3P-515 : Electrical conductivity of Zr- and Gd- doped UO 2

The UO2 fuel irradiated in the reactor contains various elements from cladding materials and fission products generated during irradiation, and reacts with them to form a solid solution. UO2 should have Mott insulator characteristics. Even with a small amount of dopants, the electrical conductivity can vary significantly. We used ZrO2 and Gd2O3 as dopants which can form the solid solution with UO2 to investigate the effect of the dopant level on the electrical conductivity. Various compositions of U1-x-yZrxGdyO2+δ were prepared, and the electrical conductivity was measured at room temperatures. Electrical conductivities of (x=0, y=0), (x=0.05, y=0.005), (x=0.05, y=0.01), (x=0.1, y=0.005) were 0.10, 1.11, 1.51, and 0.35 S/m, respectively. As the dopant level of Zr increased, electrical conductivity showed the maximum value of 1.11 S/m. Whereas the electrical conductivity increased up to 1.51 S/m as the dopant level of Gd increased.