03-03-2025
Kairos Power's reactors will include technologies based on ORNL innovations
This is the second of two stories on Kairos Power's plans for building test reactors in Oak Ridge this decade and nuclear power plants next decade using two technologies based on Oak Ridge National Laboratory (ORNL) innovations.
The three Hermes demonstration reactors that Kairos Power plans to build in Oak Ridge's Heritage Center will incorporate two technologies based on innovations originating at the nearby Oak Ridge National Laboratory.
Kairos Power scientists and engineers also are or will be meeting with ORNL experts on these technologies to acquire the knowledge they need for the Hermes reactor projects. The goal is to ensure successful demonstrations of their three planned test reactors' Kairos Power fluoride-salt-cooled, high-temperature reactor (KP-FHR) technology.
Those were two of the messages this volunteer reporter for The Oak Ridger heard in a conversation by Zoom with Edward Blandford, Kairos Power's co-founder and chief technology officer. He is responsible for all engineering and technology development functions at Kairos Power. These include hardware demonstrations, fuel and salt supply infrastructure, manufacturing, supply chain and procurement, environmental health and safety, construction management and engineering operations.
In the 1960s, ORNL ran a successful Molten Salt Reactor Experiment (MSRE) that showed the advantages of using a molten salt containing lithium fluoride and beryllium fluoride (FLiBe) instead of water for cooling a reactor that can operate at a high temperature but under low pressure. Kairos Power will use FLiBe salt to cool its Hermes reactors and carry away their heat, which for the second and third reactors will produce steam for generating electricity.
The MSR technology was championed by ORNL Director Alvin Weinberg, who co-invented the pressurized water reactor (water-cooled reactor run at high pressure), which is at the heart of two-thirds of the nuclear power plants operating in the world today.
ORNL researchers working in a program to develop the high-temperature, gas-cooled reactor were the first to invent TRISO (tristructural isotropic) nuclear fuel. For the Kairos Power reactors, the TRISO fuel will be embedded in graphite pebbles, each containing thousands of coated uranium fuel particles the size of poppy seeds. The spherical TRISO particles feature a robust, triple-layered ceramic shell that withstands high temperatures and prevents the release of radioactive fission products.
Blandford said Kairos Power is working with the Low Enriched Fuel Fabrication Facility at the U.S. Department of Energy's Los Alamos National Laboratory in New Mexico to manufacture HALEU TRISO fuel pebbles for the Hermes reactors. HALEU stands for High-Assay Low-Enriched Uranium. This nuclear fuel is enriched in uranium-235 at a level between 5% and 20%, higher than the level for traditional reactor fuel
Kairos Power partnered with Materion Corp. in Elmore, Ohio, to commission the construction and operation of the Molten Salt Purification Plant (MSPP). In 2022 it produced unenriched FLiBe for the Engineering Test Unit (ETU) series. Kairos Power is now integrating lessons learned from MSPP into a Salt Production Facility that will produce reactor-grade FLiBe enriched in lithium-7 for the Hermes reactor series.
Blandford was asked how ORNL researchers are helping the Kairos Power staff with the Hermes reactor projects. He answered that Kairos Power is acquiring information from ORNL in four main areas: the characterization of TRISO fuel, safeguards approaches, the lab's advanced manufacturing methods and capabilities, as well as the know-how and knowledge contained in documents from the lab's historical MSRE program, including ORNL's experience with the FLiBe salt coolant.
'Knowledge transfer is something that Kairos is looking for from Oak Ridge,' he said.
Kairos has committed to investing at least $100 million and creating more than 55 full-time jobs in the Oak Ridge area to support the construction and operation of the Hermes 1 reactor. DOE is investing up to $303 million through a performance-based milestone contract funded by the Advanced Reactor Demonstration Program to support the reactor's design, construction and commissioning.
In May 2021, Kairos established a cooperative development agreement with the Tennessee Valley Authority, which will provide engineering, operations and licensing support for the Hermes 1 reactor.
Successful operation of the three demonstration reactors, including the two reactors that will generate up to 28 megawatts of electricity for the grid, should enable Kairos Power to reach the next level in the early 2030s, Blandford said.
That step would be building in a not-yet-determined location the KP-X commercial demonstration plant, he added. It would house a single reactor with a power output of 50 megawatts (50 MWe) operating at near-atmospheric pressure and a reactor outlet temperature of 650 degrees Celsius made of stainless-steel structural material. The uranium fuel will be enriched in fissionable uranium-235 at a level of 19.75%.
Following KP-X, Kairos Power will deploy commercial plants with a standard configuration of two 75-MWe reactors connected to a shared power generation system for a total output of 150 MWe.
The company is partnering with Google to deploy reactors for power-hungry data centers that the search engine company will need for training artificial intelligence models. In October 2024, according to a news release, 'Kairos Power and Google signed a Master Plant Development Agreement, creating a path to deploy a U.S. fleet of advanced nuclear power projects totaling 500 megawatts by 2035.'
In a Feb. 4, 2025, news release, it was announced that 'Kairos Power, the Texas A&M University System and prospective customers have agreed to explore the potential to site one or more commercial Kairos Power nuclear power plants at the Texas A&M-RELLIS campus as part of the university's initiative to build a proving ground for the next generation of nuclear reactors.
'Texas A&M selected Kairos Power's proposal as the largest commercial project to anchor an expansion of the RELLIS campus that would advance new nuclear technologies to supply clean, firm electricity for data centers and other commercial applications.'
One Texas A&M aim is to enhance students' education by providing unprecedented access to the latest advanced reactor technologies.
Blandford was asked about the success of the Kairos Power staff's interactions with the Nuclear Regulatory Comission (NRC) staff in obtaining construction permits for the Hermes reactor series. He said the Kairos Power staff engaged with the NRC staff during each step of the construction permit application.
He compared the application process to a book report. Instead of submitting a 10-page report on a book all up front, he said, the Kairos Power staff prepared the equivalent of a short report on various sections and obtained feedback from NRC. These smaller reports, called Licensing Topical Reports, allowed the NRC staff to take formal licensing positions and parallelize the review.
Blandford was asked whether building and operating a few commercial 150-MWe KP-FHR power plants would be more economical than a 1,000-MWe pressurized water reactor used in many of the world's nuclear power plants.
He said that building and operating a new 1,000-MWe nuclear power plant incorporating a pressurized water reactor or boiling water reactor is 'a big investment for utilities to make.
"A large utility needs a substantial market capitalization to make that level of investment," Blandford said.
He added that water-cooled reactors are 'a more mature technology, but at such a large size and a scale that there's a lot of project risk in translating the design of a nuclear power plant to a particular site.' In addition, it takes at least 10 years to build such plants 'and the people that built those plants are no longer there waiting for new work.'
Blandford argued that the KP-FHR technology is at a smaller scale, 'allowing us to bring down the cost curve quicker and sooner' than can be done by megaprojects.
Also, he added, because the Kairos Power innovation is a high-temperature, low-pressure reactor, it does not require the huge, expensive pressure vessel and containment structure used by each water-cooled reactor to ensure its safe operation.
'Our reactors, which rely on what is called functional containment, are designed to have very little stored energy in the system,' he said. 'In the large, light-water reactors, accidents can evolve relatively quickly, so stored energy must be appropriately managed through active and passive means. The FHR safety case is built on removing those accident sequences from the design.'
He added that reactor costs and construction time will decrease if standardized reactor parts can be built in a factory environment and transported to multiple locations where nuclear power plants using Gen IV reactors like KP-FHRs are assembled on site. But, he stated, Kairos Power will be building and demonstrating a first-of-a-kind technology, so there will be some upfront costs in showing when the KP-FHR power plants are ready to be standardized, modularized and commercialized.
This article originally appeared on Oakridger: Kairos Power reactors will include tech based on ORNL innovations
