The Ameren Missouri Callaway Energy Center declared an "Unusual Event" Friday night, but says the public is not at a safety risk.
A representative for the company told ABC 17 News Sunday there was no timetable for reopening because repairs needed to be made and an investigation was still underway.
At 11:49 p.m. Friday, the company said a small fire erupted in a turbine building, which is in a non-nuclear part of the facility. The fire was extinguished, but the center is currently out of service as it follows normal safety protocols and procedures.
Ameren says the public was never threatened during the situation and no one was injured. They also say there was no above-normal release of radioactivity.
Both Ameren Missouri and the U.S. Nuclear Regulatory Commission have started an investigation into what caused the fire.
According to the NRC, an "Unusual Event" means there is a minor occurrence at a nuclear power plant that could reduce the overall level of safety. During such an event, no public action is advised or necessary.
It's unclear when the Callaway County center will be able to return to service. While the center is out, customers will receive their energy from other Ameren Missouri energy facilities.