ML20154A976
| ML20154A976 | |
| Person / Time | |
|---|---|
| Site: | Farley  |
| Issue date: | 05/09/1988 |
| From: | ALABAMA POWER CO. |
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| Shared Package | |
| ML20153H322 | List: |
| References | |
| NUDOCS 8805170004 | |
| Download: ML20154A976 (41) | |
Text
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h Chlorine Concentration And Exposure .
Time Necessary For Macroinvertebrate Control At(Corbicula)
Farley Nuc lear Plant i
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Prepared by:
Alabama Power Company Environmental Affairs Department
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i' Table of Contents Page Abstract i Introduction 11 Study Background 1 Corbicula Life History and Service Water Infestation 1 Control of Corbicula 2 Chlorine Minimization 4 Study Objectives 4 Materials and Methods 6 Collection of Life History Information 6 Minimization Testing 7 Water Quality 8 Results and Discussion 9 Corbicula Spawn 9 Corbicula Growth 10 Efficiency of Low Level Chlorination 11 Water Quality 14 Conclusions 14 Bibliography figures 1-6 Tables 1-2 Enclosures 1-9
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.- 1 ABSTRACT Section 423.13 b)(2 of the Environmental Protection Agency's~
Steam Electric Effluent (Guide) lines as well as Farley Nuclear Plant's NPDES Permit No. ALOO24619 Part I; page I-lb *** footnote for discharge points 001 and 002, states total residual chlorine may not be discharged from any single generating unit for more than two hours per day unless the discharger demonstrates to the permitting authority that more than two hours / day is requited for macroinvertebrate control. Alabama Power Company received approval from the Alabama Department of Environmental Management (ADEM Nuclea)r Plant.to conduct an extended The objective of theservice water study was tochlorination determine study at Farley the minimum combined chlorine concentration and ex macroinvertebrate (Corbicula) control.posure time necessary for Continuous chlorination treatments, utilizing sodium hypochlcrite, were conducted from the Fall of 1986 through the Winter of 1988. Sodium hypochlorite was metered into one unit's service water system such that total residual chlorine guidelines of 0.20 mg/l a(TRC) levelsdischarge t the river would not structure.
exceed theBiomonitoring effluent tanks containing adult Asiatic clams, located upstream and downstream of the heat exchangers, wer2 utilized to determine the minimum treatment duration. Treatments were terminated when we achieved areater than 90%
mortality of Corbicula indicator organisms or an eight week period of chlorination whichever occurred first. Results from the treatments have shown that chlorine levels of 0.20-0.30 mg/l TRC within the service water system (tnaintaining less than 0.20 mg/l TRC at the river discharge structure) are adequate for Corbicula control within eight weeks when water temperatures exceed 62*F. Seasonal change in the service water temperature was the primary factor affecting the treatment durations. Most significantly, this study demonstrated lower chlorine concentrations than previously documented were adequate for Corbicula control at Farley Nuclear Plant.
Based on the results of this study, Alabama Power Company requests the Alabama Department of Environmental Management approve a permanent chlorination program for macroinvertebrate control, outlined in the recommendations section, which allows for a chlorine discharge of more than two hours per day at Farley Nuclear Plant.
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INTRODUCTION The Environmental Protection Agency's Steam Electric Effluent Guidelines and Farley Nuclear Plant's NPDES permit Part I, page I-lb
- footnote for DSN 001 and 002 indicate total residual chlorine may not be discharged from any single generating unit for more than two hours chlor /ination day unless the discharger is necessary demonstrates more for macroinvertebrate than two control. hours /Power Alabama day of Company found it necessary to demonstrate the.need for a variance from the length of chlorination period and requested approval on October 22, 1986 from the ADEM to perform a study to determine chlorine concentration and exposure time necessary for adeguate macroinvertebrate control (Enclosure 1). Approval was granted by the ADEM on October 28, 1986 with four additions to the study program (Enclosure which were 2 . Enclosures ma)de 3 through 9 provide additional modifications as the study progressed.
The Environmental Affairs Department of Alabama Power Company has therefore conducted a study to determine the necessary chlorine concentration and duration required for adequate macroinvertebrate control. The primary objective of this study was to develop a permanent chlorination schedule which minimizes the amount of chlorine needed to prevent observable fouling of service water system components, as opposed to total eradication of Corbicula.
The chlorination study was primarily based on Corbicula information surveys, literature research and monitoring programs conducted as listed in Table 2. The purpose of the Corbicu a information surveys was to determine the density of Corbicu' a in the service water pond, to determine the length of the spawning season and determine their growth rates. This was the basis for knowing when the chlorination treatment would be necessary. The purpose of the literature research was to know what chlorination amount and duration were necessary to adequately control the Corbicula. The purpose of the monitoring programs was to determine site specific information on the minimum amount of chlorination and contact time necessary to kill an acceptable percentage of Corbicula (greater than 90%) which would not cause biofouling problems in the service water system.
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8 STUDY BACKGROUND Corbicula Life History and Service Water Infestation The exotic freshwater clam Corbicula was imported to the western United States from Asia in the early 20th centur: (Neitzel et al. 1984).
The infestation of virtually.all river systems in the southern United States can be attributed to the clam's reproductive characteristics..
Unlike native North American bivalves, the immature stage of Corbicula does not require an intermediate host, and the sexually mature adults are usually monoecious (i.e., a single individual possesses both male and female sexual organs at the same time). Each adult clam can produce up to 700 larvae per day. The juvenile clams (less than 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> old) are easily transported by current away from the adult population. '
Service water systems in generating facilities provide ideal habitat for Corbicula. Adjacent areas within the service water system with variable flow patterns of high- and low-velocity are conducive to the transporting and settling of juvenile clams. These areas also provide a continuous sou,rce of food and oxygen. Some plant operators have reported that the intake structure provides an ideal environment for the clam (Neitzel et al. 1984). The free-living juvenile clams range in size from 0.2 to 0.5 mm and are pumped into the service water system through screen and strainer openings of approximately 4.7 mm. After the young clams j settle in a suitable habitat they use a sticky mucus (the byssus) to secure themselves until the 5 mm stage is reached. After this stage, flow velocity will again influence their movement and deposition. Neitzel et al. (1984) also provided a list of locations within nuclear generation service water systems that are susceptible to clam biofouling. These locations within Farley Nuclear Plant (FNP) include the following:
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1 - branch headers supplying water to intermittent-flow cooling loops; 2 - auxiliary-building room coolers to: low pressure safety-injection pumps, high pressure safety-injection pumps, electric equipment rooms, and other pump rooms; 3 - other components such as containment cooling units; diesel generator co,olers; service-water strainers; control-room and computer-room air coolers; generator seal oil coolers; hydrogen coolers; and component cooling-water heat exchangers.
Control of Corbicula The control of Corbicula is complicated by their remarkable ability to survive environmental stress and their reproductive characteristics. The survival of Corbicula exposed to air depends on the relative humidity and can range from 7 to 27 days at temperature = of 30 to 20*C, respectively (NRC 1981). Bioassay studies at Commonwealth Edison utilizing mature clams show that regardless of whether the toxic agent was a high level of chlorine (1.0 cr 5.0 mg/l free available chlorine, FAC) or anoxia (no dissolved oxygen), 100% mortality was achieved in six to twelve days at temperatures of 29 and 18'C, respectively (EEI 1986). McMahon and Williams (1986) have reported that during overwintering periods and periods of environmental stress Corbicula_ may close its valves tightly and partially or completely respire anaerobically, leading to shell dissolution, erosion of the shell edge and degrowth. These facts clearly demonstrate this clam's ability to survive periods of stress.
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Historically FNP has used good housekeeping" of the service water (SW) components and intermittent chlorination to control clam biofouling.
Intermittent chlorination of three treatments per day at concentrations of less than 0.5 mg/l total residual chlorine (TRC) is used primarily to control microfouling (slime, fungus, etc.) and was believed to also control the Asiatic clam. During the Summer of 1986 the accumulation of sediment and Corbicula resulted in a high. temperature alarm being' received from a -
reactor coolant system charging-pump oil cooler. This event precipitated the need to re-evaluate the Corbicula control program.
The Pacific Northwest Laboratory has recently completed a number of extensive reviews of biofouling control in SW systems (Neitzel et al.
1984, Daling and Johnson 1985, and Johnson and Neitzel 1987). Basically, three, types of control are considered in the literature: heat shock, physical control and chemical control. The use of heated water to control juvenile Corbicula would require a 2-minute exposure at 120*F (49'C) (NRC 1981). The combination of heat shock with chlorination as a control method has been suggested by Sappington et al. (1986). Either of these options would exceed the 95'F (35'C) operational criterion for the FNP SW system during the su=mer and, therefore, are not viabic control options at this time. Due to the operating restrictions of the FNP SW system and the complexities of the clam's lif'e history, Corbicula control will require a combination of enhanced physical control along with chemical control.
Physical control is an essential aspect of a comprehensive i
management scheme designed to minimize Corbicula infestations. Physical control involves the routine inspection and cleaning of susceptible piping, which monitors the effectiveness of the initial screening and chemical control process. Routine dredging of the entire intake structure area is 3
- . o also necessary in order to eliminate a potentially large population of spawning clams which prefer this habitat upstream from the chlorinator.
Alabama Power Company uses commercial divers and a submersible trash pump with a flexible hose to remove the accumulated adult clams in this area.
Chlorine is currently used as a biocide by the industry, however, regulatory restrictions on chlorine discharge have become increasingly stringent over the past decade. ,The EPA published new effluent limitations for utilities in November 1982. The use of intermittent chlorination with total residual chlorine (TRC) discharge limitations of 0.20 mg/l has been found to be ineffective in controlling larvae and adult Corbicula (Johnson and Neitzel 1987).
Chlorine Minimization A variance from the 2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> - 0.2 mg/l TRC state (ADEM) and federal (EPA) guideline requires Alabama Power Company to determine the minimum amount of chlorine necessary to control Corbicula in the FNP SW system.
Daling and Johnson (1985) recommend a site-specific evaluation of the proper chlorine concentration because of water quality differences. They also recommend establishing a chlorination schedule which incorporates an optimum frequency and a minimum target concentration. Various aspects of the chlorination schedule would be determined from site-specific life history information and chlorine minimization testing using biomonitoring tanks.
Study Objectives The primary objective of this study was to develop a chlorination schedule which minimizes the amount of chlorine needed to maintain a level of control which would prevent observable fouling of SW components, as 4
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opposed to total eradication of Corbicula. Specific objectives of this study included the following:
- 1. Determine the density of Corbicula in the SW supply pond and intake structure.
- 2. Determine the extent of the Corbicula spawning season.
- 3. Determine Corbicula young of the year growth rates.
- 4. Determine if TRC concentrations ~ lethal to adult Corbicula can be maintained in.the SW system without exceeding 0.20 mg/l at the river discharge monitoring point.
- 5. Determine the time necessary to obtain a desired mortality of greater than 90% for adult Corbicula at the concentrations previously determined.
- 6. From the above information establish a permanent chlorination program that will control Corbicula infestations while minimizing chlorine discharges to the environment.
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s, MATERIALS AND METHODS Description of the Study Area Service water for the 1,720 MW nuclear generating plant is drawn from the Chattahoochee River and pumped to a 95 acre service. water supply ,
pond. Service water within the plant is used.in the turbine building heat exchangers, auxiliary heat exchangers, as dilution water and as make-up for the circulating water before being discharged back into the Chattahoochee River. Water from the supply pond is pumped separately to each of two units at a typical rate of 35,000 GPM.
Collection of Life History Information The density of Corbicula in the service water pond was determined during October 1986. Adults were collected using a Ponar dredge (23 X 23 cm) at random points and depths along four transects (Figure 1). Samples were also taken in front of the intake screens and in the wet pit area.
Sampler were sieved through a U. S. No. 8 screen, and Corbicula greater
$ :. 5 mm were counted. The density of adult clams collected during the Fall of 1986 are compared with those collected during the Fall of 1983.
The length of the spawning season was estimated by periodically determining the density of juvenile Corbicula in the service water.
Juvenile Corbicula were collected by filtering 100 gallons of service water on a weekly basis beginning in October of 1986 and continuing through December 1987. Service water was filtered at two points within each unit.
One point within the turbine building was located upstream from the heat exchangers and another was located at the Main Discharge Surge Tank (MDST) downstream from the heat exchang.e:s and prior to the merging of the once 6
, t through service water from both units. Juvenile clams were counted by microscopic examination with the aid of a Sedgwick-Rafter cell.
Corbicula growth rates within the service water system were determined by collecting sediment samples from 4 in plant side-stream ,
i biomonitoring tanks tapped into the SW system at the same points from which juvenile clams were collected. ' Clams retained in a U. S. #30 (greater than 0.6mm) screen were measured and counted in order to provide length-frequency.information on clams recruited into the side-stream tanks.
Minimization Testing Efficiency of continuous low-level chlorination was determined by exposing adult Asiatic clams housed in the previously mentioned biomonitoring tanks. During each treatment period one of the two service .
water systems was treated with sodium hypochlorite (Na0C1), exposing two biomonitoring tanks (located in the turbine building and at the MDST) to continuous low levels of chlorine. Unit One was treated four times beginning in the Fall of 1986 and ending in the Winter of 1988. Unit Iwo was treated three times beginning in the Spring of 1987 and ending in the Spring of 1988. The Na0C1 was injected into the treated unit with the use of a positive displacement picton pump. The two biomonitoring tanks tapped into the untreated service water system were uced as controls. Each i
biomonitoring tank housed at least 8 plastic trays, each containing 20 adult clams. Adult clams (greater than 0.5 inches) used to stock tanks l
l were manually collected from the service water pond. Flows through the the 30 gallon biomonitoring tanks were maintained between 4 - 5 GPM.
Clam mortalities were determined by periodically re=oving trays of clams throughout each treatment period. Mortality was determined by manual 1
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o o twisting of the clam valves or by obvious gaping. Treatment ceased when greater than 90% mortality was achieved in both of the treated tanks. Any trays remaining in the biomonitoring tank contributed toward the final nortality estimate. Each group (i.e., tray) of clams was considered a within - treatment replication. Statistical analyses were performed using oneway, Duncan multiple range and ANOVA procedures (SPSS 1986).
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Total residual chiorine-(TRC)' and free' available chlorine (FAC) were measured using the amperometric method (ASTM 1986). Accuracy was e
routinely checked using standard chlorine additions. Daily samples were also taken from each of the treated biomonitoring tanks. Chlorine concentrations were determined in accordance with ADEM's approval for the chlorination study.
Water Quality Temperature and dissolved oxygen concentrations for biomonitoring tank water were determined weekly with the use of a YSI meter.
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RESULTS AND DISCUSSION Corbicula in the Service Water Pond The densities of sexually mature (greater than 0.5 inches) adults collected during the Fall of 1983 and 1986 in the service water pond, intake structure, and wet pit are presented in Figure 2. Densities of adult Corbicula at the mouth of the intake structure (prior to intake screening) were 7 - 20 times greater than those found in the service water
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pond and the densities in the wet pit (after intake screening) were 106 -
248 times greater than those found in the pond. Adults associated with the intake structure and wet pit area take advantage of the variable flow patterns, plankton-rich waters, and protection from predation. The presence of numerous immature clams in the wet pit area suggests that Corbicula upstream from the screen are affected by natural predations. The high density of class inhabiting the intake structure suggests that they have been the primary source of contaminating spawn (juveniles and veligers) entering the FNP service water system. Clams in the intake structure were removed during the Winter of 1986 with the use of divers and a submersible pump. Approximately 40 cubic yards of clams and debris were removed. The existence of approximately 19 million clams in the service water supply pond (approximately 95 acres) guarantees the potential for contaminating spawn in the future operation of the plant.
Corbicula Spawn
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Means and ranges for monthly juvenile clam densities in the service water system are presented in Figure 3. Mean monthly temperatures within the turbine building service water are also presented.
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The density of spawn within the service water system indicates l
that the infestation of juvenile clams is constantly occurring during the eight warmer months of the year, with a major and minor spawning peak )
occurring during spring and fall, respectively. Minimal recruitment of juveniles occurs during the four months of late winter and early spring.
Spawning was not detected in January of 1987, when service water tempera-tures in the turbine building dropped'to 64*F (18'C) and resumed in May'
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when temperatures rose to 72'F (22'C). The biannual pattern of reproduc-tion with suppressed activity during the late summer has been reported by Dreier and Tranquilli (1977), Sickel (1977), Aldridge and McMahon (1978),
Cherry et al. (1986), and McMahon and Williams (1986). Optimum tempera-tures of 71-80'F (22-27'C) for juvenile release agree with those reported by Aldridge and McMahon (1978). The minimal amount of spawn during the winter and early spring at both the turbine building and MDST indicates that no significant spawning by adults occurs within the service water system during this period. Water temperatures at the MDST averaged 5'F i
l higher than those at the turbine building during this period. There were no significant differences (P greater than 0.05) in the amount of spawn between the turbine building and MDST during the eight month spawning period.
Corbicula Growth Growth rate and length-frequency information pertaining to clams recruited into the two turbine building biomonitoring tanks during the spring spawning period of 1987 is presented in Figures 4 and 5. Sediment deposited in the bottom of these tanks was collected 6, 33 and 62 days after recruitment began in the Unit 1 turbine building tank and 20, 41, 68, and 98 days after recruitment began in the Unit 2 turbine building tank.
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Maximum clam size in the two turbine building biomonitoring tanks exceeded 0.13 inches (3.1 mm) in 33 days, 0.25 inches (6.2 mm) in 62 days and 0.50 inches (12.5 mm) in 98 days. The minimum heat exchanger tubing diameter in the FNP service water system is 0.25 inches. Based on the information from the clam populations in the biomonitoring tanks (class retained by a number 30 sieve, greater than 0.6 mm) the a erage clam size in the FNP service water system would reach 0.25 inches witain 6 to 10 weeks after the initiation of the spring spawn. This growth rate is greater than those reported from Georgia and Texas. Data from McMahon and Williams (1986) showed that clams from Trinity River Texas spawned in the spring had mean generation lengths of 6 - 7 mm in August of that same year. Clams spawned in the spring from the Altanaba River, Georgia appear as the 4 mm length class in August. The greater rate of growth for clams in the FNP SW system reflects the favorable characteristics of the ,
habitat. Sickel (1977) has documented differences in growth characteristics between Corbicula populations from the Mud River, West Virginia and tne Altareba River, Georgia.
Efficiency of Low Level C,h_lorination Average TRC levels of 0.20 to 0.37 mg/l at the MDST were possible i
without exceeding 0.20 mg/l at the river discharge. Table i presents the total 1
residual (TRC) and free available (FAC) chlorine from the first six treatments l
at the two biomonitoring tanks, MDST, and river discharge. Chlorine concentrations within the SW system were similar during five of the six trea:ments. Treatment number three maintained a significantly (P less than 0.05) greater TRC concentration at the MDST when compared with the other five treatments.
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. r 1 TRC levels of greater than 0.30 mg/l were purposely maintained at the MDST during treatment three in order to determine what maximum chlorine levels were achievable without exceeding the 0.20 mg/l TRC limit at the river discharge. Chlorine levels were purposely maintained between 0.20-0.30 mg/l during the other five treatments.
The TRC level at the river discharge varied from 32% to 55% of the levels maintained at the' MDST. This variation in reduction of TRC at the river discharge is positiv'ely related to SW temperature, with the greatest reduction possible during the summer months when chlorine demand is greatest. Average TRC levels at the river dacharge for each treatment were maintained at or below 0.14 mg/1. Incidental TRC levels were greater than 0.20 mg/l during treatments 1 and 2. Experience with the Na001 feedrate additions kept all incidental TRC levels below 0.20 mg/l during treatments three through six.
The clams in the biomonitoring tanks e exposed to TRC levels similar to TRC levels at the MDST. Therefore, the 4 - 5 gpu flow rate through the 30 gallon biomonitoring tank is considered sufficient for maintaining the came level of chlorine that is found in the service water.
There were no significant differences (P greater than 0.05, paired t-test) in the TRC concentrations between the MDST valve (weighted daily average TRC) and the MDST biomonitoring tank (daily TRC). Daily concentrations of TRC in the turbine building biomonitoring tank were significantly less (P less than 0.05, paired t-test) by 0.06 - 0.08 mg/l TRC than the weighted daily values from the MDST valve during treatments 3 and 4. These differ-l ences are likely due to the chlorine demand within the samples from the turbine building during transport prior to analysis. Average chlorine values from the MDST valve should be considered more precise than those 12 l
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values from the biomonitoring tanks because there were no discernible differences between chlorine values from the MDST valve and tank and the ,
frequency of measurements from the MDST valve was much greater than from the biomonitoring tank.
Variation in treatment durations (8-56 days), dictated by the 90%
clam mortality - 8 week limit criteria, were primarily due to seasonal changes in SW temperature. Increased' water temperature would increase the metabolic rate of the clam, improving the efficiency of the biocide. Table 2 presents the average Corbicula mortality on the last day of each treatment along with the Unit treated, date of treatment, treatment days and SW temperature. Figure 6 presents the relationship between Corbicula mortality, SW temperature and treatment days. A greater than 90% mortality is not achievable within an eight week period at temperatures less than 62'F (17'C). As temperatures approach 90*F (32*C), a 90% mortality is achievable within a week. Final control mortalities for each treatment averaged 6% or less at both the MDST and turbine building, with the exception of the turbine building biomonitoring tank during treatment 4.
Average mortality in this tank reached 29%. A possible reason for this unexplained mortality may be natural mortality due to disease.
In their recent bulletin (I_mproving the Reliability of Open-Cycle Water Systems, Volume 2) Johnson and Neitzel (1987) state that "continuous chlorination at 0.60 ppm or greater is required during spawning seasons to control Asiatic clams." Our results have shown that chlorine levels of 0.20-0.30 mg/l TRC are adequate for controlling Corbicula within eight weeks at temperatures greater than 62*F.
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Water Quality With the exception of one occasion when valves were accidentally shut off, dissolved oxygen levels in the biomonitoring tanks were maintained above 4.9 ag/a during each treatment. Information from the in-line temper-ature monitors reveals that no unusual water temperature spikes occurred in the service water system during the treatments. The service water at FNP is considered soft for biological purposes, with total alkalinity ranges of' 12 - 27 ag/l and total hardness ranges of 18 - 27 ag/1.
Conclusions The following conclusions are a result of the previous life history and toxicology information and are proposed as a permanent chlorination program:
- 1. Total Residual Chlorine (TRC) levels during the treatment periods will not exceed 0.20 mg/l at the river discharge. A Free Available Chlorine (FAC) level of at least 0.20 mg/l is desired at the furthermost point of concern in the system (i.e., Main Discharge Surge Tank) during each treatment.
However, the TRC limit at the river discharge will be the controlling factor.
- 2. Annually the treatments will begin with the initiation of spawning activity, or on May 1, whichever occurs first. The initiation of spawning activity will be determined through biomonitoring. The SW of each unit will be scheduled for treatment at a nominal frequency of eight weeks between treatments. Subsequent rounds of chlorination will commence approximately eight weeks after terminating the last previous 14
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- treatment of the subject unit. All treatments will continue for eight weeks, or until greater than 90% mortality is indicated in each treated biomonitoring tank, whichever occurs first.
- 3. Initiation of treatments will continue, as necessary, through December 31 each year. ~ All treatments commenced will continue until the 90% mortality /eight week.. criterion is achieved. Any spawn from the winter will 2 ;erience low growth rates and be controlled the following year.
- 4. The side-strean biomonitoring tanks will be used during treatment periods to insure that the duration of every chlorination treatment has been minimized and the desired mortality level is achieved (i.e., 90% mortality).
- 5. During the chlorination of a unit's SW for Corbicula control; the opposite unit will receive the current chlorination program of three intermittent treatments per day in order to ,
control microfouling (slimes, fungus, etc.). t t
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i LITERATURE CITED Aldridge, D. W. and R. F. McMahon. 1978. Growth, fecundity, and bioenergetics in a natural population of Asiatic freshwater clam, Corbicula manilensis Philippi, from North Central Texas. Journal of Molluscan Studies 44:49-70.
ASTM. 1986. Standard methods for the examination of water and wastewater.
1193 pp. .
Cherry, D. S. , R. L. .Roy, R. A. Lechleitner, P. A. Dunhardt, G. T. _ Peters and J. Cairns, Jr. 1986. Corbicula fouling and control measures at the Celco"Plant', Virginia. Amer. Malacol. ~ Bull;. , Spec. Ed. No. '2 (1986):69-81.
Daling, P. M. and K. I Johnson. 1985. Bivalve fouling of nuclear power
, plant. service-water s'ystems, Vol. 2. Pacific Northwes.t Laboratory. .
NUREG/CR-4070,.PNL-5300 Vol. 2. 59 pp.
Dreier, H. and J. A. Tranquilli. 1977. Reproduction, growth, distribution, and abundance'of Corbicula in an Illinois cooling lake. Illinois Nat.
Hist. Surv. Bull. 32 (4):378-393.
EEI (Edison Electric Institute). '1986. Asiatic clams tested at' Edison ' "
Station. in:Biocurrents 2 (2):12 pp.
Johnson, K. I. and D. A. Neitzel. 1987. Improving the reliability of open-cycle water systems, NUREC/CR-4626 PNL 5876 Vol. 2.
McMahon, R. F. and C. J. Williams. 1986. A reassessment of growth rate, life span, life cycles and population dynamics in a natural population and field caged individuals of Corbicula fluminea. Amer. Malacol.
Bull., Spec. Ed. No. 2 (1986):151-166.
Neitzel, D. A., K. I. Johnson, T. L. Page, J. S. Young, P. M. Daling, 1984. Bivalve fouling of nucicar power plant service-water systems.
Vol. 1. Pacific Northwest Laboratory. NUREG/CR-4070, PNL-5300 Vol. 1.
119 pp.
NRC (Nuclear Regulatory Co= mission, Of fice of Inspection and Enforcement).
1981. IE Bulletin 81-03: Flow blockage of cooling water to safety system components by Corbicula sp. and Mytilus sp.. NRC Region II, Atlanta, Ga., RII:JPO, 50-348, 50-364. Spp.
Sappington, K. G. , S. E. Belanger, D. S. Cherry and J. Cairns, Jr. 1986.
Combination of heat shock with chlorination as a control method for Corbicula fluminea. Soc. Env. Toxic. Chem., 7th Ann. Meeting.
Abstracts.
Sickel, James B. 1977. Population dynamics of Corbicula in the Altamaha River, Georgia, in: Proc. First Intern. Corbicula Symposium, J. C.
Britton, ed., pp. 69-80. Texas Christian Univ. Research Foundation, Fort Worth, Texas.
SPSS. 1986. SPSS/PC+ for the IBM /XT/AT.
I FARLEY NUCLEAR POWER PLANT SERVICE WATER POND Bost'Remp . Aux.RiverWater V.
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3 Figure 1. Service water supply pond for the Farley Nuclear Plant ueat Ashford , Alabama.
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ADULT CORBICULA IN THE FARLEY NUCLEAR 2 POWER PLANT SERVICE WATER POND 11923 ADULT 10000
- 5 1983
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CORBICULA !! [ 1986 /
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- SERVICE WATER INTAKE MOUTH WET PIT POND Figure 2. Number of Asiatic clams in the Farley Nuclear Plant service water pond during the Fall of 1983 and 1986. Sa
- nples were taken within the pond', at the mouth of the-intake structure prior to screening, and after screening in the wet pit of the intake structure (N number of samples).
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90 y 85 sBRvIcE YATER TEMPERATURE IN THE TURBINE DUILDING B0 TEMP. 75 -
(DEG. F) 70 --
65 -
60 --
55 --
50 -- : : : . : . : : : : : : : :
400 - ,
JUVENILE 300 - '
IuNGE OF MVENILE CLAM NUMBERS CLAMS c0I.I.ECTED IN GERVICE WATER -
PER 200 -
CU. METER ~
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Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Figure 3. Mean monthly service water temperatures in the turbine building along with the means and ranges for monthly juvenile clam densitica found in the service water system from October 1986 to December 1987.
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I SIZE DISTRIBUTION OF Corbicula 9 0 -- IN THE UNIT 1 TURBINE BUILDING .
BI0 MONITORING TANK
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06/11/07 - 08/12/87 70--
60 --
PERCENT 50-- O 6 DAYS; N=0 -
COMPOSITION E3 33 DAYS; N=125 40 .
IE 62; DAYS; N=200 30--
20 -- .., 6.23 MM = 0.25 IN.
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1 2 3 4 .5 6 7 8 9 10 11 12 LENGTH GROUP (MM)
Figure 4. Percent composition of various length groups for Corbicula collected from the Unit 1 turbine building biomonitoring tank. Samples were taken 6, 33, and 62 days after recruitment from the service water began on June 11, 1987 (N = number of live clams collected). .
SIZE DISTRIBUTION OF CorMoula 70 -- IN THE UNIT 2 TURBINE BUILDING BIOMONITORING TANK 60 - 5g 05/07/87 - 08/12/87 50 --
PERCENT 40 -- . 6.23 MM = 0.25 IN.
COMPOSITION k o ao DAYS; N=0
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k .' O 41 DAYS; N=43 S
B 68 DAYS; N=84 t
20-- y ,
m E 98 DAYS; N=33 i ,
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- '!: *: : : : *: : S: : : : 1 1 2 3 4 5 6 7 8 9 10 11 12 13 LENGTH GROUP (MM)
Figure 5. Percent composition of various length groups for Corbicula collected from the Unit 2 turbine building biomonitoring tank. Samples were taken 20, 41, 68, and 98 days after recruitment from the service water began on May 7, 1987 (N = number of live clama collected).
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Figure 6. The percent mortality for Asiatic clams in the FNP SV system exposed to treatment averages of 0.20 to 0.37 mg/l TRC aloog with SW temperatures and treatment days. Includes data from treatments 1 - 6.
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Table 1. Means and ranges for daily average total residual and f ree availabic chlorine measurements
- f rom the two biomonitoring tanks, surge tank valve and river discharge during the six treatment periods. Mean values at the surge tank and river discharge were weighted according to the time of previous measurement.
TEsf Total 1 2 3 ,4 5 6
. TOTAL RESIDUAL CMLORINC .
Turbine 8tdg., diomonitoring Tank Mean .26 - .23 .29 .14 .24 .18 .22 Minisuu .20 .01 .09 .07 .14 .09 .01 Maalmae , .34 .39 40 .23 40 , .32, 40 surse Tanki 8IcoonitorIng iank -
Mean .29 .24 .34 .19 .21 .26 .26 Minisue .20 .01 .10 .12 .10 18 .01 Maxisun .37 .38 .50 .2i .30 .37 .50 Surge Tank, Service Water Yalve Mean .
.20 ~.26 - .37 .22. .24- .26 - .25 -
Minisun .11 0.0 .10 .17 .19 .18 0.0 Maalaus .27 .37 .53 .33 .29 .35 .53 River Olscharge Mean .11 .11 .12 .08 .12 .14 .12 Minisun .06 .05 .03 .04 .09 .05 .03 Manicun .16 .18 .16 .11 .14 .18 18 FREE AVAILASLE CHL0tthE Turbine Blds., Biorunitoring Tank Hean .11 .14 .14 .07 .12 .09 .11 Minisun .07 .01 .07 .04 .10 .C2 .01 Man teus .16 .25 .20 .#? .14 .17 .25 Surge Tank, Olomonitoring f ank ,
Mean .12 .13 .18 .10 .12 .14 .13 Ministm .08 .01 .07 .06 .05 .07 .01 Mamieus .16 .24 .25 .12 .20 .18 .25 Surge Tank, service Water Valve Mesa .14 .17 .20 .11 14 .14 .15 Minleus .06 0.0 .06 .08 .12 .08 0.0 Maxieun .23 .26 .29 .15 .17 .18 .29 River Discharge Mean .09 .06 .07 .04 .07 .07 .07 Minfeus .04 .03 .02 .02 .04 .03 .02 Maalaus .14 .11 .10 .07 .10 .09 .14
- Values less than 0.05 mg/l were ..$1culated as 0.0 mg/1.
- Chlorine concentrations determined usiig Dr5 ferrous titrimetric method, all other measurements conducted using the amperometric titration method.
Table 2. Treatment information along with final clam mortalities and water temperature ranges for the bicsonitoring tanks.
Water Treatment Unit Beginning Ending Exposure Biomonitoring Final Mortality Temperature Number Treated Date Date (Days) Tank Location with 95% CI ('F) 1 1 10-28-86 12-04-86 38 Turbine Bldg. (Treateo). 97.5 60.8 - 72.0 MDST (Treated) .' 97.5 70.7 - 72.0 Turbine Bldg. (Control) 5.0 -----------
MDST (Control) - ---- - --
2 2 04-07-87 05-07-87 30 Turbine Eldg. (Treated) 95.8 59.0 - 72.0 MDST (Treated) 99.2 59.4 - 77.4 '
Turbine Bldg. (Control) 0.0 -----------
MDST (Control) 0.0 -----------
-il 3 06-01-87 06-11-87 11 Turbine Bldg. (Treated) 91.3 4
. 1 78.8 - 79.9 MDST (Treated) 98.8 84.6 - 85.3
- Turbine Bldg. (Control) 0.0 =- -----
MDST (Control) 0.5 -----------
4 2 07-15-87 07-22-87 8 Turbine Bldg. (Treated) 83.9 83.8 - 86.2 MDST (Treated) 93.9 89.4 - 92.8
! Turbine Bldg. (Control) 29.3 -----------
- MDST (Control) 6.1 -----------
i 5 1 09-08-87 09-18-87 11 Turbine Bldg. (Treated) 100.0 82.4 - 83.3 MDST (Treated) 99.5 84.2 - 86.9 Turbine Bldg. (Control) 3.0 -----------
i M9ST (Control) 2.5 = - - ==----
6 1 11-11-87 01-05-88 56 Turbine Bldg. (Treated) 64.8 50.7 - 64.8 MDST (Treated) 98.6 59.9 - 68.9 Turbine Bldg. (Control) 0.0 -- --
MDST (Control) 0.0 -----------
O D tuct0suae i Alabama Power Company 000 Nom 18m Stmt Poet Office Bom 2641 54rcningham. A14Mme 35291 Telephe 205 2MM ,
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- tre sanwn ewc swem October 22, 1986 M.. Immes P. Martin A1.nbana Department of Erviromeental Management 175'i Federal Drive pentguaery, AL 36130
Dear Mr. Martin:
As discussed during our phone conversation of 0:tcher 22,1986, we are requesting your approval to conduct a stta$y to determine chlorine concentrations and exposure time necessary for Corbicula control in service water systans at the Parley Noclear Plant. The study will consist of the ,
following:
I. Three Week Study A. Maintain chlorine concentrations at the service water intake (for one unit) necessary to provide a free available chlorine (FAC) level of 0.20 reg /l at the furthectost point of concern in the systan.
B. Maintain prescribed chlorine level for a period of three (3)
I weeks.
f C. Evaluate effectiveness of chlorination on Cbrbicula i
control (larvae and adult foons)
II. Iong 'Iban Study to Evaluate (brbicula Control A. Iglanent continuous chlorination progran for the FNP service water systan, which will precita$e simitaneous chlorination of units 1 and 2.
B. Evaluate long-tean chlorination levels necessary to control (brbicula larvae.
C. Maintain chlorination levels at the service water intake (for one unit) nemmry to provide & FAC level equal to or less than 0.20 reg /l at the furthe~ < goint of concern in the systen.
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Mr. J. P. Martin Page 2 October 22, 1986 D. Evaluate offectiveness of dilorination on Oorbicula larvae control for a period of one year.
If you should have any questions concerning this regaest, please contactise.
Sincerely, D. Grogan, r Envirorraental Ompliance sdy R
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i ENCLOSURE 2 i
. a e__ ADEM ALABAMA M)--.
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DEPARTMENT OF ENVIRONMENTAL MANAGEMENT George C WaHace Governor L*e h P***** D" ** October 28, 1986 1761 Federal Drive .~~. -
Meengomery. AL g'k ~
3413o 4 204/271 7700 Mr. Willard Bowers ed' h
Hanager N \
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Alabama Power Company $ ,
Unit eo6. svaee s P.O. Box 2641 6 .
22s ommoor c=* Birmingham, AL 35291 A( f\
34209 206/942 4168 Dear Mr. Bowers Re: Farley Nuclear Plant 3
Decatur.AL asso2 We have received and reviewed John Grogan's October 22, 1986 letter ros/363 m3 relating to corbicula control at the above referenced plant. We understand that the control of these organisms has been inadequate 22o4 recimeter moed with the present level of chlorination and that operational and mow.AL regulatory concerns have arisen as a result of this problem.
36616 206/479 2336 We believe that your proposed methodology for the study is acceptable, with the following conditions:
detectable are maintained at the main discharge line, just prior to discharge to the river, during the three week and long term studies.
- 2. During the period of chlorination raep-up, chlorine monitoring is performed at DSN001(or 002) at hourly intervals until detectable levels are found, hourly intervals thereafter at the point referenced in 1., then once per 30 minute intervals until the system reaches equilibrium at no greater than the limitation levels. Thereafter, ut.less flows, chicrinc feed rates or cther considerations could impact chlorine, levels TRC and FAC shall be monitored daily at both points. If conditions do change, TRC and FAC shall be monitored once per 30 minutes until equilibrium is aaain reached.
- 3. Results from all TRC/FAC monitoring shall be submitted on the quarterly discharge monitoring reports, as appropriate, and also under separate cover on a conthly basis within 30 days after the end of each month, during the duration of the three week and long term studies.
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- 4. At'the end of the long term study, a reprot shall be submitted -
assessing the minimum level of chlorination possi' ole for corbicula [
./ control. ;
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Sincerely, >
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l James P. Martin, .E .
Chief l Industrial Branch [
- - Water Division ,
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s l' N' ENCLOSURE 3
/.
I ATIACHMENT 4 Revised ADEM Conditions For EWP Service Water Chlorination Discussions with Mr. J. P. Martin, ' Alabama Deparbeent of E:nvirorseental Management, on October 29, 1986 have resulted in a revision
. to ADEM conditions associated with the modifled chlorination prograu. In accordance with these discussions, Item 1 of Attachnent 3 (Intter fran John D. Grogan to W. C. Carr, dated October 23, 1986) should be arnended to read as follows:
'Ibtal residual chlorine discharge levels are not to exceed 0.20 ppn at the river discharge structure during the three week study and long-term prograu.
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Alabama Po.et Company 600 North 16tn Street Post Ott.ce Bos 2641 ,
0 emingham. Alabama 35291 '
Teie phone 20$ 2501000 L
Alabama Pbwer ve sewwn ewc spem mvernber 3,1986 Farley mclear Plant
. NPEES Penait Ms. AID 024619 Mr. Janes P. Martin Alabarrn Departroent of D1virorinental Management 1751 Pederal Drive Mantgcreery, AL 36130
Dear Mr. Martin:
As discussed durirn our phone conversations, we are providing ailitional informtion regarding our request to riodify chloriration of the '
service water systern at the above referenced facility.
Potential biofouling probleus associated with Corbicula were first roted in 19,8 7 at the referenced f acility. Various control practices incitding physical, biological and chernical roeans have been utilized. Sono of the more recent methods are as folicvs:
- 1. Stop log mintenance in the service water intake structure.
- 2. Clarn reaval frcru the intake structure ard systans within the plant.
- 3. Strainer Maintenance Programs
- 5. Placanent of fishes known to use Corbicula as a food source in the service water parvi In 1986, Cbrbicula were collected at toth the intake structure ard throughout the service water pord. These investigations ab>ed a significant increase since 1983. [hrity the current outage of thit 1, a large nurnber of live class have been collected in pipirn thrugh>ut the service water syston.
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/ Kr. James P. Kirtin -
Page 2
/f tbvsaber 3, 1986 de Rx: lear Regulatory &mminaion (NBC) is aware of biofoulirn conditions which can exist in generating facilities. his problaa has been noted in NRC's IE Fulletin m. 81-03 with requirements to an=== and correct problems associated with Cbebicule of blockage safety systen oorsponents.
Based on the above infonaation, modifications to the chlorination prograrn were deemed necaamy. Elevated chlorine levels within piping systians cause significant corrosion, thus our goal is to achieve the minirun anount of chlorination required to control Cbcbicula whilts raaintaining requirements to operate our systen in a safe and efficient mannet.
Past chlorination practices utilizing chemicals noted in Itan 4 have been structured such that tirse restraint conditions in the NPEES perrait for IEN 001 ard 002 were met. However, we 5111 be chlorinating on 4 continuous basis during both the three uk and Icm-tenu attdies as outlined in my letter of October 22, 1986. Followirg evaluation of past results ard results obtained fran this sttdy, we will subnit a request to your of fice as described in the *** Footnote for DSN 001 ard 002 which will dcrxnstrate that a chlorine dischstge of greater than two hours is required for recroinvertebrate control. As noted in the two sttdies, it will be necessary to exceed the present two (2) hour limit for unit chloriration in order to obtain data for cur dcmonstration.
As discussed in our phone conversation of Octcher 29, 1986, we will be maintainirn a total residual chlorine level of 0.2 m3/1 or less at the river discharge structure. It is requested that you anerd Itan 1 of ycur O:tober 28, 1986 letter to reflect the charge in apptwed total residual chlorine levels at the river discharge structure.
Should you have any questions or require additional inforrution, please contact ne.
- sincerely,
. [1---
John D. Grujan, r Envirornental (tr:pliance Jm:dy
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3 Birmingh.m. Alabema 35291 Telephone 205 25o-1000 ENCLOSURE 5 m
Alabama Power tre scute sectrc snre<n November 17, 1986 Farley. Nuclear Plant NPDES Permit No. AL0024619 Mr. James P. Martin Alabama Department of Environmental Mana( went 1751 Federal Drive Montgomery, AL 36130 l
Dear Mr. Martin:
As discussed during our November 7, 1986 phone conversation, we are providing additional information regarding the condition contained in item 1 of your October 28, 1986 letter. A change in this condition to a level of 0.20 ppm Total Residual Chlorine (TRC) or less at the river discharge structure was necessary to successfully conduct the two phase study to determine proper levels of chlorination for Corbicula control in the service water system.
Our requests of October 22, 1986 and November 3, 1986 were based on three items in the NPDES permit. .The first *** Footnote for DSN's 001 and 002 states, "Total residual chlorine raay not be discharged from any single generating unit for more than two hours per day unless the j discharger demonstrates to ADEM that discharge for more than two hours is required for macro invertebrate control..." Evidence of Corbicula in plant systems demonstrates that discharges for more than two hours will be i necessary to control this macro invertebrate. The study outlined in our l letter of October 22, 1986 is designed to determine the necessary level.
l The second, Part !!.A.4, provides conditions for bypassing. Part c.1 and 2 indicates a bypass is not prohibited and need not meet permit limits if necessary to prevent severe property damage and there are no l feasible alternatives. Our phone conversations and previous correspondence addressed existing conditions in the service water system and alternatives attempted to control Corbicula. We are bypassing our normal treatment to i meet chlorine limits at DSN's 001 and 002 during this period in order to l
find the necessary level needed for Corbicula control.
1 Part II.B.7 addresses temporary suspension of a part of the NPDES pennit when cause exists for such suspension. As discussed previously, current conditions existing in the service water system meet the necessary cause requirements which would allow for a temporary suspension of the effluent limitations and monitoring requirements for DSN's 001 and 002.
.~.
0 0 if Mr. James P. Martin Page 2 ,
November 17, 1986 J i
i As noted in our phone conversations and previous correspondence, I we are only chlorinating the service water system of one unit at a time and l are monitoring the levels of TRC in the river in the vicinity of the discharge. These measures are to insure that the impact on the river will be minimized as a result of these activities.
Should you require additional information, please contact me.
Sincere y, n // h 00hn D. Grogan, Manager Environmental Compliance JMG:dy 1
1
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' ENCLOSURE 6 L-)
ATTACHMENT 5 Revised ADEM Conditions for FNP Service Water Chlorination The discussion with Mr. J. P. Martin, Alabama Department of Environmental Management, on November 25, 1986 has resulted in a revision to ADEM conditions associated with the modified chlorination program. In accordance with these discussions the following items should be amended. .
Section I and I.B of Attachment P. (letter dated October 22, 1986 from John D. Grogan to Mr. J. P. Martin) should ,
be amended to read as follows: )
I. Four Week Study B. Maintain prescribed chlorine level for a period of four (4) weeks or 100% mortality of Corbicula indicator organisms whichever occurs first.
Item 1 of Attachment 3 (Mr. John D. Grogan's letter to Mr. W. O. Carr dated October 23,1986) should be amended to reac as follows:
- 1. Total residual chlorine discharge levels are not to exceed 0.20 ppm at the river discharge structure during the four week study and long-term program.
The extension of seven days does not alter the Non-Radiological Environmental Impact Evaluation made concerning Service Water Chlorination which was submitted to Mr. W. C. Carr on November 3,1986.
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- f. . W 4:4eama po.:, com:aa, ENCLOSURE 7 600 North 18th Stret
. Post Off4ce Eos 2141
.i Birmingham. Alacama 35291 Telepnone 205 250-1000 b :
Alabama Power the Southern eutre suvem November 26, 1986 Farley Nuclear Plant NPDES Plant No. AL 0024619 ;
Mr. James P. Martin .
Alabama Department of Environmental Management 1751 Federal Drive Montgomery, AL 36130
Dear Mr. Martin:
This letter is to confirm changes discussed in our phone conversation on November 25, 1986 to the service water chlorination study for the above referenced facility. As stated, we will extend the three weak study to a four week study or 1007, mortality of Corbicula indicator organisms whichever occurs first. We will contact your office on December 1,1986 and report whether additional time is necessary.
Should you have any questions, please contact me.
Sincerely, JohnD.Grogan[an Environmental ompi nce JMG:dy
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.Y Attachment 3 Revised ADEM Conditions for FNP Service Water Chlorination i
Discussions with Mr. J. P. Martin, Alabama Department of Environmental Management (ADEM), have resulted in revisions to ADEM's t conditions associated with the approved modified chlorination program.
They are as follows:
- Continuous chlorination for Unit 2 may continue for eight weeks or until greater than 90% mortality of Corbicula control indicator organisms is achieved whichever occurs first.
- Total residual chlorine discharge levels are not to exceed 0.20 ppm at the river discharge structure during each chlorination period.
The ADEM will make a decision regarding approval of our desired i long term chlorination procedure following completion of the one year program approved by the ADEM on October 28, 1986.
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ENCLOSURE 9
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..JA$d m . _ . . .
e Attachment !!!
Revised ADEM Conditions for FNp Service Water Chlorination Discussions with Mr. Jim Moore (ADEN) have resulted in an extension ar.d revisions to ADEM's conditions associated with the currently approved They are aschlorination follows: program scheduled for completion on October 28, 1987.
- The October 28, 1987 deadline has been lifted to allow one more chlorination for Corbicula control on each unit. This will allow for control of the Corbicula produced from the Fall spawn.
Continuous chlorination for either unit may continue for eight weeks or until greater than 90% mortality of Corbicula indicator organisms is achieved. .
whichever occurs first.
While chlorinating one unit for Corbicula control the opposite unit may be chlorinated with chlorine dioxide) as per "nor(mal" procedures fori.e., 3 periods / da service water chlorination.
Total residual chlorine levels are not to exceed 0.20 ppm at the river discharge structure during each chlorination period.
i