Plans to restart three closed nuclear facilities are under way in the United States, driven by growing electricity needs that include the power-hungry operations of large-scale data centres.

Across the entire history of commercial nuclear power, no plant that formally entered the decommissioning pathway — the regulated sequence that permanently withdraws a reactor from the grid — has subsequently returned to electricity production, even though extended shutdowns followed by restarts have occurred outside that process.

Up to USD 4.4 billion in federal loan support has been directed toward bringing three nuclear facilities back online — Palisades Power Plant in Michigan, the Crane Clean Energy Centre on Pennsylvania's Three Mile Island, and the Duane Arnold Energy Centre in Iowa — through the Department of Energy. Combined, those plants stood to put 2.25 gigawatts back on the grid, a volume of generation capacity sufficient to meet the electricity needs of around 2 million homes and businesses.

Each of the three facilities shut down ahead of its licence expiry date, with high generation costs cited as the driving factor behind the decisions. That situation has since changed. Agreements with technology corporations cover two of the facilities, with those deals guaranteeing above-market rates in exchange for supplying data centres with electricity generated without carbon emissions.

Nuclear power has emerged as a focus of the Trump administration's efforts to meet the energy demands of artificial intelligence infrastructure and industrial production. Billions of dollars in loan commitments are also flowing toward capacity-expansion work at nuclear facilities already in operation.

Bringing an idled reactor back online can deliver substantial electricity volumes at lower cost than constructing a new large-scale facility, nuclear engineering specialist Todd Allen noted, adding that national power demand has grown while those grid-connected assets already exist and remain available. Those units had been running before, and restoring them to power generation is a faster path than most of the alternatives on the table, he said.

Nuclear power produces no carbon emissions during operation, making it one pathway available to those seeking a fully decarbonised energy supply. Allen drew a parallel between bringing a shut-down nuclear facility back online and coaxing a long-dormant vehicle into operation, adding that the prospect aligned with the administration's stated push to expand nuclear power generation.

The driver still needs a valid licence and all components must function as intended — a straightforward requirement that Allen, who holds the role of associate dean for research at the University of Michigan's College of Engineering, noted applies in far more intricate form to nuclear plants, where the underlying system is considerably more layered and complex. Restarting a nuclear facility, he continued, means the operator is required to verify that all qualified staff are back on site with their certifications current, confirm that equipment and maintenance meet required standards, arrange an adequate fuel supply, and obtain regulatory approval to resume operations.

A representative from the Union of Concerned Scientists argued that public funds allocated to this area ought to be directed toward addressing safety-related risks instead. Edwin Lyman, who oversees nuclear power safety for the group, noted that the majority of US reactors were built between 1970 and 1990 and were engineered to handle the kinds of natural disasters anticipated at that time. He added that restoring those plants to an operable state would require setting appropriate safety benchmarks and committing the funding to meet them, a process he said had not yet taken place.

Iowa's sole nuclear facility, Duane Arnold, has been in operation since 1975. A permanent closure had been set for October 2020. Switching to lower-cost generation methods — wind power among them — was forecast to cut Iowa ratepayers' bills by USD 300 million. A derecho that swept through in August 2020 left the facility with damage extensive enough to force a shutdown of all activity there.

Duane Arnold falls under the ownership of NextEra Energy. NextEra Energy and Google have entered a partnership targeting a restart of the Duane Arnold facility by early 2029, with CEO John Ketchum expressing confidence in the project's feasibility and describing it as an instance of data centre operators funding their own power needs through a long-term supply contract with a hyperscaler.

The Palisades facility ran from 1971 through 2022, at which point its then-owner, Entergy, withdrew from the wholesale electricity market — meaning Iowa residential ratepayers have not been assigned any portion of the associated costs. Authorisation for the facility to keep running stretched to the year 2031. Holtec International took ownership of the facility and moved forward with decommissioning work, though every action taken up to that point remained reversible.

State officials in Michigan, seeking to protect both employment tied to the nuclear sector and the electricity it supplies, directed public funds toward Holtec's effort to bring the facility back online. A USD 1.5 billion loan approved under the Biden administration in 2024 set the facility back in operation, with disbursements continuing once the Trump administration took over. Fuel loading at the reactor got underway under Holtec's direction that August, clearing one of the last substantial hurdles standing between the facility and an operational restart.

Operations came to a halt after one of the fuel assemblies shifted away from its vertical orientation, prompting Holtec to investigate the underlying cause. Under the terms of those power purchase agreements, Palisades is to be generating electricity no later than March 2027. According to the company, the work is intended to bring reliable baseload power back online, bolster the country's energy security, and show how nuclear generation can help meet rising electricity needs.

A power-purchase agreement between Microsoft and the Crane Clean Energy Centre, located on the Three Mile Island site near Harrisburg, underpins the facility's operations. In 1979, a reactor failure at the facility — recorded as the country's most severe commercial nuclear power incident — left one unit permanently out of service while the other continued to operate. Exelon — at the time the parent company of what is now Constellation Energy — took the reactor offline in 2019, citing financial losses and the Pennsylvania legislature's decision not to provide subsidies for its continued operation.

A 20-year supply deal with Microsoft prompted Constellation Energy to put USD 1.6 billion toward bringing the reactor back online, a commitment the company disclosed during 2024. A restart of the facility is targeted for 2027. A USD 1 billion loan was extended to the facility by the Energy Department, with Deputy Secretary James Danly making an on-site visit to the plant.

A Heritage Foundation analyst took the position that reactor restart ventures carry limited financial risk and face robust market demand for their output, and on that basis contended that public funds ought not to be channelled toward the companies pursuing them. Her role at the foundation places her at the head of the Centre for Energy, Climate and Environment.

An Atlantic Council analyst framed the arrangement as a mechanism through which federal funding could be put to work securing the electricity supply. Leadership of the council's Nuclear Energy Policy Initiative falls to Gordon.

According to the World Nuclear Association, keeping existing reactors operational rather than allowing them to shut down ahead of schedule would yield greater benefits than bringing offline plants back into service.

Palisades stands to become the first nuclear facility anywhere to return to power production after entering the decommissioning process, though a number of nations — among them Canada, Armenia, Belgium, Japan, India, and South Korea — have already brought reactors back online or carried out refurbishment work following extended periods of inactivity. A number of additional nations have reactor restart programmes either under active planning or already under way.