Floodwaters rising at Cooper and Fort Calhoun nuclear power plants, Nebraska
The U.S. Nuclear Regulatory Commission (NRC) said in a statement that is was closely watching conditions along the Missouri River where floodwaters are rising at two Nebraska nuclear power plants, the Cooper Nuclear Station and the Fort Calhoun NPP.
The lowest of four levels of emergency notification remain in effects at both plants, NRC said.
“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 NPP, located in Brownville, Nebraska, is currently about 70 cm (two and a half feet) above current river levels, and is operating at full power. However, it remains under the ‘Unusual Event’ declared on June 19, NRC said.
Fort Calhoun, which is about 30 km (19 miles) north of Omaha, was shut down for refueling on April 7 and has not since been restarted. It remains under the Unusual Event declared on June 6.
“The NRC has augmented its inspection staff at Fort Calhoun where there is now two feet of water in many areas onsite,” the report said.
Cooper Nuclear Power Plant on the edge of the Missouri River surrounded by floodwaters on June 15, 2011. Photo: Corps of Engineers
An aerial view of Fort Calhoun Nuclear Power Plant taken on June 16, 2011 showing the extent of flooding at the station. Photo: U.S. Army Corps of Engineer
Flooding along the Missouri River to continue until mid-August
Water release from the reservoirs and dams along the Missouri River is expected to continue until at least mid-August, resulting “in near-record flooding along portions of the Missouri River.”
Earlier the NWS released the following statement:
“The upper Missouri River Basin (Montana, Wyoming, North and South Dakota and Nebraska) has received 100 to 800 percent of normal precipitation during the past several weeks. Snow pack runoff entering the upper portion of the river system is more than twice the normal amount.
“These conditions have resulted in Missouri basin reservoirs across eastern Montana and the Dakotas nearing their maximum levels. Reservoir water release rates are expected to stay at high release levels (150,000 cfs) into August. These extremely high flows, combined with normal rainfall, will result in near-record flooding along portions of the Missouri River.”
The graphic above shows where recent river gauge forecasts are available, and are colored according to their values. They are the most recent guidance forecasts we have issued as of the date/time stamp on the bottom of the graphic. Orange, magenta, and red dots represent river points that are forecast to be in flood. Yellow dots represent those which are under flood stage, but are high enough to merit some internal action (e.g., perhaps a crest forecast is issued, or a forecast is issued more frequently). Green dots represent stages that are below the action stage and are not high enough to merit much hydrologic concern. Gray dots mean that the status couldn’t be determined (perhaps because no forecasts for these points have been recently issued). Source: NWS Missouri Basin/ pleasant Hill