Evaluation of phases in Pu-C-O and (U, Pu)-C-O systems by X-ray diffractometry and chemical analysis

Abstract

Preparation and characterisation of the carbides of uranium, plutonium and mixed uranium and plutonium form a part of advanced fuel development programs for fast breeder reactors. In the present study, the compositions of the phases of Pu-C-O and (U.Pu)-C-O systems have been determined by chemical analysis and lattice parameter measurement. The carbide samples have been prepared by vacuum carbothermic synthesis of tabletted oxide-graphite powder mixture. Dependence of stoichiometry of Pu₂C₃ phase on the oxygen content of Pu(C,O) phase in Pu(C,O) + Pu₂C₃ phase mixture has been evaluated. Stoichiometry and oxygen solubility of (U_0.3Pu_0.7)(C,O) phase in multiple phase mixture have been determined. Segregation of plutonium in (U,Pu)₂C₃ phase of (U,Pu)(C,O) + (U,Pu)₂C₃ phase mixture and its dependence on the oxygen content of (U,Pu)(C,O) phase have also been determined from the measurement of the lattice parameter of (U,Pu)₂C₃ phase.