The earthquake that rattled Dominion Resources Inc (D).’s North Anna power station is renewing a 40-year- old debate over whether a nuclear plant should be built over a dormant fault line there, threatening the company’s plans for a third reactor at the site.
This week’s 5.8-magnitude temblor has given opponents of the plant more ammunition to question the adequacy of federal safeguards governing reactors located near seismic hot spots. The rare East Coast quake was the largest in Virginia in more than a century and cut power to North Anna’s two reactors, which lie less than 15 miles (24 kilometers) from the tremor’s epicenter.
“The quake that people say couldn’t happen here has happened here,” said Louis Zeller, science director for the Blue Ridge Environmental Defense League, an anti-nuclear group, in an interview. “This is a wake-up call.”
The earthquake bolsters support for a U.S. Nuclear Regulatory Commission task force proposal that plants expand their reviews of seismic risks, said Jim Warren, executive director of North Carolina Waste Awareness & Reduction Network.
“The industry really must begin to look beyond” events that reactors were designed to withstand, Warren said in a phone interview. That includes hurricanes and flooding as well as earthquakes.
Third Reactor Planned
Dominion, based in Richmond, is considering building a third reactor designed by Mitsubishi Heavy Industries, Ltd. (7011) at North Anna, located about 40 miles from Virginia’s capital. A final decision may not be made until 2013, after design work is complete and U.S. regulators have reviewed the company’s application to build and operate the unit, Dominion Chief Executive Officer Thomas Farrell said at a news conference in Washington July 11.
The NRC is reviewing the proposed design of the reactor, which must be able to withstand seismic activity.
“Obviously, this latest earthquake will be added to the database of information that’s used in this analysis,” NRC spokesman Scott Burnell said in a phone interview. The NRC will not license a plant that sits directly on top of an active fault, he said.
“That is not the case at North Anna,” he said.
An active fault nearby, such as the one that caused this week’s earthquake, does not automatically disqualify a site because those reactors can be built to withstand seismic activity, Burnell said. The agency still expects to make a decision on the license in 2013, he said. Jim Norvelle, spokesman for Richmond-based Dominion, said the company doesn’t expect seismic issues to delay licensing of the third unit.
Old Dispute Revived
The outage at North Anna may revive controversy over the long-dormant fault underlying the plant that was discovered as construction began in the late 1960s, Zeller said.
Federal regulators allowed the plant to proceed after determining that the fault was dormant. Rock fragments in the fault hadn’t moved since they’d been formed an estimated 500,000 years ago, according to a 1976 ruling by a U.S. appellate court upholding the licensing decision.
Zeller said his group intends to challenge that seismic analysis. Blue Ridge is among a handful of parties that gained the nuclear agency’s permission to challenge Dominion’s application for a third reactor.
“It’s the same old nonsense which ignores the obvious: this is a seismic area. The plant shouldn’t have been there in the first place,” Zeller said.
‘More Than Capable’
North Anna “was more than capable” of handling the tremors, aftershocks and power outage that the earthquake caused, Dominion’s Norvelle said. “The fault area is well- known, well-understood. We’re beyond this.”
One of the back-up generators at the North Anna plant failed, requiring the facility to use a spare. Within the last eight years, there have been at least 74 reports of inoperable back-up generators at U.S. nuclear plants, Representative Edward Markey, a Massachusetts Democrat, wrote in a letter to NRC Chairman Gregory Jaczko yesterday.
“This illustrates a long-standing concern” that back-up generators at nuclear plants aren’t adequately maintained, said Markey, who has led lawmaker calls in Washington for tighter regulations on the nuclear industry.
“The Virginia earthquake is now our local 911 call to stop delaying the implementation of stricter safety standards,” he wrote to Jaczko.
The NRC is considering new regulations for 104 U.S. commercial reactors after a March earthquake and tsunami caused meltdowns and radiation leaks at Tokyo Electric Power Co. (9501)’s Fukushima Dai-Ichi plant. By Oct. 3, NRC officials must prioritize actions to be taken in response to an NRC task-force report on safety.
The task-force was “spot-on” in its recommendation that plant owners be required to re-evaluate earthquake and flooding risks every 10 years, David Lochbaum, director of the Nuclear Safety Program at the Cambridge, Massachusetts-based Union of Concerned Scientists, said in an interview.
An earthquake exceeding the threshold for a safe shutdown of the North Anna reactors is likely to occur once every 4,762 years, Lochbaum said.
By comparison, PG&E Corp. (PCG)’s two Diablo Canyon reactors, located about 12 miles from San Luis Obispo, California, may experience an earthquake of greater-than-expected magnitude once every 256 years, according to Lochbaum’s sorting of NRC data.
Thousand Year Event
“Fukushima was expected to experience a tsunami of greater height than its sea wall about once every 1,000 years,” Lochbaum said in an e-mail. Several U.S. reactors have seismic designs that are just as vulnerable as Fukushima’s design against tsunamis, he said.
The agency should examine nuclear plants that are most exposed to greater-than-expected earthquakes, he said. Those plants include Diablo Canyon, Progress Energy Inc. (PGN)’s Robinson reactor near Florence, South Carolina, and Duke Energy Corp. (DUK)’s Oconee plant near Greenville, South Carolina, according to Lochbaum.
Federal regulators haven’t yet indicated whether they will require additional seismic testing at North Anna, said Dominion’s Norvelle. The nuclear agency is creating a new analytical model to help plants better assess their seismic risks, Burnell said.
“The current plan is for all U.S. plants to go through the additional analysis,” said Burnell. “The deadline for them to perform that analysis is not yet known.”
Julie Johnsson in Chicago at firstname.lastname@example.org