The following news article originally appeared in NEI’s Nuclear Energy Overview.
Hurricane Isaac had no impact on the three Gulf Coast nuclear energy facilities, but operator Entergy made extensive preparations, including shutting down Waterford 3 before the storm made landfall Wednesday morning.
The National Weather Service downgraded Isaac to a tropical storm Wednesday night, and Entergy said it is preparing to return Waterford 3 to the grid.
Waterford 3 is located about 20 miles west of New Orleans. The company’s River Bend facility, 25 miles northwest of Baton Rouge, and Mississippi’s Grand Gulf station remained fully operational during the storm.
Entergy spokesman Carl Rhode said Waterford 3 will return to the grid after the NRC determines the plant can operate safely and the Federal Emergency Management Agency confirms that roads, bridges and other infrastructure can handle an evacuation in the unlikely event of a nuclear accident.
Rhode said Thursday morning that Entergy is “preparing to restart but [we] do not have the all clear yet from FEMA. We will be working with them over the next few days to make sure that our emergency plans can be executed, and that will clear the way for a restart.”
Isaac’s path proved tricky to track and Waterford 3 was considered the most likely to bear the brunt of the hurricane’s impact. However, none of the facilities experienced any damage from the storm.
Waterford 3 is designed to withstand winds of up to 200 miles per hour, but, following NRC guidelines, plant workers were to begin powering down the reactors when winds reached 75 miles per hour. Entergy didn’t wait that long. Rhode said the company initiated shutdown of the reactor at 3 p.m. local time on Aug. 28, well in advance of the hurricane’s arrival.
“Fleet management decided to err on the side of caution,” he said. He added that some of Entergy’s coal and natural gas plants also reduced power preceding the storm’s arrival, though he expected none of them to power down completely. Entergy bases such decisions on maintaining the stability of the grid and the flow of electricity to customers and emergency workers, Rhode said.
He said that to further ensure safety, Entergy sequestered about 100 core personnel at each of the Louisiana nuclear energy facilities to maintain operations during and after the storm’s landfall. Entergy also sequestered a smaller contingent of workers at River Bend and Grand Gulf and all three plants retained their full security forces during the storm.
The U.S. Nuclear Regulatory Commission announced that it had sent four additional inspectors to assist resident inspectors at each of the Louisiana sites. The NRC said the additional staff would remain at the facilities for several days “to monitor the licensee’s activities and ensure safe plant operations.”
The NRC requires licensees to perform a series of actions as a hurricane approaches. These include:
- Inspecting the entire facility and securing or moving equipment that could become airborne due to high winds. They must verify that weather-tight doors and water intakes function properly.
- Testing emergency diesel generators to ensure they can provide electricity for critical operations if the plant loses access to off-site power, as happened at Waterford 3 during Hurricane Katrina in 2005. The test includes topping off diesel fuel tanks for the generators to ensure at least a seven-day supply.
- Providing regular status reports to the NRC, beginning 12 hours before the hurricane is expected to arrive.