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:
Design Criterion GDC 17. 5. 10 CFR 50.63 as it relates to an AAC power source (as defined in 10 CFR 50.2) provided for safe shutdown (non-DBA) in the event of a station blackout, and the guidelines of Regulatory Guide 1.155 as they relate to the adequacy of the AAC source and the independence of the AAC power source from the offsite power system and onsite power system and sources. For new applications, an adequate AAC source of diverse design (with respect to ac onsite emergency sources) that is consistent with the guidance in Regulatory Guide 1.155 must be provided, with sufficient capacity and capability for powering at least one complete set of normal safe shutdown loads.50 Technical Rationale51 The technical rationale for application of these acceptance criteria to reviewing offsite power systems is discussed in the following paragraphs:52 1. Compliance with GDC 5 requires that structures, systems, and components important to safety shall not be shared among nuclear power units, unless it can be shown that such sharing will not significantly impair their ability to perform their safety functions, including, in the event of an accident in one unit, an orderly shutdown and cooldown of the remaining units. This criterion requires that component parts of the offsite power system not be shared among units without sufficient justification, thereby ensuring that an accident in one unit of a multiple-unit facility can be mitigated using an available compliment of mitigative features, including required ac power, irrespective of conditions in the other units and without giving rise to conditions unduly adverse to safety in another unit. SRP 8.2-7 DRAFT Rev. 4 - April 1996 Section 8.2 cites Regulatory Guide 1.32 to establish acceptable guidance related to the sharing of structures, systems, and components of the preferred offsite power system. Meeting the requirements of GDC 5 provides assurance that an accident within any one unit of a multiple-unit plant may be