The Nuclear Regulatory Commission said two reactors were taken off line near Lake Anna in central Virginia, near the epicenter of Tuesday's earthquake, which shook buildings up and down the east coast. Seven other plants, including some in Pennsylvania and New Jersey, declared "unusual events" requiring further scrutiny.
The NRC, in an April inspection meant to identify potential risks from an earthquake at the North Anna Power Station, urged a number of fixes to earthquake "vulnerabilities" it found there. Specifically, the NRC report notes that portions of water and gaseous suppression systems and hose stations "are not seismically designed."
The report warned that "potential leakage can occur through penetrations following seismic event."
The NRC, in a May 13 letter to Virginia Electric Power Co., asked the company to report back on potential "mitigation strategies." The NRC stated in its letter that it was trying to "promptly assess" the capabilities of the nuclear plant "to respond to extraordinary consequences similar to those that have recently occurred at the Japanese Fukushima Daiichi Nuclear Station."
The results from such inspections around the country, regulators continued, "will be used to evaluate the U.S. nuclear industry's readiness to safely respond to similar events."
U.S. reactors, including the four plants operated by Dominion in Virginia, are supposed to be shut down in the event of a major earthquake such as the one that struck Japan in the spring of 2011.
Since the Fukushima earthquake and tsunami, energy companies in the U.S. already were dealing with heightened investor anxieties over the status of nuclear power in the U.S.
Following the disaster, Robert S. Harris, a specialist in corporate finance and dean of University of Virginia's Darden School of Business, testified on behalf of Virginia Electric and Power Co. before Virginia's State Corporation Commission on the company's cost of equity and general financial condition.
He noted that possible policy changes and heightened scrutiny of the industry have led to re-pricing of utility stocks and added "new uncertainties to the complicated challenge of finding a reliable, cost-effective and safe mix of power generation." And he added that "utilities with nuclear exposure have been harder hit" in the markets.