Nuclear safety: Five recent 'near miss' incidents at US nuclear power plants
4. Fort Calhoun Nuclear Plant, Nebraska – Failure of emergency equipment
On Feb. 17, 2010, the NRC sent a team to the nuclear plant after the turbine-driven auxiliary feedwater (AFW) pump automatically shut down shortly after operators started the pump during a monthly test.
The AFW system is an emergency system that remains in standby mode during normal plant operation. However, although the AFW system plays a vital role in an accident, the NRC investigators found that the pump had failed numerous times over many years. The owner had never found the cause of the problem, and therefore had never taken steps to prevent it.
The NRC identified four violations of its safety regulations.