Summary of plant life management evaluation for Onagawa Nuclear Power Station Unit-1

The Onagawa Nuclear Power Station Unit-1 (Onagawa NPS-1) began commercial operation on June 1, 1984, and has reached 30-year from starting of operation on June of 2014. To that end, we implemented the Plant Life Management (PLM) evaluation for Onagawa NPS-1 as our first experience. We decided on a Long-term Maintenance Management Policy from result of the evaluation, and then applied the Safety-Regulations change approval application on November 6, 2013 and its correcting application on April 16, 2014. Our application was approved on May 21, 2014 through investigation by the Nuclear Regulatory Agency. Also at implementation of the PLM evaluation, we considered effects of the Great East Japan Earthquake that occurred on March 11, 2011 against ageing phenomena. In this paper, we introduce summary of PLM evaluation for Onagawa NPS-1 and the evaluation that considered effects of the Great East Japan Earthquake. (author)