Three Mile Island nuclear plant to reopen — to power Microsoft's AI push

• Three Mile Island, the site of one of the US' worst nuclear disasters, may soon reopen.
• Constellation have struck a deal to give Microsoft energy to power its AI push.
• AI systems require huge amounts of energy to train and run, and tech giants are looking for new sources.

A nuclear plant at the site of one of the worst nuclear disasters in US history may soon reopen to provide power for Microsoft's AI push.

Constellation Energy has struck a deal to provide Microsoft with nuclear power for the next two decades by bringing part of the Three Mile Island nuclear plant back to service by 2028.

A spokesperson for Constellation said it plans to invest $1.6 billion to reopen one of the Pennsylvania plant's two reactors.

One of the reactors closed after a system malfunction caused its partial meltdown in 1979. The second reactor remained open after the accident before finally closing in 2019. It is this reactor that will be refurbished and reopened.

Tech giants, including Microsoft, are increasingly exploring nuclear energy as a power source for energy-hungry AI data centers.

Job postings uploaded last year suggested that Microsoft, which has invested heavily in AI through its partnership with OpenAI, was exploring using nuclear energy to power its data centers.

Bobby Hollis, Microsoft's VP for energy, told Bloomberg that the Three Mile Island reactor will help Microsoft meet its target of being carbon-negative by 2030 and that energy from the site will be used for data center expansion in Pennsylvania and nearby states.

The AI models that power chatbots like ChatGPT require huge amounts of energy to train and run, supercharging a wave of spending on data centers across the US.

That, in turn, has sparked concerns over AI's environmental impact, with experts warning that building AI systems requires vast amounts of water and emits tons of carbon dioxide.

Microsoft and Constellation did not respond to a request for comment, sent outside normal working hours.