Hurricane Florence: Duke Energy's nuclear power plants brace for impact

With Hurricane Florence set to hit the North Carolina coast on Friday, Duke Energy started to shut down its Brunswick nuclear power plant Thursday morning.

Brunswick Nuclear Plant, four miles inland in Southport, North Carolina, is currently in the path of the Category 2 storm.

"Per our procedures, operators are systematically shutting down the units, unit 1 first and then unit 2, prior to the storm making landfall," Duke Energy spokesman Chris Rimel said.

Personnel at Duke's other Carolina nuclear plants — including the Oconee plant near Seneca — have also launched storm procedures and preparations, and continue to monitor the status of the storm, he said.

More:Hurricane Florence: Up to 3M could lose power, here's how Greenville can prepare

The shutdown is consistent with information The Greenville News received Wednesday about Duke's preparations for the dangerous storm.

"If we determine that a plant site will experience sustained hurricane-force winds, our operators will begin an orderly shutdown of the generating units to be completed at least two hours prior to the expected impact," said David Fountain, Duke Energy North Carolina president, during a media call Wednesday.

Downgraded early Thursday to a Category 2 storm, Florence still has winds of 74 to 110 mph, according to the U.S. National Hurricane Center.

Tropical-force winds were expected to start hitting the North Carolina coast between 8 a.m. and 2 p.m. Thursday, and the Brunswick station is under a moderate threat of tornadoes and an extreme threat of flooding rain, according to the National Weather Service.

More:Hurricane Florence: Outer Banks horses are being left to fend for themselves

Federal oversight

The federal Nuclear Regulatory Commission sent inspectors to nuclear plants in the Carolinas and Virginia ahead of the storm to review operator preparations, according to a statement from the agency.

More:Hurricane Florence: Here's how much rain Greenville could get

The staffs at Brunswick, Robinson near Hartsville, South Carolina, and other plants worked through severe-weather procedures, including ensuring that all loose debris and equipment were removed or secured and conducting walk-down inspections of important systems and equipment, the NRC statement said.

Rimel, who works at Duke's Oconee Nuclear Station in western South Carolina, said that is what his plant did earlier this week — remove anything that could potentially become airborne.

"We moved our tables and chairs and solar panels," Rimel said.

Rimel said Oconee would follow a similar procedure as Brunswick should hurricane winds descend upon this part of the Carolinas.

"All nuclear plants in the U.S. fall under the (Nuclear Regulatory Commission) rule to shut down at least two hours before impact," Rimel wrote in an email. "But most nuclear stations (and all of Duke’s nuclear stations) continually practice worst-case scenarios for weather."

Through the storm

Duke's Fountain said Wednesday that operators will remain on site at Brunswick during the storm and will monitor wind and water levels and possible threats to the plant.

More:Hurricane Florence: Everything you need to know about the dangerous Category 2 storm

"We’ve got significant training behind this," Fountain said. "Our nuclear operators are trained, actually one out of every five weeks on simulators to manage extreme events such as weather and to safely shut down the unit."

One of the lessons learned at the 2011 Fukushima nuclear plant disaster in Japan was to keep key emergency response equipment safe and accessible for "beyond-design-basis" accidents, Rimel said. All plants maintain a hardened, storm-proof building full of trucks, tractors, generators and other equipment, dubbed FLEX equipment, for worst-case scenarios.

"All of Duke's nuclear stations have buildings like this or similar," Rimel wrote in an email. "Hurricanes, high winds and flooding are all severe weather events our operators intentionally practice in an every-five-week cycle. The FLEX equipment is for those events BEYOND what we normally plan for. We are that serious about safety."

Lakes drawn down

In anticipation of "torrential rainfall," part of Oconee Nuclear Station's preparations for the storm has been to lower the water level at lakes Keowee and Jocassee, Rimel said. Keowee is a hydroelectric plant that generates backup power as the water flows through.

As of 11 a.m. Thursday, Lake Keowee stood at 97.1 feet — 1.3 feet lower than a week before. Jocassee was down to 94.4 feet, 8 inches lower than a week ago.

He said Duke staff would continue to monitor the weather and run its hydroelectric plant at Keowee as much as possible ahead of the storm. He also asked for a little help from lake residents. About 91,000 people live within 10 miles of the Oconee Nuclear Station, according to the Union of Concerned Scientists.

"We encourage lake neighbors to stay alert to changing conditions, as significant rainfall could lead to higher lake levels," he said.

South Carolina has four nuclear facilities, according to the state's Emergency Management Division: Catawba Nuclear Station, Robinson Nuclear Plant, Oconee Nuclear Station and V.C. Summer Nuclear Station. Another three are just across state lines: Vogtle Electric Generating Plant in Georgia and the Brunswick and McGuire plants in North Carolina.