For the second time in less than a month, operators at the Prairie Island power plant have had to shut down one of the two reactors at the nuclear facility near Red Wing.

Reactor 2 was shut down Friday morning because of a malfunction in the feedwater system that brings water to the steam generators. It’s unclear when the reactor will be brought back online. Xcel Energy officials say there was no danger to plant employees or the public.

On March 7th, the same reactor had to be shut down because of a false fire alarm.