short thorium-15
TRANSCRIPT
Thoriumwhat is is it ?it’s an element, a metal... like lead or silveris there much of it ?... it’s more common than tin... and it’s all over the planet
what use is Thorium ?not much, but
45 years ago, they found that
it is, by farthe most powerful fuel
on the planetbut kept it a secret
but, isn’t Uranium...... the only nuclear
fuel ?it is the only one we use...
... with it’s derivative, Plutonium
but Thoriumis also a nuclear fuel
is Thorium different...... from Uranium (&
Plutonium)• it is not radio-active, ie fissile• its reactors are much safer...
... they can’t explode• it leaves no unspent fuel, so...
... it makes no long-term waste
• you can’t make a Thorium bomb
is that all ?• it makes (a little) short-term waste...
... but most of this ash is valuable... used in medicine and hi-tech
• it would make electricity...... cheaper than from coal
• it is as green as renewables
and is that all ?
no, burning Thorium, in a ...molten salt reactor
you can destroyall the unspent fuel from allthe Uranium (& Plutonium)
reactorswhich would otherwise
last 240,000 years
no, I didn’t believe it, either
so this is the story of
Thoriumbut first ...
Chapter 1
so
why might the children
want a silver bullet ?
What’s going on...... in Europe’s two biggest
economies ?• Germany is phasing out all nuclear power
... to close all reactors by 2022
• 80% of France’s electricity is nuclear
... 58 reactors currently operational
... 75% of citizens want to close them
Other Recent News• Lib-Cons have accepted IPCC targets
... Inter-governmental Panel on Climate Change
• UK Greens seem to have accepted that• renewables won’t solve the energy-crunch (alone)• carbon-targets imply some nuclear contribution
• post-Fukushima... safety issue is back on the agenda
• Arab-spring brings focus on oil-supply• shale-gas (fracking) is dressing-up as “green”• 500 died in US tornados• big CO2 increases in 2010
business as usual ?
IPCC carbon reduction targets• 34% by 2020 9 years to go
... already agreed
• 60% by 2030 19 years to go
... already agreed
• 80% by 2050 39 years to go
... now agreed, by Lib-Cons
but no-one has said how - yet !
? can we avoid... climate-disaster
...with just• renewables
... solar, wind, tidal, hydro, biomass
• CCS... carbon-capture & sequestration
noaccording to the IPCC
IPCC, electricity sources, by 2050
renewables now 6% up to 40%
nuclear now 16% up to 40%
fossil fuels now 76% down to 20%
why so drastic ?
+ 3 Centigrade• Amazon burns
• sea-level rises... engulfs London, New York, & islands... Bangladesh, etc ... went earlier
• Australia, west-US, southern Africa... become deserts
• billions forced to move... loss of agricultural land
• 30% - 50% less water in Africa, Mediterranean
Thames barrier
+3 Centigrade
replacement design... is 10 miles long
2010 saw a record rise in CO2 emissions
now 30 gigatonnes / annum
so there is now a 50% chance... of +4C rise by 2100
+ 4 Centigrade• Arctic ice disappears• Antarctic melting
... gives 5m rise in sea level• Italy, Spain, Greece, Turkey become deserts• mid-Europe reaches 50C in summer• southern-England’s summer climate
... it would resemble southern Morocco, now
• Arctic permafrost enters danger-zone... Methane & CO2 released to atmosphere... Methane is x 23 stronger greenhouse gas
so, the Human Race...... is at the cross-roads
avoidclimate-change
disaster inserthead in the sand
do we just wait for the apocalypse... drought, floods, famine, refugees, wars
the biggest problem...... our children will face
climate-changefrom the CO2 build-up
versus
the energy-crunchgeneration and conservation
wikipedia
wikipedia
............ ie Coal, Gas, Oil
UK nuclearpower stations ... still operational
Notice• they are all on the coast• away from people, safer• extra transmission losses
DungenessHinkley Point
Oldbury
Wylfa
Hunterston
Heysham1 & 2
Sizewell
Hartlepool
Torness
AGR
PWR
Magnox
Sizewell B ... closes 2035
all other reactors ... by 2023
UK carbon reduction targets...extrapolated to 2050 (IPCC)
2020 2030 2050 wikipedia
...... ie Coal, Gas, Oil
Coal, Gas, Oil
Nuclear
but all
new
Renew
ables
Sizewell B ... closes 2035all other reactors - close by 2023
To meet the IPCC targets for 2050... we must, without delay
• revolutionise electricity generation, the hard bit• renewables x 7, but law of diminishing returns• nuclear x 3, but closing all existing reactors
• the necessary bit• super-grid, local generation, CHP• storage, smart-consumers, reduce demand• the easy bit ?
... closing 75% of all fossil-fuelled power stations
• limit & manage climate change... storms, droughts, floods, refugees, resources
but how can we meet those targets ??
Fukushima
fuel ... Uranium (& Plutonium)reactor design ... solid-fuelproblem ... needs active cooling
result ... hydrogen explosions ... fuel melt-downs ... contamination
So every nation has an urgent problem• we must phase out fossil fuels
... or we’ll roast & drown the planet• renewables (alone) won’t keep the lights onSo why is “nuclear” not the answer
... where nuclear = Uranium (& Plutonium)
• reactors can explode• 99% of fuel is left “unspent”
... making long-term radioactive waste• fuel supply may be limited, precarious ?• enrichment and reprocessing are dangerous
... pollution, weapons proliferation risks
so, the Human Race...... is at the cross-roads
Thoriumliquid-fuelledUraniu
mSolid-
fuelled
and we do not have much time to decide
Chapter 2
so, why are weonly looking at
Uranium (& Plutonium)&
solid-fuelled reactors ?
To understand where we are now...... we must remember how we got
hereThe first 30 years ... on which, more to follow1941 - Manhattan Project1946 - McMahon Act, weapons build-up1954 - naval propulsion, subs, carriers1956 - electricity, Uranium solid-fuel1965 - Molten Salt Reactor - Weinberg1973 - Nixon sacks WeinbergThe next 40 years - Weinberg vindicated
1979 - Three Mile Island1986 - Chernobyl2011 - Fukushima
1941 Manhattan Project Robert Oppenheimer
• objective - build an atomic bomb... before Hitler does
• only 2 nuclear “fuels”... Uranium, Thorium
• but bombs need fissile isotopes... heat, neutrons >> chain reaction ((O))
• Uranium is fissile, twice over<1% is U-235 (needs enrichment) >> ((O))>99% is U-238 (fertile) >> Plutonium >> ((O))
• Thorium is not fissile, it can’t make a bomb... Th-232 (fertile) >> U-233 ((O))
1945 Manhattan Project - outcome• the decision
... to meet the objective
... make bombs from Uranium
Hiroshima ... Uranium-235Nagasaki .... Plutonium-239
• BTW ... Manhattan Project also mined Thorium• 3,200 tonnes• but never used it• it is still in Nevada
• Commission's right to seize...... "property containing deposits of uranium or thorium”
• It defined a new legal term “restricted data” as “all data concerning the manufacture or utilisation of atomic weapons, the production of fissionable material, or the use of fissionable material in the production of power”
• The phrase “all data” included every suggestion, speculation, scenario, or rumor - past, present, or future, regardless of its source, or even of its accuracy - unless it was specifically declassified
a culture of secrecy ... not just covering weaponsbut including electricity generation, thorium
1946 Atomic Energy (McMahon) Act... formed the Nuclear Regulatory Commission
• USS Nautilus - 1954• first nuclear powered submarine• PWR - Pressurised Water Reactor • built by Westinghouse
• USS Enterprise - 1962• first nuclear powered aircraft carrier• 8 x PWRs (A2W)• used U-235 enriched to 93%• built by Westinghouse
1950s ... Nuclear-Powered US Navy
convenient operational model• at sea, sealed power units, Uranium, solid fuelled• on land, fuel enrichment & reprocessing
>> weapons grade materialthe first use of nuclear power reactors
all Uranium, solid fuelled
1956 ... Calder Hall, Windscale ... electricity
• dual purpose• initially, mainly for Plutonium• then, for Plutonium and electricity (1964)• finally, just for electricity (1995 – 2003)
• US ... Shippingport reactor (1957) - electricity• Russia ... Obninsk reactor (1954) - electricity
all Uranium, solid-fuelled
• Oak Ridge Lab ran the experimental MSR... MSRE went live in 1965, ran until 1969
• proved the basic concepts, including• working at atmospheric pressure, unlike U/Pu-solid• fluid fuel, unlike U/Pu-solid• passive cooling, unlike U/Pu-solid• no long-term waste, complete-burn, unlike U/Pu-solid• burned U-233 (from Thorium), plus U-235, Pu-239• produced fission-products (ash), same as U/Pu-solid
• operated 24/5 ... switched off at the weekends... would have been handy at Chernobyl, Fukushima
• 1970-76 ... refined the design – for a LFTR... ie an operational Liquid-Fluoride Thorium Reactor
Oak Ridge (National Lab) Director was Alvin Weinberg
1965... Molten Salt ReactorUTh
Th
Molten Salt technology ... nothing to do with nuclear
• captures / stores / transfers heat, to turbines• stays liquid to very high temperatures, 1400C• replaces water, which boils at 100C
solar power, mirrors ... California
They found that...... it stored enough heat during the day
... in the molten salt... to keep the turbines running
... through the night
<< heat collector
^^ hot & cool salt tanks, I think ?
by the way“common salt” is Na Cl...
ie Sodium Chloride
but to chemists, the term “salt” ...... covers a whole class of compounds
they found that the best salt for a LFTR...
... is a combination of...• Lithium Fluoride Li F• Beryllium Fluoride Be F2
1973 ... Alvin Weinberg was fired• AW was Director at Oak Ridge NL 1945 - 73• LWR (PWR and BWR) developed at Oak Ridge• AW held patents to both PWR and BWR
... majority of today’s commercial nuclear reactors
• AW co-authored the first Nuclear Reactor textbook
...The Physical Theory of Neutron Chain Reactors
... with Nobel Laureate Eugene Wigner, 1958• AW ran the Molten Salt Reactor, 1965 - 69 (MSRE)• 1973 ... AW was fired, by Nixon administration
... for arguing that MSR was safe, and LWR was not
• all MSRE records were kept secret... even other National Labs knew nothing of MSREand that remained the situation for the next 33
years
problem withhigh pressure
Uraniumreactors
which needactive cooling
----even after shutdown
----boiling water
can lead tohydrogen explosions
andfuel melt-downs
All reactors contain both ...• unspent fuel ................. makes long-term waste• fission products (ash) ... makes medium-term waste
So, if they could explode ...... they would spread both types... locally, and even globally
Uranium solid-fuelled reactorscan explode
Thorium liquid-fuelled reactorscannot explode
Exploding Uranium Reactors
• spread fission products (ash) over wide areas• eg Caesium(55), Strontium(38), Iodine(53) • medium-term waste• 90% gone in100 years, all gone in 300 years• Iodine is all gone in 3 months ... thyroid threat
• also spread unspent fuel over wide areas• eg Uranium(92), Plutonium(94)• long-term waste• lasts 240,000 years
In normal (non-exploding) mode
Uranium (solid-fuel) reactors...... only burn ~ 1% of their fuel... so leave ~ 99% as unspent fuel... this long-term waste...
... is bundled up, with the ash
... in the old extracted fuel-rodsFor comparison, non-exploding ...Thorium (liquid-fuel) reactors...... burn 100% of their fuel... so only produce ...
... medium-term fission products, ie ash
The Nuclear Industry... ... does need strong regulation
but through a combination of• secrecy• restrictive licensing & investment• vested interests ...
... government, military, industrial
it seems to have become...... the Uranium Industry
The Uranium industry...• thrived and expanded, in the 70s, 80s
... there was no other game in town• but has suffered a series of setbacks
... they stopped building new reactors
• out of about 500 nuclear power stations
... 7 have had “uncontrolled incidents”
• to-date, notably...• Windscale• Three Mile Island• Chernobyl• Fukushima
all Uranium solid-fuelled
2006 ... MSRE files, went publicOak Ridge National Laboratory (ORNL), Tennessee
• the Molten Salt Reactor Experiment ... which ORNL ran from 1965 to 1969... and the files had been kept secret
• the papers were scanned onto 5 CDs... by Kirk Sorensen, et al... when given access in 2002
• 2006 ... MSRE files uploaded to the Internet
this kick-started the interest in Thoriumin the modern era
and here comes
the snake-oil moment ?
or is that the silver bullet ?
Thorium
...is so energy-dense that you could hold
your whole lifetime supply
in the palm of your hand
Chapter 3OK
tell me about
this silver bullet
one person’s fuel supply
... for one year Thorium ... one gram
-----------------------
Uranium ... ¼ kg(250 grams)
-----------------------
Coal ... 3.2 tonnes
How much fuel is left...??... assuming current usage
• Uranium without breeding Plute .. about 100 years• coal ............................. about 400 years
...but if they burn it all (without CCS)......the planet will become uninhabitable
How much Thorium is there... compared to Uranium
• ore ........... 4 times as much, known, so far• heat .......... 1000 times, 100,000 years• electricity.. 1600 times, 160,000 years
and Thorium is spread all over the planet
Where is Thorium ?? “known reserves” are probably an under-estimate
... not much incentive to search, yet ... low value
Country Known Reserves (tonnes)
United States 440,000Australia 300,000
Brazil 16,000Canada 100,000
India 290,000 to 650,000Malaysia 4,500
South Africa 35,000Other Countries 90,000
World Total 1,300,000 to 1,660,0003,200 tonnes, Manhattan left-overs, Nevada“rare-earth” mines ... tailings are high in
Thorium
How much Thorium ore is there..??
5 feet1 metre
@ average ~ 10grams / cubic-metrewe are standing on our personal lifetime
supply
Atomic Numbe
r
Element Code
Most Commo
n Isotope
Half-Life
89 Actinium Ac 227 22 years90 Thorium Th 232 14 billion years91 Proactiniu
mPa 231 32,760 years
92 Uranium U 238 4.5 billion years93 Neptunium Np 237 2.1 million years94 Plutonium Pu 244 80 million years
the Actinide Series... ... from the Periodic Table
Uranium is the heaviest naturally occurring element
Thorium is the second ... but there’s more of it
the rest (and above Plutonium) are too unstable to survive
Breed & Burn ... Uranium & Thoriumatomic no
>Th - 90
PA - 91 U - 92 Np - 93
Pu - 94
isotope239 O - e
> O - e
>((O))
238 O + n ^
237236235 ((O))234233 O - e
> O - e
>((O))
232 O + n ^
O + n = fertile, absorbs a neutronO - e = unstable, loses an electron (ie beta decay)((O)) = fissile, splits up, giving off heat
U-235fissile
U-238fertile
Th-232fertile
OK, how does it work ?
... a Thorium Reactor
... using Molten Salt
it’s known as a LFTRpronounced “lifter”Liquid Fluoride Thorium
Reactor
newThorium-232
FissileU-233
Core-Fluid
Dual-Fluid LFTR
fissionproducts
‘ash’
half-life = 27 days
Pa-233decays to
U-233
HeatExchange
r&
Turbine
draintanks
U-233Pa-233
U-233
FertileBreeder Fluid
WasteSeparator
Thorium-232Blanket
freeze-plugpassive cooling
neutrons neutrons
FissileSeparator
100% burn ...... no unspent fuel
cool salt
Th-232
hot salt
neutrons neutrons
fissile-trigger
fan
At Oak Ridge Lab...... where they ran the MSR... they all went home for the weekend
When they switched off the power... that included the fan... which kept the freeze plug frozen
The hot salt just ran...... into the drain tanks
The chain reaction ((O))... relies on compact geometry
so it stopped ... passive cooling
freeze-plug
Fuel Cycle ... Thorium
products££
Thoriumminingtailings
convertto metal
blanketfluid
decay
100%burn
LFTRdual-fluid
reactor
surfacestorage
300 yearwaste
83%
17%
fission products
100% fueldisposal after
10 years
> 3% U-235
unspent fuel &
fission products
Fuel Cycle ... Uranium / Plutonium
Uraniumminingtailings
convertto UF6
fabricatefuel
partialburn
solid-fuel reactor
vitrify
240,000 year waste
fuel rods
DepletedUranium
wastelong & medium
reprocessPlutonium
wastelong & medium
Uranium
Plutonium
??
??
long & medium wasteMOX
enrich
0.7% U-235
onlyonce!
Things that Thorium / LFTR ...does not do, or need• fuel enrichment
... it comes out of the ground as 100% fuel
• partial burn – leaving unspent fuel• high pressure reactor – it runs at atmospheric• high pressure containment building
... it cannot explode• active cooling
... LFTR design provides passive cooling• reprocessing – no unspent fuel in the waste• long-term waste management – there is none• make Plutonium
Things that Thorium / LFTR ...does do, or can do• uses cheap, plentiful fuel - not radioactive• runs safe, self-limiting
... at atmospheric pressure
... it’s already “melted-down”
... “negative feedback coefficient” - cannot explode
... works like an accelerator (within one minute)• makes green electricity
... runs hotter, more efficient generator, less cooling
... can make hydrogen >> petrol, NH4, fertilisers (eating CO2)
• makes medium-term waste... 83% can be isolated and sold - medicine, hi-tech... compact residue ... 17% (gone in 300 years)
• can burn up existing long-term waste ... U-235, Pu-239• allows large / small power units, safe and local
... reduced transmission losses• can support CHP, combined heat & power
Uranium / Plutonium• ~ 1GW (typical)• large footprint• difficult siting
Thorium / LFTR• ~ 10MW >> ~ ?GW• small footprint• easy siting
LFTRs could be manufactured on a production-line
like aircraft
How Efficient Is Thorium..??In order to getthe same energy out
thermal energy (ie heat) ............................ x 250electricity (at factory-gate value) .................. x 320
Electricity (with savings from “local generation” ) user-value (transmission losses, ½ the 16%?) ..... x 350CHP (waste heat, deliver ½?) ........................... x 380
Combination of both “local savings” (28%)ie ½ transmission losses & ½ CHP ......... x 410
this is a comparison of materials, not costs
How much more Uraniumdo we need to put in ??
Uranium Thorium
one tonne of ashfission products
one tonne of ashfission products
2222 MW*yr thermal-energy
2222 MW*yr thermal-energy
1111 MW*yr electricity
740 MW*yr electricity
one tonne of
natural thorium
33.4t uranium-238
0.3t uranium-235
0.3t plutonium
1111 MW*yr waste heat
1482 MW*yr waste heat
35t enriched uranium
(1.15 t U-235)
215t depleted uranium
(0.6t U-235)
250t natural uranium
(1.75 t U-235)
35 tonnes wastelasts 240, 000 years
170 kg wastelasts 300 years
830 kg £££valuable isotopes
33% 50%
equatingfission
products
Numberscourtesy ofKirk Sorensen
equatingthermalenergy
6,000 tonnes of thorium(455 quads)
and that’s without any extrasavings from local generation
5.3 billion tonnesof coal (128
quads)31.1 billion barrelsof oil (180 quads)
2.92 trillion m3
of natural gas(105 quads)
65,000 tonnesof uranium ore
(24 quads)
World Energy Consumption …2007
The Future…Energy from Thorium
…total 437 quads quad = quadrillion BTU (10 ){ie one million billion BTU}
or 33.5 GigaWatt-Years
15
Numberscourtesy ofKirk Sorensen
So the whole planet’s fuel supply for one year
... 6,000 tonnes of Thorium
... could be delivered by 150 lorries
... (eg @ 40 per)
But including “local generation savings”
... this comes down to 117 lorries
Chapter 4Alvin
gets the last laugh----
but will theyget the message ?
Renewables - prospects
time
increasing marginal costscost / MW
decreasing marginal CO2 benefits
carbonsavings
“low-hanging fruit” ... the long-term downside
so set off ... but don’t expect to go all the way
capacity
MW
OK ???
2nd dash-for-gas ?• more than 50% of UK fossil capacity...
... is already gas• natural-gas carbon-footprint...
... is about 35% of coal• but fracking-gas footprint is > than coalIn a 2nd dash-for-gas, assume for
example ...• ½ of residual coal is converted to gas• and ½ of new gas includes CHP• but if ½ of gas goes natural >> fracking• then, total carbon-footprint ...
would increase !!
2nd Dash for Gas - prospects
gas replacing coal ?
time
steady marginal costs
cost / MW
natural gas
replacing coal
CHP would reduce foot-printhigh fracking % might get worse than coal
need to move away from fossil fuels
MW
capac
ity
fracking gas
replacing natural gas
carbonsavings
The Uranium Industry...... would (no doubt) be very happy... to replace all / most existing reactors... with Uranium (solid-fuel) of course
That may even be...... the most they could hope to do
They would make a lot of £££, but ...
that would not reduce carbon
Uranium & Plutonium - prospectsUranium replacing Uranium ?
time
cost / MW
poor CO2 benefits
carbonsavings
closure of obsolete nuclear reactorswould drive the schedule ?
MW
steady marginal costs
replac
ing nuclear
replacing coal
• 2006 - Oak Ridge papers scanned >> internet... that was the starting gun
• scientist & engineers now working on updated designs
... see Washington Conference, TEAC, May 2011
• EURATOM / France have Project EVOL... working towards a prototype LFTR in 2013
• other work in Russia, Japan, Czech Rep
• India is looking at Thorium, but solid-fuel
• China (Jan 2011) launched a Thorium / LFTR program
interest is growing - despite inertia of governments
LFTRs ... who is doing what..??UTh
Th
Thorium / LFTR - prospects
time
decreasing marginal costs - scale
cost / MW
increasing marginal CO2 benefits
carbonsavings
slow start ... rapid growth ... no ceilings
replacement priorities ... coal, fracking, oil, gas
Uranium will phase itself out
MW
replacing nuclear & coal
replacing fo
ssil
Modern management methods...... for comparing options...
... are fine, when you can...... put a value on all the risks
When you can’t...... NPV & DCF tend to favour (misleadingly)...
... quick wins and short-termismDidn’t 2008 teach us that...
... the sheer scale of human systems...... is no guarantee against...
... fundamental systemic failureHow can you price an insurance premium...
... against a 5 metre rise in sea-level ?... who do you buy it from ?
Chapter 5
what next
so, the Human Race...... is at the cross-roads
Thoriumliquid-fuelledUraniu
mSolid-
fuelled
and we do not have much time to decide
UTh
Th
• Thorium / LFTR offers the way forward... in solving the problems of the energy-crunch... in (contributing to) dealing with climate-change
• the approach is basically proven... they ran the Oak Ridge reactor for five years... but for development, it requires investment
• the business/regulatory context prevents progress
... only Uranium & Plutonium (solid-fuel) is allowed
• the traditional approach was aimed at weapons
... with risk of explosions, and long term waste
... the problem now is all about power generation
• the only viable solution ... is a combination of... demand reduction, renewables, Thorium / LFTR
Conclusions
Who to watch...• Germany is gambling on renewables• France is making an each-way bet ??• US seems frozen, in the headlights...
... of its own military-industrial complex... but US scientist & engineers leading on Thorium
• China’s Thorium LFTR program...... might be the planet’s best news
• UK is due to close nuclear reactors...
... almost as fast as Germany
... but we expect to replace them, x 3
... but with what ... watch this space
U
Th
Th
??
Thorium is so energy-dense
that you could hold
your whole lifetime supply
in the palm of your hand
but only if we invest in LFTR technology
UTh
Th
Health Warning ... and acknowledgements• this is not an engineering paper• its author claims no expertise in nuclear engineering
... but has worked in the nuclear industry
... and has a degree in physics - long ago
... Fukushima prompted him to catch up with Thorium• if you wish to pursue any aspect of this topic ...
... it’s all on the web, including wikipedia
... some search suggestions, which I leaned on, thanks
• energy from thorium• thorium energy alliance• Kirk Sorensen, Robert Hargraves• Alvin Weinberg, Dr David LeBlanc• MSRE, ORNL
• the papers suggest that there are development obstacles...
... but no showstoppers ... telescope to blind eye ?• but for further info, please feel free to contact...
Uranium / Plutonium solid-fuel fuel - limited supply .........fuel - poor efficiency ........needs enrichment ............dangerous reactors .......... no CHP or transmission savings stops to refuel ..................unspent fuel, partial burn long term waste, 240K years fission products, “ash” ....... no £ from fission products bulky waste, long & mediumcannot make green H2some proliferation riskcannot burn-off long waste
Thoriumliquid-fuel4 x as much orex 250 heat, x 320 elecdoesn’t, 100% fuelsafe, localcan do bothcontinuous operationnone, complete burnnonesame, 300 years£, medical, hi-techcompact, medium onlycan, & NH4 > fertilizersreducedcan, the only way ??
can something be...
... too good to be true
... but still be true ??
There have been three ...... strategic nuclear decisions• to make bombs from Uranium• to power ships with Uranium• to make electricity from Uranium
We are now facing the 4th decision...
... how to make electricity... to meet the carbon-challenge
let’s get it right, this timechoose Thorium LFTR
thanks, Alvin
but what about the children ?
did they all
live happily ever after ?
tune in next year
to hear ifthe children manageto pick up the bullet
and slay thecarbon dragon
thank you for
persevering to the end
of something
which still seems
quite difficult to believe
Annex A
Re-processingof waste fuel
Reprocessing ... Victor Gilinsky (NRC)Reprocessing and recycle: Why renewed
interest?How would they relate to Yucca Mountain?presentation to the Nevada High Level Radioactive Waste
Committeeat the May 14, 2008 meeting Las Vegas
Three Mile Island
Reprocessing – purpose
Reprocessing – of (un)spent fuel
World commercial reprocessing...• Commercial reprocessing and recycle, as carried out in France and Britain and now in Japan, with some subsequent recycle of plutonium, adds very little, at great expense, to the fuel supply ~20%
• We already use plutonium in reactors...... about 40% of power from US reactors comes from plutonium
• Very difficult to recycle more than once...... because you build up contaminants that mess up the process
• After one cycle you still have spent fuel to dispose of
• So there is little gain (say, 20%) in terms of repository space
Why do the French and others do it?...• First their nuclear bureaucracies are more powerful and ideological
... and believe in future plutonium use• Reprocessing of foreign fuel was a moneymaker ...
... just because something is not economic...... doesn’t mean you can’t make money at it
... so long as someone foots the bill, as the Japanese did
• Note the British don’t reprocess their own LWR fuel...... and will likely phase out reprocessing altogether... and will be left with 100 tons of plutoniumTHORP
ThermalOxideReprocessingPlant
Yucca MountainRepository
• funding for development of Yucca Mountain waste site was terminated...
... 2011 federal budget - passed by Congress on April 14, 2011
• leaves the US with no long term storage site for high level radioactive waste
• currently stored on-site at various nuclear facilities around the country
worldwide, the majority of waste
is not reprocessed
Annex B
Risk Comparisonspollution
proliferation (weapons)
Risk .... Types and Phases
Phases of Operation....• pre-op ... fuel enrichment (eg centrifuges)• operational reactor• post-op ... waste management
Types of Risk....• radiation release / pollution• proliferation (of weapons)
Phase Uranium/PlutoniumSolid Fuel (Rods)
Pre-OpFuel Enrichment
(centrifuges)
medium / low riskU-235 >> Weapons Grade
OperationalReactor
high riskhigh pressure, hydrogen
---------------------------Fission Products (Cs, Sr, I)medium-term pollution
---------------------------U-235, U-238, Pu-239long-term pollution
Post-OpWaste Management
medium risk (but long time)Fission Products (Cs, Sr, I)medium-term pollution
---------------------------U-235, U-238, Pu-239
Un-Spent Fuel (long-term)
Risk of Radiation Release / Pollution
Phase Uranium/PlutoniumSolid Fuel (Rods)
ThoriumLiquid Fuel (LFTR)
Pre-OpFuel Enrichment
(centrifuges)
medium / low riskU-235 >> Weapons Grade
no riskno Enrichment
no Fissile Material
OperationalReactor
high riskhigh pressure, hydrogen
---------------------------Fission Products (Cs, Sr, I)medium-term pollution
---------------------------U-235, U-238, Pu-239long-term pollution
no riskno pressure or hydrogen
----------------------------Fission Products (Cs, Sr, I)medium-term pollution
---------------------------U-233, U-232
long-term pollution
Post-OpWaste Management
medium risk (but long time)Fission Products (Cs, Sr, I)medium-term pollution
---------------------------U-235, U-238, Pu-239
Un-Spent Fuel (long-term)
low riskFission Products (Cs, Sr, I)medium-term pollution
---------------------------no Un-Spent Fuel
Risk of Radiation Release / Pollution
Phase Uranium/PlutoniumSolid Fuel (Rods)
Pre-OpFuel Enrichment
(centrifuges)
U-235 >> weapons gradenuke
OperationalReactor *
Fission Products (Cs, Sr, I)dirty bomb
---------------------------U-235, U-238, Pu-239
nuke
Post-OpWaste Management
Fission Products (Cs, Sr, I)dirty bomb
---------------------------U-235, U-238, Pu-239Un-Spent fuel ... nuke
Risk of Proliferation (of weapons)
* probably need to distinguish between “materials bandits”and rogue states (running reactors)
Phase Uranium/PlutoniumSolid Fuel (Rods)
ThoriumLiquid Fuel (LFTR)
Pre-OpFuel Enrichment
(centrifuges)
U-235 >> weapons gradenuke
no Enrichmentno Fissile Material
no risk
OperationalReactor *
Fission Products (Cs, Sr, I)dirty bomb
---------------------------U-235, U-238, Pu-239
nuke
Fission Products (Cs, Sr, I)dirty bomb
---------------------------U-233, U-232 (gamma)
no real risk..?? **
Post-OpWaste Management
Fission Products (Cs, Sr, I)dirty bomb
---------------------------U-235, U-238, Pu-239Un-Spent fuel ... nuke
Fission Products (Cs, Sr, I)dirty bomb
---------------------------no Un-Spent fuel
no nuke risk
Risk of Proliferation (of weapons)
* probably need to distinguish between “materials bandits”and rogue states (running reactors)
** need to read Kirk Sorensen’s “rebuttal” of IEER ‘fact sheet’
Annex C
Miscellaneous
nuclear story has many threads
commerce industrymilitary
science research engineering
weapons naval motors electricity
ecology society politics
history
and they are all inter-woven
Generation IV...... new nuclear reactor designs
• “Thermal-neutron” reactors• Very-high-temperature reactor (VHTR)• Supercritical-water-cooled reactor (SCWR)• Molten-salt reactor (MSR) - Thorium / LFTR
• “Fast-neutron” reactors• Gas-cooled fast reactor (GFR)• Sodium-cooled fast reactor (SFR)• Lead-cooled fast reactor (LFR)
• Energy amplifier (ADS) – accelerator + Thorium
otherwise, Uranium/Plutonium, solid-fuelled
Radioactive Decay... .... a Half-Life is how long it takes an isotope .... .... to decay down to half of its initial level
time
level
Radioactive Decay Curve
initial
half
halflife
eg - radioactive isotopes........ in 3 Half-Lives decay down to <13%.... in 6 Half-Lives decay down to <2%.... in10 Half-Lives decay down to less than a tenth of 1%
Radioactivity.... .... distinguish between three timescales....
Type of Waste Product in 3 H-Ls
in 6 H-Ls
in 10 H-Ls
Time
short-term (fission products)... <13% <2% <0.1% Units.... Iodine-131, H-L = 8 days 24 48 80 days
medium-term (fission products)....
.... Caesium-137, H-L = 30 years
90 180 300 years
.... Strontium-90, H-L = 29 years
87 174 290 years
long-term (unspent fuel)........ Uranium-235, H-L = 700 million
years2.1 4.2 7.0 bn-yrs
.... Plutonium-239, H-L = 24,200 years
73 145 242 k-yrs
All radioactive isotopes........ in 3 Half-Lives decay down to <13% (of original).... in 6 Half-Lives decay down to <2%.... in 10 Half-Lives decay down to less than a tenth of 1%
Carbon Footprints ... of common fuelsSource Grams(CO2) /
KW.HrCoal 955
Oil 893Natural Gas 599
Photo-Voltaics 106Nuclear - Uranium 60
Wind 21Hydro-Electric 15
Derive Thorium / LFTR footprint from Uranium (60), but...• easier mining, no enrichment• no re-processing or long-term waste• simpler reactor, at atmospheric pressure• Thorium (fuel-efficiency) = Uranium x 320• looks like ...“similar to Hydro-Electric”..??
+ explosions
not shale
wikipedia
|161 including
particulate pollution
|disputed, eg
post - Chernobyl
|171,000 atBanqiao
Annual Deaths per TW.Hr
Industrial Nuclear stats look good...• but disputed due to hidden, delayed deaths..??• Thorium / LFTR should beat Uranium• many risks avoided, no explosions
nextbigfuture
Uranium
Thorium / LFTR, with all its savings, is predicted to be...
... so much cheaper than Uranium...... that it would be cheaper than coal
LWR (BWR & PWR)
• most common types• solid-fuel (rods)
• need enriched Uranium• water as coolant• water as moderator• very high pressure, x 150• need active cooling• only a partial-burn• so long-term radioactive waste (U, Pu), plus fission products• Fukushima, 6 x BWRs• Three Mile Island was a PWR• Chernobyl RBMK (Russian ‘BWR’)...
... but graphite moderator, so unenriched Uranium
reactorsteam turbine, electric
generator
coolingpump, condenserAuthor: Robert Steffens
Boiling Water Reactor
Author: European Nuclear Society
His concern ... solid-fuel reactors can be unstableUranium &/or Plutonium• solid fuel-rods• U-235 needs enrichment (LWR)
Water used as coolant• heated to ~ 500C• also slows down neutrons• so sustains chain reaction
Very high pressures• 150 x atmospheric pressure• strong container vessel• eg 20cm steel• plus massive concrete outer
Only “partial-burn” of fuel (~1%)• so U-235, Pu-239 in waste
Fuel rods damaged/replaced• eg after 1 or 2 years• scheduled closedowns
If reactors overheat ... ... water splits >> hydrogen
How good is Uranium.... ... as a nuclear fuel..??
Good news...• U-235 is fissile – so provides its own neutron source• U-238 is fertile – so converts into fissile Pu-239Bad news...• U-235 is very low % (0.7%) ... so it needs enrichment• Uranium burns (1%) in a solid-fuel reactor...
... so only an incomplete (partial) burn
... long-term waste, high-level, (99%)Question...
is residual Pu-239 an asset (weapons) ...??... or a liability (proliferation, pollution) ...??
How good is Thorium.... ... as a nuclear fuel..??
Bad news...• it needs a fissile trigger – to get the neutrons startedGood news...• once started, it is self-sustaining, in neutron flux• Th-232 is fertile – so converts into fissile U-233• there is no need for enrichment - already 100%• Thorium can breed & burn in a liquid-fuel reactor...
... so it can perform a complete (100%) burn• no U-238 to breed into Pu-239• four times more available than Uranium
UTh
Th
The US fuel supply for one year ...... which is about 20% of planet’s
... would be about 1200 tonnes... of Thorium
So, the 3,200 tonnes in Nevada ...... left over from the Manhattan Project...
... would cover about 3 years US supply
If they converted all US supply to Thorium...
... steadily, over (say) 40 years... then, the US would not need to mine
... any new Thorium... for about 12 years
After that, just to give...... only one example ...
the Lemhi Pass...... on the Montana-Idaho border...
... has ~ 1,800,000 tons...... of high-grade thorium ore
That alone...... adds up to about ~ 1,000 years...
... fuel supply...... for the whole USA
rises inSea-Level,from meltingIce-Sheets
Greenland ... 7m
West Antarctic ... 6m
Antarctic ...61m
more evaporation more cloud more rain more wind more severe events
Changesin theWeather
growth of deserts forced migrations
water supply problems agricultural changes
impacts on food production
OceanCurrentsNorthAtlanticConveyor• energy equivalent
... one million nuclear power stations• it warms northern Europe, by 5C to 10C• it’s being slowed (stopped ?) by climate-change
... maybe an ice-age for Europe ??
Breed & Burnatomic no
>Th - 90
PA - 91 U - 92 Np - 93
Pu - 94
isotope239 O - e
> O - e
>((O))
238 O + n ^
237236235 ((O))234233 O - e
> O - e
>((O))
232 O + n ^
O + n = fertile, absorb a neutron ((O)) = fissile O - e = unstable, lose an electron (ie beta decay)
first questionis Uranium (solid-fuel)...
...the only type of nuclear reactor ?
nothere is also
Thorium (liquid-fuel)
second questionhas the alternative been
tried ?
yesthey ran a
Thorium reactor (liquid-fuel)
for five years
third questionwas the alternative
successful ?
yesit was much more efficient
it was much saferit did not produce long-term
waste