An aerial view of the Fort Calhoun Nuclear Power Plant in eastern Nebraska, surrounded by Missouri River flood waters on June 24.
– Waters Encircle Nuclear Plant (Wall Street Journal, June 27, 2011):
A protective berm holding back floodwaters from a Nebraska nuclear power plant collapsed early Sunday after it was accidentally torn, surrounding containment buildings and key electrical equipment with Missouri River overflow.
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The berm’s collapse allowed floodwaters to wash around the main electrical transformers. As a result, emergency diesel power generators were started. Later in the day, power was restored.
The NRC’s Mr. Dricks said temperature monitors were working properly and temperatures of key parts of the nuclear power plant were normal. Water has not seeped into any of the containment structures, he said.
Even when in shutdown mode, a nuclear plant requires electricity to keep key components cool in order to avoid any degradation or melting of the core that could result in the release of radiation.