Three-Mile Island Accident

Three-Mile Island Accident

The Three Mile Island Unit 2 reactor (TMI-2) experienced a partial meltdown and was the most serious accident in U.S. commercial nuclear power plant operating history. Luckily,  there were no detectable health effects on plant workers or the public from the small radioactive releases, but the event spurred significant changes to nuclear power plant regulations and emergency response preparedness. —FEMA

Date of event: March 28, 1979


  • No detectable health effects
  • TMI-2 permanently shut down; all fuel removed.

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Photo: (Credit: CDC) Aerial photograph of the Three Mile Island Nuclear Power Plant.

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