The groundbreaking ceremony for the Hermes 2 plant in Tennessee – credit, Kairos Power, released
A nuclear energy firm has broke ground on the first advanced nuclear reactor plant in the country, in Oak Ridge, Tennessee.
Set to come online in 2030, it will help stymy the growth in energy costs from several large data centers run by Google in the Tennessee/Alabama area.
Beyond that, the well-researched technology aims to usher in a new age of safer nuclear power at a time when the US nuclear fleet is aging.
Headquartered in California with a manufacturing plant in Albuquerque, Kairos Power has been developing their own design for a small modular reactor run with molten salt for over 10 years in close concert with America’s nuclear regulatory agency.
The technology has faced criticism from scientists for being wasteful and overpriced, but with all things nuclear, it’s important to consider that innovation in the field which might have been carried out years ago never occurred due to the backlash from several famous reactor meltdowns.
Yet it’s arguable there’s no better time to upgrade and modernize this carbon-free power resource than now.
Two of the world’s 4 largest nuclear energy fleets, those of Japan and France, were constructed in the aftermath of the Arab Oil Embargo of the 70s, and so it’s little surprise that geopolitical circumstance is breathing life into the industry.
The massive energy demand from AI, cloud computing, and data storage is doubling up this demand, with the same firms building the facilities to power these services finding that nuclear energy is the only fossil-fuel-free method that can ensure there’s enough power on the grid.
The Kairos plant, called Hermes 2, will use molten salt as a coolant instead of pressurized water, which can operate at ambient pressures and thereby remove one of the major catalysts for reactor meltdowns: high-pressure explosions, or rather explosions coming from a rapid fall of high pressure to low pressure, such as occurred in reactor 2 of the Fukushima Nuclear Power Plant in 2011.
Kairos will also swap standard uranium fuel rods for TRISO, a next-gen preparation for uranium fuel the size of a poppy seed that consists of a kernel of uranium surrounded by a tri-carbon layer, including ceramic and graphite, which can not only withstand much higher temperatures than fuel rods, but prevent the escape of fission byproducts such as radiation.
TRISO has been under co-development by the US and UK governments since 1960. Fear of nuclear energy following events at places like Chernobyl and Three-Mile Island stymied continued research into the superior fuel product since then.
“For nuclear projects to be successful, we need more than just the right technology. We need to understand every aspect of project delivery,” said Mike Laufer, a nuclear engineer who is president and founder of Kairos, at the groundbreaking ceremony.
As the bullish uranium investor Rick Rule likes to say, Japan, which must import all its fuel, can store enough energy with uranium in a single warehouse to power Japan for 5 years.
Energy security is merely one aspect of the renewed interest in nuclear energy, with the second being concerns over the electricity consumption of data centers.
In spring, GNN reported on the passage of Republican-led bill HB 1847 in Tennessee where Hermes 2 will be located, and where Google runs 2 data centers on the grid managed by the Tennessee Valley Authority (TVA). It places an impact threshold on the grid of 50 megawatts. Anything beyond that may not be billed to the general ratepayers.
To wit, Google signed a purchase agreement with Kairos for the construction and operation a single reactor nuclear plant capable of producing 50 carbon-free megawatts.
A rendering of the plant – credit, Kairos Power, released
“To power the future, we need to grow the availability of smart, firm energy sources,” said Amanda Peterson Corio, Google’s Global Head of Data Center Energy. “This collaboration with TVA, Kairos Power, and the Oak Ridge community will accelerate the deployment of innovative nuclear technologies and help support the needs of our growing digital economy while also bringing firm carbon-free energy to the electricity system.
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“Lessons from the development and operation of the Hermes 2 plant will help drive down the cost of future reactors, improving the economics of clean firm power generation in the TVA region and beyond.”
Advanced nuclear reactors cooled by molten salt are, however, a largely new and unproven technology at scale. A succinct review published in 2022 showed that while new forms of nuclear fission may produce more waste than traditional, large light water reactors, and that the waste they do produce is more varied.
The review looked at over a dozen proposed reactor designs and fuel/coolant pairings, reflecting how like all emerging technologies, many of the methods are yet-untested on a market-scale. This would normally be a good thing—competition allows for the market to select the best technologies for proliferation, but the intense regulatory and environmental scrutiny, and the capital investment in R&D required for developing new methods of nuclear fission makes it an extremely risky business.
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TRISO, however, has seen commercial deployment—in Canada in the 1980s where it faced multiple problems, and China in the 2010s which not only saw success, but 2 world-first safety demonstrations. In the event of a total power supply loss, the decay heat inside the reactor would dissipate and cool down naturally without any human intervention or emergency core cooling.
The TRISO shell of ceramic and graphite showed no signs of compromise even at temperatures of 1,620°C—far higher than what would be encountered even in extreme accident situations. During tests in 2014 at Oak Ridge National Laboratory in Tennessee, the irradiated TRISO was exposed to more than 300 hours of testing at temperatures up to 1,800°C (more than 3,000°F), again, without showing any degradation.
While China’s HTR-PM nuclear plant used helium as a coolant, which saw issues in the Canada plant Kairos will use molten-salt, which dodges the operational issue of helium (albeit encountered in the 80s) by potentially introducing more complex waste streams.
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Kairos has worked closely with the US Nuclear Commission throughout the design and permitting of Hermes 2 and Hermes, a smaller, test-scale project of the same technology established in Oak Ridge years earlier. In the USNC’s final environmental impact assessment, the agency concluded that compared to the 57 currently-operating nuclear power plants in the US, the relatively low total quantity of uranium (4.66 metric tons) estimated to be used for the license period of 11 years makes its footprint on the overall waste disposal system in the country much smaller than light-water reactors.
The molten salt, the most potentially-hazardous of all produced waste, will be stored onsite in specialized containers until it solidifies, after which it will be treated as solid waste for the purpose of storage, according to the regulatory final decision. There are also the 11 years of operation to potentially develop better and safer methods of containment and disposal.
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