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:
ted (1) consistent with and at the frequency intervals shown in Section 5.8 and Appendix IV to ASME N511-2007, DG-1280, Page 9 (2) following removal of an adsorber sample for laboratory testing if the integrity of the adsorber section is affected, (3) after each partial or complete replacement of carbon adsorber in an adsorber section, (4) following detection of, or evidence of, penetration or intrusion of water or other material into any portion of a normal atmosphere cleanup system that may have an adverse effect on the functional capability of the adsorbers, and (5) following painting, fire, or chemical release in any ventilation zone communicating with the system that may have an adverse effect on the functional capability of the system. The leak test should confirm a combined penetration and leakage (or bypass) of the adsorber section of 0.05 percent or less of the challenge gas at a system-rated flow ±10 percent. e. Adsorber sections that fail to satisfy the appropriate leak test conditions should be examined to determine the location and cause of leaks. Adjustments, such as alignment of adsorber cells, tightening of adsorber cell holddown fasteners, or tightening of test canister fixtures, may be made. Defective or damaged adsorber cells, mounting frames, or housings should not be temporarily repaired with patching material or caulking. After adjustments or adsorber cell replacement, the cleanup system should be retested. f. Painting, fire, or chemical release is “not communicating” with the HEPA filter or adsorber if the cleanup system is not in operation, the isolation dampers 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. Conservative, well- documented administrative controls should be implemented that define the terms “painting,” “fire,” and “chemical release” with respect to the potential for degrading cleanup