ED 219 '.631,

TITLEINSTITUTtON

REPORt NO'PUB DATE

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EDRS PRICEDESCRIPTORS

IDENTIFIERS

DOCUMENT RESUME

CB 03.3 392' J

RadiolOgical Defense Manual.1 Defense Civil Preparednets Agency (DOW', Wishington:D.C.CPG-2-6.2Jun 77202p.

MFOI/PC09 Plus Pottage.*Civil Defense; *Emergency Programs; Measurement; .

Measurement Equipment; NuclearsEnerg; *Nuclear. ..-J,

1Physict; *Nuclear Warfare; Planning; PostsecondaryEducation; Radiation Biology;'.*Radiatfon Effects; .

Safety Equipment . -

Fallout; Radiation Monitors; *Radioactivity1

ABSTRACTOrfginalsly prepared for use,as a student textbook in

Radiological Defense (RADEF) courses, this manuil provides the basictechnical information necessary for an understanding of RADEF. Italso briefly discusses the need for RADEF planning and expectedpostattack emergency operations. There ire 14 chapters covering thesemajor topics: introduction t$ radiological deiense, basib concepts of ,

nuclear science, effects of nuclear weapons, nuclear radiationmeasuremanit, radiological detection and measurement instruments,,radi.dactivd exposure rate calculations, radiological monitoring. .

techniques and operations, protection from radiation, radiologicaldecontamination, RADEF,operatione, RADEF planning, and implementing er-,-=RADEF plan. A glossary concludes the manual. ,(YLB)

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* Reproductions supplied by EDRS are the hest that can be madefrom the original document. *

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CPG 2 -6.2JUNE 1977

. U.S. DEPARTMENT OF EDUCATIONNATIONAL INSTITUTE OF EDUCATION

EDUCATIONAL RESOURCES INFORMATIONCENTER (ERIC)

Alas dc4n.nt has been reproduced asrece,y,eYlrom the ptrson or organizationoriginating it

u Minor changrrs have bein mad* to improvereproduction quality

Points of view or opimons stated in this docu .mutt do not necessarily represent official NIEposition Or policy.

DEFENSI cImp,Rgek EDNESS AGENCYDEPARTMENT )isk= ,,

-1

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. .. . ,

. .

RADIOLOGICAL DEFENSEMANUAL

*(Supersedes M :11.22 -2 dated JUNE 1974 which may be used).

DEONSE CIVIL PREPAREDNeS AGENCY

DEPARTMENT OF' DEFENSE

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PREFACE

This:Manual provides the basic technicalinformation necessary for an understandingof Radiological Defense (RADEF) and briefly .

discusses the need,for,RADEF planning-andexpected postattack emergency operations.It had originally been prepared by theDefense Civil Preparedness Agency (DCPA)

- for use as a student.textbook in Radio-logical Defense Courses.

Tbis technical Malal is.snOt intended to\ provide complete R operational pro-) cedutes or direction for the developmentof RADEF plans and organizations., Such,detailed guidance will be found in otherDCPA publications.

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TABLE OF CONTENTiChapter Page

1 INTRODUCTION TO RADIOLOGICAL DEFENSE 1Discusses the nature of the radisological threat and the measures beingtaken to counteract that threat.

2 BASIC CONCEPTS OF NUCLEAR SCIENCE 5Discusses those factors in nuclear radiation physics which RADEFpersonnel should 'understand in order to carry out their responsibilitiesin the ivst effective manner.

3 EFFES OF NUCLEAR WEAPONS 25Describes how nuclear ,weapons differ in both degree and kind frornconventional explosive weapons, and what the effects of a nuclearexPlosion are, both in sequence an& nattfre.

4 NUCLEAR RADIATION MEASUREMENT 55To deal with the radiological effects of nuclear explosions it is vital to beable to detect and/to measure harmful levels or rates of radiation. Thischapter describethe principles by which we are able to do this.

5 RADIOLOGICAL EQUIPMENT 69Describes those radiological detection and measurement instrnmentsconstructed on the principles set forth in Chapter 4 which are availableto the radiological defense program.

6 RADIOACTIVE FALLOUT 8(1One of the principal effects of nuclear weapons is the production ofradioaciive Material Winch comes back to earth ,in the form of fallout.This chapter tells how fallout is formed, how it iadistributed, how it is ahazard, and how its movement can be predicted.EFFECTS.OF NUCLEAR RADIATION EXPOSURE 97This chapter tells what happens to the human body whein subjected toradiation at varioull levels, and why these biological effects occur.

8 EXPOSURE AND EXPOSURE RATE. CALCULATIONS 117A central concept in dealing with nuclear radiation is the decrease inradiation levels of radioactive fission products with the passage of time.This chaptet tells how this decrease or decay may be calculated undervarious conditions and by various,methods.RADIOLOGICAL MONITORING TECHNIQUES AND OPERATIONS 135Describes the objectives of radiological monitoring and hoW those objec-tiyes ate achieved.

-10 PROTECTION FROM RADIATION 142ibere are various kinds of 'radiation emitted from fallout..This chapterekpiains what they are, how they differ, and by what means we mayProtect ourselires from them.

11 RADIOLOGICAL PEPONTAMINATI ON 153Describes the general nature ,of radiological decontamination and theprindiplea and phases of decontamination operations.

12 RADEF OPERATIONS 164Describes the'role of RADEF at each level, of operations.

Chaptir Page

14 RADEF PLANNING 168We all accept,the need to look before we leap, but why is planning withits cost in money and manhours really of such crucial impontance? Thischapter provides some answers to that question.!

14 "PAPER PLANNING" OR REAL RADEF 179A 'plan can be just words or it can be a blueprint for action. Thedifference lies in the availability of certain skills and knowledge neces-sary to translate 'the plan into effective action. This chapter discusseswhat these are.GLOSSARY 185

+15

INTRODUCTION TO RADIOLOGICAL DEFENSE

A strong civil preparedness program isvital to this nation's security. Today, ev-ery citizen iind officials at every level ofgovernment should be concerned with pre-paring for disasters of all kinds. This bookis primarily concerned with one such po-tential disaster; that of a nuclear attackon this country.

This chapter will show why civil prepar-edness is vital to our security by statingthe nature of the threat we face and therole that 'an effective preparedness pos-ture can play in our national response tothat threat. It will also define what wemean by "radiological defense" and willindicate how such defense is organized.Another objective of this chapter, and per-haps the most important one, is to explainhow effective radiological defense requirestrained and dedicated personnel. We can-not develop a radiological defense capabil-ity unless we can count on all of our citi-zens to learn something .of the nature ofnuclear radiation and to gain an under-standing of the measureft that can betaken to defend against its effects shouldthis nation ever face nuclear attack.

THE NATURE OF THE THREAT

1.1 Any assumptions about a possible"'nuclear attack Upon the United States aredangerous since we can never be siiieabout a potential enemy's objectives oreven specific capabilities. Studies made bythe Department of Defense and others forexercise purposes use-attack Patterns 'thatrepresent current estimates of weaponsize and t4ta1 'yield that could be deliveredon this country in an all out nuclear at-tack.

1.2 Specific attack patterns assumehundreds of nuclear weapons with manymillions of tons of TNT equivalent are

CHAPTER 1

dropped on a mixture of military, indus-trial and population targets as both sur-face and air bursts. The results vary, ofco-urse, but the unmistakable fact re-mains that millions of Americans would be .killed outright in any Such attack by thedirect effects of blast and fire. The loca-tions at which weapons were detonatedwould suffer unprecedented physical dam-age and the fallout radiation from surfaceweapons would affect hundreds of squaremiles in a downwind direction from thosebursts. Additional millions of casualtieswould be caused depending on the amountof fallout protection available in the af-fected areas. In one simulated attack inwhich 800 nuclear weapons of 3,500 ,mega-tons were assumed, there would be about97 million people killed either oufright orwho died subsequently from the direct ef-fects or from fallout. Another 30 ,millionwould have been injured but would sur-vive while the remaining 67 million out ofa total population of 194 million would notbe affected. '

1.3 Three things are worth notingabout this threat. Thez,are:

First, there is no equivalent in humanexperience for the destructiveness' ofmulti-megaron hydrogen weapons. It isworth remembering that all the bombingraids on Germany in World War U .`. . by'all the allied forces . . . together totallddbut one megaton.

Second, not only arc the weapons in a, ,

new dimension of destrUction, but the de--livery systems are now in a new dimensionof effectiveness. Unless An anti-missile-missile is developed that can not only hitan enemy missile, but hit it almost imme-diately aftef it leaves,the launching pad,and further,- can discriminate betweenmissile and decoy, , the 'advantage in

1

mpdern sttiategic missile warfare seemscertain to remain with the attacker. This

, factor, coupled with the enormous destruc-tivehess of modern weapons, places apreMium on surprise.

Third, this hypothetical attack would .product casualties tp more than half of-our population undei\the conditions thenprevailing. If the condftions were changedto the extent of providing an effective civilpreparedness program, the casualtieswould be reduced to a major degree.

NOTE-

Our system of ethics is based upon thebelief that each individual life is pre-cious. TAis belief underlies all ourAmerican institutions. It is, in fact,the basic way we differ from systemsembracing totalitarianism, where theindividual' is the servant of the State,rather than our syStem where govern-ments derive ". . . their just powersfrom the consent of the governed.. . ."This central fact,. which motivates thegovernment in working for civil pre-paredness, should not be obscured bystatistics,dealing with millions of gas-ualties. "Megadeath" like "genocide"are words that spring from systems of,governnient alien to ,our way of lifeand our system of right and wrong.Unfortunately, the grim facts of themissile age force us.to consider theseterms, 'so hostile to our belief in thesupreme value, of the individual.

THE ROLE OF CIVIL PREPAREDNESS ANDRADIOLOGICAL ,CIE FE N SE

1.4 The national defensive posture of anation incorporates, among other things,the concept/of "Active" and "Passive" of-fensive and/or 'defensive capabilities. "no-tive" offensive and defensive, capabilitiesinclude items suCh as a nation's militaryforces and arms, both 'conventional andnuclear, as well as any other capabilitywhich represents an "Active" resource forimplementing and maintaining, an offen-sive or 6fensive posture. ICBM's, bomb-ers, naval ships, etc., represent obyiousexamples of an "Active" capability. "Pas-si.v.e" capabilities, however, are thoseitems lacking the visibility of, a militaryforce,, but which may contribute signifi-cantly to a nation's defensive capability.

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Civil preparedness is a pr ime example of a"Passive" capability.

1.5 The Strategic. Arms Limitat ionTalks (SALT) were designed to -effect abalance of pewer among the two primary

-nuclear powersthe United States andthe Soviet Union. The SALT negotiationswould basically effect this balance by plac-ing limitations or curbs upon.the "Active"offensive and defensive capabilities "of anation. It then becomts apparent that,assuming theeffectiveriess 'of the SALTnegotiations, a nation with a strong "Pas-sive" defensive capability occupies a posi-tion of. strength. Herein lies the impor-tance of civil preparedness and radiologi-cal defense.

1.6 Since the civil preparedness pro-gram is a vital element of a meaningful"Passive" defensive posture, it is ex-tremely iMportant that it be an effectiveelement with trained personnel ready to'provide an immediate response in a crisessituation. Thus,in terms of the 'recogniz-able nuclear threat, radiological defenseoccuPies a very realistic and substantialrole within the United States civil prepar-edness program and within the total de-fensive posture of the nation':

RADIOLOGICAL DEFENSE

1.7 In evaluating the results of a hypo-thetical nuclear attack upon the UnitedStates, seVera/ means of protestion mustbe utilized. Assuming that a crisis periodor period of marked increased interna-tional tension will probably preceed anactual attack, crisis evacuation proceaurescan remove segnfentg of the populationaway from probable high risk areas. Addi-tionally, to the -extent that it, is available,protection against blast and other directeffects should be taken by utilizing availa-ble shelters. Equally important, however,is the need in all defensive plans for pro-tection against nuclear fallout. Radiologi-cal defense maximizes this type of protec-tion.

1.8 Thus, vadiological defense is an ex-tremely important element of civil prepar-edness. Radiological defense is defined as:

8, .

011.

The Organized Effort ThroughDetection, Warning, ant

Preventi4e and Remedial MeasuresTo Minimize the Effect of

Nuclear Radiationon People and Resources.

GENERAL RADIOLOGICAL.DEFENSEREQUIREMENTS

1.9 Following are the requirements of aKund radiological and civil preparednessprogram: ,

(a) A system of shelters, equipped a.ndprovisioned to protect qur population fromthe fallout effects of a nuclear attack.

(b) Organization and planning of emer-gency actions necessary to restore a ,func-tioning society. '

THE IMPORTANCE OF SHELTERS

1.10 Sheltersboth individual andcomniunityare "keys" for survival. ThisfS. because shelter plays a dual role in aneffective radiological defense 'program;first, as a shield protecting individuals;and iebond, as a shield protecting the per-sons who, bypossessing special knowledge,

It' skills, and habits of organization, can com-bine to assure the continuing of Ifunc-tioning, democratic gociety. Thus, a. shel-ter is not only a passive shield; it is.also an'activ'e element in the system of counter-measures that would have to be taken toassure the survival of the nation after anattaek.

As radiation l,vels decline, people' tanleave their sh4lters to perform neededtasks of recovery. But when can theyleave their shelters? This and other ques-tions, such as determining what the radia-tion 'levels are 'Within the shelter, can besatisfactorily answered in one way only:through accurate measurement or moni-toring,

MONITORING AND THE MONITORINGSYSTEM'

1.11 To assure adecluate measurement!-of-fitdiation levels to. support postattackifittiöiogical.defense operations, the nation(

needs a large number of fallout monitOr-ing stations. Some of these stations maybe locate't within, coml.:11unit shelters,since such shelters form stron points ofsurvival and bases of ultini recoveryoperationg? Those-community sheltersthat provide for extended 'geographic andcommunications coverage are particularlysuited for serming in the additional capac-ity of monitoring stations.

1.12 Whether in separate monitoring..,

stations or carrying out monitoring proce-dures from community shelters, the pri-mary job of the monitor will be to supplyinformation on radiation levels, informa-tion basjc to survival and recovers opera-tions. In carrying out their duties, themonitors should receive technical direc-tion and supervision from their organiza-tional Radiological Defense Officer.,

RADIOLOGICAL DEFENSE .

ORGANIZATION

1.13 As stated in `Publif Law 85-606, itis the intent of Congress, in providinefunds for radiological defense, that the .

reiponsibility for such defense be "vestedjointly in the Federal Government and theseveral States and tHeir political subdivi--sions." The ,division of responsibilitiesamong governments, which is a central.-feature of our Federal system, is fullyreflected in the organization of radiologi-cal defense. The DCPA recommended pro-gram describe's in some detail the respon-sibility, of' each element and level of goir-ernment, and the organization establishedto give effect to these levels of risponsibil-ity.

1.14 In order to make 'the radiologicaldefense program la success, there is needfor radiological monitoring stations at .

Federal, State, and local facilities*'throughout the nation. This means thatthere is a need for money to pay for theinstruments and eiquipment required;there 'is need for mItnagement to assurethat these stations operate effectively andin one coordinated system. But there iseven more need, for trained men andwomen who can operate the equipment, dothe other specific jobs needed, and provide,

93

leaderslkip in radiological defense matterson the local level. An essential part of suchlocal leadership is the training of RADEFpersonnel. ,

1.15, DCPA training courses are.de-.. signed to, produce a core of competent ra-

diological defense personnel includingthose who will go back to their communi-ties and train others. For without trainedpeople, the best laid plans become little)more than complicated dreams. Trained

r."

men and women breathe life into plans.This is the reason behind the organizationof DCPA courses. The courses offer thetraining. If that offerhig is takento, thefullest potentialthen all the effort, andplanning, and hopes of those deeply con-.cerned with protecting our society, fromthe President on abwn, will be realized.For on men and wonien like ourselves, inthe last analysis, will lie the success ofradiological defense program.

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4. CHAPTER 2

.'BASIC CONCEPTS OF NUCLEAR SCIENCE

We will begin by ending the mystery.Since the aim of this book is to lieyouinyour Xvoik of radiological defense, it isessential 'that yOu understand what youare defending againstnuclear radiation..This, then, is theprfmary objective of

this chapter:

Understanding Nuclear RadiationThere-are many kinds of radiation, some

of which, such .as long and short radiowaves, infrared (or heat) radiation, visible-light, and ultraviolet radiation are famil-iar to all of us. However, nuclear radia-tion, the noiseless, odbrless, unseen, unfeltsomething that can be so deadly seems, asWinston Churéhill said of Russia, "a riddlewiipped.in. mystery inside an enigma".

Fortunately, this need not 15.64o. A fewconcentrated hours of study will quicklymake. rtidiation understandable.

However, dour job. Were how to stop aircontamination from automobile exbaus,we .would not get too far by confiningourselyes to the natUre of the exhaustalone. It' would be necessary to study thefuel, the way the auto engine burned thefuel, . as well as many Other things. Onlythen could we underttand, and possibilycope,with,'the factors in the. exhaustfutnes that were harmful.

The-same need exists -with nuclear -rt.t:.diation: If we are to understand it, wemust see the whole picturerwe must knowthe why as well as the *what of nuclearradiation.

Therefore, to help us understand nu--clear radiation, the major objectAre of thischapter, we must also have some grasp of:

WHAT are the kinds Of nuclear radia-tion

WHAT;is the language of nuclearphysics, the terms, signsand symbols used to de-

. scribe the world ofpthe atomand-radiation .40s

WHAT is the structure of tpe atomWier is the nature of itspartsHOW do.these parts behaveHOW is nuclear ra'diation measured

TWOEUNDAMENTASAND ABOMBSHELL

2.1 There are two physical law's,thtst wemust understand before we talk abart theatom. .-

2.2 The first of these is known as the,LAW OF CONSERVATION OF MATTER.

According to this law, the total mass of thematerial universe remains always thesame, regardless of all the. 'rearrange-

-c-nients of its component parts. This wasfirst demonstrated by the brilliant Frenchphysieist Antoine Lavoisier,, whose 'genius

. was cut'snort by the French Revolution.Lavoisier burned a candle Of knownweight until it disappeared. He thenweighed the oxygen used by the burning.candle, the wax 'that remained- and thefoul gas (carbon dioxide)eand water vaporformed by the burning candle. He foundibat,the weight of the candle ti;at disap-' peared and the-weight,of the oxygen thatcombinee with it equalled the weight oftile carbon slioxide and water vapor. Thisis oneAtemonstration4pf the LAW OF CON-

WHAT is meant by 'inptter" and "en-, ergy"

SERVATION OF MATTER.2.3 The second 'law of conventional

physics is known as the I.:AW OF CON-SERVATION OF ENERGY. This law

/NO

states,that one form of energy Fan beconverted to another form, but the total,amount of energy_in the -uni3,7eree neither-'increases nor decreases.

2.jl. Until 1 05, matter or Mass and gn-were loo ed at as separitteentities,

findeed they appear to be.2.5 Then, a young mathematician and

physicist working in the Swiss Patent Off-ice produced a bombshelL The young manwas Albert Einstein. He said, in what isprobably the most important mathemati-cal equation in history, that E Ouals ,mc2,or, in plain English, that there is an exactequivalence between mass and .energy.Mass can be convrted to energy and, evenmore strangely, energy can sornetimexbeconverted to rnasg.

2.6 According to Einstein, it is notmass dr energy as a separate entity, butrather the total mass-energy of the uni-yerse that remains cortant In his eLlua-tiOn E = mc2 E stands for energy; in 4rgs,generatedby any reaction; m is for "mass"in grams, lost in anY reaction; and e is thespeed of light, equivalent to 3 x 1010 cm persecond (186,000 miles per second).

NOTE

As you read through this and otherchapiefsgou may meet words and

'FISSION OF ONE

POONO OF URANIUM

terms new or unclear to you, such as"ergs". All of these words are includedin the,GLOSSARY found at the dnd ofthe text.

POWER IMPLICATIONS ,

- 2.7 Although no one has succeededthrough nuclear fission in converting toenergy more than a small fraction Of anymass, the advantages of nuclear fissionover chemical power (gucti as, comfiustion)are enormous. (See Figure 2.7 for someexamples). For instance, n the fission-ing of uranium, as in , the bomb droppedover Hiroshima, only a minute part, of thetotal mass of 'radioactive substance ischanged to energybut this release of. A-ergy is gigantic. The Hiroshima hlast wagequivalent to 20,000 tons of TNT. This wasproduced by the fission of 2.2.pounds ofuranium (since only a minute part of thetotal aetuallf underwent fission, the ura-nium contained in thebomb was consider-ably more than 2.2 pounds). Why so littlemass can pfoduce so much energy is pre-cisely .what \Vas explained in Einstein's.E =m6. formula.

NATURE OF MATTER-

2.8 About the year 1900 a chemist, Ifasked to expligth tilt. material world in

1400TONS Of COM-

A.).

PRODUCES AS

MuCH ENERGY AS

'COMBUSTION (Y.._

410,000.000CUBIC FEET Of NATURAL OAS

FIOURE 2.7.Nuelear energy aa commred with chemical energy. ft

FIGURE 2.7Nuclear energy as compared with chemical energy.

250000GALLOHSO DASCLINE

1 2.

S.

non-technical language, would have spo-ken somewhat a:. follows, stressing certainfacts that are still valid and are still fun-

* &mental' to an understanding of more re-. cent discoveries.

2.9 The chemist would speak of ELE-MENTS, of the ATOM, of MIXTURE§ andCOMPOUNDS, of ATO.MIC WEIGHT andthe PERIODIC TABLE. Let usrtake theseone at a time.

2.10 Elements.All material is made upof one or more efementi. These are, sub-

- stances that cannot be broken down intoother and simpler substances by ,anychemical means. Our 1900 vintage chemist'did not know it, but you will see later, thatit is possible to cause both decompositionand production of certait elements bymeans of nuclear reactions. There are nowover 100 known basic materials or ele-ments such as iron, mercnry, hydrogen,etc., that have been discovered and classi-fied. Some have never been found in anatural environment, but are manma§le.

2.11 Iron,: mercury, and hydrogenex-isting at noriml temPeratures as a solid, aliquid, and a gas respectivelyare typicalelements. By heating, a solid element'canbe changed,to a liquid and even to a gas.'Conversely, by cooling, a gaseous elementcan be changed to a liquid and even to a

.solid.2.12 The Atorn.The smallest portion of

any eleMent that shares the general char-acteristics of that element is called anATOM, which is a Greek word meaningINDIVISIBLE.PARTICLE.

A

2.13 , Mixtures.Elements, may bemixed without necessarily tindergoi*anychemical- change. For example,, if finelypowdered iron and sulfur are sti*ivtl andshaken together, the result is a mixture.-Even if it were possible to grind thiS ,inix-ture to atom-size particles,, the iron atOmsand the sulfur atoms wonici.,remain dis-tinct from each other.1-2.14 Compounds.=1),rder certain condi-

tions, however, two ore elements canbe brought together in such a way that\they unite chemicallytO form a compound.The resulting substatice may differ widelyfrom any of in 'component elements. For

example, drinking water is formed by thechemical union of two gases, hydrogen andoxygen; edible table salt is compoundedfrom a deadly gas, chlorine, and a poison-ous

2.15 Whenever a compound is TITO-duced, two or more atoms of the combiningelements join chemically to form the MOL-ECULE that is typical of the compound.The molecule is the smallest unit thatshares the distinguishing characteristic ofa cornpound.

2.16 Atomic Weight.Hydrogen is. thelightest element. Experiments have dem-onstrated that the oxygen atom is almostexactly 16 times as heavy as the hydrogenatom. Chemists express this truth by say-ing that oxygen has an ATOMIC WEIGHTof 16. Through many experiments, theatdmic weights of the remaining elementshave been foundr'

217 The Periodic Tdble.Figure 2.17 isa standard table of the elements. Theatomic number of each element appeassabove its chemical symbol. The verticalcoluMns represent family groups. Allmembersfrom the lightest to heaviestof a .family behave like one another informing (or refusing toPtorm) chemicalcompounds with other families., 2.18 While still essentiallp.correct, thiscirca 1900 chemiit's view orinatter needsto be supplemented (but not..entirely-re-placed) by an analysis of the atoin. In 1900,only a few advanced scientists had become .

convinced that the atom is divisible after_;:all. This was a neW idea, since the atom 'is'very small) baying an overall diametei-Ofabout 10-' centimeters.

THE ATOM AND ITS BUILDING BLOCKS

2.19 Small as it is, the atom" proyed tobe corposed of yet smaller particles. Infact, as shown in Figure-2.19a, it proved tobe mo*Stly empty space, with the actualmatter contained in a central mass. Thenew knowledge of the nature of the atomhas added many terms to those known toour 1900, vintage chemist. Let us take a-few . of these terms: and relate them tosome diagrams of Vie atom. The termsmost useful are NUCLEUS, ELEC-

. 13u 7

IA

er

.THE PERIODIC TABLE OF THE ELEMENTS

0

Period 1r

1H

e

II A '.(...

.. '

Groups

IIIA IVA VA VIA VIIA:

- .\.

VIII \,I \

.

IB

.

'Ifg

IIIB IVB VB ifr VIB VIIB

2He

Period 2I

3LI

4'Be

5 6 7N )

80

9F

10Ne

Period 3

#

11

Ma

.12Mg

13Al

14Si

ISp

16S '

17CI

18,Ar

1

Period 4 19X

20.Ge

31Sc.

22Ti

23NT

24, Cr

25Ma

26Fe

27Co

28Ni

29Cu

30zji

31Ga

22Ge

33As

34Se

35Br

36Kr

Period 54

37Rb

38sc

39I, .

48zr

41Nb

42mo

..43

(Tc)44Rs

ASRh

46Pd

47Ag

48Cd

49In

50SS

51Sb

52Te

831

54Xe

Period 6 55Cs

56 'Ba

67-71Lantha--aides

72Hf

71,Ta

74W

175Re

-76Os

78Pt

79An

80Hg

81TI

82Pb

83Bi

84Po

85At

(

86Rn

Peri°4 ;7\

87Fr

-88.

: Ra

89-10Acti-aides

rt`-'

s

. , ,..

--, .4

- .

14'

Lanthanide 57 58 59 60 .. 61 62 63 64 65 66 67 68 69 70 71Series La Ce pr Nd (Pm) Sm Eu Gd

.

4

Tb CY Ho Er Tm Yb Lu}

ActinideSeries

89AC

90Th

91Pa

92U

93(M1))

94(PO

95,(Am)

96. (Cm)

97(13k)

98(CO

98(Es)

100"(pm)

101(Md) .

102(--)

103(Lw)

Figure 2.1715

FIGURE 2.19a.If an atom were the size-of ihe Em-pire State Building, its nucleus would be as largeas a pea and the electrons would revolve aroundthe nucleus at a distance of several hundred feet.(Understanding that there is so much unoccupiedspace within the atom is important to an under-standing of the interaction of radiation with mat-ter.)

TRONS, PROTONS and NEUTRONS, thelatter three comprising the basic atomicbuilding blocks as shown in detail in Fig-ure.2.1913.

,2.20., The NUCLEUS is the heavy,denie &ire of the atom, containing practi-cally all of its weight. As we have seen,this nucleus is surrciunded- at quite some

.

. LINT SOMOLSNDSHT OR RELATIVE

MASS IN ATOMtCLIAS UNITS *

.

RELATIvEELECTRICAL:

PIANO(

Imams o OR I 007593 NIN * 4 I-

Namara R 0. el I 0011911 saw 0

ELECTRON

4 COI t CR

.113 OR0 000549 Now I

* AN ATOMIC MASS INNT (ov) IS EWA/ TO I II 10'24 CRAMS OR ONEsiLissTs Of A OILLYONTH OF A MILLIONTH Of A GRAM

FIGURE 219b.Atomic building blocks.

ELECTRON (llNN CAN&

0 PROTON Ihnithe Owns)

NEOTNON 1N Paw)

FIGURE 2.21.Elementary particles that make up anatom.

distance by ELECTRONS which whirlaround the nucleus at tremendous speeds.Electrons are very small and have practi-cally no weight.

2.21 If we examine the structure of thenucleus in greater &tail, we see that itconsists of little individual balls of matterthat are about the same size in all atoms.Some of these little balls of matter have a

,,poeitive electrical charge. These are calledPROTONS. Others,, called NEUTRONS,have no electrical charge and are said tobe electrically neutral. Both a proton anda neutron are muili larger 'and heavierthan an electron (see Figure 2.§1). -

2.22 For each posaively charged PRO-TON in the nucleus, there Is a negativelycharged electron in orbit around the nu-'cleus. The number of protons in the nu-

,

L HYDROGEN

Si

2. HELIUM

3. unwell 4. BERYLLIUM

FIGURE 2.22bomparing the atoms of the first fourelements.

_Olgus, therefore, aeterniines the humber of--electrotts which are in Orbit arOund the,nucleus. The: riu.raer of protons also deter-

.- 'mines thenature of the element. For exam--*le; the sinee -positive Charge on' the hy-drogen nucleus balances ,the negative-charge on-the electron. Thus, in its normal-or LJNEXcittpcstate, Me hydrogen atoth_ _

. as whdleitrelectiically neutral. The next,element heavier -than hydrogen:is h'elhtm,and it .has two electrons that move in; asingle orbit. Two positive charges in 'thehelium nucleus counterbalance the nega-tive effect of the two electrons. Lithium,the next heavier element, has three elec-trons. Only twq of these travel in thecomparatively small area near the nu-cletis, theIhird has a much larger orbit.The lithium nucleus, therefore, has 'threepositive charges. See Figure 2.22 for exam-

._ ples.2.23 If time and space permitted, the

atoMs of all the eIementa coUld be _exam-_ ined one by one. For present purposes,

hoviever, the oxygén atom (Figure 2.23)will be an adequate example.

2.24 The oxygen atom has eight pro-, Ions, and therefore eight positive charges

in its nucleus. To balance these eight pOsi-l'tive cg;ges, eight -electrons Are required.-The first two, electrIms are in the hiner

' Orbit, as" is normal in any atom abbvehydrogen. Three eider orbits, contain theOther three.pairs ofelec*ons, as -shown in

*AEC 0114i 0.1420 motor (Noki.; combo

faunae tft awns)

'F1duRE.2.23.The oxygen atom.

the drawing. One way to think of the sixV.,ter electrons, all revolving and spin-ning, is as if they were tracing a hollowshell like an ultra-light tennis ball. Scien-tists customarily' speak of electrons asbeing located in SHELLS, classified as K,L, M, N, 0, P, A, and sub-shells, in accord-ance with their energy level, which is Pro-portional to a distance from the nucleus.

2.26 Continuing with our detailed lookat the oxygen atom, we see that in addi-tion to the eight protons, and the twoshells with a total Of eight eleltrons, thereare also eight uncharged particles or neu-tron,.

2.26 With the single.exception of hydro-gen in its simplest form, all atomic nucleicontain neutrons as well as protons. Thelighter elements tend to have appro*

FIGURE 2.24.Another way of Viewing the apm Jiu'aminite solitl system. Instead of the sun at the center,ihere itthe nUcleuisrinstead Of the Pianets in orbit;1/4there are tht electrons.

'

mately equal quotas of neutrons and pro-tons; the heavier elements have more neu-trons than protons. This fact, to be ex-plained in greater detail later, iriiiipor-tant to tim understanding of.radiation.

ISOTOPES

2.27/The number of neutrons in. the-nucleus may range from zero to almo'st150. In certain elements it is found thatdifferent atoms of the same element havethe same number of protons but vary inthe number of neutrons. To the chemist,this is of little concern because the chem-ist works with the orbital electrons, andsince all of these atoms have the samenumberof protons,, they will have thesame number of electrons in orbit. Sincethey have a different number of neutronsin the nucleus, however, the various atomsof the same element will not all weigh thesame.

MASS.---A measure of the quantity ,ofmatter .

WEIGHT.A measure of 'the force with.er. which matter is attracted- to

the earth2.28 To. fhe nuclear physicist and physi-

cal _chemist, these are different forms ofthp same chemical element .differing onlyin the number of neutrons in the nucleus.Many of the isotopes are stable. Some ofthe isetopes are Unstable Mid thereforeradioactive:

2,29 Figuxe 2.29'shows various isotopesOf the eleMent hydrogen. Theteavier iso-topes Make up a very small fraction of oneperCent of the total amoimt Of hydrogenfound ii nature Ordinary water consistaof Molecule's each Of Which is, made up oftWo attans of hydrogen and' one atom ofoxygen. If -Water cOntaint hydrogen, Whichis-not the wrmal iSotope ofhydiOgen (oneproton) but .the deuterinm isatorie (oneProton'and brie neutron) it Will took like"regular water, taste like regular water,and, froni the: Ole-Mica point of view, itWill be `water. however, frOM a nuClear..point Of'irieur, this Is HtAVY WATtitbecause it is made With the heavier iso-.. . , ,

OthydrOgen.2:30 The third form of hydrogen.ealled

HYDROGENCOMMON '

STABLE FORM

DEUTERIUMRARE

.STAILE FORM

TRITIUMRARE

RADIOACTIVE FORM

FIGURE 2.29.Thotopes of the element hydrogen.

tritium contains one proton and tWo neu-trons in its. nucleus. The addition of thesecond neutron to the nucleus produces andnbalance in the proton to neutron ratiothereby causing an unstable or excitedcondition due to the exCess energy. Thik

, excess energy is einitted in the form ofradiation. Tritium is the. only isotope ofhydrogen that is radioactive.

2.31 Onry three isotoPekofthe elementhydrogen exist. Attempts to produce afourth igotope fail because the nucleus of atritium atoni will 'not capture an add-tiOnal neutron.

2.32 Figure 2.32 shows- two different ,

isotopesof uranium. Oneis called uranium288. Its nucleus contains 92 protons and146 neutrons which cernbined total 238.Particles. The other, uranium 235, con-tains 92 protons and 143 neutrona whichtotal 235 particles-Both of these will reactchemieall.y in exactly the same way,Therefore, te the chemist they are the,same. the important difference to the nu-.).Flear Physicist is the fact that, althoughboth are xadioactive, the_ 1i235 will sustaina chain reaction whereas the V" will not,.,

2,38 As. previously stated, the first ele-ment, hydrogen, has:only threeisotopes inits ftaMily. The number of isotoPes for. eachof the other elements varies ,considerably

.11

with, foreXample, as mink as 25 istotopes-=' for-the- fiftieth.element, tin.

2.34 Altogether there are over 1,200ilsotopes,,the majority of which are radio-active. Most elements have two or moreisatOpes.:While the number of neutrons inthe nUcleus does. not _materially 'affectchemical:behavior, the neutron- to proton(n:p) ratio-Of the nucleus does affect Theatom in other ways.

URANIUM23,5`-RADIOACTNE

URANIUMPO4. RADIOACTIVE - ,. , . .

i?1,OURp2.3.2.=-: LiOtoki-of #e elementuraniuni.

FIGURE 2.39a.Atoms of the element hydrogen andthe element helium.

We are close-to our main objective--understanding nuclear radiation!!!

2.35 Before the. diicovery of the'neu-tron, scientists identified any element by aone-letter or two-letter .symbol represent-ing its chemical nameH for hydrogen,' Clfor chlorine, Na for sodium (whose latin-ized technical name is natrium, hence theNa), and so on. The nuclear physicist ac-cepts these time-honored letter symbols;but when speaking in general terms, herefers to any of them as SYMBOL X.

2.36 To make precise reference to a-given atom, the nuclear physicist (1) pie-cedes symbol X with a numerical subscriptcalk" SYMBOL Z and (2) follows symbol Xwith a number (often, but not always,written-ad a sziperscript) called SYMBOLA. His identification of an atom, then,takes the form z)E., or sometimes when Z isclearly understood, simply 'XA or A. Forexample, 17235 and tU238.

2.37 SYMBOL Z.-,-The subscript Z iscalled the ATOMIC NUMBER; it tells howmany prOtons 'Pie nucleus contains (ahdsimultaneonsly, of course how many pla-netarY electrons the atom has in it's nor-mal state). For hydrogen Zis 1; for oxygenit'is 8; for uranium itis 92.

.

2.38 SYMBOL A.The final identifyingsymbol is an ATOMIC MASS NUMBER-representing the sum of the protons, andthe neutrons. :1.9.

<

SUBSTANCE SYMBOL

)

PRO-TONS(Z)

ATOMICMASS

M.IMBER(A)

NEU-TRONS

' (A-Z)

ELEC-TRONS(Z)

HYDROGEN _MI\ .I. I 0 i 1

DEUTERIUM'

1112 OR 102 ' I2 1 1

TRITIUM

, 043 OR ITS 1 3 2

OXYGEN

.906 16,

8 8

URANIUM92u238 92 231 146 92

FIGURE 2439b.Symbol meanings.

IMPoRTANT

To find the number of neutrons in anyfully identified atom, subtract Z fromA.

2.39 Let us see a few examples of theuses of these symbols. In Figure 2.39a, wesee an atom of hydrogen with the sub-script 1 as its atomic number (Z), sincehydrogen has only ,one proton, and super-script 1 as its atomic mass number (A),since the atom contains only the one pra-ton and no neUtrons. The Z number forhelium is two, since it has two protons inthe nucleus. As we have seen, each ele-ment has a distinctive atomic number rep-resenting the number of protons' in thenucleus, and we can determine the num:.

`ber of neutronain the nucleus by subtract-ing the atomic number Z from the atomicmass number A. As examples, the nucleusof 92U23s contains 146 neutrons arid thenucleus of2;C" contains 32 neutrons. Sincenovinal atoms are electrically neutral, eachatdm will have tlie same number of elec-trons as there are protons in theenucleus,i.e.,the Z numherMll equal the number ofprotons in the nucleus or the number ofelectrons in orbit abourthe nucleus. The

'subscript Z number is sometime* disre-garded because the atoni is identified 1337

Chemical symhol. Thus Hes, or 2Het bothhave the same meaning. Figure 2.39bshOWshow symbols are interpreted.

40/

2.40- The ratio of neutrons to protons'within the nucleus of the atom largelydetermines the stabilitY of the atom. The

protons being positively charged tend torepel each other. The repulsive force iscounteracted, however, by a nuclear at-tractive force called Binding Energy. Verylittle is known of this energy. However, itis known that for elements which haverelatively low atomic weights, nuclear sta-bility occurs when the number of protonsand neutrons are nearly equal. Heavierelements, those with higher Z numbers,require a higher neutron to Proton (n:p)ratio for stability. Whereas those elementsin the lower part of the periodie table(Figure 2.17). are stable when the isotoPehas an n:p ratio of,approximately one (ap-proximately the same number of neutronsas protons). The n:p ratio must increase asthe Z number increases if the stability ofthe atom is to be maintained. Beginning

vrith the element bismuth, atomic number83, when the n:p ratio increases above1.5:1 there aie to stable isotopes. The sta-ble range of n:p ratios for many elementsis not critical, i.e., there are several ele-ments with many stable isotopes.

2.41 lin unstable atom, one with a n:pratio 'either too high or too low, will even-tually achieve stability by spontaneousemission of energy and/or particles fromits nucleus. This process is known as RA-DIOACTIVITY. It may be the natural de-:cay of unstable isotopes Which occur innature or it may be das the result of artifi-cial radioactivity which has been causedby man. In,each case the nticleus is in anunstable or excited state, having an excessof energy which will 6elradiated allowingthe nucleus to achieve a stable or groundstate.

RADIOACTIVITY is the spontaneous disinte-gration of unstable nuclei with theyesult-ing emission of nuclear radiation.

2.42 Radiation is the conveyance.of 'en:ergy through space. Everyone is familiar'with the radiatio o heat from stoves,

' light from plettric lingits and the sun, andthe fact *that some kind of energy is' re-Ceived by our radio and television sets tomake them 'Otierate. The radiation of en-orgy from radioactive materials is Compa-

ANGSTROM UNIT - A PHYSICAL UNIT OF

LENGTH, EQUAL TO t/210P CENTIMETERS;

ELECTRON VOLT - THE' AMOUNT Of ENERGY

ACQUIRED _BY-ANELECTRON FALLING THROUGH

A POTENTIAL.OIFFERENCE OF ONE Imo%

ELECTRON VOLTAGE (V) IS RELATED. TO THE'

WAVELENGTH OFRADIATION (X), IN , -

ANGSTROM UNITS, APPROXIMATE,LYTHUS

V = 12420/X ,

i(VAVELENGTH XANGSTROM UNLTS

lot? wit ,4)15

c'tcLgs/sre-,

ELECTRIC

POWER;

1014 ipa 5012 1011

106CYCLES/SEC

A

41,

WAVELENGTH ANDFREQUENCY ARE RELATED BYlc X

c = VELOCITY OF ELECTROMAGNETICWAVES

=3 x.ION CENTIMETERS PER SECOND

1.? - FREQUENCY = CYCLES/SEC. = VIBRATIONS PER SECOND,

i010-10 100I

HERTZIAN

(ODIC,/ TELEVISION, RADAR)

INDUCTION.'HEATING

IENERGY

I

ELECTRON vou-swiz ics" 10 IY10 7 10

IC

X = WAVELENGTH IN CENTIMETERS

VISIBLE SPECTRUM LIMITS

4,000 ANGSTROMS- .87000 ANGSTROMS

17.5

14x 10 CYuLES/SEC.

3.7. x 10 14 CYCLES/SEC.

r

iO 104 I0 51 I .1

ohs.

CYCLES/SEC.

INFRA 1

RED

,102 10 1 10-1

e1

I lite1()

CYCLES/SEC.

ULTRA

,V CILET

VISIBLE

I r10j2 10 102

FIGURE2.42,Ele4trornagnetic sprIctrum.,

e 10-6 10 16-4 10-3

10-2 10-3 10-4 le leit

I1023

CYCLES/SEC.

GAMMACOSMIC

X RAYS

105 106 107 10

21

or'

ik

rable.to theie familiar forms of radiation'but, as indicated by Figure 2.42, ere gener-ally higher in frequency and, therefore,represent greater energies.

NOTE

Remerabedioactivity is a PROC-ESS/N-uclear radiation is the PROD-UCT of this process.

2.43 Moms in the unbalanced state de-scribed in paragraph 2.41 are said ,to beRADIOACTIVE. They are spontanemislyemitting some type of IONIZING radia-tion energy. IONIZATION is 11 processwhich results in the formation of electri-cally charged particles (IONS) from neu-tral atoms or ,molecules.

. 2.44 For a closer look at ionization:cOn-sider Figure 2.44 in which _a normal atom

bjected to a bombardment of-energy.The energy of this bombardment may1 knock an electron from its orbit into freespace, i.e., it will not be associated witha-hi-atom. It is a negatively charged parti-cle in spade and is referred to as a NEGA-TIVE ION. The remainder Of the atomfrom which the electron was dislodged isalso electricall3i unbalanced by this event.Hiving lost one electron with its negativecharge, it now has an effective net positivecharge df one since it now contains oneproton for Which there is no. counterbal-ancing 4dectron. The positively chargedatom (or atoms) is known as a POSITIVE

ION. The two, particles, the- positive ion(atOrn 6- atoms) and the negative ion (dis-Lodged electron). are known as an ION

.PAIR. The prikess which caused this sepa-ratia of particlesmaking up the atom andthe attendant electrical Unbalance isknown as IONIZATION.

NEUT/tai. UPI

FiGu4 444 oni z ati on.

2.45 Nuclear radiations are given off byatomsorhich have more than the normalcomplement of energY. The physicist saystheyare 'UNSTABLE. This unstable con-dition is often caused by too low or toohigh an n:p ratio at explained earlier.Radioactive 'atoms literally erupt fromtime to time emitting energy from thenueleus. Thele nuclear radiation emis-sions are classified as ALPHA PARTI-CLES, BETA LIARTICLEA and GAMMA *

RAYS.'Each tyfrg of radiation will be dis-cussed in ,more detail in later paragraphs;

(ZI C 5.2 + 01 ,---- 27 CO° + loons#3 RAMATIC*1)

I"- # ' -. '''

, .

FIGURi 2.47.the normil atom of Co" bombarded by a'neutron. In this case, the atom accepts this neutron inits nucleUs, the A numbeivincreases by one to Co" and the,atom M radioactive.

,

2,46 Nuclear radiation differs fromother forms of radiation in the sense thatthi nucleua of ari unstable atom contains

- an, excess of energy which will be eniittearregardless of 'man's efforts. Use of heat,chemicala or Kessure will not stop or alterthe rate of nuclear radiation emissionsfrom a radioactive atom. Man can cause orstop other:types-of radiation such as heat,light, or even other atomic -radiationswhich in .many ways Compare to nuclear'radiation. ,In the case of heat and lightradiations caused by electricity, merelyflipping a switch can start or stop theseradiations.

2.47 Many nuclear radiations arecaused by bombarding atoms with energy,causing them to radiate energy whichceases Nyhenever the bombardment stops.However, if the atoms_in the Material be-come radioactive as a result of the bom-bardment; they will then spontaneouslyeinit ionizing radiation of one or moretypes until they reach a stable condition.One of the sources of nuclear radiationcommonly encountered in radiological de-fense training is 27Co6° (Cobalt 60). Figure2.47 shows how this isotope_ of Cobalt isdeveloped from 27Co59.

2.48, Different radioactive elementsvary greatly in the frequency with, whichtheir:atoms erupt. Some radioactive mate-.'Hale in ,which 'there are only' infreqpent,einisSions :Or radiations tend to have ayery long life 'white thosewhich are veryactive, radiating' frequently, may have acomparatively sholk life. The time differ-ehee is Very great between, short and long

radioactive materials.. Some sub%starices. may stabilize themselves in asmalr part of a 4econd, while a radioactiveisotope With 'a long life may chanke ordecaY only, slightly in tbouSands 6r inir-rioif Years, Th'e rate of radioactive de- I

cay- Measured in HALP,LIFE,ttl'e tiniarequired for the radioactivity of agiven athount of a particu1ar-rnater4 todecreasa,to half its.original value:

100 '1200 mc

.

NO0 MC

\I \4 \

1.5°ss

'1;2512.5

50

uw 25

o.

12.5

6.25

IN 7 NALF`LWE PERIOOSTHE RADIATION LEVEL LILESS THAN I%0F ITSORIGINAL INTENSITY

156

HOURS. 24 48 72 90 120 144 168DAYS I 2 3 4 5 6 7

FIGURE 2.49.--Decay curve.

up to millions of years. The following ra-dioactive eIenients demonstrate this widerange of half-lives;-argon 41,109 minutes;iodine 131, 8 days; radium 226, 1,620 years;plutonium 239, 24,000 'years. Figure '2.49depicts a gamma emitting material with a24-hour half-life. This material when firstmade,radioactive has a quantity of radio-activity of,200 Millicuries. In 24 hours the'radioactivity would be down to 100 millicu-ries; in another 24 houa it would be downto 50; in another 24 }tours it would bse downto 25, etc.

,.P,

, 249. ,Thkhalf-life of a, radioactive-mate-.ria may range rom fractions ota second

_ ,

PROTACTINIUM

<- ;

AFTER34,000MORE YEARS-

C".

, AhER34,000YEARS,1

, AFTER

34,000MORE YEARS

FIGURE-2.50.Another view of half-life.

23

I.

2.50 Let us look at another exaMple.-Assume that the block shown at the upperleft in Figure 2.50 is composed entirely ofthe radioactive protactinium isotoPeknown as Pa231. The half-lif,e of this partic-ular isotope is 34,000 years. At the end of34,000 years, therefore, half of the originalprotactinium atoms will have undergonetransmutation to other elements. The restwill still be protactinium. If they wereseparated from the transmuted atoms, theprotactinium atoms would now constitutethe secorld block in Figure 2.50.

2.51 The second block will not decaycompletely in the second .34,000 year pe-riod. Unquestionably, it has only half asmany atoms as the original block; but bythat very fact it offers only half the origi-nal opportunity for atoMic reactions totake place. As before, half.of the atoms (aquarter of the original protactinium at-oms) will remain unchanged at the end ofthe second half-life.

2.52 During the third half-life, thenumber of protactinium atOms will againbe cut in halfand so on. In general'terms, then "x" grams of any radioactiveisotope will decay in accordance with the

'following series:

2124+;+;c6-1-L-F6x4+1;c84-21

x56

2.53 No matter how far this series isextended, its final term, x/n will represent.only half of the protactinium atoms thatwere intact at the beginning of the givenhalf-life. If x/n atoms have been lost dur-ing the preceding half-life through decay,an equal number still remain to start thenext half-life.

2.54 In other words, the sum of thisseries approaches x, the original numberof atoms, but (in theory at least) neverquite reaches it. There is alnays a frac-tion, equal to x/n, representing the atomsthat are still intact.

4.C

2.55 A useful rule of thumb is that thepassage of 7 half-lives will reduce the ra-dioactivity to,a little less than 1 percent of

its original activity, and in 10 half-livesthe activity will be down to less than 0.1percent. The shorter the half-life, the morehighLy radioactive the material will be.

2.56 As we will see in more detail .insuhnquent chapters, half-life has impor-tant bearings on safety. It is obvious, firstof all, that any isotope with a long half-lifeis potentially dangerous if it is produced inlarge amounts. When, such an isotope isonce formedwhether by nature or in anatomic power plant or (Juring a nuclearexplosionit will contaminate its sur-roundings for a long time to come.

-2.57 For some of the artificially pro-duced radioactive isotopes, the half-life ismeasured in hours, minutes, or even sr-onds. These isotopes are extremely active;

, that is why they decay so fast.

COMMON TYPES OF NUCLgARRADIATION

2.58 There are three common types ofnuclear radiation *with which you mustbecome familiar: ALPHA and EETA PAR-TICLES, and GAMMA RAYS.

1

2.59 Alpha Radiations emitted by ra-dioactive materials are often called alpharadiation or simply alpha. Alpha particlesare comparatiyely large, heavy particles ofmatter which have been ejected from thenucleus of a radioactiNte material withvery high velocity. The velocity withwhich these particles leave the nucletisdetermines the distance (range) that theyowill travel in any substance. As indicatedin Figure 2.59, an alpha particle carries anet positive electrical charge of two andan atomic mass of 4.00277. Thus the alphaparticle is equal to the nucleus of a heliumatom which contains two protons (with one ,

^ positive 'charge each) and two neutrons.. However, when we compare the speed of

alpha to that of beta and gamma, we findthis to be a relatively slow rate as- mightbe expected due to:alpha's she and weight,Alpha rays are literally small pieces ofmatter traveling through space at speeds

24 17

j.

. .

of 2,000 to 20,000 miles per second. When aradioactive atom decays byemitting analpha particle, transmutation of.this atomto an atom of lower atomic number (Z) andlower atomic mass number (A) occurs.

.441.0*. Si.f0C..1 ....f "O"C0411 ILICTIIK LCi./4,2 RIU41.1

A

4.14. SC P411741.1 00121 +2DCW.C.I. 10 KM...0. 11.00110 C0' MICLIC1C41

KU A 01.4.01.2 0000141 .C141. 10 ...1...OsVICO CLIC1.10M

mu u.11411 00111 MY( 11.1004104..2 vv."01 (MOO

FIGURE 2.59,--Characteristics of nuclear radiation.,

2.60 Bela Particles are :identical tohighspeed electrons. They carry a nega-tive electrical charge of one and are ex-tremely light, traveling at .speeds nearlyequal to the sp'eed of light, 18000 milesper second. Although the atomiC nucleusdoes not contain free electrons, only pro-tons and neutrons, the electrons which are,emitted as beta particles result from thespontaneous conversion of a neutron intoa proton and an electron. The neutronwhich lost or emitted-the beta particle hasbecome a 'proton with a positive chargeand thus-the atom has been ch nged.Transmutation has produced an atorn witha_higher Z number. \ .

2.61 Gamma Rays are a type of elec-trornagnetic radiation- which travel \withthe speed of light. As indicated in Figure2.59,, they have no measurable masS orelectrical charge. We have be-come ac us-tomed to.the use of X-rays in the med calfield. X-rays and gamma rays are simi ,ar,

, but there are two important differeneesbetWeeh them. First, as indicated in.Fw-ure 2.42, while there iS some overlapping,gamma rays are generally of a high rfreiluency. The basic difference, howeveis theft. source. "GaMma rays originate ithe nucleua while 2C2rctys originate in otclpud of electrons about the nucleui. Theemission of an alpha or beta particle fromthinucleus of an atom.as shown in Figure2.61, almoSt invariably leaves the nucleuswith an excess 'Of -energy (excited stath)and Will be 'accompanied by the emission of

-, g9nima rays to reach ground or stablecondition.

2.62 The, neutron is another type of ra-diation which 'accompanies certain typesOf nuclear reactions but is not 'encoun-tered in natural radioactive decay. As wasdiscussed preyiously, this type radiation is

V.6-- 0

76;v1-4

FIGURE 2.61,Excited to stable nucleus.

25

A

able to iiiduce radioactivity in stable iso-topesk

RADIOACTIVE DECAY AH'D DAUGHTERPRODUCTS-000"r

,2.63 Radioactive detay, oiten results in

"transmutations", i.e., the Change of oneelement into anOtherand the dream of theinedieval alchemists. Some radioisotopesdecaylthrectly to a stable state in onetransmutation. Others decay through aseries of transmutations or steps formingdifferent radioactive elements calledDAUGHTER PRODUCTS before finallyreaching a stable state.

2.64 Consider now What happens whena radioactive isotope emits radiation, andfollow one atom of uranium through itssuccessive transmutations: Starting withan .atom of uranium 238r-w,rtich. has 92protons and 146 neutrons, follow the .transmuttttions in Figuie 2.64.

2.65a Uraniumt2g8-emits an alpha par-ticle. An afpha particle consistpf twpprotiins and two neutrons, and therefore isan iitgynic' nucjeus in its own right. It isthe ntcleus of the helium atom. (Helium

-has a nucleus composed of two protons andtwO neutrons; With the alpha 'particle

emitted, there are now 90 protons tnd 144,ineutrons. The nucleus now weighs 234

4.

ELEMENT ANOATOMIC WEIGHT

TYPE OFRADIATION VATTED

NUMBER OF

PROTONS NEUTRONSURAMUM- 231 92' I46

ALPHA PARTICLE -2 -2THORIUM-234

DO 144SETA PARTICLE +I

PROTAC1'INIUM-234 91 143ETA PARTICLE +I .1

IMMS/16234 92 142, ALPHA PARTICLETHORIUM-230 30 140

ALPHA PARTICLE -2 -2RADIUM-2 26 ' ,', os 136

ALPHA PARTICLE -2 -2RADON-222 SW 136

ALPHA PART -2POLOMLMI2111 64 134

.ALPFIA PARMA -2 -2LEAD.414 : 112 in 132

SETA .PARTICLE +1 -11111106./711-214 63 IM

. BETA PARTICLE +I -1476411UM-214 114 130-

ALPHA PARTICLE 42 -2LEAD-210 112 126

SETA PARTICL +I -IINSMUTH-210 113 127

'SETA PARTIC E +I 7,

^.1

POLOMVOA210- ' ' 114 126, C ALPHA PAR E

LEAD-206 STABLE 016 92 124

FIGURE 2.64,The decay chain ilftwuranium atom.

units; and since the number.of protons hasbeen-changed, it is no longer uranium butis, in fact, thorium 234.

2.65b Thorium 234 emits not an alphaparticle brit a beta particle. Where doesthe beta particle come from? Rememberthat a neutrOrl is electrically ,neutral. Wehave seen that an electrically neutralstate can be reached when positive andnegative charges balance one another andthat a neutron can act like a.proton withan electrpn tightly tied onto it as shown inFigure 2.85b.

. ,

2.65c The n'egative charge of the elec-tron balances the posItive charge of theproton resulting in a neutron. When. thisnegatively charge eleGtron is\ ejected as abeta particle titie remainder 'is no longerelectrically neutral, but.now has a.positivi.charge, thus changing a neutron gt,a pro-ton.. In effect, one proton has been gainedand one ne tron has been lost, Now thereare 91 p tons and 143 -ne,utrons, Theweight is till 234, but since the number ofprOtons h a been 'changed, the nature of

'the e nt has been changed and. is nowan atom of prOtactinium 234.

2.65d Protactinium 234 also emits abeta particle so 1 proton is added, and 1neutron is subtracted;leaving 92 Proton#and 142 neutrons. Its weight is 234, butthe element is, of course, again uraniumbecause it now has 92 protons.

2.65e Uranium 2344em1ts an alpha par-tide, 2 neutrons and 2 protons are sub--tracted, leaving 230 particles in the nu-

'cleus. Since the number of protonsis. back'to 90, the element is now thorium 2-8-0.

2.65f Thorium 230 emit,s an alpha Parti-pnle. Subtract 2 protons and 2 neutrons. Itow haa,a....weight of 226, and since it has

-

sir

110-1111

FIGUREU5b,--Concept of a neutron changing into aproton by a beta particle.

r) fts)

.19

only 88 protons in the .nucleus, it is theelementradium.

2.65g Radium emits an alpha particle,802 neutrons and 2 protpritare lost leav-ing 86 protons and 136 neutrons. Our ele-ment is now radon 222 which is a gas.

2.6511 Radon 222 emits .an alpha parti-cle, leaving 84 protons altd 134 neutrons.4gain a different element is formedpo-ronium 218.

2:65i Polonium emits an alpha particle,'which leaves 82 protons and 132 neutrons,and is lead 214.

2.65j Lead 214 emits-a betwi.particlewhich increases the numbeatikotOns- by1 and decreases the_ number 'otrieutrons,by 1, leaving 83 protons arid 131neutrons.This forms bismuth 214.

2.65k Bismuth 214 emits a beta particlewhich adds 1 proton and subtracts 1 neu-,tron, leaving 84 protons and 130 neutrons.'this is polonium, 214.

2.651 Polonium 214 emits an alpha par-ticle which takes away 2 neutrons and 2protons, leaving 82 protons and 128 neu-

, trons for a mass of 210, and the element is'lead 210.1 -2.65th Lead 210 emits a bet article,

leaving 83 protons and , neutrons,which now becomes bismuth 210.

2.65n Bismuth 210 emits a beta particlewhich adds a proton and subtracts a neu-tron, leaving 84 protons and 126. neutrons.This is polonium 210.

2.65o Polonium 210 emits an alpha,which leaves 82 protons arid 124 neutrons.The total weight is 2,06; the element is lead206.

2.65p Lead 206 is stable and not radio-actiye, therefore; this is "the end of theline".

2.66 Well, that's fine, and all very inter-esting, and accounts for beta and alpharadiation, but what about gamma radia-tion? Where does that come fromZ As wesaw. in paragraph 2.61, gamma 'radiationoriginates when, the discharge of qne of

'Mega particles frOM-a-nucleuirdoes-nottake 'sufficient energy along with it toleave the nucleus: in quite a contented-state. If the particle leaving the nuéleus

does not take with it all of the energy thatthe, atom would like to get rid of in thisparticular disintegration, it throws offsome of the energy in the form of gammaradiation. Therefore gamma radiation canbe given off by many radioactive materialsin addition to.the beta or alpha radiation.

2.67 The foregoing makes it clear whygamma radiation occurs and can thereforebe detected from a radium dial wristwatch'or from uranium. ore by g prospec-tdr. Both radium and uranium are purealpha emitters, but as time passes thedecay process goes on andlorms daughterproducts in the radium and uranium. It isfrom the decay of these various radioac-tive "daughter products".that the gammaradiation is given off. Pure radium or ura-nium, freshly prepared, represents only analpha hazard and could safely be handledwith the bare hands as far as externalhazard is concerned. (Handling it with thebare hands is, not a good-idea because ofthe possibility of introducing some radiuminto the body by thirineans and, besides,heavy metals are toxic.) After the passageof time, however, the daughter productsstart to build up and alpha, beta,' andgamma radiation are. all being given offfrOm the sadiuni and its associated daugh-ters.

INTERACTION OP RADIATION WITH

MATTER

NOTE

The important thing to rememberabout nuclear radiation is that it is a"shooting out" of particles or 6its-ofenergy, some large, some smail; somefast, some slow; some weak, vd-me pow-erful. Since everything contains at-omsincluding our bones, skin, andorgans, of coursethese particlesstrike the atom's with force, the amountdepending on the kind ofparticle, andgther factors. Actually, since the atomis, as, wehave seen, made up of anextremely compact core and shells ofelectron( 8), these electrons, bear' thebiunt of the hammering given outwhen the atom is struck .by particles.As will be seen, the elect/iv= feact-to--this hammering in various ways. Thishas great significance to the study of

27,

radi4tion safety and the effects of ra-diation -On the- boay, as you will. dis-coter-later.

2.68 Alitha particles lose. their energy*rapidly- and hende have a limited renge,onliabout 6 or 7 centiMeters in air, and'are tompletely stopped by a sheet of pa-per.-Vien the alpha particle is storiped,-stabiliied, or reaches ground State, it has4iicketup tWe electrons which are- availa-.1le in, spaCe thua making it:a neutral he-

Thetas-of energy by the alpha-paricli as it. traverses space is due, to itshigh diecific ionitation, i,e., the number ofion pairs produced per tentimeter of path.Each ionization -event in air requiresabout 32-36 ELECTRON VOLTS, per ionpairproduced. The unit electron volt is theamonnt of energy acquired by a unitcharge 'of electricity when the chargemoves throiigh _a potential difference of'one volt. For Otample, if an electrOnShould start at a iiotential of zero; Voltsand be aCcelerated to a point baying aStet-Alai uf 32 vOlts; it wonld adoire anenergy egiziyalentto 32 elect*. volts. Anelettron volt ia a very sinall amount ofenergy'. gore cominkternisare thousandelectrini. Volta (ket,. arid million' electron

=-,

2.60 'The high specific ioniiation -of (al-pha pailicles; 'go;00040,000-loir-pairs per, , .

ntiMeter of air traversed, is. due to.sv-er,l. fROOTRI, .tirst, alpha iSs-a relatiVelyJirge liarticle and has a high- 1;,ositivechariot tience ft Will not onlytollide4th

h*tqr, but there will talitcjnent"(qtrQ4atio,.intata4finrii*itb,ijie-;elee-

which 0i0-4-pasOng.'1:4ese..inter-4ietiOna.4einit.*:**:10g,z0;enetgY

,electron- frOin jts urbit(ioniOition); or it may lose Unerig to' theatothliy:Merely,displaeing _electrons Irpm-their tiOrinat!:Orbiia ejecting Wei&:tr.* 1116,-aioni-,(eXeitatipn), figAre_ 4:09'isboWa;'tba:4fiteten00"-lietWeezi:' an,lexcited-E,t0*akitia,4YOsitive!ieh..'"

Or' Tit,additiOnt4being large2aruiposi-tively -charyeit; -Okq, :aipna ,partiCle 4 ititooeoinParstiVel$c:slolc,,,,ifict-by-*egkaining -in-0**idnitY;;Citthe atoins, in its Pith, tbere

nary& ION

FIGURE 2.69.--Excitation and ionization by an alphaparticle.

is a greater probability of ionizing -them.With this loss of energy there is a reduc-tion in speed and hence a steadily increas-ing amount of ionization, at first slowlyi.and, then more rapidly, reaching. a maxi?mum and then dropping sharply almost tozero. Figure 2.70: is a representative curvefor the. specific_ionization of alpha parti-cles. The range andspecific ionization var....,ies.somewhat for different radioactive iso-topes due to Variation in the energy mithwhich the alafit .particle is .ejected, 4.0.MeV'tolOOtteV. however, all alphaparti-clei:ethitteit** siiieCific nuclear reactienhave esaefitially-the same energy, arid sothe:saMerange, __

2.71 !The beta pattiele iioea tot loge -itsenergy _as rapidly as tile alpha partic*This is due te the, laCtthat it is a, verysmall parade fiasjesf Charge tlian the

4000

V 3

a2000

1000

3

orirAnctbwitomictiAs1

111:61.1itE 2.70.tpeclfie ionization of alph&particlea,

28 '2 1,

:alpha , and.lS inoVing at a -higherofsp ed: An-alpha:particle, because of

ts relatiVelY 'heavY weight,- is not easilyefletted:and tendatotravel in a Straight'tireittiSing:iyhigh degree of ionitation. A

bierticle.,, being light-Weight is easilybititiked -around in anY material'. There--fox*, #11 range in terins Of diStance fromthe =point -of origin ,te the point where it

aisociatealfself With an atom may.,vary-considerabiy., The actual distance

_ . _

-trave1ed_by the beta particle also varies toa,censiderible extent-but notas- much asthe Measurement from the pOint of origin

:to-thepoint where Complete-49n of, excessenergy occurs. Unlike alpha, the beta par-ticlesemitted-by any given nucleus.have a

_range-of velocities and ,only mean,or maxi-mum energies:can be assigned, to primarybeta.particles. Tables almost invariably

..ShOw Maximum energies. :The range- of velocities for beta

partteles-rangeS.from, about _25 to .99 per-.ientOf _thespeed of light, with-correspond--. , , _ing .energy variations from 0.626 keV to- . . ,

*y,' with a majority of them being inthe Vfeinity 'of 1 MeV. The range of the_ , ,

beta partieleis proportional to its energy.Therefor:0,, -a 3 MeV beta particle willtraVeLfUrther than- a 1 MeV.beta particle.

_

24 Range is only approximately in,.Versely.proportional to ,the dmisity of the

,

-absorbing .inaterial-4hrough which itthemoredense, the higher the

-number, the -More effective that mate-l,will-beinstopping beta particles. How-,

beCaufie:,etthe emission- of X4ayswhen beta:partiCleS react -With, high Zntirnber tilitotials, =to* Z,-riurnber "Itatis=

aluMinum, glass-04--plastics-4reqlOrMallyiuised=asbeta'shields;,

^2 7'4 ,-.14.-sii'e ON; iceilizatiski:0,140tw par-iielea4S:apProxiMately10400iowpairs-pereentiineter VarYing,aacording tOrthe., . ,

.energy-Ofithebeta44i,tijcle:and -the densityahiorbine;Material. the range of

.beta. particles IP air would b e -several ,me-,ThuS,, compared,to .the few-centime-,

-tCr'-rarige of alpha ,i111,144., bete hitiia. long

*IA -/4amina.tays do.,*(-consitt of par-&E.:* no Mais, Oat* a( the speed of

ghnce'dlosee(refièrgy as'

MOM** *TS MOS "vane1014a1011

ALM1

,

5-70. 2X0-20.03iftrAX

20.1:00-90.0O3le Im*Uto

ICU

1

ZCO- 6:0 m25-21%.

YIP 0 r 1.04T .

..-

30-5Come oositm

atat,4 IJSCOr WO-MOMS

vuocema104.000 kV=

-

5-I/

,

FIGURE 2.74.Characteristics of nuclear radiation.

rapidly as either alpha or beta particles.Gamma rays or photoni produce no directionization by collision as alpha and betabecause gamma rays have no mass. Theyare absorbed or lose their energy by threeprocesses known as the PHOTOELEC-TRIC EFFECT, the COMPTON Etl*or,and PATit PAODUCTIOg.

2.76 gamma .rays are higtfly penetrat-ing, their effective range depending on.their energy. The effect of aii on a gammaray is so small that it is. not practical tomeasure the range of garnma radiation intermls, of inches, feet, or ineters,,-but itspenetrating power is Measured in terms ofthe amount Of material .that Will be re-quired to reduce the gam* ray to somefraction of its original value.

2.77 As ,a gamma ray or photon passesthroUgh an atom it may transfer all of itsenergy tO an, orbital electron ejecting, it

.!.4 v fY .,

FIGURE 2.76,Pertetration4bisorption of nuclearradiation..

ID

frorwthe-atom. Tithe photon carries moreenerty than necessry to remove the elec-tron.frem ita orbit, this-excess energy canbetransferredto the electron in the form

Ithietic' energy. Figure 2.77 shows elec--refit- ejeCted jn this mariner. These arer;eferred jo as PifoToELECTRONS, and-the process by whieh this tranifer of en-.eigy was actoniplished is known as the.-PHOTOZILECTRIC-- EFFECT. Since theorbital electron In this case has completelyabsorbed the .energy of the gamma ray,the Photon diSappears. The photoelectronwill-ultimately lose its energy through theformation of ion pair's. The, photoelectriceffect generally occurs with' low energygamma photons of approximately one-tenth MeV or less.

PNOTON ENERGY

ELECTRON

.FiGint!-2.77;=Absorption of gamma kadiation by the1,4*(Mec3.*:01qct.

Zia'cOMPTON'OFFF_CT.:does net..'cohiP.10.05",.-40:sOkb, VS an 0.1tSt of thegamMa ray.. A gatMha Tay iosoa, a part Of

Ita-eriergY- to a free or,:4lOoseiy. hound or-: -bitafeleetron hnt will Ootithi.1.16 aa .a scat-,teret ganitinyOlietori jaflavi_er energi.:theeneryY ilf:-1.his-pitotiMICillf,e0al:,.the differ-ence in. onginaL energy 1e88 .theianionnt .ofineryi-,tiranSferia't it the -electron. the.40,iriunk ptp:ttb4 -reaCting--With--an- orbiteelectiOn;itat#44:itheu'gh it-had maSs sindeit dig/sea-the erketiOn to:be ejected- Withhigh enere and- a lqWer 'energy photonrebefriidaat:sortle angle. Both 'the'electionWhich iSejeetedat ail angle-to the path Of'the origrnal gamma Photon and the loVer'One* gamma photbri Whickit-arso at-

an angle May tanse Vrther loni-*ion. Pignii 018 , "sho-W's the, dompton-affect. -,Thlt eftect occurs with intermedil

-,`

ate gamma photons of approximately one-tenth to one MeV.

PHOTON ENERGY

03kPTONELECTRON

LOWERENERGY PROTON.

FIGURE 2.78.Absorption of gamma radiation by theConipton effect.

2.79 PAIR PROEFOCTION occurs onlywith high-energy gamma rays. In thisprocess, as the photon approaches the .nu-_cleus of-the absorbing atom, it completelyconverts itself ineo a pair of electrons. Oneof these is called a NEGATRON :but ad.- .

tuallyis an ordinary electron with a nega-tive. charge. the other particle which hasexactlyjthe seine mass as the negatron(electroa 'but carries. a .positive chargerather than anegatiVe-tharge is known-asa -POSITIWN arid. la deSignatpti by-the.syMbol e4-.. This proce'ss reqUires gamine,

*rays with aininfinurn energy of 1.02-XeV,anthat-energy levels-above this the. ôSibility-Ofthisinteraction increases. FigUre2.'79 -iaa. &Wain of thjs. reaction. .

t. .

INCIDENT PROTON.

=

FIduga 2.79-AbsorPtion of gammkradiation by pair

2.80 E,nergy in 7e3idet4 of 1.0z 14.17 isshare4 by the, negatron=positron pair in-the form of kinetic energy., The positronuSuallY,acquireS somewhat more energythan the' riegatron. Thist-process Js. OftenImert At* .an'ez«mpte. of Einstein's *ass-ertergy7theor1 {-E ne2, see;paragniph-2.5);since it is an exa ple rot*: the:Creation ofmatter .(t2lle pair o elecfrons),out of pureenergy (the gamma ray)4thas been found

-

e

,account the ,number cif -atoms per -grainand-the:Value .of the half4ife -in seconds,scientists ,have determined that the activ-

, ity of-radium-is:equal to37 x nuclear,clid*citration!s per:grant per setond..Thisvalueisnaw.the standard unit of.corapari-

that the mass of one electron is equal to0.51 MeV. Since the pair production proc-ess involves-the conversion of energy to anégatron-positron pair, the energy re-quire& must be at least two tiMes the

. energy equivalent of one electron, 0.51key. Any energy in the photon that is inexcess of 1-.02 MeV causes the ejected par-ticles to have.greater kinetic energy. Thenegitren is noW equal to the beta particle,4- -

usually a very energetic' beta particle, andWill react and .be stabilized in the samemanner as previouSly explained. The ,posi-tron has an extireMely short life, which isended by cpmbining with an electron,.However, before this happens it will causeionization, of other atoms. When' the posi-tron does join an electron thurcre-annihi-lated With the production Of two gammaphotons of 0.51 MeV each, which eventu-

.

ally will be absorbed by Compton or pho-toelectric effect.

Cuitt# AND-i0ENTGENS

To. _be-:effective in your radiologicaldefense Work, you muit geta frrmgrasp on the Ways Tadiation is nieas-uredRadiation",,like "diatante" in agenerat-,ccinCent. You- Would hive-a,'

-AVealeiinderatanding:Of distance if you.Were -vagtie about- "foot.", "inth","Mile"; "loilenieter", f`light year" andthe, other .-4vaysy which distance is_measured. The- same is true for radia,tien. .

2.81 The CURIE(Ci) is the unit used tomeasure the activity of all radioactive sub-stan'OeS.- It a measureMent of rate Of

,.-decay or, nuclear disintegr4tion that oc-- curs-within-the ,radioaCtive material: The

Curie: Thitially established the, activity(that is, thedecay rate) of radium as the

- -Otandard.-with which-the activity of anyothei-4.uhstariCe -was conipared. -

_242; By-usingAlormUla that takes into

.30n. A Curia Of .a*/ radioactive *tope,,

therefore, is the an?: of Mat'isotope thatwilkproauce 8.7 x101 nuclear disintegra-tion% per second.. Since the measure isbased on number of disintegrations, theweight of the radioisotope will vary fromthat of radium. A curie of pure Co" wouldweigh less than 0.9 milligrams, wpile acurie of U238 would. require over two metrictons. The curie is a relatively large unit.

. In training, a millicurie, niCi (one-thou-sanIth curie) and the microcurie, MCi(one-millionth curie) are common units inuse. At the opposite extreme, the curie istoo small. a unit for convenient measure-ment of the high-order activity producedby a nuclear explosion. For this purpose,the megacurie (one million curies) is used.

2.83 The ROENTGEN (R) by definitionmeasures exposure to gamma and X-rays.It is an expression of the ability, of gammaor X-ray radiation to ionize air. One R willproauce 2.083 x 109 ion pairs per cubic cen-timeter of air or 1.61 x 1012 ion pairs per'gram uf air. (See Par 4.13 for a morecomplete discpssion.)

The curie measures radioactivity.. The roentgen measures X or gamma -

radiation.

-.REFERENCES

The Effects of Nuclear Weapons.Glas-itone, SaMuel, 1964. PreparenDy the U. S.Department of Defense, 'and published bythe U. S. Atomic Energy:Commission April1962; Revised Edition Reprinted February1964. (For sale by Superintendent of Docu-ments, U. S. Government Printiv Office,-Washington, D.C. 20402. PricV4,00_, with,calculator $4,00.)

Explaining the Atom.Hecht, Selig, Ex,,,plorer Books Edition, Viking Press, Inc.,1964.

Nuelear Radiation Physits.LappRalph E. and Andrews; Howard L., Pren-tice-Hall, Inc.; 1972.'Sedrcebook on Atomic Energy.Glas-

stbne, Samuel, D. Van Nostrand Company,Inc., 1967.

Radiological Health Handbook.PdblicHealth Service, Januaiy 1970.

,

. .

4.

EFFECTS OF NUCLEAR WEAPONS

After, our introduction to the languageof nuclear physics, We are ready to usesome of these terms in arriving at anunderstanding of a nuclear detonation anda knowlegN what can be expected froma nuclear deto4ation. This is our primaryobjective arid in reachink it, we will alsocover:

%b.-

WHAT is a chain reactionWHEN doesit occur

. HOW is dlifce a chemical explosionHOW is it differentWHAT is fission and fusionHOW a nuclear weapon worksWHAT aie the effects of a niiclear

explosionWHAT is fallout

FAMILIARITY BREEDS CONTROL

3.1 ,During World War II many largecities in England, Germany, and Japanwere subjecta;to terrific attacks by high-explosiye and incendiary bombs. Beforethe war, it was fully expected that suchattacks would cause great panic amongthe civilian residents of bombed cities. Ob-servations during the attacks and subse-quent detailed studies, ,however, fail tobear out this expectation. the studiesshowed that when proper steps were taken.for the proteetion of the civilian popula-tion and for the restoration of servicesafter the bombing, there was little, if any,evidence of panic. In fact, when suchmeasures are taken the studies showedthat there was a definite decline in overtfear reactions as the air bombings contin-ued, even when the raids become heavierand more destramilNe,_

3.2 The history of nuclear defense rnq

>

CHAPTER 3

be said to have started with the explosionof the- two bombs over Japan in August,1945.

These, the first and only nuclear weaP-o s ever used against an enemy, caused

itlprecedented casualties. Many of theseasualties could have been.prevented ifhere had been sufficient warnings to per-

mit clearing the streets, and if the peopleof Hiroshima and Nagasaki had -knownwhat to expect and what to` do. For exam-ple, only 400 people out of a pdpulation ofalmost a quarter of a million were insidethe excellent tunnel shelters at Nagasaki_ .that could well have protected 75,000 peo-

.ple.3.3 Information accumulated at Alamo-

gordo, Hiroshima, Nagasaki, Bikini, En-iewetok, and Nevada, as well, hs experi-ence gained from other types of warfare,.has contributed to the store of defensiveknowledge. From this knowledge, methodsof coping with a nuclear weapon attackhave been, and are being devised.

NUCLEAR WEAPON DETONATION VS.HIGH tXPLOSIVE DETONATION

3.4 The nuclear bomb was designed asa blast weapon. Therefore, although im-mensely more powerful, it resemblesbombs of.-thp-'-cOnventional type, insokr asits destruttive effect is due mainly to theblast or shock that follows the detonation.However, nuclear detonationi do differfrom'conventional -detonations in four im-portant respects:

Firsta fairly large amount of theenergy from a nuclear detonation isemitted as THERMAL RADIATION,generally referred to as LIGHT andHEAT;

Secondthe explosion is accompaniedby highly-penetrating, harmful but IN-

3 2

25

VISIBLE NUCLEAR RADIATIONS;Third7-!the nuclear reaction PROT:)-

. .

tICTS,. which remain after the detona-tion, are- RADIOACTIVE,, emitting ra--iafions capabte of producing, harmfulconsequencesin liVing_organisms;kourfhiluclear -explosions can beMany thonsands (or millions). of timesmore powerful than the largest conven-tienal _detonations.

_ .,

'-,-IRINCIPLES.,:00 A:CHEMICAL1.DETONATION . '

.

0:5 Befóre the disdovery dhow nuclearenergy could-he Aeleased for- destructiveptiposes, :the -explosive material in bombiOf the 'type in general, use, often referred_tO ',as conventional: bombs, consistedlargely of atoms of the eleinents earbon,'nitrogen, hydrogen, and okygen, in TNT-(trinitiotoluene) or of a related chemicalmaterial. These explosive substances areUnStahle mn nature, and are easil-k- broken

, Mere-stable molecules. This proc-essis asSOCiated 'with --the liberation of arelativel4large amount ,of energy, Mainly

-Once the decomposition of a feWnthledules of Tiit-IS initiated, l3y means of**likable detOnater, the muffing: shockeaUseaStill More uiblectles to ;decompose.Akaresult, the oVerall rate at Which TNT

'-MOlecules-hreak up is 'very -bigb.--tbis, tyPeof hehavibk is -characteristic of many ex--ploSione, the prOdess 'being accomPanied-by -the liberation -of a largo quantity of_energy. in.a; -Very short period;:of time,

',within a Ifinited space:a:0 'The'iitodOCti of the decompOsition

of conyentionali*Plosives;are mainly in-'trogen sanit :Olxi.des of nitrogen,- o/ides ofoitibok-'*itter Vapor, and' Saida, notablytarbOri, *iii* are read ily- disaipated in- the

'Therefore, the sub-2stanceS- è iiii after the explosion dono inorehernythin-the peisondus 'Carbonnion OXide preSent 'in ,the 'exhaust gases*lien -atitoM,Obile-,and airplane-engines.are'Operatectin:theq)pen.,air.

NVIth a1 contentional explosive theChemical:molecnies. comprising the variousatOnware-heldtogether by- certain forces,AQinetfme0 ,-.ptPitcl -to 4s. enc bOTIO.

en- the molecules undergo decomPosi-, `

tion, there is a rearrangement qf the at-oms, and there is a change in the charac-ter of the valence bowls. As stated above,a chemical explosive is-an unstable com-pound, and in it the \valence forces arerelatively weak. In the molecule's of thedecomposition products, however, thesame atoms are bound more strongly. It ida law of physics that the conversion of any -

system in which the;constituents. are hey-together hy weak forces intoine in'whichthe forces are stronger, Must be accom-panied by the release of energy. Conse-quently, the decomposition of an unstablechemical explosive results in the libera-tion of energy.

PRINCIPLES OF NUCLEAR DETONATIONS

3.8 An atomic or nuclear explosion. re-sembles chemical explosions in the respectthat it is due to the rapid release of a largeamount of energy. But the difference liesin the fact that in the nuclear explosion,the energy results from iearrangement'Wain the central portion, or nucleus ofthe atom, rather than among the atomsthemselves as in a chemical explosion.Since-the forces existing between the pro-tons and neutrons inthe nucleua are iriuchgreater than 't'he forces between-the atomsin a -molecule of chemicat -explosive mate-rial,- -energy- changes, accompsnying nu-clear- rearrangements are very muchgreater than those- aSsociated with chemi-cal-reactions:

the .basic requirernenrfor energyrelease is-that the total mass-Of the'inter-acting species should be greater than thatof the resultant product (or products) ofthe 'reaction. As we saw in ChOterthere is a definite equivalence betweenmass and e. rimy. thus, -when a decreaseof-massliccura in a .nuelear -reaction, thereis- an aecompariying -release of a certainamount of 'eriergy reIated-to the-decreasein mass. In ;addition ,to the necessity forthe nuclear Prog4S?to he_ one in whichthere is 'a net_44,eale in mass, the J.eleaseof 'nuclear ene'relik amounts sufficient tocause an explosion requires _that t 'he i;eac-tion shouldhe able to reproduce itself onceit has been started. 'Two types of nuclear

, ,

HELIUM NUCLEUSPLUS

FUSION

-41bURE 3.9-...Fission Anil fusion-

interactimis whiCir can meet the require-nientS for the production of large amountsotencity in a shorttike-are FISSIOO andFt.1,SrON. The fiSSiOn process takes placeIffit*,001Tie: Of :the 'heaviest nuclei plighatomic iMinber), Whereas the fuSionproc-ess-inVOlVes edine, of the lightest nuclei(low atinnie nUmber).($ed Figure 3.9.)

-'

'NUCLEAR FISSION'

-240 The- fiSsile materials whielt canpresently be used to produce' nuclear 'ex-ploSiOris are the nraniuth isotopes T.23;M235, end the pintoniunt isbtoPe Pu239.

ent aneittrowentere; the nucleus ,ofthe'apprOpriate atom- thenudleus splith tfis-Sionslinto-tWo,daughter nuclei, and twolothreeneutrons(Pigure3,16). PorV233,JJ2:15,

,A114:13074!.(unlike,the;Caselortils,there is-noloWerlimitfor the .kin,etic energy thataneutron must po Ssess. to enable -itto,ceusefission-on ,captureby iv.mucleus ofany, ofthese:three- isotopes.. For this reason,'these isotopes Are7celle4lissile materiels,and.,onlithese three=ere -of practical' sip.'

the-cese of -e nonfissile nn-Clatis,-.0* energy of the incident neutron,MOSte:xceed.a,,,certein .threshold,velue -to

it-tO-eanse 'fission or 'capture. Thethreshold, values for, Mt!' and.,Th2n (Thor-

, .;

ium 222)- tire nearly 6.0: -MeV and 1`SWIeVi-respeCtiVely. Generally speaking, anyheavy nueleus can undergo fission if theegcitation energy is -large enough, e.g.,fission of gold Occurs with neutrons ofabout 100 MeV energy.

FISSION FRAINENY

..ft + tesa .45N4INERAGE) + ENERGY

?VISOR FRAGMENT

FIGUR.V 3.10-Fission of uranium 236 producesneutrons.

FISSION CIHAIN REACTION.

3.11 addition to the large amount ofenergy released in nuclear fission, the sec-ond important feet, which has made possi-ble the production, of an:explosion es .a ,

result of fission, is that the process isaccOMpallied, 0 the release of two or more .NEUWMS (Figure 2.10), The neutronsthus liberated jn the fission process, are,able to cause the fission of -other uraniuM,

or plutonium nuclei.. In each case moreneutronS are released; WhiCh can prodUcefurtbher fission, end so on: lierice, a. Singleneutron:could zstart self;sustainedlekain,of fissions, the number of nuclei jnvolved_increasi at atreinendous rate.

,3.12 Actually, 'not all the nentron; liS-

erated in the fission ;process ,are available-for causing' more-fissions. Sbnie of theseneutrons esCape _and others ere lost innon-tisSion r(ectiOnS.1 'It will 'be assuMed,

i3vievet, for 'simplicity, thakfor each ura-niunr (Or 'plutonium) nugleus undergoingfisaion, there ere tWo neutrons producedcapable 'Of initia.tirig 'further fission. Sup-POse a single neutron" is,eaptpred by anueleue in a guantity ofizranium, so- that-fission oceurs. Two neutrons ere then lib-

. ,

A solf.sustalnEtt ihaln reactlort in purtrUng or puN nig or naturaluranium itriot poulble.

27-

".--erated-alid#0*eguietWonlore nuclei.to:underie.-fiSSion. ThidreSultS in the produc-.

four neutrons aVailable for '2 s-Sion. _The fissions indrease by geometricprogression (1,2,4;8,16732;64,128,256,-

-..51471524,2048,4096,. and"- se., on)..By. theeightY4irit step Of this .process, we have

1; 2;5, ,,x-102f fiSsionskenough to fission a kilo-, -uranitim. The time re-

-qUired:::for-the 81, steps is'1/208 seconds.. Asyou :dim See this tremendous activitytakei :place. almost instantaneously, thusproducingfan explosly,expaction.

3:13' Thegetual, loss. of mass in the fis-_ ,

, sion.of urardurri,or plutonium is,only about .

one-teitth-ef a percent of the total. That is,.

.. if ll the atomic nuclei in one pound ofuranium or plutonium undergo fission, the_decrease of niess would_ be roughly. five-

: tenths-of a gram or one-sixtieth part of anokince. Nevertheless, the amountufenergyreleased by the. -disappearanCe of thisonantity of platter would be about the,Sameas that prodtteed hy thp explosion of,8;600 tens of TNT.

00404-SIO. OF ,NUCLEAR FISSION

,

3.14 When a piece of fissile material isbele* a certain size, a few of the atoms areC9ntinually undergoing fission, 'but moreneutrons escape through its surface than

:" ire,proctiiCed in fission, and an increasingChain of fiSsione is not built up. Such aMass iS celled SUBCRITICAL. On the.

'other hand when a mass (in a givensha'pe) is just great enough to support asuitaining chain reaction, it is called a, ,

cluncAL miss. As we 'can readily see,,

-(GEFORE DETONATION)

HIGH EXPLOSIVE

LIVIA liAlttatACIAT WalCAU,

FIGURZA.1.4,-Tamper

then, if several pieced of fissile material,totalling more than the critical amount,are suddenly brought together ihside astreng container or TAMPER (see Figure3.14) a nuelear detonation results.

What constitueS a CRITICAL mass de-pends upon a number of factors, includingthe density of the material (whether solidmetal pr in porous, spongy form); and alsoupon pe nature of the TAMPER andwhether it absorbs neutrons or can reflectthem back into the fissile Marge.

3.15 Published information suggeststhat an unConfined sphere of U233 metal of,about. 61/2 inches diameter and weighingabout 48 kirograms wonld 'be a' criticalamount; this would be reduded to abOut41/2- inches. diameter (16 kg.), for a U233sphere enclOsed in a heayy4,tamper (Pignre3.14). The"critical sizes for 1.12.3 and Pu239have not been disclosed. Tbe increasingmechanical compliCation of bringing to-gether, rapidly and simultaneously, anumber of subcriticai pieces offissile ma-

g practical limit to the power ofnuclear fission weapons. Another impor-tant consideration is that the size of apurely ,fission-type homb, is limited be-,cause, above a certain critical...size,. a, lump_ ,

of fissile material is- self-destructive. °

fr

NORMAL ,DENSITYSUSGRITICAL

ACTIVEMATERIAL

HIGH'DENSITY'SUPERCRITICAL

(AFTER PETONATION

8.16a. principle.

:

'PROPELLANT ACTIVE MATERIAL:(EACH TWO-THIRDS CRITICAL)

e ,N""

TAMPER:

,

`&11NNX

Vh

GUN TUBE

(BEFORE DETONKTION)

FIGUitE 3.1.61iGun assembly principle.

3.16 As we have seen, subcritical mas-ses or piedes of fissile material, whenbrought- together rapidly ean, underproper conditions, cause a chain reactionand subsequent explosion. As a very nec-essark safety precaution, it is obyious thatthe masses of fissionable material present

a nuclearbornb inirat be kept i&beritiealmitittime for -the borrib to be detonated.Aiid:'When that time arrives,_the subcriti-CalMaiseS nuist fermi a supercritical Mass

'Ansi-an-W*3,01y. One ,..wair of producing:Supercritical niasS4s. by 'forcing two orinereSUberitidalniasseS tegether..Another

te eilueoe a, subritieal masstikbtlY into a neW-Shape 'Andkr a greaterdeneity,'$Peli 'a Mass becothes Opercriti-'eal-Withoirt, the addition of any inOre stib-stall& 'tirialatter filethod, first used iri

inthe iniplosion prind,ple (kignre .3.160. In-tbie boinb, a giYen amount-Of-fissile mate=rialiauberiticalin the torin.of a thin spher-ical ibeit, became critical 'When c oth -'.Preelfed intla Solid; sphere; This ,compres-

'Sion Was )irortiOrtabOut by firing-speciallylabrieated -Shapea Pt 'ordinary high explo-.Siire arranged spherically on he vogo

A*..).thlto* eitibere When the''-eXPliisiYe'it detonated,. the MOS' is OM-PreSsied; iMpiediatelybecoininet#Pereriti,

the-atornic detonation takes plade.

the:otber inethow'as peed witihe Iliro-Ship*beMb.' The SUbdritical inaSsia, en-'Cf4eFt, in something Iike.a:gUirbaftel,wereiniptfilect againit eiCh other by:=the pction

inernical ,eXplesiVes (Vigure,

TAMPER

9

FISSION AND FUSION . . ANDTHERMONUCLEAR WEAPONS

3.17 A. fissfon explo-sion producesbriefly and in a email space,intensities oflight and heat comparable to those in thesun. A fusion explosion does still more: it-duplicates.a part of the actual process bywhich the sun and other stars produeetheir light and heat. This process-is not-chemical burning reaction. It iS a nuclearfusion reaction, in -which, :four nuclei,- of-simple hydrogen ,become one nude:AS-ofStable helium, with a converSion. of .massto radiant energy. Through' this processour sun, every seq,90, loses. about 4 ;to 5million tons of matter, radiatedA's energy:From experiments niade.,in laboratorieswith cyclOtrons and-similar devices' it wasconcluded that man could' partiallycate the, procss of the sun, by the-fusionof isotoies of hydrogen. This element isknown tO exist in three iiotopie fornis inWhich tlie nuclei have Masses-of 1, 2, imd3, respeetiVeIy. Thege are gefierally re-ferred to as hydrogen (II1), deuterium (H2or P2), and tritium (H2 or T2). Several. dif-ferent 'fusion, reactions have been ob.,

'served among the nuclei of the three,hy-cirogen isotopes, involving either two sim,V4lar or two different nuclei. In Order to.makethese:reactions occur to an apprecia,ble extentt the nuclei mu.st have :highenergies. One way -in which: thisenergycan be ensiled ie..by ineane!o4 a, charged-particle itaelerator, s,uch s. k cyclotion,as mentioned earlier. 'Another possibilityis tO raiSe' the ,:temperatyre to 'Yery; high

lel!iels. In these circumstances, the' fusionProceisee are-referred -to' ae '"thetmonu-..elearteactione".

.348: teiiveratures of the Order of aslegrees -ate-necessary in order to'

4he ,nuclear fusiOn teactions take-pIfice.`The Only-nown Way hi which suchteniper#dre Caivhe.:obtained oh earth is;by,Means,Of a:fissio4 extilosion-At temper-aturei.oi'Milliene-Of degrees, centigrade,atome ,ate ,stritped of.lnost of -their sur-rOnticlineclaid,of'electrone an4 the nuclei'MoVe 'vety high speeds experiencingMany collisiOni With one another. UndertheSe circuinStineeS, the nuclei of therater hydrogen isotoPes deuterium .aqdtritium have enough energY of motion toovereeide the, repulsive forces betweentheir -ingle positive electrical charges aidthey-4*e able tO fOse together. The-energyrelease4 in the fulion of these two nucleiiS,about one-twelfth of that-released inlhefisSion, of a eingle tI35 nucleus; but on 'an

:equal weight:baek the fusion energy is'.aboUtthree tiMes as lEirge ai the, energy Of-EissiO0 of U. The, actual quantit4of en-ergY liberatea,fot a giVen mass ofanate-"rriA déencIs on, the -particular isotope. (or

)isotOpes),iriVoived in the nuelear fusion,I-teaction.:-,Fouit'thermonuclear- 'fusion xeac,tiona4trenOted below: .

,

4-1127§.11e3 +n +3.25 MeV

+14,-.:4H1,s+H! +4.03 MeV.

W .1.,1P,-5>He4 +n +17.5840V

43 +43-3.10- +2n +11..3210V

where-Hi'-iErtha syMbol for helium and n. ,- . .

-f(iriaSs..--4.),::repreSents a' neutron: The- en-ergy case is ,eXpressed*,ii11ion=e1ettrbil-vOits-7(MeV):

atone, -deutethim and, trit-iitOtepee'of the 'gaseptis element

'ilydrogeri,haYe tof'he liqUefieit ;at a "verylifWemperature)andlinaintained there forcOntain*etit hi' -a- thermOmialear-deviCe.

afthough:it haa been .roPoite:d'hatthe'giisi4i*azicaiOhernion- t

nelear device teatO '062 was, of"thia.

1 SELF-.SUSTAINED FISSIONOF PLUTONIUM 239'ON URANIUM 235

THERM07NUCLEARREACTION'

FIGURE 3.19,-"Fiesion-fusion reaction.

type. In later weapons the deuterium iscombined chemically with the metal lith-ium in the form of a white powder. Eachneutron (1 mass unit) released by the trig-gering fission bomb splits a lithium atom(6 mass units) into the non-radioactive gashelium (4 mass units) 'and tritium (3 massunits), and the latter fuses with the deu-terium atoms present in. the compound(Figure 3.19). There is nO* limit, other thanthe convenience of delivery, to the size of afusion .or thermonuclear weapon, and it isclaiined that lithium deuteride is lesscostly than tisiile materials such as U233,

U23-5 or .13u231'.

3.20 In considering Nteapon 'designs, it. .

is ,posSible also to- have a fission-fusion-fisSiOn type weapon (Figuie 3.20). :In thepropos, of fusion, e neutron is released ata vOy high speed and it ligs enough en-ergY io split the COintrionet, atoms ofA thermonublear weapen can be designed_with a.,Ooreoffissile..M.# asa. fuSiOn

,OF URANIUM 235

s. re n+ ,04. 0+ 4.1111.4.,.

llieRMO":NUCLEARREAcTION

I ..et, 4. HID.144+ als nisswi

FISSION 'OF, uRANIum 238

FIGURE 3.20,Fisaipn-fusion-fisaion reaction.

f) $.1

tor encased in, a heavy container of U.This U238 casing will undergo fission fromthe high-speed neutrons produced in thehydrogen fusion detonlition. Since the ce.s-ing might be many times'heavier than thefissile core of U235, correspondinglY largerquantities of fission products would be re-leased as fallout from such a Weapon.

3.21 A much more detailed discussionof fission products will be taken up later inthis chapter, but it might be mentionedhere tha all existing types of nuclearweapo release fission products., "Dirty"bomb produce a great deal and "clean"bom produce little, the dirtiness depend-ing upon the ratio of fission to fusionenergy produced by the bomb. The divid-ing line between "clean" and "ditty"boMbs is, thus, a matter of opinion, but thefission-fusion-fission type of weapon /neer

) *tioned in paragraph 3.20 would be a rela-tively "dirtk" one.

ENERGY YIELD OF*A NUCLEAREXPLOSION

3.22 The power of a nuclear detonationis expressed in terms of the total amountof energy released as compared with theenergy liberated by TNT when it explOdes.A 1-kiloton nuclear detonation' is onewhich releases energy equivalent to 1,000tons of TNT which is called the kiloton(KT). The advent of thermonuclear hydro-

. gen,hombs made it, desirable to use a unitabout 1,000 times larger still, and the me-gaton (MT) unit was.adopted. It is equiva-,lent to the energy released by the detona-tion of 1,000,000 tons of TNT. The bombsdetonated over Hiroshima and Nagasaki,and those used in the 1946 test at Bikini,released roughly the same amount of en-ergyots 20,000 tons (or 20 kilotons) of TNT.In recent years, muCh more powerfulweapons, with energy yields high in themegaton range, have been developed.

. .

DISTRIBUTION OF ENERGY

3.23 Although the detonation of chemi-cal explosives, such as TNT, and the deto-nation, of a nuclear weapon both produce

heat or thermal radiation, the proportion'as well as- the quantity is much higher inthe case of the nuclear weapon. The basicreason for this difference is that, weightfor weight, the energy produced in a nu-clear explosion is millions of timei as greafas that in a chemica explosion. Conse-quently, the temperat1i.re reached in thenuclear explosion are much higher than ina chemical explosiontens of millions ofdegrees in a nuclear explosion comparedwith a fe;:v thousands in a chemical explo-sion.

3.24 For a nuclear, detonation in theatmosphere below loo,00p feet, about 85percent of the total energy appears first asintense heat. As shown in Figure 3.24,almost immediiately a considerable part ofthis. heat is converted to blast or shdck;the remaining thermal energy moves radi-ally outward at the speed of light -as heatand visible lights The remaining 15 per-cent of the energy of the nuclear explosionis released aS various nuclear radiations.Of this, 5 percent constitutes the nuclear.radiation produced within a minute or soof explosion, whereas the final 10 percentof the bomb energy is in the form of resid-ual radiation emitted over a period oftime. The residual radiation includes theFALLOUT we will discuss in later chap-ters.

-

TYPES AND'HEIGHTS OF NUCLEARDETONATIONS

'13.25 As we have seen, an exPlosion isthe release of a large quantity of energy ina short interval sof time within a limited

FIGURE 3.24.Distribution of energy in a typical airblast of a fission weaponin air at an altitude below10,000,1e.et.

, 31

space. The liberation of this energy is ac-companied by a considerable increase intemperature, so that the products of theex ldsion become extremely hot .gases.

ese gases, at high. temperature andpressure, move outward rapidly. In-doingso, they push away the surrounding me-diumair, earth, or waterwith greatforce, thus causing the destructive (blastor shotk) effects of the explosion. The term."blast" is generally used for_the effect inair, because it resembles (and is accom-panied by) a very strong wind. In water orunder the ground, however, the effect isreferred to as "shock" because it is like asudden impact.

3.26 The immediate phenomena associ-ated with a nuclear explosion, as well asthe effects of shock and blast, and thermaland nuclear radiation, vary with the loca-tion of the point of burst in relation to thesurface of the earth. -For each weapon qfspecific power, there is a critical height' ofburst above which .the fireball will ntouch the ground and, hence, it will noproduce .appreciable contamination on theearth's surface. Although many variationsand intermediate situations can arise in

_ practice, for descriptive purposes threetypes of bursts are distinguished. Themain types, which will be defined below,are air, surface, and sub-surface burst.

, _

CHARACTERISTICS OF AN AIR BURST

3.27 An air barst (frequently the mostefficieni means of accomplishing a mili-tary objective, and the type used' overJapan) is defined- as one in which the bombis exploded in the air, above Jand or water,at such a height that the fireball (at maxi .mum brilliance) does not totch the sur-face. The aspects of an air burst will be-dependent upon the actual height of theexplosion, as well as upon the energy yieldof the weapon, but the general phenomenaare much the same in all cases.

3.28 In the following discussion, it willbe supposed first, that the weapon detona-tion takes place in the air at a considera-ble height above the surface. The descrip-tions given here refer mainly to the phe-nomena accompanying the explosidn of a

1-megaton TN't equivalent nuclear bomb.The important aspects of a nuclear expia-tion in the air are summarized in Figures3.28a to 3. e.

THE FIREBALL

3.29 ,As already seen, nuclear reactionsinvolving fission apd fusion in a nuclearweapon lead to the liberation of a large.Amount of energy in a very short period oftime within, a limited space. As a result,the nuclear reaction products, bomb cas-

, ing, other weapon parts, and surroundingair are raised to extremely high tempera-tures, approaching those in the center ofthe sun. Due to the-great heat produced bythe nuclear explosion, all the materialsare converted into the gaseous form. Sincethe gases, at tjle instant of explosion, Arerestricted -to the region occupied by theoriginal constituents in the bomb, tremen-dous pressures will be produced. Thesepressures are many hundreds of thou-sands times the atrvospheric pressure,2i.e., of the order ofirmillions of pounds periquare inch.

3,30 Within a fraction of a second of thedetonatiA of the bomb, the intensely ha

g at extremely high pressure appearas a r y spherical, highly luminousmass. This is the fireball referred to inparagraph 3.26. A typical fireball accompa-nying an air burst is shown in r gure3.28a. Although the brig ss u creaseswith" time, after aboqt a ednd,2 thefireball of a 1-megaton nuclear b ec-plosion would appear to an observ r 60miles away to be many times as bright asthe sun at noon. 'f

3.31 As a general rule, the iurninosityof the fireball does not vary greatly, withthe yield (or power)'of the bomb. The gur-face.temperatures attained,' upon whichthe i?lightness depends,, are thus not verydifferent, in spite of differences in thetotal amounte of energy released,

3.32 Inlmediately after its formation,the fireball begins to enlarge in, size, en-gulfing cooler surrounding air. The growth

is

'The normal atmosphera pressure at sea level As 14.7 pounds persquare Inch (PSI).

A millisecond is one.thousandth part of a second.

t

of the fireLll is accompanied by adecrea e in temperature (and pressure)and, hence, in luminosity. At tile sametime, the fireball rises, much like tr fierydoughnut. As it rises, there are tiparaftsthrough 'the center of the doughnut and'downdrafts on the outside. .

3.33 Within seven-tenths of a millise-cond from the detonation, the fireball from_a 1-megaton bomb reaches a radius q

"about 220 feet;and this ..increases,maximum of about 3,600 feet in 10 seco'W../The diaMeter 'Ai then fume 7,200*.feetand:the fireball is rising ;at the.rate 61350 feetesecond. One,ininue, after**nation, e fireball 'has toole,k POOemission of heat and-,eniiaiilinOtof.-046air, to such an extentithtttA4V10,19110.17-J-

jItininous. _ t ,4t.a s ,'roughly 4.5 miles fron341tetAioiiit: 14.y

t

FIREBALL

PRIMARY SHOCK 'FRONT

NUCLEAR 0:!1-H.ERK;ARADIATtON'

,

not= 3.28a.Chronological development of an Mr

Nu-CLEAR a TIMARADIATIO

":" "." :` .

FRONt-,

REFLECTED S,HOCrFiONT

. --COMMENCEMENT'OP--

'MACH.REFLECTEDDVERPfikSSPRE 116- PSI'- ..

1;74-'4

MILIES 01, -I" 3 5I

FIGURE a020:Chronological development of _an air burst: 4Tseconds i(jter 1-megatan detonation..,' ----;" '`---:=-P.k1MARY'SHOCK FRoNf

-_........ ..........._

."...:' ,,, '..----\* . ' NUCLEAR6 THERMAC ..

N -RADIATION,',, .

,REFLEOED SHOCK PRONT

,,....,i .d!IND VELOCify' . I MACH_FitoNT

ISO MH P ., 1---OVERPikESSURE 6 PSI% ..'

. ','.: ',...:::,..:';':::..,;,:,':7'...-;,:i T I I - . I -4 3 ci-dt 5 6

' 4.

'cal deilelopmert of an air burst: 11 seconds after 1.inegaton detonation.. ..,

' .., .,

MILES- I,

01611E'3:28e.r7Chnol

,t

3

REFLECTED, SHOCK 'FRONT.\-"'- \

ifmiktoifri 1110,4 FRONT -%%\.. \

NUCLEAR PtApIATION.

HOT-GASEOUSBMB'RESIDUE , .

,

-AFTERWINDS

MACH FRONT_OVERPRESSURE [PSI *1

WINO VELOCITY-4o MPH

. MILES1 1 I 1

' 0 I 2 , 3 5

I - I I ITOTAL THERMAL RADIATION. CAL SO CM- 30 .20 . - 8 5-,

Fiat,' ix 8.24.C.Ilroologieal dwielopment of .an air burst.: 3t' seconds after 1-megaton detonation.,

-I -I I I6 7 8 9 10

RATE. OF FiItE130=170 MPH

RADIOACTIVE CLOUD.

WIND V,ELOCITY 275 MPH

4

L,fiDtiRli-848ev-,c,hreixiieekai-d,evekrneet-or ati-air-inirat:110 secoiids after 1-nriiiton detonation.-

. of ksecond after, thede4rUCtive high-presSUre,,

,*aVe Aevelops:I4 The. shaaroubd the fire-'Ilan and ,moVes i!aPi4iy away, behaving

a-Maiing, *ail of,highiy compreSsed'air..Aftemthilapse 'of 10,seCOnda,when the

--firebalrat 4-714-egateninUclear -,66M6 ihas'

attained ita maximum size (7,200 -feetihe blast froot is sonie-a itiiles

ftirther ahead. About a 'minute after theexplosiort,, whert ihe firehall is no liinger

the blattt waye has traveled ap-proxithately 12 miles. It is then, moVing atabout 1,100 feet per second', whith is.Slightly faster than the speed of sound at

-sealeVer

REFLECTED WAVEI- "INCIDENT WAVE

t1

1--I.

/ X // TRIPLE POINT -y, / MACH STEM I

1.P .7.771"

FIGURE 3.35.--Fusion of incident and refl

THE MACH WAVE

3.35 When the blast wave strikes thesurface of the earth, it is reflected in awayailmilar to asound wave producing anecho. This reflected blast wave, like theoriginal (or direct) wave, is also capable ofcausin,g,material damage. At a certain re-gion -on thesurface, the position_a_which

-

ected waves and formation of Mach stem.

3.36 For a `typical" air burst of a 1-megaton nuclear weapon, the Mach effedwill begin approximately,5 seconds aftek'the explosion, in a fough circle at a radius. _

Of 1.3 miles. frpm ground zero. -The terM _-"GROUNP, ZERO" referS to the point onth. earth's- surface immediately below (or 'abovathe isoint of detonation. .

3.37 At first, the height' of the Mackfront it small .(Figure 337), but as theblattfrónt continueis to move outward, tile,:height-increases steadily forming aSTEM.. During this time, ,however, the oV-erpreSsure, tbe original blaStWave,. decreases correSpondingly because., ..

of the continuous loss .pf_energy and the-eyet-indreasing, area of;:the.. -advancingfront. After the lapse of'about 46isecondi,,ci,when the gioi fiont from a .1"-Eaagatoh,-,nuClear bombis 10 miles fromigreArkii-zero,_fhp overPieSsure have: necrease'to-

t-WLZtTLD

tt

depends ChieflY On the height of the burstabove the suifaCe and the eneigy of theeXplosion, 'the direct and _reflected blast

liontig, fuse as shoWn in FigUte 3.35. Thisfusion phencnienon its called the MACkEFFZCT. thefNE4PEE8s00, the

ressnie ottke--blast watrein-eXcess Of thenon* atirioSpheric value, at the front oftne MaCii- lkgenerallYaboUt twice asOtat aS that it the direct slioCk front. Tbeinixininin'XiVerPketsure Valne, i.e., at tbe;Wit ftent, is called the Peak overpres-si0e;

I =1/IdOeNT. III t

PAIN Of TRIPLE tOilti

z ' 41','. 4' 71, cr. 41614 tjrIrjd' " C' t

,FIOX.M#8:37:0.1.itWard motion oi ,thet-121.as.t...arSve near

hei4urficelh`the Mitch region:

roughly' 1 pound, per square inch. Most ofthe material damage caused-by an airburst 'nuclear bomb is due mainly-zdi-reitiyor indirectlyto the blast (or shock)*aye. _The majority of structures will suf-fer Isome damage. from- air .blast, when theoverpressure in the blest wave is aboutone-hallf pound per square,inch or more.

3.38 The distance from ground zero atwhich the Mach stem commences, and towhich an ove6ressure of one-half poundper square inch will extend, depends onthe yield or size of the explosionand onthe height of the burst. As the height ofthe burst for an explosion of given energyis decreased, Mach reflection commences'nearer to ground zero, and the overpres-sure at the surface near ground zero be-comes larger. If the bomb is exploded-at agreater height, the, Mach fusion com-mences farther away, and the overpres-sure at the surfade is reduced. An actualcontact surface burst leads to thepossible overpressures near groun

cambia ñ Via effect occurs, sinceno reflected wave.

estzero,

ere is

3.39 IT; the .nuclear explosions over Hi-roshima and Nagasaki during World WarII, the height of, burst was about 1,850feet. It was estimated,.and has since beenconfirmed by nuclear test explosions, thata 20-kiloton bomb burst at this heightwould cause maximum blast damage tostructures on the ground for the particu-lar targets concerned. Actually, there is nosingle optimum height of lourst, with re-gard to blast effects, for any specified ex-Plosion energy yield, because the chosenheight of burst will be determined by the .

nature of the target. As a rule, strong_(pivh,ard) targets will require low air or sur-face bursts. For weaker targets, which 'areestroyed or damaged at relatively lowoverpresSures or dynamic pressures (thedynamic pressurejs a function of the windVelocity and air density, behind the blastfront), the height of burst may be raised inorder to increase the area of damage, sincethe distance at which low overpressurewould result would bel extended because of-the Mach effect.

POSITIVE AND NEGATIVE PHASES

3.40 As the blast wave travels in theair away from its source, the'. overpres-eures at the front steadily debrease, andthe pressure behind the front falls off in aregular manner. After a,s17414.,thne, 'Whenthe blast front has traVeled'e certain dis-tance frtrar the fireball, the jiressure be-hind the front drops below that of thenormal atmosphere and a so-called NEGA-TIVE PHASE of-the blast wave forms. Inthis region.the air pressure is below that of.the original (or ambient) atmosphere.

3.41 During the negative=overpressure(or suction) phase, a partial vacuum isproduced and the air is sucked in, insteadof being pushed away, as it is when theOverpressure is positive. In the positive (orcompression) phase, the wind associatedwith the blast wave blows away frOm theexprosion, and in the negative phase itsdirection is reversed.

3.42 This wind is dten referred to as a"transient" wind because its velocity de-creases rapidly with time. During the posi-tive phase, these winds may have peakvelocities of severel hundred miles perhour at points near ground-zerk and evenat more than 6 miles from the explosion of*a 1-megaton nuclear explosion, the peakvelocity may be greater than 70 miles perhour. It is evident that 'such strong windscan contribute greatly to the blast damagefollowing an air burst. The peak negativevalues of overpressure are small comparedwith the peak positive overpressures.Thus, it is during' the compression phasethat most of the destructive action of blastfrom an air burst will be experienced."However, the winds associated with thenegative phase can be quite damaging to

eakened structure's.'3.43 From the practical viewpoint, it is

of interest to visualize the changes of ov-erpressure in the blast wave with time ata fixed location. The variation of overpres-sure with time that would be observed atsuch a location in the few seconds follow-ing the detonation is 'shown in Figure3.43a. The corresponding general effects tobe expected on a light structure, a tree,and a small animal are indicated at the,

43

c't ;44. 7t

Ell

C.,

PRESSURE PHASE

a 'a'1:3

et==0

a

4

4 0

SUCTION PHASE

.

left of the figure. Additional data is pre-sented in Figures<3.43b ind 3.43c.

a.'ariation of pressure with time at a`stru

'BLAST CASUALTIES,

3.44 There are four different kinds ofinjuries caused by the blast of an atomicweapon. Victims may be injured in one or

fnced location and effect of blast wave passing over aettire. , 0-4

all of these four ways, depending -uponmany factors, including the degree of pro-tection, closeness to ground zero, size ofboMb, height of detonation, etc.. .

3.45 The four kinds of blast injuriesare: 4

(1) primary blast injuries, caused bythe high pressures of the blast wave;,- .

4 437

.a - .,..-1

ti a lk- It

A II 11,:4 q.,...

-50_-- 44 445 -0.036 - 12'

51 3.45 - 0.049- 14

740 60 - 3.44 - 0.072 - 1.7

1.- 7 ...

72 7 3.43 - 2.1 -

,99 - 3.40 - b.16 - 2.6

-45 117 3.24 - 0.28 - 3.5-5-

4-20 177 302 - Q60 - 5.5

715 278 - 2.69 - 140 - 9.4 3

-10-- 464 2.25 - 5.22 - 18.0 2

- 5 307 1.75 - 3.60 - 27.0 -0-

-o

LIGHT DAMAN TO WINDOW MANES AND DOORS. MOD(RATE *PLASTER DAMAN OUT TO NOUT IS MILLS; GLASS ICEMANPOONA OUT TO 50 NW.

`

PIN MUM iums. lama

SMOKESTACKS DAMAGE.

WOODFRAME aumpaoss, NOCIERATE OAMASE.

RAM AMC TV TRANIAITTINS TOWERS MODERATE DAMAGE.

W030-FRAIN linLoons.saysite *was.mimic a POWER UNESLINIT OF SIGNIFICANT OAMAGE,

111iLL-NANKIL NICK RADOM (APARTM(RT NOUN TYPE).MOOERATE'DAMASE.WALL...EARWIG. BRICK MALMO (APARTM(NT HOUK TYPE )SEVERE DAMAGE.UGNT sTrli-samas. INDUSTRIAL sun.saws,m000mit DANSE.uoir STEtlerRAIRE, IICUSTRIAL SUILDINDS.SEyERE DAMAGE.MULTISTORY CALL- KARIN SIRLOINS (MONUMENTAL TYPE)MOOERATE &Jaws.MULTISTORY ISALL-SEARING SUILDINGS (MONUMENTAL TY-PE)MERE DAdASE.INMOST AND RR TRUSS NUNES. MODERATE DANADE.YULTistoar,sym.-FRAke GOLDING (OFFICE TYPE). SEVEREDAMANTRANSPORTATION 'VEHICLES. MCOERATE DAMAGE

NOLTISTORY. REINFORCEDCONCRETE FRAME BUILDINGS (OFFICETYPE). SEVERE DAMAN.MULTISTORY.SLAST-RENSTANT DENNED. REINFORCED CONCRETE

MODERATE

*Januar. BLAST- PIENSTAgr tweaso.atowoacmillitarrsSUILDININI. SEVERE.

ALL ME* (MOVE GOMM) STRUCTURES. SEVERELY DAMAGED ORDESTROYED.

FIGURE 3.431xDamage ranges for a 1-MT typical air burst.

(2) thosefrom the impact of missilesthrown about by the force of the blast;

(3) result of being thrown about by the-blast; and .

(4) miscellaneous injuries, such as ex-posure to ground shock; dust inhalation;

. fires caused by the exploSion, etc..e.venty -percent of those who Bur-

, viyed, the nuclear bombing in Japan suf-fered:from; biastinjury. gince many of the

' 'suryivorawere'alsoinjured in other waystwilit-Tan-Or radiation-bOtIr-to-be:~dis-eu,ssed-later).ww.cannot sarthat this is the.percentage oflnjuries caused by blast.istevettlieles5Tblast; war-one of tpe orcauses of and,- certainly, a- majorPauie ofdeath.

THE ROMI-(RADIOACTIVEYCTOUD. , , ,

147, In,additidn to the transient windsassociated with the passage of the, blestfront, _a strong, updraft with inflowingwinds, called "afterwinds", is produced- in

, the; immediate vicinity Of the, detonationdu-Fro:1M riiing.fireball. These afterwinds

cause varying amounts of dirt ,and debristo be sucked up from the earth's surfaceinto the atomic cloud. (Refer to Figure

-3.28e.)348 At first, the risini mass of bomb

, residue carries the particles upward, butafter a time, the particles begin to spreadout and fall slowly under the inflnence ofwind and gravity. This is FALLOUT.

---THERMAL RADIATION

. 3.49 Immediately after the fireball isformed, it starts to emit thermal radiation.Because of the very high temperatires ofthe fireball, this radiation 'conSists of visi-ble light rays, invisible ultraviolet rays ofshorter wave length, and invisible in-frared riq4s of longer wave length. Theserays all travel with the speed of light. Dueto certain physical phenomena associatedwith the absorption of the thermal rhdia-tion by the air in front of the fireball; thesurface temperature of the' fireball under-goes a curious change. The teMperature

45

, STRUCTURE TYPE DAMAGE S

. _. .

EXPLOSION YIELDAbIstallia in milts). -

i0O-XT-: t i Mt I Io MT

. ..

- WOOO-FRAME Eiull..pING-, 1

RESIDENTIAL TYPE

-,

:. 'MODE/VI

.

_

3-,2 .6.6.

.

14

SEVERE '..-

\- 2.4 '5.5-

.

12

WALL-KARING, MASONRY,BUILDING, APARTMENTHOUSE TYPE

MODERATE

,I

4.7.

10

SEVERE 1.7 3.5 _ 8.7

MULTISTORY, WALL-BEARING BUILDING,MORUAIENTAL TYPE

.

..

MODERATE 1.8

:3.5

-7.4

SEVERE, 1.3 2.8, 6.1

REINFORCED CONCRETE1 i/97-EARTHQUAKE '

RESISTANT) BUILOING-,CONCRETE 'WALL, SMALL

.MODERATE

.1.5 3.4 7.2

.

SEVERE El-;

WINDOW-AREA, ,

'FOR A SURFACE BURST.THOESOIOTIVE DISTANCES ARE THREE QUARTERS OFTHOSE FOR AWAIR.11,11RST OF tiit'SAME YIELD;

-Pittaa4:43c;;-kaximunirankialroin ground zerb for structural-damte fronv air bursts. -. ,

diereaSet rapidly fOr a fraction of Et Eec-OnL surface_ temperatuip'ore:Saes-40in for a sonieWhat longer time,$fter z%Ithich :it falls-continuously. In otherwercls,, there- are ,effee*efy two su'rfSce-teni' erat.'shOrt -duration, 'whereai the Second lastsfor a Mutklonger time. This behavior is-itUiteStaridard With all-size apon$, al-

ura ion Imes- o t e twopUlgesincrease with the energy -yield ofthe wig:60On. After:about seconds -fromthe-detonation-0f a 20 ICT bomb, the fire-balL-14hoUgh Still very hot,:has cooled, toluotfineittent-that t e thermatradiationits :n6-1OrtgerinitiOrtant, whereas 9Mountsot AO:Mat-radiation still continue to he-en:IWO-fro* the-firebalt at 11 sedond'titter 1.'1=inegiton Oplosion.

aO COrrespondingto the two tempera-ture Puises,, there -are two pulses vf emis,siOn-of.thermal radiation from the:fireball

_ (Figure 846).. In the. first Puliel whichlasts about a tenth Of a second for a 1,

plosion, the temperatures aremOStly Very 'W.A.-As a result,,Inuch of -theradiation aMitted ,in thiS pulse is in -theulttaViolet r a

Of ultrairiolet radiation can _produce pain-ful *blisters; in Tnilder-forM. these .effeotsare familiar aS simburn.'However, in mostcircumitances, the .first pulse Of thermalradiation is nOt A-significant hazard, withregard: to Skin hurns,Jorseverat reasons.In the first place, only about 1 percent ofthe thermal radistion, appears in the ini-tial pulie because ofl its short -duration.

econc), the ultraViolet rays are ,reach.ly

5

glisorbed in the atmosphere, so that thedose delivered at a distance from the ex-,Plosion 'may be comparatively singlkFur-ther, it appears that the ultraviolet radia-tion from the first pulse could cankisignif-i6nt effect on the human skin onlY withinranges where peoPle would he killed out-,right by the blast and at which otherradiation effects are much more serious.- 3.51 The sitUation with regard to .the .second pulse is, however, quite different.This pulse may last for several secondsand carries about 99 percent of the totalthermal radiation energy from the bomb.Since the temperatures are lower than inthe first pulse, most of the rays reachingthe earth consist of visible and infraredlight. It is this radiation which is the maincause of skin burns of various detreessuffered by exposed individuals out to' 12miles or more from the explosion of a 1-megaton bomb, on a fairly clear da.y. Thewarmth may be felt at a distance of 75miles. For air bursts of higher energyyields, the corresponding distances, will, of-course, be greater,GeherallYi thermal ra-diation is capable of-cripsing skin burns onexposed individuals at such distances fromthe nuclear explosion that the effects ofblast ,and of the initial nuclear radiationare not significant.

THERMAL RADIATION CASUALTIES

3.52 It is convenient to divide thermal

to-6S

2 OA

..

.I___

it) 5,0.t." 4.0S ig3 3A

6 2.0.

4W

\"

.

1.0 2.0 30 4.0 5.0 40 70 0.0 11.0 100 11.0 12A

TIME AFTER EXPLOSION(RELATIVE SCALE)

FIGURE 3,50,--Emission of thermal radiation in twoI ' pulses.

. 40

burns due to a nuclear explosion into twoclasses, namely (1) primary burns, and (2)secondafy burns. As in the case of blastinjuries, the terms primary and secondaryrefer to the manner in which the burnsare inflicted. Those in the first class are adirect result of thermal radiation.from thebomb, while those in the second groupArise indirectly from fires caused by theexplosion. From the medical point of view,a burn is a b`urn; wlietherreceived -g's aflash burn from the initial thermal burstor, at a later time, from the burning envi-ronment.

3.53 Experiments in the laboratory andin the field have established criteria forassessing the degree of thermal damage tobe expected for doses of thermal radiationdelivered to human tissue within specifiedtime limits. Medical diagnosis usually re-cognizes three grades of thermal injury:first, second and third degree injury inascending order of severity. A first-degreeburn corresponds to a .moderate sunburnor erythema. Such damage, while quitepainfutis -r eparablewitltime andrequires no special treatment beyond therelief of pain. The second-degree burn in-volves the skin thickness down to andincluding portions of the dermis. A charac-teristic feature of second-degree burns isthe formation of blisters. The second-de-

, gree burn is extremely pdinful but alsoreparable with time. Infection usually oc-curs' since the protective barrier of theepidermis las been pierced, leaving thetissdes open to infective pathogens. Giventime and Opportunity to combat infection,the majority of second-degree wounds healwithout undue aftereffects though per-Manent pigmentation changes may persist.The third-degree burn *nvolyes completedestruction of the- Av ole--skin- thickness.Except for very sma area burns these arenot reparable with time but require skingrgfting in all cases.. Infection is invaria-bly present. Paradoxically, the third-de-gree burn is not as painful as the second-degree burn because the nerve endingshave been destroyed; yet third-Uegreeburns to more than 25 percent of the hu-man body area might represent. a .fatalinjury.

-

3.54 The' treatment of severe thermalnjury on areas in.excess of 25 percent ofthe whole body represents a grave medicaLproblem e'ven in a modern hospital andunder the best of circumstances. For massburn casualties under field conditions the

_situation takes, on- overwhelMing 'propor-tions. An unwarned urban populationcaught out of doors during a nuclear at-

, -tack-would -suffer-almost-tomplete-annihi=-lation from blast and thermal energy outto a radius of many miles from groundzero. While it is feasible to avoid theprompt thermal flash by taking cover, it isnot so evident how to avoid the secondaryeffects of the burning environment whichdevelops soon after the burst. It is proba-ble that burris from secondary fires engen-dered by the bomb would represent a ma-jor proportion of the casualties, even for apopulation which had-received warning ofimminent attack. (From 65-85% of theatom bomb survivors in Japan wereburned to some degree.) Figure 3.54_showsthe ranges in miles at which people, in theopen would suffer various degrees of skinburn from surface burst weapons of differ-ent power.

THERMAL EFFECTS OF WEAPONS OFDIFFERENT YIELDS

3.55 A 19MT Weapon radiates 500 timesas much heat as a 20KT. bomb. Accordingto the "inyerse square" law a 10MTweapon should produce the same amountof heat as the 20KT weapon at a distance

44911 IN MILES

wf.APON POwER 20 KT

...,

I00 Kr I mr

1

2 mi 5 WI' I04r

.

FOIST DEORa 1044

rI 5 30 II 0 I tO 150 210

%CM DOME MUM t-0 2 0

1

5 5 7 5 110 150

. TM° ef.04F_E MAN 0875 I 5 ' 47512

425 85 13.0

FIGURE 3.54.---Range of effects from surface burstson people exposed in open.

-22 times greater (since V500 = 22 approx.).But the heat from the larger bomb isspread over a much longer period, 20 sec-onds compared with a 11/2 second -flashfrom the 20KT bomb, so that more of theheat is dissipated.

3.58 Nucieltrweapons of 1-0-100KT &-Hirer at least 60 percent of the total ther-mai radiation from the second radiationpulse in less than 0.5 secoRd. Weapons inthe 1-1ogT range, while pkducing morethermal energy over a greater radius fromthe burst than weapons of 100KT or less,deliver this thermal energy at a .muchslower rate than the small weapons. Thus, "3

for equal thermal doses incident on tissue,the small weiipons are more effective in -producing thermal injury because thelarge weapons reqUire anywhere from 5 to15 seconds to deliver 60 percent of thethermal dose. For ekample, it requires 7-9cal./m.2 to produce second-degree burnsfrom a 10MT weapon. This illustrates amost important factor: The larger theweapon, the greater the time available forevasive dction. However, evasive tacticsmust be exercised before 60 percent of thetotal energy has been delivered. For per;

.sonnel well indoctrinated in evasive tac-Mei, this could mean the difference be-

-1tween a moderate sunburn and severe/thermal injury. Figure 3.56 shows thermalenergies required, to cause first, secondand third-degree burns from differentyield Weapons.

3.57 Temporary or perthanent blind-ness could be caused by the thermal radia-

_

Det.Oirot T410 147 50 a 10047 MIT 10MT 20103

FAST COKE IlluM4 2.0 2.5 23 3 2: 3.7 3.11

54:0ito 0034(1 SIAN 4 I 49 54 12 7.2 7.5

TWO DEGREE Num

"80 7.3 S I 94 OS 114

FIGURE 3.56.---Approximate thermal energies in Callcm.2,required to cause skin burns in air or surfaceburst.

1341

tion if a person is looking ip the generaldirection of-the fireball at the precise mo-ment of detonation. T.he lernk of the eyefocuses beat as well as light rays on theretina of the eye. Thus in addition to tem-

_porary_or !flasrblindnessof a few sec-onds or minutes duration froin the intenSelight, actual burns of the retina could oc-cur from undue amounts of thermal radia .tion entering the eye. Neither flash blind-ness nor retinal damage constitute majorhazards during diylight because of natu-ral restriction of the diameter of the pupilwhich limits the amount orlight enteringthe eye; furthermore the blink reflex, one

. hundred and fifty thousandths of a second,protects the eye from undue amounts of

' radiation, except in those eases where thethermal pulse is delivered within.ex-tremely short times. This is the case forlow-yield weapons and can also be true forhigh altitude bursts., 3.58 It is an interesting fact thatamong the survivors in Hiroshima andNagasaki, eye injuries directly attribut-able to. thermal radiation appeared to berelatively unimportant.' There were manycases of temporary blindness, occasionallylasting up to 2 or 3 hours, but more severeeye injuries were not common.

3.59 The eye injury known as keratitis(an inflammation of the*cornea) occurredin some instances. The symptoms, includ-ing pain caused by light, foreign-body sen-sation, lachrymation, and redness, lastedfor periods ranging from a few hours toseveral days. .

OFECT OF SMOKE, FOGAND SHIELDING

3.60 In the event of an air burst occur-ring above a layer of dense cloud, smoke,or fog, an, appreciable portion of the ther-mal radiation will be scattered up*ardfrom the top of the layer. This scattbereckradiation may be regarded as lost, as faras a poini on the ground is concerned. Inaddition, most of the radiation which pene-trates the layer will be scattered and verylittle will reach the given point by directtransmission. These two effects (smoke or

log) will result in a substantial decrease in

42

the amount of thermal energy reaching agrokind, target.

3.61 It.is.important to understand that*the decrease in thermal radiation by TOg

and smoke will be realized only if theburst point is above or, to a lesser extent,

irithin the fog (or- similar) layer. If theexplosion should occur in moderatelY` clearair beneath a layer of cloud, or fog, wine ofthe radiation which would normally pre-ceed outward into space will be scatteredback to earth-. As a result, the thermalenergy received will actually be greaterthan for the same atmospheric transmis-sion condition without a cloud or fog cover.

3.62 Unless scattered, thermal ra:dia-tion from a nuclear explosion, like ordi-nary light in general, travels in straightlines from its source, the fireball. Anysolid object, opaque material, such as awall, a hill, or adree, between a given objectand the fireball, will act Us a shield andprovide protection from thermal radiation.Transparent materials, on the othet hand,such as glass or plastics, allow thermalradiation to pass_through, only Slightlyabsorbed.

3.63 In the case of an explosion in thekiloton range, it would be necessary totake evasive action within a small fractionof a second if an appreciable decrease inthermal injury is to be realized. The timeappears to be too short for such action tobe possible. On the otherhand, for explo,sions in the megaton range, evasive actiontaken within a second or two of the ap-pearance of the ball of fire eould reducethe severity or injury due to thermal ra-diation in many cases and may eireh pre-vent injury in others.

NUCLEAR RADIATION

3.64 It was stated in paragraph 3.4 thatone of the unique features or a nuclearexplosion is that it is accompanied by theemission of various nuclear radiations,These radiations, which are quite different

, from thermal radiation, consist of gammarays, neutrons, beta particles, and a smallproportion of alpha particles. Essentiallyall the neutrons and part of the gammarays are emitted in the actual fission proc-

49

s

esti. That is, these radiations are prodUcedSiniultaneously with the 'nuclear explo-sion, whereas the beta particles and theremainder of the gafnma rays are .liber-ated'from fission products hi the course oftheir radioactive decay. The alpha parti-cles result from the, normal radioactiye

'Idetay ot the 'uraniam or plutoninm thathas escaped fission, in the bomb.*

3.65 Because of the nature of the -phe-nomena associated with a nuclear explo-,

:sion, either in the air or near the surface,it is convenient for practiCal purposes toconsider the nuclear radiation as,beingdivided into two categories; namelY, initialand residual.

---

INITIAL,NUCLEAR RADIATION

3.66 -The initial nuclear radiation isgenerally defined as that emitted from thefireball and the atomic cloud within thefirat minute after the detonation. It in- ecludes neutrons and gamma rays given offalmost instantaneously, as Velt as thegamma rays emitted by the radioactivefission products in the 'rising cloud. Itshould be noted that, although alpha andbeta particles are present in the initialradiation, they have not been considered.This is-because they are.so easily absorbedthat Olty will-not reach more than a fewyards, at most, from the atomic cloud.

3.67 The somewhat arbitrary time pe-riod of 1. minute for the duration -of theinitial nuclear 'radiation was originally,based upon the following coniderations.'As a-consequence of absorption ,by the air,the effeetive range of the fission gammarays -and thoselrOm the fission prodtibtsfrom a 26-kiloton explosion is very roughly

words, gammatraydorigisnating from, such a sOurce-af an altitude ofover 2 Miles Can be ignored as tar tul theireffect at the earth's surface is toncerned.Thus, when the atomic cloud has reacheda height of2 miles, the effects of the initialnUclear radiation are no longer signifi-cant. Since lt,takes roughly a minute, forthe cloud to rise this distance, the initialnuclear radiation is defined as that emittedin the first minute after the explosion.

3.68 The foregoing discussion is based

on the characteristics of a 20-kiloton nu-clear bomb. For a bomb of higher energy,the maximum distance over which thegamma rays 'are effective will be greaterthan given above. However, at the sametime, there is an iriirease in the rate atwhich the Cloud, rises.;Similarly for a bombOf lower energY, the effective distance Isless, but so is the rate of ascent of the'cloud. The period over which the initialnuclear radiation extends may conse-quently be taken to be approximately. thesame; napiely, 1 Minute irrespective of theenergy *ease of the bomb.

4k69. -Neutrons produced directly in thethermonuclear reactions mentioned inparagraph 3.18 are of.special significance.Some.of the neutrons will escape but oth-ers will be captured by the various nucleipresent in the exploding bomb. These neu-trons absorbed by fissionable species maylead to the liberation. of more neutrons aswell as to the emission of gamma rays,just as described above for an ordinaryfission bomb. In addition, the capture ofneutrons in non-fission reactions is us-ually accompanied by gamma rays. It isseen, therefore, that the initial radiationfrom a bomb in _which both fission andfusion (thermonuclear) processes occur,consists essentially of neutrons and-gamma rays. The relative proportions ofthese two radiations may be somewhatdifferent than for.a. bomb in which all theenergy released is due to fission, but forpresent purposes, this difference_may bedisregarded. The range of lethal effects"from. initial nuclear radiation are wellwithin the areas of severe blast andther-mall damage. .

RESIDUAL NUCLEAR RADIATION

3.16 The radiation which- is emitted 1.minute after a nuclear explosion is definedas residual nuclear radiation: Tliis radia-tion arisedmainly from the bomb residue;that is, from the fission products and, to alesser extent, from the uranium and plu-tonium which have escaped fission. In ad-dition, the residue will uSually containsome radioactive isotopes formed as a re.;suit of neutron Capture by bomb materials.

'

43

i;-;

"/

--A.notheraourceotresidual nuclear radia-tion, it the actiVity induced by neutrons-

. captured-1n various elements .present intheearth, in the.sea, orin.the substances

,whieh may,be in the explosion environ-Merit.,

3:71 .';iTifit,h1surfaceitand,iespecially, sub-, -"surface ,eltPlOsions;,the demarcation be-

. tWeen-initial:and residual nuclear radia--. tion.iisnOt as-definite. some -Of the radia-- tion:from.the -bomb residue will be withinthe range of the earth's surface at, alltiineaso- that theinitial and,residual.cate-goriee merge Continuouily into one an-other. -Oor. very deeP.underground and un-derWater burstar the initial gamma raysand neutrons produced in thefission proc-ess may be ignored. Essentially the antinuclear radiation of importance is thatarising-from tbe, bomb-residue. It can con-sequently be treated as consisting exclu-sively of the-residual radiation. In an air.arid surface burst, however, both initial

and; residUal .nuelear radiatiOn _must betakeninto*sideratiOn.

3.72 :Oneadditional iMportant cOnsider-,ationof nuclear radiation is that the resid-ual:nuclear radiation can, under some con-ditions,,represent a seriouskaxard at greatclistanees . from a nuclear explosion, wedbeyond tke range of blast,, shock, thermal

. radiation,, and initial nuclear. radiation:_ This phenomenonFALLOUTwill be dis-

cased'at lentth in later chapters.

CHARAtTERISTICS OF A SURFACE 'BUitST

3.74 An important 'difference between asurfaCe buffet and an aik burst is that in thesurface burst the atomic cloud' is muchmore heavily loaded with .debris (and so

, produces much more FALLOUT). This Will -consist, of Particle s. 'ranging in siie fromthe very-small on,ea prodneed y condens,a-tion ai the 'firehalt Coeds, tO th# anuchlarger particks which have been raised bythOtirfaee winds. The exact comPositionof The:cloud will, Of cenrse, depend on thenature Of the terrain and, the extent bfcontact with the. firéballi-&75 For a surface burst asaociated

with a moderate amount of debris; as wasthe case in several test explosions inwhich the bombs were detonated near theground, the rate of riae of the .cloud ismuch the smile as given earlier for an airburst. The atomic cloud reaches .a heightof several miles before sPreading ont intoa mushroom shape:

3.76 The lorization of dirt and othermaterial when, the fireball has touched theearth's surface, and the removal of Mate-rial by the blast wave and, winds accompa-nying the explosion, result in the forma-tion of a orater. The size of the crater willvary with the height above the surface atwhieh the bomb is exPloded and with thecharacter, Of the Soil, as well as the energyof, the boMb. It is believed that for a 1-megaton 'bomb there wodid be no apprecia-ble crater formation unless detonation oc-cure at,ari altitudeoft450 feet or less.

3.77 If-anuelearb,ornb is exploded nearthe surface of the. water, large amounts ofwater Will be vapOrized and carried upinto the atornic clOud. For example, if it issupposed, .as abOve (paragraph 3.73); that tpercent of the energy of the 1-megatonboinb Is expended in this mariner,, about10,600 tons 41 'Water' will be coriVeitedinto vaiior. At high altitudes this will con-dense to form water droplets Similar- tothose in an ordinary atmospheric clond.

,s

3.13 - In .a.surface bUrst,,the ball of firemite rapid ihitial growth will touch thesurface ,of the earth. Because of the in-tentie.heat. a considerable, amount of rock,8,4411Aieofharniateriallocated in the, areaWill,be yapOriZed and taken into the bail of

Ik 'has. been estimated 01,4;0 only. 5perce4 of a -1"Inegaton bomb's:energy isspent Uythisjoanner, soroething,like 20,-400 ions. of Vaporized, soil material Will beaddett eo thmormal cOnstituents of thefirebill.inaddition,the high twirids at theearth!s surface will cause large amounts ofdirt,- dust, .0-d other particles to be-sucked

thez,ball ,of fire rises; (See Figurh.

AIR BLAST AND GROUND SHOCK

3.78 The Overall blast effect due to theair shock from a surface bqrst will be lessthan that from an air burst for weapons ofequivalent yield. For orie thing, part of the

energy of the bomb is used up in vapor-izing materials on the surface and informing a crater. In addition, up to 15percent of the energy may go into groundshock. The main point, howevekr, is thatbecause the bomb explodes close to theearth's surface, the 6verpressure neatground zero will be much greater than foran air burst, but it will fall Off more rap-idly with increasing diitance from groundzero,.

3.79 As a result, energy will be wastedon targets close to ground zero whichcould have been destroyed by much loweroverpressures. At the same time, the over-pressures a some distance away will be

-too low to ca e any considerable damage.In other words, there will be an "over-destruction" of nea y surface targets andan "under-destruction" of those furtheraway. The energy that has gone to produceground shock may contribute, however, tothe destrzation of underground targets pro-tected from the air blast such as missilelaunching sites. Figure 3.43c, (and its leg-end), will provide additional specific infor-mation on surface bursts.

THERMAL RADIATION

3.80 The general characteristics of thethermal radiation from a nuclear detona-tion at the surface will be essentially theSame as for an air burst, described previ-ously. As stated earlier, if evasive actioncan be taken within a second or so, part ofthe heat radiation may be ayoided.

INITIAL NUCLEAR RADIATION

3.81 The initial nucleat radiation from

a surface burst will be similar to that in anair burst. However, if the low level nuclearexplosion occurred,in a more or less built-up area, the structures through which itpassed would serve to reduce, even thou*they would not coinpletely shield, thegamma radiation. For practical Inaposes,however, it would be advisable to treatthese two types of burst as the same as faras initial nuclear radiation is concerned.

RESIDUAL NUCLEAR RADIATION t

3:82 With respect to residual radioac-tivity, -a nuclear explosion at a low levelwould produce effects somewhat similar toa subsurface burst. That is, a considerableamount of dirt and ot et debris or water,would be hurled into he air, and upondescendrig, it might pr d ce a base surge(highly radioactive clou of dust or vapor)which will be contaminated partly fromthe condensation on the ground of thenuclear reaction prOducts froin the ball-offire, partly from the fallout of heavierpieces, and partly from radioactivity in-ducdd by neutrons..

CHARACTERISTICS OF A SUBSURFACEBURST

3.83 When a nuclear bomb is exploded -under the ground, a ball of fire is formedconsisting of extremely hot gases at high .

pressures, including vaporized earth andbomb residue. If the detonation occurs at

' not too great a depth, the fireball may beseen as it breaks through the surface,before it is obscured by clouds of dirt, anddust. As the gases are released, they carry..

up with thetS into the air large quantities

SHOCK FRONT

DIRT COLUMN

0 0.5 1.0

FIGURE 3.83a.Chpnologica1 development of a 100-KT shallow underground burst: 2.0 seconds after detona-

-45, .

-MI LES I -

0-1 1 1 1

0.5 4.0 1.5 2.0

noun 8.83b.Chronological development of a100-KT shallow underground burst: 9.0 secofids

CLOUD

NUCLEAR RADIAT1ON

after detonation.

THROWOUT

BASE SURGE FORMING

Fromm 3.83e.--:Chronologleal development of a 100-KT shallow underground burst: 45 see inds after detonation.r

MILES. o a 2.0,

CLOUD

NUCLEAR ,RAD ATION

bASE -SURdE COL

irrauszafiad.--Chrenological development of a 1

11

0.5 . 1.0 / 1.5 2.0i

.

KTa4Iillow underground burst: 4. minutes after detonation.

41

4

4

'1 .

0%

o

,

../

,.

_

-

%

. of eartht roele",-and debris in fhe :form of acylindrieal cojumn..The chronological devel-opment of some of the phenomena associ-ated with n underground explosion, kay-ing an energy yield. of 100 kyotorts, isrepresented by Figures 3.83a to 3.$3d.

3.84 , It is estimated from:tests made inNevada that, if a 1-megaton bomb weredropped from the air and penetrated un-derground in sandy-soil to a depth of 50feet before exploding, the resulting craterwotild be about 300 feef deep anenearly1,400 feet across: This,Aeans that approxi- 'Cr mately 10 million tong ot!soil. and rockwould be hurled upward from the earth'ssurface. The volume of the crater AO themass of material thrown up by the force ofthe explosion will increase roughly in pro- 'portion to the energy of the bomb. As theydescend to earth, the fill.r artieles of soilmay initiate a base surge s shown in

t

Figure 3.83d. .,

..../ .

AIR BLAST A D GROUND SHOC

3.85 The ya id expansion of the bu bleof hot, high-pr ssure k.ases formed in t eunderground urst initiates a shock wavein the earth. Its/effects are iomewhaesimilar to those of ar earthquake of mod-erate intensity, 9 xcept that the disturb-ance originates airly near the surface in-

. stead of at a gre t depth. The difference indepth of origin means that the pressures,in the underground a hock wave caused bya nuclear bomb probably fall off moie rap-idly with distance han do those due 'toearthquake waves.

3.86 Part of the energy from an Under-giound- nuclear explosion appears as ablast wave in the air. The fraction, of theenergy imparted to the air in the form ofblast depends primarily upon the depth ofthe burst. The greater the penetration ofthe bomb before detonation occurs, thesmaller is the proportion of the shock en-ergy that escapes into the air.

THERMAL AND NUCLEAR RADIATION

3.87 Essentially all,th< thermal rwlia-1 tion emitted by the ball of fire wyle it is

still submerged is absorbed by the sur-rounding earth. When'the hot gases ma&

;

..

,

the surface Sn and, the cooling is sorapid that the erature. drops-alinost .imjnediately t int where, there is-no .further appreciable emission o hermal,adiation. It follows, therefore, tha"b4n anunderground nuclear explosion the her-zeal radiatibn can be ignored as far a-itseffects on persodnel and as a soCrce o fireare toncerned.

.. L3 88 It ris

probabie, to, at most of the ..,neIiIons and gamma rays liberatedWithi a shorttime of thelpitiation of the,expl eiwn Will also be Ab's9rbed by theearth. But, when the fir bail reaches thesunfeleand the gases re expelled; thegamma rays (and beta rticles) from. tfission products will re ent a. form ofinitial nuclear tadiation. addition, theradiation fromellission (and nutron-induced radiartive) products preseitt inthe cloud stein, radioactive clfflid, and IDasesurge, all three otwhich are formed withina few seconds of the burst, Will contribute.to the initial effects.

3.89 However, the fallout from thecloud and the base surge are also resonsi-Ne the residual nuclear radiation. Fora subsurface burst, it is thus less meaning-,ful to make a sharp distinction. between ,initial and r idual radiation, such as isdone in t é of an air burat. The inidalnuc r adiation merges /continuouslyinto those which ire, produce:I over a pe-yiod of time following the'nuclear explo-sion.

HIGH ALTITUDE BURSTS

3.90 For nuclear detinations'at heightsup to about 190,000 feet the .density of airis such that the distribution of 'the explo-sion energy remains almost unchanged,approximating that described for an airburst, e.g., about 45 to 55 percent (of thefission energy) appears as blast and shock,and 30 to 40 percent is ihceived as thermalradiation., .

3.91 At greater altitude's, this distribu-tion begins to ,change noticeably with in-creasing height of burst, a smaller propor-

th' ",

L.ction of e energy appearing as blast. It isor thIs reason that 'tkerlevel 0(.100,000,

feet has been chosen for distinguishing

4 7I-

*

-between air bursts and high-altitudebursta.

3.92 There is, of course, no sharpchange in behavior at this elevation, andso the definition of a high-altitude burst asbeing at a height abofe 100,000 feet issomewhat arbitrary. Although there is aprogressive decline in the blast energywith increasing height of burst above 100,-000 feet, the proportion of the explosionenergy received as effective thermal ra-diation on the ground does not at firstchange appreciably. This is due to theinteraction of the primary thermal radia-tion With the surrounding air and its sub-sequent emission in a different *spectralregion. At still higher altitudes, the effec-tive thermal radiation received on theground decreases and ii, in fact, less thanat an equal distance from an air burst ofthe same total yield.

3.93 One aspect of a high-altitude burstthat has received increased attention inrecent years is the electromagnetic pulse(EMP). Its iinplications were first notedduring an experimental high-altitudeburst_oxer Johnson Island in the PacificOcean in 1962 when stieet light 'failuresand cominunications disruptions occurredon Oahu, 750 miles awdy. In an era ofintercontinental ballistic missile systems,and defenses against those missiles, thepossibility of ,a high=altitu-ae burst in anuclear attack becomes very real.

3.94 Put simply, the electromagneticpulse is, that portion of the electromag-netid spectrum (Figure 2.42) in the me-dium to low frequency range extendingroughly from the frequencies used in ra-dar and TV down to those used in electricpower. Since most of the energ,y is ra-diated in the frequency bands commonlydsed for radio and TV communications, itis sometimes called "radio-flash." It is dif-ferentiated from the thermal radiation"pulse" that produce heat and light andthe initial radiation ',!.1Tlse" of gamma andX-r ys,

3. There is concern about EMP be-cause he-energy in the pulse can be col-lecteçY and concentrated, much as thesun's rays can be focused to prance a fire,

as shown in the upper portion of Figure3.95-. The lower portion of the diagramshows some common EMP energy collec-tors. Sufficient energy van be collected bythese means to cause damage to attachedelectrical and electronic equipment.

3.96 In a surface cr near-surface burstthe relevant EMP enetgies are generallywell within the blast and thermal damageareas close to the point of nuclear detona-tion and thus cover a relatively small geo-graphical area.

3.97 By contrast, if a nuclear weapon isdetonated high above the earth's atmos-phere, the X-rays and gamma rays emit-ted downward from the explosion will beabsorbed in a big "pancake" layer of theatmosphere between .12,/2 and 25 milesabove the earth's surface, as s'hown inFigure 3.97. The gamma energy is con-verted into lower-frequency electromag-netic energy in this interaction region andpropagated downward to the earth's sur-face as a very brief but powWul electrom-agnetic pulse. Tlie strength of this pulseon the ground is much the same.as ip themoderate damage area of a,surface burst.However, very large areas, otherwise un-damaged, can be affected by the high alti-tude detonation, as the lateral extent ofthe "interaction region" is generally lim-ited only by the c(gvature of the earth.

3.98 The extent of that damage can beseen by considering a typical high-altitudeburst over Omaha, Nebraska as shown inFigure 3.98. Within the circle passingthrough Dallas, Texas the EMP hazardwould be the greatest. The outer circleshows that there is potential damage fromEMP effects over the whole area of theUnited States.

3.99 EMP can cause two kinds qf dam-age. First, functional damage that wouldrequire replacement of a component orpiece of equipment. Examples would bethe burnout of a radio receiver "front end"or the blowing of a fuse. Second, opera-tional upset of equipment such as openingof circuit breakers or erasure of a portionof the memory of a computer.

3.100 Exberiments have shown that CDraciiation detection equipment is not sus-

49

* '4:1 .g. INT:ERACTION,

;1 "

I

I

I ;.41 f I

I 'I1I

I .'

I I II

I r 1 - EM FIELDSI 1

1

EM energy Is picked up by long conductorand delivered to sonsItIveeauIpment.

EMP.ENERGY FROM HIGJ-I ALTITUDE BURST,- r

EARTH

From: Survive, November-December 1969

4:IGURE 3.97.---EMP energy from high altitude burst.

EIVIRGIIIDUND COVERAGE-Of HIGHALTITUDE EIUR4T-S

Source': 'Defense Nuc lelr Agency.

FIMME 848,-=EMErground'cOver,age of high altitude bursta

-Optible-to_ direct daitagè nor are handheld Pitigent BantilvalldetalkieS. or FMradio -receiVere. The' vulnerability of indi-iiduit..electrical or electroniC eiluipmentcart -vary itreatly, Transistor s.. 84.4_ inipro-

r- jviire[dicides, for exaMPle,, are relativelythah vacuuM tubes or

bleötiieniOtois..3.101. ttig EMP:threat and protective

measures for civil preparedness. related,equipinent are available in

tectinical phblicationa of DCPA. E Mer--gency oPeritting, Centers; broadcast radioind:TV,-telephOne and electric power sys-thins and; public safety radio are'some of

-the-Area's-of concern.3.102 Listed- beloW are seven anti-EMP

actiOns that could be applicable to localcivil preparedness operations.

1. ,Maintain a supply of spare parts..2. Bhift to emergency power at the earli-

gst possible time.a. Rely on telephone contact during

threat period' so long as it remainsoperational.

4. If radio_ coMmUnication is essentialdining-threat period, use only onesystem at a tini6. Disconnect all othersystems from antennas, cables, andpower.. .

"6: Disconnect radio base stations, whennot-in use from antennas and powerline.Plan for mobileto-mobile backup com-munications.

I. Design emergericy operating plans so: that-pperationa will adegfade_grace---

fully if coMmunications are lost:

g.

_SUMMARY-OF EFFECTS OF IlAiIOUS TYPEBURSTS.,

MAP ,Some general conclusions cah.be.OfferefineuMniary of the degree Or seyer-ity.of the particular effeCts of the varioustypea'of nuclear detonations. The ;variousdegrees are relative to, each -other for aglien,btirst tyPe, andiare best'inthrpretedin tenni of the descriptions given below.

,

; isonitharris repdMed from THE EFFECTS OF NUCLEARWRAPO-NS:'

='

HIGH-ALTITUDE BURST 5'

LIGET: Very intense.HEAT: Moderate, decreases with increas-

ing burst altitude.INMAL NUCLEAR EADIATION: Negligible.

SHOCK: Negligible.

Aut BLART: Small on the ground, deereas-ing with increasing burst altitude.

EARLY FALLOUT: None..

SUMMARY: The most significant effect willbe flash- blindness over a very largearea; eye burns will occur in personslooking directly at the explosion. Othereffects will be relatively unimportant.

AIR BURST

LIGHT: Fairly intense, but much less than.for high-altitude burst.

HEAT: Intense_ out to considerable dis-tances.

INITIAL NUCLEAR AADIATION: Intense, butgenerally hazardous out to shorter dis-

, tance -than heatSHoCH: Negligible except for vèy low air"

bursts.AHISLASTL Coriaiderable out to dstances

similar to heat effects:%EARLY FALLOUT: Negligible.

_SUMMARY: Blast will cause considerable

Structural damage; burns to exposedskin, are possible over a large 'area ande5T effecti over a "still larger area; ini-tial nuclear radiation Willhe:a hazardetelbser clistanOei; bift..tne early Eilloufhazard will-be negligible.

GROUND SURFACE BURST

LIGHT: Less than for an air burst, but stillappreciable.

HEAT: Less than for an air burst, butsignificant.

INITIAL NUCLEAR RADIATION: Less thinfor an air burst.

SHOCK: Will must damage within aboutthree crater radii, but little beyond.

*As modified by4.9S-3.102.

AIR BLAST: Greater than for an air burstat close-in distances' but considerablyless atifarther distafices.

EARLY FALLOUT: May.be considerable (fora high-yield weapon) and extend over alarge area.

SUMMARY: Except in the region close toground zero, where destruction wouldbe virtually complete, the effects ofblast, thermal radiation, and initial nu-clear radiation will be less extensivethan for an air burst; hoWever, earlyfallout may be a very serious hazardover a large area which is unaffected byblast, etc.

SHALLOW UNDERWATER BURST

LIGHT, HEAT, AND INITIAL NUCLEAR RA-DIATION: Less than. for a ground surfaceburst, depending on the extent to whichthe fireball breaks through the surface.

SHOCK: Water shock Will extend fartherthan a water surface burst. .

Am BLAST: Less than for surface burst,depending upon depth of burst.

EARLY FALLOUT: May be considerable, ifthe depth of bhrst is not too large, andin additioh there may be a highly radio-active base surge. 41.

1.1MMARY: Light, heat, and initial nuclearradiation will be less than for a groundsurface burst; early fallout can jpe sig-nificant, and at distances mot too farfrom the e3Icplosion the base surge willbe an important hazard.

WATER SURFACE BURST

LIGHT: Somewhat more intense than for aground surface burst.

HEAT: Similar to ground surface burst.INITIAL NUCLEAR RADIATION: Similar to

ground surface burst.SHOCK: Water shock can cause damage to

ships and underwater structures to aconsiderable distance.

AIR BLAST: Similar to ground surface

EARLY FALLOUT: May be considerable.

SUMMARY: The general effects of a water

surface burst are similar' to those for aground surface burst, except that theeffect of the shock wave in water willextend farther than ground shock. Inaddition, water waves can cause damageon a nearby shop by the force of thewaves and by inundation.

SHALLOW UNDERGROUND BURST

LIGHT, 'HEAT, AND INITIAL NUCLEAR RA-DIATION: Less than for a water surfaceburst, depending upon how much of thefireball breaks through the surface.

SHOCK: Ground shock will cause damagewithin about three crater radii, but lit-tle beyond.

AIR BLAST: Less than foria surface burst,depending on the depth of burst.

EmtLY ,FALLOUT: May be considerable, ifthi-apth of burst is not too large, andin addition there may be a highly radio-active base surge.

SUMMARY: Light, heat, initial nuclear ra-diation, and blast effects will be lessthan for .a surface burst; early falloutcan be significant, but-at distances nottoo far from the explosion the radioac-tive base surge will be an importanthazard. Water waves can also causedamage, as in the case of a water sur-face burst.

CONFINED SUBSURFACE BURST

LIGHT, HEAT, AND INITIAL NUCLEAR RA-,DIATION: Negligible or none. .

SHOCK': Severefrespecially. at fairly4closedistances from the burst point.

AIR BLAST: Negligible or none.SUMMARY: If the burst does not penetrate

the surface, either "of the ground orwater, the only hazai-d will be 'fromground or water shock. No other effects

- will be significant.

REFERENCES

The Effects of Nuclear Weapons.Glas-stone, Samuel,:1964.

EMP Threat ahd Protective Measures,DOD/bCD, TR-61, August 1970.

RCPA Attack Environment Manual.C.) 0

SS

NUCLEAR RADIATION MEASUREMENT

Since we cannot hear, see, smell, taste orfeel nuclear`radiation from the fallout, wemust relir entirely upon instruments inorder to DETECT its presence and MEAS-URE the degree of danger. In this chap-ter, then, we will look at:

HOW nuclear radiation may be de-tected

HOW nuclear radiation may bemeasured

WHAT instruments exist to do the de-tecting and-the measuring

HOW do instruments operateWHY do we need different types of

instrumentsWHAT are the units we use to meas-

ure nuclear radiation

, INTRODUCTION

4.1 Man is aware of his environmentthrough his senses. He can see, smell,taste, hear and feel. Yet, none of thesesenses will make him aware of the pies:ence of nuclear radiation. This situation isnot really unusual. In fact it is Jike his

,i,nability to respond direptly to thp wavesof ultraviolet light and radar, television,or radio transmission. For example, a manmay receive a serious sunburn due to ov-erexposure to 'the sun's ultraviolet rays,yet his first indication of over-exposuremay come Several hours later when hefeels pain. In this Situation he was not

, aware of the ultraviolet rays during theexposure period; however, in a sense, hedid detect the ultraviolet light indirectly'since certainlY wotild be aware, of apainful sunburn. Similarly, since man 011.7_!riot rely- on Ilia leiiies le detect nhcrearradiation he must rely on some secondarymeans such as instrumentation. I

GI

CHAPTER 4

4.2 At the present time, nuclear radia-tion detection instruments are widely usedin industry and research. X-ray films andGeiger counters are.items of everydayconversation. In this diapter we will dis-cuss the principles and theory of operationof many nuclear radiation detection in-struments, or radiological instruments aswe will refer to them. These instrumentsare very similar to other types of elec-tronic equipment. Their main diskinguish-ing characteristic is their ability to re-spond to nuclean radiation.

4.3 The term DETECTION is used inthis text to inclue only the indication ofthe presence of nuclear radiation. Theterm MEASUREMENT will be reservedfor both the detection and quantitativeestimation of the amount of nuclear radia-tion present.

PRINCIPLES OF RADIATION DETECTION

4.4 Radiological instruments detect theinteraction of radiation with some type ofmatter. Th,e different principles of radia-iion detection are characterized ,by thenature of theinteraction of the radiation,With the detecting or sensing element.Several types operate by virtue of theionization which is produced in them byThe passage of charged particles. In otherdetectors, excitation and sometimes molec-ular disassociation play important roles.

4.5 During the 18.90's, Henri Becquerelfound that photographic plates, whenplaced in proximity to ores or compounds:6f uranium, were affected in the samemanner as if they had been exposed to

,light.,This occurred even when the platpsWere prOtected by sufficient covering toassure that the strongest light could notaffect them:This date marked the discov-

SS

ery of radioactivity, and today this princi-ple is still used to detect and measure theproduct of radioactivity, NUCLEAR RA-DIATION.

4.6 The photographic detection tech-nique is relatively simple. As a chargedparticle passes through a photographicemulsion, it will generally cause change%which will result in a blackening of theemulsion when the film is developed. Thephotographic emulsion consists of finelydivided crystals of a silver halide, usuallySilver bromide, suspended in gelatin andspread evenly on a glass, cellulose, or pa-per base. When charged particles strikethe emulsion, some sort of ionization notwell understood takes place. This local dis-turbance of the electrons in thesrystals ofsilver bromide creates a latent imagewhich is invisible to the eye when formed,but which can be developed later by chem-ical action. The chemical developer acts asa reducing agent to deposit metallic silveronly at those points in the, emulsion whereradiation interacted- and in proportion tothe amount of radiation which acted onthe ,silver salt. The amount of blackeningo9, the film is a function of several factors:the time of exposure, the intensity of theexposure, the sensitivity of the film, andthe chemical prqesses of development. Byrigidly controlling these factors, the black-ening of the film can be Made proportionalto the radiation exposure.

4.7 A second method of detecting radia-tion was again first employed by Bec-querel and Rutherford in their early workwith radioactive substances. Certain ma-terials will produce small flashes of visiblelight when struck by alpha, beta, orgamma radiation. These flashes are calledscintillations. The mechanism of formationof these scintillations is very complex butessentially it involves the initial formationof higher energy (or excited) electronicstates of molecules (or atoms) hi certainmaterials. Some of the absorbed energywhich has been derived directly or indi-rectly from the incident radiation will beemitted in a very_ short tVrie as photons ofvisible or ultraviolet likht. These lightphotons are-then converted into an electri-cal current by a photomultiplier tube and

56

the current is measured. Since the lightintensity and the resulting electrical cur-rent are proportional to the rate ,of radia-tion exposure, the instrument can be cali-brated to read radiation exposure rates.

4.8 A third principle for detecting ra-diation is based on the fact that manysubstance's' undergo chemical changeswhen exposed to radiation. This is particu-larly true of chemicals in aqueous solu-tions where the decomposition of thewater itself contributes to the reaction. Ifthe extent of the chemical change can beconveniently measured, tite reaction canbe used for measuring radiation. Thereare several chemical reactions which maybe utilized in this manner. One of the firstused was the liberation of acid from achlorinated hydrocarbon such as chloro-form. Chloroform, water, and an indicatordye are sealed into a glass tube. As radia-tion penetrates thi tube, hydrochloric acidis liberated from the chloroform. The liber-ation of this acid reduces the pH of thesolution and causes a distinctive colorchange in the-dissolved indicator. The ex-tent of the color change is an estimatt ofthe radiation exposure of the tube.

4.9 Becquerel's discovery that gasesbecome electrical conductors as a result ofexposure to radiation provides us with afourth means of detecting and measuringradiation. When a high-speed particle or aphoton passes through a gas, it may causethe removal of an electron from a neutralatom or molecule causing the formation ofan ion pair. This process of ionization in agas is the basic phenomenon in all EN-CLOSED GAS VOLUME INSTRUMENTS. The elec-tron produced may have rather high ener-gies and may produce more ionization inthe gas until its energy is expended and itis efinally captured by an oppositeVcharged ion. If two oppositely charged cqi.-lecting electrodes are introduced into thegas filled chamber, the ion pairs will mi-grate to their respective electrodes. NegiN,tive ions will move toward the positivelycharged electrode and the positive ionstoward the negatively charged one. Whenthe ions reach the electrodes, they will be r:neutralized, resulting in a reduction of the

arge on the electrodes. In one type .of.

instrument this loss in charge ia used as ameasure of the radiation exposure. In. an-other type, batteries are used to replacethe charge on the electrodes resulting in acurrent flow in the external circuit. Withincertain limits, this ionization current willbe proportional to the radiation exposurerate.

4.10 In addition to the four principlesdiscussed above, there are several otherprinciples which .may be utilized for thedetection of radiation, but to date thesehave not been as widely used.

TYPES OF RADIOLOGICAL INSTRUMENTS

411 In the development of radiological'instruments, the choice of detector is animportant factor. An equally importantfactor in their design is thetype of infor-mation required by the user. Normallythis information falls into two categories:the measurement of total accumulated ex-'posure to radiation, and the instantaneousrate of exposure. The first is referred to asan EXPOSURE MEASUREMENT and the second,as an EXPOSURE RATE MEASUREMENT. As anexample of a situation in which both typesof information are required, consider thefollowink. An area is contaminated withfallout. A person is required to enter thearea and not eiCeed an" exposure of 25roentgens. This situation requires an in-strument which will measure the total ac-cumulated radiation exposure during theperiod of stay in the contaminated area.Instruments_ designed to provide suchmeasurements are called DOSIMETERS.Next, aasume that the operation to beperformed will require two hours to -corn-Plete; In-order'to deterMine if entry intothe area is practical, jt is necessary to-know the instantaneous rate of exposurefa which the person would be exposed inthe contaminated. area. Instruments de-signed to measure exposure rate are calledSURVEY AFTERS.

4:12 It is iinportant to emphasize thatradiologieal instruments measure expo-sures awd Dot abSorbed dr biological doses.Stith EXPOSURE is a Measure of thestrengt14" of the radiation field, while theABSORBED DOSE is a measure of the 6notint rgens. This, of course, assumes that the 40

of energy liberated in the absorbing mate-rial, and the BIOLOGICAL DOSE is a meatureof the biological effect of a particular ra-diation absorbed by an individual. How-ever, it is also important to emphasizethat the ultimate objective for measuringan exposure to radiation is to relate thatto a certain biological response of the ex-posed individual.

uNrrs OF RADIATION MEASUREMENT

4.13 As discussed in Chapter 2, theroentgen is the unit of radiation exposure.This unit is based on the effect of X orgamma radiations on the air throughwhich they pass. It is defined as thatquantity of X or gamma radiation suchthat the associated corpuscular eniissionper cubic centimeter of dry atmosphericair at 00 centigrade and 760 mm of mer-cury produces, in air, ions carrying oneelectrostatic unit of Charge of either sign(2.083 x 106 ion Pairs/cc). Since this unit israther large for measuring peacetime in-, cupational exposures, the milliroentgen,which is equivalent to 1/1000th of a roent-gen, is frequently used for measuringsmall exposures. Since dosimeters meas-ure exposure, they measure in ROENTGENSor MILLIROENTGENS, while survey meters,whiCh measure/exposure rates, measure inROENTGENS per hour or MILUROENTGENS perhour. It is importarit to note that the roent-gen applies only to the measurement of Xor gamma radiation, and does not apply tothe measwement- of alpha or beta. radia-tion.

4.14 These units of exposure and expo-sure rate are related by a time factoranalogous to the relationship between to-tal distance traveled and speed. For exam-ple, the total distance from Battle Creek,Michigan, to Detroit, Michigan, is approxi-mately 120 miles. A person leaving BattleCreek and averaging 40 miles per' hourwould- require three hours to travel toDetroit. Similarly, if a person -entered aradioactive contaminated area where theexposure rate was 40 roentgens per hourand remained for three hours, his totalaccumulated exposure would be 120 roent-

0,7

.

'roentgens per hour exposure rate re-- Mained constant. Just as it is ,difficult to.^.:maintain a speed of 40 miles per hOur, so

nfight..it be difficult 'to maintain a radia-tiOn field of 40 roentgens per hour, since-radioactive materials decay according tofixed natural laws. This decay will causethe 40 roentgens per hour exposure rate to*crease with time. However, if the radio:-(active material has a relatively long half-life, the decrease in exposure rate during athree-hour period may be negligible. (Withfallout, especially in the early hours afterdetonation, the decrease in exposure ratewill be appreciable during a threeAlourperiod.)

DOSIMETERS

4.15 As indicated above, it is necessaryin emergency operations to provide an in-strument'capable of measuring an individ-ual's total exposure to radiation. It is clearfrom the definition of the roentgen thatthe measurement of ionization in air isbasic to the determination- of radiationexposure. In Civil Preparedness an ioniza-tion chamber employing the principle ofenclosed gas volume has proved most sat-isfactory for exposure measurement.

4.16 To understandithe operation. of do-

7:ELEC1RODE

CASE

FOIL LEAVES

FIGURE 4.16a.ohArged electroscope.

FIGURE 4.16b.Radiation effect on chargedelectroscope.

,

simeters, consider a foil leaf electroscope(Figure 4.16a) consisting of an outsidemetal shell iii which issmouhted an exter-nally projecting electrode. An insulatorsuch as amber or sulfur insulates the elec-trode from the outside case. Two narrowstrips of a, thin foil' are cemented to theenclosed stem of the electrode to form themOving pit of the-electroscope. Normally,windows in the ease serve for viewing thefoil leaves. If an electrical charge is ap-plied to the externally projecting elec-trode, it is transferred through the elec-trode to the foil leaves. Because Of themutual repulsion of like chargeS, the:lepAres -will immediately repel each otheruntil the electrical repulsion is justcounter-balanced by the gravitationalforce tending to bring therd back together:If the air in the 'enclosed chamber is ion-ized bir radiation(Figure 4.16b), it becomesan electrical conductor and. this permitsthecharge ,on the leaves to leak away..

Since the electrical charge is reduced, theMutual repulsion of the leaves is reducedand they assume a position clOser tO-gçther. This same principle is basic to theoPeration of dosimeters. The electrostaticself-indicating dosimeter used in Civil Pre-paredness is nothing more than a sophisti-cated electroscope.

4

, FIGURE 4.17.Constrnction principles-of

4.17 The dosimeter consists of a quartzfiber electrometer suspension mounted in-side an ionization chainber (Figure 4.17).'The electrometer suSpension is supportedby meani of a highly insUlated materialinside an ,electrically conducting cylinder.The enclosed air volume ,aurrounding theelectrometer suspension it the ienizationchamber or the radiation senSitive compo-nent-of the instrnment. The indidatingeleinentiaalive micron (I/5006 in.) quartzfiher -Which is part ,ot,:the -electrometersuspension, The quartz fihorhas. an electr-ically canducting coating evaporate d. on its.surface -and has thelltaine forrn:factor asthe metal frame of .the, electronieter. tn,most dosimeters both frame and fiber areirithe'shape of a horseshoe,the fiberheingattached to two offsett an the lower ex-trenntiet of thefraine.

4:18 The dosimeter contains an lectri-ca with!,the,eleeire-.rnetev pspensfen and the, chamber Wall.The range of the dosirneter is determined

ttie ti'ae of the: capac,or, the charnber'vOluine; the sensitiviti of the eleCtrOrrie:tr,the pressure inside the _ionizationChamber 'and the optical sYStein. Onlyprestige and capacitance Variation offer a*Wide ,telection of ranges. Therefore, thefitnCtion of the electriCal 'Capacitor is tocharige the.;range of the ,dosimeter. :How-eVer; for a *0014 dosiineter, the ranceWill:be fixed hy the seleetion of thetapaci-tor at the, time ()Ott mannfacture.

. 4.19 Thech arging. switch- assembly con-sista ofa hellows and- a contact, rod,, which

;riorMaillyitolatedfroM the electrometer,

an electrottatic self-indicating dosimeter.

suspension. Only when the dosimeter isplaced oi ?. a dosimeter charger and thebellows depressed can contact be made

Lbetween the rod and electrometer. This,arrangement provides a very high electri-cal, resistance, and the hermetic sealingallowed by such construction makes thedosimeter readings essentially _indeisendrent of huMidity and pressure changes,

,4.20 tOdUseq,con the quarti fiber is a 75to 126 poWer MicroSoope which magnifiesthe iniake of the qUartz fiber ta that it isviiible. the microsco-pe consists etone ob-jective lens; one eyepiece tens, and con-tains a,scale or reticle at the real imageofthe. q:iiartz ,fiber. The scale is graduatedinroefitgent or milliroentgins depending ontherange.Of the inttruigent.:

4.21 in preparation for exposure to ;Ilkdiation, the .dosiineter is thiNei, to4bout100 to 115 volt'a to h;riniliki image !:;f-thequarti fiher te Zere on the scale. (Pigure4.21). In charging the dosimeter, an exter-nal source of electrical ,pgwer islised, theionization Chamber is held at,grod pa-tential and the metal frame and fiber, ofthe electrometer assume the other ex-treme of the Voltaie difference. The fiberis repelled from thesframesince both are

_at the same potential. The pesition of thequartz Ober will then yary with the poten-tial difference. This variance is linear forthe voltage range, covered by the scale.

-When the inttruinent readi.fUll 'kale, thepotential difference is not zero but usuallyseine intermediate voltage between 76 and.

,125 !Olt&(59.

FIGURE 4.21.Zero dosimeter reading:

4.22 As the dosimeter is exposed to Xor gaMma radiation, the photons will; in-teract with the wall ,of-the ionizatiOnchamber producing secondary .electrons

4:22a).. These electrons enter theneneitive volume of the dosimeter and:ion-

.- izet e-,41r. molecules. Under theinfluente.Of the-electrical field in theehamber, the,-ierijiairs Migrate to the_ electrode of opp o-

-eharge and are neutralized: This;:ga0agii :a Proportionate discharge of -theCaPacifor.isystetn and decreases the poten-tial :between the electrrometerand: the ehatriber wali. the .quartz fiber04:y Ogisiimetaleiv position corresponding

- tat)* 'new, potential 'difference: Thisisreflected bit ini:-upleale movement of the

:

an eledrostatictlesiineter. ,

FIGURE 4.22b.-80 R dosimeter reading.

hairline image of the quartz fiber (Figure4.22b).

The movement of the fiber is a functionof the total amount of radiation to whichthe dosimeter is exposed, regardlees of therate -of exposure to radiation.

4.23 If the dosimeter reading is zero atthe start of a period, the exposure may beread directly from the dosimeter. How-ever, any initial dosimeter reading must'be subtracted from the final reading toobtain a correct indication of the totalexposure. For example, if a dosimeterreads 10 rems at the start of a period andreads 55 rems at the end, the exposureduring the period is 45 reins. Performance'characteristics of dosimeters will be dis-cussed in the next chapter.

DOSIMETER. CHARGERS

..,4.24 The design of ,dosinigter ihargertihag progressed to the point that thelatermodels- all use transistorized, circuits toprovide the required charging voltage. Al-though some of the earliest Chargers werenot transistoriieq, probably all futureones Will' b,e beCause of the ease of 'opera-

CHARGING CONTACT

LIGHT SWITCH,OPiN

FIGURE 4.25a.Initial condition.

WOW SWITCH OPEN

DOSIMETER

.

p,04:1T Siviitht 0_0,SED

'FIGURE 4.r:h.Reading posion.

-CHA

IMETER

SWITCH C OSED

1401

1;14,EIGHT SWITCH CLOSED

FIGURE 4.25e,Charging.position.

tion of the transistorized models an4 pro-

4.26. In:the transistorized chargei, theeireuft,iati:Otvered by a sin* 1,5 volt bat-40: "The eh-44ring contact lawshowp in its'lnitliii-coriditioii in Figure 4 25a When a4eSiMeter Is Placed On ther-okopq don-

114 and, pressure is wlic4, the Iight;a:Witch ,eloises and -the billb lights _(kigur4.25b). go*ever,in thii Iisitionthe doSi .

eterigiinhOt be Charged, sines the dOsi*- charging switch is still open. so-tiOn4 'Pressnre must be 'apPlied' to losethilcisarit-ek(Fi-gtife-4,25eY. Alralisiii or 6S-Cilla4r cOnterts the ,direct CUrien from a

'light battery tO alternating currentMe:transformer cari "st up" the

VOltage 1(1.5 yoitri) to e yoltagtd:bY the deSimetét. e current is

wiltutz OLTAOOr- zip, you's,

AwnwatitAKEtT.cIøG*

I.FIGURE 4:254Simplified diagram cif !c CD V-750

LIosimeter charger./

then reCtified by a diode Eu4i'potentiel of220 volts maximum is ailable at thecharging.contact. A volta e dontrof iaused --

to adjust. the output vo tage to the exactvalue required to 'brin the dosiMeter toZero.

4.26 The mechan of 'charging a do-simeter with this t pe of charger will bediscussed in the ne ch4ter.

SURVEYMETER

4.27 ,Nr-d* cUssions ,in paragraph 4.11established' :additional requirement Airazyinitrurrie t WhiCh-;would measure expo-sure rate, or' use in Stir:Toy Operalions;This init ment Wail meaiure the rateof fOrma ion, of ion pairs rather than thetotal n ,ber- that are Troduced_by radia

ditelhe enclosed gas volume prin!.ciple as again proved most satisfactory!ST- vil.Preparedness-uses.

4 There are tWo types of Civil. Pre-edness, exposure rate instrUments

ich- depend on the .principle of, ele ctri calollectiOnot ions .(enclosed .gas -volume) for

their -inieration.-The., Charaiteristics Of .

eaCh depend mainly ,on the yoltage atwhich the enclosed gas volume is-oPerated.To:understand their operation, it as neces-sary teinvestigate the behavior of ions inan electrical field. A sYstem for investigat-ing this 'behavior is illustrated in Figure4-08. leCensiSts of a chainber filled withair In, which, age.fixed two parallel metalplates to act-as.electrodes. The electrodesare connected to-a batte,ry in such a waythat the voltage can be increased steadilyfrom zero to:several-hundred volts. A me-

#

,

FIGURE 4.28rCircuit for measuring the behavior ofions in an electrical field:

ter is placed in.ttie circuit to measure thesize of the electrical current produced.

4.29 Normally, the air rn the ioniiationchamber will not conduct electricity andno current will fldw in the external circuit.If a single ionizing radiation enters thechamber when a small difference of poten-tial is appliedqo the electrodes, a,numberof ion pairi _will be produced .which willmove to7 the oppositely charged electrode.When these itarges collect, a currentpulse will be measured by t,he meter in the

...external circuit. If. a _constant source ofgamma radiation is used and the size ofhe current .ptilse is plated against the

Voltage applied to the eleetrodes, the

AnomelmiTIONCONTINUOUS DISeHARGE

, IONIZATION CHANNER

PROPORTIONAL

GEIGER MULLER

A.

cAmmARAXS-47

00 INCREASING VOLTAGE 4...- - - -

VOLTAGE APPUED ACROSS THE CHAMBER

FIGURE 4.29--I'ulse size v. applied voltage for gamma, radiation.

curve in Figure 4.29 Will result. For 'con-venience, the curve is diVidento fiv,eregions, A, B, C, D and E.

4.30 ,When the Nioltage applied to arelectrodes is, low, the eledhcal accelerat-ing force is small.. Thus, s the ions moverather slowlY and have sufficient time torecombine with other iqns of opposite signin the vicinity. The size of the pulse meas-ured will be leis than if-all of the ion pairsfoimed succeeded in reaching the elec-trodes.-Asthe applied.yoltage is increased,the ions fravel faster. Their chances ofrecombination are lessened' and' the pulse.size inereaSes. Finally, as the applied volt-age is ,increased sufficiently, all 'of theprimary ion pairs will be collected at theelectrodes. This voltage is referied to asthe saturation voltage. 'As theelectrodevoltage increases above this point, no in-creak in the size of current pulse is imme-diately experienced since all of the pri-mary ion pairi have been collected. There-fore, the pulse size remains relatively con-stant throughout region B of the curve inFigure,4.29.,The actual voltage range overwhich the pulse size is constant dependson ,many factors, which include the gasused in the Chamber, the pressure of thegas, and tlie distance between the elec--trodes.

4.31, Region B of the curves is referredto as the ionization chamber region, and'instruments designed to operate in thisregion are called ionization 'charmber in-struments. SinN batteries are Usually.usdas the ,pP;pe, .0* PleOricALTPNYerjilir. _

ItAl5EF- instruments, this region is we4'adapted for their use. If the operatingvoltage for a particular ionization 'cham-ber is chosen at the upper end "of theplateau, the size of the electrical pulse,produced by radiation wilt not vary appre-ciably as the electrode voltage decrea'seswith both age and use of the batteries.

4.32, As the applied vblta e is increased.beyond the 'onization chamb r region; thesize of thel Ise is increased. n region Cof the curve, the increased electrical fieldcauses tlie primary ions io gain sUfficientkinetic energy to sause secondary ioniza-tion of other atoms and molecules in thegas. This secondary ionization leads to an

inerease in the size of the pulse, whichamounts to an internal amplification ofthop.ulsein the_enclosbd gas volume: This

------iinTiplifiCatiOriliiereases with applied volt"age aria remaing linear until 'an internalan...3plificatiOri factor of approximately 1,000is,obtained, Region C is the proportional

i. .region, and nstruments operating-in this

region are called proportional counters.No- Civil Preparedness instruments oper-ate in this.range.

preportionartekron, a large.-number ot secondary ion pairs are pro-d.uced at only one point within the en-Closed gas volume. However, when the ap-plied voltage is increased further, the sec-

--ondary ionizatidir occurs threughout theenclosed gas voltime. Therefore, since theamplification is so great in the GeigerMuller region, the size of the pulse isalmost independent .of the number of ion.

Thiii-produced:fihns,-pne initial ionizingevent 'Occurring within-the_..enclosed gas

-,-yoluinetwill=-initiate an-ELECTRON AVA-LANCHE (explained in paragraph. 4.46)'Which 'will spread quickly throughout theentire tube: Instruments operating in thisregion will produce one large 'pulse foreach ionizing event to' which the tube issubjected. Gas arriplification factors of the

zerderof 100 million are common.r4:34\- When the operating Voltage ex-

, "ceeds. the Geiger Muller region, it.is sohigh that once ionizatpakes place inthe gas, there is a continuous discharge ofelectricity so that it cannot, lie used foribunting purposes. The upper- end of theGeiger Muller region is marked by this-breakdown voltage.

OPERAVION OF ION CHAMBER SURVEYMETERS"

4;35 The development of ionizationcharnber=e44.rvey meters has also pro-gressed to"the point that, the later modelsof -ionization chamber survey meters and,probably future models' will .use a modifi-cation' of the eimplified schematic circuitdrawn in Figure 4.35. The. batik 'compo-nents 'of this circuit are: (1) an ionizationchaniber, sourceof electrical power,and---(3)-a measuring circuit consiking of

I`

63r

an electrometer tube and an indicatingmeter.

4.361 The detectitig element of the in-strument is an hermetically sealed air-equivalent ionization chamber. It consistsof a conducting cylindrical container of,plastic and:steel called the shell and a thinconducting tlis-k, which is located in thecenter of the shell, called the collector.These are respectively 'the positive andnegative electrodes and are insulated fromeach other by an extrelifely hiih resist-ance feed-thru insulator. A collecting volt-age 'is applied to these two chamber elec-trodes.

ft

FIGURE 4.35.Simplaed eireuii diagram for a CivilPreparedhess ion chlaiber survey meter.

4.37 When the instrument is exposed toradiation, some of the energy of the radia-tion field is absorbed within the walls ofthe ionization chamber. Asa regult, elec-trons are ejected Troin the wills into the-air contained wiChiri ther,chamber. Asthese.electrons traverse the chamber,they create a considerable amount of ioni-

, zation in the air. llider the influence ofthe electric Tield existing between theeh-amber electiedesz the ions move ,to theelectrode having the opposite charge; that

t

is,-positive ions move toward the collectingdisk and the negative ions toward theshell. The arrival of these ions at theelectrodes constitutes a current, the mag-nitude of which is proportional to the num-ber of ions collected. Since the number ofions created is proportional to the radia-tion exposure rate, this ionization currentis prowortional to the exposure rate in theionization-chamber.--

4.38 A very small ionization current(approximately 0.00095 microamperes atfull scale on the most sensitive range)flows through a " h-meg" resis r anddevelops a measu able voltage. Thi volt-age is applied to the grid of a vacuum abecalled- an electrometer tube because it iscapable of measUring voltages at etremely small current values. The electeo-meter tube. is connected as a triode. Itsthree elements are: (1) the filament which,when heated by current from the 1.5 voltbattery, emits electrons, (2)-the grid,which controls the flow of these electronsaccording to the voltage applitd to it, and(3) the plate, whieh rpceives the elPctronsand passes them to the circuit in the form'of a measurable current.

4.39 -.Measurement of the grid voltageof the electrometer tube is accomplishedhy metering the change in plate current(Ip) directly. With-the-- selPctor switch inthe zero position, the high-meg range re::sistor.is removed from the grid circuit so

-.that no signal voltage dan be developed asa result of any ionization chamber cur-rent. The quiescent value of the plate cur-rent is then exactly balanced by the buck-ing-current (Q so that the resultant cur-rent through the meter is zero. Th.e buck:ing current is adjusted breians of thezero adjust potentioMeter.

4.40 When the selector switch is pladpdin a range position, one of the high-megrange resistors is reinstated into the gridcircuit. The ,ionization current, therefore,produces a positive 'signal voltage acrossthis resistor, which in turn results in anincrease in the plate current. Thus, theresultant current throUgh the miter is nolonger zero and the meter measures-41wincrease in plate current. Since thischange isproportional to the magnitude of

the radiation field, the Meter scale Can becalibrated directly in roentgens per hour.

4.41 Prior to use for' measuring exTo-sure rates, the static plate current mustbe ,cancelled by the reverse filament cur-rent to obtain 'zero meter current (zeroreading). at zero radiation levels. Since itwill probably be necessary to zero theinstrument in a radiation field, a section ofthe selector switchis used to short oht-thehigh-meg resistor and prevent any ioniza-tion signal from being sented by the gridcircuit. Thus, when the S-elector _switch(Figure 4.4T) is in the zero position, zeroradiation conditions are duplicated andthe zeroing process can be gccomplishedeven in tIle presence of a high radiationfield.

FIGURE 4.41,Se1ector switch and zero contro).

4.42 The proper functioning of themeasuring circuit including the batteriesmay be checked by turning the selectorswitch tethe circuit check position (Figure4.41) and observing the meter readingl. Inthis position, a predetermined voltage isimpressed on the grid of the electrometertube to make the meter read approxi-mately full scale. Peterioration of any ofthe components or batteries inthe circuitwill change this reading. Therefore, thisvoltage can be used to check the entiiecircuit 'at the exception of the ionizatonchamb high-meg resistor.

4.43 All radiological instrumentsshould be calibrated prior to their ini ialfield use and :pethdicalw thereafter._, _ismgy beldone by -using Calibrated sourceof radioactive meter' l. If the instrumentdoes not read,proPerly when, placed in aradiaticfn field"of knOWn exposure rate, thecalibration control can be adjusted to givethe desired meter indication corréspond-ingto the-knownfenwstire ratE;

4.44 Sensitiyity _of the instrument ischi-nig-ed. by sWitehing high-meg resistors.This is accomplished -by, the selector switch(Figure 4.41). On each range the meterxeading must \be multiplied by 0.1, 1, 10,and 100 to obtain the measured exposurerate.

OPERATION OF GEIGER COUNTERS

4.45 Geiger counter_operation is. basedon the iönizatiori ot gases similar to theoperation of ionization c_ha3nber_survey_

Trieref . rn theoniztiôn chaMber instru-. ment, a very small current' is developed,

amplified, and then measured on a sensi-tive meter. The current is gThooth in chaA

----owtiber since the many ionizing events Ire(averaged. Geiger counters differ materi-ally in that the current flow is not smoothbutit is.delivered in-surges or pulses.

4.46 Geiger counters take advantage ofthe extreme gas amplification_ that can beob ined when' high accelerating voltagesare pplied to the electrodes within thechamber. As ion pairs are formed in thegash they will move with increasing veloc-ity toward the electrodes until either re-combination or collision with another airmolecule occurs. The average distance be-'tween, successive collisions is referred toas the mean free.path. If the mean freepath is small and tlie accelerating voltagerelatively high, each ion will gain only asmall amount of energy between collisions.'As the operating Pressure of .the Geigertube is reduced, the mean free path isincreased, causing the Lons' to gain addi-tionaLenergy between collisions. When thekinetic energy of the ions is' sufficient,they will cause secondary ionization.These secondary-ions will Who be acCeler-

- 'sited- by the-electrical field 'and will pro-,

duce further ionization. This cumulativeincrease in ions is similar to a single rockprecipitating an avalanche anct is, there,

,_fore, often referred to as ELECTRON AVA-LANCHE. This avalanche may produce asmany as 100 million_ other ion pairs foreach initial ion pair produced in the cham-ber. the gas amplification factor of thetube under these conditions would beab`out 100 million.

-4,47__ Consider,,a Geiger tube filled witha gas, frequently argon or neon, to anabsolute pressure of ten centimeters ofmercury and exposed to a constant radia-tion intensity. If the number of pulse's persecond occurring within the tube is plottedagainSt the voltage applied to the elec-trodes, a characteristic curve similar toFigure 4.47 is produced. This curve differsfroni the curve in Figure 4.29 in that thenumber _of _pulses. is ..plotted against theapplied voltage rather than the size of thepulse._Since$ under the_ operating condi-tions placed on the tube, no gas amplifica-tion occurs at low voltages, there is athreshold below which no pulses will be,recorded. As theyoltage increases and thegas amplification factor increases, thenumber of pulses increases. At first, onlythe most ionizing particles would becounted and the weak ones lost. As thevoltage increases, however, practically ev-ery particle entering the tube wil; becounted: When this condition occurs, The

, APPLIED VOLTAGE

FIGURE 4.41.---Number of pulses vs. applied voltagefor a Geiger tube.

7-1 65

_

curve will flatten out. This is called theGeiger plateau and it is desirable that itbe long and flat so that the counting ratedoes not depend strongly upon the appliedvoltage. Above the Geiger plateau voltage,the tube goes into a continuous dischargestate and is not suited for counting pur-poses.

4.48 Avalanche formation will takeplace in the vicinity of the central wire ofthe Geiger tube, since here the eleckricfield is high and each electron on its wayto the central wire acquires sufficient en-ergy for further ionization in each meanfree path. Thus, a large number of elec-trons and positive ions will be formed nearthe center wire in the first ,avalanche. Theelectrons having a small mass and alreadypositioned close to the central wire willmoye toward it with high velocities andwill be completely collected in about onemillionth of a second. The heavier positiveions travel more slowly out to the nega-tively charged cylinder. This causes a posi-tive ion cloud or space charge which re-duces the electric field and stopsite ava-lanche formation. In about one ten thou-sandth of a second, the positive ions or

- space charge will reach the cylinder wall.As a positive ion approaches very close tothe cylinder, it will pull an\ electron fromthe cylinder-and he converted to a neutralmolecule. Generally, the eleatron will 'move into one of the upper energy levels ofthe molecule resulting in an excited molec-ular state. The electron will move to theground state and in so doing may producephotons in the ultraviolet region whichWill have sUfficient energy to liberate pho-toelectrons fiom the metal cylinder. Withhigh tube voltages, this single photoelec-tron will start a second avalanche and,thus the entire process will be repeatedover and over again. Tbis-repeatid dis--chitige must be stopied and the tube re-stored to its initial condition if the tube isto be used to measure radiation. The proc-ess by which the tube Is prevented fromrepeating the discharge is called que,uh-ing.

4.49 Quenching may be accomplishedeither electronically or, by adding a suita-

.66

ble gas to the Geiger tube. Utilizing asuitable electronic circuit, the operatingvoltage of the Geiger tube can be momen-tarily Teduced below the voltage requiredfor a self-perpetuating discharge as sooi .

as the avalanche begins. Other Geigertubes, called self-quenched tubes, utilize asmall amount of alcohol or halogen gas toquench the discharge. In this ease, bothargon and alcohol molecules fiarticipate inthe avalanche. As the positive ions mi-grite to the electrode, the-argon ions hav-ing an ionization potential of 15.1 voltscollide with alcohol molecules with an ioni-zation petential of 11:3 volts. This differ-ence in ionization potential causes thecharge to he transferred to the alcoholmolecules and only these ions reach theelectrode. As they approach the electrode,they will pull electrons from the cylinderwall. The energy of the excited states ofthe alcohol molecules:will dgnssociateother alcohol molecules rather than causefurther ionization. The self-perpetuatingdischarge is prevented in this manner.

4.50 Since some of the quenching gas isdisassociated at each discharge, the sup-ply is constantly depleted and the Geigertube will havea limited useful life of aboutone billion counts. Halogens, particularlychlorine and bromine, are currently beingused as .quenching gases in argon-filledcounters and have some advantages overthe alcohol-quenched tubes. Since the hal-ogen atoms will recombine after the disas-sociation process, tubed filled with this gaswill Shave essentially an unlimited life.Halogens, however, are extremely reactivegases and great care murt be exercised inchoosing electrode mterial.s.

4.51 Figure 4.51 illustrates a typicalsimplified circuit diagram of a Geiger-counter. The Geiger tube consists of a thincylindrical .shell *hich serves as the cath-ode, a fine wire anode suspended along thelongitudinal.axis of the shell, and a smallamount of a quenching gas. A potential ofapproXimately 900 volts is applied between,the two electrodes.

4.52 When radiation penetrates thetube, a gas molecule is ionized. The result-ing ion pair is accelerated toward the elec-trodes by the electric field. Because of the

7°

,

high accelerating voltages, the creation ofadditional ions is very rapid, thus produc-ing a discharge (airalanche) in the tube.This llischarge results in- a pullo in the7-

I

_

FIGURE 4.51.--Simpfifie4 circuit of a Geiger counter.

external circuit- The frequency of such .pulses,is proportional to the strength ofthe radiation field. The small amount ofhióèiijas intheint,e serves to stop eachlischarge and restore the tube to its

condition.4.53 ke`pulse output from the Geiger

tube is ambIified by conventional elec-tronic means and then measured by a_

sensitive,,ineter,which-sinnS-up--the4adia---tion effects in the form of a reading in

either-counts-per minute-or, in-the-case of-gamma rays, milliroentgens per hour. In,addition to the meter indication, mostGeiger counters are provided with head-phones which detect the pulses from theGeiger tube and produce an audible click.

REFERENCES

Sourcebook -on Atomic Energy las-stone, Samuel,D. Van Nostrand, 19

Nutlear --Radiation Physics.--Lapp,,RalptrE: and Affi-vOroiviiid L.,' Pren-tice-Hall, Inc., 1972.

7 3-67

RADIOLOGICAL EQUIPMENT

Having covered the theory of radiologi-cal instrumentation in the previous chap-tgr, we are ready to move to the practicalapects of detecting and measuring nu-ckar radiation. This means it is time foralook it the various types of radiologicalequipment available and the different sit-qations in which each item would be ap-plies!. In addition to learning what wehave in the way of different 'pieces ofequipment, we will also be shown:

WHAT the equipment can doWHAT it cannot doWHEN to uSe a particular piece of

equipmentHOW lo check it, operate it and care

- for it

RADIOLOGICA*I. INSTRUMENTREQUIREMENts

5.1 There is no exact equivalent of com-bat experience upon which to base therequirements for Civil Preparedness ra-diological equipment. HoweVer, extensivetests of nuclear weapons under knownconditions have indicated the kink andextent of residual radiation that could.re-sult from the use of such weapons. Theknowledge gained from these and othertypes of experiments makes it possible torelate radiation conditions to biological ef-fects bn iman and thus establish equip-ment requirements.

5.2 Because of the many variables as-sociated with the detonation of a nuclearweapon,.it is not possible to predict accu-rately_the radiation levels that will resultfrom fallout. Furthermore, no single in-strument meets all of the operational re-quirements that Tight result from a nu-ckar attack: Therefore, Li wilie arpabilityfor radiation measurement is required.

CHAPTER 5

DS_PA has developed several instrumentsthai, together, provide this.wide monitor-ing capability. These instruments fall intotwo distinct-classes:

Radiation survey meters for use by mon-itoring personnel in.determining contami-nated areas and radiation exposure rates.,

Exposure measuring instrument( (do-simeters) needed by all Civil Preparednessworkers such as fire fighters, fixst eiders,rescue teams, and radiation monitors whohave to perform their emergency duties incontaminated areas.

5.3 SURVEY METERS provide the informa-,tion required for -locating contaminated-areas and for estimating the degree of thehazard. Since it would not be practical tocompute your total radiation exposurefrom survey meter measurements if theexposure rate varied during the exposureperiod, DOSIMETERS are also needed for re-cording the total amount of an individual'sexposure. Estimates of total exposure andrelated birological effects can be made onthe basis bf exposure rate measurements,decay rates, and probable exposure times,but these estimates should be used forplanning purposes only. Determination ofactual exposure times and exposures dur-ing emergency operations must be basedon both the exposure rate, as read onsurvey meters, and on the total exposuras indicated by dosimeters. .

5.4 Alpha, beta, and gamma radiations. may be .present in radioactive fallout.

Sinte the hazards from these radiationswill be discussed in detail in later chap-ters, it suffices here to indicate thatgamma radiation is an external( hazardand, under certain conditions, bed' radia-tion may also be an external hazard. In-Addition; thede three types 'of radiationmay be internal hazards.

69

a

5.5 Alpha radiation does not present anexternal hazard, since it will not penetrateboyond the surface layers of the skirl. Al-pha emitters m-ust get inside the bodyiii4fOre they can iau-se appreciable damage.-Bbeause alpha emitters will probably notpresent a significant hazard relative tothe beta find gamma hazard immediatelyWowing a nuclear attack and for sometime thereafter, and further, because ofthe difficulty in developing portable alphaOeasuring instruments, DCPA does not

-provide a standatd instru-ment sensitivelo`this type of nuclear radiation. During the

/ recovery phase, the determination of theseriousness of the*alplia contamination infood and water will probably be accom-

- plished by laboratory-type instruments.

MEASURING BETA AND GAMMARADIATION

-5;6 -Since the biolOkicareffects- of betaand gamma radiation differ, radiological_instruments must discriminate betweenthem. Measurement of beta radiation iscomplicated by the very wide range ofenergies of these particles. Most beta de-tection instruments will not respond toextremely low energy beta particles. How-ever, that portion of the beta radiationthat can be detected should be detected, sothat its proportion to the total radiationexposu-re_can bie-determined. This is neces-

o estimfite possible damage by each-ype of radiation. It should be noted, how-

ever, that the units of measurement usedon radiological instruments to show accu-mulative exposures and expostire rates ofgamma radiation are the roentgen and theroentgen per hour and the roentgen isdefined in terms, of X or gamma radiationexpOsure in air. Therefore, these units donot relate directly to measurements ofbeta radiation. Consequently, meter indi-cations of beta radiation can be inter-preted only in a general way.

5.7 The sensitivity requirement of a ra-diation instrument depends upon the typeof information itis expected to provide. Aninstrument used to measure the Contami.nation of personnel, food, water, equip-ment, or living quarters must Andicate '70

very small amounts of radiation abovenormal background radiation. This type ofinstrument would therefore have little usein areas of heavy contamination.

5.8 To provide adequate monitoring,portable radiolOgical instruments shouldbe capable of measuring gamma exposurerates as high as 500 RIhr and also indicatewhen exposure rates exceed this figure.Measurement above this amount is notnecessary for portable survey instru-thents, because a higher level of radiationVionld be so dangerous as to preclude-fur-ther surface operations.

5.9 When surface level exposure ratesare very high or when rapid monitoring oflarge areas is required, aerial monitoringmay be practical. Survey meters designedfor this purpose must be extremely sensi-tive in order to giye correct readings ofradiation levels on the ground. Remotereading instruments used to indicate ra--diation leveis outside 'fallout shelters arealso required _and should indicate gammaexposure rates up to at least 500 Rihr.

5.10 Within the entire grOup of radiol-ogical instruments developed by DCPA,the capability exists for measurement ofionizing radiation exposure rates rangingfrom a minimum of natural backgroundradiation to a maximum of 500 RIhr. Thiswide range of measurement capability isconsidered adequate for all operationalneeds.

TYPES OF DCPA RADIOLOGICALINSTRUMENTS

5.11 Each of the DCPA radiological in-struments will be dvscusied in terms of itsuses, significant operating characteristics,important specifications, and the care addmaintenance to be ticcomplished by theinstrument operator or monitor.

1CD V-700

5.12 The CD V-700 radiation surveymeter (Figure 5.12) is Tt)highly sensitivelow-range instrument that can measuregamma radiation and discriminate be-tween beta and gamma radiations. DCPArecommends its use primarily in long-termclean-up and decontamination operations!'

s

FiGuitr5.12.CD'11-700, low range beta-gammasurvey meter.

5.13 The inst ment can also be used intraining progranis where low radiation ex-*pure rates will be encountered. The de-tecting. elenient of the -CD-y-700 is aaiig0 Aub6 :Shielded so that only thegainme-eXposure rateismeasUred di betaand- garnina cen be detected together withthe-Shield- open. A headphone for audibleindicatiOn is sUpplied with this instru-

: Ment.

IMPORTANT SPECIFICATIONS OF THE CD

7

1. -RANGE: 0-0:5; '0=5;0, 0-50 milliroerit-gensTerliour.

2. DETECTS: beta end gamma-radiation.8-. A660146: ± 15% of trite exposure

-ratotwtobaitio -0 cesium 137.4, 'RESPONSE 9'5% -of filial reading

'in-aiProXimately seconithr.TEDOERAii.OftElirkstrument Shall oper-atO properlyfrom 7 10° F, to + 125° P.

; inistruMitnt shallwerateproPerlY from ,sea level to 25;000 feet.

1., JAMMING: .e*pOsure rates from 50 mil-, liroenigeris4er,hour to 1 roentgen. per

lionr lif*O'procluce., off-scale readings.,svslolTryitn. sunlightia-Sh ncif siffeCt the O' oration of the

?,

9. EI:ECTROMAGNETIC .INTERFERENCE:the instrument shall operate properlyin normally encOuntered electromag-netic. hey's.

0:tOPEEATiCNAL CHEZt SOURCi: -a per-menentlY sealed radioactive sourceshall' provide a reading of 2 mR/hr0.5 .mR/hr when the probe, with betashield Open, is lield over it.

11. BATItERY PPE: 100 hours continuoususe (Minimum).

.OPERATOR. USEi. CARE Ik.t4D

MAINTENANCE:OF THE-CD V-400

5:14 Batteries.,=-Whetiever the instru-ment fails tO respond to the radioactivesource on the side.of the instrUment, checkthe batteries. Replace bad batteries in ac-cordance with the instructions in the man- .

ual accompanying the instrUment. 1

During extended storage 13eriods1 thebatteries should' 46 remóved froth' theinstrument and' stored iii a cool, dryplece. _ ' --Battery cOntacts should be inspected

monthly, and. any .dirt or corrosion-presentshould be removed..Whenever the instru-mentis not in ruse, MAKE CERTAIN IT fS,TIMNED oFE:; otherwise, -the. batterieswill- be 'depleted and' the instrumetit Ten.,.dereclineffectiv,0,

5.15 Geiger Tu0s,The Oeigertubes, in .

the4later-tOdeli-of the =0 Vi--7011-atelialo-_gen:quenched -so Iliet tbeir,opereting lifeis linaffeeted.14r,lise,anci,,therefore, rarely,,xequirefz_replacenient ifOivever,Wlien-fre0h:'betteriesere installed:and:the instrUmentdoes not woric 'correctly, jt-rno fieceg,-_,-satY to replace the Geiger tube To,checkfOr a faulty Geiteg tube, replace the sus!

% towed- tube' with .a goecVtube 4'roin a prop-erly lopeiatinrOD V2700.,

5.16: Hedclphones..If the operator.6hoOies t. uie the headtliones with- thein'struinerit, they Maybe screWed into the.connector provided at the lewer left Cornerof the initruinent 'cover: I* using theheiaphone, the operator will note thateach litilse-er co4nt is indicated- by a dis-tinctly audible. ciick. ilav_hen the headphonesere .not in- use, the protective cap on theheadphone receptacle should be 'replecodi.

a

71-

*-171

5.17 carrying Strap.The instrument-may be carried in the hand or by a strapover the shoulder: The strap anchors areiirranged in such a way that the meter is

-sisible_when egrried over_the...rightehOultder,

5.18 -Controle.There is only one con-trol on this instrument for the operator's_use. This 'Control, called the selectorswitch, includes *an off position and three044 labeled X 100, X 10, and X-1. On'the' X .1i-the X-100-rangesrthemeter readings must be multiplied by a

7:factor 10,. and 100,_respectivelytoobtain themeasured exposure rate.

5,19 Operational Check.The selectorSwitch shouldhe turned to the X 10.range,Tile beta shield on the probe-,should-,ber..rotated. to the fully open position and the_probe placed_ as close as possible to theradioactive sample located, either on thebottom. surface of the .case or .underneath-the manufacturer's name plate (see in-struMent manual). The open. area of the

-Trobe _must bedirectly facing the radioac-.meter should be adjusted

\toireatt:-2-1 5 millitoeritgens-per hoOr. Noexternal radiation must be present when

iP10.010.his,:tcheclo. The source should- bensed,:te."determine the operability of the-instrument.only. It is not intended to re-

. :place:the need for calibratinft the instru-ment affainot a.known source.._540 .Calibration,The instrument

should be -calibrated periodically to yerifythat it ismeasuring correctly.

_

_ v.21 Contamination.At .41 times the=operatorShOuld etteMpt to preyent radiol-Ogical-contamination of the inStrument,partionlarly of the, probe. in. case of' con-

. taniinlitieri; the instriimerit can be cleanedCieth dampened in, a -Mild soap solu-

'_tion.---

1/4,14-6.4 The cp V-415 (Figure 5.22) is a

-. high-range gamma survey meter for gen---,e-farpOitattack operational use. Thetecting -eletrient .of, the bp V,-715 is anionitationehamber.. The instrument is de-

_ ....signed, tor, ground. survey and for use infallOnt shelters. It Willhe used,by a radiol-

1

FIGURE , 5.2,1=cD -V,715, high-range- garkinsi supeyniitter.

-

ogical-monitor for the major _portion of_survey, requirements in the period immedi-ately following a nuclear weapon attack.The CD V-715 hag replaced the now obso-lete CD V410 mediuitrange 0-50 R/hreamma snrvey meter.

MPORTANT SPECINCATIONfOisTFTE -01/4715 _

1. RANGE: 9-0.5, 0-5.0, 0-50, 0-500.roent-operate from -20°F. to 110° F._

2., bETECTS: gamma radiation. only.3. ACCURACY: -± 20% of true exposure rate

from cobalt 60 or cesium 137.4. SPECTRAL DEPENDENCY: ± 15% for,

gamma radiation energies between 89keV and 1.2 MeV.gp$PC04_r.1.4_,P; .95% of fiO4 reading5.

6.

7.

8.

9.

in 9 seconds.TEMPERATURE: instrument shall oper-ate properly from --- 20° F to + 125° F.PRESSURE.:-..instrutnent-shall operateproperly from sea level to 25,000 feet.JAMMING: exposure rates from 500roentgens per hour to 5,000 roentgensper hour shall produce off-scale read-ings at the high end. ,ELECTROMAGNETIC INTERFERENCE: in-strument shall operate properly iri nor-mally encountered electromagneticfield

77

.01111tATORAISC,:CARE ANDJAAMINANtE 00-THtieD-V-11'5,

p4tter4-Bgatery.replacernent is,noxinally.:regnired, whenever_ the instru=--,ment,Canrno.longer be zeroed or when the.rnaer, indicates below the "CIRCUIT

flAND".. Batteries should, be re-placed in accordance with:the instructionin_ the instrument manual. If the instru-ment i. to be stored for more than a fewulfelc,s-,,the batteries should be removed a-ndstored in- a coot dry,location. For instru-inentSin;cofitinuoUs use, batteries shouldbe refoOred monthly and the battery con-tacts cleaned of any dirt or corrosion pres-ent..

5:24 Controls.Two controls', are pro-vided. One control, the selector switeh, hasseven positions: ciicuit check, off, zero, X100, X 10, X-1, an X 0.1 ranges. On the X641.;_)r 1, X 10, and 100 ranges, the meterreadings !mist be _ultiplietby_ a aC,torsc();I: `1 16; -Eta rtibi reepectiirely in order to

taiii,..thp, measured exposure rate: The"seco:nd cOntrol, the zerO Contrel, is used toad,j4ithe Meter readhig to zero during anoperatiOnal check.

-0:25 CarrYing SWap.The instrumentPci!lipped, with a carrying strap whieh

allay be adjusted to any length-to suit theoperator.

__0.fierational" Cheek.rtirp the se-:lector :Oilteh:io the- Op position, wait -a

tube toWarin UP and adjust the zero control tomake the-rneter read zero. Turn the selec-tor SWithh to ,the circuit check position.the Meier should read, within the red'band,inarked "Circuit..Check": As the se-"lee* switch is turned through the zerapbsitibit to the four ranges, recheck the,

'No the- selector switch tothe.X_JOk X '10; XI, and X 0.1 range.,,'When_iia'radiation,ls present, the readingshO41i1 not be More than two scale divj-ions uP 'scale. If difficUlty is .encountered

step in the Operational cheek,'referio the-instrument Inanual for correci._Ore, tiroOdure._ _Many medels have inter-

= ba,:tidjuetinents: which May,Cprrect thedifftu1tyDuing4rma1 ugeLthe COY,

715 should-be zeroed fiequently, at leastevery half hour.

5.27 Calibration.-7The CD V;715should be calibrated periodically to vOfy

-the acctiriCy of ifs measurements.-5.28 Contamination.The operator

should attempt to prevent radiologicalcontamination of the instrument at all,times. In case of contamination, the hi-stfument can be'cleaned by a cloth damp-ened in a mild soap solution:

5.29 Modification (c:D A77717:).-7-gqin,of the CD' it-715's are etjuipped by themanufacturer With a removable ionizationchamber attached to 25 feet of cable. Thismodification, called the CD V-717, pro-vides a remote reading capability' for fel.-lout monitoring station's. The ,operatingcharacteristics are identical to the CD V-715 except that the removable ionizationchamber-must be placed outside the 'shel-ter in an unshielded area and protected

_frompossible contamination,by placing itfin a bag or corer of light-weight material.'All readings Mak then be, observed fromwithin the fallout monitoring station.After the early .periods of heavy falloutand -the requireMent for a reripte readinginstrunient din:finishes, the reinovable ion-ization chamber should be checked for con.ftamination With the CDT-700; decontami-nated if néceSSary, and ,returned to thecase. The eD V-717 inay,then be vsed forother rOonitoring operations.

_'

____FIGORE..5.29mtOPS,71.7.,Itemo eion,Chamber-

-74

44%

' - _ - _

-

':-.0 -IC 7

noulet-6.366742k1.,teta-gamrna-survey meter.

CO V-720_=

. 5.30 The CD 'V-720 (Figure 5.30) is ahigh range (0-500 Whr), beta-gamma, sur-

.-. vey meter designed for postattack use byMonitors. It will-be used in high-levei con-tamination-areas where civil-preparedness

,

operations -are necessary and for -makinghi6,71eVel beta radiation determinations.

e Federal agencies maintain a,PlOilije number of these instrtVents tofulfill' *it SPecial requirements. The de-tecting ,element of the CD V-720 is aniohization chamber, shielded so that. _ _

gamma radiation only can be measured, orboth beta and gamma can be detected. withthe shield open;

OPERAPPRUSErCARE AND.,:mmtirgsmcf OPTHE CD V-720

5.31 The use, care, and maintenance ofthe C,D y-qp, are similar to the use, care,

= :and maintenance of the OD V-7I5. (Referto-paiagriaphs,5.4to 5.28 fOrdetails:)

CD DOSIMETERS

5:32, Personnel who ,muSt work in con-, , ._ larninatecl .areas require radiation inte-gratinginstrurnentS to keep them continu-

,,; t ously inforined df their exposure. For thispurpose DOA recommends the Use of the1401f-inckatjng -qOartz7fiber electrostatic

, , .

,

FIGURE 5.32.--CD operational dosimeters.

5.33 DCPA has procured three dosime-ters for operational use. These are the CDV-730, with a range of 0-26.roentgens, theCD V-740, with a range of a-loo rbentgens,,and the CD V-742, with a range of 0-200roentgens. The CD ST-730 is used when a,monitor expects:small repeated exposuresover a long period of time. The CD V-740and cp V-742 dosimeters are recom-mended for use when personnel could beaccidentally exposed to large doses of ra-diation. They should be used when person-nel are required to enter fields .of highradiation or remain* low radiation fieldsfor long -periods during. postattack sur-vival and recovery missions. After currentstocks of the CD V-730 and OD V-740 aredepleted, DCPA will procure and issue the,CD .V.442 only. For training purposes, theCD V-138 with A range of 0-200 milliroent-gens is,recommended.

.

7 IMPORTANT SPECIFICATIONS OF THE dbDOSIMETERS

1. RANGE: CD y-138 0-200 milliroent-gensCD V-730 0-20 roentgensCD V-740 0-100 roentgensCD V-742 0-200 roentgens

2. DETECT: gamma radiation. -

,

79

Acbxtit4e 10% 'of true exposuresfromccobalt0-or cesiuin 137

4. SPECTRAL DEINDENCY: :t 20% of trueexposure for gamma radiation energieS

-between 60- keV and 2 MeV.15. ELECTRICAL LEAKAdE: CD V-730 and

CD It-742. Beginning ten minutes afterexposure,, leakage shall not exceed 5% of,full seale in a fonr-hour period. Begin-ning 48 hours after exposure, leakageshall not exceed 2% of full scale in 96hourS.-CD V,440. Leakage shall not-exceed 2%of full scale in 24 hours.CD AT-138. Beginning 10 minutes afterexposure, leakage shall not exceed 5%of full scale in 4 hours. Beginning 48houri after exposure, leakage shall notexceed 3% of full scale in 48 hours.

6. GEOTROPISM: reading shall not varymore _than -±4% of full scale when ro-tatekabout the horizontal axis.

7., TEMPERATURE: instrument shall oper-itte-prePerlyfroin -40° F to +150°F.

_Instrument -shall operate. properly from sea level to 25,000 feet.

9: SHOCK: instrument shaljAilierate prop-erly after four drops from a height oflourfeet.Onto a hard:wood floor.

'OPERATOR.USErCARE ANDmoTOIANcE.oF:THE,Dosuoultot

'.5:34, -Afaintenance.NO maintenanceshould 'bp performed bY the 'titer on the-self-indicating electrostaticdosinieters.

6.35' th,e instrunienta are'received; tbe operator should check the

_ abilityA&-zero the-dosimeter, cheek itaresponse to-raliationcand.,dheck its electr-

.iCal reakage characteristics. When Usingthe doshneters, the operator should' keep.

,as cross, to -,iero- as possible.and Shoul4 preVent -the dosimeter frontbecoming --centaininated. When not' in use,thedOsimeters should ,be charged and, sto-

,,,red'in .

Since most ,eleetrostatic dosime-ters.mill require -a "soak-in" charge' aftertoneternt sterageln 'an uncharged condi-

Such. dosimeters should be chargedandthe reading obserVed for a few hours

- e

FIGURE 5.37,-CD V-750, dosimeter charger.

before use. A second charging may be re-quired before the instruments are readyfor operation._

CD V-750

5.37 The CD V-1750 doiimethr cha ger isused to read and charge self-indicatingeleCtrestatic dosimeters (Figure 5.37). Astandard 1.5 volt flashlight cell is used asthe source of electrical power.

IMPORTANT:SPECIFICATIONS FOR THE-co V-750

1. JAW& VURCE: instrument must pro-vide itrumination for reading and/orcharging the dosimfiter.

2. TEMPERATURE: instrument shall -oper-ate properly from -20° F to +125° P.

3. PRESSURE:_ instrument shall operateproperly ?rom sea level to 25,000 feet,

4. SHOCK: instrument shall oPerate prop-erly after 6 four-foot drops onto a hardwood floor.

OPERATOR USE, CARE ANDMAINTENANCE OF THE CD V-750

5.38 Batteries.The 1.5 volt flashlightcell should be replaced when the lampdims noticeably on actuating the charging.Switch. Replace bad _batteries in accord-ance with instructions in the instrumentmanual. WHENEVER THE _INSTR15:7_

7'5

NT IS: STORED FOR moRg THAN AW WEEICS,, TtlE. BATTERY SHOTILD

MQVEDTO PREVENT FOSSIBLE_ .

.39 dpiii-44n8.-----To read a dosinieter;oye the dust cap- from the charging

tack,,plage,_ the- dosimpter On thetcharg-contact, arid_ press lightly to light the

k. Read:the dosimeter and replace the,d st Cover -when finished. -The dosimeter

alsobe read by holding it toward anyight ieurce suffi.Cient to illuminate theairline. To-.chargea 'dosimeterfollowthe

precedure printed on the CD V-750.

caN-457 (Figure 5.40) is a

Geiger counter which has been especiallydesigned for elissroom demonstration use.Tt operates on, a normal 110.volt AC powersupply and produces both visible .and audi-

, ble responses cO_ritiCle'ar -radiatiOn:-The-instrinnent ia used "in 'teaching basic -nu--clear radiation plmics and for decontami-

'dernenst atiofr440n-, r n .e,

FIGURE:5.40.PD-V-457, classroom demonstrationunit.

tp;i1418

FIGURE 5.41.geiled source -capsuies, Open andsealed.

sealed sources (Figure 5.41) and accessoryequipment. It should be hoted _that thisTraining Source Set has been designedspecifically for use in training exercisesand is riot intended as ari acculate calibFa-tion source.

DAVI:he CD V7-778 Training:Source Setconsists of the tollowing itemth

6-5.0 mCi ,Cobalt 60 Sealed Spurces,totaling §0 mCi, CD V-784

1-:-Lead Container, small CD V-791)1Lead Container, medium (CD V-

792)2LoCis foi Lead dontainer CD V-7921Long-Handled Tongs for Handling

Sources (CD 11-788)87-Radiation Area Signs2-07200 mR Dosimeters (CD V-138)1-,,-Dosimeter Charger (CD V-750)1Geiger Counter'-(CD-V-70_0)

CO:V-794;5..43 'The CD V-794 (Figure 5.43) is a

calibration unit containing a Cesium 137Source of approximately 430 curies. Theprimary shield...is composed of" depleteduranium, and is sicaped te beam the radia:thin from the radioactive cesium into aShielded ekposure'chaMber. Interposed inthe radiation beam path is an attenuatordisk by means of Which radiation levels of

5.4r ',The CD V-77840- millicurie Train- 0.4, 4,-40, And 400 R/hr are produced in theing Slurce Set consists ot six Cobalt 60 exposure chamber. Jigs are provided to

- .1.r_°.1.1

'8:1 .

FIGURE 1..42.--CD, V-778, Wainini(Source,Set.

properly position the instruments duringcalibration. The range switch and calibrat-ing petentiotheters are adjuStell throughflexible linkages leading outside of the ex-posure chamber. The Unit is designed toprOvids,tiitable protection from radiationhazards fothe oPerator.

"CD1/4575.44 The barrier Shielding Demonstra-

ter .$4, bb IF-1-51, is a low range radiation,deteetion instrument, couPled-tcra neon

, lighted remote readMit indicator that'isreadily visible' in large conference roomsbr sin1l Aud1toitOr1s1-44t4,:the large, 414catfir, a Jec,torer, can show:how radiationfrOM a radioactiire souree is, affected bydistance4ndahielding.

**OR amv.mt ,Of cesiunt 137, whichglyet off gamMa rays, is housed in a leadoomhall:hiounted in the dernpstratjon plat-term. A hOte in the pdatf6rm leads to the.efs,tuni SoiirCe, and gamma radiation is

beamed vertically. The aperture is nor-many dosed by a_ tungsten plug whiPh is

FIGURE 5.43.CD V-794, calibration-unit.

824

77"

104:740

aiflocied in ,poition. Abupted directly.oyiirthelole Cs 4 ,-cwor ghlier tube thatis 4*, t e radiation beam when ,the

a.-radiation absorbing mate-Jj40jst..04hp.:,,plattfkrm hole, the intensity of

e.rs,01,09,/y-beam is attentytted, result-,.4.,:10440Wep.eiposure,rate readout. Cora,-

palsoni3Of ,rA4,44404- 4bsorbing materialsaty =Yea.* ,-placingtem- inhradiation

i*eAtifery-ifiriple Mathematical rola-diStances from 0.,.

4ouree'4,-,f4Monitrated 11F.,00.3bling3#PlirP,4 deteetiir and_Otiing:1 Met dpon the

elbn t e large indicatoy

Aerial 'aryeY Me-esigned for limited

z

.ppstattacic peratiouase in slow low-flying aircraft. The 78r will. be -u'sedby jsPecially trained, monitors. The fourmajor. comPonen'ts of the Ci), Y-781 aerialsuryey iet aret detector'unit (threedeigey-Mueller tubes); -Metering _unit with"three range R/hr, 0-1,0 Rihr,and 0-10 R/hr); sinnilator unik:With dialscorresponding iO the metering uhit; and a

, rmagnetic tape recorder.

IMPORTANT seggIFI TIONrco THE CD,,V4111

1, AANGE: 0-0.1, 0-14), and 0-10 roenV ygens per.hour.

2. ,N.TCTS:,gannna, radiation only.3. ACCuitAciet:4--1-06/0 azDtrueeipoture rate

from Cob.41Pqao-orCes,luill-P7--..c.ALORA.,:Twm. is, perform'ed by the$i4t.e maintenan'ce shops

\ 7- '

-

-

.5: TEkPERATURE: the instrument will,operatfrfroni- 20°--F. to i10°F.ipmarimm-to 95%: 7-

1. AiTiTUDE,;- to 2G,000 feet; preferablybelow 1,000 feet.OPERMING-TTME: 40 'hours on nine

'flashlight batteri.e.s ("P" cent':ta ? itials-nsit the metering dials shallnot be'nfO're -than10%.

10. READiNG TIME: not less than 15 sec-ondspreferably 1 minute.

11. SliOCK AND. VIBRATION: instrument isdesigned to withstand normal shockand vibration encountered in smallaircraft operations

12. ,DETECTOR UNIT: contains threeGeiger-Mueller tubes similar to the CDt-700. The detector unjt should becarefully handled when installing bat-.teries,.TIARMUii liME: 2 minutes.,

opERAtiON'At- ado iitioaDoitEs-

4, TRACKING ERR,OR; between t e

5:46- Ifetering ekrit.--Trior-to- mounting.,

-

the 'metering unit into, the aircraft, theinstrument ,s_hould be. operatiOnallychecked' with-the use of the simutator unit.- .

- The folloWing procedures should be use&T1. Attach-the cable of-the metering. unit

to- the connector providid on the sim-ulator unit. .

2. Position the ,power switch on the me-terinb grit to "Battery" power posiztion. and,gerv the instrument a war-Mup period of at least 2 minutes.

3. By rotation of the meter-reading con-,

trol knob on the simulator unit, checkeach of the three meters at half scale.

4. Starting with the- metering controlknob in the extreme counterclockwiseposition, slowly rotasie the knob clock-wi4e. The tracking error between the.:meirs of the simulator unit and cor-responding meters .on, the;.metering. ,

unit should be no, more than 10% at. "any simulated-expOsure ,fate...

'5.47-Tlie--audiOTOiitPht may be. checkedby plugging in the headSet to the metekugunit. TheTalir:iiio oUtp,hRittld be onr..225.

r,- --.;

: -";

J

1,- -

$AtiA.":00*:11tiii4i=iiletet-', CD 'VI-781, odel =1- .,".. _I _ .?",r

,

79

vie

to 275 cycles per second (within one or Wo-notea of iniddle c) for normal radiatiOnbackground. The.3udio output can be oper-ated with the simuiator unit. \

8.48 Afte(r installation of the CD V--7g1_Aerial Survey Meter into the aircraft, theoperational check is performed as follows:

In\silintent Battery Supply"a. Observe meters prior to turning onb.'intrumeht, Meters should indi-

cate zero within one scale division(the instrument has no zeroed-justment)..

b. Vosition the power switch on them'etering unit to the "Battery"power sWitch position and allowthe instrument awarmup period .ofat least 2 minutes.

c. Observe the meters after warmupperiod. Meters should continue to rindicate zero within one scale divi-sion when onlY normal backgroulitiradiation is present. In the eventexternal radiation from fallouctr;prohibits.this hheck, it "sfii4ro-be '4sStinted the instruinent is operat-

, ing properly if it indicates radia-tiiin levels alfove normal back-ground.

*d. "Presi the -"BattfkrY Check" switch.The 9-0.i 14hr met-er 'should read.

4

. at, or slightly above, the batterycheck poInt. 4

Aircraftl7ower Supply .

a. When the aircraft electrical itioter,skurce is used, position the powerswitck on the metering unit to the'Plane" power fiosition.

b. Repeat steps c and d, above.

THE TAPE RECORDER

5.49 The manufacturer's manual sup-plied with the recorder indicates precau-tions to be lbserved arixi provides detailedinstructioni for operation. A monitor ex-pecting to Use the redorder should,practiceusing it until he is proficient botli on theground and in flight. The recording andplayback of preliminary survey informa-tion will provi4e a cheek'of the recorder'soperability. Prior to a mission, the '"Bat-tery Voltage Indication" .should be obi.served and batteries repiacedNif required..

1

REFERENCES

Handbook for Radiological Monitors.FG-E15.9, April 1963. Instrument manualsaccompanying eaCh instriment.

Handbook.for Aerial Radiological Moni-tors.FG--B-5:9.1, July 1966.

v

RADIOACTIVE FALLOUT

NOw we are ready for a closer look at ourenemyRADIOACTIVE FALLOUT. We -

have learned how it is produced through anu'clear detonation and we have learnedhow to measure it when it arrives. Thisprompts a question:

Must we wait until fallout actually ar-rives before we can ecide where it isgoing and what to do about'it?

. . and the answer is . . .

.NO! ! !

True enough, we cannot detect nor can-we-measure fallout before it arrive§ biit wedefinitely do not have to just sit and waitfor it. Although it may appear that the:fallout makes its own rules, .its movement

, is affected by. a number of elements, some'of Which we can meast.ii-e. This lets usmake predictions about the behavior offallout, to estimate its location. In short:tyhen we take qur close look at fallout inthia chapter, we5vill see how RADEF tech-niqiies can prov,ide life-saving and morale-supporting warnings of the direction offallout Movement. We will see:

WHY there is fallouta

HOW.* fallout is,formed-HOW . it, rs sPread

. WHAT influences that spread .-WgERE :is fallout most likely to landWHEN, to expect it

CHAPTER 6

to learn more about fallout that we startto lose sight of this central and simpleidea. Words like "clean bomb" and"dirtybomb"; "early fallout" and "worldwide-fel:lout"; "fission products" and "fusion prod-ucts"; "local fallout" and "late fallout";"surface burst" and "air burst"; "stron-

tium 90" and "carbon 14'z makenS-w-Onderif we know what fallout is after all, despitethat built in definition. So, let us look atthese words and see what they-mean.

SOURCES OF RADIOACTIVE MATERIAL

62 Lei us first-es:insider wriere the ra-dioactive material in fallout comes from?How many Sogrces are there and are all .

equally important? rs,.6.3 When uranium or plutonium are-fis,

sioned the heavy atoms are split intosmaller atoms and k.yast arnouit of en-eigy ia released. Millions upon millions ofthese atomic nuclei are split...or fissionedin.the explosion of a nuclear weapon. About200 different isotopes of about 35 elementsare produced as fission products. Most ofthese are radioactive, decaying by-emis-sion of beta particles frequently- accom-

.. Panied by gamma radiation. TheSe -fission-' products constitute t\he largest single

source ,of radioactive material in the tel-t,

lout.6.4 What about the radioactivity of the

fusion products? The different fusion reac-tion* used in fissionfusion,type.weaponsmay:prOdncetritiiiiii '(a radioactiire hydro-.ken isotope) ,and the neutrons produ'ced inthe reaction' thay cause the formation -of,-radioactivekarbon (carbon 14) from thenitrogen in the air. However, the carbon14 produced is small relative to that nor-mally present in the atmosphere. Only in-sofar as possible genetic effects might the-oretically f3e incurred over the next sev-,

0 -;1 4

INTRODucTION

6.1 "FallaUt" is one- of those wordswhich define thernselves. Say the word,.and you haVe grasped s eaSential mean-ine the fallback-to earth of radioactive/34irticlesiirodnced by the detonation of a*iciear weapon. It is only *when we begin

eral thousand years could carbon 14 ortritium be considered passible hazards.Otherwise, fusion products are neglected:as an illtportant source of radioactive ma-terial contributing to the immediate post-attacksurvival problem.

6.5' The uranium and plutonium whichmay have escaped fission in the nuclearweapon represent a further possiblesource of residual nuclear radiation. Thefissionable isotopes of these elements emitalpha particles and also some gamma raysof low energy. However, because of theirvery long half-lives, the activity is verysziall cornpared with that of the fissionproducts.

66 It will be seen later that the alphaparticles from uranium And plutorfium, orfrom radioactive sources in general, arecompletely absorbed in an inch or two ofair. This, together with the fact that theparticles, cannot penetrate ordinary cloth-ing, indicates that uranium andplutoniumdeposited on the earth do not represent aSerious, external hazard. Ev,en if they ac-tually come in contact with the body, thealpha particles emitted are unable to pen-

'etrate the unbroken skin.8-,7 The last source of-radioactive mate-

rial, to be considered is the neutron in-,duced activity:The neutrons liberated inthe -fission process,'but which are not in-volved in the propagation of the fissionchain are ultimately captured -by theweapon materials through which theymust, pass before they can escape, by ni-trogen (especially) and oxygen in the at-mosphere, and by.. various.,elements pres-ent in the earth's surface. As a result ofcapturing neutrons4ubstances may be-come radioactive. They, ,consequently,emit beta particles, frequently -accom-panied by gamma radiation, over an ex-tended period of time following the explo-sion. Such neutron-induced activity, there-foreris part of the residual nuclear radia-tibn.

6.8 The activity induced in the weaponmaterials is .highly variable, since it isgreatly depenaeint upon the design orstructural characteristics of the weapon.

' Paragraphs 6.5 through 6.18 are reprints of elected paragraphsfrom The Wets of Nuclear Weapons.

Any radioactive isotopes produced by neu-tron captore in the residues will remainassociated with the fission products. Inthe period from 20'hours to 2 weeks afterthe burst, depending tO some extent uponthe weapon materialsj such isotopes, asuranium-237 and -239 and neptunium-239and -240 can contribute up to 49 percent ofthe total activity of the weapon residues.At other times, their activity is negligiblein comparison with that of the fissionproducts.

6.9 An important contribution tol theresidual nuclear radiation can also Arisefrom the activity induced by neutron cap-ture.in certain elements in the earth andin sea water. The extent of this radioactiv-ity is highly variable. The element whichprobably deseives most attention, as faraS environmental neutron-induced activ-ity is concerned, is sodium. Although this-is present only to a small extent in aver-

oage soils, the ,amount of 'radioactive so-dium-24 fornied bY-neutron capture can bequite appreciable. This isotope has a half-life of 15 hours and eniits both beta parti-cles, and more important, gamma rays ofrelatively high enertsy.

6:10 How much radioactive material isavailable for distribution as fallout?

6.11 At i minUte after a nuclear explo-sioh, when the residual nuaear radiationhas been postulated as beginning, thegamma-ray activity of the 2 ounces of fis-sion products Ow a 1-kiloton fission yieldexplosion is cthnparable with that of about30;000 tons of radium in equilibrium withits decay prodiicts. It is seen, thereforethat for explosions in the megaton-energyrange the amount of radióactkvity pro-duced'is enormous. Even though there is adecrease from the 1-minute value by afactor of over 3,000 by the end of the day,the radiation intensitly will still be large.

6.12 It has been alciiilated that if allthe fission products' from an explosionwith a 1-megatim fission, yield could bespread uniformly over a smooth area of10,000 square miles,, the radiation expo-sure rate After 24 'houts would be 6 roent-gens per hour at a level of.,3 feet above theground. In actual practice, a uniform dis-

, tribution would be improbable, since ael

8 '7

-7

large proportion of the fission productswould_ be deposited nearer ground zerothan at farther distances. Hence, the ra-diation intensity will greatly exceed theaverage at points gear the explosion cen-ter, whereas at Illaell greater distances itwill usual y be less, The' above example' does not i elude any neutron induced ac-tivity.

FORMATION OF FALLOUT

6.13 In a surface burst, large quan-titieS of earth or water enter the fireballat an early stage and are fused or vapor-iz.ed. When sufficient cooling has occurred,the fission products and other radioactiveresidues become incorporated with theearth particles as a result of the condensa-tion of vaporiz-ed -fission products intofused particles of earth, etc. A small pro--portion of the Solid Partieles formed uponfurther cooling are contaminated fairlyuniformly throughout with radioactive fis-sion produCts and other weapon residues,but in the majority the contamination isfonfid mainly jn as thin shell near the sur-face. In Water droplets, the small fissionproduct particles occur at discrete points

'within the drops. As the violent disturb-ance due to the explosion subsides, the

'contaminated particles and droplets grad-uallr fall back, tO-earth: This effect is re-ferred tol as the,"fallout". It is the associ-ated radiioactiviiy in the fallout, whichdecays-over a long _period of time, that isthe main:SOUrde.of residual nuclear radia-

-tións.634 'Thelektent and nature of the fal-

.

-can r nge between Wide extremes.044he-actual behavior willbe determined by

a Combination -of cireumdtances aisoCiatedWith the ,energy yield and design of theweapon, the height of the explosion, thenature of the surface beneath the point ofburs , and the meteorologi al conditions,which we willfdiscuss later. In the case of

- dr d r bare, for example, occurring at anappOciable- distance above' the earth's

"434iftiCe.,'So that no surface materials aresucked into the -cloud, negligible fallout isprOduced Thus at Hiroihima and Naga-

," Saki, where approximately P-kilotOn de-Ivicet Were ekplocled 1,i5Q feet above the

7

surface, casualties due to fallout were ,

completely absent. ,

6.15 On the other hand, a nuclear ex-plosion occurring at or near the eartit'ssurfaee can result in 'severe contaninationby the radioactive fallout. In the &sè othe 15-megaton thermonuclear devictested at Bikini Atoll on March 1, 195the B,RAVO shot of Operation CASTLthe eniuing faliout caused substantialcontamination over an area of more thari,7,000 square miles. The contaminated re-gionwas roughly cigar-shaped and ex-tended more than 20 statute miles upwind .and over 320 miles downwind. The width .in the crosswind direction was variable,the maximum being over 60 miles.

6.16 It should be understood that thefallout is a gradual phenomenon extend-ing over, a period of time. In the BRAVO

'-' exPlosion, for e ample, about 10 hours 1

elapsed before t e contaminated particles I

began to fall at t e extremities of the 7,000square mile area. By that time, the radio- i

active cloud had thinned mt to such. an , ..

extent that it was no long,* visible, Thisbrillgs up the important fact that falloutcan occur even when the cloud cannot be_seen. Nevertheless, the area of contamina-tion which presents the most serious haz-ard generally, results from the fallout ofvisible-particles.

1

ablished6.17 The fallout pattern fromiparticles

of visible size will 1-ive been eswithin about 24 hours after the burst. This ---is referred to as "early-fallout and-is alsosometimes called "local" br "efose-ie fal-lout. In addition, there is,the deposition ofvery small particles Which , descend veryslowly over large areas of the. earth's sur-face. This is the "delayed fallout," alsoreferred 'to as "worldwide fallout,'-' towhich residues, from nuclear explosions ofvarious typesair, bigh-altitude, surface,and Shallow subsurfacemay contribute..

6.18 Although the test of March 1, 1954produced the most extensive local falloutyet recorded, it should be -pointed out that ;the phenomenqn was not necessarily char- sacteristic of (nOr restricted to) thermonu-,clear explosions. I is very probable that ifthe same device h &been detonated at an 'i

appreciable distan e above ,the .Coral Is- '

83-, ,

'

land, so that the large fireball did nottoUch the surface of the ground, the earlyfallout, would have been of insignificantproportions:

WHAT GOVERNS THE LOCATION OFEARLY FALLOUT-

6.19 There are several factors goverrk.ing the location of early fallout. These are:

1. Kind of Weapon.2. Yield of the burst.3. Altitude of the burst.4. Ileight.and dimension of the cloud.5. Distribution of radioactive particles

within ,the cloud.6: Radioactivity associated with various

particle sizes.7.. Rate of fall of the particks. '

8. Metecirological conditions, illaudingwind structure to the top of the cloud:arid...ariy type of precipitation.

6.g0 These faCtora are so interrelatedthatjt is .almost inippssible to isolate the

Teifedts O:*ani orie factor :-(Tith pkecision.HoWeVei, -it is possible to discuis the gen-etal sigkificance of each factor.; 6.21 Kind, of Weapon.Since the fusiOiiproducts-do not niake a significant contri-butiokof 'Pailioactive ,matefial- o-fallout,

-even --whe-n-.trie-Welpon fs a diermonuclearone (i.e., fiiiion is involved), only tli.e fi8-siot yield 'of ovioen Weapon is important

ln.deterraiiing_the total_ amount of radioac-:::tii)e..fallout: Tor example, although the to---_tal--arnount of, radioactive material pro--cinOed-'would.be aPproximately the same in

a'1.nregatdn.50% "fission. yield weapon and'a 2 niegaion.25 .% fission yield weapOn, the

. - .=--reSUlting' fallOnt Patterns would -probablydiffe,bcause of the greater height ob-talined iisr the 2 megaton. cloud.-- 0.2'2 Altitude of the Burst (This is acrucial factor).The fraction of the totalradioactivity of the bomb residues thatappear in the early fallout depends upo)the .extent that the fireball touches tlie4urface, Thustthe proportion of the availa-ble' activity ocontributing, to early -falloutincreases, as the height of Intrst degreasesand irrore.of-the.firehall conies into Contact016 -ar* etil;" . -."

6.23. Height and bintension of theCloi.41.It is obvious that the phYsicat.,skeof the cloud at the time of stabilizationwill have an effect on the distribution ofearly-fallout.:The height to which the indi-vidual particles are carrie.d principally de-termines how far downwind a giVen par44-cle size will drift, and the horizontal ex-tent of the cloud affects the width of thearea over which fallout will occur.

6.24 The eventual height reached bythe nuclear, cloud depends upon the en-ergy of the bomb ahd upon the tempera-ture and density of the surrounding air.The greater the amount of energy liber-ated the greater will usually be the up-ward thrust due to buoyancy and so thegreater will be the distance the cloud as-cends. It is probable, however, that themaximum height obtainable by the nu-clear cloud is affected by the height of thetropopause, which is the boundary layer,between the xelatiiely stabje air of theIstratosphere and the more turbulentosphere. (See Figure..6.24.)

STRAfOSPHEREf-TROPOPAUSE

-TROPOP,HERE

,-- -,...--......,

NIv-/ N

/ / .?/ o \lk:).%

FIGURE 6,24.-144 eartills atmosphere.

6.25 The height of the tropopause isusually slightly above 50,000 feet in thetropics and at 30,000 to 40,000 feet in mid-dle latitudes in the summer. In winter, inthe middle latitudes,. it is somewhat loWeron the average than irr4he summer. Forsmaller kiloton. weapons, the height of thetropopause generally limits.the height ofthe nuclear cloud. t ven for larger si*e

-

q9

-FAET

'130,000'

Il0;000

90,000

70,000

50;000

30,000

.roo,KT . . 1)41 '.-za MT. ,.:

FIGPRE 64:Representative nuclear detonation cloud-heights.

We-46ns in the megatori range, the devel-4irtent of the cloud slows down as thealOud builds upinto the stratosphere.

4. Thus the lower the tropopause, the lessthe total height of the cloud. Figure 6.25

- illustrates- rougir estimates of some possi-,bre Cloud, heights under "typical" 'condi-tions. 'v ;

26'.= rbtatflbutiOn. of Radioactivityoithin.tM'.loiuis.Ffgure e 6.26 summa.

"iitektheldiitriliutiori of radioactivitywithin the, nticlear- cleud; You will note:-Outt:Okojciinately-09%,ofthetotal activ-ity in -;he cleUd and airy. 10% orlesS tri.--the stem sectioizjth the, bulls ofthe itetiyity-in tie base' of the :cloud. It-is:1Urther ,assumed that the',.hUllc,of the re--diOaCtiVe,Material that .4'ontributes .to

.early:fallbut ,will, be' at'ort below aboutSNOOOleet: Aboyethiaaltittide the 01-'6-elear`iyilt.iiro4blY- 'be'ln..,4 finely divided

4.ill-,C-Oritribi.ite -most to' the'WerldiOdefallotit,: .

Ain.ount_., of :Radipactivity.014048,1:PAW* q2:08;::.410111,

eX1001:1041' evidence radioactive parW

:officqopty We** (A mi-

I

cron is r millionth of a meter). It isAuite'possible that even smaller particles existlince the lower limit of this range is the,.limit of the resolving power of the electrop.,*,microscope. To determine the fallout pat,:-.4terns from a nuclear detonation,it is nec-essary to icnow the distribution of the totalradioactiyity among particles of various

6.2,0-Dhstribution of radiolketivity.-

$

Mies. Knowledge in this area is still ratherlimited because of the difficulty in obtain-ing large and repreientative samples ofradioactive debris-from a nuclear cloud.

6.28 Rate of Fall of Partieles.The par-ticles carried up into the atmosphere by anuclear detonation are acted upon bygravity and carriekby the winds. Since

wind directions and speeds usually varyfrom one level to another, each particlefollows a constantly changing course, andchanging speed as- it falls to earth. The.'rate of fall depends upon the particle size,shape and weight and the characteristicsof the sir. The stronger the wind in eachlayer the further the particles will be car-

EFFECT OF PARTICLE SIZE (WIND di INITIAL HEIGHT90,000 FT. ASSUMED CONSTANT)

60,000 FT. 01,

30,000 FT.

GROUND

-EFFECT' OF HEIGHT (WiND a PARTICLE SIZE ASSUMED

111

-11,1 %MIER

srittlig N

LARGE PARTICLESFALL FAST, LANDCLOSE

SMALL IN1RTICLES

90,000 FT.

60,000 FT. --111,

, 30,000 FT.-

CONSTAN7)LOWER PARTICLESLAND SOONER,

SERUPPER PARTICLESFALL LONGER,LAND FARTHER

GROUND aa a a

EFFECT OF WIND (PARTICLE SIZE ASSUMED CONSTANT)90,000 Ft 'fko. .

,i7,z. I -

-STRONG

60,000 FT. WIND

30,000 Ft,

GROUND alba a_EFFECT OF VARIABLE

90,000 FT. 4--

0PARTICLES LAND FARTHER,

11 1MORE SPREAD OUT

itI \\PARTICLES,LAND CLOSE

WEAKWIND

60,000-Ft

30,060 ft

GR0LIND:

WIND (PARTIdLE SIZE a INITIAL0 HEIGHT ASSUMED CONSTANT)

PARTICLE:5 'MOVEMENT IS'. SUM OF ALL WIND FORCES

'FIGURE 6.28,F'actors:affecting_diStribution of radioaltive partkles.4 -

ried in that layer. The faster the particlefalls, the less influence the wind will haveon it and the closer to ground zero it will

I land. The 'higher the altitude at which itbegins to -fall, the longer it will be carriedby the wind, and under most Conditionswhen the wirids at different altitudes donot oppose one another-the farther it willtravel. (See figure 6.28.)

6.29 Meteorological Conditions.Windsare the principal factor which affect themovement of the nuclear cloud. Even withthe same type, yield, and altitude of deto-nation, different wind conditions will pro-duce different falloutAnatterns of irregularshape. The speed anorvertical shear of theupper air winds will also affect the concen-tration of railioactive material on theground. A fallout pattern under conditionsof strong winds aloft would differ fromthat of weak winds ih two ways. First, thestrong wind would spread the materialover a larger area tending to reduce theconcentration close to the source. Second,at a given distance the fallout would ar-rive sooner and would have had less timeto decay.

6.30 The United States has a variety ofupper air winds. During the winter, spring,and'fall seasons the United States Nindsare pritharily the "prevailing westerlies."By this it is.meant that the winds Oyer theUnited States blow more frequently fromthe west*n quarter than froth-any-otherquarteA of the compass. The westerlies inthe middle latitudes become increasinglypredominant with increasing height up to-about 40,000feet. Nt 5,060 feet the windsare from the western quadrant about halfthe time; while at 30-40,000 feet they are

"- from that quadrant about three-fourths ofthe time. Above 40,000 feet, the percent-age of westerly winds again decreases.

6-.31 The predominance of westerlywind direction changes with the seasons.Upper winds blow from the west moreoffen during winter than during summer.The increase in frequency of other direc-tions in the summer is more pronounced in .

the southeastern portion of the country,where direciions *bent/Ie.-variable at alllevels. Along the Pacific Coast, the windsblow less constantly from the west than in

5"

other sections of the cotentry. Southwes-terly. and northwesterly winds _are morecommon. Above 60,000 feet, easterly windsoccur frequently in all seasons and are therule in summer over most of the UnitedStates.

6.32 In deicribing- direction of falloutfrom the point of detonation (GZgroundzero), the terms "upwind" and "down-wind" are often used. The "downwind"direction is the direlkion toward which thewind blows, while "upviind" Means againstthe wind. When applied -to falloutf theterms upwind and downwind will apply tothe resultant or total effect of all thewinds through which the pgrticles havefallen. An upwind component results fromthe very rapid expansion of the cloud in alldirections immediately after detonation.The disturbances at the time of the explo-sion will deposit radioactive material inupwind and crosswind directions for rela-tively short distances from ground zero.

6.33 Since the direction of fallout is de-termined by winds up to at least 80,000feet, and since winds in the upper airfrequently are quite different than windsat the surface, surface wind directionscannot be used as an indication' of direc.&""tion of flow of high atmosphere winds. it itnot at all uncommon ,te have east, south,or north winds at the snrfaceand westerlywinds aloft. .

6.34 In considering the possible area offallout, wind speed is as important as winddirection. Depending on particle size, thedirection determines the sector tp whichthey are carried; and the speed governshow far they will travel before coming to,the arth. Wind speeds over the UnitedStates generally are less in the summerth4n in winter at all heights and above all,sections of the United States. The only'exceptions would be during the paksage ofhurricanes or tornadoes which producevery strong surface winds in the warmseasons. This difference between seasonsis greatest in the southeastern portion ofthe country, where winds become particu-larly light and variable in the summer..buring the winter, upper winds along thePacific Coast generally have lower speedthan in any other section- of the United

117 ,92

v

States, Wind speeds increase with altitudefrom the surface up to a level between30,000 and 40,000 feet!. Above this levelthey usually deciease in speed until at60,000 to 80,000 feet they become rela-tively light.

6.35 The winds of greatest speed us-ually occur between 30,000 and 40,000 feet,Winds exceeding .50 m.p.h. being the ruleall over the country in winter and in thenortheast in the summer. In this layer,winds greater than 100 m.p.h. are at timesexperienced over all areas of the UnitedStates, but have been observed most oftenover the northeast, where they are foundabout 25% of the time. In this northeast-ern area, winds of 200 m.p.h. occur frte-quently, with speeds -df 300 m.p.h. ob-served on rare occasions. The high speedwinds usuallfr occur in narrow meanderingcurrents within the broad belt of middle-latitude wOterly. winds, and are called"jet-streams".

0.36 The strongest winds encounteredby a falling particle have the greatestproportional influence on its, total move-ments. The strongest winds are usually ataltitudes in the vicinity of 40,000 feet.These winds would largely determine thegemral directi6n and length of the fallout

Uleliottgit, all the winds- ii to iit-Crethan twice that height could be

6.37 Fallout pAterns 'cher the -UnitedStates would probably differ in shape and.extent. In the northern half of the countryconsiderably longer patterns would be ex-pected, spreading toward the east becauseof the strong upper air westerly winds.The passage of low pressure areas wouldcause shifts from a more northeasterly toa more southeasterly spread of the falloutpattern from one day to another. In thesummer, particularly in the southern partof the country\ a great variety of patternsmight be expeeted with a broad irregularspreading in all directiOns in some cases,and elongated streaks in others. It shouldbe remembered Islso that in an area whereseveral target cities are situated within difew hundred miles of one another, falloutfrom more than one detonation might occuraf,the:Same Place.

Si

-6.38 Variation of the winds by day andnight has littO effect on factors that de-termine fallout patterns. Winds a fewhundred feet aboveground fre-quentlychange 'from day to night, but those higherup, which have the greatest effect on thefallout lipeern, do not follow a daily cycle.Cloudiness or fog alone are not believed tohave a marked effeCt On fallout, althoughthe combination of fallout particles -withcloud droplets may result in a faster rateof fall. Some cloud types also have upwardand downward air currents. The down-ward currents might tend to bring some ofthe radioactive debris down more rapidlythan it would otherwise settle.

6.39 In addition to the wind, precipita-tion in a fallout area will affect the radio-active deposition. Rain drops and snowflakes collect a large proportion of theatmospheric impurities in their, paths.Particles of radioactve 'debris -are"washed" or "scrubbed" out of tfle air, byprecipitation. The result is that containi-nated material, which would be Spread_over a much larger area by the slower dry.weather fallout process, is rapidly broughtdown in local rain or snow areas. It isconceivable that hazardsus conditions canoccur in rain Ateas where ordinary falloutestimges alight indicate a safe condition.This sdrubbing reduces the amount of con-tamination jeft in the air to fall out far-ther

6.40 Terriiin features will also cause avariation in the degree-of deposition. Hills,valleks and slopes of a few hundred feetwould probably not have a great effect on'the fallout radiation levels. Hoirever,large mountains or ridges could cause sig-nificant variation in deposition by receiv-ing more fallout on the sides facing thesurface wind. This 'is true for both dryweather fallout and "rainout".

WORLDWIDE FALLOUT

6.41 Worldwide fallout by definition ismuch more widespread than early fallout.Worldwide fallout is that portion of the-bomb residues which consists of very finematerial that remains suspended in theair for times ranging from days to years.

These fine particles can be carried :overlarge areas by the wind and may ulti-mately be deposited on Parts of the earthremote from the point of burst. It shouldnot be inferred from this term, however,that none of the fine material is depositedin are'ainear the explosions nor that suchmaterial is deposited uniformly over theearth.

6.42 You will recall that early fallout isimportant only when the nuclear burstoccurs at or near the earth's surface sothat a large amount of debris is carried upintoethe nuclear cloud. Contributions toWorldwide fallout, however, can come fromnuclear explosions of all types, exceptthose so far beneath the sUrface that theball of fire does not break through andthere is no nuclear cloud, or those deto-nated in outer space. With regard toi themechanism of the worldwide fallout, a'clis-Unction must be drawn between the be-havior of explosions of low energy yieldand those of high energy yield. If the burstoecurs in the loNier part of the atmospherethe ucleak- Cloud from a detonation in thekJ, oton range will not generally rise abovethe top of the :troposphere, conseqUent1y7nearly all the fine particles present in the'bomb debris from sucli'explosions will re- ,Main in the troposphere until they areevrtually deposited.

6.43 The fine fallout particles front, thetroposphere are _deposited in a coinWexway, COmplex, since varimis processes inaddition to simple gravitational settlingare involved. The most important of theseprocesses appears to be the scavenging ef-.fect of rain or other forms of moistureprecipitation. Almost all of the tropos-pheric fallout will be deposited within twoto three months after the detonation so

'that bomb debris dpes not remain for verylong in the troposphere.

6.44 While the fine debris is suspendedin the troposphere the major part of thematerial is moved by. the wind at highaltitudes. In general, the wind pattern issuch that the debris is carried rapidly inan easterly direction, making a completecircuit of the globe in some 4 to 6 weeks.Diffusion of the cloud to the north andsoUth is relatively slow, with the result

,

that most of the fine tropospheric fallout,is deposited in a short period of weeks in a-fairly nat.row band andt encircling theearth at the latitude of the nuclear deto-nation.

6.45 For explosions of high energy yieldih the megaton range nearly all the bombdebris will pass up throUgh the tropo-sphere and enter the stratosphere. Thelarger pellicles 'will be deposited locallyfor a surface or sub-surface burst, whilethe very fine particles from bursts of alltypes can be assumed to be injected intothe stratosphere. Due to their finenessand the absence .of clouds and rainfall atsuch high altitudes, the particles will set-tle earthward very slowly. Althoughagreement does not exist as to the mecha-nism that produces'observed differences in'worldwide fallout, it is now clear that non-uniform circulation of stratospheric debrisbetween the hemisphereS is a characteris-tic Mwor1dwide fallout. Also tto agreementexists as to the residence tinle for,world-vide fallout in the upper atmosphere, but-it appors to be somewhere between 1 to 5y eaxi:

6.46 During its long residence in thestratosphere, the bomb residues diffuseslowly but widely, so that they enter thetroposphere at many points sover theearth's surface. Once in the troposphere,fine material behaves like that which re-mained initially in that part of the atmos-phere, and is brought to earth fairly rap-idly by rain or snow.

6.47 An important feature of the strat-ospheric worldwide fallout is the fact thatthe radioactive particles are, in effect, sto-,.red in the stratosPhere with a small frac-tion conttnuously dribbling down to theearth's surface. While in stratospheric,storage, the debris does not represent adirect radioactive hazard. In fact, duringthis time most of the activity of the-short-lived isotopes decays away and some of theactivity of the longer-lived isotopes is ap-preciably reduced. Thus, tratosphericworldwide fallout is a slow, continuous,non-uniform deposition of radioactive ma-terial oyer the entire surface of the earth,the rate of depOsition depending on thetotal amount of bomb debris still present

T.-

in the stratosphere, the season of the yeararid the amOunt of precipitation.

IMPRESENTATION 00 EARLY FALLOUT,

. 6.48 In a somewhat idealized situation,it is to be exPected that, except for thevery smallest particles which descend over

..Ja wide area,_the fallout of the larger parti-clea loll to 'earth forming a, kind of elon-gated (or cigar shaped) pattern of contami-nation. The shape 'and dimensions will be'determined by tbe wind velocities and di-rections At all altitudes kbetween theground and the nuclear cloud. It should beemphasized that these _elongated Vi'lloutpatterns are ideali4ed, and an _actual fal-lout pattern, will not conform ,to these pat-

,. terns.6,49 AtapartieulartiMe.aher the deto.

nation of a nuclear' weapon, the radiation'.POosure rate IS apt to be highest at,:g-round zero; and Will decrease as the dis-, tante froth..ground, zero increases. This is

--because the. aMount -of fallout-,iper unitarea is also- likely Ao be less. -There isanother factor that contributes to this de...crease irkexposure rate with increasing

-distancenthe explosion.-This-faCtOr istime. The:later times of arrivatof thefallout -af these greater distances meanthat, the fission products have decayed to'IsOme extent while the particles were sus-._pendectin the air.;

6:50 Some *apt' the Manner in whichatallout pattern may develop over a large

_area during the .,period of several hours.f.ellowinua-high-yield nuclear surfaceburst May be seen in Figure -6,50.. Foraimplicity of representation,- the actualcoMpIex wind pattern is replaced by IanApproximately equivilent or effectibe-Wind of 15 miles per hour. Figure 6:50-shows -a- numher of contours, for certainarbitrary _exposure rates that could possi-14Y,hivebeettobserVed.on the ground at 1,6, and. 18 hoUrs + 4 H + 6; H + 18)4*§POtlYely After fhe explosion. It shouldbe-Underite,od- that the, yarieus exposureOites.ellange giadually from one contourlineto the. next,'Sirritiarly, the last contour'line-Shown does noVrepresent the:limit of

_

20 .0 0 10 20 SO 40 SO 40 SO 40 SO 100 .10 120 40 40 MO .60 ao 40 .10,

1900300

30

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10030

300100.30

10

RI HOUR

FIGURE 6.50.Contours from fallout at 1, 6, and 18hours after a sui\face burst with a fission yield inthe megaton range (15 m.p.h. effective wind). Val-

' ues given are in roentgens per hour..

contamination since the OcpOsure rate willfall off steadily over a.greater distence.

, 6.51 Consider fiftt, it'locatzon 3koil1esdownwind from ground zero.,AVOne hourafter the detonation the observed expo-sure rate is seen to be about 30 R/hr; at 6hours the exposure rate which lids be-tween the contours for 1,000. and 300 R/hr.has increased to about 800 R/hr; but at48hours it is down to roughly 200 R/hr. Theincrease in exposure rate from 1 to 6 hoursineiins the fallout was not complete onehografter detonation. The decrease from 6to .18 hours is then due to the naturaldecay of the fission products. On theotherhand a total radiation exposure receivedat the given location at one hour after theexplosion would be ielatively small be-cause the fallout has only:just started toarrive. By 6 houri the total exposure couldreach over 3,000 R and by 18 hours a totalexposure of some 5,0004R could have accu-mulated. Subsequently, the total exposurewould continue to increase but at a slowerrate.

6.52 Next, consider ci point 100. milesownwind from ground zero.----At one hour

after the explosion the exposure rate, asindicated in Figure 6.50, is zero since thefallout will not have reaChed the specifiedlocation. At 6 hourS the exposure rate is 19

95

_

R/hr and at 18 hours about 50 Rthr.. Thetotal (infinite) exposure will not be asgreat as al locations sloser to ground zerobecause the quantity of fission productsreaching the ground decreases at increas-ing distances from the explosion.

UNCERTAINTIES IN FALLOUTPREDICTIONS

6.53 Idealized fallout patterns are use-ful for planning purposes, but they are notblueprints of the actual, fallout patternthat would occur. There are juit too manyuncertainties or variables involved in fal-lout, affecting both distribution, of earlyfallout and rate of decrease of radioactiv-ity, to make precise prediction possible. .

6.54 It is difficult to estimate the ex-tent of the induced radioactivity because

.,"odifferences in type of weapon, the .

:height i;f burstoknd the nattfre of the Sdif °or other mateirial in which neutron born-

., bardment has caused 'radioactivity. 'Fur-jhermore, the eicistence of \unpredictablehot_ spots will affect local radiatin expo-sUie,rates, a§ will the nature of, the ter-rain (buildings, trees,etc., may reduce theaverage, radiation exposure rate above the

_graund..to .70..or. 75- percent -Of- the valuemeasured in open, fiat terrain); weather-ing (wind:may move surface-deposited fat-lout front 'one area to another or rain mayWash it into the soil); fractionization (any

FIGUR? 6.5-4.4allout patterns from nuclear test*:detonation at the Nevada Teit Site.

AfE MEAD

FIGURE 6.54b.Fallout patterns from nuclear testdetonation at the Nevada Test Site.

FIGURE 6.54c..Falha patterns trom nuclear tesi'detonation at the Nevada Test Site.

C:

_sne a, several processes, apart from radio-.

active decay), that results in change in thecoMposition of the'radioactive weaPon de-bris); fission products of differing ag9Land -

other.factors. These uncertainties or ..Tari-ables mean that the cigar-shaped fa loutpatterns are idealized, not necessarily"real. Tb se,e film the idealized pattern dif-fers from an actual pattern, refer to Fig-Orei . a through 6.54c whi`ch sh4w fill-t'lou Pa erns ,from actual test detohationsM 4 e istevada Test Site. These patterns

- were teloped from monitored Teadingstaken s ortly after the test shots:

6.55 So far we have examined' the fal- ,

lout problem in general terms without ,

trying to show the magnitude ot the sittta-,

,

_.

.tion, that cotild eicrst if the entire. nation-should be attackedt The 'map in Figure6.55a illustrates .an ass\umed hypothetical

- nuclear attack. Each circle represents a 20megatob surface PxplOsion. There are 50 ofthese. 'Each square represents a 10 mega=ton surface burst. There are 100 of these.Each triangle represents a 5 megatonburst and there are also 100 of these. In

. this hypothetical attack there are 256weapons dropped or& 144 different targetswhich include military, industrial and pop-tjlation objectives. The toAl yield of these'250 weapons is equivalent to 2500 mega-tons or 2.5 billion tons of TNT!

6.56 Figure 6.55b shows the areathatwould bp affected by fallout and the theo-retical levels of radiation one' hour after

the attack. The fallout areas would be 30to 50 miles long, depending upon windspeed and In the center of these areas thelevels of radiation could be greater than3,000 R/hr at H + 1.-

,

6.57 Figure 6.55c illustrates the situa-tion 6. hours after ttack. Fallout wouldhave sprea'cl oye'r out 40% of the na-tional land area. Hoviever, the radiationlevels would have decayed by ap.proxi-mately a tactpr of ten. The exposure ratesin these areas would range from one R/hralong tbe border to perhaps 400 R/hr inthe-center. Figure 6.55d iillustrates theareas that would be affected-by fallout oneday after attack. Approximately 70% ofthe country's total area would be coveredby fallout exposure rates greater than 0.2R/hr. About 18% of the.lb.nd area wouldhave a very Serious fallout condition.

F1GGRE15.55a.Hypothetical attack pattern.

92

FIGURE 6 55b.HypotheticaI ttack,.1-1 +1 situation.Exposure rates exceed )0 4tIhr.

FIGURE 6.55c.Hy pothetica1 attack, H +6 situation.Exposure rates exceed 1 R/hr.,

Nowlie7 Ae1;03-,02011, -_-megasmirrr,,

NAL:110-VAP01,11 Pea*yea41:au.AVIIVA

FIGURE 6.55d.Hypothetical attach, H +24 sitaution.Exposure rates exceed .2 R/hr.

6.58 Shortly after the first.day radioac-tiVe decay would ilegin to predominateover further HPposition of fallout Theboundaries of these fallout areas wouldgradualiy shrink.

Figure 6.55e illu,strateg the situation orie'week after attack during which time theradioaictive areas would hai.4e. peen de-creasing in size ana the exposure ratesdecreasing as a retult of decay. Only aboutone-third of thee nation"s area would be

D7

FIGURE 6.55e.Hypothetical attack, H +1 weeksitirtion. Exposure rated exceed .2 R/hr.

FIGURE 6.55f.Hypothetical attack, H. +2 monthssituation. Exposure rates exceed .2 R/hr.0

covered by fallout exposure rates exceed-ing 0.2 R/hr. This reduction in exposurerate would continue.' Two montfis afterattack, the situation might exist as illus-trated in Figure 6.35f. We would find .onlyisolated elongated islands where.the levelsof radiation would exceed 0.2 R/hr.,.6.59 It is emphasized that this training

exercise represents just one attack pat-, tern applied to the wincIS and weather ofone day. Had a different attack patternbeenA"elected or the weather for anotherday, the fallout situation would have de-veloped quite differen9y.

6.60 To illustrate the effects of differ-_ ent wind patterns on a hypothetical nu-clear attack; figure 6.60 shows a falloutpr ection for a 156 weapon-384 megatonattac -\nsing the wind. cOnditions that ex-

on June 28, 1957,6.61 Figure 6.61 sh-ows the theoretical

fallout from the identical attack pattern

the Itameground zeros and the same

weapon yieldsbut, based on the weatherofJuly,12, 1957. You will note that the axisof fallout deposition of many locations hasshifted by more than 12 4 degrees. On an-other day. the wind could swing in anyother direction and tum safe areas onthese maps into areas of extreme falloutdangar.

FALLOUT FOREdASTING

6.62 We have seen that one of the mostsignificant factors affecting the dispersionof fallout Was the wind. We also saw thatdata can be obtained on wind directionand speed at various altitudes. Since amajor inflUence on fallout' is .one aboutwhich considerable data are known, it ena-bles us to predict with some degree 'ofaccuracy the probable pattern of falloutdispersion. The 'requirements of fallout

FIGURE 6.60.Hypothetical attack, fallout patternfor winds.of June 28, 1957.

FIGURE 6.61.HYpothetical attack, fallout patternfor winds of July 12, 1957.

DP 93

prediction 'frornwind direction 'and slieed. are two: accurate data and current data..

Both of these conditions are met by thenetwork of rawin observatories estab-lished by the United States and Canadian

. Weather Services.6.63 The purpose of preparing fallout

forecast plots is to provide graphic esti-mates of areas that are likely( to receivefallout and the approV,mattktime'of falloutarrival. Figure 6.63 illustates a falloutforecast plot. The area inside the heavy'UP shaped pattern and the dashed three-hour line represents land which could becovered with fallout within three hours ofa nuclear surface detonation upon the city'of Roanoke. The dash'ed One-hour and two-hour lines represent fallout tar:rival timesand provide for forecasting Mllout arrivalat various places within the forecast plot.

For example, at Lynchburg, fallout wooldbe forecast to arrive about one hour afterdetonation. .

Information provided thkorecasts islimited to areas that may be coverpd ,byfallout sand the approximate times of fali,lout arrival within the forecast area. Pre2dieted radiation levels or exposure ratesare not includ-ed in t7he forecasts.

6.64 Meteorologic.al data for the con-struction of fallout forecast plots are avail-able to all levels of government in theform ot "DF" messages which arp trans-mitted by teletype over the nationalweather service network. Data points areshowq on Figure 6.64. Arrangemeuts forthe receipt of D'F messages should bemade to iupport operations iri the event ofa fallout emergency.

6.65 The Deferise Civil lfreparedness

94

FIGURE 6.63.--A fallout forecast plot.

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:Agene'y has prepared.a manual of detailedinstructions on the construction and use offallout forecasts. This manual is entitled"Users ManualMeteorolokicar Data forRadiological Defense," '(FGE-5.6/1). TheManual explains the "DPP' message for-mat, giNtes instructions on preparing fal-lout forecast areas, and ill'ustrates how to

, estimate falloutAIrrival time for opera-tional Use. The manual may be obtainedthrough regular civil preparedness-nels.

.

REFERENCES

ILM

MIA

HAT

Tile Effects of Nuclear Weapons.Glas-stone, Sainuel, 1964.,

Fdllut Firom. Nuclear Tests.ilearingsbefore the Special Subcommittee on Ra-diation of the Joint Committee on AtomicEnergy, Congress of the United States,May 1959.

Use.rs MandalMateorologOal DIta forRadioloOcal Defense,FG=t7,5.6/1, July1970.

1 0.0 -

95

fi

EFFECTS OF NUCLEAR RADIATION EkPOSURE

We have learned that nuclear radiationis a form of energy:which has the power todamage living cells or tissue. In thii chap-ter, our ol?jective is to explain:

WHAT are the effectself nuclear radia-tion

HOW are they producedWe are going to take a look into a human

cell and see what happens when it is sub-jected to nuclear radiation, what kind ofdamage is produced and the effects of thisdamage. And there is something else wewill learn, too, something that i; VITAL in-effective RADEF work:

WHAT is the tolerance of the humanbody to nuclear radiationhowmuch can we standhow longcan we stand it

INTRODUCTION

'7.1 Late one November afternoon in1895, as the *German 'physicist WilhelmRoeritgen was sending an electric currentat high voltage through a vacuum tube, henoticed A welak light that shimmered on alittle bench he knew was located nearby.It seemed as if the spark of light insidethetube was being reflected in a mirror. Strik-ing a mata, he saw that a screen withsome barium salt crystals on the benchwas shining with fluorescent' brilliance._Later, he held a piece of palier, then aplaying card, and then a book'between thetube and the screen. He was amazed to seethat, even with the book placed in front ofthe tube, THE CRYSTALS STILL BE-ICA'ME FL'UORESCENT. Iiespite everylaw of science (as then understood) he hadto admit it: SOMETHING, some unknownor-"X" quantity, was passing right throughthe solid book..He then tried to see if other

CHAPTER 7

materials would stop the "something".Eventually, he tried placing a 'thin sheetof lead between the tube and the crystals_and found that it did stop the passage ofthat something. Trying further experi-ments, he picked up a small lead piece andheld it up before the tube. Ile was stag-gered to see that not only did the rounddark shadow of the disk appear on thescreen of barium crystals, BUT THAT.HECOULD DISTINGUISH THE OUTLINEOF HIS THUMB AND FINGERS. Notonly that, but within this outline weredarker shadows: THE BO,NES OF HISHAND. Theie phenomeha were so con-trary to common sense, that Roentgenworked in secrecy, afraid that he might bediscredited for suclh "unscientific" work.Even his best friends were kept in thedark. When one insisted on knowing whatwas going on, Roentgen said, "I have dis-covered something interesting, but I donot kno* whether or not my observationSare correct."

7.2 Finally, after continued experi-ments including the first X-ray photo-graph (taken of his wife's hand), Roentgenrealized that he must tell the world of hisfindings. He reported all his experiments,stating that the phenomena were causedby some form of invisible radiant energy.He called this energy 4'X-rays", the "X"standing for unknown:

'7.3 The story 'broke in the ViennaPresse on January 5, 14896, and soon scien-tists all over the world, including ThomasEdison, were excitedly experimenting withthis new kind of ray. The boon to medicineof X-rays, or Roentgen-rays as they ,werelater called, wai obvious: examining bro-ken bones and- fractures; locating tumorsor other abnormalities. For some, X-rayswere even a source of amusement, a hobby

10197

or playtoy. In 1896, the following adver-tisement appeared in the magazine Scien-tific American:

"Portable X-ray apparatus for physi-cians, professors, photographers andstudents, complete in handsome case,including coil, condenser, W/o sets oftubes, battery, etc., for the price of$15.00 net, delivered in the United

rrIStates with full guarantee."Not understanding the nature of X-

ras, those early users of this new form ofenergy did not treat it with respect. It waseven customary to use the hand as a fluo-roscopic test object in controlling the qual-ity of the roentgen or X-rays. Soon, thosewho were exposed to continual large.dosesof X-raysr patients, doctors, students, sci-

6 entists alike, began to notice painful ef-fects. One, Dr. Emil H. Grubbe pf Chicago,-said: "I had developed dermatitis on theback of my left hand which, was so acutethat I sought medical aid." The "dermati-tis" was a radiation burn, and Dr.Grubbe's fingers and hands had been sobadly burned by the X-rays that subse-quently they were amputated piecemealas the damaging effects of ;overexposurespread. a

7.5 Since it was noticed that exposureto X-rays caused the hair to fall out, someconcluded that X-rays were a good way toremove excess hair. One example, cited byDr. W. E. Chamberlain of Temple Univer-sity, shows what could happen:

A doctor in a small town heard that X-rays make hair fall out. His comely little_secretary complained of having hairyarms. Apparently unaware of the poten-tialities for harm, the doctor adminis-/tered X-rays. with his portable radi-ographic machine. Horrible X-ray burnsdeveloped, and in due time the younglady's arms had to be amputated.7.6 By 1922 it was eitimated that 100

radiologistsad perished from overexpo-sure to radiation. Continued experimentsclearly showed that all living tissue couldbe destroyed provided it was bombardedwith .a sufficiently high dosage of radia-

lion.7.7 A few months after Roentgen dis-

cOVeredl-rays, the French scientist HenriBecquerel found that certain uranium98

salts gave off .penetrating rays, similar inoperation to X-rays. Later, Pierre Curieand his wife, Magrie, tried to find the sub.-stance responsible for the radiation thatBecquerel had observed. It was MarieCurie who termed thig activity RADIOAC-TIVITY, to which you wereAtroduced inChapter 2. After intensive work, the Cur-ies found two new radioactive elements,"polonium" and "radium". From repeated 'overexposures in her work with radioae-tive substances, Madam Curie suffered ra-diation injury and subsequently died fromthe delayed effects of radium damage. Herdaughter, Irene Curie, carried on themother's wprk, and she too died from over-exposurerto radiation.

'7.8 What happens when living tissue isbombarded with radiation? Why does itcause so muS havoc to the body? These,and other questions will be answered insubsequent paragraphs.

NUCLEAR RADIATION INJURIES

7.9 Each advance in man's power overnature has brought with it art. element ofdanger. X-ray and nuclear radiation is noexception. We adopt a policy of acceptablerisk in every facet of our lives., Societymust decide what risk it will accept ic theuse of nuclear radiation. The ,scieAtistmust clearly, set forth the hazards.

The prithary biological-effect of nuclearradiation on life is in the cell. The normallife process in a cell uses a very smallamount of energy wit'h a high degree ofself-regulation. When ionizing radiationstrikes a cell it disrupts the living process.The specialized parts of a cell, such as thegenes, are damaged not onry by direct hitsbut also by the chemical poisons producedby ionization of the cell fluid. Many'Yearsago radiologists .noted that the number ofcells damaged by a given exposure to ra-diation is a simple function of the numberof living cells present. In other words, thenumber of cells damaged per unit of doseis constant. The number of cells in whichgenetic damage occurs is also a function ofdose.

7.10 A higher plant or animal such asman consists of many cells. Higher forms

1 02

MOP.,

of life are a society of specialized andinterdependent cells..Radiation damage toone organ or group of Specialized cells candisturb other organs and weaken thewhole organism. Man's life functions arecarried out within a very iiarrow 'range oftemperature, air, nutrients, water and ra-diation. This cooperative action of cellsand tissues makes higher forms of lifemuch more Nulnerable to radiation thanlow'er forms of life. Furthermore, individu-als of the same species react differently toa radiation dose just as people react differ-,ently to a cold.

RADIATION UNITS

7.11 'The radiation unit is known as theroentgen. By definition, it is applicableonly to gamma rays or X-rays and not toother types of ionizing radiation, such asalpha and beta parlicles and neutrons.Since the roentgen( refers to a specificresult in air accompanying the passage ofan amount of radiation through-air, it doesnot imply any effect whicb it would pro-duce in a biological system. Because ofthis, the roentgen is, strictly speaking, ameasure, of radiation "exposure." The ef-fect pn a biological system, however, isexpressed in terths of an "absorbed dose."By comparing the actual biological effectsof different types of ionizing radiation, itis possible to convert the aksorbed doseinto a "biologically significant dose" whichprovides an index of the biological injurythat might be expected.

7.12 The absorbed dose of radiation_was originally expressed in terms of a unitcalled the "rep," the name being derivedfrom the initial letters of "roentgen equiv-alent physical." It was used to denote adose of about 97 ergs of any nuclear radiartion absorbed per gram -of body tissue;7however, for various reasons this unit hasproved to be some'what unsatisfactory. Inorder to avoid difficillties arising in theuse of the rep, a new unit of radiationabsorption, called the "rad," has come intogeneral use. The rad is defined as theabsorbed 'dose of any nuclear radiationwhich is accompanied by the liberation of100 ergs of energy per gram of absorbing

material. For sOft tissue, the differendebetween the rep and the rad is small, andnumerical values of absorbed dose for-merly expressed in reps are essentially .unchanged when converted to rads.

7.13 Although all ionizing radiationsare capable of producing similar biologicaleffects, the absorbed dose (measured inrads) which will produce a certain effectmay vary appreciably from one type ofradiation to another. This difference inbehavior is expressed by. means of the"relative biological effectiveness" (orRBE) of the particular nuclear radiation.The RBE of a given radiation is defined asthe ratio of the absorbed dose in rads ofgamma radiation (of a specified energy) tothe absorbed dose in rads of the given'yadiation having the same biological ef-fect.

7.14 The value Of the RBE for a partic-ular type of nuclear radiation. dependsupon several factors, including tile, dose*rate, the energy of the radiation, the kindand degree of the biological damage, ahdthe nature of the organism or tissue underconsideration. As far as nuclear weaponare concerned,, the important criteria aredisabling sickness and death.

7.15 With the concept of the RBE inmind, it is now useful to introduce anotherunit, known as the 'Irem," an abbreviationof "roentgen equivalent mammal (orman)." The rad is a convenient unit for

-*expressing energy absorptiOn, but it doesnot take into account the biological effectof the particular nuclear radiation. ab-sorbed. The rem, however, which is de-

. fined _by: dose in rems = RBE X dose in`rads, provides an indication' of the extentof biological injury (of a given type) thatwould result from the absorptiOn of nu-clear radiation. Thus, the rem 'is a doseunit of biological effect, whereas the rad isa unit of absorbed energy dose and theroentgen (for X or ganima rays) is one ofexposure.

2 Because I roentgen exposure kives about I rad absorbed dote in4

tissue for photons of intermediate energies (0.3 to 3 MeV), the absorbeddose for gamma (or X-) rays is often stated, somewhat loosely. In"roentgens " However, for photon energies outside the range from 0.3to 3 MeV, the exposure in roentgens is no longer simply related to theabsorbed dose in rad.

99

7.16 All radiation Capable of producingionization (or excitation) directly or indi-rectly, e.g., alpha and beta particles, X-rays, gamma rays, and neutrons, causeradiation injury of the s e general type.However, although the etcts are qualita-tively similar, the varidis radiations differin the depth to which they penetrate thebody and in the degree of injury corre-sponding to a specifthd amount of energyabsorption. As seen above, the latter dif-ference is expressed by means of the RBE..

7.17 The RBE for gamma rays ii ap-proximately uinty. For beta particles, theRBE is also close to unity; this means thatfor a given amount of energy absorbed in

' living tissue, beta particles produce aboutthe same extent of injury within the bodyas do X-rays or gamma rays. The RBE fOralpha particles from radioactive sourceshave been variously reported to be from 10to 20, but this is believed to be too large inmost cases pf interest. For nucleafweaponneutrons, the RBE for acute iadiation in-jury is now taken ael.0, but it is apprecia-bly larger where the formation of opacitiesof the lens of the eye (cataracts) is con-

. cerned. In other words, neutrons are muchmore effectiVe than gamma rays in caus-ing cataract's.. ,

.,

7.18 In considering the possible effectspn the body of gamma radiations from

N, external sources, it is necessary to distin-guish between an "Aute" (or "one.shot")exposure and a "chronic" (or extended)exposure. In-an acute exposure the whole

, radiation dose is received in a relativelyshaft interval of time. This is thecase, forexample, in connection' with the initial nu-clear radiation. It is not possible to definean acute doie.,preciselY, but it may besomewhat arbitrarily taken to be the dosereceived 'during a 24-hour period. Al-though the delay.ed radiationS from earlyfallout persist for longer times, it is duringthe first,day that the main exposure wouldbe received and so it is regarded as beingacute. On the other hand, an individualentering a'fallout area after thefirst dayor so antriemaining for some time., wouldbe consiilered to have been subjected to achronic.exposure._

100.

7.19 The importance of making a:dis-tinction between acute -and chronic expo-sures lies in the fact that, if the dose rateis Tot, too large, the body can achievepartial,recovery from some of the conse-quencei of nuclear radiations while stillexposed. Thus, apa:rt from Certain effectsmentioned later, a larger total gamma-radiation dose would be required to pro-duce a certain degree of injury if the dosewere spread over a period of several weeksthan if the same dose were received withina minute or so.

7.20 All living creatures are always ex-posed to ionizing radiations from variousnatural sources, both inside and outsidethe body. These are chronic exposures con-tinuing for a lifetime. The chief internalsource is the radioisotope potassium-40,which is a normal constituent of the ele-ment potassium as it exists in 'nature.Carbon-14 in the body is also radioactive,but it is only a minor source of internalradiation: Some potassium-40, as well asradioactive uranium, thorium, and radiumin varying amounts, is also,prsent in soiland rocks. The so-called "cosmic rays,'originating in .apace, are another impor;tant source of ionizing radiations in na-ture. The radiation dose received fromthese rays increases with altitude up to-about 90,000 feet; at 15,000 feet, it is morethan five times as great as-at sea 'level'.The high radiation levels encountered inthe Van Allen belts at much higher alti-tudes do not contribute to the backgroundradiation on earth.

GENERAL RADIATION EFFECTS

7.21 The, effect of nuclear radiations onliving organisms -depends not only on thetotal dose, that is, on the amount ab-sorbed, but also on the rate of absorption,i.e., on whether it is acure or chrOnic, andon the regipn and extent of the body ex-posed., A few yadiation phenomena, suchas genetiE effects, apparently depend 'pri-marily upon the total dose received and toa lesser extgnt OD the rate of delivery. Theinjury; caused by radiation to the germcells under certain conditions appears tobe ctimuLative. In the- majority of hi-stanceg, however, the biological effect of a

- 194

a&

a

given total dose of radiation decreases asthe rate of exposure decreases. Thus, to-cite an extreme case, 1,000 rems in a singledose would be fatal.if the whole body wereexposed, but it would probably not haveany noticeable external effects' in the Ma-jority'r of persons if detivered more or lessevenly over a period of 30 years.

7.22 Th,e injury caused by a certaindose of radiation will depend upon theextent and part of the body _plat is ex-posed. One reason for this is that *hen theexposure is restricted, the unexposed re-gions can contributb to the recovery of theinjured area. But if the whble body isexposed, many organ's are affected andrecovery is much more difficult.

7.23 Different portibns of the .bodyshow different sensitivities to ionizing ra-diations, an'a there are vaiiations in de-gree of sensitivity. among individuals. Ingeneral, the most radiosensitive parts in-clude the limphoid tissue, bone marrow,spleen, organs of reproduction, and gp-trointestinah tract. Of intermediate sensi-

, tivity are the skin, -lungs, and liver,whereas mustle, nerves, and adult bonesare title least sensitive.

EFFECTS OF ACUTE RADIATION DOSESo-

7.24 Befgrbthe nuclear bombings of Hi-roshima and Nagasaki, radiation injurywas a rare occurrence and relatively little'was known of the. phenomena associatedwith whole-body exposure and radiationinjury. In Japan, howevyr, a large numbera individuals were eiposed to doses ofradiation ranging from insignificant quan-tities to amounts Which proved fatal. Theeffects were often complicate'd by -otherinjuries and shock, so that the symptomsof radiation sickness could not always be,isolated. ,Because of the great number ofpatienti and t,he lack of facilities after the

-.exPlosions, it was impossible to make de-tailed observations and keep accurate rec-ords. kevertheless, certain importaht con-clusigns have been drawn from Japaneseexperiende with regard to the effects ofnuclear radiation on the human organism.

7.25 Since 1945, prther information ohthis subject has been gathered from other

sources. These include a few laboratoryaccidents involving small number mof hu-man beings, whole-body irradiation ,used intreating various' diseases and malignan-cies, and extraPolation to mari of observe:-tions on animals. In addition, detailedknowledge has been obtained from a care-ful study of over .250 persons in the Mar-shall 'Islands, who were accidentally ex-posecl to nuclear *radiatioh from falloutfollowing the test explosion on March. 1,1954. The exposed individuals includedboth Marshallese and a small group ofAmefican servicemen. The whole-body re-

' diation doses ranged from relatively%mallvalues (14 rems), which produce noobvious symptoms, to amounts (175 .rems)which caused Marked 'changes in theblood4orming system'.

7,26 o single source of data directly',yields the relationship between the physi-

cal dose of ionizing radiation and the clini-cal effeet in man. Hence, thereiiino com-plete agreement concerning the effect as-sociated witli a specific dose-or dose range.Attempts in the past have been made torelate particul(r symptoms to,certain nar-row ranges of exposure; however, the dataare incomplete and associated with mahycomplicating facto,rs that makeinterpretation difficult. For iostance, theobservations in Japan were very sketchyUntil 2 weeks following the exposures, andthe people at that time we're s'ufferingfrom malnutrition and preexisting bacte-rial and paraSitic infections. Come-quently,, their sickness was often erro-neously attributed to the effects of ioniz-ing radiation when Auch'was not necessar-ily the case. The existing Conditions mayhave been aggravated ay the radiation,but to what extent it is impossible to esti-mate in retrospect.,

7.27 In attempting 'to relate the radia-tion' dose to the effect on man, it should bementioned, that reliable, information hasbeen obtained for doses up to 200 rems. Asthe dose increases from 206 to 600 reinsthe data from exposed humans decreaserapitlly and must be supplemented moreand more by extrapolations based, on ani-mal studies. Nevertheleds, -the conclusionsdrawn can be accepted with a reasonable:

Uzi101

-

-

RANGE0 TO 100 REMS

SUBCLINICALRANGE

10070 1,000 REMS THERAPEUTIC RANGE OVER 1,000 REMS LET/4AL RANGE 1

100 TO 200 REMS .200 TO 600 AEMS 600 TO 1,000 REMS 1,000 TO 5,0,00 REM4 OVER 6,000 REMS

CLINICALSURVELLANCE

THERAPY EFFECTIVE THERAPY PROMISING.

THERAPY PALLIATIVE.

INCeENCE OFVOMITING

NONE

..

100 REMS 5%200 ROA 50%

300 RE MS 100% 100% 100%.. .

DELAY TIME - 3 HOURS 2 HOURS 1 HOUR ''`ap MINUTES ;. .

LEADING ORGAN NONE

1 .,

HEMATOPOIETIC TISSUEGASTROINTESTINAL

TRACT.

....CENTRAL NERVOUS

SYSTEM

,

CHARACTERISTIC

SIGNSNONE

MODERATELEUKOPENIA

SEVERE LEUKOPENIA; PURPURA; HEMOR-RHAGE; INFECTION.

EPILATION ABOVE 300 REMS -

I t

DIARRHEN FEVERDISTURBANCE OFELECTROLYTE

BALANCE..

a

CONVULSIONS;TREMOR; ATAXIA;

' LETHARGY. .

CRITICAL PERIODPOST-EXPOSURE

.

- ,-'

4 TO 6 WEEKS ,8.TO 14 DAV.

I TO 48 HOURS

THERAPY

..,

REASSURANCE -----ThEMATOLOGICREASSuRANCE;

SURVEILLANCE.

BLOOD TRANSFUSION;ANTIBIOTiCS.

-

CONSIDER BONEMARROW TRANS-,

PLANTATION.

MAINTENANCE OFELECTROLYTE .,

BALANCE.-4-

- /

(I, SEDATIVES

G000, GUARDED HOPELESSPROGNOSIS EXCELLENT EXCELLENT

d)NVALESCENT PERIODINCIDENCE OF DEATH

',NONENONE

SEVERAL WEEKSNONE

,

I TO 12 MONTHS'OTO 80% (vor)

,

LONG80%70100% (vor)

- 96 70100%s

.

'DEATH OCCuRS WITHIN - - 2 MONTI1g .,. _

2 WEEKS 2 DAYS,

.CAUSE OF DEATH '"-7/

,.

,HEMORRHAGE; INFECTION

,

CIRCULATORYCOtLAPSE .

RESPIRATORY FAILURE;, BRAIN EDEMA. -

...

fAl.LIATIVE-AFFORbING RELIEF; BUT NOT A CURE.HEMATOPOIETIC TISSUE-BLOOD FORMING TISSUE.LEUKOPENIA-REIDUCTION IN NUMBER OF WHITE BLOOD CELLS (Ieukocytos). .

FiGultE 7.28.Summary of effects from brief nuclear radiation exposure.

PURPURkLIV1D SPOTS ON THE SKIN OR MUCOUS MfiMBRANEeEOEMA-ABNORMAL ACCUMUL TION OF FLUIDS N TME TISSUE

4-

degree of cOnfidenee. Beyond 600 rems,however, observations on man are so spo-radic that the relationship between doseand biological ;Wed' must 'be inferred orconjectured alinoit entirely from observa-tions made on animals exposed to ionizingradiations.

7.28 With th.f, foregoing facts in mind,Figure 7.28 is presented as the best avail's-ble -Summary of the effects of v.arious,whole-body dose rangesvof ionizing radia-tion on Yunnan beings. Below 100 rems, the. .

response is almost completely subclinical;that is to say, there is no sickness requir-ing special attention. Charles may, never-theless, be occurring in the blood, as willbe seen later. Between 100,and 1,000 reinsis_the_rang , . erop

".

of recovery arb so poor 'that theralv nIaly-. .

be rest 'cted laigely ,to p-alliative mess-.uies. It s of interest however, to*subdi-vide thi leth'ai range intot two, parts in ''which the chariipteristic, clinital effectsare. different. Although the dividing linehas been somewhat arbitrarily.set at 5,000... .:'reins in -Figure'.1.28, human data are solimited, that this doseleVel might wellhave any value from 2,000 to 6,000, reths.In the renge from 1,00Q to (roughly) 5,0,0brems, the pathQ115gical. changes' are'mostmarked' in the gastrointestinal' tract,whereas in the range above 5,0Q0' rems, it.,is .the central neivous systeni which ex-,

300.'hibitS the major injury.

medical treatment, will be succe sful atthe lower end and may be successful at theupper end. The earliest symptoms of-radia-tion injury are.nausea and vomiting,which may commence within about 1 to 3hours of exposure, accompanied by discom-

. fort (malaise), loss of appetite, and fatigue.The most significant, although not imme-diately obvious, effect in the range under;consideration, is that on the hematopoietictissue, i.e., the organs concerned w,h theformation of blood. An ,important manifes-tation of the cbanges in the functioning of-these organs is leukopenia, that is, a de-.cline*in the number of leukocytes (whiteblood.cells). Loss of hair (epilation) will beapparent about 2 weeks or so after receiptof a dose exceeding 300 rems.

7.29' Because of the increase in the se-verity of the radiation injury and the vari-ability in response to treatment in therange. from 100 tO 1,000 reins, it is conven-ient'to subdivide it into three sub-sections,as shown in Figure 7.28. For whole-body

- exposures from 100 to 200 reins; hospitali;,..zation is generally not required, but above

200 rems admission to. a. hospital is neces-ssary sOthat the patient may receive suchtreatment.as,.maly be indicated. Up to 690rams, there is reasonable confidence in the

! clinical pirents and/appropriate therapy,but for doses in exc'esa of this ambuntthere is Considerable uneertainty and vari-ability in response,

7.30 Beyond 1,000 rems, the prospects

The syperposition of .radiation ef-fects upon irMio-s-Ifom other causearnaybeexpected to. result in an increase in tne:number of cases of shock. For axainple,,thecombination of sublethal nucleaeradiationexposure and moderate thermal burns will :-

produce earlier antl more severie shockthan would the comparable' burns 'alone.The heling of wounds orall kinds will bk.retarded because of the .susceptibility toNsecondary infection 'Accompaffying radia-tion injury and for other reaions. In fact,infections, which could normally be ;dealt

-with by the body, *May prwe fatal in suciicases.

I .

CHARACTERISTICS: OF ACUTE WHOLE-.BODY RADIATION INJURY

.,7.32 Single doses in.the...range of from

25 to 160 rems over the' whoje body willproduce nothing othei than blood changes.These/hanges do not usually occui- belowthis range arid are not produced consist-ently at doses below 50 rems. Disablingsicknessi,does not occur ancrexposed,indi-viduals should be able to proceed Withtheir usual duties.,Thus, for ,

doses of 25 to 100 reins': no illnessExpOsure of the whole body tO a

radiation dose in the range of 100 to ZOOrems result in a tcertain amount ofillness but it will rareli be fatal. Doses ofthis.`m,agnitude were 'common in Hiro-,shima and Nagasaki,- particularly amongpersons who were at some distande fromthe nuclear explosion. Of the 267 individu-

107 103

,

',"7

a

:

ara

als accidentally exposed to taIlout in theMarshall Islands forlOwing the test explo-sion /of .March 1, 1954, a group.4f 64 re-ceived radiation doses in this range. Itshquld be pdinted out that the exposure ofrthe Marshallese was ,not strictly of aeacute type, sinte it extenaed over a periodof some 45 hours. More.than half the dose,however;was received within 24 hours andthe observed effects were similar to those .to be Orpected from an acute e-xposure ofthe same amohnt. Thus, for

doses of 100 to 200 renis ; slight or noillness

7.34 The illness 6.91 radidtfon%doses'inthis range does not presents serious prd6-lém in that moSt p,stients-will suffer littlemore than discomfort and fatigue and oth-

ders may. have no symptoms at all..Theremay be some pauses and vomiting on thefirst day or so folloWA, irradiation, butsubsequently there is a so-called "latentperi2c1,4 up to 2 weeks Or more, duringwhich the patient has no disabling illnessand can proceed with his regular occupa-tion. The usual symptoms, such as loss ofappetite and malaise, may reappear, but ifthey do, they are mild. The chhnges in thecharacter df-the blood, which accompanyradiation injurx, become significant dur-.ing the latent period and persist for sometime. If there are no coMplications, due to,other injuries or to infection, there-will be.

. recovery in essentially all.cases. In gen-eral, the more'severe 'the .early stages ofthe radiation sickpess, the -longer will bethe process of .recovery. Adequate care

,.dnd.the use.,of antibiodei, as may be,catecrclinically, can greatly expedite-corn- ,

. .plete recovery of the small proportion ofmore serious cases. .

7.35 Por do4es between 200 -ane1,000,rems the probability of survival is.good atthe lower..exkil-orthe range but POor at theupper end. The initial'symptoms are simi-lar to. those commOn hi- radiation injury,namely, nausea, vomiting, diarrhea, loss ofappetite, and malaise. The/rarger the dose,the sooner will these symptoms develop,generally during- the initial daSr of theexpo'Sure. After. the first day or two the*symptomsdisappear and there may belatent period of several days to 2 weeks

104

4.d ng hih the patient feels relatively

..I'llyugh important changes are oc-cuvilig in the blood. Subsequently, thereis a return of symptoms, including fever,diarrhea, and a step-like rise in tempera-ture which may be due te accompanyinginfect' Thus, for

doses of 200 to 1,000 rems : survivalpossible

7.36 Commencing abont 2 or 3 weeksafter exposure, there is a tendency lbbleed into various organs, and small hem-orrhages under the skin (petechiae) areobserved. This tendency may be marked.Particularly common are spontaneous..bleeding' in the rbouth qnd from the liningof the intestinal fract. There may be bloodin the urine dve to bleeding in the..kidney.The hemorrhagic tendency dependsmainly upon, depletion of the platelets inthe blood, resulting in defects in the blood-Clotting mechanism. Loss of hair, which isa 'prominent consequence of radiation ex-posure, also starts after about 2 weeks,immediately following the latest period,for doses over_300 rems. (See Figure 7.36.)

FIGURE 7.36.Epi1atioq due to radiation exposure.

6 rlta,1/43

;

7.37 Susceptibility to infection ofwound's, burnsrand Other Lesions; can be aserious complicating factor. This wouldTe--spit to a large degree from loss of thewhite blood-cells, and a marked depressionin the body's immunological procesg. Forexample, ulceration about the lips maYcommence after the latent period andspread from the maith through, the entiregastroinestinal tract in the:termina.L.stage

, of the sickness. The multiplication of bac-eria, made possible by the decrease in thewhite cells of the blood and injury to other;immune mechanisms of the .body; allowsan pverwhelmingrinfection to develop.

7.38 rAmo'ng .other effects observed inJapan was a tenden'cy toward spontaneousinternal bleeding' near the end of the firstweek. At the same time, swelliglig and in-flammation of the throat was not uncom-mon. The development of severe radiation

- illness amorig the Japanese was accan-,panied by, an increase in the body temper-ature, which was probably due to second-ary infection. Generally there was a step-like rise between .the fifth and seventh'days, sometimes as early as the third dayfollowing expoSure, and usually: continu-ing until the day of death.

7.39 In addition to fever, the more seri-ous cases exhibited severe emaciation anddelirium, and death occurred within 2 to 8weeks. Examination after death revealeda decrease in size of and degenerativechanges in testes and ovaries. Ulcerationof the mucous,membrane of the large in-testine, which is generally indicative ofdoses of 1,000 rems or more,, was also notedin some cases.

.

7.40 Those patients in Japan whb sur-vived for 3 a 4 months, and did not sue-"cumb to tuberculosis, lung disease, orother complications, gradually recovered.

j There ivas no evidence of permanent_loss--of hair, and examination .of 824 survivors

some 3 to 4 years later showed.that theirblood composition, Was not. significantlydifferent from that ofa cpntrol group in acity !pit subjectelttgluclear attack.

7.41 Very large dOsee of whole-body ra-diation (apvfoximatély 5,000 rems ar more)result in. "pfompt changes in the central

.nervolzs system_The symptoms are hyper-

excitability, ataxia (ladk of muscufar coor-dination), respiratory distress, and inter-mittent stupor. there is almost immediateincapacitation, and death is certain in. afew hours to a week or so after the,acuteexposure. If the dose is in the range from1,000 to roughly 5,000 rems, it is the gas-trointestinal system which -exhibits theearliest severe clinical effects. There is theusual vomiting .and nausea followed, inmore or less rapid' succession, by prostra-tion, diarrhea, anorexia (lack- of appetiteand dislike for food), and, fever. As ob-served after the nuclear detonations in

:Japan,'the diarrhea was frequent and se-.vere in character, being watery at firstand tending to become bloody later; how-ever, this/may have been related to preex-isting,diseases Thus,Tor. large dose (over 1,000 rems) : survival

improbable7.42 The sooner the foregoing symp-

toms of radiation injury develop thesooner ill-death likely to result.Although rthere may be no pain during the first few

.dayi, patients experience .malaise, accom-panied by'marked depression and fatigue.At thetlower end of thd dose range; theearly stages of the severe radiation illnesare followed by a lprent period of 2 or 3days (or .more), during which the patientappears to be free from sympto-ms, al-though iirofound changes are taking placein the body, es?ecialjy in the blood-form-ink tissues. This period, when it occurs, isfollowed bY a recurrence of the early

-symptoms, often accompanied by deliriumor coma, terminating-in death usu:ally-within a,few days to 2 weeks. 4

EFFECTS OF RADIATION ON BLOODCONSTITUENTS,

7.43 Among the biological conse;.quences of exposure of the whole body to asingle dose of.nuclear radiation, perhapsthe most striking and characteristic arethe changes which take place in the blood

-and blOod-forming organs. Normally, thesechanges will occur only for doses ireater.Wan 25 reins, Much information on thehematological :response 6f human beingsto nuclear radiation was obtained after

105t.

4

the nuclear, explosions in Ja.pan and alsofrom observations on victims of laboratoryaccidents. The situation which developedAn the Marshall Islands hi March 1954,'however, provided the opportunity for avety thorougfi study of the effects of smalland moderately large doses 'of radiation(up to 475 rems) on the blood of humanbeings. ,The descriptions given below,which are in general 'agreement with theresults obseryed in Japan, are basedlargely on this study.

7.44 One of the most striking hemato-logical changes associated with radiationinjury is in the number of white bloodcells. Among,these cells are the neutto-phils, formed chiefly in the bone marrow,which are concerned with resisting bacte-rial invasion of the body. The number ofneutrophils in the blood increases rapidlyduring the course of certain Vypesof bacte-rial infection ,to cornbat the invading orga,nisms. Loss of ability to meet the bacterialinvasion, whether due to radiation or anyother injury, is a very grave matter, and-bacteria which are normally held in checkby,the neutrophils can then multiply rap-idly, causing serious consequences. Thereare several types of white blood cells withdifferent specialized functions, but whichhave in common the general property ofresisling infection or remoVing toxic prod-ucrs from.the body, or both.

7A5 After the body has been exposed toradiation in th,e sub-lethal range, i:e.,about 200 rems or less, the total number ofwhite blood cells may show a trarvitoryincrease during the first 2 days or so, andthen decrease below normal levels. Subse-quently the white count may fluctuate andpossibly rise above normal on occasions.During the seventh or eighth weeki, thewhite cell count becomes .stabilized at lowlevels and a minimum probably occurs atabout this time. An upward trend is ob-servedAn succeeding weeks but completerecovery may require several monthsor

1.46 The neutrophil count parallels thetotal white blood cell count, so that theinitial increase observed in the latter isapparently due toillIcreased mobilizationof neutrophils. Complete return of the1-06

'or

nurnber of n eutrophils to normal does riotoccur for stverlil months.

7.47 In contrast to the behavior of theneutrophils, the number Of lymphocytes,produced in partg of the lymphatic tissuesof the body, e.g., lymph nodes and spleen,shows a sharp drop soon after exposure toradiation. The lymphocyte count continuesto remain considerably below normal forseveral months and recovery may requike,many months or even years. However, tojudge from the observations made in Ja-pan, the lymphocyte count of exposed indi-viduals 3 or 4 years after exposure was notappreciablY different from that of unek-posed.persons. . -

7.48 A significant h'ematologicalchange also occurs in the platelets, a con-stituent a the blood which plays an impor:tant role in blood clotting. Unlike the' fluc--tuating total white count, the number ofplatelets begins to,decreaSe soon after ex-posure and" falls steadily and reaches aminimum at the end of aboutsa month. Thedecrease in the nurrber of plateiets is fol-lowed by partial recovery,, but a normalcount may not be attained for several

'months'or.even years after exposure. It isthe decrease in the platelet count whichpartly explains the appearance of hemor-rhage and purpura in rafliation injury.

7,49 The red blood cell (erythrocyte)count-also undergoes a decrease as a re-sult of radiation exposure and henlor-rhage,.so that symptoms of anemia, Cg.,pallor, become -apparent. However, thechange in the nuMber of erythrocytes ismuch less striking than that which occursin the white blood cells and platelets, espe-cially' for radiation doses in. the range of200 to 400 rems. Whereas the response inthese, celis iA rapid, the red cell countshows little or no change for several days.Subsequently, there is a decrease whichmay continue for 2 oK 3 weeks, followed bya gradual increase in individuals who sur-viVe.

7.50 As an ,index of severity of radia-tion exposure, particularly in the suble-thal range, the total white cell or neutro-phil counts are of limited usefulness be-.cause of the wide fluctuations and the factthat several weeks may elapie before the

14.1 o

dr'

maximum depression is obsered. Thelypmphocyte count is of more value in thisrespect, particularly in the lbw dose range,shthe depression occurs within a few hourgof exposure. However, a marked decreasein the number of lymphocytes is observedeven with low doses and there is relativelylittlg difference with large doses.

7.51 The platelet count, on the otherhand, apRears to exhibit a regular pattern,with the maximum depression being at-tained at approximately the same time forvarious exposures in the sublethal range.Furthermore, in this range, the degree ofdepression from the normal value isroughly proportional to the esti'matedwhole-body dose. It has been suggested,therefore, that the platelet count mightserve as_a convenient and relatively sim-ple direct method for: determin41g the se-verity of radiation injury in the sublethalrange. Thp main disadVantap is that anappreciable decrease in the platelet countis not apparent until some time after theexposure.

LATE EFFE-CTS OF IONIZING RADIATION7.52 There are a number of conse-

quences of nuclear radiation which maynot appear for some years after exposure.Among them, apart from genetic effects,are the formation of cataracts, non-spe-cific life shortening, leukemia, other formsof malignant disease, and retarded devel-opment of children in utero at the-time ofthe exposure. Information conterningthese late effects has been obtaihed fromoontinued studies of various types, includ-ing those in Japan made chiefly under thedirection of 4.11e. Atomic Bonib Casu'Alty,

7.53 The Atomic Bomb. Casualty Coril-rilissinn was established in 1947 to providesurveys and studies ori the delayed effectsof the A-bornbs. Over 400 reports had beenissued by 197$. A nationwide enumeration'was made tin Japan at the tinie of the 1950national census to identify who was in

'The Aryinic Bomb Casualty CM/IMMO of the U.S. National Acad.emy of Sciences-National Research Council is sponsored by the AtomicEnergy Commission and administered in cooperation with the Jima.nese National Institut, of Retail. One of its purposes is to study, theiong.torm effects of exposure to nuclear radiation

Hiroshima and Naghsaki at the time ofburst. The major Atomic Bomb CasualtyCommission studies relate to the survivorswho were alive during the initial survey,about five years after. the burst. There-.fore, the sample excludes the more se-.verely injured who died prior to 1950.These exposed people have been studied,through both a biennial physical examina-tion and after death by an autopsy pro-gram. 'Because, of different, latent periodsthe effects of radiation .have developedwith.the years since 1947. For example, inthe 1970's,.as leukemia decreases, malig-nant neoplasms (tumors) are rising rap-idly, for those exposed in utero or in child-hood. Some of the most significant find-ings from various studies are extractedhere in paragraphs 7.54-7.61 from the 1973technical report of the Atomic Bomb Cas-ualty Commission's report "Radiation Ef-fects on Atomic Bomb Survivors."

'bENETIC EFFECTS

7.54 Significant effects of parental ex-posure' to the A-bomb on stillbirth or in-fant mortality rates, birth weight of child,or on the frequency of congenital malfor-mations haVe nOt been detected. The sexratio (natio of male to female babies) wasexpected to decrease if the mother had,been' irradiated, and to increase with pa-ternal irrailiation. An earlier study sug-gested such a shift, but additional datafailed to confirm this hypothesis. No rela-tionship has been observed between ph-rental exposure and the mortality of chil-dren. No significant increase in leukemiaincidence has been observed in the off-spring of persons exposed to A-bomb ra-diation. A preliminary study of the off-spring of A-bomb survivors showed no 'evi-dence of radiation effects on chromosomes.Recent studies show white corpuscle dam-age after 20 years (see 7.61).

RADIATION INJURIES

7.55 Three major symptoins of 'acuteradiation exposure Were observedloss ofhair, bleeding, and mouth lesions. Acuteradiation symptoms increased from 5% to10% among those exposed to total dose of

107

50 rem to 50% to 80% of those with about300 rem exposure, after which the propor-,don leveled off.

DELAYED EFFECTS ON GROWTit ANDDEVELOPMENT

7.56 'Head circumference and heightwere significantly smaller in children inutero whose mothers. were exposed coldevidenced major radiationsymptoms. Con-sistently smaller head and chest circum-

, ferences, weight, standing and srftingheights at ages 14 to 15 years were fbundamong Nagasaki children whose motherswere exposed to high doses. Height,weight and head circurnferences at 47years of age wEre significantly smaller inthe Hirosh-inia in utero children whose'mothers were exposed. Decreased head

. circumference was most prominent amongthose in the first trimester of gestation attime of burst (ATB). Body size was smallerand body maturity advanced in the Hiro-shima exposed children. Adult height wassignificantly less among Hiroshima chil-dren 0-5 years of age ATB (at time ofburst) exposed to high doses. Dose effectdeclined with increasing age ATB, butadult weight was less regardless of ageATB. Tissue samples from the exposedpopulation suggest accelerated ageingamong those exposed. There was no radia-

1, tion effect on bone growth among thoseexposed to ladiation in utero ATB.

DELAYED EFFECTS OF DISEASE

OCCURRENCE

7.57 The first' demonstrated delayed ef-fects of the A-bombs were radiation Cata-racts in about 21/2% of survivors" within1000 meters from ground zero ATB. Cata-racts were the only delayed manifesta-tions of ocular injury from the A-bornb.The latent period for subjective disturb-ances from cataracts appears to have beenabout two years. Prevalence of mental re-tardation was high in those exposed inutero less than 1500 meters from groundzero. Mental retardation was more fre-quent in those exposed between the 6thand 15th weeks of pregnancy, the period ofhrain development. For in utero children,

1011'

the death rate for all causes, especiallyamong infants, increased with intenradiation exposure of the mother How-ever, no increase in mortality fro s J9Ice-mia and other cancers was obse Norelationship betweeh rheumatoid ..,,ritisand radiation dose has been found. neg-ative finding does not .mean that certaineffects will not occur later. Abnormalitiespf the minute surface blood vessels werefound in those under 10 years ATB who.were.exposed to 100 rem or more. Lip andtongue mucous membrances were morefrequentiy affected than were nail foldand eyelids. These findings suggest thatA-bomb exposure affected.the entire vas-cular system. There was no evidence of .arelationship between the prevalence ofcardiovascular diseases and radiation ex-posure, on between mOrtality from cardiov-ascular diseaSes and radiation.

NEOPLASMS

7.58 There were minor elevations inmortality from causes other than neo-plasms (abnormal growth) but, all in all,there was little evidence of radiation ef-fect on other causes of death, includingtaerculosis, stroke, and other diseases ofthe circulatory system. Lung cancer mor-tality increased with dose. This increasewas particularly significant for those ex-posed at ages 35 years and over ATB. Theoccucrence of thyroid cancer was higher inWomen than in men and showed asignifi-cant elevation with the increase in dose.For those less than 20 years ATB, no sexdifference for thyroid cancer was evident.Salivary gland .tumors increased morethan five-fold among survivors exposed tohigh radiation doses compared with thenonirradiated population. the relativerisk of breast cancer was significantlyhigher among the- heavily =irradiatedwomen. Women Who were xoung at thetime of the bomb are now entering theages of high risk froth breast cancer. Norelationship has been found to date be-tween radiation dose and-prevalence ofcancers of the stomach, gall bladder andbile duct, liver, bone, and skin. Mortalityfrom disease was higher among survivorswho received large radiation doses Than

112

(

among those with small dosesor those note cities. EXcessive mortality was espe-h* h for leukemia where the radia-

appeared to be present evenamong ,those estimated to have received10-49 rem. Mortality fronicanoer apantfrom leukemia was also elevated in survi-vors with large radiation'doses, but couldbe __demonstrated with reliability only'among those with doses exceeding 200

in'ciallçtion "effe

rem.

LEUKEMIA

7.59 Leukemia rates in the high dosegroups,. have declined persistently duringthe period 1950 to 1970, but have notreached the level experienced by the gen-eral population. However, death rates forcancer of other sites have increasedsharply in recent years. The latent period

'for radiatidn induced cancers other thanleukemia appears to be 20 years, or more.There was increased leukemia with a dose-response relationship with the peak occur-ringabout six years after exposure. Theeffeies greatest. among those exposedduring childhood. The lowest dose cate-gory with a high frequency of leukemtawas 20-49 1.em. This effect at 291-49 remwas lqund in Hirirshtt where neutronsconstituted a substantial fraction -of thetotal dose. In Nagasaki, -exposure to neu-trons was very small and no &saes of leu-kemia occurred amongourvivors expbsedto 5-99 rem.

MALIGNANT NEOPLASMS

7.60 After a latent period of about IS.years, children who received radiationdoses of 100 rem or more have begun to

*develop an excessive number of malignant- neoplasms. Now,. 25 years a ter exposure,

the accumulated increase is nost striking,with no evidence that a peak has beenreacAed. During thenext 10 years, thesepersons will be entering ages when cancerincidence ordinarily begins to increase.Forty cases of anezi:. confirined inA-bomb survivors in Year period, butthe increase in risk due to radiation expo-sure was not significant when compared tothe population. The prevalence of thyroid

disease increased with dose among Hip-shirna females and among those 0-19 yeirsATB in Nagasaki. An increase in preva-

^ lence of miscellaneous eye diseases afterradiation exposure wis noted, exceptamong females age 50 or more ATB.

OTHER FINDINGS "s.

7.61 No consistent differences havebeen found by radiation expostke for preg-nancy, birth and ,stylbirth rates, and zeropregnancies. Studies' of cultured lympho-cyte's (white corpuscles) have demon-strated that radiation induced chromo-some changes still persist more than 20years after exposure. Furthermore, theirfrequency appears to be proportional tothe exposure dose. A highSproportion ofthose in utero whose mothers received adose of at least 100 rem evidenced complexchromosomal abnormalities as comparedto the comparison groups. There has beenno manifestation of clinical disease associ-ated with chromosomal abnormalities.

EXTERNAL .HAZARD: BETA BURNS

7.62 Injury to the body from externalsources of beta pIrticles can' arise in twogeneral ways. If the beta-particle emit-tell, e.g., fission products in the fallout,

- come into actual contact with the skin andremain for an appreciable time, a form ofradiation damage, sometimes referred toas "beta burn," will result. In addition, inan area of extensive 'early fallout, thewhole surface of the body will be exposedto beta particles.coming from many direc-tions. It is true that clothing will atten-mete this radiation to a considerable ex-

" tent; nevertheless, the whole body couldreceive "'large dose "from eça particleswhi9h might be significant.

7. Valuable information concerningthe development and healing of beta barns_has been obtained from observatipns ofthe Marshall Islanders whd were' 'Axposedto fallout in March .1954; Within:about 5hours of the, burst, radioactive materialcommenced to fall on some of,the islands.Although the fallout was observed as awhite powder, consisting largely of parti-cles of lime (calcium oxide) resulting from

109

the decomposition of coral (calcium car-bonate) by heat, the isalnd inhabitants didnot realize its significance. Because theweather was hot and damp, the Mar-shalese emained outdoors; their bodieswere moist and.they wore relatively littleclothing. As a result, appreciable aniountsof fission products fell upon their hair andskin and remained there for a considerable ,time. Moreover, since the islanders, as arule, did not wear shoes, their :bare feetwe're continually subjected to contamina-tion from fallout on the ground.

7.64 During the first 24 to 44 hours, anumber of individuals iu the more highlycontaminated groups experienced itchingand a burning sensatipn of the skin. Thesesymptoms were less marked among thosewho were less ,contamined with early fal-lout. Within a day to two all skin symp-toms subsided and disappeared, but aftbrthe lapse of about 2 to 3 weeks, epilationand skin- lesions were apparent off theareas of the body which had been contaim-inattd by fallout particlep. There was ap-parently .no erythema, either in the earlystages (primary.) or later (secondary), asmight have been expected, but this mayhave been obscured by the natural colora-tion of the.skin.

7.65--The first evidence of- skin damage.,was increased pigmentation, in the form ofdark colored patches and raised areas (ma-cules, papules, and rasied plaques). These Iflesions developed on the exposed parts Of

, the bqdy not protected by clothing, andoccurred usually in the following order:scalp Iwith epilation), neck, shoulders,depressions in the forearm, feet, )imbs,nd trunk. Epilation and lesions of the

scalp, neck, and foot were most frequentlyobserved (see Figures 7.65a and 7.65b).

7.66 In add,ition, a bluish-brown pig-mentation of the fingernails was very com-mon' amortg the Marshellbse and alsoamong American Negroes. The phenome-non appears to be a radiation. responsepeculiar-to the dirk-skinned races, since itwas not apparent- in any of the whiteAmericans who were exposed 'at the Sametime. The nail pigmentation occurred in anumber of individuals who did 'not have'skin lesiops. It is probable that this. was1410

FIGURE 7.55a.Beta burn on neck shortly afterexposure.

FIGURE 7.65b.Beta burn on feet shortly-afterexposure.

caused ,by gamma rays, rather than bybeta particles, as the same effect has beenobserved in dark-skinned patientsundergoing X-ray treatment in clinicalpractice.

7.67 Most of the lesions were superfi-cial without blistering. Microscopic exami-nation at 3 to 6, weeks showed that thedamage was mogt marked in The outerolayers of the skin (epidermis), whereasdamage' to.the deeper tissue was much lesssevere. This is consist6nt -with the shOrfrange of beta particles irf animal tissue:After formation or dry scab, the lesions,healed rapidly leaVing h central depig-

___mente.rrounded by an irregularzone of ihcreased pigmentation. Normal

\

FIGURE 7.68a.Beta burn on neck after healing.

pigmentation gradually spread outward inthe course of a few weeks.,

7.68 Individuals who had been morehighly contaminated developed deeper le-sions, usually on the feet or neck, accom-panied by mild burning, itching end pain.These lesions were wet, weeping, and ul-cerated, becoming covered by a hard,scab; however, the majority heeled r.eadilywith the regular treatmeint generally em:'ployed for other skin lesions not connected

; with radiation. Abnormal pigmentation ef-fects 'persisted for some time, and in sev-

FIGURE 7.68b.Beta burn on feet after healing.

eral cases about a year elapsed before thenormal (darkish) skin coloration was re-stored (see Figures 7.68a and 7.68b).

7.69 Regrowth of hair, of the usualcolor (in contrast to the skin pigmentation)and texture, began about 9 weeks aftercontamination and was 'complete in 6months. By the same time, nail discolora-tion had groWn out in all but a few individ-uals. Seven years later, there were only 10cases which continued to show any effectsof beta burns, and there was no evidenceof malignant changes. Blood studies ofplatelets and red blood cells indicated lev-els lower than average at 5 years afterexposure; at 7 years after exposure theplatelets continued to be slightly de-pressed. It thps 'appears that repair ofbone marrow injury was not complete atthis time. In the 1961 examination of theMarshallese people there was' a possibleindication of bone growth retardation inchildren 34414, Were babies at tile time ofthe explosion.

INTERNAT. HAZARD

-, 7.70 Wherever fallout occurs there is achance that radioactive material will en-ter the hody through the digestive' tract(due to the consumption of food and watercontaminated with fission products),through the lungs (by breathing air con-taining, fallout particles), or .thropghwounds or abrasions. It should be notedthgt even a very small quantity of radioac-tive material present in the body can prorduce considerable injury. Radiation expo-sure of varidus organs and tissues from,internal' sources is continuoust subjectonly to depletion of the quantity of activeplaterial in the body as.a result of physical(radioactive decay) ar41 biological (elimina-tion) processes, Ft.ithermore, Iiriternalsources of alPha emitters, e.g., plutonium,or of beta particles, or soft (low-energy)gamma-ray emitterd, can dissipate theirentire energy within a small, Possibly sen-sitive, volume of body tissue; thus calvingconsiderable damage.

4/4

7.71' .The situation just des&ibedsometimes aggravated by the fact that-grtain chemical elements tend to concen-

. 111

trate in specific cells aY tissues, some ofwhich are highly sensitive to radiation.The fate of a given radioactive elementwhich has entered the -blood stream willdepend upon its chemical nature. Radioso-topes of in element which is a normalconstituent of the body Fill follow thesame metabolic processes as the naturallyoccurring, inactive (stable) isotopes of thesame element. This is the case, for exam-,ple, with iodine which tends to concentratein the thyroid gland.

7.72 An element not usually found inthg 'body, except perhaps in minute traces,'will behave like onetwith similar chemicalproperties that is normally present. Thus,'among the absorbed fission products,strontium and barium, which are similarchemically to calcium, are lwgely depos-ited in the calcifying tissue of hone. Theradioisotopes of the rare earth elements;e.g., cerium, which constitute a considera-ble proportion of the fission products, andplutonium, which may be present to,someextent in the fallout, are also "bone-seek-ers." Since they are not chemical ana-logues of calcium, however, they are de-posited to a smaller extent and in otherparts of the bone than are strontium andbarium. Bone-seekers, are, nevertheless,potentially very hazardous because theycan injure the sensitive bone marrowwhere many blood cells are produced. Thedamage to the blood-forming tissue thusresults in a' reduction in the number ofblood cells and so affects the entire bodyadveisely.) a

7.73 The extent to which early falloutcontamination can $.0..j-nto the bloodstream will depend upon two main factors:(1) the size of the particles, and (2) theirsolubility. in the body fluids. Whether theamaterial is subsequently deposited insome specific tissue or not will be deter-mined by the chemical properties of theelements present, as indicated previously.Elements Which do not tend to concen-trate in a particular part of the body areeliminated fairly rapidly by natural proc-,esses.

7.74 The amdunt of yadi6active Mate-rial absorbed,frOm early\fallout by inhale-tiOn appears to be relatively small., The

reason is that the nose can filter out al-most all particles over 10 microns (0.001centimeter) in diameter, -and about 95 per-cent of those exceeding 5 microns (0.0005centimeter). Most of the particles descend-ing in the fallout during the critical periodof highest activity, e.g., within 24 hourg ofthe explosion, will be considerably morethan 10 microns in diameter. Corise-quently, only a small proportion of theearly fallout particles present in the airwill succeed in reaching the lungs. Fur-thermore, the .optimum size for passagefrom the alveolar (air) space of the lungsto the blood stream is as small as 1 to 2 -microns. The probability of entry into thecirculating blood of fission products andother weapon residues present in the earlyfallout, as a result of inhalation, is thuslow. Any very small particles reaching thealveolar spaces may be retained there orthey may be removed either by physicalmeans, e.g., by coughing, or by tbe lym-phatic system to, lymph nodes in the me-diastinal (middle' chest) area, where theymay accumulate.

7.75 The extent of absorption of fissionproducts and hther radioactive materialsthrough the intestine is largely dependentupon the solubility of the particieW;Witearly fallout, the fission produc4 as wellas uranium and plutonium are chieflypresent as oxides, many oxides of stron-tium and barium, however.aresolub1e, sathat these elements enter, the bloodstream more 'rekdily and find their wayinto the bones.' The element iodine is alsochiefly present in a soluble form and so itsoon enters-the blood And is concentratedin the thyroid gland.

7.76 In addition to the tendency of 'aparticular element to be talten 'up by aspecifib organ, the main consideration, indetermining the hazard from a given ra-diOactive iSotope inside the body is thetotal radiation dose de1iver4d/while it is inthe bodY (or specific organ). The most im-portant factors in' determining this doseare the mass and half-life of the radioiso-tope, the nature and-energy of the radia-tions emitted, and the lengths of time it

Ever/ander these conditions, only about tO percent of the strontiumor barium is tiftually absorbed.

y 7 --a- U"

16

stays in the body. This time is dependentupon the "12iologkal half-time" which isthe time taken for the amount of a partic-.ular element in the body to decrease tohalf of its initial value. due to eliminationby natrual (biological) processes. Combina-tion of the radioactive half life and biologi:cal half-time gives rise to the effectivehalf-life," defined as the time required forthe amount of a specified radioactive iso-tope in the body to fall to half of itsoriginal value.as a result of both radioa,c'-dye decay and natural elimination, inmost cases of interest, the effective half-.life in the body as a whole is essentiallythe same Us that in the principal tissue (ororgan) in which the element tends to con-,centrate. For some isotopes it is difficult toexpress the behavior in terms of a singleeffective half-life becttise of their compli-cated metabolic mechanisms in the humanbody.

7.77 The isotopes repr6senting thegreatest potential internal hazard arethose with relatively short radioactivehalf-lives and comparatiyely long biologi-cal half-times. A certain mass of an isotopeof short radioactive half-life will emit par-tièles at a greater rate than'the s'amemass of another isqope,possibly of thesame element, having longer half-life.Moreover the long biological half-time"Means that the active material will not bereadily eliminated from the body by_natu-ral processes. ,For exaMple., the elementiodine has a fairly long biologicalmaff-time -In many indiyiduals. Ihe actual 'value var-ies oNier a..i4e 7ange.- from a feivelays insdnie P.416ple'to maNtYears mothers, hue,on the ave4ge,iI-lis about 90 ilays.,Jodineis q-uickly taken up by the thyrhid gland.from -w15,ictp, it is generally eliminatedslowly. Zhe radioisotOpe iodine-13J a.,'fairly common fission product,.has a radio-active halfIlife of only' 8 days. Conse-quently, if a sufficient,. quantity of, this 'isotope enters the blood stream it is capa-ble of causing serious damage to the thy-roid.glan because it reakains there dur-ing essen ia ly,the wholeof itsradioactivelife.

7,78 At short times after a detonation,. other ra&isotopes of iodi`Ae, e.g., iodine

133 and 135, would contribute .materiallyto the total dose to the thyroid gland.Howeyer, their radioactive half-lives aremeasured in hours, and so they decay toinsignificant levels within a few days oftheir formation. It should. be Mentionedthat, apart from inimediate injury, anyradioactive materiarthat enters the body,even if it has a short effective .half-life,-may c9ntribute to damage whigh does notbecome apparent for some time.

7.79 In addition to radioidine, the rilOstimportant potentially hazardou's fissionproducts, assuming sufficient amounts getint() the body, fall into two groups. Thefibt, and more significant, contains stron-tium 89, strontium 90, cesium 13-7, andbarium 140, whereas the second consists ofa- group of rare earth and related ele-ments, particularlY cerium 114' and thechemically similar yttrium 91.

7.80 Anothei;potentially hazardous ele-ment, which -may be present to some eic-telit.-is, the enly fallout,*is pintonium, inthe form of the alpha-particle emittingisotope plutOnium 239. This isotope has a

- long radioactive half-life (24,000 years) aswell as a lctfig biological half-time (about200 years). Consequently, once it is depos-ited in the body; mainly on certain sur-faces of the.bone, the amount of plutoniumpresent ind its activity.decrease at a. veryslow rate. In spite of their shortIange inthe body, *the:AcOntinued action of alphaparticles 'over a period.of years can causesignificant injury. In sufficient amounts,radlum, which is very simijar to plutoniumin tehese reSpects, Hs-known to cause necro-

'Os and tumors of the bone, and anemia--resulting.in death:.

7.81 Expetimenta1 evidence indicates-that nearlY all, if_:not all, inhaled Wilton-

limn deposits in the lungs where,a Certainportion, less than 10 peirnt, relnains.Some of this is found in tht bronchiallyiph nodes.,For thi& reason, the primaryhazard from inhaled, plutonium is to thePangs and bronchial lum'ph nodes. It is ofinterest to note that despite the largeamounts orradioactive material whichmay:pass through the kidneys in the proc-ess of elimination, these organs ordinarily"are not greatly affected, BY contrast, ura-

117 113

fk

Iiium causes damage to the kidneys, but asa chemical poison rather than because ofits radioactiVity.

7.82 Early fallout-Accompanying thenuclear air burstacaer-Npan was so insig-nificarit that At was4r6rObierved. Conse-quently, no,information was Available ,con-cerning the potentialities, of,fission prod-ucts and other weapon rktOes as inter-nal sources of radiationollbwing the in-cident in the Marshall Islands in March1954, how'ever, data of great interest wereobtained. Because they were not aware ofthe significance of the fallout, many of theinhabitants ate contaminated food anddrank contaminatedy.rater from open con-tainers for periods up to 2 days.

7.83, Internal deposition of fission prod-ucts resulted mainly from ingestion ratherthan inhalatiOn for, in aadition to the rea-sons given abo<the radioactive p"articlesin the air settled dit fairly rapidly, but

..cetntaminated fobd, water, and utensilsfreti-all the time. The belief thatingestion was the chief' source of internalcontamination was 'supported by' the ob-servations on chickens and pigs made soonafter the explesion. The gastrOintestinaltract, its .contents, and the liVer werefound to be more highly contaminatedthan lungTftue.

7.84 From radiochemical analYsis ofthe urine .of theMarshallese subjected tothe early fallout, it was pdssible to 'esti-mate the body burden, i.e., the amountsdeposited in thetissues, of various iso-topes. It was- found that fodine 131 madethe major contribution to the activity atthe beginning, but it soon disappeared be-cause of its relatively short radioactivehalf-life (8 days). Somewhat the same wastrue for barium 140 (12.8 days half-life),but,..the' activity levels of the strontiumisotopes were more persistent. Not only dothese isotopes have longer radioactivehalf-lives, but the biological lialf-time--61the element is also relatively long.

7.85 No elements other than iodine,strontium, barium, and the rare parthgroup were found to be retained in appre-ciable amounts in the ,hody. Essentially atlother fission product and weapon residueactivities were rapidly eliminated, because

114

ot either..the short effective half-lives ofthe radioisotopes, the sparing solubility ofthe oxides, or the relatively'large size of-the fallout particles.

7.86 The body burden' of radioactivematerial among the more highly contami-nated inhabitants of the:Marshall Islandswas never very large and it decreasedfairly rapidly in the course of 2 .or 3months. The activity of the strontium iso-topes fell off somewhat More slowly thantWat of the other radioisotopes-, because ofthe longer -radioactive half-lives andgreater retention in the bone. Neverthe-less, even strontium *could not be regardedas a dangetous source of internal radia-tion in the cases studied. At 6 monthsafter the explosion, the urine of most indi-'viduals contained only barely detectablequantities of r;dioactive material.

7.87 The most heavily exposed grpup,some 64 Marshallese inhabitants of Ron-gelap atbll, fevived an estimated 175 remwhole-body dose before being evacuated.While internal contamination was of con-cern in 1954; the consensus of the scien-tists and medical people was Piet internalburdens of radionuclides were not likely,toprOduce injurY, even in the heavily ex;posed. group.*All earl3 symptoms were dueto Whole-body exposure doges and to skin;deposited fallout particles. Based on anal-ysis of urine samples, iewas accepted thatthe Marshall Island people Viere fully re-covered from their accidental exposure tothermonuclear fallout in 1954.

7.88 In.1963 a thyroid nodule was dis-covered dulling routine examination of a12-year-old-girl,,and in,the following yedrsadditional cases were discovered duringthe annual medical surveys. By 1969, 15 ofthe 19 children who- had been under 10years of age at the time of exposuie haddeveloped thyrpid nodules, and, anothertwo had severe atrophy of tlie thytoidgland. The method of treatmegt of all 15nodule cases was either parti4 or totalremoval 'of the thyroid gland.

7.89 No children in the less-heavily ex-posed group, with whole-body doses up toabout 70 rem, have developed thyroid nod-ules to date. Adults in the Rongelap grouphave deireloped thyroid nodules, but the

rate of incidence has been less than Viothe rate for children.

7.90 It seems clear that the couise* ofthe thyroid Abnormalities was beta irra-

4diation by the radioiodines concentratedinithe thyroid gland after ingestion andiorinhalation. It is likely there is more trou-ble ahead over the years forIslanders, both adults who w heavilyexposed sand those who were chiraren inthe 70 rem exposure gropp, It is thoughtthe latency period for neoplasms is in-versely related to dose- This theoreticalrule of latency may explain the bunchingof thyroid effects ffom 9 to.14 years afterexposure.

7.91 The experience of the'Marshallesechildren illustrates one combination ofconditions leading to a serious radiniodinethreat in nuclear warfare. The childrenwere exposed, for the first two days, to allof the radiological effects of the falloutfield, estimated to be 100 R/hr at .1 hourafter detonation. They received whole-body exposure of about-175 rem. The airthey breathed, thfring and after fallout.deposition swas unfiltered. They ate eon-.

taminated food and drank cOntaminated'water.

7.92 Had the exposure at Rongelapbeen even a 'fact& of three higher, morethan half of the exposed people would.have died within a month from the whole-,body ganima radiation exposure. Studiesindicate that in a nuclear attack againstthe U.S., expsurg coujd' be a factor of 30or higher than at Rongelap in some areas._-Fallout shelters htsing a protection factorof forty would be necessary to limit theshelter period whole-body xposure to 175rem, i.e., the dose that the people at Ron-gelap received.

Protection against the threat ofinlale and ingested iodines could be nro\vided if (1) onlY filtered air were breathed,and (2) only preattack-stored food andwater were consumed for 30-40 days or 4-5P." half-lives. Sin'ce vapor filters arel notprovided in fallout shelters, anrradioiod-ine in the gaseous state would reach the

'Tina; Report, Inhalation of Radloiodine from Fallout Hazards arilCduntermeasures, Defense Civil Preparedness Agency, Washington,D C 20301, August 1972, Number 2380.

114

shelterees: particles stopped by particlefilters could still release their radioiodine .into the ventilation sy`stem. Although it isnot possible to predict, even within orderof magnitude, the thyroid doseFtthat couldbe caused by inhalation of fallout radioiod-ines, the threat of inhaled ,radioiodines isreal. Fortunately, this threat is likely toaffect only small areas of the country andit can be colotered safely and inexp,en-sively by,tbe timely administration of sta-ble "blocking" iodine to veduce the thyroiduptake of radioiodines. In general, the up-take of radioiodides by inhalation is -be-lieved to be minor compared to that fromingest-ion.

WHOLE-BODY EXPOSURE

7.94 There is *agreement among mostauthorities that a single whole-body. expo-sure of 200 R w,ill not affect the averageadult to the extent that he is ihcapable ofperforming his oTdinary activities,. In fact;whole-body exposures of 200-3'00 R havebeen given to many patients with ad-anced cancer without any manifest

harmful effect on their physical fiondition. 'Cha1g4 in the_4b1dod count, occurred, aswas expected, but these were not .suffi-cient reqtiire medical treatments. TheMarshall Islanders who had the largestexposuye to fallout, received about 175 Rover a period of 36 hours. In this, group,Which included people of all ages, the onlyevidence -of. acute radiation sickness wasvomiting on the day fallout occurred(about 10 percent reported this symptom)and changes in the white blood cell countand platelet count several weeks later.There is also general agreement that asingle whole-body exposure of 200 R or lessshould not cause radiation sickne§s severe-enough to require medical care in the ma-jority (9 out of 10) of healthy adults.

7.95 The exlicted results of variousradiation expdsures, if received over var-ious periods of time, are shown in thefollowing figure (Figure 7.95). (This figure .

is tentative; it may be modified as a resultof recommendations currently being devel-oped by the National Council of RadiationPrptection*and Measurements. The num-berF,4mvever, are believed to be realistic.)

4.1 1 5

Roentgen Exposure

Acute in Any

Effects

,

1 Week 1 Month 4 Months

Medical Care Not Needed 150 200 300

Some Need Medical CareFew if Any Deaths

250 350 500

Mon Need Medical CareSO% + Deaths

450 .... 600 .

.

Uttlia or no p ctical consideration

FIGURE 7.95'.Radiation Exposure Doses.

7.96 To illustrate use of the figure,most people receiving no more than a totalof 150 R during a time interval less dian aweek (1 hour, 1 day, 3 days, for instance)are not expected to need medical care norto become ineffective in work perform-ance. Also, people receiving more than 500R during one:month will need ,medicalcare, and 50% .or more may die. ..

7.97 This "penalty figure" is. intendedfor use by ciyil preparedness officials dur-ing 'a war, emergency to provide them asimple 'and straightforward basis for tak-,ing into account the radiological elementsof the problem. For example, replenish-ment of :a. shelter's inadequate water s-dp-ply might be justified if a small crew coulddo sib, and if each member's total week'sexposure could be kept to less than 150 R,or the month's ekposure less than 200 R.

7.98 It is known that radiation in-creases the chances of genetic damage and

. Taken from DCPA Attack Environment Manual, Ch4tor 1,

4111101,

...

;

other long-term effects. These effects arecomparatively minor. In a war emergency,first minimize the number of deaths andsecond, keep,. the number of people forwhom medical care is needed as small aspossible. When circumstances permit,. Rre-ferreeconsideration should be given tochildren and adults still capable of pro-creation. As conditions permit, emergencymeasures should, be terminated and nor-mal standards reinstituted.

REFERENCES

The Effects of Nuclear Weapons.-7-Glas-stone, Samuel, 1964.

DCPA Attack Enyironment Manual.Radiation Effects on Atomic Bomb Sur-

vivors.Technical Report 6773, AtomicBomb 'Casualty Cominission, 1973.

Final Report-Inhalation of Radióiodinefrom Fallout: Hazards and Countermea-sures. ESA-TR-72-01-1)CPA Research

Contract No. DAHC20-70-C-0381, 1972.

I1

4

,

..

.,

)

.0

fi

411.

. CHAPTER

EXPOSURE AND EXPOSURE RATE CALCULATIONS

1,Jp toc this pointwe- have learned thatthe effects of radiatiOn exposure are im-portant and Vire have seen what the medi-cal consequence§ are for. exposures overdifferent periods of. time. We need a meansof calculation that- will assist us in meet-ing -guidelines established for emergencyworkers. ,Tall order? Complated mathe-rhatici? Not at all. At least not at the endof. this Chapter because by then we willhave learned:

HOW to determine exposure and ex-posure rates

HOW to predict, future exposure and. exposure rates

WHEN.can someone leave-shelter and-

for how longWHY prediction and measurement

- are possible

INTRODUCTION

8.1 In chapter 6 we saw that falloutarrives at particular locations with re-

- spect to ground zero at various times afterburst, depending on such factors as dis-tance, meteorological Conditions,

8.2- It was also shown that radioactivecontamination from fallout cou,ld deny theuse of considerable areas for an apprecia-ble period of time. Thus, even without tbtmaterial destruction from blast or thermalradiation, many areas; facilities and equip-ment could not be used or occupied forsome time without extreme danger.

8.3 In deciding what protective meas-ures should be taken, including survey,:monitoring operations in an area contami-.nated with fallout,lt is necessary:

1. To make some estimate of the perniis-sible time of stay for a 'prescribed ex--posure, or

2. To determine the exposure thatwohl e received in a certain timeperi d.

3. To determine an "entry time.'1 for aprescribed exposure and a prescribedstay time.

8.4 If the radiation exgosure rate fromthe fission prOducts,produeed by a singleweep.= is known at a certain time in agiven location, this knowledge may beused to estimate the exposure rate at anyother time at the same location assumingthat there has been no externally pro-duced change in the fallout (i.e.,,from addi-tional contamination or by decontamina-tibn). In any such calculation, the conceptof RADIOACTIVE DECAY IS VERY IM-PQRTANT.

DECAY OF FISSION PRODUCTS

8.5 As we saw in Chapier 2, eitch ra-dioisotope has a 'characteristic desakscheme (half-life). These range from a fewmillionths of a second to millions of years.When a number of different radioisotopesare presentin this case the fission prod-uctS of the bomb (fallout)no one half-life_applies for'the composite. For thee fission.prodAts, the sharet--lived radioisotopes pre-

-"Torninate in the period Anmediately follow-ing the burst. Since their lf-lives (decayrates) are so short (rapidI, the radiationlevel falls off quickly after the detonation.And as thesf short-lived radioisotopes ex-pend themselves through decay, thelonger half-liSe isOtopes form an increasingproportion of the fission prbducts and therate of decay of the fission prodUcts de-creases. Because of this pattern of decay,the material deposited on the ground- atincreasing times 'after 'the burst will beless aiid lees radioactive.121

117

8.6 In calculating the radiation expo;sure (or exposur:e rate) dUe to fallpiit fromffssion products, the gamma rays (becauseof their long range and Pénetratin &. power)are.of greater significance than the betaparticles, provided of course that the ra-dioactive material is not-actually in con-tact with the skin or inside'the body:

87 ,Even though-there arg, 'different'proportions of gamma ray emitters amongthe radioisotope§ in fallout at differentperiods of time, the fact quit there is apattern of decay dogs permit the develop-ment throtigh estiniates-orcaleii4W14146,134;&' 8.8.-.The 7:140 rule of thumb for ratt\ of decay.:.;levels of exposure and exposure rate atcertain times after a detonation ant-in --;fact, permits prediction of exposure and STANDARD DECAY

.

TIME (+NV DECAY RADIATION WORM

-44

1000

7 1110 :, 100 Rfiii

49 1/100 10 R/hr

'343 1/1000 1 R/hr .

exposure rate with a iair degpee...of acpu- -THE ExibSURTftfIRATE FORMULAracy. There dreyiliair-WaIrsTyr-comirig upwith these estimates or calculations, someemploying a rule ot thlimie some employ-ing .mathematical formulae, and othersemploying graphic, preientations (norno- Lgrams).

NOTE

No coniputatiot 91 ,expoure or expd-sure rate should be made until they'begin to decrease. You SHOULD. NOT,CALCULATE EXPOSURE RATES..WHILE THEY ARE INCREASING.Further, calculation is no sulistitutefor-accurate instrument readings.

9s

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

TH1"711rWt7t-E-OF-THUMB

8.8 After exposure rates ha begun toy ,

decrease, you can get erou ea of fu-''ture rates by using the 7:10 rule. Simplystated, this rule is that for every seyn- -

;fold increase in time alter detonation,there is a-ten-fold- decrease in exposurerate. Figure 8.8 demonstrates thls oiule ofthumb.,

8.9 irkerefgre, we seetha , through useof this rule ofthumb, if a 50 R/hr radiation-exposure rate exists Wthree hours afterdetonation, by the en'd of 21 11.214s it willhave' decrea,sed to 5 R/hr, and by the endof 147.hours it will have decreased to 0.5 R/hr..

8.10 , The following forinula is used-calculating expo-sure rates:

R, .=R T"

8:T1 In this eqttation:R = rate at a specific timeR, = rate orl tiour after detonation -

(H 1-.1)T = time (hours) after detonationn .1-- 1.2 (fallout decay exiionent)

9

140TE

When n is equal to 1.2 the situation isreferred to as standard decay. When nassumes other values nonstandaAl decay conditions pxist.

STANDARD DECAYAN -EXPOSbRERATE PROBLEM

8.12 If the exposure rate at a givphlocation .one hour after detonation. was 30,;:'R/hr, what would the rate be' at thisloca../.-1 0-rion 12 hairs after detonation?

SOLUTIOIAR, = 30 R/hrR ?

T = 12 hoarsn = 1.2

Substitute values in t.h,e.'abor fcw.rp#11f,tR, =RT"

23434, =R(12)"

30 =41 (19.74)*30

R = 1-5-7-7r- 1.52 R/hr

'From Figure 8.14' (12)-" =19.73

STANDARD DECAYTHE EXPOSUREFORMULA

8.13 The following formula is used incalculating exposure.

E = . T21-n)n 1

8.14 In this equation:E exposure from time T1 to T,R, = exposure iate one hbur after

detonation (H + 1)T, = time of entry

= time of exitn = 1.2 (fallout decay exponent)

8.15 As an aid in using either formula- presented above, Figure 8.14 gives the

computed values of T'.2. and T-').2 for vari-ous selected values of T.

STANDARD DECAYAN EXPOSUREPROBLEM

8.16 What exposure would a monitoringteam receive in a radioactive contami-nated area if the team entered the- area 5hours after a nuclear burst and stared fora period of 10 hours? The exposure rate atH + 1 wa's 50 R/hr.

SOLUTION

R, = 50 R/hrT, = 5 hoursT, -= 5 +10 =.15 hoursn

Substitute values in the above formula:RE = ,

-T21-9n 1 ,).

E =1.2 - 1

(51-1.2 _ 151-1.2)

5015-0.2)

E = 250 (0.725 -0.582)**E = (250) (0.143)E = 36 R

**From Figure 8.14 5-0.2 =0.725 and 15-0.2=0.582

STANDARD DECAYEXPOSURE RATENOMOGRAM

8.17 If, of the factors (1) time afterdetonation; (2) exposure rate at H +1, and(3) exposure rate at:a particular time, weknow any two, then the other one can befound by using a nomogram developed spe-cifically for expoiure rate calculatibns.(You will recoghize these factors as com-ing from the formula of paragraph 8.10,namely, R1=RTn). The .nomogram appears,as Figure 8.17 and is based upen thestandard fallout decay exponent of 1.2.

8.18 To u,se the exposure rate nomo-° 'gram 4hown in Figure 8.17, connect any

two known quantities with a straightedgeand read the unknown quantity directly.

STANDARD DECAYAN EXPOSURERATE NOMOGRAM PROBLEM

h8,19 If the exposure rate in an area is

60 R/hr t H + 5, what will be the rate atH + 10?

8.20 Solution: With 'a straightedge, con-nect 60 R/hr on the "Exposure Rate atH + T" column mith 5 hours on the "Time

,After Burst" column. The tate of 410 R/hrta read on the "Exposure Rate at H 4. 1"column. Next, connect, with the straight-5dge, 10 hours on the "Time After Burse"column with 410 Rihr on the l'Exposure:Rate at H + 1" column and read the an-sw.er directly from the "Exposure Rate atH + T" column,

126n8wer: 26 R/hr,4"3`,

, T =TIMEIN HOURS

. T1.2

..

^PIT-v.c. T TIMEIN HOURS

T1.2 T-0.2 T=TIMEIN -HOURS

.

T 1.2 T-02

48.0 io4.1 0.461.0.1 0.0631 r 1.586 1.9.0 ' 34.23 0.555 49.0 106.7 0.4590.2 0:1450 1.381 20.0 36.41 0.550 50.0 109.3 0.457

-0.3 -0.2358 1.273 21.0 38.61 0.544 55.0 122.6 0.4490.4 0.3330 1.202 22.0 4+0.82 0,539 6o.o 136:1 U.4410.5 0.4352 1149 23.0 43.06 0.534 65.0 149.8 0.4340.6 0.5417 1.110 .24.0 45.31 0.530 70.0 - 163.7 0.4270.7 0.6518- 1.074 25.0 . 47.59 0.525

72.0 169.4 0.425:0.8 0.7651 1.046 26.0 49.89 0.521 ' 75 .0 177.8 0.4220.9

1.9,J

0.88121.0010.

1.0211.000

27.028.0

. 52.2054.52

10.518

0.514

,;36.0

85.0192.2206.7

0.4170,412

1:5 1.627 0.922 29.0 ,56.87 0.510 90.0 211.1 0.4072.0 2.300 0.871 ' 30.0 , 59.23 0.506 95.0 4 236.2 0.402

, 2.5 3.003 0.833 31.0 61.61 0.50396.0 239.2 0.401

3.0 3.737 0.803 32.0 64.00 0.500 100.0 251.2 0.3984.o 5.278 0.758 33.0 66.41 0.497 120.0 ', 312.6 0.3845.0 6.899 0.725 34.0 .68.83 0.494 140.0 376.2 '0.°3726.o 8.536 0.698 35.0 '71.27 0.491 144.0 389.1 s0.376

, 7:0 10.33 0.678 36.0 73.72 _ 0.483 160.0 442.5 0.362'8.0 12.13 . 0.660 37.0 76.18 0.486 168.4(1 wk) 468.1 0.3609.0 13.96 , .0.644 38.0 78.66 0.483 180.o 508.5 0.354

10.0 15.85 j ,0.631 39.0 - 81.15 0.480 220.0 577.1. 0.347'11.Q 17.77 0.619 40.0. 83.67. 0.478 250.0 754.3 0.332

..12.0 19.73 0.668. 41.0 86.17' 0.476 300:0 938.7 v0.31913.0 21.71 0.599 42.0 88.70 0.474 336.0 (2 wk ) 1075.0 0.31314.0 23.74 0.590. 43.0

'44.091.23 0.472 504.0 e3 wk 1745.0 0.288

15.0. 25.78 0.582 93.79 0.470 '672.0 4 wk 2471.0 0.272'27.86 0,574 45.0 96.35 0.467 720.0 1 mo. 2611.0 0.268 -

IT:0 29.96 , 0.567 46.0 98.93 05 1440.0 2 mo. 6166.0 0.234..1.8.0 32.09 0.560 47.0 101.5 0463 2160.0 3 Mb. 10031.0 0.216

FIGURE 8.14,-V-2 and Vs-2 for selected

124

4

sci°°

3°"' i2000 ,--

1000

SOO

1Wow. Rate

L at 11+tThRt)

i

Exposur. ht.at H+1

(R) --t

4-T

'1

2

4

600

300

200 1-

too 450

40-

204_

10 4-

81-6 ar-t

Time After Burst

2 -34

411' =.17) 8 74

10 -,

-I-.

-14.-300

7-. tit

8

10

+20

30

60

SO

100

-

600

soomoo

20-2,/-1

30-140-1

1-, 260 -1812 4- 3100-2/-4

'7162028

4,7-36

2000

3000

-.1-5000

FIGURE 8.17,-Exposure rate noinogram.

STANDARD DECAY7ENTRY TIMESTAYTIMETOTAL EXPOSURE NOMOGRAM ,.

.8.21 Just as if is possible to develop a

nomogram for -expasure. rates- and timethrough the use of the exposure. rate for-mula and standard fallout decay exponentof 1.2, so can we produce -a nomogram forthe exposure formula.

125

z

8.22 This nomogram is found in Figure8.22.

8.23 To use this norhogram, connecttwo known quarltities with a straightedgeandiocate The -point on the "EIR1"e6Tumnwhere qe straightedge crosses it. Connectthis point with a third known quantity andread the answer from the appropriate col-umn.

121:

)

Teta Tamura(E)

japasers hts (1 km)4

40

SO

20

40.404SO 11201

20373001--400.r-uor

Stay Tim (Ws)

100 bOO 1.011-0

200073000 .07

S000..037

1.04

001000 .031

./32

FIGURE 8.22.Entry time-stay time-total-exposure nomogram.

STANDARD DECAYAN ENTRY TIMENOMOGRAM PROBLEM

8.24 The exposure rate in an area atH + 7 is 35 R/hr. The stay time is to be 5.hours and the minion exposure is set at 35R. What is the earliest possible entrytim e?

8.25 Solution: Find the exposure rateat H + 1 from the ,Exposure Rate, Nomo-gram (Figure 8.1'?):. Connect this value onthe 'Expogure Rate at 11,+ 1" column with35 R on the "Total E)R9sure':. column andread 0.1 on the "E/R,"" clumn. Connect 0.1on the "E/R," column with 5 hours on"Stay Time" Column and read the answerfrom the "Entry Time" column.

AnfiVieff H '24.

STANDAAD DECAYA STAY TIMENOMOGRAM PROBLEM

8.26 Entry into an area with an expo-

122 ,

a

sure rate of 100 Rthr at H + 1 will be madeat H + 6. What will be the maximum mis-sion stay time, if the exposure is riot to.exceed 20 R?

8.27 Solution: Connect 20 R in the "To-tal Exposure" column with 100 R/hr in the"Exposure late at H + 1" column andread 0.2 in tIvp "E/R,"column! Connect 0.2in the "t/R," column with 6 hours in the"Entry Time" column, and read the an-swer directly froin the "Stay Time" col-umn.

Answer: 2.1 hours.

STANDARD DECAYAN EXPOSURENOMOGRAM PROBLEM

8.28 Find the total exposure for an in-dividual who must work in an area inwhich the exposure rate was 300 R/hi atH + 1. Entry will be made at H + 11 andthe length of stay will be 4 hours.

r

8.29 Solution: Connect H +11 on the"Entry Time" column with 4 hours on the"Stay Time" 'column and read 0.19 fromthe "EIR," column. Connect 0.19 in the "E/R," column with 300 R/hr on the "Expo-sure Rate at H +1" column and read theanswer from the "Total Exposure" col-umn.

Answer: 60 R.

,

WHAT METHOD SHOULD MONITORSUSE? -

8.30 Nomograms, based on theoreticalfallout radiaton -decay charact ristics,should be used by monitors w en it isnecessary for them to make y6ugh esti-mates of future exposure rat s and expo-sures that might be expected in perform-ing necessary tasks outside the shelter.However, when fallout from several nu-

ll clear weapons, detonated more than 24hours apart is deposited in an area, thedecay rate may differ markedly from theassumed decay rate. For this reason, cal-culations using nomograms should be,,lim-ited as follows:

The time of detonation must beknoWn with a reasonable degree ofaccuracyplus or minus one hour forforecasts made within the first twelvehours, and plusNor minus '2-3 hoursfor later forecdsts.

b. If nuclear detonations occur morethan 24 hours apart, predicted ratesmay be considcrably in.errot. In thiscase, use the H hour of the latestdetonation to compute "Time AfterBurst".

c. At the time of calculation, eXposurerates must have been decreasing forat least 2-3 hours, and forecastsshould be made for periods no fartherin the future than the length of timethe radiation levels have been ob-served to decrease.

8.31 Have we covered the subject ofexPbsure and- expgsiireiate calculatiOns?That question prompts another question.What level of the RADEF organizationare we talking about? Monitors? In thatcase, yes, we have covered exposure and

127

a.

expoiure rate callulations. 'How about theRADF Officr Have we taken care ofhim yet? You'll find that answer below,

AN OPEN LETTER TO. RADEF OFFItERS

We have arrived at the point whereyou will have to bear down hard. Thisjs the point at which yoint.own profes-sionar-type RADtF knowledge makesits depant" from, the, standardkADEF know-how'that will be sharedby so many members.of your RADEForganization.

The following paragraphs are notimpossible but then neither are theyeasy. If you miss a point, go back and .reread it because the basic material isreally here. You will probably notice,here and there, .some repetition overthe preceding paragraphs but it isintdnded as an aid to better under-standing.

We wilj begin with * * *

A REVIEW OF RADIOACTIVE DECAY

8.32 Each radioactive isotope has a--characteristic half-life. These range from afew millionths "of a Second to millions ofyears. However,'-wkeri'many radioisotopescontribUte to the exposure rate, as in thecase of the fission products from a nuclearweapon, no one half-life aPplies for thecomposite. With fission products there is_apredominance of siroxt-lived radioisotopesin the period imlnediately following theburst; hence the exposure rate decreasesvery rapidly. As these short-lived radioiso-topes expend themselves, the longer half-life isotopes become dominant and the de-cay rate of the fission products decreases.

8.33 We know that radioactive decay ofthe fission products can be estimated us-ing the general equation R, = RP where R,equals the exposure'rate at unit time, Requals the exposure rate at any time Tmeasured from the time of burst, and n isthe fiallout decay exponent. Time may bemeasured in any units7-minutes; hours,'days, weeks, etc.; provided unit tiine and T

-are expressed in the same units.

STANDARD MECAYA WORD ABOUTTHE EXPPNENT (1.2)

8.34, Attempts to fit observed decay of

1 i3

't.

fallout from actual' tests with a generalequation of tthe form RI=RTn" have re-quired Values oFn ranging from about 0.9to 2.2. We.have learned that attempts topredict the decay of actual fallout fields on

-e,the basis of any given decay law (i.e.,assuming some constant value for n) arealmost certain to be grossly inacettiate.The value of n will vary with bomb design,the amount ant type of neutron-inducedjactivity, fractiona nd in a particulararea, with weathering nd decontamina-tion.

8.35 .For planning purposes, a value ofn = 1.2 is frequently used and, fog. plan-ning, this value is quite satisfactory. How-ever, accurate ibtformation of exposurerates and rates of decay must depend onrepeated mOnitoring under the same condi-tions at the same locations.

PLOTTING THE EXPOSURE RATE HISTORY

8.30 Since the fallout at any locationmay eonsist of radioactive material fromsev,eral, different weapon's detonated atmaterially different times, it will be im-practical. to 'keep track of the individualcontributions and ages of each set of fis-sion products comprising the fallout. Themost practical method of forecasting expo-sure rates under these conditions appearsto be based upon-the technique of plottingobserved rates 4:Tersus time after detoba-

' tion on log-log paper and extrapolating theplotted curve.

8.37 Plo4 of this tyPe for two or threerepresentatjve points across a communitywill generally be adequate. If the' require-ment exceeds this, it may be advantageousto compute the value of the fallout decayexponent n and use the general equationRib!=RT11 to predict future exposure ratesin areas where the fission product compo-sition is ehe same.

S.38 R1=RxTx" and R1=RJ)," etc. Theniost -useful form of the general equationwill _probably be R,T,P=RET. Applicationof this formula is discaued in a laterparagraph (8.55).

8.39 The procedure for plotting ob-served exposure rates is as follows. FromNUDET (report ot time of detonation) re-

124

41-,

ports or simply from observations of theflash, the hlast wave,..or the cloud of thedetonation, the time of burst of mostweapons within a radius of 100 to 200miles will be' known. Thiis, the RADEFOfficer will know the time of formation ofmost of the fission products in his immedi-ate area and from the current "DF" reporthe will generally know which specific deto-n4tion is causing the major fallout prob-lem in his community.

8.40 The RADEF OffiCer can then plotor direct th plotting of observed exposurerates agai st time on log-log paper., Fu-ture fat s can be estimated by projectingthe cur e to. future times of concern.

8.41 However, as a practical limit, fore-casts of future exposure rates generallyshakld be made for periods no farther inthe future than the length of time exposurerates have been' observed tp decrease.

8.42 For example, if exposure rate pb-servations- have been decreasink for thepreceding 12 hours, they will be plottedand,.provided the plot for the last fewhours approximates a straight line, thecurve can be extritolated (extended) for12 additional hours to forecast the ratesduring that time period. Caution must beexercised in extrapolating the curve dur-ing periods of fluctuation,

8,43 If, after aperiod during which thelogarithmic decay is approximately astraight line, the rate is observed to mate-rially increasethis indicates the arrivalof significant additional fallout. If the ex-posure rite appears to he equal to or lessthan the maximum exposure rate fromerlier fallout, continue the original plotbased on the "H hour" of the originalfallout.

8.44 However, if considerable time haselapsed since arrival of the first fallout,and the increase in exposure rate equalsor exceeds the maximum exposure ratefrom earlier fallout, plot a new graph us-ing the estimated H hour of the latestfa ll out arth e refereime-time.

8.45 After the plot indicates an orderlydecrease Snearly a ,straight line log-logplot), extrapolation of the curve can againprovide a reasonable basis for estimating

1 1)8AV,

exposure rates for future periods subjectto the-above-mentioned restriction.

8.46 It should be emphasized that theactual exposure 'rate may vary consider-ably fx-Rm the forecast rate. Thus, 'opera-tions likely to iequire high radiaton expo-sures arould' be carried out on the basis ofobcerved rates, not forecast rates. Theforecast is simply- a guide -to aid a localcbordinator in planning his forthcomingsurviV"al and recovery operations.

8.47 A forecast exposure rate could beconsiderably in-Nerror if additional falloutoccurred after the forecast was- made or ifthe rate of decay,,changed materially fromthat indicated by the plots on the log-loggraph.

8.48 The latest fallout analysis, basedupon current exposure rate reports,should be the basis for current operations.Plans for future operations should bebased t.ipon Ple current fallout analysis)modified according to Jhe forecast from aIog-log plot:

A PRACTICAL EXAMPLE

8.49 The following exercise presents ahypothetical situation. in which we willpredict future exposure rates from a seriesof radiological reports. (The curve whichwill be Used does notnecessarily representa fallout decay cut-ve which might be ex-pected in an actual situation.)

8.50 We are given certain data as for

Time afterburst (Hours)

Exposure rate(R/hr)

Time after Exposure rateburst (Hours) (R thr)

IF 0 18 -2 0 20

,380390

3 1 22 4104 23 24 4155 250 26 4106

.790 28 495

7 - 910 30 4008 860 36 3259 805 42 280

....

10 . 750 48 24012 640 54 21014 549 60 18516 460

- -1. First, we plot the data as indicated bythe arrows inFigure 8.50a. '

2. Next, we draw a smooth, curve -. through the plotted points as shown.'

in 'Figure 8.50h.3. lfow, in order to forecast the expo:

sure rate at H + 80 a'nd H 90,0veextend the curve to 90 hours as adotted line. This is shown in Figure8.50c.

4. Assume that we now receive addi-,tional monitored data as follows:

Tame afterburst (hours)

Exposure rate' Teme atter Exposure rate(RIhrCI.burst (hours) (R/hr)

70 155 100 103.80 131 110 ' 9190 115 120 83

5. We plot the additional data.6.' Then we draw a smooth cUrve

through these additional points asshown in Figure 8.50d. Notice thecomparison between -the forecast ex-posure rates and the actual up-datedplot. ,

8.51 The fallout decay exponent n maybe computed directly from the plotted ex-posure rate curve since n ,is numericallyequal to the slope of the curve. Further, nis constant only when the plotted line isstraight. We can determine fi from thegraph by dividing the measured distanceAY in inches by the measured distance AXin inches as indicated in Figure 8.50e.

8.52 Looking at Figure 8.50e, let's de-terming n at H + 110. We see that AY andAX are the vertical and horizontal dis-tandes, respectively, covered by the curvein the area of our interest. we measurethese distances in inches, divide AYlky_AX,and.find that n at H + 110 is equal to 1.1.

8.53 Now, if practicai, n !Can be used toforecast exposure rates as indicated in thefollowing eximple. (A table of logarithmsand a brief explanation 'of their use isincluded ai Figures 8.53a and 8.53b.)

8.54 BefOre working out 6ur example,go back and reread paragraph '8.38. Youwill find it helpful in solving the example.

"8.55 Now for the sample problem in

125

.exp-osure rate forecasting using a .com-Puted vbzlue of n. The exposure rate at the rate at.1.1 + 8 days.,

R,, = 108 R/hr _,RxTyn. = Rytn'. ,T,, =. 4 days. , (10,8) (4). " :=.(1t,) (8)"

= ? log 108 t 1.1 log 4=lg Ry + 1.1 log 88 dars, (2.0334) + 1.1 (.6021) = log R.), + 1.1 (.9031)

n = 1.1 log R; = 2.0334 + 0.6623 0.9934 = 1.7023Answer: Ry = 50.k/hr.

EXPOSURE CALCULATION FROM ANEXPOSURE RATE .HISTORY CURVE

4 days iS 108 R/hr; if n = 1.1, predict

8.56 DCPA recommended radiologicaldefense reporting procedures proyide foraccumulated exposure reports each dayfrom fallout monitoring stations for thefirst -six days following an- attack. Thesereports will be based on dosimeter meas-urements, which are the sir/Vest Means ofdetermining exposures. Dosimeter* inte-grate the exposure over a period of timeand account- direcWy for the decrease inexposure rates due to decay.

8.57 However, there may be insianceswhen the RADEF Officer must estimateexposure from a series of exposure rate

...measurements. The following paragraphswill provide a quick and easy method ofestimating such exposures.

8.58 It is relatively, simple to forecastexposure rates and, consequently, total eX-posure of individuals when the falloutdecay exponent remains constant overlong periods of time. These estimates, how-ever, are normally made only after falloutis Complete.

8.59 If we are concerned with estimat-ing the total exposure for the periods (1)- offallout deposition, (2) when the value ofthe fallout decay exponent is changingrapi:d,ly,.. or (3) when fallout from, severaldetonations contributes to the exposurerate, calculation of these estimates be-comes more coMplex.

8.60 A satisfactory estimate of total ex--,posure can be .obtained by plotting expo-sure rates versus time after detonationand determining total exposures from thegraph.

126

eir

8.61 First, divide the expovre periodinto small increments. When the slope oftte curve is changing rapidly, the incre-nitnts should be small. When the slope isrelatively straight over the exposure pe-riod, the increments may be larger. Theincrements need not be equal in size.

8.62 As a general rule, an incrementshould noi exceed ode.' half of the timefrom detonation to th lbeginning of theincrement. For exampl 'if the incrementsbegins at H 4- 10, il eh uld not be largerthan 5 hours. Howe:ver,if the slope of fhesurve chahgeS appreciably during thistime, it may be neces'sary to use evensmaller increments. Duiing the initial pe-riods of fallout deposition, the incrementsshould be no larger than 1 hour.

8.63 Now rook at Figure 8.63 to see howa sample exposure period is .broken intoincrementS.

8.64 Next, w&determine the averageexposure rate within each increment andmultiply this by the elapsed dine. This willgive us the exposure for each incrementand the sum of these exposures will giveus the total exposure fior the period. Thecalculations involved are presente,1 below.

A v e r a g e exposure

A v e r a g e title xIncrement exposure rate elapsed thrte.exposure

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VIGURE 8,53a.-Common Lorifht,ps.

4

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I.

This disdassion of,logarithms will deal onlywith the_so-called "common" logarithms whiehuse a base equal to 10.

A

First, a definition of a logarithm::4 -

the lbgarithm of a number N to thebase a is the'expoilent x or the powerto which the base,must be raised toequal the nuMber N. ,

In other wordst

log N is the logarithm of N to thebase 10

Thus:

if N = 10x, then x = log N

FUrther:

'log N = characteristic + mantissa

(For instance, log 12.3 = 1 + .(5864 = 1.086h)

The mantissa (or delmal piri Oithe logarithn)is found from the tables of logarithms (Figure8.53a).

The chaNt'eristic is determined in accordancewith two rules:

.4116

if the nuMber kris greater than 1, thecharacteristic of its'logarithm is one

less than the number of digits to ttid leftof its decimal point . . .

or

if the number 11 is less,than 1, thecharacteristic of its logarithm is neg7

if.the first digit which is not-. zero is found in'the,kth decimal plAce,

the characteristic is -k.

Now, to use logarithms-to multiply two numbers,M and N, find log M and-log N:

if N = 10x, then x = log DT'

if M = 10Y, then y = log M

To multiply M times N:

x + y = log ME+ log N = loge(MA.

When x (the logarithm of N) is added to y (thelogarithm of M), the sum is another logarithm,the logarithm of M times N. The antilogarithmof this value of x plus y is M times N. Orr

I.antilog (x + y) = antilog (log M + log h)

= M times N,4,

Antilogs are found by using the tables in re-verse, i.e., enter the.tablei with a log (nota number) in-Order to find a number (not a

,log).

-MN

FIGURE 8.53b,--1Jsing Common Logarithms.

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. 11 II .1 I

' CHAPTER 9

RADIOLOGICAL MONITORING TECHNIQUES AND OPEIATIONS

Consider, for just a moment, what .kindof radiological defense could we build if wedid not have 'radiological monitoring? Itwouldn't be worth much, would it? Radiol-ogical defense is built on facts and radiol-ogical monitoring provides those facts forRADEF decisions and actions. Once a )nuclear attac.k is past, this becomes evenmore true with each passing hour for justas long a time as radiation remains, adanger., So if there is a technique in thisbusiness of midiological monitoring (andthere is, very definitely), let's take a lookat it to find out:

BOW to MonitorWHEN to monitOrWHAT to monirorWHO to monitorWHERE to"nionitor

.

(. . . as to WHY lo monitor, we havelearned all the reasons for that one quite afew pages back!)

INTRODUCTION

93 The data supplied by radiologicalmonitors is the key to RADEF decisions.ori what to. do and how to do it. And in-timeofoemergency these decisions may be thekey to living or dying. Let's, take a closerlook af this vital activity.

WHAT IS RADIOLOGICAL MONITORING'?

9.2 Radiological monitoring ,is definedas the detection and measurement of ra-diation emitted by fallout. With the ipfor- .

mation gained through monitoring we can:(1) determine extent and location of fal-lout; (2) validate predictions about fallout;and (3) decide on a course of action.

MONITORING TECHNIOUES 1

i9.3 The following paragraphs describetlie detailed techniques and procedures forconducting each type of radioiogical moni7toring activity. Fallout station monitorsare responsible for performing all of theMonitoring techniques outlined in this sec-tion. Shelter monitors are responsible forperforming all of the techniques, exceptfor unsheltered exposure rate measure-ments and unsheltered exposure measure-ments.

SHELTER AREA MONITORING

=9.4 E pns,) tre-ratea-shouki-be-measuredinside of a shelter, or a fallout monitoringstation to determine the best shielded por-tions of the shelter and its immediate ad-joining areas. Procedures for tilis monitor-ing are as follows:

1. Use-the CD V-715.2. Check the operability of the instru-

me,nt.3. Hold the instrument at belt height (8

feet above the ground).4-. take readings ,at selected 'locations

throughout the shelter and adjoiningareas and record these on_a sketch ofthe area.

UNSHELTERED EXPOSURE RATEMEASUREMENTS

9.6 Fallout monitoring stations reportunsheltered exposure rate readings. Pro-cedures for observing unsheltered expo-sure rates are as follows:

1. Use the CD V-715.

Paragraphs 93 through 9 30 are based upon the HANDBOOK FORRADIOLOGICAL MONITORS, FG-E-5.9.

135'

2. Check the operability of the instru-ment.

3. Take San exposure rate reading at aipecific location in the fallout moni-toring station. This should be done assoon as the exp6sure rate reaches orexceeds 0.05 R/hr.

4. Go outside immediately to a pre----:----plannedfiocation in a-clear, flat area

(preferably unpaved), at least 25 feets. away from bUildings, and take an out-

side reading. The outside readingshould be taken within three minutesof the reading in step 3 above.

5. Calculate the outside/inside ratio ofthe fallout monitoring station, by di-viding the outside exposure rate bythe inside exposure rate. The protec-tion may vary from location to loca-tion within the station. The outside/inside ratio referred to here is ap,pro-priate only for the location where theinede exposure rate measurement isobserved.

6. MUltiply future inside exposure-Tarereadings by the oftitside/in*I3e ratio atthe selected location to o tain theOutside exposure rate. For exaMple:If the inside reading is 0,5 R/hr andthe outside reading is 80 R/hr, theratio can be found by dividing theoutside reading by the-inside readin'e.Thus, 8a$ 0.5 = an outside/inside ra-tio of 160. If a later inside reading atthe same location in the fallout moni-toring station is 4 R/hr, thus outsideexposure rate can be calculated bymultiplying the ratio by the insidereading. Thus, 160 x 4 = 640 R/hr.

7. Recalculate the outside/inside ratio atleagt onde every 24 hours during thefirst few days postattack, unlesilheoutii4exposure rate is estimated tobe above 100 R/hr, This is necessacybecause the _energy of gamma radia-tion is changing, thus changing theoutside/inside ratio of the falloutmonitoring station.

8. Record and report the exposure ratemeasurement in accordance wjth theparticular RADEF . organization

136

standard operating procedure. NOTE:It is anticipated that radiation re-ports from the county level Ok govern-ment upwards would be limited to:a. A flash report immediately upon

measurement of .5 R/hr and in-creasing.

b. A severe radiation report when theradiation level reaches 50 R/hr andincreasing.

c. The highest or radiation peak levelif above 50 R/hr.

d. The time when the decaying expo-sure rate passes downward and be-low 50 R/hr.

e. The time whefi the radiation leveldecays to .5 R/hr.

9. Take all exposure rate measurementsoutside after the unsheltered expo-sure rate has decreased to 25IUhr.

9.6 The CD V-717 remote reading in-strument may be used for taking outsideexposure rate. Measurements. The CD V-717 is used as described below:

Position thP instrunionf at a selectedlocation within the fallout monitoringstation.

2. Place Ole removable ionization cham-ber 3 feet above the ground in a rea-sonably flat area and at least 20 feetfrom the fallout station. Preferablythis should be done prior to kalloutarrival. Ie is desirable to cover theionization chamber with a light plas-tic bag or other lightweight material.

3. Observe outside exposure rates di-rectly.

4. Record and report exposure rates inaccordance With the ---:partitular,RADEF organizationitandard opera- -

ting procedure.

UNSHELTERED EXPOSARE

MEASUREMENTS

9..7 Fallout monitoring stations reportunsheltered exposure readings. Proce-dures for taking these readings are listedbelow:

1, Zero a Cti V-742. 4

2. Measure the unsheltered exposure

140

4

'f.

kate in accordance with paragraph9.5.

3: Select an insiile 1o:cation' where theexpoSure rate is approximately one-tenth to one-twentieth of the unshel-tered exposure rate and positiortlheCD V-742 at this location.,

. 4. Determinethe outside/inside fatio forthis location in accordance with theprocedure explained previously.

5. Read,the CD V-742 daily. If the dailyexposIfte at this location could exceed.200 R, estimate the time required for'a 150 R exposure on the CD V-742.Record this reading, rezero the do-simeter, and reposition it. To deter-mine the daily unsheltered exposure,multiply the daily exposure at this!location by the outside/inside ratio:

6. Record the readings and rezero theinstrument.

PERSONNEL EXPOSURE MEASUREMENTS9.8 The monitor must determine the

daily exposure of all shelterees or fallout-monitoring statiön occupants. Procedures

for determining daily exposures are asfollows:

1. Zero all available CD V-742's.,2. Position thetosimeters so that repre-

sentative shelter exposures will bemeasured by the instruments.-Themonitor must exerciSe judgment inpositi3Oning these instruments. Theoutside/inside ratio may vary consid-erably at different locations withinthe shelter. 'The instruments shouldbe-placed within the areas of greatestoccupancy, which may change withtime. During the early high radiationperiod, occupaney wilt be coneen-trated'in the high protection areas ofthe shelter. Later, the occupancy ofthe shelter can be expanded"-If repre-sentative readings are to be obtained,the dosimeters must follow the loca-

, thin shifts of the occupants.3. If several dosimeters are positioned

in one compartment, read the dosime-ters each day and average the totale36hosures. Recharge dosimeters

RADIATION. EXPOSURE fl EGO fID

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which read more than half scale. Ifsome shelters are divided into com-partments or rooms that may havedifferent outside/inside ratios, the ex-posure should be measured- or calcu-lated for each comMtment.

4. Instruct the shelter occupants to re-cord-th-eir-individual exposures ontheir radiation exposure record (Fig-u're 9.8), as approved .by the sheltermanager. Exposure entries should bemade to the nearest roentgen. Con-tinue to read the dosimeters eachday. Record the accumulated expo-sure, if ineasurable.

9.9 If monitors or other persons are, required to go 'outside, these additionalexposures should be measuredtand re-corded.

PERSONNEL MONITORING

9.10 The present DCPA concept is thatany amount of contamination, remainingon clothing -after brushing--and-&aking asa countermeasure would be insignificantas a health hazard.

FOOD AND WATER MONITORING9.11 Eood 'and water mdnitOring crite-

ria and techniques are being reevaluated,and are subject to change. During an earlyfallout condition, the radiation level is

141137

g

likely to be above the range of the CD,V-700. and, in effect, render it unaidtable fordetermining whether food and water sup-plies are acceptable for human consump-tion.

Q.12 Since radiation passing throughfood does_not contaminate it, the only dan-ger Wo did be the actual swallowing of fal-lout particles that hapPen to be on or hithefiiod itself (or on the can or packagecontaining the food). Fallout particlesihonld be wiped or washed off. Reapingthreshing, canning and other processingwould prevent dangerous quantities of fal-lout from getting into most procetsedfoods. It is believed that ordinary precau-tions, normally taken in preparing foods toeat, would keep radiological contaminationwithin accelitable limitations.

9.13 Water systems might be affectedby radioactive fallout, but the risk wouldbe sniall. Water stored in covered con-tainers,- or in covered wells would not becontaminated after an attack. Even in un-covered-containers, indoors, such as buck-ets Or bathtubs filled with emergency sup-

Ti

1. Know the specific actomplishment,extent, and impo'rtance of each moni-toring mission.

2. Know the..4116wable exposure for eachmission and the expected exposurerates to be encountered.

3. Make allowances for the exposure tobereceived traveling to and.frtom themonitoring area. Obtain informationabout the condition of roads, bridges,etc., that might interfere .with themission and _lengthen exposure time.

9.17 Next, consider the clothing whichwill be needed for the mission. -

1. Tie pants cuffs over boots or leggings.2. When dusty conditions prevail, wear

a protective mask, gloves, head cover-ing, and sufficient clothing to coverskin areas. If no masks,are available,cover the nose and mouth with ahandkerchief.

9.18 Very important, of course, is theequipment needed for the mission.

1. Use the CD V-715. the exposurerates are expected to be below 50 mR/hr a1wearry-th-e-CD-V109.plies of water, it is highly unlikely that the

wittei would be contaminated by falloutparticles. Practically all of the fallout par-ticles that drop into open reservoirs, lakes,and streams.would settle to the bottom.

9.14 Do note discard food and waterknown, or, suspected to be contaminated.It should be placed in storage and usedWhen other less contaminated food is notlonger. available. If only contaminatedfood sir water is available use supplies withthe smalleit amount of contamination

AREA (MOBILE) MONITORING

9.15 Area monitoring is used to.locatezones of contamination and determine the/exposure rates within these zones. The,monitor should be informed by his Radiol-ogical Defense Officer concerning routesto be followed, locations where readings,are needed, the mission exposure,"and theestimated time needed to accomplish themission.

9.16 First, plan to keep personnel expo-sures as low as possible:

1311

2. Wear a*CD V-742.3. Carry contamination signs, if areas

are to be marked. This may also re-quire stakes, heavy cord, hammer andnails for posting the signs.

4. Carry a pencil, paper, and a map withmonitoringpoints marked.

3.19 The procedures for area monitor-ing are as follows:

1. Zero the dosimeter before leavingthe shelter and place it in a pocket toprotect it from possible contamina-tion.

2. Check the operability of the CD V-715 and CD V-700, if it 'is to be used.

3. Use vehicles such as autos-, trucks,bicycles, or motorcycles whdn dis-tances are too great to cover quicklyon foot. Keep auto and truck cab win-dows and vents closed when travelingunder extremely dusty conditionS.The use of a bicycle or motorcyclemay be more practical if roadwaysare blocked.

4. Take readings at about three feet

1 2

-"-

(belt high) above the ground. If read-, ings are taken from a moving vehi-`

cle, the- instrumept should be posi-.tioned on the seat beside the driver.If readingi are to be taken outside p.vehicle, the monitor should moveseveratfeet away from the vehicle totake the reading.

5. 'Record -the w'rettposure rate, the timeanI Iocatim for each reading. ,Ifreadings are 'taken within a vehicle,this should be noted in the report.

6. Post markers, if required by the mis-sion. The-marker ,should face awayfrom the restricted area. Write thedate, time, and exposure rate on theback of the marker.

7. Read the pocket dosimeter at fre-quent: intervals42_ determine whenreturn to shelter- should, begin. 'Al-lowances shouldbe made for the ex-

,

posure to be received during return,to the shelter.

8. Remove outer clothing on return tothe shelter and visually check allpersonnel for contamination.

W.-Decontaminate, if required.10. Report results of the survey.11. Record radiation eiiposure (see Fig--

ure 9:8).

EXPOSURE RATE READINGS FROMDOSIMETERS

9.20 Survey instruments should alwaysbe used to measure exposure rates. How-ever, if no operable survey instrumentsare available, dosimeters can be used tocalculate exposure rates by following theAteps listed below.

1. Zero a CD V-742.2. Place the zeioed dosimeter at a se-

lected location.

1- r

5. Divide sixty minutes by the numberof minutes the dosimeter was ex-Posed. Multiply this number by theineasilred exposure. Example: If theexposure is 10 R for a measured inter:val of five minutes, the rate can becalculated as follows: .

(60 5) x lb = 12 X 10 =120 Rihr.

MONITORING ,OPERMIONS,,--

921 Radiological monitors, whether as-signed to community shelters or falloutmonitoring stations, perform essentiallysimilar operations. Any departures fromthe operations described here will be theresult of decisions by State and local orga-nizations and mukt be reflected in theirstandard operating procedure's. If local orState standard operating procedures arenot in exiitence, monitors should followthe procedures outlined in the followingparagraphs.

°READINESS OPERATIONS

9.22 During peacetime, wall assignedmonitors should:

1. Participate in refresher training ex-ercises and tests as scheduled tomaintain an organized monitoring ca-pability.

2. Prepare a sketch of the monitoringstatiOn or shelter and adjoining areasfor use during shelter occupancy.

3: Plan a location in the shelter in coor-dination with the shelter manager toserve as the center of monitoring op-erations.

4. Make all' operational sets availableonce-every two-years to the-4Mbmaintenance shop for repolibration,iepairs if necessary, and new batter-;pc

3. Expose the dosimeter for a measuredinterval of time, but do not remain inthe radiation field while the dosime-ter is being eXposed. This intervalshould be sufficient to-:allow the do-iimeter to read at leasi 10 R. It maytake one or two trials before theproper interval can be selected.

4. Read the dosimeter.

SHELTER OPERATIONS

9.23 Upofi attack or arning of attack,a shelter monitor 6 rts to the sheltermanager in his assigned shelter and per-forms the following CHECK LIST of oper-ations in order:

113

1. Perform an operational check on allsurvey meters.

139

2. Charge dosimeters.3, Position dosimeters at- predesigt, .

mated locations in the she/ter.4. Report to the shelter manager on

the conditions of the instrumentsand the pOsitioning of dosimeters.

5heck to see the doors, windows, orother openings are closed during fal-lout deposition.

6. Begin outside monitoring to deter-mine the time of fallout arrival. Ad-vise the shelter manager when therate begins to increase.

'7. Insure that all persons who haveperformed outside missions in con-taminated areas, follow the protec-tive actions indicated:

8. Food and water stored in the shelterShould be acceptable for consump-tion. Leav,e contaminated items out-side the shelter or place them inisolated storage near the shelter.

9. Take readings at selected locationsthroughout the shelter and recordthe exposure rates on preparedsketches of-thearea. Particular at-tention shotild be given to monitor-ing any occupied areas close to fil-ters in the ventilating system. Showthe tinT of readings on all sketches.

10. Furnish all sketches to the sheltermanager and recommend one of thefollowing courses of action:a. If exposurerates are not uniform,

occupy the areas with lowes't ex-posure rates. -

b. If 'space prohibits locating allshelterees in the better protected

z.areas, rotate personnel to distrib-ute exposure evenly. DO not ro-tate personnel unless thire is a

. significant difference in file expo-sure between the best and theleatt protected shelter occupants.

11. Repeat the above procedure at leastonce daily. If there is a rapid changein the exposure rate; repeat at leastonce every six hours.

12. Inform the shelter manager teno-tify the appropriate emergency oper-ating center and request guidance if:

1,40

a...The inside exposure rate _reachesor exCeeds la 4/hr at any timeduring thp shelter period.

b. The calculated exposure will ex-'ceed 75 R. within any two days pe-riod-of shelter.

13. Issue each shelter occupant a Radi-tion Exposure Record. As approved"by the shelter manager, advise eachperson once daily Of their exposureduring the previous 24 hours..Followprocedures in paragraph 9.8 to calcu-late exposure of shelter occupants.

9.24 During the latter part of the shel-ter period, when there is a less frequentneed for in-shelter monitoring, some of theshelter wonctors may be required to pro-vide monitoring services in support ofother emergency operations. A monitoringcapability should always be retained inthe shelter until the end of the shelterperiod,

9.25 At the conclusion of the shelterperiod, all shelter monitors, except thoseregularly assigned to emergency-services,may expect reassignment.

FALLOUT MONITORING STATIONOPERATIONS

9.26 For his own protection and theprotectiowscif all members of a fallout mon-itoring stAtion, the monitor should per-form' the same shelter operations as de-scribed in paragraph 9.23. In addition, thefallout station monitor will measure, re-cord, and report unsheltered Ocposure andexposure rates to the appropriate EOC.Unless otherwise specified by the localstandard operating procedure, the monitorwill:

1. Make a FLASH REPORT when theoutside exposure rate reaches or -ex-ceeds 0.5 R/hr.

2. Record and report exposure and expo-sure rates in accordance with localrepOrting requirements.

MONITORING IN SUPPORT OFEMERGENCY OPERATIONS

9.27 As soon as radiation tevels de-crease sufficiently to permit high priority

114

operations and later, as operational recov-ery activities including deeontaminationof vital areas and structures are begun, allfallout station monitors and most commu-,nity shelter monitors are required to pro-vide radiological monitoring support tothese ,qpertiQns..RadJQlog1cal Defense Of-ficers will direetr the systematic monitor-ing of areas, routes, equipment and facili-ties to determine the /extent of contamina-tjon. This information will Help the CivilPreparedness organization determinewhen people may, leave shelter, whatareas may be occupied, what routes maybe used, and what areas itnd facilitiesmust be decontaminated.

9.28 Many government services persOn-nel, such as fire, police, health, and wel-

, fare personnel, will serve as shelter moni:tors or fallout station monitors during iheshelter period. However, as operational re-covery activities are begun, they will haveprimary responsibility in their own fields,with seeondary responsibilities in radiol-

.

ogicat defense. Most services will providefor a radiological-monitoring eapability forthe protection of their operational crewsperforming emergenZy activities. The .ca-pability is provided until the RadiologicalDefense Officer determines that it,is notrequired. Services provide this capability-from their own ranks, to th4,e extent practi-cal, supported by shelter monitors and fal-lout station monitors, when requiretd.

;

9.29 When a service is directed to per-. forom a mission, the emergency operatingcenter furnishes the follovring informa-tion:

1. The time when the service may leaveshelter to perform its mission,

2. The illilowable exPoStrie for the com-plete mission; that is, from time ofdeparture until return to shelter.

3.. The exposure rate to be expected inthe area of the mission.

9.30 The monitor supporting emer-gency operations Will:

1. Read his instruments frequently dur-inf each operation and advise the in--dividual in charge of the mission onnecessary radiological protectivemeasures and when the crew mustleave the area and return to shelterto aioid eAceeding the planned mis-sion exposure.2. ,

. Determine the effectiveness of decon-tamination -ineasures,if-auppdrtindecontamination operations.

3. Monitor equipment on return to shel-ter, or base of operations, to deter-mine if it is contaminated, and if so,direct decontamination of that equip-ment.Advise the crew on persminel decon-tamination if necessa0.

4.

141

CHAPTER 10

PROTECTION FROM RADIATION _

Different forms of protection from nu- eclear radiation are available to us. Some ofthese alv all right, some are excellent andsO'me are poor.

We need information on these forms ofprotection and thia. chapter will eve usthat information. We will see:: HOW time can provide protection

, HOW distailce can provide protec-tion

HOW shielding can provide protec-tion

WHAT makes a shelter

t-----WHAT-else-is--necessary

ALPHMPARTICLES TILAV* ONLYMOUT AN INCH IN AIR ANDAXE STOPPED SY A SHEET OFPAPER OR THE SKIN TISSUE

SETA.PAIDCLES TRAVEL A FEW FEET IN MRAND ARE STOPIID SY AN INCH OfWCr00 OR A THIN SHEET OF ALUMINUM

GAMMA-RAYS TRAVEL NUN.,DREDS OF FEET INAIR AND ARE REDUCEDSY THICK LEAD ORCONCRETE

INTRODUCTION,

10.1 As we haye seen in previous,chap-ters, the residual nuclear radiation fromfallAt presents a number of difficult andinvolved problems. This is iq not only be-cause the, radiatiOns are invisible, and re-quire special instruments -for their detec-.tion and measurement, but also becalise of,the widespread -and long lasting characterof the fallout,- In the event of a surfaceburst of a high yield nuclear weapon, thearea 'contaminated by the fallout could 1/e'expected to extend well beyond that inwhich casualties result from blast, ther--mai radiation, and the initial nuclear ra-diation. Further, whereas the other effectsof a nuclear explosion are over in a fewseconds, the residual radiation persists fora considerable time.

10,2 In Chapter 6 we learned that ra-dioactive material .released by a nuclearexplosion consists of: (1) radioactive parti-cles created by the fissioning of the bombmaterial, (2) particles made radioactive byneutrons released at the time of explosion,

142

°WIVEoh, v P

1?-S 4.9.09

FIGURE 10.2,-Three kinds of nuclear radiation.

(3) the unfissioned material of the bombitself. The unfis'sioned material is oner-allyelpha emitting, while the'fission prod-ucts and the neutron-induced radioactiveisotopes are beta-gamma emitters. SeeFigure 10.2 to refresh your memory aboutthe penetrating power of the.3 major kindsof radiation.

PROTECTION FROM-EXTERNAL RADIATION

10.3 To protect against external radia-tion, (basically gainma rays), there arethree tfiings you can put between you andthe fallout causing the radiation: TIME,DISTANCE, AND A SHIELD. Protectionis'provided by: (1)1controlling the length oftime of exposure; (2) controlling the dis-tance between the body and the source ofradiation; and (3) placing an absorbingmaterial between the body and the sourceof radiation. 4

10.4 It is not generally possible to useonly one factor of. protection. The factor-oftime is always involved, that is, time isusually used in combination with distance,

_

54

shielding, or both. For comparison, con-sider the problem of protecting the eyes'from ultraviolet rays when taking a sun-bath. Ultraviolet rays may be harmful tothe eyed. A certain amount can be toler-ated, but beyond this point dainage maybe eaused. The eyes can be protected inthree ways. First is to regulate.the time

ebt "tinder the sunlamp. Second. is toregulate the distance maintained betweenthe eyes 'and the sunlamp. Third is toshield the eyes with sunglasses. The den-ser the glasses, the more ultraviolet raysare filtered out and therefore an individ-ual can be closer to the lamp and staythere a longer period of time without hurt-ing his 4,7es. In order,to understand eachof the three factors of protection, it isnecessary to discuss them separately.

TIME

10.5 For simplicity, let us disregard thedecay of the radioactive materials in fal-lout and assume that we are in an areawhere the exposure rate remains constantat 25 R/hr. In one hour, we would beexposed to 25 roentgens ofradiation. If westayed 2 holm's, we would be exposed to 50R. If we stayed 4 hours, our exposurewould be 100 R, and for an 8 hour stay wewould receive an exposure of 200 R. Thus,time-could he u-Seil as a protective measureby keeping the period of exposure down toan absolute minimum. For instance, ifwork must be done in a high radiationarea, the work should be carefully plannedto minimize the stay time in the con-

ma area.10.6 As iscussed in Chapter 8, the

cay of radioactive materials will cause theradiatio levels from fallout to,decreasewith time. In the early periodetter deto-nation, the decrease in, exposure rates isvery rapid. At later times, the decrease isnot as rapid because the longer lived fis--sion products make the majoricontributionto the exposure rate. Knowledge of thegeneral decay pattern of radioactive fal-lout suggests an additional w,ay in whichtime is important. All work in contami-nated areas should be postponed as longas practicable after the detonation of nu-

clear weapons in order to permit radiationlevels to decrease,. It should be remem-..bered, however, that it is possible for ra-diation levels to inerease after long pe-riods of.decreasing exposure rates, be-_cause of the deposition of additional fal- -

lout.

DISTANCE

10.7 The effect of distance from a fal-lout field is iomettmes misunderstood.When the distances are large in relation tothe size of the radioactive source,. the ex-posure rates decrease by the square of thedistance from the source. This ,!`inversesquare law" can be an effective protectivemeasure when using the sealed sources(sometimes called point sources) in aDCPA Traiatig Source Set. However, in afallout field, which consists of billions of"point sources" spread over large areas,the inverse squa're law is of no value to aRADEF Officer in computing the decreasein exposure rates with distance from con-taminated areas.

10.8 the fact that exposure rates dodecrease with distance from a fallout fieldwill be very important to us, however,when we discuss the protective features oflarge buildings later 'in this chapter. Dis-tance is also important to the RADEFOfficer when,he considers the use of decon-:thmination as a radiological countermeas-ure. An area called a buffer 'zone is us-ually decontaminated around a vital facil-ity to increase the distance of the falloutfield from the facility. The function of thebuffer, zone is to reduce the gamma expo-sure rate which originates in the sur-rounding unreclaimed area.

SHIELDING

10.9 You will.recall that the damagingeffects of gamma rays comes from the factthat the rays strike electrons in the bodyand knock them out ot their orbit, and ifthis happens to sufficient electrons in thebody, radiation injury occurs. If vie wish tostop a high proportion of the rays beforethey get to us, we can place between our-selves and thesource of the radiation amaterial which has a lot of electrons in its

1471

043

makeup. The more electrons there are inthe makeupof the material the more ra-diation will.be stopped.

10.10 Figure 10.10 shows lead andwater in a kough comparison of theiratomic makeup. Sinee lbadi has a lot moreelectrons in the orbits of each ato thandoes Water, lead makes a bqffer shieldthan. water.

10.11 Figure 10.11 shows the relativeefficiencY of various shielding materials.These materials are efficient in about the'proportions shoWn cm the chart In stop-

. ping the same amouIt t of gamma. Variousshielding materials a uSed in variousapplications, depending ip n the purposeto be se ed. Lead, for instance, is quitecompact and is most suitable where spacerequirements are a factor, On the otherhand, Water is used where it is necessaryto see through the shielding material andto work through it with a long-handledtool to perform necessary operations, suchas, in processes in atomic plants wheresawing or cutting the radioactive mate-rials is necessary:

10.12 When considering fallout shel-ters, protection is generally achieved intwo ways: One metho.d is to place a barrierbetween the fallout field and the individ-

I LEAD

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FIGURE 10.11,Relatiye efficiency of variouLshielding materials'.

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WOOD

WATER

FIGURE 10-10,--Comparison between lead atom andwater molecule.

ual. This is termed "barrier shielding."The second method is to increase the dis-tance of the individual from the falloutfield contributing to the individual's expo.'sure. This is termed "geometry shielding."

10.13 In most analyses it is necessaryto consider the effects of both barrier andgeometry shielding. This is termed "com-bined shielding."

10.14 The heavier the barrier betweenfallout and the individual, the greater thebarrier shielding- effect. Examples of bar-riers in structures are walls, floors, andceilings.

10.15 Geometry shielding is determinedby the extent of the fallout field affectinganindividual, and/or his distance from it.Consiaer an example of geometry shield-ing.

10.16 If two buildings are of the sameheight and similar construction, but ofdifferent area, the protection from groundcontamination would be greater on thefirst floor in the building with the .largerarea. On the/ other hand, if two buildingsare of equal area and similar construction,but differ in height, protection fromground contamination would be greater onthe upper floor of the higher building.

THE SHELTER PROTECTION FACTOR -

10.17 - The effects of geometry shieldingand barrier shielding are combined into aterm very useful for considering the effec-tiveness of various types of shelters. Thiscombined term is TI-IE PROTECTION

4 8

4.

FACTOR: One definition is: a calculationof the relative reduction in the amount ofradiation that would be received by a per-son in a protected location, compared tothe_amount he would receive -if-he wereunprotected in the saX44oca ion. (SeeGlossary for the diffeince bet out-

- side/inside ratio and protection faCtor.).10.18 If a shelter has a protection fac-

tor of 100, an unprotected person at thesame ocation would be exposed to 100times'i ore radiation than someone insidethe shelter. -,

,

41: 10.19 Where conditions are favorable,ded protection can be had for little extra

cost: 1,Vhfie licensed public shelters have amimmum of PF 40, a higher degree ofprotetion up to say 1,000 is advantageous.This ill fxequently be possible in buildingprotec Ion into new structures.ae .

10.20',_ There are two ways to go aboutsetting up adequate shelters: COMMU-NITY ACTION and FAMILY VICTION. Itshoifk be stressed that they ae not mu-tually exclusive. In fact, they supplementeach ther in a very necessary way. Mostpeopl spend the largest part of their timeat o near their homes and there arestro g sociological advantages to keepingfanii y grouPs together in a time of crisisand, ardship. However, for many people itis n t practical to truct home shelters.And, even if one p sesses-the finest shel-ter n the world,j it will do no.good if he iscau ht away from home at a time of dan-ger us fallout.

PU LIC SHELTERS

11.21 Further, experience in Europe in. W. rld War II and other human experi-en es under disaster conditions hp.vepo nted to distinct advantages of the pub-lic shelter when compared-with the familysh lter. There are several reasons whyg up shelters are preferable in many cir-c mstances:

A larger than family-size group prob-ably would be better prephred to facea nucleaT attack than a singllparticularly if some members shouldbe away from home at the time ofattack.

FIGURE 10.22,-Grouy shelte'ring in a large building.

2. There would be more opportunity tofind first aid and' other emergency,skills ina group, and the risk of radia-tion exppsure after an attack could bemore 'widely shared.Commynity shelters would provideshelter for persdns away from their

Jairg-nes at the time of an attack.4. Group Slielters could serve as a focus

for integrated community recoveryactivities in a postattack period.

5. Group shelters could serve other corn-munity purposes, as well, as offer pro-tection from fallout following an at-tack.

10.22 These are the reasons why theFederal _Gov,ernment has been involved_with a number of activitiesinvolving-gUltdance, technical assistance, andmoheyto encourage the development ofpublic shelters. The overall program,

° which got underway with the Nationalat,

4 145

She lter urvey, aims at securing shelteirsin exist'ng and new structures, markingthem, an making them availEible to thepublic, in_,an emergency, Where there areriot enough public shelters to accommo-date all citizens, efforts are being made topr,ovide more. ,In some cas6s, such dslarge cities, it may net be possible to buildindividual family fallotit shelters. Groupihelters Auch as illustrated in Figuh;10.22may be required to provide adequate pro-tection in such situations. /FAMILY SHELTERS

*A Home Sheltfr Mag Save Your Life10.23 Even though public fallout Lhel-

ters usually offer many advantages overome shelters, in many lacesespecially

:suburban and rura there are fewpublic shelters. If theresis one near you, ahome fallout shelter may s ye your life.

10.24 The basemena o some homesare usable as famili fal ut shelters asthey now stand, without any alterations orchangesespecially if the house has twoor more stories, and its basement is belowground level.

10.25 However, most honje basementsvAuld need some imprdvements in order to

FIGURE 10.24.Home basement.

'Paragraphs 10.23 through 10.57 ar from the DCPA. publication "InTim. of-Emergency," H-14, March 10.58.

shield their occupants adequately from,the radiation given off by fallout particles.Usually, householders can make these im-

'provments thems ves, with imoderate ef-fort and at low co t. Millions of/homeshave been suzvey for the Defense CivilPreparedhess Agency (DCPA) by the U. S.Census Bureau, and these householderShave received inforthation .on how muchfallout protection their basements wouldprovide, and how to improve tr:iis .protec-

, tion. . ,

Shielding Material Is Required10.26 In setting up any home fallout

shelter, the basic aim is to plaC enough"shielding material" betwe e ople inthe sheltei and the .fallout particles out-side.

10.27 Shielding material is any sub-stance that would absorb and deflect theinvisible rays given off by fallout particles

-outsye the house, and thus reduce thearhotilit of radiation reachirT the- -occti -pants of the shelter. The thicker or denserthe shielding material is, the mkre itwould protect the shelter occupants.

10.28 Some radiation protection is pro-vided by the existing; standard walls and'ceiling of-a basement. But 4f they arethick or dense enoukh, other shielding ma-terial will have tojip added.

10.29 Concrete, bricks? eartt and sandare some of the, materials that are denseor heavy enough to provide fallout protec-,tion. For comparative purposes, 4 inches ofconcrete would provide the same shieldingdensity as:

5 to 6 inches of bAcks.6" inches of sand or gravel.

(May be packed into bags, cartons,-boxes, or other containers for easier.--handling.) ' I

7 fnches of earth.-

8 inches of hollow concrete blocks (6inches if filled with sand).

10 inc s of water.14 incIks of books or magazin....18. inches of wood.How to PreRare a Home Shelter10.30 If there is no public fallmit shel- -

ter near plur home, or if you would prefer

to use a famfiy-type shelter in a time ofattack, you should prepare a home falloutshelter. Here is how to do it:

10.31 A PERMANENT 'BASEMENTSHELTER. If ybur home basement--.-orone corner of itis below ground level,your best and easiest action 'would be toprepare a permanent-type family shelterthere. The required shielding materialwould cost perhaps $1004200, and if youhave basic carperitry or masonry skills youprobably could do the work. yourself in ashort time.

.10.32 Here,ere three methods of provid-ing a permanent family shelter in the"best" corner of your home basementthat is, the corner which is most belowground level.

ceiling Modification Plan A10.33 If-nearly all your basement is

below ground level, you can use this pranto build a fallout shelter area in one cor-ner of it, without changing the appearance

, r )14,

'41

ofit or interfering with its normal pOW use.

10.34 However, if 12 inches or mo e ofthe basement wall is above ground I vel,this plan should not be used unless uadd the "optional walls" shown in thesketch.

10.35 Overhead protection is obtainedby screwing plywood sheets securely, tothe joists, and then filling the spaces be-tween the joists, with bricks or concreteblocks. extra beam and a screwjackcolumn may be needed to support the ex-tra weight.

10.36 Building this shelter requiressome basic woodviorking skills and about$1504200 for materials. It can be set upwhile the house is being built, or after-ward.

Altd-nate Ceiling Modification Plan B_10.37 This is similar to Plan A except

that new extra joists are fitted into part ofthe base.ment ceiling to support theadded

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optional walls

beam

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screwjack column

FIGURE 10.33,--Cei1ing modification Wan A.

EXISTINGJOISTS

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half basementceiling width

FIGURE%7,A1ternate ceiling modification Plan B.

weight of the s 'elding (insteag of using abeam and a so ewjack column).

10.38 The new wooden joists are cut tolength and notched at the ends, then in-stalled between the existing joists.

148

half basementceiling length

10.39 After plywood panels are screwedsecurely' to the joikts, bricks or concreteblocks are then packed tightly into thespaces between ..the joists. The bricks orblocks, as well as the joikts themselves,

152

will reduce the amount of fallout radiationpenetrating downward into the basement.

10.40 Approximately one-quarter of thetotal basement ceiling should be 'rein-forced with extra joists and shielding ma-terial.

10.41 Important: This plan (like PlanA) should not be used if 12 inches or moreof your basement wall is above groundlevel, unless you add the "optional walls"inside your basement that are shown inthe Plan A sketch.

Permanent Concrete Block iv?. Brick Shel-ter Plan C

10.42 This shelter will provide excellentprotection, and can be constructed easily

ii

at a cost of $150 in most parts of thecountry.

10,43 Made of concrete blocks 0? bricks,the shelter should be located in the cornerof your basement that is most belowground level. It can be built low, to-serveas a "sitdown" shelter; or by making ithigher you can have a shelter in whichpeople can stand erect.

10.44 The shelter ceiling, however,should not be higher than the outsidegroudd level of the liasement corner wherethe shelter is luated.

10.45 The higher your basement isabove ground level, the thicker you shouldmake the walls and roof of this shelter,

Place entranceway onside or e'ral not facing' -x"posed Gesement wall

Increase thlbkness of shelter wallfacing expoSed basement wail bYfour Inches

Fy6RE 1.0.42,Permanent concrete lock or brick shelter plan C.53

149

FIGURE 10.49.--Preplannedtv

since your- regular basement walls willprovide only limited shielding against out-side radiation.

10.46. Natural ventilation is providedby the shelter entrance, and 6.37 the airvents shown in ihe shelter'wall.

10.47 This shelter can "be used as astorage room or for other useful purposesin non-emefgency periods.

A Preplannecl Basement Shelter10.48 If your home has a basement but

you do not wish to set up a permanent-type basement shelter, the next best thing

1.50

snack bar shelter plan D.

would be to arrange to assemble a "pre-planned" home shelter. This simply meansgathering together, in advance, the shield-ing material you would need to make yourbasement (or one part of it) resistant tofallout radiation. This -Material could bestored in or around" your home, ready foruse whenever you decided to set up yourbasement shelter. Here are two kinds ofpreplanned basement shelters.

Preplanned Snack Bar Shelter Plan D10.49 This is a snack bar built of bricks

or concrete blocks, set in mortar, in the

FIGURE 10.51.Preplanned tilt-up storage unit plan E

1-4

"best" COrner of your basement (the cor-ner that is most below ground level), Itcan be converted qUickly into a falloutshelter by lowering a strong, hinged "falseceiling" so that it rests on tile snack bar.

, 10.50 When the false ceilingis loweredinto place in a time of emergency, thehollow sections of it can be filled withbricks or concrete blocks. These can bestored conveniently nearby, or can be usedas room dividers or recreation room furni-ture (see bench in Figure 10.49).

Preplanned Tilt-Up Storage Unit Plan E10.51 A tilt-up storage unitin the best

icorner of your basement s anothermethod of setting u'p a "preplanned" fam-ily fallout shelter.

10.52 The top of the storage unit shouldbe hinged to the wall. In peacetime, theunit can be used as a bookcase, pantry, orstorage facility.

10.53 In a time of emergency, the stor-age unit can be tilted so that the bottom ofit rests on a wall of bricks or concreteblocks that you have stored nearby.

10.54 Other. bricks or blocks shouldthen be placed in the storage unit's' corn-, partments, to provide an overhead shieldagainst fallout radiation.

FIGURE 10.56.Covering base ment.wi ndows

10.55 The fallout ptotection offered' byyour home basement also can be increasedby adding shielding material to the out-side, exposed portion of your basementwalls, and by covering yotir basement win-dows with shielding material.

10.56 You can cover the abovegroundportion of the basement walls with earth,sand, bricks, concrete blocks, stones fromyour patio, or other material.

10.57 You also can use any- of thesesubstances to block basement windowsand tbus prevent outside fallout radiationfrom entering your basement in that man-ner.

INDIVIDUAL PROTECTIVE MEASURES

10.58 If the presence of fallout is sus-pected before an individual can reach shel-ter, the following actions will help mini-mize its effects.

1. Cover the head with a hal, ora_piof cloth or newspaper.

2. Keep all outer clothing buttoned orzipped. Adjust clothing to cover asmuch exposed skin as possible.

3. Brush outer clothing periiidically.4. Continue to destination as rapidly as

practicable.10.59 Assume that all persons arriving

at a shelter or a fallout monitoring stationafter fallout arrival, and 'all individualswho have perl'ormed outside missions arecontaminated. All persons should followthe protective measures below: .

r. Brush shoes, and shake or brushclothing to remove contamination.This should be done before entering,the shelter area.

2. Remove and store all outer clothingin an isolated location.

3. Wash, brush, or wipe thoroughly, cpn-taminated portions of the skin andhair being careful not to injure theskin.

COLLECTIVE PROTECTION

10.60 buring fallout deposition, all win-dows, doors, and nonvital vents in shel-tered locations should be closed to control

155 151

the contamination entering th9'.' shelter.Similar protective measures sh6uld be ap-plied to vehicles.

10.61 :When radiation levels becomemeasurable inside the shelter, make a sur-vey of all shelter areas to determine thebeist protected locations. Repeat this pro-cedure periodically. This information isused to limit the exposure of shelter occu-pants.

I

TASKS OUTSIDE OF SHELTER

10.62 When personnel leave shelter ap-propriate protective measures should betaken to prevent the contfrmination oftheir bodies. Clbthing will not protect per-sonnel from gamma radiation, lnit will pre-vent most airborne contamination fromdepositing on the skin. Most clothing issatisfactory, hosiever, loosely woven cloth-ing should be avoided. Instruct shelteroccupants to:

1. Keep time outside of shelter to a mini-mum when exposure rates are high.

2. Wear adequate clothing and cover asmuch of the body as practical. Wearboots or rubber ,galoshes, if a'vailable.Tie pants cuffs over them to avoidPossible contamination-of feet and an-kles.

,3. A'void highly contaminated areaswhenever possible. Puddles and very .dusty areas where contamination ismore probable should also be avoided.

4. Unger dry and duSty conditions, do,not stir up dust unnecessarily. IfIdusty conditions mrevail, a man's;hankerchief or a folded piece ofclosely woven cloth should be wornover the nose and mouth to keep theinhalation of fallout to a minimum.

, 152

5. Avoid unnacessary contact with con-taminated surfaces such as buildingsand shrubbery.

10.63 Individiials using vehicles foroutside operations should remain in thevehicle, leaving it only when necessary. Toprevent contamination of the interior ofthe vehicle, all windows and outside ventsshould be close.d when dusty conditionsprevail. Vehicles provide only slight pro-tection from gamma radiation but they doprovide excellent protection from beta andprevent contamination of the occipants.

FOOD AND WATER

10.64 To the extent practicable, pre-vent fallout from becoming mixed intofood and water. Food and water which isexposed to radiation, but not contami-nated, is not harmed and is fit for humanconsump4n. If it is suspected that foodcontainersNraicontaminated,Ihey shouldbe waNhed or wiped prior to removal of thecontents. Food properly removed fromsuch containers will be safe for consump-tion.

10.65 Water in covered containers andunderground Sources wiil be safe. Beforethe arrival, of fallont, open supplies ofwater such as cisterns, open wells, orother containers should he covered. Shutoff source bf supply of potAhtiaily contami-nated water.

REFERENCES

The Effects of Nuclear Weapons.Glas-stone, Samuel, 1964,

Handbook for Radiological Monitors.DOD/OCD, FG-E-5.9, April 1963. -

In Time of Emergency, DCPA H-14,February 1977

1!7't_, 0

RADIOLOGICAL DECONTAMINATION

Although there are many forms of pro-tection against nuclear radiation, as welearned in the preceding chapter, they areobviously not foolproof. Even if they were100% effective, there is still the case ofunavoidable contamination, contaminationwhich could occur during the performanceof a critically important mission, contami-nation which ,could be deliberately andknowingly accepted. Obviously, then,. weneed anothr RADEF tool to take care Ofcontamination. That tool is DECONTAMI-NATION and this chapter will explain:

HOW to tell if decontamination isnecessary

WHAT are the `steps in decontamina- Idon

HOW does a decon worker protecthimself from contamination

WHAT should be done to decontami-pate an area, a structure, anorange, somebody namedHenry, a cat, the power com-pany, a ,red sportshirt or a-farm tractor

INTRODUCTION

11.1 Closely allied with the problem ofmonitoring, discussed in Chapter 9, is the

.problem of decontamination. The two are,in fact, closely linked and cooperation andcoordination between monitors and decon-tamination personnel is a basic require-ment if wasted effort or unnecessary haz-ard are to be avoided.

,

WHAT IS CONTAMINATION?

11.2 As we saw in Chapter 6, the radio-% active fallotit froni a nuclear explosion

consists of radioisotopes that have at-tached themselves to- dust ,paiticles or

/57

CHAPTER 11-

water droplets. This material behavesphysically like any other dirt,or moisture.In fact, the phenomena of radioactive con-tamination is exactly the same as getting"dirty" EXCEPT that very small amountsof "dirt" are required to produce a hazardand that the "dirt" is 'radioactive.

WHAT IS DECONTAMINATION?

11.3 The objective of radiological de-contamination is to reduce the contamina-tion to an acceptable level with the leastpossible expenditure of labor and mate-rials, and with radiation exposure to de-contamination personnel held to a mini-Mum commensurate with the urgency ofthe task. RadioactiVity cannot be de-stroyed or neutralized, but in the event ofnuclear attack, the fallout radiation haz,ard could be reduced by removing radioac-tive particles from a contaminated suffaceand safely disposing ofthem, by coveringthe contaminated surface ivith shieldingmaterial, Such as earth, or by isolating aconiathinated object and, waiting for theradration from itfto decrease thiough theprocess of natural radioactive decay,

11.4 This ghapter is directed' te thosepersons who are responsible for planningand establishing radiological decontami-nation operations in States and localities.It contains guidance on the yarious typesof decontamination procedures and therelative effectiveness of each.

DtCONfAMI4ATION 'OF' PERSONNELAND CLOTHING-

11.5 State and local public welfare de-partments and agencies, as the welfarearms of their respectiv,e governments,have primary resporisibility for planningaod preparing the facilities and develop-

153

1

ing capabilities essential to provide emer-gency welfare at the local level. Voluntarysocial welfare agencies will assist.

11.6 Decontamination of personnel andclothing of personnel engaged in recoveryoperations would be the responsibility ofthe various operational services, such asfire departments, police departments, anddecontamination teams. Many personswould be responsible for decontaminationof themselves and their familieS in accord-ance with instructions of the local govern-ment.

PERSONNEL

11.7 It is important that all people, andparticularly those directing emergency op-erations, understand that the total radia-tion injury from fallout is a composite dueto several causes, including contaminationof the surrounding areas, contaminationof skin areas, iind ingestion and inhalationof fallout -materials. -To keep the total ra-diation injury low, the effect of eaCh po-tential source of radiation on the totalradiation exposure must be kept in mind,and each contributing element should bekept as low as operationally feasible. Nor-mally,*ordinary personal cleanliness proce-dures will suffice for personnel decontami-nation in the postattack period.

11.8 All persohs seeking shelter afterfallout starts should brush or shake theirouter clothing before entering the shelterarea. Ordiifary brushing will remove mostof the contaminated material from theshoes and clothing, and often may reducethe contamination to, or below a permissi-ble level. It is important to brush or shakefrom the upwind side. Under rainy condi-tions, the outer clothing should be re-moved before entering the shelter area.

Upon entering the shelter area and assoon as practicable, wash, brush, or,wipethoroughly the exposed portions of thebody, Mich as the skin and hair. If suffi-cient quantities of water are availahle,persons should bathe, giving particular at-tention to skin areas that had not beencovered by clothing.

154tz- 3

THE INJURED

11.9 It is desirable that -contaminationof medical facilities and personnel be keptat a minimum. Medical personnel, whoseskills would be needed for the saving oflives, should be protected from radiationto the extent feasible. Persons entering amedical treatment station or hospitalshoulkbe monitored, decontaminated ifnecessary, Old tagged to show that he is-not contaminated. To do this, a check pointcould be established at a shielded locationat each medical treatment Ikation andhospital. Although decontamination proce-dures for the injured are the same asthose previously described for personneldecontamination (i.e., the removal of outerclothing, and other clothing if necessary,and finally the washing of contaminated

%body areas, if required) special factors alsomust be considered. In the face of urgencyfor decontamination, there will be manycasualties who are unable to decontami-nate themselves and whose cohdition willnot permit movement. For...some- cases aemedical examination will determine thatfirst aid must take priority over decontam-ination. Also, it may not be possible t)decontaminate some casualties without se-.riously aggravating their injuries. Thesewill have to be segregated in a controlledarea of the treatment facility.

CLap.IING

11.10 Thorough decontamination ofclothing cari be deferred until after theemergency shelter period when supplies ofwater and equiment are available. Equip-ment for decontamination of clothing in-cludes whisk brooms, or similar types ofbrushes, vacuum cleaners (if available)and laundry equipment. For more effec-tive decontamination of clothing, washerand dryer equipment should be available.Since there is normally little accumulationof "dirt" in a washing machine, virtuallyall of the decontaminant would be flusheddown the drain. The chance of significantresidual contamination of the washing ma-chine appears to be qtkite ,small. Althoughthere is little serious danger involved in

washing, direct contact with the contami-nation should be kept to a miniumum.

_ 11.11 The procedures for decontamina-tion of clothing should be as follows: First,brush or shake the clothing outdoors; sec-ond,.vacuum clean; third, wash; andfourth, if the previous procedures are noteffective, allow natural radioactive decay.Monitoring of the clothing upon comple-tion of each step will indicate the effective-ness of the decontamination procedureand indicate any need foil further decon-tamination. In many cases, dependingupon the amount and kind of radioactivecontaminant, brushing or simply shakingthe clothing to remove the dust particlesmay reduce the contamination to a negli-gible amount. If two thorough brushingsdo not reduce the contamination to anacceptable level, vacuum cleaning shouldbe attempted. Care should be taken indisposing of the contaminated materialfrom the dust bag of the vacuum cleaner.If the clothing is still contaminated after&ry methods of decontamination are com-pleted, it should be laundered. Clothingusually can be decontaminated satisfac-torily by washing with soap or detergent.

11.12 Any clothing that still remainshighly contaminated should then be storedto alloW the radioactivity to decay. Stor-age, should be in an isolated location sothat the contaminated clothing will notendanger personnel.

DECONTAMINATION OF FOOD,AGRICULTURAL LAND AND WATER

11.13 State and local public agencies,assisted by radiological defense personnel,will be responsible for the decontamina-tion of food and water. Stored foods inwarehouses, markets, etc., will be the re-sponsibilitS7 of the agency controlling thedistribution of the food items. Water sup-ply personnel of the local government orprivate organizations will be responsiblefor mbnitoring, and if required, decontami-nation of the water supplies they operate.Each personior family not expecting to beprotected in a 'community shelter, is re-sponsible for providing, before attack, suf-ficient food and water to supply its needi

for at least 2 weeks, since outside assist-ance may not be available during thisperiod.

FOOD

11.14 The following _guidance is pro-vided for individuals and groups who needto use food which may have been contami-nated with fallout. Before opening a foodpackage; the package should be wiped orwashed if contamination is suspected.Caution should be taken when yiping orwashing outer containers to avoid cptam-inating the food-itself. When possible, thepackage surface should be monitored witha radiation detection instrument beforeremoving the food as a check on the effec-tiveness of the decontamination proce-dure.

11.15 Meats and dairy products thatare wrapped or are Icept within closedshowcases or refrigerators should be freefrom contamination. Fallout on unpack-aged meat and other food items could pres-ent a difficult salvage problem. Freshmeat colloid be decontaminated by trim-ming the outer layers with a sharp knife.The knife should be wiped or washed fre-quently to prevent contaminating the in-cised surfaces.

11.16 Fruits and vegetables harvestedfrom fallout zones in the first month pos-tattack may require decontamination be-fore they can be used for food. Decontami-nate fruits and vegetables by wafhing theexposed parts thoroughly to remove fal-lout particles, and if necessary, peeling,paring or removing the outer layer in sucha way as to avoid contamination of theinner parts. It should be possible to decon--taminate adequately frUits, such as ap-ples, peaches, pears, and vegetables, suchas carrots, squash, and potatoes, by wash;ing and/or paring. This type of decontami-nation can be applied to many food itemsin the home.

11.17 Animals should be put undercover before fallout arrives, and shouldnot be fed contaminated food and water, if -uncOhtaminated food and water are. avail-able. If the animals are suspected of beingexternally contaminated, They should be

159 155

washed thoroughly before being-processedinto food.

11.18 Even when animals have re-ceived sufficient radiation td cause latersickness or death, there will be a shortperiod (1 to 10 days following exposure,depending on the amount) when the ani-mals may not show any symptoms of in-jury or other effects of the radiation. rfthe animals are needed for food, if theycan be slaughtered during this time with-out undue radiation exposure to theworker, and if no other disease 'or abnor-mality would cause unwholesomenesst themeat would be safe for use as food. In thebutchering process, care should be takento avoid contamination of the med, and toprotect personnel. The contaminated partsshould be disposed of in a posted locationand in such a manner as to present anegligible radiological or sanitation haz-ard. If any animal shows signs of radiationsickness, it should not be slaughtered forfood purposes until it is fully recovered.This may take several weeks or months.Animals, showing signs of radiation sick-ness (loss of appetite, lack of.vitality, wa-tery eyes, staggering or poor balance)should be separated from the herd becausethey are subject to bacterial infection andmay not have the recuperative powersnecessary to repel diseases. They couldinfect other animals of the herd.

AGRICULTURAL LAND

11.19 The uptake of radioactive falloutmaterial would be a relatively long termprocess, and the migration of fission prod-ucts through the soil Ivould be relativelyslow. Therefore, crops about to be har-vested at the time fallout occurs would nothave absorbed great amounts of radioac-,

.tive material from the soil. However, ifcrops are in the early stages of growth inan intense fallout area, they will absorbradioactive materials through their leavesor roots and become contaminated. Thus,if eaten by livestock or man, it may causesome internal hazard. Before use, the de-gree of contamination should be evaluatedby a qualified person. Foods so contami-nated could not be decontaminated easily

156 160

because the contaminants would be incor-,.

orated into' their- cellular structure. Donot destroy these contaminated foods.

11.20 4iming of acid soil will reduce theuptake of strontium since .the plant sys-tem has a preference for calcium overstrontium and has some ability to discrim-indte. The plant's need for calcium leads tothe absorption of the similar elementstrontiuni. In' soils low in exchangeablecalcium, more strontium will be taken upby the plant. By liming acid soils, morecalcium is made avaijable to the plant, andless strontium will be absorbed.

11.21 Another methono limit the up-take of strontium is to grow 'crops with lowcalcium content such as potatoes, cereal,apples, tomatoes, peppers, sweet corn,-squash, cucumbers, etc., on areas of heavyfallout. Other foods with high calcium con-tent such as lettuce cabbage, kale, broc-coli, spinach, -celery, collardS, etc., could begrown in areas of relatively light fallout.

WATER

11.22 Following a nuclear attack, waterin streams, lakes and uncovered storagereservoirs might be contaminated by ra-dioactive fallout. The control of internalradiation hazards to personnel will be de-pendent, in large part; upon proper selec-tion and treatment of drinking water.

11.23 If power is not available forpumping, or if fallout activity is too heavyto permit operation of water treatmentplants, the water stored in the home maybe the only source of supply for severalweeks. Emergency sources of potablewater can be obtained from hot watertanks, flush tanks, ice cube trays etc. It isadvisable to have a 2-weeks emergencywater ration (at least 7 gallons per person)in or near shelter areas.

11.24 Emergency water supplies maybe available from local industries, particu-larly-beverage and milk bottling plants, orfrom private supplies, country clubs, andlarge hotels or motels.

11.25 If contaminated surface watersupplies must be used, both conventionaland specialized treatment processes may.-be employed to decontaminate water. The

degree of removal will depend upon thenature of the contaminant (suspended ordissolved) and upon the specific radionu-clide content of the fallout..- 11.26 Radioactive materials absorbed

iii precipitates or sludges from watertreatment plants must lie disposed of in asafe manner. Storage in low areas or pits,Or bdrial in areas where there is littlelikelihood of contaminating undergroundsupplies, is recommended.

11.27 Several devices for treating rela-tively small quantities of water underemergency conditioni have been tested.Most of them use ion exchange or absorp-mt

tion for removal of radioactive contami-nants.

a. Small commercial ion exchange unitscontaining either single or mixed-bed res-ins, designed to produce softened or demi-neralized water from tap water, could beused to remove radioactive particles fromwater. Many of them have an indicator,which changes the color of the resins toindicate the depletion of the resins' capac-ity. Tests of these units have indicatedremovals of over 97 percent of ali radioac-tive materials.

b. Emergency water . treatnient unitsconsisting of a colunin containing severala-inch layers of sand, gravel, humus,coarse vegetation, and clay have beentested for removal of radioactive materialsfrom water. This type of emergency watertreatment unit remov,ed over 90 percent ofall dissolved radioactive materials.

c. Tank-type home 'water softeners-arecapable of removing up to 99 percent of allradioactive materials, and are especiallyeffective in the removal of the hazardousstrontium 90 and cesium 137 contami-nants.

DECONTAMINATION OF VEHICLES ANDEQUIPMENT

11.28 decontamination of vehicles andequiPment of the various operational serv-lees,,,such,as fire departments, police de-partments, and decontamination teams,will be the responsibility of the variousservices, aided by radiological defensesirvices. Individuals will be responsible

for decontamination of their own vehiclesand equipment in accordance with instruc-tions of local government.

EXTERIOR OF VEHICLES AND EQUIPMENTAND,VEHICLE INTERIORS

11.29 The simplest and most obviousmethod for partial decontamination of ve-hicles and equipment is by water hosing.Quick car-washing facilities are excellentfor more thorough decontamination.

11.30 Special precautions should beused when vehicles and equipment arebrought in for maintenance. The malfunc-tioning part of*the vehicle or equipmentshould be checked for excessive contami-nation.

FIGURE 11.31.Equipment decontamination.

11.31 Hosing should not be used on up-holstery or other porous surfaces on theinterior of vehicles, as the water wouldpenetrate and carry the contaminationdeeper into the material.

11.32 The interior of vehicles can bedecontaminated by brushing or vacuunicleaning. Procedures for decontaminatinginteriors of vehicles by ,,vacuum cleaningare similar to those used orr the interior ofstructures.

VEHICLES AND EQUIPMENT'USED BYDECONTAMINATION PERSONNEL

11.33 Upon completion of missions in acontaminated area, vehicles and equip-ment used by decontamination personnelhould be monitored, and decontaminated

1 61 ,

157

if necessary. Complete decontaminationmay,not be necessary, but attempts shouldbe made to reduce the hazard to tolerablelevels.

11.34 A decontamination station set upat a control point adjacent to the stagingarea would be the best place for decontam-inating vehicles and equipment. A pavedarea would be desirable so that it could behosed off after the equipment is decontam-inated. Monitoring should follow the appli-

n of each decontamination method.

DECONTAMINATION OF VITAL AREASAND STRUCTURES

11.35 The operational planning aspectsof decontamina0on of vital areas andstructures are very complex and requiretrained decontamination teams from gov-ernment services, industry, and privateand public utilities under the direction of adecontamination specialist. All methodsdescribed in this chapter are commontechniques With which personnel of theemergency services are generally familiar.Operational details associated with use ofthe equipment are not discussed. Howl.ever, operational aspects peculiar to ra-diological -recoverY are emphasized. Themethod of decontamination selected willdepend upon the type and extent of con-tamination, type of surface contaminated,the weather and the availability of person-nel, material, and equipment. Each type ofsurface presents an individual probleniand may 'require a different method ofdecontamination. The type of equjpment'and skills required for radiological decon-tamination are not pew. Ordinary equip-ment now available,'such as water hoses,street sweepers, and pulldozers, and theskills normally usedLin operating theequipment are the basic requirements forradiological decontamination.

PAVED AREAS. AND EXTERIOR OFSTRUCTURES

11.36 Decontamination of paved areasand the exterior surface of structures re-quires two principal actions; loosening thefallout material from the surface and re-

158

moving the material from the surface to aplaCe of disposal. Some decontaminationmethods for paved areas are street sweep-ing and motorized flushing. Firehosingmay be used for both paved areas and theexterior of structures.

11.37 Street sweeping is termed a drydecontamination method because water isnot used. There are many advantages ofthis method over wet methods. In the ab-sence of adequate water supplies for largescale decontamination procedures, drystreet sweeping would be the preferredprocedure. Also, during told weather, wetdecontamination procedures may not bepractical.

11.38 Most commercial street sweepershave similar operating characteristics. Apowered rotary broom is used to dislodgethe debris from streets into a conveyorsystem which, transports it to a hopper.Thus, a removal and bulk transport sys-tem is inherent in the design. Some swee-pers utilize a fine water spray to dampenthe turface ahead of the pickup broom tolimit dust generation. This use of a sprayprevious to brushing would reduce the ef-fectiveness of the procedure for decontam-ination because the combination wouldtend to produce a slurry which wouldmake complete removal of surface contam-ination more diffictilt.

11.39 A variation in equipment of thistype is the sweeper in wiiich the broomsystem is enclosed in a vacuum equipped

FIGURE 11.38,Commercial street sweeper.

04. t)

using. The material picked p by theroom and the dust trapped by he filtorsre collected_in a hopper.11.40 Normally a single opera or is re-

uired per street sweeper. Howe er, be-ause fallout material would be oncen-rated in the hopper, the operator ay be

jected to a high yadiation ex ()sure.may make it necessary to rota e per-

nel for street sweeping operation . Theperator should he instructed to k ep a

close check on his dosimeter, and dumpthe hopper often at the predesignatedposal area, as precautions to keep his ac-cumulated radiation evosure low.

11.41 In decontamiAating paved areasby street sweeping, decontamination fac-tors' better than 0.1 can be realized, de-pending upon the- rate of operation andthe amount of fallout material.

11.42 The flushing or sweep'ing actionof water is employed in decontaminatingaved areas by motorized flushing. Con-entional street flushers using two for-ard nozzles and one side nozzle under a

ressure of 55 pounds per square inch (psi)re satisfactory for this purpose. In flush-

i g paved areas, it is important that fal-1 t material be moved towards drainagefa ilities.

1.43, Decontamination factors of 0.06to u .01 can be realized by motorized flush-ing, depending upon the rate of operationand he type and roughness of the surface.

11. if The flushing oresweeping actionof water also is used in decontaminatingpaved areas and the exterior of structuresby fir hosing. Equipment and personnelare co monly available for this method.Employ ent of the method is dependentupon an \ adequate postattack water sup-ply. Whe decontaminating paved areasand struct res, it is,important that falloutmaterial b swept toward predesignateddrainage f cilities, and, where possible,downwind fr m operational personnel.

11.46 Standard fire fighting equipmenLand trucks equipped with pumping appa-ratus may be 4sed in this decontamination

.' For decontamination of vital areas and.structurea the term decon-

tamination factor (11F) is used This represents the decimal fractionremulnlflX after decontamination is accomplished.

method. The most satisfactory operatingdistance from kozzle to the point of impactof the water stream with open pavevientsis 16 to 20 feet. On vertical surfaces, thewater should he directed to strike the sur-face at an angle of 300 to 45°. As many asthree men per nozzle may be required forfirehosing.-

11.46 When decontaminating roughand porous surfaces or when fallout mate-rial is wet, the use of both firehosing andscrubbing are recommended for effectivereduction of the radiation hazard. Initialfirehosing should be flone rapidly to re-move the bulk of fallout material. Hosingf011owed-gy scrubbing would remove r..estof the remaining contaminAtion. Two addi-tional men per hose my be required forthe scrubbing operation.

11.47 Decontamination factors between0.6 and 0.01 can be realized by arehosingtar and gravel roofs with very little slope,and 0.09 to 0.04 in decontaminating compo-sition shingle roots that slope 1 foot inevery 21/2 feet. Decontamination factors of0.06 can be realized in firehosing.of pave-ments.

UNPAVED LAND AREAS

11.48 Decontamination of unpaved landareas can be accomplished by removingthe top layer of soil, covering the areawith uncontaminated soil, or by turningthe contaminated surface into the soil byplowing. The two latter methods employsoil as a shielding material.

11.49 The effectiveness of any of the-methods is dependent on the thoroughnesswith which they are carried out. Spills urmisses and failure to overlap adjoiningpasses should be avoided. Reliance shouldbe placed on radiation detection instru-ments to find such areas, although inheavily contaminated areas the falloutmaterial may be visible: Large spills ormisses should be removed by a second paisof the equipment. Small areas can be de-contaminated with the use of shovels,front end loaders, and dump trucks.

11450 Large scale scraping operationsreqd-lre heavy motorized equipment toscrape off the top layer (several inches) of

113 159

-`8

'Lb

14111,

FIGURE 11.48,Turning contaminated soil.

ocontaminated soil, and. carry the soil tosuitable predesignated dumping grounds.'The contaminated soil should be deposited'100 Or more _feet beyond the scraped areairposiible; if not, at least to the outer edgeof the scraped area. Scraping can be donewith a motorized scraper, motor grader, orbulldozer. Effectiveness of the proceduredepends upon the surface conditions. Indecontaminating unpaved areas by scrap-ing, decontamination factors over 0.04 canbe realizecl, if all spills and misses arecleaned up.

11.51 The motor grader is designed !qr.,grading operations, such as for spreadingsoil or for light stripping. This grader canbe'etffecive1y on any long marrowarea where contaminated soil. can bedumped along the edge of the cleared area.The blade should be set at an angle Suffi-cient for removing several inches of thecontaminated soil. The scraped Up earthshould be piled along the ground in awindrow parallel to the line of Motion. Thewindrow can be either pushed to the sideof the, contaminated field and buried bythe grader or removed by other pieces ofearthmoving equipment.

11.52 The bulldozer can be useful inscraping small contaminated areas, bury-ing material, digging sumps for contami-nated drainage, and in back;filling sumps.It would be' particularly suitable in roughterrain where it could be used to clear

,obstructions and as a prime mover to as-sist in motorized scraping. The contami-

,

160

,nated soil stripped, off by a bulltrocershould be deposited at tile outer edge ofthe scraped area, or beyond, if prvticable.

11.53 Filling nray offer no advantagfover scraping, either in, effectiveness orspeed, Its principal use would be herescraping procedures could not be/u5ed,either because of rocky ground or,kfecatiseof permanent obstructions. Fill' g can beused in combination with oth9f methods toachieve a low decontaminati n factor. Theobject of filling is. to cove the contami-nated area with uncontami ated soil or fillmaterial to provide shiel mg. For these'operationka motorized scraper, bulldozer,,mechanical shovel, or dump trubk andgrader may be used. ,

11.54 'The effectiveness of rela-tively flat surfaces will vary with thedepth of fill. A 6-inch fill of earth canreduce the radiological hazard directlyabove, ton decontamination factor of 0.15,and a 12-inch fill can redlice the hazard toa cicontamination factor of 0.02.

11.55 Plowing prOvides earth shieldingfrom radiation by turning tbe contanti-nated soil under., It is a rapid rneam1/4 ofdecontamination, but may not be suitablein areas in ,which personnel must oAeraieor travel over the ploweg surface. Medepth of :plowing should be frOm 8 to 10inches. In decontaminating unpaved lividnreas by plowing, decoptamination lactor$of 0.2 can be realized if the depth of plo*ing is from 8 to 10 inches.

11.56 Two or more methods can be-ap-plied in suCcession, achieving a reductionin the radiation field not possible, practi-cal, or economical with one method alone.Any of three combinations of methods-7scraping and filling, scraping and plowing,or plowing, leveling!and fillingcould" beeffective in unpaved areas In solpe cases,any of the three might be more ra icIthanindividual remoylit of spillage: Th equip-ment used would be the same as in c mpAt-nent methods Previously discussed.

11.57 Because large earthmovingequipment could not be used in Omanareas, such as those around a building,othe: methods of decontarnination must beused. If the area is ldrge enough for a

C 4

*small garden type tractor, orloaders,: these can be uSed fer plo ing andscraping the soil. Improvised methods ofserapint small areas, such as using a jeepto tow a manually operated bucket scoop,

--'--could -be -used: Tfrere -Would ieinain sonteareas. requiring hand labor with shovels,to dig up or.iemove the'top layer of soil, orsod. Equipinent and manpower require-,ments for-loading and hauling the soil-to adisposal area should be included in esti:mate of decontamination "costs". Therates of operation of these methods wouldVary with the type of terrain.and its vege-..

tative cOver. The various procedures canresult in decontathination factors of 0.15 to

el*

INTERIOR OF STRUCTURS

,..4:111313 The two principal methods for de-,. ft contaminating interiors of structures are

vacuum cleaning and scrubbing With soapand water:Vacuum cleaning is useful forthe decontamination of furniture, rugs,and floors. Floors, tables, walls, and othersurfaces can be decontaminated by scrub-bing(th-e-"i)t with soap and water. Mild de-.tergents can be substituted for soap. Rags,hazid brushes (ot power-driven rotarybrushes, if available), mops, and broomsare suitable for scrubbing.

-

COLb WEATIER DECONTAMINATIONPROCEDURES

11.59 pold weather .deconbapation,methods will depend upon the weatherconditions prior to and after the arrival offallout.:Yarious problems such as fallouton various depths of snow, on frozenground 9r pavement, mixed with snow orfreezing. rain, and under various depths ofsnow could occur after a contaminatingattack.' The iiresence of snow or ice wouldcomplicate the situation 'since large quan-tities of these materials would have. to bemoved along with the fallout material. Inaddition, snoW anrze-coUld cause loss ofm9bility to men and to equipment. Falloutmay bd clearly visible as a dark film orlayer of soil or powder on or within snowunless it precipitates with the snow,

p

11.60 The principalAold wealther decon-11tamination methods for paved areas, andstructures are: (1) Snow loading, (2) sweep-ing, (3) snow plowing, and (4) firehosing.

X461 Snow loading, is accomplishedwith -a front-end leader and is applicablefor snow'covers.: When fallout is on snow,the front-end loader bucket is used toscoop up the contaminant' andlop layer ofsnow, which are ferced into the bucket bythe forward mOtiOn of the .vehicle. Thesnow cover sheuld be observed closely forpieces of contaminated debris ',vhich mayhave penetrated to some depth. The-loadercarries the contaminated mateiial to ,adump truck which removes it to a dunipingarea. The 'remaining 'clean snow is re-moved by normal snow-removal proce:.dures. DecontaminationJactors of appro)fi-

. mately 0.10 can be realiied by- this process,depending mainly Tel--the amount-of spil,lage.

FIGURE 11.61,Front-end loader.

11.62 Pavement sweepers ca be died -:for fallout on dry-paveinent, traffiepac,kedsnow, or reasonably leVel-frozen soil or ice.Pavement sweepers, are more effectivethan firehosing where there is a drainageproblem, or whe,n temperatures are frlow.Sweepers will not effectively pick up con-taminant on wet pavement above tljefreezing or slush point on ibe or pa'ckedsnow. Decontamination factprs are ap-proximately 0110.

11:63 Snow plowing is applicable for alldepths of contaMinated snoW. When fat-

461

185

lout is iiieCipitated with snow,. all of thesnow must be removed to the dumpingarea. Blade snowplows, road graders, orbulldozers in echelon,' windrow the con-

_ taminated snow to qne side until the bladesare stalled by the snow mass. A snowloAder can be used to put- the contami-nated snow in dump trucks, which move itto tlie clumping area., Decoptaminationfactors 44 0.15 can be realized by thismethod.

11.64 Firehosing is Dossible and can beused on paved areas and exteriers,ofstrUctures slightly below freezing temper-atures. Pirehosing is npt recommend dwhere slush from snqii will clog drainProblems associated with firehosing below32° F are freezing of the w'ater, therebysealing the contaminant in ice and caiisingSlippery conditions for the operating per-sonnel. The principle of operation, andequipment used° in temperate weather,will be the same under cold weather condi-tions. The effectiveness of firehosing willdepend on surface and standard exposure

rates, and the decontamination factorwill vary from 0.5 to 0.1.

11.65 In small areas, such as roofs ofbliildings, and around buildings, wherelarge snow remoVal equipment could notbe used, other methods of decontamina-tion must be used. With small amounts ofdry snow on roofs or paved areas, sweep-ing, the area with .brooms is satisfactory.With larger amounts of snow, with thefallout material on top of the snow, ormixed with the snow, shoveling the snowand removing it to an area where largesnow removal equipment can be used ispiacticable. The ratespf operation of thes-e-methods Would, vary with the amount ofsnow to be remolied 'aud the type of sur-face to be decontaminated. 'The.,yariousrocedures can result in decontaminationetors of 0.1510 0.1.11.66 In order to locate needed services

.and to guide the movement of decontami-nation equipment (through .heavy snowcovers, cololed poles should mark streetcorners, drains, hydrants and hidden ob-

.

AGEN4 ' TYPE OF SURFACE' SITUATIONS

iTEAM,

.

cPAINTED OR OILEDi NONPOROUS.

.

.ROOMS WHERE CONTAMINATED SPRAY _CANBE CONTROLLED. BOILDNGS;

-...sl%.

DETERGENTS,

NON-POROUS '(METAL, PAINT, PLASTICS:-ETC.). INDUSTRIAL 'FILMS,OILS, GREASES.th

.

SURFACE COVERED WITH ATMOSPORICDUST-AND GREASE. FIXED OR MOVABLEITEMS.

COMPLEXING-AGENTS

-METAL OR PAINTED.

-f_AS-AN:ADJUNCT1

LARGE , UN WEATHERED SURFACE. SURFACE-Si-WHERE CORROSION IS NOT TOLERABLE.'

TO WATER. OR STEAMTRE-ATMENT.' 1

* ORGANICSOLVENTS PAINTED OR GREASED.

-.

FINAL CLEANING. WHERE COMPLETE IM-MERSION DIPPING OPERATIONS AREPOSSIBLE. MOVABLE ITEMS. T..

,

* INORGANICACID

METAL OR PAINTED;tSPECIALLY THOSEEXHIBITING' POROUS DEPOSITS, SUdii ASRUST, MARINE GROWTH. ..

DIPPING OF MOVABLE ITEMS.

* CAUSTICS PAINTED. . LARGE, SURFACES. DIPPING OF PAINTEDOBJECTS.

ABRASIONS METAL AND PAINTED LARGE, WEATHERED SURFACES. FIXED ORMOVABLE ITEMS.

* UNUSUAL HAZARDS ARE ASSOCIATED WITH THESE METHODS, AND SPECIAL PRECAUTIONS ORPROTECTIVE EQUIPMENT AND,REQUIRED.

.

1

,

FiGURE 11.67.Small scale decontamination methods.

_

stacles. Open ground areas planned for REFERENCEpostattack use should be cleared of rocks,

Decontamination Considerations Forstumps, etc., prior to the arrival of snow.Architects and Engineers, DCPA TR 7111.67 Figure 11.67 lists other decon-

1976tamination method's that may be used on asmall scale, for specific areas of high con-tamination.

-

41%

a."

,

a

0H_.4. to

,..

163

CHAPTER 12

RADEF OPERATIONS_

The man-in-the-street often thinks ofmodern war a,s "push button war" withVisions of all our forces moving automati-cally at the pressing of a button on' thePresident's desk. This just isn't so, ofcourse. If there is no' such thing as "pushbutton war", how Much more so is thereno such thing as "push button radiologicaldefense." We may have sensitive machinesand instruments to measure nuclear ra-diation, but these devices must be, oper-ated/ interpreted and the informationacted upon. It is the prime objective of thischapter to exPlain how and by whomRADEF operations are carried out, andhow the responsibilities for such opera-tions vary among different types ofRADEF personnel and within the variouslevels of government.

INTRODUCTION.-

12.1 To be effective, radiological de-fense countermeasures require rapid de-tection, measurement, reporting, plotting,analysis, and evaluation of fallout contani-ination for use during the early. periodafter attack and trained radiological per-sonnel are needed at all levels of the gov-ernmentFederal, State, and local, to pro-vide such information and skills.

12.2 The RADEF Officer and otherRADEF personnel, in carrying out theirresponsibilities, act in a "staff" ratherthan in a "command" capacity. They pro-vide an important part of the technicalinformation upon which Civir Prepared-ness command decisions Will be based.

12.3 It must 'be stressed that thouglxRADEF prsonnel serve in a staff capac-ity at the various levels of government,fallout radiation, is a physi,cal not apoliti-canhenonienon. Ii) short, fallout doe's notrecognize city, state, or county bounda-164

ries. As a consequence, effective RADEFcountermeasures demand cooperationvong the various RADEF crfanizations.This cooperation must beboth horizontaland vertical: horizontal among organiza-tions on the same level of government(e.g., different 'counties or States); verticalamong levels (e.g., city and State). Also,cooperation must not wait until an at-tackit must be planned for and workedat'noia.

WHO WILL CARRY OUT RADEFOPERATIONS?

12.4 To carry out the various funeionsof radiological defense, there is need forRadiological Defense Officers, AssistantRadiological Defense Officers, Monitors,Analysts, and Plotters. The following par-agraphs define each of these positions andsummarize duties and responsibilities.These definitions are necessary at thispoint to avoid repetition in the later level-by-level description of the operationalprocess.

DEFINITIONS

12.5 Radiological Defense Office);.Aperson who has tieen trained to assumethe, responsibility for policy recemmenda-dons for the radiological defense of aState, county, locality, facility, or a rela-tivelyiarge group of organized personnel.

This officer must be conyersant withmeasurement and reporting protedures,capable of evaluating the probable effectsof reported radiation on the people and'their environment, and capable of recom-mending appropriate prOtedive measures

Istich as,.ernecrial mover/lent, shelter, andecontanunatton) t bitaken as a result ofthe evaluation.

1 r.

12.6 Assistant Radiological Defense 01.-ficer.Definition similar to that of theRadiological Defense Of ic Less admin-istrative capability is.require , ut the

-capabilities- iMechabove d'teshould be borne in mind that the .term"assistant" is an organizational di4inc-tion rather than indicative of anythingless than 100% possession of all necessaryRADEF Officer qualifications.

"12.7- Monitor.A person who has beentrainvd to detestjecord, and report radia-

...

tion Otiposures and exposure rates. He willprovide limited field guidance on radiationhazards associated with operations toWhich he is assigned.

12.8 Ana/vatA person who has, beentrained to prepare monitored radiologicaldata in analyzed form for use in the areaserved as well as by other levels of govern-ment to which reports of such data aresesty.1:givill also evAluate the radiationde tierns as a basis for estimates offuture exposure rates and radiation expo-

., sures associated with emergen-ey opera-.tions.12.9 Plotter.A person trained to re--

cord incoming data in appropriate tabularform and to plot such data on maps. Hewill also perform routine computations un-der direction.

LEVEL7BY-LEVEL RADEF OPERATIONS

12.10 F'qllout monitaiing station activi-ties.Upon receipt of warnink of likelyattack, monitors (at least four should beassigned to each station to-provide 24-hourcontinuous monitoring), will be advised ofthe likelihood of attack. They will thenbegin to carry out the emergency plan.Upon arrival at the monitoring station, allequipment and procedui.es shoUld bechalked and an operational readiness re-polt made to the emergency operatingcenter (EOC) RADEF Officer, thuslrerify-ing that the station is ready to opeiate.The monitoring stAtion will send the EOCa FLASH REPORT the first time the uric-sheltered exposure rate equals or exceeds0,5 R/hr. The station alsmends seheduled'EXPOSURE RATE REPORTS and EXPO-

PORTS .vhen'ever)a declining rate.trend isreversed and there is a rapid increase.

1'NOTE

F'or thc monitoring station, and for alllevelsythe time before fallout arrives isa time of intense activity. Notr a mo-ment should be log' by RADEF person-nel between afrivta at assigned loca-tions and performance of all prescribedreadiness actions.

*12.11 Shelter monitoring activities.Aftet checking hia equipment, the shelterMonitor will make an operational -readi-ness report to the shelter manager (who,in turn, will report that fact to the EOC).The shelter monitors will measure andreport to the shelter manager the dailycumulative exposure of shelter occupants.Thjs in-shelter exposure will be reportedto the EOC if it exceeds 75 R. Should thisbe exceeded during the first two days inshelter, or_ should the exposure rate ex-ceed 10 R/hr, an EMERGENCY REPORTshould be sent to the EOC requesting ad--vice. The shelter monitor will also reportto the shelter manager as to the dailyexposure rate. Should any occupied area ofthe shelter be receiving a fire" of 2 R/hr ormore, the monitor will'report on the expo-sure rates within various areas of theshelter so that the manager may moveshelter cupants to safer positions in the

r. The shelter may also be desig-as station in the regulak monitor-

which instance the opera-in paragraph 12.10 will

also be performed.

shenaing netwtione escrib

12.12 The Ideal emergency operatingcenter.Local emergency operating cen-ters first determine that monitoring sta-tions are in a state of operational readi-ness. Subsequently, the local EOC's willreceive reports from these monitoring sta-tions and shelters and will transmit sum-mary-type data to the State EOC. In addi-tion, and as previously agreed upon, thisdata, can be made available to neighboringEOC's. The eeports to the State EOC willinclude flash reports made .a_pon their re-ceipt-from aity of the monitoring stationswithin the network of the local EOC. Expo-SURE REPOIO'S, plus SPECIAIr RE- ,---inirmd exposure rate reports will also be

165

--/("' Q1.

made in summary form .to the State EOCas determined by the State Civil Prepared-neth Plan. The exposure rate report willinclude a-typical exposure rate if the areawithin the jurisdiction of the local EOC issmall. The local EOC's will also report theaccumulated unsheltered exposure atleast once each day to the State EOC. Itshould be noted that the term "local EOC"ig used here to designate the operatingechelon or echelons between the monitor-ing 'statioN and the State EOC. (A verylarge gity.may_baxe.local area EOC'sSand-

---wiched- in between the stations and thelocal EOC's.) In addition, some States mayhave county EOC's between the local and

_State .EOQ's...Tbese various EOC's mayreport to a:gab:State EOC depending onthe State's-geography and population.

12.13 The State Emergency OperatingCente.r.This _is_ the commons' level foreach State's Civil Preparedness organiza-tion. The State EOC receives reports fromlocal, local area, county and/or sub-StateEOC's within the State and will, in turn,send to the approprjate DCPA regionaloffrce flash reports summarizing thespread of fallout across the State as wellas exposure rate analyses. The State EOCwill also send selected flash reports asappropriate to the local EOC to alert them

_ _DLapproaching fallout and exposure ratereports to advise local centers of exposurerates in neighboring communities. Neigh-boring States, in addition, and Canadianprovinces can also be sent flash repor,tsand exposure rate analyses by the StateEOC. State EOC's tied into a national

tat

166 .)

RADEF system through the DCPA re-gions to which they report.

12.14 In addition to collecting and re-porting data, RADEF Officers at the State(sometimes sub-State) level have :the re-sponsibility of providing the data for fal-lout warning and other fallout advisoriesissued to the general j2opulace by the Gov-ernor or other properly, designated civilauthority. There are many possible typesof advisories which could be issued de-pending upon local conditions.

EMERGENCY OPERATING CENTERPERSONNEL

12.15 Communities over 500 population,State and county governments, and cer-tain field installations of Federal agenciesrequire other radiological defense person-nel in addition to monitors. These are theRADE-F- Officers, Assistant RADEF Offi-cers, Plotters, and -Analyst.b -located at--EOC's. Their functions were summarizedin paYagraTh-Thrt2:rtinZa."-As irrule, ruralareas will need only monitors. The numberof Assistant Radiological Defense Officerswill depend on community size. Large ci-ties will require several, while small com-munities may require none,

12.16 A suggested guide to the numberof Analysts and .Plotters for communitiesof various sizes is shown in Figure 12.16. ARadiological Defense Officer can "doublein brass," filling in for a variety of RADEFpersonnel where no other individual isavailable to perform the particular func-trim.

POPULATION- PLOTTERSNEEDED

ANALYSTSNEEDED

Under 2,500 1 1

2,500 to 25,000 1 1

25,000 to 250,000 4 2

Over 250,000 6 3

. .

-

FIGURE 12.46.Requirements guide for p14ters and analysts.

1

NOTE

This 4.-s a "one-way street," however,becausean analyst for example, CAN-NOT perform the...frnctions of a Wa-diotogecal Defense Offiesrunless he ISa Radiological Defense Officer.

A REPORTING NETWORK

124/ The monitoring stations must be

linked into a well organized and extensivereporting system, running up through thesub-State and State organization all the.way to-the national center. It is vital thatthe data. produced at each level shouldsupport the higher levels. Also, data mustbe consistent between and among report-ing levels. No correcCconclusions can bedrawn from data that employ different,units of measurement or time bases.

I "7

167

1.

CHAPTER 13

RADEF PLANNING

In a church in Caracas, Venezuela, apickpocket, hoping to stir up some excite-ment, duiiing -which he could work moreea*, shouted "Fire." There was no firebut the congregation stampeded anyway.When the screaming mob finally burst outof the church, many huddled forms wereleft behind, trampled and broken. Fifty--three of them, including 22 children, wouldnever discover that there wa.s.no fire.

After the Titanic smashed agai,st aniceberg a Mrs. Dickinson Bishop left $11,-000 in jewelry behind in her stateroom,but asked her husband to dash back topick up a forgotten muff. Another passen-ger_ on the sinking vessel, Major ArthurPeuchen, grabbed three oranges and agood-luck pin, overlooking $300,000 in se-curities he had in his cabin. Still anotherpassenger carried into the lifeboat nothingbut a musical toy pig.

There are, 'countless cases of personswho in their haste to escape hotel fires,jump from upper story windows locatedjust few feet from a fire escape.

The cause of this strange and illogicalbehavior is panic and the cure is planning.The major objective of this chapter is todescribe the importance of planning toeffective Radiological Defense. ,

THE EXPERIMENTAL EVIDENCE

was held by one of the participants in theexperiment. The idea, of course, was topull the cones out of the bottle. Whenconditions such as we might have during asudden emergency arose and there was"every man for himself", traffic jams oc-curred. Sometimes but one or two coneswere jerked free before the rest werehopelessly snarled.

But, when the participants were giventime for prior consultation and planning,there were no trahic jams. In one instanceall the cones were removed in under, 10seconds.i.

13.2 But what happens when there areno plans? We saw the experimental evi-dence. Cones get jammed. Strings gettwisted. The evidence of real life is just assimply stated: people get killed and in-jured; property iets destroyed. li,is saidthat casualty statistics are people with thetears wiped off. Let's look behind the sta-tistics and examine a few of the legion oftearful stories.

THEY HAD NO PLANS

13.3 A bustling city of -30,000 was lc=cated at the point where two swift streamsmet. The city was built along the low riverbanks, surrounded by .steep hills. As aresult of this situation, the lower pait ofthe city suffered from floods every spring.

13.4 Upstreanf was a huge dam, origi-13.1 In a series of 42 iaryin experi= nally built to gtore water for a cAnal but

ments With from 15 to 21, subje ts, the %.. -Nprogress made the canal uneconomical, sopsychologit Alexander Mintz clearly .It was abandoned and maintenance haltedshowed the yvide differenc,e between on the dam. Gradually the dam deterio-

planned and unplanned 'behavior in a pe- rated. Water seeped out in a hundred pla-riod of stress. The experimental situation ces and within a few years the water levelconSisted -of a large glass bottle with a had dropped to half...When a small breaknarrow mouth. Inserted in this bottle were -

a Rumber of aluminum cones. These cones ' Nip-Adaptive Group Behavior, Alexander Mintz, Readings in Socialwere attached to strings each _of which, Psychology, p. 190-195, Hehry Holt & Co New York, 1952

16$" 9

btcurred, the water level was low and onlypart of the city was flooded.

13.5 Subsequently, a hunting and fish-ing club leased the dam and the lake itimpounded. The club tried to repair thedam. Their work seemed sound. But intothe break had been dumped tree stumps,sand, leaves, straw and other debris. Lateron, heavy rains caused many leaks in thedam and floods in the city.

13.6 Finally, there was an even heavierrainfall. After six-inches of rain, the waterlevel in the dam rose rapidly. Crews hiredby ihe hunting and fishin'g club worked torepair the leaks but therising waters kepteating away at the rotten structure.

13.7 Finally, a civil engineer inspectedthe dam. He realized it would not hold andtried to get word to the ,city below. Therewere no telephones and the storms haddowned the telegraph wires. Word did notget through: MeanWhile, the workerswatched in horror as the waters began toroar over the tppof the dam racing for the

'ciry, 12 miles away and 400 feet lower inelrvation.

13.8 A half million cubic feet of waterrushed through that breach oicking up onthe way trees, houses, boulders. When itreached, the city it'was a wall 30 feet highmoving at- 20 miles an hour. The result:annihilation! The city was destroyed, and2,000 people lost their lives in an instant ofterror.

13.9 But the disaster'need never havehappened had the warnings of the damitself been heeded during the precedingquarter century. Even if no efforts hadbeen made to remove the causethe ob-viously unsound condition of the damitseems unbelievable that no one plannedfor a possible serious break, and no oneplanned a warning system.

AND STILL NO PLANS

13.10 But we need not go all the wayback to the Johnstown flood to see theeffect of lack of planning. The greatestmanmade disaster in recent Americanhistory;is replete with examples of lack ofplanning, from its ,beginnings in the holdof a sh.ip in Galveston Bay to its end a few

hours later in a devastated city, ravagedto the tune of 552 dead, 3,000 injured andmaimed and over $50,000,000 in propertydamage.

13:11 It all began with a few w ofsmoke froin the cargo of fertiffier carriedon board the SS Grandeamp. A crewmaninvestigated, but even after shifting sev-eral bags of the fertilizer, he could findnothing. He tried throwing buckets ofwatec in the, direction of the smoke. Noeffect!. -Next he tried a fire extinguisher.Still- no effect. So Iae called for:a fire-hose.'But the foreman objected. Hosing downthe cargo would ruin it. The Captain or-dered the hatches battened down and theturning on of the steam jets. Turning onsteam to "fight fires is standard marinefirefighting Practice, and has been foryears. But this fertilizer was ammoniumnitrate, which, when heallbd to about 350degrees Fahrenheit, becomes a high explo-.sive.

13.12 Someone should have known howto deal with this explosive fertilizer. Some-one should have made plans for putting mita possible fire in or near the nitrate,. Butno one had. And so, at 12 minutes after 9on the Morning of April 16, 1947, the 10,-419-tog Grandeamp and all those aboardwere blown to bits. The explosion, calcu-lated as equivalent to 250 five-ton block-busters (1.25 kilotons) going ff at once,dropped 300-pound pieces of lhe Grand-camp 3 miles away. Two sm ll planes,flying at about 1,000 feet above he harbordisintegrated from thd tronen ous con-cussion. The blast swept across çhe com-plex of oiI refineries and chemica plants,smaihing them flat and setting o f otherexPlosions and fires.

_13.13 As a result of this explosion andthe later and even more violent blast fromanother ammonium nitrate laden ship, theSS High Flyer, chaos reigned in TexasCity. Though the citizens of_ the cityworked with courage and initiative to helpthe injured, for the first few hours theirwork was uncoordinated.

13.14 Thve was no disaster plan.13.15 The head of the Texas City disas-

ter organization is quoted as saying: "We

169

had an organization, but it was designedfor hurricane. We weren't prepared foranything like this. In a hurricane, youhave some warning and' you can get yourorganization ready. But we had no warn-ing in this, and our organization was scat-tered all over town. And do you know whathappened at our meeting to develop a dis-aster organization just 3 weeks before the

,explosion? People pooh-poohed the idea!'

.MORE. LACK_OF PLANNING,

13.16 On September 5, 1934, the SSMorro Castle steamed out of Havana har-bor. A seagoing hotel, the ship wascrammed with passengers heading back toNew Yort after a Carj4ean vacation. Theship wai equipped with all- the latestecluipment to detect, cpnfin and extin-guish fires.

13.17 Captain Wilniott was confident inthe fire safety of his ship: But 2 days laterhe was dead of a heart attack and hissecond in command had scarcely gottenaccustomed to being Captain wherl a decknight watchman reported a fire.

13.18 After investigating, a belatedalarm was sounded arld the crew tried toput out the fire. The ship was equippedwith fire doors which, if shut in time,might have kept the fire from spreadingpast the point If origin.

13.19 But nj one had been assigned toclose the fire doors. .

13.20 This, and other evidence of seri-ous planning deficiencies, caused the Act-ing Captain and Chief Engineer to be sent-enced to prison for incompetence and ne-glect of duty (they were later cleared by ahigher court) and the steamship line wasfined $15,000 for failure to enforce safetyregulations and for placing iniqualifiedpersonnel in charge of the ship. The finalcost was 134 dead and $4,800,000 propertyloss.

ANOTHER CATASTROPHE

13.21 Or take the case of the formerFrench liner Normand:ie. The lack of plan-\

'Quoted in THE FACE OF DISASTER, Donald Robinson. p. 130.Doubkday & Co., New York. 1959.

_ning is summed up in a straight-from-the-shoulder report of the National Fire Pro-tection Association:

"The fire-spreading conditions aboardthis vessel had been allowed to becomeso bad during the egecution of a $4,000,-000 conversion contract that a waywardspark from a cutting tool, inexcusablylanding in a kapok life preserver, wassufficient to culminate in the total de-struction of an uninAred $53,04000ship. Because although the incipientoutbreak started in broad daylight un-der the eyes of 1,750 employees of thecontractorplus another 1,650 Navy,Coast guard and subcontractor person-nelnot one of them had the rudimen-tary training required to stop thethingor -eVen the wit to promptly callin somebody with the training. By thetime,..the fire department was sum-moned, the blaze had advanced so farthat a fifth alarm was required, puttingto work more apparatus than is ownedby cities the size of St. Paul, Minn., orToledo, Ohio."

'A FINAL TRAGEDY

13.22 Finally, there was the CoconutGrove fire. ,

13.23 The Coconut Grove was manYthings. It was a fire trap infested withsafety violations (for which the owner waslater sentenced to prison for from 12 to 15years). If was the last hour for 450 per-sons. It was also an example of lack ofplanning, from the major, exit door thatopened inward (where some 100 bodiesWere found jammed), to the narrow stair-ways, to the inflammable decorations,even to the lack of planning in sending thevictims to hospitals.

13.24 BOston's City Hospital received129 fire victims, thus greatly overloalding'its facilities. Massachusetts General Hos-pital received only 39 and could have han-dled many more. Thirty other victims weredistributed arhong 10 other civilian hospi-tals. Seventy-eight percent were sent toCity Hospital simply because that is whereaccident victims usually were sent.

13.25 Na one planned for the disaster

when masses of people would simultane-ously, become the victims of accident.

....THEY HAD PLANS-

1:3.26 When an exploding ammunition_ship faced South Amboy, N.J., with thesame situation as Texas City, the mayorhad a disaster plan all set to go. Immedi-ately the rescue operation went into highgear.

13.27 Men knew where they were sup-.._p.osqd. t? go, and -they-went there:-Off-dutypace were automatically called in. Roadblocks controlled traffic keeping the sight-seers out and letting relief supplies in.Liaison was established, per plan, with theState Police and the National Guard.

13.28 The property destructiOn atSouth Amboy was nearly as great as -atTexas City ($36,000,000) but the loss of lifewas far less (31 dead):

PLANNING PAYS OFF

13.29 In what was termed "the mostsuccessful exercise . . . ever heacd of inthe United States", some 200,0V peopleevacuatfd low lying areas on the Texascoast to avoid hurricane Carla.

13.30 The succeSs and smooth function-ing of this gigantic movement had manyreasons. According to the Gov\ernor. ofTexas, "The success of evacuation was theresult of careful planning which began 10years ago in the Governor's office when itsDivision of Defense and Disaster Reliefwas set ap." A Red Cross official added,`.

. . critics said the Government waspouring money down a rathole (for plan-ning). It wasn'tit was this plan we wereable to use. The State has a CD plan andmade the plan workthat is .why we wereable to do so much"...

13.31- The head of the Texas Depart-ment of Public Safety, when asked whythe operation bad been such a resoundingsuccess, answered, "Why? It was done be-cause of preplanning and training". Acounty judge added, "Let people know thevalue of preplanning": In Louisiana, theLake Charles Civil Defense Office statedthat, "The biggest lesson of Carla was that

all of the of u into some 3 or 4 yearsof intense raining and planning paid off.When it was needed, the organization was-ready to foll-tit was only a matter ofcalling the staff together and giving them

_the job."3

EMERGENCY VERSUS CATASTROPHE13.32 Despite differences in dictionary

definitions, often the only real differencebetween an emergency and a catastrophe

-ispriorplanning.13.33 Perhaps the best concrete exam-

ple is the damage control system used byall major modern navies. Naval combatships are not designed from the standpointof wishful thinkingoptimistically hopingthat there will be no hits and do_ damage.Rather, naval vessels are designed withthe' point of view th4t the ship that cantake the most' punishment and still fighton is the ship that will survive and winvictory. Hence, naval combat vessels haveelaborate, but very practical, damagecontrol systems. These systems includewatertight compartments of various sizes,provisions for pumping, for counter-flood-ing to restore balance, of standby andauxiliary power, intensive training and ef-fective organization of the crew, and manyother features. All these are the result ofthe analysis of thousands of accidents atsea, naval engagements, and just plainhard, logical thinking. Thus, when a shipslides down the ways it is the product ofcountless plans, not the last of which isplanning to keep an emergency from turn-ing into a disaster.

AN IMPORTANT LESSON

13.34 You might well wonder what thepreceding paragraphs have to do with ra-diological defense planning as such. Howdoes the Morro Castle, the Coconut Grove,our Navy's damage control systems, orJohnstown, Pennsglvania, relate to theproblems of planning for ivil prepared-ness; what do the explosive qualities ofammonium nitrate have to do with de-

'Quotes from Department of Defense. Office of Civil Defense, Hurri-cane Carla p 93 Supermtendentof Documents, U.S. Government

Printing Office; Washington, D.C.

:,

fense against ,or recovery from n-uclearattack? The answer is both simple andlogical. -

13.35 The cases which have 'been docu-'mented above all serve as illustrations of asingle, vital truth. Namely, planning con-sists of a two-pronged approach to a poten-tial problem area which can be summa-rized as:

1. LOGICAL ASSUMPTIONS

2. PRACTICAL ANSWERS

This is no less the case for radiologicaldefense planning than for any other type.The sole purpose-is:if the preceding para-graphs has been to "set the stage" alongthese lines for our consideration ofRADEF planning which will follow.

RADIOLOGICAL DEFENSE PLANNING

13.36 In the previous Chapter, we tooka level-by-level look at the operations ofthe RADEF organization from the basicMonitoring station on up to_ the_Sta,teemergency- operating Center. We will fol-low this same procedure in this chapterbut, first, -some general comments onRADEF planning are in order.

WHERE DOES PLANNING ORIGINATE?

13.37 Though there is obviously a needfor careful planning in RADEF, most peo-ble are aware that, this does not meanthese plans can be finalized in Washingtonand shipped out to the States and local .communities to adopt and put into effect.On the contrary, with a country. as diverseas the United States, a plan worked toutfor,Chicago, or New York will not be !thesame, indeed -should not be the same, as aplan 'devised for a farm community or aseacoast area. An understanding of thewide diversity of the United States is be-hind the establishment of a Federal sys-tem of government by the Founding Fath-ers. They knew that differing situationsrequired different, methods. This is allotrue in RADEF, for at the various levels ofgovernment, state; county arirlocaCsomeradiological defense functions are similar,some are materially different and the em-

phasis on a given function may appropri-ately vary from level to level.

!PLANNING-RESPONSIBILITY RESTS ON-GOVERNMENT AT ALL LEVELS

13.38 At the community or urban level,detailed and current radiological intelli-gence would be essential for warning anddirecting the protective action to be takenby the local populace as-well as for controlof radiation exposure to personnel per-forming locally 'directed emergency andrecovery functions as called for in thecomplete 'Civil Preparedness plan.

13.39 At the higher levels of govern-ment, there is increasing responsibility forplanning, coordinating, and, as necessary,directing protective, remedial and recov-,ery actions and brograms beyond the ca-pabilities of the individual communities.In order to -perform such ,RADEF func-tions within the framework of the overallplan, the State, county or:local level needsareawide intelligence which is dependentupon reliable monitoring and reporting.

172

13.40 Each State has the major respon-sibility for planning, development and im-

-plementation of Civil Preparedness pro-grams, and intrastate administration ofFederal assistance for development of'emergency operation capabilities at localto State levels.

13.41 Although the State plan need notpresent complete detail of all purely localradiological defense operations, local capa-bility is a prime requisite for successfulstatewide operations and must be pro:vided for as a part of the 'more basic Stateplan. Having a State plan is, alone, justnot enough. !

NOTE

Don't forget: The primaty responsibil-ity for Civil Preparedness planning,and therefore RADE F, rests with theprimary legal authority for whatevergovernment unit is involved.

13.42 Once again, planning i the re-sponsibility of the Coorxlinator of Ciyil Pre---.paredness at each )evel. In 'large or com-plex jurisdictions; a special pranninggroup

1might be established to assist the

. -, fl

director in making the plan. This specialgroup should :work with him (or his dep.=uty). The members of such a group gener-ally should be relieved from all, or many.of their other duties to give major timeand attention to planning.

NOTE

When authenticated by the proper offi-cial, acting within the legal purview ofhis, authority, the Civil Preparednessoperational plan bears the full force oflaw.

13.43 Remember, a sound planning cyc.cle is a continuous planning cycle. Thereare excellent reasons for this.

NO PLAN WILL EVER BE COMPLETE ORFINAL

13.44 Many wars have been lost be-cause generals learned their lessons toowell and formed their plans too firmly. Thelessons they learned weie from the pre-vious war. They analyzed the tactics, theystudied the success and defeats, the ad-vances and retreats. They would nevermake those mistakes. And'they never did.They made new mistake's because,. whilelearning their lessons, and building plansori the basis of those lessons, the worldwas 'changing. New methods were appear-ing. Thus, the French army in World WarI, learning well the lessons of the previousFranco-Prussian War, deterrnined to at-tack, attack, always attack. Unfortn-nately, the introduction of machine guns,barbed wire, heavy artillery, and othe,r .

new weapons gave the advantage to thedefense. When the pride of France brokeagainst the German defense's in Alsaee-Lorraine, the war then passed into taphase dictated not by.old Rlans but by newweapons. Thousands of lives were lost togaibia few yards of soil. Any lessons basedon the early phase of World War I wouldequally have been incorrect during WorldWar II, for the tank, self-propelled artil-ler*, and parachute troops gave the initia-tive once again to the attack., 13.45- Yesterday's plans,often do not fittoday's, problemst, and those who will notlift their eyes from the plans to take a

3

hard look at reality may be doomed to facedisaster.,13.46 Anyone could Aroduce a plan, for

example to counter the Texas City disaster now that it is history. The real trickwould have been to plan for it before ithappened as was done in South Amboy.

NOTE

Remember, the, difference betweenemergency and castastrophe is plan-ning!

MONITORING STATION PLANNING,

13.47If Mr. Jones, newly appointedRADEF Officer for the town of Anywhere,U?S.A., were to address himself to thequestion of planning for the monitoringnetwork which he feels is necessary tosupport his radiological defense effort, thelogical starting point might well be, takenas the determination, in view of popula-tion and 'geography, of the total number-ofradiological monitoring stations he will re-,

quire. This may be logical but it is alsowrong!-' The Correct starting point wouldbe a careful perusal .of RADEF plans al-ready in existence for his city ok his coun-try or eiren his State.13.48 Every State has an emergency op-

erations plan already in existence. Someplans are better than others and, logically,some RADEF anneXes to these plans aremore complete than others. But, in anyevent, before Mr. Jones does any planning,he should check tosee how m4ch planninghas already been done. If he disagreeswith the plan, he has just discovered hisreal starting, point for building up, aADEF capability for the town. of Any-where, U.S.A.:

13.49 But suppose, for-the sake of argu-ment, Mr. Jones found a well-conceivedRADEF annex to his existing area- Civil,Preparedness plin, one which spelled out 'requirements, locations, numbers of moni-tors and so forth in 'complete and correctdetail.,Suppose, further that he inheriteda going monitor instruction program, hadall -the equipment' he reqUired- and had along waiting list of people begging him fora chance to be radiological Monitors. Give

"ij 173

him his full quotft of monitoring stIons;all with ,e Ootection factor of 100 plustwoway radios a'r well as telephones.-Would it be possible for him to still have amonitoring station problem in the midst ofall this plenty? .

13.50 The answer, of course, is yes. He_would have a very- definite problem in=spite of.all the RADEF assists spelled outebove if he could npt point to at least onemore plus feature, that of a functioninprograni of instrument maintenan , re-pair ahd calibration. His other e viable,RADEF assets would not count r' muchin an emergency if only, say % of hismouitoring equipment could be .either op-erated or relied upon.

9

13.54 Yes, it does, but only if Mr. Jonesso. wants ,to ignore the potential need for,perforrning tasks outside shelters. We canbe reasonably sure he won't, though, be-cause he recognizes there is more to moni-

, tering than just _taking readings and. re-porting them. We can rest assured thatau-r_Vz_ Jones will see to it that his planproyiggsfor adeqUate and continuous dis-Onfination of such important instruction.

SHELTER MONITORING PLANNING

13.51 knywhere, U.S.A., has a suffi-cient number of .public shelters and themost marginarprotection factor in any oneof them is at least ,100. Adequiate equip-ment is available and already in Place ineach shelter to permit it to perform itsselflprotecting monitoring function. Mr.Jones was pleased when he learned_ this,buf he was doubly pleased when he alsolearned that there was no personnel- re-quirement,for monitors, every shelter hadits full quota. Now, perhaps, lie can moveto one of his other RADEF prOblem areas?

13.52 If he does-move away from shelzter Monitoring at this point, he could beMaking a very big mistake. The availabil-ity of a- faellity, the required equipmentand the personnel to operate it are all

.essential ingredients fo a RADEF capabil-ity, true enough, but they are not suffi-Cient to guarantee it. A fourth teeter isrequire4, an all-iMportantlactor,'and that

,

13.53 ut let's say that Mr. Jones in-vestigates and finds that his local plancalls for a systematic series of field exer-cises on a {egular basis. One exercise se-ries hasp just concluded and every singlemonitor passed with flying colors. Theydemonstrated a firm grdsp of reportingiequirements. Surely, this would indicatethat training is maintained at an ade-quate leyel.

174

EMERGENCY OPERATING CENTERPLANNING 'LOCAL AREA1

13.55 By the time he began to review orprepare the portion of the local planwhichdeals with his ,own EOG, Mr. Joas hadlearned quite a few lessons about nUMTv-ing anything to chance. He aPproachedthis task carefully and thoughtfully, mak-ing certain, first pf all; that the ,selectedfacility was adequate both from the stand-point of sufficient space as well s suffi-cient space for thedisplay of RADIIF data.

13.56 Further, he made sure t at therewould beprovision F'or an adequ e staff ofplotters and analysts as- well as communi-cation personnel. When he realized thatthese people had t9 be trained, providedwith forms, penciI4 paper, pencil sharpe-ners, food, water, etc., etc., he began toworry about the.size of the job which facedhim as RADEF Officer.

13.57 One night he sat bolt upriglit inbed with the shocked -.realization that al-though he had taken care Of all of theiemany items in his EOC planning, he didnot know the protection' factor of thebuilding which would house the center!

13.58 He had, he realized, just takenthe appearance of the building at its facevalue and assumed that% its protection fee"tor would be satisfactory. He recognizedthe ,enorrnity of his mistake immediatelyand lost no time the next day before ask-ing and learning that the protection factorwas more than adequate (much to his re-lief).

13.5g But he did not recegnize his realmistake until it was pointed out by hiswife when he told her what had happened,or rather, what could have happened._

11 fl:f3

"G'eorge," she said, "it's simple. You needan assistant and that's all there 4. to-itrShe was right, of course, because GeorgeJones had made a very human mistake,one which is not confined to the ;tanks ofRadiological Defense Officers qther. He,had simply failed to notice the point atwhich he was "spreadinghiniselftoo thin"and his RADEF plan encompassed morearea than one man could handle.

13.60 While in the State capital on abusiness trip, George Jones dropped in onthe State 'i,adiological Defense Officer torentW aCquaintance and in -thecourse of their conversation told him how,

°well Fred Green, the new AssistantRADEF Officer for Anywhere, U.S.A., wasworking Out in the job. He mentioned theseries of events which had led to the ap-pointment and was intrigued to hear theexpression, "unmanageable span of con-trol," doe& in reference to his probl,

. 13.61 It was in exceptionally apt de-scription, he concluded as-he drove hothethat evening, and:this set,him to thinkingin terms of the-span of control of his, ownlocal RADEF organization. He had dis-cussed "span of control" (although not insuch a precise term) sufficiently with Fred

,Green to assure hiMself that it -did notTepresepl a problem to their Giganization.

s he turnpd into his driveviay, however,he was ,struck by the sudden thought that,this comfortable situation might not .betruce of the County Emergency Operatingcenter to which his organization reported.He dedded to look into the matter furtherat hiaearliest opportunity.

13.62* Three mofithi later, the AnY-Wheke, U.S.A., Emergency Operating Cen-ter was duly entered in the State CivilDefense Plan and all other supporting doc-timats. George's suspicion had proved tobe 'correct, something that the CountyCivil Preriaredness COO-Mina-tor had beenthinking of himself for some time. He hadrecogniZed,that the analysis load thrownon his-Own RADEF Organization would

'..SimPlk be_ too large to handle .if-an emer--gencY aliedlci occur during the evening-10,01, a titne When the bulk of popula-tton in the c-otinty had redistrib ted itself.

into a-series of sm-all suburban communi:tiesreach with its-own little-EOC:

13..63 'In-explairiing- his situation toGeorge Jones, he ruefully acknowledgedthat all initial planning had been based onthe concept of a daytime emergency andfor many months no one:tied though)t tG ex-amine the county RADEF setup in terms'of how it would functton in the eveninghours. He went on to point out that themistake had been uncovered, interestinglyenough, throdgh the reappraisal of appar-ently inadequate means.of alerting.certainkey operating,personnelduring the eve-ning hours. This had led, in turn, to theinteresting discovery that a surprisingnumber of his volunteers had acceptedequivalent assignments in their own homecommunities, some of which weEe as far astwenty-eight miles away from the countyseat: The County Coor\dinator acknowl-edged that all of these people had advised . .his office of their decisitai and, -further, \that his office 'had complete' records ofithese facts. When his secretary had cas-ually mentioned that t,hey seemed to be infor a rough time if an emergency shouldever start in the evening, though, he Sud-denly realized that his, fine daytimeRADEF organization would be a desper-ately overworked gf it ever had. to-commence functioning during the night.

13.64 AS he worked with George Joneson the neW plans which calledfor severalof the newer local EOC's to report to theAnywhere, U.S.A., Area Einergency Oper-Eifing Center rather than to the CountyEOC, the phraseduce the span of con-trol to .manageaFJle props)rtions," washeard over and ov again becatiee it is --

such an apt expressi n of the purpose ofan area -E0C. I to

13.65 George Jo es realized, that the'wOrk he had done with the County Coordi-nator would be extremely worthwhile forthe county as a whole. ever though IVmeant that his own RADEF organizationwas\taking on a substantial a,dded respot-sibility in receiving,.q,nalyzing,.sumrnari -ing and reportin&the additional datawhich the sev.u.al To* operating centersyiould be sending viewed -the.Changed situation, he kneir that his pw9, ,

tJ.

personal span of control r'rcl Fred Green's 13.69 "Just a minute!" he thought,as well had both been stretched past the "Why not use that big camera over in ourdanger point and something would have to County Records Section and make copiesbe done about it. He and Fred would have of their map for' ourselves?'1to review their entire tables of organize- 13.70 The more.. he tliought about thetion as well as all theirIlinitial plarring idea, the better he liked it. In the firstconcepts. UndOubtedly, at least one mew place, there simply wasn't any be,tter mapassistant would be required, perhaps even available anywhere, either in or out of thetwo. "One thing is certain," thought State. Second, he tidked oft, it will beGeerge; Jones, "if I have to make mistakes maintained by an outiide gariizationin this RADEF work, at least I'm going to and every time a major c ange occurs, amake new mistakes!" riew set.ormaps can be produced in jUst a

.13.66 The Courity..Coordihator reflected very few minutues. Third ,. he realized, itthat the new plans growing out of his would be an invaluable addition to theefforts with George Jones were a big help resources of, his operations center. He de-in more ways than one. Now he had more cided to lose no time in putting his plantime to devote to an item which- he had into effect.never felt was all should be, specifically, 13.71 When the first copies of the Statethe county's radiological monitoring nett Highway Department's map were deliv-work. There was a -perfectly adequate ered to his office, the County Coordinatornumber and distribution c't. urban monitor- lost no time in looking them over. Heing stations, true enough, brit he was not decided that the quality of reproductioncomfletely satisfied with his sefup in rural was very good, that the 'maps would fill hisand mobile monitoring. After all, the prob- requirement perfectly. Inspecting thelems of a county EOC could be consider- maps a little more closely, he noticed thatably more complex than those of a local the 'span of roads which would connectEOC in that county-type RADEF prob- with the new bridge to be built in a neigh-lems had to be approached from the stand- boring county were just about complete,point of area as well as population. Al- even though work hed not y begun onthough this could ,be true for a local EOCTrthe bridge itself. He was r minded of rt--was alwayi true for a county EOC. conversation he'd had with eorge Jones a

13,67 The more Willa-ugh/ about it,the few days beforein which George had beenmore the CountiCoordinator was con- telling him what a boon the new bridgevinced,that a county EOC wasvractically would be. George, had mentioned that hisa State EOC on a smaller scale. delivery trucks had a choice whenever

13.68 He was certain, fo'r instance, that they had a stop to make in the nextthe 'State Civil Preparedness organization county. They could drive ten miles upriverhad n easier time with maps than he did on a road that was only fair to get to the

clo qiot bridge or they could grive eighteen 'bec use ,the Highway Department had downriver on a very good road land .co lete up-to-the-minute information onev road in the State, all new construe- -ima e their crossover there. The ne

bridge couldn't go up too soon, de far asw e"

Ition, road conditions, etc., etc. As a matterof face, 'the-County Division Office of the orge Jones was concerned..Highway Dep,artment (which was loeated 14.72 A sudden thought hit the Counlyjust down-the hall from his own'office) was , Coordinator._the proud.possessorbf one of those master 13.78 he never could think aboutMaps that the ,State used in its .highway Geo`rge Jones very much without alsoimaintenante and constructiorr program,,It thinking about "span of control" whichwas a reaLbeauty, showed,everything that q.lways led him, in turn, to consider

- anyone cotIld.possiblY.want io know about george's area' EOC and how well the planroads in,,the State:And it was so rfuick. was working out in actual practice. _Tbe.-better, than the map* ithat!,he lid Ills words, "area ,EOC" and the fact that hemobile monitors exes1. . . ju'st 'been thinking about Ilis mobile

; -

1111

4

monitoring a few seconds before were the STATI EMERGENCY OPERATING CENTERtwo -things that sparked his idea.- He PUNNINGlooked at the map once more. There it was!13.78 Slime weeks later, the State Ra-13.74 If George! Jones' trucks had to diological Defense Officer dropiesii-4n ontravel either ten or eighteen miles to'cross. - the County Coordinator to see how his newthe riv6-, why then so would the mobile Substate,E0C planning was shIping up.monitoring teams sent out by the County. He was, of course, particularly interestedCooltliOTTNor of the nexteounty! in any RADEF developments which might

be of use to him in his role of RADEFadvigor to other OC's ;within the State..He didn't really expect to pick up anythingso far as his own operation in the StateEOC was concerned because, after all, ithad beef a going concern for at least 2years aAd a great deal of time and talenthad been devoted_to enáking it so.

.13.75 "But if the area on our side of theriver were to be monitored by our Ownteams," he mused, .,"then our neighborswouldn't have to make those lone tripsjust to get acrOss the river. We're' 'alreadyacross the rier as far as they are con-

, cerned. Whyl couldn't we take this .areaover and mimitor it for them? if we. didtake over, our crews would be receivingonly a fraction of the radiation exposurewhich their crews would be getting!"

r13.70 Little did the County Coordina-tor, realize that his idea Would proltucethe first sub-state E.,OC in his -state and,further, that his oWn county EOC. woVdbeconie it! He coulsee the basic reason-ing behind the move, however, once it hadbeen explained to hini because, after all;

;Ale <vould be taking eaver just about half ofthe ara monitorin work of the neighbor-ing county arid so might as well take,overarea RADEF control as -well.. He had beena little skeptical abottt the manpower re-qUirements represented by the new re-sponsibility, but wag pleasantly surprised

display of the RADEF situation while itto learn that he would be getting a lioostthe State*E0C ifroln n the:training of was in Use by the director and members of

his staff.

13.79 As the County Coadinator wasshowing him the new setup, he noticed two'transparent plastic panels which had beenvertically mounted on sturdy pairs of legs.The panels, were pushed back in a cornerout of the way and were apparently with- .

out any use that he,conkd discoverNHeinquired about them.

13:80 "Oh,, that's my own, personal lit-tle brairr-child," said the County Coordina:-tor, "and I Ton% mind telling you I'm sort;of proud, of it, too, even though I don'tknow-anyone whO Vies a similar system..You see, I was having some real difficul-,ties "in the. trial runs we,had held,here .-insofn't -as 'using the in`formation we hadplotted .and analyzekl. Thbre was too muchconfusion in trying to maintain a.current

.additional monitors because the State cen-ter expected ta have him to oda.'tional area .responsibilities as soon aswas organized to hthldle them.

13.77 "One' lesson I've- learned fromthis," he told.George Jones' when deticrib-ing the new RADEF plan to him later on,"is that you never c4 really foOet aboutthat 'span of control' 'deo that you werethe first to point out t me. Even thoughthis latest move had ts beginning, ideacompletely outside such a concept, it wasstill a case of reducing t e span of control.

$

13.81 "These plastic panels are the an-swer to the problerd," he went on. "tomor-row molning, a man is coming in to paint.the outline, of our control area, plus themajor features such na roads, the river,and go forth, on each panel. In an actualeikercise, the panels will be out in the jcenter of our operating area so that ever-yone who has to can see- t'hem. Our Plot-ters will use gi-ease pencils and, teritinilbackwards, will spot in eXposure informa-tion on one and exposure. rate Ulfprmationon the other.,Our. Analysts,", hetontinued,to manageable proportions, at least so far "will be in front-of the paneli and they willas the StatecitOC was concerned." also use grease pencils to draw in contours,

1 8 1 1.77

as well is add any other informationwhich IA might need in a graphic form. Ofcourse there are many ways to display thedata and this only represents one way."

13.82 "Say, now," exclaimed the State ,RADEF Officer, "this is really something:As a matter of fact, I think I might evenbecome the" first ofpcial thief of your ideabecause it strikes me as a refinetnentworth introducing into our State EOC!You can appreciate how much I need sucha system if you need it to control a piece ofthe total area that. I have to wOrry about.It just goes to show that no plan is everreally final and that includes first of all,our own State Plan."

,

ONE FINAL WORD

13.83 Noi operations plan, howeversound in concept and complete in detail, isof much value if it is untested or untried.The readiness posture of a plan is meas-ured by its ability to be implemented.Therefore, each operational plan should besubjected to one or more tests as, a part ofthe planning cycle. Plan tests should bemade as realistic as possible, and.each testshould be evaluated by dualified observersas well a's by the participants. Followingthe test, an evaluation report 'shoul4 bemade. The report and-evaluation shouliol beused as the basis for revision and the startof a new p1an2ing cycle.

1 r)

4

4

,w

"PAPER PLANNING" OR REAL RADEF?

To implement the RADEF plan, ofcourse, a variety of elements is required.It is necessary to have equipment and afacility in which to store and use it thatmuch certainly is obvious. Further, theequipment and the facility cannot do muchby themselves, putting them to use takespeople, sometimes a rather large numberof people, to say nothing of money. And,finally, these people must have some ideaof what they are to do or else the equip-ment will remain inert and the facility willbe without purpose. This is just anotherway of saying that RADEF personnel needtraining. :

But what should come first, where is thestarting point? How can you tell when youHaves:balanced RADEF team? How do you

maintain a RADEF capability once it is es,tablished? And so forth.

The objective_of this chapter, then, is toput these various essentials of an effective-RADEF plan into- their peoper-ierspective... to demonstrate what is necessary tobreathe life into a paper plan and turn itinto an honest-to-goodness RADEF capa-bility.

INTRODUCTION

14.1 We saw in Chapter 13 that planningcan spell the differeiwe between an emer-genCy which is 'promptly dealt with on asystematic basiS and, on the other hand,an utter catastrophe. We saw that plan-ning guides us to the best use of'all availa-ble resources, and, ultimately4. helps savelives. We saw that effective planning re--quires organized, equipped, trained per-sonnel as an essential ingredient. We be-gan to see.that all this requires money.

14.2 Now we are ready to break thisplanning ingredient down into its essen-tial 'parts. 'These are the basjc tools of

,

CHAPTER 14

iS

RADEF planning and an effectiveRADEF organization. There are four ofthem.

EQUIPMENTFACILITIESPERSONNEL--TRAINING

We will examine these four item insequence in this chapter. As we do sb, itwould be well to remember that theserequirements do not come from inspira-tions or viSions. They come, instead, as a,result of t1 le. planning process which is, inturn, a two-step pr-ocdure.'

14.3 To repeat our summary of thesetwo steps, the first consists of the estab-lishment of some reasonable, sensible,well-thought-out, practical assumptions.The second step is,qne of meeting thesea.skumptions with reasonable, s'ensible,well-thought-out, practical answers.

'EQUIPMENT-

14.4 In considering Me question of ra-diological instruments and equipment, itimmediately begomes apparent that one ofthe first que,itions to be answered is,"what kind and how much?" as well as;"`where can we get it?"

14.5 To answer the last question first,the Defense Civil Preparedness Agencyhas made radiological equipment availableto the States through their duly consti-tuted Civil Preparedness organizations.This is a "through official channels" typeof exercise and therefore a detailed pres-entation of .the fifty different channels isobvibusly outside the scope of this discus-sion.

14.6 Although a detailed answer to thefirst question in paragraph 14.4 is evenfurther outside our scope, it is neverthe-less possible to demonstrate an importantpoint abont RADEF planning in offering a

183 179

'comment on it. Specifically, the answershould lie in your own plan or its RADEFannex and, if it does not, then that plan isdrastically in need of additional work!,

Thtfael that such an- goswershould be found in an existing plan alsohighlig4ts another 'feature of planning.The elements of a plan are interdependentand interrelated if the plan is a good one,and further, if any one of these elementsshould change or alter in anrway, such achange should .be the signal for a reap-praisal and possible revrsion of the plan.

14.8 In considering equipment require-ments for a Particular radio!ogical defensearea, it is important to remeMber that thisdoes not merely mean operational equip-ment but, in addition, includes trainingequipment. In this regard, an individualresOnsible for a -DCPA Training SourceSet must. hold a Byproduct MaterialUser's Certificate from his respective.State.. And here, incidentally, is furtherproptof the interaction of ostensibly sepa-rate-elements in the RADEF plan.

14.9 Not only is the RADEF Officer re-sponsible for obtaining the required opera-tional equipment and making sure thatsufficient training equipm.ene is available,he is also responsible f9r maintenance. Tothis.,ebd-r-a-"chief qnonitor" 'slibuld bap-POinted for each monitoring station. Fur-ther, supplementary instruitents miglit bereasonably required and it is up to theRADEll' Officer to determine if this is thecase as well as to prepare the necessaryjustification to obtain theni.

14.10 If a RADEF plan is to be capableof executIon,' there must a sufficientnuniber of radiological monitoring stationSand communications over which they canmake their reports. The RADEF Officer isresponsible for converting a number on apiece of paper (the local area RADEFplan) into a real monitoring and reportingnetwork.

14,11 Since this monitoring and report-ing network, will not be worth much with-out a place to receive such reports, thisleads the IRADEF Officer next to the facil-

100

ity for his local EOC. He must also have -

radiological monitoring for communityshelters under close control. While some ofthese community 6.1-ielters might presum-ably be a part of his regular monitoringnetwork in addition to their missiiin ofRADEF protection for the shelter, otherswill not. But in any event he will be re-sponsible for the, adequacy of the 'facilityinsofar as it coricerns atiy aspect ofRADEF.

14.12 Protection factor is, of course, ofparamount imprtance in determining thesuitability of a RADEF facility and this isanother area for which the RADEF Offi-cer is responsibe. He must assure himselfthat each facility ,which has been mappedin as a part of the RADEF operation has asufficient protection fdctor. In addition toprotection factor, an important-feature of__such facilities will be their ability to fitinto the local communications plan. Inother words, each facility which is selectedand added td the overall RADEF networkmust be capable of carrying out itsts-signed function while simultaneously per-forming the vttal task of self-protection.

14,13 Before leaving the question of fa-cilities, a word on arrangements for emer-gency food and w,ater-for monitoring per-4-01inel would be i order.

14.14 Food and W-ater stocks, it could beclaimed, Are not reallNt a part of the consid-eration of a facility:It could be arguedequally well that food and Ni,rater are cer-tainly not radiological "equipment". Thepoint is, however, no matter what label isplaced' upon these two commoditjes, hu-man beings cannot exist or function verylong without either one. Thus it behoovesthe RADEF Officer to make certain thathis facilities have adequate stoc4 of theseitems.

PERSONNEL

14.15 One of the largest contributingfactors to RADEF personnel requirementsis found in the radiological monitoring net-work.

14.16 Once again, the particular localCivil Preparedness plan or its RADEF an-nex should provide the explicit answer to-thiS question and, if it does not, the prob-

1 S'4

S.

lem is not one .of the monitoring networkbut rather one of conIpleting the plan first.Although the final answer to this questionrau,st remain a local one to be based uponpopulation, industrial distribution, geog-raphy and the like, there are, neverthe-less, certain criteria which can be used.Federal and State governments period,Lcally issue guidelines on the number ofmonitoring stations needed in rural andurban areas. This information should beconsidered only as a starting point in eval-uating 'the RADEF inonitdring networkrequirements because final answers willalways deperld upon the individualities ofthe particular local area in question.

NOTE

Do you think in terms of so many menfor this job, so many men foothat one,or'so many_inen in he...goe,. and-soforth? 17-You do, then . .

STOP RIGHT NOW!

(;}

andoother facilities which have an Jul-e-quate protection factor, appropriate per-sonn0 who are normally,, employed atthese facilities represent anothq excel-lent source of monitors.

14..19 In rural and suburban arek'swhere a home shelter may have been 'des-ignated as a part of the monitoring andreporting system, members of the familywho will occupy the shelter should, if pos-sible, be recruited as a part of the,RADEForganization.

14.20 Once again, since a I4rge cadre ofmonitors will be needed, the selection ofpersonnel for training should be fairlybroad. Remember that'women; as Nell asmen, can perform a very significant role inmonitoring, and certainly should not beoverlooked in any recruitment-effort.

14:21 -Tor deionTathiriatiOn fiaining, se-lection of key personnel should be primar-ily among the fire, sanitation, rublic.worksand'engineering services. HoWever, se1ec7,tion should also be extended:t6 those per- -sonnel who operate street sweeping- andflushing equiprnent, road grad,ers, scrap-ers, and earth moving tand:demolitionequipment.,"Selection cli,-sicaiey person-nel will be froni Stateriounty; andpal dmployer;,but'shotilTalsobesxteriaato, others. óh 'as* higlwdy constructioncontractors, since riinSt. of the equipment-

needed for decOnfamination work will befound in these areas to say nothing'of_a

.ready, source of personnel trained in its

there are millions df intelligent, sin-cere, 'capable women in our country.There are undoubtedly thousands .inyour own RADEF area. Be sure thatyou remember this in 'your planningand personnel recruitment activi- .`ties!!!14.17, As a general rule, RADIEF. per,-

sOnnel should be selected prirharily fronf..State and local government eipployees.This will provide all the advantages of t.

_working on tlfe basia of an existing orgarill'zational frainework. For monitors, it issuggested that, firemen, State-highwtiy_pai,trqlmen, highway 'maintenance persrinel,their auxi4ries and their reserves"be se-lected for training. Furthe'f, radiation.monitoring should be included,as-a pa'rt ofehe basic training for all, new recruits inthese services and refresher monitortraining should be routinely scheduled, fprall pergonnel. To supplement this initiVlcadre of Monitors; 'high school and collegescience teachers, selected State, county,'and municipal employees in the engineer-ing, sanitation, welfare,' dnd health serv-ices could alsO be selected- for monitortraining.

14.18 In areas where monitoring sta-tions have been Rstablislied in iiidustrialplants, hospitals, commercial byildings

'-1 85

TRAINING14.22 There are two basic areas of

training, the training of monitors and thetraining of the'RADEF staff. Tbe latter isof particular importance for it is impera-tive that the leadership staff be providedin order to form a seed-bed for providingfurther training to other personnel.

RADEF,OFFICER AND RADIOLOGICALMONITORING.FOR INSTRUCTORSTRAINING

14.23 Local and .State jurisdietionshave the responsibility for obtainingtrained Radiological Defense Officers.

1 81

Upon completion of his training, theRADEF Officer provides instruption to thepeople who have been selected for hisRADEF staff andsthe monitors needed inhis comthunity. .

14.24 B&sure you don't overlook theresource represented by the capabilitiesexistent in the Armed Forces tb supple-ment' monitor training resources.

14.25 As .monitprs are trained, theRADEF Officer should assign them to aspecific monitoring station for operaltbnalpurposes. Generally, mOnitors should beassigned to facilities which are near where'they normally work ocieside. Each moni-tor will-be ordered to report to his desig-nated shelter or monitoring station in anemergency. All monitors should be in-structed to find some, shelter in the event

they -cannot, reach their assigned station.'In addition, provision must be made, forthe families of, morlitors, both as a morktle

,factor and also by way of avoiding-possibleconfusion during an emergency.-

14.26 Upon completion of- his -training,each monitor will be furnished a HAND-BQOK FOR RADIOLOGICAL MONI-TORS,4.9 containing detailed in-strtfitions tor Monitoring and reportingoperation( as well as special' instructions

,c9.11:MIlipg his responsibilities for dealingwith rotitine and emergency radiation con-ditions. DCPA will provide these manualsfor distribution to the monitors.

'14.27 Continuing training of monitorsto provide for personnel attrition and re-fresher training of monitors on an annualto 6 months basis should be- arranged for-..py the lochl RADEF Officer.

14.28 The following paragraphs providea summary of some important points for.'persons concerned with establishing-RADEF training programs, either for ra-diological mOnitors or for the RADEFstaff.

S.

TRAINING REQUIREMENTS

14.29. The first step is to'find out whatwe need in the way of training. We must

Is? \ A

determine how many monitors we need. Todo this it is necesiary to analyze the localRADEF plan since training requirementswill stem from the assessment containedin the plan. (If no plan is available,moneshould be developed first.)

RECRUITMENT OF RADEF PERSONNEL

14.80 After we have found how manytrained personnel are needed, it will benecessary to recruit the manpower fortraining. By far the best sources will befull-time municipal, county and State em-ployees. Since they are also one of the bestsources for Civil Preparedness pe'rsonnelother than RADEF, coordination will benecessary to avoid conflicting assign-ments. Another possible difficulty is that,RADEF activities have no exact counter-,parti-n--existink _governments, In bthef,words-, the Civil Preparedness plan which'fits the police fcirce'into the law and order'role Or the sanitation department into thedecontamination role during ,an emer-gency will not find a ready-made govern-mental activity whibh-fits RADEF activi-ties.

NOTE

It is imporiant, both for motivationand realism in training, that the stu-dent have aeassignment based on theRADEF plan BEFORE he begintito undergq training.,

TRiINING LOCATION

14.31 The courses shopld be taught inlocations convenient for tb tdentsince many will presumably be volunteers,it is doubly important that all impedi-ments to training, such as disfant plaiesand inflexible or inconvenient class hourg,be removed. If On-the-job traiping can be,arranged 'with local government authorit'.,ties,. this will materiallir aid in the rapidtraining-pfonnitors and others.

,

TRAINING LOGISTICS14.32 It ,is important that training

equipment be ordered at the earliest mo-ment after training requirements are de-termined, and that the necessary user per-mits needed for handling Training SourceSets be applied for. The Defense Civil Pre-paredness Agency provides a "Radiologi-cal Monitoring Training Package," K-24which includes an Instructor Guide, andsupporting visual aid material. This, too,should be obtained'without delay and insufficient quantity.

TRAINING ASSISTANCE

14.33 It is vital that liaison be estab-lished with .all agencies, public and pri-Arate,,that can offer assistance in teachingor recruitment. Whatever instructor capa--bilities already exist on the local levelshould be ap-praised and utilized. Find outfrom the already existing Civil Prepared-ness organization what iT availab.-Othercities' in your :areal may haie.a. fully func-tioning organization with a number ofqualified instructors. There's no advan-tage in '"going it alone" so, if you can gethelp from outside your immediate jurisdic-tion, don't hesitate to take it. After all,fallout will not recognize any boundaries.

TRAINING METHODS

14.34 As we have seen, we are nottrainingjust for training's sake nor are wetraining to increase theoretical or aca-demic knowledge. We ckre training for spe-cific jobs. Hence, the selection of courseconteit material should aim at:

tr ining to do a particular jobtraining to initill degirable habitstraining to enhance operational knowl-edge

To achieve these ends, course materiar4should stress student participation. Pas-sive lecture methods'should be avoided infavor' ols the active approach featuringdemonstration, exercises, laboratory, andqueStion and ansWer methods. Teachingaids, models, slides, films, vugrephs, flan-nel boards, And ôt1Wr visual aids should be

Sed when they support learning as an

end in themselves. Incidentally, one of themost important things to do when usingsuch 'equipment is to check It out in ad-vance; be sure it works, and that you kri\owhowto use it.

s

TRAINING EVALUATION

14.35 It is'important that there be fre-quent tests of skills learned in the trainingcourses. Such evaluation should be on pro-ficiencythrough demonstrationratherthan student reproduction of academic ortheoretical knowledge. Make. it realisticshould be the guide .to effective trainingand evaluation Of such training.

NOTE

The best things in life may be free, butbuilding and training a RADEF or-ganization is not! At any level of gov-ernment, there is a requiremvnt ofbudgeting for RADEF. DON'T FOR-GET,,T0- PUT RADEF IN THEBU_D ET!

A BIRD'S-EYE-VIEW OF RADEF

14.36 It's no secret to anyone who hashad any contact with radiological defensethat, as a subject, it is technical and it iscomplex. Although a single individual as-signment can be presented in a relativelysimple, straightforward manner, the sumof all such assignments covers a very widerange of knowledge and presents a rather

icomplicated picture.14.37 This situation leads us to a single

simple question, "Who will tie all theseloose ends to'gether?". We have radiologi-cal instruments, monitoring stations, shel-ter radiological requirements, trainingsource sets, data to be pldtted, curves to bedrawn, reports to be received, reports tobe sent, the list is literally endless and yetsome sort of knowledgeable coordinationmust take place between all these facetsand elements and bits and pieces.

14.38 For the sake of argument, let'sconsider what would be necessary if wewere to decide to go into a manufacturingbusiness. Let's for example, make it furni-ture manufacturing. Immediately Yip real-ize that we need someone who knowssomething about building furniture. This

1) 143

leads us to a conclusion that he shouldalso know something about the wood andothqr materials which will be required,wheie to find them and how to Use them..He must be aware of the availability anduses of a whole variety of special tools.And he must know a great deal more aswell. We are aware of how foolish wewould be to hire cabinet makers, salesmen,clerks, and so forth until we were certainwe had our man who knew the furnituremanufacturing business. This example isso obvious it's almost ridiculous, isn't it?

14.39 But it is not ridiculoUs when theradiological defense parallel is drawn be-cause it is surprisingly easy to becomebogged down in the many technical consid-erations of RADEF work and, as a result,lose sight of a basic fact. That fact is:

Monitors, facilities, instructors, hi-struments, communications,,,decon-tamination teams, RADEF plans-andall the rest of it do not-constitute aradiological defense capability . . .

unless . . .

RADIOLOGICAL DEFENSE OFFICERS

are available to tie the paqkage to-gether into the real countermeasure

.------ror survival that RADEF is meant tobe.

Just as most other facts can be ex-pressed in corollary terms, this onecan be given such expression wiAequal ease. The corollary is:

Provided that there are sufficientRADIOLOGICAL DEFENSE OFFICE4

available, a radiological defense cape-bilitY is in process of building, regard-less of inadequacies in any otherRADEF area.

14.40 These facts can be expresse&on anational scale as well as a purely local one.Our national RADEF capability requiresfacilities, monitors, instruments and manyother elements of survival in the nuclearage . . . and must include a cadre of capa-ble, trained Radiological Defense Officers.With such a group, we can have a nationalRADEF capability but without it, never.

RADEF OFFICERS.ARE MADE, NOT BORN!

14.41 There is no such thing as beingappointed an expert on any given subjeaand radiological defense is no differentfrom any other subject in this regard. Theonly road to becoming a Radiological De-fense Officer is study and tiaining.

14.42 But what about Joe Smith whohas just received his doctoratok in, of allthings, nuclear.physics? Can't we at leastrecognize him as a Radiological DefenseOfficer because of his provable knowledgeof atomic structure, fission, radiation, cur-ies and, things like that?

14.43 No, we cannot recognize DoctorJoe Smith, nuclear physicist, as a Radiol-ogical Defense Officer unless he has been

\ trained as a Radiological Defense Officer.14.44 The point may seeni Obvious but

it is -nevertheless very well taken. Cer-tainly there is nothing wrong with' havinga RADEF Officer who is also a nuclearphysicist, no more so than there is any-thing wrong with having one who is a sci-ence instructor, industrial scientist, or anengineer, but none of these individuals willbe a RADEF Officer until he has actuallybeen trained as such.

14.45. Along the-se general lines, it is agood idea to- remember that the DCPAcourses which lead up to qualifying as aitADpF Officer have been developed with aview toward proxiding the technical infor-mation-which will be required to do the job.The individual _is, of course, expected tocarry out a certain amount of independentstudy as well as keep himself up to date onthe subject tIvough continuing elosecontact via the channels 9f his own CivilPreparedness organization.

IMPORTANT

Our nation ne-eds thousands of capa-ble, trained RADEF Officers . . . In-strutters can and will provide thetraining . . . the individual, however,must provide the capability!.

GLOSSARY

A ,

ABSORBED DOSE: see DOSE,

AFTERWINDS: Whld currents set up inthe vicinity of a nuclear explosion di-rected toward the burst center, result-ing from the updraft accompanying therise of the fireball.

AIR BURST: The explosion of a nuclearweapon at such a height that the ex-panding fireball does not touch theearth's surface when the luminosity is amaximum (in the second pulse).

.ALPHA PARTICLE: A particle emittedspontaneously from the nuclei of someradioactive elements. It is identical with

, a helium nucleus, having a mass of fourunits and an electric charge of two pogi-tive units. See Radioactivity.

AMBIENT: Going or moving around; alsoenclosing encompassing.

ATOM: The smallest (or ultimate) particleof an element that still retains the char-acteristics of that element. Every atomconsistS of a positively charged centralnucleus, which carries nearly all themass of the atom, surrounded by a num-ber of negatively charged electrons, soithat the whole system is electrically/neutral. See Element, Electron, Nucleus. -

ATOM/C. BOMB (OR WEAPON): A termsometimes applied to a nuclear weaponutilizing fission energy only. See F'is-sion, Nuclear Weapon.

ATOMIC CLOUD: See Radioactive Cloud,

ATOMIC NUMBER: See Nucleus.I

1 When possible, definitions have been reprinted from the glossary ofThe Effects of Nuclear Weapons, February 1964.

189

GLOSSARY .

ATOMIC WEIGHT: The relative weight ofan atom of the given element. As a basisof reference, the atomic weight of thecommon isotope of carbon (carbon 12) istaken to be exactly 12; .the atomicweight of hydrogen (the lightest ele-ment) is then 1.008. Hence, the atomicweight of any element is approximatelythe weight of an atom of that elementrelative to the weight of a hydrogenatom.

AVALANCHE EFFECT: 'The multiplica-tive process in which a single chargedparticle accelerated by a strong electricfield produces additional charged parti-cles through collision with neutral gasmolecules. This cumulative increase ofions is also known as Townsend ioniza-tion or a l'ownsend avalanche. Ava-

.--lanche occurs in the Geiger tube of.a CL -

V-70 Or.'

BACKGROUND RADIATION: Nuclear (orionizing) radiations arising from withinthe body and from the surrodndings towhich individuals are always ,exposed.The main sources of the natural back-ground radiation are potassium-40 in-the body, pbtassiurn-40 and thorium,uranium, and their decay prodOcts (in-cluding radium) present in rocks, andcosmic rays.,

BARRIER SHIELDING: Shielding gainedby intirposing a physical barrier be-tween! a given point and radiationsource.

BETA PARTICLE: A charged particle offery small mass emitted spontaneouslyfrom the nuclei br certain radioactiveelements. Most (if not all) -Of the direct

1 $S

fission proOucls emit Jnejkative) betaparticles. Physically, the beta particle isidentical with an electron moving athigh _yeloeity. gee Electron, rissionProducts, Radioactivity: .

INDING ENERGY: The tremendous en-ergy which holds the neutrons and pro-.tons of an atomic nucleus together.

BIOLOGICAL DOSE: See Dose.

BLAST WAVE: A pulse of air in which thepresure increases sharply at the frontsaccompanied by winds, pro5agated con-tinuously from an explosion. See ShockWave.

BODY BURDEN: The amount of radioac-tive material in the body at a giventime.

CALJBAATIONDetermination f varia"--

tion in accuracy of radiological instru-ments, Radioactive sources are used toproduce kr..2Awn exposure rates at speci-fied distances. The variation in accuracyof a radiological instrument can be de-termined by comparing it with theseknown exposure rates.

-CHAIN RE-ACtiTION.,. When qa 'fissionablenucleus is split bx a ,peuVon it releaseSenergy_ anaone or more neutrons; Thesein turn split more fissionable-nuclei re-leasing more energy and neutrons, thusm*aking the process a self-sustainingchain reaction.

CHROMOSOME: One of thel particles intOyvhich a portion of the celfnucleus splitsUp prior to cell division: assuined to bedeterminants of species and of sex. .

'CLEAN WEA150N: One in which meas-ures have been taken to reduce theamount of residual radioactivity rela-

_

tive to a "normalr weapon of the same° energy Yield.- 0,r<

COMPTON EFFECT: The scattering olphotons (of gamMa or X-rd'ys) by theorbital electrons of atoms. In a'collision-between a (primary) photon and an elec:tron, some of the energy of the photon istransferred to the electron which is gen-.

erally ejected from the atom. Another(secondary) photon, with less energy,

-then movea-off in new direvtion t anangle to -the direction of motion of theprimary photon.

CONTAINED UNDERGROUND BURST:An underground detonation at such adepth that none of the radioactive resi-dues escape through the surface of theground.

CONTAMINATION: The deposit of radio-° active material on the surfaces of struc-

tures, areas, objects, or,personnel, fol-lowing a nuclear explosion. This mate-rial generally consists of fallout inwhich fission products and otherweapon debris have become ,incorpo-rated with particles of dirt, etc: Contam-ination can also arise from the radioac-tivity induced in certain substances bythe action of neutrons .from a. nuclear.ex6losion. See Decontamination, Fal-lout, Induced Radioactivity, Weapon De:bris.

CONTAMINATION CONTROL.; Action toprevent the spread of fallout and reducecontamination of people, areas, equip-ment, food and water.

COSMIC RAYS: Very high energy particUr- Tlate (particles) ahc electroma°gnetit -'

(rays) radiations whi h originate out insp,Ace and constantly bombard theearth.

CRITICAL MASS: The minimum mass 'Ofa fissionable material; that . will justmaintain a _fission chain reaction underprecisely specifieii Conditions, such asthe nature' of the material and its pu-rity, the nature and- thickness of thetamper (or4neutron reflector), the den-sity (or compression), and the physicashape (or geometry). For an explosion toccur, the systern must be supercritici.t., the mass tf material must exceathe critical mass under the existingconditions. See Supercritical. .

CUME (Ci): A unit pf radioactivity; it isthe quantity of any radioactive species.in Which 3.700 x 10nuclear disintegra-tions occur , per second. The GAMMA

CURIE is sometimes defined corre-,spondingly as the quantity of materialin which this number ofgamma-ray pho-tons are emitted per seCond.

CYCLOTRON: An appavatus which ob-tains high-energy electrically- chargedparticles by whirling them at immensespeOs in a strong magnetic field; usedespecially to create 'artificial radioactiv-ity; an atom smasher.

DAUGHTER PRODUCT: The product (dif-fexent element) formed when a radioac-tive material decays. Some radioactiveelements will form many daughter prod-

. ucts during their decaii to a stablestate.DECAY (OR RADIOACTIVE DECAY):

The decrease in activity of any xadioac-tive material with the passage of time,due to the spontaneous emission fromthe atomic nuclei of either alpha or betaparticles, sometimes accompanied bygamma radiation. See Half-Life, Radio-activi

DECONTAMINATION: The' reductibi; orremoval of contaminating radioactive'material from a structure, area, object,for persen. Decontamination may be ac-

.

cothplished by1(1). treating the surface soas to remove Or decrease the contamina-tion:, (2) letting the material stand sothat -the radioactivity is decreased as aresult of nat ral decay; and (3) coveringthe contami ation.

DEUTERIUM: Ati isotope of hydrogen ofmass 2 Units; it is sometimes referred toas heavy hydrogen. It Can be used inthermonuclear fusion reactions for_therelease of energy. Deuterium-is ex-tracted from water which always con-tains 1 atom Of deuterium to about 6,500-atoms of.ordinary (light) hydrogen. SeeFusion, Thermonuclear.

DIRTY WEAPON: One which produces a. larger *amount of radioactive residuesthan a "nOrmal" weapon of theyield.

DOSE ': A (total or accumulated) quantityof ionizing (or nuclear) radiation. Theterm dose can be used in the -sense ofthe exposure dose, wypressed in roent-gens, which is, a masure of the total- 'amount of ionization that' the quantityof radiation could produce in air. Thislshould be distingnished from the ab-sorbed doee, given in reps or rads, whichrepresent the energy absorbed from the-radiation per gram of specified body tis-sue. Further, the biological dose, inrem's, is a measure of the biological ef-fectiveness of the radiation exposure.See RAD, REM, REP, Roentgen.

DOSE RATE ,As a general rule, theamount of ionizing (or nuclear) radia-don to which are individual would beexposed or which. he would receive per'unit of time. It is, usually expressed asroentgens, rads, or rems per hoLfr or inmultiples or submultiples Of these units,.such as ! milliroentgens per hour. Thedose rate is commonly, used to. indicatethe level of radioactivity in a contami-nated area.

.

DOSIMETER: An instrument for measur-ing and registering total accumulated`exposure to ionizing radiations.

DRAG LOADING: The-force on an object.or structure due to the transient winds1accompanying .the passage of a blastwave. The drag pressure is the product,of the dynamic pressure and the dragcoefficient which is dependent upon theshape (or geometry) of the structure orobject. See Dynamic Pressure.

DYNAMIC PRESSURE: The air pressurewhich results from the.mass air flow (orwind) behind the shock front of blastwave. It is equal tO4the product of halfthe density of the air through which theblast wave passes and the square of theparticle (or wind) velocity behind theshock front as it impinges on the objector structure.

"In this revised text,"exposure" and "exposure rate" have been sub-stituted for "dose and "dose rate" in those instances where the Meas.urement is explicitly or implied in roentgen units. pose and dose ratehave been retained where the meaning is an absorbed quantity or ritein rad or rem units. .

91

187

.

E

EARLY FALLOUT:-See !hal lout.

ELECTROMAGNETIC PULSE (EMP)4Energy radiated 'by a nuclear detona-'tion in the- meditnn-to-low frequelncyrange that maKaffect or damage e14ctri7cal orelectronic compOnents and equip-ment.

gLECTROMAGNtTIC RADIATION: Atraveling wave motion resulting from,oscillating magnetic and electric fields.Familiar electromagnetic radiationsrange from X-rays (and gamma rays) ofshort wavelength, through the .ultravi-olet, yisible, and infrared regions, to ra-dar and radio waves of relatively long.wavelength. All electromagnetic radia-tions travel in a vacuum with the veloc-ity of light. See Photon.

,

ELECTRON: A particle of 'very smallmass, carrying a unit negative or posi-tile charge. Negative electrons, stir-., rounding the nucleus; are present in allatoms; their number is equal to thenumber of positive charges (or protons)in the particular nucleus. The term elec-tron, where used alone, Commonly refersto these negative electrons. A positiveelectron is usually,called a positron, anda negative electron is sometimes calleda negatron. See Beta Partcle. .

ELECTRON VOLT (eV): The energy im-parted to an electron when ,it is moved

, through a potential difference of 1 volt.-It is equivalent to 1.6 x 10-12 erg:

ELEMENT: One of the distinct, basic vari-eties of matter occuring in naturewhich, individually or in combination,compose substances of all kinds. APprox-imately ninety different elements areknown to exist in nature and severalothers, including plutonium, have beenobtained as a result of nticlear reactionswith these elements.

EMERGENCY OPERATING CENTER(EOC): The protected site from which,civil governm'ent officials exercise direc-'don and-cot-OA in an ergency.

ENERGY:'Capaeity for p rforming work.

111,11

EPIDERMTS: The outer-skin.

EPILATIdN: Loss of hair.

ERG; A unit Of energy or w'iork. An erg isthe energy required for,an electron toionize about 20 billion molecules of air.

ERYTHEMA:_ A_superficial skin diseaseChafacterized by abnormal redness, butwithout swelling orfever.

'EXCITATION: The raising or transfer-ring of an atom from its normal energyleirel to a higher energy level.

EXPOSURE CONTROL: Procedurestaken to keep radiation exposures ofindividuals or groups from exceeding arecommended level, such as keeping out-side missions as short as possible.

EXPOSURE: SeeDose.

EXPOSURE RATE: SeeD6se Bate.

FALLOUT: The process or phenomenon ofthe fallback to the, earth's surfzice ofparticles contaminated with radioactive !material from the radioaitive cloud. Theterm is also applied in a collective senseto the contaminated particulate matteritself. The early (or local) fallout is de-.fined, somewhat arbitrarily, as thoseparticles which reach' the earth within24 hours after a nuclear explosion. Thedelayed (or worldwide) fallout consistS ofthe smaller particles which ascend intothe upper trOposphere and into thestratosphere and are carriefl by winds toall parts of 'the earth. Th e! delayed fal-kilt is brought to earth; mainly by rainand snow, over extended periods rang-ing from months to years.

FALLOUT MC'',NITORING STATION:deSignated facility for the collection ofradiological data by trained and assignedmonitors using' instruments Stored orassigned to that location. It should havegood fallout protection and relativelyreliable cOmm'unications. ExamplesMight be a fire station, police or public

-workh buildini, public fallout shelter,etc.

I a?

,

,

FILM BADGE: A small Metal or plasticframe, in the form of a *badge, worn- bypersonnel, ay containing X-ray (or sim-ilar photographic) film for esthnatingthe total amount of ionizing (or nuclear)radiation to which an individual ,hasbeen exposed.

FIREBALL: The luminous sphere of hot,gases which form a few millionths of asecond after a nuclear explosion as theresult of 'the absorption by the sur-rounding meditim of the`thermal X-raysemitted by the eXtremely hot (severaltens of millions degrees) weapon resi-dues. The exterior sof the fireball in air isinitially sharply defined by the lumi-nous shock front and later by,the limhsof the hot gases themselves (radiationfront).

FIRE STORM: Stationary mass fire, gen-erally in built-up urban areas, generatoing 'strong, inrushink winds from all .si-

e. des;, the winds keep the fires fromspreading while adding fresh oxygen toincrease their intensity. s

FISSION: The process' whereby the nu-cleus .of a particular heavy element

. splits into (generally) two nuclei oflighter elements, with the release ofsubstantial amounts of energy. themost important fissionable materialsare uranium 235 a/nd plutonium 239.

FISSION FRACTION: The fraction (orpercentage) of the total yield of a nu-clear weapon which is due to fission. Forthermonuclear weapons the averagevalue of the fission fraction is about 50pery.ertt. ,

FISSION PRODUCTS: A general term nit,

the complex mixture of substances pro-duced as a result of nuclear fission. Adistinction should be made betweenthese and the direct, fission products orfission fragments which are formed bythe actual splitting of the heavy-ele-ment nuclei. Something like 80 differentfission fragments result from roughly 40.different modes of fission of a given 4nuclear species, e.g., Uranium 235 or plu-tonium 239. The fission fragments, being

s radioactive, immediately begin to decay,

ID3

forming additional (daughter) products,with the result that the confplex mix-'ture of fission products so formed con-

, tains about 200 different isotopes 'of 36elements..

FLASH BURN: A burn caused by eices-sive exposure (of bare skin) to thermalradiation. See Thermal Radiation.

FRAdTIONATION: Any one of seveialprocesseshapart from radioactive decay;which results in change in, the comi:sosi-ton of thd radioactive weapon debris.As a result bf fractionation, the delayedfallout generally' contains relativelymore of strontium 90 and cesium 137,which have gaseous precursors, thandoes the early fallout from a surface,burst.

FREE AIR OVERPRESSURE (OR FREEFIELD OVERPRESSURE): The unre-flected pressure, in excess of the azrbient atmospheric pressure, created inthe,air by the, blast wave from an explo-

ftion.

FUSION: The process whereby the nucleiof light elements, especially those of the

Asotopes of hydrogen, namely, deuteriumand tritium, combine to form the nu-cleus of a hiavier element with the. re-lease of substantial amounts of energy.See Thermonuclear.

G

GAMMA RAYS (OR RADIATIONS): Elec-tromagnetic radiations of high energyoriginating ip atomic nuclei and accom-panying many nuclear teactions, e.g.,fissibn, radioactivity, and neutron,cap-ture,. Physically, gamma raysare identi-cal with X-rays of high energy, the onlyVssential difference being that the X-rays do not originate frorp atomic nuclei,but areProduced in other ways, e.g., byslowing down (fast) electrons of htghenergy. 'See Electromagnetic Radiation,X-Rays. ,

GEIGER COUNTER: An electrical devicewhich can be used tor detecting andmeastiring relatively low levels of nu,clear radiation.

189

GENETIC EFFECT: The effect (of nuclearradiation, in particular) 'of producingchanges (nutations) in the hereditarycomponents (genes) in the germ Cellspresent in'the reproductive organs (gon-ads). A mutant gene causes changes inthe next generation which may or may

, not be apparent.GEOMTRY SHIELDING: Shielding

gained by distance from the source ofradiation. '

GRAM: A unit of mass.and weight in themetric system equal to approximatelyone-thirtieth of an ounce.

GROUM) ZERO: The point on the surfaceof land qr water vertically below orabove thelcenter of a burst of a nuclear(or atomic) weapon; frequently abbrevi-ated to GZ. For a buTst over or underwater, the term surface zero shouldpreferablybe

GUN-TYPE WEAPON: A device in whichtwo or more pieces uf fissionable mate-rial, each less than a critical mass, arebrought together very rapidly so as toform a supercritical mass which can ex-plode as the result of a rapidly expand-ing fission chain.

H

0HA,LF-LIFE: The .time required for the

activity qf a given .radioactive si;ecies to'decrease to hajf of its initial value due.to radioactive decay. The half-life is acharacteristic property of aach radioac-tire species and is independent of itsamount or condition. The effective half-life of a given isotOpe is the time inwhich the quantity in. the body will de-e ase to half as a result of both radioac-ye ded'ay and biological elimination.

HALF-VALUE THI,CKNESS: The thick-ness of a given material which will ab-sorb half the gamma radiation incidentupon it. This thickness depends on thenature, of the materialit is roughlyinversery proportional to its densityand also on the energy of the gammarays.

HALOGEN: The family of elements con-

190,

ttaming fluorine, chlorin4, broMine, ,io-dine and astatine.

HEAVY HYDROGEN: Se, Deuterium.

HEAVY WATER:,Water containing heavyhydrogen (deuterium) atoms in place .ofthe 6rmal hydrogen..atoms.

HIGH-ALTITUDE BURST: This is de-fined, 'somewhat arbitrarily, as a deto:nation at an, altitudes over 100,000 feet.Above this level the distribution of theenergy, orthe explosion between 'blastand thermal radiation changes appreci-

' ably with incyeasing altitude dupe tochanges in the fireball phenomena.

HOT SPOT: Region in a contaminatedarea in' which the level ot. radioactivecontamination is somewhat greaterthan in neighboring regions in the area.See Contamination.

HYDROGEN BOMB (OR WEAPON): Aterm sometimes applied to nuclearweapons in which part of the explosiveenergy is obtained from nuclear fusion(or thermonuclear) reactions. See F'u-sion, Nuclear Weapon, Thermonuclear.

IMPLOSION WEAPON: A device in whicha quantity of fissionable material, lessthan a critical mass, h-as its volume sud-%denly decresed by compression, so thatit becomes supercritical and an explo-sion can take plabe. The compression isachieved by means of a spherical ar-rangement of specially fabricated ishapes of ordinary high explosive which'produce an inwardly directed implosionwave, the fissionable material being atthe center of the sphere. See Supercriti-cal.

INDUCED RADIOACTIVITY: Radioactiv-ity produced in ceftain materials as aresult of nuclear reactions, particularlythe capture of neutrons, which are ac-companied by the formation of unstable(radioactive) nuclei. The activity in-duced by 'neutrons from a nuclear (oratomic) explosion in materials dontain-'Mg the elements sodium, manganese,silicon, or aluminum may be significet.

104

I ,

INFRARED: Electromagnetic radiations4 of wavelength between the longe$t visi-

ble* red (7,000 Angstroms- or 7 x 1024.,millimeter) and about 1 miliiineter. Seeglectromagnetic Radiation.

INITIAL NUCLEAR RADIATIOn: NU-, clear radiation (essentially neutrons

and gamma rays) emitted from the fire-- ball and the cloud column during the

first minute af ,. er a nuclear (or atomic)explosion. The 'rn' limit of one minuteis set, somewh arbitrarily, as that r.e-quired for the source of part of the ra-diations (fission products, ,e'tc., in theradioactive cloud) to attain such aheight that only insignificant amountsreach the earth's surface. See Residual

,Nuclear Radiation.

INTENSITY: The energylet any radia-tion) incident upon (or flowing through)unit area, perpendicular to the radiationbeam, in.unit time. The intensity ofthernial radiation is generally expresse4in calories per square centimeter peisecond falling on a given surface at any

,N.;specified,instant. As applied to fluclearradiation, the term intensity is some-

' times used, rather loosely, to expressthe exposure rate at 'a given location,e.g, in roentgeris.(or milliroentgens) perhour.

INTERNAL RADIATION: Nuclear radia2tion (aiTha and beta Partias andgamma radiatiOn) resulting fro/ft radio-

_active substances in t)-ie body. Impor:tant sources are iodine 131 in the thy-roid glanfieand strontit0 90 and pluton-ium 239 in the bone,

INVERSE SQUARE LAW: The law whichStates that when radiation (thermAl 'or'nuclear) from a point' source is emitteduniformly in all directions, the amountreCeived per unit area at any given dis-tance from the source, assuming no ahrsorption,4s.linversely proportional to thesquare orthat distance. .

IONIZATION: The separation of. a nor--mally electrically neutral atom or mole-cule into electrically charged compb-nents. The term is Also employed to de-scribe,the degree or extent to which this

separation occurs. In the senSe2used inthis book; ionization referrespecialiy tothe removal of an electron (negativecharge) from the atorri or molecule,either directly or, indirectly, leaving apositively charger ion.The separatedelectron and ion are referred to as anion pbair. See Ionizing Radiatilon.

ION'PAIR: See loniiation.IONIZING RAMATION: Electromagnetic

radiation (gamma rays or X-rays) arparticulate radiation (alpha particleS,beta particles, neutrons, etc.) capable orproducing ions, i.e., electrically chargedp-articles, directly or indirectly, in itspassage through matter.

ISOCROME: A lin,e corinecting thosepoints on die earth at which falloutfrom any- one weapon is forecast toreach the surface/let the same time.

ISOTOPES: Forms Of the same elementhiving identical chemical properties butdiffering in their atomic masses (due todifferent numbers of neutrons in theirrespective nuclei) aris in their ntplearproperties, e.g., radioactivity, fission,etc. For example, hydrogen has threeisetopes, with mdsses of 1 (hydrogen),'2

(deuteriuM), and 3-(tritium) units, reypec-tivelYe. The first two of these are stable(nonradioadi4W, but the third (tritium)is a riviioactive isotope. Both ol the corn-.mon isotOpes of urantum; with Masses Df235 and 238 units, respectively, are-ra-,dioactive, emitting alpha particles, buttheir' half-lives' are different. Further-more, uranium 2.135 is fissionable by neu$trons of all eneggies, but uranium 238will unArgo fisOt n only with nearonsof high energy, See Nucleus.

,

J.0 (None)

$K

KILO-ELECTRON VOLT (keV): Anamount Of energy equar to 1,000,electronvolts. See Electron Volt.

KILOTON ENERGY (KT): The energy of anuclear (or atomic) explosion which isequivalent to that produced by the ex-

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plosion of 1 kiloton (i.e., 1,000 tons) ofTNT, i.e., 16'2 calories of 4.2 34110'6 ergs.See Megaton Energy, TNT Equtivalent.

1.

LD/50 or LD-50 or LD50: Abbreviations formedian lethal dOse. See Medic:M. LethalDose.

MACH EFFECT: See Mach Stem.MACH STEM: The shock fr,ont formed by

the fuSiori of the incident and reflectedshock' fronts from an explosion. Theterm is generally used with reference toa blast wave, propagated in the air, re-flected at the surface of the earth. TheMach stem is hearly perpendicular tothe reflecting surface and presents aslightly convex (forward) front. Theyeah stem is also called the Mach front.

MALAISE: Uneasiness. Discomfort.

MASS: A measure of the quantity of mat-ter. The material equivalent of energy.Mass and energy are different forms ofthg same thing.

,MASS NUMBE-R: See Nitbleus..

MED,IANLETHAL DOSE: The ampunt ofiqpizing (or nuclear) radiation exposuieover, the whole body which, it is ei-pected, ygothd be fatal to 50 percent of Xlarge group of living creatures or orga-

'' nisms. ft is commonl* (although not uni-versally) accepted that about 450 roent-gens, received over the whole body inthe course of a few' days or less, is themedian letWal dose for human beings.

MEGACURI,E: ,One million curies. SeeCurie.

MEGATON ENERGY (MT): The energy,of a nuclear explosion which is equiva-lent to 1,000,000 tons (or 1,600 kilo-tops)of TNT, i.e.,10'6 calories or 4.2 x 1022 egs.See TNT Equivalent. **

MEV (MeV): Million electron volts, a unitof ,energy Rommonly used, in nuclearphysics. It is equivalent to 1.6 x10-6 erg.A,pproxiinately 200 MeV of energy areproduced for every nucleus that under-goes fission. See Electrov..Volt.

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MICROCURIE: A one-millionthipart 'of a.curie. See Curie.

4

MICRON: A one-millionth pa-a-I:of a-meter,i.e., 10-6 meter or.10-4 centimeter; it isroughly four one-hundred-thousandths(4 x10-6) of an inch.

MICROSgCOND: A one-millionth part of asecond.

MILLICURIE (mCi): A one-thousandthpart of a curie.

MILLIREM: A one-thousandth part of arem.

'MILLIROENTGEN (mR): A one-thou-sandth,part of a roentgen.

MILLISECOND: A one-thousandth partof a second.

MITOSIS: The process by which livingcells multiply in the pody by splitting or

4

MOLECULE: The smallest unit of a chem-ical compound. For example a molecule

. of water consists of two hydrogen atomscombin,ed with one atom,.of oxygen(H20), and a 'molecule of sugar contsistsof a combination of twelve carbon at-oms, twenty-two hydrogen atoms, and

4e1even oxygen atoms (C,2H2201).

MONITOR: An individual trained to meas-ure, record, and report radiation expo-sure and 'exposure rates; provide limitedfield guidance on radiation hazards as-sociated with operations to which he isassigned; and perform operator's main-tenance of radiological instruments.

MONITORING: The procedure or opera-tion of locating and measuriAg radioac-tive contamination by means of surveyinkruments which carfdetect and meas-ure ionizing radiations. The individualperforming theoperation is called a,

monitor..

MI'JTATION: A change in thestharacteris:tics of an organism produced by alteringthe,usual hereditary pattern..Radiationcan cause mutations in altliving things.

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NEGATIVE PHASE: See Shock Wave.

- 1 (Ay-,t.

.

NEUTRON: A neutral particle, i.e., withno electrical charge, of approximatelyunit mais, present in all atomic nuclei,except those of ordinary (light) hydro-gen. Neutrons are required to initiatethe fission process, and' large numbersof neutrons are produced by both fissionand fusion reactions in nuclear explo-.....,sions.

4NUCLEAR FISSION: See Fission.

NUCLEAR.RADIATION:'rarticulate andelectromagnetic radiation emitted fromatomic nuclei in various nuclear proc-esses. The importanVnuclear radiations,from the weapons 4andpoint, are alphaand beta ,partiOles, gamma rays, andneutrons. All nuclear radiations are ion-izing radiations, but the reverse is nottrue; X-rays, for example, are includedamong ionizing radiations, but.they arenot nuclear radiations since they do notoriginate from atomic nuclei. See Ioniz-.ing Radiation, X-Rays.

NUCLEAR REACTOR: An, apparatus inwhich nuclear fission is sustained in aregulated self-supporting chain reaction.

'NUCLEAR WEAPON (OR BOMB): A gen-eral name given to any weapon in whichthe explosion results from the energyreleased by reactions involving atomicnuclei, either fission or fusion or both.Thus, the A- (or atomic) bomb and theH- (or hydrogen) bomb are both nuclearweapons. It would be equally true to callthetn 4atomic weapons, since it is theenergy of atomic nuclei that is involvedin each case. However, it has 'becomemore-or-less customary, although it isnot, strictly accurate, to refer to weap-ons in which all the energy results fromfission as A-bombs or atomid bombs. Inorder to hiake a distinction, those weap-ons in which part, atdeast, of the energyiesults from thermonuclear (fusion) re-actions among the isotopes of hydrogenhave been called. H-bombs or hydro'genbombs.

NUCLEON: The common name for a con-stituent particle of a nucleus such .as aproton or neutron.

NUCLEUS (OR ATOMIC NUCLEUS): Thesmall, central, positively charged regionof an atom which carries essentially allthe mass. Except for the nucleus of ordi-nary (light) hydrogen, which is a singleproton, all atomic nuclei contain bothprotons and neutrons. The number ofprotons determines the total positivecharge, or atomic number; this is thesame for all the atomic nuclei of a givenchemical element: The total number ofneutron's and protons, called the massnumber, is closely related to the mass(or weight) of the atom. The nuclei ofisotopes of a given element contain thesame number of protons, but differentnumbers of _neutrons. They thus havethe same atomic number, and so are thesame element, but they have differentmass numbers (and masses). Tfie nu-clear properties, e.g., 'radioactivity, fis-sion) neutron capture, etc., of an isotopeof a given. element are, determined byboth the number of neutrons and thenumber of protons. See Atom, Flement,Isotope, Neutron, Proton.

NUDET: Repori of nuclear detonation.

0ORGAN: Organized group of tissue having

one or more definite functions to per-form in a living body.

OUTSIDE/INSIDE RATIO (OD: Themeasured rati6 of the fallout gammaradiation exposure rate at some pointoutside a shelter to the exposure rate atsome point inside the shelter. For radiol-ogical defenae purpose's, the specific out-side point selected should have minimalprotection. (See Protection Factor.)

OVERPRESSURE: The transient pres-sure, usually expressed in pounds persquare inch, exceeding the ambjentpressure, manifested in the shock (orblast) wave from an explosion. The vari-ation of the overpressure with time de-pends on the energy yield of the explo-sion, the distance from the point ofburst, and the medium -in which theweapon is detonated. The peak overpres-sure is the maximum value of the over-

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pressure at a given location arid is gen-erally experienced at the instant theshock (or blast) viave reaches that loca-tion. See Shock Wave.

PAIR PRODUCTION: The processwhereby a gamtna-ray (or X-ray) pho-ton, with energy in, excess of 1.02 MeV.in passing near the nucleus of an atomis converted into a positive electron anda negative elctron. As a result, thephoton ceases to exist. See Photon.

PEAK OVERPRESSURE: The maximumoverpressure value at the blast front.

PERIODIC TABLE: A chaFt showing thearrangement of chemical elements inorder of increasing atomic number inaddition to grouping according to cer-tain chemical similarities.

PERSONNEL *EXPOSURE MEASURE-MENTS: The measured exposure re-ceived by shelter occupants and opera-tions personnel in the field.

PHOTOELECTRIC EFFECT: The processwhereby a gamma-ray (or X-ray) pho-ton, with energy somewhat greater thanthat of the binding energy of an electronin an atom, transfers all its energy tothe electron which 'is consequently re-moved from the atom. Since it has lostall,its energy, the photon ceases to exist.See Photon.

PHOTON: A unit or "particle" of electrom-agnetic radiation, possessing a quantumof energy which is characteristic of theparticular radiation. If v is the fre-quency of the radiation in cycles persecond and X is the wave length in centi-meters, the energy quantum of the pho-ton in ergs is hv or hcX where h isPlanck's constant, 6.62 x 10" erg-sec-ond and c is -the velocity of light(3.00 x 1010 centimeters per second). Forgamma rays, the photon energy is us-ually expressed in million electron volt(MeV) units, i.e., 1.24 x 10'°X where X isin centimeters or 1.24 < 10-2/X if X is inAngstroins.

PIG: A container (usually lead) used to

194

transport and store radioactive mate-riaI;. The thick walls protect the personhandling the container from nuclear ra-diatia

PLUTONIUM: (Chemical symbol Pu.) AManmade transuranium element,atomic number 94. When uranium 238 isbombarded with neutrons in an atomicreactor some of the uranium is con-verted by nuclear reactions into pluton-ium, a fissionable material.

POINT SOURCE: A point at which radio-activity is concentrated as,opposed to anarea over which radioactive materialmight be spread. The DCPA Training

rSource Set sealed capsule is an e9mpleof a point source.

POSITRON: Positively charged electron.

'POSITIVE PHAS: See Shock Wave.

PROTECTION FACTPR (PF): The ratio ofgamma radiation exposa-e at a Stand-ard Unprotected Location to exposureat a protected location, such as a falloutsh'elter. The Standaid Unprotected Lo-cation is defined as a point 3 feet abovean infinite, smooth, ground plane unifor-mally covered with fallout. Protectionfactor is a calculated %alue suitable forplanning purposes as an indicator ofrelative protection. (See Outside/InsideRatio.)

PROTON: A' particle of mass (approxi-mately) unity carrying a unit positivecharge; it is identical physically withthe nucleus of the ordinary (light) hy-drogen atom. All atomic nuclei containprotons. See Nucleus.

(None)

RAD: A unit of absorbed dose of radiation;it represents the absorption of 100 ergsof nuclear- (or ionizing) radiation pergram of the absorbing material or tis-sue,

RADEF: Radiological Defense.

d'3

RADIOACTIVE CLOUD: An dll-inclusiveterm for the mixture of hot gases,smoke, dust, and, other particulate mat-ter from the weapon itself and from theenvironment, which is carried aloft inconjunction With the rising fireball pro-duced by the detonation of a nuclearweapon.

RADIOACTIVITY: The spontaneous dis-integration of unstable nuclei with theresulting emission of nuclear radiation.

RADIATION EXPOSURE RECORD: Thecard issued to individuals for recordingtheir personal radiation exposures.

RADIATION INJURY: The harmful ef-fects caused by ionizing radiation.

RADIOLOGICAL DEFENSE: The organ-ized effort, through warning, detection,and preventive and remedial measures,to minimize Ur effect of nuclear radia-tion on peoplerand resources.

RBE (RELATIVE BIOLOGICAL EFFEC-TIVENESS): The ratio of the number ofrads of gamma radiition of a certainenergy which will produce a specifiedbiological effect to the number of rads ofanother radiation required to producethe same effect is the RBE of this latterradiation.

REM: A unit of biological ,dose of radia-tion; the name s derived from the initialletters of the term "roentgen equivalentman (or mammal)." See RAD.

REMEDIAL MOVEMENT: Movement ofpeople postattack to a less contami-nated area or a .better protected loca-tion.

REP: A unit of absorbed dose of radiationnow being replaced by the rad; the namerep is derived from the initial letters ofthe term "roentgen equivalent physi-cal." Basically, the rep was intendes) toexpress the amount ,of energy absorbedper gram of soft tiswe is a result ofexposure to 1 roentgen of gamma (or X-),raidation. This is estimated to be abgut97 ergs,- although the actual Value de-pends on certain experimental diiiawhich are not precisely known. The rep

41,

is thus defined, in general, as the dose ofany ionizing radiation which results inthe absorption of about 97 ergs of en-ergy per gram of soft tissue. For softtissue, the rep and the rad are essen-tially the same, See RAD, Roentgen.

RESIDUAL NUCLEAR RADIATION:Nuclear radiation, chiefly beta particlesand gamma rays, which persists for._some time following a nuclear (oratomic) explosion. The radiation is emit-ted mainly by the fission products andother bomb residues in the fallout, andto some extent by earth and watar con-stituents, and other matgrials, in whichradioactivity has been i*duced by thecapture of neutrons. See Fallout, In-duced Radioactivity, fnitial Nuclear Ra-diation.

ROENTGEN (R): A unit of exposure togamma (or X-) radiation. It is definedprecisely as the quantity of gamma (orX-) radiation such that the associatedcorpuscular emission per 0.001293 gramof air produces, in air, ions carrying oneelectrostatic unit quantity of electricityof either sign. From the accepted value(34 electron volts) for the energy lost byan .electron in producing a positive-neg-

ative ion pair in air, it is estimated that1 roentgen of gamma (or X-) radiation,would result ,in the -absorption of about87 ergs of energy per gram of air.

SAP

SHELTER: A habitable"structure or spacestocked with essential provisions andused to protect its occupants from'fal,lout TadiatiOn.

'SHIEEDING: Any material o'r obstructionwhich absorbs radiation and thus tendsto protedt personnel or materials fromthe effects of a nucleai- explosion. Amoderately thick layer of any opaquematerial will provide satisfaltory shield-ing from thermal radiation, but a con-siderable thickness of material of highdensity may be needed for nuclear ra-diation shielding.

SHOCK WAVE: , A continuously, pro,pa-. gated pressure pulse (or wave) in the

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surrounding medium which may be air,water, or earth, initiated by the expan-sion of the hot gases produced in an

, explosion. A sho wave in air is gener-ally referred to as blast wave, becauseit resembles and is accompanied bystrong, but trfnsient, winds. The dura-tion of a shock (or blast) wave is distin-guished by two phases. First there is thepositive (occompression) phase duringwhich the pressure rises verY sharply toa value that is higher than ambient and'then decreases rapidly to- the ambientpressup. The Positisq phase for the dy-namic pressure is somewhat lonOr thakfor overkes,sure, due to the manentumof the moving air behind the shockfront. The duration of the positive phaseincrease's and the maximum (peak) pres-sure decreases with increasing distancefrom an,explosion of given energy yield.In thp second phase, the negative (orsuction) phase, the pressure falls belowambient and then rpturns to the am-bient value. The duration of the nega-tive phase, is approximatelY constantthroughout the blast wave history andmay be several times the duration of thepositive phase. Deviations from the am-bient pressure during the negativephase are nevei large and they decreasewith increasing distance from the explo-sion, See' Dynamic Pressure, Overpres-sure.

tSOMATIC: Of/or relating to the body, as

opposed to the spirit; physical.

SPECT/RUM: An image, visible or invisi-ble, formed by rays of light or otherradiant enetgy, in which parts .are ar-ranged according to their refrangibilityor wave-length, so that all of the samewave-length fall together while those Ofdifferent wave-lengths are separatedfrom each other, forniing a regular pro-ressive. series. .

STRATOSPHERE: A relatively stablelayer Of the atmosphere between thetropopause and a height of about. 30.miles in which the.temperature changes,iery little (in polar and terriperatezones) ox increases (in the tropics) withincreasing altitudes. In the stratosphere

..

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/clouds of water never form and there ispractically no convection. See Tropo-

_pause, Troposphere. ....

SUBCRITICAL: The inability of a fission'-able maferial to support a self-sustainedchain reaction.

SUBSURFACE BURST: tee UndergroundBurst, Underwater Burst.

SUPERCRITICAL:, A term used to de-scribe the state of a given fission systemwhen the quantity of fissionable mate-rial is greater than the criqcal mass

' under, the existing colidilions. A 'highlysupercritical system is essential for theproduction of energy at a very rapid

. rate so that an explosion may occur. See.Critical Mass.

SURFACE BURST: The explosion of anuclear (or atomic) weapon, at the sur-face of the land or water or at a heightabove the surface less than the radius ofthe fireball at maximum luminosity (inthesecond thermal pulse). An explosionin which the weapon is detonated ac-tually on the surfaq (or within 5W"feet, where W is the explosion yield inkilotons, above or below the surface) iscalled a contact surface burst or a true,surface burst. See Air Burst.

SURVEY METER: A portable instrument,such as a Geiger counter or ionizationchamber, used to detect nuclear radia-tion and to measure the exposure rate.See Monitoring.

SYNDROMt, RADIATION: The complexof symptoms characterizing the diseaseknown as Adiation injury, resultingfrom excessive exposure of the whole (ora large -part) of the body to ionizing.radiation. The earliest of these symp-toms are nausea, vomiting, and diar-rhea, which mak be followed by loss ofhair (epilation), hemmorhage; inflamma-thin of the mouth .and throat, and gen-eral loss of energy. In severe cases,where the radiation exposure has beenrelatively large, death may occur within

, two to four weeks. Those who survive 6weeks' after the receipt of a Single expo-sure of radiation may lenerally be ex-pected to recover.

2 0 0

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TAMPER: A strong container.

THERMAL ENERGY: The energy emit-ted from the fireball as thermal radia-tion. The total amount of .thermal en-ergy reeeive&-per unit area at a speci-fied distance from a nuclear (or atomic)explosion is generally expressed., interms of calories per square centimeter.See Thernzql Radiatidn. f

,

THERMONUCLEAR: An9adjective refer-ring to the procdss (or' processes) inwhich very ingh temperatures are usedto bring about the fusion of light nuclei,such as those-ef the hydrogen igotopes(deuterium and tritium), with the .ac-conyanying liberation 'of energy. Athermonuclear bomb is a weapon inwhich part of the explosion energy re-sults .from 'thermonuclear fusion reac-tions. The high temperatures requird-are obtained by means of a fission explo-sion. See Fusion.

,

THERNIAL RADIATION: Electromag-netic radiation emitted s(in two pulsesfrom an air burst) from the fireball as aconsequence of its very high tempera-ture; it consists essentially of ultravi-olet, visible, and infrared radiation's. Inthe eariy stages (first pulse of an airburst), when the temperature of thefireball is extremely high, the ultravi-olet radiation predominate in t.he see-,ond pulse, the temperatures are- lowerand mast of the thermal radiation lies ihthe visible and infrared regions of thespectrum. From a high-altitude burst,the thermal radiation' is emitted in asingle short pulse.

TNT EQUIVALENT: A measure of ihe'energy released in the detonation of anuclear weapon, or in the explosion of agiven quantity of fissionable material,expressed in terms of the weight of TNTwhich would release the same amount ofenergy when exploded: The TNT equiva-lent is usually stated in kilotons or me-gato s. The basis. of-the TNT equiva-leflc# is that the explosion of 1 ton ofTN releases 109 calories of energy. SeeKilotori, Megaton, Yield.

,

TRANSMUTATION: The changing of Oneelement into another by a'nuclear reac-tion.

TRITIUM: A radioactive isotope of hydro-gen, having a. mass of 3 units; it isproduced in nuclear reactors by the ac-tion of neutrons on lithium nuclei.

TROPOPAUSE: The imaginary.baundary. .

layer dividing the stratosphere from thelower part of the atmosphere, the tropo-sphere. The tropopause normally occursat4an altiture of about 25,000.to 45,000feet in polar and temperate zones, andat 55,000 feet in the tropics.

TROPOSPHERE: The region of the atmbs-phere immediately above the earth'sstirface and up to the tropopause inwhich the temperature falls fairly 'regu-larly with increasing altitude, cloudsform, convection is active, and mixing iscontinuous and more or less complete.

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ULTRAVIOLET: Electromagnetic radia-tion of wave length between the short-est visible violet and soft X-rays.

UNDERGROUND BURST: The exp'losion-of _a nuclear weapon with its centermore than 5W" teet, where W is theexplosion yields hi kilotons, beneath thesurfac,e of the ground. -See ContainedUnderground Bturst.

UNliERWATER The explosion ofa nuclear weapon ith its center be-neath the sUrface of the water.

UkANIUM: (Chemical symbol U.) The'heaviest naturally.occurrini radiciactiveelement, atomic number' 92. The only

, appreciable souroe of fissionable mate-, rial occurring in naturkis in uranium

ore. This contains aboul 0.7% of thefissionable isotope Um and 99.3% of thenonfissionable isotope U238.

V

(N o n'e)

W

WEIGHT: A measuye of the force withwhich matter is attracted to the earth.

197

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MVORLDWIDE FALLOUT: See Fallout.

- X

X-RAYS: Electromagnetic radiations;of,

_ high energy having wave lengths.

aiorter than those in are ultravioletregion,.i.e., less than 10-6 cm or 100Angstroms. As generally produced by X-ray machines, the'y are brethisstralilungresulting from the interaction of elec-trons of 1 kilo-electron volt or more en-ergy with a metallic target. See gammaRays, Electromagnetic Radiatiop.,

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YIELD (OR ENERGY YIELD): The totaleffective energyJeleased in a miclearexplosion.. It is usually' expressed interms of-the equivalent tonnage-of TNTrequired to produce the same energyrelease in an explosion. The total energyyield is manifested as nuclear radiation,thermal radiatton, and,shock ()4 blast)energy, the actual distributiOn.being de-pendent -upon the, medium in which goexplosion occurs (primarily) and alsoupon the type of weapon ;and the i'imeafter detonation. .

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