Document: NRC Regulatory Guide
Document ID: 5ec01b96-5209-446f-95b3-7342d73ba086
Document Type: regulatory_guide
Title: Design, Inspection, and Testing Criteria for Air Filtration and Adsorption Units of Post-Accident Engineered-Safety-Feature Atmosphere Cleanup Systems in Light-Water-Cooled Nuclear Power Plants + HISTORY - HISTORY 12/2011 – DG-1274 , Proposed Revision 4 10/2000 – DG-1102 , Proposed Revision 3 (Rev. 4)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML1124/ML11244A045.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.52
CFR Part: 
CFR Title: 

Content:
ated flow plus or minus 10 percent. To be credited with 99-percent removal efficiency for particulate matter in accident dose evaluations, a HEPA filter bank in an ESF atmosphere cleanup system should demonstrate an aerosol leak test result of less than 0.05 percent of the challenge aerosol at system rated flow plus or minus 10 percent. The test should be documented in accordance with Section TA-6000 of ASME AG-1-2009 with addenda. d. HEPA filter sections in ESF atmosphere cleanup systems that fail to satisfy the appropriate leak-test criteria should be examined to determine the location and cause of leaks. Adjustments, such as alignment of filter cases and tightening of filter holddown bolts, may be made; however, patching or caulking materials should not be used in the repair of defective, damaged, or torn filter media in ESF atmosphere cleanup systems: such filters should be replaced and not repaired. HEPA filters that fail to satisfy test criteria should be replaced with filters qualified under Regulatory Position 4.d of this guide. After adjustments or filter replacement, the ESF atmosphere cleanup system should be retested as described above in this regulatory position. The 7 Painting, fire, or chemical release is “not communicating” with the HEPA filter or adsorber if the ESF atmosphere cleanup system is not in operation, the isolation dampers for the system are closed, and there is no pressure differential across the filter housing. This provides reasonable assurance that air is not passing through the filters and adsorbers. A program should be developed and consistently applied that defines the terms “painting,” “fire,” and “chemical release” in terms of the potential for degrading the HEPA filters and adsorbers. This program should be based on a well-documented, sound, and conservative technical basis (i.e., the criteria should overestimate the potential damage to the filter and adsorber). 8 In Section FD-1130 of ASME AG-1-2009 with