The rapid expansion of artificial intelligence has driven a sharp rise in energy demands across the United States, triggering heightened competition among Big Tech companies to secure reliable energy sources for their sprawling data centers. Increasingly, these influential corporations are turning their attention to nuclear fission, drawn by its promise of consistent, uninterrupted power around the clock.
Nuclear fission, which has experienced revived interest after years of closures and public skepticism, offers tech firms not only the benefit of stable, predictable electricity but also newly developed reactor designs that promise safer and more flexible energy solutions. Unlike traditional nuclear plants built around massive, single reactors capable of producing over 1 gigawatt, the emerging generation of reactors employs a modular design. Known as small modular reactors (SMRs), they can be mass-produced and combined as needed, bringing potential cost reductions and simpler operational logistics.
Though no SMRs have yet been constructed in the United States, tech giants including Amazon, Google, Meta, and Microsoft have shown strong confidence in the nuclear industry, placing substantial investment funds and contractual commitments behind promising nuclear startups.
One such enterprise is Kairos Power, which has received backing from Google in the form of a commitment to purchase approximately 500 megawatts of power by 2035, with its first reactor scheduled for commissioning by 2030. Kairos’ design utilizes a molten fluoride salt as both coolant and thermal medium—a safer approach due to the salt’s high boiling point and zero-pressure operation. Its reactors are fueled by specialized pebbles encased in robust carbon and ceramic shells, engineered for enhanced safety and meltdown resistance. The startup has also garnered substantial government support, including $303 million in funding from the U.S. Department of Energy, and in November 2024 it secured regulatory approval to commence building two test reactors in Tennessee, each planned at around 35 megawatts. Ultimately, the company aims for commercial reactor versions producing roughly 75 megawatts each.
Another promising initiative, Oklo, backed notably by OpenAI CEO Sam Altman through his investment fund AltC, targets the data center sector directly with liquid-metal-cooled reactors based on proven Department of Energy designs. Oklo’s reactor concept offers a reduced nuclear waste profile compared to traditional reactors, though the company experienced a regulatory setback when the U.S. Nuclear Regulatory Commission denied its initial licensing application in January 2022. Oklo expects to resubmit an amended application in 2025, while already securing an agreement to supply 12 gigawatts of power to data-center firm Switch by 2044.
Further innovating in modular nuclear solutions is Saltfoss, formerly known as Seaborg. The startup focuses on deploying SMRs cooled by molten salt. Saltfoss proposes an unconventional approach, setting modular nuclear reactors aboard ships called “Power Barges.” Supported through a $60 million investment—its investors include Bill Gates, Peter Thiel, and Unity co-founder David Helgason—the company has partnered with Samsung Heavy Industries to construct these floating nuclear power assets.
Similarly, TerraPower, founded by Bill Gates, has placed its bet on the Natrium reactor design, a mid-sized, sodium-cooled plant featuring advanced molten salt energy storage. With construction already underway on its first unit in Wyoming as of June 2024, TerraPower’s facility will offer 345 megawatts, significantly smaller than traditional multi-gigawatt nuclear facilities but larger than most SMR-variants. Unique among contemporaries, Natrium’s built-in molten salt storage system enables it to flexibly produce electricity according to varying demand, storing heat produced during low-consumption periods for later energy generation.
Finally, X-Energy secured a powerful endorsement from Amazon through a $700 million series C-1 investment round led by Amazon’s Climate Pledge Fund. X-Energy’s reactor design breaks with recent U.S. and European nuclear trends by embracing a gas-cooled approach. Its Xe-100 high-temperature reactor uses helium gas, which circulates through approximately 200,000 billiard-ball-sized fuel pellets to drive a steam turbine, producing an estimated 80 megawatts of electricity per reactor unit. Development agreements signed by X-Energy outline the delivery of approximately 300 megawatts across planned deployments in Virginia and the Pacific Northwest.
As Big Tech commits significant resources to these nuclear startups, the future landscape of data center energy needs appears increasingly likely to include nuclear fission as a central pillar, an illustration of deepening synergy between technological innovation and the revitalized nuclear power sector.
