Document: NRC Regulatory Guide
Document ID: cde52d5a-adf9-49be-9d1f-59449dfca895
Document Type: regulatory_guide
Title: TRIAL - Acceptability of Probabilistic Risk Assessment Results for Non-Light Water Reactor Risk-Informed Activities
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML2123/ML21235A008.pdf
Revision Date: 2023-05
Chapter: 
Section ID: RG-1.247
CFR Part: 
CFR Title: 

Content:
t is important to assess the feasibility of a human action (even during quantification). Further, ESQ-C7 requires that human actions be feasible in order to use their respective HEPs in event sequence quantification. Since the NLWR PRA Qualification CC-I ASSESS the feasibility of the HFEs before assigning the final HEPs using the criteria in HR-H2. For HFEs determined to be feasible, USE conservative estimates for the HEPs of the HFEs in the event sequences that survive initial quantification. CC-II ASSESS the feasibility of the HFEs before assigning the final HEPs using the criteria in HR-H2. For HFEs determined to be feasible, PERFORM detailed analyses for estimation of HEPs for risk- significant HFEs. For the HEPs of HFEs that are not risk-significant, ENSURE the requirement for CC-I is met. RG 1.247, Appendix A, Page A-18 Table A-7. Staff Position on ASME/ANS RA-S-1.4-2021, Technical Requirements for Human Reliability Analysis Index No. Issue Position Resolution standard does not explicitly require a feasibility assessment, this step in the HRA process may be missed, which would cause the PRA model to underestimate the risk from that human action. HR-G2 and HR-G3 ------------------------ No objection ---------------------------------- HR-G4 Communication is an important performance-shaping factor for actions taken outside the main control room (e.g., in fire scenarios) and that require complex coordination, such as the use of FLEX equipment. As such, all aspects of communication should be evaluated when estimating HEPs. Clarification CC-II (p) communication among personnel on the same team and on different teams. HR-G5 through HR-G16 ------------------------ No objection ---------------------------------- Table 4.3.6.1-9 HR-H1 ------------------------ No objection ---------------------------------- HR-H2 Having a limited set of feasibility criteria and constraining their applicability only to recovery actions (i.e., a special case of post- initiator actions) may