Document: NUREG-0800
Document ID: 861c72fa-b163-4443-a01e-48d1504c12a6
Document Type: srp
Title: INTERLOCK SYSTEMS IMPORTANT TO SAFETY
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML1515/ML15159B156.pdf
Revision Date: 2023-06
Chapter: 7
Section ID: 7.6
CFR Part: 
CFR Title: 

Content:
rmal conditions and to maintain it in a safe condition under accident conditions. Therefore, the staff finds that the interlock systems satisfy the requirements of GDC 13 and 19. The staff conducted a review of these systems and finds that they comply with the reliability guidance of (IEEE Std 279-1971 or IEEE Std 603-1991). Based on this review, the staff finds that the redundancy requirements of General Design Criteria 34, 35, 38, 41, and 44 have been met. The review included the identification of those systems and components for the interlock systems that are designed to survive the effects of earthquakes, other natural phenomena, abnormal environments, and missiles. Based on the review, the staff concludes that the applicant or licensee has identified those systems and components consistent with the design bases for those systems. Sections 3.10 and 3.11 of the SER address the qualification programs to demonstrate the capability of these systems and components to survive these events. Therefore, the staff finds that the identification of these systems and components satisfies the requirements of General Design Criteria 2 and 4. The staff reviewed the bypassed or inoperable status indication of safety interlocks. The staff finds that appropriate bypass indications are provided to give the operators timely information and status reports so the operators can mitigate the effects of unexpected system unavailability. The bypass indications satisfy the guidelines of RG 1.47, “Bypassed and Inoperable Status Indication for Nuclear Power Plant Safety Systems.” Therefore, the staff concludes that the safety interlock systems satisfy the applicable requirements of 10 CFR 50.55a(h) and 10 CFR 50.34(f)(2)(v). 7.6-8 Draft Revision 6 – August 2015 The nonsafety interlock systems are appropriately isolated from safety systems. Therefore, the staff concludes that the isolation of these systems from safety systems satisfies the requirements of 10 CFR 50.55a(h) and the