What's in Spent Nuclear Fuel? (after 20 yrs)

http://www.popsci.com/science/gallery/2010-05/gallery-whats-left-elements Neodymium -- 60 1 kg/T Reserves: Unknown but scarce Cost: $28 per pound Critical for: Electric motors Outlook: Poor This irreplaceable rare-earth metal is used to make light, powerful magnets in motors in cars, hard drives and wind turbines. Lack of Neodymium could be a limiting factor in the adoption of green technology, such as gearless wind turbines. It’s also used in military lasers for targeting and communications. Even though there are about 100 million tons of it in reserves, rising demand means the U.S. needs to scout out more deposits and improve extraction techniques for mixed ores. Tellurium 52 100 g/T Reserves: 22,000 tons Cost: $66 per pound Critical for: Solar cells Outlook:Fair Almost all tellurium is found as a trace element in copper ore, and very little can be recycled. No other element turns sunlight into electricity as well, and solar cells using tellurium semiconductors are inexpensive. If the tech proliferates, manufacturers might have to move on to less-efficient or pricier elements, such as selenium.

Excellent resource page here. I will be referring to it often. Keep in mind that the market price and availability of lesser used elements is somewhat complex. Most importantly these prices are only somewhat supply & demand driven. In general one can count on all sorts of manipulation going on in the way of price support. Thus it would be unwise to assume that the prices represent any firm potential for making money by exploiting used nuclear fuel.

I've always doubted the economics of trying to recover fission products. However, does anyone know the isotopic distribution of Xenon from either LWRs or LFTR/MSRs? There may be a short term but large demand for the isotope Xe136 (naturally about 9%). My university has a large particle physics group and are part of a team designing neutrino experiments that need Xenon enriched in 136 (they have basically taken everything Russia can provide just for a small scale experiment). http://www-project.slac.stanford.edu/exo/ David L.

I exchanged emails with someone on the Xenon project. Their goal (if funded) is a machine using 10 tonnes of enriched Xenon enriched to 80 to 90% 136 (at least a 100 tonnes natural). With the entire world's production about 40 tonnes a year this is a tall order! Lars (or anyone), are there other fission yields that decay to stable Xenon (ideally 136) or do those percentages include things that reasonably quickly turn to Xenon. I wonder what Le Hague does with their Xenon? David L.

As a propenent of LFTR, I think the most important number in this is that after 3 years in an LWR, 95% of the "fuel" has not been touched!

This post reminds me of earlier posts, including one that had the spent uranium graphic, about fluoridating waste to reduce its volume and separate uranium for re-enrichment. I think that it would be simpler to extract U-Pu to create MOX fuel for CANDU reactors and just give the rods to Canada. The waste volume reduction could justify the cost. Recovering useful elements is a bonus. BTW, I thought online reprocessing was a major part of the molten salt reactor concept. Regularly pull out the U (and TRU, depending on the design) and put it back in the reactor along with fresh fuel. Separating the FPs is a different problem

The main problem with fuel separation and regeneration isn't technical (though it might be economically unfeasible of course) but legal. Most countries (maybe even international treaties like the NPT) ban the refining of spent nuclear fuel for fears that it might produce quantities of weapons grade material. This fear was driven by the anti-nuclear lobby as far back as the 1970s and has never been corrected. It has cause fast breeder reactors to be shut down while still under construction (research Kalkar for a prime example). I've done some nuclear waste related research as part of graduate work in the 1990s, developing new non-destructive methods of classifying low grade waste as nuclear or non-nuclear for disposal purposes. These laws were the main reason for that research, it was legally impossible to even sample the waste material for chemical analysis of its content. All had to be determined solely from analysing emitted radiation (or in case of the method I used, scattered radiation from bombarding the samples with a known source). If nuclear waste material can be refined and broken down into different category batches, storage requirements (and duration) go down drastically, removing the main remaining problem many have with nuclear energy (no doubt this alone is a reason some people don't want such technology to be employed). The Uranium, Plutonium, and some other elements can be reused for new fuel rods, other elements used for radiochemistry and medical uses, and the remaining nuclear material stored in smaller containers for shorter periods (it will be mainly extremely high radioactive waste, no more than a small bucket a year for an average reactor to be stored for a few decades at most). I've since left the field, so don't know the current state of technology, but that's as things stood when I was engaged in it.