Experience of on-line surveillance at ONAGAWA-1 BWR plant

Abstract An on-line system was installed on ONAGAWA-1 to monitor plant situations and to accumulate basic data for about 4 years, from start up test to 3rd cycle operation. Some kinds of anomalies were undergone during that period. Anomalies can be classified into several categories by growing modes of phenomena. It was verified that the system is useful to identify anomaly cause for the various kinds of anomaly modes. Some examples of experiences are introduced and discussed here.