Document: NRC Regulatory Guide
Document ID: 8a2332d3-66ca-40af-84e1-507db8b26559
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:
sis. The objectives of the HRA PRA element are to identify and define the HFEs that can negatively impact normal or emergency plant operation and quantify their probabilities. The HFEs associated with normal plant operation include the events that leave the system (as defined by the success criteria) in an unrevealed, unavailable state. The HFEs associated with emergency plant operation represent those human actions that, if not performed or performed incorrectly, do not allow the needed system to function. Quantification of the probabilities of these HFEs is based on plant- and accident-specific conditions, where applicable, considering recovery actions and including any dependencies among actions and conditions. References such as, but not limited to, NUREG-1792, “Good Practices for Implementing Human Reliability Analysis (HRA),” issued April 2005 (Ref. 34); NUREG-1842, “Evaluation of Human Reliability Analysis Methods Against Good Practices,” issued September 2006 (Ref. 35); and NUREG-2198, “The General Methodology of an Integrated Human Event Analysis System (IDHEAS-G),” issued May 2021 (Ref. 36), provide good practices for meeting the following technical characteristics and attributes that are needed for the HRA PRA element for an internal events PRA during the applicable POSs. The characteristics and attributes needed to achieve the objectives of the HRA PRA element are as follows: • The HRA PRA element is performed on a POS-by-POS basis. • The HFEs that would result in initiating events (initiators), and pre- and post-initiator HFEs that would impact the mitigation of initiating events are identified and defined. • Recovery actions and dependent HFEs are identified. • The credit for recovery actions is justified. • Calibration errors or other errors that may impact equipment performance during the applicable POS are considered. (Note: The calibration errors or other errors may occur at a different POS from the POS being analyzed.) •