Scrutinising the claims of the thorium nuclear lobby

Don’t Jump on The Thorium Bandwagon – It’s Not Green, Not Viable, And Not The Answer To Our Energy Problems Prevent Disease.comNov 10, 2013 by KELLEY BERGMAN

“………Numerous claims of advantages for thorium as a nuclear fuel and for LFTR (Liquid Fluoride Thorium Reactor) design have been made over conventional solid fuel reactors.

Nuclear Weapons Proliferation

Claim: thorium reactors do not produce plutonium, and so create little or no proliferation hazard.

Response
: a LFTR could be adapted to produce plutonium of a high purity well above normal weapons-grade, presenting a major proliferation hazard. Beyond that, the main proliferation hazards arise from:

  • the need for fissile material (plutonium or uranium) to initiate the thorium fuel cycle, which could be diverted, and
  • the production of fissile uranium 233U.Claim: the fissile uranium (233U) produced by thorium reactors is not “weaponisable” owing to the presence of highly radiotoxic 232U as a contaminant. Response: 233U was successfully used in a 1955 bomb test in the Nevada Desert under the USA’s Operation Teapot and so is clearly weaponisable notwithstanding any 232U present.


Safety

Claim: LFTRs are intrinsically safe, because the reactor operates at low pressure and is and incapable of melting down.

Response
: the design of molten salt reactors does indeed mitigate against reactor meltdown and explosion. However, in an LFTR the main danger has been shifted from the reactor to the on-site continuous fuel reprocessing operation — a high temperature process involving highly hazardous, explosive and intensely radioactive materials. A further serious hazard lies in the potential failure of the materials used for reactor and fuel containment in a highly corrosive chemical environment, under intense neutron and other radiation.


State of Technology

Claim: the technology is already proven.

Response
: important elements of the LFTR technology were proven during the 1970s Molten Salt Breeder Reactor (MSBR) at Oak Ridge National Laboratory. However, this was a small research reactor rated at just 7MW and there are huge technical and engineering challenges in scaling up this experimental design to make a ‘production’ reactor. Specific challenges include:

  • developing materials that can both resist corrosion by liquid fluoride salts including diverse fission products, and withstand decades of intense neutron radiation;
  • scaling up fuel reprocessing techniques to deal safely and reliably with large volumes of highly radioactive material at very high temperature;
  • keeping radioactive releases from the reprocessing operation to an acceptably low level;
  • achieving a full understanding of the thorium fuel cycle.


Nuclear Waste

Claim: LFTRs produce far less nuclear waste than conventional solid fuel reactors.
Response: LFTRs are theoretically capable of a high fuel burn-up rate, but while this may indeed reduce the volume of waste, the waste is more radioactive due to the higher volume of radioactive fission products. The continuous fuel reprocessing that is characteristic of LFTRs will also produce hazardous chemical and radioactive waste streams, and releases to the environment will be unavoidable.

Claim: Liquid fluoride thorium reactors generate no high-level waste material.
Response: This claim, although made in the report from the House of Lords, has no basis in fact. High-level waste is an unavoidable product of nuclear fission. Spent fuel from any LFTR will be intensely radioactive and constitute high level waste. The reactor itself, at the end of its lifetime, will constitute high level waste.

Claim: the waste from LFTRs contains very few long-lived isotopes, in particular transuranic actinides such as plutonium.
Response: the thorium fuel cycle does indeed produce very low volumes of plutonium and other long-lived actinides so long as only thorium and 233U are used as fuel. However, the waste contains many radioactive fission products and will remain dangerous for many hundreds of years. A particular hazard is the production of 232U, with its highly radio-toxic decay chain.

Claim: LFTRs can ‘burn up’ high level waste from conventional nuclear reactors, and stockpiles of plutonium.
Response: if LFTRs are used to ‘burn up’ waste from conventional reactors, their fuel now comprises 238U, 235U, 239Pu, 240Pu and other actinides. Operated in this way, what is now a mixed-fuel molten salt reactor will breed plutonium (from 238U) and other long lived actinides, perpetuating the plutonium cycle.

What Can You Do? 

Spread the word about Sardinia. More information is available athttps://docs.google.com/open?id=0B-F67wRS5N7sR3hYMl9id0xkNWs where the original 7500-word research document is stored.

Contact your congressional representatives and demand the closure of the Sardinia NATO bases.

Do we really want another polluting energy source with high-level waste which is non-renewable and highly carcinogenic? Before jumping on the thorium bandwagon, please share this information, do your own research and think twice before spreading the hundreds of myths (not facts) about this very dangerous alternative to uranium.

Sources:
nuclearfreeplanet.org
nonukes.it
industrytap.com
envirosagainstwar.org

Kelley Bergman is a media consultant, critic and geopolitical investigator. She has worked as a journalist and writer, specializing in geostrategic issues around the globe.http://preventdisease.com/news/13/111013_Dont-Jump-on-The-Thorium-Bandwagon-Not-Green-Not-Viable-Not-The-Answer.shtml

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Nuclear scientists raise problems with proposed Liquid Fluoride Thorium Reactors (LFTRs)

Thorium Cycle questions and problems http://daryanenergyblog.wordpress.com/ca/part-8-msr-lftr/8-3-thorium-lftr/Questions have also been raised by some nuclear scientists about the Thorium cycle, in particular the proposed one that the LFTR would use. I’m not a nuclear physicist so I’ll merely forward you on to the relevant paper here, and a rebuttal here. The crux of the argument seems to be the proliferation risk (I’ll come back to that one later), the fact that a number of its spend fuel outputs (such as Technetium-99) are “nasty stuff” with a long half life and the fact we’ll still need supplies of Uranium to get Thorium reactors going again whenever we have to turn it off (which will happen at least once a year or so during its annual maintenance shutdown). They also highlight a number of technical issues, which I discussed in the chapter on HTGR’s.

Certainly the fission products from a Thorium reactor are a worry, Technetium-99 has a half life of 220,000 years, uranium-232 produces thallium-208 (a nasty wee gamma emitter), Selenium-79 (another gamma emitter with a 327,000 year half-life), evenThorium-232 is a problem with its half life of 14 Billion years (and while the T-232 isn’t a major worry, all the time during this 14 Billion years it will be decaying and producing stuff that is!).

The UK based NNL (National Nuclear Laboratories) also pour cold water on the idea of Thorium fuelled reactors (see here). While the report is low on detail (they seem to be saying “trust us we’re scientists who work with nuke stuff… and we smoke pipes!”) they do highlight the major time delays it would take to establish and get working a Thorium fuel cycle (10-15 years with existing reactors, 30 with more advanced options), point out that under present market conditions its unlikely to be economically viable and will (as the points above raise) offer only a modest reduction in nuclear wastes.

MIT recently undertook a study of future nuclear fuel supplies. The Thorium cycle barely gets a mention, and even then its usually in relation to Fast Reactor programs (of which the US currently has none) and modifed LWR systems, rather than the MSR.

Obviously, once we exhaust the world’s U-235 stockpiles, LFTR’s and any other Thorium fuelled reactors will cease to function. Indeed long before then the spike in Uranium prices will have rendered MSR’s (and all other nuclear plants) uneconomically viable (of course there’s plenty who’d say that’s already the case!). The LFTR fans usually groan at this point and state that “all we need is a little plutonium”. Now while I’m quite sure that in the fantasy world which the LFTR fans inhabit Plutonium is available in any good hardware store but back in the real world, it’s a little harder to come by! As with the HTGR’s using Thorium (if its possible) would certainly help stretch things out….a bit! But not by nearly as much as the supporters of Thorium reactors would have you believe.