Document: NUREG-0800
Document ID: fe8ec6c2-e960-404c-854f-55c77bde1672
Document Type: srp
Title: NUREG-0800
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML2400/ML24005A077.pdf
Revision Date: 2024-05
Chapter: 7
Section ID: 7
CFR Part: 
CFR Title: 

Content:
viewer should confirm whether any changes made to the PRA model constitute PRA maintenance or a PRA upgrade, based on the corresponding definition in the identified guidance. SRP Section 19.2 provides guidance for performing a focused-scope review of the risk analysis on an application-specific basis, as needed. The reviewer should determine whether the application explains how the CCF is modeled in the PRA and provides justification that the modeling includes the impact of the CCF. In providing the justification, the application should evaluate DI&C system interconnectivity and address DI&C system spatial separation that could significantly influence the risk due to fires, earthquakes, and other hazards. This can be accomplished through detailed modeling of the DI&C system in the PRA or the use of surrogate events, which could be existing basic events in the PRA or new basic events added to the PRA that include the impact of the CCF on the plant. The application may address each CCF using a different approach (i.e., the application may address some CCFs through detailed modeling of the DI&C system and other CCFs using surrogate events). Since a CCF could affect a single plant system or function or multiple plant systems or functions, considerable care should be taken in reviewing how the CCF is modeled. The I&C technical reviewer and risk analyst should coordinate the review to ensure that the application sufficiently addresses the impact of the CCF on plant systems and functions. Acceptance Criteria for Modeling Common-Cause Failures If the application meets the following acceptance criteria, the reviewer should conclude that the application provides sufficient information on modeling the CCF to determine its risk significance: a. The application identifies the base PRA used for the risk-informed D3 assessment, identifies the basis for the technical acceptability of the base PRA (e.g., a specific revision of RG 1.200 or equivalent guidance for new reactors, such