Document: NUREG-0800
Document ID: d804e0bf-cdaf-4241-8a9e-1eaa21d9ca1a
Document Type: srp
Title: ENGINEERED SAFETY FEATURES SYSTEMS
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0523/ML052350475.pdf
Revision Date: 2023-06
Chapter: 7
Section ID: 7.3
CFR Part: 
CFR Title: 

Content:
nts that are specific in nature. For example paragraph 4.9 of IEEE Std 279 requires that the design include means for checking the availability of each system input sensor during operation. Appendix B outlines a straight- forward procedure that can be used to determine whether or not this requirement is met. Appendix.B discusses the requirements of IEEE Std 279 and how they are used in the review of the protection system. Although the primary emphasis is on the equipment comprising the protection system, the reviewer should consider the protective functions on a systems level. It is necessary that the ESFAS design be compatible with the ESF systems and EAS systems and that the ESFAS design and the accident analysis are compatible. It is not sufficient to judge the adequacy of the ESFAS only on the basis of the design meeting the specific requirements of IEEE. Std 279. It is also necessary to judge the functional relationship between the-ESFAS and the ESF systems themselves. An important part of the review is the engineering drawing review at the OL stage. The drawing review should confirm that the design and layout meet the applicable criteria listed under subsection II. A site visit should be performed before the evaluation findings are written for an OL. The site visit should include an audit verification that the design and layout criteria reviewed during the drawing review are implemented. An outline of topics for a site visit is provided in SRP Appendix 7-B (Ref. 6). In certain instances, it will be the reviewer's judgment that for a specific case under review, emphasis should be placed on specific aspects of the design, while other aspects of the design need not receive the same emphasis and indepth review. Typical reasons for such a nonuniform placement of emphasis are the introduction of new design features or the utilization in the design of design features previously reviewed and found acceptable. However, in all cases, the review must be sufficient to