Dominion Virginia Power's North Anna nuclear power station has restored off-site power, eliminating the need to rely on its back-up generators. The station remains in an Alert, the second lowest of the four emergency classifications of the US Nuclear Regulatory Commission.
The station's two nuclear reactors shut down following an earthquake near the station that occurred Monday at 1:51 p.m. EDT (8/23). The reactors shut down automatically and no damage has been reported to systems required to maintain the station in a safe condition. Several aftershocks felt in the region that occurred later in the day did not affect the station.
As designed, four diesel generators supplied power to the station while the off-site power was unavailable. One of the four generators was taken off-line to repair a generator coolant leak, but a fifth generator at the station was activated to replace it until the offsite power was restored. Repairs are complete to the diesel generator.
The company also inspected the Lake Anna Dam after the earthquake and determined it sustained no damage. Station inspections are continuing to assure no damage has resulted from the seismic event.
No release of radioactive material has occurred beyond those minor releases associated with normal station operations.
The earthquake was felt at the company's other nuclear power station, Surry Power Station in southeast Virginia, but not as strongly. Both units at Surry continue to operate safely. Surry has exited a Notification of Unusual Event (NOUE) it declared earlier Monday, the least serious of four NRC emergency classifications.
US nuclear power stations, including Dominion's four stations, were built to seismic standards for their regions.
The North Anna nuclear power station is located in Louisa County in central Virginia, northwest of Richmond and generates 1,806 megawatts from its two units - enough electricity to power 450,000 homes.
Dominion’s North Anna nuclear power station restores offsite power