Nuclear power for AI: inside the data center energy deals

Updated December 11, 2025

December 2025 Update: Big tech signing 10GW+ of new US nuclear capacity in past year. Microsoft's 20-year $16B Three Mile Island restart (835MW) targeting 2028. Google/Kairos Power signing first US corporate SMR fleet deal (500MW, 2030+). Amazon investing $20B+ converting Susquehanna to AI campus. Meta issuing RFP for 1-4GW new nuclear. Global DC electricity growing from 460 TWh (2024) to 1,300 TWh (2035).

Big tech companies signed contracts for more than 10 gigawatts of possible new nuclear capacity in the United States over the last year.¹ Microsoft committed to a 20-year, 835-megawatt power purchase agreement to restart Three Mile Island.² Google ordered up to 500 megawatts of small modular reactors from Kairos Power.³ Amazon invested over $20 billion converting the Susquehanna site into a nuclear-powered AI data center campus.⁴ Meta issued a request for proposals targeting 1 to 4 gigawatts of new nuclear generation.⁵ Nuclear power transformed from a declining industry to the centerpiece of AI infrastructure strategy.

The pivot reflects fundamental math. Global electricity generation for data centers will grow from 460 terawatt-hours in 2024 to over 1,000 terawatt-hours in 2030 and 1,300 terawatt-hours in 2035.⁶ Nuclear provides 24/7 carbon-free baseload power that renewables cannot match. As hyperscalers exhaust available grid capacity and face sustainability commitments, nuclear becomes the solution that satisfies both requirements.

Microsoft and Three Mile Island

Nearly 50 years after a partial meltdown made Three Mile Island synonymous with nuclear disaster, the plant prepares to return powering Microsoft's AI data centers.⁷ Microsoft signed a 20-year agreement with Constellation Energy for electricity from the reactivated facility.⁸ The deal, worth $16 billion, will power Microsoft's AI data centers through the Crane Clean Energy Center, as the plant will be renamed.⁹

The 837-megawatt Pennsylvania facility expects to reopen in 2028.¹⁰ Microsoft will take 100 percent of the plant's output.¹¹ The 20-year duration significantly exceeds Microsoft's traditional solar and wind PPAs, reflecting the scale and reliability required for AI infrastructure.¹²

The reactor that will reopen was not involved in the 1979 accident.¹³ Constellation shut down Unit 1 in 2019 due to operating losses.¹⁴ Microsoft's commitment provides the revenue certainty required to justify the restart investment.

Progress continued through 2025. Constellation submitted a request to rename the facility in February, an updated decommissioning report in March, and applications to rescind exemptions granted during decommissioning from April through June.¹⁵ Governor Josh Shapiro appeared with Constellation and Microsoft executives on June 25, 2025, welcoming returning workers and highlighting nuclear power's role in Pennsylvania's energy plan.¹⁶

Google and Kairos Power SMRs

Google and Kairos Power signed what appears to be the first corporate agreement to develop a fleet of small modular reactors in the United States.¹⁷ The deal covers up to 500 megawatts across six to seven reactors.¹⁸ Reactors will come online through 2035, with the first targeted for 2030.¹⁹

Google and Kairos will deploy an advanced nuclear plant connected to the Tennessee Valley Authority's electric grid by 2030.²⁰ The Hermes 2 reactor developed by Kairos will dispatch 50 megawatts of electricity.²¹ TVA will purchase the electricity through a power purchase agreement, making it the first US utility to sign an offtake agreement with an advanced nuclear plant.²² The electricity will power Google's data centers in Montgomery County, Tennessee, and Jackson County, Alabama.²³

Kairos uses a molten-salt cooling system combined with ceramic, pebble-type fuel to transport heat to a steam turbine.²⁴ The company received a construction permit from the Nuclear Regulatory Commission in November 2024.²⁵ An operating license application will follow before plant startup.

The financial structure allocates risk appropriately. Kairos and Google bear the financial risk of building the first-of-a-kind project.²⁶ TVA provides the revenue stream through the PPA.²⁷ The arrangement ensures consumers do not carry first-of-a-kind costs while enabling the technology to reach commercial scale.

Amazon's nuclear investments

Amazon invested $650 million in a data center campus next to Pennsylvania's Susquehanna nuclear power plant.²⁸ AWS acquired Talen Energy's campus next to the Susquehanna Steam Electric Station and expanded it significantly.²⁹ In May, AWS received a 1,600-acre rezoning request to develop 15 data center buildings.³⁰

Amazon announced over $20 billion in investment to convert the site into an AI-ready data center campus powered entirely by carbon-free nuclear energy.³¹ The investment dwarfs the initial acquisition, reflecting the scale of AI infrastructure Amazon plans.

Amazon also invests in next-generation nuclear technology with a direct investment in Maryland-based X-energy.³² Amazon signed a deal with Energy Northwest, a utility in Washington state, to fund the initial phase of a planned X-energy small modular reactor project.³³ Amazon backed 5 gigawatts of new X-energy SMR projects in October 2024.³⁴

Meta and Oracle expand nuclear plans

Meta announced a request for proposals to nuclear developers targeting 1 to 4 gigawatts of new nuclear generation to power data centers and AI, starting in the early 2030s.³⁵ Meta seeks both small modular reactors and larger nuclear reactors.³⁶ Earlier in 2025, Meta entered an agreement with Constellation Energy to buy electricity from an existing Illinois nuclear plant.³⁷

Oracle announced plans to construct a gigawatt-scale data center powered by three small modular reactors.³⁸ CEO Larry Ellison stated that building permits for the three SMRs were already secured, though he did not elaborate on location or construction timelines.³⁹

Oracle's largest data center reaches 800 megawatts containing acres of NVIDIA GPU clusters able to train the world's largest AI models.⁴⁰ The SMR-powered gigawatt facility would exceed this scale, requiring power sources that the grid cannot reliably provide.

SMR development accelerates

President Trump issued four executive orders addressing nuclear energy on May 23, 2025, focused on speeding deployment of new nuclear technologies including SMRs.⁴¹ Executive Order 14300 set aggressive new licensing deadlines.⁴² The policy support catalyzed significant private-sector engagement.⁴³

A Standard Design Approval issued in May 2025 for the NuScale US 460, a 462-megawatt SMR, came two months ahead of schedule.⁴⁴ The accelerated approval demonstrates that regulatory timelines can compress with political priority.

After 2030, SMRs will enter the mix providing baseload low-emissions electricity to data center operators, with hyperscalers currently among the key corporate backers of SMR development.⁴⁵ The most optimistic estimates place SMR deployment beginning in the early 2030s.⁴⁶

The economies of scale that make SMRs attractive require volume deployment. The more units deployed, the greater the scale economies.⁴⁷ The data center industry inspires nuclear innovation by creating demand at scale.⁴⁸

Current nuclear role and limitations

Nuclear power currently supplies roughly 15% to 20% of data center electricity.⁴⁹ Natural gas supplies over 40% of electricity for US data centers, renewables about 24%, and coal around 15%.⁵⁰ While nuclear's share is expected to remain stable through 2030, the industry views nuclear as the endgame solution for sustainable AI.⁵¹

Goldman Sachs forecasts 85 to 90 gigawatts of new nuclear capacity would be needed to meet all data center power demand growth expected by 2030.⁵² Well less than 10% will be available globally by 2030.⁵³ The gap between demand and supply ensures continued reliance on natural gas and renewables through the decade.

Key downsides to nuclear include time to power and cost.⁵⁴ Capital expenditure for nuclear power plants is estimated at 5x to 10x that of natural gas.⁵⁵ Nuclear costs between $6,417 and $12,681 per kilowatt compared to $1,290 per kilowatt for natural gas.⁵⁶ The economics favor nuclear only where carbon-free requirements justify the premium.

Existing nuclear plants offer faster paths to power than new construction. Restarting decommissioned plants like Three Mile Island or purchasing output from operating plants through PPAs provides nuclear power years before SMRs reach commercial deployment.

Strategic implications

The hyperscaler nuclear commitments signal a long-term view of AI infrastructure requirements. Twenty-year PPAs and SMR development timelines assume AI electricity demand persists for decades. Organizations planning AI infrastructure should consider whether nuclear aligns with their horizons and sustainability requirements.

Location strategy increasingly considers nuclear access. Proximity to existing or planned nuclear facilities provides power options that grid-constrained locations lack. The concentration of AI infrastructure near nuclear plants will accelerate as hyperscalers execute their announced plans.

Cost premiums for nuclear power may be acceptable for organizations with strong carbon commitments. As renewable energy credits become less meaningful and scope 2 emissions scrutiny increases, 24/7 carbon-free power from nuclear offers sustainability advantages that intermittent renewables cannot match.

The regulatory environment for nuclear improved substantially in 2025. Executive orders and accelerated approvals suggest that political support exists for nuclear expansion. Organizations that dismissed nuclear as too slow or too risky should reevaluate based on current policy trajectories.

Nuclear represents the only proven technology that can deliver gigawatt-scale, carbon-free, 24/7 baseload power. Hyperscalers reached this conclusion and committed billions accordingly. Other organizations building AI infrastructure at scale will likely follow their lead.

Key takeaways

For strategic planners: - Big tech contracted 10GW+ new nuclear capacity; Microsoft's $16B Three Mile Island PPA, Google's 500MW Kairos SMRs, Amazon's $20B Susquehanna investment - Meta issued RFP for 1-4GW new nuclear generation; SMR deployment expected early 2030s - Twenty-year PPAs signal AI electricity demand persists for decades; location strategy increasingly considers nuclear proximity

For finance teams: - Nuclear costs $6,417-$12,681/kW vs $1,290/kW for natural gas—economics favor nuclear only with carbon-free requirements - Goldman Sachs forecasts 85-90GW new nuclear needed by 2030; less than 10% available globally - Microsoft's 20-year PPA duration significantly exceeds typical solar/wind agreements; revenue certainty justifies restart investment

For infrastructure architects: - Nuclear currently supplies 15-20% of data center electricity; natural gas provides 40%+ - Three Mile Island 837MW restart expected 2028; first Kairos SMR (50MW) targeted for 2030 with TVA grid connection - Existing plant restarts provide faster path to nuclear power than new SMR construction

For operations teams: - NuScale US 460 (462MW SMR) received Standard Design Approval May 2025, two months ahead of schedule - Executive Orders set aggressive new licensing deadlines; regulatory environment improved substantially in 2025 - Current generation global electricity for data centers: 460 TWh (2024) → 1,000 TWh (2030) → 1,300 TWh (2035)

References

1. MIT Technology Review. "Can nuclear power really fuel the rise of AI?" May 2025. https://www.technologyreview.com/2025/05/20/1116339/ai-nuclear-power-energy-reactors/

2. Data Center Dynamics. "Three Mile Island nuclear power plant to return as Microsoft signs 20-year, 835MW AI data center PPA." 2024. https://www.datacenterdynamics.com/en/news/three-mile-island-nuclear-power-plant-to-return-as-microsoft-signs-20-year-835mw-ai-data-center-ppa/

3. CNBC. "Google, Kairos Power plan advanced nuclear plant for Tennessee Valley Authority grid by 2030." August 2025. https://www.cnbc.com/2025/08/18/google-kairos-nuclear-smr-tennessee-valley-authority-tva-data-center-ai.html

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