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:
ad to core damage or large early release. The model is adapted from the internal events, at-power PRA model to incorporate unique flood- analysis aspects that are different from the at-power, internal events PRA model. Table 9. Summary of Technical Characteristics and Attributes of an External Flood PRA for the At-Power Operating Mode Element Technical Characteristics and Attributes External Flood Hazard Analysis • Probabilistic flood hazard analysis - results in frequency of external flood at the site - based on site-specific data - reflects recent information • Uncertainties in the models and parameter values - properly accounted for - fully propagated - allow estimate of mean hazard curve DG-1362, Page 30 Table 9. Summary of Technical Characteristics and Attributes of an External Flood PRA for the At-Power Operating Mode Element Technical Characteristics and Attributes External Flood Fragility Analysis • Flood fragility estimate - plant-specific, - realistic - all SSCs whose failure contributes to core damage or large early release included - walkdowns focus on as-built and as-operated plant configuration External Flood Plant Response Analysis • External flood PRA model - includes all significant flood-caused initiating events - includes other significant failures (both those that are caused by the flood and those that are random failures) that can lead to CDF or LERF/LRF - adapted from the internal events, at-power PRA model - incorporates unique flood-analysis aspects that are different from the at- power, internal events PRA model. Technical Elements for Other Hazards At-Power PRA This section identifies the technical elements for Other Hazards, at-power PRA. As discussed in regulatory position C.1.1, Other Hazards are those hazards that are not categorized under the internal events, internal flood, internal fire, seismic, high wind or external flood hazards groups and cannot be screened out by a screening analysis, as described in regulatory position