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They don't produce plutonium. Department of War (later the Dept of Energy) had a LFTR (liquid fluoride thorium reactor) running at Oak Ridge but the primary goa

by mikece 7y ago

They don't produce plutonium. Department of War (later the Dept of Energy) had a LFTR (liquid fluoride thorium reactor) running at Oak Ridge but the primary goal there was to produce plutonium for the military's nuclear weapons arsenal, not electricity. In addition to having a far more plentiful fuel source, a LFTR runs at ambient atmospheric pressure so it's not necessary to have a massive containment dome surrounding the reactor in case of a core loop breach. Also, the chemistry of a LFTR tolerates the addition of partially spent uranium fuel (popularly mislabeled as "nuclear waste") which is then consumed in the normal fuel lifecycle of a LFTR. Why this wonder of chemistry isn't more commonly known is beyond me: we could simply solve the Yucca Mountain problem by recycling the partially spent fuel stored there into liquid metal reactors like the LFTRs. The downside is that if you have to scram a LFTR the core chemistry solidifies (it's liquid metal, after all) and restarting is time and energy intensive. Ultimately, though, because the LFTR didn't produce plutonium for bombs the Department of Defense didn't have interest in running it.

godelski 7y ago
I disagree with this. 233U is part of the Th cycle. You definitely get transuranic elements out, though admittedly less. There is an advantage though, you can produce power and pull out enriched uranium while doing that; an enticement plant that generates power. (Note: we already use reactors that have low plutonium yields) The real reason that we don't have thorium reactors is that it's difficult. All the kinks aren't worked out. Compound that with that it's hard to implement new reactor designs and the process becomes really slow to work out those kinks. The answer, unsurprisingly is extremely complicated but certainly isn't just because it doesn't produce Pu, or rather creates low yields. This myth needs to die.
- arcticbull 7y ago
  I think it's fair to say our expertise in Uranium cycle fuel came out of the fact it generates substantially more plutonium for nuclear weapons. This was a huge reason it was selected over Thorium initially. Now, it may just be momentum. I argue it's because back in the day, it didn't product Pu.
  - godelski 7y ago
    Also keep in mind that the Uranium cycle is SIGNIFICANTLY easier. I'd argue that that played a major role. But I'm also not denying that weapons didn't play a role.

by mikece 7y ago

godelski 7y ago

I disagree with this. 233U is part of the Th cycle. You definitely get transuranic elements out, though admittedly less. There is an advantage though, you can produce power and pull out enriched uranium while doing that; an enticement plant that generates power. (Note: we already use reactors that have low plutonium yields) The real reason that we don't have thorium reactors is that it's difficult. All the kinks aren't worked out. Compound that with that it's hard to implement new reactor designs and the process becomes really slow to work out those kinks. The answer, unsurprisingly is extremely complicated but certainly isn't just because it doesn't produce Pu, or rather creates low yields. This myth needs to die.

arcticbull 7y ago
I think it's fair to say our expertise in Uranium cycle fuel came out of the fact it generates substantially more plutonium for nuclear weapons. This was a huge reason it was selected over Thorium initially. Now, it may just be momentum. I argue it's because back in the day, it didn't product Pu.
- godelski 7y ago
  Also keep in mind that the Uranium cycle is SIGNIFICANTLY easier. I'd argue that that played a major role. But I'm also not denying that weapons didn't play a role.