Document: NRC Regulatory Guide
Document ID: 7d480029-59df-44fe-9db8-c1c86566dac9
Document Type: regulatory_guide
Title: Operation and Maintenance Code Case Acceptability, ASME OM Code (Rev. 5)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML2219/ML22196A063.pdf
Revision Date: 2023-05
Chapter: 
Section ID: RG-1.192
CFR Part: 
CFR Title: 

Content:
ppropriate RG 1.200 capability for specific hazard group(s) (e.g., seismic and fire) is not available. (6) Section 4.2.4, “Reconciliation,” Paragraph (b), is not endorsed. The expert panel may not classify components that are ranked HSSC by the results of a qualitative or quantitative PRA evaluation (excluding the sensitivity studies) or the defense-in-depth assessment as a low safety significant component (LSSC). DG-1407, Page 11 Code Case Number Table 2 Conditionally Acceptable OM Code Cases Title/Condition OMN-3 (2022 Edition) (cont’d) (7) Implementation of Section 3.3, “Living PRA,” must be consistent with the following: (1) To account for potential changes in failure rates and other changes that could affect the PRA, changes to the plant must be reviewed, and, as appropriate, the PRA updated. (2) When the PRA is updated, the categorization of structures, systems, and components must be reviewed and changed if necessary to remain consistent with the categorization process. (3) The review of plant changes must be performed in a timely manner and must be performed once every two refueling outages or as required by 10 CFR 50.71(h)(2) for combined license holders. Note 1: The OM Code Case methodology for risk ranking uses two categories of safety significance. The NRC staff has determined that this is acceptable for ranking all component types. However, the NRC staff has accepted other methodologies for risk ranking MOVs, with certain conditions, that use three categories of safety significance. Note 2: These conditions are identical to those imposed on OMN-3 in previous revisions to RG 1.192. OMN-4 (2022 Edition) Requirements for Risk Insights for Inservice Testing of Check Valves at LWR Power Plants (1) Valve opening and closing functions must be demonstrated when flow testing or examination methods (nonintrusive, or disassembly and inspection) are used. (2) The initial interval for tests and associated examinations may not exceed two fuel cycles or 3