One of the two units at Dominion Virginia Power’s North Anna nuclear power plant, which suffered a prolonged shutdown due to the August earthquake on the East Coast, had to reduce power because of a mechanical problem.
The plant detected the leak Monday morning in an instrument air line in Unit 1, and then officials manually took it from 100 percent of operating capacity to 4 percent while they made repairs, said officials at the Nuclear Regulatory Commission (NRC).
They quickly completed the repairs and workers began powering Unit 1 back up, NRC spokesman Joey Ledford said.
The utility expects Unit 1 to be back at full power soon, said Richard Zuercher, a spokesman for Richmond-based Dominion.
Unit 2 at North Anna, 45 miles northwest of Richmond, remained operating at full power.
The leak found Monday led to the second power reduction in one of the units at North Anna since they restarted after shutting down because of the 5.8-magnitude earthquake Aug. 23.
Both units remained offline until November, but less than a week after Unit 2 restarted, officials reduced power in the unit to 98 percent so workers could check out what appeared to be a faulty resistor on a feedwater flow instrument. Dominion returned the unit to full power within days.