Meta Platforms has struck an agreement with Constellation Energy to keep one of the utility's reactors in Illinois operating for 20 years, in the Big Tech company's first such deal with a nuclear power plant.
Constellation Energy shares rose 13.4% to $355.5 in premarket trading.
Big Tech companies are looking to secure electricity as US power demand rises for the first time in two decades on demand from artificial intelligence and data centres.
Illinois helps subsidise Constellation's nuclear plant, the Clinton Clean Energy Center, with a ratepayer-funded zero emissions credit programme that awards benefits for generation of power virtually free of carbon emissions.
That expires in 2027, when Meta's power purchase agreement will support the plant with an unspecified amount of money to help with re-licensing and operations.
The deal could serve as a model for other Big Tech companies to support existing nuclear while they also plan to power data centres with new nuclear and other energy sources.
Urvi Parekh, head of global energy at Meta, said: "One of the things that we hear very acutely from utilities is they want to have certainty that power plants operating today will continue to operate."
Joe Dominguez, CEO of Constellation, said, "We're definitely having conversations with other clients, not just in Illinois, but really across the country, to step in and do what Meta has done, which is essentially give us a backstop so that we could make the investments needed to re-license these assets and keep them operating."
Bobby Wendell, an official at a unit of the International Brotherhood of Electrical Workers, said the agreement will deliver a "stable work environment" for workers at the plant.
The deal also allows Constellation to expand Clinton, which has a capacity of 1,121 megawatts, by 30 MW. The plant powers the equivalent of about 800,000 US homes.
Clinton began operating in 1987 and last year Constellation applied with the US Nuclear Regulatory Commission to renew its licence up to 2047.
