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