RED WING, Minn. (AP) — Operators of the Prairie Island nuclear power plant in Red Wing are shutting down one of its two units because of a fire alarm.
Xcel Energy says there's no indication of a fire, but managers began taking Unit 2 off line Thursday morning so investigators can determine why the alarm was tripped.
Under rules established by the U.S. Nuclear Regulatory Commission, the operators declare a "notification of an unusual event." It's the lowest of four emergency classifications established by the commission.
Xcel says there's no threat to public safety. Unit 1 continues to operate at full power.