Document: NRC Regulatory Guide
Document ID: 22ccfd5e-c5d8-4615-a02c-32369aa9f533
Document Type: regulatory_guide
Title: Acceptability of Probabilistic Risk Assessment Results for Risk-Informed Activities (Rev. 3)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML1930/ML19308B636.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.200
CFR Part: 
CFR Title: 

Content:
---------------- Table 2-2.6-1 -------------------- No objection -------------------- Tables 2-2.6-2(a) thru 2-2.6-6(e) DA-A1 thru DA-A4 -------------------- No objection -------------------- DG-1362, Appendix A, Page A-14 Table A-2. Staff Position on ASME/ANS RA-Sa-2009 Part 2, Technical and Peer Review Requirements for At-Power Internal Events Index No Issue Position Resolution DA-B1, DA-B2 -------------------- No objection -------------------- DA-C1 thru DA-C14, DA-C16 -------------------- No objection -------------------- DA-C15 This SR provides a justification for crediting equipment repair (SY- A24). As written, it could be interpreted as allowing plant-specific data to be discounted in favor of industry data. In reality, for such components as pumps, plant-specific data is likely to be insufficient and a broader base is necessary. Qualification …IDENTIFY instances of plant-specific experience or and, when that is insufficient to estimate failure to repair consistent with DA-D9, applicable industry experience and for each repair, COLLECT…. DA-D2 thru DA-D8 -------------------- No objection -------------------- DA-D1 Other approved statistical processes for combining plant-specific and generic data are not available. Clarification CC II and III: …USE a Bayes update process or equivalent statistical process that assigns that assigns appropriate weight to the statistical significance of the generic and plant specific evidence and provides an appropriate characterization of the uncertainty. CHOOSE…. DA-D9 New requirement needed, DA-C15 was incomplete, only provided for data collection, not quantification of repair. (See SY-A24.) Qualification Cat I, II, and III: For each SSC for which repair is to be modeled, ESTIMATE, based on the data collected in DA-C15, the probability of failure to repair the SSC in time to prevent core damage as a function of the accident sequence in which the SSC failure appears. DA-E1 thru DA-E3 -------------------- No objection