Proactive material degradation research subjects for LWR

The predictive and preventive maintenance technologies are of increasingly importance for the long term operation (LTO) of Light Water Reactor (LWR) plants. In order for the realization of LTO, it is essential to prevent the degradation phenomena from emergence using proper maintenance programs on foreseeing the phenomena and evaluating their rates of development. In this paper, the research subjects which should be required for the aging degradation phenomenon in LWR structural materials which were discussed in the Proactive Aging Management Group Meeting of Tohoku-Hokkaido Research Cluster of NISA Project are introduced. (author)