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:
us operation). This will tend … ES-B4 SR refers to incorrect SR Clarification … equipment identification per SRs ES- B1 through ES-B3B4. DG-1362, Appendix A, Page A-25 Table A-4. Staff Position on ASME/ANS RA-Sa-2009 Part 4, Technical and Peer Review Requirements for At-Power Internal Fire Index No Issue Position Resolution ES-C1 There is a concern with the way in which the term “significant’ has been used. It is ambiguous as to whether the reference is to the total CDF, the internal events CDF, or the fire CDF. In order to avoid ambiguity, it is necessary to have a definition of the term “significant.” The terms “significant accident sequence,” “significant accident progression sequence,” “significant basic event,” “significant cutset,” and “significant contributor” are defined in Part 1 within the context of the hazard group, so that in Part 3, they should be interpreted as being measured with respect to the fire risk. Clarification NOTE-ES-C1-3: … is not a significant contributor (as defined in Part 1), … ES-C2 -------------------- No objection -------------------- ES-D1 -------------------- No objection -------------------- 4-2.3 – CS 4-2.3 -------------------- No objection -------------------- Table 4-2.3-1 -------------------- No objection -------------------- Tables 4-2.3-2(a) thru 4-2.3-4(c) CS-A1 thru CS-A9, CS-A11 -------------------- No objection -------------------- DG-1362, Appendix A, Page A-26 Table A-4. Staff Position on ASME/ANS RA-Sa-2009 Part 4, Technical and Peer Review Requirements for At-Power Internal Fire Index No Issue Position Resolution CS-A10 PP-B1 already allows physical analysis units to be defined in terms of fire areas. As such the distinction between CCI and CCII is unnecessary. Clarification Cat I: IDENTIFY the fire areas … and CONFIRM … terminal end locations. Cat II: IDENTIFY … and CONFIRM … terminal end locations. Cat I and II: IDENTIFY the physical analysis units, consistent with the