oEPA
United States
Environmental Protection
Agency
Industrial Envirinmental Research
Laboratory
Research Triangle Park NC 27711
EPA-600/7-80-026
January 1980
Assessment of Corrosion
Products from Once-
through Cooling Systems
with Mechanical
Antifouling Devices
Interagency
Energy/Environment
R&D Program Report
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RESEARCH REPORTING SERIES
Research reports of the Office of Research and Development, U.S. Environmental
Protection Agency, have been grouped into nine series. These nine broad cate-
gories were established to facilitate further development and application of en-
vironmental technology. Elimination of traditional grouping was consciously
planned to foster technology transfer and a maximum interface in related fields.
The nine series are:
1. Environmental Health Effects Research
2. Environmental Protection Technology
3. Ecological Research
4. Environmental Monitoring
5. Socioeconomic Environmental Studies
6. Scientific and Technical Assessment Reports (STAR)
7. Interagency Energy-Environment Research and Development
8. "Special" Reports
9. Miscellaneous Reports
This report has been assigned to the INTERAGENCY ENERGY-ENVIRONMENT
RESEARCH AND DEVELOPMENT series. Reports in this series result from the
effort funded under the 17-agency Federal Energy/Environment Research and
Development Program. These studies relate to EPA's mission to protect the public
health and welfare from adverse effects of pollutants associated with energy sys-
tems. The goal of the Program is to assure the rapid development of domestic
energy supplies in an environmentally-compatible manner by providing the nec-
essary environmental data and control technology. Investigations include analy-
ses of the transport of energy-related pollutants and their health and ecological
effects; assessments of. and development of, control technologies for energy
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This report has been reviewed by the participating Federal Agencies, and approved
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This document is available to the public through the National Technical Informa-
tion Service. Springfield. Virginia 22161.
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EPA-600/7-80-026
January 1980
Assessment of Corrosion Products
from Once-through Cooling Systems
with Mechanical Antifouling Devices
by
Charles M. Spooner
CCA/Technology Division
Burlington Road
Bedford, Massachusetts 01730
Contract No. 68-02-2607
Task No. 28
Program Element No. INE827
EPA Project Officer: Theodore G. Brna
Industrial Environmental Research Laboratory
Office of Environmental Engineering and Technology
Research Triangle Park, NC 27711
Prepared for
U.S. ENVIRONMENTAL PROTECTION AGENCY
Office of Research and Development
Washington, DC 20460
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DISCLAIMER
Tills Final Report was furnished to the Environmental Protection Agency
by GCA Corporation, GCA/Technology Division, Burlington Road, Bedford,
Massachusetts, 01730, in fulfillment of Contract No. 68-02-2607, Work Assign-
ment No. 28. The opinions, findings, and conclusions expressed are those of
the author and not necessarily those of the Environmental Protection Agency.
Mention of company or product names is not to be considered as an endorsement
by the Environmental Protection Agency.
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ABSTRACT
About 67 percent of currently operating steam electric power plants in
the UnJ.te.d States use once-through cooling systems. Corrosion and biofouling
severely reduce the thermal efficiency of heat exchange in the condenser tubes
so that various cleaning mechanisms are in use. Once-through systems are
cleaned chemically or by manual or on-line mechanical methods.
The U.S. Environmental Protection Agency is concerned that the use of on-
line mechanical cleaning methods may lead to increased levels of metals in the
effluent due to abrasion of the condenser tubes. This project estimates the
significance of this effect based on comments from utilities experienced with
the Amertap system and from the manufacturer.
The industry generally does not keep a close account of the causes and
magnitude of condenser tube corrosion; however, based on observations offered
.by the utilities, the Amertap and other systems do not appear to contribute
to loss of metal through abrasion in any measurable way. No sufficiently
accurate data are available demonstrating that elevated metal levels exist
in cooling water effluent over those in the intake water. Recommendations
to evaluate this problem more fully are made.
This report was submitted in fulfillment of Contract No. 68-02-2607 by
CCA/Technology Division under the sponsorship of .the U.S. Environmental Pro-
tection Agency. This final report covers the period January 15, 1979 to
December 21, 1979, and work was completed on December 31, 1979.
iii
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CONTENTS
Abstract ill
Figures v
Tables v
List of Conversions from English to SI Units vi
Acknowledgment vii
1. Introduction 1
Chemical Cleaning 1
Manual Cleaning 3
On-line Mechanical Cleaning 4
Purpose and Arrangement of Report 7
2. Conclusions and Recommendations 12
3. Condenser Tube Construction and Its Fouling 14
Condenser Tube Materials 14
Condenser Tube Fouling 17
4. Economics of Continual Mechanical Cleaning 18
References 25
Appendices
A. Amertap - Condenser Tube Cleaning Systems in the
United States 26
B. Utility Responses to Information Request 34
iv
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FIGURES
Number Page
1 Distribution of chemicals added to once-through cooling
water systems in Maryland 2
2 Increase in generating coses as tube cleanliness
decreases 3
3 Schematic arrangement of Amertap tube cleaning system 5
4 Schematic of M.A.N. system reverse flow piping 6
TABLES
Number Page
1 Power Plants Which Have Replaced Condenser Tubes After
Installing Amertap Systems 9
2 Distribution of Replaced Condenser Tubes by Cooling Water
Source and Condenser Tube Material (Number of Installations). 9
3 Questionnaire Recipients 10
4 Distribution of Condenser Tube Construction Materials Among
Electric Utilities Using the Amertap System 14
5 Distribution of Alloys, Once-Through Systems, Amertap-
Equipped 15
6 Condenser Tube Materials for all Electric Utility Units
Using the Amertap System 16
7 Typical Amertap System Costs (in 1979 Dollars) 23
8 Effect of Amertap System on Electricity Costs 24
i
B-l Utility Responses to Information Request on Amertap
. Performance 36
B-2 Water Quality Data for Utility Number 4 39
B-3 Water Quality Data for Utility Number 5 40
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LIST OF CONVERSIONS FROM ENGLISH TO SI UNITS
TO CONVERT INTO MULTIPLY BY
gallons/day cubic meters/day 0.003785
cons (shore) tonnes (metric) 0.9078
gallons/minute liters/second 0.06308
feec/second meters/second 0.3048
VI.
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ACKNOWLEDGEMENT
The author acknowledges the significant contributions of Mr. David W.
Bearg and Mr. Robert J. Bouchard of GCA/Technology Division for their contri-
butions. Thanks are due Mr. Paul W. LaShoto (GCA/Technology Division) for
the economic analysis of Section 4.
The advice of Dr. Theodore G. Brna, EPA Project Officer, Emissions/
Effluent Technology Branch, is sincerely appreciated.
vn
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SECTION 1
INTRODUCTION
In che United Staces about 67 percent of currently operating steam electric
power plants use once-through cooling systems. Flows through these systems dom-
inate the discharge from each facility and, furthermore, these once-through
systems used by the electric utility industry lead to discharges of greater
volume than seen in nearly any other industry. Flow rates range typically from
500,000 to 700,000 gallons per day per megawatt (electric)1 or gal/day-MW(e).*
The U.S. Environmental Protection Agency is concerned that the use of me-
chanical cleaning systems to remove corrosion scale and/or algal growth will
introduce significant quantities of metals into the effluent from electric gen-
erating plants using once-through cooling systems. The objective of this project
is to estimate the magnitude of metal discharge from the abrasion of condenser
tubes based on weight loss over the service life of the tubes.
Uninhibited biological growth inside condenser tubes leads to serious heat
exchange impairment, excessive tube blockage and accelerated metal corrosion.
These problems result in substantial reduction in power output, the derating of
the plant, and ultimately, the need for makeup electric power.
There are three fundamental approaches to the control of condenser tube
fouling:
Chemical cleaning
. Manual cleaning
On-line mechanical cleaning
All three of these techniques apply to once-through cooling systems; how-
ever, they are used also in closed systems. Condenser tube fouling in closed
cooling systems is generally controlled by continuous use of a biocide. Manual
and mechanical cleaning would be applied during system shutdown for maintenance.
CHEMICAL CLEANING
On-line chemical cleaning involves the use of biocides and corrosion in-
hibitors to maintain clean surfaces. While chlorine is the most commonly used,
*
English rather than metric units are used in this report since this is the
practice within the industry. A list of English to SI conversion factors is
given on page vi of this report.
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other chemicals used include caustic soda, alum, sodium dichromace, sulfuric
acid, calcium hypochlorite, phosphate, and lime. Figure 1 shows the distribu-
tion of chemicals added to once-through cooling water systems as reported in
a Rtudy of Maryland power plants.2
_1 1 1
0 10
1 \J
2
UJ 0
I *
O
B
19
* 7
^H- 6
"3
^~ 5
1°
OL
u. 3
O
?
ID
00 |
2 0
sc
-
-
-
_
_
_
°1, "* '
=> .' :
'; ^
3. ' .
'* ft
° *i
i t' ^
SV.V
*i''
-/;^
..'., 0
l^""'
>J J
"'/' '.
*'.'',°-
VV^°
^
"vii
JVr/
'^IX1'-?
;Vv
' ;J':
«. -
....
' r . ' ' * " °
£ 11 ' c"'^
^ ^ ^ ^ ^ ^vV^
4*V
V f &
Source: Reference 3, page 38.
Figure 1. Distribution of chemicals added to once-through
cooling water systems in Maryland.
Chlor1nation for biocidal control is both a highly effective and less
expensive control method than more complex chemical formulations. Chlorine
usage nationwide for the steam electric utility industry is estimated at an
average of 0.1 ton/year-MW.3
The use of chemicals, and particularly chlorine, is a matter of concern
because either the chemicals themselves or their products of reaction are
highly toxic to the aquatic ecosystem. Chlorine is added to the system at
or near the inlet of the condenser in sufficient quantity to produce a free
available chlorine level of 0.1 to 0.6 mg/1 in the Discharge. The amount
and frequency of chlorine addition is a function of biological growth in the
tubes and of the chemical chlorine demand by ammonia and other chemical species
in the water. The efficacy is reduced when the chlorine is in.a combined state,
such as occurs when chlorine and ammonia react to form chloramines. On the
other hand, discharge of residual free chlorine is discouraged because of the
potential production of highly toxic chlorinated hydrocarbons in the receiving
waters.
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MANUAL CLEANING
Manual cleaning, performed while the condenser is off-line, uses high
pressure water or air combined with various types of plugs, scrapers or
brushes. Off-line chemical cleaning and descaling are also considered manual
approaches.
The main drawback in any manual cleaning system is the requirement that
the unit be shut down during the cleaning process. Utilities, therefore,
have divided their condensers into smaller subunits, allowing only a portion
of the condenser tube system to be removed from service during reduced load
periods, eliminating the need for a complete shutdown.
The manual cleaning process itself tends to be inefficient since the
average cleanliness factor between cleanings is relatively low compared with
the other two methods and because the procedure is highly labor intensive.
As tube cleanliness decreases, condenser backpressure increases, causing the
turbine heat rate to increase and generating capability to decrease. Figure 2
shows this relationship for a 675 MW power plant. Additional detail on the
relationship between condenser cleanliness factors and operating costs is pro-
vided in Section 4.
200
u
o
o
o<
Ul
0«J
x <
a.
100
O
_J LJ
4 (t
J
U
3
GENERATING UNIT- 675 MW
FUEL COST -#0.45 PER l06Btu
CAPACITY COST-$2l.80/kW/YEAR
ANNUAL CAPACITY FACTOR - 66.5%
1
0 60 70 80 90 100
CLEANLINESS FACTOR IN PERCENT
Source: Reference 2, page 277.
Figure 2. Increase in generating costs as tube
cleanliness decreases.
w
The cleanliness factor is widely used in the electric utility industry where
large heat exchangers are used to express the relative (percentage) loss in
heat transfer rate relative to the clean heat transfer rate (100 percent).
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In Che interests of economy, electric utilities have attempted to reduce
tho number of maintenance workers at power plants; however, as the number of
workers has declined, hourly wages have risen to offset any savings. The
number of tubes in the average condenser has also increased. It has been
estimated that in 1963 the average utility condenser contained 10,000 tubes
and that in 1973 the average condenser contained approximately 40,000 tubes.
As larger plants come into service, the number of tubes will continue to
rise.
The work required to clean the tubes manually is difficult, hot, dirty
and wet. Also, because it must be done during periods of reduced demand,
manual cleaning is generally done at night or on weekends. Furthermore, at
nuclear units, workers may be exposed to some slight amount of radioactivity.
Consequently, manual cleaning is not viewed as being particularly desirable
by workers or by management.
ON-LINE MECHANICAL CLEANING
Equipment for automatic on-line mechanical cleaning of condenser tubes is
manufactured primarily by two companies. One, the Amertap Corporation of Mineola,
New York, uses a system for recirculating sponge balls through the condenser
tubes (Figure 3). The other, the M.A.N. Corporation of West Germany, utilizes
a brush and cage system (Figure 4). Each system maintains on-line condenser
tube cleanliness during normal operation of the plant by mechanical abrasion
rather than through a chemical effect. Of the two, Amertap has been the more
popular in the United States. About 200 Amertap on-line cleaning systems are
either in use or on order for utilities in this country.
Amertap Sponge Ball System
The basic principle of the Amertap system is to circulate slightly over-
sized sponge rubber balls with the cooling water through the condenser system.
The balls are forced through the tubes by the pressure differential created
across a ball upon entering a tube. After traveling through the length of the
tubes, the balls are collected in a basket at the discharge end. From the
collection basket the balls are continually pumped to the inlet for recircu-
lation. An schematic diagram of the Amertap system is shown in Figure 3
(see also Appendix A).
The Amertap sponge balls are nearly the same density as the water and,
after being Injected into the cooling water system, distribute themselves
randomly throughout the waterboxes. The number of balls, in the system is
approximately 10 percent of the number of tubes in the condenser, and the sys-
tem is designed so that each ball has a normal circulation time of 20 to 30
seconds. Consequently, each tube is polished approximately every 5 minutes.
The constant rubbing action of the balls cleans the inner walls by wiping
away deposits, scale and biological fouling. Any tube that becomes partially
blocked at the entrance or within its length, however, will not be unblocked
by the balls. Their effectiveness lies in removing soft chemical precipitates,
scale or slimes before they become fixed in place. Since the balls are porous,
a certain amount of water flows through the balls and loosens any accumulated
deposits on the ball surface.
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OUTLET HATER
Ml
COOLING
iTER
OUTLET
STRAINER
SECTION
I
TUUIIE EIBAUST
STEM
1
. CONDENSER
\*' DOME
NATCH FOR INSERTING
OR REMOVING BALLS
}
7
L^
II ATI AM
px
t
$
^, 9AL\. CQLLttIIR6
BASKET
BASKET SHUTOFF
FLAP
PUMP
BALL
COLLECTOR
,INLET HATER
MX
SPONGE RUBBER
BALLS (TYPICAL)
COOL 116 WATER
INLET
Source: Reference 3, page 32.
Figure 3. Schematic arrangement of Amertap tube cleaning system.
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NORMAL ROW PI PING
BACKWASH Fl
OPEN
CLOSED
PING
PIPING
0
SECTION OF
CONDENSER BEING
/
FROM INTAKE '
FROM INIAKL
10 UUTFALL
mm ITT AII ._
/
1
H
'0 ,
'C
' C
(
-j t
}
^h
:
>
/
-c
/
II
I
''c /
^c
:
y*
1
1
/
:
'0
'0
(
-|/
*
f
'f-
>
/»
'0
"
'O
1
/
'C
.
Source: Reference 3, page 34.
Figure 4. Schematic of M.A.N. system reverse flow piping.
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Two types of sponge balls are used In the Amertap system: regular sponge
balls and abrasive-coated sponge balls. The regular balls are used to main-
tain tube cleanliness and are used during normal operation. The abrasive-
coated balls are to be used only when old deposits need to be removed by
scouring, primarily following plant shutdowns.
The M.A.N. Brush and Cage System
The M.A.N. system uses an individual titanium wire brush about 50 mm long
for each condenser tube. The outlet end of each condenser tube is fitted with
a small plastic cage where the brush remains between cleaning cycles. When
the cooling water flow is reversed, all brushes in the condenser are forced
through the tubes to plastic cages at what was formerly the inlet end of the
tube. Returning the cooling water flow to its normal direction forces the
brushes back to their resting position at the outlet end of the condenser
tubes. As with the Amertap system, the rubbing action cleans inner tube walls
by wiping away deposits. A schematic diagram of the reverse flow piping
arrangement of the M.A.N. system is shown in Figure 4.
The plastic cage length is about 75 mm. To attach the plastic cage to
the tube ends, the tube ends have to extend 10 mm beyond the tube sheet.
Therefore, inlet tube ends have to be straight instead of flared as is the
usual practice to avoid inlet end erosion.
To use the system successfully, there must be a capability to reverse the
cooling water flow direction with whatever frequency of reversal is desired.
In practice, valves are timed to cycle through a flow reversal and return at
an assigned frequency. Twice daily is normal. This requirement for the pro-
vision of a routine flow reversal is the major reason for the lack of interest
in the M.A.N. system.
Various metals are expected to be contained in the cooling water discharge,
the species and concentration depending upon inlet water quality, the composi-
tion of the condenser tube alloy and its rate of corrosion or erosion. Highly
polished, clean condenser tube surfaces are less susceptible to corrosion and
erosion than those that are fouled. However, there^remalns some question
whether the maintenance of a highly cleaned surface leads to elevated metal
levels in the cooling water due to abrasion.
PURPOSF: AND ARRANGEMENT OF REPORT
This report reviews what little data are available on the abrasion poten-
tial of the Amertap system and its potential effectson water quality. Numerous
telephone interviews and a letter-questionnaire sent to selected equipment
suppliers and electric utilities using the Amertap system form the basis of our
conclusions since this system is the most widely used in this country. Of 10
questionnaires sent, 6 responses were received from the above sources. Ini-
tially, it was hoped that the utilities would have records detailing Installed
and end-of-service weights for condenser tubes. Apparently this information
is of little use considering the effort required to obtain it. Even in terms
of scrap value, the utility is apparently credited fo-r the initially installed
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weight (if the condenser tube assembly rather than its weight at the time of
removal and replacement. Lacking precise measurements of inlet and outlet
trace element chemistry, the probable discharge levels and rates of wear on
condenser tubes either with or without the Amertap system cannot be estimated
witli any certainty.
In an attempt to determine the extent of any corrosion problem posed by
use of mechanical cleaning systems, a survey was proposed. Power plants that
used mechanical cleaning systems and had, for one reason or another, been
forced to replace their condenser tubes would first be identified, then con-
tacted. These candidate plants were pared down to a reasonable number for a
quick survey to gather information on unit operating histories. Perhaps the
data on which most emphasis was placed were the weights of condenser tubing
at purchase and at removal, the difference in weights indicating the amount
of corrosion.
Unfortunately, the survey had a number of problems conceptually. Deter-
mining the amount of corrosion that had occurred in the mechanically-cleaned
system was, in and of Itself, irrelevant without comparison to some control
condenser subject to identical water quality and flow rates. Certainly some
corrosion would occur in the control; the incremental increase in corrosion
due to the use of an Amertap system as well as the percentage of increase in
corrosion are of interest, not the absolute amount.
In any case, those power plants that had replaced condenser tubes since
putting an Amertap system into operation were identified. A total of 85
plants with 198 separate Amertap systems were contacted; the condenser tubes
at 10 of the Amertap installations had been replaced. These plants are listed
in Table 1.
Clearly, data gathered at some of these plants were not particularly
useful. For Pennsylvania Electric's Seward Plant, Consolidated Edison's
Arthur Kill No. 2, and both Monongahela Power plants, the Amertap system was
in use for only a portion of the time the condenser tubes had been used. It
would be impossible to allocate the corrosion into two categories, that which
occurred before Amertap and that which took place after Amertap; yet, this
would be particularly useful.
Table 2 provides a description of the condenser tubes replaced, charac-
terized by water source and ,by tube material. This distribution can be com-
pared witli Table 4 which describes the distribution of all operating Amertap
systems by the same parameters. Some interesting comparisons are possible.
For example, although only 11 percent of all Amertap systems are used to
clean copper-nickel condenser tubes, 55 percent of the condenser tubes re-
placed after installation of an Amertap system were copper-nickel alloy which
may indicate that on-line mechanical cleaning is inappropriate. Similarly,
although over 50 percent of the Amertap installations clean stainless steel
tubes, no stainless tubes have been replaced after installation of an Amertap
system.
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TABLE 1. POWER PLANTS WHICH HAVE REPLACED CONDENSER TUBES AFTER
INSTALLING AMERTAP SYSTEMS
Company
Ponnnylvaiiia Electric
Consolidated F.d i son
Los Anguluf) Department
of Water and Power
Monongahclu Power
Potomac K lee trie
NarragunBetl Electric
I1 lam
Seward
No. 5
Arthur Kill
No. 2
No. 3
llaynes Station
No. 1
Albright
No. 3
Rivesville
No. 5
Morgantoun
No. 1
No. 2
Manchester St.
South St.
Condenser lube'
Admiralty
Aluminum-bronze
Aluminum-brass
70/30 Copper-nickel
Admiralty
Admiralty
70/30 Copper-nickel
70/30 Copper-nickel
Copper-nickel
Copper-nickel
Yr.-u-H
Of IIBI-*
13W4*
S/U
l*
1
15/4
21/10
5
4
-
Where two figures are given, the first refers to the age of the tubes,
the second to the age of the Amertap system, both at the time of tube
replacement.
TABLE 2. DISTRIBUTION OF REPLACED CONDENSER TUBES BY COOLING WATER SOURCE
AND CONDENSER TUBE MATERIAL (NUMBER OF INSTALLATIONS)
Alloy
Once-tlirough cooling
Recirc-.ulatlon
cooJ Jng
TotaJ hy
condenser
tube
Ocv.ii ii Estu.iry River Lake Cooling Cooling . .
matcri.aJ
pond tower
Steel
Admiralty Kruss
Copper-Nickel
(70/30 & y()/IO)
Aliinilniim Hr:i.ss
'I'11 mi I inn
Arniin lr.nl Copper
Alum I mini
Told I hy ciool Inn
wtiler Huurcr
LI
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However, the sample set. considered is extremely small. Rased on less
than u do/.en locations that have replaced condenser tubes after operating
with the Amertap system, these observations must be considered statistically
insignificant. Other factors, not evident in this cursory review, undoubtedly
contribute to the rate of corrosion. Water quality, operating procedures,
and cli.lor IniiL I.OM practices arc examples of parameters that ran affect r.nr-
roslun to Homu extent. These factors muwt be conw.lde.red before making any
judgment an to the role of the Amertap system In condenser tube corrosion.
TABLE 3. QUESTIONNAIRE RECIPIENTS
. . Response
Recipient . .
r received
Consolidated Edison Yes
Duke Power Company No
Long Island Lighting Company Yes
Los Angeles Department of Water and Power No
Mississippi Power Company No
Monongahela Power Company Yes
Narragansett Electric Company No
Pennsylvania Electric Company Yes
Potomac Electric Power Yes
Tennessee Valley Authority Yes
To develop the data necessary to assess the effects of Amertap operation
on corrosion, a questionnaire was proposed and mailed to 10 companies, listed
In Table 3.
The questionnaire consisted of a request for the following Information
for each unit equipped witli an Amertap system:
.1. The date the turbine went commercial, average load factor,
and MW rating
2. The date the Amertap system was operational
3. The condenser tube material
4. The quantity of cooling water in gal/min, and the linear
velocity of water through the tubes (ft/sec)
5. The range of surface temperatures of the.tubes
6. The frequency of Amertap usage for both sponge rubber
and abrasive balls
10
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7. The type and frequency of other condenser tube cleaning
programs used before or after the mechanical cleaning
system installation
8. A description of chlorination practices including duration,
dosage, and frequency as well as annual chlorine usage for
the year prior to and the year immediately after the instal-
lation of the Araertap system
9. Any analytical data on metals emitted from the cooling
water system
10. Any available data on increased plant efficiency related to
operation of Amertap system
11. Any available water quality data of the intake water
12. The cost of the Amertap system (capital, operating, and
maintenance).
Response to the questionnaire was, at best, mixed: six companies re-
sponded in some form, although the quality and completeness of the responses
varied widely. Companies that did not respond to the data request within a
reasonable length of time were given up to three follow-up phone calls to
request cooperation. In some cases the phone calls were effective in stimu-
lating n reply; in four cases, each of which received the maximum three follow-
up calls over a 2-month period, no reply was ever received. Information ob-
tained from the utilities is presented, in summary form, in Appendix B.
In no case were original tube weights and tube weights on removal avail-
able. An informal telephone survey of New England utilities revealed that
although the sale of scrap metals including corroded condenser tubes is common
practice, the process is not as formalized as had been hoped. Scrap metal
accumulated during normal plant operations is sold for salvage, but no attempt
Is made to differentiate condenser tubing from other metals as, for example,
old chain link fence. When the pile of scrap gets large enough, scrap metal
buyers will be invited to bid. As a rule the utility will hot weigh the scrap
before sale, and utility representatives felt that although the buyer may weigh
his purchase, no attempt is made to categorize the scrap by original use.
Some scrap is sold on the basis of original or estimated weight. These
methods do not expressly consider any effects of corrosion that may have
occurred during use.
11
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SECTION 2
CONCLUSIONS AND RECOMMENDATIONS
A carefully designed study to investigate metal levels in once-through
cooling water discharge has not been undertaken to our knowledge. Based on
our review of the scanty literature available and from the more revealing in-
formation provided by the electric utility industry (1) it appears that cor-
rosion due to abrasion is not a significant problem; moreover (2) there are
Indications that the use of an abrasion system for condenser tube cleaning
ultimately leads to lower releases of metals to the discharge in that the
highly corrosive conditions developing locally with extensive biofouling are
eliminated. This observation is supported in the responses to the question-
naire and letter surveys regarding the exact nature of condenser tube failure.
Local corrosion or pitting occurs at foci of structural weakness, such as at
welded seams or as a result of the localized corrosion cells. The more or less
uniform removal of the metal that would be expected if abrasive sponge balls
do indeed remove metal is not reported.
The operation of electric generating units presents a unique difficulty
In assessing by analytical chemistry the possible significance of metals dis-
charged. The extremely large volumes of water discharged and the very low
concentrations of metal contaminants make it difficult to distinguish pollution
from background. The use of published average metal concentrations for sea-
water is not appropriate for power plants drawing water from estuarine and
surface waters. The true value can be estimated only through repeated sampling
of the water at the intake and discharge.
Analytical techniques, such as neutron activation analysis and atomic
absorption spectroscopy coupled with extractive chemistry, are sufficiently
well developed and sensitive enough to detect the metals of interest in the
waste stream. The problem, however, is one of interpreting the analysis with
respect to metals due to natural levels in the water feed and that added from
mechanical abrasion. The natural variability in composition of the intake
water is of the same magnitude as the variation anticipated from abrasion.
In addition, there are other sources of metal discharges from the condenser
tubes due to local corrosion effects which are more a function of chemistry
of metal-water interactions than to effects of mechanical abrasion. Finally,
a basic difficulty in planning a sampling program rests with the necessarily
short sampling times which are inadequate for the characterization of the low
concentrations of metals released over a period of tens of years.
12
-------
Evaluation of the degree of metal removal by the processes discussed above
might also be accomplished through controlled experiments at the bench, or pre-
ferably, at the pilot scale.
13
-------
SECTION 3
CONDENSER TUBE CONSTRUCTION AND ITS FOULING
CONDENSER TUBE MATERIALS
As stated previously, about 67 percent of the currently operating steam
electric plants in this country have once-through cooling systems. The large
surface area required for efficient heat transfer in the condenser is pro-
vided by arrays of tubes, numbering from 5,000 to 50,000 per installation,
7/8 to 1 inch O.D. and from 20 to 60 feet in length. The tubes may be con-
tained in one or as many as six shells, depending on their size and number.
The selection of condenser tube material for a given installation will
depend on the anticipated corrosion potential of the cooling water source and
other conditions of service. Tube materials may be stainless steel (e.g.,
304 or 316), brass alloys (e.g., admiralty brass and aluminum brass), aluminum
bronze, arsenical copper, or 90/10 or 70/30 copper-nickel.
'Hie distribution of condenser tube materials for the 152 Amertap instal-
lations currently reported to be in service is shown in Table 4.
TABLE 4. DISTRIBUTION OF CONDENSER TUBE CONSTRUCTION
MATERIALS AMONG ELECTRIC UTILITIES USING
THE AMERTAP SYSTEM
Alloy Number Percent of total
Stainless Steel
Admiralty Brass
Copper-Nickel (70/30 & 90/10)
Aluminum Brass
Titanium
Arsenical Copper
Arsenical Aluminum
78
33
17.5*
11
7.5*
4
1
51
22
11
7
5
3
1
Total 152 100
One condenser with two different shells.
14
-------
KestricCing the population of Amertap installations to include only
die 85 once-through cooling situations, the distribution becomes (Table 5)
TABLli 5. DISTRIBUTION OF ALLOYS, ONCE-THROUGH SYSTEMS,
AMERTAP-EQUIPPED
Alloy Number Percent of use
Stainless Steels
Admiralty Brass
Copper-Nickel (70/30 & 90/10)
Aluminum Brass
Titanium
Arsenical Copper
Arsenical Aluminum
36
14
12.5*
11
7.5*
3
1
42
16
15
13
9
4
1
Total 85 100
One condenser with two different shells.
The selection of condenser tube material by source of water supply is
given in Table 6. Clustering in this table indicates differences in tube
material selections for saltwater and freshwater supplies.
Stainless Steel
The alJoys of stainless steel in use as condenser tubes are Types 304
and 316. The nominal composition of these two alloys is as follows:
AISI Type 304: 19 percent Chromium, 10 percent Nickel, and
71 percent Iron
AISI Type 316: 17 percent Chromium, 12 percent Nickel,
2-1/2 percent Molybdenum, and 68-1/2 per-
cent Iron.
These alloys exhibit high resistance to corrosion. The stainless steels owe
their unusual corrosion resistance to a condition know as "passivity,"
believed by most investigators to result from the presence of thin films of
oxide on the surface of the metal. Passivity exerts a greater influence on
the resistance of stainless steel to corrosion than on resistance of most
other commonly used metals and alloys. This "passive film," stabilized by
chromium, is considered to be continuous, nonporous, insoluble, and self-
healing. If broken, the film will repair itself when reexposed to a suitable
oxidlng agent. Stainless steels are best employed under fully aerated
(oxidizing) conditions so as to favor the passive state. In addition, the
15
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TABLE 6. CONDENSER TUBE MATERIALS FOR ALL ELECTRIC UTILITY UNITS
USING THE A>ERTAP SYSTEM
Manmade lake _ - . Total
Ocean Estuarv River Lake or ° by condenser
i - j tower ' , . n
cooling pond tube material
Stainless Steel 1 33 2 8 34
Admiralty Brass 12 2 4 15
Copper Nickel
(70/30 & 90/10) 3.5 7* 2 1 4
Aluminum Brass 7 4 - -
Titanium 0.5 7 - -
Arsenical Copper - - 3 1
Arsenical Aluminum 1 - - -
Total - by cooling
water source 11 20 50 4 13 54
85 67
78
33
17.5
11
7.5
4
1
152
Includes one unit on ship channel.
Source: Amertap Corporation (Appendix A)
-------
alloy surface should always be kept clean and free of surface contamination.
Otherwise differential aeration or concentration cells are set up which cause
pitting and localized rusting.
A.n typos of Htfii.n.lus.s steel are likely to pit or groove in seawater.
Tliu Hl.nl ill i!sn nl.loyH aw n f.ruup art- far morn i-uisci-pt I l>k- to loc-./i 1.1/.<>d ;H.I:;ic.k
than tlir. cnpiit'r-bnHu anil nickel-base alloys. Hi in effect In notlcunblc In l.liu
very limited use of stainless steel condenser tubes in ocean and estuarine
applications. The one estuarine installation listed in Table 6 uses Type 316
stainless steel. The presence of molybdenum in this alloy greatly improves
its resistance to pitting in seawater. In fact, this Amertap installation has
been in service with the same condenser tubes for approximately 11 years.
In all of the Amertap installations with stainless steel condenser tubes
reviewed in this study, there have been no tube replacements or any other
indication that the use of a mechanical cleaning system on stainless steel
condenser tubes increases the potential for metal removal from the tubes.
On the contrary, since stainless steel is highly susceptible to attack under
anoxic conditions where oxygen cannot reach the surface of the metal, the use
of an Amertap cleaning system should reduce the potential for corrosion with
the attendant release of corrosion products. Recommendations to insure satis*-
factory service life stress the surface condition required of the steel. Smooth
surfaces, which are free from defects, all traces of scale, and other foreign
material reduce the probability of corrosion. Generally, a highly polished
surface has greater resistance to corrosion.
Brasses and Bronzes
Brasses are all basically binary alloys of copper and zinc; however,
ternary, quaternary and higher systems containing lead and other elements
have been developed for specific purposes. Admiralty brass, for example,
has excellent corrosion-resistant properties and is widely used for condenser
tubing where fresh, brackish, or acid mine waters serve as water sources.5
CONDENSER TUBE FOULING
The probability and nature of condenser tube fouling is, in part, a
function of quality of the feed cooling water. High total suspended solids (TSS)
will, lead to pitting and erosion of individual tubes. This action is seldom
uniform along the length of a tube but concentrates at points of higher velocity
due to constrictions or irregularities. This type of failure is seen at the
point of welding of the tube to the'tube sheet.
The general nature of chemical attack by dissolved species in sea and
brnr.kish water has been described elsewhere.6 Estimation of concentrations .
of chemical species from published values is not sufficiently accurate for the
purposes here, however. The concentrations, and particularly concentration
ratios, of major chemical species in seawater are remarkably constant. Dilution
effects hecau.se of mixing with freshwater in estuaries and along the coast gen-
eral.) y require, at least, that a salinity measurement be made to reference the
value obtained with Standard Sea Water. A single source of analytical data7
gave n value of 20 ppb for copper with the datum taken from literature values.
17
-------
SECTION 4
ECONOMICS OF CONTINUAL MECHANICAL CLEANING
Condenser tubes and other pieces of heat exchange equipment operate more
efficiently and more economically when kept clean. Biofouling, scale-formation,.
and corrosion are impediments to heat transfer; consequently, an improperly
maintained condenser tube will be unable to effect the transfer of as much
heat as a clean tube. To effect the same heat transfer in an unclean tube, the
temperature difference between the fluid in the tube and that outside the tube
must Increase. As tube cleanliness decreases, condenser pressure increases
causing the turbine heat rate to increase and generating capability to decrease.
Correcting these process inefficiencies can have considerable associated
benefits.
However, the benefits arising from enhanced operating efficiency are not
attained without cost since all methods of condenser cleaning have some asso-
ciated expense. For each, there is a cleanliness factor at which the costs
of cleaning are offset by the benefits of enhanced heat transfer. The clean-
liness factor serves as an adjustment to the overall heat transfer coefficient
in thermodynamic computations, correcting for impediments to heat transfer
under actual conditions.
If cleaning operations are costly, the cleanliness factor will be allowed
to deteriorate significantly before cleaning. Conversely, if the operation
is relatively inexpensive, tube cleanliness will be permitted to decline only
slightly before cleaning begins. Conceptually, once installed, the Amertap
system is so inexpensive to operate that it is allowed to clean continually
to prevent even the slightest degradation.
One evaluation technique for reviewing the performance benefits of an
Amertap system is to compare the capital, operating and maintenance costs with
the savings attributable to the increased cleanliness factor of the condenser
tubes.
The projected economics for this type of analysis were performed by
Southern Services, Incorporated for Alabama Power's new 818 MW Miller steam
electric generating station, Unit I.8
Capital costs for the Amertap system were annualized using a 15 percent
capitalization factor, consistent with the assumption of a 30-year plant life
and Alabama Power's costs of capital at the time of the computation. Operat-
ing costs were estimated based on an average plant load factor of 58 percent.
18
-------
No maintenance labor costs were attributed to the Amertap system since
no additional workers would be required if an Amertap were installed instead
of a conventional cleaning apparatus.
Annual costs were estimated as follows:
1. Installed cost $150,000
2. Cost of additional power to compensate
for increased pressure drop by strainers
required to keep debris out of the
condenser 44,000
3. Cost of additional power to pump
recirculating balls 18,000
4. Cost of replacement balls 63,000
Total annual cost $275,000
The benefits attributable to the operation of the Amertap system are
derived from the assumption that the tube cleanliness factor will be maintained
at 92.5 percent relative to the industry standard of 85 percent. This 7.5 per-
cent increase in cleanliness can be considered conservative since 85 percent
cleanliness cannot be relied upon in uncleaned tubes.
The analysis performed by Southern Services applied this improved clean-
liness to determine the extent to which heat transfer characteristics were
Improved and to estimate the reduction in turbine back pressure. This resulted
in a projected annual heat rate savings of $369,060 and a capacity savings of
$62,000, equivalent to an annual capacity saving of $9,300, so that the projected
total annual savings is $378,360. Subtracting the projected costs from the es-
timated benefits yielded an annual net savings of $103,360. Any increases in the
real dollar cost of fuel will translate directly to increased savings.
This incremental analysis considers the.worst case. The increase in
cleanliness is clue to the use of the Amertap system. Consequently, any heat
rate savings should be credited to the mechanical cleaning system. However,
costs atributable to the Amertap system in this analysis should include only
incremental costs to be incurred over and above the costs of conventional
cleaning since those dollars would have to be expended merely to maintain
an 85 percent cleanliness factor. Thus, a more detailed analysis of all cost
elements would be expected to show a lower Amertap cost and a higher net
saving. Most industry analyses of changes to operating systems are performed
in this manner. Sunk costs or costs of existing procedures are neglected and
only those costs or benefits occurring at the margin are considered.
Florida Power and Light Company9 estimates that it is saving approximately
$2 million annually at Turkey Point nuclear plant Unit 3 with an Amertap system.
Unlike earlier studies which tended to be somewhat cavalier and hazy about re-
sults, rising fuel costs have caused greater emphasis to be placed on fuel sav-
ing based on a careful recordkeeping in recent years. As a result, much of the
19
-------
data reported l>y Florida I'ower and Light are hard claLa, ratlier than estimates
or approximations.
The performance of Unit 3 was monitored closely in 1977 and 1978. Actual
turbine backpressures were recorded for comparison with the backpressures
which would be expected for given inlet temperatures and pressures with a
clean condenser. A loss of efficiency due to dirty condenser tubes shows up
when the actual backpressure is higher than expected. During 1977, the
condensers' loss in efficiency and consequent increase in heat rate caused
average losses in unit output equivalent to $2.4 million. Similar calcula-
tions for 1978 with a continuous cleaning system installed showed a loss in
MUh cost of only $455,000. Thus, the Amertap system saved approximately
$2 million dollars, less the capital and operating costs of the system itself.
Unit 4 at Turkey Point is essentially identical to Unit 3 and operates
subject to the same conditions. In March 1978 both units' condensers were
cleaned; Unit 3 was equipped with an Amertap system and Unit 4 was not. Data
gathered from March through July showed annualized savings in Unit 3 of
$2,061,000 attributable to increased condenser efficiency. Again, the capital
and operating costs of the system must be subtracted from the savings to ob-
tain the net benefit attributable to the use of the Amertap system.
An additional analysis of Amertap condenser cleaning systems was per-
formed by Duke Power Company and was published in June 1978.10 This analysis
considered fuel savings and increased station capacity due to improved heat
rejection capability of the surface condensers, greater heat rejection being
reflected in lower turbine backpressure.
Duke Power's first automatic cleaning system was installed in the Marshall
Unit No. 1 condenser late in 1966. The 350 MW coal-fired unit had been
operating for about a year before the system was added. Within 3 weeks, the
absolute backpressure dropped by 0.2 in. Hg, improving the unit heat rate by
approximately 0.24 percent. Early in 1967, Marshall personnel circulated
abrasive-coated rubber balls through the condenser to remove the more stubborn
deposits that had accumulated on tube walls prior to installation of the clean-
Ing system. Circulation of the abrasive balls for 18 days improved condenser
performance still further, lowering backpressure to 0.6 in. Hg absolute. Sys-
tem performance convinced Duke Power to retrofit a similar cleaning system on
the 350 MW Marshall Unit No. 2's condenser in July.1968, and also to equip the
671 MW Marshall Unit Nos. 3 and 4's condensers with them. The total fuel
savings attributed to operation of the Marshall cleaning systems through 1975
is more than $700,000 based on an estimate of a 0.15 percent heat rate improve-
ment and actual fuel costs for the period.
In addition to saving fuel, improved turbine performance means increased
station capacity. From 1970, the first year all four units were equipped with
automatic condenser cleaning systems, through 1975, Marshall station's gener-
ating capability increased an average of 3 MW on a base plant capacity of
2042 MW.
20
-------
Duke Power performed a more complete economic analysis for the cleaning
Hyutems at Allen station, which has newer equipment than Marshall. Allen 3,
4 ;u«l 5, tsach rntecl at 275 MW, have net unit heat rates of 9613 Btu/kWh at a
backpressure of 1.5 in. Hg absolute. Unit 5 was equipped with an automatic
cleaning system in July 1974 and Unit 3 in March 1975; Unit 4 has no such
system. A comparison of condenser heat transfer rates during the period July
1973 to September 1976 indicated that after manual cleaning performance of
all units improved somewhat, but that the decrease in heat rate was short
lived. In comparison, units with continuous cleaning systems maintained low
heat rates throughout the evaluation period. Duke Power engineers estimated
n 0.67 percent improvement in Unit 5's heat rate and a 0.32 percent increase
in Unit 3's performance. More practically, this meant a reduction in fuel
cost for Unit 5 of $234,300 for the period and for Unit 3 a reduction of
$67,00(1. Since no changes were made in Unit 4's operations, it had no im-
provements in heat rate, no increase in costs and no net savings.
The calculation of the payback period for a mechanical cleaning system
used by Duke Power is as follows:
The first step in calculating the payback period for a mechanical clean-
ing system is to determine the fuel cost saving attributed to the use of that
cleaning system. These are the data required for computations (numbers in
parentheses are 1976 data for Duke Power's Allen Unit 5):
Heat rate (9613 Btu/kWh)
Electricity produced by the unit (1,618,677 MWh)
Power generation cost ($0.01079/kWh)
Improvement in heat rate contributed by continuous
condenser cleaning (0.67 percent)
The total energy input to Allen Unit 5 in 1976, with the condenser clean-
ing system in service, was;15.560990 x 1012 Btu. The heat input that would
have been required if a condenser cleaning system had not been used is:
9613 Btu/kWh i (1 - 0.0067) = 9677.8 Btu/kWh;
(15.560990 x 1012 Btu) x (9677.8 Btu/kWh * 9613 Btu/kWh) =
15.665885 x 1012 Btu
Thus, Lhc fuel-cost saving in 1976 amounted to:
(15.665885 x ]012) - (15.560990 x 1Q12) = 0.104895 x 1012 Btu;
(104,895 x 106 Btu) x ^($O.Ol079/kWh) x 1/0.009613 x io6 Btu/kWh)]
= $117,738
21
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A saving also resulted from the elimination of manual cleaning, estimated
to cost $4908 per year.
From these savings, one can subtract the additional operating costs in-
curred by using the continuous cleaning system, as well as the installed cost
of the system. At Allen Unit 5, the circulating pumps had to overcome an addi-
tional 0.5 ft of head because of the strainer installed in the circulating
water system to catch the cleaning balls after passing through the condenser.
This resulted in a pump loss of 16.94 kW. The two pumps used to recirculate
the cleaning balls from the strainer on the condenser discharge, back to the
suction side of the exchanger required another 7.43 kW. Additional pumping
costs attributed to condenser cleaning were:
(16.94 kW + 7.43 kW) x 7200 hr/yr* x $0.01079/kWh = $1893/yr
The annual cost of replacement cleaning balls, based on 1976 data, was
$3532 per year.
Therefore, in 1976 the total saving attributed to use of the condenser
cleaning system without considering capital and installation costs was:
Fuel - $117,738
Manual cleaning - 4,908
Pump penalty - (1,893)
Replacement cleaning balls - (3,532)
Saving - $117,221
The saving for the period beginning July 1974, when the system was
insta.lled, through 1976 was:
Fuel - $234,300
Manual cleaning - 12,270
Cost of Amertap cleaning
system and debris filter - (112,817)
Cost of installation - (100,000)
Pump penalty - (4,733)
Replacement cleaning balls - (8,830)
Saving - $ 20,190
*
Those unfamiliar with electric power plant operation may assume that this
figure means the plant operated at an 82 percent capacity factor (7200/
8760 = 82 percent). In actuality the plant was available 82 percent of the
time, but operated at reduced load some of that time with a resultant capacity
factor of 67 percent.
22
-------
Thus the equipment paid for itself in less than 2-1/2 years and is now
returning a significant saving. Note, too, that since today's fuel costs are
above 1976 levels the net annual saving exceeds the $117,221 figure calculated.
Another saving that should be considered, though difficult to estimate,
is the elimination of outage time to manually clean condenser tubes. Normally,
2 days would be required for this task at Allen and Marshall. Even if cleaning
during peak generating periods is avoided, the unit load loss - 13.2 million
kWh - and startup costs can run as high as $9800. '
It is difficult to determine how much of this should be allocated to manual
cleaning of condenser tubes, since other necessary maintenance activities are
usually performed simultaneously. However, without the requirement for condenser
tube cleaning it would be possible to schedule these shutdowns less frequently.
One more economic advantage of continuous cleaning is the extension of
operating life for many types of surface condensers. Operating data indicate
that tubes last longer because scale, organic fouling and silting - all of
which can contribute to erosion and corrosion - are eliminated. In addition,
the need for more radical cleaning methods - acids, for example - which also
may limit tube life, are not necessary.
Prior to installation of the continuous cleaning systems at Marshall and
Allen, biological fouling in the form of algal slime was particularly heavy at
certain times of the year. The only way to combat it was to inject substantial
quantities of chlorine into the water. Continuous cleaning has eliminated the
need for this.
Amertap system costs can also be considered in the context of how much
installation and operation will add to consumer charges. Table 7 gives costs
for new and retrofit systems at a small and a large power plant.
TABLE 7. TYPICAL AMERTAP SYSTEM COSTS (IN 1979 DOLLARS)
Plant size Installation
100 MW New
Retrofit
1000 MW New
Retrofit
Capital cost
(S/kW)
1.60
1.98
0.77
0.95
Operating
cost
(mills/kWh)
0.029
0.029
0.013
0.013
*
Total cost
(mills/kWh)
0.082
0.095
0.038
0.044
*
t. » i .. capital cost x capital recovery factor
Total cost = ' : c r * + operating cost
annual operating hours v B
A capital recovery factor of 15.94 percent was used, consistent with
a 15.85 percent cost of capital and a 35-year unit life. A capacity
factor of 55 percent was also assumed.
SOURCE: Reference 1, p. IV-21 and IV-23.
23
-------
rt.-portL'tl Ln Tali I e 7 ilo not consider any anv.I.ng.s which would occur
from reduced chlorine consumption or Crom omitting manual tube cleaning.
Chlorination and cleaning practices vary widely from plant to plant, depend-
ing predominantly upon water quality.
Tlie effects of Amertap installation and operation on the cost of elec-
tricity produced at eight typical generating stations are shown in Table 8.
In no case are costs Increased by more than 0.5 percent, but even these small
increases present a conservative worst case. In addition to savings from
reduced chlorine consumption and termination of manual tube cleaning, the
Amertap system is expected to maintain condenser tube cleanliness at a con-
sistently high level, contributing to minimizing turbine heat rates and
maximizing generating capability.
TABLE 8. EFFECT OF AMERTAP SYSTEM ON ELECTRICITY COSTS
Plant size
100 MW
1000 MW
Fuel
type
Coal
Oil
Coal
Oil
Nuclear
Installation
New
Retrofit
Retrofit
New
Retrofit
Retrofit
New
Retrofit
Baseline cost
of electricity
(mills/kWh)
31.8
22.0
39.6
30.4
20.6
35.8
28.0
19.4
Amertap system
cost
(mills/kWh)
0.08
0.10
0.08
0.04
0.04
0.04
0.04
0.04
Increase due
to Amertap
system
(percent)
0.3
0.5
0.2
0.1
0.2
0.1
0.1
0.2
SOURCE: Reference 1, p. IV-13, IV-14 and Table 1.
Any utility's decision to install or not install a mechanical cleaning
system is predicated upon more than technical feasibility and operating eco-
nomics. That decision takes place within a regulatory climate created by the
various regulatory authorities which differ from state to state. All utili-
ties have an allowed rate of return set by a regulatory agency; that allowed
rate of return may be insufficient, excessive or equitable. Should the
allowed rate of return be insufficient, companies will avoid investing in
capital such as mechanical cleaning systems, choosing instead to incur higher
operating costs, in this case for chlorine or manual cleaning, because these
costs can be passed through to the consumer directly. Conversely, if an ex-
cessive rate of return is permitted, the firm will maximize its capital in-
vestment. With an equitable rate of return, regulatory distortions are re-
moved, and decisions can be made on purely technical and economic grounds.
24
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REFERENCES
1. Temple, Barker and Sloane. Economic Analysis for the Revision of Steam-
Electric Utility Industry Effluent Limitation Guidelines, (Draft) EPA.
April 1979.
2. Development Document for Effluent Limitation Guidelines and New Source
Performance Standards for the Steam Electric Power Generating Point
Source Category, U.S. Environmental Protection Agency, EPA-440-l-74-029a.
October 1974, p. 287.
3. Yu, H.H.S., G.A. Richardson, and W.H. Hedley. Alternatives to Chlorination
for Control of Condenser Tube Biofouling. U.S. Environmental Protection
Agency, EPA-600/7-77-030, March 1977, p. 38.
4. Weg Scheider, J. J. Cleaning Heat Exchange Tubing in Industry With the
Automatic On-Load Tube Brushing System. Cleaning Stainless Steel ASTM
STP 538, American Society for Testing and Materials, 1973. p. 211.
5. Uhlige, H. H. The Corrosion Handbook. John Wiley & Sons, Inc.
New York, 1948.
6. Uhlige, H. H. Corrosion and Corrosion Control. John Wiley & Sons, Inc.
New York, 1963.
7. Long Island Lighting Company. Internal Report, September 1970.
8. Southern Services, Incorporated. Internal Report by D. Stinson, 1974.
9. O'Neil, G. W., Jr., C. J. Baker, and P. J. Harding. On-Line Tube
Cleaner Saves $2 million/yr. Electrical World, V. 192, No. 1,
July 1, 1979.
10. Holland, T. E., and P. J. Harding. Help Maintain High Efficiency by
Cleaning Steam Condensers Continuously, On-Line. Power. V. 122, No. 6,
June .1978.
25
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APPENDIX A
AMERTAP
CONDENSER TUBE CLEANING SYSTEMS IN THE UNITED STATES
Source: Amertap Corporation. Amertap Reference List.
Woodbury, New York.
Reproduced with permission of Amertap Corporation.
26
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COMPANY
Alabama Power
Company
Allnuheny Pownt
System
Allied Chemical Corp.
Arkansas Puwui
ft Light Compnny
Baltimore Gnr. It
Eloclrii: Co.
Browiisvilln Public
Utility Homcl
Calgnry Power Corp.
Cnmlinii Power 6
Light Co.
Control Maim:
Puwor Coniin.
STATION
Barry
Gaston
Farley
(Nucleml
Gorges
Miller
Fort Martin
Harrison
Hatfield's
Ferry
Pleasants
Hopewell, Va.
Arkansns
Nuclear Ono
White BluHs
Indopondonce
Calvnrt Cliffs
(Nucloail
SiRay
Sundance
L.V. Sutton
Mainu Yankee
Atomic
C.W. SOURCE
Mobile River-
Cooling Tower
Makeup:
Coosa Rivur
Cooling Tower
Maknup:
Chatlahoochie
River
Warrior River
Cooling Tower
Makeup:
Black Warrior
River
Cooling Tower
Makeup:
Monongahela
River
Cooling Tower
Makeup:
River Water
Monongahela
River
Cooling Tower
Makeup:
River Water
Cooling Tower
Makeup:
Ohio River
Cooling Tower
Cooling Tower
Makeup:
Dardanelle
Reservoir
Cooling Tower
Makeup:
Arkansas River
Cooling Tower
Makeup:
White River
Chesapeake Bay
Cooling Pond
Makeup:
Rio Grande
Cooling Pond
Freshwater Lake
Seawater
TURBINE
NO. MW
5 712
5 900
5- Heat Exch
1 860
2 860
10 712
1 660
2 660
3 660
4 660
1 500
1 - Heat Exch
2 500
2 -Heat Exch
1 650
1 Heat Exch
2 650
2 -Heat Exch
3 650
3 -Heat Exch
1 540
2 540
3 540
1 600
2 600
Refri. Cond.
2 950
1 700
2 700
700
700
1
2
1 800
2 800
5 22
6 26
2 300
2 110
1 800
TUBE
MATERIAL
.Admiralty
304 SS
. 304 SS
Titanium
Tiliinitmi
304 SS
Admiralty
Admiralty
Admiralty
Admiralty
304 SS
304 SS
304 SS
304 SS
304 SS
304 SS
304 SS
304 SS
304 SS
304 SS
304 SS
304 SS
304 SS
304 SS
304 SS
304 SS
90/10CuNi
90/10CuNi
90/10CuNi
90/10CuNi
90/10CuNi
CuNi
CuNi
Admiralty
Admiralty
304 SS
90/10 CuNi
AL. Brass
CONSULTANT
Southern Services, Inc.
Southern Services. Inc.
Southern Sorvicos. Inc.
Bochtnl Corp.
Southern Serivces, Inc.
Southern Services, Inc.
Burns ft Roe, Inc.
Gibbs& Hill. Inc.
United Engineers ft
Constructors. Inc.
United Engineers ft
Constructors. Inc.
Self
Bechtel Corp.
C.T. Main
C.T. Main
Bechtel Corp.
Self
Montreal Engineering
Self
Self
ORDER
YEAR
69
71
72
75
75
69
75
75
75
75
65
65
65
65
70
70
70
70
70
70
67
67
68
74
74
77
73
74
74
69
69
75
75
77
74
76
27
-------
COMPANY
Central Plants, Inc.
Central Power 6
' Light Company
Cleveland Electric
Illuminating Co.
Colorado Springs
City of
Commonwealth
Edison Company
Conornaugh Project
Consolidated
Edison Co.. N.Y.
Consumer's Power
Company
Dairyland Power
Cooperative)
STATION
Bunker Hill
Cnnlury City
Davis
Joslin
Nueces Bay
Perry
(Nuclear)
R.D. Nixon
Braidwood
(Nuclear)
Byron
(Nuclear)
Collins
LaSalle
(Nuclear)
Zion
(Nuclear!
Conemaugh
Arthur Kill
Campbell
Genoa No. 3
C.W. SOURCE
Cooling Tower
Makeup:
City Water
Cooling Tower
Makeup:
City Water
Corpus Christ!
Bay
Gulf of
Mexico
Nueces Bay
Lake Erie
Cooling Tower
Cooling Lake
Makeup:
Kankakee River
Cooling Tower
Makeup:
Rock River
Man-made Lake
Makeup:
Illinois River
Man-made Lake
Lake Michigan
Cooling Tower
Makeup:
Conemaugh River
Newark Bay
Lake Michigan
Mississippi River
TURBINE
NO. MW
Freon
Condenser
Freon
Condenser
Turbine
Slii.'iin Corul.
liiiliiiiii
Slii.'iin (lonil.
l-'ruon
Condenser
1 355
1-HeatExch
2 355
2- Heat Exch
1 240
1 - Heat Exch
6-HeatExch
7 320
7- Heat Exch
1- Main 1200
2- Main 1200
1-Aux
2-Aux
1 200
1 1120
2 1120
1 1120
2 1120
1 500
2 500
3 500
4 500
5 500
1 1100
2 1100
1 1100
2 1100
1 900
1- Heat Exch
2 900
2 -Heat Exch
2 335
3 500
3 800
1 300
1- Heat Exch
TUBE
MATERIAL
Copper
Copper
Coppur
('ll|)|ll!l
Copper
Alu-Brass
Alu- Brass
Titanium
Titanium
Alu-Brass
Alu-Brass
316 SS
Alu-Brass
Alu-Brass
304 SS
304 SS
304 SS
304 SS
316 SS
304 SS
304 SS
304 SS
304 SS
304 SS
304 SS
304 SS
304 SS
304 SS
304 SS
304 SS
304 SS
304 SS
304 SS
304 SS
304 SS
304 SS
Alu-Brass
Titanium
304 SS
304 SS
304 SS
CONSULTANT
Self
Self
Sargent & Lundy
Engineers
Sargent & Lundy
Engineers
Sargent ft Lundy
Engineers
Gilbert Assoc. Inc.
Lutz. Daily & Brain
Sargent ft Lundy
Engineers
Sargent ft Lundy
Engineers
Sargent ft Lundy
Engineers
Sargent & Lundy
Engineers
Sargent & Lundy
Engineers
Gilbert Associates. Inc.
Self
Gilbert Commwlth.
Burns ft Roe. Inc.
ORDER
YEAR
73
70
70
, "'
73
71
71
73
73
69
69
67
70
70
74
74
74
74
75
74
74
74
74
74
74
74
73
73
69
69
68
68
68
68
66
67
J
76
66
66
28
-------
COMPANY
Dayton Puwnr 6
Light Company
Delmerva Power 0
Light Company
. Duke Powor
Company
Duqiirisno l.i(jlit Co.
E.I. duPont
det Nomours & Co.
East Kentucky Runil
Cooperative
Florida Power
& Light Co.
General Foods
Corporation
STATION
Killen
Stuart
Edge Moor
Allen
Belews Crook
Catnwba
Cherokee
Marshall
McGuire
(Nuclear)
Oconee
(Nuclear)
Perkins
Bcovor
Vnllov
Beaumont Works
Spuilock
Turkey Point
(Nuclear!
Hoboken
Plant
Houston
Plant
C.W. SOURCE
Cooling Tower
Makeup:
Ohio River
Ohio River
Cooling Tower
Mnknup:
Ohio Rivnr
Delaware River
Catawba River
Bnlews Creek
Lake
Cooling Tower
Makeup:
Catawba River
Tower
Lake Norman
Lake Norman
Lake Keowee
Freshwater
Cooling Towct
Makeup:
Ohio River
Cooling Tower
Makeup:
Freshwater
Cooling Tower
Makeup:
Ohio Rivet
Biscaync Bay
Cooling Canal
Cooling Tower
Cooling Tower
TURBINE
NO. MW
1 600
2 600
1 600
2 600
3 600
4 600
4 162
5 410
3 75
3 300
5 275
1 1100
2 1100
1 1150
1-Aux.
2 1150
2-Aux.
1 1300
2 1300
3 1300
1 350
2 350
3 671
4 671
1 1150
1-BFPCond.
2 1150
2-BFPCond. .
1 900
2 900
1 1300
2 1300
3 1300
2 880
Process
Steam Cond
Process
Heat Exch
Process
Heat Exch
3500 Ton
Refrigeration
Condenser
2 500
3 740
4 740
Process
Heat Exch
Process
Heat Exch
Process
Heat Exch
Process
Heat Exch
TUBE
MATERIAL
90/10 CuNi
90/10 CuNi
Ars. Cu
Ars. Cu.
Ars. Cu.
Ars. Cu.
Ars. Admir
Admiralty
Admiralty
Admiralty
Admiralty
304 SS
304 SS
304 SS
304 SS
304 SS
304 SS
304 SS
304 SS
304 SS
Admiralty
Admiralty
304 SS
304 SS
304 SS
304 SS
304 SS
304 SS
304 SS
304 SS
304 SS
304 SS
304 SS
304 SS
90/10 CuNi
304 SS
90/10 CuNi
90/10 CuNi
304 SS
A
Alu- Brass
Alu-Brass
'Copper
Copper
Copper
Copper
CONSULTANT
Ebasco Services, Inc.
Ebasco Services. Inc.
Ebasco Services. Inc.
United Engineers ft
Constructors
Bechtel Corp.
Self
Self
Self
Self
Self
Self
Self
Self
Self
Self
Self
Self
Self
Stone ft Webster
Boston
Self
Self
Self
Stanley
Bechtel Corp.
Lewis Refrigeration
Self
Lewis Refrigeration
Self
ORDER
YEAR
76
76
66
66
68
71
64
71
78
73
72
70
70
74
78
66
67
67
67
71
73
71
73
68
68
78
78
70
72
73
74
76
75
75
71
75
69
75
29
-------
COMPANY
Goorgio Pownr Co,
Hoorner Waldorf Co.
Homor City
Project
Hoosier Energy
Houston Lighting Et
Power Co.
(own SnulNHrn
Utilities
Jersey Cunirul
Power Ei Light Co.
Knnsns Power ft
Light Company
Koystorii)
Project
Lony Island
Lighting Cninp;iny
I.OB AnuHlus Diipl.
of Wiitfir ft Powm
Mnlmpolilfin
Etlisiin Cnmpony
Mississippi
F'owni Compmiy
STATION
Central Georgin
Hutch
(Niicliiflf)
Plum
Scherer
Wansloy
Ystes
St. Paul
Homor City
Morom
Doopwater
Ottuinwn
Throii-Mile
Island
(Nuclear)
Jeffrey Energy
Contor
Keystone
Bnrrutl
Glnnwood
Hiiynns
Ttiini.'-Mile
Island
(Nuclear)
Plum O.-iniol
Jiic:k Wttlson
C.W. SOURCE
Cooling Tower
Makeup:
River Water
Cooling Tower
Makeup:
AIIHtiuili Hivni
Ocniulgon Rivor
Rum Creek
Cooling Tower
Makeup:
River Water
Cooling Tower
Makeup:
Chatahoochee
River
Wells
Cooling Tower
Makeup:
Yellow Creek
Lake
Houston Ship
Channel
Cooling Tower
Makeup:
Des Moinus River
Cooling Tower
Makeup:
Susquehanna River
Cooling Tower
Makeup:
Wells
Cooling Tower
Makeup:
Plum-Creek
Broad Channel
Long Island Sound
Seal Beach Bay
Cooling Tower
Makeup:
Susquehanna River
Lake
Cooling Tower
Makeup:
Biloxi Rivor
TURB
NO.
1
2
1
14
1
2
6
7
1
1
2
1
2
7
1
1- Aux.
2
1
2
1
2
1
2
4
5
1
2
3
4
1
1
2
5
INE
MW
900
900
800
818
900
900
350
350
5
663
663
490
490
190
675
800.
680
680
900
900
175
175
100
100
230
230
230
230
840
500
500
553
TUBE
MATERIAL
304 SS
304 SS
Admiralty
90/10CuN
304 SS
304 SS
Admiralty
Admiralty
304 SS
304 SS
304 SS
90/10
90/10
CuNi
90/10
CuNi
304 SS
304 SS
304 SS
304 SS
Alu-Brass
Alu- Brass
Alu-Brass
1 Alu-Brass
70/30 CuNi
Alu-Brass
70/30 CuNi
70/30 CuNi
304 SS
Admiralty
Admiralty
90/10 CuNi
(
CONSULTANT
Southern Services, Inc.
Southern Snrvicns, Inc.
Soil
Southern oervices. Inc.
Jackson 8 Moreland
Self
Gilbert Associates. Inc.
United Engineers &
Constructors, Inc.
Self
Black Et Veatch
Burns Et Roe. Inc.
Black Et Veatch
Gilbert Associates, Inc.
Self
Self
Self
Gilbert Associates, Inc.
Southern Services, Inc.
Southern Services, Inc.
JRDER
YEAR
74
74
70
II
73
73
71
71
77
67
67
77
66
77
69
76
65
65
64
64
57
60
60
60
75
75
68
73
73
76
30
-------
COMPANY
Monongahela
Power Co.
Narragansett
Electric Company
New Brunswick
Electric Power
Commission
Newfoundland ft
Labrador Hydro
Northeast
Utilities
Northern
Petrochemical
Company
Northern States
Power Company
Ohio Edison
Company
Ontario Hydro
Pennsylvania
Electric Company
Pennsylvania Electric
and N.Y. State Elec.
6 Gas
STATION
Albright
Rlvesville
Willow Island
Manchester St.
South Street
Coleson Cove
Holyrood
Millstone
(Nuclear)
Morris
Ethylene
Plant
King
Prairie Island
(Nuclear)
Sherburne
Niles
Sammis
Bruco
(Nuclear)
Nanticoke
Thunder Bay
Seward
Shawville
Homer City
C.W. SOURCE
Cheat River
Monongahela
River
Ohio River
Narragansett Bay
Providence River
Bay of Fundy
Conception Bay
Long Island Sound
Cooling Tower
Makeup:
Wells
St. Croix River
Mississippi River
Cooling Tower
Makeup:
Mississippi River
Mahoning River
Ohio River
Lake Huron
Lake Erie
Mission River
Conemaugh River
W. Branch
Susquehanna River
Cooling Tower
Makeup:
Blacklick Creek
TURBINE
NO. MW
3 125
5 51
6 95
2 165
9 40
10 40
11 40
1 47
7 47
1 300
2 300
3 300
3 150
3 1200
1-HeatExch
2-HeatExch
1 610
1 560
2 560
1 680
1-HeatExch
2 680
2-HeatExch
1 125
2 125
5 350
6 600
7 625
5 800
6 800
7 800
8 800
2 500
2 150
3 150
5 150
1 "125
2 125
3 165
4 165
3 -Main 600
3-Aux 600
TUBE
MATERIAL
304 SS
304 SS
304 SS
Admiralty
90/10CuNi
90/10CuNi
90/10CuNi
304 SS
CuNi
Yarcalbro
Alu-Brass
Alu-Brass
70/30 CuNi
Inh. Admir.
Inh. Admir.
304 SS
304 SS
304 SS
304 SS
304 SS .
' 304 SS
304 SS
Ars. Admir.
Ars. Admir.
Ars. Admir.
Ars. Admir.
Admir.
304 SS
304 SS
304 SS
304 SS
Admir.
304 SS
304 SS
304 SS
304 SS
304 SS
304 SS
304 SS
304 SS
ORDER
CONSULTANT YEAR
Self
Self
Self
Self
Self
Self
Montreal Engineering
Stone 6 Webster, Inc.
Self
Pioneer Service ft
Engineering .
Pioneer Service 6
Engineering
Black frVeatch
Self
Commonwealth
Associates, Inc.
Self
Self
Self
Self
Self
London/ Monenco
London/ Monenco
Self
Self
Ebasco Services, Inc.
65
65
63
67
64
64
64
62
62
73
77
74
75
75
65
68
68
72
72
72
72
64
64
66
66
69
77
77
77
77
70
77
77
64
62
62
62
61
74
74
31
-------
COMPANY
Pennsylvania Power
6 Light Co.
Phillips Petroleum
Potomac Electric
Powor Company
Public San/ice
of Oklahoma
Salt Rivoi Project
South Carolina
Electric ft Gas Co.
Southern Calif.
Edison Co.
Southwestern
Public Sorvico Co.
STATION
Montour
Susquehanna
(Nuclear)
Borger, TX
Refinery
Chalk Point
Morgantown
Comanche
Navajo
Summer
(Nuclear)
Wateree
Williams
Cootwater
Mohave
San Onofre
(Nuclear)
Harrington
Jones
Nichols
C.W. SOURCE
Cooling Tower
Makeup:
N. Branch
Susquehanna River
Cooling Tower
Makeup:
Susquehanna River
Tower. Well
Water Makeup
Patuxent River
Cooling Tower
Makeup:
Patuxent River
Potomac River
Cooling Lake
Makeup:
Treated Sewage
Water
Lake Powell
Lake
Wateree River
Cooper River
Cooling Tower
Makeup: Wells
Cooling Tower
Makeup:
Colorado River
Pacific
Ocean
Cooling Tower
Makeup:
Treated Sewage
Water
Tower/Treated
Sewage Makeup
Cooling Tower
Makeup:
Treated Sewage
Water
Cooling Tower
Makeup:
Treated Sewage
Water
TURBINE
NO. MW
1 814
2 814
1 1120
2 1120
1 12
1 330
2 330
3 600
4 600
1 625
2 625
1 120
1 750
1 900
1-Aux.
1 375
2 375
1 600
1 - Heat Exch
3 236
4 236
1 775
2 775
1 450
2 1140
3 1140
1 343
1 - Heat Exch
2 318
2 -Heat Exch
3 350
1 250
1- Heat Exch
2 250
2 -Heat Exch
1 100
2 100 .
3 250
3 Heat Exch
TUBE
MATERIAL
304 : SS
304 SS
304 SS
304 SS
Admiralty
70/30 CuNi
70/30 CuNi
70/30 CuNi
70/30 CuNi
70/30 CuNi
70/30 CuNi
Admiralty
Are. Cu.
304 SS
304 SS
304 SS
304 SS
304 SS
304 SS
90/10 CuNi
90/10 CuNi
Admiralty
CuNi/Titanium
Titanium
Titanium
316 SS
Admiralty
316 SS
316 SS
316 SS
316 SS
Admiralty
316 SS
Admiralty
Admiralty
Admiralty
316 SS
Admiralty
CONSULTANT
Ebasco Services. Inc.
Bechtel Corp.
Self
Self
United Engineers &
Constructors
Bechtel Corp.
Burns & Roe, Inc.
Bechtel Corp.
Gilbert Assoc., Inc.
Gilbert Assoc.. Inc.
Gilbert Assoc., Inc.
R.M. Parsons
Bechtel Corp.
Self
Bechtel Corp.
Self
Self
Self
Self
ORDER
YEAR
69
70
73
73
77
73
73
72
72
69
69
72
76
73
73
67
68
70
70
74
74
75
73
73
73
74
75
75
77
'68
69
71
71
71
71
66
74
32
-------
COMPANY
Tonnessoe Valley
Authority
Toxnco. Inc.
Union Carbide Corp.
(LindeOiv.)
United Illuminating
Company
U.S. Steel Co.
Virginia Eloctric
Power Co.
Wast Pcnn POWHI
Ciimpnny
Yniiiujstown Shoot &
Tuho Company
STATION
Bellefonte
Brown's Ferry
(Nuclear)
Mnilsvillo
Phipps Bend
Soquoyah
(Nuclear)
Watts Bar
(Nuclear)
Widow's Creek
Port Arthur
Refinery
Tulsn Rofinery
Duquesne
English
Southworks
Chicago
Mount Storm
North Anna
(Nuclear)
Surry
(Nuclear)
Mitchell
Campbell
C.W. SOURCE
Tower
M/U Tenn. River
Cooling Tower
Makeup: .
Wheeler
Reservoir
Cooling Towci
M/U Ciimhiirliind
Tower, M/U
Holston River
Chickamauga
Reservoir
Tennessee River
Guntersville
Lake
Cooling Tower
Makeup:
Neches River
Cooling Tower
Monongahela
River
Mill River
Lake Michigan
Cooling Pond
North Anna
River
James River
Monongahela
River
Mahoning River
TURBINE
NO. MW
1 1213
2 1213
1 1100
2 1100
3 1100
1.2.3.4 1300
1.2 1300
1 1171
2 1171
1 1218
2 1218
8 500
3 14
Process
Steam Cond
Process
Heat Exch
Process
Meat Exch
Process
Steam Cond
Process
Heat Exch
Process
Heat Exch
1 17
Oxygen Cooler
2 15
3 15
4 15
5 15
7 40
8 40
Air Compressor
Oxygen Compressor
Turbo- Blower
1 565
2 565
3 565
1 892
2 892
3 950
4 950
1 815
2 815
3 250
1 18.5
Turbo Blower
TUBE
MATERIAL
90/10 CuNi
Admiralty
Admiralty
Admiralty
90/10 CuNi
90/10 CuNi
90/10 CuNi
90/10 CuNi
Admiralty
Admiralty
Admiralty
Ars. Admir
Red Brass
Admiralty
Red Brass
Admiralty
Admiralty
Carbon Steel
Admiralty
Admiralty
316 SS
316 SS
316 SS
. 316 SS
316 SS
316 SS
! 304 SS
304 SS
304 SS
304 SS
304 SS
304 SS
304 SS
304 SS
304 SS
304 SS
90/10 CuNi
90/10 CuNi
304 SS
Admiralty
Admiralty
CONSULTANT
Self
Self
Sell
Self
Self
Self
Self
Self
Stone & Webster
Self
Self
Self
Self
Union Carbide
Ingersoll Rand
Stone & Webster
Engineering Corp.
S tone & Webster
Engineering Corp.
Stone & Webster
Engineering Corp.
Self
Self
ORDER
YEAR
76
68
68
68
77
70
70
74
74
66/69
68
70
70
72
73
76
73
64
67
63
64
57
64
63
63
66
66
71
65
65
69
70
70
72
72
67
67
64
68
72
33
-------
APPENDIX B
UTILITY RESPONSES TO INFORMATION REQUEST
1. Sample Information Request
2. Responses
-------
1. SAMPLE INFORMATION REQUEST
The following is a sample information request sent to various power
companies with experience in the operation of Amertap systems. Of particular
interest are those stations which have replaced the condenser tubes since the
mechanical cleaning system was put into effect.
1. The age of the condenser tubing at the time of installation of
the mechanical system and at the time of replacement of the
tubing.
2. The weight of the tubing at the time of purchase and at the
time of replacement.
For all of the units with Amertap systems, we request the
following information:
1. The date the turbine went commercial, average load factor, and
MW rating.
2. The date the Amertap system was operational.
3. The condenser tube material.
4. The quantity of cooling water in gallons per minute, and
the linear velocity of water through the tubes (ft/sec.).
5. The range of surface temperatures of the tubes.
6. The frequency of Amertap usage for both sponge rubber and
abrasive balls.
7. The type and frequency of other condenser tube cleaning
programs used before or after the mechanical cleaning system
installation.
8. A description of chlorination practices including duration,
dosage, and frequency as well as annual chlorine usage for
the year prior to and the year immediately after the
Installation of the Amertap system.
9. Any analytical data on metals emitted from the cooling
water system.
1.0. Any available data on increased plant efficiency related
to operation of Amertap system.
11. Any available water quality data of the intake water.
12. The cost of the Amertap system (capital, operating, and
maintenance).
35
-------
TABLE B-l. UTILITY RESPONSES TO INFORMATION REQUEST ON AMERTAP PERFORMANCE
"ijer.i- Sc. co=n«:iil
""? operation
i 1959
: -969
: 1957
: 1954
2 3 1954
4 1959
i 1960
3 1
1964
2 1965
4 3 1975
'- 1970
5 1971
1 1975
5 2 1974
3 1975
4 1977
Ava . lead ,_.
3k
360
5:5
83.9 137
35.9 121
57.2 123
S7.4 173
38.5 178
IOC
-
-
-
82.9
84.3
66.51 550
5 yr/avg.
78.07 1,098
2 yr/avg.
84.97 1,098
2 yr/avg.
83.78 1.098
1 yr/avg.
Aaertap
operational
1567
1569
1965
196s
-
1965
I960
1975
1975
1975
1970
1971
1970
1974
1975
1977
Condenser
age at t'jte
installation/ aaterial
replaceaent
c yr 'i a.-. Ai-Brunze
!0 yrs Ti
Sev/3 yr Ti
3 yr/13 yr 304SS
Phelps
Dodge
Super lay
(units 2.
3. 4 i 5)
Al-arass
Sew/2 yr Cu-NI
Sew/ 3 yr 70-30
70-30
10 yr 70-30
70-30
New Adnl-
ralty
Cu-Si
SO- 10
Sew Admi-
ral r.y
Cu-Ni
90-10
New Adal-
Cu-Nl
91-10
New Admi-
ralty
Cu-Sl
o-io
cc usate
range
3 nr-da'.ly
continuous
8 hr/day
1 vl./J m>
daiiy-
severai hrs
-
June-Sepc
(co:ic inuous)
-
-
32'F
-
100'F
32JF
90"F
60*F Continu?-js
8 0.5" Amertap
Hg
185'F Continuous
9 17" Hg Amertap
60"F Contl.-.r^us
@ 0.5" Aaertap
Hg
135*F Continuous
Q 5" Hg Aoertap
Type
cf bails
Sponge
rubber
Abrasive
Sponge &
abrasive
20". -
abrasive
801 -
sponge
-
Sponge
ball?
Sponge
balls
Sponge
balls
Sponae
balls
Sponge
balls
Abrasive
balls
Abrasive
balls
Abrasive
balls
Other CMerlution
aethods practices
9CI 100 g-il for
(yearly) :0 nin
Jtechanical "-vilorinej*1
rubber balls
Steel balls I hr/dav
(yearly)
S/A S/A
-
_
_
_
2OOO IDS/
day/unit
(0.2 ag/llter)
Nylon brushes
before
Anertap in-
stalled
every 6 wk
before &
yrs after
Aiaertap
(all units)
Capital
outlay
_
68.000
65,916
190,153
«.:;.
499.900
499.900
318,000
316,000
316,000
65.188
63.188
762.378
762.378
Flan
Telocity
or rate
5.7 ft/sec
5.9 it/sec
6.97 ft /sec
99.600 gaa
6.99 it/sec
68.000 ipn
6.57 ft /sec
37.000 gpo
7 ft/sec
7 ft/sec
7 ft/sec
7 ft/sec
7 ft/iec
7 ft /sec
250,000 gpn
7 ft/sec
250.000 gpn
7 ft/sec
200.030 gpo
7 ft/sec
200.000 gpn
Water
source
Oceac
River
Ocean
River
River
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2. RESPONSES
A1 summary of operating characteristics and details of condenser tube
cleaning practices is given in Table B-l. Additional data for several plants
are given below.
UTILITY NUMBER 1
Suspended Solids, ppm 14
pH 7.0
TDS, ppm 18,000
Conductivity, mmhos 24,000
Sodium, ppm Na 6,600
Calcium, ppm Ca 340
Magnesium, ppm Mg 720
Sulfate, ppm S0i» 1,200
Chloride, ppm NaCl 15,100
Silica (reactive), ppm 1.55
Alkalinity, ppm None
Chemical Oxygen Demand, ppm 2.5
Prior to the installation of the Amertap system, Unit 2 was chemically
cleaned with foaming HC£ acid on an annual basis.
Rubber balls were inserted manually and circulated by air and water
jetting.
Each section is chlorinated separately with approximately 100 gallons
per dose for 20 minutes duration for each section, adjusted to maintain a
plant effluent level of less than 0.2 ppm free chlorine.
UTILITY NUMBER 2
Average Average Average suspended
Date Average pH acidity Fe ; solids
Unit No. 1
2-79
8-79
6-77
1-77
5.13
4.46
4.18
4.7
2.0
4.5
4.3
1.3
8-72
4.2
Unit Nos.
2, 3, 4, 5
(same units as table above)
7.88
6.38
9.15
14.5
1.36
34.67
12.2
6.8
8.8
454
Chl.orination was stopped when the Amertap system was put into operation.
The frequency of usage for sponge and abrasive balls depends on river
water quality. Generally, the Unit 1 system operates for a few hours daily
using 50 percent sponge rubber and 50 percent abrasive balls. The use of
Amertap balls ranges from $1500 to $1600/month at a cost of $22.50/100
abrasive balls and $17.10 for sponge rubber.
37
-------
Unit No. 2 la operated during June, July, August, and September. During
this time the systems are operated 100 percent of the time. Abrasive balls
are used 20 percent of the time; sponge rubber balls are used 80 percent of
the time.
WATER QUALITY DATA FOR UTILITY NUMBER 3
The following is a summary of analytical data for copper discharged from
the cooling water system of a single power station. The tests were run over
a 7 day period in .1964. Samples were collected every 48 hours at two different
localities.
Abrasive balls were in continuous use over this period. After the
first 16 hours, high copper values were recorded. The levels decreased
gradually and were negligible by the end of the test.
Copper (ppb)
Analysis No. I 2 3 4_
No. 1 inlet 23 20 14 15
No. 1 outlet 47 29 17 12
No. 2 inlet 17 19 21 11
No. 2 outlet 19 17 16 15
UTILITY NUMBER 4
Units 1 and 2 were originally installed with Amertap Systems. The
systems performed well, cleaning the condenser tubes in-service. In 1973,
condenser tube leaks developed due to thinning and pitting of the walls. The
injection of sawdust into the circulating system kept the units in-service
but reduced the Amertap operation.
While operation of the Unit No. 5 system is reported to be satisfactory,
systems In Units 3 and 4 have never given satisfactory service and are used
infrequently.
UTILITY NUMBER 5
The Amertap system is used continuously during normal operation. The
abrasive balls are used during startup following a long outage where the
circulating pumps have been off and the condenser dewatered. During normal
operation, if rubber ball consumption becomes excessive, abrasive balls are
used until the rate of use returns to normal.
Unit No. 1 required brushing with nylon brushes approximately every 6
weeks before Amertap installation. With Amertap, brushing is reduced to twice
yearly. Units 2, 3, and 4 were installed with Amertap systems. No other
cleaning system has been used except during an outage when water at high
pressure is passed through the tubes to remove debris.
38
-------
TABLE B-2. WATER QUALITY DATA FOR UTILITY NUMBER 4
VO
Parameter
pH
Calcium Hardness as CaCOs
Magnesium Hardness
Total Hardness
Total Suspended Solids
Total Dissolved Solids
Total Solids
Total Alkalinity
Conductivity
Sulfates
SO 2
Other Phosphate
Total P_hosphate
Dissolved Oxygen
Zinc
Iron
Copper.
Manganese
Sodium
Chromium
Nickel
Minimum
6.9
60
50
110
0.3
320
453
44
622
39
0.63
0.2
0.3
7.7
0.044
0.27
0.012
0.07
592
0.01
Average
-
299
1,317
1,485
32
8,592
8,647
65
13,479
1,467
1.60
0.6
0.9
9.6
0.068
0.89
0.020
0.092
949
< 0.01
0.02
Maximum
8.0
600
1,850
2,600
133
12,986
13,009
76
18,600
2,487
5.20
3.3
4'. 6
13.2
0.136
3.70
0.026
0.114
1,134
-
0.05
3/28/79
(data for
single day)
7.2
120
380
500
58
2,399
2,457
48
3,600
2,157
2.60
0.5
0.8
10.4
-
1.67
0.012
-
1,084
< 0.01
0.01
Units
Standard
units
mg/1
mg/1
mg/1
mg/1
mg/1
mg/1
mg/1
pmhos/cm
mg/1
mg/1
mg/1
mg/1 .
mg/1
mg/1
mg/1
mg/1
mg/1
mg/1
mg/1
mg/1
-------
TABLE B-3. WATER QUALITY DATA FOR UTILITY NUMBER 5
Raw Water
Intake
Analyses
Average for Weekly Samples
Alkalinity
Date
1974
1/9-12/30
Minimum
Average
Maximum
Phen.
pH CaC03
7.5
7.8 0
8.3
Total
CaC03
mg/1
. 38
63
80
Total
Hard.
CaC03
mg/1
53
70
83
Cond.
Solids
Dissolved Suspended
pmhos/cm mg/1
125
148
170
14
93
162
rag/1
2
- 6
36
Alkalinity
Date
1975
-1/6-12-/30
Minimum
Average
Maximum
Date
1976
1/6-6/30
Minimum
Average
Maximum
£»
7.4
-
8.0
7.5
7.7
8.2
Phen.
CaC03
mg/1
0
0
0
0
0
0
Total
CaC03
mg/1
37
57
67
50
58
65
- Qnl -i
j~
dO.Lj.ua
Dissolved
mg/1
10
89
272
36
82
126
Suspended
mg/1
2
11
58
1
6
16
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TECHNICAL REPORT DATA
(Please read Inunctions on the reverse before completing/
1. REPORT NO.
EPA-600/7-80-02 6
3. RECIPIENT'S ACCESSION NO.
4. TITLE AND SUBTITLE
Assessment of Corrosion Products from Once-through
Cooling Systems with Mechanical Antifouling Devices
6. REPORT DATE
January 1980
6. PERFORMING ORGANIZATION CODE
7. AUTHORIS)
Charles M. Spooner
8. PERFORMING ORGANIZATION REPORT NO.
GCA-TR-79-46-G
9. PERFORMING ORGANIZATION NAME AND ADDRESS
GCA/Technology Division
Burlington Road
Bedford, Massachusetts 01730
10. PROGRAM ELEMENT NO.
INE827
11. CONTRACT /GRANT NO.
68-02-2607, Task 28
12. SPONSORING AGENCY NAME AND ADDRESS
EPA, Office of Research and Development
Industrial Environmental Research Laboratory
Research Triangle Park, NC 27711
13. TYPE OF REPORT AND PERIOD COVERED
Task Final; 1-4/79
14. SPONSORING AGENCV CODE
EPA/600/13
IB. SUPPLEMENTARY NOTES JERL-RTP project officer is Theodore G. Brna, Mail Drop 61.
919/541-2683.
ie. ABSTRACT rj;he rep0rt gives results of an assessment of corrosion products from
steam-electric power plant once-through cooling systems equipped with mechanical
antifouling devices. (About 67% of the currently operating plants in the U.S. use
once-through cooling systems. Various cleaning mechanisms, used to minimize the
reduction of the thermal efficiency of heat exchange in the condenser tubescaused
by corrosion and biofouling--include chemical and off- and on-line mechanical
methods.) On-line mechanical cleaning may lead to increased levels of metals in the
effluent due to abrasion of the condenser tubes. Since some abraded metals at suf-
ficiently high concentrations harm aquatic organisms and lead to other environmen-
tal damage, metal concentrations in cooling water discharges which stem from on-
line mechanical condenser tube cleaning systems need to be determined. This report
addresses the significance of this effect, based mainly on comments from utilities
experienced with the Amertap system and from the manufacturer. The industry
generally does not keep a close1 account of the causes and magnitude of condenser
tube corrosion; however, based on observations offered by the utilities, the Amertap
and other systems do not appear to contribute to loss of metal through abrasion in
any measurable way. Further evaluation is recommended.
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.lDENTIFIERS/OPEN ENDED TERMS
COSATl Field/Group
Pollution
Steam Electric
Power Generation
Cooling Systems
Corrosion Products
Biodeterioration
Assessments
Condenser Tubes
Cooling Water
Pollution Control
Stationary Sources
Biofouling ,
Mechanical Antifouling
Devices
13B
10A
13A
11M
06A
14B
IB. DISTRIBUTION STATEMENT
Release to Public
19. SECURITY CLASS (This Report/
Unclassified
21. NO. OF PAGES
48
20. SECURITY CLASS (This page I
Unclassified
22. PRICE
PA Form 2220-1 (B-73)
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