Constellation Energy has announced a landmark 20-year power purchase agreement with Microsoft to restart a shuttered reactor at the Three Mile Island nuclear facility in Pennsylvania. The Unit 1 reactor, which closed in 2019 due to economic pressures, is slated to return to service by 2028, pending regulatory approval. This move underscores the escalating energy demands of artificial intelligence and cloud computing, which require massive amounts of constant, carbon-free electricity. Proponents of the deal argue it will create thousands of jobs and provide a stable energy source to meet climate goals. However, some environmental advocates and local community members have expressed caution, citing concerns over nuclear safety and waste disposal. The deal marks the first time a retired U.S. nuclear plant would be returned to service, signaling a potential shift in the national energy landscape.