The worst nuclear accident to ever occur in the United States, Three Mile Island, is set to reopen and will sell its power exclusively to Microsoft as it looks for new energy sources to support its artificial intelligence goals.

Constellation Energy said on Friday that, subject to approval from the Nuclear Regulatory Commission, the five-year-old Unit 1 reactor might be restarted in 2028. In order to assist artificial intelligence, Microsoft plans to buy the carbon-free energy generated from it to power its data centres.

The 20-year deal, which Constellation described as its largest ever, had undisclosed financial details.

“Nuclear plants are the only energy sources that can consistently deliver on that promise, and they provide an abundance of energy that is carbon-free and reliable every hour of every day, which is necessary to power industries critical to our nation’s global economic and technological competitiveness, including data centres,” a press release from Constellation CEO Joe Dominguez stated.

Businesses and proponents of clean energy are looking to nuclear energy as a dependable baseload source of zero-carbon power. One major benefit is that, in contrast to wind and solar power, nuclear energy can run continuously.

Nonetheless, environmental organisations have long criticised nuclear power for its waste. The waste is currently housed at more than 70 active and closed plants across the country as there is still no permanent disposal for it in the US.

Constellation estimates that the reopening of Unit 1 reactor will increase the number of direct and indirect jobs by 3,400 and supply the grid with more than 800 megawatts of electricity. Additionally, the factory is estimated to boost Pennsylvania’s GDP by $16 billion.

In noon trade, Constellation (CEG) shares surged by more than 16%.

The most notable event at a commercial nuclear power station in US history occurred at Three Mile Island, which is close to Harrisburg. One of the plant’s two reactors partially melted down, resulting in the most devastating disaster. Following the accident, the Unit 2 reactor, which is next to Unit 1, has been shut down since 1979.

President Joe Biden’s climate bill, which includes billions in tax subsidies to encourage nuclear power in addition to wind, solar, and clean hydrogen, is what made the deal possible. Congress and the Biden administration have also invested billions of dollars in funding to prevent the closing of outdated plants that were scheduled for closure.

According to Alan Ahn, deputy director for nuclear at think tank Third Way’s climate and energy program, “there’s not a lot of historical precedent on regulatory approval” in the US for restarting a closed plant.

The Palisades nuclear station in Michigan, which was set to close until the federal government intervened with more than $1 billion to save it, is being repowered by regulators and businesses. Ahn noted that Three Mile Island has been inactive for a number of years longer.

However, Ahn noted that as tech firms explore for more power sources to meet their AI demands, they are increasingly considering nuclear energy, which is carbon-free and helps them meet their ambitious climate goals.

“When discussing the increased power requirements resulting from artificial intelligence, data centres must essentially operate at maximum capacity around-the-clock.Other than nuclear power, there aren’t many options, according to Ahn. “It’s getting quite obvious that the tech corporations are

really carefully examining nuclear.”

According to the press release, Bobby Hollis, vice president of energy at Microsoft, “this agreement is a major milestone in Microsoft’s efforts to help decarbonise the grid in support of our commitment to become carbon negative.”