Condensate System(CM) Flashcards
(79 cards)
1
Q
What are the primary purposes of the Condensate System?
A
- Take Condensate from the Condenser Hotwell
- Purify and filter for chemistry requirements
- Reheat to improve efficiency
- Deliver it to the suction of the feedwater pumps for feeding the steam generators
2
Q
What are the secondary purposes of the Condensate System?
A
- Provide a cooling medium for:
A. Condenser Steam Air Ejectors(CSAE)
B. Gland Seal Condenser(GS)
C. Steam Generator Blowdown(BB) heat exchangers - Provide water to Auxiliary Feedwater Condensate Storage Tank(CACST) for temperature and chemistry requirements
- Provide water from Hotwell Pumps for:
A. Turbine Exhaust Hood Spray(TS)
B. Main Feedwater Pump seals(CL)
C. Condensate Booster Pump seals
D. “C” Heater Drain Tank Pump Tandem Seals***
E. Condensate Storage System(CS) loop seals
F. Main and CFPT Condenser seal trough makeup - Provide water from CBPs for “C” Heater Drain Tank Pump mechanical seals***
3
Q
What is the primary purpose of the Condensate Storage System(CS)?
A
Provide a readily available source of deaerated water for makeup to the condenser.
4
Q
What are the secondary purposes of the Condensate Storage System(CS)?
A
- Alternate supply of makeup to the Auxiliary Feedwater System(CA)
- Collect and store miscellaneous drains
- Supply Auxiliary Electric Boiler Feedwater System
- Receive condenser water on high hotwell pump pressure or high hotwell level
5
Q
Where does water that’s condensed in three sections of the main condenser accumulate?
A
All of the condensing sections of the main condenser allow water to be piped back to the ‘A’ Hotwell which extends under the ‘B’ and ‘C’ sections.
6
Q
How does the water flow from the ‘B’ and ‘C’ Condensers to the A Condenser?
A
The ‘B’ and ‘C’ sections are connected to the ‘A’ Condenser via Cascade Pipes.
7
Q
What is the precaution associated with the Cascade Pipes?
A
If the condenser cascade pipes have been drained, they are filled prior to filling the condenser hotwell. This prevents damage due to floating the cascade pipes.
8
Q
What is the system designator for the Condensate System?
A
CM
9
Q
What is the normal range for Hotwell level?
A
5.5 to 5.8 feet
10
Q
How is Hotwell normal level controlled?
A
The Hotwell normal makeup valve, CS-47, aligns automatically to makeup to the Hotwell as level lowers.
11
Q
Where does normal makeup water to the Hotwell come from?
A
The Upper Surge Tank(UST)
12
Q
When is Emergency Hotwell Level Control used, and what valves provide this function?
A
- Emergency makeup is not used during normal operating conditions and are maintained closed in Mode 1 and 2. They are used in accordance with procedural guidance during Mode 3 and 4.
- Valves: CS-33 and CS-57
13
Q
Where does Emergency Makeup to the Hotwell come from and where can it be discharged?
A
- Emergency makeup water comes from the Upper Surge Tank.
- Water can either be discharged above or below the normal Hotwell level. The line that discharges above the normal Hotwell level is used for deaeration when vacuum is established.
14
Q
How does the Hotwell Normal Makeup Valve, CS-47, fail on a loss of air?
A
CS-47 fails closed on a loss of air
15
Q
How does a Auxiliary Feedwater(CA) auto start affect the Hotwell Normal Makeup Valve, and why?
A
- The normal makeup valve will fail closed on a CA auto start
- This ensures that the volume in the UST is available for CA
16
Q
How is the Hotwell Normal Makeup Valve reset following a CA auto start?
A
One control board reset button per train must be depressed to restore the valve to its normal makeup duties
17
Q
What affect does a simultaneous under-voltage of TA, TB, and TD have on the Hotwell Normal Makeup Valve?
A
A simultaneous undervoltage on all three Hotwell Pump buses causes the auto makeup feature to be blocked. When the undervoltage condition clears, the blocking signal clears, and the valve resumes normal makeup duties without operator assistance.
18
Q
How do the Hotwell Emergency Makeup Valves, CS-33 and CS-57, operated to control level?
A
The valves open sequentially i.e. CS-33 will open fully, then CS-57 opens.
19
Q
How do the Hotwell Emergency Makeup Valves, CS-33 and CS-57, fail on a loss of air or power?
A
Both valves will fail closed on a loss of air or power.
20
Q
What is the design/capacity of the Hotwell Pumps?
A
- 4 stage centrifugal, vertically mounted
2. 50% capacity, 12720gpm
21
Q
What system provides cooling to the Hotwell Pump motors?
A
Recirculating Cooling Water(KR)
22
Q
What is the power supply for the Hotwell Pumps?
A
HWP A - TA
HWP B - TB
HWP C - TD
23
Q
What system provides seal water to the Hotwell Pumps, and when?
A
- Seal water for the Hotwell Pumps is initially supplied from the Demineralized Water System(YM)
- Following the start of the first Hotwell Pump the seal water is shifted to water from the pump discharge.
24
Q
What is the purpose of the Hotwell Pump Suction Vent Valve?
A
The suction vent valve continuously vents back to the condenser to ensure the piping is maintained full of water.
25
What is the purpose of the Hotwell Pump Discharge Vent Valve, and when does it operate?
1. The discharge vent valve will open when the pump is off, and closes 30 seconds after a Hotwell Pump start.
2. The discharge vent ensures the pump casing remains full of water in the event that air is sucked through the shaft seal.
26
What is the order for operating the Hotwell Pump suction and discharge valves?
The Hotwell Pump suction valve is opened before the discharge valve, and closed after the discharge valve to prevent over-pressurizing the suction piping.
27
What is the interlock between the Hotwell Pump and the Hotwell Pump Discharge Valve?
1. The Hotwell Pump will not start if the discharge valve is closed.
2. The discharge valve cannot be closed when the Hotwell Pump is running.
28
What will cause a Hotwell Pump to automatically start?
1. A full load rejection if the turbine load is greater than 56%
2. A loss of one main feed pump turbine if turbine load is greater than 56%
3. Condensate Booster Pump suction pressure lowers to 75psig
29
What will cause a Hotwell Pump to automatically trip?
The “Windmill” Protection Circuit
30
What is the “Windmill” protection circuit initiate conditions and when is the protection invoked?
1. Initial conditions:
A. CF pump suction valves open
B. Less than 900psig S/G inlet pressure
C. CF pump oil pump in operation
2. Protection invoked when oil pressure falls below 4.0psig and will cause:
A. HWP trip
B. CBP trip on signal from HWPs being tripped
31
What is the logic required for starting the first Hotwell Pump?
The following valves must be closed as part of the electrical interlock:
1. CM-42 and CM-186, Polisher Bypass Valves
2. All 5 Polisher Effluent Isolation Valves
3. CM-878, Seal Supply Header Isolation Valve
4. CM-83, Load Rejection Bypass Valve
****CM-35, Hotwell High Level Control Bypass and CM-877, System Slow Fill Valve are only procedural requirements and not required for the electrical interlock****
32
What is the purpose of the Hotwell High Level Control Valve, CM-33, and when is it utilized?
1. CM-33 is designated as the minimum flow path for the hotwell pumps, and is normally closed in modes 1, 2, and 3 with the assumption that minimum flow will be provided by the flow through the main feedwater pumps and their associated recirculation valves.
2. CM-33 is placed in AUTO in modes 4(S/Gs not used for heat removal), 5, 6, and No-Mode.
33
How does the Hotwell High Level Control Valve, CM-33, function in AUTO?
1. When Hotwell level is high CM-33 will open to recirculate water to the Upper Surge Tanks.
2. When Hotwell Pump discharge pressure is high(335psig) CM-33 will open for minimum flow.
3. When all 3 Hotwell Pump breakers are open CM-33 will open to allow the Upper Surge Tanks to keep the Condensate piping full of water.
34
What is the affect on the Hotwell High Level Control Valve if power is lost simultaneously to TA, TB, and TD, and why?
The auto open feature for CM-33 will be overridden, and will fail closed to ensure UST inventory is available for CA.
35
What loads are supplied by the CM System Seal Supply Isolation, CM-878?
Through this connection to the CF Pump Seal Injection Header the following loads are supplied:
1. Main Feed Pump Seal Injection
2. Condensate Booster Pump Seals
3. Loop Seal Makeup(between the UST and the CST)
4. Turbine Exhaust Hood Spray
5. Condenser Seal Trough Makeup
6. “C” Heater Drain Tank Pumps Tandem Seals
36
What is the purpose of the Generator Load Rejection Bypass Valve, CM-83?
The Generator Load Rejection Bypass Valve opens anytime Condensate Booster Pump suction pressure lowers to 150psig:
1. When the valve is in Auto it will modulate to control CBP suction pressure when it lowers to 150psig by bypassing all of the low pressure header components.
2. If the valve is not in auto two conditions will cause it to open as if it were:
A. Full load rejection with turbine load above 56%
B. Loss of a main feedwater pump with turbine load above 56%
37
What is the capacity of the Polishing Demineralizers?
1. Five polishing demineralizers with a capacity of 25% each
| 2. Pressure drop across the CPDs is regulated by the bypass valves
38
What is the maximum pressure drop across the Condensate Polisher-Demineralizers?
41psid
39
What are the normal settings for the CPD Bypass Valves?
1. The Bypass Valves are normally operated in AUTO with a maximum setpoint of 20psid
2. Valve demand displayed on the controller should be equal to or greater than 10%
40
What is the purpose of the Condenser Steam Air Ejectors?
The Condenser Steam Air Ejectors(CSAE) condense steam used by the three sets of condenser steam air ejectors.
41
How many sections do the Condenser Steam Air Ejectors have, and where do they drain to?
1. Each condenser steam air ejector has two sections:
A. Inter-condenser
B. After-condenser
2. The Inter-Condenser drains to the Main Condenser
3. The After-Condenser drains to the CST, and vents to the Unit Vent
42
What is the purpose of the Gland Steam Condenser?
The Gland Steam Condenser(GS) condenses steam used to seal the turbine glands.
43
Where does the Gland Steam Condenser drain to?
The Gland Steam Condenser drains to the CST, and is exhaust via a fan to the Unit Vent.
44
What is the precaution associated with isolating Condensate flow to one of the Steam Generator Blowdown Recovery Heat Exchangers(BB)?
Prior to isolating flow to one of the BB Recovery Heat Exchangers flow rate is adjusted to 3000-4000gpm to ensure maximum flow rate through the remaining heat exchanger is not exceeded, and that suction pressure for the CBPs is not reduced to less than 190psig.
45
What is the purpose of providing Condensate flow to the Auxiliary Feedwater Condensate Storage Tank(CACST)?
Flow from the Condensate system is provided to the respective units CACST to ensure proper chemistry and temperature for the tank. The CACST then overflows to the CST of the unit supplying the flow. Enough flow is supplied to each CACST to ensure that the level is greater than or equal to 100%.
46
How many 'G' and 'F' Heater trains are there, and what is their capacity?
1. There are three 'G' and 'F' heater trains located in the neck of the Main Condenser.
2. Each heater train is approximately 33% capacity
47
How will a 'G' or 'F' Heater high level affect the Condensate flow path ?
On a high level in in the heater:
1. The associated inlet and outlet valves for the heater train will isolate
2. The bypass will open and pass approximately 50% flow
48
Why is the 'G' or 'F' Heater bypass valve open until approximately 40% power during startup?
Opening the bypass valve during a plant startup will limit heater level fluctuations.
49
What is the design/capacity of the Condensate Booster Pumps, and how many are there?
1. There are three CBPs, each with a capacity of 50%
2. Single stage centrifugal pumps, horizontally mounted
3. Design flow - 12720gpm
50
What are the power supplies to the Condensate Booster Pumps?
1. CBP A - TA
2. CBP B - TB
3. CBP C - TD
51
What is the order for operating the Condensate Booster Pump suction and discharge valves?
The CBP suction valve is opened before the discharge valve, and closed after the discharge valve to prevent over-pressurizing the suction piping.
52
What is the interlock between the Condensate Booster Pump and the Condensate Booster Pump Discharge Valve?
1. The Condensate Booster Pump will not start if the discharge valve is closed.
2. The discharge valve cannot be closed when the Hotwell Pump is running.
53
What system provides the cooling water to the Condensate Booster Pump Oil Cooler?
Recirculating Cooling Water(KR)
54
What is the minimum required lube oil pressure to start a Condensate Booster Pump?
7psig
55
When will the Auxiliary Lube Oil Pump for the Condensate Booster Pump operate?
1. The auxiliary oil pump will start on an oil pressure of 8psig an lowering
2. The auxiliary oil pump will shutdown when the attached lube oil pump has raised pressure to 13psig
56
When will the Condensate Booster Pump trip on low oil pressure?
There is no trip associated with lube oil pressure, just a start permissive
57
What will cause an automatic start of a standby Condensate Booster Pump?
1. A low main feed pump suction pressure of 300psig
2. A loss of one main feed pump if turbine load is greater than 56%
3. A full load rejection if turbine load is greater than 56%
58
What will cause an automatic trip of a Condensate Booster Pump?
1. Suction pressure of 50psig
2. All 3 Hotwell Pump breakers are open
3. Condensate flow less than 3000gpm for 20 seconds will trip any running CBP
59
What is the minimum flow requirement for the Condensate Booster Pumps?
1600gpm
60
How many 'E' and 'D' Heater trains are there, and what is their capacity?
1. There are two trains of 'E' and 'D' Heaters
| 2. Each heater train is 50% capacity
61
What is the capacity of the 'E' and 'D' Heater train bypass valve?
The bypass is 50% capacity
62
How many 'C' Heaters are there, and what is their capacity?
1. There are two 'C' Heaters
| 2. Each heater is 50% capacity
63
What is the capacity of the 'C' Heater bypass valve?
The bypass is 50% capacity
64
Where do the 'C' Heater drains go, and where do they ultimately end up?
1. The 'C' Heater shell side drains end up in the 'C' Heater Drain Tank.
2. The drains are pumped from the drain tank by the 'C' Heater Drain Tank Pumps to the Condensate Header downstream of the 'C' Heaters.
65
What are all of the inputs into the 'C' Heater Drain Tank, and what feedwater flow is it equivalent to?
```
1. The inputs to the drain tank are:
A. 'C' Heater Drains
B. 'B' Heater Drains
C. MSR Drain Tank Drains
D. CF Pump Seal Drains
2. The amount of water drained to the 'C' Heater Drain tanks is equivalent to approximately 32% of total feed flow at 100%
```
66
When are the 'C' Heater Drain Tank Pumps operated?
The drain tank pumps are operated at greater than or equal to 70% power
67
What will automatically trip the 'C' Heater Drain Tank Pumps?
* ***These two trips are provided to prevent "dead-heading"the Condensate system****
1. Main turbine trip
2. Full Load Rejection with turbine load greater than 56%
Additionally the drain tank pumps will trip on an Emergency Low 'C' Heater Drain Tank Level
68
What is the interlock between the High and Low Pressure Cleanup Valves, CM-123 and CF-26?
One valve must always be open
69
What is the generic flow path of Low Pressure Cleanup?
Hotwell -> Hotwell Pumps -> Polishing Demins -> Air Ejector Condenser -> Gland Steam Condenser/ BB Heat Exchanger -> G and F Heaters -> CBPs -> E, D, and C Heaters -> Back to the UST Dome.
70
What is the generic flow path of High Pressure Cleanup?
Hotwell -> Hotwell Pumps -> Polishing Demins -> Air Ejector Condenser -> Gland Steam Condenser/ BB Heat Exchanger -> G and F Heaters -> CBPs -> E, D, and C Heaters -> Windmills the Main Feed Pumps -> B and A Heaters -> UST Dome
71
What is the purpose of the Cleanup Flow Control Valve, CM-127?
The Cleanup Flow Control Valve is located at the inlet to the Upper Surge Tank Dome and is used to control cleanup flow by utilizing a controller in the Control Room.
72
How does the CM-127 controller respond in the Automatic Mode?
1. Whatever the setpoint was while in manual will be the current setpoint when shifting to automatic
2. The 'S' position on the controller is the only position in automatic that will allow the potentiometer to change a setting on the controller.
73
How does the CM-127 controller respond in the Manual Mode?
1. Operator directly controls the valve in manual
2. The setpoint tracks with the actual flow rate continuously
3. Only the 'V' and 'P' positions will allow the potentiometer to change a controller setting.
74
What is the capacity of the Condensate Storage Tank, and what are the inputs?
1. One 30,000 gallon capacity tank per unit
2. Inputs:
A. CSAE after condenser and separator drains
B. Heating water converter drains
C. Various steam traps
D. AEB feed pump recirc
E. CACST overflow
F. Condenser seal trough drains
G. Waste and recycle evaporator condensate returns
H. Misc. Drains
75
How do the Condensate Storage Tank Pumps operate on a high level condition?
The CST Pumps alternate as the "Lead" pump on High Level:
1. The "Lead" pump will start at 92%(Hi level)
2. The other CST pump will start at 96%(Hi-Hi level)
3. Both pumps will stop at 8%
76
What feature of the Condensate Storage Tank Pumps allows the operators in the Control Room to transfer water in the event of a loss of Instrument Air(VI)?
By holding the "ON" button the CST Pumps will run regardless of a low level indication, caused by a loss of VI, to allow transferring water from the CST to the UST.
77
What is the purpose of the Upper Surge Tank Dome?
The Upper Surge Tank Dome collects and deaerates water for the Upper Surge Tank System. The Upper Surge Tank Dome is maintained under a vacuum by the 'B' Condenser to facilitate deaeration.
78
What is the purpose of the Upper Surge Tanks?
1. Two 42,500 gallon Upper Surge Tanks per unit provide a surge and makeup volume for the Condensate System.
2. The UST provides makeup to the Hotwell and is a suction source for the Auxiliary Feedwater Pumps(CA).
79
What are the generic steps for the initial fill of the Condensate System?
1. Gravity fill the system from the Upper Surge Tank through CS-20 and CM-35.
2. Start the first Hotwell Pump:
A. Satisfy all of the valve interlocks to allow pump start
B. CM-33 will provide a minimum flow path to the UST
3. Fill the Upper Surge Tank Dome using the Hotwell Pump that was initially started.
4. Look for the "CM SYS FILL LEVEL HI" status light
5. Open the valves that were closed for the Hotwell Pump start.
6. Setup the Polisher bypass valves per procedure
7. Align for Cleanup
