With electricity demand rising sharply, especially from data centers, nuclear operators are looking to squeeze more power out of existing plants. Constellation, the largest US nuclear operator, announced plans to spend over $4.3 billion on uprates across 11 reactors, adding nearly a gigawatt of capacity. The Department of Energy also committed a $4.2 billion loan to Vistra for upgrades at plants in Pennsylvania and Ohio, which will add 433 megawatts. These projects are backed by long-term power purchase agreements with Google and Meta.
Power uprates involve upgrading turbines, pumps, and other equipment, and using more highly enriched or fresh fuel to generate more steam. The practice dates back to the 1970s, but slowed in recent decades as demand plateaued and cheap gas squeezed nuclear economics. Now, with AI-driven electricity demand booming, interest has returned. On a per-kilowatt basis, uprates are cheaper than building new reactors, though still more expensive than new solar with storage or combined-cycle gas plants.
Estimates of the total additional capacity available from US uprates range from three to eight gigawatts, with the Nuclear Regulatory Commission already expecting applications for 2.4 gigawatts through 2032. But that is a small fraction of what is needed: PJM, the grid operator covering much of the East Coast, projects about 30 gigawatts of additional peak demand from AI by 2030. Uprates are a relatively easy win for zero-emissions power, but meeting the full scale of demand will eventually require building new reactors.