Document: NUREG-0800
Document ID: 8c755ba5-45e1-492e-b36c-5fa2fa5b3e29
Document Type: srp
Title: Appendix 7-A
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0525/ML052500545.pdf
Revision Date: 2023-06
Chapter: 7
Section ID: 7
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CFR Title: 

Content:
protective action will correct the most severe abnormal situation anticipated without exceeding a safety limit. Limiting safety system settings are settings for automatic protective devices related to those variables having significant safety functions. Setpoints found to exceed technical specification limits are considered a malfunction of an automatic safety system. Such an occurrence could challenge the integrity of the reactor core, reactor coolant pressure boundary, containment, and associated systems. 2. Relevant Guidance Draft Reg. Guide DG-1045, proposed revision 3 to Reg. Guide 1.105, "Instrument Setpoints for Safety Systems," provides guidance for ensuring that instrument setpoints are initially within and remain within the technical specification limits. The guidance of this Reg. Guide is referenced to ISA-S67.04 Part I, "Setpoints for Nuclear Safety-Related Instrumentation Used in Nuclear Power Plants." ISA-S67.04, Part II, provides additional background information. Rev. 4 — June 1997 Appendix 7-A BTP HICB-12-2 Regulatory Guide 1.153, "Criteria for Power, Instrumentation, and Control Portions of Safety Systems," endorses IEEE Std 603, "IEEE Standard Criteria for Safety Systems for Nuclear Power Generating Stations," as an alternative to ANSI/IEEE Std 279. Section 4.4 requires the identification of functional requirements pertinent to establishing instrument setpoints. Section 6.8 requires that setpoints be determined using a documented methodology, such as that described in ISA-S67.04. While IEEE Std 603 references ISA-S67.04-1988 for setpoint methodology, the Staff has not endorsed this version of the standard. The Staff is endorsing ISA-S67.04, Part I, via revision 3 of Reg. Guide 1.105. Draft Reg. Guide DG-1045 contains this proposed revision. IEEE Std 498 (Withdrawn), "IEEE Standard Supplementary Requirements for the Calibration and Control of Measurement and Test Equipment Used in the Construction and Maintenance of Nuclear Power Generating