America has just contracted for the output of a new nuclear reactor, and nobody is building one. Google and Constellation Energy announced on Tuesday a twenty-year agreement to put 890 megawatts of nuclear capacity onto the PJM Interconnection grid, the largest in the United States. The companies describe that as roughly what a new reactor produces. It will arrive in stages between 2028 and 2032, and it will come out of eleven reactors that are already running.
The mechanism is called an uprate, and it is as unglamorous as the word suggests. Constellation will spend more than $4.3 billion replacing equipment at eleven units across six sites in Illinois, Pennsylvania and New Jersey, improving thermal and electrical efficiency so that the same reactors, burning the same fuel in the same buildings, push more electricity onto the wire. No new site. No new licence for a new plant. Roughly 7,200 construction jobs during the work, and about 4,400 existing ones sustained by it.
Which raises the question nobody in the coverage asks: if that margin was sitting inside the fleet, why has it been sitting there? The engineering is not novel and the reactors are not young. The binding constraint on American nuclear output was never engineering. An uprate costs billions up front and returns electricity over decades, and an operator will not commit that capital against a wholesale price that moves every hour. What it needs is somebody to sign for twenty years. For most of this century, nobody with that appetite existed. Then the data centres arrived.
Only a quarter of what Google signed on Tuesday is actually new, though, and that is the part worth holding onto. Reuters puts the total contracted figure at 3,590 megawatts. The other 2,700 comes under a separate fifteen-year supply deal drawing on Constellation's existing fleet — power that already exists on that grid, now spoken for by one customer rather than available to whoever else is bidding. Adding 890 megawatts to a grid and reserving 2,700 of its existing output are different acts, and only one of them makes the country better supplied.
Nor was electricity the only thing changing hands. Constellation took Google Cloud and Gemini Enterprise under an expanded five-year technology alliance, building what the companies call an AI blueprint for energy. The buyer of the power is also a vendor to the seller of it. Constellation's shares closed up 12.3 percent.
Everyone is doing this now. Amazon signed for 690 megawatts at Calvert Cliffs last week on the same twenty-year shape, releasing more than $3 billion of investment. Three Mile Island is restarting for Microsoft. Google has a NextEra plant coming back in Iowa.
The reactors could always have done this. What showed up in 2026 was somebody prepared to sign for twenty years.
The binding constraint on American nuclear output was never engineering.
