TBCCW Flashcards
What is the purpose of the TBCCW System?
Transfers heat from the component it serves to the service water system.
Maintains a lower pressure than the served loads and the cooling Service water to not introduce water into other systems and not let any leakage out to environs
What is the normal cooling to the Cribhouse CW Pump Thrust Bearings? backup?
U2 TBCCW. Backup from U3 via unit crosstie.
What are the TBCCW Loads?
BACCCERR A/Cs
Bus Duct Coolers - both normally in service
Alternator Exciter Cooler
CRD Pp Seal Coolers and Bearings - SW Backup
Circ Water Pp Thrust Bearings - U2 or U3 side
C/CB Pp Bearing Housing
EHC Oil Coolers - TCV to control TBCCW flow
RFP Lube Oil Coolers
RFP Mech Seal Coolers
A/Cs
IA AC
RW Sparging Air Comp - TCV to control TBCCW flow
Resin Transfer AC
SA AC
What is the purpose fo the TBCCW Expansion Tank?
Allows water expansion due to temp changes
Provides NPSH to TBCCW Pumps
Provides make-up water to system
Provides leak detection capability
What provides make-up to TBCCW Expansion Tank?
Clean Demin via AOV and level switch
How does TBCCW prevent expansion tank overflow on inleakage?
Internal overflow to 48” SW discharge Header
How many TBCCW Pps are their and their power source? Trips?
2 per unit - A by 25-1 (35-1) ; B by 27-1 (37-1)
Trips on Breaker trips ONLY
How is TBCCW Hx temp controlled?
SW cooling Water throttled by TCV (common TCV for both Hx) AOV located on SW outlet of Hx. Monitors TBCCW Water Hx Outlet Temp
Impact of loss of SW to TBCCW?
TBCCW Hi Temp Alarm
Expansion Tank Level rise - Hi/Lo Alarm
Loss of Normal Power to TBCCW Pp?
No auto start - must manually start standby pump
Impact of TBCCW Hx Tube Leak?
SW into TBCCW and causes level increase in Expansion Tank
Loss of Instrument Air impact on TBCCW?
Expansion Tank Makeup Valve fails closed - manual bypass exists
TBCCW Fails open - causes increase in heat load to TBCCW system
