Condensate - .5 Flashcards
What is the purpose and functions of the Condensate System?
Deaerate and condense turbine exhaust and deliver purified condensate
1. Cool SJAE condensers
2. Serve as heatsink for bypass valves, FWH drains, other cycle effluents
3. Provide water to CRD
What are the protective functions for RFP associated with the loss of condensate pumps?
- Loss of 1 PCP: RFP Runback to 86.3% (4816 RPM) and Intermediate recirc runback (45%) (– pcp is physically lower than an scp, so RFP runs back lower !)
- Loss of 1 SCP: RFP Runback to 89.3% (4961 RPM) and Intermediate recirc runback (45%)
What is the series of events that occur during a PCP Start Enable?
or
Which conditions illuminate the PCP Start Enable light?
Suction Valve 100% Open
Discharge Valve 100% Closed
Hotwell Level > 6”
SJAE/SPE Bypass Valves 100% Open or at least one other PCP running.
What is the series of events that occur during a SCP start enable?
Suction Pressure ≥ 30 psig
Suction valve full open
Discharge Valve 100% Closed (Does not auto open on start)
Lube Oil Pressure > 6 psig (16 psi reset)
At least 2 PCPs Running
What are the PCP Pump Trips?
Electrical Protection Relays (All other Auto Trips Disabled)
What are the SCP pump auto trips?
Electrical Protection Relays
Lube Oil Pressure ≤ 6 psig
Low Flow (< 3000 gpm for 30 sec)
What conditions require the operator to manually trip the PCPs?
1). Suction Valve NOT Full Open (AB.RPV-4, R.O)
2) Hotwell Level < 6” (Low-Low, 2/3 logic)
3). HV-1710 < 30% open w/in 75 seconds of Open Demand (min flow)
And
* 1 or More PCP Running and NO SCP Running
Or
* 2 or 3 PCP Running and 1 SCP Running
**Does NOT Auto Close (unless placed in Lockout)
Discharge Valve (HV-1680)
-Not > 35% Open (40 Sec after Pump Start), or
-Not Full Open (99 Sec after Pump Start), or
-Full shut
What conditions require the operator to manually trip the SCPs?
Suction Valve NOT Full Open (AB.RPV-4, R.O)
Suction Pressure < 30 psig (10-15 sec)
What starts the SCP Aux Oil Pump?
Start if SCP LO Pressure is < 6psig
Starts if Shaft driven oil Pump Suction > 35psig indicates reverse rotation of SCP.
What are the Condensor Vacuum automatic actions?
- 4.5”HgA – Intermediate RR upon loss of 1 CW pump (3 remaining)*
- 5-6”HgA – Low Condenser Vacuum Alarm
- 5.8”HgA – Full RR upon loss of 1 CW pump (<2 remaining)*
- 7.5”HgA – Main Turbine Trip
- 10”HgA – RFPT Trip
- 21.5”HgA – MSIV closure
- 22.9”HgA – Bypass valve closure
- 5 psig – rupture discs
*High pressure signal must exist at the time of the pump trip (approx. 1 sec) to initiate runback signal.
What controls Hotwell level?
Hotwell level is controlled by makeup from and reject to CST
* Hi alarm – 54”
* Lo alarm – 30”
What are the SCP, PCP and total pumps heads?
PCP – 202 psig
SCP – 535 psig
Total – 737 psig
Where does the condensate prefilter operate and what occurs on a loss of power?
- Filter Discharge of PCP after SJAE/SPE
- Bypass fails open on loss of power
Describe the when the SJAE/SPE Bypass valves are operated and what occurs when the valve receives a loss of it actuating medium.
- Must be open to start 1st PCP
- Maintain 10.83psid across SJAE/SPE to ensure proper flow
- Fail open on loss of air
What valve in Condensate provides flow to the CRD suction?
HV-1677 Reject Bypass - Sends 140 gpm to CRD suction (taps off immediately after the con-demins.
What occurs if you get a high level in FWH 1 or 2?
Hi-Hi level in FWH 1 or 2 will isolate Condensate through that train #1 or #2 drain coolers. (protects turbine from water)
What is added in the common suction line for the PCP?
Oxygen is added in the common suction for the PCP pumps.
How does the SCP min flow valve operate and what happens on a loss of operating medium?
SCP min flow valve Passes 4500gpm, If flow is > 4500 gpm, valve is full closed. – fail open on loss of air
How does the Condensate Reject Bypass Valve fail on a loss of operating medium?
fails open on a loss of air
How does the SJAE/SPE Condenser Bypass Valve fail on a loss of operating medium?
fails open on a loss of air
What is the required position of the Condensate Pre-Filter bypass valve?
Ensuring AL-HV-8814 is open is not a permissive required for start of a condensate pump. However, unless this valve is opened, the condensate pump will not have a flow path to the condensate min flow valve
What conditions will cause a breaker INOP on the Condensate pump breakers?
a) Loss of breaker control power
b) Loss of trip coil continuity
c) Spring not charged within 3.0 seconds
after breaker closure
d) Breaker not in OPERATE position
* Racked out to TEST or DISCONNECT
* Breaker control switch in PULL TO LOCK
Describe the PCP min flow valve operations.
When in lockout the valve will close and inhibit the start logic for the PCP.
When in Auto the valve will open in response to:
· > 1 PCPs running with no SCPs
· One SCP running with > 2 PCPs
and the open-close pushbutton
NOTE: the valve will not auto close in auto, but needs to be manually closed.
What happens when 3 PCPs are running with no SCPs?
CNDS RECIRC CAPACITY EXCEEDED annunciator will alarm
What is the purpose of the Main Condenser 3 min Condensate Retention time?
Allows time for decay of short lived radionuclides before condensate leaves condenser
What is the PURPOSE of the steam inlet Expansion Joint in the Condensate system and How it is sealed to prevent air inleakage?
Counters differential expansion between the Low Pressure Turbine and the condenser Exhaust trunk.
Sealed to each LP turbine with a rubber expansion joint.
Normally a dry area, but it is enclosed by a dam which could receive water from the Condensate Storage Tank.
What is the purpose of the Condensate System reject Bypass Valve (FV-1677)?
Constant supply of deaerated water to CRD Pump suction
What is the purpose of the SJAE/SPE Condenser Bypass Valve (PDV-1719)?
Maintains constant d/P 10.83 psid across condensers to ensure adequate and constant condensate flow .
Interlock to start first PCP (must be open)
What action is required to raise cooling water flow to SJAE and SPE condensers?
Raise d/P setpoint on controller (1ADPD1719)
Valve throttles closed forcing more condensate through the condensers.
Why is the SJAE/SPE Bypass Valve (PDV-1719) 100% open when starting the first PCP?
Flowpath for PCP Minimum Flow Valve (HV-1710)
What are the power supplies for the PCPs and the SCPs?
PCP: a) AP102 10A110
b) BP102 10A120
c) CP102 10A102
SCP: a) AP137 10A110
b) BP137 10A120
c) CP137 10A104
.
In what order do system automatic actions occur as main condenser vacuum degrades from “full vacuum” to atmospheric pressure on a loss of Circ Water?
Intermediate RR Pump runback if loss of vacuum is concurrent with loss 1 CW Pump
Full RR Pump runback if loss of vacuum concurrent with only 2 (or less) CW Pumps running
Main Turbine trip
RFPT Trip
MSIVs shut
BPVs shut
A HIGH-HIGH Water Level has occurred in 1A FWHTR. What is the automatic response?
Closure of Condensate System Inlet and Outlet valves for 1A, 2A FWHTRs and 2A External Drain Cooler
Several tubes have ruptured in FWHTR 2A causing a High-High level trip. What auto action occurs and what is the purpose for this action?
1A and 2A FWHTR condensate inlet and outlet valves isolate on high level in FWHTR 2A
Protects the main turbine from water induction
Where do RFP seals get cooling and sealing water from?
SCP Discharge
Plant is at 97% normal alignment
“B” PCP trips. What is the auto response by RPV Level Control and RR?
Single PCP trip
RFP’s runback to 86.3%
RR receives runback signal to 45% speed.
The unit is at 100%.
BP102 PCP trips.
RPV drops to Level 4
RPV recovers to 35” and is stable.
Assuming no further automatic plant responses occurred, what action is REQUIRED?
Should have RR Runback to 45% speed on loss of PCP > 73.65% total feed flow.
FW Flow Runback to 86.3%
Reduce RR pump speeds to 45%.
The reactor is at 100% with all Feed and Condensate Pumps are in service
The breaker for ‘C’ SCP trips.
What automatic actions occur?
Single SCP Trip
Both RR pumps runback Intermediate (45% speed)
FW flow runback to 89.3%
With all condensate and RFPs operating:
1. Loss ONE (1) PCP with feedwater greater than 73.65% will cause a RFP runback to ________________ and a(n) _____________ RR pump runback.
2. Stopping ONE (1) SCP, with feedwater > 73.65% will cause a feedwater runback to ______________ and a(n) _____________ RR runback.
86.3%
Intermediate
89.3%
Intermediate
Plant is at 97%.
“B” PCP trips.
What is auto response?
Single PCP trip
RFP’s runback 86.3%)
RR intermediate runback
What is the purpose of the Condensate Drain Tank?
- Collects drains, from:
- SPE Shell
- RFP Shaft Seal Leak off
- TB Sample Sink
- Vacuum drags to condenser.
What is the bases for having hotwell level at a certain level?
- 5 min full load reserve
- # mins retention for short lived radionuclides.
What are the shut off heads for the SCP’s and PCP’s?
- PCP’s - 202#.
- SCP’s - 535#.
- Combined - 737#
