The US Department of Energy has issued a conditional commitment of up to $5 billion to finance uprates and upgrades at Constellation Energy nuclear plants. The announcement came on October 27. The program covers eight plants in Illinois, Maryland and Pennsylvania and represents nearly 1.1 GW of added capacity.
Uprates are upgrades that allow an existing reactor to generate more electricity. Turbines, steam-side components and control systems are replaced with more efficient equipment. The site, the license and the grid connection stay the same. That is why the megawatts arrive faster than they would from a new reactor.
The federal financing adds to private capital. According to Constellation, 20-year agreements with Google and Amazon support more than $7 billion in investment for about 1,080 MW. The Google deal, signed on October 6, covers 890 MW from 11 units at six sites across Illinois, Pennsylvania and New Jersey, with more than $4.3 billion in spending. The first uprate is expected by 2028, with the full batch completed by the end of 2032.
The projects vary in size. At Limerick, near Philadelphia, one upgrade will add 348 MW to a 2,317 MW plant. At Salem, in New Jersey, the increase will be 97 MW. A Constellation spokesperson said each plant has its own plan, with a common aim: getting more megawatts from the same site using more efficient technology. The Amazon agreement, meanwhile, covers Calvert Cliffs in Maryland, where an uprate of about 190 MW is planned between 2030 and 2032. A deal with Meta supports a 30 MW expansion at Clinton, Illinois.
The push is driven by data center electricity demand, as operators look for stable power that is available now. Tech companies are paying upfront for long-term contracts, and Constellation is turning that spending into contracted revenue. Vistra is following the same path: it secured a $4.2 billion DOE loan supporting 433 MW of uprates with Meta as the customer. According to a Jefferies analysis, the two transactions cover much of the uprate potential in the PJM region, against a national estimate of 3 to 5 GW.
The regulatory calendar is already set. According to the Nuclear Regulatory Commission’s schedule, Constellation expects to file 12 uprate applications between the fourth quarter of 2026 and 2030. If approvals arrive on time, the existing US fleet could add more than a gigawatt before any new reactor enters service.
