|Dominion's North Anna nuclear reactors|
The units were shut down on August 23 as a result of a 5.8 magnitude earthquake which had its epicenter about 11 miles from the plant.
In a press statement Eric Leeds, the NRC's head inspector for the review of the reactors said:
“The earthquake shook the reactors more strongly than the plant’s design anticipated, so Dominion had to prove to us that the quake caused no functional damage to the reactors’ safety systems."
“We’ve asked Dominion dozens of detailed questions, and our experts have examined Dominion’s answers as well as information from our own inspections. We’re satisfied the plant meets our requirements to restart safely, and we’ll monitor Dominion’s ongoing tests and inspections during startup of both reactors.”
Inspections and more inspections
The NRC’s independent actions included an Augmented Inspection Team (AIT) that examined the plant shortly after the quake, as well as a restart readiness inspection in mid-October.
Both Dominion and NRC’s results showed only minor damage that did not affect North Anna’s safety systems. The NRC held public meetings near the plant on Oct. 3 regarding the AIT’s findings, and on Nov. 1 regarding the restart readiness inspection findings and the staff’s technical review.
More quake related actions
|Seismograph Image: Ohio DNR|
• Updating North Anna’s Final Safety Analysis Report to incorporate information from the quake and subsequent analysis;
• Additional characterization of the fault responsible for the Aug. 23 quake, as well as any special ground motion effects at North Anna;
• Re-evaluating plant equipment (including an assessment of potential improvements) identified in earlier seismic reviews;
• Developing any needed inspections or evaluations for components within the North Anna reactor vessels; and;
• Permanently updating seismic monitoring equipment for the North Anna reactors and dry-cask spent fuel storage facility.
The staff’s letters to Dominion, as well as its technical evaluation, will be available on the NRC’s Virginia quake Web page.
It will take Dominion's reactor operations staff about a week to bring the two units up to their full operating capacity.
Prior Coverage on This Blog
- October 2011 - Dominion & NRC set path to re-start reactors
- September 2011 - Shifting views on nukes and quakes
- August 2011 - Safe shutdown of North Anna
# # #