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:
s for each PRA element sufficient to understand the bases of the results of the PRA, including any analysis that is unique to a PRA analysis element. • The documentation describes the identification and analysis of sources of uncertainty, related assumptions, and reasonable alternatives sufficient to understand the bases of the results of the PRA. • The documentation describes assumptions and limitations of the PRA due to a lack of data or available plant information. RG 1.247, Page 52 • The documentation describes the bases for and impact of risk-significant contributors. • The documentation describes the walkdown process, where applicable, and results of the walkdown. In cases where walkdowns cannot be performed, the documentation describes the evaluation of available data and findings of investigation(s) of the plant design and operations information and the results of that evaluation. • The documentation describes the results of and bases for each screening analysis, which includes but may not be limited to documenting the selection and application of screening criteria, assumptions used and their validity, the identification and characterization of associated uncertainties, and how the bases for a given screening analysis were confirmed. C.1.4 Plant Representation and Probabilistic Risk Assessment Configuration Control Plant representation is defined in terms of how closely the PRA represents the as-designed, as-to-be-built, or as-to-be-operated plant or the as-built and as-operated plant. In general, PRA results used to support an application should be derived from a PRA model that represents the as-designed, as-to-be-built, or as-to-be-operated, plant or the as-built and as-operated plant to the extent needed to support the application. Consequently, the PRA is maintained and upgraded, as needed, to ensure that it represents the as-designed, as-to-be-built, or as-to-be-operated plant or the as-built and as-operated plant, depending on where it is