The return of Three Mile Island

The nuclear plant on Three Mile Island in Pennsylvania, home to one of the worst nuclear accidents in US history, is getting a second life, thanks to artificial intelligence.

Under a new, 20-year deal, Constellation Energy will restart the famed power plant, which closed in 2019, and sell the energy to Microsoft to fuel its data centers. This is an opportunity for the computing giant to meet its incredible demands for computer processing power required for its AI ambitions and do so with a so-called clean energy source. The White House and tech leaders recently discussed a plan to use more clean energy sources for AI data centers amid conflict between the government and private sector’s AI ambitions and climate goals. Still, it could take years for the plant to get inspected, licensed, and gain federal approval from the US Nuclear Regulatory Commission to restart.

The Electric Power Research Institute has estimated that data centers could consume 9% of US electricity annually by 2030, up from just 4% in 2023. In May, Microsoft also signed a deal with Brookfield Asset Management to deliver the tech company 10.5 gigawatts of new renewable energy between 2026 and 2030, a massive amount that The Verge remarked was equivalent to half of California’s wind and solar capacity.

Three Mile Island’s Unit 2 had a partial meltdown in 1979, but its Unit 1 was undamaged and remained operational until 2019, when it was shut down due to financial pressures. Constellation Energy told The Wall Street Journal that Unit 1 was “arguably the best-performing reactor in America.” There are currently 94 active reactors in the country.