Document: NUREG-0800
Document ID: debf22b1-f3aa-4c75-a43c-f162d22de1c8
Document Type: srp
Title: of the plant safety analysis report (SAR).  Although the NRC did not endorse the annexes of
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML1515/ML15159A491.pdf
Revision Date: 2023-06
Chapter: 7
Section ID: 7.6
CFR Part: 
CFR Title: 

Content:
IEEE Std 7-4.3.2 in RG 1.152 subsections in this SRP appendix address guidance from some of the annexes. The criteria contained in IEEE Std 7-4.3.2, in conjunction with requirements in IEEE Std 603-1991, establish minimum functional and design criteria for computers used as components of a safety system. Although intended for digital safety systems, the criteria of IEEE Std 7-4.3.2 can be applied to any digital I&C system. For nonsafety digital I&C systems covered by SAR Sections 7.7 and 7.8, which are systems that have a high degree of importance-to-safety based on risk, graded application of the criteria of IEEE Std 7-4.3.2 could be considered by the reviewer. Data communications systems covered by SAR Section 7.9 are support systems to I&C systems. Hence, the criteria and guidance for the communications systems are the same as those for the principal I&C systems they support. The coordination review needed for each I&C system is discussed in SRP Section 7.0. 3. DEFINITIONS This SRP appendix does not provide any additional definitions to those that appear in IEEE Std 7-4.3.2. 4. SAFETY SYSTEM DESIGN BASIS (IEEE Std 7-4.3.2, Clause 4) Clause 4 of IEEE Std 603-1991 requires that the specific bases established for the design of each safety system be reviewed to determine whether they are consistent with the requirements of Clause 4 of IEEE Std 603-1991. Section 4 of SRP Appendix 7.1-C provides review guidance. 5. SAFETY SYSTEM CRITERIA (IEEE Std 7-4.3.2, Clause 5) Clause 5 of IEEE Std 603-1991 requires that safety systems shall, with precision and reliability, maintain plant parameters within acceptable limits established for each design basis event. The following subsections address the criteria in the order they are listed in IEEE Std 7-4.3.2. For some criteria there are no additional criteria beyond what is stated in IEEE Std 603-1991 and the appropriate subsection of SRP Appendix 7.1-C is referenced. 5.1. Single-Failure Criterion (IEEE Std 7-4.3.2, Clause 5.1)