Shutdown Cooling System Flashcards
State the function of the Shutdown Cooling (SDC) System.
The Shutdown Cooling (SDC) System removes decay heat and pump heat from the Reactor Coolant System (RCS) during:
Normal Plant Shutdowns and Cooldowns
Small Reactor Coolant System pipe breaks
Describe the flow path for Shutdown Cooling.
Low Pressure Safety Injection Pump suction valves from the Refueling Water Tank are isolated and suction is realigned to each Low Pressure Safety Injection pump from its respective Reactor Coolant System Hot Leg through the Shutdown Cooling suction isolation valves.
The Low Pressure Safety Injection pumps circulate Reactor Coolant System water through the tube side of the Shutdown Cooling Heat Exchangers which uses Component Cooling Water as the cooling media in the heat exchanger shell side.
Flow returns to the Reactor Coolant System Cold Legs.
Reactor Coolant System temperature is controlled by varying the flow through the Shutdown Cooling Heat Exchanger and/or total Shutdown Cooling flow through the loop injection valves.
State the purpose of the Shutdown Cooling Suction Isolation Valves
Shutdown Cooling Suction Isolation Valves provide isolation of the Shutdown Cooling System from the Reactor Coolant System
State the purpose of the Warmup Valve
The Warmup Valve allows a slow heatup of the Shutdown Cooling System to reduce thermal stresses on system piping and prevent overcooling of the Reactor Coolant System.
