Molecular dynamics simulation of collective behaviour of Xe in UO₂

This paper performs atomic simulations of the nucleation and growth of Xe bubble in UO_2 at 1600 K. The bubble growth was simulated up to the bubble containing 50 Xe atoms. The Xe atoms were added directly to the bubble one by one, followed by a relaxation of the system for several picoseconds. The simulations estimated the bubble pressure and radius at different Xe concentrations. The results indicate that the bubble pressure drops with the increasing Xe/U and bubble size at low Xe concentration, while the pressure will increase with the Xe/U ratio at high Xe concentration. The swelling of the system associated with the bubble growth was also obtained. Finally, the recovery of the damaged structure was investigated.