NRC Keeps an Eye on Gulf Coast Flooding

Victor Dricks
Senior Public Affairs Officer
Region IV

Torrential rains have been battering the Gulf Coast since Friday, but have not adversely affected any of the nuclear power plants in Louisiana, Mississippi, or Arkansas.

louisiana map_sealThough skies have now cleared over Baton Rouge, the area has been especially hard hit by flooding. But this has had no significant impact on the River Bend nuclear power plant, about 25 miles northwest of the city, or the designated routes that would be used to evacuate the public in the event of a nuclear emergency.

The Waterford 3 nuclear plant, located in Killona (about 25 miles west of New Orleans), has been similarly unaffected. “We’ve had some heavy rain here over the weekend but there has not been any real impact on the plant,” said NRC Resident Inspector Chris Speer.

Flooding is one of the many natural hazards that nuclear power plants must be prepared for. Every nuclear power plant must demonstrate the ability to withstand extreme flooding and shut down safely if necessary. Most nuclear power plants have emergency diesel generators that can supply backup power for key safety systems if off-site power is lost.

All plants have robust designs with redundancy in key components that are protected from natural events, including flooding. These requirements were in place before the Fukushima accident in Japan in 2011, and have been strengthened since.

As of Tuesday, Arkansas Nuclear One, in Russellville, has gotten about five inches of rain since Friday, NRC Resident Inspector Margaret Tobin said. “It’s a little muddy at the site, but that’s about it.”

At Grand Gulf plant in Mississippi, 20 miles southwest of Vicksburg, only light rain has been reported. “We actually had very little rain at the site, compared to what was expected,” said Matt Young, the NRC’s Senior Resident at the plant.

The NRC is closely following events and getting periodic updates from the National Weather Service on conditions that might affect any of the Gulf Coast nuclear plants. Additionally, the resident inspectors are monitoring local weather conditions to remain aware of conditions that could affect continued safe operations of the plants.

Natural Hazards Are Part of the Planning

Scott Burnell
Public Affairs Officer

 

Up to now the 2014 Atlantic hurricane season has been pretty calm, but the NRC always keeps an eye out for the strong weather-related events and other natural events the world can generate. We make sure both U.S. nuclear power plants and the agency are prepared for high winds, storm surge and a whole lot more.

Most recently, the seven reactors affected by 2012’s Superstorm Sandy remained safe. Other plants have safely withstood powerful storms, including Waterford 3 in Louisiana handling the effects of 2005’s Katrina and Turkey Point in Florida safely taking a direct hit from 1992’s Andrew.

Sandy may have left a mess in New York, but the nuclear reactors in its wake remained safe. Photo courtesy of FEMA
Sandy left a mess in New York, but the nuclear reactors in its wake remained safe. Photo courtesy of FEMA

Flooding can happen with or without storms, and U.S. plants are designed to and safely ride out significant events, such as when Fort Calhoun in Nebraska dealt with an overflowing Missouri River in 2011. Also in that year, Vermont Yankee remained safe as the Connecticut River valley suffered severe short-term floods from Hurricane Irene’s remnants.

Japan’s Fukushima Dai-ichi nuclear accident in March 2012 showed the world what flooding (in this case from a tsunami) can do to a reactor. The NRC’s learned several flooding-related lessons. from the accident. As a result of NRC direction, U.S. plants are using the latest software and technical know-how to re-analyze all flooding sources. This will help the NRC determine if the plants need to consider higher flooding water levels when establishing plans to stay safe. This effort has also examined existing flood protection and all plants have taken steps to confirm they can implement reliable flood safety plans. In the meantime, several plants have also chosen to enhance their flood protection.

An earthquake caused the tsunami that devastated Fukushima, and again U.S. plants are designed to stay safe in the face of quakes that affect their area. Virginia’s North Anna plant was hit by an August 2011 quake centered a short distance away. The earthquake was strong enough to be felt across the East Coast; it shook North Anna with a little more force than what the plant was originally designed to withstand. North Anna remained safe – multiple inspections showed the plant’s systems were undamaged. This was unsurprising, since plant systems are designed to withstand a combination of events that can exceed the forces generated by an earthquake alone.

As with flooding, the NRC has learned from Fukushima’s quake and other recent earthquakes, and we’re having every U.S. plant reanalyze earthquake hazards to see where enhancements might be needed. All the plants east of the Rockies have taken the first step in that process, and the other plants will do the same next March.

U.S. reactors are also designed for (and have safely survived) hazards such as tornadoes, droughts and other severe weather events. Even with all this preparation, Fukushima reminds us to prepare for the unexpected. The NRC’s approach here involves every U.S. reactor having additional portable systems to restore and maintain safety functions.

All of this work helps ensure the public stays safe when natural disasters strike that may impact U.S. nuclear power plants.