Crane Clean Energy Center Restart

Constellation is spending $1.6 billion to restart a reactor that shut down in 2019. Three Mile Island Unit 1, renamed the Crane Clean Energy Center, will return 835 megawatts to the PJM grid under a 20-year power purchase agreement with Microsoft. It’s the most significant restart of a U.S. commercial reactor that had already started down the decommissioning path.

Project Scope

This is heavy industrial refurbishment of standing plant, not new construction. The steam generator, main generator, rotor, turbines, feedwater heaters and condensers all require full inspection and requalification. Three new main power transformers are being built under a separate construction contract, with an additional $35 million committed to get them on site during 2026.

Financing closed in November 2025 with a $1 billion loan from the Department of Energy’s Loan Programs Office. Staffing is past 64 percent, with nearly 400 full-time employees hired against a permanent target of 600. Refueling outages will bring 1,500 to 2,000 workers on site roughly every two years once the plant runs.

The regulatory track is the schedule driver. As of July 2026 the NRC environmental review and public comment process is under way. FERC granted an interconnection-rules waiver on June 1, 2026. The site is on schedule to receive nuclear fuel by the end of 2026, and NRC operating authorization is estimated around May 2027.

Why It Matters

Restarting a reactor is cheaper than building one, and until recently nobody was certain it was achievable at all under the modern licensing regime. Crane is the test case, and the arithmetic so far is favorable. $1.6 billion for 835 megawatts works out to roughly $1,900 per kilowatt of capacity, against figures many times that at Vogtle.

That gap is why the data center industry is paying attention. Microsoft’s PPA is what made the project financeable, and it establishes a template: a hyperscaler underwrites the restart, the operator takes execution risk, the grid gets firm capacity. A handful of other U.S. units have intact structures and lapsed licenses.

The constraint isn’t engineering. It’s that each restart consumes NRC review capacity, and the queue is finite.

Project Team & Details