Modeling and Measurement of Thermal Properties of Ceramic Composite Fuel for Light Water Reactors

Abstract

The thermal modeling of a composite fuel consisting of continuous second phase in a ceramic (uranium oxide) matrix has been carried out with aid of detailed examination of the microstructure of the composite and the interface structure. BeO and SiC were considered as second phase dispersed in UO2 matrix by weight from 0–15% to enhance the thermal conductivity. It is found that with 10% SiC, the thermal conductivity increases from 5.8 to 9.8 W/m-K at 500 K. A finite element analysis computer program ANSYS was used to create composite fuel geometries with set boundary conditions to produce accurate thermal conductivity predictions. The results were compared to analytical calculations as previously performed with the series geometry to verify the validity of using ANSYS in producing accurate thermally enhanced nuclear fuel models. Good agreement was found between experimental measured thermal conductivity for BeO-UO2 matrix and the model predictions.

ACKNOWLEDGMENTS

This work was partly supported by U.S. Department of Energy under Nuclear Energy Research Initiative (NERI) research grant.