Prediction of the dependence of KJC(T) on neutron fluence for RPV steels on the basis of the Unified Curve concept

A method is proposed that allows the prediction of the transformation of fracture toughness in the brittle-ductile transition temperature region as a function of neutron fluence for RPV steels. The method is based on the Unified Curve concept and a probabilistic local approach model proposed earlier by the authors as well as on physical analysis of the effect of impurities and carbide size on the local strength of a material. The results calculated with the proposed method are compared with available experimental data.