NRC Tracking Flooding at Two Nebraska Nuclear Power Plants

Washington, DC—(ENEWSPF)—June 23, 2011. The U.S. Nuclear Regulatory Commission (NRC) is closely watching conditions along the Missouri River where floodwaters are rising at Cooper Nuclear Station and the Fort Calhoun nuclear power plant in Nebraska.

Unusual Event declarations remain in effect at both plants, the lowest of four levels of emergency notification. NRC officials are maintaining close contact with the National Weather Service, the U.S. Army Corps of Engineers and both plants.

“We are closely following events at both plants,” NRC Region IV Administrator Elmo Collins said.

“Both plants have activated their flood response plans and taken appropriate steps to protect vital structures, systems and components from rising floodwaters and maintain their plants in a safe condition.”

Cooper is operating at full power. Fort Calhoun shut down for a refueling outage on April 7 and operators have decided not to restart the plant until flood waters recede.

Both plants have made extensive preparations to protect the sites against rising floodwaters.

Cooper, located in Brownville, Nev., sits two and a half feet above current river levels. It remains under the Unusual Event declared on June 19.

Nebraska Public Power District officials have installed barriers to protect buildings and structures from flooding. A berm has been placed around the plant’s electrical switchyard for additional protection. The licensee does not expect floodwaters to impact vital plant equipment.

The NRC has augmented its inspection staff at Fort Calhoun where there is now two feet of water in many areas onsite. In addition to the two resident inspectors, three more inspectors and a branch chief are there to provide around the clock coverage of licensee activities.

Fort Calhoun, which is about 19 miles north of Omaha, remains under the Unusual Event declared June 6.

The licensee has erected a water-filled berm around the powerblock – vital areas including the containment and auxiliary buildings. The berm is eight feet tall and 16 feet wide at the base, and provides protection for up to six feet of water. The dam also protects several pieces of equipment which have been brought onsite, including an additional emergency diesel generator for supplying AC electrical power, water pumps, firefighting equipment and sandbagging supplies.

An earthern berm protects the electrical switchyard and concrete barrier has been built around the electrical transformers to protect them. Satellite phones have been distributed to key workers and extra food and water has been stockpiled.

Existing diesel fuel tanks have been topped off and two additional fuel tanks have been brought onsite. If there is complete loss of power on site temporary pumps that run on gas can circulate cooling water through the spent fuel pool and reactor core. Plant capabilities remain undiminished, despite the rising water.

Source: nrc.gov