Loss of off-site power experience at US nuclear power plants-all years through 1984

The purpose of this study is to aid the nuclear power industry in its continuing monitoring of the reliability of off-site power sources at US nuclear plants. The author explains how the power supplies for plant loads are configured. More than half the sites studied in the paper have never had a loss of all offsite power and three quarters of them have never had a loss of power longer than 30 minutes. There were just 2 losses of all off-site power longer than 30 minutes in 1982 and 1983, and none in 1984. This sort of improvement is to be expected, the author notes, since losses of off-site power should continue to decline with time. It is expected that future losses of off-site power will be mostly random and few in number