Evaluation of the Neutron Irradiation Embrittlement of RPV Steels: Development of Embrittlement Trend Curve and Investigation of Through Wall Attenuation

Full text: Accurate estimation of the through-wall mechanical property profile (attenuation) in reactor pressure vessel (RPV) steels is the key technology to evaluate the structural integrity of the RPVs of light water reactors. Prediction of the amount of embrittlement of RPV steels due to neutron irradiation during plant operation is the most important part of the estimation, and huge amount of efforts have been devoted worldwide to develop accurate and reliable embrittlement trend curves (ETCs). On the other hand, consideration of the profile of initial mechanical property through the wall thickness of RPV steels is also very beneficial in evaluating the actual structural integrity of RPVs. In this talk, we will review the development of ETCs for the RPV steels in Japan, and demonstrate recent results on the research activity on through-wall attenuation. (author)