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:
essment of the effects associated with residual CCF vulnerabilities that have not been either eliminated from further consideration or mitigated in some manner, and whether the assessment demonstrates that (1) the consequences of the residual CCF remain acceptable or (2) the residual CCF is not risk significant The reviewer should consider whether the applicant’s assessment has properly identified and addressed CCFs and whether the applicant has incorporated appropriate means to limit, mitigate, or withstand or cope with (i.e., accept the consequences of) possible CCFs and sources of CCF vulnerability that can result in spurious operations. Alternatively, if the application includes a risk-informed approach, the reviewer should consider whether the assessment demonstrates that the residual CCF is not risk significant. 1.1 Common-Cause Failure Position and Discussion The foundation of BTP 7-19 is the NRC position on D3 from SRM-SECY-22-0076, which is centered on the four points below: 1. The applicant must assess the defense in depth and diversity of the facility incorporating the proposed digital I&C system to demonstrate that vulnerabilities to digital CCFs have been adequately identified and addressed. The defense-in-depth and diversity assessment must be commensurate with the risk significance of the proposed digital I&C system. 2. In performing the defense-in-depth and diversity assessment, the applicant must analyze each postulated CCF using either best-estimate methods or a risk-informed approach or both. When using best-estimate methods, the applicant must demonstrate adequate defense in depth and diversity within the facility’s design for each event evaluated in the accident analysis section of the safety analysis report. When using a risk-informed approach, the applicant must include an evaluation of the approach against the Commission’s policy and BTP 7-19-10 Revision 9 — May 2024 guidance, including any applicable regulations, for risk-informed