Nuclear Notes is produced by the Breakthrough Institute, and covers the policy, regulation, technology, and business of advanced nuclear energy in the United States and beyond.
Every Thursday, we track what’s really going on in the field: the new rules moving through the Nuclear Regulatory Commission, the advanced reactors moving from design to deployment, the companies going public and the utilities merging, and the executive orders and acts of Congress reshaping how the country builds. We explain not just what happened, but why it matters and how the pieces fit together.
A Partial Reconciliation of Two Nuclear Agencies
Fifty-one years after Congress broke up the Atomic Energy Commission into the Nuclear Regulatory Commission and another agency that later became the Department of Energy, the NRC has established a smoother pathway for reactors authorized by the DOE and the DOW to get licensed by the NRC.
The new rule, which takes effect on Nov. 25, follows up on Executive Order 14300, signed by President Trump in May 2025, which aimed to accelerate nuclear energy deployment.
The relationship between the DOE and the NRC is complicated. The entity that preceded them, the Atomic Energy Commission, was mandated to promote nuclear energy and also to regulate it, roles that Congress eventually decided were incompatible. And the major function of the DOE has always been to produce and manage the nation’s stockpile of nuclear weapons. Second on its list is cleaning up the environmental mess made by Cold War efforts to produce more bombs. The DOE has always had a role in promoting nuclear energy and doing research that improves the operation of commercial reactors, in part through the U.S. National Laboratories, but in the last few years it has become far more active in fostering new reactor designs.
The rule does not allow for cross-licensing but is supposed to streamline the NRC licensing process and reduce duplicative reviews. Applicants will have to identify how approvals given by DOE or DOW satisfy NRC rules. In fact, an analysis by a group of nuclear lawyers notes that the NRC “has not established a presumption of equivalency” between a DOE approval and an NRC approval, and that the NRC will not limit its review “to risks that were not previously evaluated” by other agencies; it may re-evaluate questions that other agencies say have already been resolved.
“This rulemaking does not affect the NRC’s commitment to conducting independent reviews, nor does this rulemaking alter any underlying regulatory requirements an applicant must meet,” said the NRC. “Nothing in this rule delegates to DOE, DOW, or any other agency the NRC’s functions to evaluate a request for NRC approval, and nothing in this rule allows the NRC to forgo an independent review.” It also cautions, “the scope of a DOE or DOW authorization or associated testing may not fully represent a commercial reactor configuration or the breadth of analyses necessary for an NRC licensing basis.”
But the rule will save money for applicants and the NRC itself, the agency said. It did not say how much.
The Breakthrough Institute commented extensively on the draft rule, and highlighted some ambiguities in its language. While the final product advances several of the Breakthrough Institute’s goals, the Commission did not incorporate much of the Breakthrough Institute’s advice. For example, the rule repeatedly says that the NRC will “leverage” the licenses from the DOE, but never defines the term. It also leaves ambiguous how the NRC will determine whether information generated to obtain a license from the DOE or the military can reduce the depth of the NRC’s review. It does explain clearly how an authorization from the DOE or the military leads to an NRC review that is different from what is done under older procedures.
Alongside the final rule, NRC staff released a white paper laying out how the agency might actually use work already done under DOE authorization, and walked stakeholders through it at the second “License to Launch” workshop on Oct. 28. The paper is not official guidance; that is still to come. And for now, the paper covers only DOE; military authorizations will be addressed later. But it is the clearest signal yet of how the new pathway will work in practice.
The paper sorts DOE information into three tiers, from the material the NRC can rely on heavily to material that serves only as background, and it is explicit that a DOE approval serves as evidence, but is not a substitute for the NRC’s own findings. Classification of the material by tier will be decided case by case, and the paper does not say how much independent verification the NRC will need before relying on DOE’s findings. Unless the final guidance answers that, developers will be planning around a pathway whose payoff they can’t predict.
Now there are developers racing to sell reactors to military bases, which want the reactors to insulate themselves from reliance on the civilian grid. With the Pentagon as a launch customer, a less expensive commercial version could follow for civilian customers with a special need for reliability, or who have major operations distant from the grid.
And, under DOE auspices, four new reactors achieved initial criticality by the symbolic date of July 4 of this year. Criticality is a significant step, but still short of the commercial product those developers are working toward.
Properly implemented, information from DOE and DOW experience can help reduce duplication and improve NRC review focus as prototypes and military-deployed reactors enter the commercial space.
Uranium Fuel Infrastructure Moves Forward
Global Laser Enrichment, a company that plans to recover fissile uranium from a huge inventory of depleted uranium hexafluoride left over from Cold War-era operations, has reached a major milestone: issuance of a final environmental impact statement by the NRC. The company said it expects to receive a license early next year.
The company, known as GLE, is using a new generation of enrichment technology. One of the first enrichment technologies developed during World War II was gaseous diffusion, which separated uranium isotopes by pushing gas through a semi-porous membrane. Currently, enrichment plants pump uranium hexafluoride gas into centrifuges, which spin and separate uranium isotopes by mass, capturing the U-235, the kind that splits easily in reactors. GLE would do that work by using lasers to selectively excite one isotope, allowing separation.
Natural uranium contains only 0.71 percent U-235, and modern centrifuge plants leave behind about 0.1 percent U-235, but gaseous diffusion was much less efficient and left about half of the U-235 behind. GLE would process those “tails” as its feedstock and produce uranium at enrichments used by commercial reactors today.
Centrifuges use less than one-tenth as much electricity as gaseous diffusion did. Laser excitation is said to be even more efficient, although the company has not said by how much.
If the technology is a success, it would solve two problems. It would help meet growing demand for enrichment, driven by new interest in nuclear reactors and by an impending ban on imports from Russia, and it would solve an environmental problem for the Department of Energy. The uranium hexafluoride tails are in old tanks that are deteriorating, and the fluorine in uranium hexafluoride is a major hazard, as it can form hydrogen fluoride, a toxic and corrosive substance. Removing most of the remaining U-235 would prepare the other materials for “deconversion,” in which the uranium is converted to a stable form, essentially uranium rust, and the fluorine can be sold in the commercial market for re-use.
GLE has a 655-acre plot adjacent to the Energy Department’s former gaseous diffusion plant in Paducah, Kentucky.
The Energy Department is supporting the GLE plant and three other enrichment projects. Two are conventional centrifuge projects, and the third, proposed by a company called General Matter, has not publicly described its technology but also wants to build near Paducah.
What’s the Best Job for an SMR?
Small Modular Reactors may be best suited to providing industrial heat off the grid, rather than wholesale electricity production, according to a study by researchers at the University of Michigan.
The industrial market could sustain 91 gigawatts of nuclear capacity, which could be deployed using credits in the Inflation Reduction Act with “high internal rates of return, whereas dedicated power production is uneconomic.”
That seems to be the logic of the first of X-energy’s gas-graphite reactors, which is planned for a Dow chemical plant in Texas. That plant will provide high-temperature steam; others, according to the study, could make hydrogen.
The study was published in August and is now being promoted by the Department of Energy.
A Reactor Developer Wants a Six-Pack
The Nuclear Company, which says it will build a fleet of Westinghouse AP1000s and gain synergies by continuously repeating construction, announced plans for six of them in Lewis County, on the Ohio River at the northeastern tip of Kentucky.
It wants to start construction on the project, called Prosperity One, in 2028, following seismic studies, environmental assessments, planning for interconnection with the grid, and other activities. If built, it would be the largest cluster of nuclear reactors in the country.
The owner of the site Sam Howard said in a statement, “I have nine grandchildren, and all of them live in Lewis County. I want them to have the opportunity to stay.” The area has high unemployment, he said, and the project would provide employment for generations.
But there was no immediate indication of how such a project would be financed and no apparent engagement yet with the NRC.
Radiant Scores a Hat Trick
The U.S. Navy has picked Radiant Industries to supply a prototype microreactor for its Naval Weapons Station Crane in Indiana. Radiant has already been selected by the Army and the Air Force for other projects; it is the only microreactor company picked by all three services.
The reactor has an output of one megawatt and is meant to supply critical loads at the base. But given the Navy’s longer-term strategy of moving to laser weapons, the reactor, called Kaleidos, could have other uses. The reactor is helium-cooled and runs on TRISO fuel, and differs from water-based reactors in its ability to restart quickly after a shutdown. In light-water reactors, certain fission products, such as xenon-135, are neutron absorbers and are referred to as “poisons.” Those reactors sometimes have to wait for the poisons to break down before they can restart. Kaleidos can recover more quickly.
Radiant says Kaleidos can be shipped by air, truck, or ship.
Correction: Last week’s newsletter incorrectly described the design change made by Kairos Power in its Hermes 2 reactor. The initial plan was for two 25-megawatt reactors, but this was changed to a single 50-megawatt unit. Power generation was always part of the plan.
Thanks for reading!