Document: NRC Regulatory Guide
Document ID: dff52070-b179-4367-bf66-5d1107c54315
Document Type: regulatory_guide
Title: Design, Inspection, and Testing Criteria for Air Filtration and Adsorption Units of Normal Atmosphere Cleanup Systems in Light-Water-Cooled Nuclear Power Plants + HISTORY – HISTORY 06/2012 – DG-1280 , Proposed Revision 3 10/2000 – DG-1103 , Proposed Revision 2 (Rev. 3)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML1127/ML11273A057.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.140
CFR Part: 
CFR Title: 

Content:
erature and relative humidity, contribute to the aging and weathering of filters and adsorbers and reduce their reliability. Components of the normal atmosphere cleanup systems need to be designed for reliable performance under the expected operating conditions. Initial and inservice testing and proper maintenance are also primary factors in ensuring system reliability. Component and system design should support and facilitate testing, inspection, and maintenance through built-in layout and accessibility features. This regulatory guide only discusses impregnated activated carbon since it is the adsorber media used almost exclusively. Section FF of American Society of Mechanical Engineers (ASME) AG-1b- 2009, “Code on Nuclear Air and Gas Treatment”(Ref. 6), provides the terminology and describes the characteristics of adsorbent media. Previous revisions of this regulatory guide endorsed industry standards. This revision endorses updated industry standards. In addition to filtration systems used to treat exhausts from containment and auxiliary building atmospheres, cleanup systems are also used to treat process streams from power cycle waste offgas systems. These systems treat radioactive process and effluent streams characterized by the presence of noble gases, radioiodines, and mixtures of hydrogen and oxygen gases. These systems also operate to meet the “as low as reasonably achievable” requirements of 10 CFR 50.34a and 10 CFR 50.36a. The design of treatment systems used in power cycle waste offgas systems are characterized by the presence of hydrogen recombiners, compressors, delay tanks or vessels either empty or containing large amounts of activated carbon (e.g., hundreds of kilograms or thousands of pounds in PWRs or tens of thousands of kilograms/pounds in BWRs). The ASME Committee on Nuclear Air and Gas Treatment (CONAGT) has indicated their intention for future editions of the ASME AG-1 code to detail requirements for power cycle waste offgas systems.