Energy Department loans $1B to help finance the restart of nuclear reactor on Three Mile Island

The U.S. Department of Energy will provide a $1 billion loan to help Constellation Energy restart the 835 MW reactor at Three Mile Island—renamed the Crane Clean Energy Center—under a plan Constellation announced last year that includes a roughly $1.6 billion restart and a 20‑year power purchase agreement with Microsoft to supply its data centers; the reactor, offline for five years, is targeted to resume operations in 2027. Issued under the $250 billion energy infrastructure program authorized in 2022 (terms undisclosed), the loan lowers Constellation’s financing costs and signals federal support for nuclear as a tool to meet rising data‑center demand and decarbonization goals, even as the site’s 1979 accident and a 2019 shutdown for economic reasons highlight ongoing operational and political sensitivities.

Analysis

The U.S. Department of Energy will provide a $1 billion loan to Constellation Energy to finance restarting the 835‑megawatt Three Mile Island reactor, renamed the Crane Clean Energy Center, which Constellation aims to return to service by 2027. Constellation announced last year it would spend roughly $1.6 billion to restart the mothballed unit under a 20‑year power purchase agreement with Microsoft to supply its data centers; the reactor has been offline for five years. The loan is being issued under the $250 billion energy infrastructure program authorized in 2022 and is intended to lower Constellation’s financing cost, though specific loan terms were not disclosed. The project supports rising data‑center power demand and federal policy priorities for nuclear and AI, and the reactor’s 835 MW capacity is cited as equivalent to powering about 800,000 homes, which contributes to the moderately positive market tone.

Key execution and policy risks remain material: Constellation must restore turbine, generator, main power transformer and cooling and control systems, creating potential for cost overruns and schedule slippage against the $1.6 billion restart plan. The site carries legacy reputational and regulatory sensitivity from the 1979 accident and a 2019 shutdown that reflected uneconomic operations absent state subsidies. Investors should treat the DOE loan as credit enhancement that improves project viability but require disclosure of loan covenants, PPA credit quality and permitting progress before re‑rating project risk.

Key Decisions for Investors

• Await disclosure of the loan's commercial terms and Microsoft PPA details before materially increasing exposure to Constellation Energy, since the federal loan reduces financing risk but undisclosed covenants and pricing are decisive for valuation
• Monitor technical execution milestones and the 2027 restart timeline—completion of turbine, generator, transformer and cooling/control upgrades—and reassess exposure if cost overruns or schedule slippage threaten the $1.6 billion budget
• Factor political and regulatory sensitivity from the site's accident history into position sizing; consider limited, staged exposure or hedges until regulatory approvals, construction progress and PPA credit support are evidenced