In Development
Hermes
35 MWth low-power demonstration reactor validating Kairos Power's KP-FHR design, construction methods, fuel program, and operating approach in Oak Ridge, Tennessee.
Kairos Power is commercializing its fluoride salt-cooled, high-temperature reactor (KP-FHR), which combines TRISO pebble fuel with FLiBe coolant in a compact, low-pressure design aimed at grid and AI-data-center loads.
Latest update Oct 7, 2026
01
Overview
The company runs an iterative, vertically integrated development model centered on Hermes 1, a 35 MWth demonstration reactor under safety-related construction in Oak Ridge, and Hermes 2, an electricity-producing demonstration plant for the TVA grid under a Google fleet agreement totaling up to 500 MWe by 2035. A May 2026 NRC amendment extended Hermes 1's construction-completion deadline to April 2029 (Kairos still expects to finish building the test reactor in 2028); Hermes 2 broke ground April 17, 2026 and is targeted for first grid power around 2030. In August 2026 Kairos launched NuCAMP, a 12-month manufacturing and workforce partnership at Oak Ridge, and named former SpaceX launch-operations director Dr. Mike McGuire as VP of Operations and Site Delivery. On September 2, 2026 it appointed Ignacio Redondo, formerly SVP of Finance at Nextracker, as its first CFO. On September 4 it completed the first phase of its ETU 3 hardware demonstration - a reduced-scale Hermes 2 reactor-cavity mockup used to test modular precast shielding and remote handling. A September 10, 2026 company update said Engineering Test Unit 2 in Albuquerque comprises more than 30 factory-built skids whose module integration is underway, with hot argon testing next, and that Hermes 2 will use skids fabricated in Albuquerque and shipped to Oak Ridge. Kairos's careers page still lists 500+ employees, and a June 24, 2026 manufacturing update said the Albuquerque Pebble Development Lab had produced more than 60,000 annular surrogate fuel pebbles at about 950 per day for ETU 2 and other tests.
kairospower.comUpdated Sep 20, 2026
Analysis · 5 min read · Jul 16, 2026The long view on Kairos Power: strategy, technology and what to watch02
What's next5
2026-2027
Produce HALEU TRISO fuel for Hermes 1
Using DOE-allocated HALEU and Los Alamos National Laboratory's LEFFF capability to manufacture the first fuel pebbles needed for Hermes 1 startup and operation. As of late August 2026 Kairos has finished installing process equipment at LEFFF and is commissioning the pilot line with depleted uranium before introducing HALEU; no fuel pebbles for Hermes 1 have been reported produced yet. Company updates through September 10, 2026 (ETU 2 modular integration) did not announce a first HALEU pebble; the June 24 pebble campaign was surrogate (non-nuclear) fuel for ETU 2.
Later in 2026
Complete ETU 2 integration and hot argon testing
Finish module installation and piping/electrical connections on Engineering Test Unit 2's more than 30 factory-built skids in Albuquerque, then run hot argon testing (valves, inert gas, temperatures and pressures) before heating the Flibe salt system. Kairos described ETU 2 as the world's largest planned Flibe molten-salt test once operations start later in 2026, and said the modular path will feed Hermes 2 construction.
2026
Produce first HALEU TRISO pebble for Hermes 1 and file an operating-license application
TargetNeither reported as of Sep 29, 2026
2028-2029
Bring Hermes 1 online
Completing construction, fuel loading, and startup of the Hermes 1 low-power demonstration reactor in Oak Ridge to validate Kairos Power's reactor, fuel, and operating model. After a May 2026 permit amendment, Kairos expects to finish building Hermes 1 in 2028, with the NRC construction-completion deadline now set at April 30, 2029. ENR reported in late August 2026 that Barnard is installing 51 safety-related drilled piers for the Hermes 1 foundation after rehearsing the process on ETU 3.
2030
Deliver first Google-backed grid power
Advance Hermes 2 into operation as the first TVA-grid deployment under Kairos Power's Google agreement, proving the transition from demonstration to commercial power sales. Newly appointed VP of Operations and Site Delivery Mike McGuire (Aug 3, 2026) is tasked with taking the plant from construction through commissioning. ETU 3 Phase 1 (completed Sept 4, 2026) is feeding shielding and remote-maintenance lessons into the Hermes 2 cavity design, and a September 10 update said Hermes 2 will use factory-built skids fabricated in Albuquerque - the same modular path now being integrated on ETU 2.
03
Latest news4
Samsung C&T backs Kairos Hermes 2 with up to $100M
Kairos Power and Samsung C&T Engineering and Construction Group signed a binding term sheet on September 21 for Samsung C&T to provide up to $100 million in a mix of direct investment and in-kind engineering services, subject to regulatory approvals, to support the Hermes 2 plant in Oak Ridge, Tennessee. Samsung C&T will join Kairos's integrated EPC team, initially on power-generation systems and balance of plant, while Kairos leads the nuclear island. The cash-versus-services split was not disclosed. Untracked Samsung C&T is the counterparty.
www.kairospower.com www.world-nuclear-news.org www.kairospower.com
Kairos Power names Ignacio Redondo as first CFO
Kairos Power appointed Ignacio Redondo as its first Chief Financial Officer, the advanced nuclear reactor developer announced September 2, 2026. Redondo, most recently senior vice president of finance at solar-tracker maker Nextracker, will lead corporate fundraising, investor relations, financial reporting and compliance as Kairos scales toward serial production of its salt-cooled Hermes reactors in Oak Ridge, Tennessee.
Kairos Power launches NuCAMP nuclear manufacturing initiative
Kairos Power launched NuCAMP on August 18, 2026, a 12-month collaboration at its Oak Ridge Reactor Demonstration Campus aimed at advancing nuclear construction and manufacturing methods and training the workforce to build them at scale. Partners include Oak Ridge National Laboratory, the University of Tennessee-Knoxville, the Institute for Advanced Composites Manufacturing Innovation, Barnard Construction and two community colleges, with Samsung C&T and Cambridge Vacuum Engineering advising.
Kairos Power validates first molten-salt reactor fuel code
Kairos Power completed verification and validation of KP-BISON, the first fuel performance code built for a molten-salt reactor, on July 16, 2026. The code models how TRISO fuel particles behave and hold structural integrity at the high temperatures inside Kairos's fluoride salt-cooled reactor design, and the company plans to submit the reports to the NRC as part of the licensing basis for its Hermes 2 demonstration plant.
04
Products3
- In Development
Hermes 2
Commercial-scale demonstration plant that extends the Hermes learning loop into electricity production for the TVA grid and Google-backed demand.
In DevelopmentKP-FHR (Commercial)
Kairos Power's modular commercial reactor platform for grid, data center, and industrial users, designed around paired 75 MWe units that scale into larger multi-unit plants.
05
Key metrics
- Employees
- 500+
- Hermes 2 Status
- Ground broken Apr
17, 2026; ops targeted 2030; ETU 2 modular skid integration underway Sept 10, 2026; ETU 3 Phase 1 cavity mockup completed Sept 4, 2026
- Future TRISO Fuel Supply
First customer for BWXT's $500M Wyoming TRISO plant; phased build - groundbreaking 2028, startup 2030, full production 2031
- Leadership
- CEO Mike Laufer
first CFO Ignacio Redondo (appointed Sept 2, 2026); VP Operations & Site Delivery Mike McGuire (Aug 3, 2026)
- Surrogate Fuel Pebbles
60,000+ annular surrogate pebbles produced in Albuquerque at ~950/day (June 24, 2026)
- Samsung C&T Hermes 2 package
- Binding term sheet up to $100 million
(direct investment plus in-kind engineering), subject to approvals (Sept 21)
- Hermes 1 HALEU pebble / operating license
- No first HALEU TRISO pebble reported
no OLA filed as of Sep 29, 2026
- Samsung C&T cash versus in-kind split
Kairos-stated $70M equity of up to $100M mix; Samsung-stated about $70M investment; not closed
- Hermes 1 HALEU pebble / operating license
- No first HALEU TRISO pebble reported
no OLA filed as of Oct 4, 2026
- Samsung C&T Hermes 2 package
Binding term sheet still up to $100 million mixed investment and in-kind, subject to approvals, not reported closed
- ETU 2 modular integration
Final plant-equipment skid installed as of the Oct 1 newsletter; hot argon testing still later in 2026
- Hermes 1 HALEU pebble / operating license
- No first HALEU TRISO pebble reported
no OLA filed as of Oct 4, 2026 deep audit
06
Operations & revenue
Operating status
Pre-revenue
Development-stage nuclear developer. Hermes 1 remains under safety-related construction with a 2028 build-finish target and an April 30, 2029 NRC construction-completion deadline. Hermes 2 is under construction after the April 17, 2026 groundbreaking, with first TVA/Google grid power targeted around 2030. The 1 October Path to Deployment newsletter says the team installed the final ETU 2 plant-equipment skid, still describes pebble output as the 60,000th surrogate annular graphite pebble, and restates the Samsung C&T package as up to $100 million in mixed direct investment and in-kind engineering, subject to regulatory approvals. It does not report a first HALEU TRISO pebble, an operating-license application, or a closed Samsung investment. NRC Hermes and Hermes 2 pages last reviewed 15 September 2026 still cover construction permits only. Samsung C&T's 22 September newsroom still says it is pursuing about $70 million and claims US commercial-reactor EPC priority, which Kairos's own release does not say. Careers copy still lists 500-plus employees. Wikipedia still lists a $630 million DOE TIA versus the company $303 million ARDP figure and still says as of February 2026 Kairos is preparing an OLA. The Tennessee FAQ still says Hermes 2 construction is set to begin soon despite the April groundbreaking. The Sept 16 40,000-pebble URL still 404s.
Pipeline & contracts
DOE Milestone Contract Support
Performance-based ARDP support of up to $303M for the design, construction, and commissioning of Hermes and related risk-reduction work.
Future Power Purchase Agreements
Kairos plans to sell energy, ancillary services, and environmental attributes under PPAs tied to its Google agreement to develop, build, and operate up to 500 MW of advanced reactors by 2035 (first plant online around 2030), beginning with Hermes 2 delivering up to 50 MW to the TVA grid.
07
Timeline28
2026
Receives NEI Groundbreaker Award at NECX Dallas
Kairos said in its 1 October Path to Deployment newsletter that it received the Nuclear Energy Institute Groundbreaker Award at the Nuclear Energy Conference and Expo in Dallas in September 2026, an industry recognition for progress toward commercial deployment of advanced nuclear technologies. It is an award, not a licensing or construction milestone.
Path to Deployment newsletter recaps Samsung term sheet and ETU 2 final skid
On October 1, 2026 Kairos published a quarterly update saying the team installed the final plant-equipment skid on non-nuclear ETU 2, restating the Samsung C&T package as up to $100 million in mixed direct investment and in-kind engineering subject to regulatory approvals, and describing pebble output as the 60,000th surrogate annular graphite fuel pebble. It does not report a first HALEU TRISO pebble from LEFFF, an operating-license application, or a closed Samsung investment.
Samsung C&T signs up to $100M Hermes 2 term sheet
On September 21, 2026 Kairos Power and Samsung C&T Engineering and Construction Group signed a binding term sheet for Samsung C&T to provide up to $100 million through a mix of direct investment and in-kind engineering services, subject to regulatory approvals, to support Hermes 2 in Oak Ridge. Samsung C&T will join Kairos's integrated EPC team, initially on power-generation systems and balance of plant, while Kairos leads the nuclear island. The cash-versus-services split was not disclosed.
ETU 2 modular skid integration underway for Hermes 2
On September 10, 2026 Kairos published a detailed update on Engineering Test Unit 2 at its Albuquerque Manufacturing Development Campus: more than 30 truck- or rail-shippable skids grouping reactor functions (including a dedicated chemistry-control skid and a Flibe inventory-management system with recirculation), with most hardware made in-house, including the ASME U-stamped reactor vessel. Module installation and piping/electrical integration inside the ETU 2 enclosure is underway, followed by hot argon testing before heating the salt system. Lessons from ETU 2 are intended to flow into Hermes 2, which will use skids fabricated in Albuquerque and shipped to Oak Ridge.
Albuquerque lab produces 60,000+ surrogate fuel pebbles
On June 24, 2026 Kairos said its Pebble Development Lab in Albuquerque had manufactured more than 60,000 annular surrogate fuel pebbles on an automated line at about 950 pebbles per day - more than three times the earlier manual rate - for ETU 2 (the world's largest planned Flibe molten-salt test) plus other campaigns in Alameda and Oak Ridge. Each pebble is laser-marked for tracking. The company is already designing a fourth-generation production system aimed at commercial fuel-supply scale.
ETU 3 Phase 1 hardware demonstration completed
On September 4, 2026 Kairos completed the first phase of its Engineering Test Unit 3 demonstration in Oak Ridge: a reduced-scale mockup of the Hermes 2 reactor cavity with 12 modular precast wall elements (four joint designs) used to test radiation-shielding seams and remote robotic maintenance. ORNL's Manufacturing Demonstration Facility 3D-printed the polymer composite forms; Tindall Corporation cast the panels in South Carolina; Barnard Construction installed them. CTO Ed Blandford said the work is meant to standardize shielding interfaces and online maintenance for the commercial KP-FHR fleet.
Ignacio Redondo appointed as first CFO
On September 2, 2026 Kairos named Ignacio (Nacho) Redondo, formerly Senior Vice President of Finance at Nextracker, as its first Chief Financial Officer. Based in Alameda, he will oversee fundraising, investor relations, cost accounting, reporting, and compliance as the company scales from demonstration hardware toward a Google-backed commercial fleet.
Mike McGuire named VP of Operations and Site Delivery
On August 3, 2026 Kairos appointed Dr. Mike McGuire, most recently Senior Director of Launch and Recovery Operations at SpaceX after a 25-year U.S. Army Special Operations career, as Vice President, Operations and Site Delivery. He will lead Hermes 2 delivery from construction through commissioning and startup and oversee multi-site operations across Albuquerque, Oak Ridge, and future commercial deployments.
2026
BWXT details Wyoming TRISO plant construction timeline
In July 2026 BWXT confirms its Pronghorn Industrial Park site near Gillette, Wyoming for the proposed $500M TRISO fuel plant for which Kairos Power is the first named customer, and lays out a phased schedule: finish permitting in 2027, break ground in 2028, start up the facility in 2030, and reach full commercial TRISO production in 2031. This adds a long-term domestic fuel-supply option for the Hermes program beyond the Los Alamos-based pebbles used for Hermes 1.
NuCAMP nuclear manufacturing and workforce partnership launches
On August 18, 2026 Kairos Power launches the Nuclear Center for Advanced Manufacturing and Precast (NuCAMP), a 12-month collaboration at its Oak Ridge Reactor Demonstration Campus to advance nuclear manufacturing and construction methods (precast concrete, large-format and wire-arc additive manufacturing, electron beam welding) and to train workers for the buildout. Partners include Oak Ridge National Laboratory, the University of Tennessee-Knoxville's Tickle College of Engineering, the Institute for Advanced Composites Manufacturing Innovation, Barnard Construction, and two community colleges, with Samsung C&T Engineering & Construction Group and Cambridge Vacuum Engineering advising; the program also proposes two new master's degree tracks plus welder, production-technician, and K-12 training pathways.
KP-BISON fuel performance code verified and validated
On July 16, 2026 Kairos Power completes verification and validation of KP-BISON, its fuel performance code modeling how TRISO fuel particles behave and retain integrity in a high-temperature, salt-cooled reactor. The team validated the code against real-world AGR-2 irradiation experiment data from DOE's Advanced Gas Reactor program using the same UCO fuel specification as Kairos's fuel. Co-founder and CTO Ed Blandford called it the first set of TRISO safety codes to reach this milestone in the U.S., and the first ever for a salt-cooled reactor application; Kairos will use the resulting reports to support its NRC fuel safety case for future reactor licensing.
Alameda manufacturing facility earns ISO 9001:2015 certification
On June 3, 2026 Kairos Power announced that its Alameda, California manufacturing facility passed an ISO 9001:2015 quality-management audit with zero findings, becoming the company's second ISO-certified site alongside its Manufacturing Development Campus in Albuquerque. The certification formalizes standardized quality processes as Kairos scales toward serial reactor-hardware production for Hermes and the Google-backed fleet.
NRC extends Hermes 1 construction deadline to 2029
The NRC approves Kairos Power's request to extend the latest date for completing Hermes 1 construction by 28 months, from December 31, 2026 to April 30, 2029. Kairos cited first-of-a-kind site-prep and design work - including removing legacy structures from the test-reactor footprint in coordination with the DOE - and now expects to finish building the Hermes test reactor in 2028.
ET-10 graphite qualified for Hermes reactor components
Kairos Power and supplier Ibiden Co., Ltd. complete a three-year qualification program for ET-10 graphite, machining and destructively testing roughly 3,000 specimens to the ASME Section III, Division 5 (HHA-III-4100) standard for reflector blocks and internal structural components used across the Hermes reactor series - reportedly the first graphite grade qualified under that code for high-temperature reactor components.
BWXT names Kairos first customer for planned Wyoming TRISO fuel plant
BWXT discloses Kairos Power as the first customer and partner for its proposed $500M TRISO fuel fabrication facility at Pronghorn Industrial Park near Gillette, Wyoming, backed by a $100M Wyoming state grant and targeting full production by 2031. The plant would manufacture fresh TRISO fuel only (no waste handling) and builds on the companies' September 2025 TRISO manufacturing collaboration, adding a long-term domestic fuel-supply option beyond the Los Alamos-based pebbles used for Hermes 1.
Kairos breaks ground on the Hermes 2 demonstration plant in Oak Ridge, the first deployment under its Google-backed advanced reactor fleet plan.
ORNL signs five-year, $27M strategic partnership
On February 19, 2026, Oak Ridge National Laboratory and Kairos Power announce a five-year, $27M partnership - the fourth ORNL-Kairos collaboration since 2020. ORNL will test and evaluate reactor technology, manufacture components, and assess TRISO pebble fuel performance under operating-relevant conditions, reinforcing the fuel and materials science underpinning the Hermes program.
Finalizes a DOE contract for HALEU to support Hermes 1 startup and operation, clearing a key fuel-supply milestone for the demonstration reactor.
2025
ETU 3.0 reactor vessel installed in Oak Ridge
In July 2025 Kairos installs the 14-foot-tall reactor vessel for its third Engineering Test Unit (ETU 3.0) on its Oak Ridge campus, adjacent to the Hermes sites. The vessel was fabricated in the UK with Cambridge Vacuum Engineering and the University of Sheffield's Advanced Manufacturing Research Centre using electron-beam welding, and the ETU 3.0 building - a test bed for streamlined nuclear construction methods - is being erected around it, with construction targeted for completion in summer 2026.
In August 2025, Kairos, Google, and TVA announce a power purchase agreement under which Hermes 2 will deliver up to 50 MW to the TVA grid as the first deployment under the broader Google order book.
Begins nuclear safety-related construction on Hermes 1 in Oak Ridge, moving beyond site prep into the licensed reactor build phase.
2024
Secures NRC construction permits for the Hermes 2 commercial-scale demonstration plant, making it the first electricity-producing Gen IV reactor project permitted in the U.S.
Signs a master plant development agreement with Google to develop, construct, and operate a U.S. fleet of advanced reactor projects totaling up to 500 MW by 2035.
Starts excavation and groundwork for the Hermes low-power demonstration reactor at the East Tennessee Technology Park in Oak Ridge.
2023
2021
Engineering Test Unit program begins
Launches its iterative Engineering Test Unit (ETU) program - full-scale, electrically heated, non-nuclear prototypes of the Hermes reactor used to validate salt-coolant technology, integration, and construction methods. ETU 1.0 went on to log more than 2,000 hours of pumped-salt operations and produced the company's first high-purity FLiBe coolant.
2020
2016
08
Funding
$303Mdisclosed across 1 round with a stated amount
