On March 28 , 1979 , equipment failures and operator error contributed to loss of coolant and a partial core meltdown at the Three Mile Island Nuclear Power Plant in Pennsylvania . The mechanical failures were compounded by the initial failure of plant operators to recognize the situation as a loss-of-coolant accident due to inadequate training and human factors , such as human-computer interaction design oversights relating to ambiguous control room indicators in the power plant 's user interface . The scope and complexity of the accident became clear over the course of five days , as employees of Met Ed , Pennsylvania state officials , and members of the U.S. Nuclear Regulatory Commission ( NRC ) tried to understand the problem , communicate the situation to the press and local community , decide whether the accident required an emergency evacuation , and ultimately end the crisis . The NRC 's authorization of the release of 40,000 gallons of radioactive waste water directly in the Susquehanna River led to a loss of credibility with the press and community
Three Mile Island Nuclear Power Plant
Three Mile Island accident
Nuclear power in the United States