Kairos Power selected engineering firm Samsung C&T to help build its 50-megawatt demonstration nuclear reactor for Google, targeting a complete operational build by 2030. Under the terms of the agreement, Samsung C&T makes an equity investment in Kairos alongside providing direct engineering services. The combined package totals up to $100 million, with direct equity making up $70 million of that overall amount.
Samsung C&T brings major construction experience to the deal, having built or supported roughly a dozen nuclear reactors globally. Partnering with an established builder gives Kairos heavy industrial experience as nuclear startups race to meet rising electricity needs from tech facilities.
Kairos sits among several nuclear startups gaining momentum from surging energy demands across computing data centers. Google signed an initial agreement with Kairos in late 2024, asking the nuclear startup to construct a series of reactors capable of producing half a gigawatt of clean electricity by 2035.
Kairos is currently constructing two test reactors in Oak Ridge, Tennessee. The first unit, Hermes 1, functions as a low-power demonstrator to help engineers refine commercial designs. The second unit, Hermes 2, serves as the company’s initial commercial-scale reactor setup. Power output generated from Hermes 2 will count directly as the first 50 megawatts required under the Google supply deal.
The Nuclear Regulatory Commission granted Kairos construction approval in late 2024 to build out the Oak Ridge test reactors. Kairos expects Hermes 2 to begin active power generation by 2030, keeping the build schedule aligned with its original corporate timeline and Google agreement.
The Hermes 2 design uses fluoride salt as a high-temperature coolant. While researchers have discussed liquid salt cooling systems for years, no commercial-scale plant currently uses the technology. Fluoride salts feature extremely high boiling points, keeping internal operating pressures low and reducing the risk of high-pressure pipe blowouts or system failures.
Kairos also uses an advanced nuclear fuel configuration known as TRISO. TRISO fuel seals tiny uranium seeds inside layers of ceramic and carbon materials, which are then packed into billiard-ball-sized spheres. This custom structural design withstands extreme heat and prevents meltdowns even under severe operating failures.
Kairos has roughly four years to complete its first commercial reactor, an aggressive schedule inside the traditional power sector. To meet its long-term delivery targets with Google, Kairos must scale up manufacturing and installation even faster. Teaming up with Samsung C&T provides the industrial backing needed to turn these advanced nuclear designs into working power plants.