The categorical exclusion says routine discharge of liquid radioactive effluent is prohibited, with infrequent batch releases allowed only below DOE's derived concentration standards (NE O 458.1) and 'in accordance with local utility permits'; gaseous effluents are 'negligible'; HEPA-filtered ventilation keeps negative pressure; 'No Clean Air Act permits are required'; and the public dose limit is 100 millirem a year. The NSDA says radiological air emissions 'will be evaluated' for the EPA's radionuclide air standard (40 CFR 61 Subpart H), with EPA coordination through DOE's Idaho Operations Office, and promises environmental monitoring data sharing and 'Regular environmental reporting' to state agencies. The NSDA's continuous-monitoring list covers neutron flux (three channels), core outlet temperature, primary coolant pressure and area radiation levels, and it commits to real-time fission-product ('fission break') monitoring with shutdown required on high coolant activity; the CX describes that shutdown as automatic. No environmental monitoring results, EPA air-emission determination, utility discharge permit, or state report naming Ward 250 was found on DOE, EPA or Utah DEQ pages read as of 29 September 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 “Routine discharge of liquid radioactive effluent is prohibited.”
• 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 “No Clean Air Act permits are required.”
• Ward250 Nuclear Safety Design Agreement, No. 100403, Rev 02 (status: Draft; issued for Public Release) (Valar Atomics, 2025-10) primary company “Radiological air emissions will be evaluated for compliance with 40 CFR 61 Subpart H”
• Ward250 Nuclear Safety Design Agreement, No. 100403, Rev 02 (status: Draft; issued for Public Release) (Valar Atomics, 2025-10) primary company “Regular environmental reporting maintains transparency with state environmental agencies.”
• 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 “with automatic reactor shutdown on detection of elevated primary coolant activity”