Samsung C&T to invest up to $100M as Kairos Power builds 50MW reactor for Google

Samsung C&T commits up to $100 million to Kairos Power

Kairos Power has brought in Samsung C&T to help build the 50 megawatt reactor it is developing for Google, with the South Korean engineering firm contributing a package worth up to $100 million. According to TechCrunch, the deal pairs a $70 million equity investment with in-kind engineering services, and Kairos announced the arrangement on Monday. The company is aiming to complete the reactor by 2030.

Samsung C&T brings more than money. TechCrunch reports the firm has built or helped build roughly a dozen nuclear reactors around the world, construction experience that Kairos will need as its delivery schedule accelerates.

Two reactors under construction in Oak Ridge

Kairos is currently building two reactors in Oak Ridge, Tennessee. Hermes 1 is a low-power demonstration unit meant to help the company refine its commercial design, while Hermes 2 is its first commercial-scale plant. Per TechCrunch, Hermes 2's output will count as the first 50 megawatts of the Google agreement.

The Nuclear Regulatory Commission approved construction of the reactors in November 2024, and Kairos expects Hermes 2 to begin operating in 2030, in line with its original deal with Google.

A first-of-a-kind reactor design

Hermes 2 will be a fluoride salt-cooled high-temperature reactor, a design that has been proposed for years but, as TechCrunch notes, has never been built at commercial scale. Fluoride salts boil at high temperatures, which keeps pressures inside the system low and limits the risk of high-pressure blowouts if parts fail.

The fuel is unconventional too. Kairos is using TRISO, which encases tiny seeds of uranium in layers of ceramic and carbon that are then loaded into billiard ball-sized spheres. The arrangement is intended to prevent meltdowns.

The Google deal and the clock

Google signed its agreement with Kairos in the fall of 2024, calling for reactors capable of generating roughly half a gigawatt of electricity by 2035. Hermes 2 supplies the first 50 megawatts of that total.

TechCrunch describes the roughly five-year timeline for the first plant as accelerated but manageable by nuclear industry standards. The bigger challenge comes next: fulfilling the Google contract will require Kairos to build subsequent reactors faster than the first, and that is where Samsung C&T's construction background could prove decisive.

Why it matters

Kairos sits among a wave of nuclear startups that have gained from the surge in electricity demand driven by AI data centers, and hyperscalers like Google are now treating reactors as capacity to be ordered rather than merely hoped for. The Samsung deal is a concrete step in that shift: it supplies both capital and an experienced builder for a project that still has to prove a never-commercialized reactor design.

The stakes extend past this single plant. If Hermes 2 starts up on schedule in 2030, it bolsters the argument that advanced nuclear can be delivered on data-center timelines. If it slips, the half-gigawatt commitment due by 2035 becomes much harder to meet, and the broader bet on nuclear-powered cloud infrastructure looks shakier. Either way, the next five years in Oak Ridge will be a useful signal for the sector.