The viability of plutonium-consuming reactors and their associated fuel cycles for the disposition of surplus fissile material

The National Academy of Sciences (NAS) has suggested that surplus plutonium should be made to satisfy the spent fuel standard, i.e., that plutonium be made as inaccessible as the existing and growing inventory of plutonium in spent commercial nuclear fuel currently being generated domestically. The utilization of plutonium-based fuels in reactors is one way in which the spent fuel standard can be achieved. For this reason and others, the NAS recommended that plutonium-based fuels be considered for the disposition of plutonium declared surplus to national security requirements. The NAS gave special emphasis to water-cooled reactors using mixed oxide (MOX) fuels. This paper examines the technical viability of water-cooled reactors to use MOX fuels, considering proposed new light water reactors in the US, operating light water reactors in the US, and operating heavy-water moderated CANDU reactors in Canada. This paper focuses primarily on the effects of MOX utilization on reactor performance and operations and on the cradle-to-grave infrastructure that was predicated on low enriched uranium (LEU) fuels. The paper will describe the operations and facilities that are required to convert existing plutonium inventories into feed material for fuel fabrication and the fuel cycle that relates to utilizing MOX fuels.