Recent occurrences at nuclear reactors and their causes

The safety-related occurrences for which reports were received at the Nuclear Safety Information Center during May and June 1977 are listed. Occurrences are listed which resulted in reactor shutdown or which occurred during operation but were not discovered by testing and did not result in reactor shutdown. Included is a listing of events which were discovered by testing but had little, if any, effect on operation. The occurrences listed are those at operating research reactors and at power reactors that are in commercial operation