# Is Samsung C&T's $100M Bet the Construction Credibility Kairos Power Needed?

[Kairos Power](https://smrintel.com/companies/kairos-power) has secured up to $100 million from Samsung C&T — split as $70 million in equity and the remainder in in-kind engineering services — to advance its 50 MWe [fluoride salt-cooled high-temperature reactor](https://smrintel.com/glossary/fhr) demonstration at Oak Ridge, Tennessee, with a target commercial operation date of 2030. The deal, announced Monday, pairs a first-of-a-kind advanced reactor design with one of the few engineering firms on the planet that has actually built nuclear power plants at scale. Samsung C&T has constructed or contributed to approximately a dozen reactors globally, according to Kairos.

This is not a letter of intent. This is $70 million of equity on the balance sheet and a construction partner with a verifiable nuclear track record — a combination that materially changes the risk profile of the Hermes 2 project. The reactor, a [FOAK](https://smrintel.com/glossary/foak) commercial-scale fluoride salt design, is slated to deliver the first 50 megawatts of output under Kairos's fall 2024 power purchase agreement with Google, which called for roughly 500 MWe of nuclear capacity by 2035.

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## What Kairos Is Actually Building in Oak Ridge

Two reactors are under active construction at the Oak Ridge site. Hermes 1 is a low-power demonstrator intended to validate the core design and generate operational data. Hermes 2 is the commercial-scale unit — the 50 MWe machine that will count toward the Google contract.

The NRC granted construction permits for both reactors in late 2024, clearing the primary regulatory hurdle that has stalled other advanced reactor programs. Kairos expects Hermes 2 to begin operating in 2030.

The design is a [fluoride salt-cooled high-temperature reactor](https://smrintel.com/glossary/fhr). Fluoride salts carry a meaningful safety attribute: their high boiling points allow the primary circuit to operate at low pressure. Low system pressure dramatically reduces the consequence of a pipe failure or component breach — the high-pressure blowout scenario that has historically driven large, expensive [containment structure](https://smrintel.com/glossary/containment) requirements in light water reactor designs.

The fuel is TRISO — tristructural isotropic particles, where tiny uranium fuel kernels are encapsulated in concentric layers of carbon and ceramic. Those particles are then embedded in graphite spheres roughly the size of billiard balls. The ceramic and carbon layers act as a distributed containment at the fuel-particle level, providing an intrinsic barrier to fission product release during accident conditions. TRISO has been manufactured and tested for decades but has not yet powered a commercial-scale reactor — Hermes 2 would change that.

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## Why Samsung C&T, and Why Now

The nuclear construction market has a fundamental supply-side problem: engineering and construction firms with genuine nuclear-grade project experience are scarce, and the ones that exist are heavily committed. Samsung C&T's portfolio of roughly a dozen reactor projects gives it a depth of nuclear construction competence that most Western EPC firms cannot claim.

For Kairos, the strategic value of the Samsung C&T relationship extends beyond the capital. The in-kind engineering services component means Samsung C&T's workforce and institutional knowledge are being embedded into the Hermes program — design-for-constructability inputs, construction sequencing, quality assurance protocols. Those contributions matter enormously for a company attempting to build a reactor type that has never been erected at commercial scale.

The Google contract's structure also creates a secondary urgency. Fulfilling the 500 MWe commitment by 2035 requires Kairos to move from Hermes 2 into serial construction faster than the typical FOAK-to-NOAK learning curve would allow. Samsung C&T's experience with serial reactor construction — and the supply chain relationships that come with it — is precisely what Kairos needs to compress that timeline.

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## Skeptical Read: What This Deal Does Not Resolve

Several material uncertainties remain, and the Samsung C&T announcement does not address all of them.

**TRISO fuel supply at scale.** TRISO particles have been produced in research quantities but scaling to fuel a commercial reactor fleet requires manufacturing infrastructure that is still maturing in the United States. Kairos has not publicly detailed its fuel supply chain for the units beyond Hermes 2.

**Fluoride salt material compatibility at operating temperatures.** High-temperature fluoride salts are corrosive. Managing structural material degradation over a multi-decade plant life is a materials science challenge that the Hermes 1 demonstrator is partly designed to characterize — but the data will arrive late in the Hermes 2 construction timeline.

**LCOE at commercial scale.** The 50 MWe Hermes 2 unit will carry a FOAK cost premium. What Kairos and its investors need to demonstrate, before the Google contract's remaining ~450 MWe gets built, is a credible NOAK cost trajectory. Samsung C&T's involvement strengthens the construction execution case, but the economics of serial production remain to be demonstrated in hardware, not spreadsheets.

**2035 volume commitment.** Getting from 50 MWe in 2030 to approximately 500 MWe by 2035 implies a deployment pace that no advanced reactor developer has yet achieved. The partnership buys credibility; it does not eliminate schedule risk.

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## Industry Trajectory: Tech-Sector Capital Is Reshaping Nuclear Finance

The Kairos-Samsung C&T deal is the latest evidence that hyperscaler power demand is fundamentally restructuring how advanced reactor projects get capitalized. Google signed its original Kairos agreement in fall 2024. Microsoft has backed [TerraPower](https://smrintel.com/companies/terrapower) and struck agreements with [Constellation Energy](https://smrintel.com/companies/constellation-energy). Amazon has made comparable commitments across multiple developers.

What makes the Samsung C&T structure notable is the equity-plus-services model. Rather than a simple construction contract, Samsung C&T is taking an ownership stake — aligning its incentives with Kairos's long-term success in a way that a fee-for-service EPC arrangement does not. For other advanced reactor developers watching from the sidelines, this structure may represent a template: pair the technology with a construction-capable strategic investor who has skin in the commercial outcome.

The broader question for the advanced nuclear sector is whether the Google-Kairos timeline — a 2030 operational date for a FOAK commercial-scale FHR — can actually be held. If Hermes 2 delivers on schedule, it will be among the fastest FOAK advanced reactor deployments in modern nuclear history and will validate both the FHR design class and the accelerated permitting pathway the NRC enabled with its late-2024 construction permits.

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## Key Takeaways

- Samsung C&T is investing up to **$100 million** in Kairos Power — **$70 million in equity** plus in-kind engineering services.
- Samsung C&T has built or contributed to **approximately a dozen nuclear reactors** globally, giving Kairos a construction partner with a verifiable track record.
- The investment supports **Hermes 2**, a **50 MWe fluoride salt-cooled high-temperature reactor** under construction in Oak Ridge, Tennessee.
- Kairos received NRC [construction permits](https://smrintel.com/glossary/construction-permit) for Hermes 1 and Hermes 2 in **late 2024**; Hermes 2 is targeted for operation by **2030**.
- Hermes 2 output will count as the first 50 MWe of Kairos's agreement with Google, which calls for approximately **500 MWe of nuclear capacity by 2035**.
- The FHR design uses TRISO fuel and low-pressure fluoride salt coolant — a design class that has never operated at commercial scale.
- The equity-plus-services structure aligns Samsung C&T's incentives with Kairos's long-term commercial success, departing from the standard EPC contract model.
- Critical unresolved risks include TRISO fuel supply at scale, fluoride salt material compatibility data, and the construction pace required to meet the 2035 volume commitment.

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## Frequently Asked Questions

**What is the Samsung C&T investment in Kairos Power?**
Samsung C&T is committing up to $100 million to Kairos Power, comprising $70 million in equity and the remainder in in-kind engineering services. The deal was announced on September 21, 2026, and is tied to construction of the Hermes 2 reactor in Oak Ridge, Tennessee.

**What is the Kairos Power Hermes 2 reactor?**
Hermes 2 is a 50 MWe fluoride salt-cooled high-temperature reactor under construction in Oak Ridge, Tennessee. It is Kairos Power's first commercial-scale reactor and uses TRISO fuel — uranium particles encapsulated in ceramic and carbon layers within graphite spheres. It is targeted to begin operating in 2030.

**Why did Kairos Power choose Samsung C&T as a construction partner?**
Samsung C&T has built or contributed to approximately a dozen nuclear reactors globally. For a first-of-a-kind design like the FHR, pairing with a firm that has direct nuclear construction experience reduces execution risk. Samsung C&T's equity stake also aligns its long-term interests with Kairos's commercial success.

**What is Kairos Power's agreement with Google?**
Google signed a deal with Kairos Power in fall 2024 calling for the delivery of approximately 500 MWe of nuclear power by 2035. Output from Hermes 2 will count as the first 50 MWe toward that commitment.

**What is a fluoride salt-cooled high-temperature reactor?**
An FHR uses liquid fluoride salt as a coolant instead of water. Fluoride salts have very high boiling points, which allows the reactor to operate at low pressure — reducing the risk of high-pressure failures and simplifying containment requirements. The design class has been studied for decades but Hermes 2 would be the first commercial-scale FHR to operate.

**Has Kairos Power received NRC approval to build Hermes?**
Yes. The NRC granted construction permits for both Hermes 1 (the low-power demonstrator) and Hermes 2 (the commercial-scale unit) in late 2024. This clears the primary federal regulatory hurdle required to proceed with construction.