The U.S. Department of Energy (DOE) has finalized a $1 billion loan to Constellation Energy Generation to restart a nuclear reactor at the Three Mile Island (TMI) plant in Pennsylvania. This move aims to provide clean, reliable power to data centers for tech giant Microsoft and is a significant step in the Trump administration’s broader push to expand nuclear energy capacity in the United States.
Three Mile Island’s Revival and the Loan Details
The $1 billion loan from the DOE’s Loan Programs Office (LPO) will partially finance the restart of the 835-megawatt (MW) Unit 1 reactor, now rebranded as the Crane Clean Energy Center. This reactor ceased operations in 2019 due to economic challenges but was never fully decommissioned. The funding is part of a larger $1.6 billion plan by Constellation to bring the unit back online, with the company aiming for full operation by mid-2028, and possibly as early as 2027.
A key driver for the restart is a 20-year power purchase agreement between Constellation and Microsoft, which will utilize the nuclear power for its burgeoning artificial intelligence (AI) data centers. This partnership underscores a growing trend of major technology companies investing in nuclear energy to meet the substantial and continuous power demands of AI workloads.
Government’s Push for Nuclear Energy
The loan aligns with the Trump administration’s “Energy Dominance” agenda and its executive order “Reinvigorating the Nuclear Industrial Base.” Energy Secretary Chris Wright emphasized that the DOE’s loan office will primarily focus on financing new nuclear power plants and restarts to meet increasing electricity demand, lower energy costs, and strengthen grid reliability. The administration has set an ambitious target to have ten new reactors and five gigawatts of nuclear uprates under construction in the U.S. by 2030.
This initiative reflects a bipartisan recognition of nuclear power’s role in achieving a carbon-free electricity system and ensuring energy independence. While the Biden administration also supported nuclear energy, focusing on extending existing reactors and developing new advanced units, the current administration has escalated efforts to accelerate new reactor construction and restarts.
The Three Mile Island Legacy
The Three Mile Island plant, located in Londonderry Township, Pennsylvania, is famously known for a partial meltdown in Unit 2 in 1979, which led to its permanent shutdown. However, the reactor being restarted, Unit 1, operated safely from 1974 until its economic closure in 2019 and was unaffected by the 1979 incident. The restart requires approval from the U.S. Nuclear Regulatory Commission (NRC) following comprehensive safety and environmental reviews.
The project is expected to create over 600 American jobs and provide an estimated $16 billion boost to Pennsylvania’s gross domestic product. This marks the first major nuclear restart in recent U.S. history, with other plants like the Palisades reactor in Michigan also working towards recommissioning.
Economic and Environmental Implications
The revival of Three Mile Island Unit 1 highlights nuclear energy’s renewed economic viability, especially with the surging demand for constant, carbon-free power from data centers and AI operations. Nuclear power plants offer a reliable, round-the-clock, carbon-free energy source, making them an attractive partner to intermittent renewable sources like wind and solar in decarbonizing the electricity grid.
The DOE loan, along with private investment, is crucial for these early-stage nuclear projects, helping to bridge the gap between demonstration and commercial deployment. This federal support aims to de-risk future projects, attract more private capital, and ultimately ensure U.S. leadership in meeting growing global energy demands.
