High-Assay Low-Enriched Uranium (HALEU) is uranium enriched to between 5% and 20% uranium-235 concentration, sitting above conventional low-enriched uranium (LEU, below 5%) but below the 20% threshold that defines highly enriched uranium (HEU). HALEU is the critical fuel feedstock for nearly every advanced reactor design under development, including TerraPower's Natrium, X-energy's Xe-100, Oklo's Aurora, Kairos Power's Hermes, Radiant's Kaleidos, and Westinghouse's eVinci. The higher fissile content enables smaller reactor cores, longer refueling intervals, higher fuel burnup, and improved reactor economics compared to conventional LEU fuel.
The HALEU supply chain represents the single most significant bottleneck for the advanced nuclear industry. Until 2024, Russia's TENEX (a Rosatom subsidiary) was the only commercial supplier of HALEU globally. The U.S. ban on Russian enriched uranium imports created an urgent need for domestic and allied-nation production capacity. As of early 2026, Centrus Energy (NYSE: LEU) operates the only U.S. HALEU production capability at its Piketon, Ohio facility, where a 16-centrifuge demonstration cascade has delivered over 900 kg to the Department of Energy. In January 2026, Centrus received a $900 million DOE task order to build a full-scale cascade of 120 centrifuges capable of producing 6 metric tons of HALEU per year, with plans to scale to 12 metric tons annually.
The DOE's HALEU Availability Program, mandated by the FY2024 National Defense Authorization Act, set production targets of 3 metric tons by September 2024, 8 metric tons by December 2025, and 10 metric tons by June 2026, though actual production has fallen behind these milestones. The total federal investment in HALEU and LEU enrichment exceeds $2.7 billion. Internationally, Urenco received NRC authorization in September 2025 to enrich up to 10% (LEU+) at its U.S. facility, with first deliveries to fuel fabricators in 2026, while planning a dedicated HALEU facility at Capenhurst, UK for production in the early 2030s. Orano is preparing an NRC license application for a new U.S. enrichment facility targeting production by 2031 at approximately $5 billion in total cost. Closing the gap between HALEU demand from reactor developers and actual production capacity remains one of the industry's defining challenges.