Centrus to Supply HALEU Fuel for Radiant’s Kaleidos Microreactors

Centrus Energy (LEU ) and Radiant announced on September 8, 2026, a definitive multi-year contract for Centrus to supply the high-assay, low-enriched uranium (HALEU) fuel needed to deploy multiple Kaleidos microreactors. Under the agreement, Centrus will begin delivering HALEU before the end of the decade, adding another domestic source of fuel to support the commercial scale-up of Radiant’s Kaleidos fleet. The agreement includes prepayments from Radiant to Centrus to support Centrus’ domestic commercial enrichment capacity program, and the companies said it adds another HALEU customer to Centrus’ backlog.

Centrus is a supplier of nuclear fuel and services based in Bethesda, Maryland, and Radiant is a developer of transportable, plug-in ready nuclear microreactors. The companies described the contract as strengthening Centrus’ position as a fuel supplier for next-generation nuclear technologies while expanding its role in the emerging microreactor market. For Radiant, the agreement adds another domestic source of HALEU as the company moves from its first Kaleidos test toward commercial and national security deployments, reinforcing the fuel supply it continues to build in parallel with the reactor itself. Radiant also published the announcement on its own news page, dated September 9, 2026.

“The contract with Radiant marks another important step in building the domestic fuel supply chain needed to support the next generation of nuclear energy,” said Amir Vexler, president and chief executive officer of Centrus. Vexler said expanding the company’s work to include microreactor developers such as Radiant strengthens the U.S.-based fuel supply network and helps ensure emerging nuclear technologies have access to the reliable fuel they need to reach commercialization.

“You can’t deploy nuclear reactors without fuel, so we have approached our fuel supply the same way we have approached the reactor: build it in parallel, and don’t depend on any single path,” said Dr. Rita Baranwal, chief nuclear officer of Radiant. Baranwal said the agreement gives Kaleidos a continued source of HALEU for commercial and national security applications.

Because Centrus’ technology is U.S.-origin and relies on a U.S. manufacturing supply chain, the enrichment Centrus provides to Radiant will be “unobligated,” meaning it can be used for national security applications, according to the announcement. The companies stated that Centrus’ AC100 centrifuge design is the only deployment-ready U.S.-origin technology available for unobligated enrichment today. Radiant is developing transportable microreactors designed to provide power for remote locations, data centers, defense applications, and other commercial and industrial uses.

Kaleidos Design and Deployment Pipeline

Radiant describes Kaleidos as a 1-megawatt-electric (1 MWe) portable microreactor that is transportable by land, sea, or air and deployed directly at customer sites. Each unit provides up to five years of power before refueling and is engineered with a 20-year operating life cycle, according to the company. Radiant manages fueling, refueling, and spent-fuel storage at its own facilities, an arrangement the company said allows customer sites to return to greenfield condition within two years or less after a unit is removed and means customer sites never store spent fuel onsite.

On July 23, 2026, Radiant announced that the U.S. Department of Energy (DOE) had conditionally selected it to receive a second allocation of HALEU, intended to fuel Radiant’s microreactor for the Department of the Air Force’s Buckley Space Force Base in Aurora, Colorado, which will be delivered by 2028. Radiant said it was the sole private-sector recipient in DOE’s third round of HALEU allocations, named alongside NASA, whose allocation will fuel its SR-1 Freedom mission to Mars. DOE had previously selected Radiant for a HALEU allocation supporting its planned Kaleidos Development Unit test at Idaho National Laboratory. In April 2026, the Department of the Air Force and the Defense Innovation Unit selected Radiant to develop and operate a microreactor at Buckley under the Advanced Nuclear Power for Installations initiative, with the first Kaleidos reactors planned for delivery in 2028.

On August 20, 2026, Radiant announced a long-term fuel supply agreement with Standard Nuclear (STDN ) for tri-structural isotropic (TRISO) fuel fabrication to support planned Kaleidos deployments to government and commercial customers through the early 2030s. Radiant said the agreement strengthens its fully owned, end-to-end supply chain alongside its 300,000-square-foot R-50 manufacturing, fueling, and storage campus in Oak Ridge, Tennessee. The company has signed a commercial agreement with Equinix for 20 Kaleidos units. Kaleidos is undergoing a full-scale test campaign at Idaho National Laboratory’s Demonstration and Operation of Microreactor Experiments (DOME) facility, where DOE awarded Radiant exclusive access for a full year following a competitive selection process.

Prior Partnership and Enrichment Capacity

The supply contract extends a relationship the companies established on January 26, 2023, when Radiant announced a partnership with Centrus to establish the domestic HALEU supply chain needed for broad commercial deployment of Kaleidos. Under that agreement, Centrus was working to identify a path to provide a future HALEU supply to Radiant for as many as 20 Kaleidos microreactors. The 2023 announcement described Kaleidos as using a helium primary loop coolant instead of water, with a HALEU fuel core designed to run five years without refueling, and Radiant said at the time that it planned to test a demonstration reactor within four years at Idaho National Laboratory’s DOME facility.

The Radiant prepayments support Centrus’ domestic commercial enrichment capacity program. On July 1, 2026, Centrus announced it had signed a contract finalizing a competitively awarded $900 million task order from the Department of Energy to deploy commercial-scale HALEU production capacity in Piketon, Ohio. The fixed-price HALEU Enrichment contract includes options, at the Department’s discretion, for up to $170 million in HALEU purchases for departmental missions, bringing the total contract value with all options to $1.07 billion. Centrus said the initial build-out will include 12 metric tons of annual HALEU production capacity as well as capacity to meet its existing low-enriched uranium (LEU) backlog of $2.4 billion, with the first new capacity expected to come online by 2029.

Centrus completed all HALEU production called for under its prior demonstration contract, finishing the final 900 kilograms of HALEU UF6 in mid-June 2026, two weeks ahead of schedule, for a cumulative total of more than 1,900 kilograms over the life of that contract. Until the new capacity comes online, Centrus intends to privately operate its existing HALEU cascade at the American Centrifuge Plant in Piketon on a commercial basis to begin supplying the near-term needs of its customers, and it is working with the Department of Energy on agreements to enable that transition, including a long-term lease extension for the plant. Centrus has said its expansion is underpinned by public and private funding along with commercial contracts, a framework that includes national security missions, third-party investments such as prepayment, direct foreign investment, and LEU and HALEU commercial contracts.