According to the U.S. Nuclear Regulatory Commission, the reactor was operating at 25 percent of capacity after a complete shutdown at 1:30 p.m. Saturday.
An incident report filed with the NRC and posted on is Web site Monday morning said the reactor was operating at 100 percent capacity when a main feedwater pump flow lowered unexpectedly.
Safety systems performed as expected, and heat from nuclear decay was removed using steam pumps, the report said, categorizing the incident as a “non-emergency.”
NRC spokesman Joey Ledford said the incident remains under investigation by the commission’s inspectors stationed at the Burke County nuclear-power site.
“At this point, this looks like an uncomplicated reactor trip with no enforcement consequences,” he said. “However, the residents, as always, will follow up to make sure there are no safety implications.”
Unit 2 was unaffected by the incident and remains at 100 percent capacity.
Plant Vogtle is also undergoing a $14 billion expansion involving the addition of two Westinghouse AP1000 reactors, scheduled for completion in 2016 and 2017.
The project was licensed in February by the Nuclear Regulatory Commission. About 2,200 workers are involved in the construction adjacent to the existing units.