A Demonstration Plant for the TVA Grid: Kairos Power Breaks Ground on Hermes 2

On April 17, 2026, Kairos Power said in a release on its own pages that it had broken ground on the Hermes 2 Demonstration Plant in Oak Ridge, Tennessee. The company calls Hermes 2 "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)." Parts of the release follow, not the whole. The quotations it gives from the people who spoke at the event are not reported here, and the other company and the contractor it names are not named.

What the Plant Will Supply

The plant, in the company's words, "will supply up to 50 megawatts of clean electricity to the Tennessee Valley Authority (TVA) grid," helping, in the release's words, "to decarbonize" the data centers of another company in Tennessee and Alabama. The release calls Hermes 2 the company's first deployment under a deal with that company "to develop an advanced reactor fleet."

Hermes 2, the release says, "will build on lessons learned from the Hermes Low-Power Demonstration Reactor (Hermes 1), which commenced nuclear construction at the same site last year." The company calls Hermes 1 "currently the only Gen IV reactor under active nuclear construction in the U.S." And as "the immediate precursor to Kairos Power's full-scale commercial plants," the release says, Hermes 2 "will further advance technology, licensing, supply chain, and construction certainty for the company's future deployments."

The supply is given as a ceiling, and the release puts no date on it. When power first reaches the TVA grid is the question it leaves open for a lender.

Plans for Modules

The company "will fabricate Hermes 2 reactor equipment modules at its Manufacturing Development Campus in Albuquerque, N.M., and ship them to Oak Ridge for assembly." The civil structure "will leverage modular construction methods, incorporating precast concrete and a seismically isolated foundation." The construction methods piloted with the Hermes series "are expected to shrink project timelines, lower nuclear construction costs, and enable a standardized, repeatable design." A construction company is the general contractor for both Hermes reactor projects.

The Site at Oak Ridge

At the event, the release says, guests "observed foundation work now in progress for Hermes 1" and saw the supporting infrastructure the company has built "to enable testing and construction activities that will help drive down costs for the fleet."

Hermes 2 "will be built on the footprint of the former Oak Ridge Gaseous Diffusion Plant at the K-33 site," which, the release says, the U.S. Department of Energy "reclaimed through a historic cleanup effort and returned to the community for economic development." Kairos Power acquired the land in 2021, along with the adjacent K-31 site, for its reactor demonstration campus.