The federal government is now a lender to the restart of the reactor once known as Three Mile Island Unit 1. On November 18 the Department of Energy said its Loan Programs Office had closed a $1 billion loan to Constellation Energy Generation to help finance the Crane Clean Energy Center, an 835 MW plant on the Susquehanna River in Londonderry Township, Pennsylvania. The output is already spoken for. Constellation signed a 20-year power purchase agreement with Microsoft in September 2024, and the restart was the first major deal in which a hyperscaler underwrote the return of a retired nuclear unit.
The loan does not change who buys the power. It changes how quickly and cheaply the plant can be brought back, and it puts a federal stamp on the idea that data center demand in PJM is a reason to recover existing capacity rather than wait for new builds.
The terms
DOE described the deal as the first project to receive a concurrent conditional commitment and financial close under the current administration. The money comes from the Energy Dominance Financing program, which the department says was created under what it calls the Working Families Tax Cut, the tax law signed in July. The project page on DOE's website says the loan is backed by the full credit and balance sheet of Constellation, which the department presents as a way to reduce risk to taxpayers.
Constellation's filing with the Securities and Exchange Commission gives the mechanics. On November 17 the company entered into a loan guarantee agreement with DOE and a note purchase agreement with the Federal Financing Bank, under which the bank committed $1.0 billion. The structure is a multi-advance term loan: Constellation can draw in stages until the balance reaches $1.0 billion or until September 15, 2030, whichever comes first. The filing describes the project as the restart and repowering of the Christopher M. Crane Clean Energy Center.
DOE says the reactor ceased operations in 2019 but was never fully decommissioned. Its project page calls Crane the second restart in U.S. history of a reactor that had been shut down for decommissioning, and estimates about 627 permanent jobs at the plant during operations. The department's release puts the plant's output at the equivalent of about 800,000 homes.
What Microsoft bought
The September 2024 announcement set out the commercial logic. Constellation called the Microsoft deal its largest power purchase agreement ever. Microsoft will buy energy from the restarted plant as part of its goal to match the power its data centers in PJM use with carbon-free energy. At the time, Constellation said the plant was expected to be online in 2028, subject to Nuclear Regulatory Commission approval following a safety and environmental review, as well as state and local permits. Constellation also said it would seek license renewal to extend operations to at least 2054.
The restart work is substantial. Constellation's release listed investments in the turbine, generator, main power transformer, and cooling and control systems. It cited a study by The Brattle Group, commissioned by the Pennsylvania Building and Construction Trades Council, that estimated 3,400 direct and indirect jobs, $16 billion in added state GDP, and more than $3 billion in state and federal taxes.
The plant sits next to Unit 2, which shut down after the 1979 accident and is being decommissioned by a separate owner. Unit 1 operated independently and was closed for economic reasons in September 2019.
Why the timing fits PJM
The loan closes in a market that has run short of slack. PJM's 2026/2027 Base Residual Auction, held in July, cleared at $329.17 per megawatt-day in every zone, the cap agreed with Pennsylvania Governor Josh Shapiro. PJM said the auction procured 134,311 MW of generation resources. Total capacity cost came to about $16.1 billion, up from $14.7 billion a year earlier. PJM's independent market monitor later estimated that data center load accounted for $7.27 billion of that cost.
In that setting, 835 MW of firm, zero-carbon output on an existing site is valuable in a way that new capacity cannot match on timing. A new gas plant ordered now faces turbine backlogs measured in years. A new nuclear unit is a decade away at best. A restart uses a site that already has a grid connection, cooling water, and a trained workforce pool nearby. The cost is concentrated in refurbishment and licensing rather than construction.
The loan's federal backing also matters for the next auctions. Every megawatt of firm supply that returns to service in PJM pushes against the shortfall the market faces as data center load grows. The monitor's analysis found that the load forecast behind the July auction already included 11,993 MW of existing and planned data center demand, and that figure is still climbing.
The objections
Not everyone is comfortable with the arrangement. The core question is whether public credit should support a plant whose output has been sold to one of the world's most valuable companies. DOE's answer is that the plant adds supply to the PJM grid as a whole, which helps hold down prices for every customer, and that the loan is secured by Constellation's balance sheet. Critics of hyperscaler nuclear deals argue that dedicating existing or restored nuclear output to a single buyer takes clean power out of the pool that other customers and state policies rely on.
Crane differs from the Susquehanna arrangement between Talen Energy and Amazon, which drew objections at FERC in 2024 because it was structured as co-location behind the meter. Crane will deliver into the grid, with Microsoft buying the energy financially. That structure keeps the plant's capacity in PJM's market and leaves transmission charges with the grid. Talen and Amazon moved Susquehanna to the same front-of-the-meter model in June.
What remains
The NRC still has to approve the return to power operations. DOE's release says the restart is pending NRC licensing approvals, and Constellation's 2024 timeline depended on that review and on state and local permits. The interconnection is another open item: a restarted unit must secure deliverability on the transmission system before PJM counts its full capacity.
For now, the loan settles the financing question. A data center buyer, a federal lender, and a utility owner have each committed to the same proposition: that the fastest route to more firm power in PJM runs through plants that were closed, not plants yet to be built.