A berm is a level space, shelf, or raised barrier separating two areas. Since the Missouri River began flooding, contractors have been busy installing sandbags and earthen berms to protect the Fort Calhoun Nuclear Power Plant from flooding.
But KETV7 of Omaha, Nebraska, reports that a temporary berm designed to hold back floods at the nuclear power plant has collapsed. A piece of equipment punctured the aqua dam (or berm) at about 1:30 a.m. Sunday.
Water now surrounds two buildings at the plant, but federal officials and the Omaha Public Power District said there’s no danger although the head of the Nuclear Regulatory Commission has been dispatched to inspect the plant.
ABC News reports, June 27, 2011, that the breach of the berm allowed Missouri River flood waters to reach containment buildings and transformers and forcing the shutdown of electrical power. Backup generators are cooling the nuclear material at the Fort Calhoun Nuclear Station. The plant has not operated since April, and officials say there is no danger to the public. Nevertheless, federal inspectors are on the scene.
Meanwhile, there was no protecting thousands of homes in Minot, N.D., where flooding of the Souris River hit its peak today, flooding more than 4,000 homes.
Wikipedia says that “According to officials, the Fort Calhoun plant was built to withstand a 500 year flooding event and though by June 14, 2011, much of the facility was surrounded by the swollen Missouri River, Omaha Public Power District officals were confident that enough redundancies were in place to ensure adequate safety. It was reported on June 17, 2011 that the plant was in “safe cold shutdown” mode and that four weeks worth of additional fuel had been brought in to power backup generators, should they be needed. The Army Corps of Engineers indicated that with average precipitation, the Missouri River would not go above 1,008 feet above sea level and OPPD officials stated that the current flood protection efforts would protect the plant to 1,010–1,012 feet above sea level. Officials indicated the spent fuel pool is at 1,038.5 feet above sea level. The Federal Aviation Administration has declared a “temporary flight restriction,” in a two nautical mile radius, centered on the Fort Calhoun nuclear facility. This restriction went into effect on June 6, 2011, at 4:31 PM, and remains in effect “until further notice.”
The Omaha World-Herald today reports: “Water now surrounds the auxiliary and containment buildings [of the Fort Calhoun nuclear plant], which are designed to handle flooding up to 1,014 feet above sea level. The river is at 1,006.3 feet and isn’t forecast to exceed 1,008 feet.”
On Sunday the Missouri River was more than 3 feet below the level that would require Nebraska’s other nuclear power plant — Cooper Nuclear Station, near Brownville — to shut down. NPPD thinks it can continue operating the plant through the summer.
According to Wikipedia, in 2010, the population within 10 miles of Fort Calhoun was 20,639; the population within 50 miles was 953,410. The closest major city is Omaha, with a population of 408,958, whose center is 18 miles from the plant.