Losses of off-site power at U.S. Nuclear Power Plants through 1992

This report provides a database describing losses of all off-site power at U.S. nuclear generating units. It includes the 13 years 1980 through 1992. Beginning with the report published in 1991 (NSAC-166), the database and statistics are being presented on a open-quotes generating unitclose quotes referenced basis rather than a open-quotes siteclose quotes referenced basis. The site basis was flawed in that for a loss of off-site power to one unit at a multi-unit site, the arithmetic netted out as if all the units at the site had lost off-site power. This caused the true loss of off-site power experience to be overstated by 30 to 50%. The generating unit basis corrects this shortcoming. During 1992 there were 8 losses of all off-site power at U.S. nuclear generating units. Their durations were 5 1/2 days, 5 1/2 days, 7:34, 0:57, 0:36, 0:35, 0:20 and 0:06. They represented 0.074 losses per generating unit year. Experience for the most recent 3 years (90, 91, 92) was 0.043 losses (of all durations) per generating unit year. For the 13 years 1980 through 1992 there were 0.039 losses of all durations per generating unit year