NRC Staff Says Plants Are Safe From Flooding, Will Consider Climate Change Science
Jan. 9, 2014—The NRC staff told the commissioners this week that nuclear energy facilities are protected against flooding and that the agency is learning how to apply new knowledge from climate change science to licensing activities.
“Some national and international reports on climate change have indicated that more frequent and intense extreme weather events may challenge the operational safety of nuclear power plants in the future,” Mark Satorius, the NRC’s executive director for operations, said at a Jan. 6 commission briefing. “Ensuring [nuclear power] plants are adequately protected against natural phenomena—especially flooding and extreme weather—has been and continues to be an integral part of the staff’s licensing and oversight program.”
Eric Leeds, director of the NRC’s Office of Nuclear Reactor Regulation, pointed out that numerous nuclear power plants in the path of Hurricanes Katrina and Sandy performed admirably.
“While U.S. plants have coped well with these events, certainly Fukushima emphasizes the importance of remaining vigilant in overseeing plants and maintaining our understanding of the state-of-science for extreme weather and flooding,” Leeds said. “The plants are protected from flooding and other extreme weather events today and as our understanding of the hazards change, we will ensure the plants remain protected tomorrow.”
Chris Cook, branch chief of the division of site safety and environmental analysis in the NRC’s Office of New Reactors, said the agency is monitoring new developments in climate change science and their potential effect on flooding at plant sites.
“Regarding climate change, we monitor the latest updates and information from national and international organizations. We also factor into the hazard calculation the limited period of record and uncertainties,” he said. “The NRC continues to make realistically conservative assumptions for predicting maximum flood heights at nuclear power plant sites.”
Cook said that in the aftermath of Hurricane Katrina, the NRC formed a storm surge research program to develop “modern risk-informed hazard assessment techniques” in association with the National Oceanic and Atmospheric Administration and the U.S. Army Corps of Engineers. He also said that the 2004 Indian Ocean tsunami led the NRC to develop a tsunami safety study in 2005 and a long-term tsunami research program with NOAA and the U.S. Geological Survey. Cook said that both programs resulted in significant increases in knowledge and are being used as part of new reactor reviews.
“Our understanding and knowledge continues to evolve,” said Leeds. “We continue to evaluate flooding and other extreme weather events as new information is gathered from operating experience, new reactor reviews, new information on climate change and from new technology.”
Leeds said that plants should have the capability to cope with a wide range of extreme scenarios.
“I want us to be able to mitigate any type of event. I like mitigating strategies,” Leeds said.
The industry’s FLEX mitigating strategy, being implemented as a part of post-Fukushima safety enhancements, provides additional layers of backup power and reactor cooling capability by stationing supplemental emergency equipment—generators, battery packs, pumps, air compressors and battery chargers—on reactor sites and at off-site storage locations.
An archived webcast of the Jan. 6 flooding briefing is available on the NRC’s website.