Three Mile Island Decommissioning
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.
Constellation owns TMI Unit 1, which started operations on September 2, 1974.
FirstEnergy, which owned TMI Unit 2, sold the unit to Energy Solutions in December 2020 to complete its decommissioning process. Unit 2 was permanently shut down in 1979.