Pipe diffusion at dislocations in UO sub(2)

We present the results of a combination of static and dynamic simulations employing empirical potentials, investigating the structures of dislocations in UO sub(2) and show how the dislocation core structure influences the rate of O super(2) and U super(4+) diffusion along the dislocation (i.e. pipe diffusion). In the region immediately surrounding the dislocations there is a significant reduction in the activation energies and diffusion coefficients for O super(2) and U super(4+) diffusion, however only out to a cylindrical radius of approximately 20 A from the dislocation centre. The contribution of pipe diffusion to the overall O super(2) and U super(4+) diffusion is also discussed.