The NSDA scheduled submittals of the NSDA (22 Sept 2025), PDSA (1 Nov 2025) and final DSA and TSRs (6 Jan 2026), each with a 45-day DOE review, construction complete by 13 April 2026 and initial criticality on 30 June 2026. POWER (19 June 2026) reports preliminary DSA approval in February 2026 and final DSA approval on 23 April 2026; its links for both dates go to Valar's LinkedIn posts, which require a login and were not read. Valar's Castle Country page says Ward 250 operates with 'DOE-approved safety documentation and a completed operational readiness review'. ANS reports, citing Boston's LinkedIn post, that the federal review was led by Bob Boston, a manager at DOE's Idaho Operations Office, and that a joint test group had to sign off on key start-up steps before DOE authorized the criticality test. DOE's 18 June 2026 release calls Ward 250 'the first DOE authorized reactor built outside of a national laboratory' but does not mention the DSA, the readiness review or the startup approval. DOE's categorical exclusion, signed 22 April 2026, already describes what 'the Documented Safety Analysis demonstrates', the day before the reported final approval (it may refer to the DSA as submitted). No DOE document approving the PDSA, DSA, TSRs or startup was found on DOE's sites as of 29 September 2026 (see safe-007). DOE's Office of Environmental Management wrote on 14 July 2026 that its staff took part in DOE's review of the pilot microreactor designs 'from preliminary to final design', and that 17 EM team members took part in the readiness review for the four pilot reactors that went critical by 4 July, naming Ward 250 (dir-031); the article gives no Ward 250 dates or documents. Under 10 CFR 830.207(a), the rule the NSDA names, a contractor may not begin operating a new Hazard Category 1, 2 or 3 facility before DOE issues a safety evaluation report approving its safety basis; DOE's statement that Ward 250 was authorized and went critical fits that step having been completed, though the report itself was not found (safe-041).

• Valar Atomic's Ward 250 Becomes Second Reactor to Go Critical Under DOE Pilot Program (POWER magazine (Sonal C. Patel), 2026-06-19) news
• Castle Country | Valar Atomics (Valar Atomics) primary company “DOE-approved safety documentation and a completed operational readiness review”
• Valar's Ward 250 reaches criticality in Utah (American Nuclear Society, Nuclear Newswire, 2026-06-22) news
• Department of Energy Celebrates Second Advanced Reactor Achieving Criticality (U.S. Department of Energy, 2026-06-18) primary government “the first DOE authorized reactor built outside of a national laboratory”
• Ward250 Nuclear Safety Design Agreement, No. 100403, Rev 02 (status: Draft; issued for Public Release) (Valar Atomics, 2025-10) primary company
• 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 “The Documented Safety Analysis demonstrates”