The solidus and liquidus temperatures of UO2–Gd2O3 and UO2–Er2O3 fuels

The melting temperatures of UO2–(4, 6, 8, 12) wt% Gd2O3, UO2–(2, 4, 8) wt% Er2O3 and UO2 fuels were measured. The fuels were prepared by sintering the green pellets of powder mixtures. Fuel fragments were loaded into a tungsten capsule filled with helium, and then they were melted by an induction heating. The melting temperature was measured by the thermal arrest method during a heating of the capsule. The solidus and liquidus temperatures of UO2–Gd2O3 and UO2–Er2O3 were also determined. The solidus temperatures of UO2–Gd2O3 and UO2–Er2O3 were almost 150–280 and 180–270 °C lower than their liquidus temperatures, respectively.