NRC's mission is to license and regulate the nation’s civilian use of radioactive materials, to provide reasonable assurance of adequate protection of public health and safety, to promote the common defense and security, and to protect the environment. This includes through licensing reviews and oversight of high-assay, low enriched uranium (HALEU) fabrication, utilization, transportation, and storage.
Historically, commercial power reactor fuels have consisted of uranium dioxide (UO2) pellets with enrichment of less than or equal to 5 weight percent uranium-235 (U-235) encapsulated by zirconium (Zr)-alloy cladding. HALEU is defined as uranium enriched to greater than 5 weight percent and less than 20 weight percent of the uranium-235 (U-235) isotope. In general, industry representatives have indicated that operators of existing conventional light-water reactors (LWRs) expect these facilities to use HALEU enriched to between 5 and 10 weight percent U-235 and designers of advanced reactors propose to use HALEU enriched to between 10 and 20 weight percent U-235. As documented in an NRC report to Congress, the NRC’s regulatory framework has sufficient flexibility to accommodate licensing reviews and decisions related to HALEU. For more information, read the Report to Congress.
Page Last Reviewed/Updated Thursday, April 10, 2025