“It was a manual trip late last night and they are in the process of repairing the equipment,” said Joey Ledford, a spokesman for the U.S. Nuclear Regulatory Commission, whose senior inspector at the Burke County site was notified immediately.
The unscheduled shutdown, or “scram” as it is known in the nuclear industry, occurred at 11:02 p.m. Tuesday when the flow of seal leakoff “exceeded the procedural limits for continued operation of the pump,” plant operators wrote in an incident report to the NRC.
All systems operated correctly in response to the reactor trip, the report said, and the event was categorized as a nonemergency.
Unit 1 was unaffected by the issue and remained in operation Wednesday at 100 percent capacity.
Although commercial power reactors are shut down roughly every 18 months for scheduled refueling and maintenance, unscheduled shutdowns are rare.
The last such incident at the site was reported in April, when Unit 1 was taken offline as a precaution after a main feedwater pump flow lowered unexpectedly.
Plant Vogtle’s Units 1 and 2 went online in 1987 and 1989.
The plant is also the site of a $14 billion expansion that involves two new Westinghouse AP-1000 reactors scheduled to go online in 2016 and 2017.