CCSW Flashcards
What is the Purpose of the CCSW system?
Removed heat from primary containment by providing cooling water to LPCI Hx to limit suppression pool bulk temp
Why does CCSW need to limit Torus Bulk Temp?
So Torus can withstand hydrodynamic loads during blowdown
Assure steam condensation during LOCA
Ensure adequate NPSH for ECCS pumps
What are the minimum requirements for containment cooling per UFSAR?
Minimum of 1 of 2 Hx, 2 CCSW Pps, and 1 LPCI Pp in same loop
For the CCSW Vault Cooler, how many fans are required to operate and what is the required inlet water temp?
2 of 4; max water temp of 95F
What is the non safety CCSW purpose?
Limit Torus Bulk Temp to within operating limit input of HPCI and ERVs during and after surveillances.
What pressure difference is required for the CCSW/LPCI system and why?
CCSW to be >=20psid than LPCI to prevent leakage of radioactive materials outside
Which side of the LPCI Hx are LPCI and CCSW on?
LPCI - Shell
CCSW - Tube
Where is the CCSW Discharge and why?
48” SW Discharge Header because it is Rad Monitored
What supplies CCSW Keep Fill?
Normal - SW - tapped off supply line to ECCS room coolers
Alt - from DGCWP - normally aligned, but check valve isolates SW supply from DGCWP supply
What is the CCSW interaction with CR HVAC?
U2 CCSW Supplies Backup cooling to B Refrigerant Condenser Unit, from either subsystem, normally Div II.
Requires flow of 121gpm (3621gpm TOTAL if lined to B CR HVAC)
What are the 3 sources for ECCS Room Cooler Cooling and how are they aligned?
SW normally
CCSW - check valves allow CCSW to align whenever on
DGCWP may align via manual valves - WILL INOP EDG
Which CCSW Pps are in the vault?
B&C
How many coolers are there per CCSW Pp (in vault)?
2 per pump, each with 2 fans - cooled by CCSW discharge
What starts the CCSW Vault ROOM COOLERS?
Auto start when CCSW Pp Starts
What prevents flooding of CCSW Vault?
Sub Door
Flood Seals
AO Drain Valve in floor - auto closes when Condensate floor water level reaches 5 ft.
What are the trips for teh CCSW Pps?
Overcurrent
What is used to maintain CCSW/LPCI PSID & What is the normal setpoint?
Hx Discharge Isolation Valve controlled to maintain pressure at least 20psid
What is the normal position of the LPCI Hx Discharge valve (3A/B) and what happens on CCSW pump start?
Valve normally closed, & interlocked with CCSW pump breakers so that when pumps are not running it will automatically cycle closed
When pump starts it will position as demanded by the controller signal
Controller normally in manual to prevent excessive wear on motor.
Where does the Hx DP signal come from and what happens if it fails?
Signal comes from ATS. If fails, controller will fail downscale closing the valve
What are power supplies for CCSW Pps?
A/B - 23(33)
C/D - 24(34)
What are teh power sources for CCSW Cooler Fans?
DI (A&B) - MCC 28-2 (38-3)
DII (C&D) - MCC 29-2 (39-2)
What are the CCSW Hx Discharge Valves and their power sources?
1501-3A/B
A- Div I - MCC 28-1(38-1)
B - Div II - MCC 29-4 (39-1)
What controls the LPCI Hx Discharge Valve and what is the power source?
Div I Flow Controller - Instrument Bus
Div II Flow Controller - ESS
What is the CCSW Pp Response to a LPCI Initiation Signal?
Initially trip (if running) because not immediately needed and to limit EDG loading. When pumps trip, 1501-3A/B cycle close.
318 key swithc supplied to allow bypassing CCSW Pp trip signal.
What does the CCSW 318 kelock switch do?
When switch is placed in Manual Override, CCSW Pps can be restarted.
If 318 switch is tanek to manual Override with initiation and Pps started, and signal clears then returns with 318 still in Man. Override, pumps will continue to run.
Trip signal will auto clear when LPCI signal clears
What are the normal flows and Hx psid expected when 1 pp running? 2pp?
1pp - 3500gpm - 7psid
2pp - 5000gpm - 20psid
What impact does U2 CCSW Pp Operation have on the 2/3 DG and DGCW? How is this prevented?
2/3 DGCWP discharges to common CCSW LPCI Hx discharge
If cooling water inlet <82F, no restrictions
If cool water inlet >82F and <91, then no more than 3 CCSW Pps may operate
If >91F then NO MORE THAN 2 CCSW pps may operate
IF CH Inlet >95F CCSW INOP
