Service Water Flashcards
What is the purpose of Service Water?
Provide strained river water of suitable water and quality for plant equipment cooling requirements.
TO achieve design objective:
Meets cooling requiremnt during Rx Shutdown mode
*****Cools RBCCW during ALL OPERATING CONDITIONS
Operate at higher pressure than any load it services
Provide inexhaustible supply of make-up water to Hotwell via STANDBY COOLANT SUPPLY so feedwater flow can be maintained
*****Provide cooling to auxiliary loads in RB, TB, and aux buildings during ALL modes of operation
Where does SW discharge from the plant?
2 headers:
36” non-contaminated Header
48” Contaminated Header - Monitored
What support does SW provide for FP?
normal keep fill, EMERGENCY Packup
What provides power to the Stanby Coolant Isolation MOVs?
MCC 25-1 (35-1)
How does SW provide backup to TBCCW for CRD pumps?
Manual swap to SW if TBCCW lost
What is the power supply for the SW pumps?
Bus 23/24 (33/34)
2/3 SW Pump can be supplied by 24 or 34
How many SW pumps must be running?
at least 2
How many SW strainers are there? Purpose?
Power?
When do they reposition?
3 in parallel to remove debris from SW Pp Discharge
Powered by 28-2
Strainers automatically clean when DP reach ~4-5psid or manually by pushing start P/ or placing Auto/Manual Switch in manual
On a High D/P, all three reposition at same time then backwash one at a time
What is the largest heat load to SW?
RBCCW - and coolant must ALWAYS be maintained
How is SW flow to It’s loads controlled?
TCV at outlet of: RBCCW Hx TBCCW Hx Turbine Oil COolers Control HVAC Condensers Main Generator H2 Coolers
What impact does a LOCA have on SW?
If all 3 pumps (2 units and 2/3) are running and supplied by the same unit, then the “A” pump will load shed
What provides power to the isolation valves in SW system?
Unit 250vdc MCC -
TBCCW Hx, H2 Cooler and SWC - to be isolated as non-essential laods during emergency conditions
