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 ------- 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 systems; and integrated assessments of a wide range of energy-related environ- mental issues. EPA REVIEW NOTICE This report has been reviewed by the participating Federal Agencies, and approved for publication. Approval does not signify that the contents necessarily reflect the views and policies of the Government, nor does mention of trade names or commercial products constitute endorsement or recommendation for use. This document is available to the public through the National Technical Informa- tion Service. Springfield. Virginia 22161. ------- 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 ------- 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. ------- 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 ------- 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 ------- 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 ------- 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. ------- 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 ------- 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. ------- 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. ------- 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). ------- 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. ------- 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. ------- 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. ------- 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 ------- 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. ------- 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 ------- 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 ------- 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 ------- 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 ------- 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 ------- 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 ------- 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 ------- 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 ------- 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 ------- 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 ------- 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) ------- |