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:
on DG-1362, Page 26 Table 6. Summary of Technical Characteristics and Attributes of a Seismic PRA for the At- Power Operating Mode Element Technical Characteristics and Attributes - broad-band, smooth spectral shapes for lower-seismicity sites acceptable if shown to be appropriate for the site - uniform hazard response spectra acceptable if it reflects the site-specific shape • Assess whether for the specific application, other seismic hazards should be included in the seismic PRA, such as - fault displacement - landslide, - soil liquefaction - soil settlement Seismic Fragility Analysis • Seismic fragility estimate - plant-specific - realistic - includes all systems that participate in accident sequences included in the seismic-PRA systems model - basis for screening of high capacity components is fully described • Seismic fragility evaluation performed for critical SSCs based on - review of plant design documents - earthquake experience data - fragility test data - generic qualification test data (use is justified) - analytical approaches using plant- and location-specific seismic demand information - walkdowns • walkdowns focus on as-built and as-operated plant configuration, including: - anchorage - lateral seismic support - potential systems interactions Seismic Plant Response Analysis • The seismic PRA models include - seismic-caused initiating events - seismically induced SSC failures - nonseismically induced unavailabilities, - other significant failures (including human errors) that can lead to CDF or LERF/LRF • The seismic PRA models - adapted to incorporate seismic-analysis aspects that are different from corresponding aspects found in the at-power, internal events PRA model - reflects the as-built and as-operated plant being analyzed • Quantification of CDF and LERF/LRF integrates - the seismic hazard - the seismic fragilities - the systems analysis DG-1362, Page 27 Technical Elements for Screening and Conservative Analysis of Hazards for an