SchrodingerZ writes "The nuclear power station on Three Mile Island in Pennsylvania shut down abruptly this afternoon. Its shutdown was caused when one of four coolant pumps for a reactor failed to work. 'The Unit 1 reactor shut off automatically about 2:20 p.m., the plant's owner, Exelon Corporation, reported. There is no danger to the public, but the release of steam in the process created "a loud noise heard by nearby residents," the company said.' If radiation was released into the environment, it is so low that it thus far has not been detected. The plant is a 825-megawatt pressurized water reactor, supplying power to around 800,000 homes, thought there has been no loss of electrical service. Three Mile Island was the site of a partial nuclear meltdown in 1979. The Unit 2 reactor has not been reactivated since."