Document: NUREG-0800
Document ID: 6209b3e7-917d-48d2-a299-4d1230aa5b51
Document Type: srp
Title: Revision 5 - March 2007
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0705/ML070550070.pdf
Revision Date: 2023-06
Chapter: 7
Section ID: 7
CFR Part: 
CFR Title: 

Content:
ndition during an accident. In addition, a remote shutdown capability is required to permit the reactor to be safely shut down. GDC 20, "Protection System Functions," requires in part that the reactor protection system provide automatic initiation so that (1) fuel design limits are not exceeded and (2) accidents are sensed and mitigated. Both require timely operation of protection system components, thus establishing the timing requirements for detecting parameters exceeding their setpoints and equipment actuation in the protection system. GDC 21, "Protection System Reliability and Testability," requires in part high functional reliability of safety systems. Timely operation is necessary for high functional reliability of safety systems. GDC 23, "Protection System Failure Modes," requires in part the protection system to be designed so that if it fails, it fails into a safe state given the anticipated failure modes and conditions in which the failure occurs. This is a design architectural issue aimed at staying within timing limits. GDC 25, "Protection System Requirements for Reactivity Control Malfunctions," requires in part reactivity control to prevent fuel design limits from being exceeded. This requires timely operation of the protection features of the reactivity control system. GDC 28, "Reactivity Limits," requires in part a limited reactivity rate-of-change to prevent (1) fuel limits from being exceeded and (2) a non-coolable core geometry. The protection system must meet the timing requirements imposed by this criterion. BTP 7-21-3 Revision 5 - March 2007 GDC 29, "Protection Against Anticipated Operational Occurrences," requires in part defense against anticipated operational transients to assure an extremely high probability of accomplishing safety functions. To assure this, the protection system must be demonstrated to operate within the time constraints of each anticipated operational transient. 2. Relevant Guidance IEEE Std. 603-1991 is a system-level