Japan's government perceives a need to reduce its supply of surplus plutonium by using plutonium in MOX fuel rather than disposing of the plutonium as waste. Japan's nuclear industry hopes that shipments of mixed-oxide fuel from Europe to Japan will prove less controversial than previous transports of pure plutonium. The MOX shipments are being portrayed as posing no environmental or security risks. Two shipments of separated plutonium in 1984 and 1992 raised an outcry in countries along the potential shipping routes because of plutonium's extreme radiotoxicity and its weapons utility. With shipments of pure plutonium oxide now virtually ruled out for political reasons, British and French reprocessing companies are counting on MOX as an acceptable way to send back to Japan the plutonium they have processed from Japan's spent nuclear fuel.
Plutonium is an essential ingredient of nuclear weapons.
Less than 8 kilograms is enough to construct a bomb. The plutonium in fresh MOX fuel can be separated from the uranium by straightforward chemical means and can be used directly in a nuclear weapon. Therefore, the most stringent physical-protection measures should apply to this MOX shipment, which is the first of many and will set a precedent for how future shipments are protected. In 1992, the United States required Japan to use a gunboat to escort a shipment of plutonium from France to Japan. Nonetheless, Japan continued to press the United States not to require an armed-escort vessel for MOX fuel shipments.