Kairos breaks ground for first 4th-gen nuclear reactor in US to power Google data centers

Kairos Power, a maker of small modular reactors (SMRs), has broken ground on its second nuclear reactor, Hermes 2, in Oak Ridge, Tennessee. This is the first fourth-generation nuclear reactor that will demonstrate power production in the US.

With a focus on meeting energy demands while reducing carbon emissions, countries are once again considering nuclear power. Interesting Engineering has previously reported how China is building a large number of nuclear power plants.

However, the US is taking a different approach by switching to small modular reactors (SMRs), which are easier to build and have a lower risk profile.

Almeda, California-headquartered Kairos Power is among many nuclear energy startups that are building SMRs. The technology is preferred, since the nuclear plant components are modular, can be built at scale and the plant is designed to shut down in case of an accident. Kairos’ first SMR, Hermes-1, is also built in Oak Ridge, Tennessee.

What is Hermes?

Kairos built Hermes-1, a low-power demonstration reactor, a scaled-down version of its fluoride salt-cooled high-temperature reactor technology. This is the first non-light-water reactor approved by the US Nuclear Regulatory Commission (US NRC).

Hermes-1 is not built to produce electricity, which is a crucial step in demonstrating the incorporation of components such as the tri-structural isotropic (TRISO) coated fuel particle and flibe molten fluoride salt coolant.

Lessons learned from the assembly of Hermes-1 will be used to build Hermes-2, which, when ready, will supply 50 MW of carbon-free energy to the Tennessee Valley Authority grid and help power Google’s data centers in Tennessee and Alabama.

How will the SMR be built?

Kairos Power will fabricate the components required for the Hermes-2 project at its Manufacturing Development Campus in Albuquerque, New Mexico. Barnard Construction Company, which has been contracted to build both the Hermes projects, will assemble the components once they reach Oak Ridge.

The construction process will use modular methods, including precast concrete and a seismically isolated foundation. These are aimed at improving the structure’s safety and reducing the construction costs and timelines. The standardized and repeatable design can then be used to build other small nuclear plants at multiple locations.

“For nuclear projects to be successful, we need more than just the right technology. We need to understand every aspect of project delivery. Hermes 2 is where that all comes together,” said Mike Laufer, co-founder and CEO at Kairos Power CEO in a press release.

Interestingly, Hermes-2 is being built on the site that previously housed the Oak Ridge Gaseous Diffusion Plant, continuing its legacy of working with nuclear material. The plant is a precursor to a full-scale commercial plant and will help Kairos Power advance its technology, supply chain, and construction capabilities.

“By pioneering a standardized, repeatable design, Kairos Power is addressing the historical challenges of nuclear construction costs,” added Amanda Peterson Corio, Global Head of Data Center Energy, Google.

“This shift toward a more efficient, factory-based manufacturing approach is a proven path toward lower-cost, cleaner power for our operations and the communities we serve.”