The November 2025 NOVA release says the NOVA core used HALEU TRISO fuel and 'the same fuel' as Ward 250. DOE defines HALEU as enriched between 5% and less than 20% U-235. Valar's October 2025 NSDA design table lists Ward 250 fuel enrichment as 4.95% U-235 under 'LEU limits', which is below the HALEU range. The October 2025 NSDA also gives two different outlet temperatures (650 C nominal in the design table, 750 C as a performance objective), and the company's NSDA web summary says testing up to 650 C. DOE's own shipping review (Safety Evaluation Report, May 20, 2026) authorized limited shipments of HALEU TRISO fuel compacts, enriched to at most 19.9% U-235, from Los Alamos's criticality center in Nevada, with their end use as fuel elements in Ward 250 (safe-010). That matches the NOVA wording, not the NSDA's 4.95%. Whether the approved safety analysis was updated to HALEU is not public; the DSA would settle it (disc-001).

• Los Alamos National Laboratory and Valar Atomics Announce Project NOVA Criticality Milestone in Nevada (Valar Atomics (joint announcement with LANL), 2025-11-18) primary company “a series of criticality experiments on a HALEU TRISO”
• Ward250 Nuclear Safety Design Agreement (Document 100403, Rev. 02) (Valar Atomics, 2025-10) primary filing “4.95% U-235”
• Safety Evaluation Report, Letter Amendment of Certificate of Compliance No. 9979 for the Model 9979 Package, Docket 26-35-9979 (U.S. Department of Energy, Packaging Certification Program, 2026-05-20) primary government “enriched to a maximum of 19.9 wt.% U-235”
• What is High-Assay Low-Enriched Uranium (HALEU)? (U.S. Department of Energy, Office of Nuclear Energy, 2024-12-03) primary government “By definition, HALEU is enriched between 5% and less than 20%”