Document dYZ4eyNO9REKL23Mr65JV9185

* RESULTS Preliminary tests proved techniques customarily employed in anti-biotic sensitivity testing, not applicable in the quantitation of the inhibitory response of niirex, heptachlor, and the PCBs. These toxicants are insoluble in water and the diffusion rates through the - agar were variable, yielding non-quantitative zones of inhibition. A relative inhibitory effect, however, could be distinguished between the bacterial strains and toxicant levels tested by using the method described in Table 1. Of the 85 bacteria tested, 26 demonstrated zones of inhibition to at least one of the test compounds (Table 1). The PCBs were markedly more inhibitory than the organochlorine pesticides. Only 3% of the strains screened showed inhibition at 0.5aig of mirex and heptachlor. This concentration of A r o e l o ^ 1016 and 1242, however, inhibited 31% of'the bacterial strains. Further, o.lmg of Aroclor^ 1016 inhibited 69% of these strains and Aroclox 1242 inhibited 62%. We attempted to correlate PCS-sensitivity response with biochemical activity or cell composition (Table 2)* PCD-sencitive bac- i teria were both Gram positive and negative and no morphological correlation was noted. However, a comparison of biochemical activities of sensitive and non-sensitive bacteria tested showed two distinctly different groupings. Amylase and gelatinusc pi*-F-4wet:-So was .s-iiow*. Hy 76% and 86% respectively, of the sensitive strains; hov:evcr, of the total bacterial strains screened, only 33% and 42% of the population;; v* showed these activities. No other biochemical activity differed NEV 0256<t9 738904 NEV 025650 738905 Table 2. Comparison of Physiological Activities of PCft-sensitlvo and Non-sensitive Microorganisms Bacteria Tested Urease Sensitive Non-Sensitive 13 Production of: Amylase Lipase Gelatinase 76 33 ' 86 33 2*3 42 5 6 Nitrate deduction 29 37 ^Percentage of cultures tested showing positive reaction, 100 cultures .tested. Citrate Gram Utilization Reaction 43 50 41 distinctly from the non-sensitive bacterial populations. No \ characteristic gran reaction was shown by the PCB-sensitive bacteria DISCUSSION S. The sensitivity disc testing procedure commonly, used in clini cal bacteriology has been successfully applied here as a rapid method for detecting PCB-sensitive estuarine microorganisms in pure culture. Although the procedure is qualitative only, it can serve to eliminate many hours of tedious experimentation involved in the isolation of suitable test organisms for more detailed examinations. '* This Dethod has been used previously by investigators to study the effects of pesticides on grov?th of bacteria (Uiddus/ et al. 1971; Trudgill^' et al. 1971).. However, no significant response has been Bhown screening estuarine microbes and chlorinated hydrocarbon pesticides in this study. Conversely, PCS sensitivity in estuarine bacteria was quite dramatic (Figure 1) using this method. % el. (1973) demonstrated no sensitivity to 0.02 tng PCB by Keil et Coli InfSC. using the same method on non-marine medium. C*we experiments in- S'* dicated PCBls stimulate growth of E. coli. No explanation for (Rot A 1-, t.his difference between stimulation in E. coli.and inhibiton in -A- estuarine bacteria,Ihas been determined at this time. The implications of this inhibition, if wide spread in the environment, are obvious. The sensitivity of a large number of heterotrophic bacteria to PCBs nay be of considerable importance in an estuarine environment. PCCs have been shown to pei-sist in estuarine sediments in relatively high concentration (9 ppm). Sediment corcl taken in close proximity to another showed markedly different concentrations .(0.06-9 ppm) indicating the PCBs are pro- NEV 02oobl 738906 \. ' bably absorbed onto particulate organic natter during transport and deposition in estuarine sediments (Butler, 1974). The aforemehtioned concentrations, when considered absorbed onto distinct detrital particles, are not unlike those shown to be inhibitory to hetrotrophic growth in this study. Consequently, PCBs could in hibit the normal turnover of carbon in estuarine sediments by inhibition of specific heterotrophic bacteria attached to organic detritus. t v NfcV 025652 738907 Ahmed, M. and D.D. Focht. 70-72 (1973). REFERENCES 1 Bull. Environ. Contain. Toxicoll10, I Bout-quin, A. W., In: The Microbial Degrad. of Oil Pollutants, Eds. Ahearn, D.G. and S.P. Meyers, 237-2A3 (1973). Butler, P. A. Personal Communication (1974). Keil, J. E., S. H. Sandifer, C. D. Grber, and L,, E. Priester. 6 i ? 3 7 - r y ; . <??1 Paris, Doris and. David L. Lewis. Residue Reviews 4 5 , 95-124 (1973). Trudgill, P. W . , Widdus, and J. A. Rees, J. of Gen.. Microbiol. 69, 1-13 (1971). Ware, G. W. and C. C. Roan, Residue Reviews 33, 15-45 (1970). tyjLddus, R., P. W. Trudgill, and D. C. Turnell, J. of Gen. Microbiol. 69, 22-31 (1971). I NV 025653 738908 ! -3- IKTRODUCTION Polychlorinated biphenyls (PCB) have been used in a wido variety of industrial and consumer applications over the past 40 years, but it was only recently that evidence began to appear that these materials had been widely dispersed throughout the environ ment, By letter dated February 1$, 1970 the Monsanto Company, sole US producer of PCB's, notified all of its customers of'the potential problem of environmental c o n tamination" by these liquids and recommended "that all possible care should be taken in the application, processing, and effluent disposal of these products to prevent them becoming environmental c o n taminants," Monsant o has begun a program to discontinue sales of PCB'a for use in paints, plasticizers, specialty inks, adhesives, paper coatings and all other open-system applications. The Monsanto Company has declared, however, that it will continue to eell PCB's for closed-systern electrical uses. This decision is a tacit .recognition of the important role that PCB's play in the. safe, reliable, and efficient delivery of electric power from the generating plant to the user. In the spate of published reports and st itements that have appeared in recent years on P C B 's there has been no meaningful exposition of this role of PCB's in electrical equipment - why, where, and how they are used; what alternatives are available; and what the consequences would be to the users of such equipment if PCB's were no longer / available. We hope that this report will provide such an It 738909 N t V 0 ^i>6 bh -A-' BACKGROUND PCB's pre used by the electrical industry as components of certain types of transformers ond capacitors The nature and function of those devices are described in the separate sections of this roport devoted to them. At this point it is sufficient to say: 1. T r a n s f o r m e r s are 'devices for c o n v e r t i n g e l e c t r i c a l power from one voltage and current level to Another, and the cond u c t i n g parts of these devices must be separated from each other by a suitable insulating 'medium* 2. Capacitors are devices for storing electrical energy through the physical separation of charged metal surfaces by an Insulating medium* Prior to 1930 the most commonly used insulating medium was mineral oil* The early 1930's saw the commercial development of insulating liquids that were mixtures of synthetic chlorinated aro matic hydrocarbons, principally various polychlorinated biphenyls. By controlling the composition of these mixtures, the manufacturer could obtain desired combinations of thermal, chemical and dielectric properties thAt resulted in Insulating liquids with mu c h greater oxidation and fire resistance than mineral oils. During the past AO years these liquids have become widely used in certain types t of transformers and capacitors and are recognized as a distinct class of insulating materials designated by the international term "askarel". The definition of the term "askarel", the composi tions' of the liquid that comprise this class of materials, and the various trademarks by which they, are known commercially are described in the following section headed "Askarel". NEV 025655 738910 i *5* The particular a$karel6 used in transformers end capacitors arc different; so also are the reasons for, and the extent and consequence* of, their use in these two types of electrical equip-' meat* However, certain general comments can be made at this point concerning their use in both types of equipment: 1, Askarel - i n s u l a t e d transformers and capacitors are delivered to customers as sealed units from w h ich there is no escape of askarel under normal operation during their expected lifetimes of 10 to more than 30 y e a r s . H o w e v o r , certain types of equipment failures can rupture the case and permit the loss of some askarel to the environment* Such failures occur at a rate of about 0*02% of the units in service per y e a r 2* PCH's can get into the environment during the manu- * facture, delivery, improper use, maintenance, repair, and disposal of transformers and capacitors. In addition to specific control measures instituted by individual manufacturers and recommended by them to the equipment users, the A merican National Standards Institute has established ANSI Committee C107 on Use and Dispo s a l of Askarel Used in Electrical Equipment* Its memb e r s h i p s (see Appen d i x 1) is divided into separate working groups on transformers end capacitors which will recommend national standards and procedures n ecessary to prevent the loss of PCB's to the environment at all stages from equipment I manufacture through ultimate disposal. 3* The record of reliable and safe performance that .insulated transformers and capacitors have Ntv 02t>o56 738911 I I6 compiled during the past four decades is reflected in the various codes, standards, and regulations th'at now e f f e c tively require or encourage the continued use ofaskarel-insulated equipment in many Applications l NEV 025657 738912 7 -7ASKAREL D r f1n 11Ions * . 1. A iynthetic nonflammable insulating liquid which, when decomposed by Che electric arc, evolves only nonflammable gaseous mixtures* (From the National Electrical Code 1971 and the American National Standards Institute C-42 series, "Definitions of Electrical Terms.") 2, Tho term askarel generally describes a w idely used, broad class of nonflammable synthetic halogenated hydrocarbon insulating liquids used as electrical insulating media. Askarels of various compositional types are used. Under arcing conditions the gases produced, while consisting of p r e domi nantly non-combustible hydrogen chloride, can yield varying amountB of combustible gases depending upon the askarel type. Insulation systems incorporating these askarels and cellulosic or other organic materials may, when arced, produce gaseous mixtures which aro moderately flammable*. (From ASTM (American Society for Testing and Materials) Method D 2283-71, Port 29, 1971 issue; will also appear in the 1972 issue of the IEEE (Institute of Electronic and Electrical Engineers) o"Guide for Acceptance and M a i ntenance of Transformer Askarels In Equipment."; Adoption was also recommended to the International Electrotechnical. Commission by its Subcommittee 10B (Insulating Liquids Other than Hydrocarbon Oils) of Committee 10 (Liquid and Caseous Dielectrics) as reported in item number 9 of minutes m# mai e9 It+fs 1AV, U . v. 1071 \ 738913 NcV 02bb3b 6- Compositlono ' Polychlorinated biphenyls are derivatives of the hydrocarbon, biphenyl, which has the chemical formula Fr o m one to ten of the hydrogen atoms in a molecule of biphenyl can be replaced by chlorine atoms, and the chemical identity of the resulting chlorinated compound depends both-on the number of chlorine atoms that have been introduced into the molecule and on the specific sites in the molecular structure at which they are introduced. The commercial material m a n u f actured by Monsa n t o under its registered trademark Aroclor consists of mixtures of these specific chlorinated compounds. They are usually identified by the weight percent of chlorine in the total mixtures, e.g. Aroclor 1254 c o n tains 547. chlorine. The Aroclors commonly used in the electrical Industry are Aroclors' 1260, 1254, and 1242. ,t Aroclor 1242, used primarily in capacitors, contains about 77. of pentachlorobiphenyls and higher. In September 1971 Monsanto introduced a new capacitor-grade askarel, Aroclor MCS-1016, which is essentially Aro c l o r 1242 that has been specially processed to reduce the content of p e n t a c hlorobiphenyls and higher to less than 0.4%. . As a general rule, the nonflammability of liquid PCB's, their vapors, and their arc-formed gaseous products is greater the higher the degree of chlorination of the liquid. Studies by Monsanto suggest that the resistance of PCB's to d e g r a d a t i o n in the environ# ment may also Increase with Increasing chlorine content. Analytics' methods for low levels of PCB's (reported in parts per m i l lion or parts per billion) in marine, aquatic, and wildlife environments do not always identify the specific compounds that are present, but in i 1 6 letter of February 19, 1970 to its customers, Monsanto NtV 025659 738914 -9- V'*i beer, i jnd ir, the environment end appear to prosent no potential iroblcv. to the r n v i r o n m e n t . " iTradem--arks * !i Tho following trademarks are used by electrical manufacturers to designate the askorelc used in their products: Manufacturer Trademark *iv vox Allis-r naimers . V>*' f.* Hyvol Chlorextol ' American Corp. Abestol Cornell Dubilier General Electric Dykanol . Pyranol y Kuhlman Electric Saf-T-Kuhl Elemex Sangamo Electric Diaclor Wagner Electric Noflamol Westinghouse Electric Inerteen Toxic and Biological Effects of PCB's Systematic investigations of the toxic and biological effects of PCD's have been undertaken only within the past few years, and the d e s c r i p t i o n and evaluation of the results is beyond the scope ,/.r ' -r re; Tome Investigators suggest that reports of certain toxic reactions may be caused by highly poisonous compounds (c.g. chlorinated dibencofurans) found to be contaminants in some PCB preparations* In the United States, medical records show that over a nearly 40~year period the only adverse health effects experienced by US workers exposed* to P C B r6,either during the manufacture of these liquids or of electrical equipment containing these liquids,have been limited to occasional cases of non-chronic chloracne or other temporary skin lesions or irritations. * NEV 025660 738915 10 TRANSFORMERS Defin tioti , A transformer is a device for transferring electrical energy from one alternating current circuit to another by electromagnetic means. It has no moving parts and performs Its function by linking two electric current- carrying circuits (the colls, usually copper wire) via a common magnetic flux carrying-circuit (the core, usually a special grade of iron). A transformer may be designed to effect a change in voltage or current from one circuit to the other or simply to obtain electrical energy from one electrical circuit without making a conductive connection between it and a second electrical circuit. The transmission of electrical energy from one point to another Is * essentially the transmission of a required number of kilovolt-amperes (kva). By means of transformers the kva's may be generated at a low voltage suitable for the windings of generators, stepped up to higher voltages and lower currents suitable for transmission of electricity over long distance wires, and then at the desired destination stepped down to a lower voltage and larger current suitable for utilization by electrically powered equipment. The almost universal use of the alternating current system for the trans mission and distribution of electrical energy is largely due to this ability of transformers to link up circuits of different voltages and currents. Thus the generator, the transmission lines, the secondary distribution system, and finally the great variety of ultimate loads can each be operated at the voi- $ tage most suitable to its particular function. Without this unique ability of the transformer to adapt the circuit voltage to the individual require ments of the different part6 of the system, the enormous development and progress in the transmission And distribution of electrical energy during the past 60 years would not have been possible. NEV 025661 738916 '? ' *11- Why Askarels are Used in Transformers The coile and core of roost transformers are enclosed in sealed metal tanks that are filled with an Insulating liquid, usually mineral oil. Under certain conditions of sudden power surges high-current electric arcs are produced inside the transformer which can generate and ignite flamnable and explosive gas mixtures formed from the mineral oil and other cellulosic in sulating components In the transformer. Because of the nonflammability of liquid askarels, their vapors, and their arc-formed gaseous products, transformers filled with askarels arc free of these fire and explosion hazards and may be used in locations where failures of oil-insulated transformers would present a potential danger to life and'property. This safety factor is the only advantage that askarel- insulated transformers have over oil-insulated transformers of the 60me size and rating. The density of askarels is about 1.7 times that of mineral oil, so askarcl-insulated transformers are heavier than their oil-filled counter parts. Askarels themselves are more expensive than mineral oils, and their solvent characteristics require the use of more expensive insulation compo nents on the internal parts of the transformer, so the complete units are more expensive. As a consequence, askarel-lnsulated transformers have captured only those market applications (less than 5%, but growing) where considerations of safety and reliability are paramount. Their use in such applications is usually required or encouraged by the provisions of electrical codes, fire underwriting policies, or governmental regulations. / Note: Prior to the mid-1950's the liquid used in askarel-lnsulated transformers was a 50-50 weight mixture of Aroclor 1260 (607, chlorine) with trichlorobcnzenes; then the benzene component wa6 changed to a mixture of trl- and tetrachlorbenzcnes; and in 1971 the Aroclor component was changed to Aroclor 1254 (547. chlorine). NEV 025662 738917 -12Types n n d A p p lications of Askarol-Insulatod Transformers Thcro arc two broad classifications of transformers r porrer transformers, which aro used to step up voltages; and distribution transformers, which are used to step down voltogos. The many typos of transformers that are included within these two clesslficatione are listed in Appendix 2, The applications that accompany the listing apply only to those units of a given type that arc m a n u factured with askarel as the insulating liquid. Most units ofthe types listed arc still oil-insulated. We estimate that the total number of askare1-insulatcd units that have been put into service in the United States since 1932 is 125,000, and virtually all of these units are still in service. The l ifetime-before-failure is often longer than 30 years, and almost all units that do jfail are rebuilt and returned to service. The current production rate of new askarcl-insulated transformers units is about 5,000 per year. Most of these transformers are located inside public, commer cial, or Industrial buildings; on the roof tops of such buildings; or in close proximity to such buildings, and require no special enclosures other than what are necessary to prevent accidental hazardous mechanical or olectrical contact of persons with the equipment. However, the National Electrical Code does specify vaults for the indoor lnrtallatlon of askarel-insulated transformers j ated more than 35,000 vclts* A s k a r e 1 - insula ted transformers arc, limited by the electrial properties of these liquids to ratings below 69,000 volts. The amount of askarel used in various types of transformers ranges from 40 to 500 gals, (516 to 6,450 lbs,) with an average of about 235 gals. (3,032 lbs.). During 1968, the last complete "normal" year for the electrical industry, the total amount of 738918 0^5663 13- .r c H *c used In Crmuiformers was approximately 1.3 million gallons (8,4* thousand tons). P r o r.o >it A 1 ternatives to Askar c 1-Insu la ted T r a n s f o r m e r s If l'CB's were to be no longer avail a b l e for c l o s e d - s y s t e m electrical uf es -- as they are no longer a v a i l a b l e from K o n s a n t > for o p e n - s y s t e m a p p l i c a t i o n s . - - vh o t a l t e r n a t i v e s to a s k a r c l - i n s u l a t c d transformers could now be supplied by the clcctricol industry, and what would be the effect upon the user should askarel-insulated > transformers no longer be a v a i l a b l e eit h e r as new or r e p l ac e m e n t units? The only present alternatives to a s karcl-insulatcd transformers arc o i l - i n s u l a t e d tra n s f o r m e r s or dry-t y p e tra n s f o r m e r s (either those open to the a t m o s p h e r e or those that arc g a s - f i l l e d and sealed) A. Oil -ins u l a ted t r a n s f o rmers 1. If one d i s r e g a r d s safety c o n s i d e r a t i o n s , there are no technical reasons why oil-insulated transformers could, not be directly substituted for askarcl-insulatcd t r a n s f o r m e r s . The size of the unit*would be unchanged; . .. the w e i g h t and cost w o u l d be less, 2, T h e r e are legal restrictions' to such a direct substitution. a. Some local r e g u l a t i o n s (e.g. Chica g o ) prohib i t the use of o i l - i n s u l a t e d units in c e r t a i n l o c a tions whore askarcl-insulated units arc allowed. b. Where o i l - i n s u l a t e d t r a nsformers would not be s p e c i f i c a l l y p r o h i b i t e d os ^on-site replacements.' for askavnl-insulated units, the National .Electrical Code imposes special restrictions upon their mode of installation. Although 738919 Ntv O^^OO^ -14- 35,000 volts must be Installed in vaults, all oil-insulated transformers require vaults, except that alternative fire protection arrange ments arc permitted for units rated not over 600 volts. Assuming that space were available inside an existing building to accommodate these special auxiliary safety provisions, the c o 6 1 of their construction could range from $5,000 to $50,000 per transformer, c. Oil-insulated units can be installed outdoors if they are suitably isolated from flammable structures or if these structures are suitably safeguarded against fires originating in the transformers. The power output must thon be brought to the point of use inside the building via cables or insulated buses, and the cost of cable and bus installation could * also range from $5,000 to $50,000 per tr&ns- . former. The outdoor transformer would have to be of a higher rating than the indoor one it would replace because of voltage drop and consequent power losses in the cable or bus runs, B Dry-type transformers . , * In most locations, dry-type transformers (either those open to the atmosphere or those that are gas-filled and scaled) could not be directly substituted for a6karel-insulatcd transformers. There are several restrictions to such a direct substitution: / ? NEV 025665 738920 15 1, The provisions of the National Electrical Code ' arc more stringent for certain classes of dry- type transformers than for comparable askarcl- insulated units 2 Present technology is not available for d e s i g n ing and manufacturing reliable dry-type trans formers above KVA and/or 15 KV. 3, The reliability of dry-type transformers is less than that of comparably rated liquid-insulated transformers Oil- and askarel-in6ulated units show much greater resistance to switching and lightning surges than do dry-type units An EEI survey of failures in network transformer banks I showed a 77 per year failure rote for dry-type units compared to 027 for liquid-insulated units. Furthermore, liquid-insulated transformers have a much greater overload capability* Many liquid-insulated units can sustain a 1007. o v e r load for 8 hours and a 2007 overload for 2 hours I These transformers are able to m a i n t a i n continuity of electrical service during periods of temporary outage of related equipment* . A* Some dry-type transformers are larger by 10 to 30% than comparably rated liquid-insulated units, and t most are more expensive. 5* Dry-type transformers are noisier by 5-10 dB than are liquid-insulated transformers* 6. Bccauso their insides require regular cleaning, the maintenance costs for open dry-type transformers are higher than those f.or sealed dry-type transformers NfcV 0^5660 738921 -16er for: liquid-insulated transformers, which arc also sealed. 7. Open dry-type transformers, which are cheaper . than sealed dry-type transformers, cannot be used in certain corrosive or hazardous atmospheres, c, g. on furnaces or on electrostatic precipitators near hot stacks. Summary 1. For t e c h n i c o l o r legal reasons it would be impossible to replace most askarel-insulated transformers now in service by oil-insulated units of equivalent / rating and reliability without major construction changes that would be required to compensate for the fire and'explosion resistance of the askarelinsulated units, 2, For certain applications and locations, dry-type transformers could replace askarel-insulated trans formers, but with a significant reduction in system reliability. NEV 025667 738922 *17- CAPACITORS Definition t A capacitor is a device that stores electrical energy. It consists of two metal surfaces or electrodes separated by an insulating m e dium such as air, paper, plastic film, or oil. W h e n a voltage is applied across the electrodes, electrostatic energy is stored in the insulating medium. In typical industrial capacitors the electrode material is aluminum foil and the Insulating medium or dielectric is paper tissue and/or plastic film,which for m a n y applications is impregnated wi t h a liquid dielectric. A liquid inpregnant is used to fill the voids w i thin the paper or plastic film structure, to fill the voids between sheets, and to contribute to the capacitance or c h a r g e carrying ability of the composite. Voids must be eliminated within capacitors that are to be used above 200-300 volts, which exceeds the dielectric breakdown Btrength of air. In our definition of transformers we emphasized their importance in the transmission and distribution of electrical power (kilovolt amperes) from the generating plant to the ultimate load. If the load were purely resistive (e.g. an electric heating element) no further m o d i f i c a t i o n of the power supply delivered to it would be required. Other loads (e.g. induction motors) may require that a portion of the k i l o v olt-ampere6 delivered to them be used to p r o vide a magnetizing current, which does not contribute directly to the useful power output of the load. This portion of the total kva delivered to the load is d e signated as reactive kilovolt- a m p e r e s (k/ars). It has been found more economical to produce kvars from total kva's near the point of load rather than near the point of kva generation, and capacitors provide the most efficient way of 738923 KfcV 02566 -18- cffccting Chis transformacin at Che point of load* Why Askarols are Used in Capacitors Prior to 1930 most liquid-filled capacitors were made with mineral oil. The subsequent subs t i t u t i o n .of asksrels for mineral oil made possible significant technical improvements in the sise* reliability* and life of these capacitors. A * S ize The single most important property of a' liquid be used in a' capacitor is its dielectric constant (the ratio of its ability to 6tore electrostatic energy relative-to air). The dielectric constant of * capacitor-grade askarcl (Aroclor 1242) is 5.85 while that of mineral oil is 2,25. V h e n c a p a c i t o r 'tissue is impregnated with these liquids the dielectric t% f constant of the paper-liquid composite is 6.1 for . askarel and 2.9 for mineral oil. Furthermore* because of the relatively close match between the dielectric constants of cellulose, (6.6) and askarel (5. 8 5 ) ; it is possible to stress askarel- i m p r e g n a t e d * paper to 00-500 volts/rail,, while the stresses that can be applied to comparable paper-mineral oil capacitors are limited to 300-350 voits/mi*. * The combined effect of these technical advantages of askarels has be e n to permit a reduction of capacitor sizes to less than 147. of what theywere in 1924. In 1965 a new dielectric system consisting of paper- polypropylene fllm-askarol was introduced w i ! stress capability up to 900 volts/mil. overall. r< favorable 6tress distributions* the ability askarel ....... - increase, the dielectric strength of polypropylene NtV 0 >669 738924 -19- is partly responsible for this improvement. Reliability and life Asknrcls arc thermally and oxida t i v e l y more stable than mineral oils, and discharges, which can occur in capacitors,' are less likely to generate gases from askarel6 than from mineral oils. The chemical stability of askarels in the presence of capacitor tissue and plastic films and the favora !'- . discributions between solid and liquid referred to above have made it possible .to design low-cost capacitors with a life expectancy of more than 10 , years life In lighting applications and more than 20 years in electric utility application. In ' each application the first-year failure rates are less than 0.27. This level of life and reliability had not been achieved prior to the introduction of askarels. Furthermore, the non-flammability of askarels is greater than that of mineral oil, which reduces the fire hazard that might otherwise accompany those failures that result in' rupture of the case. W h e reas the transformer m a n u f acturer has had to essentially "design around" the properties of' askarels in order to be able to t a k e .advantage of the safety factor that they impart to his equipment, the capacitor m a n u f acturer has been able to "design with" the properties of askarels and obtain significant technical improvements along w i t h the imp- cd saf-ty * factor. As a.result askarels have v i r t v ' - j \nted mineral oils in more than 90% of the power and industrial NV 025070 738925 I -20* N o t e ; Prior to 1952 the liquid used in askarel-impregnated capacitors was Aroclor 125/4 (54% chlorine); it was then replaced by Aroclor 1242 (42% chlorine), which has better electrical properties; and as noted in the. "Askarel" section, in September 1971 Monsan t o Introduced a new capacitor-grade askarel, Aroclor KCS-1016, which . is a modified Aroclor 1242, Unlike askarcl-insulated transformers, the liquid in a skarel-impregnated capacitors contains only Aroclors and does not contain added bhlcrobenzencs. T ypes and Applications of A s k a r e 1-impregnated Capacitors The principal types of askarel-impregnated capacitors and their applications arc described in Appendix 3* Almost 80 million such capacitors are manufactured annually, most of them for first time use. Unlike transformers, capacitors are not rebuilt and returned to service after failure. They arc disposed of (see "Background" section, item concerning ANSI Committc C107) and replaced by new capacitors. Capacitors used in lighting and air conditioning applications 0,09 contain 0.005 to *$9 gals. (0,05 to 1,0 lbs.) of askarel per unit. The largest power capacitors' contain about 6,7 gals (77 lbs,) of Askarel, The most popular size contains about 3.1 (36 lbs.) The National Electrical Code requires that any installation of capacitors In which any single unit contains more than 3 gallons of co mbustible liquid shall be in a vault like t'.iat required for transformers. .During 1968, the last complete,"normal" year for the electrical industry, the total amount of PCB's used in capacitors was approximately 14.4 thousand tons, I < ..... . NEV 025671 738926 1*) { j; ( i) (: AJ to nvn I v r a to A h r e 1 - T.mp ro g ti ;it e d C a p a c i t o r s If PCI)* were to be no longer available for c loscd-sy r.tcm e l ectrical uses -- as they are no longer a vailable from M o n s a n t o for o p e n - s y s t e m 'n p p l i cations -- what alte r n a t i v e s to a s k a r o l - i m p r e g n a ted capacitors could now be supplied by the electrical Industry, and what would be the effect upon the user should asliarcl-imprcgnatcd `c a p a citors no longer be a v a ilable either as new or r e p l a c e m e n t units? Possible a l t e r natives to a s k n r c l - i m p r e g n a t e d c a p a c i t o r s are c a p a c i t o r r, impregnated wi t h m i n e r a l oil, tor c a p a c i t o r s impregnated with certain other liquids, A. Mineral Oil Replacement of askarels by mineral oil would essentially return c apacitor t e c h n o l o g y to its prc-1932 level. Some specific consequences of such a replacement would be: 1, S a f e t y . None of the possible liquid a l t e r n a t i v e s s to askarels arc nonflammable, and a fire hazard would be created by any capacitor failures that were a c c o mpanied .by rupture of the case. Pres e n t l y the use of capacitors containing flammable liquid is governed by the National E l e c t r i c a l Code 'Arti c l e s A CO and 501. 2- S i z e and C o s t . A few specific examples vi.ll illustrate the size and cost penalties associated with a switch from ask a r c l to m i n e r a l oil in ca p a c i t o r s . The most popular sized power c a p a c i t o r s today arc rated at 200 KVAK, If mineral oil were substituted fov Askavcl the volume of the c a p a c i t o r v/oultl be Ufc.V quadrupled and the direct labor and material costs a s sociate d with itr. m a n u f a c t u r e wo u l d increase by 70%, Tod ay power capa c i t o r s arc available in A00 :cv.\K 738927 -22- ; KVAR because of increased heat dissipation problems f with increased volume. In addition to increases in direct corte, the power capacitor Industry would face increased capital expenses estimated at ' $2,000,000 to provide the increased volume of material at p r o j e c t e d .KVAR requirements. Steel companies faced with increased size, co6t and flammability of capacitor banki^'/. indue.: jcheating furnaces would probably not install new .Induction heating Capability. Utilities would have difficulty with substAtion*size Ln crowded urban areas. An increase in the size of capacitors for air conditioning would not be critical. In lighting applications a 3,75/.075 uf 540 VAC rating for high output applications is typical. If mineral oil were substituted for ashctrel, the. capacitor would be 71% larger and materials would cost 46% more* Lamp ballast manufacturers would have to increase the size of the ballast to a c c o m m o date the larger capacitor. This would change the thermal performance of the unit and require U.L, approval of new ballast designs* Lighting fixture manufacturer* would also face redesign costs to take larger allasts. Reliability. Users of capacitors in all application areas. have come to expect long life and very low initial failure rates. The present performance star dards have been achieved after many ye of fi- '<1. testing and accelerated testing by an- ` and users* The reliability of designs containing I 567 738928 -23- minerol oil in many applications would be uncertain. Available records show that capacitor reliability prior to tho availability of askarcl was only a fraction of whnt it is today. A. Replacement M a r k e t . The implications of changes in capacitor size hav.e been, d iscussed in terms of new designs. In each major application area some capacitors are sold for replacement business. Power and induction heating capacitors are generally installed in racks of a few to thousands of c a p a citors. It would not be possible to make simple substitutions for failed capacitors while m a i n taining the system rating. In air conditioners replacement of failed c a p a citors might be as simple as installation of new brackets. On the other hand,' tight designs might not take a larger capacitor at all. lighting systems would be seriously affected by Increases in capacitor siae. Larger replacement ballasts would not fit into existing fixtures without altered mounting arrangements. It is possible that space requirements would force complete replacement of lighting fixtures for the want of a replacement ballast. t 5. Material S o u r c e s . Mineral Oil is currently used in a relatively small number of specialty capaci tors. In this country there is a single source of capacitor-grade mineral oil with limited facilities for acid refining of crudes from a single oil fxold. Increased demand -ould require 738929 NtV -2A- exponded facilities and investment and considerable development in defining technical requirements for capacitor-grade mineral oil. Efficient use of. mineral oil in capacitor designs would require higher density capacitor tissue than is currently produced in this country, ^t the least this would require extensive paper machine modification. Capacitor winding techniques and machino6 would need to be developed for winding tighter rolls. B* Other Liquids . 1, Castor 0 1 1 The dielectric constant of castor oil is 4.5 and this material is useful as an impregnant in D.C. energy storage capacitors. However, A.C. capacitors filled with this liquid have relatively 6hort lives and are not very stable under A,Cm discharges and in the presence of water derivable from the-cellulosic paper. 2* Dibutyl s e b a c n t c . This ester is especially useful in high frequency parallel plate capacitors because of its low, flat loss characteristics over a broad frequency range.' In this type of c o n s t ruction the liquid is the sole dielectric material. W h e n used in c o n junction with paper, this esfsr is also . unstable * 3 .S..i-l-i-c-one Fluids These materials have a dielectric constant of 27 and would generally be subject to .the same disadvantages as m ineral oil' vH ^o J C Alternative Designs In addition to liquid dielectric substitutes, olternatives 738930 -25/ to the paper-liquid dielectric might be considered. These would involve the use of plastic film coated with aluminum foil or vapor-deposited aluminum as electrodes. Since the free volume of the system is less than that of paper the capacitance of the system is les6 dependent on the dielectric constant of the liquid and the stress distribution between M;e plar^ic films and low dielectric constant liquids is moi* closely balanced. Such dielectric systems are difficult to construct completely free of voids. It is expected that several years will be required to achieve the required level of reliability in such dielectric systems NEV 025676 6 rs 738931 -/. u - l'OSSl l'.l.K DKVP.T.OPHKNT O)' NEW NSUI.AT m : 1.TQUJ DS The cose o.f asknrel liquids is shout: $2.00 pci* gallon, compared to about $0.30 per gallon for mineral oil. Thus, long before there were any environ mental concerns about rCB's there was a strong economic incentive to find other less-expensive insulating liquids with the d'esirnblo characteriseics of nsknrols. Since the 1930's, at least 10 major chemical or electrical companies have invested large amounts of time and money in this search, all with no success. There ore today no fluids that can be used as ono-for-one replacements for PCB's. The continued search for new fluids would probably start with fluorochemicals. Fluorochcmicals arc nonflammable, nbntoxic, and as far as is presently known represent no environmental hazard. High-boiling fluorochcmicals might thus be potential replacements for ?CB's. Considerable laboratory study, over at * least a one-year period, of the physical, chemical, and dielectric properties of these materials would be required in order to identify specific candidate materials. At least another year would be required to develop a finished product based upon a fluorochcmical. On one hand, the physical and dielectric properties would certainly be sufficiently different so that substantial engineering redesign by electrical manufacturers would be required to accommodate a fluorochcmical. On the other hnnd a one-year lead time is needed to construct a chemical plant to produce the identified fluorochcmical in the millions of pounds that would be required per year. Furthermore, a significan: program of environ mental testing would be needed to ensure that the new material was.indeed not an ecological hazard. The foregoing arc all h i g h l y o p t i m i s t i c tine estimate: The cost of manufacturing fluorochcmicals is inherently high. Prices of high-boiling liquids are $10 - 15 per pound, or*higher. At best one would .hope NEV 025677 738932 -t fm I .. that in sufficient volume the price might approach that of Teflon, currently $3 U per pound. Even this optimistic figure is approximately twenty times the cost of PCB's, and since the value of PCB in.a transformer is roughly ono-tenth the total value of the transformer, the total cost of a fluorochcmical-lnsulated transformer would be at least three times that of an equivalent askarel unit NV 025678 738933 Appendix 1 Membership of ANSI Committee C107 on Use and Disposal of Askarel Used in Electrical Equipment Number of Representatives 2 2 1 1 1 1 2 1 1 5 2 2 1' 1 Organisation Represented Department of the Army Environmental Protection Agency U.S, Department of Agriculture Tennessee Valley Authority General Services Administration National Bureau of Standards Certified Ballast Manufacturers Association Edison Electric institute Institute of Electronic & Electrical Engineers National Electrical Manufacturers Association Monsanto Company Commercial Waste Disposal Companies Engineering Consulting Firm Capacitor Manufacturer Serving as an independent Member NEV 025679 738934 I Appendix 2 Types of Askarcl-Insulated Transformers # A. Distribution Transformers ' ` 1. Network (up to 2500 KVA) 2. Single- and three-phase (up to 2500 KVA) 3. Pole-mounted and station (up to 500 KVA) The application of these transformers in power distribution systems places a great premium upon their reliability and high overload capability (which they share with comparable oil-insulated units): such as 100% overload for 8 hours and 200% overload for 2. hours. .A. Precipitation (high voltage DC) These transformers are part of the power supply for electrostatic precipitators, which are gaining increasing use in preventing air pollution by particulate matter. They are generally installed close to hot gas stacks in an atmosphere that would be a fire hazard to oil-insulated transformers and a corrosion hazard to open dry-type transformers. Sealed dry-type transformers are impractical for high voltage DC, .* B. Power Transformers 1. Secondary substation a. Load center units b. Secondary substation generation units c. Switchboard units , d. Integral units e. Motor control units Theso5aoifrisc the largest group of askarel-insu'.ated transformers, % and they find widespread application in the automobile paper i NEV 025&80 738935 -30- chemical, textile, steel, nonferrous metal, cement, mining, and petroleum industries. They are used In commercial and public buildings, such as schools and hospitals; in defense and nuclear energy installations.; and by private and public utilities* 2. Master unit substation 3. Primary unit substation A. Limited ampere substation * 5. Industrial furnace . These transformers are used in the hot, dirty atmosphere In proximity to glass melting and induction furnaces, which require high current, low voltage power supplies (more than 2300 KVA at no more than 13.8 KV). Existing technology does not permit construc tion of scaled dry-type transformers for these power ratings, 6. Rectifier These transformers are used for large rolling mills and DC industrial power supplies, and arc covered by the same comments given for industrial furnace'transformers. ^ 7. Transportation a. Third rail These transformers are used for rapid transit systems, and are basically serving a rectifier function. b. Locomotive '* Prior to 1932, all on-board transformers were open dry-type. Because of problems with them, railroads went to askarel-lnsulated transformers. The changes in locomotive design since the 1930's would not now accomodate open dry-type transformers as replacements NEV 025681 738936 -31- for askarel units. A recent trend has been to replace askarcl by oil units, and this will continue unless new DOT regulations require nonflammability. 8. Multiple-unit car (MU) These transformers are mounted under the flat-bed of passenger cars. They ride along in this location, about 8 inches" ~ the r.<T, *t . speeds up to 150 mph. The transformer must be ruggedly built to with stand the impact of flying debris and constant vibration. Power to the cars is brought In through an overhead catenary and is fed to the underside of the car where the transformer, controls, and propulsion equipment are located. Present voltage is 11 KV, but new electrification is expected to be 25.XV. Space and weight are critical in this application. There are only about 33 inches above the'rail. The width of the trainsfo mer is limited by the width of the car. Only oil- or askarel-insulated units would provide the required performance levels in the space available. As with locomotive application* present DOT regulations do not restrict the use of flammable liquids, and the use of askarel units has been dictated largely by the economic considerations of fire Insurance rates. NEV 025682 738937 0*1 - ./ / . , Appendix 3 . ' Typco of AsUarcl-Insulatcd Capacitors .* * A. tilp.h Voltflfte Power Generally AC capacitors are used to improve the power factor of a circuit Powor factor is the ratio of true power in watts to the apparent power as obtained by multiplying the current flowing to the load by the circuit voltage. The power factor correction can be made directly at the load or at utility substations. In the latter case high.voltage units will be designed for 4,800 to 13,800 volt service* To the utility engineer the use of capacitors is* purely a matter of econdmics. The main benefits that result from the use of capacitors are 1. Reduction of losses associated with the delivery of eleetrl* cal power to the point of use* 2. Reduction of the investment required in equipment for de- llvering electrical power to the point of use, which may be broken down into: - a. Reduction of current for the same kilowatt load. b. . Reduction of the kva rating of equipment required to handle the same kilowatt load. c. Reduction of the voltage drop for a given kilowatt load. d. Control of. delivered voltage if the capacitor kva is varied, * Electric utilities also use capacitor banks in series with dlstri> bution circuits to improve voltage regulation. High voltage utility capacitors', low voltage power capacitors, and lnductior heating capacitors are manufactured at the rate of 200,000 per year, about 2 to 3% of which are for replacements; the balance are for new installations. - NEV 025083 738938 -33- B. Low Voltage Power Capacitors installed in industrial plants at the demand site (typi cally large motors and welders) are designed for 230 to 575 volt service Capacitors installed near the loads are the.most efficient way to supply the magnetizing current to produce the flux necessary for the operation of inductive devices. Rates for the sale of power are generally struc tured to encourage power factor correction at the site eliminating the need for the electric utility to transmit both power-producing current and magnetizing current all the way from the generator to the plant site. The same considerations apply to induction heating applications the principal difference being that capacitors for this rapidly growing appli cation are designed for operation at 960 to 9600 Hz. C. Lighting Capacitors improve the efficiency of lighting syrterns. A fluorescent or mercury vapor lamp can be ballasted without the use of a capacitor but the power factor of the lighting system would then be in the range of 50 to 60%. For commercial or industrial lighting with either fluorescent or high intensity discharge lamps, the use of a capacitor in the circuit * provides part of the lamp ballasting and brings system power factor into the range of 90 to 95%. The current market for these applications is about 44,000,000 units annually of which about 10% are estimated to be replacement ballasts. D. Air Conditioning I As in the lighting applications, the capacitor improves system effi ciency. Air conditioners could be made to operate without capacitors, as do home refrigerators, but because of the higher capacity required for current air conditioners, the resultant line/would virtually eliminate home "plug ins" and would still further overburden a seriously threatened national .. ' NtV 025684 738939 -34 - power network. Almost all air conditioner pump motors are of the split- winding type on which the capacitor provides phase differential for the so-called start winding, thus delivering good starting torque. The proper 6ize capacitor permits high (907. ) power factor after 6tart-up, The current market for this application is about 12,000,000 units an nually, with about 57. of these estimated to be for replacement usage, Ei Industrial Electronics This market category is a catchall covering many varied applications, two important ones being motor run and power supply applications. Motor run applications are for pumps, fans, and farm feed equipment, and do not differ significantly from air conditioning applications. The power supply market uses capacitors principally to provide high power factor, but through careful design the capacitor can also provide wave shaping where desired. The market is estimated at 23,000,000 units per year with no estimate as to the relative 6ize of the replacement market. NEV 025685 738940 9R9S70 A3N V I ! !* rV* 9 I. L LSO it* X0 * t: ri M7) 2" r*. * ^> *< -k >- ur A .: ` c< 1 9r S ** *t is j y* i S * ,\ - sr j ir r- Z . 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