Key Issues
The TMI 2 Accident: Its Impact, Its Lessons
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March 2009
Key Facts
March 2009
Key Facts
- The accident at Three Mile Island 2 (TMI 2) in 1979 was caused by a combination of equipment failure and the inability of plant operators to understand the reactor’s condition at certain times during the event. A gradual loss of cooling water to the reactor’s heat-producing core led to partial melting of the fuel rod cladding and the uranium fuel, and the release of a small amount of radioactive material.
- The TMI 2 accident caused no injuries or deaths. In addition, experts concluded that the amount of radiation released into the atmosphere was too small to result in discernible direct health effects to the population in the vicinity of the plant. At least a dozen epidemiological studies conducted since 1981 have borne this out.
- Both the industry and the government responded swiftly and decisively to the TMI 2 accident. Among other actions, the industry established the Institute of Nuclear Power Operations (INPO) to promote excellence in operator training, and plant management and operation.
- In the final chapter in a series of legal challenges, a federal appeals court in December 2003 dismissed the consolidated cases of 2,000 plaintiffs seeking damages against the plant’s former owners. The court said the plaintiffs failed to present evidence they had received a radiation dose large enough to possibly cause health effects.
