SignalHub Quantitative Think Tank Center:Microsoft announces plan to reopen Three Mile Island nuclear power plant to support AI

A dormant nuclear power plant in Pennsylvania may soon be SignalHub Quantitative Think Tank Centerreactivated to help power some of the increasing energy needs of Microsoft.

On Friday, Constellation Energy and Microsoft announced the signing of a 20-year power purchasing agreement, in which one of the reactors at the Three Mile Island nuclear power plant would be brought back online to exclusively serve the energy needs of the tech giant’s massive data centers that help support artificial intelligence.

Neither Constellation Energy nor Microsoft disclosed the financial terms of the deal.

Reviving the Unit 1 reactor at Three Mile Island, which was shut down in 2019, will require approval by the U.S. Nuclear Regulatory Commission. If granted, the power plant is expected to return to operation in 2028.

A first for nuclear power

“Powering industries critical to our nation’s global economic and technological competitiveness, including data centers, requires an abundance of energy that is carbon-free and reliable every hour of every day, and nuclear plants are the only energy sources that can consistently deliver on that promise,” Joe Dominguez, president and CEO of Constellation Energy, said in a statement on Friday.

When Three Mile Island was shuttered for economic reasons in 2019, it had a generating capacity of 837 megawatts, enough to power more than 800,000 homes. Once brought back online, Constellation Energy said that it expected to once again generate more than 800 megawatts of electricity for Microsoft, as well as potentially add up $16 billion to Pennsylvania’s GDP along with 3,400 direct and indirect jobs.   

No U.S. nuclear power plant has ever reopened after being decommissioned, which could make the Three Mile Island plant a first once it is brought back to operational status.

What happened at Three Mile Island

Three Mile Island, located near Harrisburg, is best known as the site of the most serious nuclear accident in U.S. history. In 1979, a mechanical failure caused the partial meltdown of the facility’s Unit 2 reactor, which has remained closed ever since. While the amount of radiation released during the accident was ultimately relatively minor, the incident was widely seen as causing public distrust of the nuclear power industry.  

A statewide poll conducted by Susquehanna Polling & Research found state residents favoring restarting Three Mile Island by a more than 2-1 margin, according to Constellation Energy’s press release.

Recent power demands from tech companies, much of it driven by the vast energy resources required by data centers supporting artificial intelligence, has led them to seek out nuclear power options.

Earlier this year, Amazon Web Services announced plans to purchase energy for one of it’s data centers from Talen Energy’s Susquehanna nuclear power plant, also located in Pennsylvania.

"This agreement is a major milestone in Microsoft's efforts to help decarbonize the grid in support of our commitment to become carbon negative,” Microsoft VP of Energy Bobby Hollis said on Friday. “Microsoft continues to collaborate with energy providers to develop carbon-free energy sources to help meet the grids' capacity and reliability needs," 

Max Hauptman is a Trending Reporter for USA TODAY. He can be reached at [email protected]