Document: NUREG-0800
Document ID: ac4cde5a-7464-48b8-9067-860c672cbb68
Document Type: srp
Title: STATION BLACKOUT
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0705/ML070550061.pdf
Revision Date: 2023-06
Chapter: 8
Section ID: 8.4
CFR Part: 
CFR Title: 

Content:
e. The AAC power source should have sufficient capacity to operate the systems necessary for coping with an SBO for the time necessary to bring and maintain the plant in a safe-shutdown condition. The plant systems, functions, and features discussed in Sections C.2 and C.3.3.1 to C.3.3.4 of RG 1.155 should be appropriately addressed as safe-shutdown non-DBA loads (including loads associated with any alternative or added capacity battery charging, water, or air sources to handle SBO). For new applications, the AAC source should be 8.4-12 March 2007 of diverse design (with respect to onsite sources); have adequate capacity, independence, and reliability; and have capability for powering at least one complete set of normal safe-shutdown loads. At sites where units share onsite emergency sources, the AAC power sources should have the capacity and capability to ensure that all units can be brought to and maintained in a safe-shutdown (non-DBA) condition. B. The staff reviews the independence of the AAC power source under SRP Section 8.2 to verify that the AAC source (or sources) 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. The review should determine that sufficient information has been provided to demonstrate adequate AAC source independence as follows: i. With respect to independence between the AAC power source used for SBO and the preferred and onsite power systems, electrical ties between these systems and the physical arrangement 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. ii. An acceptable design should not have the AAC power source normally directly connected to the preferred power system or to the blacked-out unit’s onsite EAC power system. No single