DOE Offers Constellation Up to $5B for Nearly 1.1 GW of Nuclear Uprates

The US Department of Energy has offered Constellation Energy a conditional loan commitment of up to $5 billion to finance nuclear uprates and modernization at eight Constellation plants that could add nearly 1.1 GW, DOE announced on Oct. 27.

DOE's Office of Energy Dominance Financing named Braidwood, Byron, Clinton, Dresden, LaSalle and Quad Cities in Illinois, Calvert Cliffs in Maryland and Limerick in Pennsylvania. POWER Magazine reported that DOE made the announcement during Energy Secretary Chris Wright's visit to Byron. The agency said the output would serve the PJM Interconnection and Midcontinent Independent System Operator (MISO) regions, and that the commitment includes an option to finance uprates at other Constellation plants.

For data-center load, the point is firm megawatts from reactors that already run. Uprates add output at existing plants rather than at new sites, a different route from the reactor restarts Voltgrid News has tracked. DOE said the projects would power more than 930,000 homes. It did not tie any of the output to data centers.

What a Conditional Loan Commitment Means

A conditional commitment is DOE's statement of intent to lend, not money in hand. DOE said Constellation must meet technical, legal, environmental and financial conditions before the department signs definitive financing documents and funds the loan, and Constellation said the commitment is not a final investment decision on any single uprate.

An uprate raises the output of a reactor that already runs, through measures such as equipment and turbine upgrades. DOE says the work across the eight plants will add nearly 1.1 GW. The Google and Amazon agreements already back part of that capacity, so the useful question is how much of the loan finances uprates customers have already paid to start, and DOE has not said.

Conditional, and overlapping with customer deals

POWER noted that the scope of the federal financing is unclear because it appears to overlap uprates that customers already back.

Constellation said its 20-year agreements with Google and Amazon have prompted more than $7 billion of investment to add roughly 1,080 MW. Google's 20-year agreement funds uprates that add 890 MW of new capacity across 11 units at six sites, and Amazon's 20-year agreement includes an uprate of about 190 MW at Calvert Cliffs, targeted for 2030 to 2032, according to Constellation and POWER. Meta's agreement supports 30 MW at Clinton. Constellation said the financing could reduce borrowing costs and potentially accelerate development, according to POWER.

Plant sizes and the policy target

POWER listed the plants' net generating capacity, from Constellation's 2025 annual report, as Braidwood 2,386 MW, Byron 2,350 MW, Calvert Cliffs 1,789 MW, Clinton 1,092 MW, Dresden 1,845 MW, LaSalle 2,320 MW, Quad Cities 1,403 MW and Limerick 2,315 MW; Constellation owns 75% of Quad Cities. Together the eight plants have 15 operating reactors.

The offer follows a similar Oct. 5 offer of up to $4.2 billion to Vistra, POWER reported. DOE says its UPRISE program, launched in March 2026 under an executive order calling for DOE to facilitate 5 GW of power uprates from existing reactors, has now identified 95% of the 5-GW uprate and restart goal; POWER puts the identified potential at about 4.7 GW.

What is not confirmed yet

DOE has not said how the nearly 1.1 GW divides among the plants, and Constellation has not publicly confirmed how Google's 890 MW is spread across reactors, POWER said. The proposed uprates would carry varying Nuclear Regulatory Commission licensing requirements, depending on reactor design, equipment and the scope of each increase. Voltgrid News covered the NRC's final rule on reactor applicants citing DOE test data earlier this month. The NRC's expected-applications list shows 12 Constellation uprate applications between the fourth quarter of 2026 and 2030, but it does not name the plants, so they cannot yet be matched to this loan. No loan has been funded.