Phase diagram of the UO2–FeO1+x system

Phase-relation studies of the UO2–FeO1+x system in an inert atmosphere are presented. The eutectic point has been determined, which corresponds to a temperature of (1335±5)°C and a UO2 concentration of (4.0±0.1)mol.%. The maximum solubility of FeO in UO2 at the eutectic temperature has been estimated as (17.0±1.0)mol.%. Liquidus temperatures for a wide concentration range have been determined and a phase diagram of the system has been constructed.