Constellation, an energy company that provides electricity and natural gas to customers in 16 states and Washington, announced on Sept. 20, 2024, that it plans to restore and restart Unit 1 at Three Mile Island, a nuclear plant near Middletown, Pennsylvania, that was shut down in 2019. Microsoft has signed a 20-year agreement to purchase electricity generated by the plant to offset power demand from its data centers in the mid-Atlantic region.
Three Mile Island was the site in 1979 of a partial meltdown at the plant’s Unit 2 reactor. The Nuclear Regulatory Commission calls this event “the most serious accident in U.S. commercial nuclear power plant operating history,” although only small amounts of radiation were released, and no health effects on plant workers or the public were detected. Unit 1 was not affected by the accident. University of Michigan nuclear engineering professor Todd Allen explains what restarting Unit 1 will involve, and why some other shuttered nuclear plants may also get new leases on life.
