Study of Uranium-Plutonium Carbide-Based Fuel Simulating High Burnup

Carbide-based fuels simulating high burnup were prepared by addition of inactive fission product elements. They contained fission product phases of the UMoC₂ and U₂RUC₂ type, and a rare-earth oxide phase. The thermal conductivity of the material is within the range observed for carbide-based fuels free of fission products. The diffusion of plutonium was considerably enhanced by the addition of fission products. The solid fission product swelling rate of a carbide-based fuel was estimated to be 0.5% per at.% burnup.