US offers Constellation up to $5 billion conditional loan for nuclear plant upgrades

The US Department of Energy (DOE) offered Constellation Energy a conditional loan commitment of up to $5 billion on Oct 27 to finance uprates, which are upgrades that raise the output of existing nuclear reactors, at eight of its plants in Illinois, Maryland and Pennsylvania. DOE says the work would add nearly 1.1 gigawatts of capacity, enough to power more than 930,000 homes.

Energy Secretary Chris Wright announced the commitment at Constellation's Byron plant in Illinois. The loan is not final, and Constellation must still meet conditions before any money is lent.

The terms

The commitment comes from DOE's Office of Energy Dominance Financing. It covers six Illinois plants (Braidwood, Byron, Clinton, Dresden, LaSalle and Quad Cities) plus Calvert Cliffs in Maryland and Limerick in Pennsylvania. It also includes an option to finance future uprates at other Constellation facilities.

The eight plants have 15 operating reactors with about 15.5 gigawatts of net capacity attributable to Constellation, POWER Magazine reported. DOE estimates the work would support more than 10,000 project-related jobs.

Constellation must satisfy technical, legal, environmental and financial conditions before DOE signs definitive financing documents and funds the loan, according to DOE. Constellation said the commitment is not a final decision to proceed with any individual uprate or at every plant under consideration, and that the federal loan could lower its financing costs.

The customer deals behind the uprates

Constellation said 20-year power agreements with Google and Amazon have led it to invest more than $7 billion to add about 1,080 megawatts of nuclear capacity. A separate agreement with Meta supports a 30-megawatt expansion at Clinton.

The Google-backed capacity is due to start arriving in 2028 and be complete by the end of 2032, and the Amazon-backed Calvert Cliffs uprate is scheduled for 2030 to 2032, POWER Magazine reported. The Google-backed reactors do not exactly match the eight plants named for the loan, according to the construction trade publication ENR.

Who is exposed

Constellation, the largest US nuclear operator, is the prospective borrower. Its shares rose as much as 5.3% on Oct 27 and closed up 2.6%, the Philadelphia Inquirer reported.

Alphabet's Google and Amazon buy the added output under their 20-year agreements with Constellation, and Meta's agreement covers the Clinton expansion.

The federal program

The offer is DOE's second nuclear uprate loan commitment in October. On Oct 5, DOE offered Vistra a conditional commitment of up to $4.2 billion for Beaver Valley in Pennsylvania and Davis-Besse and Perry in Ohio, work it says would add 433 megawatts.

Both fall under DOE's Utility Power Reactor Incremental Scaling Effort, launched in March 2026 under a Trump executive order that calls for 5 gigawatts of uprates at existing reactors. DOE says 94% of the 5-gigawatt uprate and restart goal has now been identified.

What comes next

Neither DOE nor Constellation has given a date for closing the loan, and Constellation told ENR it had nothing to add on which plants would move first. Constellation reports third-quarter results on Nov 9, with a conference call at 9 a.m. Eastern time.