Three Mile Island Generating Station Unit 1 (TMI Unit 1) permanently shut down on September 20, 2019, leaving a 45-year legacy of safe, reliable, carbon-free electricity generation and service to the community. It now enters a new era—the safe decommissioning and dismantlement of its components, systems and buildings.
Exelon Generation owns TMI Unit 1. The unit started operating on September 2, 1974.
FirstEnergy, which owns TMI Unit 2, announced the pending sale of that unit to Energy Solutions in July 2019. Unit 2 has been shut down since 1979.