Saturday, March 12, 2011
The Three Mile Island accident was a partial core melt in Unit 2 (a pressurized water reactor manufactured by Babcock & Wilcox) of Three Mile Island Nuclear Generating Station in Dauphin County, Pennsylvania, near Harrisburg in 1979. The plant is owned and operated by General Public Utilities and the Metropolitan Edison Co. was the most significant accident in the history of American industry of commercial nuclear power generation, resulting in the release of up to 481 PBq ( 13 million curies) of radioactive waste gases, but less than 740 GBq (20 curies) of the dangerous especially iodine-131.
The accident began at 4 am on Wednesday, March 28, 1979, with failures in nuclear non-secondary system, followed by a relief valve stuck open piloted (RVP) in the primary system, allowing a large number nuclear reactor coolant to escape. Mechanical failures were compounded by the initial failure of plant operators to recognize the situation as a loss of coolant accident due to lack of training and human factors such as industrial design errors concerning ambiguous indicators control room in the user interface of the power plant. The scope and complexity of the accident revealed in the course of five days, as employees of Metropolitan Edison (Met Ed, the utility of plant operation), the Pennsylvania state officials, and members of the U.S. . Nuclear Regulatory Commission (NRC) sought to understand the problem, report the situation to the press and local community, you must decide if the incident requires an emergency evacuation, and ultimately ending the crisis.
In the end, the reactor was brought under control, although the details of the accident were not discovered until much later, after extensive research by both a presidential commission and the NRC. The Kemeny Commission report concluded that "there not be any case of cancer or the number of cases will be so small that it will never be possible to detect them. The same conclusion applies to the possible health effects." Several epidemiological studies in the years since the accident have supported the conclusion that the accident released radiation had no noticeable effect on the incidence of cancer in residents near the plant, although these findings have been challenged by a team of researchers.
Public reaction to the event was probably influenced by the release of the movie The China Syndrome 12 days before the accident, which happens to represent a nuclear reactor accident. Communications officials during the initial stages of the accident were considered confusing.The crystallized accident safety issues among anti-nuclear activists and the general public, resulted in new regulations for the nuclear industry, and cited as a contributing factor the decrease in new reactor construction was underway in 1970.
The accident began at 4 am on Wednesday, March 28, 1979, with failures in nuclear non-secondary system, followed by a relief valve stuck open piloted (RVP) in the primary system, allowing a large number nuclear reactor coolant to escape. Mechanical failures were compounded by the initial failure of plant operators to recognize the situation as a loss of coolant accident due to lack of training and human factors such as industrial design errors concerning ambiguous indicators control room in the user interface of the power plant. The scope and complexity of the accident revealed in the course of five days, as employees of Metropolitan Edison (Met Ed, the utility of plant operation), the Pennsylvania state officials, and members of the U.S. . Nuclear Regulatory Commission (NRC) sought to understand the problem, report the situation to the press and local community, you must decide if the incident requires an emergency evacuation, and ultimately ending the crisis.
In the end, the reactor was brought under control, although the details of the accident were not discovered until much later, after extensive research by both a presidential commission and the NRC. The Kemeny Commission report concluded that "there not be any case of cancer or the number of cases will be so small that it will never be possible to detect them. The same conclusion applies to the possible health effects." Several epidemiological studies in the years since the accident have supported the conclusion that the accident released radiation had no noticeable effect on the incidence of cancer in residents near the plant, although these findings have been challenged by a team of researchers.
Public reaction to the event was probably influenced by the release of the movie The China Syndrome 12 days before the accident, which happens to represent a nuclear reactor accident. Communications officials during the initial stages of the accident were considered confusing.The crystallized accident safety issues among anti-nuclear activists and the general public, resulted in new regulations for the nuclear industry, and cited as a contributing factor the decrease in new reactor construction was underway in 1970.
