Nuclear power for data centres SMRs restarts and the tech industry energy bet

[RightNutter82]

TL;DR

• Large technology companies are signing nuclear power deals to meet rising data centre demand with firm, low carbon electricity
• Microsoft agreed in 2024 to buy power from the restarted Three Mile Island Unit 1, now the Crane Clean Energy Center, with Constellation targeting 2027 while warning in 2026 that grid reconnection was moving slower than hoped
• Google signed with Kairos Power in 2024 for up to 500 MW of small modular reactors by 2035, Amazon backed X-energy, and Meta announced agreements in January 2026 that could support up to 6.6 GW of nuclear capacity by 2035
• SMR projects are advancing: Ontario's Darlington BWRX-300 received a construction licence in 2025, and the UK selected Rolls-Royce SMR in 2025 with Wylfa named as the site for its first units
• Challenges include cost, construction timelines, fuel supply, regulation and grid connections, so most new nuclear capacity for data centres will arrive in the 2030s

Why tech companies turned to nuclear

Data centres need enormous amounts of electricity, and AI is pushing demand higher. Many technology companies have also committed to ambitious climate goals, such as running on carbon free electricity around the clock. Wind and solar have grown rapidly and remain central to those plans, but they vary with weather and time of day. Companies want firm, always available power to match data centres that run continuously

Nuclear power offers that combination of firm output and low carbon emissions. A single large reactor can produce around a gigawatt of electricity continuously for decades. That profile matches the needs of large data centre campuses well. Since 2024, a wave of deals has made the technology industry one of the most important new customers for nuclear energy

Demand forecasts drive the urgency. Utilities in several US regions have sharply raised projections for electricity demand, citing data centres among the main drivers, and the International Energy Agency expects global data centre demand to roughly double by 2030. Firm, clean supply is scarce in many of those regions. Technology companies see nuclear as one way to secure it

This thread explains the main types of deal, from restarting retired reactors to backing small modular reactors, summarises progress as of late 2026 and sets out the challenges. It aims to be factual and balanced, since nuclear power is a subject on which people hold strong and differing views. The focus here is on what is happening and what the obstacles are. Readers can draw their own conclusions about desirability

Restarting retired reactors

The fastest route to new nuclear output is restarting plants that closed for economic reasons but remain physically intact. In September 2024, Microsoft and Constellation Energy announced a 20 year power purchase agreement to restart Three Mile Island Unit 1 in Pennsylvania, which closed in 2019 and is unrelated to the unit damaged in the 1979 accident. The plant was renamed the Crane Clean Energy Center. Constellation later brought its target restart date forward to 2027, and the US Department of Energy announced a loan of up to one billion dollars to support the project

Progress has met some friction. In early 2026, Constellation's chief executive said grid interconnection as a capacity resource was moving more slowly than expected, and reports cited the possibility of transmission constraints delaying full reconnection. The company said its 2027 goal remained in sight. Inspections reportedly showed the plant's equipment in good condition. The project is a closely watched test of how quickly retired reactors can return

In Michigan, Holtec International has been working to restart the Palisades plant, which closed in 2022. In August 2025, Palisades formally moved from decommissioning back to operational licensing status, allowing fuel to be received and restart work to proceed under regulatory oversight. Restart activities continued into 2026. Palisades would be the first US reactor to return from decommissioning

Restarts are limited by the small number of suitable closed plants. Most retired reactors have already been dismantled or are too far into decommissioning. Restarts therefore provide valuable but modest additions. Long term growth must come from uprates and new reactors

Licence extensions are another quiet contributor. Many existing reactors have received approval to operate for 60 or even 80 years, preserving capacity that might otherwise have retired. Long term contracts from technology companies can help justify the investment needed for extended operation. Keeping existing plants running is often the cheapest source of firm clean power

Uprates and existing plants

Another route is increasing output from operating reactors through uprates, which upgrade equipment such as turbines and steam systems. In January 2026, Meta announced agreements with Vistra to support uprates at the Perry, Davis-Besse and Beaver Valley plants, adding about 433 megawatts by the early 2030s. Meta had earlier signed a long term agreement with Constellation in 2025 for power from the Clinton plant in Illinois. Such deals help keep existing plants running and expand their output

Co-locating data centres directly at nuclear plants has been debated. Amazon bought a data centre campus next to Talen Energy's Susquehanna plant in Pennsylvania in 2024, but in November 2024 the Federal Energy Regulatory Commission rejected an amended interconnection agreement that would have expanded the co-located arrangement, citing concerns about grid costs and reliability. Talen and Amazon later restructured their deal as a front of the meter power purchase agreement. The episode highlighted questions about how large loads should share costs of the grid

Small modular reactors

Small modular reactors, or SMRs, are designed to be smaller than traditional reactors, typically up to around 300 megawatts per unit, with components built in factories to reduce cost and construction time. Some designs use conventional light water technology, while advanced designs use different coolants such as molten salt, sodium or helium gas. Supporters argue SMRs could be deployed more flexibly and financed more easily than large plants. Critics note that factory economies of scale must still be proven in practice

Technology companies have backed several designs. In October 2024, Google signed an agreement with Kairos Power to purchase power from a fleet of molten salt cooled reactors, aiming for up to 500 megawatts by 2035, with the first unit targeted around 2030. The same month, Amazon announced investments in X-energy, which develops high temperature gas cooled reactors, with an ambition to support more than five gigawatts of capacity by 2039. These deals provide early demand signals that help developers raise capital

In January 2026, Meta announced agreements that could support up to 6.6 gigawatts of new and existing nuclear capacity by 2035. They include funding development of TerraPower's Natrium sodium cooled reactors, with rights to energy from up to eight units, and a campus in Ohio with Oklo targeting first power as early as 2030, alongside the Vistra uprates. The scale of these commitments is striking. Delivering them will depend on regulatory approvals, supply chains and construction performance

Projects outside the technology sector are moving too. In April 2025, Ontario Power Generation received a licence to construct the first of up to four GE Vernova Hitachi BWRX-300 reactors at its Darlington site, often described as the first SMR construction licence in the G7. In the UK, Great British Energy Nuclear selected Rolls-Royce SMR in June 2025 as its preferred technology, and the government later named Wylfa in Anglesey as the site for the first units. In the US, the Nuclear Regulatory Commission approved an uprated version of NuScale's SMR design in 2025

Advanced reactors face their own licensing journeys. Kairos Power received a construction permit for its Hermes test reactor in Tennessee in 2023, and TerraPower began non nuclear construction at its Natrium site in Wyoming in 2024. These steps are milestones on long paths to commercial operation. Regulators are adapting processes to handle new designs

Policy support

Governments have increased support for nuclear energy. In the US, a set of executive orders signed in May 2025 set a goal of significantly expanding nuclear capacity by 2050 and directed reforms to speed up licensing. Federal loan programmes and tax credits support new projects and restarts. Bipartisan legislation such as the ADVANCE Act of 2024 aimed to modernise the Nuclear Regulatory Commission's processes

Other countries are also expanding nuclear ambitions, including the UK, France, Canada, Poland and several Asian nations. International pledges at climate conferences have called for tripling global nuclear capacity by 2050, supported by a group of countries and some financial institutions. Technology company demand adds a private sector dimension to these public plans. Together, they represent the most significant renewed interest in nuclear power in decades

The challenges

Cost and schedule are the biggest concerns. Recent large reactor projects in Western countries, such as Vogtle Units 3 and 4 in Georgia, which entered service in 2023 and 2024, ran years late and far over budget. SMR developers argue factory construction will avoid such problems, but first of a kind projects often face overruns. NuScale cancelled a planned project in Utah in 2023 after projected costs rose and subscribers dropped out

Fuel supply is another issue. Many advanced reactor designs require high assay low enriched uranium, known as HALEU, which has limited commercial supply outside Russia. The US and allies are investing in domestic enrichment capacity, but scaling up takes years. Fuel availability could constrain deployment timelines for some designs

Regulation, waste and public acceptance remain important. Licensing new reactor designs is demanding by design, because safety is paramount. Long term solutions for spent fuel are still being developed in many countries, although Finland's Onkalo repository is approaching operation. Local communities' views vary, and earning trust takes time and transparency

Grid connections affect nuclear as much as data centres themselves. As the Crane restart shows, connecting large generators and loads requires transmission upgrades and regulatory approvals. Even when a power plant is ready, delivering its output where it is needed can take longer. Grid investment is a shared bottleneck

What this means for AI and climate

Most new nuclear capacity from SMRs and advanced reactors will arrive in the 2030s, not the 2020s. In the meantime, data centres will rely on existing grids, renewable energy, storage, efficiency and, in some places, natural gas. Restarts and uprates add capacity sooner but in limited amounts. Tech companies' nuclear deals are therefore long term bets rather than immediate solutions

If the bets pay off, the benefits could extend beyond data centres. Proven, cost effective SMRs could supply industry, district heating and grids around the world. Technology companies' willingness to sign long term contracts could help bring designs to commercial maturity. If they disappoint, companies will need to lean harder on other clean energy sources

What to watch

• Whether the Crane Clean Energy Center and Palisades return to full commercial operation on schedule
• Construction progress and costs at Darlington's BWRX-300 and other first SMR projects
• NRC licensing decisions for Kairos, X-energy, TerraPower and Oklo designs
• HALEU fuel supply development
• Grid interconnection policy for large co-located loads
• Updates to technology companies' clean energy and emissions reports

Closing thoughts

The technology industry's embrace of nuclear power is one of the most significant energy developments of the AI era. Restarts, uprates and SMR agreements signal strong demand for firm, low carbon electricity. Real progress is visible, from licensing milestones to construction starts, but costs, timelines, fuel and grid connections will determine how much capacity arrives and when. Following the projects closely will reveal whether this bet reshapes both computing and energy

Please share updates on specific projects in the replies, with sources. Views on the role of nuclear energy are welcome as long as they stay respectful and evidence based. Experts in energy, engineering and policy would add a great deal here


Key references for citation

• Constellation and Microsoft, Crane Clean Energy Center power purchase agreement, September 2024
• Holtec International, Palisades return to operational status, August 2025
• Google and Kairos Power agreement, October 2024; Amazon and X-energy announcement, October 2024
• Meta, nuclear energy agreements with Vistra, TerraPower and Oklo, January 2026
• Canadian Nuclear Safety Commission, licence to construct BWRX-300 at Darlington, April 2025
• Great British Energy Nuclear, selection of Rolls-Royce SMR, June 2025
• International Energy Agency, Energy and AI, April 2025