Unit 2 of Minnesota’s Prairie Island nuclear plant shut down automatically Monday morning, according to Nuclear Street sources.
Safety systems for the reactor tripped at 7:22 a.m., sources indicate. The unit shut down safely, the plant responded as expected, and no injuries were reported. The cause of the trip is under investigation. It appears to be a weather-induced generator lockout, sources said, and one possibility is that lightning struck a power line leading to a plant substation.
Operated by Xcel Energy 28 miles southeast of Minneapolis, Minn., Prairie Island uses two, roughly 550-megawatt Westinghouse pressurized water reactors licensed in 1974, according to the Nuclear Regulatory Commission. Unit 1 at the plant was shut down April 29 for scheduled refueling.
According to an NRC reactor-status list, unit 2 was operating at full power when the trip occurred.