Development of a reduced oxidation model for hyperstoihiometric UO2+x

A numerical treatment was developed for predicting fuel oxidation in uranium-dioxide fuel, using a system of two time-dependent partial differential equations for hyperstoichiometry and temperature. This model was developed as a simplification from a previous mechanistic treatment, against which the current treatment is benchmarked, that also includes equations for hydrogen and steam transport in the fuel-to-sheath gap and fuel cracks. These factors were addressed in the reduced treatment using semi-empirical correlations to increase the model's robustness and computational speed. Further work has involved testing the model against experimental data available from coulometric titration experiments performed at the Chalk River Laboratories. (author)