The Three Mile Island Accident

The largest commercial nuclear disaster in United States history occurred on March 28, 1979 at the Three Mile Island nuclear power facility in Dauphin County, Pennsylvania.  The accident was a result of secondary system maintenance that caused the failure of a pilot-operated release valve in the primary system.  This malfunction led to the leakage of reactor coolant.  This problem was exacerbated by human error including lack of proper human-computer interaction and training with the control room’s user interface [1].

three mile island
This photograph of the Three Mile Island nuclear reactor facility points out the location of the coolant leak in reactor number 2.

The concerns for human health and safety resulting from the disaster retarded the construction of nuclear reactors and anti-nuclear activists gained support from the general public.  The amount of radioactive gases and iodine released into the environment remains unknown.  However, studies analyzing cancer rates in the area have shown that the accident caused no significant health impacts to humans.  An estimated $1 billion cleanup effort began in 1979.  The cleanup did not officially end until 1993 [2].

(Composed by Dan Kervick; Edited by Sean Hanczor)

References

  1. Minutes to Meltdown: Three Mile Island – National Geographic
  2. “14-Year Cleanup at Three Mile Island Concludes”. New York Times. August 15, 1993. Retrieved March 28, 2011.