Thermal Diffusivities and Thermal Conductivities of UO₂-Gd₂O₃

Thermal diffusivities of samples of UO2 and UO2 doped with 3, 5, 7 and 10 w/0 Gd2O3 were measured over the temperature range of 298~2,023 K by a laser flash method. Then thermal conductivities were calculated from them. The thermal conductivity decreased with increasing Gd2O3 content at low temperatures, while it was independent of Gd2O3 content at high temperatures. An expression of the thermal conductivity was proposed for (U, Gd)O2 solid solution as a function of Gd2O3 content and temperature by applying Klemens' model.