Document: NUREG-0800
Document ID: b2d15b43-96b5-4876-877d-f6ba1944c6d7
Document Type: srp
Title: INTERLOCK SYSTEMS IMPORTANT TO SAFETY
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML1602/ML16020A092.pdf
Revision Date: 2023-06
Chapter: 7
Section ID: 7.6
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Content:
REVIEW RESPONSIBILITIES Primary - Organization responsible for the review of instrumentation and controls Secondary - None Review Note: The revision numbers of Regulatory Guides (RG) and the years of endorsed industry standards referenced in this Standard Review Plan (SRP) section are centrally maintained in SRP Section 7.1-T, “Regulatory Requirements, Acceptance Criteria, and Guidelines for Instrumentation and Control Systems Important to Safety,” (Table 7-1). Therefore, the individual revision numbers of RGs (except RG 1.97) and years of endorsed industry standards are not shown in this section. References to industry standards incorporated by reference into regulation (IEEE Std 279-1971 and IEEE Std 603-1991) and industry standards that are not endorsed by the agency do include the associated year in this section. See Table 7-1 to ensure that the appropriate RGs and endorsed industry standards are used for the review. 7.6-2 Revision 6 – August 2016 I. AREAS OF REVIEW The objective of the review is to confirm that design considerations such as redundancy, independence, single failures, qualification, bypasses, status indication, and testing are consistent with the design bases of these systems and commensurate with the importance of the safety functions to be performed. 1. This SRP section describes the review process and acceptance criteria for those interlock systems important to safety that operates to reduce the probability of occurrence of specific events, or to maintain safety systems in a state that assures their availability in an accident. These systems include: • Interlock systems to prevent over-pressurization of low-pressure systems (e.g., residual heat removal) when these systems are connected to high-pressure systems (e.g., primary coolant). • Interlocks to prevent over-pressurization of the primary coolant system during low-temperature operation of the reactor vessel. • Valve interlocks to assure the availability of emergency core