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:
cludes the same characteristics and attributes as for at-power, as well as the following: ─ differentiation between calibration errors that may impact equipment performance at-power versus low-power and shutdown POSs ─ increased emphasis on contributions to initiating events ─ performance of the analysis on a POS basis ─ identification of dependent HFEs, particularly between those resulting in initiating events and those associated with responses to the initiating events ─ justification for credit of operator actions credited for recovery in slowly developing scenarios (e.g., recovery times greater than 24 hours) Quantification • Quantification includes the same characteristics and attributes for at-power, as well as the estimation of CDF and LERF/LRF for each POS Level 2 Internal Events Plant Damage • The plant damage state analysis includes the same characteristics and attributes as for at-power DG-1362, Page 33 Table 11. Summary of Technical Characteristics and Attributes of a Level 1 and Level 2, Internal Events PRA for the Low Power and Shutdown Operating Modes Element Technical Characteristic and Attributes State Analysis Severe Accident Progression Analysis • The severe accident progression analysis includes the same characteristics and attributes as for at-power, as well as the following: ─ estimation of containment capacity based on the capacity of temporary closure, although for some POSs, containment may be open or have a reduced pressure capability ─ assessment of the feasibility of the ability of operators to close containment before (1) adverse environmental conditions (e.g., temperature, radiation, humidity, noise) prevent closure or (2) core cooling is impacted Quantification • Quantification includes the same characteristics and attributes as for at-power. Source Term Analysis • The source term analysis includes the same characteristics and attributes as for at- power. NOTE: (1) For low-power and shutdown conditions, the