The site of America's worst nuclear accident is being rebuilt to run again. This time, it has exactly one customer. Microsoft.
In 1979, Three Mile Island's Unit 2 suffered a partial meltdown, the most serious commercial nuclear accident in American history. Unit 1, sitting right next to it, was not involved. It kept running safely for another forty years.
Unit 1 was first licensed in 1974 and operated without incident until 2019, when its owner shut it down for economic reasons rather than safety ones. Cheap natural gas had made the plant unprofitable to run. Before it closed, it could power more than 800,000 average homes. Its license would have run until 2034 had it simply kept operating.
The plant has a new name now, the Christopher M. Crane Clean Energy Center, and a single reason for existing. Constellation Energy signed a 20 year deal to sell every megawatt of its power to Microsoft, to help run the company's data centers.
Constellation says the project is "surging forward," pointing to a recent waiver from federal energy regulators that makes it easier to reconnect the plant to the grid. The company is targeting a restart in 2027, backed by a billion dollar federal loan to speed the work. Roughly 835 megawatts would flow into the mid Atlantic grid once it's running again, enough to matter directly to the data centers straining that same grid today.
Eric Epstein has lived near the plant for decades and runs a local watchdog group called Three Mile Island Alert. He is fighting the restart in three separate places at once, the Nuclear Regulatory Commission, Pennsylvania's environmental regulator, and the river basin commission that controls the plant's water rights.
Epstein argues Constellation doesn't have access to enough water to cool a restarted reactor, and will need new storage facilities to hold what he calls a toxic stew of nuclear waste already sitting on the site, tonnage he says could double or triple depending on how the relicensing plays out. At a public hearing in July, he raised a more immediate concern too, whether the emergency evacuation plan, currently being rewritten by FEMA, accounts for something as ordinary as a Friday night football game with three highways jammed with traffic and snow on the ground.
Epstein says regulatory guardrails are being dismantled to hit an AI driven deadline. The Nuclear Regulatory Commission, mid reorganization to streamline its own licensing process, says it's still doing its job.
At the plant's most recent public comment meeting, the two sides looked almost nothing alike. Opponents were nearly all older residents who remember 1979 firsthand. Supporters were often younger and further away, a nuclear engineering student, an industry veteran, two advocacy groups based outside Pennsylvania entirely.
Local officials touted the economic case. Constellation and its backers say the restart is creating roughly 3,400 direct and indirect jobs, with more than 600 full time, family sustaining positions once the plant is running in Dauphin County. A retired director of Pennsylvania's own radiation protection bureau told the room he wasn't worried about the company's safety record or the state's ability to respond in an emergency, a notable vote of confidence from someone who spent his career on the regulatory side of exactly this kind of question.
Pennsylvania voters go to the polls in November 2026. The NRC isn't expected to decide the plant's fate until months after that. Epstein has pointed out the irony directly. An election that could shape the state's energy politics will be over before the actual decision gets made.
Nuclear material is scheduled to arrive on site by the end of this year regardless, held in storage until regulators sign off. Nothing about the timeline is fully settled, not the water permits, not the waste plan, not the NRC's own final review. What's already decided is who Crane will sell its power to. What's still being fought over, one hearing and one lawsuit at a time, is whether the people living next to it ever really got a say.