Thoria hosted plutonium incineration in thermal and fast reactors

On the basis of reactivity considerations, it is shown that thoria hosted weapon and reactor grade Plutonium can be used to fuel thermal and fast nuclear reactors. Disposition and incineration rates have been calculated for normal and extended lifetimes of the fuel. Excess weapon plutonium (W-Pu) arising from warhead dismantling can be disposed of in this manner without the production of new plutonium and bring the W-Pu to the Spent Fuel Standard. To go beyond the Spent Fuel Standard, and tackle the proliferation problem associated with the global Pu stock build-up from Pu in spent fuel, requires a more radical approach. On the basis of the present calculations, extended irradiation in both the thermal and fast thoria fuelled systems appears possible but will not lead to complete elimination without repeated reprocessing and recycling. The constantly deteriorating isotopic quality of the rest Pu will, however, severely limit the number of times such material can be recycled. For this purpose therefore, it appears that dedicated accelerator driven actinide burners will provide a more flexible and faster approach to rest Pu and minor actinide burning. 7 refs., 4 figs., 1 tab