What is Dominion doing to make nuclear plant safer following earthquake?

Posted on: 7:04 pm, August 15, 2012, by , updated on: 07:47am, August 16, 2012

LOUISA COUNTY, Va. (WTVR)- For several minutes Wednesday morning, emergency alarms sounded at Dominion’s North Anna Power Plant in Louisa County. The alarms were a part of an emergency drill.

Last August, a 5.8-magnitude earthquake rattled the East Coast and caused widespread damage. It also forced the shutdown of both nuclear reactors at North Anna.

The event marked the first time a nuclear power plant in the United States had to be shut down as a result of an earthquake.  North Anna was also the first plant to experience seismic activity that it wasn’t designed to handle.

While Dominion’s engineers and members of the Nuclear Regulatory Commission (NRC) later assessed and repaired minor damages to the plant, the two nuclear reactors never sustained damage and the backup safety systems never failed. 

Backup diesel generators operated safety equipment after the plant lost its off-site power.

“The safety systems performed well and the operators performed well,” said Dominion design engineer Dan Stoddard.  “It was really a demonstration of the safety of the plant.”

However, over the past year, Dominion has been working with the NRC to make the plant safer.  Dominion executives said more than $21 million and 110,000 man hours have been invested for plant improvements.

Several seismic monitors have been placed throughout the grounds of North Anna, and an earthquake recording system has been installed in the reactors’ control room.

The plant is also in the process of initiating a flex plan that includes new equipment and training to ensure that backup systems can tolerate any emergency; including a full-power outage caused by an earthquake, excessive flooding, or any other natural disaster.

“No matter what occurs, we are able to have water, electrical power and a means to keep the fuel cool,” said Stoddard.  “Then we know that we’re keeping our people safe, we are keeping the plant safe and we’re keeping the public safe.”

Dominion engineers said they hope to complete other safety evaluations and upgrades within the next year.

Meanwhile, Dominion has submitted an application to the NRC to build a third nuclear reactor at the North Anna Power Station.  The application approval is expected in 2015, however Dominion has not finalized plans to build another reactor.