Distribution of fission products among molten fuel and reactor phases. II. Distribution of fission products between molten Fe and a molten UO$sub 2$--basalt mixture

The solubility of uranium dioxide in molten basalt was determined at 1550 deg C to be between 5 and 7 wt % and at 2200 deg C to be between 50 and 55 wt %. The distribution of some of the more important heat-producing fission products between molten iron and a molten UO/sub 2/--basalt mixture was studied. This was done to evaluate the use of basalt as a fuel diluent and sacrificial material in a fast breeder reactor and to predict the fission product heat distribution in such a system. It was found that La, Ce, and Nb were distributed to the molten- UO/sub 2/--basalt mixture, and Mo and Ru were distributed to the molten-iron phase. (auth)