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Used fuel from thermal reactors can be processed into fuel for fast reactors. The fast reactor burns up all the transuranium elements so that the waste ends up

Used fuel from thermal reactors can be processed into fuel for fast reactors. The fast reactor burns up all the transuranium elements so that the waste ends up with only the short lived fission products. These short lived products decay to background in 300 years or so, so the amount of time it needs to be stored is much more manageable. https://en.wikipedia.org/wiki/Integral_fast_reactor#Advantages https://en.wikipedia.org/wiki/Integral_fast_reactor#Advantag...

cletus 5y ago
So if we can process nuclear waste in fast reactors like this, why haven't we done so with existing nuclear waste? Scale? Cost? Something else?
- LargoLasskhyfv 5y ago
  Probably because all (usable) waste (the fuel rods) needs to be disassembled (reprocessed) to enable usage somewhere else. With new casings. Which then needs to be disassembled too, after the contents are 'sucked empty'.
- opwieurposiu 5y ago
  The cost issue: Storing spent fuel is pretty cheap because it is not very voluminous. The USA has produced about 85k tons of spent fuel, which would fit into a single football stadium. This means the cheapest thing to do is just kick the can down the road. The proliferation issue: Waste burners require processing of spent fuel, which some states believe is a weapons proliferation risk. The sodium issue: Liquid sodium requires very careful construction of the steam generators and piping to keep it from contacting air or water. This is a sort-of solved problem in that all the sodium cooled reactors have experienced sodium leaks from time to time, but those leaks have been fixed without significant radioactive release. This is an issue that improves with operator experience. The russians do have one waste burning fast reactor running, the BN-800. If they can do it, so can we. https://en.wikipedia.org/wiki/BN-800_reactor https://en.wikipedia.org/wiki/BN-800_reactor
  - r00fus 5y ago
    French also reprocess. In fact, other countries pay them to reprocess their fuel. The US doesn't do this ostensibly due to proliferation risk [1] however, I am of the opinion that was due purely due to pressure from the coal lobby. [1] https://en.wikipedia.org/wiki/Nuclear_reprocessing#History https://en.wikipedia.org/wiki/Nuclear_reprocessing#History
- himinlomax 5y ago
  Because the plants to do so were not built or were dismantled (SuperPhénix) due to anti-nuclear activists.

cletus 5y ago

So if we can process nuclear waste in fast reactors like this, why haven't we done so with existing nuclear waste? Scale? Cost? Something else?

LargoLasskhyfv 5y ago
Probably because all (usable) waste (the fuel rods) needs to be disassembled (reprocessed) to enable usage somewhere else. With new casings. Which then needs to be disassembled too, after the contents are 'sucked empty'.
opwieurposiu 5y ago
The cost issue: Storing spent fuel is pretty cheap because it is not very voluminous. The USA has produced about 85k tons of spent fuel, which would fit into a single football stadium. This means the cheapest thing to do is just kick the can down the road. The proliferation issue: Waste burners require processing of spent fuel, which some states believe is a weapons proliferation risk. The sodium issue: Liquid sodium requires very careful construction of the steam generators and piping to keep it from contacting air or water. This is a sort-of solved problem in that all the sodium cooled reactors have experienced sodium leaks from time to time, but those leaks have been fixed without significant radioactive release. This is an issue that improves with operator experience. The russians do have one waste burning fast reactor running, the BN-800. If they can do it, so can we. https://en.wikipedia.org/wiki/BN-800_reactor https://en.wikipedia.org/wiki/BN-800_reactor
- r00fus 5y ago
  French also reprocess. In fact, other countries pay them to reprocess their fuel. The US doesn't do this ostensibly due to proliferation risk [1] however, I am of the opinion that was due purely due to pressure from the coal lobby. [1] https://en.wikipedia.org/wiki/Nuclear_reprocessing#History https://en.wikipedia.org/wiki/Nuclear_reprocessing#History
himinlomax 5y ago
Because the plants to do so were not built or were dismantled (SuperPhénix) due to anti-nuclear activists.