Document: NRC Regulatory Guide
Document ID: 22ccfd5e-c5d8-4615-a02c-32369aa9f533
Document Type: regulatory_guide
Title: Acceptability of Probabilistic Risk Assessment Results for Risk-Informed Activities (Rev. 3)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML1930/ML19308B636.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.200
CFR Part: 
CFR Title: 

Content:
enomena that have not been screened out. The types of high wind events that should be considered in the analysis are site dependent. These can include tornados and their effects, cyclones, hurricanes, and typhoons, as well as thunderstorms, squall lines, and other weather fronts. It is assumed that the high wind PRA is based on modifications made to an existing up-to-date internal events, at-power PRA. The technical elements for a high wind PRA are similar to those for a seismic PRA. Because of its dependence on the internal events model, the high wind PRA incorporates the elements of regulatory positions C.1.2.1 and C.1.2.2, as necessary. High Wind Hazard Analysis estimates the frequency of high wind at the site using a site- specific probabilistic wind hazard analysis that incorporates the available recent regional and site-specific information and uses up-to-date databases. Uncertainties in the models and parameter values are properly accounted for and fully propagated to allow the derivation of a mean hazard curve from the family of hazard curves obtained. High Wind Fragility Analysis is an evaluation that is performed to estimate plant-specific, realistic wind fragilities for those structures, or systems, or components (or their combination) whose failure contributes to core damage or large early release. High Wind Plant Response Analysis uses a high wind PRA systems model that includes all significant high wind-caused initiating events and other failures that can lead to core damage or large early release. The model is adapted from the internal events, at-power PRA model to incorporate unique high wind analysis aspects that are different from the at-power, internal events PRA model. Table 8. Summary of Technical Characteristics and Attributes of a High Wind PRA for the At- Power Operating Mode Element Technical Characteristics and Attributes High Wind Hazard Analysis • Probabilistic wind hazard analysis - results in frequency of high wind at the site - based