Numerical simulation of irradiation-induced grain-boundary phosphorous segregation in reactor pressure vessel steels using rate theory model with first-principles calculations

Ebihara, Kenichi   ; Yamaguchi, Masatake   ; Nishiyama, Yutaka ; Onizawa, Kunio ; Matsuzawa, Hiroshi*

In order to evaluate numerically the grain-boundary segregation of phosphorus in reactor pressure vessel steels, the neutron irradiation-induced segregation was simulated under the condition of the irradiation experiments using the bcc lattice model incorporating the parameters which are obtained by the first principles calculations. The following results were obtained from the simulation results: (1) The grain-boundary P coverage becomes close to experimental results by increasing the sink strength of vacancies and interstitial atoms. (2) The irradiation-rate dependency of the grain-boundary P coverage is not observed. (3) The irradiation temperature dependency of the grain-boundary P coverage is different from the result reported previously.