What shall we do with the separated Pu?

A summary is given of a report ''Management of Separated Plutonium: the technical options'' by an expert group of the OECD's Nuclear Energy Agency. The group has reviewed experience with Pu handling and use in the civil nuclear industry. They conclude that in the next 15 to 20 years Pu can be effectively recycled in thermal reactors in the form of mixed oxide (MOX) fuel and details are provided of MOX fuel fabrication status in OECD countries. Future reactor options are being researched in many countries. These include: Pu burning fast reactors using oxide fuels; alternatives to oxides such as plutonium-uranium nitride and carbide; Pu annihilation in CANDU reactors; high temperature gas-cooled reactor options which would burn Pu to the point of almost not needing reprocessing. Final disposal options must be considered if separated Pu is not used as a fissile energy source. The group reviewed vitrification and burial in deep boreholes. They noted that both physical security and nuclear criticality are significant issues to be addressed if Pu borosilicate glass is to be placed in a repository. The greatest unknown for the alternative of placing Pu directly into a custom deep borehole facility in small criticality safe containers, is the uncertain regulatory status. Regulations applicable to a dedicated Pu disposal facility do not currently exist. (UK)