Kinetic Monte Carlo simulations of defect accumulation in neutron-irradiated bcc Fe were presented. Comparisons of the kinetic Monte Carlo simulations with experiments were made to discuss the validity of the proposed kinetic Monte Carlo model. Then, the effect of environmental variables such as irradiation temperature, dose rate, and neutron spectrum was studied using the technique. The magnitude of dose rate effect was irradiation-temperature dependent, and it was found that a threshold dose rate, below which defect accumulation was not affected by the difference of dose rate, exists when irradiated at 600K. An evaluation of the number of vacancy jumps of both irradiation-induced vacancies as well as thermal vacancies was done to study a possible effect of dose rate on a solute diffusion in bcc Fe. The results showed that the total number of vacancy jumps was dose rate dependent at very low and high dose rates while there was a dose rate independent region in between.

Modeling the Microstructural Evolution in BCC-Fe during Irradiation using Kinetic Monte Carlo Computer Simulation. N.Soneda, S.Ishino, A.Takahashi, K.Dohi: Journal of Nuclear Materials, 2003, 323[2-3], 169-80