Process for recovering uranium and plutonium from irradiated nuclear fuel oxides

A process is described for recovering uranium and plutonium from liquid-metal-cooled nuclear reactor irradiated fuel assemblies as well as a process for preparing uranium nitride, plutonium nitride, and mixed uranium--plutonium nitride reactor fuels. The fuel oxides are separated from the fuel assemblies and reduced in a liquid-metal reduction solvent, thereby forming uranium and plutonium metal dissolved therein. This solvent is then contacted by a bed of particulate calcium nitride or magnesium nitride to react the dissolved uranium and plutonium with the particulate nitride to form insoluble particles of uranium nitride, plutonium nitride, and uranium--plutonium nitride mixtures. The bed of reacted particles is then removed from the solvent and retorted to remove any remaining liquid solvent and to volatilize any unconverted calcium nitride or magnesium nitride. This results in recovering the uranium and plutonium in the form of uranium nitride, plutonium nitride and uranium--plutonium nitride mixtures. (U.S.)