What is the function of the CSS?
- Post accident limit of containment pressure rise to 55 psig or less.
- Pressure of 50% or less of 55 psig within 24 hours.
- Barrier to limit radioactive release (iodine entrapement),
- HPSI subcooling during RAS,
- HPSI pressure boost on loss of charging pumps due to fire.
What is the left train CSS?
Left Train Containment Cooling?
Left Train Containment Spray
- 1-1 EDG
- P-54B/C
Left Train Containment Cooling
- 1-1 EDG
- P-54B and P-54C
- CV-3001 and its spray header
What is the right train CSS?
Right Train containment cooling?
Right Train Containment Spray
- P-54A via 1-2 EDG
Right Train Containment Cooling
- 1-2 EDG
- P-54A
- CV-3002 / its spray header
- CACs VHX-1, VHX-2, and VHX-3
Describe the design of a CS pump.
Vertically split, horizontal centrifugal pumps with mechanical seals and auxiliary gland.
- 1,340 gpm at 195 psia injection
- 1800 at 175 psia recirc.
2300v, 250 hp, 55 amps at full load.
Describe the harsh environment features up the CS pumps.
- Can operate continuously without seal cooling with pumped fluid at 130F.
- Can only operate for 10 minutes with no seal cooling and pumped fluid at 320F
What are the CS throttle valves?
CV-3001/3002
- 6-inch globe valves
- powered by instrument air, backup via N2 Station 5.
- Full open on CHP.
- Fail open on loss of air/power.
What is the control and throttle power for CV-3001?
Closing: D-11-1 and D-21-1 Opening and Throttling D-11-1
What is the control and throttle power for CV-3002?
Closing, Opening, and Throttling D-21-1
What “arms” a containment spray pump?
SIAS
When do the CS throttle valves throttle and why?
On RAS at 2% in SIRW tank to reduce NPSH requirements of CS pumps.
What is RAS and its logic?
Switch from SIRW to Sump on 24” (2%) in SIRW.
1 out of 2 taken twice.
Left Channel LS powered via Y-10 (327) and Y-20 (328)
Right Channel LS powered via Y-30 (329) and Y-40 (330)
- LS from Y-10 or LS Y-30 AND LS from Y20 or LS Y-40
- Fires RAS relaying
Describe the containment sump.
22 feet in diameter, seven 4-inch floor drains, five 16-inch inlets, one 24-inch inlet and two 24-inch outlets to ECCS (CS & HPSI) pumps. One 4-inch outlet to radwaste.
Only two of the five 16-inch inlets, attached to passive strainers, are credited flow paths.
What are the passive strainers and what is unique in terms of flow path?
Installed on two of the 16-inch inlets and allow passage of no larger than 0.095 inch particles while meeting NPSH requirements.
They are the only post LOCA credited flowpath.
What is NaTB?
Sodium Tetraborate Decahydrate. Apprx 9k lbs in strainer baskets. Keeps ph >7 post RAS to maintain iodine captured via spray system.
What is the normal flow path of the CS system?
Not in service. Pump suction/discharge locked open, mini-flow locked closed, CV-3001/3002 spray control valves closed.
PRV-3001/3002 setpoint?
95 psig +/- 5 psig
What opens CV-3071, P-66A Subcooling?
P-66A running and RAS signal.
What opens CV-3070, P-66B Subcooling?
P-66B running and CV-3030 open
What happens if CV-3030 does not open?
RAS closes CV-3001 after a 30-second time delay.
What happens on CHP?
P-54A/B start, CV-3001/3002 open provided SIAS present.
P-54C will start 20-seconds later.
White light on pump controls indicate they have SIAS signal and are waiting on CHP.
What is the left-train RAS signal?
Y-10 and Y-20 powering LS-0327/0328.
What is right-train RAS signal?
Y-30 and Y-40 power LS-0329/0330.
What happens on RAS?
- Sump outlets open
- SIRW outlets close
- SIRW recirc valves close if in ‘A’ postion
- CCW highcaps open and tcv’s close
- LPSI pumps trip
- CV-3001/3002 go to throttled
- Subcooling for operating HPSI pump opens.
How is CS lined up to fill SI tanks?
- SDC System goes through only E 60B.
- SIT fill goes through E 60A.
- Note: This is only done in Modes 5 or 6. This is NOT the normal way to fill the SITs.
- Only one Spray Pump is used and its Recirculation path is unisolated. Flow from the Spray system through the Spray recirculation line and into the SIT fill and drain header.
- Multiple tanks are filled at the same time for better pump performance. Due to the relatively low flows, this fill operation is limited to <= 8 hours for any one pump.
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CCW39
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CCW Alarms8
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Containment Air Coolers40
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Containment Spray System31
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Electrical Distribution36
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125 V DC, 120 Volt Preferred AC and Instrument AC Power17
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Main Generator49
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Service Water34
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EDG75
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Station Power39
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Vessel & Internals30
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Station Power Alarms24
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Primary Coolant System47
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Primary Coolant System Alarms13
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Primary Coolant Pumps30
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Primary Coolant Pump Alarms14
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Chemical Volume and Control37
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CRD61
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Primary Vent System20
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Pressurizer Level Control43
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Containment Building50
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Safety Injection System50
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Safety Injection System Alarms16
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Shutdown Cooling13
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Main Steam System42
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Main Steam System Alarms6
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Main Steam System Tech Specs8
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SGWL38
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Main Condenser, Condensate and Feedwater56
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Main Condenser, Condensate and Feedwater Alarms22
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Main Condenser, Condensate and Feedwater Tech Specs3
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Extraction Steam and Heater Drains38
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Extraction Steam and HD Alarms4
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Auxiliary Feedwater System50
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Auxiliary Feedwater System Alarms7
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Auxiliary Feedwater System Tech Specs16
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Main Turbine Control and Supervisory45
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Main Turbine Control and Supervisory Alarms32
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Pressurizer Pressure Control23
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DC Power Supplies3
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Instrument and Service Air39
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CRHV57
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CRHV Tech Specs16
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Purge and Vent54
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Fire Protection System41
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Spent Fuel Pool34
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Rad Monitoring44
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Shield Cooling21
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Nuclear Instrumentation38
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RPS41
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RPS Trips11
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Thermal Margin Monitor50
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PPC12
