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:
odes used to perform the analyses for developing the success criteria are validated and verified for both technical integrity and suitability to assess plant conditions of interest for prevention of a release and release in each of the reactor-specific release categories, and the computer codes accurately analyze the phenomena of interest. Qualified personnel who are well trained in the use of the codes perform the analyses of interest. The characteristics and attributes needed to achieve the objectives of a success criteria analysis PRA element are as follows: RG 1.247, Page 22 • Each of the modeled event sequences and event sequence families is defined. • The analysis defines the key safety functions, supporting systems, structures, radioactive material release barriers, components, and operator actions to support defensible technical basis development. • The analysis identifies and characterizes the sources of model uncertainty related to the success criteria analysis PRA element. • The success criteria are fully documented to provide traceability of the work. C.1.3.5 Systems Analysis Probabilistic Risk Assessment Element This section identifies the objectives and the characteristics and attributes of the systems analysis PRA element for an NLWR PRA that addresses all radiological sources, all hazards, all POSs, and all levels of PRA analysis. The objective of the systems analysis PRA element is to identify the various combinations of failures that can prevent a system from performing its function as defined by the success criteria. The model representing the various failure combinations includes the system hardware and instrumentation (and their associated failure modes) and human failure events (HFEs) that would prevent the system from performing its defined 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