The DOE announces $5B loan to Constellation for nuclear uprates

The pro-nuclear Trump administration continues to put its money where its mouth is.

On Tuesday, the U.S. Department of Energy announced a conditional loan commitment of up to $5 billion to boost the output of 15 reactors at eight nuclear power plants in Illinois, Maryland, and Pennsylvania by a combined 1.1 gigawatts. 

It’s the latest sign of Trump’s support for the United States’ biggest existing source of carbon-free electricity that doesn’t vary with weather conditions. It’s also the third multibillion-dollar ​“uprate” announcement in a month relating to Constellation Energy, which runs the plants as part of the country’s largest commercial nuclear reactor fleet. 

On Sept. 30, Constellation revealed that it had finalized a power purchase agreement with Amazon in support of a 190-megawatt uprate at its 1,790-MW Calvert Cliffs nuclear plant in Maryland. Then, on October 6, the company said it would spend $4.3 billion in partnership with Google to increase generating capacity at 11 of its nuclear plants by a total of 890 MW.

Among the eight facilities announced by the DOE this week, at least six could get funding from multiple sources: the 2,317-MW Limerick power plant in Pennsylvania, which Constellation spokesperson Paul Adams said earlier this month would increase its output by 348 MW; the Braidwood, Byron, LaSalle, and Quad Cities plants in Illinois; and Calvert Cliffs. 

A fifth DOE-backed plant in Illinois, Clinton, was already in line for a 30-MW uprate under a 2025 deal between Constellation and Meta.

Power uprates generally involve ​“adding new and more efficient equipment and technology that will allow us to get more megawatts from the same plant,” Adams told Canary Media earlier this month.

The commitment from the DOE bureau formerly known as the Loan Programs Office ​“builds on billions of dollars in private-sector investment already supporting Constellation’s efforts to increase nuclear output,” Constellation said on Tuesday, while stressing that its announcement ​“does not, by itself, represent a final Constellation decision to proceed with any individual uprate or at every facility under consideration.” 

It’s unclear whether the DOE’s loan commitment will benefit the same uprate projects funded by the three hyperscalers or support separate projects that will further raise the plants’ output. Constellation did not respond to a request for clarification by press time.

Still, if the uprates announced at the eight plants this week move forward, Constellation would boost its nuclear fleet’s generating capacity by about as much as a new AP1000 reactor would — at significantly lower cost. The U.S. has thus far built only two AP1000s, both in Georgia, at a combined cost of more than $30 billion.

Nuclear energy boosters would like many more AP1000s to be built on U.S. soil. So would the Trump administration, which wants to see 10 new large reactors under construction by 2030 — most or all of which would probably be AP1000s — as part of its moon shot goal of quadrupling the country’s nuclear generating capacity by 2050. 

Late last month, the administration said it would back the construction of six new AP1000s and two South Korean–designed reactors of similar scale as part of a $350 billion trade deal with the East Asian country. A few weeks later, a startup staffed with veterans of the Georgia builds said it could construct six new reactors at a site in Kentucky, beginning in 2028.

Experts say AP1000 construction costs will decline as more projects get underway and the thousands of engineers, tradespeople, and laborers tasked with building them get more practice. As evidence, they note that Georgia’s second AP1000 cost about 30% less to build than its first.

But industry allies say uprating existing power plants and restarting recently retired reactors remain the fastest and most affordable ways to increase nuclear generating capacity in the near term. Given the long development timelines for large nuclear plants, both will be needed to meet the Trump administration’s goal of adding 5 GW of new nuclear capacity by 2029.

“The $5 billion loan from DOE’s Office of Energy Dominance Financing shows that DOE thinks investing in uprates to existing facilities will be a cost-effective way to increase our domestic nuclear energy capacity, and believes there is a reasonable prospect of repayment on the loan,” said Erik Cothron, manager of research and strategy at the Nuclear Innovation Alliance, a pro-nuclear ​“think-and-do” tank.

Even uprates are a heavy lift for power plant owners like Constellation, however. Cothron suggested external financing is key to see them through.

“The Google-Constellation partnership and the DOE loan guarantee are complementary. They show that private investment in uprates is increasing, while the public loan guarantees can help make the capital-intensive uprates even easier to finance,” he said.