Simulation of radiation induced grain boundary segregation in stainless steels under boiling water reactor conditions

The radiation induced segregation (RIS) at grain boundary (GB) in neutron irradiated type 316 stainless steel (SS) under boiling water reactor (BWR) condition was simulated by using the Fe-Cr-Ni-Si-Mo system model in which vacancy and interstitial mechanisms were considered for solute migration. The material constants used in the model were fixed to fit the experimental results on RIS at GB. The calculated depth and width of concentration profiles near GB in type 316 SS were comparable to the reported experimental results. The degrees of GB segregation were enhanced at lower neutron flux, and the tendency of flux dependence was similar to experimental results. The theoretical model is applicable to predict the RIS at GB to type 316 SS irradiated in BWR. (author)