On the rate of in-reactor UO2 densification

A mathematical model for the in-reactor densification of UO2 pellets is developed. Its four paremeters are estimated by fitting it to experimental results published in the literature. The model agrees qualitatively as well as quantitatively with the experiments. The model states a decreasing surface energy and an activation energy for thermally activated diffusion of 136 kJ/mole. (Auth.)