WATERFORD — The Millstone nuclear power plant’s number 2 and 3 reactors were shut down early Sunday morning due to a loss of “off-site power,” according to a spokesman for the Nuclear Regulatory Commission.
Neil Sheehan, public affairs officer for the NRC, said Sunday in a release that all safety systems functioned as designed and that there were no health or safety issues to the public as a result.
Sheehan said the plant’s emergency diesel generators activated and provided power to the safety systems until power could be restored.
Sheehan said the shutdown, which occurred at about 7:15 a.m., was classified by the NRC as an “unusual event,” the lowest of the agency’s four emergency classifications.
Sheehan said it was not immediately known what caused the loss of off-site power, but added that preliminary indications were the it was initiated in the plant’s “switch yard” and that the local power transmission company was working to restore electrical flow.
Sheehan said that off-site power was restored early Sunday afternoon and that the cause was determined to be an electrical fault or short in a power line.
The reactors were still shut down pending a review of the incident, Sheehan said.