Effect of Nd and Pr addition on the thermal and mechanical properties of (U, Ce)O2

The thermal conductivity, Young’s modulus, and hardness of (U0.65−xCe0.3Pr0.05Ndx)O2 (x = 0.01, 0.08, 0.12) were evaluated and the effect of Pr and Nd addition on the properties of (U, Ce)O2 were studied. The polycrystalline high-density pellets were prepared with solid state reactions of UO2, CeO2, Pr2O3, and Nd2O3. We confirmed that all Ce, Pr, and Nd dissolved in UO2 and formed solid solutions of (U, Ce, Pr, Nd)O2. We revealed that the thermal conductivity of (U0.65−xCe0.3Pr0.05Ndx)O2 (x = 0.12) was up to 25% lower than that of x = 0.01 at room temperature. The Young’s modulus of (U0.65−xCe0.3Pr0.05Ndx)O2 decreased with x, whereas the hardness values were constant in the investigated x range.