Three shuttered nuclear plants are being prepared for a return to service, a move tied to the rising demand for electricity that large-scale data centre operations have helped push upward.

History holds no documented case of a commercial nuclear reactor returning to power generation once formal decommissioning procedures — the process by which a unit is permanently withdrawn from service — had been set in motion, although extended shutdowns have occasionally ended in a return to operation.

Up to USD 4.4 billion in federal loan support has been directed toward bringing three previously shuttered nuclear facilities back online — Palisades in Michigan, the Crane Clean Energy Centre on Pennsylvania's Three Mile Island, and the Duane Arnold Energy Centre in Iowa — with their combined output of 2.25 gigawatts projected to meet the electricity needs of around 2 million homes and businesses. Each of the three facilities shut down ahead of its licensed operating deadline, primarily because the power they generated carried a price tag that market and regulatory assessments deemed too high.

Agreements between two of the facilities and technology firms guarantee those buyers carbon-free electricity at above-market rates to power their data centre operations. Plans drawn up by the administration would direct nuclear energy toward powering artificial intelligence systems and manufacturing operations. Billions of dollars in loans are being directed toward upgrades at existing nuclear plants, with the aim of drawing greater electricity output from those already-running facilities.

Restarting an existing reactor, according to Allen, can deliver substantial electricity output relatively quickly and at lower cost than constructing an entirely new large-scale facility. Drawing on his role as associate dean for research at the University of Michigan's College of Engineering, Allen framed the process of bringing a shuttered nuclear facility back online in terms of everyday vehicle ownership — just as a car left sitting in a driveway for years still demands a current licence and fully functioning components before it can safely return to the road, a dormant reactor faces the same baseline requirements before resuming operation.

Restarting a mothballed nuclear facility requires its operator to rehire and recertify a specialised workforce, verify that all systems and scheduled upkeep meet required standards, secure an adequate fuel supply, and obtain renewed authorisation from the relevant regulatory body.

Public funds directed at nuclear projects ought to prioritise addressing safety-related risks, according to Edwin Lyman, who oversees nuclear power safety work at the Union of Concerned Scientists. A large share of the country's nuclear plants took shape across the two decades spanning 1970 to 1990, with their safety specifications drawn from the hazard assessments and engineering standards of that period. Lyman pointed to a pattern of weather events growing both more frequent and more intense, then added that returning the plants to an operational state remained achievable if those responsible established adequate safety standards and committed the funding needed to reach them.

Iowa's only commercial nuclear facility, the Duane Arnold plant, began generating power in 1975 after taking shape during the middle years of that decade. A permanent shutdown had been set for October 2020. Switching to lower-cost generation — wind power among the options — was forecast to trim roughly USD 300 million from the bills Iowa ratepayers would otherwise face. A derecho in August 2020 brought wind damage that knocked the plant offline, ending its activities earlier than planned.

Duane Arnold falls under the ownership of NextEra Energy. Ketchum, the company's chief executive, expressed that leadership held a positive view of the prospects for restoration.

Palisades had been licensed to continue operating until 2031. Holtec International took ownership and proceeded with decommissioning work, with each phase of that process remaining reversible. State funding flowed to Holtec alongside active backing from Michigan authorities for the plant's reopening bid. A USD 1.5 billion loan approved under the Biden administration in 2024 set the plant's revival in motion, with disbursements carrying forward once the Trump administration took over.

Fuel loading at the reactor got underway at Holtec's facility that August, marking one of the final steps required before the unit could be brought back online. Operations came to a halt after one of the fuel assemblies shifted away from its vertical orientation, prompting Holtec to launch an investigation into what had caused the displacement. Under the power purchase agreements in place, Palisades is contractually obligated to be generating electricity no later than March 2027.

A partnership between NextEra Energy and Google is targeting a Duane Arnold restart sometime before 2029. According to Ketchum, a long-term agreement with a hyperscaler underpins the arrangement, leaving Iowa's residential ratepayers entirely outside the cost structure.

A power-purchase agreement ties Microsoft to the Crane Clean Energy Centre, a facility situated on Three Mile Island outside Harrisburg. A mechanical failure at the plant in 1979 stood as the most serious malfunction documented up to that point at any commercial nuclear facility operating within the country. One reactor was put out of service by the incident, leaving the facility to operate on a single remaining unit. Exelon — at that point the parent company of what is now Constellation Energy — took the reactor offline in 2019, citing financial losses and the Pennsylvania legislature's choice not to provide subsidies for its continued operation.

Under a 20-year supply arrangement with Microsoft, Constellation Energy committed USD 1.6 billion in 2024 toward reactivating the reactor, with the facility targeted for a return to operation by 2027. A USD 1 billion loan from the Department of Energy went toward the project, with Deputy Energy Secretary James Danly making an on-site visit to the facility.

A position put forward by The Heritage Foundation's Jack Spencer held that robust market appetite for the power already makes a case against tapping public money to bring the reactors back online. Federal financing, in the view put forward by Atlantic Council researcher Jennifer Gordon, offers a practical mechanism for drawing in private investment and ensuring the electricity supply that demand requires. At the council, Gordon holds responsibility for leading the Nuclear Energy Policy Initiative.

Nuclear reactor restarts drew a favourable response from the World Nuclear Association, though the organisation indicated that keeping existing plants operating rather than shutting them down ahead of schedule would represent the more desirable path.

Palisades stands to become the only nuclear facility anywhere to restore electricity output after formally entering decommissioning — a distinction that nonetheless sits alongside documented cases of reactor restarts and refurbishments following extended dormancy in Canada, Armenia, Belgium, Japan, India, and South Korea. A number of those countries have either begun the process of bringing reactors back online or are weighing that path.