The Robinson nuclear plant in South Carolina issued an emergency declaration Friday for a fire alarm that was later found to be in error.
The alarm at 4:07 p.m. indicated the presence of a fire on the third floor of the containment building, according to the Nuclear Regulatory Commission. Fifteen minutes later, operators declared an unusual event, the NRC's lowest level of emergency notification, per federal regulations.
The plant's fire brigade responded and confirmed the incident was a false alarm after a containment walkdown. The plant remained at full power throughout the event and did not call the local fire department. The unusual event declaration was in effect for less than a half hour before it was cancelled.
Operated by Duke Energy, Robinson uses a single Westinghouse three-loop pressurized water reactor that generates 724 megawatts. It is located near Hartsville, S.C.