Big Tech's Nuclear Ambitions: Powering the Age of AI with Advanced Fission

The rise of artificial intelligence is reshaping industries, economies, and even our daily lives. But beneath the surface of sophisticated algorithms and powerful computing lies a fundamental requirement: immense amounts of energy. Training and running large language models, powering complex AI computations, and maintaining the vast data centers that house this infrastructure demand electricity on a scale previously unimaginable. After years of relatively flat growth in U.S. electricity demand, the needs of AI and data centers have sent projections skyrocketing. This unprecedented demand has forced the world's largest technology companies — the very pioneers of the AI revolution — to embark on a quest for reliable, high-density power sources.

For many, this quest has led to a surprising destination: nuclear fission. Once seen by some as a sunset industry facing decades of plant closures and public skepticism, nuclear power is experiencing a notable resurgence. This renewed interest is fueled by the urgent need for carbon-free, always-on (baseload) power that can meet the insatiable appetite of modern computing infrastructure. While experimental approaches like fusion continue to attract significant investment, fission, the proven technology behind all current nuclear power plants, is the focus for immediate, scalable solutions.

Why Nuclear Fission? The Power Needs of AI

Artificial intelligence workloads, particularly those involving deep learning and large neural networks, are incredibly computationally intensive. Training a single large AI model can consume as much electricity as hundreds of typical U.S. homes in a year. As these models grow larger and more complex, and as AI is integrated into more applications and services, the cumulative power demand of the tech sector is set to increase dramatically. Data centers, the physical homes for this computing power, are already major electricity consumers. Adding AI at scale exacerbates this challenge.

Traditional renewable energy sources like solar and wind are crucial for decarbonization, but they are intermittent. They require significant battery storage or backup power to ensure continuous operation, which is essential for data centers that must run 24/7. Fossil fuels provide baseload power but contribute to carbon emissions, conflicting with the climate goals many tech companies have set. Nuclear fission offers a compelling alternative: a low-carbon source that can generate electricity continuously, regardless of weather conditions.

For tech companies operating critical infrastructure like data centers, a stable, predictable power supply is paramount. Downtime is incredibly costly. Nuclear power plants, unlike most renewables, can operate at full capacity for extended periods, providing the kind of reliable baseload power that AI workloads require. This inherent stability is a major part of nuclear fission's appeal to the tech sector.

The Evolution of Nuclear Technology: From Goliaths to Modules

The nuclear power plants of the past were often massive, bespoke construction projects, designed to generate over a gigawatt of electricity. While powerful, their sheer scale, complexity, and lengthy construction timelines contributed to high costs and significant financial risks. This model, coupled with public perception issues and regulatory hurdles, led to a slowdown in new plant construction in many Western countries for decades.

However, a new generation of reactor designs is promising to overcome these shortcomings. The concept of Small Modular Reactors (SMRs) is central to this shift. Instead of building one giant reactor on-site, SMR designs envision smaller, standardized reactor modules that can be mass-manufactured in factories and then transported to the deployment site. This modular approach offers several potential advantages:

• **Lower Upfront Costs:** Smaller size means lower initial capital investment compared to large plants.
• **Shorter Construction Times:** Factory fabrication and modular assembly can significantly reduce on-site construction time and complexity.
• **Scalability:** Multiple modules can be deployed incrementally to match growing power demand.
• **Increased Safety:** Many new SMR designs incorporate advanced passive safety features that rely on natural forces (like gravity or convection) rather than active systems, making them inherently safer.
• **Location Flexibility:** Their smaller footprint and potentially enhanced safety features could allow SMRs to be sited closer to where power is needed, such as near industrial facilities or data centers.
• **Reduced Waste:** Some advanced reactor designs aim to burn nuclear fuel more efficiently or even consume existing nuclear waste, reducing the volume and longevity of radioactive waste.

While the promise of SMRs is significant, it's important to note that, to date, no SMR based on these new designs has been built and operated commercially in the United States. The path from design to deployment involves rigorous testing, licensing, and overcoming manufacturing and supply chain challenges. Nevertheless, the potential benefits have captured the attention and investment of major tech players.

Big Tech's Bet on Fission Startups

Leading technology companies are not just expressing interest in nuclear power; they are actively investing in and signing power purchase agreements with nuclear fission startups. This direct engagement signals a serious commitment to securing future energy supplies and a belief in the potential of these next-generation nuclear technologies. Companies like Amazon, Google, Meta, and Microsoft have all made moves in this space, backing a diverse range of startups developing different reactor types and deployment strategies.

Here are some of the nuclear fission startups that have garnered significant backing from Big Tech:

Kairos Power: Molten Salt and Fuel Pebbles

Kairos Power, based in Alameda, California, is one of the startups leading the charge in developing advanced SMR technology. They received a major vote of confidence from Google, which promised to buy approximately 500 megawatts of electricity from Kairos by 2035. The ambitious timeline targets the first reactor coming online as early as 2030.

Kairos Power's small modular reactors utilize molten fluoride salt as the coolant. This choice of coolant is a key feature of their design. Molten salts have high boiling points, which means the cooling system can operate at lower pressures compared to traditional water-cooled reactors. This lower operating pressure is expected to enhance safety by reducing the risk of a sudden loss of coolant accident. The molten salt also serves to transport heat from the reactor core to a steam turbine, where it is converted into electricity.

The reactor core itself contains fuel in the form of pebbles. These pebbles are coated in multiple layers of carbon and ceramic shells, designed to contain the radioactive fuel even under extreme temperatures, providing a robust barrier against the release of fission products. This 'TRISO' (Tristructural-isotropic) fuel concept is known for its inherent safety characteristics.

Kairos Power has also received substantial support from the U.S. government, including a significant award from the Department of Energy as part of its advanced reactor demonstration program. In a crucial step towards deployment, Kairos received approval from the U.S. Nuclear Regulatory Commission (NRC) in November 2024 to begin construction on two test reactors in Tennessee. These initial units, at 35 megawatts each, are smaller than the company's planned commercial reactors, which are expected to generate 75 megawatts individually. The construction and operation of these test reactors will be vital steps in demonstrating the safety and viability of Kairos' technology on the path to fulfilling its agreements with companies like Google.

Oklo: Liquid Metal Fast Reactors and Data Center Deals

Oklo is another SMR company that has explicitly targeted the data center market, recognizing the immense power needs of this sector. The company gained significant visibility due to its backing by OpenAI CEO Sam Altman, who also played a role in taking the nuclear startup public through a reverse merger with his special purpose acquisition company (SPAC), AltC, in July 2023. While Altman stepped down as Oklo's chairman in April 2024 as OpenAI began negotiating its own energy supply agreement with the company, his initial involvement highlighted the tech industry's growing interest in nuclear power. Oklo has also attracted investment from prominent venture capital firms like DCVC, Draper Associates, and Peter Thiel's Mithril Capital Management.

Oklo's reactor design is based on a concept developed by the U.S. Department of Energy: a liquid metal-cooled fast reactor. This type of reactor uses a liquid metal, such as sodium, as the coolant instead of water. Liquid metal coolants can operate at higher temperatures and lower pressures than water, potentially leading to higher efficiency and enhanced safety. A key feature of Oklo's design is its potential to reduce the volume and radiotoxicity of nuclear waste compared to traditional light-water reactors. Fast reactors can utilize a wider range of fuels, including recycled nuclear material, which could help address the challenge of spent fuel management.

However, Oklo's journey has not been without its challenges. The company's initial license application for its Aurora power plant design was denied by the NRC in January 2022, citing concerns about the application's completeness and technical details. Oklo has stated its intention to resubmit a revised application, targeting sometime in 2025. Despite this regulatory setback, the company has continued to pursue commercial opportunities. In a significant development, Oklo landed a massive deal to supply data center operator Switch with up to 12 gigawatts of power by 2044. This ambitious agreement underscores the scale of demand from the data center industry and the potential role nuclear power could play, even as Oklo navigates the regulatory process.

Saltfoss: Nuclear Power on the High Seas

Saltfoss, formerly known as Seaborg, shares Kairos Power's interest in molten salt reactor technology but envisions a unique deployment strategy. Based in Denmark, Saltfoss is developing SMRs cooled by molten salt, similar in principle to Kairos' design. However, Saltfoss plans to install two to eight of these reactors onto a ship, creating what they call a Power Barge. This mobile or near-shore deployment concept could offer flexibility in providing power to coastal areas, islands, or industrial facilities located near waterways.

The startup has raised nearly $60 million to advance its concept, including a seed round that attracted notable investors such as Bill Gates, Peter Thiel, and Unity co-founder David Helgason. Saltfoss has also formed a strategic partnership with Samsung Heavy Industries, a major South Korean shipbuilder, to construct both the specialized ships and integrate the Saltfoss-designed reactors. This collaboration aims to leverage established shipbuilding expertise for the modular construction and deployment of their floating nuclear power plants. While the concept of floating nuclear power is not entirely new, Saltfoss's approach using advanced molten salt SMRs represents a novel application tailored for specific market needs and potentially faster deployment compared to land-based plants.

TerraPower: Liquid Sodium and Molten Salt Storage

Founded by Bill Gates, TerraPower is developing a different type of advanced reactor called Natrium. Unlike the smaller SMRs being pursued by some other startups, the Natrium design is larger, intended to generate 345 megawatts of electricity. While not an SMR in the strictest sense (many SMR definitions cap capacity around 300 MW), it is still smaller than many of the gigawatt-scale reactors built in the 20th century. The Natrium reactor uses liquid sodium as its primary coolant, similar to Oklo's design. Liquid sodium is an efficient heat transfer medium that allows the reactor to operate at higher temperatures and lower pressures than water-cooled reactors.

A distinctive feature of the Natrium design is its integrated molten salt energy storage system. Nuclear reactors are most efficient when operating at a steady power output. However, electricity demand fluctuates throughout the day. The Natrium system addresses this by using a large vat of molten salt to store excess heat generated by the reactor when electricity demand is low. When demand peaks, this stored heat can be drawn upon to generate additional electricity via a steam turbine, effectively allowing the plant to increase its power output significantly for a period. This flexibility makes the Natrium design particularly well-suited to complement intermittent renewable sources on the grid.

TerraPower broke ground on the first Natrium power plant in June 2024 in Wyoming, on the site of a retiring coal plant. The project is supported by the U.S. Department of Energy's Advanced Reactor Demonstration Program. Investors in TerraPower include Gates' own Cascade Investment fund, as well as prominent venture capital firms Khosla Ventures and CRV, and industrial giant ArcelorMittal. The Natrium project represents a significant step towards demonstrating the viability of non-light water reactor technologies and their potential role in providing flexible, low-carbon power.

X-Energy: High-Temperature Gas-Cooled Reactors

X-Energy is another SMR developer that has attracted substantial investment from Big Tech, notably receiving a hefty $700 million Series C-1 funding round led by Amazon's Climate Pledge Fund. This investment was coupled with announcements of development agreements aimed at deploying 300 megawatts of new nuclear capacity in the Pacific Northwest and Virginia, regions with growing data center footprints.

X-Energy's technology centers around high-temperature, gas-cooled reactors (HTGRs). This design approach uses helium gas as the coolant, which flows through the reactor core to absorb heat. While HTGRs have been explored in the past, they have not seen widespread commercial deployment in the U.S. or Europe compared to light-water reactors. X-Energy's Xe-100 reactor is designed to generate 80 megawatts of electricity per module.

Similar to Kairos Power, X-Energy's design utilizes robust, billiard ball-sized fuel 'pebbles'. These pebbles contain the nuclear fuel encased in multiple layers of ceramic and carbon coatings, providing a high degree of containment and allowing the reactor to operate at very high temperatures. The hot helium gas exiting the reactor core can be used to generate electricity via a steam turbine or potentially for high-temperature industrial processes, offering versatility beyond just power generation.

Amazon's significant investment through its climate fund underscores the company's view of advanced nuclear as a critical component in achieving its decarbonization goals, particularly for its energy-intensive cloud computing infrastructure (AWS) and logistics operations. Amazon's backing of X-Energy, alongside Meta's exploration of nuclear options for its data centers and Google's deal with Kairos, illustrates the broad tech industry trend towards embracing nuclear power.

The Driving Force: AI's Unprecedented Energy Appetite

The connection between AI and nuclear power is direct and increasingly critical. The computational demands of AI are growing exponentially. Training larger, more sophisticated models requires massive parallel processing, which translates directly into high electricity consumption. Furthermore, running AI inference — applying trained models to new data — at scale for services like search, recommendation engines, autonomous vehicles, and generative AI applications requires distributed computing power, often housed in data centers located around the globe.

Estimates vary, but some projections suggest that AI-related electricity consumption could double or even triple within the next few years. This surge is happening at a time when grids are already under pressure from increasing electrification (e.g., electric vehicles) and the transition away from fossil fuels. Tech companies, committed to both powering their operations and meeting sustainability targets, find themselves in a challenging position. They need vast amounts of reliable power, and they need it to be clean.

Renewables like solar and wind are becoming cheaper and more widespread, but their intermittency remains a fundamental challenge for applications requiring constant power. While battery storage is improving, the scale of storage needed to back up large data centers for extended periods is immense and costly. This is where nuclear power, with its high capacity factor (the percentage of time a plant is generating power), becomes attractive. A nuclear plant can provide a steady stream of clean electricity, complementing renewables and reducing the need for fossil fuel backups.

The development of SMRs is particularly appealing because they could potentially be deployed closer to data center locations, reducing transmission losses and infrastructure costs. Imagine a future where a cluster of SMRs provides dedicated, carbon-free power directly to a large AI data center campus. This vision is driving tech companies to invest in these startups, aiming to accelerate the development and deployment of these technologies.

Challenges and the Road Ahead

Despite the enthusiasm and investment from Big Tech, the path to widespread deployment of advanced nuclear reactors is not without significant challenges. Regulatory approval is a major hurdle, as demonstrated by Oklo's initial license application denial. The U.S. Nuclear Regulatory Commission has a rigorous process to ensure safety, and navigating this process for novel reactor designs takes time and significant effort. While Kairos Power received approval for construction of test reactors, moving to commercial deployment requires further licensing steps.

Manufacturing and supply chain development for SMRs are also critical. The SMR concept relies on the promise of factory fabrication to reduce costs and speed deployment. Building the necessary manufacturing infrastructure and establishing a reliable supply chain for specialized nuclear components is a complex undertaking that requires substantial investment and coordination.

Public perception, while potentially improving, remains a factor. Concerns about safety, nuclear waste disposal, and security persist in some communities. Startups and the industry as a whole must effectively communicate the safety features of new designs and address waste management solutions.

Finally, the economics must prove out. While SMRs promise lower costs than large traditional plants, they still represent significant capital investments. Demonstrating that these plants can produce electricity at a competitive price point, especially compared to increasingly cheap renewables, is essential for long-term success.

Despite these challenges, the involvement of Big Tech provides a powerful impetus for the advanced nuclear industry. Their financial backing, technical expertise, and, crucially, their massive and growing demand for reliable, clean power offer a potential pathway for these startups to move from design and testing to commercial reality. The partnerships between tech giants and nuclear fission startups like Kairos Power, Oklo, Saltfoss, TerraPower, and X-Energy represent a significant convergence of the digital and energy worlds, driven by the fundamental need to power the future of artificial intelligence sustainably. The success of these ventures could not only help meet the energy demands of the AI age but also play a vital role in global decarbonization efforts.