Document: NUREG-0800
Document ID: cd35e91a-3d44-430c-9102-2c8a74c133ab
Document Type: srp
Title: SAFE SHUTDOWN SYSTEMS
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML1602/ML16020A086.pdf
Revision Date: 2023-06
Chapter: 7
Section ID: 7.4
CFR Part: 
CFR Title: 

Content:
bility of systems required for safe shutdown. 7.4-7 Revision 6 – August 2016 and maintain hot and cold shutdown. This control equipment should be capable of operating independently of (i.e., without interaction with) the equipment in the main control room. This equipment may include the remote shutdown station and other local controls. The design of remote shutdown stations should provide appropriate displays so that the operator can monitor the status of the shutdown. Typical parameters for PWR displays are pressurizer pressure, pressurizer level, reactor coolant temperature, steam generator pressure, steam generator level, source-range neutron flux, level indication for tanks involved in shutdown, and shutdown system diagnostic instrumentation. Typical parameters for BWR displays are reactor vessel water level and pressure, suppression pool level and temperature, emergency or isolation condenser level indication for tanks involved in shutdown, and shutdown system diagnostic instrumentation. The remote shutdown capability should be capable of accommodating expected plant response following a reactor trip, including protective system actions that could occur as a result of plant cooldown. For example, in the cooldown of a PWR, reactor cooling system pressure will eventually drop below the safety- injection initiation setpoint. Because the control room is not available, it may be impossible to block this trip. Therefore, the remote shutdown capability must be able to accommodate this condition. Access to remote shutdown stations should be under strict administrative controls. The equipment in the remote shutdown stations should be designed to the same standards as the corresponding equipment in the main control room. Remote shutdown station-control transfer devices should be located remote from the main control room and their use should initiate an alarm in the control room. The location should be consistent with the procedures for remote, alternative, and