Card Set Information
shieldcooling advanced systems
Shield cooling pump low discharge pressure alarm EK-1302
Minimum shield cooling system components for design basis
1 set of cooling coils
CV-0932/CV-0934, shield cooling coil inlet supply valves
Air operated, fail open diaphram valves
2 position open/close keyswitch on C-08/C-03
Interlocked with low flow alarm
-when valve is closed, low flow alarm is bypassed
P-77A/B shield cooling pump controls
3 position switch
Pull to standby
-pump auto starts on low discharge pressure of 35 psig
Purpose of the shield cooling system?
Designed to maintain structural concrete temperature less than 165
F to prevent concrete weakening due to loss of moisture
Required to be in operation whenever PCS temperature is >165
CV-0927, shield cooling surge tank makeup valve
Opens at 23% (34")
Closes at 86% (74")
Makeup from T-81
-alternate from T-2, may need to throttle MV-CD172 T-2 HX inlet to create sufficient head
We do not use, it leaks, CV-0939 is caution tagged closed
CV-0939 shield cooling surge tank isolation
Closes on CHP/CHR
Controlled from open/close switch on C-13
Caution tagged closed
Minimum/maximum shield cooling flow
--30 gpm per coil
--limited by the heat exchanger
What is required if shield cooling return temperature > 165
F and shield cooling high temperature alarm will not clear?
T-62, shield cooling surge tank
-capacity based on total change in system water volume as a result of maximum possible change in water temperature from a cold start condition at 60
F to 212
How is shield cooling temperature controlled?
Throttling MV-CC106, HX outlet valve
Normal shield cooling flow
-normally 20-25 gpm to floor coil
When is shield cooling placed/removed from service?
Chemistry control of shield cooling system
Chem add tank T-97 on the east mezz
Add through surge tank sight glass
550-1000 ppm sodium nitrite
What are the P-77A/B shield cooling pumps ratings and power supplies?
180 gpm each
Approximately 61 psig discharge pressure (35 psig and suction head of 26 psig)
What is the shield cooling low flow alarm setpoint?
</= 80 gpm on the inservice coil
The alarm is bypassed when the inlet supply valve is closed
What is the shield cooling high temperature alarm setpoint?
What are the high/low alarm setpoints for T-62, shield cooling surge tank?
-95% (80 inches)
-4.5% (20 inches)