PPCHEM

The International Edition

POWER PLANT CHEMISTRY

The Journal of All Power Plant Chemistry Areas
®

January/February 2019
Generator Cooling
◾ Corrosion and Deposits in
Water-Cooled Generator Stator ANALYTICAL INSTRUMENTS
Windings: Part 3: Removal of Flow
Restrictions
Acid conductivity monitoring -
Sampling, Monitoring, No more resin change
AMI CACE
Analytics Conductivity After Cation Exchange (CACE) has never
been easier to measure than with the new EDI technology
for cation removal from the sample
◾ Electrochemical Corrosion Potential
Monitoring in BWRs SWAN Analytische Instrumente AG
www.swan.ch

PowerPlant Chemistry®
Interview
Abstracts 2018
◾ 2018's Scientific and Technical
Contributions
Water Steam Cycles
Call for Papers /
Guidelines for the Authors
Events

ISSN 1438-5325 Visit us at https://www.ppchem.com Volume 21 (2019) No. 1

1
PowerPlant Chemistry 2019, 21(1)
 WAESSERI GMBH BECOMES PPCHEM AG
As of January 1st, 2019, the publishing house Waesseri GmbH was transformed into
the new company PPCHEM AG.
This change goes beyond branding and introducing a new company form: new fields
of activities are also being introduced.
PPCHEM AG represents a new company, as is reflected by an amended strategic
alignment and new corporate design. The company will be active in the following
three business areas:
◾ PUBLISHING
◾ CONFERENCES&SEMINARS
◾ CONSULTING &TRAINING

PUBLISHING
The PowerPlant Chemistry® journal has been publishing for more than 19 years,
with its 20th anniversary coming up. This milestone will be celebrated with the
July/August 2019 journal issue. PPCHEM AG will continue publishing the journal
in the same well-established manner and present publishing policy as before. The
journal will also continue to publish an interesting mix of scientific peer-reviewed
papers and technical reports from the power industry, all of them relating to the
topics of water treatment, cycle chemistry in power and industrial plants.
The following two new business areas "conferences/seminars" and "consulting/
training" will mainly be covered by Michael Rziha, who will join PPCHEM AG by
February 1st as Chief Key Expert for Plant Chemistry. Michael Rziha will conduct
worldwide seminars, lectures and conferences on all power plant chemistry related
topics, as well as provide individual technical consultancy.

CONFERENCES&SEMINARS
PPCHEM AG will continue to organize international conferences and forums as in
the past years with over 30 events organized all over the world. PPCHEM AG will
also introduce seminars and technical trainings for operators. Further details will be
published soon – Stay tuned!

CONSULTING &TRAINING
PPCHEM AG will also be offering technical consulting services related to water
treatment and to cycle chemistry in power and industrial plants of all types and
sizes. During the design phase of a power plant, owner's engineers and EPCs can
obtain expert advice and support. Power plant operators can contract PPCHEM AG
for site-specific support ranging from assessments, troubleshooting, to the optimis-
ation of cycle chemistry regimes and the related trainings of operators.
With the reorganisation and the added expertise, PPCHEM AG repositions itself to
better serve its customers, building on the legacy of Waesseri GmbH and its precur-
PPCHEM AG sor organisation.
P.O.Box 433 | 8340 Hinwil | Switzerland
Phone +41 44 940 23 00
info@ppchem.com | www.ppchem.com
2
382 PowerPlant Chemistry
PowerPlant Chemistry 2019,
2019, 21(1)
21(1)
 PPC
PPC
PPCHEM
HEM
HEM
ISSN 1438-5325
ISSN 1438-5325
ISSN 1438-5325
ISSN 1438-5325
PPPOWER
OWERPP LANTCC HEMISTRY
OWER P LANT CHEMISTRY
LANT HEMISTRY
Single issue price: 27.00 € (+ postage and VAT).
Single issue
Single issue price:
price: 27.00
27.00 € (+ postage
€ (+ postage and
and VAT).
VAT).
Single issue price: 27.00 € (+ postage and VAT).
®
®
®

January/February 2019
Contents
Contents
Contents

Editor's Comments 3

Generator Cooling 8
◾ Corrosion and Deposits in Water-Cooled Generator Stator Windings:
Part 3: Removal of Flow Restrictions
Thomas Bauer, Matthias Svoboda, and Robert Svoboda

Sampling, Monitoring, Analytics 26

◾ Electrochemical Corrosion Potential Monitoring in BWRs
Yoichi Wada, Kazushige Ishida, Masahiko Tachibana, Nobuyuki Ota,
and Makoto Nagase

PowerPlant Chemistry® Interview 40

Abstracts 2018 42
◾ 2018's Scientific and Technical Contributions

Call for Papers / Guidelines for the Authors

Events Calender, Events 2, 4, 22, 50

Imprint 56

Acid conductivity monitoring – No more resin change

SWAN has reinvented Conductivity measurement
After Cation Exchange (CACE).
ANALYTICAL INSTRUMENTS

The AMI CACE continuously measures conductivity before

and after cation exchange without the need to change res-
Acid conductivity monitoring -
No more resin change in columns every month and replace or regenerate resin.
AMI CACE
An EDI module is removing the cations from the sample in
Conductivity After Cation Exchange (CACE) has never the same way the conventional resin used to do.
been easier to measure than with the new EDI technology
for cation removal from the sample The monitor AMI CACE is a key component in controlling
SWAN Analytische Instrumente AG water steam cycle chemistry. Its new EDI technology is
www.swan.ch
significantly reducing maintenance cost and the environ-
mental impact, saving resin and regeneration chemicals.
• No resin change or regeneration required
• No rinse down time required, short response time
• Less/No bias from ion leakage from resin
• Continuous monitoring of sample flow to validate
results
Water Steam Cycles For more information, please feel free to contact
swan@swan.ch or visit our homepage www.swan.ch.

PowerPlant Chemistry 2019, 21(1) 33

 Events Calendar

Events Calendar

2019 Venue Event Information

March 19−21 Crowne Plaza Heidelberg International Conference on https://iapws-ffs.cvent.com/FFS2019

City Centre Film Forming Substances
Heidelberg, Germany (FFS2019)

March 24−28 Music City Center CORROSION 2019 http://nacecorrosion.org/

Nashville, TN, USA

May 14−16 Titania Hotel The Sixth Meeting of the EHF https://EuropeanHRSGForum.cvent.
Athens, Greece (European HRSG Forum) com/EHF2019

July 7−12 Hotel Špik Nuclear Corrosion Summer School 2019 https://meactos.eu/meetings/nucoss
Kranjska Gora, Slovenia

July 22−24 Hilton Orlando HRSG FORUM with Bob Anderson http://www.cvent.com/events/hrsg-
Orlando, FL, USA forum-2019/agenda-d48c8b49853643f-
d9e8f97cc761636cc.aspx#

August 18−22 Seaport 19th International Conference on Environ- http://envdeg.ans.org

Boston, MA, USA mental Degradation of Materials in Nuclear
Power Systems – Water Reactor

September 9−13 Seville, Spain EUROCORR 2019 https://efcweb.org

September 26−27 The Kimpton Donovan, PowerPlant Chemistry Forum https://www.ppchem.com/conferences/

Washington, DC, USA "Power Cycle Chemistry in a Changing
World"

September 29− The Banff Centre for Arts and IAPWS 2019 Annual Meeting www.iapws.org
October 4 Creativity
Banff, AB, Canada

Early October Brasil Power Cycle Instrumentation Seminar https://www.ppchem.com/conferences/

Exact venue and dates
to be announced

October 23−24 Congress Centrum/Maritim Hotel Chemistry in Power Plants https://www.vgb.org

Würzburg, Germany

October 30– Convention Centre Australasian HRSG Users Group 2018 http://www.ahug.co.nz/
November 1 Brisbane, Australia Conference and Workshops

November 10−14 Hilton Orlando Lake Buona Vista − The International Water Conference® https://eswp.com/water/overview/
Disney Springs Area (IWC)
Orlando, FL, USA

November 13–14 Johannesburg, South Africa PowerPlant Chemistry Forum https://www.ppchem.com/conferences/

Exact venue to be announced

November 18–19 Dubai, United Arab Emirates PPCHEM SEMINAR https://www.ppchem.com/conferences/

Exact venue to be announced "The Economic Benefit of
Power Plant Chemistry"

November 20–21 Muscat, Oman PPCHEM SEMINAR https://www.ppchem.com/conferences/

Exact venue to be announced "The Economic Benefit of
Power Plant Chemistry"

PowerPlant Chemistry® wants to inform you of all power plant chemistry-related conferences and other events taking place world-wide. Please
help us to make our EVENTS CALENDAR more complete. Send us information on planned events by e-mail to info@ppchem.com. We will in-
clude it in the next version of our EVENTS CALENDAR. Your cooperation is much appreciated.

4 PowerPlant Chemistry 2019, 21(1)

Editor's Comments

Editor's Comments January/February 2019

Dear PowerPlant Chemistry readers:

While writing these comments, we are in the final stages of editing the articles and putting together the
final shape of this issue. The first issue of this year is being published with a delay and not as planned in
our editorial schedule. The main reason for this is the changes in our publishing house, which have meant
a lot of extra work over the past three months.

As you might already have noticed, the PowerPlant Chemistry® journal is being published under a new
company since the beginning of this year. More details about this change are given in the announcement
inside the front cover of this issue.

To give you a bit more information on the changes in the publishing house, I decided to conduct an in-
terview with Michael Rziha, who joined us on February 1 as the Chief Key Expert for Plant Chemistry. You
can find the interview on page 40 of this issue.

The main message I would like to convey to all of our readers is the following: the journal will remain an in-
dependent and valuable source of power plant chemistry related information. The PowerPlant Chemistry®
journal has been published for more than 19 years, with its 20th anniversary coming up in summer 2019.
This milestone will be celebrated with the July/August 2019 journal issue. PPCHEM AG will continue pub-
lishing the journal in the same well-established manner and with the same publishing policies as before.

There will be one big change though: as we have been preparing a new homepage for the company
(www.ppchem.com), we have decided to also design a new webpage for the journal. The webpage will be
available for the 20-year anniversary this summer. With the new webpage we will be able to offer a new
way of subscribing to our digital journal (E-paper and online access) as well; we will keep you updated and
will inform all of our subscribers as soon as the final form of the webpage is ready.

There will likely still be some unanswered questions even after you read all the information about the
changes in the publishing house; please don't hesitate to contact me directly by e-mail or phone to get
the answers to your open questions – I'm looking forward to hearing from you.

Tapio Werder
Editor in Chief
PowerPlant Chemistry® Journal

PowerPlant Chemistry 2019, 21(1) 5

 The Third International Conference on
Film Forming Substances (FFS 2019)
19–21 March 2019 at the Crowne Plaza Heidelberg City Centre in Heidelberg, Germany

The conference will be of major interest to:

operational personnel, technical managers, plant engineers, boiler operators,
cycle and plant chemists, corrosion scientists and service providers as well as
manufacturers of components and chemicals.

The major themes of this international conference will be dedicated to advancing the knowledge and introducing the
latest science about film forming substances (FFS). Scientific papers and case studies will provide excellent insights
into the latest developments in this field of cycle chemistry as well as numerous examples of the application of film
forming substances (amine and non-amine based) in fossil, combined cycle, biomass, nuclear and other plants.
This IAPWS international conference is being organized by BHT GmbH and PPCHEM AG.

The International Steering Committee

Barry Dooley (Chair), Structural Integrity, UK
Jörg Fandrich, Framatome, Germany
Keith Fruzzetti, EPRI, USA
Marco Lendi, Swan, Switzerland
Michael Rziha, PPCHEM AG, Switzerland
Roy van Lier, Yara, Belgium
Tapio Werder, PowerPlant Chemistry Journal, Switzerland

The conference language will be English.

For more information on the agenda, please contact

Barry Dooley at bdooley@structint.com or bdooley@IAPWS.org.
Selected papers will appear in the PowerPlant Chemistry® journal.

Venue
Crowne Plaza Heidelberg City Centre
Kurfürsten-Anlage 1
Heidelberg 69115 Germany

Registration
For more information and to register, please visit the event website at https://iapws-ffs.cvent.com/FFS2019.

Sponsors and Exhibits

There will be a special vendor exhibition at the conference. Sponsorship opportunities are also available.
For more information please visit the event website at https://iapws-ffs.cvent.com/FFS2019 or contact Tapio Werder at
tapio.werder@ppchem.com.

Gold Sponsorship Regular Sponsorship

bht gmbh    

The Journal of All Power Plant Chemistry Areas
®

6 PowerPlant Chemistry 2019, 21(1)

1
 The Third International Conference on
Film Forming Substances (FFS 2019)
19–21 March 2019 at the Crowne Plaza Heidelberg City Centre in Heidelberg, Germany

Agenda / Programme
Day 1 – Tuesday, 19th March 2019. FFS2019 Agenda

8:00 Registration and Welcome Coffee / Tea

8:45 to 9:00 Opening Remarks

Session 1
9:00 to 9:30 Influences of FFS on Oxide Growth around Generating Cycles
B. Dooley, Structural Integrity, UK, D.H. Lister, University of New Brunswick, Canada, and J. Fandrich,
Framatome GmbH, Germany
9:30 to 10:00 Longterm Preservation with FFA – Current State after Two Years of Standstill
R. Wagner, Reicon, Leipzig, Germany

10:00 to 10:15 Short Presentation and Open Discussion Period

10:15 to 10:45 Morning Coffee/Tea within Exhibits

Session 2
10:45 to 11:15 Fate and Distribution of Film Forming and Alkalizing Amines in Steam-Water Cycles
Y. Xue, M. Vanoppen and A. Verliefde, Ghent University, Belgium, A.M. Brunner and D. Vughs and
H. Huiting, KWR Watercycle Research Institute, The Netherlands, and W. Hater, Kurita Europe GmbH,
Germany
11:15 to 11:45 The Approach to Improving Steam Facility Efficiency Focusing on Hydrophobicity of Film-forming
Amine in Water-Steam Cycles
S. Mori, Kurita Water Industries, Japan
11:45 to 12:15 Preservation for Cycling Plants with an ACC
M. Rziha, PPCHEM AG, Switzerland

12:15 to 13:30 Working Lunch within Exhibits

Session 3
13:30 to 14:00 30 Years of Experience with Film-Forming Amines at a Norwegian Fertilizer Production Site
R. van Lier and A. de Smet, Yara Belgium SA/NV, Belgium, L.-M. Olsen, M. Halasa and T.A. Fjærem,
Yara Norge AS, Norway
14:00 to 14:30 Investigations on the Impact of Steam Properties on Film Formation
M. Bos, J. Cappaert - de Vos and K. Schreyenberg, Kerncentrale Borssele, N.V. EPZ, The Netherlands,
J. Fandrich and U Ramminger, Framatome GmbH, Germany, and J.-L. Bretelle and C. Wesoluch,
Electricite de France, France
14:30 to 15:00 Incorrect Application of a FFS and Consequences on the Water/Steam Cycle
D. Addison, Thermal Chemistry, New Zealand

15:00 to 15:15 Short Presentation and Open Discussion Period

15:15 to 15:30 Afternoon Coffee/Tea within Exhibits

PowerPlant Chemistry 2019, 21(1) 7

2
 The Third International Conference on
Film Forming Substances (FFS 2019)
Session 4
19–21 March 2019 at the Crowne Plaza Heidelberg City Centre in Heidelberg, Germany
15:30 to 16:00 The Effect of Boiler Conditions on the Thermolysis of Film Forming Amines
E. De Meyer and A.R.D. Verliefde, Ghent University, Belgium, and W. Hater, Kurita Europe GmbH,
Agenda / Programme
Germany
16:00 to 16:30 A Corrosion Comparative Study between Carbohydrazide and FFAP in Power and Desalination
19th March 2019. FFS2019 Agenda
Plant
Day 1 – Tuesday,
M. M. Rahman, DTRI, Saudi Arabia and L. Lensun, Helamin, France
8:00
16:30 to 17:00 Registration
Film-forming and Welcome
Amines for Coffee
Closed/ Cooling/Heating
Tea Water Systems
C. Foret and P. Bleriot, Kurita, France, and W. Hater, Kurita, Germany
8:45 to 9:00 Opening Remarks
17:00 to 17:30 Short Presentation and Open Discussion Period
Session 1
Day to
9:00 1 Concludes
9:30 Influences of FFS on Oxide Growth around Generating Cycles
B. Dooley, Structural Integrity, UK, D.H. Lister, University of New Brunswick, Canada, and J. Fandrich,
18:00 Evening Social Event
Framatome GmbH, Germany
9:30 to 10:00Longterm Preservation with FFA – Current State after Two Years of Standstill
R. Wagner, Reicon, Leipzig, Germany
Day 2 – Wednesday, 20th March 2019. FFS Agenda
10:00 to 10:15 Short Presentation and Open Discussion Period
8:00 Opening Coffee/Tea and Remarks
10:15 to 10:45 Morning Coffee/Tea within Exhibits
Session 5
8:30 to 9:00
Session 2 Study of the Presence of a Mixture of Film Forming Amines (FFA) on Platinum Surface Exposed
in the Secondary Circuit Physico-chemical Conditions of the Pressurized Water Reactor (PWR)
10:45 to 11:15 Fate and Distribution of Film Forming and Alkalizing Amines in Steam-Water Cycles
M. Roy and D. You, SECR CEA, France, R. Lecocq and L. Verelst, Engie Laborelec, Belgium,
Y. Xue, M. Vanoppen and A. Verliefde, Ghent University, Belgium, A.M. Brunner and D. Vughs and
S. Delaunay and J. Tireauc, EdF R&D, Renardières, France
H. Huiting, KWR Watercycle Research Institute, The Netherlands, and W. Hater, Kurita Europe GmbH,
9:00 to 9:30 Experience using a Film-forming Corrosion Inhibitor at a Combined Cycle Power Station in UK
Germany
L. Barre, Nalco Water, France, D. Cicero, Nalco Water, USA, and A. South, Nalco Water, UK
11:15 to 11:45 The Approach to Improving Steam Facility Efficiency Focusing on Hydrophobicity of Film-forming
The Effectiveness
9:30 to 10:00 Amine of FFSs
in Water-Steam in Mitigating FAC under Two-phase Flow Conditions; Experiments
Cycles
with a Commercial Product containing
S. Mori, Kurita Water Industries, Japan Oleylpropanediamine (OLDA) at High pH with
Diglycolamine (DGA)
11:45 to 12:15 Preservation for Cycling Plants with an ACC
N. Leaukosol, S. Weerakul and D.H. Lister, University of New Brunswick, Canada, and S. Mori, Kurita
M. Rziha, PPCHEM AG, Switzerland
Water Industries, Japan and W. Hater, Kurita Water Industries, Germany

12:15 to 13:30 Working Lunch within Exhibits

10:00 to 10:15 Short Presentation and Open Discussion Period

Session 3
10:15 to 10:45 Morning Coffee/Tea within Exhibits
13:30 to 14:00 30 Years of Experience with Film-Forming Amines at a Norwegian Fertilizer Production Site
Session 6 R. van Lier and A. de Smet, Yara Belgium SA/NV, Belgium, L.-M. Olsen, M. Halasa and T.A. Fjærem,
Yara Norge AS, Norway
10:45 to 11:15 Filming Product Application in the PWR/PHWR Secondary System: An Update on the EPRI
14:00 to 14:30 Investigations on the Impact
Nuclear Qualification Programof Steam Properties on Film Formation
M. Bos, J. Cappaert - de Vos and K. Schreyenberg,
K. Fruzzetti, M. Mura and S. Shulder, EPRI, USA, andKerncentrale
M. Kreider, Borssele,
C. Marks N.V. EPZ,
and J. The Netherlands,
Reinders, Dominion
J. Fandrich and U Ramminger,
Engineering, Inc., USA Framatome GmbH, Germany, and J.-L. Bretelle and C. Wesoluch,
Electricite de France, France
11:15 to 11:45 Layup for Longterm Outage and Mothballing of Water and Steam Cycles using Film Forming
14:30 to 15:00 Incorrect
Technology Application of a FFS and Consequences on the Water/Steam Cycle
D.
C. Addison, ThermalRWE,
van der Westen, Chemistry, NewA.
Germany, Zealand
Verstraeten and M. Jansen, Anodamine Europe, The
Netherlands
15:00 to 15:15 Short Presentation and Open Discussion Period
11:45 to 12:15 Short Presentation and Open Discussion Period
15:15 to 15:30 Afternoon Coffee/Tea within Exhibits
12:15 to 13:30 Working Lunch within Exhibits

8 PowerPlant Chemistry 2019, 21(1)

2
 The Third International Conference on
Film Forming Substances (FFS 2019)
Panel Discussion Session 7
19–21 March 2019 at the Crowne Plaza Heidelberg City Centre in Heidelberg, Germany
13:30 to 15:00 Panel Session on Film Forming Substance
Chair: B. Dooley, Structural Integrity, UK
Agenda / Programme
15:00 to 15:30 Afternoon Coffee/Tea within Exhibits
Day 1 – Tuesday, 19th March 2019. FFS2019 Agenda
Session 8
8:00 Registration and Welcome Coffee / Tea
15:30 to 16:00 Ontario Power Generation(OPG) OPG Film Forming Substances Experiences: Anodamine
Application and ODACON Qualification
8:45 to 9:00 Opening Remarks
P. Cao, A. Garg and P. Woods, Ontario Power Generation, Pickering, Canada, and E. Cornthwaite,
Ontario Power Generation, Darlington, Canada
Session
16:00 to116:30 Update on Roadmap to an IAPWS Technical Guidance Document for Nuclear Plants
9:00 to 9:30 Influences
W. Cook andof D.
FFS on Oxide
Lister, Growth
University around
of New Generating
Brunswick, Cycles
Canada, and others
B. Dooley, Structural Integrity, UK, D.H. Lister, University of New Brunswick, Canada, and J. Fandrich,
16:30 – 17:00 Framatome GmbH, Germany
Short Presentation and Open Discussion Period
9:30 to 10:00 Longterm Preservation with FFA – Current State after Two Years of Standstill
R. Wagner, Reicon, Leipzig, Germany
Day 2 Concludes

10:00 to 10:15 Short Presentation and Open Discussion Period

Day 3 – Thursday, 21st March 2019. FFS2019 Agenda

10:15 to 10:45 Morning Coffee/Tea within Exhibits

8:00 Opening Coffee / Tea and Remarks

Session 2
10:45 to 11:15 Fate and Distribution of Film Forming and Alkalizing Amines in Steam-Water Cycles
Session 9
Y. Xue, M. Vanoppen and A. Verliefde, Ghent University, Belgium, A.M. Brunner and D. Vughs and
8:30 to 9:00 H. ENGIE Laborelec
Huiting, – 25 Years
KWR Watercycle of FFS Institute,
Research Follow-up The– "Where is theand
Netherlands, evidence?"
W. Hater, Kurita Europe GmbH,
M. Vermeersch,
Germany Engie Laborelec, Belgium
9:00 to
11:15 to 9:30 FirstApproach
11:45 The FFS Trial to
Application
Improvingat NPP Blayais:
Steam OperatingFocusing
Facility Efficiency Experienceon and Lessons Learned
Hydrophobicity of Film-forming
J.-L. Bretelle, C. Wesoluch,
Amine in Water-Steam Cycles and E. Bres, Electricite de France, France, U Ramminger and J. Fandrich,
Framatome
S. GmbH,
Mori, Kurita WaterGermany,
Industries,and R. Wagner, Reicon, Germany
Japan
®
9:30 to
11:45 to 10:00 Experiences for
12:15 Preservation with
Cycling PlantsG851
Cetamine withfor
an Layup
ACC of Power Plants
J. Jasper and A. de Bache, Kurita
M. Rziha, PPCHEM AG, Switzerland Europe GmbH, Germany

10:00to
12:15 to13:30
10:30 Working
MorningLunch
Coffee/Tea
withinwithin Exhibits
Exhibits

Session310
Session
10:30to
13:30 to14:00 Study
11:00 30 Yearsofof
FFA Thermolysis
Experience withinFilm-Forming
the Water/Steam
Amines Cycle
at aofNorwegian
Power Plants
Fertilizer Production Site
S.van
R. Lier andand
Vidojkovic A. Smet,
A. de Verliefde,
YaraGhent University,
Belgium SA/NV, Belgium
Belgium, L.-M. Olsen, M. Halasa and T.A. Fjærem,
11:00 to 11:30 Yara Norge AS,Cycle
Water-steam NorwayProtection with Anodamine, Working Mechanism and some Recent Results
of European Applications
14:00 to 14:30 Investigations on the Impact of Steam Properties on Film Formation
M.Bos,
M. Jansen and A. Verstraeten,
J. Cappaert - de Vos andAnodamine Europe, The
K. Schreyenberg, Netherlands
Kerncentrale Borssele, N.V. EPZ, The Netherlands,
11:30 to 12:00 J.Adsorption
Fandrich and U Ramminger,
of Oleyl Framatomeon
Propylenediamine GmbH,
MetalGermany,
Surfaces and J.-L. Bretelle and C. Wesoluch,
Electricite de France, France
T. Petrick, J. Jasper, D. Disci-Zayed and W. Hater, Kurita Europe GmbH, Germany
14:30 to 15:00 Incorrect Application of a FFS and Consequences on the Water/Steam Cycle
Short
12.00 to 12:30 D. Presentation,
Addison, Final Discussion
Thermal Chemistry, Period and Concluding Remarks
New Zealand

12:30to 15:15 Short

15:00 LunchPresentation and Open Discussion Period

15:15 Day 3 Concludes

13:30to 15:30 Afternoon Coffee/Tea within Exhibits

PowerPlant Chemistry 2019, 21(1) 9

2
 Corrosion and Deposits in Water-Cooled Generator Stator Windings: Part 3: Removal of Flow Restrictions

Corrosion and Deposits in Water-Cooled Generator Stator

Windings: Part 3: Removal of Flow Restrictions
Thomas Bauer, Matthias Svoboda, and Robert Svoboda

ABSTRACT

Flow restrictions in generator stator bar hollow conductors can be removed either mechanically or chemically. Both
methods have their advantages and disadvantages and in certain cases only a combination of both leads to success.

Mechanical cleaning can open up completely plugged hollow conductors at the inlet or outlet of the bars, while chem-
ical cleaning thoroughly removes all copper oxides, also within the bars. However, as with all chemical cleaning meth-
ods, there must be access for the chemicals to the copper oxide deposits so the chemicals can dissolve and remove
the plugging.

To prevent metallic deposits, it is important that the chemical cleaning be performed under oxidizing conditions. Addi-
tionally, it might also be useful to apply a post-cleaning surface treatment under certain conditions.

It is recommended to take any kind of plugging seriously and to start reacting when first signs of plugging occur. Once
severe conditions have developed, this might lead to power downrates, a decrease in insulation lifetime, forced outages
or in the worst case even irreversible damage to the generator.

INTRODUCTION

Flow restrictions in hollow conductors of water-cooled The first chemical cleanings were done with strong acids
generators are most commonly caused by copper oxide like sulphuric or phosphoric acid. As these acids do not
deposits but may also be caused by various debris that effectively dissolve cuprous oxide, oxidizing substances
has entered the recirculating water, or even by mechani- and complexing agents were considered.
cal deformation of the hollow conductors. The decreasing
heat transfer results in local hot spots in the winding, de- In 1977 Seipp conducted the cleaning of a stator water sys-
creased insulation lifetime, load limitations and potential tem with ammonium persulphate, which intrinsically in-
forced outages and irreversible damage to the generator. cludes an acid as well as an oxidizer. Although very effec-
To prevent these potentially serious financial losses, it is tive, the quantities of base metal dissolved (some 20−40 kg)
useful to have options for removing the flow restrictions. prompted the development of other methods.

This is the fourth part in a series of five papers to appear In 1980 Gamer and Seipp (Brown Boveri) successfully
in this journal on corrosion and deposits in water-cooled applied complexing agents in combination with an oxidiz-
generator windings [1–5]. This information has also been er [8] and this was further developed throughout its first
included in more detail in EPRI publications on this subject successful application. In 1996 the first on-line cleaning
[6,7]. was conducted at the 1 350 MVA Seabrook generator; the
chemical cleaning was carried out while the generator was
operating at full load.
HISTORY
Today different methods and acronyms are used by the
Water cooling of generators had its beginning in the 1950s, industry: mechanical cleaning, reverse flow flushing, or
and since the early 1960s, more and more units have been chemical cleaning by complexing agents, acids or com-
installed. It was not until the early 1970s that flow restric- plexing acids.
tions due to copper oxide deposits were first reported. By
the mid 1970s most major manufacturers had tried one or
another type of hollow conductor cleaning. There are no
clear publications documenting this development as its full
magnitude was not yet known at that time.

10 PowerPlant Chemistry 2019, 21(1)

Corrosion and Deposits in Water-Cooled Generator Stator Windings: Part 3: Removal of Flow Restrictions

CRITERIA FOR CONSIDERING GENERATOR erator failure. Preventive maintenance reduces the risk of
CLEANING unplanned failure as well as the cost and time needed for
repairs. A proactive approach which takes early action be-
A significant number of utilities have taken proactive mea- fore symptoms are evident is recommended [9].
sures against hollow conductor fouling and performed
chemical cleaning as part of their preventive maintenance CLEANING OPTIONS
plan.
In this context, "cleaning" stands for the removal of de-
posits within the generator winding and other components
Table 1 lists criteria for when, at the latest, cleaning of the
of the stator cooling water systems (e.g. strainers).
hollow conductors should be considered. As this table is
of a general nature, the listed values are generous and
The types of deposits to be removed can mainly be divid-
should be narrowed for the individual cases.
ed into two categories:
Although some of the cleaning methods seem to require • Foreign material: this includes paint chips, wires from
significant outage time, it must be considered that this is steel brushes, dirt, gasket material, textiles, cigarette
minor compared to the consequences of a related gen- butts, insects, etc.

Diagnostic Method Cleaning Recommended at

mid-term** short-term**
Any trend that indicates arriving at a specification limit*** within
12 months 2 months
Assessment of operating parameters Events indicating a problem****
Review of operating history Events indicating a problem****
Review of system water chemistry Events indicating a problem****
Strainer and filter clogging history Increased frequency of clogging****
Normalized pressure drop / flow, relative to original
Pressure drop > 20 % > 40 %
Stator water flow < 10 % < 20 %
Individual bar * flow, relative to average within group < 7.5 % < 10 %
Normalized temperature on-line
Water outlet temperature (rise above inlet) > 10 % > 20 %
Water outlet hose temperatures
top bar * relative to top bar average > 5 °C (9 °F) > 7 °C (13 °F)
bottom bar * relative to bottom bar average > 4 °C (7 °F) > 6 °C (11 °F)
Stator slot * temperature relative to average — > 10 °C (18 °F)
of all slots
Visual inspections
Cooling water system components Increased fouling****
Stator bars Visible deposits, but flow not Visible deposits, flow restricted
yet restricted
DC High-Potential Test Suspicion of conductive deposits****

Table 1:
Criteria for considering cleaning of the stator bars, in a typical water-cooled generator. The diagnostic methods refer to those listed and
discussed in reference [3]. Action is recommended when one of these criteria has already been fulfilled. This table may be adapted to an
individual generator's characteristics. However, there should be a substantiated reason for choosing different values and it should not
be a way to legitimize a bad condition.
* This item refers to one or more individual bars, hoses or slots that deviate from the rest within a group of comparable conditions.
** Mid-term means action within 1 year and short-term means action within 2 months, and less if there is a faster trend in deterioration.
*** Do not trust the situation if it stabilizes without evident reason; "things that go away by themselves may come back by themselves".
**** Criteria will be plant-specific and subject to engineering judgment.

PowerPlant Chemistry 2019, 21(1) 11

 Corrosion and Deposits in Water-Cooled Generator Stator Windings: Part 3: Removal of Flow Restrictions

• Corrosion products of system materials: most promi- fully, the mechanical tool can scratch or even completely
nent are the corrosion products of the copper hollow destroy the bar. Scratches on the copper surface have an
conductors increased surface area and roughness, and thus are prone
• CuO (cupric oxide) to future crystal growth of copper oxides.
This oxide is predominant in high-oxygen water and is
Chemical Cleaning
formed either during permanent high-oxygen conditions
or during temporary oxygen excursions (incidents). The cleaning effect is accomplished by the effect of the
• Cu2O (cuprous oxide) chemicals dissolving the matter to be removed. The dis-
solved impurities can then be either drained or removed
This oxide is predominant in low-oxygen water. It trans-
with an ion exchange bed.
forms readily to CuO when the water is subjected to
higher oxygen levels or another oxidizing substance
Chemical methods can be directed specifically towards
(e.g. hydrogen peroxide).
the matter to be dissolved. Usually chemical cleaning for
• Cu (metallic copper) generator cooling water systems is tailored to the removal
Deposits of small copper particles or even plated out of copper oxides. As will be explained later, the chemical
copper are also sometimes found in generator cooling removal of copper corrosion products requires oxidizing
water systems. media.

The actual deposit in a hollow conductor is always a mix of Limitations of Cleaning

these oxides. In low-oxygen plants, Cu2O is predominant,
• Hollow conductors that are completely blocked and do
and in high-oxygen plants CuO. Metallic copper is usually
not have any water flow usually cannot be cleaned by
only a minor component.
any type of chemical cleaning. They require a preceding
mechanical cleaning.
Deposits in generator cooling systems also comprise
some iron oxides, even in the usual case where all steel
in the system is of stainless grade. Quantities however are • With all the cleaning methods available, one important
small and there is no known report of substantiated plug- point should however be kept in mind: the cause of the
ging. It is therefore considered that iron oxides do not mer- plugging is not eliminated by the cleaning; reoccurrence
it the application of special techniques for their removal. of plugging cannot be excluded. Cleaning thus is not
the final solution to the problem, but only removes the
Mechanical Cleaning symptoms.
The cleaning effect is accomplished by the effect of me-
chanical force upon the matter to be removed. Typical
tools include piano wires, drills, chisels, water jets and METHODS FOR CLEANING OF HOLLOW
CO2 blasting, for instance. Mechanical methods are – to CONDUCTORS
a variable degree – effective on dirt and debris, as well
as on deposited corrosion products. Drawbacks include Mechanical Cleaning
limited access to the deposits – within a stator bar, only Mechanical cleaning is understood in this publication to be
the inlet and outlet are typically accessible. The bar itself the removal of substances by means of a tool. Flushing is
with the Roebel transposition can hardly be fully penetrat- discussed separately.
ed with a mechanical cleaning tool. If not performed care-

Figure 1:
Plant O3. Water box before (left) and after (middle) mechanical cleaning. Right: after subsequent complexant cleaning [10]. Note that
all photos were taken from the same water chamber.

12 PowerPlant Chemistry 2019, 21(1)

Corrosion and Deposits in Water-Cooled Generator Stator Windings: Part 3: Removal of Flow Restrictions

For mechanical cleaning, the hollow conductors must be 60

accessed by the cleaning tool. Such a cleaning tool may
be anything from a simple piece of stiff wire to a small ro-

Number of Bars in Interval [−]

50
bot. A practical device is a pre-bent guiding tube that fun-
nels the wire into the hollow conductor. This guiding tube 40 Before cleaning
After mechanical cleaning
can be for example a small copper tube that is easily bent After mechanical and chemical cleaning
30
into the right shape, or a memory-shaped plastic tube that
bends easily when warm but snaps into the desired shape 20
when cooling down. This tube is directed either by direct
vision or by videoscope. 10

This method may, at its best, cover the hollow conductor 0

0 1 2 3 4 5 6 7 8 9 10 11 12
ends and some parts of the hollow conductor. The small Flow Interval [L ∙ min−1]
cross section (typically on the order of 1.5 x 4 mm), the
length (typically on the order of 5–10 m), and the twisted Figure 2:
form at the Roebel transpositions hinder a deep penetra- Plant Figure
PN3. Flow 2 distribution in the stator bars before and after
tion of cleaning tools into the hollow conductor. cleaning. The flow through each stator bar was measured on its
outlet water hose by ultrasonic flow testing. Each bar was then
It is evident that major disassembling is required for a me- related to the matching flow interval. The figure shows the num-
ber of bars in each interval. Before cleaning, the flow was severely
chanical cleaning. It can only be done with the generator
impaired, and about 1/3 of all hollow conductors were complete-
shut down and the stator water connections disassem- ly plugged (black curve). Mechanical cleaning opened all hollow
bled. conductor passages and improved flow distribution of the indi-
vidual bars considerably (blue curve). The final step towards nor-
An example is the case of Plant O3 (Figure 1). During a mal flow distribution was then the following complexant cleaning
normal visual inspection at a planned outage, severely (red curve).
20
plugged hollow conductors were found. To prepare the
18
machine for a global chemical cleaning, a mechanical
Number of Bars per Interval [−]

16
cleaning was done with the water hoses removed and the A similar effect is sometimes observed when pressure
14 2 Yeras earlier
water chamber and the hollow conductor ends directly ac- shocks or sudden
Before flow changes are made with the sta-
12
cessible. A wire with a rounded tip was then pushed into After
tor cooling water, e.g. by adding the standby pump. Such
10
the conductor to open up the completely blocked hollow effects are also conceivable when changing the cooling
8
conductors (Figure 1, left and middle). The two completely water temperature.
6
blocked hollow conductors on the bottom left were me-
4
chanically opened, but still had substantial deposits. After- Even though some improvement could be possible in in-
2
wards, a complexant cleaning was performed on the entire dividual cases, this is not recommended practice. These
0
system. Post-inspection of the same waterbox (Figure 1, transients may produce unpredictable results. For exam-
−60 −55 −50 −45 −40 −35 −30 −25 −20 −15 −10 −5 0 5 10 15 20 25 30 35 40 45 50
right) revealed that all copper oxides had been removed ple, more plugging Flowcould
Intervalresult due to
[% Deviation the
from release of a crud
Average]
and full cooling efficiency was re-established. burst that is caught in other plugged conductors. Clean-
ing effects
Figure are3small and the technique does not provide
Another example is the case of Plant PN3 (Figure 2). This a thorough cleaning. Additionally, there is also no way of
stator had severely plugged hollow conductors. Assisted controlling these processes, so they should not be a pre-
visual inspection identified 196 out of a total of 576 hol- ferred option.
low conductors in the bottom bars as being completely
plugged. Mechanical cleaning was done with the water Such action may however be useful for saving a bad gen-
hoses removed and the water chamber and the hollow erator availability situation.
conductor ends directly accessible. A stiff wire with a
rounded tip (to prevent scratching) was then pushed into Water Flushing, Air/Water Flushing
the conductor to remove the oxide plug. Subsequent indi-
vidual conductor flow testing showed that all plugged con- A sometimes useful technique to remove substances from
ductors were opened and bar flow distribution improved the conductors is reversing the water flow. This especial-
considerably. However, for full restoration of flow, a subse- ly liberates the conductor inlets from larger debris but is
quent chemical cleaning was necessary. also capable of flaking off copper oxide deposits. Hard
deposits that resist even mechanical cleaning tools (Figure
1, middle photo) can however rarely be removed by water
Effect of Load Changes and Flow Changes
flushing.
It has been observed that in generators with increased
temperatures those temperatures sometimes improve The installation required for reversing the flow varies from
when a temporary load reduction is carried out. A 20 % plant to plant. Some plants are already equipped with
load reduction for half an hour may already be sufficient. crossover pipes and valves permitting flow reversal with

PowerPlant Chemistry 2019, 21(1) 13

 60

50

Number of Bars in Interval

Corrosion and Deposits in Water-Cooled Generator Stator Windings: Part 3: Removal of Flow Restrictions
40 Before cleaning
After mechanical cleaning

30 After mechanical and chemical cleaning

no further installations. Most other plants however require Figure 3 and Figure 4 give examples of the effects of re-
20
temporary piping, which necessitates plant shutdown. It is verse flow flushing in plant S3. In both cases considerable
important
10 to provide fine filtration of the recirculating water quantities of oxide sludge as well as other debris were re-
in order to remove the substances from the system. Plants moved by the hot reverse flow flushing (Figure 5). Water
with0 stainless steel mesh 5filters 6
or strainers should con- flow was quantified with ultrasonic flow measurements at
0 1 2 3 4 Flow Interval (L/min) 8 9 10 11 12
sider temporary 20-micron filter cloth inserts on the mesh. the outlet water hose of each bar. The flow distribution of
the individual bars showed some improvement, but it was
Figure
Reverse flow 2flushing should be done with the maximum not dramatic (Figure 3). This demonstrates that reverse
achievable flow. To be more effective, the coolers can be flow flushing is good for doing "heavy duty cleaning", but
shut off to have the water temperature run up to around is not sufficient to completely remove compact oxide plug-
50 °C. The duration of flushing depends on the nature and ging. To have all copper oxides in the system removed, it
degree of plugging. In some cases, even after 5 days of is crucial to also perform a chemical cleaning after the hot
hot reverse flushing there was still some debris being re- reverse flow flushing. The improvement in plant S3 can be
moved from the stator. seen in Figure 4.

20

18
Number of Bars per Interval [−]

16

14 2 Years earlier
Before
12
After
10

0
−60 −55 −50 −45 −40 −35 −30 −25 −20 −15 −10 −5 0 5 10 15 20 25 30 35 40 45 50
Flow Interval [% deviation from average]
Figure 5:
Plant S3. Oxide flake removed by hot reverse flow flushing (as
Figure 3:
Figure 3
Plant S3. Bar water flow distribution after hot reverse flushing.
in Figure 3). It is evident that the flushing has chipped off oxide
flakes.
It can be seen that bar flows had not changed much from the val-
ues obtained 2 years earlier (green and black curves). Hot reverse
flow flushing did remove some deposits but did not significantly Another useful technique is to backflush individual bars
improve the flow distribution (black and red curves). with high-pressure air or a mixture of air and water drop-
lets. When choosing the pressure, attention has to be giv-
en to the mechanical limits of the bar and its connections.

20
Complexant Cleaning
18
Number of Bars per Interval [−]

16 The mechanism of complexant cleaning is as follows [11]:

14 2 Years earlier
Before
12 After Copper oxides dissolve slowly in water until the equilibri-
10 um concentration is reached. The equation for the disso-
8 lution of CuO is:
6
4
CuO +H2O  Cu(OH)2  Cu2+ + 2OH–
2
solid  dissolved  dissolved/dissociated
0
−60 −55 −50 −45 −40 −35 −30 −25 −20 −15 −10 −5 0 5 10 15 20 25 30 35 40 45 50
Flow Interval [% deviation from average] The equilibrium concentration will be determined by the
solubility product [12]. If a chelating agent (complexant) is
Figure 4: added to the system, it will react with the Cu2+ ion and thus
Plant Figure 4 flow distribution after hot reverse flushing
S3. Bar water
remove it from the system, hence keeping the dissolution
plus chemical cleaning. This is the same plant as in Figure 3, but
at a later year. It can be seen that stator water flow had signifi-
going.
cantly deteriorated compared to 2 years earlier (green and black
curves). Hot reverse flushing plus chemical cleaning improved It is important to note that the chelating agent does not
the flow distribution significantly (black and red curves). dissolve the oxide. The oxide has to go into solution on

14 PowerPlant Chemistry 2019, 21(1)

Corrosion and Deposits in Water-Cooled Generator Stator Windings: Part 3: Removal of Flow Restrictions

its own. The chelant only removes the dissociated prod- Due to the diluted solution, on-line chemical cleaning typ-
uct and thus forces the continuous dissolution of the solid ically takes longer than off-line cleaning, on the order of
copper oxide. The chelant by itself does not dissolve or 10–15 days. However, it does not interfere with plant op-
attack the solid substance. 20 eration.
18

Number of Bars per Interval [−]

The strength of the chelation is16 described by the sta- Choice of complexant The choice has to make due
2 Years earlier
bility constant. For instant, Fe3+14, Cu2+ and
BeforeFe2+ make consideration of the properties of copper and its oxides:
12
strongly bonded complexes with the chelant ethylene-di-
After

amine-tetraacetic acid (EDTA). 10 • CuO (cupric oxide)

8
6 Cu2+ forms a large number of complexes.
Complexant cleaning can be done off-line as well as
4
on-line Differently from acids, complexants do not need • Cu2O (cuprous oxide)
2
a minimum strength for reacting with copper oxides. The Cu+ also makes certain complexes, most notably with
0
chemical reaction is independent of the chemical concen- NH3 and CN–. Other complexants that are active only
−60 −55 −50 −45 −40 −35 −30 −25 −20 −15 −10 −5 0 5 10 15 20 25 30 35 40 45 50
tration. Thus, the process can be done with aFlow sufficiently on Cu2+ may dissolve Cu2O with disproportionation into
Interval [% deviation from average]
dilute solution so it does not interfere with any conductivity Cu2+ ions and metallic copper. In such a case an oxidant
limits. Complexant cleaning therefore can be done off-line is required to support cleaning.
as well as on-line, that is, with the Figure
generator4 in operation. • Cu (metallic copper)
However, special care and safeguards need to be in place
Metallic copper can be attacked by certain complexant
to prevent a conductivity spike, which can trip the gener-
mixes, even in the absence of oxidizing agents.
ator.

30

On-line complexant cleaning

28
Temperature above Inlet [°C]

25

Average

23

20

18

15
-75 -50 -25 0 25 50 75 100 125 150 175 200
Run Time [hours]

Figure 6:
Plant P6. Improvement of stator slot temperatures by on-line complexant cleaning. All 72 stator slot temperatures were normalized
Figure 6
to a constant reference load. Chemical cleaning started at zero hours run time. The improvement of the average temperature by 4 °C
as well as the additional improvement (up to 10 °C) of the hotter bars can be seen. At the end of the cleaning, all slots were within the
normal spread of temperatures.

PowerPlant Chemistry 2019, 21(1) 15

 Corrosion and Deposits in Water-Cooled Generator Stator Windings: Part 3: Removal of Flow Restrictions

A complexant is of practical use for cleaning only if the sol- has recently been conducted [10]. Compared to acids,
ubility of the reagent and the resulting copper compound complexants are not particularly aggressive to system ma-
in water is sufficiently large. The use of intermediate solu- terials.
bilization agents complicates process chemistry and may
lead to secondary reactions. EDTA, like its readily water-soluble salt Na2H2-EDTA, is a
long-time traditional cleaning agent for copper and has
Some complexing agents seem promising for CuO, others been used in a large number of generator cleanings.
for Cu2O. A few of them even seem suitable for both but
might come with the drawback of poor solubility in water.
Application of complexant cleaning Because of their
relatively benign properties complexants are usually ap-
The art of complexant cleaning consists of choosing the
plied by recirculation in the generator cooling water sys-
appropriate complexing agent together with the right bal-
tem using the system recirculation pump.
ance of oxidant. Too much oxidizer may produce more
oxides than the complexant can dissolve, while too little
The hollow conductors may have a bare surface after
oxidizer makes the dissolution incomplete or may even
complexant cleaning. Depending on the water chemistry,
leave conductive deposits on the isolating hoses. It has
re-establishment of a stable oxide layer may require a fol-
to be considered that some oxidizer is lost for cleaning
low-up treatment. Without such reoxidation there may be
by reactions other than those with deposits of copper and
a risk of rapid reoccurrence of the plugging (within a few
copper oxides, e.g. by the formation of oxygen gas that
weeks).
may vent off.

It is also important to consider its effect on all other in- Experiences Complexant cleaning of generator cool-
volved materials and components. Especially the effect ing systems using EDTA has been successfully applied
on the brazing material for the hollow conductors and the in more than 250 generator cleanings since 1980. If done
water boxes needs close attention. A thorough analysis properly, that is, with proper quantity and timing of the in-

15 1 000
Cleaning
900
12.5
TC Temperatures, Deviation from Average [°C]

MVA 800
10
#3 700

7.5
600
#3 [MVA]
5 500

400
2.5

300
0
200

-2.5
100

-5 0
0 30 60 90 120 150 180 210 240 270 300 330 360 390 420
Run Time [days]

Figure 7:
Plant O2:Figure 7
Outlet temperatures of the individual TC elements, before and after off-line complexant cleaning. The deterioration of flow
before and the improvement after the cleaning can be seen. Temperatures were measured with TC elements at the outlet water hoses
of each group of stator bars (one top bar in parallel with one bottom bar) and normalized to standard load (880 MVA). The dashed red
curve (MVA) displays the actual generator load; the dips indicate periods where the plant was shut down.

16 PowerPlant Chemistry 2019, 21(1)

 Corrosion and Deposits in Water-Cooled Generator Stator Windings: Part 3: Removal of Flow Restrictions

10 mal operating conditions within the normal range of devi-

ations from average.
Number of Bar Groups in Interval [−]

9
8
7 Before Ultrasonic flow measurements before (Figure 8, black) and
After #3
6 after cleaning (Figure 8, red) revealed a similar pattern as
5
for the temperatures. The flow in eight water hoses was out-
side the ± 7.5 % tolerance range for deviation from aver-
4
age, and one hose in particular (the one with TC #3)
3
showed a very low flow through the bar, 19.3 L ∙ min–1.
2
#3 #3 After the off-line complexant cleaning, the average flow
1
increased by 20 %, from 28.8 L ∙ min–1 to 34.4 L ∙ min–1.
0 Additionally, only one bar remained outside the ± 7.5 %
18 20 22 24 26 28 30 32 34 36 38 40
range. For instance, the originally worst bar improved
Flow Interval [L ∙ min−1]
(TC #3) from 19.3 L ∙ min–1 to 32.2 L ∙ min–1.
Figure Figure
8: 8
Plant O2. Ultrasonic flow measurements on the individual stator Acid Cleaning
bar water hoses, before (black) and after (red) off-line complex-
ant cleaning. The improvement in flow by the cleaning can be The mechanism of acid cleaning is as follows, as given
seen. Each water hose combines the water flow from the same with the example of sulphuric acid:
group of bars (one top bar in parallel with one bottom bar) as
used for the TC for temperature monitoring (Figure 7). CuO + H2SO4  Cu2+ + SO42– + H2O
solid  dissolved/dissociated
jection and with the right balance of complexant and oxi-
where the CuSO4 is soluble in water and can be flushed
dant, the method gives good cleaning results.
away. The acid directly dissolves/attacks the solid sub-
With proper complexant cleaning, only the copper ox- stance.
ides and a minor amount of metallic copper are removed.
Quantities are usually below 5 kg. Compared to this, acid Acid cleaning is an off-line method Acids need a cer-
cleaning dissolves some 20–40 kg of copper, the major
25 tain minimum strength – in other words, a certain pH is
Number of Bars in Interval [−]

part coming from

Before acid dissolution
flush of base metal. necessary – to be active for a dissolution process; if it
20 After first flush
After second flush is used in a too dilute form it is not effective for clean-
There are also
+ mechcases
where improper use of com- clean reported ing. For this reason, acid cleaning is usually associated
15
plexants has resulted in the removal of > 100 kg of base with a relatively high conductivity of the cleaning solution
copper from the system. Thus, even with a gentle method
10 (> 1 000 µS ∙ cm–1). Given the fact that most generators
as with complexant agents, proper application is the key limit the conductivity of water to < 10 µS ∙ cm–1 for opera-
to
5 having the process under control at all times. Otherwise tion, acid cleaning can only be done when the generator
severe damage to the generator might be the outcome. is off-line, that is, not under electric potential. In addition,
0
-25 -20 -15 -10 -5 0 5 10 acid cleaning usually requires some major disassembly of
If the balance of chemicals is not right, the generator may components.
Flow Interval [% deviation from average after second flush]
plug again within a short period or even cause damage to
the generator. Choice of acid The choice has to make due consider-
Figure 11 ation of the properties of copper and its oxides:
Figure 6 gives the results of an on-line complexant clean-
ing. This was at a 635 MVA generator for a nuclear power • CuO (cupric oxide)
plant that suffered deterioration of stator cooling [13]. The This oxide is dissolved by most acids.
rapid increase in slot temperatures in the days before the • Cu2O (cuprous oxide)
cleaning can be seen in Figure 6. An emergency on-line
This oxide is dissolved by hydrofluoric, sulphuric, phos-
complexant cleaning brought back the temperatures to
phoric and dilute nitric acid, and also by the principal
the normal range within a few days. A total of 4.9 kg of
organic acids with disproportionation into Cu2+ ions
copper was removed. More than 85 % of this copper orig-
and metallic copper [14,15]. This metallic copper can
inated from oxides in the system.
subsequently be dissolved with concentrated oxidiz-
ing acid [14]. In order to provide a good dissolution of
Figure 7 and Figure 8 show data from an off-line complex-
Cu2O, acid solutions must therefore be oxidizing and
ant cleaning at plant O2. During operation, the water in the
have a sufficient strength.
bar outlet water hoses had increasing temperatures (Fig-
ure 7, especially the green and red thermocouples (TCs)),
with deviations from average of up to 14 °C (TC #3). After
the chemical cleaning, the temperatures returned to nor-

PowerPlant Chemistry 2019, 21(1) 17

 Corrosion and Deposits in Water-Cooled Generator Stator Windings: Part 3: Removal of Flow Restrictions

Figure 9:
Material tests in a mixed solution of phosphoric and sulphuric acid, together with hydrogen peroxide.
1: bare copper sample before acid treatment. 2–5: after acid treatment. 2: copper sample with brazing material; severe attack with
cleaning. 3,4: epoxy coated sample to simulate a repair method; the coating detached with cleaning. 5: two copper plates bonded
with cyanoacrylate to simulate a "super-glue" repair method; both the copper and the cyanoacrylate were attacked. Reprinted from
reference [10].

Sulphuric and phosphoric acids have been traditional

agents for generator cleaning. Their effectiveness how-
ever is limited. Also considering the risk of plate-out of
metallic copper, their use without any oxidizers cannot be
recommended.

Citric acid and other organic acids like glycolic acid and
gluconic acid have demonstrated their benefits. Their
function is probably also related to complexing properties.

It is known that NH4+ has strong complexing properties on

Cu and on Cu+. Ammonium salts of acids together with an
oxidizer are therefore promising for the removal of gener-
ator deposits. (NH4)2S2O8 (ammonium-peroxo-disulphate,
Figure 10:
Plant B2. Equipment for acid cleaning. The equipment is placed or ammonium persulphate) is a substance that combines
on the turbine floor, next to the opened generator. both these features.

When using an acid, it is also important to consider its

effect on all other involved materials and components. Es-
• Cu (metallic copper) pecially the effect on the brazing material for the hollow
Metallic copper is a relatively noble metal that is not conductors and the water boxes needs close attention.
dissolved by non-complexing solutions free of oxidizing This was analyzed in detail several years ago and a drastic
agents [14]. Specifically, it is not soluble in acids like hy- effect on and removal of brazing materials by acids [10]
drochloric, sulphuric or phosphoric acid, but is soluble was demonstrated; examples are shown in Figure 9.
if an oxidizer (e.g. oxygen from air, hydrogen peroxide
etc.) is present, or in oxidizing acids like nitric acid. Application of acid cleaning The acid may be applied
either by
As with the use of chelants, when oxidizing acids or ox-
idizing acid solutions are used attention has to be given • recirculation in the generator cooling water system with
to an adequate balance between oxidizer and acid. Too the system pump, or with a temporary pump; or
much oxidation may produce more oxides than the acid • application on disassembled bars, either individually or
can dissolve, while too little oxidation makes the disso- in groups.
lution incomplete or may even leave conductive deposits
on the isolating hoses. It has to be considered that some Recirculation of acid in the system challenges all other
oxidizer is lost for cleaning by reactions other than those system materials. The consequences of possible leaks
with deposits of copper and copper oxides. also have to be considered. Leaks outside the generator
may cause a safety hazard as the set-up of such a system
There are of course acids that have complexing proper- is not designed for this kind of treatment. Leaks inside the
ties; they do not necessarily require an oxidizer. Also, not generator may cause severe damage.
only the acid, but also the more convenient salts may be
used. Complexants were discussed earlier in this paper. Acid flushing of disassembled bars avoids involvement
of non-targeted components and facilitates risk man-
agement. However, major disassembly of the generator

18 PowerPlant Chemistry 2019, 21(1)

Corrosion and Deposits in Water-Cooled Generator Stator Windings: Part 3: Removal of Flow Restrictions

The air flow test showed that this cleaning did not produce
25
a satisfactory result. A second acid flush of 75 min brought
Number of Bars in Interval [−]

Before acid flush

20 After first flush more improvement. Following this second acid flush the
After second flush
+ mech clean bars with the smallest flow were opened and mechanically
15
cleaned (Figure 11). In those 20 bars, 10 out of the total
10 of 160 hollow conductors were found to have still been
plugged. Due to outage time constraints, further mechani-
5
cal cleaning was not possible.
0
-25 -20 -15 -10 -5 0 5 10 The cleaning removed 30 kg copper from the stator. A visual
Flow Interval [% deviation from average after second flush]
inspection showed that the copper surfaces had become
Figure 11: rough, and the brazing had been pitted. Another 30 kg
Figure 11
Plant B2. Flow distribution in the stator bars before and after of copper were removed from the brass-tubed coolers.
acid cleaning.
The spent cleaning liquid was clear and had a green color.
Within a few hours however it turned turbid and precipi-
is necessary, and it is not comfortable to have temporary
tation of red sludge took place (the main component was
plastic tubing carry acid to the inside of the stator housing.
amorphous copper). This indicates that care must be tak-
Acid cleaning usually employs inhibitors to keep the attack en that copper is not precipitated from the cleaning solu-
on the hollow conductor material under control. They may tion during some stage of the acid cleaning.
however reduce the effectiveness of the cleaning.
Cationic Purification
As with complexant cleaning, the hollow conductors may
have a bare surface after acid cleaning. Depending on the This is a process developed by EdF (Electricité de France)
water chemistry, re-establishment of a stable oxide lay- and has been implemented in some of their nuclear power
er may require a follow-up treatment. Without such reox- generators [16].
idation there may be the risk of rapid reoccurrence of the
plugging within few weeks. The generator cooling water is continually sprayed into the
air space when entering the water tank. The mixed bed
filter is temporarily replaced by a cation exchanger. The
Experiences Public reports on the experiences with acid
water thus is oxygen saturated and has a slightly acidic pH
cleaning of generators are rare. Good results have been
caused by carbon dioxide. Copper oxides and copper are
achieved with ammonium-peroxo-disulphate and with cit-
slowly dissolved and subsequently removed by the cation
ric acid [13].
exchanger.

Even with the use of inhibitors the quantity of copper re- Copper solubility changes along the path of water through
moved from the stator by acid cleaning is on the order the different parts of the system (e.g. solubility changes
of 20–40 kg, which is much more than the oxide deposit, with temperature etc.). Therefore, attention has to be paid
which is usually 2–5 kg. This means that substantial quan- that the dissolved copper is not redeposited in the sys-
tities of base metal are also dissolved. tem before it is removed by the cation exchanger. This re-
quires an exact knowledge of the local solubility as well
Figure 10 and Figure 11 illustrate an acid cleaning of a as the deposition kinetics, which strongly depend on sys-
440 MW generator. Stator water flow had decreased from tem design and operating parameters. Without such pro-
the normal value of 1230 L ∙ min–1 down to 1003 L ∙ min–1 gramming and close supervision there is a big risk that the
and was subsequently brought back to 1192 L ∙ min–1 with cleaning may go wrong. The process also corrodes the
this cleaning. bare metal, which can be excessive on sites with locally
high turbulence (flow accelerated corrosion). Cationic pu-
The stator was opened and the 108 stator bars were as- rification was designed to be applied intermittently.
sembled into groups of up to 8 bars in parallel. Each group
As the method has however been in limited use only, it will
was then separately treated with acid in a special cleaning
not be considered further.
circuit (Figure 10). A solution based on ammonium-per-
oxo-disulphate together with hydrogen peroxide was ap-
Follow-up Treatment after Chemical Cleaning
plied at ambient temperature for 45 min in counterflow
After thorough chemical cleaning, the copper surface is
direction. After this acid treatment, the bars were rinsed
bare metal, which is stable in water and – differently from
down to low conductivity, and then flushed with air, at the
chemical cleaning of steel – does not require a passiva-
same time measuring the air flow through each bar.
tion. If the water then contains oxygen, an oxide layer is
formed again. Experience has shown that – depending on
water chemistry – this oxide layer may however not always

PowerPlant Chemistry 2019, 21(1) 19

 Corrosion and Deposits in Water-Cooled Generator Stator Windings: Part 3: Removal of Flow Restrictions

On-/ Benefit Days

Off-line Required

Method

excellent
off-line

on-line

some

good

5–15

> 15
fair

<5
Mechanical cleaning x x x x
Load changes, flow changes x x c
Water flushing, water/air flushing x x x
Acid cleaning x x x x
Complexant cleaning
off-line x x x
on-line x x c
Mechanical cleaning combined with
acid cleaning, complexant cleaning x x x x
Water flushing, water-/-air flushing in combination with
acid cleaning, complexant cleaning x x x x

Table 2:
Comparison of methods for removing flow restrictions. "On-/off-line" specifies under which condition the method is available. "Benefit"
is understood to be the degree of improvement normally achieved by the method. "Days required" indicates the time typically needed
in 24/7 operation. c = a continuous process that does not interfere with generator operation.

be stable. It may dissolve, migrate and redeposit, thus even be the risk that particles may get stuck more severely
plugging the generator within a short period. This can be in the conductors than before.
avoided by applying a directed reoxidation.
Acid cleaning can be effective for severe and persistent
Thus, in these cases, a controlled reoxidation might be plugging but is not effective on complete plugging. It at-
useful [17]. The process can be optimized by the use of tacks base material substantially. In order to minimize
additives. adverse effects on system materials and to permit better
control, it should be performed by cleaning either individ-
In contrast to high-oxygen systems, where reoxidation is ual bars or a small group of bars in parallel. This requires
a must, it is important to evaluate its usefulness on a case partial disassembly of the generator. The risk of acid leak-
by case basis for low-oxygen machines. Under certain ing out of the system (especially onto the rotor) has to be
conditions, a controlled preoxidation might be useful and taken into account. Acid cleaning is only possible off-line.
reduce the reoccurrence of plugging significantly.
Complexant cleaning employs relatively benign reagents.
Attack on base materials is very limited when it is done
CHOICE OF THE METHOD properly. Complexant cleaning works at small concentra-
tions, so on-line cleaning (with the generator in operation)
Comparison and Assessment of These Methods is possible if the necessary precautions are taken. Besides
maintaining plant availability, on-line cleaning provides
Mechanical cleaning is able to locally remove severe and
real-time monitoring of the cleaning effect, permitting im-
even complete plugging, but it does not provide a com-
mediate reaction if the process goes differently than ex-
plete removal of deposits. Even if the method helps to re-
pected. With off-line cleaning, many effects of cleaning
instate a basic flow, the remaining deposits may still cause
are only seen at the subsequent restart. As smooth and
unsatisfactory flow and may be the nucleus for renewed
easy as a complexant cleaning sounds, it needs expert
deposition. Also, mechanical cleaning may require consid-
supervision to use the right chemicals, oxidizing agents
erable effort for disassembling the stator bar connections.
and additives at the correct time with the correct concen-
tration. Otherwise severe damage to the generator might
Water flushing is relatively simple, but has only limited be the outcome.
effectiveness. It will neither remove severe plugging nor
provide a complete removal of deposit layers. There may

20 PowerPlant Chemistry 2019, 21(1)

Corrosion and Deposits in Water-Cooled Generator Stator Windings: Part 3: Removal of Flow Restrictions

Hollow conductors that are completely blocked and do not ACKNOWLEDGEMENTS

have any water flow usually cannot be cleaned by any type
of chemical cleaning. They require a preceding mechanical The authors want to acknowledge the contributions to the
cleaning. development of chemical generator cleaning processes
by various persons involved in the past, especially by G.
The most efficient method to remove deposits is the com- Gamer, H. G. Seipp, H. Sandmann, S. Romanelli and D.
bination of mechanical with chemical cleaning. Rutz.

This assessment is summarized in Table 2.

REFERENCES
Recommendations
[1] Svoboda, R., Blecken, W. D., "Corrosion and De-
The first step is a diagnosis of the cooling conditions of posits in Water-Cooled Generator Stator Windings:
the generator. Proactive monitoring gives reliable trends in Overview of Water Cooling of Generators", Power-
long-term performance and may already indicate the na- Plant Chemistry 2018, 20(5), 290.
ture and intensity of plugging.
[2] Svoboda, R., "Corrosion and Deposits in Wa-
If the generator is heavily fouled, mechanical cleaning ter-Cooled Generator Stator Windings, Part 1: Be-
should be considered. This especially applies if some haviour of Copper", PowerPlant Chemistry 2018,
hollow conductors are completely plugged. Mechanical 20(5), 297.
cleaning should be followed up by a complexant cleaning.
[3] Svoboda, R., Chetwynd, R., "Corrosion and Deposits
If the generator is not heavily fouled, water or water/air in Water-Cooled Generator Stator Windings, Part 2:
flushing or complexant cleaning can be applied. Detection of Flow Restrictions", PowerPlant Chemis-
try 2018, 20(6), 326.
Water flushing may be an easy first try for the removal of
plugging. Expectations should however not be too high. [4] Bauer, T., Svoboda, M., Svoboda, R., "Corrosion and
Also, when there is no visible success, flushing should be Deposits in Water-Cooled Generator Stator Wind-
terminated in order not to solidify deposits more than they ings, Part 3: Removal of Flow Restrictions", Power-
already are. Plant Chemistry 2019, 21(1), 8, this article.

Complexant cleaning is the recommended option. It is [5] Bauer, T., Svoboda, M., "Corrosion and Deposits in
possible off-line as well as on-line. On-line cleaning does Water-Cooled Generator Stator Windings, Part 4:
not interfere with generator availability, and also provides Operating Experience with Flow Restrictions in Sta-
real-time monitoring of the cleaning effects. However, on- tor Cooling Water Systems", PowerPlant Chemistry
line cleaning takes some time (usually 10–15 days) and is 2019, 21(2), to be published.
expensive.
[6] Turbine Generator Auxiliary System Maintenance
Guide Volume 4: Generator Stator Cooling Water
OPERATING THE GENERATOR AFTER CLEANING System: 2013 Update, 2013. Electric Power Research
Institute, Palo Alto, CA, USA, EPRI 3002000420.
The cause of the plugging is typically not eliminated by
cleaning; reoccurrence of plugging cannot be excluded. [7] Guidelines for Detecting and Removing Flow Restric-
Cleaning thus is not the final solution to the problem and tions of Water-Cooled Stator Windings, 2002. Elec-
only removes the symptoms. tric Power Research Institute, Palo Alto, CA, USA,
EPRI 1004704.
Besides searching for and controlling the root cause of
plugging, it is recommended to review and upgrade the [8] Seipp, H.-G., "Betriebserfahrungen mit wasserge-
operating practices of the system. This includes: kühlten Generatorwicklungen", VGB Kraftwerkstech-
nik 1983, 63(5), 408.
• Redefining chemistry and operating parameters
• Optimizing system equipment, instrumentation and pa- [9] Chetwynd, R., Sarette, T., Svoboda, R., "A Pro-Ac-
rameters to maintain cleanliness tive Approach towards Maintaining the Integrity of
Large Electric Generator Water-Cooled Windings",
• Optimizing monitoring equipment and practice Proc., 5th SFEN Conference on Contribution of Ma-
• Optimizing outage lay-up practice terials Investigation to the Resolution of Problems
• Providing adequate training and management informa- Encountered in Pressurized Water Reactors, 2002
tion (Fontevraud, France) Société Française d'Energie
Nucléaire, Paris, France.

PowerPlant Chemistry 2019, 21(1) 21

 Corrosion and Deposits in Water-Cooled Generator Stator Windings: Part 3: Removal of Flow Restrictions

[10] Bauer, T., Svoboda, M., Dockheer, S., Svoboda, R., Matthias Svoboda (M.S., Environmental Sciences, ETH
"Chemical Cleaning of Water-Cooled Generators: Zurich, Switzerland) started working in the power plant
Effect on System Materials", PowerPlant Chemistry chemistry laboratory at Alstom in 2003. He developed
2014, 16(2), 94. methods for trace analysis in remotely taken feedwater
and steam samples. During this work, the focus shifted
[11] Guidelines for Chemical Cleaning of Conventional towards chemical aspects of water-cooled generators. In
Fossil Plant Equipment, 2001. Electric Power Re- 2008 he changed to the generator service department and
search Institute, Palo Alto, CA, USA, EPRI 1003994. was responsible for chemical cleanings of generator stator
coils, consulting and engineering. In 2014 he co-founded
[12] Svoboda, R., Palmer, D. A., "Behaviour of Copper in SvoBaTech AG, an independent provider of services cen-
Generator Stator Cooling-Water Systems", present- tered on the improvement and upgrade of stator cooling
ed at the 15th International Conference on the Prop- water systems. Their special expertise is chemical clean-
erties of Water and Steam, 2008 (Berlin, Germany). ing of water-cooled generator windings.
International Association for the Properties of Water
and Steam. Robert Svoboda (Ph.D., Physics, University of Vienna,
Also published in: PowerPlant Chemistry 2009, 11(2), Austria, postdoctoral studies on reactor metallurgy in
70. Saclay, France) joined the chemical laboratory of Alstom
Power, Baden, Switzerland, in 1969 (formerly part of Brown
[13] Nasri, L., Leinonen, P., Puzzuoli, F. V., Swami, D., Boveri & Cie), where he headed the Power Plant Chemistry
"Ontario Power Generation Operational Experience Section, and in 1992 the Power Plant Chemistry Depart-
with Stator Conductor Bars Fouling", PowerPlant ment in Mannheim, Germany. Since his retirement in 2007
Chemistry 2003, 5(3), 155. he has been staying active as a consultant. His work is
concentrated on water chemistry, corrosion, and radiation
[14] Pourbaix, M., Atlas of Electrochemical Equilibria in technology. He has extensive experience with generator
Aqueous Solutions, 1966. Pergamon Press, Oxford, water cooling; since 1989 he has chemically cleaned more
UK, ISBN 978-0915567980. than 70 generators and has been responsible for another
80 generator cleanings. Robert Svoboda is an Honorary
[15] Pascal, P., Noveau Traité de Chimie Minérale, 1957. Fellow of the International Association for the Properties of
Masson & Cie., Paris, France. Water and Steam. He is also a member of the International
Advisory Board of the PowerPlant Chemistry journal.
[16] Drommi, J.-L., Mesnage, F., "How to Prevent Hollow
Conductor Plugging: EdF Solution for Aerated Sys-
tems", PowerPlant Chemistry 2003, 5(4), 203.
CONTACT
[17] Svoboda, R., Sandmann, H., Seipp, H.-G., Liehr, C.,
"Water Chemistry in Generator Water Cooling Sys- Thomas Bauer
tems", Proc., Interaction of Non-Iron-Based Materi- SvoBaTech AG
als with Water and Steam 1996 (Eds. R. B. Dooley Lauriedstrasse 7
and A. Bursik), 1997 (Piacenza, Italy). Electric Power 6300 Zug
Research Institute, Palo Alto, CA, USA, EPRI Switzerland
TR-108236. thomas.bauer@svobatech.com

Matthias Svoboda
THE AUTHORS SvoBaTech AG
Lauriedstrasse 7
Thomas Bauer (Ph.D., Material Science, Swiss Federal In- 6300 Zug
stitute of Technology (ETH) Zurich, Switzerland) worked for Switzerland
Siemens Transformers Austria during his master studies mat.svoboda@svobatech.com
and after completing his Ph.D., he joined Alstom Thermal
Power in Baden, Switzerland, in 2012. He there worked
in the field of water-cooled generators and especially on
chemical cleaning of stator and rotor coils and was the
project manager of R&D projects related to water-cooled
generators. In September 2014 he co-founded SvoBaTech,
where his key expertise is focusing on designing and com-
missioning of hydrogen-leakage-monitoring-systems and
alkalization systems as well as the chemical cleaning of
stator and rotor coils.

22 PowerPlant Chemistry 2019, 21(1)

Visit IAPWS at www.iapws.org/

The International Association for the Properties

of Water and Steam

and download IAPWS Releases, Guidelines, and other documents.

For example:
– Release on the Ionization Constant of H2O (2007)
– Guideline on the Henry's Constant and Vapor-Liquid Distribution Constant for Gases in H2O and D2O
at High Temperatures (2004)
– Technical Guidance Documents
TGD1-08 "Procedures for the Measurement of Carryover of Boiler Water into Steam"
TGD2-09(2015) "Instrumentation for Monitoring and Control of Cycle Chemistry for Steam-Water Circuits of
Fossil-Fired and Combined-Cycle Power Plants"
TGD3-10(2015) "Volatile Treatments for the Steam-Water Circuits of Fossil and Combined Cycle/HRSG
Power Plants"
TGD4-11(2015) "Phosphate and NaOH Treatments for the Steam-Water Circuits of Drum Boilers of Fossil and
Combined Cycle/HRSG Power Plants"
TGD5-13 "Steam Purity for Turbine Operation"
TGD6-13(2014) "Corrosion Product Sampling and Analysis for Fossil and Combined Cycle Plants"
TGD7-16 "HRSG High Pressure Evaporator Sampling for Internal Deposit Identification and Determin-
ing the Need to Chemical Clean"
TGD8-16 "Application of Film Forming Amines in Fossil, Combined Cycle, and Biomass Power Plants"

IAPWS
is an international non-profit association of national organizations concerned with the properties of
water and steam, particularly thermophysical properties and other aspects of high-temperature steam,
water and aqueous mixtures that are relevant to thermal power cycles and other industrial applications.
IAPWS objectives are
– To provide internationally accepted formulations for the properties of light and heavy steam, water
and selected aqueous solutions for scientific and industrial applications
– To provide technical guidance, obtained by international consensus of experts, on cycle chemistry
and technology for steam power cycles in fossil, combined cycle/HRSG and biomass plants
– To define research needs and promote and coordinate research on steam, water and selected
aqueous systems important in thermal power cycles
– To collect and evaluate the resulting data, and to communicate and promulgate the findings
– To provide an international forum for exchange of experiences, ideas and results of research on high-
temperature aqueous media

PowerPlant Chemistry 2019, 21(1) 23

 The Sixth Meeting of the EHF
(European HRSG Forum)
14–16 May 2019 in the Titania Hotel, Athens, Greece

The conference will be of major interest to:

operational personnel, technical managers, plant engineers, boiler operators, cycle and plant chemists, corrosion
scientists and service providers as well as manufacturers of components and chemicals.
The major themes of this international conference will be HRSG tube failures (HTF) (FAC, thermal fatigue, creep-fatigue,
under-deposit corrosion), pressure part failure mechanisms related to condensate, drains, and attemperator systems,
identifying and avoiding damaging thermal transients in pressure parts, water treatment and cycle chemistry for HRSGs,
HRSG preservation for different operational modes, behavior and measurement of total iron for operation and daily
start/stop, material selection and new material applications, optimization of plant controls, environmental aspects, fast
start HRSGs, and balance of plant including the steam turbine, condenser, and air-cooled condenser.
This IAPWS international conference is being organized by BHT GmbH and PPCHEM AG.

The Conference will be held in English.

Venue
Hotel Titania
Panepistimiou 52
Athens 10678 Greece

Registration
For more information and to register, please visit the event website at https://EuropeanHRSGForum.cvent.com/EHF2019
or contact Ladi Bursik at ladi.bursik@bht-gmbh.com.

The International Steering Committee

Barry Dooley (Chair) (Structural Integrity Associates, UK)
Bob Anderson (Competitive Power, USA)
Dan Blood (Uniper Technologies, UK)
Jose-Maria Bronte (Bahía Bizkaia Electricidad, Spain)
Ladi Bursik (BHT GmbH, Germany)
Jean-François Galopin (Cockerill/CMI, Belgium)
Raymond Gunnewijk (Siemens Heat Transfer Technology, The Netherlands)
Roula Kastanaki (Public Power Corporation, Greece)
Michael Rziha (PPCHEM AG, Switzerland)
Stuart Strachan (GE, UK)

For more information on the agenda, please contact Barry Dooley at bdooley@structint.com or bdooley@IAPWS.org.

Selected papers will appear in the PowerPlant Chemistry® journal.

Sponsors and Exhibits

There will be a special vendor exhibition at the conference. Sponsorship opportunities are also available.

For more information please visit the event website at https://EuropeanHRSGForum.cvent.com/EHF2019 or contact
Ladi Bursik at ladi.bursik@bht-gmbh.com.

1
24 PowerPlant Chemistry 2019, 21(1)
 Initial Agenda for European HRSG Forum
Initial Agenda for European HRSG Forum
(EHF2019)
(EHF2019)
Titania Hotel, Athens, Greece, 14 – 16 May 2019th th

Titania Hotel, Athens, Greece, 14th – 16th May 2019

Day 1 – Tuesday, 14th May 2019

Day
8:00 1to–9:00
Tuesday, 14th May 2019
Registration and Welcome Coffee/Tea

8:00
9:00 to 9:00
9:10 Registration and Welcome Coffee/Tea
Opening Remarks

9:00
9:10 to 9:10
9:35 Opening Remarksfor Issues Associated with Aging CCGT Plant
New Guidelines
D. Humphrey, RINA Consulting Ltd., UK
9:10 to 9:35 New Guidelines for Issues Associated with Aging CCGT Plant
9:35 to 10:00 HRSG Experiences in PPC
D. Humphrey, RINA Consulting Ltd., UK
P. Tsiampas and R. Kastanaki, PPC, Greece
9:35 to 10:00 HRSG Experiences in PPC
10:00 to 10:05 P. Tsiampas and
Discussion R. Kastanaki, PPC, Greece
on Presentations

10:00 10:35 Discussion

10:05 to 10:05 on Presentations
Morning Coffee/Tea

10:05
10:35 to 10:35
11:00 Morning Coffee/Tea
Combination of Load Monitoring Capabilities with Fatigue Crack Growth (FCG) Assessment
J. Rudolph, Framatome, Germany
10:35 to 11:00 Combination of Load Monitoring Capabilities with Fatigue Crack Growth (FCG) Assessment
11:00 to 11:25 Inspection of Expansion Joints
J. Rudolph, Framatome, Germany
J. Waterhouse, Dekomte, UK
11:00 to 11:25 Inspection of Expansion Joints
11:25 to 11:50 Return of Experience with Pilot Operated Pressure Relief Valves
J. Waterhouse, Dekomte, UK
J.-F. Galopin, CMI, Belgium
11:25 to 11:50 Return of Experience with Pilot Operated Pressure Relief Valves
11:50 to 12:15 Experiences with the Application of Film Forming Amine in the Water-Steam Cycle of the
J.-F. Galopin, CMI, Belgium
Marchwood CCGT Power Plant
11:50 to 12:15 Experiences
A. Pearshouse, with the Application
Marchwood of Film
Power Ltd., FormingWatercare
J. Woolley, Amine in International
the Water-Steam Cycle
Ltd., and of the Kurita
W. Hater,
Marchwood
Europe GmbH, CCGT Power Plant
Germany
A. Pearshouse, Marchwood Power Ltd., J. Woolley, Watercare International Ltd., and W. Hater, Kurita
12:15 to 12:30 Europe GmbH,
Discussion on Germany
Presentations and General Open Floor Discussion

12:15 14:00 Discussion

12:30 to 12:30 Lunch on Presentations and General Open Floor Discussion

12:30
14:00 to 14:00
14:25 Lunch
Modulating and Start-Stop Upgrades for Power Stations
K. Van Wijk, Advanced Valve Solutions, USA
14:00 to 14:25 Modulating and Start-Stop Upgrades for Power Stations
14:25 to 15:00 K. Van Wijk,
General Open Advanced Valve Solutions, USA
Floor Discussion

14:25 15:30 General

15:00 to 15:00 Open
Afternoon Floor Discussion
Coffee/Tea

15:00
15:30 to 15:30 Afternoon Coffee/Tea
16:20 Presentations on Plant Assessment Updates
Update on HRSG Cycle Chemistry Control and FAC
15:30 to 16:20 Presentations on Plant Assessment Updates
B. Dooley, Structural Integrity, UK
Update on HRSG Cycle Chemistry Control and FAC
Update on HRSG Thermal Transient Assessments
B. Dooley, Structural Integrity, UK
R. Anderson, Competitive Power Resources, USA
Update on HRSG Thermal Transient Assessments
R. Anderson,
16:20 to 17.00 General Competitive
Open Floor DiscussionPower Resources, USA

16:20 20:00 General

18:00 to 17.00 Open Floor
Greek Reception Discussion
(Exact Time will be announced)

18:00 to 20:00 Greek Reception (Exact Time will be announced)

2
25
PowerPlant Chemistry 2019, 21(1)
 Initial Agenda for European HRSG Forum
(EHF2019)
Titania Hotel, Athens, Greece, 14th – 16th May 2019
Day 2 – Wednesday, 15th May 2019

Day
8:301to– 8:55
Tuesday, 14th MayCCGT
Improved 2019 Flexibility using HRSG Ambient Air Injection
M. Coates and S. Simpson, Uniper Technologies, UK
8:00 to 9:00 Registration and Welcome Coffee/Tea
8:55 to 9:20 Metal Temperature Characteristics of HRSG HT Zone Heating Surface with M701F5
L. Zeling, MHPS Dongfang Boiler, China
9:00 to 9:10 Opening Remarks
9:20 to 9:45 CO2 Capturing – A Techno Economic Approach based on an Ongoing European Research Study
9:10 to 9:35 A.
New Gottfroh, ELPEDISON
Guidelines S.A.,
for Issues Greece with Aging CCGT Plant
Associated
D. Humphrey, RINA Consulting Ltd., UK
9:45 to 10:10 Discussion
9:35 to 10:00 HRSG on Presentations
Experiences in PPC and General Open Floor Discussion
P. Tsiampas and R. Kastanaki, PPC, Greece
10:10 to 10:40 Morning Coffee/Tea
10:00 to 10:05 Discussion on Presentations
10:40 to 12:20 Workshop on Cycle Chemistry for Combined Cycle/HRSG Plants
B. Dooley,
10:05 to 10:35 Morning Structural Integrity, UK and M. Rziha, PPCHEM AG, Switzerland
Coffee/Tea

12:20 to
10:35 to 11:00
13:45 Combination
Lunch of Load Monitoring Capabilities with Fatigue Crack Growth (FCG) Assessment
J. Rudolph, Framatome, Germany
13:45 to 14:10 PressureWave + Application on a HRSG at a Syngas Plant in Italy, Heavy Blocked Tubes - A Case
11:00 to 11:25 Inspection of Expansion Joints
for PW+
J. Waterhouse, Dekomte, UK
M. Bürgin and J. Goud, BANG&CLEAN Technologies AG, Switzerland
11:25 to 11:50 Return of Experience with Pilot Operated Pressure Relief Valves
14:10 to 14:35 Modernizing Water-Steam Sampling and Analysis Systems
J.-F. Galopin, CMI, Belgium
C. Ioannou, Solidus Assyst Ltd., Greece and M. Sigrist, Swan Systeme AG, Switzerland
11:50 to 12:15 Experiences with the Application of Film Forming Amine in the Water-Steam Cycle of the
14:35 to 15:00 Robin Condition Monitoring: Does your Equipment Work on its Operating Curve?
Marchwood CCGT Power Plant
C. Van Honacker, ENGIE Europe – Generation, Belgium
A. Pearshouse, Marchwood Power Ltd., J. Woolley, Watercare International Ltd., and W. Hater, Kurita
Europe GmbH, Germany
15:00 to 15:30 Afternoon Coffee/Tea
12:15 to 12:30 Discussion on Presentations and General Open Floor Discussion
15:30 to 15:55 Chemistry in a Digital Era
A. Senecat, Laborelec, Belgium
12:30 to 14:00 Lunch
15:55 to 16:20 Plant Chemistry in HRSG Design. Philosophy and Case Studies
14:00 to 14:25 Modulating and Siemens
A. Papathomas, Start-Stop Upgrades
Heat for Power Stations
Transfer Technology B.V., The Netherlands
K. Van Wijk, Advanced Valve Solutions, USA
16:20 to 16:45 An Overview of FAC Failures in HRSGs in Iran
V. Araban, P. Emamgholizadeh, and F. Mirzaei, Mapna Boiler & Equipment, Iran
14:25 to 15:00 General Open Floor Discussion
16:45 to 17:15 Discussion on Presentations and General Open Floor Discussion
15:00 to 15:30 Afternoon Coffee/Tea

15:30 to 16:20 Presentations on Plant Assessment Updates

Day 3 – Thursday, 16th May 2019
Update on HRSG Cycle Chemistry Control and FAC
B. Dooley, Structural Integrity, UK
8:30 to 8:55 Design Safety Cases Allow Defective Plant to Continue Operation
Update onSSE
J. MacArthur, HRSG Thermal Centre,
Engineering Transient Assessments
Glasgow, UK
R. Anderson, Competitive Power Resources, USA
8:55 to 9:20 Control Valves Performance and its Impact on HRSG KPIs
P. Galik, Emerson
16:20 to 17.00 General Flow
Open Floor Controls, UK
Discussion
9:20 to 9:45 Water Chemistry of a Combined Cycle Plant using a Heller Dry Cooling System
18:00 to 20:00 Greek ReceptionCMI
E. Radermecker, Energy,
(Exact TimeBelgium
will be announced)

9:45 to 10:10 Discussion on Presentations and General Open Floor Discussion

10:10 to 10:40 Morning Coffee/Tea

26 2
PowerPlant Chemistry 2019, 21(1)
 Initial Agenda for European HRSG Forum
(EHF2019)
Titania Hotel, Athens, Greece, 14th – 16th May 2019

Day
10:401 to
– Tuesday, 14th
11:40 The May 2019
Latest IAPWS Updates – Air In-Leakage, Film-forming Substances and Generator Chemistry
B. Dooley, Structural Integrity, UK and M. Rziha, PPCHEM AG, Switzerland
8:00 to 9:00 Registration and Welcome Coffee/Tea
11:40 to 12:05 Recent Reheater Tube Failures
S. Gomez, BBE, Spain, R. Anderson, Competitive Power Resources, USA, and B. Dooley, Structural
9:00 to 9:10 Opening Remarks
Integrity, UK
12:05toto9:35
9:10 Total-Iron
12:30 New at Cycling
Guidelines CCPP's
for Issues – The Underestimated
Associated Parameter
with Aging CCGT Plant with Cost Intensive Effects
M. Rziha, PPCHEM AG, Switzerland
D. Humphrey, RINA Consulting Ltd., UK
9:35 to 10:00 HRSG Experiences in PPC
12:30 to 13:45 P.
Lunch
Tsiampas and R. Kastanaki, PPC, Greece

13:45 to 10:05
10:00 Characterization
14:10 Discussion of Pressure Wave Cleaning Technology for Application to Heat Recovery Steam
on Presentations
Generators and Implications for Potential Tube Damage
S. Rosinski
10:05 to 10:35 Morning and B. Carson, EPRI, USA, and R. Anderson, Competitive Power Resources, USA
Coffee/Tea
14:10 to 14:35 Risk Based Inspection (RBI) within the Ageing Management System COMSY
10:35 to 11:00 Combination of Load Monitoring
J. Rudolph, Framatome, Germany Capabilities with Fatigue Crack Growth (FCG) Assessment
J. Rudolph, Framatome, Germany
14:35 to 15:00 Update on Automatic Ultrasonic Superheater Drain Control
11:00 to 11:25 Inspection
R. Anderson,ofCompetitive
Expansion Joints
Power Resources, USA
J. Waterhouse, Dekomte, UK
11:25
15:00 to 15:30 Return
to 11:50 of Experience
Discussion with Pilot
on Presentations andOperated
General Pressure Relief
Open Floor Valves
Discussion
J.-F. Galopin, CMI, Belgium
15:30 to 12:15 Experiences
11:50 with Remarks
EHF2019 Closing the Application of Film Forming Amine in the Water-Steam Cycle of the
Marchwood CCGT Power Plant
A. Pearshouse, Marchwood Power Ltd., J. Woolley, Watercare International Ltd., and W. Hater, Kurita
Europe GmbH, Germany

12:15 to 12:30 Discussion on Presentations and General Open Floor Discussion

12:30 to 14:00 Lunch

The conference is being organized by
14:00 to 14:25 Modulating and Start-Stop Upgrades for Power Stations
K. Van Wijk, Advanced Valve Solutions, USA
BHT GmbH
14:25 to 15:00 General Open Floor Discussion

15:00 to 15:30 Afternoon Coffee/Tea

bht gmbh
15:30 to 16:20 Presentations on Plant Assessment Updates
Update on HRSG Cycle Chemistry Control and FAC
B. Dooley, Structural Integrity, UK
Media Partner
Update on HRSG Thermal Transient Assessments
PPC
R. Anderson, Competitive Power HEM Journal
Resources, USA


16:20 to 17.00 General Open Floor Discussion

18:00 to 20:00 Greek Reception (Exact Time will be announced)

  

The Journal of All Power Plant Chemistry Areas
®

2
27
PowerPlant Chemistry 2019, 21(1)
 Electrochemical Corrosion Potential Monitoring in BWRs

Electrochemical Corrosion Potential Monitoring in BWRs

Yoichi Wada, Kazushige Ishida, Masahiko Tachibana, Nobuyuki Ota, and Makoto Nagase

ABSTRACT

The status of Hitachi-GE Nuclear Energy's electrochemical corrosion potential (ECP) sensor development and ECP
measurement in boiling water reactors (BWRs) is reviewed. Hitachi-GE Nuclear Energy (Hitachi-GE) has been dedicat-
ed to developing and providing ECP sensors and applied ECP monitoring to various BWRs since the ECP has been
an index of stress corrosion cracking (SCC). Hitachi-GE considers simultaneous use of at least 2 types of ECP sensor
and employment of a guard drive circuit for the ECP measuring system to be essential. Results of ECP measurement
in hydrogen water chemistry (HWC) showed that the ECPs were above 0.1 V(SHE) before HWC and decreased with an
increase in the hydrogen concentration in the feedwater. Compared to the bottom region, the ECP in the primary loop
recirculation system decreased at lower hydrogen dosage. Hitachi-GE recommends long-term and in-situ ECP moni-
toring because the ECP is affected by core management and the direct measurement of the ECP is more meaningful
for SCC evaluation.

NOMENCLATURE AND ABBREVIATIONS

ABWR advanced boiling water reactor m-ZrO2 monoclinic zirconium dioxide (zirconia)
ATR advanced thermal reactor NMCA noble metal chemical addition
BDL bottom drain line (or application)
BNC connector bayonet Neill-Concelman connector NWC normal water chemistry
BWR boiling water reactor PLR primary loop recirculation system
CUW clean-up water system PSL PLR sampling line
DH dissolved hydrogen PWR pressurized water reactor
DO dissolved oxygen RPV reactor pressure vessel
ECP electrochemical corrosion potential RW reactor water
FI flow indicator RWCU reactor water clean-up system
FW feedwater SHE standard hydrogen electrode
GND ground SS stainless steel
Hitachi-GE Hitachi-GE Nuclear Energy Ltd. YSZ yttria stabilized zirconia
HWC hydrogen water chemistry ΦECP [V(SHE)] electrochemical corrosion
IGSCC intergranular stress corrosion cracking potential
JSME Japan Society of Mechanical Engineering Φref [V(SHE)] reference potential
MI cable mineral insulated cable Φmanifold [V(SHE)] electrochemical corrosion
MS main steam potential of manifold
∆meas [V] measured potential difference

INTRODUCTION

The intergranular stress corrosion cracking (IGSCC) of struc- lower part of the core supports, which are required to be
tural materials such as type 304 stainless steel (304 SS), of high strength as well, are made of nickel base alloys.
type 316L stainless steel (316L SS), and nickel base alloys
has a large impact on the safety, reliability, and economic The IGSCC of structural materials occurs when effects
efficiency of a boiling water reactor (BWR). Figure 1 gives overlap, including degradation of the corrosion resistance
a schematic view of a BWR with the names of some rep- of materials, generation of residual tensile stress at welds,
resentative components and locations. The reactor pres- and the presence of a corrosive environment (high oxidant
sure vessel (RPV) is made of low-alloy steel. Regarding concentration, high electrochemical corrosion potential
fuels, the fuel cladding and the channel box are made of (ECP), high caustic anion concentration, etc.). In this case
zirconium alloys. Main internal components such as the Hitachi-GE Nuclear Energy Ltd. (Hitachi-GE) recommends
core shroud, jet pumps, control rod guides, and the pri- applying a combination of corrosive environment mitiga-
mary loop recirculation system piping are made of SS. The tion techniques and stress improvement techniques for

28 PowerPlant Chemistry 2019, 21(1)

Electrochemical Corrosion Potential Monitoring in BWRs

Factor Corrosive Environment Stress Material

Parameter Oxidant (O2, H2O2) Residual tensile stress Sensitization
ECP Hardening layer
Impurity Segregation
Crevice
Countermeasure Corrosive environment Peening (water jet, shot, etc.) Replacement or cladding
mitigation (HWC, NMCA) Inductive heat stress with higher corrosion-
High-purity control improvement resistant materials
Polishing to remove Polishing to remove
residual stress part hardening layer
Table 1:
IGSCC parameters and Hitachi-GE's countermeasures.

Parameter Value
Temperature ca. 280 °C at core inlet
Pressure ca. 7 MPa
Conductivity below 0.1 μS · cm –1 (at 25 °C)
Flow rate several m · s –1, maximum 60 m · s –1
Radiation γ-rays and neutron at several MGy ∙ h–1 (at core region)
Chemical species concentration H2 O2 H2O2
Normal water chemistry 10−20 μg · kg –1 100−200 μg · kg –1 200−300 μg · kg –1
Hydrogen water chemistry 60−200 μg · kg –1 0 μg · kg –1 > 10 μg · kg –1
Table 2:
Reactor water conditions.

existing plants as a comprehensive preventive maintenance mea-

sure. A combination of the techniques can not only expand the pro-
Reactor
pressure tection region but can also lead to an effect of superposition for both
vessel types of techniques. In particular, the pressure boundary of the BWR,
such as the lower part of the RPV, needs to be protected by at least
one of these techniques to reduce the risk of IGSCC initiation and
propagation; if applying a single countermeasure IGSCC risk remains
since the IGSCC mechanism is not completely understood yet. The
IGSCC factors and countermeasures are summarized in Table 1.
Fuel Control rod

Downcomer Today, corrosive environment mitigation technologies such as hydro-

Core shroud gen water chemistry (HWC) [1,2] and noble metal chemical addition
Core (NMCA) [3,4] have been widely adopted in BWRs all over the world to
Control
Jet pump rod guide suppress IGSCC of structural materials. The components and piping
of a BWR are exposed to an oxidative environment under normal
Lower water chemistry (NWC), which means no hydrogen is added to the
plenum
reactor water. In Table 2, typical conditions under NWC and HWC are
listed with common BWR conditions. Due to radiolysis of water by
Primary loop the high-intensity radiation field of gamma rays and neutrons at the
recirculation core and the release of gaseous chemical species to steam, oxygen
system
(O2) and hydrogen peroxide (H2O2) are present in reactor water at
Bottom concentrations of several hundreds of µg ∙ kg–1 and in excess of the
drain line hydrogen (H2) amount under NWC. In contrast, under HWC, because
of the recombination reaction of injected H2 with O2 and H2O2, the
concentrations of O2 and H2O2 become much lower than those un-
Figure 1: der NWC, e.g., below 10 µg ∙ kg–1 at a high H2 concentration in the
Schematic view of a BWR. feedwater.

PowerPlant Chemistry 2019, 21(1) 29

 Electrochemical Corrosion Potential Monitoring in BWRs

The oxidant concentration is reduced under HWC and as shown in Figure 2. Hitachi-GE has conducted various
subsequently the ECP of structural materials, which is ECP monitoring campaigns at several BWRs with differ-
considered a primary control parameter of IGSCC, is re- ent designs and rated power, that is, BWRs in the design
duced below the level required to mitigate IGSCC. In the range from BWR type 2 to BWR type 5, an advanced boil-
case of NMCA, the electrocatalytic effect of noble metals ing water reactor (ABWR), a pressurized water reactor
such as platinum and rhodium deposited on the material (PWR), and an advanced thermal reactor (ATR). To achieve
surface for H2 oxidation enhances lowering of the ECP of this ECP monitoring, the required ECP sensors can be cat-
the material under HWC. For example, in the Japan Soci- egorized into 2 specifications based on the temperature
ety of Mechanical Engineering (JSME) Code: Rules on Fit- and pressure at power, and the size for installation, since
ness-for-Service for Nuclear Power Plants, a crack growth the operating conditions are the same in ATRs as they are
rate disposition curve under HWC is allowed if it can be in BWRs [8]. This is explained in the next section.
confirmed that the ECP is below –0.1 V(SHE) [5]. Also, his-
torically, –0.23 V(SHE) is considered a protection potential
for IGSCC [6]. Therefore, it is necessary to quantify the ECP SENSORS
effectiveness of HWC and NMCA by monitoring ECP for
comparison with the disposition curve for crack growth Currently Hitachi-GE provides 6 types of ECP sensor
evaluation. Much effort has been devoted to this all over (Table 3).
the world [6,7]. Electric
• Ag/AgCl type FY
Plant Type Power Year '95 '96 '97 '98 '99 '00 '01 '02 '03 '
• Platinum '84 (standard)
(Pt) type
1984 1995 1996 1997 1998 1999 2000 2001 2002 2003 2
In this paper, ECP measurement in actual BWRs in Japan (MWe)
by Hitachi-GE is reviewed. The ECP sensors developed A1 •
ATR Pt type (pinhead)
165
for continuous in-reactor monitoring are explained, which • Ag/Ag2O type / zirconia membrane
B1
is still difficult and challenging because of sensor reliability BWR2 357
• Fe/Fe3O4 type / zirconia membrane
and durability. Also, monitoring points in the BWR primary
B2 BWR5 1 100
• Zirconium (Zr) type
coolant system, which are limited but are used in actual
plants, are illustrated. An electric measurement systemB3 for BWR4 784
ECP measurement is also explained. These ECP sensors are mainly designed for use at ex-re-
B4 ABWR 1 350in the BWR except for the Pt pinhead type
actor locations
B5 for in-core measurement
BWR3 460 in PWRs [9] and the Fe/Fe3O4
ECP MONITORING ACHIEVEMENTS type zirconia membrane ECP sensor, which was devel-
B6 BWR3 460
oped for measurement at in-reactor locations [10]. There-
Hitachi-GE has been dedicated to developing and provid-
B7 fore,
BWR5 specifications
820 of the conditions of use are as follows:
ing ECP sensors for HWC application at Japanese utilities conductivity is below 1 µS ∙ cm–1; pH range is from 5.8 to
P1 PWR 1 160

HWC operation 㻱㻯㻼㻌㼙㼛㼚㼕㼠㼛㼞㼕㼚㼓㻌㻔㼎㼛㼠㼠㼛㼙㻌㼐㼞㼍㼕㼚㻌㼘㼕㼚㼑㻕

㻔㼛㼙㼕㼠㼠㼑㼐㻌㼕㼚㻌㼠㼔㼑㻌㼏㼍㼟㼑㻌㼛㼒㻌㻼㼃㻾㻕 㻱㻯㻼㻌㼙㼛㼚㼕㼠㼛㼞㼕㼚㼓㻌㻔㻼㻸㻾㻌㼟㼍㼙㼜㼘㼕㼚㼓㻌㼘㼕㼚㼑㻕
㻱㻯㻼㻌㼙㼛㼚㼕㼠㼛㼞㼕㼚㼓㻌㻔㼏㼛㼞㼑㻘㻌㼑㼠㼏㻚㻕
Electric
FY
Plant Type Power Year '95 '96 '97 '98 '99 '00 '01 '02 '03 '04 '05 '06 '07 '08 '09 '10 '11
(MWe) 1984 Figure
'84 1995 1996 1997 2 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011
1998 1999
A1 ATR 165 decommissioning

B1 BWR2 357

B2 BWR5 1 100

B3 BWR4 784

B4 ABWR 1 350

B5 BWR3 460

B6 BWR3 460

B7 BWR5 820

P1 PWR 1 160

Figure 2 HWC operation 㻱㻯㻼㻌㼙㼛㼚㼕㼠㼛㼞㼕㼚㼓㻌㻔㼎㼛㼠㼠㼛㼙㻌㼐㼞㼍㼕㼚㻌㼘㼕㼚㼑㻕

Hitachi ECP monitoring achievements. 㻱㻯㻼㻌㼙㼛㼚㼕㼠㼛㼞㼕㼚㼓㻌㻔㻼㻸㻾㻌㼟㼍㼙㼜㼘㼕㼚㼓㻌㼘㼕㼚㼑㻕
㻔㼛㼙㼕㼠㼠㼑㼐㻌㼕㼚㻌㼠㼔㼑㻌㼏㼍㼟㼑㻌㼛㼒㻌㻼㼃㻾㻕
㻱㻯㻼㻌㼙㼛㼚㼕㼠㼛㼞㼕㼚㼓㻌㻔㼏㼛㼞㼑㻘㻌㼑㼠㼏㻚㻕

Figure
30
2
PowerPlant Chemistry 2019, 21(1)
Electrochemical Corrosion Potential Monitoring in BWRs

Sensor Type Specification Feature

Ag/AgCl • Conductivity < 1 μS · cm –1 • Much plant experience
• pH 5.8–8.6 • Can work without H2
• Temperature 302 °C
• Generates theoretical
• Pressure 8.62 MPa
potential in H2-rich
environments
Pt Standard • Durable

Pinhead • Conductivity < 1 μS · cm –1 • Generates theoretical

• LiOH: 2.2–3.5 μg · kg –1 potential in H2-rich
• Temperature 320 °C environments
• Pressure 15.4 MPa • Compact

ZrO2 Ag/Ag2O Same as • Generates theoretical

mem- Ag/AgCl and Pt potential without H2
(standard) sensors • Stable
brane Fe/Fe3O4

• Can work without H2

• Durable
Zr

Table 3:
Hitachi-developed ECP sensors.

8.6; temperature is below 302 °C; and pressure is below Sensor Lifetime (cycle)
8.62 MPa. In the case of the Pt pinhead type ECP sensor,
Pt > 1 (max. 3)
these are: conductivity is below 1 µS ∙ cm–1; LiOH range is
from 2.2 to 3.5 mg ∙ kg–1; temperature is below 320 °C; and Ag/AgCl ca. 1
pressure is below 15.4 MPa. Table 4:
Sensor lifetimes in actual plant use
The Ag/AgCl type ECP sensor has been used in many BWR
plants in the past and we have acquired a great deal of ex-
perience. Since this sensor generates a reference potential
via the equilibrium reaction AgCl + e– = Ag+ + Cl− at satu-
rated concentration, this sensor can work without H2. This
sensor generates about 0.2 V(SHE) reference potential in
the BWR environment. However, since this sensor has liq-
uid junction for detection, the response in water chemistry
transients is slow and slow leakage of chloride ion from Figure 3:
the vessel and reductive deposition of silver ion onto the Appearance of the Ag/AgCl and the Pt sensors for plant use.
vessel and liquid junction surface may occur when it has
been in use for a long period. Thus, this sensor has grad-
ually been replaced with the ZrO2 membrane ECP sensor. In Table 4, the lifetime of Hitachi-GE's sensors in actual
plant use is summarized. The appearance of the Ag/AgCl
The Pt type ECP sensor has also been used in many type ECP sensor and the Pt type ECP sensor are shown in
BWRs together with the Ag/AgCl type ECP sensor. Since Figure 3. These sensors have a long body to form multiple
this sensor generates a reference potential via the equilib- pressure boundaries within the body. The lifetime of the
rium reaction H+ + e– = ½ H2, this sensor can work under Pt type sensor is estimated to be more than 1 year, and
stoichiometrically H2-rich conditions only. However, since the maximum is 3 years. In contrast, the lifetime of the
the reference potential of this sensor agrees with the theo- Ag/AgCl type ECP sensor is estimated to be about 1 year.
retical value at each H2 concentration, the Pt sensor is tak- However, it is currently difficult to exactly define the sen-
en as the primary ECP sensor, which can calibrate other sors' lifetime or their lifetime degradation, since most sen-
ECP sensors. This means that the sensor generates about sors were already removed after a 1-cycle operation even
−0.5 V(SHE) reference potential under HWC. The structure though they were still functional. Based on the Hitachi-GE
of this sensor is simpler and more durable than any others, experience, the Pt type ECP sensor is more durable than
in particular the Ag/AgCl sensor. the Ag/AgCl type sensor.

PowerPlant Chemistry 2019, 21(1) 31

 Electrochemical Corrosion Potential Monitoring in BWRs

faster and the potential is more stable at operating tem-

peratures than with the Ag/AgCl sensor.

The Fe/Fe3O4 type ECP sensor for in-reactor measurement

is under development for Hitachi-GE but the Fe/Fe3O4 type
ECP sensor has been used in many foreign plants [6,12].
The appearance of the Fe/Fe3O4 type ECP sensor for lab-
oratory use is shown in Figure 6. This sensor generates a
reference potential via an equilibrium reaction (Eq. (2)):

Figure 4: 4H2O + 3Fe = 8H+ + 8e– + Fe3O4 (2)

Appearance of the Pt pinhead type sensor for plant use.

The Pt pinhead type ECP sensor was used in a Japanese

PWR once [9]. This sensor was set at the upper core re-
gion in the PWR through the one thermoelectric couple
tube and was designed to have a very small sized de-
tection part and small diameter flexible mineral insulated
(MI) cable. The appearance of the Pt pinhead type ECP
sensor is shown in Figure 4. This sensor generates about Figure 6:
–0.8 V(SHE) reference potential in the PWR environment. Appearance of the Fe/Fe3O4 sensor for laboratory use.

The Ag/Ag2O type ECP sensor has been used in one BWR This sensor generates about –0.8 V(SHE) reference po-
plant in the past but we have a great deal of experience tential in the BWR environment. Although the features are
with use in the Hitachi laboratory [11]. The appearance of the same as with the Ag/Ag2O type ECP sensor, the fill-
the Ag/Ag2O type ECP sensor for laboratory use is shown ing in the zirconia membrane is changed from Ag/Ag2O to
in Figure 5. Since this sensor generates a reference poten- Fe/Fe3O4 for the in-reactor use to avoid production of the
tial via the equilibrium reaction in Eq. (1), this sensor can long-lived radionuclide 110mAg from Ag in case of breakage
work without H2 and generate a reference potential which of the zirconia membrane. Figure 7 shows that the devel-
can be calculated theoretically but affected by the pH of oping Fe/Fe3O4 type ECP sensor is stable for almost 140
water. days for the long-term durability confirmation test in a lab-
oratory environment. Fluctuation of the reference potential
generated by this sensor to the stable Zr electrode was
sufficiently within the range of allowed variation, that is,
±50 mV during about 140 days immersion.

Electrode Insulant Housing

(Zr) (Al2O3 or YSZ) (Type 316L SS)

Figure 5:
Appearance of the Ag/Ag2O sensor for laboratory use. Figure 8:
Appearance of the Zr sensor for laboratory use.

H2O + 2Ag = 2H+ + 2e– + Ag2O (1) The Zr type ECP sensor is to be used in a BWR plant but
we have a great deal of experience with use in the Hitachi
Fortunately, since the BWR operates with pure water and laboratory [13]. The appearance of the Zr type ECP sensor
the pH at operating temperature is almost neutral, the for laboratory use is shown in Figure 8. While the mecha-
potential can be taken as constant during plant use. This nism by which this sensor generates a reference poten-
sensor generates about –0.8 V(SHE) reference potential in tial is not well understood, it must be a slow corrosion of
the BWR environment. The detection part of this sensor is Zr metal with constant potential. A schematic diagram is
made of a zirconia membrane, which is a solid state elec- shown in Figure 9 [13]. The fundamental electrochemical
trolyte; this sensor cannot work at low temperatures below reaction is shown in Eq. (3):
150 °C such as during the startup operation period due to
low ion mobility in the zirconia. However, the response of Zr + 2H2O  ZrO2 + 2H2 (3)
this sensor in the water chemistry transient is sufficiently

32 PowerPlant Chemistry 2019, 21(1)

 Electrochemical Corrosion Potential Monitoring in BWRs

Figure 7

External reference
0.7 (Ag/AgCl)

0.6 Measurement of the ∆E between Fe/Fe3O4

PC
stable Zr electrode and Fe/Fe3O4 electrode
0.5
EFe/Fe 3 O4 electrode –EZr electrode [V]

Electrometer
0.4 L H Pt

0.3 Scanner Zr
Stable
316L SS
0.2

0.1
+50 mV
0

-0.1 – 50 mV

-0.2
0 50 100
Elapsed Time [day]

Figure 7:
ee 99 Result of the long-term durability confirmation test for the Fe/Fe3O4 type ECP sensor.

M−ZrO22 was
M−ZrO was
formed
formed on
on
surfaces
surfaces
[−]
Signal [−]

m−ZrO
m−ZrO22
Raman Signal
of Raman

Zr
Zr electrode
electrode
Intensity of
Intensity

100
100 300
300 500
500 700
700 900
900
Wave
Wave Number
Number [cm
[cm –1]]
–1

Figure 9:
Fundamental electrochemical reaction on Zr surface and the results of surface Raman analysis.

This is based on the formation of monoclinic ZrO2 on centration in a simulated BWR operating environment.
the surface of the electrode [13]. This sensor can work Also, Figure 10 shows that this sensor is very stable for
without H2 but is affected by temperature and oxidant at almost 6 000 h in a laboratory environment. Regarding
high concentrations above several mg ∙ kg−1 [14]. These Figure 11, the detection part of this sensor is made of
are shown in Figure 10 and Figure 11. It has been con- metal zirconium and can work from low temperatures.
firmed that the potential can be constant as –0.8 V(SHE) However, it was found that the temperature depen-
at a maximum of 8 mg ∙ kg−1 dissolved oxygen (DO) con- dence of the Zr electrode is not simple and a calibration

PowerPlant Chemistry 2019, 21(1) 33

 Electrochemical Corrosion Potential Monitoring in BWRs

0.0 25 curve is required. The electrochemical reaction occur-

ring on the surface of the Zr may change above 200 °C.
Potential of Zr Electrode

-0.2 20 Above 200 °C, the potential of the Zr electrode in the BWR
operating environment is given as shown in Eq. (4):

DO [mg · kg –1]
Temperature 280 °C
-0.4 15
[V(SHE)]

Conductivity < 6 μS · m –1

-0.6 10 E = –0.0019 T – 0.24 V(SHE) (4)

-0.8 5 where T is the temperature in °C. This gives about – 0.8 V(SHE)
at 280 °C in the BWR environment. The response of this
-1.0 0
0 1 2 3 4 5 6
sensor in the water chemistry transient is also sufficiently
Immersion Time [kh] faster and the potential is more stable at high tempera-
tures than that of the Ag/AgCl sensor.
Figure 10:
Long-term stability of the Zr electrode with changing oxygen
concentration.
0.6 USE OF ECP SENSORS
Potential of Zr Electrode, E [V(SHE)]

0.4
Since each type of ECP sensor has different properties as
0.2 Above 200 °C
probably, E is explained above, Hitachi-GE considers simultaneous use
0.6 0.0 controlled by the
same mechanism
of at least 2 types of ECP sensor to be essential [6]. Since
the Pt type ECP sensor is the primary sensor, it is desir-
Potential of Zr Electrode, E [V(SHE)]

0.4 -0.2
E = −0.0019T − 0.24 able to set the other type of ECP sensor together with the
0.2 -0.4 Above 200 °C Pt type ECP sensor at the same monitoring position if
probably, E is
0.0
-0.6 controlled by the HWC is to be obtained. An example of the use of several
same mechanism
-0.8 types of ECP sensor is shown in Figure 12. The ECP was
-0.2
ure 11 E = −0.0019T − 0.24 monitored at a sampling line of the primary loop recircula-
- 1.0
-0.4 100 150 200 250 300 tion (PLR) system of a 820 MW BWR type 5 in Japan [15].
Temperature, T [°C] In this case, 1 Pt sensor and 2 Ag/AgCl sensors were set
-0.6
in the ECP manifold in series. Under NWC, that is, with a
-0.8
H2 concentration in feedwater (FW) of 0 mg ∙ kg–1, the Pt
- 1.0 ECP sensor doesn't work, and the data was omitted from
100 150 200 250 300
this plot, but both ECPs measured by the 2 Ag/AgCl ECP
Temperature, T [°C]
sensors showed good agreement with each other as
Figure 11: 0.2 V(SHE). Above 0.2 mg ∙ kg–1 H2 concentration in the
Temperature dependence of the potential of the Zr electrode. FW, the measured ECPs by 3 ECP sensors were in good
agreement with each other as to their values and depen-
dency on H2 concentrations in the FW. In particular, each
measured ECP showed the same value and slope in the
range from 0.2 to 0.3 mg ∙ kg–1. This is important to con-
0.3 firm that the Pt sensor becomes a hydrogen electrode
0.2 䕻 Ag/AgCl −1 and the Ag/AgCl sensor shows proper reference potential.
0.1 䕿 Ag/AgCl −2 Since these sensors' outputs were within an error limit of
䕧 Pt ± 0.05 V of each other at high H2 concentrations in the FW,
0.0
Sampling Line [V(SHE)]

raw data were shown in this case. However, if the data are
ECP at PLR System

-0.1
ECP target different from each other beyond the error limit, the data
0.3 -0.2
obtained by the Pt sensor is given priority and the others
0.2 䕻 Ag/AgCl −1
-0.3 are treated as reference values.
0.1 -0.4 䕿 Ag/AgCl −2

0.0 -0.5
䕧 Pt Combined use of an analysis model with ECP monitoring
Sampling Line [V(SHE)]
ECP at PLR System

-0.1 -0.6 is essential to evaluate the effectiveness of the HWC and

0.0 0.2 0.4 0.6 0.8 1.0
ECP target 1.2 1.4 the NMCA since locations where the ECP sensors can be
-0.2 H2 Concentration in FW [μg · kg –1]
set are limited. In this paper, details of the ECP model are
-0.3
gure 12 not described. However, the Pt sensor behavior in ECP
Figure
-0.4 12:
ECP measured at PLR sampling line in Japanese BWR type 5 monitoring in an actual BWR plant is illustrated with the
-0.5
plant during mini-test [15]. model in Figure 13 [16,17]. The ECP, ΦECP, is obtained as:
-0.6
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 ΦECP = –∆meas + Φref (5)
H2 Concentration in FW [μg · kg –1]

34 PowerPlant Chemistry 2019, 21(1)

Electrochemical Corrosion Potential Monitoring in BWRs

dotted line is the reference potential of the Pt ECP sensor

Temperature of reactor water: 280 °C
Linear flow velocity: 2 m · s –1 calculated only with the H2 concentration with Nernst's
0.3
Hydraulic equivalent diameter: 5 cm equation. The chain line is the Pt sensor potential calcu-
True SS potential corresponding to lated with the models considering the effect of co-existing
0.2
data with Ag/AgCl or zirconia membrane ECP sensor O2 and H2O2 reactions on the Pt surface. To obtain an
0.1
ΦECP like the dashed line, the chain line needs to be used
0.0
as Φref under HWC. However, since we don't know the
ECP [V(SHE)]

Apparent SS potential with Pt sensor

-0.1 O2 and H2O2 concentration around the ECP sensors ex-
-0.2
Pt potential calculated with actly, the dotted line was used as Φref in the actual plant
-0.3 H2, O 2, and H 2 O 2 concentration monitoring, and as a result, the solid line was obtained
with the model based on
-0.4 the mixed potential concept
as ΦECP with the Pt type ECP sensor in the past. Then,
-0.5
because of the mixed potential of O2 and H2O2 on the Pt
Pt sensor potential calculated only with H 2 concentration surface, the obtained ΦECP with ∆meas and Φref not con-
-0.6
0 10 20 30 40 50 60 70 80 90 100 sidering the mixed potential effect was severely lower than
Effective H2 in Feedwater [μg · kg –1] the true SS potential under NWC and at the lower effective
H2 concentrations. It appeared asymptotically approach-
Figure 13: ing the true potential above 50 µg ∙ kg–1 effective hydrogen
Explanation of ECP data with Pt sensor measured in an actual
concentration in this calculation case. In the case of the
BWR plant.
Japanese 820 MW BWR type 5 plant as shown in Figure 12,
the ECP measured with the Pt sensor was affected by the
with the measured potential difference, ∆meas, and the mixed potential below a H2 concentration of 0.2 mg ∙ kg–1
reference potential, Φref. The true ECP of the SS in HWC (effective H2 is 30 µg ∙ kg–1) in the FW and showed an as-
behaves like the dashed line. This calculation was con- ymptotic approach to the ECPs obtained with the Ag/AgCl
ducted for a 1 100 MW BWR type 5 with Hitachi's radioly- sensors above a 0.2 mg ∙ kg–1 concentration in the FW.
sis model [16] and ECP model [17]. Flow conditions were
given as 2 m ∙ s–1 of the linear flow velocity, 5 cm of the
hydraulic equivalent diameter, and 280 °C of the reactor ELECTROCHEMICAL MEASURING SYSTEM IN
water temperature. The axis of abscissa is the effective PLANTS
hydrogen concentration, which is defined as the hydrogen
concentration in the FW times the flow rate of the FW di- A schematic diagram of Hitachi-GE's standard ECP mea-
vided by the flow rate of the core flow rate and determines suring system is shown in Figure 14. The measuring sys-
the hydrogen amount injected into the reactor water. The tem employs the guard drive circuit to reduce measure-

ECP sensor
Calibrated by Pt
under excess H2
conditions in-house
before installation Guard

High

2m Low
Electrometer
• Keithley6514, etc.

ECP=  manifold (SHE)

Manifold
={ manifold (SHE) −  sensor (SHE)}   sensor (SHE)
=−(measured value) +  sensor (SHE)
Penetration
  sensor (SHE)

RW ∆  = sensor (SHE) –  manifold (SHE)

=  sensor (GND)

Manifold   manifold (SHE)=GND

GND
Prefilmed in NWC in-house 0 (SHE)
before installation

Figure 14:
Hitachi's standard ECP measurement system with a guard circuit.

Figure 14
PowerPlant Chemistry 2019, 21(1) 35
 Electrochemical Corrosion Potential Monitoring in BWRs

ment error and to improve transient responsiveness [18]. This can be derived as below based on the schematic re-
The electrochemical measuring system is explained using lation of potential in Figure 14.
the example of an ECP sensor that is set to the ECP man-
Φmanifold = Φmanifold – Φref + Φref
ifold through a T-shaped structure.
= –(Φref – Φmanifold) + Φref
= –∆meas + Φref
The manifold and sampling line, which were replaced for
the measurement, had been oxidized in high-temperature
Judging from the above equation, all ECP sensors set at
water with 8 mg ∙ kg–1 of DO in Hitachi-GE's factory to
the same measuring point should have common ground
reduce the consumption of oxidant species in the pipe
to obtain comparable data. In the case of the manifold,
during measurement. During measurement, the reactor
a change in water chemistry between the upstream ECP
water flows through the manifold. All ECP sensors are also
sensor and the downstream ECP sensor should be mini-
calibrated in the factory with the Pt electrode in the HWC
mized.
environment before shipping.

The output of the ECP sensor installed at the manifold is

INSTALLATION OF ECP SENSORS IN PLANTS
measured with an electrometer and stored in data logger
equipment. The ECP sensor and the electrometer are con-
Hitachi-GE has experience with ECP measurement at lo-
nected electrically with a coaxial cable via a BNC connec-
cations in the actual plant as below.
tor. The ECP sensor is connected with the high terminal of
the electrometer through the core line of the coaxial cable. • In-core
To form the guard drive circuit, the manifold, the low ter- • Ex-reactor
minal of the electrometer, the chassis of the electrometer,
and the shield of each coaxial cable have been ground-
Among these, the ECP sensors developed by Hitachi-GE
ed. This guard drive system allows the shielding of cables
were used at ex-reactor locations such as the BDL and the
from any electromagnetic field emitted from surrounding
PLR (location was shown in Figure 1).
components and reduces undesirable impedance in the
cable. With this measuring system, the potential between
Figure 15 illustrates the setting of the manifold for ECP
the high terminal and the low terminal (ground) is mea-
sensors in the BDL [20]. The BDL is chosen to measure
sured. Since the resistance of the reactor water (pure wa-
the effectiveness of HWC or NMCA at the lower part of the
ter) is very high, the electrode of the ECP sensor can only
RPV, called the plenum. The reactor water in the BDL is
pick up the potential of the closest electric conductor that
branched and flows to the PLR sampling line through the
is part of the inner surface of the manifold. This principle is
manifold. Figure 16 illustrates another measuring system
explained in the literature [19]. If several sensors are set to
with a flange [20]. The ECP sensors are set in the flange,
the manifold, each sensor should have its own measuring
which is set directly to the BDL. The reactor water through
system separately. In the laboratory, a measuring system
the BDL is branched downstream of the flange and con-
consisting of one scanner and one electrometer is used to
nected to the PLR sampling line. Figure 17 is a schematic
measure potentials of several ECP sensors and electrodes
diagram of the manifold type measuring system, but the
by switching the input of the high terminal successively
manifold is set in the PLR sampling line directly [15]. The
[10,14] (see Figure 7). However, Hitachi-GE does not rec-
PLR is chosen to measure the effectiveness of HWC or
ommend the use of the scanner in the actual plant mea-
NMCA in the PLR since the water chemical conditions are
surement to keep redundancy. If either the electrometer or
different at various locations of the entire primary coolant
the scanner fails, no ECP sensor output can be measured
circuit.
in the case of the scanner-based measuring system. How-
ever, if we connect each ECP sensor with the electrometer
In each case of ex-reactor measurement, it is important
separately, the probability of simultaneous failure of the
to set either the ECP sensor manifold or the ECP sensor
electrometers becomes much lower.
flange as close as possible to the RPV or the PLR piping
to minimize changes in water chemistry caused by ther-
mal decomposition of H2O2 on the piping surface or in the
CALCULATION OF ECP WITH MEASURED DATA
bulk and consumption of oxidant on the piping surface by
corrosion or catalytic reaction. However, in-situ measure-
As shown in Eq. (6), the ECP of the manifold, Φmanifold,
ment of the ECP is desired nowadays because the ECP
is given as
represents the local state of the material surface regarding
Φmanifold = –∆meas + Φref (6) corrosion and the direct measurement of ECP is more in-
formative for crack growth evaluation.

36 PowerPlant Chemistry 2019, 21(1)

Electrochemical
ManifoldCorrosion
Type Potential Monitoring in BWRs

To turbine
From condenser
Coaxial cable
Data acquisition system

PLR
pump
Electrometer

BDL
ECP Data logger Memory
sensors Personal
RWCU card computer

Coaxial cable

BNC connector
FI
ECP sensor

Cooler
Reactor water
(Analysis of Manifold
PLR sampling DO, DH, H2, O2)
Flange Type
Figure 15:
ECP monitoring location at BDL and system configuration for a manifold type sensor housing.

To turbine
From condenser
Coaxial cable
Data acquisition system

PLR
pump
Electrometer

ECP BDL Data logger Memory Personal

sensors RWCU card computer

Coaxial cable

BNC connector
FI
ECP sensor
Cooler RPV

(Analysis of
DO, DH, H2, O2)
PLR sampling Flange

Figure 16:
ECP monitoring location at BDL and system configuration for a flange type sensor housing.

Figure 16

PowerPlant Chemistry 2019, 21(1) 37

 surfaces

Intensity of Raman Signal [−]

m−ZrO2
ee 99
Electrochemical Corrosion Potential Monitoring in BWRs

Zr electrode
Manifold Type
M−ZrO22 was
M−ZrO was
formed
formed on
on
O2, H2
surfaces
surfaces
RPV Dose rate
Turbine

[−]
Signal [−]
MS system monitor
100 300 500 700 900 m−ZrO
m−ZrO22
Air Pre-

Raman Signal
Wave Number [cm –1] ejector heater Condenser
FW system
Heater Condenser

of Raman
Recombiner Stack
Zr
Zr electrode
electrode

Intensity of
Off-gas system

Intensity
RWCU O2
system injection

Heat H2
PLR system exchanger injection
100
100 300
300 500
500 700
700 900
900
O2, H2, pH, conductivities,
0.6 Wave
Wave Number
Number [cm
[cm–1–1]]
PSL metal ions, activities

Potential of Zr Electrode, E [V(SHE)]

0.4
Figure 9 Cooler O2, H2,
0.2 Above 200 °C
ECP sensors conductivity, pH probably, E is
0.0 controlled by the
same mechanism
Figure 17: -0.2
ECP monitoring location at PLR and system configuration for a manifold type sensor-0.4
housing [15].
E = −0.0019T − 0.24
0.6
-0.6
Potential of Zr Electrode, E [V(SHE)]

0.0 25 0.4
Figure 17 -0.8
Potential of Zr Electrode

RESULTS OF ECP MEASUREMENT IN PLANTS 0.2 Above 200 °C

-0.2 20 11
Figure - 1.0 probably, E is
0.0 100 150 controlled by250
200 the 300
DO [mg · kg –1]

Temperature 280 °C
Results of ECP measurements in
-0.4 HWC mini-tests in 15 Japa- Compared to the BDL, the ECP insame
the mechanism
Temperature, PLR
T [°C] sampling line
[V(SHE)]

Conductivity < 6 μS · m –1
nese BWRs are shown in Figure 18 [21–23]. The mini-test -0.2 at lower hydrogen dosage (Figure 12) [15]. The
decreased
-0.6 10 E = −0.0019T − 0.24
is a ramping test to see the response of water chemistry effectiveness
-0.4 of the HWC in each BWR type depends on
parameters
-0.8
such as DO, ECP, impurity ions and short- the downcomer dose rate, which is determined by plant
5 -0.6
term behavior for a defined period. The ECPs measured design parameters, and the jet pump mixing ratio [24].
in the -1.0
BDL were above 0.1 V(SHE) in NWC and showed 0 -0.8
a decreasing0 1
tendency 2to below
3 –0.4 4 V(SHE) 5 6
Figurewith
11 an in- Figure -19
1.0 is an example of long-term ECP monitoring at
Immersion Time [kh]
crease in hydrogen concentration in the FW. However, the the PLR sampling
100 line
150in a Japanese
200 460250
MW BWR 300type 3
Temperature, T [°C]
decreasing tendency of the ECP differs in each BWR type. plant [25]. This figure shows variation of the ECP through-
Figure 10
out one operating cycle. In this plant, the amount of hydro-
Figure 11
gen injected is controlled as effective hydrogen concentra-
0.3 tion. Therefore, the hydrogen concentration in the reactor
BWR2 water is 0.3
not affected by a change in the core flow rate
e 10
0.2
re 10 due to core management. Thus, the increase 䕻 in the ECP
Ag/AgCl −1 in
BWR3 0.2
0.1
the lower half of the loop must be caused 䕿 by Ag/AgCl
the increase
−2
0.1
0
BWR5 in the core flow rate and the decrease in the downcomer
0.0
0.0 25
25 ECP monitoring is recom-
䕧 Pt
ECP [V(SHE)]

0.0
dose rate. Therefore, long-term
Sampling Line [V(SHE)]
ECP at PLR System

ABWR
Electrode
Zr Electrode

-0.1
-0.1
mended to control the continuous hydrogen injection in
ECP target
-0.2 -0.2
-0.2 lower the ECP over20
order to-0.2 20
the whole operating cycle [6].
]]

-0.3
–1

Temperature
Temperature280
280°C
kg–1

-0.3 °C
[mgg ·· kg

-0.4
-0.4 At present,
-0.4 the existing ECP 15sensors are becoming more
15
[V(SHE)]
[V(SHE)]

Conductivity
Conductivity <<66μS
μS··mm–1–1
of Zr

0.3
-0.4 durable, and can be used for longer periods (ca. one year)
-0.5
DO [m
Potential of

in ex-reactor
0.2 locations than10 䕻 Ag/AgCl
previous sensors as −1
explained
-0.5 -0.6
-0.6 -0.6 10
Potential

DO

0 0.5 1.0 1.5 above.

0.1 However,
0.0 Hitachi-GE
0.2 0.4 will continue
0.6 0.8䕿 1.0to develop
Ag/AgCl −2
1.2 1.4a
Hydrogen Concentration in Feedwater [μg · kg–1] H2 Concentration in FW [μg · kg can
]
-0.8
-0.8 more
0.0 durable ECP sensor so that the 䕧ECP Pt be used –1

55
Sampling Line [V(SHE)]

to monitor the plant condition everywhere in a reactor at

ECP at PLR System

Figure 18 Figure 12 -0.1

Figure 18: Figure
power.12 ECP target
-1.0
ECPs measured at the bottom drain-1.0
line in a mini-test. BWR -0.2 00
type 2 [21], BWR type 3 [22], BWR type005 [21], ABWR
11 [23].22 33 -0.3 44 55 66
Arrows mean the ECPs were decreasing.
Immersion
Immersion Time
Time
-0.4
[kh]
[kh]
30 -0.5 PowerPlant Chemistry 2019, 21(1)
-0.6
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4
38 PowerPlant
H2 Concentration Chemistry
in FW [μg · kg –1] 2019, 21(1)
Electrochemical Corrosion Potential Monitoring in BWRs

2.3 6.3

Rate [103 kg ∙ s−1]

Rate [104 t ∙ h−1]

Core Flow
Core Flow

2.1 This plant controls H2 injection rate to keep H2 concentration in 5.8

RW constant during operation based on the effective H2.
1.9 5.3
1.7 4.8
0.5 1 000

DO in CUW, Effective H2 [µg ∙ kg−1]

0.4 ECP DO in CUW Effective H2
0.3
0.2
ECP at PLR [V(SHE)]

0.1 100
0
-0.1
-0.2 10
-0.3
-0.4 FW flow rate
Effective H 2 = H 2 in FW ×
-0.5 Core flow rate

-0.6 1
0 50 100 150 200 250 300 350 400
Operating Time [days]

Figure 19:
Variation in ECP measured at PLR sampling line in a Japanese BWR type 3 plant throughout one operating cycle [25].

CONCLUSIONS REFERENCES

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[2] Law, R. J., Indig, M. E., Lin, C. C., "Suppression of
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[3] Hettiarachchi, S., Law, R. J., Miller, W. D., Diaz, T. P.,
recommended.
Cowan, R. L., "First Application of NobleChemTM to
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the ECPs were above 0.1 V(SHE) before HWC was in- Industrial Forum, Inc., Tokyo, Japan.
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PowerPlant Chemistry 2019, 21(1) 39

 Electrochemical Corrosion Potential Monitoring in BWRs

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[11] Sakai, M., Takahashi, T., Watanabe, R., "Durability [18] Tachibana, M., "Investigation of Error Reduction
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[13] Ishida, K., Tachibana, M., Wada, Y., Ota, N., Aizawa, [21] Takiguchi, H., Sekiguchi, M., Abe, A., Akamine, K.,
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40 PowerPlant Chemistry 2019, 21(1)

Electrochemical Corrosion Potential Monitoring in BWRs

[22] Goto, H., Uchida, S., Wada, Y., "Experience with Hy- Masahiko Tachibana (Ph.D., Engineering, Tohoku Univer-
drogen Water Chemistry at Japanese BWR", Proc., sity, Japan) joined Hitachi, Ltd., in 1992 and has a 26-year
13th Chino-Japanese Seminar on Nuclear Safety, background in research and development for water chem-
1999 (Taipei, ROC), Japan Atomic Industrial Forum, istry, in particular electrochemistry and corrosion tests of
Inc., Tokyo, Japan. structural materials in the simulated BWR environment, at
Hitachi, Ltd. He is a senior researcher.
[23] Murai, S., Kinoshita, K., Takamori, K., Akamine, K.,
Nakamura, M., Wada, Y., Takagi, J., "Hydrogen Wa- Nobuyuki Ota (B.A., Engineering, Tokyo University of
ter Chemistry Test in ABWR", Proc., 7th Internation- Fisheries, Japan) joined Hitachi-Engineering, Ltd., in 1989
al Conference on Nuclear Engineering, 1999 (Tokyo, and has a 29-year background in the design of BWR water
Japan). Japan Society of Mechanical Engineers, To- chemistry, in particular corrosive environment mitigation
kyo, Japan, ICONE-7305. for BWRs. He is a senior engineer and has been working
at Hitachi-GE Nuclear Energy, Ltd., since 2007.
[24] Wada, Y., Uchida, S., Nakamura, M., Akamine, K.,
"Empirical Understanding of the Dependency of Hy- Makoto Nagase (Ph.D. Engineering, Tokyo University,
drogen Water Chemistry Effectiveness on BWR De- Japan) joined Hitachi, Ltd., in 1984 and has a 23-year
signs", Journal of Nuclear Science and Technology background in research and development for water chem-
1999, 36(2), 169. istry, in particular radioactive corrosion product behavior
and chemical decontamination for BWRs, at Hitachi, Ltd.,
[25] Sato, T., Hikino, K., Ochibe, S., Uemura, S., Tsuyuki, and an 11-year background in engineering, in particular
M., Usui, N., Ota, N., Wada, Y., Proc., Annual Meet- chemical decontamination and recontamination reduction,
ing of the AESJ, 2011 (Fukui, Japan). Atomic Energy at Hitachi-GE Nuclear Energy, Ltd. He is a chief engineer
Society of Japan, Tokyo, Japan, A47 [in Japanese]. and has been working at Hitachi-GE Nuclear Energy, Ltd.,
since 2007.

THE AUTHORS
CONTACT
Yoichi Wada (Ph.D., Engineering, Tohoku University, Ja-
pan) joined Hitachi, Ltd., in 1991 and has a 27-year back- Yoichi Wada
ground in research and development for water chemistry, Hitachi Europe Ltd.
in particular corrosive environment mitigation for BWRs, at 12th Floor 125 London Wall
Hitachi, Ltd. He is a senior researcher and has been work- London EC2Y 5AJ
ing at Hitachi Europe Ltd. in the UK since 2018. United Kingdom
E-mail: Youichi.wada@Hitachi-eu.com
Kazushige Ishida (Ph.D., Engineering, Saitama Universi-
yoichi.wada.ya@hitachi.com
ty, Japan) joined Hitachi, Ltd., in 1994 and has a 24-year
background in research and development for water chem-
istry, in particular corrosive environment mitigation for
BWRs, at Hitachi, Ltd.

POWERPLANT CHEMISTRY®
appreciates any information on planned conferences, workshops, and
meetings in the field of power plant chemistry. The information received
from event organizers will be edited and printed on a space available ba-
sis at no cost to event organizers.
Visit us at https://www.ppchem.com

PowerPlant Chemistry 2019, 21(1) 41

 PowerPlant Chemistry® Interview

PowerPlant Chemistry® Interview

Tapio Werder

On January 1st, 2019, the publishing house Waesseri GmbH was transformed into the new company
PPCHEM AG. To introduce this change to our readers, Tapio Werder, Editor in Chief of the PowerPlant
Chemistry® journal, talks to Michael Rziha, Chief Key Expert for Plant Chemistry at PPCHEM AG.

INTERVIEW

Tapio Werder: Michael, for several weeks now you have I will continue to serve the journal as a member of the IAB
been working with me at PPCHEM AG. Could you explain and will continue to review any paper submissions you
to our readers how your new position within the publishing send to me if you consider me to be the appropriate ex-
house will impact your role as a member of the Interna- pert. Like all of the members of the IAB, my reviews are
tional Advisory Board (IAB) of the PowerPlant Chemistry® based on the current state of the art and latest guidelines,
journal? such as IAPWS, VGB, or other applicable standards, and
of course on my plant operational experience. If there is
a possible conflict of interest because of the topic or the
authorship of the submission, I don't review an article at all
and other members of the IAB take over. Only through this
well-established review process can the high quality of the
articles published in the journal be maintained.

Therefore, the journal will remain completely unchanged

in this matter.

Waesseri GmbH has been involved with the organization or

has been the main organizer of seminars and conferences
in the past like the Power Cycle Instrumentation Seminars
(PCIS) or the PowerPlant Chemistry Forums (PPCFs). What
are your plans in regard to these events?

In the past seven years, Waesseri GmbH has organized

more than 20 Power Cycle Instrumentation Seminars
(PCISs) and 8 PowerPlant Chemistry Forums (PPCFs) and
Michael Rziha: First of all, I would like to thank you for the
I have been regularly involved as a speaker or steering
opportunity to introduce the new company to your readers
committee member in many of these past events. These
in more detail. I think that we need to make a few points
series will be continued by PPCHEM AG in the future – in
clear from the beginning of our joint activities to avoid con-
the events calendar of this issue the readers can find more
fusion and misunderstandings among the worldwide read-
information on these events.
ership of the PowerPlant Chemistry® Journal.
We will also increase our involvement in all kinds of con-
There will be a clear distinction between the three busi-
ferences, international meetings, etc., related to power
ness areas of PPCHEM AG:
plant chemistry. This could be, for instance, future collab-
orations with selected organizations, such as IAPWS, or
1. publishing of the PowerPlant Chemistry® journal will
any other organization worldwide involved in power plant
remain the responsibility of you, the editor in chief;
chemistry related matters.
2. organizing of the conferences and seminars will be a
joint endeavor of the editorial team of the journal and
Besides the events you have mentioned above, what new
myself;
kinds of events will PPCHEM AG plan in the future?
3. the consulting and training services will be part of my
responsibilities and will be my main business activity
as chief key expert for plant chemistry.

42 PowerPlant Chemistry 2019, 21(1)

PowerPlant Chemistry® Interview

We will organize various seminars around the world on all and of course on the plant operational experience I have
major topics of power plant chemistry, such as: gained during the last decades with various plant types,
designs, and sizes worldwide.
• Guidelines such as IAPWS, VGB, and other applicable
standards I will provide consultancy for all different phases of a pow-
• Plant and boiler/HRSG design (also materials) er plant project, such as :
• Feedwater, boiler, and steam chemistry
• Early design/assistance for detailed system specifica-
• Flow-accelerated corrosion tions, and design review of existing specs and P&IDs
• Chemical cleaning • Support for chemical cleaning during the planning and
• Sampling and monitoring including data evaluation and execution phases
data management • Commissioning/chemical assistance during initial start-
• Water treatment plants and condensate polishing plants up
• Cooling water treatment • Operation
• Lay-up and storage • Cycle chemistry review/opportunities for optimization
• Commissioning • Review of chemical operating regime and practices
• Air inleakage • Evaluation of risks
• Chemical dosing systems • Review of sampling and monitoring, as well as assis-
tance for refurbishment and/or optimization
But we will also offer individual and customized in-house • Troubleshooting and RCA
chemistry training, meaning we will come to the individ- • Long-term support and assistance
ual company/organization and will conduct a tailor-made
training for all types of staff (including for non-chemistry
If your readers would like to know more about my activi-
experts, managers, plant operators, etc.) and thus for any
ties, I invite them to visit the website www.ppchem.com.
level of required knowledge.
And of course, I'm available for any questions by email.
Besides that, we are planning to organize regular seminars
Michael, I thank you for your time and responses to my
and training courses in Switzerland. With this, let me call it
questions. I believe these explanations show quite clearly
a "triple pillar concept," I believe we can serve the different
that the PowerPlant Chemistry® journal will remain an in-
needs and possibilities of all interested organizations and
dependent and valuable source of power plant chemistry
people around the world.
related information.
PPCHEM AG will also be offering technical consulting
I'm sure that we will receive comments on this interview
services related to water treatment and cycle chemistry in
from our readers. They will all be passed on to you. Thanks
power and industrial plants of all types and sizes. Could
again, Michael.
you explain in more detail what your activities will include?

What I have mentioned above about the publishing prin-

ciples of a journal is of course also valid for the consulting
business: it is and always will be my highest principle to
be absolutely neutral and independent. All consultancy will
be based on the current state of the art and latest guide-
lines, such as IAPWS, VGB, or other applicable standards,

PPCHEM AG | P.O.Box 433 | 8340 Hinwil | Switzerland

info@ppchem.com | Phone +41 44 940 23 00 | www.ppchem.com

PowerPlant Chemistry 2019, 21(1) 43

 2018's Scientific and Technical Contributions

2018's Scientific and Technical Contributions

Emmanuel K. Quagraine Chloride Contamination of the Water/Steam Cycle in Power Plants: Part V.
Evidence for Chlorinated Compound Vapor Ingress Even after Condenser
PPCHEM 2018, 20(1), 4–22 Re-tubing and Tubesheet Coating
This paper builds on earlier hypotheses that at the power plant under discussion chlo-
rinated compounds with significant vapor pressures can ingress in gaseous form into
the condenser shell through weak seals and/or porous de-alloyed brass tubesheet at
tube-to-tubesheet joints and are converted into chloride in the water/steam circuit.
Aqueous seepage from the cooling water (CW) is also implicated, but is minor.
Dezincification is the main corrosion mechanism.

The issue was addressed by tubesheet hole repairs with titanium epoxy and plastic
epoxy application on all tubesheet faces. Yet failures linked with chlorine species
attacks became obvious soon after such repairs, showing variations in the boiler chlo-
ride to sodium ratio. More sustained chloride cycling in the boiler to levels before the
condenser repairs was observed only after an episode which led to spikes in the con-
densate extraction pump (CEP) dissolved oxygen (DO), CEP sodium, CEP conductivity
after cation exchange (CACE), and steam sodium, and to increasing of the differential
oxidation reduction potential at the CEP and deaerator outlets. Merely ~ 4.3 % of the
chloride ingress from the CW system was estimated to be due to water leakage; the
remainder was attributed to vapor ingress of chlorinated compounds. Inspection of the
condenser waterboxes and the shell confirmed deterioration of epoxy cladding and
tube-to-tubesheet joints.

The current paper provides further evidence from the period in which breaches may
have occurred to the epoxy coating to support the concept that it is gaseous chlorine
compounds and not necessarily water from the recirculating CW which is responsible
for the chloride contamination of the water/steam cycle.

Mohammed Mahmoodur Carbohydrazide vs Hydrazine: A Comparative Study

Rahman,
Hydrazine has been extensively used by the Saline Water Conversion Corporation
Saad Abdullah Al-Sulami, and
(SWCC) in high-pressure boilers as an effective oxygen scavenger for the last several
Fahad A. Almauili
decades. However, due to its toxicity there have been serious thoughts of replacing it
with a safer and more effective alternative.
PPCHEM 2018, 20(1), 34–49
Carbohydrazide, which is marketed under different trade names, was believed to be a
good alternative to hydrazine that provides all of the additional benefits desired of an
alternative oxygen scavenger of being safe to handle but without the deleterious impact
on the cycle chemistry.

Trial tests with carbohydrazide on one of Al-Jubail Power Plant's boilers provided
evidence that it is a good alternative to hydrazine. After two weeks of optimization, it
was found that maintaining residual hydrazine in the range of 30–40 µg · kg–1 in feed-
water (economizer inlet) was an appropriate method of controlling the dose rate of
carbohydrazide and hence provided the optimum conditions for passivating the boiler.
Accordingly, a dosing rate of 0.7 mg · kg–1 of carbohydrazide was found satisfactory for
running the boiler smoothly.

This paper is a summary of the initial trials performed 12 years ago and serves as an
introduction to a second article which will be published later this year in this journal.
During the past 12 years, SWCC has been using carbohydrazide in all of its 8 plants.
SWCC has done some studies with different brands and with 6–12 % carbo-hydrazide
used in the steam cycle as well as during lay-up – this experience will be presented in
the next paper.

44 PowerPlant Chemistry 2019, 21(1)

2018's Scientific and Technical Contributions PPChem

Abstracts 2017 2017's Scientific and Technical Contributions

As every year, the January issue closes with abstracts of all the articles published in
PPCHEM 2018, 20(1), 54–62
this journal in the last year. Back issues of our journal are – with few exceptions – still
available; interested parties can receive PDF files of all articles by e-mail. The order
forms may be downloaded from our homepage.

Ute Ramminger, Investigation of the Efficiency of Film Forming Amines for System Component
Ulrich Nickel, and Corrosion Protection by the Inhibition of the Electrocatalytic Reaction of N,N-
Jörg Fandrich diethyl-p-phenylenediamine with Chloropentaaminecobalt(III) Complex
The application of film forming amines (FFAs) as an effective protection against general
PPCHEM 2018, 20(2), 72–79
and selective corrosion phenomena has been proven as a successful water chemistry
improvement method for water-steam cycles of pressurized water reactors (PWRs).
Since 2011 Framatome GmbH (formerly AREVA GmbH) has performed ten FFA applica-
tions worldwide as a regular complement to the applied secondary side water chemistry
treatment with the main goal of establishing a hydrophobic and protective film on all
inner surfaces of the water-steam cycle which are exposed to corrosion attack.

So far well-known practices have been applied to evaluate the effectiveness of the film
formation on metal and metal oxide layers, for example hydrophobicity testing and con-
tact angle measurements. Electrochemical methods have been investigated with
respect to their applicability to provide additional information on the homogeneity of FFA
films on metal and metal oxide surfaces and thus their ability as corrosion inhibitors.

This paper describes a method to determine qualitatively the completeness and homo-
geneity of the film formation on FFA pretreated corrosion specimens by the inhibition of
the electrocatalytic reaction of a N,N-dialkylated p-phenylenediamine with chloropenta-
aminecobalt(III).

Zhi-gang Li, Case Studies and Findings on High-Temperature Oxidation in Supercritical/Ultra-

Yu-bo Zhang, and Supercritical Boilers
Bing-yin Yao
After investigating and analyzing several cases where large areas of the oxide layer
exfoliated from the steam-touched surfaces of tubes in the high-temperature areas in
PPCHEM 2018, 20(2), 82–89
supercritical and ultra-supercritical boilers in 2013, this paper sorts out factors affecting
the growth of oxide layers in high-temperature areas of the boiler and exfoliation of
these oxide layers from the steam-touched tube surfaces.

The results indicate that, firstly, stainless steel (TP347H) tubes with coarse grain size
show a faster rate of oxide growth at high temperatures; secondly, early oxide layer
exfoliation tends to appear in boilers with steam temperatures lower than the design
value; thirdly, alarm values for the tube wall temperature from boiler manufacturers
cannot effectively prevent oxide growth; and finally, there is no direct relationship
between oxygenated treatment of the boiler feedwater and the exfoliation of large areas
of the oxide layer.

Emmanuel K. Quagraine Chloride Contamination of the Water/Steam Cycle in Power Plants:

Part VI. Confirmation of Chlorinated Vapor Ingress Hypothesis by Regression
PPCHEM 2018, 20(2), 94–112 Model Prediction of Boiler Chloride to Sodium Ratios
This paper builds on earlier hypotheses that chlorinated compounds with significant
vapor pressures can ingress in gaseous/vapor forms into the condenser shell through
weak seals and/or porous de-alloyed brass tubesheet at tube-to-tubesheet joints. The
issue was addressed by tubesheet hole repairs with titanium epoxy and plastic epoxy
application on all tubesheet faces.

PowerPlant Chemistry 2019, 21(1) 45

 2018's Scientific and Technical Contributions

The paper consists of two parts: 1) a cursory review of the literature on oxidative
degradation of polymers and how it can initiate leak paths for gas, vapor, and liquid
permeation; and 2) derivations and validations of predictive models to account for
variations in boiler chloride to sodium ratios (BCSRs) at various stages of operation after
the epoxy resin repairs and condenser re-tubing. The models (developed using multiple
regression analysis) explained the variations well and confirmed the hypotheses of
chlorinated compound vapor ingress alongside water seepage into the condenser shell
from the cooling water (CW).

Earlier (the first 1½ years) in operation, vapor diffusion flux of chloramines, being favored
by temperature increase, was implicated as the dominant process of chlorine contami-
nant transfer from the CW into the water/steam cycle, resulting in higher BCSRs.
However, this mode of transport was sporadic in these early stages. At later stages of
operation, after an episode that seemed to have caused damage to the titanium epoxy
and tube-to-tubesheet joints, the chloride cycling became more persistent. The derived
model at this stage however showed (by p-statistics) a weak influence of temperature. It
also suggested: a) a blend of both diffusive and convective flows of chloramines as
transfer processes promoting higher BCSRs, and b) convective flux of liquid (aqueous
CW) contributing relatively higher sodium (than chloride), thereby lowering BCSRs.
Through all stages, CW free chlorine was found as the main influencing factor on the
convective flux of aqueous CW into the water/steam cycle.

Barry Dooley Film Forming Substances (FFS) Conference, FFS2018

Highlights and Press Release
PPCHEM 2018, 20(2), 116–117
The second FFS International Conference was held on the 20th – 22nd March 2018 in
Prague, Czech Republic chaired by Barry Dooley of Structural Integrity. FFS2018
attracted about 70 participants from 30 countries.

FFS is supported by the International Association for the Properties of Water and Steam
(IAPWS).

The meeting provided a highly interactive forum for the presentation of new information
and technology related to FFS, case studies of plant applications, and for open discus-
sion among plant users, equipment and chemical suppliers, university researchers and
industry consultants. The conference provided a unique opportunity for plant users to
discuss questions relating to all aspects of FFS with the industry's international experts.
A panel session was held which focused on a number of the key questions and uncer-
tainties about FFS some of which are highlighted below.

Wolfgang Hater, Experience with the Application of a Film Forming Amine in the Connah's Quay
Bill Smith, Triple Stage Combined Cycle Gas Turbine Power Plant Operating in Cycling
Paul McCann, and Mode
André de Bache
Due to the changing conditions of the energy market, many power plants have various
periods of non-operation, ranging from a few days to months. Unprotected unit shut-
PPCHEM 2018, 20(3), 136–144
down represents a serious corrosion risk and thus a risk for the integrity of key plant
parts, such as the boiler or steam turbine. However, the established conservation
methods of the water-steam cycle are not always applicable under the constraints of
the modern power market, with unpredictable shutdown periods, while at the same
time the plants have to remain available and may be required to run at short notice.
Film forming amines (FFAs) offer excellent potential for the required flexible conser-
vation process. The Uniper combined cycle gas turbine power plant located at
Connah's Quay, UK, has assessed the applicability of FFAs for boiler and steam turbine
protection.

46 PowerPlant Chemistry 2019, 21(1)

2018's Scientific and Technical Contributions
PPChem

Besides a product based on a combination of FFAs with alkalising amines, a newly devel-
oped product containing solely the FFA was applied. Some key benefits could be demon-
strated. The protection of the boiler and steam turbine could be achieved for a period of at
least one month. The technology was able to protect all components of the water-steam
cycle, including the areas of predominantly dry steam. Compared to dehumidification or
nitrogen capping, minimal manpower was required for conservation. By the application of
the newly developed product, the drawback of increased cationic conductivity levels was
overcome, which remained close to the normal operation values. Due to the encouraging
results, FFAs are now applied in all 4 units of the Connah's Quay power plant.

Robert Svoboda Interpretation of Stator Cooling Water Chemistry Data

Key parameters for chemistry monitoring of stator cooling water are conductivity, elec-
PPCHEM 2018, 20(3), 154–162
trochemical potential (ECP), pH, and the concentrations of oxygen, copper, and of pos-
sible chemical additives (like NaOH for alkaline treatment). While conductivity, oxygen,
and ECP merit continuous supervision, periodic analysis (e.g. once a month) may be
sufficient for the other parameters.

The relation between the copper concentration and conductivity permits an assessment
of the susceptibility of the system with regard to deposition and corrosion, as well as of
possible impurity ingress. For alkaline treatment, measurement of conductivity and the
sodium concentration indicates whether the alkalization is running properly. Oxygen
concentration is a valuable indicator, but is ambiguous with low-oxygen regimes. Here,
oxygen ingress may be detected by an elevated oxygen concentration in the water.
However it is also possible that the oxygen is being consumed so rapidly that it does not
show up in the water analysis.

Akash Trivedi Use of Microfluidic Capillary Electrophoresis to Measure Chloride and Sulfate at
µg · kg–1 Levels
PPCHEM 2018, 20(3), 164–167
This paper describes a new approach to on-line monitoring of trace levels of chloride
and sulfate based on microfluidic capillary electrophoresis (MCE). In this new analytical
system, replenishment of the sample and reagent in the MCE cartridge has been auto-
mated to provide fully unattended operation. This system provides very high sensitivity
(at the single µg · kg–1 level) for simultaneous determination of chloride and sulfate, com-
parable to that of ion chromatography. The instrument has been successfully deployed
in a power plant application.

Barry Dooley European HRSG Forum (EHF2018) – Highlights and Press Release
Another hugely successful fifth annual meeting of EHF was held on the 15th–17th May
PPCHEM 2018, 20(3), 168–169
2018 in Bilbao, Spain chaired by Barry Dooley of Structural Integrity. EHF2018 attracted
72 participants from 16 countries including: Belgium, China, Czech Republic, France,
Germany, Greece, Hungary, Iran, Ireland, Israel, Spain, Scotland, Switzerland, The
Netherlands, UK and USA.

EHF is supported by the International Association for the Properties of Water and Steam
(IAPWS), and is held in association with the Australasian HRSG Forum (AHUG) and the
US HRSG Forum (HF). There were four exhibitors: Anodamine, Atlantium, Mettler-Toledo
/ Manvia and PPChem / Waesseri. The host organization was Bahia de Bizkaia
Electricidad, S.L. (BBE) with Mr. Jose-Maria Bronte, Director General, in attendance.

This year the EHF included 28 presentations, a Panel Discussion on Attemperation and
a Workshop on HRSG Materials Aspects. The meeting provided a highly interactive
forum for the presentation of new information and technology related to HRSGs, case
studies of plant issues and solutions, and for open discussion among the plant users,

PowerPlant Chemistry 2019, 21(1) 47

 2018's Scientific and Technical Contributions

equipment suppliers, and industry consultants. EHF again provided a unique opportu-
nity for plant users representing 18 generators to discuss questions relating to all
aspects of HRSG operation with the industry’s international experts.

Conference EPRI 12th International Conference on Cycle Chemistry in Fossil and Combined
Cycle HRSG Plants (ICCC12): Details Advances in R&D
PPCHEM 2018, 20(4), 188
Another immensely successful International Conference on Cycle Chemistry in Fossil
and Combined Cycle HRSG Plants was conducted June 26–28, 2018, in Arlington,
Virginia, by the Electric Power Research Institute (EPRI). Pre- and post-conference
workshops were conducted on cycle chemistry program treatment and optimization and
on neutralizing amines and film-forming products (FFP).

Conference 17th International Conference on the Properties of Water and Steam (ICPWS) and
International Association for the Properties of Water and Steam (IAPWS)
PPCHEM 2018, 20(4), 190–192 2018 Executive Committee and Working Group Meetings
Between September 2nd–7th, 2018, 140 scientists and engineers representing 27 coun-
tries convened in Prague, Czech Republic for the 17th International Conference on the
Properties of Water and Steam (ICPWS) and the annual meetings of the IAPWS
Executive Committee and Working Groups. The ICPWS conferences began in 1929 in
London, UK and are typically held every fourth or fifth year in conjunction with the
annual IAPWS meetings. The purpose of the conference is to connect scientists with
the engineers who use their information, providing the researchers with guidance on
useful problems and the engineers with the latest research results.

Barry Dooley and Derek Lister Flow-Accelerated Corrosion in Steam Generating Plants
Flow-accelerated corrosion (FAC) has been researched for over 50 years at many loca-
PPCHEM 2018, 20(4), 194–244
tions around the world, and scientifically all the major influences are well recognized.
However, the application of this science and understanding to fossil, combined-
cycle/HRSG and nuclear plants has not been entirely satisfactory. Major failures are still
occurring and the locations involved are basically the same as they were in the 1980s
and 1990s. This paper reviews the latest theory of the major mechanistic aspects and
also provides details on the major locations of FAC in plants, the key identifying surface
features of single- and two-phase FAC, the cycle chemistries used in the plants and the
key monitoring tools to identify the presence of FAC. The management aspects as well
as the inspection, predictive and chemistry approaches to arrest FAC are described, and
the different approaches that are needed within fossil, HRSG and nuclear plants are
delineated.

Mike Caravaggio and Smart Cycle Chemistry Alarms: Intelligent, Actionable Alarms
Brad Burns
Fossil and combined cycle power plant operations continue to evolve and introduce
new challenges to the management of the cycle chemistry program. Two of the main
PPCHEM 2018, 20(5), 264–275
drivers have been cost reduction and increased flexible operation. This has led to a
reduction in cycle chemistry expertise at plants, while there has been a simultaneous
increase in the complexity of managing the chemistry program. The development of
smart cycle chemistry alarms is a methodology to respond to these challenges and
improve corrosion and deposition control at power plants. The concept is simple: use
independent signals to diagnose and confirm excursions and chemistry events as they
occur in the power plant so that non-expert personnel can respond appropriately. This
paper discusses the philosophy for developing smart alarms. It builds on cycle chem-
istry validation work presented at previous Electric Power Research Institute (EPRI)
International Cycle Chemistry conferences and will include some application examples
of the EPRI approach to smart cycle chemistry alarms.

48 PowerPlant Chemistry 2019, 21(1)

2018's Scientific and Technical Contributions

Iain Duncanson, Dispersant Injection Strategy Optimization at South Texas Project

Dan Sicking,
The use of dispersants in pressurized water reactors has been extensively qualified by
Keith Fruzzetti,
the Electric Power Research Institute (EPRI) as a viable and effective technology for
Michael Garner,
significantly reducing the fouling rate of steam generators and has contributed to
Charles Clinton, and
improvements in steam generator thermal performance. Several specific strategies for
Chancey Pence
the application of dispersants are qualified for use at utilities including continuous online
injection, steam generator wet layup and long-path recirculation (start-up).
PPCHEM 2018, 20(5), 278–288
The South Texas Project has been at the forefront of the industry dispersant implemen-
tation program and is the first nuclear utility to implement dispersant injection with the
use of full flow, deep bed condensate polishing. The South Texas Project dispersant
injection program was implemented as a continuous, online strategy for optimizing
steam generator thermal performance and managing steam generator deposit inven-
tories. Operating experience has shown that an online batch-type dispersant injection
strategy may provide similar benefits to those realized from an online continuous injec-
tion strategy whilst providing cost saving benefits and minimizing exposure of conden-
sate polisher resin to dispersant. This paper summarizes South Texas Project dispersant
experiences and provides rationale for transitioning to a batch-type injection strategy.

Robert Svoboda and Corrosion and Deposits in Water-Cooled Generator Stator Windings:
Wolf-Dietrich Blecken Overview of Water Cooling of Generators
The most common and severe problem related to corrosion and deposits that has arisen
PPCHEM 2018, 20(5), 290–294
with generator water cooling throughout its more than 50 years of history is plugging of
copper hollow conductors. This article gives an introduction to a series of four additional
articles to appear in this journal on these issues, in particular problems with copper
hollow conductors. The main goal of this series is to give a detailed update on the
mechanism, prevention, diagnosis, and removal of flow restrictions in water-cooled
generator windings.

Robert Svoboda Corrosion and Deposits in Water-Cooled Generator Stator Windings:

Part 1: Behaviour of Copper
PPCHEM 2018, 20(5), 297–309
The most common and severe problem that has arisen with generator water cooling
throughout its more than 50 years of history is plugging of copper hollow conductors. A
4-step model of the occurrence of this plugging was developed to indicate the influenc-
ing parameters. The steps are oxidation of the copper surface, release of the oxidized
copper, migration of the released copper, and re-deposition of the migrating copper. It is
observed that these steps are influenced by water chemistry as well as by system and
component design. From the operating side, adherence to a suitable water chemistry
regime as well as proper lay-up practice help to avoid or mitigate flow restrictions.

Robert Svoboda and Corrosion and Deposits in Water-Cooled Generator Stator Windings:
Russell Chetwynd Part 2: Detection of Flow Restrictions
Useful methods for detecting flow restrictions in stator bar cooling channels include
PPCHEM 2018, 20(6), 326–336
review of operating parameters and history vs. original design, of generator cooling
water chemistry, of strainer and filter clogging history and of results from diagnostic
chemical cleaning, as well as monitoring of stator water flow vs. pressure drop, individ-
ual stator bar water flow measurements, monitoring of on-line stator temperatures,
visual inspections, and DC high-potential (Hipot) testing. A combination of these meth-
ods can be selected under consideration of plant specific hardware features and cost-
to-benefit relation.

A proactive approach to detecting flow restrictions is recommended in order to permit

advanced planning of any needed corrective actions, thus reducing the risk of

PowerPlant Chemistry 2019, 21(1) 49

 2018's Scientific and Technical Contributions

unplanned maintenance downtime, or even component failure. Managing flow restric-

tions at an early stage reduces the risk of severe plugging of conductors that may well
prove difficult to remove later on.

Daniel M. Wells, The Future of Nuclear Power Plant Chemistry Control

Paul L. Frattini,
Chemistry control in nuclear power plants continues to evolve in the types of additive
Keith Fruzzetti,
chemistry and purification technologies applied, as well as in how important parameters
Susan Garcia,
are monitored and controlled. New chemistry technologies are being evaluated, quali-
Joel McElrath, and
fied, and demonstrated throughout the industry that have the potential to fundamentally
Michelle Mura
alter and significantly improve chemistry control in these plants. Many of these tech-
nologies could improve operations and maintenance, as well as economic viability.
PPCHEM 2018, 20(6), 338–345
For example, filming products (including filming amines) could significantly reduce pres-
surized water reactor (PWR) secondary flow-accelerated corrosion (FAC) and corrosion
product transport, improving steam generator (SG) performance and reducing the need
for SG chemical cleanings. The application of potassium hydroxide (KOH) to the reactor
coolant system (RCS) for pH control in "Western-designed" PWRs may ultimately result
in significant cost savings for the industry, both relative to the cost of the bulk chemical it
replaces (compared to costly enriched lithium-7, 7Li), and in the reduced risk of lithium-
assisted corrosion issues of irradiated stainless steels and zirconium-based fuel cladding
alloys. In boiling water reactors (BWRs) materials mitigation technologies such as online
noble chemistry continue to expand throughout the industry, with utilities seeking more
options – including continuous application, which would reduce the overall cost of the
application. Demonstration of these technologies over the next few years will further the
ability of other plants to complete their own cost-benefit analysis and start utilizing them.

Regarding chemistry monitoring in nuclear power plants, most continue to rely on man-
ually intensive methods for both sampling and analysis. Several utilities have applied
online monitoring methods for some parameters but may still struggle with maintenance
of older instruments. Many utilities may have purchased older generations of technolo-
gies only to find the maintenance costs and performance did not live up to expectations.
Outside of nuclear power plant applications, technologies such as online ion chro-
matography and inductively coupled plasma (ICP) analyses have continued to evolve
and improve, and are applied widely. Moving to completely automated and higher
frequency analysis of chemistry parameters may allow for reducing the total number of
monitored parameters while also moving toward fully automated plant chemistry, which
may eventually include automated control. This paper highlights the current develop-
ment status of these new technologies and provides a vision for the overall future
impacts of full utilization in nuclear power plants.

Raymond M. Post, An Evolution in Cooling Water Treatment

Rajendra P. Kalakodimi, and
For over four decades, the most common water treatment program for power plant and
Brad Buecker
large industrial cooling tower systems has relied on a combination of inorganic and
organic phosphate (phosphonate) chemistry. The formulations were designed to minimize
PPCHEM 2018, 20(6), 346–352
scale formation and provide corrosion protection, primarily through precipitation chem-
istry and operation at an alkaline pH. Two important factors are driving an evolution away
from phosphate-based chemistry towards polymer treatment methods. One is the
increasingly problematic issue of phosphorus discharge and its effects on the formation
of toxic algae blooms in receiving bodies of water. The second is the growing evidence
that well-formulated polymer programs are more effective than phosphate/phosphonate
technology for scale prevention and corrosion protection. This article examines important
aspects of this evolving chemistry, and how it can improve cooling system reliability at
many plants.

50 PowerPlant Chemistry 2019, 21(1)

2018's Scientific and Technical Contributions

Tapio Werder Report on the PowerPlant Chemistry Forum in Delhi, India

This contribution is a report on the seventh PowerPlant Chemistry Forum (PPCF), held in
PPCHEM 2018, 20(6), 354–364
Delhi, India, on November 22–23, 2018. The PPCF Delhi was organized by Waesseri
GmbH, publisher of the PowerPlant Chemistry Journal, together with the International
Association for the Properties of Water and Steam (IAPWS). Both SWAN Analytische
Instrumente AG, Switzerland, and Forbes Marshall Pvt. Ltd., India, provided financial
and organizational support by their sponsorship.

The agenda consisted of six sessions covering different aspects of water/steam cycle
chemistry: cycle chemistry for fossil supercritical and subcritical units, chemistry in
generator cooling water systems, cycle chemistry in nuclear plants, sampling and instru-
mentation as well as new technologies were the topics covered during the two days.
Each session consisted of two to three presentations given by an expert in the field,
followed by open floor discussions. A short summary of each presentation is given in
this report.

For the first time in this series of events, a workshop on the activities of the IAPWS was
included in the agenda. During this workshop the formation of a preliminary national
committee of India was discussed and an initial group of interested experts formed as a
result.

PPChem

Chemists and engineers from fossil and nuclear power plants and from industrial power generation, vendors,
OEMs, consultants, E&As, and others in more than 60 countries on all continents read PowerPlant Chemistry®.

You can reach them by advertising in our journal.

PowerPlant Chemistry® is shipped worldwide.

Some examples:

• Argentina • Australia • Austria • Bahrain • Belgium • Brazil • Bulgaria • Canada • Chile •

• China • Colombia • Croatia • Cyprus • Czech Republic • Denmark • Egypt • Finland •
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• Ireland • Israel • Italy • Jamaica • Japan • Korea • Kuwait • Malaysia • Malta • Mexico •
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• Ukraine • United Arab Emirates • United States •

Visit us at https://www.ppchem.com or write to info@ppchem.com

Hintergrund-Bild: "Erde ab 2006.tif"

PowerPlant Chemistry 2019, 21(1) 51
 
     
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52 PowerPlant Chemistry 2019, 21(1)

Many fine companies from throughout the world have
placed ads in the PowerPlant Chemistry journal. Why?
They know that advertising in our journal pays off.
The readers of this journal are decision makers in all
power plant chemistry-related fields.

What are you waiting for?

The PowerPlant Chemistry journal's circulation

covers more than 60 countries in Europe, Asia, North and
South America, Africa, and Australia.

Check out our Media Information 2019 at

https://www.ppchem.com

and contact us (info@ppchem.com). We are ready to serve you.

PowerPlantChemistry
PowerPlant Chemistry2019,
2018,21(1)
20(5) 315
53
 Call for Papers / Guidelines for the Authors

Call for Papers / Guidelines for the Authors

INTRODUCTION nical paper will peer review the submitted paper. The
reviewer's (reviewers') comments will be anonymously
PowerPlant Chemistry® covers all aspects of power
passed on to the author (main author). The author may
plant chemistry. Some examples in alphabetical order:
decide whether he or she wants to improve his or her
paper in accordance with the reviewer's (reviewers') re-
Analytics, Chemical Cleaning, Chemical Thermodynam-
commendations.
ics, Component Failures, Condensate Polishing, Cooling
Water, Corrosion, Cycle Chemistry Guidelines, Cycling & PPCHEM AG reserves the right to refuse the publica-
Peaking, Deaeration, DeNOx and DeSOx Processes, tion of papers that have not been improved or whose
Deposition, Flue Gas Cleaning, Fly Ash, Instrumentation, refusal has been recommended by the reviewer(s).
Layup, Physical Chemistry, Plant Cycle Chemistry, Sam-
pling, Startup, Steam Chemistry, Trouble shooting, Waste- Reports on utility experience are, as a rule, not subject
water Treatment, Water Treatment, and all other power to external reviews.
plant chemistry-related topics.
COPYRIGHT
PowerPlant Chemistry® is also interested in releases on
new products, techniques, procedures, etc. Printing of PPCHEM AG must receive a signed publishing license
releases is free for current advertisers (on a space avai- agreement before the paper can be accepted for publi-
lable basis). Other parties: Please refer to the Adverti- cation in the PowerPlant Chemistry® journal.
sement Rate Table in our Media Information.
TEXT
PAPER SUBMISSION
Spelling
All papers presented to PowerPlant Chemistry® must be
Spelling should be either consistently American or
submitted in English, exclusively in electronic format.
con- sistently British. Uppercase letters should only be
Please also submit a PDF file of your paper for compa-
used at the beginning of proper nouns. Abbreviations
rison.
should only be used if very necessary – as with a long
word combination like heat recovery steam generator
Please prepare papers for submission according to the
(HRSG) – and should be explained with the first use.
following format specifications:
Author's (Authors') Names
Paper size: A4 or US Letter
Columns: Single-columned Use the full names of all authors, e.g., Kevin C. Miller,
Margins: 2 cm or 0.8 inch Karl-Heinz Strassenhauer, etc.
Font: Arial
Font size: 12 pt Title of the Paper
Line spacing: Single-spaced (1) Do not use very long titles. The maximum length of the
Paragraphs: A single line between paragraphs, title is twelve words.
no indentation
Section headings: Principle subhead (first level): Bold, Abstract
upper case
An abstract of the paper summarizing the topic and
Second level: Bold, headline-style
conclusions (150 words maximum) appears at the be-
capitalization
ginning of the paper and on our homepage.
Third level: Bold, run into the
paragraph Units
Footnotes: Please avoid using footnotes.
All units used must be SI units; the latest rules of IUPAP,
The submission of a paper does not guarantee publica- IUPAC, ISO, etc. should be followed. The use of other
tion. All materials sent to PowerPlant Chemistry ® may units is only possible as supplemental information and
be subject to editing. must be written in parentheses following the correct SI
term.

PAPER REVIEW Mathematical and Chemical Equations

At least one internationally recognized expert active in All equations used should be clear and understanda-
the area covered by the submitted scientific and tech- ble. They should be positioned on a separate line in

54 PowerPlant Chemistry 2019, 21(1)

Call for Papers / Guidelines for the Authors

the text and numbered. All symbols used should be ex- Examples:
plained in plaintext. In papers which contain more than
[1] Simkine, V., Vance, C. P., Physical Chemistry, 1999.
10 different symbols a separate list of notation defining
United Publishers, Hockenheim, Germany.
all symbols used should appear at the beginning of the
paper. [2] Hömig, H. E., Metal and Water, 1964. Vulkan-Ver-
lag Dr. W. Clasen, Essen, Germany, 2nd Edition [in
Example: German].

Thermal decomposition of hydrogen carbonate ions Periodicals

and carbonate ions according to Eqs. (1) and (2), re-
spectively, results in the formation of carbon dioxide Author's surname, initials, "Title of the Article", Journal
(CO2): (in italics) year (in bold), volume(issue), page (the first
page of the article).
2HCO3–  CO32– + CO2 + H2O (1)
Examples:
CO32– + H2O  2OH + CO2
–
(2) [3] Dooley, R. B., Anderson, R., "Assessments of
HSRGs – Trends in Cycle Chemistry and Thermal
FIGURES Transient Performance", PowerPlant Chemistry
2009, 11(3), 132.
Figures (drawings, graphs, and photographs) can either
be reproduced in color (four color offset printing pro- [4] Friggens, H. A., Holmes, D. R., "Nucleation and
cess) or in black and white. Growth of Magnetite Films on Fe in High Temperature
Water", Corrosion Science 1968, 8(12), 871.
All figures should be submitted in separate *.TIF or
*.JPG files. Figures embedded in PDF, Excel, or Power- Conference Proceedings
Point files are also acceptable. Author's surname, initials, "Title of the Presentation", Proc.,
Title of the Conference (in italics), year (in bold) (venue/city,
The minimum width for any submitted figure is 86 mm; state, country). Conference organizer, city, state, count-
photographs additionally must have adequate resolu- ry, order number, page (the first page of the paper).
tion (300 dpi).
Examples:
Do not include too many details in a single figure. In ta-
bles, all columns have to include a column heading and [5] Lister, D., Weerakul, S., Caravaggio, M., "The Ef-
units. fects of a Film-Forming Amine on Flow-Accelerated
Corrosion in Single- and Two-Phase Flows", Proc.,
The captions of all figures should be included on a se- International Conference on Flow-Accelerated Cor-
parate page at the end of the text. rosion, 2016 (Lille, France). Électricité de France,
Paris, France.
[6] Ramminger, U., Fandrich, J., Drexler, A., "An Inno-
vative Strategy for Secondary Side System Lay-Up
REFERENCES
using Film-Forming Amines", Proc., 7th Internatio-
All references must be complete and conform to the fol- nal Steam Generator to Controls Conference, 2012
lowing examples. The references must be mentioned in (Toronto, Canada). Canadian Nuclear Society, To-
the text or in the figure captions using square brackets ronto, ON, Canada.
with the reference number.
Presentations Not Published in Conference
Examples: Proceedings
All relevant information on underdeposit boiler tube fail- Author's surname, initials,"Title of the Presentation", pre-
ure mechanisms is summarized in [14]. sented at Title of the Conference (in italics), year (in bold)
(venue/city, state, country). Conference organizer, city,
Figure 4: state, country.
Dissolved iron, chromium and nickel concentrations
dur-ing the trial plant cleaning [15]. Example:
[7] Post, R., Buecker, B., Shulder, S., "Power Plant
Books Cooling Water Fundamentals", presented at the 37th
Author's surname, initials, Title of the Book (in italics), Annual Electric Utility Chemistry Workshop, 2017
year (in bold). Publisher, city, state, country of publica- (Champaign, IL, USA). University of Illinois at Urbana-
tion. Champaign, Champaign, IL, USA.

PowerPlant Chemistry 2019, 21(1) 55

 Call for Papers / Guidelines for the Authors

Articles in Books or Edited Proceedings [14] Technical Guidance Document: Steam Purity for Tur-
Author's surname, initials, Title of the Book (in italics) or bine Operation, 2013. International Association for
Proc., Title of the Conference (in italics) (Eds.: initials the Properties of Water and Steam, IAPWS TGD5-13.
surname) (in italics), year (in bold). Publisher, city, state, Available from http://www.iapws.org.
country of publication, order number, page (the first
page of the paper). Patents
Inventor's surname, initials, Title of the Patent (in ita-
Examples: lics), year (in bold). Patent office, Publication number.
[8] Simonson, J. M., Palmer, D. A., Interaction of Iron-
Based Materials with Water and Steam (Eds.: B. Example:
Dooley, A. Bursik), 1992. Electric Power Research [15] Lok, G. W., Peters, S., Olivier, G. A., Measurement of
Institute, Palo Alto, CA, USA, EPRI TR-102101, the Cation Conductivity of Water, 1998. United States
4-1. Patent and Trademark Office, US 6017445 A.
[9] Petr, V., Kolovratník, M., Physical Chemistry of Aque-
ous Systems: Meeting the Needs of Industry (Eds.: Private Communication
H. J. White, Jr., J. V. Sengers, D. B. Neumann, J.C. Person's full name (affiliation), year (in bold).
Bellows), 1995. Begell House, New York, NY, USA,
703. Example:
[16] John W. Brown (PowerPlant Chemistry GmbH,
Technical Reports Neulussheim, Germany), 1999.
Title of the Report (in italics), year (in bold). Organiza-
tion, city, state, country, order number. Multiple Reference
Example: [17] Bellows, J. C., Proc., 76th International Water-
Conference, 2015 (Orlando, FL, USA). Engineers'
[10] PWR Primary Water Chemistry Guidelines, Revision 4,
Society of Western Pennsylvania, Pittsburgh, PA, USA,
1999. Electric Power Research Institute, Palo Alto, CA,
IWC 15-25.
USA, EPRI TR-05714, V1.
Also published in: PowerPlant Chemistry 2016,
Ph.D. Thesis 18(4), 184.
Author's surname, initials, Title of the Thesis (in italics),
year (in bold). Ph.D. Thesis, University, city, state, coun- BIOGRAPHIES
try. Biographies of all authors appear at the end of the text.
Example: The biography should start with the full name of the re-
spective author and his or her academic qualifications.
[11] Chempik, E., Detailed Study of Surface Active Sub-
stance Effect on Power and Structural Parameters of Example:
Wet Steam Turbines and Behavior of Major Steam-
Water Equipment, 1980. Ph.D. Thesis, Moscow Power John B. Smith (B.S., Applied Chemistry, University of
Institute, Moscow, USSR. Auckland, New Zealand, Ph.D., Physical Chemistry,
University of Glasgow, Scotland) is ...
Online Sources The maximum length of a biography is 100 words.
Author's surname, initials, Title of the Article/Document
(in italics), year (in bold). Organization, order number. CORRESPONDING AUTHOR
Available from URL. Each paper closes with a complete mailing and E-mail
Example: address of the author who is responsible for corre-
spond- ence from and to our readers.
[12] Storm, R. F., Typical Causes of Slagging and Fou-
ling Problems in Boilers, 2015.
Available from http://www.powermag.com.
WHERE TO SUBMIT

[13] Barton, N. A., Erosion in Elbows in Hydrocarbon Mailing addresses for your submissions:
Production Systems: Review Document, 2003. E-mail: tapio.werder@ppchem.com
Available from http://www.hse.gov.uk.
PPCHEM AG, P.O. Box 433, CH-8340 Hinwil

56 PowerPlant Chemistry 2019, 21(1)

Call for Papers / Guidelines for the Authors

PowerPlant Chemistry® Editorial Schedule 2019

PowerPlant Chemistry 2019, 21(1) PowerPlant Chemistry 2019, 21(2)

Call for papers closing: 07.01.2019 Call for papers closing: 18.02.2019
Editorial deadline: 18.01.2019 Editorial deadline: 29.03.2019
Printing date: Beginning of February Printing date: Beginning of April
Mailing date: End of February Mailing date: End of April

PowerPlant Chemistry 2019, 21(3) PowerPlant Chemistry 2019, 21(4)

Call for papers closing: 23.04.2019 Call for papers closing: 08.07.2019
Editorial deadline: 24.05.2019 Editorial deadline: 09.08.2019
Printing date: Beginning of June Printing date: Middle of August
Mailing date: Middle of June Mailing date: End of August

PowerPlant Chemistry 2019, 21(5) PowerPlant Chemistry 2019, 21(6)

Call for papers closing: 19.08.2019 Call for papers closing: 28.10.2019
Editorial deadline: 20.09.2019 Editorial deadline: 29.11.2019
Printing date: End of September Printing date: Beginning of December
Mailing date: Beginning of October Mailing date: Middle of December

Explanation:

Call for papers closing: Printing date:

By the date stated for each issue, we should at least After this date, changes can no longer be made be-
have a first draft of the paper to send to our reviewers. cause the new issue is being printed.

Editorial deadline: Mailing date:

By the date stated for each issue, the paper should The new issue is sent to our readers.
have its final form and be released by the author and
the editorial team in Hinwil.

PPCHEM AG | P.O.Box 433 | 8340 Hinwil | Switzerland

info@ppchem.com | Phone +41 44 940 23 00 | www.ppchem.com

PowerPlant Chemistry 2019, 21(1) 57

Imprint
PowerPlant Chemistry® Journal (ISSN 1438-5325)

Publisher: PPCHEM AG
P.O. Box 433
8340 Hinwil
Switzerland
Phone: +41 44 9402300 BACK ISSUES OF THE POWERPLANT
E-mail: info@ppchem.com CHEMISTRY® JOURNAL
Editor in Chief: T. Werder (Switzerland)
tapio.werder@ppchem.com
The PowerPlant Chemistry® journal has become a
valuable source of power plant chemistry-related
International Advisory Board: information. The large number of published papers
Professor A. Bursik (Germany) represents the state-of-the-art in power plant che-
R. B. Dooley (UK) mistry; the journal is also used as a platform for the
Structural Integrity Associates exchange of power plant chemistry-related expe-
M. Gruszkiewicz (USA) rience. Many engineers and power plant chemists
Oak Ridge National Laboratory have confirmed that regularly reading this journal
Professor D. D. Macdonald (USA) helps them in the responsible performance of their
U.C. Berkeley jobs.
B. Stellwag (Germany) In this regard, two very important pieces of infor-
R. Svoboda (Switzerland) mation.
M. Rziha (Switzerland)
PPCHEM AG
First the good news:
All back issues of PowerPlant Chemistry® are still
Copyediting and Proofreading: available; you may easily complete your library. The
K. Brock (USA/Germany)
procedure is very simple: visit our homepage at
Graphics and Layout: www.ppchem.com and in the section "Back Issues
K. Gubser (Switzerland) & Individual Articles" download the order form. Fill
in the form, sign it, and send it to us. The contact
Production: Appenzeller Druckerei (Switzerland) information is given on the order form.
Frequency: PowerPlant Chemistry® is published six And now the bad news:
times a year
All back issues of PowerPlant Chemistry® are still
International copyright laws protect the journal and all ar available; however, the number of copies available
ticles. All rights including translation into other languages is very limited. We serve our customers on a first
are reserved. come first served basis. Those who wait too long
may come away empty-handed. For this reason, act
The journal may not be reproduced in whole or in part by
any means (photocopy, electronic means, etc.) without fast!
the written permission of PPCHEM AG.

The authors, the editors, and the publisher do not assu-

me liability for the correctness of data or for typographical
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All materials sent to PPCHEM may be subject to editing.

Materials will not be returned if not accompanied by a
selfaddressed stamped envelope.

Visit us at www.ppchem.com

58 PowerPlant Chemistry 2019, 21(1)

 PPCHEM

First Announcement and Call for Papers

The 2019 PPCHEM PowerPlant Chemistry Forum USA
Power Cycle Chemistry in a Changing World

INVITATIO
26 – 27, September 2019 – Washington, DC
NVITATION
N ON
MISTRY FORUM

The Forum will be of major interest to:

November 22 and 23, 2018

operational personnel, technical managers, plant engineers, boiler operators, cycle and plant chemists,
corrosion scientists, and service providers as well as manufacturers of components and chemicals.

Delhi,
The official language India
of this conference will be English.

The Forum will provide excellent insights into the latest developments in cycle chemistry and numerous
examples from fossil, combined cycle, biomass, nuclear, and other plants from around the world will be
shared. The conference will consist of both invited and contributed technical papers.
Share your experience with your colleagues and take advantage of the chance to present a case study
HEMISTRY

covering one of the topics listed below.

Presentation Topics (final agenda pending):

• Cycling Operation and its Challenges • Chemical Control and Monitoring
• Lay-Up for Cycling Plants
• Welcome
Chemical Treatment fortoCycling
the 7thPlants
PowerPlant Chemistry •Forum.Chemistry during Start-Up
• Effective Cycle

%


!
"


Chemistry Management 
• 

 Systems and Instrumentation
Sampling
• Industrial Steam Raising Plants /Cogeneration Plants • Life-Cycle Chemistry Optimization
The PPCHEM
 
"
!
#



 
!

$

NT CHE

Call for Papers

$

  
# 



$

  
 


 consist
The conference will 

"
"

 

of both invited and 

"



!

contributed technical papers. 
 -
Abstracts must 

be submitted 
 
by July 19, 2019, to guarantee consideration.
The presenters will be notified of acceptance by August 2, 2019.
Abstracts and suggestions for presentations 




"


 should be sent to:
Michael Rziha, Chief
  

 
PPCHEM
Key Expert Plant Chemistry,  
AG,



michael.rziha@ppchem.com 
$


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!
!

"

    


Steering Committee


 
• Michael Rziha, (Chair), PPCHEM AG, Switzerland • Chad McKnight, Southern Company, USA
WERPLA

• Randy Turner, 



Swan Analytical USA, Inc.
 
"

 • Erin Westberg, Florida Power and
• David Addison, Thermal Chemistry, New Zealand Light/NextEra, USA
• Doug Hubbard, American Electric Power, USA • Steve Shulder, EPRI, USA


 



 
!

!
"


• Mike Rupinen, LG&E and KU, USA
!
   .
OWER

Sponsors and Exhibits

There will be a special vendor exhibition at the conference.
Contact the conference coordinator for more information or visit https://www.ppchem.com/conferences/
POW

Tapio Werder, Editor in Chief, PowerPlant Chemistry® Journal, tapio.werder@ppchem.com

260
PowerPlant ChemistryPPC
2019,
HEM21(1)
FORUM, Delhi, India, 2018 PowerPlant Chemistry 2018, 20(5)
59
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60 PowerPlant Chemistry 2019, 21(1)