Our work in Heritage Center
Kairos Power is building the Hermes reactor series at the former East Tennessee Technology Park in Oak Ridge. Here, we are piloting advanced construction techniques and gaining operational experience to support further optimization and cost reduction for our commercial fleet. The project will build on the region’s distinguished nuclear legacy while taking a major step toward validating KP-FHR technology and commercial deployment.
Site facilities
Hermes
Demonstration Reactor
Hermes 2
Demonstration Plant
Engineering Test Unit 3
Modular Systems
Learning through iterative development
At Kairos Power's Oak Ridge campus, the Hermes demonstration reactor series will advance our iterative development approach, providing an accelerated, milestone-driven path to commercial deployment. We design, build, test, and learn with full-scale hardware demonstrations to gain real-world data and operating experience to inform our commercial design.
Hermes 1 is the first non-water-cooled reactor approved for construction in the U.S. in more than 50 years. It will pave the way for Hermes 2–our first commercial-scale plant, enabling the delivery of clean electricity to the TVA grid.
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Frequently asked questions
Growing from a broad research effort at U.S. universities and national laboratories and now employing more than 500 team members nationwide, Kairos Power was founded to accelerate the development of a clean, safe advanced reactor technology that has the potential to transform the energy landscape in the United States and around the world.
In order to achieve the scale of cost reductions necessary to make advanced reactors competitive with fossil fuels, Kairos Power is singularly focused on the development of a safe and affordable source of energy that will be able to scale to meet the increasing need for dispatchable clean energy. Through our iterative approach, we rapidly apply insights from engineering, manufacturing, and testing to demonstrate our advanced reactor technology works and can be delivered at target cost.
Kairos Power started nuclear construction of the Hermes Demonstration Reactor in Oak Ridge in May 2025. The construction and operation of Hermes is a key step on our path to commercializing our fluoride salt-cooled high-temperature reactor (KP-FHR) technology.
The Hermes 2 Demonstration Plant will be co-located with Hermes at our Oak Ridge campus, building on lessons learned from the first Hermes reactor to demonstrate KP-FHR technology at a larger scale and supply clean, reliable electricity to the grid.
Both Hermes and Hermes 2 have been approved for construction by the U.S. Nuclear Regulatory Commission, with Hermes being the first non-water-cooled reactor in more than 50 years to receive this permit.
The location of Oak Ridge, Tennessee, was chosen based on the unique combination of regional workforce capabilities, proximity to highly capable local collaborators, such as Oak Ridge National Laboratory, the University of Tennessee, and the Tennessee Valley Authority, and the infrastructure and characterization data available for the selected site.
Tennessee has historically played an important role in nuclear technology development, and Kairos Power looks forward to building on this legacy to enable the next generation of clean, safe, and affordable advanced reactors for the U.S. energy markets and around the world. Aligned with our mission to improve people's quality of life while protecting the environment, Kairos Power is committed to protecting the health and safety of everyone who works in, visits, or lives near our Oak Ridge facilities.
The Hermes demonstration reactor series will be built at Heritage Center in the East Tennessee Technology Park. Previously home to the K-33 gaseous diffusion enrichment plant, the site was remediated in a historic cleanup effort by the U.S. Department of Energy and returned to the Oak Ridge community for economic investment. Kairos Power acquired the land and announced plans to build there in 2021.
Our Hermes Demonstration Reactor broke ground in July 2024 and started nuclear construction in May 2025. Construction of the Hermes 2 Demonstration Plant is set to begin soon, with both facilities expected to be operational before the end of the decade.
Kairos Power will be the owner and operator of both the Hermes Demonstration Reactor and the Hermes 2 Demonstration Plant.
Kairos Power is responsible for all costs associated with the construction, operation, and future decommissioning of both Hermes and Hermes 2. To date, Kairos Power has been nearly exclusively funded through private investment.
In December 2020, Kairos Power was selected by the U.S. Department of Energy to receive an investment of up to $303 million from the Advanced Reactor Demonstration Program to support Hermes' construction and commissioning. Part of this funding will go to support work at Oak Ridge National Laboratory that will enable the Hermes project.
Our outstanding safety record is the result of a concerted team effort by everyone in the company. From the rigorous protocols we employ in our testing and manufacturing facilities to the passive safety of our advanced reactor technology—Kairos Power’s commitment to safety is visible in every aspect of our operations. We believe there is no higher priority than protecting the health and safety of our employees and the communities in which we operate.
