Energy Department offers Constellation $5bn for 1.1GW of nuclear uprates at eight plants

The conditional loan commitment of up to $5 billion would support uprates at 15 reactors across eight plants in Illinois, Maryland and Pennsylvania. Six of the plants are in Illinois: Braidwood, Byron, Clinton, Dresden, LaSalle and Quad Cities. The others are Calvert Cliffs in Maryland and Limerick in Pennsylvania, according to the Energy Department.

The department estimates the added output could power more than 930,000 homes and support more than 10,000 project-related jobs across the fleet. The additional electricity would increase supplies across the PJM Interconnection and Midcontinent Independent System Operator regions, the department said.

What an uprate does

Uprates are not new reactors. They add equipment and modify systems at operating plants so the same site produces more megawatts, the department said. At Limerick, a 2,317-megawatt station in Montgomery County, Pennsylvania, Constellation plans a 348-megawatt increase, spokesperson Paul Adams told Canary Media. The department's announcement did not break out how much financing or added capacity would go to each plant.

Why uprates cost less than new reactors

The US has built only two AP1000 reactors, both in Georgia, at a combined cost of more than $30 billion, Canary Media reported. The 1.1 gigawatts in this plan is roughly one AP1000's output. Canary Media reported the uprates would cost significantly less, though it gave no cost estimate for the program.

Constellation has pursued uprates before. In 2023 it said it would invest $800 million in new equipment to raise combined output at Braidwood and Byron. The first phase of the Byron work has been completed, the American Nuclear Society reported on May 13.

Conditions and private deals

The money is not committed. Constellation must satisfy technical, legal, environmental and financial requirements before the department executes definitive loan documents and disburses funds. The Office of Energy Dominance Financing administers the loan, the department said.

Constellation said the announcement "does not, by itself, represent a final Constellation decision to proceed with any individual uprate or at every facility under consideration."

Private deals are already signed. The loan is the third multibillion-dollar uprate announcement tied to Constellation in a month. On Sept. 30, Constellation finalized a power purchase agreement with Amazon supporting a 190-megawatt uprate at Calvert Cliffs, a 1,790-megawatt plant in Maryland. On Oct. 6, it said it would spend $4.3 billion with Google to add 890 megawatts at 11 of its reactors. Clinton was already in line for a 30-megawatt uprate under a 2025 deal with Meta.

At least six of the eight DOE-backed plants could draw on more than one funding source, Canary Media reported. It is unclear whether the loan will support the same projects the three hyperscalers are paying for or separate ones that would raise output further. Constellation did not respond to a request for clarification.

The program behind the loan

The Energy Department started UPRISE, the Utility Power Reactor Incremental Scaling Effort, in March 2026 to speed output gains at reactors already running. Projects covering 95% of the administration's 5-gigawatt target have been identified, according to the department. The 1.1 gigawatts would be about a fifth of that goal, which the administration wants to meet by 2029.

The loan includes an option to finance future uprates at additional Constellation plants, the department said.