A mesoscale kinetic Monte Carlo model developed to investigate the diffusion of silver through pyrolytic carbon and silicon carbide was described. This could include defects including grain boundaries, reflective interfaces, cracks and radiation-induced cavities that could either accelerate silver diffusion or impede diffusion by acting as traps for silver. The key input parameters to the model (diffusion coefficients, trap binding energies, interface characteristics) were deduced from available experimental data, or were parametrically varied until more precise values became available from lower length-scale modeling or experiment. The predicted results, in terms of the time/temperature dependence of silver release during post-irradiation annealing and the variability of silver release from particle to particle were compared to available experimental data.

Kinetic Monte Carlo (KMC) Simulation of Fission Product Silver Transport through TRISO Fuel Particle. G.M.De Bellefon, B.D.Wirth: Journal of Nuclear Materials, 2011, 413[2], 122-31