Thermal conductivity measurements on UO2+x from 300 to 1,400 K

Abstract

In order to evaluate the thermal conductivity of oxidized fuel pellets of leaker fuel rods, UO2+x samples with x between 0.00 and 0.20 were prepared by an oxidation or a sintering method. Sample thermal diffusivities were measured by using a laser flash method from 300 to 1,400 K and their thermal conductivities were evaluated from multiplying the thermal diffusivities by the sample densities and the specific heat capacities derived from the literature. The thermal conductivities of UO2+x were decreased with increasing hyperstoichiometry and they were expressed as a function of their hyperstoichiometry using the concentration of U5+ formed with the excess interstitial oxygen atoms. © 1996 Taylor and Francis Group, LLC.