Kairos Power Breaks Ground on Hermes 2 Demonstration Plant
KP-FHR groundbreaking at Oak Ridge TN, up to 50MW to TVA grid, first Gen IV non-LWR NRC construction permit, first deployment under Google agreement, targeting 2030 operations
Kairos Power Breaks Ground on Hermes 2 Demonstration Plant
Abstract
Kairos Power broke ground on Hermes 2 in Oak Ridge, Tennessee on April 17, 2026 — its first commercial-scale, power-producing reactor and the first Gen IV (non-light-water) reactor design to receive an NRC construction permit.
Key Contributions / Findings
- Reactor technology: KP-FHR — fluoride-salt-cooled, high-temperature reactor, using TRISO-coated-particle fuel and Flibe molten fluoride-salt coolant.
- Capacity: up to 50 MW of electricity to the Tennessee Valley Authority (TVA) grid.
- Google partnership: Hermes 2 is the first deployment under Kairos's 2024 agreement with Google to develop an advanced-reactor fleet — power is intended to help decarbonize Google datacenters in Tennessee and Alabama.
- Manufacturing model: reactor modules are factory-built in Albuquerque, NM, then shipped to Oak Ridge for on-site assembly — the SMR "factory-built" thesis in physical practice, not just marketing.
- Timeline: targeting first power by 2030. Hermes 1 (a lower-power, non-power-producing demonstration unit) is under construction at the same Oak Ridge site and directly informs Hermes 2's design.
Why It Matters (lens: energy — SMR pipeline)
Directly fills the flagged knowledge gap ("Kairos Power KP-FHR — technical details and Hermes 2 construction timeline less documented than Natrium/Xe-100"). Hermes 2 is the physical, groundbreaking-stage evidence behind the Google-Kairos PPA already in the KB (hyperscaler-nuclear-procurement.md, Aug-2025 "first corporate SMR PPA, 50MW by 2030 → 500MW"). The company's own site now supplies the construction-permit precedent (first Gen IV non-LWR permit), the fuel/coolant chemistry, and the factory-to-site assembly model that the earlier PPA-only source lacked.
Limitations
- No cost/capex figures disclosed on the company update; NRC permit terms and full regulatory timeline require a separate Federal Register / NRC docket pull for exact dates.
Source: Kairos Power Breaks Ground on Hermes 2 Demonstration Plant — Kairos Power, April 17, 2026.