Information fusion technique for evaluating radiation embrittlement of reactor pressure vessel steels

A new approach that utilizes the information fusion technique was developed to predict the radiation embrittlement of reactor pressure vessel (RPV) steels. The Charpy transition temperature-shift data is used as the primary index of the RPV radiation embrittlement in this study. Six parameters, Cu, Ni, P, neutron fluence, irradiation time, and irradiation temperature are used in the embrittlement prediction models. The results indicate that this new embrittlement predictor achieved about 66% and 53% reductions, respectively, in the uncertainties for the update General Electric (GE) Boiling Water Reactor (BWR) plate and weld data compared to the Nuclear Regulatory Commission (NRC) Regulatory Guide 1.99, Rev. 2 (RG1.99/R2). The implications of irradiation temperature effects for the development of radiation embrittlement models are also discussed.