Document: NUREG-0800
Document ID: a8853b5a-7119-4e4d-8880-496c64ff5b6c
Document Type: srp
Title: INSTRUMENTATION AND CONTROLS - INTRODUCTION
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML1602/ML16020A050.pdf
Revision Date: 2023-06
Chapter: 7
Section ID: 7.1
CFR Part: 
CFR Title: 

Content:
s that provide information for manual initiation and control of safety systems. These systems indicate that plant safety functions are being accomplished and provide information from which appropriate actions can be taken to mitigate the consequences of anticipated operational occurrences and accidents. Information systems important to safety also provide information on the normal status and the bypassed and inoperable status of safety systems. Information systems important to safety are discussed in Section 7.5 of the SAR. 7.1-3 Revision 6 - August 2016 E. Interlock systems important to safety operate to reduce the probability of occurrence of specific events or maintain safety systems in a state to assure their availability in an accident. These systems differ from protection systems in that interlock system safety action is taken prior to accidents, or to prevent accidents. Interlock systems important to safety are discussed in Section 7.6 of the SAR. F. Control systems are used in normal operations and in control plant processes that have a significant impact on plant safety but are not relied on to perform safety functions following anticipated operational occurrences or accidents. Control systems are reviewed to assure that they conform to acceptance criteria and guidelines, that the controlled variables can be maintained within prescribed operating ranges, and that the effects of operation or failure of these systems are bounded by the accident analyses in Chapter 15 of the SAR. Control systems are discussed in Section 7.7 of the SAR. G. Diverse I&C systems are provided expressly for diverse backup of the RTS and ESFAS. Diverse I&C systems account for the possibility of common-cause failures in protection systems. The diverse I&C systems category includes the anticipated transient without scram (ATWS) mitigation system, as required by Title 10 of the Code of Federal Regulations (10 CFR) 50.62, “Requirements for reduction of risk from anticipated transients