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Kairos Hermes 2 Demonstration Plant

Oak Ridge, Tennessee, United StatesUnder construction
Evidence
Headline capacity
Not established in published records
Updated
Oct 28, 2026
Utility
Tennessee Valley Authority

On September 21, 2026, Kairos Power announced a binding term sheet with Samsung C&T for up to $100 million in direct investment and in-kind engineering support, subject to approvals, and integrated engineering, procurement and construction collaboration for Hermes 2. The announcement is not evidence that the full amount has closed or been paid in cash; it is the same transaction cross-referenced by the Oak Ridge parent campus. First Google-linked power-producing Kairos deployment, now described as one 50-MWe reactor targeting 2030 operation. Kairos Hermes 2 Demonstration Plant is in Oak Ridge, TN, US and is a generation site with under construction status.

Program relationships

Google–Kairos Advanced Nuclear Orderbook · Program

Capacity

Operating IT capacity: Not established in published records

A missing figure does not mean zero. Planned, utility and generation figures are not operating IT capacity.

Development

Original two-unit 28-MWe configurationChanged or cancelled

2 buildings

NRC construction permits covered two 14-MWe units; public licensing reconciliation with the current design remains open.

Revised single-reactor 50-MWe plantUnder construction

1 building

Current company design targeting 2030 operation.

Milestones (4)
NRC issues two original Hermes 2 construction permits

Nov 21, 2024 · Recorded actual event

Completed · Permit approved

Source not linked
TVA PPA and single-reactor 50-MWe redesign announced

Aug 18, 2025 · Recorded actual event

Completed · Status changed

Source not linked
Hermes 2 groundbreaking ceremony

Apr 17, 2026 · Recorded actual event

Completed · Construction started

Source not linked
Target year for electricity delivery

2030 · Forecast / planned record

Forecast · Event type not stated

Source not linked

Participants

Google

Customer

Sources by role
Customer (1)
Customer (1)
Kairos Power LLC

Developer

Sources by role
Developer (1)
Developer (1)
Other participants (2)
Tennessee Valley Authority

Utility provider

Sources by role
Utility provider (1)
Utility provider (1)
U.S. Nuclear Regulatory Commission

Government authority

Sources by role
Government authority (1)
Government authority (1)

Technical specifications

Grid delivery structure

Source report

TVA grid injection with Google clean energy attributes

Source

Additional project facts

Current output

Source report

50 MWe

Source

Current unit count

Design

1 reactor

Source

Operations target

Forecast

2030

Source

PPA status

Source report

Binding PPA between Kairos Power and TVA

Source

Groundbreaking date

Actual

2026-04-17

Source

Infrastructure & permits

Technical details (2)
Electric grid

Under construction

50 MWe

Single current reactor design; generation output.

Utility service

Secured or contracted

50 MW

TVA buys plant output; Google receives clean-energy attributes.

Permit · Status not stated

Hermes 2 CPTR-7 / CPTR-8

U.S. Nuclear Regulatory Commission

Nov 21, 2024

Sources (2)

Public-source research. Plans may change. See Evidence for sources and qualifications.

Related projects (3)
Kairos Oak Ridge Reactor Demonstration Campus

Under construction · Oak Ridge, Tennessee, United States

Same locality: Oak Ridge · Shared participant: Kairos Power LLC

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Google Montgomery County Data Center

Operating · Clarksville, Tennessee, United States

Shared participant: Google · Shared participant: Tennessee Valley Authority · Same market: Tennessee, United States

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xAI Colossus 1

Operational · Southwest Memphis, Shelby County, Tennessee, United States

Shared participant: Tennessee Valley Authority · Same market: Tennessee, United States

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