By KERRY SMITH BUCK

MIDDLETOWN, Penn. – As of May, the regulatory pathway to reopen the Three Mile Island Unit 1 nuclear reactor – known now as Crane Clean Energy Center – is in a critical, high-scrutiny phase, with 2026 identified by regulators as the pivotal year for safety inspections.

Three Mile Island is located on a 445-acre island in the Susquehanna River in Londonderry Township in Dauphin County, Penn., near Middletown, Penn and 10 miles southeast of Harrisburg, the state capital.

Microsoft is actively partnering with Constellation Energy to revive the former nuclear reactor. The tech giant has signed a 20-year power purchase agreement to secure the 835-megawatt plant’s carbon-free energy and hopes to see a restart in 2028, adding power to the grid for purposes of operating a growing number of U.S. data centers. Putting the 835-megawatt number in context, it’s enough energy to power more than 500,000 homes.

The U.S. Nuclear Regulatory Commission is currently conducting intensive onsite physical plant inspections and reviewing licensing amendments, a process expected to last throughout 2026.

PJM Interconnection, the regional grid operator for the area containing the Three Mile Island nuclear plant, is experiencing delays in completing the necessary transmission upgrades needed to restart the plant. PJM says these upgrades could take until 2030 or 2031 to be completed.

To combat the grid delay, Constellation Energy has requested Federal Energy Regulatory Commission approval for a workaround to transfer capacity interconnection rights from an older, fossil-fuel-fired plant (Eddystone – located on the Delaware River, 90 miles east-southeast of Three Mile Island) to the Crane Clean Energy Center.

Constellation Energy is also seeking approval from the U.S. Nuclear Regulatory Commission related to waste handling and fire protection systems.

The project is facing criticism over its request for a huge volume of water from the Susquehanna River – approximately 73.2 million gallons a day.

The U.S. Dept. of Energy has formally closed on a $1 billion loan for the restart, providing a significant financial boost to the project.

Amazon Web Services is not partnered with Crane, but it does have separate, similar deals for other nuclear power sources in Pennsylvania. Like Microsoft, Amazon is focusing on carbon-free energy to power its data centers. The company is actively investing in and acquiring access to small modular reactors (SMRs).

At the Associated General Contractors of America conference in Orlando in March, AWS Senior Manager of Data Center Construction Procurement Matt Raponi said the trend is clear: it’s up to data center builders to seek and obtain their own power rather than drain an already strained U.S. electric grid.

“Owners and developers are solving their own power needs,” Raponi said. “This is a major trend that will continue to accelerate. It really is a bellwether in terms of controlling one’s destiny in creating new power sources.”

Washington State is the site of several small modular reactors in which Amazon is invested. The tech giant is partnering with X Energy to build Cascade Advanced Energy Center near Richland, Wash. that would initially provide up to 960 megawatts by the 2030s.

Both Amazon and Microsoft are developing data center projects in Pennsylvania near the Susquehanna River.