It was noted that the diffusion of species in this material was often the result of thermal activation plus radiation-induced diffusion. An attempt was made to estimate to what extent radiation-induced diffusion contributed to the diffusion of lattice atoms in UO2. Irradiation was represented by using molecular dynamics simulation of displacement cascades induced by uranium primary knock-on atoms between 1 and 80keV. As the atoms were easier to displace as their vibration amplitude increased, the temperature range which was investigated was 300 to 1400K. Cascade overlaps were also simulated, and the material was shown to melt at the end of cascades, yielding a reduced threshold energy displacement.

A Molecular Dynamics Study of Radiation Induced Diffusion in Uranium Dioxide. Martin, G., Maillard, S., Brutzel, L.V., Garcia, P., Dorado, B., Valot, C.: Journal of Nuclear Materials, 2009, 385[2], 351-7