United States | News & Politics

You know you’re old when Three Mile Island is living memory rather than history.

The reactor accident began at 4:00 a.m. on March 28, 1979, and released radioactive gases and radioactive iodine into the environment. It is the worst accident in U.S. commercial nuclear power plant history, although its small radioactive releases had no detectable health effects on plant workers or the public. The accident was the largest release of radioactive material in U.S. history until it was exceeded by the Church Rock uranium mill spill four months later. On the seven-point logarithmic International Nuclear Event Scale, the TMI-2 reactor accident is rated Level 5, an "Accident with Wider Consequences."