What new technologies are being developed to minimise the long-term storage of spent nuclear fuels?
Nuclear power is very clean and carbon neutral. But spent nuclear fuel has a storage lifetime of 300,000 years.
Reprocessing used nuclear fuel is currently carried out on large scale using the “Plutonium Uranium Reduction and Extraction” (PUREX) process. During this process, the fuel is reduced to 15% of its original weight and the extracted uranium and plutonium are used as “Mixed Oxide Fuel”. This has been carried out at scale by the UK at Sellafield (now curtailed) and continues in France at La Hague.
The residual high-level waste has a storage lifetime of 9,000 years. Much of the remainder of the long-term radiotoxicity of the residual waste is due to traces (0.1%of the original fuel) of the minor actinides. Separating these minor actinides from the chemically very similar lanthanides and other fission products is the next key step in the future reprocessing of spent nuclear fuel.
So, what’s the challenge? The actinides can be used as a fuel in the next generation of nuclear reactors and converted into benign products. But the accompanying lanthanides would “poison” the reactor, causing it to shut down.
In this recording of an online talk, Laurence Harwood reports on the important progress that has been made in the advanced reprocessing of spent nuclear fuel. The used fuel need not be a liability but a source of yet more power.