Google Deal Backs 890 MW of Constellation Nuclear Uprates at 11 PJM Reactors

Google and Constellation Energy, the largest nuclear operator in the U.S., have signed a 20-year power purchase agreement designed to support $4.3 billion of upgrades at 11 nuclear units across the PJM Interconnection. The program is slated to add 890 MW of generating capacity from Constellation's existing reactors by the end of 2032, with the first uprate expected online by 2028. The scale makes the agreement one of the largest corporate-backed nuclear uprate programs announced to date, and it arrives just one week after Constellation signed a separate nuclear agreement with Amazon covering 690 MW from the Calvert Cliffs plant in Maryland. Combined, the Google and Amazon agreements will bolster about 1,080 MW of planned Constellation nuclear uprates through long-term contracts with technology companies.

The mechanics of the Google deal rest on equipment and technology upgrades at 11 nuclear units across six sites in Illinois, Pennsylvania, and New Jersey. According to reporting from Nuclear Newswire, the sites will likely include Braidwood, Byron, LaSalle, and Quad Cities in Illinois; Limerick in Pennsylvania; and Salem in New Jersey. The six sites host 12 reactors, though Constellation has not revealed which unit is excluded or how the 890 MW will be allocated among the units. Ownership structures vary across the fleet: Constellation wholly owns and operates Braidwood, Byron, LaSalle, and Limerick, while it holds a 75% ownership stake in Quad Cities and a 43% stake in Salem, which is operated by PSEG. The agreement also includes a separate 15-year supply arrangement covering 2,700 MW from Constellation's existing PJM fleet.

The evidence comes from a single full-text source, Power Magazine, which reported the announcement on October 7, 2026. The source notes that Constellation enters the Google agreement following its $21.8 billion acquisition of Calpine in January, a deal that expanded the Baltimore-based company's portfolio to roughly 55 GW of generating capacity spanning nuclear, natural gas, geothermal, hydro, wind, solar, oil, and battery storage. Constellation's nuclear fleet produced 88.8 TWh during the first six months of 2026 and recorded a 92.7% capacity factor across the plants it operates. The company had already signed an additional 920 MW of long-term nuclear PPAs with investment-grade customers, generally lasting 15 to 20 years and beginning between 2029 and 2032. Among those is a 176-MW PPA with Walmart signed in June for the Dresden Clean Energy Center in Illinois, which includes 30 MW of expanded generating capacity from planned uprates.

The sector implications are significant for PJM and for the broader commercial nuclear landscape. The Google agreement adds another major tranche of existing-reactor expansion to PJM at a time when hyperscalers are seeking firm, carbon-free power to support data center growth. The deal also includes a strategic framework to evaluate new clean generation, storage, and demand response opportunities across the U.S., with near-term efforts prioritized in PJM. On the technology side, Constellation selected Google Cloud and Gemini Enterprise under an expanded five-year technology agreement. The source also notes that the U.S. Department of Energy's Loan Programs Office, through its Energy Infrastructure Reinvestment financing authority, has more than $289 billion in available authority and can finance up to 80% of eligible project costs, a mechanism that could support nuclear uprate and modernization work more broadly.

Several limitations and unknowns remain. The source is a single secondary report, and Constellation has not confirmed the specific sites or the allocation of the 890 MW among units. The first uprate is not expected online until 2028, leaving a multi-year execution window with potential regulatory, supply chain, and construction risks. The source also references a conditional loan commitment of up to $4.2 billion from the Department of Energy to finance uprates and modernization at Vistra's Beaver Valley plant, suggesting that federal financing may play a role across the sector, but the dossier does not specify whether Constellation will pursue similar support for the Google-backed program. What to watch includes Constellation's confirmation of the six sites, the timing of individual unit uprates, and whether the strategic framework with Google produces additional clean generation or storage projects beyond the initial 890 MW.