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:
onstructed, and tested consistent with Section CA of ASME AG-1b-2009. c. HEPA filters should be designed, constructed, and tested consistent with Sections FC of ASME AG-1b-2009. HEPA filters should be compatible with the chemical and physical composition and physical conditions of the air stream. Each HEPA filter should be tested for penetration of a challenge aerosol, such as dioctyl phthalate or 4-centistoke poly- alpha olephin, in accordance with Section TA of ASME AG-1b-2009. d. HEPA and Type II adsorber cell mounting frames should be designed and constructed in accordance with Section FG of ASME AG-1b-2009. e. Filter and adsorber sections should be arranged in accordance with Section HA of ASME AG-1b-2009. f. Filter housings, including floors and doors, and electrical conduits, drains, and other piping installed inside filter housings should be designed and constructed in accordance with Section HA of ASME AG-1b-2009. g. If the relative humidity of the atmosphere entering the air cleanup system can be expected to exceed 70 percent during normal operation, the design should include heaters or cooling coils, or both, to maintain relative humidity at or below 70 percent to ensure adsorption unit efficiency. Heaters should be designed, constructed, and tested in accordance with Section CA of ASME AG-1b-2009. DG-1280, Page 6 h. Adsorber cells should be designed, constructed, and tested in accordance with Section FD for Type II or Section FE for Type III or Section FH of ASME AG-1b-2009 for Type IV adsorber cells. (1) Design of an adsorber section should consider possible iodine desorption and adsorbent autoignition that may result from radioactivity-induced heat in the adsorbent and concomitant temperature rise. If needed, prevention and mitigation features could include low-flow air or inert gas bleed, cooling coils, cleanup unit isolation, or water sprays. (2) If a water-based fire suppression or prevention (cooling) system is installed in a normal atmosphere