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State

Design disclosed

A disclosed design is not a tested one.

Open question

What has the technology itself been shown to do, at what scale and under what conditions?

  • Not established in reviewed sources: Any test or operation of a Hermes 2 reactor itself (no reactor has operated at this site yet)
  • Not established in reviewed sources: NRC review or approval of the single-reactor, 50 MWe redesign
  1. Current stateDesign disclosed21 October 2025 · Company reported · Kairos Power (newsletter)

    Before: Not established in reviewed sources. Source: Kairos Power (newsletter) ↗

  2. Earlier statementTesting reported10 January 2024 · Company reported · Kairos Power

    Before: Not established in reviewed sources. Source: Kairos Power ↗

  3. Earlier statementDesign disclosed15 September 2023 · Regulator issued · U.S. Nuclear Regulatory Commission (Federal Register)

    Before: Not established in reviewed sources. Source: U.S. Nuclear Regulatory Commission (Federal Register) ↗

Evidence detail

Design disclosed

Hermes 2 design as described in the NRC docketing notice (original two-unit design)

A disclosed design is not a tested one.

“The Hermes 2 facility would contain two fluoride-salt cooled, high- temperature reactors that use solid tri-structural isotropic fuel in pebble form, intermediate liquid-sodium loops, and a common power conversion unit.”
Attribution
Regulator issued
Publisher
U.S. Nuclear Regulatory Commission (Federal Register)
Dated
15 September 2023
First public disclosure
15 September 2023
State before
Not established in reviewed sources
Source read
11 November 2026

Inspect primary source: U.S. Nuclear Regulatory Commission (Federal Register) ↗

What this does and does not establish

An exact passage match shows the source says this. It does not prove the underlying claim is true.

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