This study proposes to estimate to what extent the radiation-induced diffusion

contributed to the diffusion of lattice atoms in UO2. Irradiation was simulated using

molecular dynamics simulation of displacement cascades induced by uranium

primary knock-on atoms between 1 and 80keV. As atoms were easier to displace

when their vibration amplitude increased, the temperature range which was

investigated was 300 to 1400K. Cascade overlaps were also simulated. The

material was shown to melt at the end of cascades, yielding a reduced threshold

energy displacement. The nuclear contribution to the radiation induced diffusion

was compared to thermally activated diffusion under in-reactor and long-term

storage conditions.

A Molecular Dynamics Study of Radiation Induced Diffusion in Uranium Dioxide.

G.Martin, S.Maillard, L.Van Brutzel, P.Garcia, B.Dorado, C.Valot: Journal of

Nuclear Materials, 2009, 385[2], 351-7