Extraction Steam and Heater Drain
ACADs (08-006) Covered
1.1.5.4.4
4.2.7.15
5.2.1.5d
5.4.3.2
Keywords
Feedwater heater, condensate heating, drains, inadequate drain path,
heater drain pumps, bleeder trip valve.
Description
This document provides instructor notes and references to materials which can be
used to develop a lesson on extraction steam and heater drains.
Supporting Material
Systems Training Manual Volume 17 "Feedwater Heater Extraction Steam
and Drain System"
PALO VERDE
NUCLEAR GENERATING STATION
Instrumentation & Controls Training
Classroom Lesson
I&C Program
LP Number: NIA9902XC009
Title: Extraction Steam and Heater Drain System
Date: 07/12/2000
Rev. : 01
Rev Author: Norman R. Cooley
Technical Review:Robin T. Meredith
Duration : 1 Hour
Teaching Approval:
I&C Program
Title: Extraction Steam and Heater Drain System
Lesson Plan #:
Page: 2 of 11
NIA9902XC009
INITIATING DOCUMENTS:
Site Maintenance Training Program Description
PROCEDURES
NONE
REQUIRED TOPICS
NONE
CONTENT REFERENCES
Systems Training Manual Volume 17 "Feedwater Heater Extraction Steam and Drain System"
Tasks Covered
The following tasks are covered in Extraction Steam and Heater Drain System:
Task Number*
Task Statement
Total tasks:
0
I&C Program
Title: Extraction Steam and Heater Drain System
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TERMINAL OBJECTIVE:
1.0
Given the appropriate references,, the participant will be able to recognize the
components, functions and operation of the Extraction Steam and Heater Drain
System.
1.1
Identify the major functions associated with the Extraction Steam and Heater
Drain System.
1.2
Recognize the operation of the Extraction Steam and the Heater Drain
Systems.
1.3
Identify the components of the Extraction Steam and Heater Drain System.
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Title: Extraction Steam and Heater Drain System
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Lesson Introduction:Extraction Steam and Heater Drain System
CLASSROOM GUIDELINES
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If applicable, remind students of class guidelines as posted in the classroom.
Attendance Sheet
Pass the attendance sheet around and have it signed in black ink.
Materials
Ensure that student materials needed for the class are available for each student. (For materials
required, refer to the list of materials on the cover page.)
Questions and Participation
Emphasize student participation and remind them of your philosophy on asking and answering
questions, If applicable.
ATTENTION STEP
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Give a brief statement or story to get student concentration focused on the lesson subject matter.
LESSON INTRODUCTION

Give a brief statement which introduces the specific lesson topic. Should be limited to a single
statement.
MOTIVATION
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Focus students attention on the benefits they derive from the training. At Instructors discretion. The
need for remotivation in each succeeding lesson must be analyzed by the Instructor and presented as
necessary.
Instructor should include how the STAR process can be used to improve or enhance Operator
Performance, if applicable.
Lesson Terminal Objective
Read and discuss lesson terminal objective and review lesson enabling objectives, if desired.
Topic
If applicable, briefly preview the lesson topic outline and introduce the major points to be covered.
The objectives review may have been sufficient.
REINFORCE the following PVNGS management expectations as opportunities become available
Nuclear Safety
Industrial Safety Practices
STAR and Self-Checking
Procedure Compliance
Communication Standards
ALARA
Prevent Events
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Course Terminal Objective
Given the appropriate references, the participant will be able to recognize the components, purposes and
capabilities of the Plant Systems and Components as demonstrate by 80% overall proficiency on a series
of three written examinations.
I&C Program
Title: Extraction Steam and Heater Drain System
Lesson Plan #:
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T.Obj 1.0
Given the appropriate references,, the participant will be able to
recognize the components, functions and operation of the Extraction
Steam and Heater Drain System.
EO 1.1
Identify the major functions associated with the Extraction Steam
and Heater Drain System.
1.1.1 Main Idea
A. Functions
1.
Direct extraction steam from Main Turbine to the HP and LP FW heaters for the purpose of FW
and condensate heating to increase cycle efficiency.
2.
Collect condensate from HP FW heater shells, first and second stage reheater drains and MSR
drains in the heater drain tanks and pump it to the FW pump suction.
3.
Collect condensate from LP FW heater shells and drain it to the Main Condenser.
I&C Program
Title: Extraction Steam and Heater Drain System
EO 1.2
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Page: 7 of 11
NIA9902XC009
Recognize the operation of the Extraction Steam and the Heater
Drain Systems.
1.2.1 Main Idea
T001, T001A and T001B
A. General Description
1.
Connects Main Turbine and Condenser to Condensate and FW systems.
2.
Supplies and drains shell side of closed FW heaters.
3.
Collects and drains condensate from (4) MSRs.
4.
The (3) LP FW heater trains receive extraction steam from LP turbines. (4 heaters/train)
5.
The (2) HP FW heater trains receive steam from HP turbine. (3 heaters/train)
6.
(2) Heater Drain Tanks receive drains from No. 5 and No. 6 heaters and moisture separator drain
tanks.
7.
(2) Heater drain pumps pump this water back into the FW pump suction lines.
B. Major Sub-systems
1.
Heater Extraction Steam.
2.
Heater Drain.
C. Sub-system Overviews
1.
Heater Extraction Steam Sub-system
a.
Extends from turbine extraction nozzle to FW heater shell inlet nozzle.
b.
Extraction steam from various turbine stages piped to shell side of each FW heater.
c.
Uncontrolled flow to heaters determined by stage pressure and temperature, heater surface
area and condensate/FW flow and temperature.
d.
FW heaters (5), (6) and (7) provided with (1) non-return and (1) gate valve on extraction
steam lines.
e.
FW heater (4) has (2) non-return valves and FW Heater (3) has (1) non-return valve.
f.
FW heaters (1) and (2), located in condenser neck have neither non-return nor gate valves.
g.
Each LP turbine provides extraction steam to its respective LP heater train.
1) Extraction lines to heaters 3A, 3B, 3C, 4A, 4B, 4C, 6A, 6B, 7A, 7B are
cross-connected.
2) Cross-connections allow unit operation without all high and low pressure heaters in
operation.
2.
Heater Drain Sub-system
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Title: Extraction Steam and Heater Drain System
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T002
a.
Extends from:
1) LP FW heaters to the next lower LP heater and/or the condenser.
2) HP FW heaters, reheater drain tanks and/or moisture separator drain tank to injection
point of condensate line into S/G FW pump suction line.
b.
Bypass drain lines to the condenser provided for all FW heater shells except heater No. (5)
which is served by bypass drain line from heater drain tank.
c.
Minimum flow recirculation is provided from each heater drain pump to heater drain tank.
d.
Seal and cooling water for the heater drain pumps provided from discharge of condensate
pumps.
e.
LP Heater Drains.
1) Drains normally cascade to the condenser.
2) Level control valves in drain lines automatically maintain normal water level in the
heaters.
a)
In event of inadequate drain path, high level controller from heater shell opens
dump valve to condenser.
b)
High level signal alarms in Control Room.
3) High-High level signal from a heater shell automatically isolates entire train via
isolation valves and via bleeder trip valves admitting extraction flows to the heater
drain.
4) Drainage occurs as a result of differential pressure between shell and downstream
receiver.
f.
HP Heater Drains.
1) Normal drains from HP heaters, moisture separators and reheater drain tank.
2) Heater Drain Pump pumps contents of tank to FW suction header. Flow regulated by
tank level.
3) Inadequate drain path, high level controller opens dump valve to condenser.
4) High-High level signal automatically closes extraction line isolation valve and all other
draw lines to the heater.
5) Heater No. (7) cascades to shell of heater No. (6) which drains to heater drain tank.
6) Heater No. (5) connected to drain tank by a vent and gravity drain.
7) Drain tank drained by (50%) capacity drain pump to S/G FW pump suction.
I&C Program
Title: Extraction Steam and Heater Drain System
EO 1.3
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Identify the components of the Extraction Steam and Heater Drain
System.
1.3.1 Main Idea
A. Systems Components
1.
Heater Drain Pumps, (2)
a.
Each takes suction on one heater drain tank.
1) Motor driven, vertical, (5)-stage, (50%) capacity centrifugal units.
2) Water enters through suction line, travels downward to first-stage double volute
impeller.
2.
b.
Water pumped vertically upward through (5) stages to discharge.
c.
Discharge to S/G FW pump suction.
LP FW heater
a.
(3) parallel trains of (4) heat exchangers.
1) Shell side is extraction from LP turbine which enters at top, drains from bottom.
2) Tube side is condensate which enters heater at one end passes, horizontally through
bottom half set of tubes, returns through top half set of tubes to outlet.
3) Each heater has a condensing and a subcooling zone.
3.
HP FW Heaters
a.
(2) Parallel trains of (3) heat exchangers.
b.
Shell side is steam extraction from HP turbine.
1) Enters through single opening in top.
2) Drains at bottom of heater shell.
c.
Tube side is feedwater
1) Enters at bottom of heater.
2) Passes through U-tubes.
3) Exits at top of heater.
4.
Bleeder Trip Valve
a.
Modified version of swinging disc-type check valve.
b.
Located in a number of extraction lines.
1) Prevents reverse flow upon turbine trip.
2) Ensures turbine will not overspeed.
I&C Program
Title: Extraction Steam and Heater Drain System
c.
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Equipped with side-mounted pneumatic cylinder operating mechanism, spring loaded to
assist in disc-closure.
1) This lifts the check valve disc out of the steam flow path during normal operation to
prevent erosion of the disc.
d.
Automatically closes on discontinuation or reversal of flow.
SUMMARY OF MAIN PRINCIPLES
Objectives Review
Review the Lesson Objectives
Topic Review
Restate the main principles or ideas covered in the lesson. Relate key points to the objectives. Use a
question and answer session with the objectives.
Questions and Answers
Oral questioning
Ask questions which implement the objectives. Discuss students answers as needed to ensure the
objectives are being met.
Problem Areas
Review any problem areas discovered during the oral questioning, quiz, or previous tests, if applicable.
Use this opportunity to solicit final questions from the students (last chance).
Concluding Statement
If not done in the previous step, review the motivational points which apply this lesson to students needs.
If applicable, end with a statement leading to the next lesson.
You may also use this opportunity to address an impending exam or practical exercise.
Should be used as a transitional function to tie the relationship of this lesson to the next lesson. Should
provide a note of finality.