Heater Drains Flashcards
What are the heater drain pump trips?
LO LO level in the heater drain tank
Suction valve closed
Lo Flow - “A” (1.0 mlbm/hr)
“B (.8 mlbm/hr)
45 second time delay
MPD
BUV
(FTCKTS______)
Where are the low pressure feedwater heaters located?
In the main condenser
What will isolate a LPFWH string?
Hi and HI HI level in the feed water heater
What isolates when LPFWH isolates?
Condensate side
What are the power supplies to the Heater Drain Pumps?
A - 13
B - 14
When are HDP put in service?
> 40%
How much flow comes from the heater drain pumps? (percentage of total flow)
30% from heater drain pumps
70% from condensate system
What will low water level in the heaters cause?
Flashing (Erosion)
What will high level in the heaters cause?
Backing up (dump valves open)
What’s the purpose of the heater drains?
Provide continuous removal of non-condensable gas from steam (shell) side of the feed water heaters. Allows water to be returned to feedwater system
What’s the purpose of the MSR drains?
Collect water from feedwater system to increase:
- efficiency
- operating stability
- reliability
Where do the LPFWHs drain to?
1 drains to condenser
4 drains to 3
3 drains to 2
2 drains to condenser
Where do the HPFWHs drain to?
5 drains to HDT
6 drains to HDT
Where does the 1st stage reheater drain tank drain to?
HDT
Where does the 2nd stage reheater drain tank drain to?
2nd stage drains to #6 HPFWH, which drains to HDT
When does the HPFWHs dump control logic reset to a lower level?
< 45% CTP
When does the HPFWHs dump control logic reset to normal level?
> 48% CTP or < 6% CTP
What auto closes level control valve for #5 HPFWH?
Hi-Hi level in 5A and 5B OR
HI-Hi level in HDT AND 5A or 5B
When will #6 HPFWH isolate and what valves does it close?
Hi-Hi level closes inlet from 2nd stage reheater drain tank
What isolates when HPFWH isolates?
Supply steam
What level in moisture separator drain tank will trip main turbine?
Hi-Hi level in the MSR separator drain tank
Where do dump valves drain to?
Main condenser
Where do drain valves drain to?
their associated drain tank location
Where do relief valves drain to?
Main condenser
What 2 tanks will trip the main turbine if it reaches a Hi-Hi level?
Moisture separator drain tank
Moisture separator shell drain tank
When does LPFWH dump valve control reset to a lower level?
< 38% CTP
When does LPFWH dump valves control reset to normal logic?
> 42.5% CTP
Where does the CTP calculation come from for the dump valve logic?
APRM channel 4 and total flow
What must be running for level control valve to work automatically?
Heater Drain Pumps
When will heater drain tank level control valves open with at least one pump running AND discharge valve open?
> 0%, 520A starts to open
50% 520A is full open
100% F520 A/B full open
If level continues to rise, 518 A-E will open sequentially with “E” opening first
How is level controlled in the heater drain tank with no pumps running?
F520 A/B are interlocked closed
F518 A-E open to maintain level. E opens first
