How to treat plutonium from disassembled nuclear weapons

In the trend of nuclear disarmament, the control of large quantity of the nuclear substances, particularly plutonium, taken out from disassembled nuclear weapons has become a great international concern. From the viewpoint of the nonproliferation of nuclear weapons, environmental effect and economy, USA worked out the policy of abolishing plutonium, and examines the concrete measures. It is said that now the world faces the crisis of nuclear proliferation as the trend to independent nuclear armament is seen worldwide, and the capability of controlling nuclear substances in former USSR and east Europe decreased. High enriched uranium can be diluted, but there is not the effective means to degrade plutonium. The disassembling of nuclear warheads is not new, and the pits containing plutonium are stored in canisters. In Russia, the production of MOX fuel using plutonium is considered, but the cost of this method is high. The final disposal of plutonium is planned to be carried out similarly to the high level waste from nuclear power stations. The evaluation of the effect of Japanese plutonium plan may be necessary. (K.I.)