HARRISBURG, Pennsylvania, April 26, 2026, 10:03 EDT
Restarting Three Mile Island Unit 1 isn’t getting any simpler for Constellation Energy Corp. The company needs clearance to pull as much as 73.2 million gallons daily from the Susquehanna River to supply the Crane Clean Energy Center. According to the Susquehanna River Basin Commission, the application is still pending. If approved, about 21 million gallons per day wouldn’t make it back to the river, the commission’s documents show.
The water request has landed a headline-grabbing nuclear restart—this one tied to a Microsoft-backed power contract—squarely in the same messy debate over data centers: questions about cost, benefits, and local impact, especially on water and the electric grid. According to local reports, the commission will accept written comments through May 4, after a public hearing triggered criticism about water use amid ongoing drought in parts of Pennsylvania.
Crane Clean Energy Center, the former nuclear facility rebranded by Constellation, sits at the heart of the company’s argument: legacy nuclear plants have a role powering the energy-hungry future of AI and cloud computing. According to Pennsylvania’s environmental regulator, Constellation locked in a 20-year power deal with Microsoft, which has agreed to take all the output from the upgraded 835-megawatt site.
Constellation is pitching a restart plan it says would bring 835 megawatts of carbon-free electricity back online, while also creating 3,400 jobs—counting both direct and indirect positions. The company projects $3.6 billion in tax revenue at the state and federal level, plus a $16 billion economic boost for Pennsylvania. If it gets the green light from federal, state, and local regulators, Constellation expects the plant could be operational in 2027.
The plant’s new water request comes in under its earlier power-generation approval, which stood at 122.8 million gallons daily, the basin commission’s fact sheet shows. Still, the ask tops the 44 million gallons per day permitted for decommissioning, handing critics a clear target as the proposal shifts from press release to actual permitting.
There’s a hitch: permits, local pushback, and grid bottlenecks might not stick to Constellation’s timeline. The Pennsylvania DEP put out a draft wastewater discharge permit on April 2, with public comments running through May 18. Meanwhile, Reuters reported PJM Interconnection’s early response suggested the plant might not connect to the grid until as late as 2031.
Constellation CEO Joseph Dominguez told investors the company remains on track to bring the unit online in 2027. “We are working on that with PJM, and we continue to expect to start this unit in 2027,” he said, according to Reuters. Dominguez also noted plans to request a transfer of certain grid rights from the Eddystone gas-fired plant over to the Crane site with federal regulators. Reuters
The federal stance still leans supportive for nuclear operators. The U.S. Department of Energy’s UPRISE program wants to tack on 5 gigawatts of nuclear power by 2029, using reactor uprates—essentially squeezing more output from existing plants—and restarts. According to Reuters, Constellation, Vistra, Duke Energy, Southern, and Entergy could be among the names set to gain. Rian Bahran, a DOE nuclear official, put it flatly: uprates are “the most cost effective and immediate way to increase nuclear capacity.”
So, Crane’s story reaches beyond just one site. Constellation is now hunting for bigger-ticket power agreements as data center demand surges. Rivals like Vistra and NextEra are also getting linked up with large tech firm contracts or nuclear restarts. James Richards at the Nuclear Innovation Alliance told Reuters Events that the boom in data centers looks like “a major impetus” for this renewed nuclear push. Reuters
Constellation has been signaling a ramp-up in spending. Last month, the company outlined a $3.9 billion capital plan and bumped its share buyback authorization to $5 billion. Reuters also reported Constellation secured over 5,650 megawatts in long-term clean-energy deals, some linked to Meta and Microsoft.
Shares carried some of that renewed optimism into the new week. Constellation finished Friday at $313.53, a jump from Thursday’s $292.77, hitting an intraday peak of $314.20, per the company’s investor page citing LSEG figures.
Investors won’t have to wait long for more details. Constellation’s annual meeting hits Tuesday, with the Q1 earnings call set for May 11—both sessions primed for fresh scrutiny on Crane, water permits, grid delays, and whether red-hot data-center power demand justifies the stock’s rich valuation.
