An experimentally validated mesoscale model for the effective thermal conductivity of U-Zr fuels.

An experimentally validated mesoscale model was developed to simulate the effective thermal conductivity (ETC) of metallic U and U–Zr nuclear fuels. The effects of microstructure, temperature, composition, and interfacial thermal resistance (ITR) were investigated. Companion experiments were conducted to validate the model. The numerical simulations clearly demonstrate that accounting for the interface (Kapitza) thermal resistance and Zr precipitation is necessary to improve the model predictions. The dependence of the effective Kapitza resistance of depleted-U and U-10Zr on temperature was determined. For both materials, the largest difference between the model calculations and the experimental data was about 4.5%, which is within the precision of the experimental measurements. [ABSTRACT FROM AUTHOR]