Document: NUREG-0800
Document ID: 18405759-3ae6-4408-b6ab-7b3ca11fcd9f
Document Type: srp
Title: SAFE SHUTDOWN SYSTEMS
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0705/ML070550085.pdf
Revision Date: 2023-06
Chapter: 7
Section ID: 7.4
CFR Part: 
CFR Title: 

Content:
ms design against the guidance of IEEE Std 603-1991, or IEEE Std 279-1991, depending on the applicant/licensee’s commitment regarding these design criteria. For computer-based safe shutdown systems, the guidance is provided by IEEE Std 7-4.3.2-2003 as endorsed by Regulatory Guide 1.152, Revision 2. These procedures are detailed in SRP Appendix 7.1-B for IEEE Std 279-1971, SRP Appendix 7.1-C for IEEE Std 603-1991, and SRP Appendix 7.1-D for IEEE Std 7-4.3.2-2003. SRP Appendices 7.1-B and 7.1-C discuss the requirements of IEEE Std 279-1971 and IEEE Std 603-1991, respectively, and how they are used in the review of safe shutdown systems. SRP Appendix 7.1-D discusses the criteria of IEEE Std 7-4.3.2-2003 and how they are used in the review of safe shutdown systems. Although the primary emphasis is on the equipment comprising the safe shutdown systems, the reviewer should consider the safe shutdown functions at the system level. The safe shutdown systems design should be compatible with the SAR Chapter 15 design bases accident analyses. It is not sufficient to evaluate the adequacy of the safe shutdown systems only on the basis that the design meets the specific requirements of IEEE Std 279-1971 or IEEE Std 603-1991. 1Shutdown remote from the control room is not an event analyzed in the accident analysis in Chapter 15 of the SAR. Specific scenarios have not been specified on which the adequacy of shutdown capability remote from the control room is evaluated. However, smoke due to a fire in the control room has long been recognized as the type of event that could force the evacuation of the control room and result in a need to shut down remote from the control room. Regulatory Guide 1.189, “Fire Protection for Operating Nuclear Power Plants,” establishes the bases for safe shutdown with respect to fire protection. Specifically, fire damage limits as they impact safe shutdown have been established therein. These limits do not require consideration of an additional,