Service Water Flashcards
LCO 3.7.8 “Service Water System” requirements
2 SWS trains shall be operable
LCO 3.7.9 “Ultimate Heat Sink” requirements
The Ultimate Heat Sink shall be operable
“A” critical service water header loads
CCW EESG cooler EDG 1-2 VC-10 ESS seals cooling backup AFW P-8C suction backup
“B” critical service water header loads
CAC Containment fire water WESG cooler EDG 1-1 VC-11 ESS seals cooling backup AFW P-8C suction backup
Ultimate heat sink operability
<=85 F
>=568.25 ft
Traveling screens power supplies
F-4B - MCC 6
F-4C - MCC 5
Traveling screens auto backwash setpoint
Every 8 hours
Differential level of 6” (alarms at 9”)
Service water pumps power supplies
P-7A/C - D bus
P-7B - C bus
Service water pumps capacities
8000 gpm @ 70-80 psi
Service water pump auto start
40 psi low discharge pressure of either operating pump
If only 1 pump operating, placing one of the other 2 in standby will cause it to start because it sees discharge pressure @ 0 psi on the other “operating” pump
Basket strainer DP setpoints
Alarms at 7 psid
Inoperable at 12 psid
Filtered service water loads
Cooling Tower Pumps
P-910 Vacuum Pump
P-25A/B/C SW Booster Pumps
C-16A/B Vacuum Priming Pumps
F-13A/B, Seal Water Supply Strainers, auto backwash
Timer - 4x/day
High DP - 1.5 psid, alarms locally @ 3.5 psid
P-5 Warm Water Recirc Pump suction and discharge
Suction from cooling tower makeup basin, discharges to service water bays
P-5 power supply
LCC-13
P-5 use
De-icing traveling screens
Service water response on SIS
All 3 pumps start
Non-Crit header isolates (CV-1359)
CAC outlets open
VHX-4 inlet closes
Service water response on RAS
CCW service water inlets fail open
CCW high capacity outlets fail open to hard stops
CCW TCV’s close
Service water response to loss of offsite power
NSD sequencer starts all 3 pumps:
P-7A/B start 7 seconds after EDG breaker closes
P-7C starts 26 seconds after EDG breaker closes
Service water response to loss of offsite power with SIS
DBA sequencer starts all 3 pumps:
P-7A/B start 7 seconds after EDG breaker closes
P-7C starts 26 seconds after EDG breaker closes
Precaution for operating all 3 service water pumps and both dilution water pumps with plant offline
Could exceed NPDES limits
Precaution while CCW valves to ESS coolers are open
Service water CV’s to ESS coolers and their air supplies shall remain closed to prevent draining CCW to the lake
Precaution for operating all 3 service water pumps with high header pressure
> 90 psi, will cause indicated low flow through the system, and could cause damage to piping or pumps
Precaution for taking service water pump control switch to either close or trip
Will take the pump out of standby
LCO 3.7.8 “Service Water System” applicability
Modes 1-4
LCO 3.7.9 “Ultimate Heat Sink” applicability
Modes 1-4
LCO 3.7.8 “Service Water System” required actions if less than 100% of the required post accident SW cooling capability available.
Enter LCO 3.0.3 IMMEDIATELY
What are the requirements for 100% SWS post accident cooling capability with only 1 service water pump?
CV-1359, non-critical sw header isolation, operable
AND
Either CV-0824, SW return from containment, or CV-0847, SW supply to containment, operable
What are the requirements for 100% SWS post accident cooling capability with only 2 service water pumps?
CV-1359, non-critical sw header isolation, operable
OR
Either CV-0824, SW return from containment, or CV-0847, SW supply to containment, operable
What are the requirements for 100% SWS post accident cooling capability with 3 service water pumps?
No special requirements. With all 3 pumps available, 100% required cooling capability can be provided, even with flow to non-critical header and to containment
What is a concern with breaching CV-0824, SW Return From Containment?
Valve is in West Safeguards, so it is at a lower elevation than the SW discharge into the Makeup Basin. Has the potential to drain the Makeup Basin into West Safeguards.
What is the Service Water availability in the event of an electrical fire which can start and stop equipment (Appendix R)?
Only P-7B, due to a remote-local transfer switch on its breaker on “C” Bus
What are the consequences of engaging the manual operators on CV-0823, CCW Heat Exchanger (E-54A) Outlet, and CV-0826, CCW Hx (E-54B) Outlet?
This defeats the RAS signal feature of opening these valves to their hard stops.
Could also open valves past their hard stops when operating manually.