes nuclear fuel.

Classical confinement: The best possible plasma con-finement, in which the only mechanism by whichparticles escape the plasma is through rare, but in-evitable, collisions between plasma particles thatcause them to migrate across the magnetic fieldtowards the plasma edge. Classical confinement isalso referred to as “classical diffusion. ’

Classification: Restricting the dissemination of certaininformation for reasons of national security. Onlypeople holding security clearances granted by thegovernment are permitted access to classified in-formation.

Closed confinement concept: Magnetic configurationin which the plasma is confined by magnetic linesof force that do not lead out of the device. Closedconfinement concepts all have the basic shape ofa doughnut or inner tube, which is called a torus.

Collaboration: An intensive type of international co-operation involving a substantial degree of programintegration, funding commitment, and joint man-agement.

Commercial feasibility: Fusion power’s acceptancein the marketplace as a source of energy that isenvironmentally and socially acceptable and eco-nomically competitive when compared to alternatesources of energy.

Compact toroids: A class of magnetic confinementconfigurations in which the chamber containing theplasma need not have a central hole through whichexternal magnet coils must pass. Examples are thespheromak and the field-reversed configuration.

Compression heating: Method of heating a plasma bycompressing it into a smaller volume. The plasmais compressed by modifying the external magneticfields.

Conceptual design: The basic or fundamental designof a fusion reactor or experiment that sketches outdevice characteristics, geometry, and operating fea-tures but is not at the level of detail that would per-mit construction.

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Confinement: Restraint of plasma within a designatedvolume. In magnetic confinement, this restraint isaccomplished with magnetic fields.

Confinement concept: A particular configuration ofmagnetic fields used to confine a fusion plasma.Various confinement concepts differ in the shapeof their magnetic fields and in the manner in whichthese fields are generated.

Confinement parameter: The product of plasma den-sity and confinement time that, along with temper-ature, determines the ratio between power producedby the plasma and power input to the plasma. Alsocalled “Lawson parameter. ”

Confinement time: A measure of how well the heatin a plasma is retained. The confinement time ofa plasma is the length of time it would take theplasma to cool down to a certain fraction of its ini-tial temperature if no heat were added.

Confining magnets: External magnets used to gener-ate the confining magnetic fields in a fusion device.

Containment building: In a fission reactor, the con-tainment building is a thick concrete structure sur-rounding the pressure vessel that encloses the re-actor core and other components. It is designed toprevent radioactive material from being releasedto the atmosphere in the unlikely event that any-thing should escape from the pressure vessel. Theneed for containment buildings for fusion reactorshas not vet been determined.

Conventional tokamak: A tokamak device not incor-porating advanced steady-state current drive orplasma shaping technology. See “Tokamak,” “Ad-vanced tokamak. ”

Coolant: Fluid that is circulated through a componentor system to remove heat. In a fusion reactor, thecoolant would flow through the blanket to removethe heat generated by fusion reactions.

Cooperation: In the context of international activities,cooperation refers to all activities involving nationsor individuals from different nations working to-gether.

Critical temperature: The temperature below whicha superconducting material loses all resistance toelectricity. See “Superconductivity.”

Curie: A unit of radioactivity. One curie of a radio-active substance is that amount that undergoes 3.7x 1010 (37 billion) nuclear transformations persecond,

D-D reaction: Fusion reaction in which one nucleusof deuterium fuses with another. Two different out-comes are possible: a proton plus a tritium nucleus,or a neutron plus a helium-3 nucleus.

D-T reaction: Fusion reaction in which a nucleus ofdeuterium fuses with a nucleus of tritium, forming

an alpha particle and a neutron and releasing 17.6million electron volts of energy. The D-T reactionis the most reactive fusion reaction.

Decay heat: See “Afterheat.”Decommissioning: The steps taken to render a plant,

particularly a nuclear reactor, safe to the environ-ment at the end of its operating lifetime.

Dense z-pinch: An open confinement concept inwhich a strong electrical current is suddenly passedthrough a fiber of frozen D-T fuel, turning it intoa plasma and at the same time generating a power-ful encircling magnetic field to confine the plasma.The dense z-pinch is in a very preliminary stage ofdevelopment.

Density: Amount per unit volume. By itself, the term“density” often refers to particle density, or thenumber of particles per unit volume. However,other quantities such as energy density or powerdensity (energy or power per unit volume, respec-tively) can also be defined.

Detritiation systems: Systems to remove tritium fromair or water that are important to ensure the safetyof tritium-handling facilities.

Deuterium (D or 2H): A naturally occurring isotopeof hydrogen containing one proton and one neu-tron in its nucleus. Approximately one out of 6,700atoms of hydrogen in nature is deuterium. Deu-terium is one of the fuels (along with tritium) neededfor the D-T fusion reaction, the most reactive fu-sion reaction.

Diagnostics: The procedure of determining (diagnos-ing) exactly what is happening inside an experi-mental device during an experiment. Also, the in-struments used for diagnosing.

Diffusivity: The ability of a substance, especially a gas,to diffuse through another substance.

Direct conversion techniques: Conversion of the ki-netic energy of plasma particles directly into elec-trical energy without first converting it into heat.Since conversion into heat and the subsequent re-conversion to electricity impose inherent inefficien-cies, direct conversion could improve the efficiencyof a fusion generating station.

Divertor: A component of a toroidal fusion deviceused to shape the magnetic field near the plasmaedge so that particles at the edge are diverted awayfrom the rest of the plasma. These particles areswept into a separate chamber where they strikea barrier, become neutralized, and are pumpedaway. In this way, energetic particles near theplasma edge are captured before they can strikethe walls of the main discharge chamber and gen-erate secondary particles that would contaminateand cool the plasma. Diverters have also been


found to be responsible for establishing a mode ofenhanced tokamak confinement called the “H-mode. ” See “H-mode scaling.”

Driven fusion reactor: A fusion reactor operating be-low breakeven that must be driven with moreenergy than it produces. Such a reactor might serveto generate neutrons for a fusion materials test fa-cility.

Electromagnetic radiation: Radiation consisting ofassociated and interacting electric and magneticfields that travel in a wave at the speed of light. Ra-dio waves, microwaves, light, x-rays, and gammarays are all forms of electromagnetic radiation; theydiffer from one another in wavelength and fre-quency.

Electron: An elementary particle with a unit negativeelectrical charge and a mass 1/1 837 that of a pro-ton. In an atom, electrons surround the positivelycharged nucleus and determine the atom’s chemi-cal properties.

Electron cyclotron frequency: The frequency atwhich electrons in a plasma gyrate about magneticfield lines. The electron cyclotron frequency in-creases with increasing magnetic field strength andis typically hundreds of gigahertz, substantiallyhigher than the ion cyclotron frequency. See also“ion cyclotron frequency. ”

Electron cyclotron resonance heating (ECRH): Aprocess in which only electrons gain energy froman applied radiofrequency field operating at theelectron cyclotron frequency. The electrons thenheat other plasma particles through collisions.

Electron temperature: The temperature of the elec-trons in a plasma. Electron temperature can differfrom ion temperature. Some of the mechanisms bywhich energy is lost from the plasma, in particularradiation losses, depend on electron temperature.

Electron volt (eV): A unit of energy equal to theenergy that can be acquired by singly charged par-ticle (e.g., an electron) from a one-volt battery.Since the temperature of a system is proportionalto the average energy of each particle in the sys-tem, temperature is also measured in electron volts;at a temperature of 1 eV, equal to 11,6050 K, theaverage energy of each particle is roughly 1 eV. Asa unit of energy, one eV equals 1.602 X 10-19 Joule,3.827 X 10-20 calorie, 1.519 X 10 -22 Btu, or 4.45X 10-26 kilowatt-hour.

End cell: In the tandem mirror confinement concept,the end cell is a magnetic mirror used to plug eachend of the central cell. The function of the end cellis to generate an electric field that will keep theplasma in the central cell from leaking out. See also“Central cell.”

Energy gain (Q): The ratio of the fusion power pro-duced by a plasma to the amount of power thatmust be added to the plasma to sustain its tem-perature.

Engineering feasibility: The ability to design and con-struct all the components, systems, and subsystemsrequired for a fusion reactor.

Engineering test reactor: A next-generation fusion ex-periment to study the physics of long-pulse ignitedplasmas, provide opportunities to develop and testreactor blanket components under actual fusionconditions, and integrate the various systems of afusion reactor.

Equivalent Q: For a plasma not containing tritium, ameasure of what Q would have been i n a tritium-containing plasma that attained the same temper-ature and confinement parameter. See “Confine-ment parameter. ”

External heating: See “Auxiliary heating. ”External magnets: Magnet coils outside the fusion

plasma that generate those confining magneticfields that are not generated by currents within theplasma itself.

Fast breeder reactor: A fission reactor in which fastneutrons are used both to induce fission reactionsin the fuel, producing power, and to react with fer-tile materials, converting them to more fissile fuel.See “Fast neutron,” “Fertile material, ” and “Fis-sile material. ”

Fast neutron: A neutron with energy greater than100,000 electron volts.

Fertile material: Material that is not fissile but can beconverted to fissile material through neutron irradi-ation. See “Fissile material. ”

Field-reversed configuration (FRC): A magnetic con-finement concept with no toroidal field, in whichthe plasma is essentially cylindrical in shape. TheFRC is a form of compact toroid.

Financial liability: Costs, including those associatedwith death, injury, property damage, and loss ofrevenue, to which an electric utility would be ex-posed in the event of the worst credible accidentattributable to a generating station.

Fine-scale plasma instabilities: Turbulence and otherinstabilities occurring over distances the size of theorbits of individual plasma particles (electrons andions) about magnetic field lines. Also called “micro-in stabilities.”

First wall: The first physical boundary that surroundsthe plasma. The first wall can refer either to the sur-face of the blanket that faces the plasma, or to aseparate component between the blanket and theplasma.


Fissile material: Material that can be used as fuel infission reactors.

Fission: The process by which a neutron strikes a nu-cleus and splits it into fragments. During the proc-ess of nuclear fission, several neutrons are emittedat high speed, and heat and radiation are released.

Fission/fusion hybrid: A reactor using a fusion coreto produce neutrons that in turn either induce fis-sion reactions or breed fissile fuel in the reactorblanket. Fission/fusion hybrid reactors can produceenergy, fissile fuel, or both.

Flux: The amount of a quantity (heat, neutrons, etc.)passing through a given area per unit time.

Fossil plant: A powerplant fueled by coal, oil, or gas.Fusion: The process by which the nuclei of light ele-

ments combine, or fuse, to form heavier nuclei, re-leasing energy.

Fusion power core: That portion of a fusion reactorcontaining all the systems having to do specificallywith the fusion process, such as the plasma cham-ber, the blanket, the magnets, and the heating, fuel-ing, and impurity control systems.

Fusion self-heating: Heat produced within a plasmafrom fusion reactions. Since alpha particles pro-duced in fusion reactions remain trapped within theplasma, they contribute to self-heating by transfer-ring their energy to other plasma particles in colli-sions. Fusion-produced neutrons, on the otherhand, escape from the plasma without reacting fur-ther and do not contribute to self-heating.

Gauss: A measure of magnetic field strength. Thestrength of the earth’s magnetic field on the earth’ssurface is about one-half gauss; magnetic confine-ment fusion devices typically have maximum mag-netic field strengths of tens of thousands of gauss.

Gigahertz: A measure of frequency equal to 1 billionhertz, or 1 billion cycles per second. See “Hertz.”

Gravitational confinement: The fusion process thatoccurs in the sun and other stars in which fusionplasmas are confined by the gravitational fields gen-erated by their own masses. Enormous masses (con-siderably more than that of the planet Jupiter) arerequired for gravitational confinement.

Greenhouse effect: Possible warming of the earth dueto excess heat trapped in the atmosphere by in-creasing levels of carbon dioxide and other “green-house gases.”

Greenhouse gases: Gases such as chlorofluorocar-bons, methane, nitrous oxide, and carbon dioxidethat, in the upper atmosphere, have the propertyof retaining heat that would otherwise escape fromthe earth to space. Accumulation of such gases mayaffect global climate. See “Greenhouse effect. ”

“H-mode” scaling: A mode of tokamak behavior inwhich confinement time does not degrade as in-creased amounts of auxiliary power are used toheat the plasma. This scaling has been observedin tokamaks that have diverters, and it is believedto be closely related to conditions at the edge ofthe plasma. See “L-mode scaling. ”

Half-life: The time required for one-half of the atomsof an unstable radioactive element to decay intoatoms of other substances, Each radioisotope hasa unique half-life, which can range from fractionsof a second to billions of years.

Heads-of-state agreement: An agreement betweennations signed by their respective heads-of-state,For the United States, the head-of-state is thePresident,

Heat exchanger: A device for transferring heat fromone fluid to another without allowing them to mix.Heat exchangers are used in nuclear reactors totransfer heat out of the reactor core without cir-culating the coolant, which becomes radioactive,through the rest of the generating station,

Heat load: The amount of heat that a reactor com-ponent must withstand. Both the choice of materi-als for the component and the amount of coolingthat must be provided to it depend on the compo-nent’s anticipated heat load.

Helium nucleus: See “Alpha particle, ”Hertz: One cycle per second; a measure of frequency.High energy gain: A fusion reaction producing many

(1 O or so) times as much power as must be inputto the reaction to maintain its temperature.

High-level waste: Radioactive waste that is extremelyradioactive and would pose a serious health andenvironmental risk if released into the environment.Disposal of high-level waste must minimize the pos-sibility of its release.

Hydrogen (H): The lightest element. All hydrogenatoms have nuclei containing a single proton andhave a single electron orbiting that nucleus. Threeisotopes of hydrogen exist, having O, 1, or 2 neu-trons in their nuclei in addition to the proton. Theterm hydrogen is also used to refer to the most com-mon isotope, technically called “protium,” that hasno neutrons in its nucleus.

Ignition: The point at which a fusion reaction be-comes self-sustaining. At ignition, fusion self-heatingis sufficient to compensate for all energy losses; ex-ternal sources of heating power are no longer nec-essary to sustain the reaction.

Impurities: Atoms present in a plasma that are heav-ier than fusion fuel atoms. Impurities are undesira-ble because they dilute the fuel and because they


increase the rate at which the plasma’s energy isradiated out of the plasma.

Induced radioactivity: Radioactivity created whennon-radioactive materials are bombarded by neu-trons and become radioactive. Radioactivity can beinduced in essentially any material by exposure toneutrons, but the half-life and intensity of this radio-activity depends strongly on the material.

Industrial base: The industrial capability to design andmanufacture the components of a fusion plant, toconstruct such plants, and to accomplish the pre-processing and reprocessing of fuels.

Inertia: Inertia is the property of an object to resistexternal forces that would change its motion. Un-less acted upon by external forces, an object at restwill remain at rest, and an object moving in astraight line at constant speed will continue to doso. Under the influence of external forces, objectswith differing inertias wiII respond at different rates.The inertia of an object depends solely on its mass.

Inertial confinement: An approach to fusion in whichintense beams of light or particles are used to com-press and heat tiny pellets of fusion fuel so rapidlythat fusion reactions occur before the pellet has achance to expand. The pellet’s own inertia, or itsinitial resistance to expansion even when it is be-ing blown apart, holds the pellet together longenough for fusion energy to be produced.

Information exchange: Sharing technical approachesand experimental data through any or all of sev-eral channels, including meetings, conferences,symposia, workshops, and publication in techni-cal journals.

Inherent safety: In this report, inherent safety is theabiIity to assure, solely through reliance on passivesystems and laws of physics, that no immediate off-site fatalities can result from any mechanical mal-function, operator error, or natural disaster. Trueinherent safety can be assured only by having solittle hazardous material that even complete releasecould not cause an off-site prompt fatality, or byhaving so little stored energy that even if all thestored energy were released at once, the resultantexplosion or fire would not be powerful enoughto disperse a fatal dose of hazardous material, See“Active protection” and “Passive protection. ”

Instabilities: Small disturbances that become ampli-fied, or become more intense, once they begin. Acone balanced upside-down on its tip is subject toan instability, since once it begins to wobble, it willbecome more unbalanced until it falls over. Astable system, on the other hand, responds to dis-turbances by opposing them. Small disturbancesin a stable system decrease in intensity until they

die away. If a ball sitting in the bottom of a bowlis disturbed, for example, it wiII eventualIy cometo rest again at the bottom of the bowl.

Insulator: Material that does not conduct electricity.Ion: An atom (or molecularly bound group of atoms)

that has become electrically charged as a result ofgaining or losing one or more orbital electrons. Acompletely ionized atom is one stripped of all itselectrons.

Ion cyclotron frequency: The frequency at which ionsin a plasma gyrate about magnetic field lines. Theion cyclotron frequency increases with increasingmagnetic field strength and is typically tens to hun-dreds of megahertz. See also “electron cyclotronfrequency.”

Ion cyclotron resonance heating (lCRH): A processin which only ions gain energy from an appliedradiofrequency field operating at the ion cyclotronfrequency. The ions then heat other plasma parti-cles through collisions.

Ion temperature: The temperature of the ions in aplasma. Ion temperature can differ from electrontemperature. Since it is the ions that fuse i n fusionreactions, it is the ion temperature that determinesthe fusion reaction rate. See also “Electron tem-perature.”

Ionization: The process of removing or adding anelectron to a neutral atom, thereby giving it an elec-tric charge and creating an ion. The term is alsoused to denote removal of an electron from a par-tially ionized atom to make a more completelyionized one.

Ionizing radiation: Radiation energetic enough to ion-ize matter that it passes through. Depending on itsintensity, ionizing radiation poses a health risk. Ex-amples are alpha and beta particles, emitted byradioactive substances, and electromagnetic radi-ation having frequencies in the far ultraviolet, x-ray,and gamma ray regions.

Isotope: Different forms of the same chemical elementwhose atoms differ i n the number of neutrons i nthe nucleus. (All isotopes of an element have thesame number of protons in the nucleus and thesame number of electrons orbiting the nucleus. )Isotopes of the same element have very similarchemical properties and are difficult to separate bychemical means. However, they can have quitedifferent nuclear properties.

Joint construction and operation: Pooling resourcesto construct and operate an experimental facilityjointly.

Joint planning: Activities between nations that coordi-nate experimental and theoretical programs andidentify areas of future cooperative research.


Joint research: Making major national facilities avail-able to researchers from other nation’s programsin exchange for financial or technical contributions.

Kinetic energy: Energy of motion. The energy releasedin a fusion reaction is originally in the form of ki-netic energy of the reaction products. When thesereaction products (alpha particles and neutrons)collide with atoms or nuclei in the plasma or in thereactor structure, they slow down and their kineticenergy is converted into heat.

“L-mode” scaling: Mode of tokamak behavior inwhich confinement time degrades as increasingamounts of auxiliary heating power are input intothe plasma. See “H-mode” scaling.

Large-scale plasma instabilities: Deformations of boththe overall confining magnetic field and the plasmathat can lead to sudden escape of the entire plasmafrom confinement.

Laser fusion: A form of inertial confinement fusion inwhich a small pellet of fuel material is compressedand heated by a burst of laser light. See “lnertialconfinement .“

Lawson parameter: See “Confinement parameter.”Light-water reactor (LWR): A fission reactor in which

ordinary water is used as coolant and as a neutronmoderator. See “Neutron moderator. ”

Limiter: Device placed inside the plasma chamber tointercept particles at the edge of a plasma. By“scraping off” these particles from the plasma edge,the limiter defines the size of the plasma.

Liquid-metal fast breeder reactor: (LMFBR) A fissionfast breeder reactor with a liquid metal coolant. See“Fast breeder reactor.”

Lithium (Li): A light, chemically reactive metal thatcan be converted i n the blanket of a fusion reactorinto the tritium fuel needed for fusion reactions.

Load change, capability for: The mechanical andthermal characteristics of an electric generating sta-tion that limit its rate of response to changes in loador that restrict the time required for startup orshutdown.

Long-lived radioactivity: Radioactive isotopes havinglong half-lives.

Low-activitation materials: Materials that, under neu-tron irradiation, do not generate intensely radio-active, long-lived radioactive isotopes. Examples in-clude certain vanadium alloys and ceramics suchas silicon carbide. Fusion reactors made of low-activation materials would accumulate far lessradioactivity over their lifetimes than reactors madewith more conventional materials such as steels.Low-activation materials also produce less afterheatfollowing a reactor shutdown than more conven-tional materials. See “Afterheat.”

Low-level waste: Waste containing sufficiently lowlevels of radioactivity that it does not pose a majorhealth or environmental risk. Disposal of low-levelwaste does not require the stringent precautionsnecessary for high-level waste.

Magnetic confinement: Any means of containing andisolating a hot plasma from its surroundings byusing magnetic fields.

Magnetic field: The property of the space near a mag-net that results, for example, in the attraction of ironto the magnet. Magnetic fields are characterizedby their direction and their strength. Electricallycharged particles moving through a magnetic fieldat an angle with respect to the field are bent in adirection perpendicular to both their direction ofmotion and the direction of the field. Particles mov-ing parallel to a magnetic field are not affected.Therefore, magnetic fields cannot prevent plasmaparticles from escaping along field lines.

Magnetic field line: A (possibly curved) line whosedirection at every point is given by the directionof the magnetic field through that point. Electricallycharged particles in a magnetic field tend to gyratearound magnetic field lines; they can travel alongthe field lines much more easily than they can crossfield lines.

Magnetic mirror: A generally axial magnetic field thathas regions of increased intensity at each endwhere the magnetic field lines converge. These re-gions of increased intensity “reflect” charged par-ticles traveling along the field lines back into thecentral region of lower magnetic field strength.

Magnetohydrodynamics (MHD): The study of elec-trically conducting fluids under the influence ofelectric and magnetic fields. MHD theory can beused to provide a good approximation to plasmabehavior in many instances.

Megahertz: One million hertz, or one million cyclesper second. See “Hertz.”

Microinstabilities: See “Fine-scale plasma insta-bilities.”

Minimum-B mirror: An open magnetic confinementconcept with a magnetic field that is low in strengthin the central region but that gets stronger in alldirections away from the center. Particles in aminimum-B mirror tend to be “reflected” by thehigher field regions back towards the center. Never-theless, losses from the minimum-B mirror are toogreat for it to be a viable fusion concept by itself.

Minimum load: The power output level below whicha generating plant cannot operate continuously.

Ministerial agreement: An agreement signed by thesecretaries or ministers of the involved departments


or ministries. In the United States, ministerial agree-ments in fusion are signed by the Secretary ofEnergy.

Multilateral agreement: An agreement between threeor more nations.

Neutral beam heating: Heating a confined plasma byinjecting beams of energetic (typically greater than100 keV) neutral atoms into it. Neutral atoms cancross magnetic lines of force to enter the plasma,where they transfer their energy to plasma parti-cles through collisions. In these collisions, the neu-tral beam particles become ionized, and, like theother electrically charged plasma particles, are thenconfined by the magnetic fields.

Neutron: A basic atomic particle, found in the nucleusof every atom except the lightest isotope of hydro-gen, that has no electrical charge. When boundwithin the nucleus of an atom, the neutron is sta-ble. However, a free neutron is unstable and de-cays with a half-life of about 13 minutes into anelectron, a proton, and a third particle called anantineutrino. The mass of a free neutron is 1.7 X10-24 grams.

Neutron flux: A measure of the intensity of neutronirradiation. It is the number of neutrons passingthrough 1 square centimeter of a given target in 1second.

Neutron irradiation: Exposure to a source of neu-trons. Both fission and fusion reactors can provideneutron irradiation.

Neutron moderator: A material that slows neutronsdown without absorbing them.

Neutron multiplier: A substance that reacts with neu-trons to produce additional neutrons.

Neutron wall loading: The energy per unit area perunit time (or energy flux) carried by neutrons intothe first wall of a fusion reactor. The higher the neu-tron wall loading, the more rapidly the first wall willsuffer radiation damage, the more radioactivity willbe induced, and the more frequently first wall com-ponents will have to be replaced.

Non-ohmically heated plasma: Plasma heated withauxiliary or external heating.

Nuclear fission: See “Fission. ”Nuclear fusion: See “Fusion. ”Nuclear grade: Designation given to components

used in important safety-related systems in nuclearreactors certifying that the components meet strin-gent quality control standards,

Nuclear physics: The study of atomic nuclei and nu-clear reactions.

Nucleus (nuclei): The central core of an atom, con-sisting of protons and neutrons, that contains over99.95 percent of the atom’s mass.

Ohmic heating: Heating that occurs when an elec-tric current is passed through a resistive medium.Although plasmas are excellent conductors of elec-tricity, they are nevertheless resistive enough to beheated when they carry large electric currents.Ohmic heating becomes less efficient as the plasmagets hotter, and most confinement configurationstherefore require auxiliary (or non-ohmic) heatingto reach ignition.

Open confinement concept: Magnetic configurationin which the magnetic field lines leave the system.The magnetic mirror is one example.

Order of magnitude: A factor of 10.Outage rate: The percentage of time that an electric

generating station is unavailable due to componentfailures or other unforeseen conditions that requirethe unit to be removed from service.

Overnight construction cost: Total construction costof a facility if it could be built instantaneously. Over-night construction cost does not include allowancesfor inflation, nor does it include finance chargessuch as the interest payments on funds borrowedto begin construction.

Oxidation chemistry: Study of chemical reactions ofsubstances with oxygen.

Part-load efficiency: The ratio of the change in effi-ciency of an electric generating station to the changein load when the load is decreased from full loadto half.

Particle collisions: A close approach of two or moreparticles during which quantities such as energy,momentum, or charge are exchanged.

Passive protection: Ability to ensure the safety of areactor without the use of active safety systems.Various degrees of passive protection exist. At onelevel, the safety of a reactor design might be en-sured provided that certain passive systems andcomponents (e.g., coolant loops or tanks) remainedintact. Before the safety of such a plant could bedemonstrated, it would have to be proven that nocredible accident could interfere with the opera-tion of those passive systems or components. At amuch more stringent level of passive protection,called “Inherent safety, ” materials properties andthe laws of physics alone would be sufficient toensure the safety of the reactor. No assumptionsconcerning the integrity of any reactor systems orcomponents would need to be made. Such an “in-herently safe” reactor would remain safe even ifit could somehow be crumpled up into a ball. Seealso “Active protection” and “Inherent safely. ”

Personnel exchange: The transfer of personnel be-tween different nation’s programs through visits orassignments.


Plant capital cost: The total cost necessary to bringthe plant to commercial operation. It includes thecosts of items such as engineering and design work,materials, construction labor, construction manage-ment, interest during construction, escalation, salestax, equipment, and land.

Plant licensability: How readily a generating technol-ogy such as fusion can be expected to receive reg-ulatory approval.

Plant life: The total time a plant can be operated be-fore decommissioning.

Plasma: An ionized gaseous system composed of ap-proximately equal numbers of positively and neg-atively charged particles and variable numbers ofneutral atoms. The charged particles interact amongthemselves, with the neutral particles, and with ex-ternally applied electric and magnetic fields. Theplasma state is sometimes called “the fourth stateof matter” due to the fundamental differences i nbehavior between plasmas and solids, liquids, orneutral gases.

Plasma current: Electrical current flowing within aplasma. In many confinement schemes, plasmacurrents generate part of the confining magneticfields.

Plasma exhaust: Particles escaping from the plasmathat are collected by limiters or diverters.

Plasma physics: The study of plasmas.Plant safety: The capability of the plant to be built

and operated with minimal injury to plant person-nel or to the public and minimal damage to prop-erty internal or external to the plant.

Plutonium (Pu): An element that fissions easily andcan be used as a nuclear fuel for fission reactorsor fission weapons. Plutonium is not found in na-ture, but it can be produced by irradiating uraniumwith neutrons in a nuclear reactor.

Pneumatic injector: Device that injects fuel pelletsinto plasmas at high speed by accelerating themwith compressed gas.

Poloidal direction: On a torus, the poloidal directionruns around the torus the short way, perpendicularto the toroidal direction. See “Toroidal direction. ”

Poloidal divertor: A type of divertor. See “Divertor.”Post-shutdown systems: Systems in a nuclear reactor

that must operate after the reactor is shut down toensure that the afterheat does not build up to a levelhigh enough to damage the reactor or pose a safetyhazard, Such systems would be unnecessary in re-actors not generating much afterheat, or ones inwhich the afterheat could be removed by purelypassive means.

Power density: The amount of energy generated perunit time per unit volume of a reactor core; thepower per unit volume.

Project Sherwood: The code-name under which fu-sion research was secretly conducted in the UnitedStates from 1951 until 1958.

Proliferation: The development of nuclear weaponsby countries not now possessing them. Proliferationrefers primarily to fission-based nuclear weapons.

Prompt fatalities: Deaths due to the immediate effectsof a reactor accident or malfunction. Since deathsfrom radiation overdoses are not instantaneous ex-cept at extremely high doses, prompt fatalities in-clude those due to radiation overdoses acquiredsoon after an accident even if death does not oc-cur immediately. Prompt fatalities do not, however,include deaths many years later from cancer thatmay have been induced by radiation exposure.

Proof-of-concept experiment: Experiment done at arelatively early stage of development of a confine-ment concept to determine the limits of plasma sta-bility, explore how the confinement propertiesappear to scale, and develop heating, impurity con-trol, and fueling methods. Successful completionof such an experiment verifies that the confinementconcept appears capable of operating successfullyon a scale much closer to that needed in a reactor.

Proof-of-principle experiment: Experiment one stagebeyond the “proof-of-concept” stage to determineoptimal operating conditions, to establish that theconcept is capable of being scaled to near-reactorlevel, to extend methods of heating to high powerlevels, and to develop efficient mechanisms for fuel-ing and impurity control.

Protium (H or 1H): The most common isotope ofhydrogen, accounting for over 99 percent of allhydrogen found in nature. The nucleus of a pro-tium atom is a single proton with no neutrons.

Proton: An elementary particle with a single positiveelectrical charge. Protons are constituents of allatomic nuclei. The atomic number of an atom isequal to the number of protons in its nucleus.

Pulsed operation: Non-continuous operation of a fu-sion reactor. This term refers to reactors that mustperiodically stop and restart. In pulsed operation,individual pulses may last as long as hours.

Pumped limiter: A limiter that collects particles at theplasma edge, allows them to recombine into neu-tral gas atoms, and pumps the gas out of the vacuumchamber. A pumped limiter can operate for alonger period of time than a simple limiter, whichdoes not remove the collected particles and cantherefore become saturated. See “Limiter.”

Pure fusion reactor: Reactor that generates all itsenergy from fusion reactions in the plasma andtritium-breeding reactions in the blanket. A purefusion reactor is distinguished from a fission/fusionhybrid reactor, which either generates energy or


produces fissionable fuel by including fertile or fis-sile material in the reactor blanket. See “Fission/fu-sion hybrid. ”

Quality of confinement: See “Confinement pa-rameter. ”

Radiation: The emission of particles or energy fromatomic or nuclear processes. Radiation is alsosometimes used as a shorthand for “electromag-netic radiation, ” which refers specifically to emit-ted energy and does not include particles.

Radiation dose: A general term denoting the quan-tity of radiation absorbed.

Radiation exposure: The amount of radiation pass-ing through a particular target.

Radiative cooling: Loss of heat from a system throughelectromagnetic radiation. Since electromagneticradiation carries energy away, a system that radi-ates will cool down.

Radioactive inventory: The total amount of radio-active material present.

Radioactive material: A material of which one ormore constituents exhibits radioactivity.

Radioactivity: The inherent property of the nuclei ofunstable isotopes to spontaneously emit particlesor energy and transform to other nuclei. Such radio-active isotopes can be either natural (e.g., carbon-14, which is produced by cosmic rays interactingwith the earth’s atmosphere) or manmade (e.g.,plutonium).

Radiofrequency power: Electromagentic radiationhaving frequencies in the radio or microwave por-tions of the electromagnetic spectrum and extend-ing up to the infrared band.

Radiofrequency (RF) heating: Heating a plasma bydepositing radiofrequency power in it. Only radia-tion at certain specific frequencies—e.g., the elec-tron cyclotron frequency or the ion cyclotronfrequency–will be absorbed by the plasma. See“Electron cyclotron resonance heating” or “Ion cy-clotron resonance heating. ”

Radioisotope: A radioactive isotope; in particular, aradioactive isotope of a substance whose naturallyoccurring isotopes are not radioactive.

Reactive: Able to participate easily in chemical or nu-clear reactions.

Reactor potential: A qualitative description of a fu-sion confinement concept denoting how easy itwould be to design, build, operate, and maintaina fusion reactor based on that concept, as well ashow acceptable such a reactor’s environmental, so-cial, economic, and safety characteristics would be.

Reactor-scale experiment: Experiment to test a con-finement concept by generating a plasma equiva-lent to that needed in a full-scale reactor. Such an

experiment must achieve reactor-level values ofbeta and must demonstrate temperature, density,and confinement times sufficient for the produc-tion of net fusion power. Furthermore, its heating,fueling, and other technologies must also be ableto support a reactor-level plasma.

Rem: A measure of the effect of radiation on biologi-cal systems (acronym for Roentgen equivalent man).Different types of radiation (e.g., alpha particles,beta particles, neutrons, and gamma rays) havedifferent biological effects. Therefore, doses are cor-rected by a different factor for each type of radia-tion to convert them into reins. One rem of anytype of ionizing radiation produces the same bio-logical effect as one Roentgen of ordinary x-rays.

Remote maintenance: Conducting maintenance onreactor systems or components by remote control,rather than “hands-on. ” Remote maintenance willbe required in fusion reactors and in many futurefusion experiments because the radioactivity levelsnear and inside the plasma chamber will be toohigh to permit human access.

Resistance: The difficulty with which an electric cur-rent passes through a material. For a given amountof electric current, the higher the resistance, themore electrical energy will be dissipated as heat.

Reversed-field pinch: A closed magnetic confinementconcept having toroidal and poloidal magneticfields that are approximately equal in strength, andin which the direction of the toroidal field at theoutside of the plasma is opposite from the direc-tion at the plasma center.

Roentgen: A measure of radiation intensity.Routine release: Releases that occur as a result of nor-

mal, or routine, plant operation.Runaway reaction: A reaction whose rate increases

as the power level rises, In such a reaction, any risein output power increases the reaction rate, boost-ing the output power still further, and so on. Sucha reaction is unstable, growing larger and larger un-til some other mechanism—e.g., exhaustion offuel–limits the reaction power.

Scaling: Extension of results or predictions measuredor calculated under one set of experimental con-ditions to another situation having different condi-tions. One of the most important functions of aconfinement experiment is to determine how con-finement properties scale with parameters such asdevice size, magnetic field, plasma current, tem-perature, and density. It is important to understandthe scaling properties of a confinement concept—either empirically or theoretically—to assure thatfuture experiments have a reasonable probabilityof succeeding.


Scaling relationship: The trend in behavior of a pa-rameter as other parameters are varied. See “Scaling.”

Scientific feasibility: The successful completion of ex-periments that produce high-gain or ignited fusionreactions in the laboratory using a confinementconfiguration that lends itself to development intoa net power producing system.

Self-regulating: A system which, when disturbed insome way, will respond in a manner that tends tocompensate for the disturbance. A self-regulatingreaction would be the opposite of a runaway one;if the reaction power level were to increase, thesystem would respond by lowering the reactionrate, permitting the power level to drop back downagain. Such a system is also called “stable. See also“Runaway reaction” and “instabilities.”

Shield: A structure interposed between reactor com-ponents, such as magnetic field coils, and the fu-sion plasma to protect the components from theflux of energetic particles produced in the plasma.

Simple magnetic mirror: A magnetic field consistingof a cylinder filled with an axial magnetic field ofrelatively constant strength, with regions of strongermagnetic field at each end. The stronger field re-gions tend to “reflect” plasma particles back intothe cylinder. However, too many particles never-theless escape out the ends of the cylinder for thesimple mirror to be a viable fusion concept.

Volubility: Ease with which a substance dissolves inanother substance.

Spheromak: A magnetic confinement concept inwhich a large fraction of the confining magneticfields are generated by currents within the plasma.The spheromak is a form of compact toroid.

Spin: An inherent property possessed by subatomicparticles analagous to the rotation of the earth. Justas the spin axis of the earth points towards theNorth star, the spin axis of a subatomic particlepoints in some direction. The spin axis of a suba-tomic particle can be oriented in a particular direc-tion by use of a magnetic field.

Spin polarization: Preparation of many particles, suchas deuterium and tritium nuclei, so that their spinspoint in the same direction. If the spins of deu-terium and tritium are polarized, the D-T reactionrate is enhanced.

Spin-offs: The secondary, or auxiliary, benefits ofhigh-technology research and development pro-grams in applications other than those which arethe primary motivation for research.

Steady-state operation: Continuous operation, with-out repeated starting and stopping.

Steam generator and turbine: In an electric generat-ing station, the steam generator uses the heat pro-

duced by the power source to boil water intosteam, which is passed through a turbine to turnan electrical generator.

Stellarator: A toroidal magnetic confinement devicein which the confining magnetic fields are gener-ated entirely by external magnets.

Superconductivity: The total absence of electrical re-sistance in certain materials under certain condi-tions. Until recently, superconductivity had onlybeen found to occur in certain materials cooled towithin a few degrees of absolute zero. Since late1986, however, a new class of materials has beendiscovered that become superconducting at tem-peratures far higher than the materials previouslyknown. An electrical current that is established ina superconducting material will persist as long asthe material remains below its critical temperature.See “Critical temperature.”

System studies: Studies presenting preconceptual de-signs for fusion reactors that serve to uncover po-tential problems and determine how changes in de-sign choices affect reactor characteristics. Systemstudies are particularly valuable in guiding thereseach program by identifying areas where furtherresearch and development can have the greatestimpact.

Tandem mirror: Type of open magnetic confinementconfiguration in which both ends of a simple mag-netic mirror, called the central cell, are plugged byend cells to improve confinement. Each end cellis itself a magnetic mirror that generates an elec-tric field to prevent particles in the central cell fromescaping, See “Central cell” and “End cell. ”

Technological feasibility: In this report, acquisitionof both sufficient scientific understanding and suffi-cient engineering and technological capability todesign and build a fusion reactor; attainment ofboth scientific feasibility and engineering feasibility.

Temperature: A measure of the average energy of asystem of particles. Given sufficient time and enoughinteraction among the different portions of any sys-tem, all portions will eventually come to the sametemperature. In short-lived plasmas, however, theion and electron temperatures usually differ be-cause of insufficient interaction between the two.Plasma temperatures are measured in units of elec-tron volts, with 1 electron volt equal to 11,6050 K.

Thermal instability: Potential instability in a burningplasma arising from the fact that the fusion reactionrate increases strongly with temperature. It is notyet known to what extent burning (ignited) plasmaswill be subject to this instability, or whether other,self-regulating aspects of plasma behavior will pre-dominate. See “Runaway reaction.”


Thermonuclear fusion: See “Fusion. ” “Thermonu-clear” refers to the extreme temperatures requiredfor the fusion process to take place.

Thermonuclear weapons: Nuclear weapons utilizingthe fusion process, also called hydrogen bombs.Thermonuclear weapons are very large-scale exam-ples of the inertial confinement approach to fusion.

Theta pinch: A pulsed device in which a fast-rising,strong (100 kilogauss) magnetic field compressesand heats a plasma column in a few microseconds.The magnetic field is parallel to the axis of a plasmacolumn.

Tokamak: A magnetic confinement concept whoseprincipal confining magnetic field, generated by ex-ternal magnets, is in the toroidal direction but thatalso contains a poloidal magnetic field that is gen-erated by electric currents running within theplasma. The tokamak is by far the most developedmagnetic confinement concept. See also “Conven-tional tokamak” or “Advanced tokamak.”

Toroidal direction: On a torus, the toroidal directionruns around the torus the long way, in the direc-tion that the tread runs around a tire. More gener-ally, “toroidal” refers to devices in the shape of atorus.

Torus: The shape of a doughnut, automobile tire, andinner tube.

Transformer: Device in which a changing electricalcurrent in one electrical conductor generates achanging magnetic field, which in turn induceselectrical current in a second conductor. The plasmacurrent in a conventional tokamak is establishedby a transformer in which one of the conductorsis a set of coiIs located in the hole in the centerof the plasma torus and the second conductor isthe plasma itself.

Treaty: The highest level of formality for an interna-tional agreement. Treaties involving the UnitedStates must be ratified by a two-thirds majority ofthe U.S. Senate.

Tritium (T or 3H): A radioisotope of hydrogen that hasone proton and two neutrons in its nucleus. Tritiumoccurs only rarely in nature; it is radioactive andhas a half-life of 12.3 years. In combination withdeuterium, tritium is the most reactive fusion fuel.

Tritium breeding: Production of tritium in the blan-ket of a fusion reactor by irradiating lithium nucleiwith fusion-produced neutrons. Lithium nuclei un-dergo nuclear reactions with neutrons that yieldtritium nuclei and alpha particles.

Turbulence: Random or chaotic flow of a fluid, suchas that of water in the rapids of a river.

Umbrella agreement: General agreement betweennations establishing a willingness to cooperate ina specific subject area and outlining general pro-cedures, but not specifying particuIar activities orterms.

Unit rating: The electrical capacity of a generatingstation.

Uranium (U): A very heavy, radioactive elementfound in nature that can be used as nuclear fuel.Two uranium isotopes are important in nuclearenergy: uranium-235 can undergo nuclear fission,and uranium-238, the most plentiful isotope, canbe used to produce plutonium.

Waste handling and disposal: The in-plant handling,on-site disposal (or transportation), and off-site dis-posal of waste materials formed as byproducts ofthe energy production processes.

Index

Accidents, risk and severity of fusion reactor, 17-18,106-108

Acid deposit ion, 29, 119Advanced fuel cycles

concepts for, 90-92, 116reactor safety, radioactive waste production, and, 18,

108, 109-110

Advanced Toroidal Facility (ATF), 142, 60, 143Afterheat, 18, 106, 110, 1 1 1Agreements

major internat ional, 158-163, 158types of internat ional cooperat ive, 157-158, 157

Alcator project, 146, 23, 147American Physical Society, 131Argonne Nat ional Laboratory, 93

Atomic Energy Act of 1954, 40Atomic Energy Commission (AEC), 8, 9, 40-44

Auburn Universi ty, 147

Austria, 159, 184, 185

Axisymmetric Divertor Experiment (ASDEX), 71, 159, 72

Balance of plant, systems in, 12, 72, 73, 73Beta parameter, scientific progress in improving, 70-71,

80-81, 92, 94Bi lateral agreements

Japan-European Community, 182United States-European Community, 163

United States-Japan, 161-163

United States-U.S.S.R., 163Blanket

development program, 97-98

funct ion and development of fusion reactor, 81-84radioact iv i ty of , 109

Breakevenconf inement t ime required for, 33experiments, 9, 46scientific progress in attaining, 68-70

Breeder reactors, 18, 44, 46

DOE deemphasization of, 48

weapons grade mater ia ls produced by, 112

See also Fission/fusion hybrid reactorsBreeding ratio, 82, 84Budget, Bureau of the, 44

Bureau of Mines, U. S., 113

California, 21, 41, 141, 148wind energy use in, 123

Canada, 172Carbon dioxide (CO2 ), accumulation from fossil fuel

use, 5, 29, 119, 120-121

Carter, Jimmy, DOE creation by, 9, 48

Chernobyl (U.S.S.R.), 107, 121

Climate, CO2 effects on, 5, 29, 112, 119, 120-121Closed confinement concepts, 58-63

See also Confinement

Coaldomestic reserves of, 19, 119technologies, 119-120See also Fossil fuels

Co l labora t ion

applicability of existing projects to future fusion,170-173, 173

benefits and risks of, 25, 164, 166, 190

costs of international, 25, 164-165, 193, 194internat ional , on fusion faci l i ty construct ion and

operation, 10, 15, 24-25, 156, 158-163, 183-185management approaches to, 170-173obstacles to, 25-26, 166-170, 194prospects for, 24-25, 182-185report’s definition of, 156

See also CooperationColleges. See UniversitiesCommercialization

fusion power, 5, 8, 15-16, 19, 30, 101, 116-119,

123-125, 150-151, 189, 190, 192, 193, 195, 197,

99, 100public urgency for, 3, 19-20, 124, 125transition in responsibility and, 23, 150-151

Compact Igni t ion Tokamak (CIT)funding for, 95-97operation of, 190, 197preliminary design of, 96recommended construction and costs of, 13, 52-53,

138-139Compact toroids, 61-63Comprehensive Program Management Plan of 1983

(CPMP), 51Compression heating, 74, 76Confinement

concepts, 8, 11-13, 34-35, 47-48, 57-65, 12, 57conclusions concerning approaches to, 65-66future issues involving, 94-95interrelationship with temperature, 33, 70plasma parameters achieved by various concepts of,

69Confinement parameters. See Lawson parametersConfinement Physics Research Facility (CPRF), 61Congress, U.S.

AEC abolishment by, 9

energy supply concern in, 47fusion power development and, 35-36, 44MFEE Act, passed by, 9, 51

Coope ra t i onadministrative issues and international, 169-170incentives for, 24, 25, 155, 164-166international, in fusion R&D, 3, 6, 9, 14, 15, 24-26,

44, 63, 66, 139, 155-186

obstacles to international, 25-26, 166-170

possible areas for international, 182-183

report conclusions on internat ional , 185-186

229


report’s definition of, 156types of, and levels of agreement, 156-158, 157See a/so Collaboration

Coordinating Committee (COCOM), 166Cornell University, 147costs

blanket design and reactor, 83CIT, 13, 52-53, 138-139difficulty in estimating future reactor, 113-116engineering test reactor, 98, 99, 114, 190of first wall/blanket test program, 97of fusion reactors, 113-116, 190fusion’s commercial acceptance and electr ic i ty,

117-118

future fusion research, 15, 26,99-101, 113-116, 155,

156, 190, 191, 192, 193, 194, 195, 197

long-term burn device, 97, 98

magnet ic conf inement systems development, 94-95,96, 97, 190, 191, 192, 193, 194, 195, 197

of materials irradiation test facilities, 97near-term fusion research, 21-22, 134-139, 22, 134,

135, 136, 137, 138, 139

of nuclear- technology study device, 98

superconducting magnets effect on reactor, 85, 86,

96, 115

See also Economics; FundingCritical temperature, 85, 86

D-D fusion reaction, 31, 92D-T fusion reaction, 32

accident risk from, 17-18, 106-108breakeven experiments using, 9, 46in dense z-pinch confinement, 64disadvantages of, 91energy released from, 6, 31plasma heating from, 74-75remote maintenance for, experiments, 88, 90See also Fuel

D-T fusion reactorsopposition to constructing, 46-47principal locations of potential hazardous agents in,

109See also Reactors

D -3He fuel cycle, 91-92, 116, 91See also Advanced fuel cycles; Fuel

Decay heat. See AfterheatDefense

applications of fusion research, 35, 39-40, 133concerns about international collaboration { 26, 164,

166-167plasma physicists working in, 21, 132

Dense z-pinch, 64-65, 66, 65Density, plasma, and confinement time, 33-34Department of Defense (DoD), 21, 133, 140Department of Energy (DOE)

fusion development policy, 3, 13, 14, 16, 23, 24, 26,30, 48-50, 52, 53, 93-94, 105

fusion research management by, 9, 40, 48-52international activities in fusion cooperation report by,

192-193

magnetic field exposure guidelines of, 108-109National laboratories, 21, 41, 140-143, 1 4 1Office of Energy Research, 48Office of Fusion Energy, 21, 23, 93, 132plasma physics funding by, 20, 131-132, 132Tritium Systems Test Assembly operation by, 88

Department of Health and Human Services (DHHS),135

Deuterium (D)in fusion reactions, 6, 30-31, 113supply of, 19, 113See a/so D-T reaction; Fuel; Hydrogen

Developmentalternate paths for concept, 66-67, 67classification of confinement concepts by level of, 12,

57plasma physics, 20, 31-33, 39, 131-132technical issues in fusion, 94-98, 189-191

Diverters, 80, 93Division of Plasma Physics of the American Physical

Society, 131Doublet Ill (D Ill) tokamak

international cooperation on,management of, 171-172

Doublet II I-D (D III-D) tokamak,162

Economics

62-163

59, 71, 148, 15, 75,

of international cooperation on fusion research, 3-4,15, 24, 25, 26, 155, 164-166

of nuclear fission power, 121-122renewable energy source, 123

safety assurance levels and fusion reactor, 115See a/so Costs, Funding

Education, fusion program’s benefits to, 20, 132, 140Efficiency

energy, 119, 120, 121, 190, 192energy conversion, 96, 116plasma current generation, 79

Electric Power Research Institute (EPRI), 48fusion acceptance poll by, 118, 118fusion research by, 149

Electricitycomparison of prospective long-range, supply options,

123, 124production as long-term fusion research goal, 8, 16,

30, 105systems in a fusion station generating, 12, 72, 13, 72

Energyadvantages of fusion power as source of, 3, 19, 29-30,

113, 117, 118, 123, 124availability of fusion, 116-117conversion by fusion blanket, 81-82demand and fusion development, 19-20, 124, 125desirability of fusion, 117-119direct, conversion techniques, 92, 116feasibility of fusion as a source of, 5, 8, 15-16, 30,

116-117, 123-125Federal funding of non-fusion, R&D, 134-139, 138fusion as an, program, 16-20, 31, 105-128

Index ● 2 3 1

fusion’s context, 19-20, 125, 190

loss mechanisms in plasma heating, 74, 76near-term benefits of fusion, program, 20, 133, 190projections of global primary consumption of, 125,

126

released by D-T reaction, 6, 31renewable sources of, 9, 47, 122-123source problems, as incentive for fusion development,

5-6, 9, 17-18, 19-20, 29-30, 192, 193, 195-196, 197See a/so individual sources of

Energy gain (Q), 67-68Energy Research Advisory Board (ERAB), 119

fusion program review by, 50, 51-2, 52-53industry representatives on, 148international cooperation panel of, 168

Energy Research and Development Administration(ERDA), 9, 40, 47, 50

Engineering test reactor (ETR), 9, 47, 139costs of, 98, 99, 114, 190

See also International Thermonuclear ExperimentalReactor (ITER)

England. See United Kingdom (U. K.)Environment

fossil fuel’s pollution of, 5, 29, 119-121fusion reactors’ effects on, 5, 18, 29-30, 31, 81, 83,

109-112, 110, 111Environmental Protection Agency (EPA), 135ESECOM report, 106

levels of safety assurance derived from, 107-108radioactive waste hazard and, 109-110reactor costs examined in, 115

Europe. See European Community (EC)European Atomic Energy Community, 159European Community (EC)

ETR plans of, 98fusion goals of, 29, 180fusion program status by, 16, 48fusion research in, 60, 61, 62, 63, 86internat ional cooperat ion by, 140, 158, 159, 160-161,

163, 170-171, 172-173, 180, 189JET development by, 158, 160-161

See a/so individual countries ofEuropean Laboratory for Nuclear Research (CERN), 172European Space Agency, 172

Facilitiescost of fusion research, 138-139, 190-191, 139development of future fusion research, 12-15, 94-98,

138-139, 190-191joint construction and operation of, 24-25, 156siting fusion, 26, 115, 160, 168See also Reactors; individual facilities

Field-reversed configuration (FRC), 62, 74, 63FINESSE study, 97, 98First wall. See BlanketFission/fusion hybrid reactors, 16, 19, 105, 112, 114,

202See a/so Breeder reactors

Fission reactors, safety of, 18-19, 106Fossil fuels, 5, 29, 119-121

See a/so Coal; Natural gas; OilFrance, 86, 184

See a/so European Community (EC)Fuel

advanced fusion, cycles, 18, 90-92, 108, 109-110,116, 91

fission reactor, supply, 122injection of, 18, 76-79, 106, 78production of, from fusion reactors, 16, 81, 82-83, 84,

85, 88, 91, 105, 112, 181supply of, for fusion reactors, 5, 19, 113See also individual fuel types

FundingD Ill-D, 162-163European Community fusion program, 161Federal, of non-energy R&D, 134-139, 134, 135, 136,

137Federal, plasma physics, 20, 131-132, 132magnetic fusion research, 3-4, 9-10, 12-13, 15, 21-22,

23, 26, 30, 40, 44, 46, 47, 48-51, 95, 121-122,134-139, 4, 5, 22, 41, 42, 134, 138, 139, 141

See a/so Costs; EconomicsFusion Engineering Design Center, 142Fusion Engineering Device (FED), 50Fusion Experimental Reactor (FER), 182Fusion power core systems, 12, 48, 72, 73, 74-90, 14,

73Fusion self-heating, 74, 76Fusion Working Group, 184

GA Technologies, Inc., fusion research by, 59, 61, 71,148, 149{ 162-163

General Atomic Corp., 41, 144General Electric Co. (GE), 41, 44Geneva Summit of 1985, 179, 181, 184Georgia Institute of Technology, 147Germany, Federal Republic of, 63, 71, 159

See a/so European Community (EC)Gorbachev, M., 179, 181, 184Gravitational confinement, 34

Hawaii, 123Helium, 31High energy gain, 8, 30Hiroshima University, 163Hitachi Corp. 149H-mode scaling, 93Hydrogen

as fuel in fusion reaction, 6, 9, 17-18, 29, 30-31, 46,64, 74-75, 88, 90, 91, 106-108

isotopes of, 30-31See also Deuterium; Tritium

Ignitionconfinement time required for, 33research, 13, 95-97scientific progress in reaching, 68, 69, 94sustainability of fusion reaction when reaching, 8, 30See a/so Plasma

— —


Incentivesfossil fuel curtailment, 121for fusion development, 5-6, 9, 17-18, 19-20, 29-30,

117-118Industry

base for fusion, 118, 150-151competitiveness of United States, 164, 167-168fusion research involvement by, 6, 22-23, 41, 44, 51,

147-151, 22, 134, 138, 147fusion research “spin-offs” used in, 133plasma physicists in, 132See a/so Private sector

Inertial confinement, 35, 205-207, 206Institute for Plasma Physics, 159Integrated Fusion Facility (IFF), 116International Atomic Energy Agency (IAEA), cooperation

facilitation by, 158-159, 185International Energy Agency (IEA), cooperation

facilitation by, 159-160, 163, 171International Fusion Superconducting Magnet Test

Facility, 159, 89, 160International Thermonuclear Experimental Reactor

(ITER)collaboration in design of, 98potential for collaboration on, 179-185proposed development of, 14, 26, 53, 183-185siting decision for, 168status of, 184-185See also Engineering test reactor

International Tokamak Reactor (lNTOR), 159management of, 170, 184-185

Issuesfusion power core system, 75, 77-79, 80, 81, 83-84,

85, 86-88technical, in fusion development, 94-98, 189-191

JapanETR plans of, 98fusion goals of, 29, 182fusion program status is, 16, 48fusion research in, 60, 61, 62, 63, 64, 86international cooperation by, 159, 161-163, 172-173,

181-182, 184role of industry in fusion development in, 149

Japan Atomic Energy Research Institute (JAERI), 149,159

Joint European Torus (JET), 16, 48, 158, 160-161, 163,180, 15, 161

costs of, 95management of 170-171shielding use in, 85

Joint Institute for Fusion Theory (JIFT), 163JT-60 Tokamak (Japan), 16, 48, 17, 183

cost of, 95

KMS Fusion, Inc.inertial confinement fusion research at, 207

Large Coil Task (LCT), 86, 159management of, 171

Large Helical System, 60Lawrence Berkeley Laboratory

inertial confinement fusion research at, 207Lawrence Livermore National Laboratory (LLNL)

fusion research at, 21, 41, 48, 64, 86, 141inertial confinement fusion research at, 207See also National laboratories; Research

Lawson parameters, 34, 42of advanced fuels, 91magnets obtaining high, 93TFTR-achieved, 52increase in, due to tokamaks, 44, 45

Licensing. See RegulationLithium

supply, 19tritium breeding and, 82-83, 84, 113

Los Alamos National Laboratory (LANL)fusion research at, 21, 41, 48, 61, 62, 65, 88, 142-143inertial confinement fusion research at, 207See also National laboratories; Research

Macrotor, 146Magnetic confinement, 11-12, 34

status and comparison of international, programs, 16,48, 155, 174-178, 174, 175, 176, 177, 178

See also ConfinementMagnetic fields

in closed confinement configurations, 58-59, 58motion of charged particles in, 34, 63, 34potential hazards from, 108-109, 109use of, for plasma confinement, 11-12, 34, 47-48,

57-66, 12, 57Magnetic field utilizaiton factor. See Beta parameterMagnetic Fusion Advisory Committee (MFAC)

CIT review by, 96, 97industrial participation in fusion findings by, 149, 150industry representatives on, 148university research funding by, 145

Magnetic Fusion Energy Computing Center (MFECCAct), 133, 141

Magnetic Fusion Energy Engineering Act of 1980 (MFEEAct), 9, 50-51, 191

Magnetic Fusion Engineering Center, proposed creationof, 5 0

Magnetic Fusion Program Plan, 1985 (MFPP), 10, 52Magnetic mirrors, design and development of, 48, 50,

63-64, 64Magnets

function and development of fusion reactor, 85-88,115-116

See also Magnetic fieldsMaintenance, remote, for fusion reactors, 88-90Manhattan Project, 39Massachusetts Institute of Technology (MIT), 64, 146,

147Materials

and neutron irradiation, 183development for fusion reactors, 84, 97production in fusion reactors, 203requirements for fusion reactors, 19, 113superconducting, 84, 85, 86-88, 96, 115

Index . 233

testing, 97McCormack, Mike, 50MFTF-B, 48, 64, 141, 49, 87

COSt Of , 138

superconducting magnets in, 86Military. See DefenseMirror Fusion Test Facility-B. See MFTF-BMitsubishi Corp., 149Mitterand, F., 184Model C Stellarator, 46, 10, 4 5Model ing

global energy demand, 125, 126fusion generating stations, 105fusion scaling relationship, 58, 71-72See a/so System studies

Monitoringreactor blanket modification, 112tritium processing, 88

Multilateral agreementsinternational, 158-161See a/so Cooperation; Collaboration

Muon-catalysis, approach to fusion, 207-208

National Academy of Sciencesfusion personnel estimates by, 140physics research review by, 39See a/so National Research Council

National Aeronautics and Space Administration (NASA),133, 135

National Committee on Radiation Protection andMeasurements, 109

National Institutes of Health (NIH), 135National laboratories

fusion R&D conducted by, 21, 41, 140-143General Atomics as, 44personnel in, 21, 132, 140See a/so Facilities; individual laboratories

National Research Councilfission/fusion hybrid reactors, report by, 114international cooperation report by, 156, 165plasma physics report by, 132See a/so National Academy of Sciences

National Science Foundation (NSF)general science research by, 135plasma physics funding by, 132

National security. See DefenseNatural gas, 120Naval Research Laboratory, 62, 65

inertial confinement fusion research at, 207Neutral beams

injecting, to generate current, 79plasma fueling using, 76plasmas heated with, 68-70, 74, 75, 93

New Jersey, 21, 41, 140New Mexico, 39Next European Torus (NET), 170, 180Nixon, Richard M., 47, 163Nixon-Brezhnev Accord, 163Nuclear Regulatory Commission, U.S. (NRC), 110, 135

Oak Ridge National Laboratory (ORNL)magnetic fusion research by, 21, 41, 46, 48, 142materials needs study by, 113pellet fueling technology development by, 77See a/so National laboratories

Office of Fusion Energy (OFE)research by, 21, 23, 132Technical Planning Activity coordination by, 93

Office of Technology Assessment (OTA)fusion energy context workshop by, 36, 123issues in international cooperation workshop by, 36,

166objectives of fusion assessment by, 35-36report findings of, 4-6selected studies examining other energy technologies

by, 119Ohmic heating, 61, 74, 148-149Ohmically Heated Toroidal Experiment (OHTE), 61,

148-149, 24, 149Oil, 120

See a/so Fossil fuelsOpen confinement concepts, 63-65

See a/so ConfinementOperational Test Reactor (OTR), 181

Pennsylvania State University, 147Perhapsatron, 9, 43Personnel

international exchange by, 156, 159, 161, 163magnetic fusion, 21, 139-140

Petroleum, 120See a/so Fossil fuels

Phaedrus, 64, 146Phillips Petroleum Co., 148Physics, 35, 147

plasma, 10, 20, 31-33, 39, 46, 131-132, 197Plasma

behavior of burning, 95-97burn control, 80-81confinement concepts, 8, 11-12, 34-35, 47-48, 57-66current generation, 79definition of, 8, 31-33, 33energy loss mechanisms, 74, 76fueling, 76-79, 78heating, 69, 74-76, 77instabilities in, behavior, 11, 33, 42, 44, 57, 64, 68,

76, 80-81reaction product control, 79, 80research, 44, 59, 93See a/so Magnetic fields

Plasma physicsadvances in, 10, 20, 31-33, 39, 46, 131-132, 197Federal funding of, 20, 131-132, 132

Plutonium, 40breeding in nuclear reactors, 112declassification of, generation technology, 43

Policyfusion energy promotion, 117Japan’s energy, 29, 182


U.S. fusion development, 3-4, 14, 23, 24, 26, 48-50,52, 53, 93-101, 127-128, 182-185, 189-197

world fusion development, 29, 99, 101, 127-128,179-185

PoliticsD-T experiment’s effect on, 46international cooperation and, 25, 26, 160, 163, 165,

181Princeton Beta Experiment (PBX), 71Princeton Beta Experiment Modification (PBX-M), 59, 71Princeton Large Torus, 77Princeton Plasma Physics Laboratory (PPPL), 142

CIT facility at, 53, 138-139fusion research at, 21, 41, 59, 62, 70-71, 95-97, 140spin polarization research at, 90-91TFTR construction at, 47, 49See a/so National laboratories

Princeton University, 140Private sector

fusion research involvement in, 6, 21, 22-23, 41, 44,51, 117, 147-151, 22, 134, 138, 147

plasma physicists in, 132See also Industry

Process heat, production by fusion, 203Project Sherwood, 8, 40-42

declassification of, 42-44Protium. See HydrogenPublic opinion

on fusion power acceptability and development, 3, 8,9, 30, 46, 202

on nuclear fission power, 121, 122Pumped limiters, 80

Q. See Energy gain

Radiationdamage to blanket materials, 83routine emissions from fusion reactors of, 111-112

Radioactive waste, fusion reactor, 18, 29-30, 83,109-110, 110

Radiofrequency (RF)heating, 74, 75-76, 93injecting, power to generate current, 79

Reactionrequirements for fusion, 6-8, 29, 30, 31-35, 7, 32runaway, 18, 106

Reactor potential, 66Reactor relevance, 48, 50

energy gain as measure of, 67-68Reactors

blanket design’s influence on, 83breeder, 19, 44, 46, 48, 112characteristics of fusion, 16-20, 105-106, 127confinement concept requirements for viable fusion,

66development of, 8, 9, 12, 46, 47, 48, 49, 51, 52, 53,

72-73, 139fusion test, 9, 14, 26, 47, 53, 98, 168, 179-185

nuclear weapon proliferation potential of fusion,18-19, 48, 112, 122

routine emissions from fusion, 111-112shutdown and emergency cooling systems of, 18, 106See a/so Facilities, individual types of

Reagan, Ronald, energy policy of, 51, 136, 179, 181,

184Regulation

fusion power, 8, 16, 30, 117, 118, 118impact of reactor cost of, 114, 115, 116

Renewable energy sources, 9, 47, 122-123Rensselaer Polytechnic Institute, 147Research

advanced fuel, 90-92causes of growth in fusion, 9, 46closed confinement concept, 48, 59, 60, 61, 62-63cost of, facilities, 138-139, 190-191, 139costs of fusion, 15, 99-101, 113-116, 155, 156, 190,

191, 192, 193, 194, 195, 197declassification of fusion, 9, 42-44, 155defense-related fusion, 35, 39-40funding fusion, 3-4, 9-10, 12-13, 15, 21-22, 23, 26, 30,

40, 44, 46, 47, 48-51, 95, 134-394, 5, 22, 41/ 42goal of current fusion, 8, 16, 30, 105history of magnetic confinement fusion, 8-10, 39-53ignited plasma, 13, 52inertial confinement, 35, 205-207international cooperation in fusion, 3, 6, 9, 14, 15,

24-26, 44, 53, 155-186, 193-194issues affecting future fusion, policy, 24-26, 94-98,

189-191on magnetic fields’ safety risk, 108-109materials, 157muon-catalysis, 207-208near-term benefits from fusion, 6, 20, 131-134, 191nuclear fission technology, 122open confinement concept, 64participants in magnetic fusion, 21-23, 29, 40-41,

140-151plasma heating, 75-76, 93plasma physics, 59, 197progress and future directions in fusion, 9, 48-50,

93-101, 189-197superconducting materials, 86-88

Research and development (R&D) See. Development;Research

Reversed-field pinch, 60-61, 78, 79, 61

Safetyassurance levels, 107-108, 115fission reactor, 121fusion reactor, 5, 17-18, 30, 31, 81, 93, 106-108occupational, on fusion reactor site, 108-109, 109shielding and personnel, 85tritium processing, 88

Sandia National Laboratoryinertial confinement fusion research at, 207

Scaling, 58, 71-72

I ndex ● 2 3 5

H-mode, 93Schedule, future fusion R&D, 3-4, 15-16, 98-99,

116-117, 127-128, 190, 194, 196, 99, 100Science. See Research; TechnologiesSecond Geneva Conference on the Peaceful Uses of

Atomic Energy, 44Self-reference, 235Senior Committee on Economics, Safety, and

Environmental aspects of magnetic fusion energy.See ESECOM report

Shieldingradioactivity of, 109reactor, 84-85

Siting, facilities, 26, 115, 160, 168Soviet Union

ETR plans of, 98fusion goals of, 29, 180-181fusion research in, 16, 48, 60, 62, 63, 64, 86international cooperation by, 159, 163, 180-181, 184plasma confinement breakthrough by, 9, 44-46, 59

Space station, proposed management of, 172-173Special Nuclear Materials, Atomic Energy Act’s

definition of, 40Spectra Technologies, 62Spheromak, 61, 78, 79, 62Spin polarization, 90-91STARFIRE, 115

as reference base for ESECOM report, 108, 110, 110,111

Stellarator, 59-60, 60conversion of, into tokamak, 46, 59international cooperation on, 159

Strategic Defense Initiative (SDI), 21, 133, 140, 167Superconducting materials

recent advances in, 86-88use in magnet coils, 84, 85, 86, 88, 96, 115

Swiss Institute for Nuclear Research, 159Synthetic fuels, production by fusion, 203System studies, 12, 48

on fusion-generated electricity costs, 114generating stations, 105See a/so Modeling

Tandem Mirror Experiment (TMX), 48Tandem Mirror Experiment Upgrade (TMX-U), 48, 64,

91

Tandem mirrors, 63-64, 65, 141, 64TARA device, 64, 147Technical Planning Activity (TPA), 93-95, 97, 98-101,

116

Technologies

advances in fusion, 72-73, 93, 97-98declassification of nuclear, 43-44fossil fuel, 119-121fusion energy competitiveness with other energy,

19-20, 105, 119-126magnetic fusion research “spin -off,’ 6, 20, 22, 44,

132-133nuclear fission, 43-44, 121-122pellet fueling, 76-79, 93, 78

plasma heating, 74-76, 93reactor-relevant, 48, 50renewable energy, 9, 47, 122-123transfer of, 24, 25, 26, 158

Temperature, fusion reactions and, 6-8, 31-33, 42, 69,70

Tennessee, 21, 41, 142Testing. See ResearchTexas Experimental Tokamak (TEXT), 146Theta pinch. See Reverse-field pinchThree Mile Island (U.S.), 121 ‘Tokamak Fusion Test Reactor (TFTR

breakeven experiments using, 70construction of, 47, 49cost Of, 95, 138planning for, 9, 16, 47shielding use in, 85

Tokamaks

40, 11, 47

breakeven experiment results using, 68-70cooperation on experiments using, 159-160fusion requirement demonstration by, 11-12, 57, 58,

59, 65ignition experiments using, 70major world, 59progress in parameters of, 93, 94Soviet development of, 9, 44-46, 59See a/so Confinement; Magnets, Magnetic fields,

individual devicesTore Supra tokamak (France), 86, 163Toroidal chamber with magnetic coil. See TokamakTorus, magnetic fields encircling, 58, 59, 60-61, 58Toshiba Corp., 149Transfer

currency, 169, 171, 172technology, 24, 25, 26, 158

Tritium (T), 40

breakeven attainment research, 46, 47, 70breeding in fusion reactor blanket, 81, 82-83, 84, 85,

88, 91, 201-202declassi f icat ion of , generat ion technology, 43in fusion reactions, 6, 30-31hazards from accidental release of, 18, 106, 108

routine atmospheric releases of, 111

See a/so HydrogenTritium Systems Test Assembly (TSTA), 88, 143, 90Truman, Harry, 39T-7 tokamak (Soviet Union), 86T-1 5 tokamak (Soviet Union), 15, 48, 86, 180-181, 88

Umbrella agreements, 157-158, 159, 161-163United Kingdom

fusion research in, 62, 63JET facility located in, 160, 161verification of Soviet tokamak results by, 45-46See a/so European Community (EC)

United Kingdom Atomic Energy Agency, 161United States

commitment to international cooperation, 168ETR plans of, 98fusion goals of, 29, 179


fusion program status in, 16, 4 8 inertial confinement fusion research at, 207fusion research in, 49, 59, 60, 61, 62-63, 64, 86 University of Texas, 146, 163international cooperation by, 10, 26, 156, 159, University of Washington, 147

161-163, 171-173, 179, 184 University of Wisconsin, 64, 146, 147stature of, and fusion research, 20, 44, 45, 133-134, Uranium

192, 196, 197 breeding in nuclear reactors, 112Universities supply of. 19, 43, 122

DOE support of, 21, 132fusion R&D conducted by, 21-22, 41, 132, 139,

143-147, 145

See a/so Private sectorUniversity Fusion Associates (UFA), 21, 146University of Arizona, 147University of California

at Irvine, 147at Los Angeles (UCLA), 146, 147at Santa Barbara, 147

University of Illinois, 147University of Maryland, 62, 147University of Michigan, 147University of Rochester

Utilities ‘ ‘ ‘fusion energy’s acceptability to, 116, 117-119, 190,

118fusion research “spin-off” technology and, 13 3See a/so Private sector

Versailles economic summit, 183-184

Wastes, from fusion reactors, 18, 29-30, 83, 109-110,110

Western Europe. See European Community (EC)

ZT-40, 144

72-678 ( 248)