The development and utilization of quantitative assessment method with regard to the Operating Experience information analyses of nuclear power plants

The method to evaluate quantitatively and to rank recommendations for improvement created from Operating Experience information of nuclear power stations was developed to practically apply. Regarding safety of nuclear power stations, the amount was evaluated by core damage frequency which relates to level 1 PRA and early containment failure frequency which relates to level 1.5 PRA. On the other hand, reliability of operation of nuclear power station was evaluated with probability of automatic plant shutdown. As a result of this evaluation, it was realized that effective recommendations for improvement includes situations such that there are large number of components which are affected by the recommendation, and that it is expected to reduce the frequency of occurrence of accidents/events such as Loss of Coolant Accident (LOCA), Steam generator tube rupture (SGTR), and transients. (author)