A response on EROEI and fuel cycle/reactor efficiency

A comment posted on Oil Drum today
A response on EROEI and fuel cycle/reactor efficiency

The entire business of EROEI studies is a diversion from the question of reactor efficiency. We know that vast amounts of energy are locked up in uranium and thorium. What we need to be doing is studying the efficiencies of fuel cycle/reactor systems in extracting that energy, rather than expending our time arguing about the EPOEI of one system. Any review of the uranium/light water reactor fuel cycle will review that it does an extremely poor job of extracting the potential energy of nuclear fuel.

EROEI studies never note the different between the energy economies of the CANDU reactor and the LWR. CANDU reactors have a demonstrated ability to operate with almost nuclear fuel including natural uranium. The EROEI of natural uranium CANDU fuel cycles should be examined. There are presently 18 CANDU reactors operating in Canada. Other CANDU reactors operate in India, China, Korea Argentine, and Romania. CANDU Reactors can be operated using "spent" nuclear fuel from LWR. The EROEI for recycled fuel would be very large, since recycled fuel would enter the CANDU with only the energy input of transportation and fuel fabrication. Tests have been run on CANDU reactors.
http://www.nuclearfaq.ca/index.html

The Indians has just completed construction the Advanced Heavy Water Reactor (AHWR) a CANDU type reactor to run on thorium cycle fuel.
http://www.npcil.nic.in/nupower_vol13_3/ahwr.htm
http://www.hindu.com/2008/04/09/stories/2008040959691700.htm

It is one of the most advanced reactors in the world, and should have an EROEI significantly better than the EROEI of Light Water Reactors. The Indians plan to embark on serial production of AHWR type reactors, before 2020.

A second reactor type whose EROEI should be examined, is the Russian BN-600. Although the BN-600 is a developmental LMFBR reactor that has successfully delivered commercial nuclear power since 1980. The Japanese have purchased BN-600 technology from the Russians, and may build duplicates.
http://en.wikipedia.org/wiki/BN-600_reactor

Thirdly, the Indiana are engaged in a significant thorium fuel cycle. The Indians have already built and tested both thorium fuel cycle proof on concept and developmental thorium fuel cycle reactors and have built or are building prototype thorium fuel cycle reactors including the just completed AHWR, the soon to be completed Prototype Fast Breeder Reactor (PFBR) at Kalpakkam, and the more advanced , Fast Thorium Breeder Reactor (FTBR) underdevelopment at the Bhabha Atomic Research Centre in Mumbai.is second thorium fuel cycle breeder. The Indians are in the last stage of a 3 stage developmental program for a complex Uranium/thorium reactor fuel system, that is many times more energy efficient than the Uranium/light water reactor fuel system.

The Indians plans to build thorium fuel cycle reactor capable of producing 20 GWy of electrical energy by 2020, and to produces 30% of their electricity from thorium cycle reactors by 2050. Indian scientists calculate that the assurred thorium reserve of India is large enough to provide it with electrcity for 400 years. Given the extent of Indian thorium cycle reactor development, and future plans and EROEI of nuclear industry EROIE that ignores the Indian plans is at the very least incomplete.

Further, any discussion of nuclear EROEI ought to note that that real world LWR EROEI using MOX is much than the EROEI of normally fueled French LWRs. The use Pu-239 in nuclear weapons absorbed the original energy input into weapons fissionable materials. The energy input into recycled fuel (MOX) would equal the energy requirements for disassembling nuclear weapons, fabricating MOX, and transporting it to the reactor. Reactor grade Plutionium can also be a source of MOX. U-238 in the MOX can be assummed to come from Depleted uranium stockpiles.
http://en.wikipedia.org/wiki/MOX_fuel

American civilian power reactors are being used to dispose of surplus Russian U-235. Fully half half of the uranium used in American reactors USA is ex-Russian military U-235. One sixth of the current world U-235 supply comes from recycling Russian nuclear weapons. In addition, Pu-239 from American and Russian nuclear weapon stockpiles, not ony can but should be used as reactor fuel.

The estimated US U-235 stockpile was estimated to be in the range of 750 tons in the early 1990s, of which 174 tons (23% of the total) have been declared surplus.[13] More than 30 tons of the excess HEU has been blended down, reducing the total stockpile to something in the range of 720 tons. The US has a plutonium of 111.4 tons. The UK acknowledges possession of a military stockpile of 7.6 tons of plutonium, 21.9 tons of HEU (U-235). The Japanese hold a plutonium stockpile of from 16 to 20 tons. In 2000 the US and Russia agreed to each dispose of 34 tons of weapons-grade plutonium. Estimates of the total world stockpile of weapons grade plutonium range as high as 300 tons.
http://www.nti.org/e_research/cnwm/monitoring/declarations.asp

In addition to surplus stockpiles of reactor grade plutonium, mostly found in "spent nuclear fuel" equals 400 tons. http://www.dhushara.com/book/explod/nuclears/pluteu.htm Civilian plutonium stockpiles are growing and constitute the largest single problem associated with "nuclear waste." But even if all civilian reactors shut down, the disposal of military and civilian plutonium would be a significant problem. By far the best solution from an EROEI viewpoint would be to burn the plutonium in breeder reactors or thorium converters as the Indians plan to do.

EROEI studies of nuclear power commit numerous other EROEI errors.

EROEi calculations do not evaluating reactor grade plutonium reprocessing in the UK, France and Germany, despite the fact that reactor grade plutonium returned to reactors amounts to largely free energy. http://www.inesap.org/bulletin16/bul16art15.htm

Various sources describe the amount of fissionable material remaining in “spent” nuclear fuel. The Wikipedia reports that 1% of the fuel mass of “spent fuel” is reactor grade plutonium. While unburned U-235 would constitute >.83 percent of the "spent" fuel mass. The Wikipedia also reports, “Fissile component starts at 0.71% 235U concentration in natural uranium). At discharge, total fissile component is still 0.50% (0.23% 235U, 0.27% fissile 239Pu, 241Pu).”
http://en.wikipedia.org/wiki/Spent_nuclear_fuel

Plutonium based fuel can be used in Heavy Water Reactors.
http://www.cap.ca/news/moxsummary.ps

With Heavy Water Reactors a burnup rate of 50% of reactor grade plutonium is possible with the use of a U-238 fuel cycle, and 75% with the use of a Th-232 fuel cycle.
http://www.nuclearfaq.ca/mox.htm

The encyclopedia of the earth reports

Reactor grade plutonium contains about 55-70% of fissile Pu-239, and >19% of non-fissile Pu-240, non fissile isotopes of Plutonium will never constitute more 30% of reactor grade plutonium.

In contrast. studies of the use of ex-nuclear weapon Pu-239 in MOX fueled light water reactors suggest that only a net burnup on only 1/3 of the original plutonium, leaving an unsatisfactory burn is disposal of plutonium.

http://64.233.167.104/search?q=cache:tDm1iQnQSJ4J:www.fissilematerials.org/ipfm/site_down/ipfmresearchreport03.pdf+Spent+fuel+plutonium+content&hl=en&ct=clnk&cd=38&gl=us

Depleted Uranium contains 0.25-0.30% U-235. http://www.world-nuclear.org/info/inf14.html
Thus the Uranium enrichment process looses 35% to 42% of the U-235 in natural uranium. 20% of reactor fuel U-235 fails to fission after absorbing reactor neutrons, thus becoming non-fissile U-236. (WASH-1097) Another 25%+ of reactor U-235 remains when the fuel will no longer support a chain reaction. In addition, plutonium remaining in the reactor amounts to nearly 25% of the original U-235 in the fuel charge. Thus the net fissile burnup rate in a light water reactor is only 30% of the original U-235 charge.
In contrast CANDU reactors contain about 0.2% U-235.
http://www.nuclearfaq.ca/brat_fuel.htm

An equal amount of spent CANDU fuel will be PU-239. Hence Heavy Water Reactor fuel post-reactor fuel is more truly spent, while spent light water reactor fuel, contains more fissile material than natural uranium a fuel that can be used in Heavy Water Reactors.

Heavy Water reactors are also more efficient in burning U-235. Assuming 0.1% U236 content in "spent fuel" (WASH-1097), this means that 57% of the U-235 in natural uranium gets burned up heavy water reactors, verses a burnup of around 35% of the U-235 in natural uranium for light water reactors.

Since part or most of the nuclear energy of uranium and plutonium in post reactor LWR nuclear fuel is capturable by other reactors, it should be added to the energy output of light water reactors in a fair assessment of the uranium.LWR guel cycle..

Various sources describe the amount of fissionable material remaining in “spent” nuclear fuel. The Wikipedia reports that 1% of the fuel mass of spent fuel is reactor grade plutonium. While U-235 would constitute >.83 percent of the fuel mass. The Wikipedia also reports, “Fissile component starts at 0.71% 235U concentration in natural uranium). At discharge, total fissile component is still 0.50% (0.23% 235U, 0.27% fissile 239Pu, 241Pu).”
http://en.wikipedia.org/wiki/Spent_nuclear_fuel

Plutonium based fuel can be used in Heavy Water Reactors.
http://www.cap.ca/news/moxsummary.ps

With Heavy Water Reactors a burnup rate of 50% of reactor grade plutonium is possible with the use of a U-238 fuel cycle, and 75% with the use of a Th-232 fuel cycle.
http://www.nuclearfaq.ca/mox.htm

The encyclopedia of the earth reports

Reactor grade plutonium contains about 55-70% of fissile Pu-239, and >19% of non-fissile Pu-240, non fissile isotopes of Plutonium will never constitute more 30% of reactor grade plutonium.

One Kg of fissile Plutonium burned in a reactor produces 10 MWh of electrical power. Thus one ton of fissile plutonium will produce 1 GW years of electrical power.
http://www.eoearth.org/article/Plutonium

Studies of the use of nuclear weapon Pu-239 in MOX fueled light water reactors suggest that only a net burnup on only 1/3 of the original plutonium, leaving an unsatisfactory burn is disposal of plutonium.

http://64.233.167.104/search?q=cache:tDm1iQnQSJ4J:www.fissilematerials.org/ipfm/site_down/ipfmresearchreport03.pdf+Spent+fuel+plutonium+content&hl=en&ct=clnk&cd=38&gl=us

Depleted Uranium contains 0.25-0.30% U-235. http://www.world-nuclear.org/info/inf14.html
Thus the Uranium enrichment process looses 35% to 42% of the U-235 in natural uranium. 20% of reactor fuel U-235 fails to fission after absorbing reactor neutrons, thus becoming non-fissile U-236. (WASH-1097) Another 25%+ of reactor U-235 remains when the fuel will no longer support a chain reaction. In addition, plutonium remaining in the reactor amounts to nearly 25% of the original U-235 in the fuel charge. Thus the net fissile burnup rate in a light water reactor is only 30% of the original U-235 charge.
In contrast CANDU reactors contain about 0.2% U-235.
http://www.nuclearfaq.ca/brat_fuel.htm
An equal amount of spent CANDU fuel will be PU-239. Hence Heavy water reactor fuel is truly spent, while spent light water reactor fuel, contains more Fissile material than ordinary Heavy Water Reactor fuel does.


Assuming 0.1% U236 content (WASH-1097), this means that 57% of the U-235 in natural uranium gets burned up heavy water reactors, verses a burnup of around 35% of the U-235 in natural uranium for light water reactors.

Such great inefficiency leaves a great deal of nuclear fuel unused by light water reactors, but re-enrichment of so called "depleted uranium tailings" is currently being conducted at Paducah,
http://www.courier-journal.com/apps/pbcs.dll/article?AID=/20080406/NEWS01/804060477/1008
and in Russia.
http://www.greenpeace.fr/stop-plutonium/en/trade_russia_en.php3
And research continuses on improving the burnup ratio of LWRs.

In short some of the inefficiencies of the uranium/light water reactor fuel cycle are either being corrected or are amenable to correction. Nuclear EROEI is a snapshot in time, that often ignore the complexity of nuclear fuel cycles, as well as the effect of reactor, enrichment and fuel recovery technologies on nuclear fuel efficiency. Since it is impossible to generate a single number in calculations involving so many independent variables, the value of nuclear EROEI studies which arrives at a single number is very questionable, and a meta-analysis of such studies will lead to a distorted and inaccurate picture. The best we should hope for is a range of EROEI numbers for a given fuel cycle, with the possibility of a comparison between the ranges of various fuel/reactor options.