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:
efined functions. The basic events representing equipment and HFEs are developed in sufficient detail in the model to account for dependencies among the various systems and to distinguish the specific equipment or human events that have a major impact on the system’s ability to perform its function. The scope of considered HFEs does not include human-induced security events (e.g., sabotage, malevolent acts). The characteristics and attributes needed to achieve the objectives of a systems analysis PRA element are as follows: • The models are developed in sufficient detail. • The models reflect the as-designed, as-to-be-built, and as-to-be-operated plant (as applicable). • The models reflect the success criteria for the systems to mitigate each identified event sequence. • The models account for both inter- and intra-system dependencies, including support systems, and impacts of dependencies and abnormal environments. • The models include both active and passive components and failure modes that impact the functions of the system. • The models include common-cause failures, human errors, unavailability resulting from test and maintenance, and phenomenological effects, as well as dependencies on POSs. • The models include mission times, failure modes associated with system maintenance, component actuation and functionality, and associated HFEs. • The models include the sources of model uncertainties related to the system analysis. RG 1.247, Page 23 C.1.3.6 Human Reliability Analysis Probabilistic Risk Assessment Element This section identifies the objectives and the characteristics and attributes of the human reliability analysis (HRA) PRA element for an NLWR PRA that addresses all radiological sources, all hazards, all POSs, and all levels of PRA analysis. 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