Document: NUREG-0800
Document ID: 81256f55-72dd-4777-9472-f373c71c4554
Document Type: srp
Title: AC POWER SYSTEMS (ONSITE)
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0705/ML070550065.pdf
Revision Date: 2023-06
Chapter: 8
Section ID: 8.3.1
CFR Part: 
CFR Title: 

Content:
afety-related circuits in which the testing procedures did not provide sufficient overlap to completely test multiple logic pathways as required by technical specifications. The reviewer should verify that licensees have compared electrical schematic drawings and logic diagrams for the reactor protection system, EDG load shedding and sequencing, actuation logic for the onsite power system and the standby EDG, and actuation logic for ESF systems against surveillance test procedures to ensure that all portions of the logic circuitry, including the parallel logic, interlocks, bypasses and inhibit circuits, are adequately covered to fulfill the TS requirements. The licensee’s review should have included relay contacts, control switches, and other relevant electrical components within these systems, utilized in the logic circuits performing a safety function. The Maintenance Rule Section 50.65(a)(4) requires that licensees assess and manage the increase in risk that may result from proposed maintenance activities before performing the maintenance activities. Regulatory Guide 1.182, used as a companion guide to Regulatory Guide 1.160, provides guidance for assessing and managing the increase in risk that may result from maintenance activities and for implementing the optional reduction in scope of SSCs considered in the assessment. The review should 8.3.1-33 Revision 3 - March 2007 verify that grid reliability evaluations are performed, as part of the maintenance risk assessment required by 10 CFR 50.65 before performing “grid-risk-sensitive” maintenance activities, including, but not limited to, surveillances, post-maintenance testing, and corrective and preventive maintenance. Such activities are those which could increase risk under existing or imminent degraded grid reliability conditions, including: (1) conditions that could increase the likelihood of a plant trip, (2) conditions that could increase the likelihood of LOOP or SBO, and (3) conditions that have an