The Largest Flibe Test in the World


Published: November 16, 2023

The Kairos Power team closed out a productive summer, achieving major licensing milestones for the Hermes demonstration reactor and putting the Engineering Test Unit through its paces with the commencement of Flibe operations. Read on for the latest.

Molten Salt Operations Get Underway

The Engineering Test Unit (ETU) has officially become the largest Flibe system in the world! In October, the team at KP Southwest, Kairos Power’s testing and manufacturing facility in Albuquerque, N. M., began the careful process of loading 14 tons of molten fluoride salt coolant into ETU, initiating the largest Flibe transfer since the Molten Salt Reactor Experiment in 1969.

ETU represents a major step in our rapid iterative approach to technology development and reflects our culture of learning by building. Scaled at the same size as the Hermes demonstration reactor with nearly identical operating parameters, ETU is a non-nuclear prototype of Kairos Power’s fluoride salt-cooled high-temperature reactor (KP-FHR) that demonstrates the integration of principal systems, structures, and components. Lessons learned from ETU will be integrated into Hermes and future iterations on the path to commercializing KP-FHR technology.

Kairos Power produced the Flibe for ETU at our Molten Salt Purification Plant on the Materion campus in Elmore, Ohio. The last batch was successfully delivered to KP Southwest in August, marking a significant achievement in our partnership with Materion and our vertical integration strategy to achieve cost certainty by bringing the production of critical materials and components in-house.

WATCH: Kairos Power & Materion partner to deliver a molten salt milestone

Being the first to build and operate a plant to produce Flibe at an industrial scale has generated a wealth of lessons that will help de-risk salt production for future iterations. Further, as we commence Flibe testing with the Engineering Test Unit, our team at KP Southwest benefits from extensive knowledge about molten salt behavior and beryllium handling protocols gained from over a year of Flibe operations with MSPP.

Loading molten salt coolant into the Engineering Test Unit

Loading molten salt coolant into the Engineering Test Unit To load the system with salt, operators individually pre-heat the transport canisters, each containing two tons of solid Flibe. One by one, the canisters are moved onto the loading station, where argon gas is used to push the molten Flibe into ETU’s intermediate storage tank.

Throughout the highly coordinated operation, prioritizing the health and safety of our employees and the environment is paramount. In the months leading up to Flibe operations, our team developed extensive safety protocols, performed dry runs to practice maintenance procedures in full personal protective equipment (PPE), and practiced donning and doffing PPE in specially designed changing rooms.

Operators supervise testing from the Engineering Test Unit control room

Operators in the Argos control roomThere are always eyes on ETU as operators monitor the system from two control rooms – one co-located with ETU at KP Southwest and one at Kairos Power headquarters in Alameda, Calif. From these vantage points, operators can observe real-time data from thousands of sensors on human-machine interfaces that display temperatures, pressures, oxygen levels, moisture readings, and the decreasing weights of the Flibe canisters as their contents flow into the system.

As we accelerate our experience with large-scale Flibe operations, establishing operating protocols, training personnel, and executing maintenance procedures, we learn important lessons to optimize plant operations for Kairos Power’s future nuclear iterations. This illustrates the value of our rapid iterative approach, which enables learning early in development to gain the maturity needed to deliver future iterations faster, better, and with cost and schedule certainty.

Once all 14 tons of Flibe are circulating in ETU, operators will embark on a multi-month testing program that will continue to provide learnings and data until the system is decommissioned to make way for the next iteration – ETU 2.0.

Expanding Infrastructure in Albuquerque

Kairos Power continues to grow our manufacturing capabilities and infrastructure at KP Southwest to support our iterative testing program and critical fuel and salt workstreams. This summer, the team began construction on the Modular Systems Facility, which will support ETU 2.0 subsystem development.

Kairos Power's testing and manufacturing facility in Albuquerque, New Mexico The Modular Systems Facility under construction at KP Southwest The Modular Systems Facility under construction at KP Southwest The Modular Systems Facility at KP Southwest

ETU 2.0 is Kairos Power’s first iteration to demonstrate modular construction, which provides a number of benefits aligned with our iterative development approach. By building each subsystem for ETU 2.0 as a modular skid, we will be able to complete entire subsystems and perform qualification testing in parallel before moving the skids into the ETU enclosure for assembly. This will enable us to advance ETU 2.0 construction while ETU 1.0 operations and decommissioning are still in progress.

The ability to concurrently design and build modular skids for ETU 2.0 is made possible by our commitment to vertical integration. Since opening KP Southwest in 2020, Kairos Power has invested heavily in standing up the internal manufacturing capabilities to be a nuclear hardware delivery company.

At KP Southwest, we are producing components from stainless steel and graphite, U-stamped pressure vessels, non-nuclear TRISO pebbles, and other specialized parts for our testing program. We are currently in the process of building out a vessel shop where we will make reactor vessels for future iterations, along with the TRISO Development Lab, where we will advance fuel manufacturing techniques that will be implemented off-site to produce the fuel for Hermes.

This undertaking is a significant cross-functional effort by our engineering design, manufacturing, and operations teams, who work together to capture and apply lessons learned from each iteration of the plan-design-build-test process.

Coming Soon to Oak Ridge

The infrastructure and experience that Kairos Power is building in Albuquerque will directly support our deployments in Tennessee, including the Hermes demonstration reactor. But Hermes won’t be our first hardware demonstration in Oak Ridge. In August, we announced that the third ETU iteration – ETU 3.0 – will be constructed on land owned by Kairos Power adjacent to the Hermes site at Heritage Center Industrial Park.

The strategic decision to build ETU 3.0 in Oak Ridge will accelerate our civil construction experience locally, building relationships and generating learnings that will transfer directly to the Hermes project. It’s one more way that we can leverage experience from the ETU series to take risk off the table prior to our first nuclear build.

Kairos Power plans to break ground at Heritage Center in early 2024. But first… one crucial step remains before construction on Hermes can begin in earnest.

NRC Wraps Mandatory Hearing for Hermes Construction Permit

On October 19, the Nuclear Regulatory Commission convened its mandatory hearing on the construction permit application for the Hermes demonstration reactor. This followed the issuance of the NRC’s Final Safety Evaluation Report and Final Environmental Impact Statement for Hermes earlier in the summer.

Kairos Power co-founders, CEO Mike Laufer, CTO Edward Blandford, and CNO Per Peterson, along with VP of Regulatory Affairs and Quality Peter Hastings, testified during the proceeding at NRC Headquarters, where they addressed questions from the Commissioners regarding Hermes’ safety and environmental reviews.

Throughout the hearing, the Commissioners praised the NRC staff and Kairos Power team for the conciseness, quality, and clarity of the submissions they received. Chair Hanson affirmed, “One of the things I’m most proud of being here at the NRC is thinking about the tremendous amount of learning and improvement that’s happened on the part of the staff, not just in the last couple of years, but certainly on the Kairos front.”

During the hearing, Commissioner Wright referenced a letter from the City of Oak Ridge complimenting both the NRC and Kairos Power for their engagement with the community throughout the application review process. We are grateful for all those who participated in that process, drafting letters of support and submitting public comments that directly resonated with the Commission.

In his closing remarks, Laufer thanked Kairos Power’s many local stakeholders for their support, concluding, “We value our relationships with our neighbors in Oak Ridge and seek to be a good community partner that brings value to the region, as we leverage proven technology with historical roots in that location as well as other locations around the country.”

With the mandatory hearing now complete, the Commission is expected to vote on the Hermes construction permit before the end of the year.

Kairos Power Submits CPA for Hermes 2

Building on the successful review of the Hermes Construction Permit Application, Kairos Power has submitted an application to build a new iteration, Hermes 2, which has been formally accepted for review by the NRC. The proposed two-unit demonstration plant would produce electricity and be deployed in Oak Ridge on the same site as the first Hermes reactor to further de-risk technology, construction, supply chain, and licensing for a multi-reactor plant.

“We are excited to continue engaging with the NRC as we pursue a new hardware iteration that will leverage the experience we are accumulating from the Hermes demonstration reactor to advance our mission in East Tennessee,” said Laufer. “While a few important details must fall into place before we can fully commit to building it, Hermes 2 presents a unique opportunity to accelerate commercial deployment of KP-FHR technology while bringing value to the local community over the long term.”

Kairos Power’s Commitment to the Community

Everything we do at Kairos Power is driven by our mission to improve people’s quality of life while protecting the environment. That’s why we are committed to engaging and supporting the local communities where we operate.

In October, Kairos Power celebrated Nuclear Science Week by connecting with local students at the National Museum of Nuclear Science & History. Team members shared their passions for advanced nuclear technology, its role in the clean energy transition, and career opportunities in this rapidly growing field with students from across the Albuquerque Public School district.

Earlier this summer, Kairos Power hosted Supply Chain & Procurement Meet & Greets in Albuquerque and Oak Ridge to meet diverse local businesses interested in joining our supplier network. We recognize the value of a resilient supply chain comprising companies with different perspectives, talents, cultural traditions, and backgrounds, and we are committed to building a strong local vendor base that reflects the diversity of the communities we serve.

Kairos Power held a supplier fair in Oak Ridge to connect with diverse local businesses

The Kairos Power team at the company's supplier diversity fair in Oak Ridge

Thank you to the many local businesses that came to learn about opportunities to get involved in Kairos Power’s clean energy mission. If your company is interested in joining our supplier network, particularly if you are certified as a diverse-owned business, get in touch at newsupplier@kairospower.com.

Ready for a Career in Clean Energy?

Kairos Power is honored to be named a Top Workplace in the Bay Area and New Mexico for the second year in a row! This recognition is a testament to our incredible team and the people-centered culture we cultivate within our company.

Kairos Power was named a Top Workplace in the Bay Area in 2023

Kairos Power was named a Top Workplace in New Mexico in 2023

The Kairos Power team is made up of wildly capable people with a diverse range of backgrounds, skill sets, and industry experience who are united in their commitment to improving people’s quality of life while protecting the environment.

We are hiring in many disciplines at multiple locations around the country. Visit kairospower.com/careers to learn how you can join our growing team.

Until Next Time

From everyone at Kairos Power, we wish you a joyful holiday season and a prosperous new year. Be sure to connect with us on LinkedIn and Twitter to continue following our progress as we take on 2024.

Opening Soon!

Embark on a journey through the past and future of molten fluoride salt reactor technology at the American Museum of Science and Energy’s newest exhibit, opening December 6, 2023. Reaction Time: The Fluoride Salt Future explores the origins of the technology that started in Oak Ridge and Kairos Power’s iterative approach to commercializing it with a spotlight on the Hermes demonstration reactor.

AMSE is open daily. Visit amse.org for hours and ticket info.

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