* NRC sending special inspection team to North Anna
* No plant restart until determined it can operate safely
* No significant damage identified at plant yet
* Unclear how long plant will be closed - NRC spokesman
(Adds comment from nuclear watchdog, paragraphs 16-18)
By Ayesha Rascoe
WASHINGTON, Aug 29 The historic earthquake that
shut Dominion Resources Inc's (D.N) North Anna nuclear plant in
Virginia last week may have shaken the facility more than it
was designed to withstand, the U.S. nuclear regulator said on
The Nuclear Regulatory Commission said it had sent a
special inspection team to the plant rocked by the
5.8-magnitude quake, after initial reviews from Dominion
indicated the ground motion may have exceeded North Anna's
The plant cannot be restarted until the operator can show
no "functional damage" occurred to equipment needed for safe
operation, the NRC said.
"The company and the NRC will continue to carefully
evaluate information to determine if additional actions may be
necessary," the regulator said in a statement.
It will probably take about three or four weeks before the
team's preliminary findings are released, NRC spokesman Roger
Hannah said. He would not speculate on how long the plant might
be closed, saying it would depend on the team's assessment.
If it does turn out that the quake exceeded North Anna's
design specifications, Hannah said the team's analysis could
find that the plant could withstand quakes stronger than what
was originally intended.
But the team could also call for changes such as back
fitting or reinforcing equipment for more powerful
"It could be they would be shut down for a while, we just
don't know at this point," Hannah said.
MORE KNOWN MIDWEEK
Dominion said the North Anna reactors, which entered
service in 1978 and 1980, were designed for an earthquake of up
to 6.2 magnitude, but the NRC does not use that scale to
measure seismic design specifications. Instead, the commission
looks at ground-motion measurements.
Dominion spokesman Rick Zuercher said on Monday that more
will be known by midweek about whether the quake exceeded the
station's design as further analysis is conducted on seismic
plates from the station's containment building.
Zuercher said physical inspections of the plant have found
no major damage beyond cracks in office building walls, some
broken tiles, loose insulation on pipes and small damage to the
main transformer area where power is sent to the grid.
"We welcome the team to the site and will be sharing
information with them," Zuercher said.
The NRC has been reviewing the ability of U.S. plants to
cope with disasters after an earthquake and tsunami nearly led
to a complete meltdown at Japan's Fukushima nuclear complex
earlier this year --- the world's worst nuclear crisis since
An NRC task force set up in the aftermath of the Japan
crisis urged a shift in the NRC's safety regime that would
force plants to plan for catastrophes far worse than design
specifications allowed for, as well as require that companies
assess seismic and flooding hazards at plants every 10 years.
Critics have urged the NRC to move more quickly to adopt
these changes to ensure plants are prepared for disasters, with
last week's earthquake further fueling these calls.
The earthquake "does change the equation," said Jim Warren,
executive director of NC Warn, a North Carolina climate and
nuclear watchdog group. Warren said if last week's quake did
exceed North Anna's design specifications, that will bolster
the task force's recommendation about changing the NRC's safety
NRC Region II Administrator Victor McCree stressed that
the NRC's decision to send a team to the plant does not mean
that Dominion has "responded inappropriately or that the
station is less safe as a result of the quake."
McCree said in a statement that the team will help the
commission understand the effects of the quake on North Anna
and gather information that will help the NRC's evaluation of
earthquake risks at all U.S. nuclear plants.
(Additional reporting by Eileen O'Grady and Timothy Gardner;
Editing by Bob Burgdorfer, Alden Bentley and Dale Hudson)