Quoted exactly and dated only as precisely as the source. Copies of one release count as one origin. A withdrawn statement stays visible and is labelled.
4 August 2023 · Permissions · Whole project
Application submitted
Construction permit application, two-unit Hermes 2 facility
Regulator issued U.S. Nuclear Regulatory Commission (Federal Register) · Authority: U.S. Nuclear Regulatory Commission · Jurisdiction: United States (federal)
“The U.S. Nuclear Regulatory Commission (NRC) is providing public notice of receipt and availability of an application for construction permits for a two-unit reactor facility from Kairos Power, LLC. The application for the construction permits was received on July 14, 2023.”
Source: U.S. Nuclear Regulatory Commission (Federal Register) ↗ · Open in the ledger · What this does and does not establish · source read 11 November 2026
15 September 2023 · Permissions · Whole project
Application accepted for review
Construction permit application accepted for docketing (Docket Nos. 50-611 and 50-612)
Regulator issued U.S. Nuclear Regulatory Commission (Federal Register) · Authority: U.S. Nuclear Regulatory Commission · Jurisdiction: United States (federal)
“The U.S. Nuclear Regulatory Commission (NRC) staff accepts and dockets an application for a construction permit for the Hermes 2 test reactor facility to be built in Oak Ridge, Tennessee. DATES: This action becomes effective on September 11, 2023.”
Source: U.S. Nuclear Regulatory Commission (Federal Register) ↗ · Open in the ledger · What this does and does not establish · source read 11 November 2026
15 September 2023 · Technical milestones · Whole project
Design disclosed
Hermes 2 design as described in the NRC docketing notice (original two-unit design)
Regulator issued U.S. Nuclear Regulatory Commission (Federal Register)
“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.”
Source: U.S. Nuclear Regulatory Commission (Federal Register) ↗ · Open in the ledger · What this does and does not establish · source read 11 November 2026
10 January 2024 · Technical milestones · Whole project
Testing reported
Non-nuclear Engineering Test Unit (ETU), same KP-FHR technology, Albuquerque; not Hermes 2 hardware
Company reported Kairos Power
“Kairos Power has successfully completed 1,000 hours of pumped salt operations with its non-nuclear Engineering Testing Unit (ETU) at the company’s testing and manufacturing facility in Albuquerque, N.M.”
Source: Kairos Power ↗ · Open in the ledger · What this does and does not establish · source read 11 November 2026
14 October 2024 · Customer / offtake · Whole project
Agreement signed
Google–Kairos Master Plant Development Agreement for a 500 MW fleet by 2035 (this release does not name Hermes 2; later releases call Hermes 2 its first deployment)
Joint release Kairos Power · Counterparty: Google · Bindingness not stated
“Kairos Power and Google have signed a Master Plant Development Agreement, creating a path to deploy a U.S. fleet of advanced nuclear power projects totaling 500 MW by 2035.”
Source: Kairos Power ↗ · Open in the ledger · What this does and does not establish · source read 11 November 2026
29 November 2024 · Permissions · Whole project
Permission issued
Construction permits CPTR-7 and CPTR-8, two units of the Hermes 2 test reactor facility (not an operating licence)
Regulator issued U.S. Nuclear Regulatory Commission (Federal Register) · Authority: U.S. Nuclear Regulatory Commission · Jurisdiction: United States (federal)
“The U.S. Nuclear Regulatory Commission (NRC) is providing notice of the issuance of Construction Permits CPTR-7 and CPTR-8 to Kairos Power LLC (Kairos) for the two units of the proposed Hermes 2 test reactor facility. DATES: The Construction Permits CPTR-7 and CPTR-8 were issued on November 21, 2024.”
Source: U.S. Nuclear Regulatory Commission (Federal Register) ↗ · Open in the ledger · What this does and does not establish · source read 11 November 2026
2025 · Customer / offtake · Whole project
Agreement signed
TVA's annual report statement of the Hermes 2 PPA
Customer statement Tennessee Valley Authority (annual report, Form 10-K, FY2025) · Counterparty: Tennessee Valley Authority (TVA) · Bindingness not stated
“In 2025, TVA signed a PPA to purchase up to 50 MW of electricity from the Kairos Power Hermes 2 Plant in Oak Ridge, Tennessee.”
Source: Tennessee Valley Authority (annual report, Form 10-K, FY2025) ↗ · Open in the ledger · What this does and does not establish · source read 11 November 2026
Target stated 25 July 2023 · Construction · Whole project
Target: construction, July 2025
Original schedule in the 2023 construction permit application (earliest construction start; first unit completion July–December 2027)
Secondary report World Nuclear News
“According to the application, the earliest start date for construction of Hermes 2 is expected to be July 2025 with the first unit projected to be completed by July 2027 at the earliest and December 2027 at the latest.”
Source: World Nuclear News ↗ · Open in the ledger · What this does and does not establish · source read 11 November 2026
18 August 2025 · Customer / offtake · Whole project
Agreement signed
Power purchase agreement, Kairos Power and TVA, Hermes 2 output (Google receives the clean energy attributes)
Joint release Kairos Power · Counterparty: Tennessee Valley Authority (TVA) · Bindingness not stated
“Through a new power purchase agreement (PPA) between Kairos Power and TVA, Kairos Power’s Hermes 2 Plant in Oak Ridge, Tenn., will deliver up to 50 megawatts (MW) of reliable, 24/7 energy to the TVA grid that powers Google data centers in Tennessee and Alabama.”
Source: Kairos Power ↗ · Open in the ledger · What this does and does not establish · source read 11 November 2026
18 August 2025 · Customer / offtake · Whole project
Agreement signed
Google's account of the Hermes 2 PPA between Kairos Power and TVA
Customer statement Google (blog) · Counterparty: Tennessee Valley Authority (TVA); Google · Bindingness not stated
“Today we announced the first deployment of Kairos Power’s advanced nuclear reactor — the Hermes 2 Plant in Oak Ridge, Tennessee — through a new power purchase agreement (PPA) between Kairos Power and Tennessee Valley Authority (TVA).”
Source: Google (blog) ↗ · Open in the ledger · What this does and does not establish · source read 11 November 2026
21 October 2025 · Technical milestones · Whole project
Design disclosed
Redesign: one 50 MWe reactor in place of the original two-unit plant
Company reported Kairos Power (newsletter)
“To accelerate our mission, we are enlarging Hermes 2 to a 50 MWe plant powered by a single commercial-scale reactor – a step change in scale from the smaller 14 MWe reactors envisioned in the original dual-unit plant concept.”
Source: Kairos Power (newsletter) ↗ · Open in the ledger · What this does and does not establish · source read 11 November 2026
23 May 2026 · Construction · Whole project
Site work
DOE account of the Hermes 2 groundbreaking (separate from Hermes 1 nuclear construction)
Government record U.S. Department of Energy, Office of Nuclear Energy
“Kairos Power initiated nuclear construction on their Hermes test reactor in May 2025 and broke ground on their Hermes 2 reactor in April 2026.”
Source: U.S. Department of Energy, Office of Nuclear Energy ↗ · Open in the ledger · What this does and does not establish · source read 11 November 2026
17 April 2026 · Construction · Whole project
Site work
Groundbreaking on Hermes 2 (Kairos calls it the start of construction; nuclear safety-related construction not reported)
Company reported Kairos Power
“Today, Kairos Power broke ground on the Hermes 2 Demonstration Plant in Oak Ridge, Tenn. – the company’s first commercial-scale reactor and the first-ever power-producing Gen IV reactor to receive a construction permit from the Nuclear Regulatory Commission (NRC).”
Source: Kairos Power ↗ · Open in the ledger · What this does and does not establish · source read 11 November 2026
21 September 2026 · Financing · Whole project
Conditional
Samsung C&T strategic investment in Kairos Power (company level), binding term sheet, subject to regulatory approvals; stated purpose is Hermes 2 delivery
Joint release Kairos Power · Counterparty: Samsung C&T Engineering & Construction Group · Other instrument · Up to USD 100m
“Samsung C&T has agreed to provide up to $100 million through a combination of direct investment and in-kind engineering services, subject to regulatory approvals, to enable the successful delivery of the Hermes 2 Demonstration Plant in Oak Ridge, Tennessee.”
Source: Kairos Power ↗ · Open in the ledger · What this does and does not establish · source read 11 November 2026
Target stated 18 August 2025 · Operational delivery · Whole project
Target: commercial operation, 2030
Start of operations of the redesigned single-reactor Hermes 2 (stated as 'begin operations')
Joint release Kairos Power
“To accelerate the delivery of clean energy to Google, Kairos Power will increase Hermes 2’s output from 28 MW to 50 MW generated by a single reactor, scheduled to begin operations in 2030.”
Source: Kairos Power ↗ · Open in the ledger · What this does and does not establish · source read 11 November 2026
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