Extraction Steam and Heater Drains

Question 1

Hi hi Level alarm on a FW heater performs the following 6 functions:

Answer 1

1. Closes ES isol (MOV)
2. Closes non-return check valve AOV
3. Closes incoming drain
4. Opens ES spill valve
5. Closes MSR drain (15/17 FWHs)
6. Emergency and normal drains open (Should be open prior to HI HI, different level switch)

Question 2

Spill valves open when ____ and close when _____.

Answer 2

Opens on a turbine trip, hi hi level in FWH, or hi level in ES low point drain (12-14 only).
Closes when respective ES isol valve is open.

Question 3

EH 5042 ___ on a turbine trip and supplies _____.

Answer 3

Closes
Non-return check valves, MFP LP steam supply, MSR drain tanks, and spill valves.

Question 4

HD005A-D (2nd stage reheat drain tank outlet AOV) will auto ____ at _____ psid to prevent_____.
Must have ____ psid to reopen.

Answer 4

Close
<375 psid
overpressurizing 17 FWH
>500 psid

Question 5

HD046A/B are controlled by _____ with a setpoint of _____.
_____ provides feed forward and gain adjustment to the HDT level controller (Prop/int).

Answer 5

HDT level
60%
Validated turbine impulse pressure

Question 6

Purpose of non return check valves:
ES lines______ and _____
MSR drain tank lines____ and _____

Answer 6

ES lines
1. Prevents turbine overspeed by preventing reverse flow of flashing steam. Trips closed on turbine trip.
2. Prevents water entering turbine on FW heater flooding or tube rupture.

MSR drain tank lines
1. Prevents reverse flow of flashing steam. Trips closed on turbine trip.
2. Prevents reverse flow of flashing steam. Trips closed on turbine trip.

Question 7

Why do ES Isolation Valves and ES Non-Return Check Valves automatically close on a High-High Heater Level?

Answer 7

Prevent water induction into the Main Turbine in the event of a heater tube rupture

Question 8

What Valves are operated by the Turbine Throttle Valve relays ?

Answer 8

ES NRCV’s, ES Spill Valves

Question 9

What Valves Operate on a Heater High-High Level ?

Answer 9

ES Isol (MOV), ES NRCV, Upstream Htr NLCV, ES Spill Valve

Question 10

Normal heater drains (LCVs) fail _____ on loss of instrument air with the exception of FWH _____ which fail ____.

Answer 10

Closed
FWH 16 and 17 which fail as is

Question 11

FWH emergency drain valves fail ____ on loss of IA with the exception of FWH ____ which fails ____.

Answer 11

Open
16 which fails as is

Question 12

What is the typical arrangement for the 15, 16, and 17 Heaters ES Supply piping?

Answer 12

ES Spill Valve/Low Point Drn Vlv, ES Isol MOV, ES NRCV, and ES Low Point Drn Vlv

Question 13

What is the typical arrangement for the 12,13 and 14 Heaters ES supply piping?

Answer 13

ES Spill Valve, ES Isol MOV, ES NRCV (14B only exception)

Question 14

What are all of the potential inputs to the Heater Drain Tank?

Answer 14

15 DC, MSR Shell DT’s, FW Pump seals, _A MFP warmup, AS Condensate return, Secondary sample returns, Makeup from CB, and HD Pumps recirc.

Question 15

What is the LP steam supply for feedwater pump turbines?

Answer 15

‘A’ MSR only

Question 16

Where does Gland Water that is supplied to the Heater Drain Pumps drain to?

Answer 16

HD pump discharge