Google Secures 500 MW SMR Fleet from Kairos Power in Landmark Data Center Power Deal

The artificial intelligence revolution has an insatiable appetite for electricity, and the world's largest technology companies are increasingly turning to the atomic age to feed it. In a landmark move for both the tech and energy sectors, Google has partnered with California-based Kairos Power to deploy a 500-megawatt fleet of small modular reactors (SMRs) by 2035. The initiative recently reached a major milestone with a new power purchase agreement involving the Tennessee Valley Authority (TVA), ensuring that the first of these next-generation reactors will directly power Google's data centers in Tennessee and Alabama.[1]

The agreement represents the world's first corporate commitment to purchase nuclear energy from multiple SMRs of a single design. Rather than relying on the traditional, decades-long process of building massive gigawatt-scale nuclear plants, Google is backing Kairos Power's strategy of deploying smaller, factory-built reactors. The first commercial-scale unit, the 50-megawatt Hermes 2 demonstration plant in Oak Ridge, Tennessee, officially broke ground in April 2026 and is scheduled to come online by 2030. This initial deployment serves as the critical proving ground for the broader 500-megawatt fleet.[1][2][3]

To understand why a search and advertising giant is funding nuclear engineering, one must look at the staggering energy projections for artificial intelligence. Global data centers are projected to consume up to 945 terawatt-hours of electricity annually by 2030—roughly equivalent to the entire power consumption of Japan. Training and running large language models requires massive, uninterrupted power that cannot easily be paused when the wind stops blowing or the sun sets. For hyperscalers, securing reliable electricity has become the primary bottleneck to future growth.

While Google has historically relied on wind and solar to meet its sustainability targets, those variable renewable sources require extensive lithium-ion battery storage to provide round-the-clock power. 'The end goal here is 24/7, carbon-free energy,' noted Google's senior director for energy and climate, emphasizing that advanced nuclear technology is the missing complement to wind and solar. Small modular reactors offer firm, baseload power that can be sited close to the data centers that need it most, effectively bypassing the transmission constraints that currently plague the broader electrical grid.[1]

Kairos Power is not building the pressurized water reactors that have dominated the global nuclear industry since the 1950s. Instead, the company is commercializing a fluoride salt-cooled high-temperature reactor, known as the KP-FHR. This Generation IV technology uses a molten fluoride salt called Flibe as its primary coolant, representing a dramatic departure from traditional light-water systems. The shift in coolant material fundamentally alters the physics of the reactor, unlocking efficiencies and safety margins that were previously impossible with older designs.[1][4]

The use of molten salt fundamentally changes the safety and engineering profile of the reactor. Traditional water-cooled reactors must operate under extreme pressure to prevent the water from boiling into steam. If that pressure is lost, the reactor risks a catastrophic meltdown. Molten fluoride salt, however, remains in a stable liquid state at extremely high temperatures without needing to be pressurized. This means the reactor can operate at near-atmospheric pressure, completely eliminating the risk of steam explosions and allowing for much thinner, cheaper containment structures.

The fuel itself is also highly specialized. Kairos uses TRISO, or TRi-structural ISOtropic, coated particle fuel, a technology originally developed at the Oak Ridge National Laboratory. TRISO fuel consists of tiny uranium kernels encased in multiple layers of carbon and ceramic. These microscopic containment vessels are virtually indestructible, capable of withstanding temperatures far beyond what the reactor can physically generate. This ensures that radioactive byproducts remain permanently trapped inside the fuel itself, even in the event of an extreme operational failure.[3]

Bridging the gap from a promising laboratory concept to a commercial power plant is notoriously difficult in the nuclear industry—a phase often referred to as the 'valley of death.' Kairos Power is navigating this perilous transition by utilizing a rapid, iterative development approach. Rather than attempting to build a full-scale commercial plant on the first try, the company is scaling up in deliberate, manageable steps, using Google's financial backing to de-risk each successive phase of engineering. This philosophy mirrors the agile development cycles native to the tech industry, prioritizing physical testing and incremental learning over decades of theoretical modeling.[1]

The first step in this iterative process is Hermes 1, a non-power test reactor currently under construction in Oak Ridge, which allows engineers to test the molten salt systems and reactor vessel design in a real-world environment. The lessons learned from Hermes 1 are already being fed directly into Hermes 2, the 50-megawatt power-producing plant that will supply Google. By the time Kairos begins deploying the subsequent 75-megawatt commercial units required to reach Google's 500-megawatt target, the fundamental engineering will have been proven, refined, and licensed multiple times.[3]

Manufacturing is another area where the Google-Kairos partnership aims to completely rewrite the nuclear playbook. Historically, nuclear plants are bespoke mega-projects built entirely on-site, leading to notorious cost overruns and schedule delays that stretch into decades. Kairos is pioneering a factory-built small modular reactor model. The complex reactor equipment modules will be fabricated at the company's dedicated manufacturing development campus in Albuquerque, New Mexico, and then shipped to the Oak Ridge site for final assembly. This centralized production strategy is designed to drastically reduce on-site labor costs and improve quality control.[4]

This modular approach allows for highly standardized, repeatable construction. The civil structures housing the reactors will utilize precast concrete and seismically isolated foundations, further shrinking project timelines and reducing site-specific engineering requirements. By standardizing the design and manufacturing the most complex components in a controlled factory environment, Kairos hopes to achieve the economies of scale that have long eluded the traditional nuclear sector. If successful, this manufacturing pipeline will make advanced reactors a financially competitive, off-the-shelf product rather than a generational infrastructure gamble.[4]

The integration of this new power source into the existing electrical grid is being actively facilitated by the Tennessee Valley Authority. Under the July 2026 agreement, the TVA will purchase the electricity generated by Hermes 2 and distribute it through its network to directly power Google's regional data centers. This public-private partnership ensures that the new generation capacity directly offsets the massive draw of the hyperscale computing facilities, preventing the tech giant's growth from straining the local power supply or raising rates for residential communities.

Google is not alone in this atomic pivot. The broader technology industry has committed over $10 billion to nuclear partnerships, with roughly 22 gigawatts of small modular reactor projects currently in development globally. Amazon has secured agreements for advanced reactors in Washington state and purchased a massive data center adjacent to an existing nuclear plant in Pennsylvania. Meanwhile, Microsoft has backed the restart of the Three Mile Island facility. Across the board, hyperscalers are realizing that their artificial intelligence ambitions are fundamentally constrained by the physics of power generation.

The regulatory environment is also adapting to accommodate this new era of nuclear innovation. When the Nuclear Regulatory Commission approved the construction permit for the Hermes demonstration reactor, it marked the first time a non-water-cooled reactor had been approved for construction in the United States in more than half a century. This regulatory breakthrough establishes a vital precedent, paving the way for other advanced reactor designs to navigate the complex licensing process with greater predictability and speed. The NRC's willingness to evaluate novel coolants and fuels is a critical signal to investors that the sector is open for business.

Ultimately, the Google-Kairos agreement represents significantly more than just a corporate procurement deal; it is a vital catalyst for the next generation of clean energy infrastructure. By providing guaranteed demand and upfront capital, Google is helping to de-risk a transformative technology. If Kairos Power can successfully deliver its 500-megawatt fleet on time and on budget, it will prove that advanced nuclear can be deployed at scale, eventually providing reliable, carbon-free power not just to server farms, but to cities and heavy industries worldwide.[1]