Document: NUREG-0800
Document ID: a2680f96-0e15-402d-89ab-688ff09806a8
Document Type: srp
Title: with respect to the specified station blackout event/duration.13
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0520/ML052070497.pdf
Revision Date: 2023-06
Chapter: 8
Section ID: 8.3.2
CFR Part: 
CFR Title: 

Content:
t of the interface equipment should minimize the potential for the loss of any system (i.e., preferred, onsite, or AAC) preventing access to any other system and the potential for such a loss to cause further failures in other systems.124 b. An acceptable design should not have the AAC power source normally directly connected to the preferred power system or the blacked-out unit's onsite emergency ac power system. No single point vulnerability should exist whereby a single active failure or weather-related event could simultaneously fail the AAC and preferred power sources or simultaneously fail the AAC and onsite sources. The power sources should have minimum potential for common failure modes.125 c. The AAC components should be physically separated and electrically isolated from safety-related components or equipment as specified in the separation and isolation criteria applicable to the unit's licensing basis and the criteria of Appendix B of Regulatory Guide 1.155. Based upon compliance with all relevant independence criteria and guidelines, it should be demonstrated that provisions for the AAC source will not, at any time, adversely affect the functioning of offsite and/or Class 1E onsite power systems. Also, failure of the AAC power components must not adversely affect the Class 1E ac power systems.126 DRAFT Rev. 4 - April 1996 8.2-28 d. The reviewer verifies that provisions for an AAC source meet the relevant criteria specified in Regulatory Guide 1.155 Appendix B, satisfy Regulatory Guide 1.155 Positions C.3.3.5.1 and C.3.3.5.2, will not adversely affect the preferred power system or its specified functions, and will not adversely affect the onsite power system or its specified safety functions. Careful examination should be made of the physical arrangement of circuits and incoming source breakers [to the affected Class 1E bus(es)], separation and isolation provisions (control and main power), permissive and interlock schemes proposed for source breakers,