SUMMARY REPORT ON EVENTS RELATED TO LOSS OF OFFSITE POWER AND STATION BLACKOUT AT NPPs

This Summary Report presents the results of a comprehensive study (Volkanovski et al., 2015) on Loss of Offsite Power (LOOP) and Station Blackout (SBO) events registered in IRSN (Institut de Radioprotection et de Sûreté Nucléaire), GRS (Gesellschaft für Anlagen- und Reaktorsicherheit mbH) in time period 1992 to 2011 and the Nuclear Regulatory Commission (NRC) Licensee Event Reports (LERs) database and the IAEA International Reporting System (IRS) in the time period 1990 to 2013. The events were classified considering predefined categories. An analysis of the distribution of the identified events within the categories and type of plant operational modes was performed. The LOOP frequency was determined for each database and four LOOP event categories: plant centered, switchyard centered, grid related and weather related. The obtained frequencies obtained for critical and shutdown operations are presented. Based on the observations of the identified LOOP events, the activities that may result in reduction of the number of LOOP events and minimize consequences on plant safety are enlisted.JRC.F.5-Nuclear Reactor Safety Assessmen