Three Mile Island Powering The Future 1974 Baseball T-Shirt

Three Mile Island Nuclear Generating Station (TMI) was originally built by General Public Utilities Corp. (GPU), and operated by Metropolitan Edison Company. Construction began in 1968 and the plant was commissioned in 1974. Located on Three Mile Island in Londonderry Township, Dauphin County, Pennsylvania on Lake Frederic, a reservoir in the Susquehanna River. With two reactor units and four cooling towers, TMI was capable of producing more than 800 megawatts of carbon-free electricity. In 1979, a partial meltdown of the Unit 2 reactor (TMI-2) released radioactive gases into the environment, making it the worst accident in U.S. nuclear power plant history. The Unit 1 reactor (TMI-1) continued operation until it was shut down in 2019.