Steve McIntosh, Senior Policy Adviser at ANSTO writes:
Crispin Rovere's comment on possible South Korean desires for nuclear weapons needs a reply. I don't feel qualified to comment on the political factors, but the penultimate paragraph overlooks some facts:
Firstly, the South Korean proposal is to utilise an alternative technology to the reprocessing technology currently used to reprocess spent fuel in France and the UK. Pyroprocessing is claimed not to involve the separation of plutonium, which instead goes with fission products and other actinides into a waste stream. Secondly, the 10,000 tons of spent fuel from power reactor operation currently held by South Korea are unlikely to be of much relevance to a nuclear weapons program.
The long period during which fuel is in a power reactor (around 18 months) means that the plutonium present in the spent fuel is not particularly suitable for weapons purposes — rather than pure Pu-239 (the isotope used in weapons), it is a mix of isotopes including Pu-239 but also other isotopes which either can cause pre-detonation or are so short-lived as to make handling much more hazardous. In summary, even if it were possible to modify the pyroprocessing operation to extract plutonium, the extracted plutonium would not be used in a weapons program. For this reason, no country extracts plutonium from spent fuel from power reactors to make nuclear weapons — rather they irradiate natural uranium in smaller reactors for a period of around 30 days, which maximises Pu-239 production while minimising production of the other isotopes.
