Investigation of processes for converting weapons plutonium into MOX fuel at the TOMOX facility

On November 12, 1992, the governments of France and Russia signed a cooperation agreement on civil uses of nuclear materials from Russian weapons. This agreement includes the AIDA/mixed-oxide (MOX) program for converting dismantled Russian weapons plutonium into MOX fuel to supply existing and future Russian VVER and BN reactors. AIDA/MOX covers six areas: strategic approaches, the neutronic aspects of loading reactors with military plutonium, the chemistry of alloyed plutonium and conversion into sinterable oxide, MOX fuel fabrication, possible reprocessing of MOX fuel, and incineration of weapons plutonium in new reactors. The short-term use of existing reactors requires a facility for converting weapons plutonium to MOX fuel; the TOMOX-1300 facility should be capable of processing 1300 kg of weapons plutonium annually to fabricate 26.5 tonnes of MOX fuel (1.5 t for the BN-600 reactor and 25 t for four VVER-1000 reactors). Research and development (R&D) undertaken from 1992 to 1996 by several Russian institutes under Minatom and by various Commissariat A l`Energie Atomique (CEA) divisions to select the processes to be implemented in the TOMOX plant is presented and analyzed in this paper.