DOE announced categorical exclusion B5.26 on 2 February 2026 (91 FR 4550), already included in its procedures (the notice says it is 'effective on February 2, 2026'), and invited comments until 4 March 2026 (csite-020). On 4 March the Nuclear Information and Resource Service filed comments for itself and 25 groups, including HEAL Utah and Uranium Watch of Moab, arguing among other things that the exclusion expressly allows multiple reactors in one facility, that stacking exclusions and judging segmentation or 'extraordinary circumstances' would be shielded from public input, and that public involvement improves reviews. Uranium Watch wrote that coverage of the Valar reactor gave no information on worker and resident protection, emergency response planning, spent-fuel storage, who to contact, oversight or the need for NRC licensing if power is sold to non-federal entities. DOE's categorical-exclusion page, read 29 September 2026, still says DOE 'will consider' comments received by 4 March and links no response. DOE applied B5.26 to Ward 250 on 22 April 2026; that determination says no extraordinary circumstance applies, a category it defines to include scientific controversy about environmental effects. The exclusion's text, as printed in the determination, says 'a project may include multiple reactors within a nuclear facility'.

• Comments regarding DOE categorical exclusion for advanced nuclear reactors, Docket DOE-HQ-2025-0405 (NIRS and 25 co-signing groups incl. HEAL Utah and Uranium Watch) (Nuclear Information and Resource Service et al., 2026-03-04) analysis “the exclusion expressly would allow DOE to apply it to multiple reactors”
• Categorical Exclusion for Advanced Nuclear Reactors (DOE NEPA page) (U.S. Department of Energy, Office of NEPA Policy and Compliance) primary government “DOE will consider comments on this categorical exclusion received on or before March 4, 2026.”
• NEPA Determination DOE-ID-26-005: Valar Ward250 Research Reactor (categorical exclusion B5.26) (U.S. Department of Energy, Office of Nuclear Energy (Idaho), 2026-04-22) primary government
• NEPA Determination DOE-ID-26-005: Valar Ward250 Research Reactor (categorical exclusion B5.26) (U.S. Department of Energy, Office of Nuclear Energy (Idaho), 2026-04-22) primary government “a project may include multiple reactors within a nuclear facility”
• Categorical Exclusion for Advanced Nuclear Reactors, 91 FR 4550 (FR Doc. 2026-02071), DOE's posted copy (U.S. Department of Energy (Federal Register notice), 2026-02-02) primary government “For the purposes of this category, a project may include multiple reactors”