Multiple Recycling Characteristics and Cost of MOX Fuel Using Weapons-Grade Plutonium in Commercial PWR

After the ratification of START-I the question of how to dispose safely and effectively of excess weapons plutonium, of which there is estimated to be about 501 in the USA and 501 in Russia, has become an important international issue. One of the most likely options is the proposal to use the excess weapons plutonium as MOX fuel in commercial LWRs. This paper evaluates fuel material flow and fuel cycle costs when weapons-grade plutonium is mixed with reactor-grade plutonium to fabricate the MOX fuel and to be recycled in Japanese commercial LWRs. The results show the MOX fuel using weapons- and reactor-grade mixed plutonium facilitates multiple recycling, because the weapons-grade plutonium improves the isotopic composition of the MOX fuel working like a “purifier” of the degraded recycled plutonium. And they also indicate that it might be an economically realistic method in Japan to use the excess weapons plutonium in the commercial LWRs as MOX fuel if the fabrication cost and the reprocessing cost of MOX fuel are moderate compared to those of UO2 fuel, assuming the MOX powder using weapons-grade plutonium would be provided free of charge.