Preparation of component failure rates for reprocessing plant PSA

Tamaki, Hitoshi ; Yoshida, Kazuo ; Ueda, Yoshinori*

A risk-informed regulation will be applied to not only nuclear power plants but also nuclear fuel facilities in Japan. It is important for risk-informed regulation to assure the results of PSA. Component failure rates used in the frequency evaluation play an important role to assure the quality of PSA. Reprocessing plants are recognized as having higher risk than that of other nuclear fuel facilities. However, accident frequencies happened in reprocessing plants are evaluated almost using component failure rates estimated from operation experiences of nuclear power plants because those parameters estimated from experiences of reprocessing plants are limited. In order to improve the quality of results of accident frequencies in reprocessing plants, a project was launched in 2005 at JAEA. This project is consisted of two activities and is performed under entrustment from JNES. One is the estimation of component failure rates based on maintenance data from Tokai Reprocessing plant which has been operating since 1977 in Japan. The other is the preparation of component failure rates for frequency evaluation of accidents in reprocessing plants. This presentation will introduce the second activity.