Plant life management activities of LWR plants in Japan

Plant Life Management Activities of Japanese LWR plants have been conducted since the early 1990s by the utilities and MITI (Ministry of International Trade and Industry) cooperatively. The Plant Life Management study consists of two phases. Both phases (parts) of study were carried out confirming the integrity of long-term operation of the three oldest Japanese LWR plants, that is Tsuruga Power Station Unit No.1 (BWR), Mihama Power Station Unit No.1 (PWR) and Fukushima Dai-ichi Nuclear Power Station Unit No.1 (BWR). The Part 1 study was conducted for the purpose of getting the outlook of long-term safety operation, and was completed in 1996. The Part 2 study was conducted ensuring the integrity of the long-term operation in terms of not only safety but also reliability, The results of the Part 2 study were completed and made public in February 1999. Then the results of the study arc intended to be included into the existing maintenance programs of the three LWR plants. The same kind of study is intended to be conducted for the younger LWR plants before their operation periods reach thirty years. Furthermore, through this study, the Rand D items to be considered in the Plant Life Management were extracted, and their results wilt be reflected in the maintenance program. (author)