ML18283B695
ML18283B695 | |
Person / Time | |
---|---|
Site: | Browns Ferry ![]() |
Issue date: | 06/30/1976 |
From: | Tennessee Valley Authority |
To: | Office of Nuclear Reactor Regulation |
References | |
RH-76-2-BFl | |
Download: ML18283B695 (42) | |
Text
RH-76-2-BFl ENVIRONMENTAL RADIOACTIVITY LEVELS BROWNS FERRY NUCLEAR PLANT July-December 1975 JUNE 1976
CONTENTS Introduction ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ' ~ ~ ~ ~ ~ ~ 1 Figure 1 Tennessee Valley Region ~ ~ 2 Table 1 Environmental Radioactivity Sampling Schedule 4 Figure 2 Atmospheric and Terrestrial Monitoring Network 5 Atmospheric Monitoring . ~ 7 Table 2 Radioactivity in Air 9 Table 3 Maximum Permissible Concentrations for Nonoccupational Exposure . 11 Table 4 Rain 12 Table 5 - Total Fallout Deposited 14 Table 6 Charcoal Fglters . 15 Terrestrial Monitoring 17 Figure 3Milk Monitoring Network 18 Table 7 Milk ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ 20 Table 8 Vegetation . 21 Table 9 S oil ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ 23 10 Private Well Water Table Table Table ll- Public Water .
12 Environmental Gamma Radiation Levels .
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24 25 26 Table 13 Poultry and Food Crops . 27 Reservoir Monitoring 29 Table 14 Sampling Schedule Reservoir Monitor ing ~ ~ ~ ~ ~ ~ 31 Figure 4Reservoir Monitoring Network . 32 Table 15 River Water, Dissolved Activity. 0 ~ ~ 33 Table 16 River Water, Total Activity 34 Table 17 River Water 35 Table 18 Fish r ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ 36 Table 19 Plankton . 37 Table 20 Sediment . 38 Table 21 C 1am ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ 39 Quality Control ~ ~ 41 Data Analysis ~ ~ ~ ~ ~ ~ ~ ~ 41 Conclusions ~ ~ ~ ~ ~ ~ ~ 41
ENVIRONMENTAL RADIOACTIVITY LEVELS BROWNS FERRY NUCLEAR PLANT JUNE-DECEMBER 1975 Introduction The Browns Ferry Nuclear Plant (BFNP), operated by the Tennessee Valley Authority, is located on a site owned by TVA containing 840 acres of land in Limestone County, Alabama, bounded on the west and south by Wheeler Reservoir (see figure 1). The site is 10 miles southwest of Athens, Alabama, and 10 miles northwest of Decatur, Alabama. The plant, when com-
- pleted, will consist of three boiling water reactors; each unit is rated at 3,293 MWt and 1,098 MWe. Unit 1 achieved criticality on August 17, 1973, and began commercial operation on August 1, 1974. 'nit 2 began commercial operation on March 1, 1975. However, neither unit has operated since March 22, 1975, when.a fire in the cable trays necessitated the shutdown of both reactors.
The preoperational environmental monitoring program established a baseline of data on the distribution of natural and manmade radioactivity
~
in the environment near the plant site. However, seasonal, yearly, and random variations in the data were observed. In order to determine -the potential increases in environmental radioactivity levels caused by the plant, comparisons were made between data for indicator stations (those near the plant) and control stations (those remote from the plant).
Field staffs in the Division of Environmental Planning and the Division of Forestry, Fisheries, and Wildlife Development carried out the sampling program outlined in tables 1 and 14. Sampling locations are shown in figures 2, 3, and 4. ,All the radiochemical and instrumental analyses were conducted in a central laboratory at Muscle Shoals, Alabama. Alpha and beta analyses were performed on Beckman Low Beta II and Beckman Wide Beta II low background proportional counters. Two Nuclear Data Model 2200 multichannel analyzer systems were used.to analyze the samples for specific gamma-emitting radionuclides. Data were coded and punched on IBM cards or automatically printed on paper tape for computer processing specific to the analysis conducted. An IBM 370 Model 165 computer, employing an Alpha-M least squares code, was used to solve multimatrix problems associated with estimating the activities of the gamma-emitting nuclides.
'A primary difficulty in sample analysis was the detection of very low radionuclide concentrations. The minimum sensitivities are those concentrations where the percent counting error is 100%, calculated assuming a 3-sigma counting error, when standard sample sizes and counting time are employed. The minimum sensitivities are therefore those concentration values below which it is impossible to state, at the 99 percent confidence level, that any amount of radioactivity above background exists in the sample. The sensitivities, based wholly on counting statistics, are listed
=
for gross alpha, gross beta, and tritium analyses.
'c LOUISVA.LE TENNESSEE VALLEY REGION i (TVA NUCLEAR PLANT SITES) V A VOWENSSQRO l
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K E N T U K Y r Lr~
+LC PAOUCAH 8OWUNG GREEN I 1 M 0.
5 I'-.J PER r
/t'
( /NN ~~ j /
rr I (
/ ASHVILL C L.r OAK RIDGE j N rrC A R. "1
+~3 I / Cl JACKSONCP
/ IO (xr
(
/
/ (~p /
NENPHIS ~NP J 8" I I rW/
CHATTANOOGARL l
o 8NP ~ f S C A R
\ +HUNTSVILLE \ J XE" MUSCLE SHOALS NP Ig /
IJ LEGEND
/ ~
AEE- HRRTNIRLLE NUCLERR PLRNI fggif-PHIPPS BEND NUCLEAR PLANT M I SS. IJ QPQK- LIQUID METAL FAST BREEDER I
A L A B A M A GEORG I A ~-WATTS REACTOR BAR NUCLEAR PLANT 39/-SEOUOYAH NUCLEAR PLANT "BELLEFONTE NUCLEAR PLANT
- BROWNS FERRY NUCLEAR PLANT YQP- YELLOW CREEK NUCLEAR PLANT*
- Proposed
Standard sensitivities are not listed for specific gamma-emitting radionuclides determined by the Alpha-M program because they are not available. Since the minimum sensitivities are not defined, some concentrations reported may not represent actual concentrations.
They may be mathematical artifacts of the Alpha-M program. Concentra-tions with errors (estimated by the Alpha-M program) larger than the reported concentrations are listed as "not detectable" (ND). The errors reported define the statistical distributions of the errors estimated by the Alpha-M least squares program.
Table 1 ENVIRONMENTAL'ADIOACTIVITYSAMPLING SCHEDULE Air Charcoal Rain- Heavy Particle ~
River Well Public Aquatic Life station ioaation pitter ritter water Fallout toil ~re etation Milk water Mater water and Sedinent Muscle Shoals W W M M Q M Lavrenceburg 'W W M M Q Fayetteville W W M M Q Cullman W W M M Rogersville W W M M Athens Decatur Courtland W W M,
M M
M M
Q Q
'Q Site NW-1 W W M M Q Q Site N-2 W .
W M M Q Site NE-3 W W M M Site NW-4 W W M M Q Q Farm B W Farm Bi Farm H Farm T Farm L Wheeler Dam Elk River Tennessee River M, Champion Paper Co.
Various Local Communities Q W - Weekly M Monthly Q - Quarterly
Figure 2 ATMOSPHERIC AND TERRESTRIAL MONITORING NETWORK RM.28F
,, LAWRENCEBURG
@PULASKI FAYETTEVILLE gP 0
RM-38F WILSON PM-IBF WHEELER ROGE SVII L FLORENCE DAM ATHENS t
PM-28F FFIEL, MUSCLE HUNTSVILLE SHOALS BROWNS FERRY RM-I BF NUCLEAR PL NT LEIGHTON TUSCUMBIA COURTLAND PM-4 F DECAT R PM-3BF0 IO MILES yRUSSELLVILLE GUNT SVIL HARTSELLE DAM 25
,'ALEYVILLE RM-58F CULLMAN 45 MILES 0- ENVIRONMENTAL MONITORING STATION NOTE: THE FOLLOWING SAMPLES ARE COLLECTED FROM EACH STATION:
AIR PARTICULATES RAINWATER RADIOIODINE SOIL HEAVY PARTICLE FALLOUT VEGETATION
ATMOSPHERIC MONITORING The atmospheric monitoring network is divided into three groups. Three local air monitors are located on the plant site in the quadrants of greatest wind frequency. One additional station is located at the point of maximum predicted offsite concentration of radionuclides. Four perimeter air monitors are located at distances out to 10 miles from the plant, and four remote air monitors are located at distances out to 45 miles. These monitoring stations are shown in figure 2. The remote monitors are used as control or base-line stations. At each monitor, air is continuously pulled through a Hollingsworth and Voss HV-70 particulate filter at a regulated flow of 3 ft /min. In series with, but downstream of, the particulate filter is a charcoal filter used to collect iodine. Each monitor has a collection tray, and storage container to obtain rainwater on a continuous basis and a horizontal platform that is covered with gummed acetate to catch and hold heavy particle fallout. Thermo-luminescent dosimeters are used to record gamma radiation levels at each remote and perimeter station.
Each of the local and perimeter air monitors is fitted with a GM tube that continuously scans the particulate filter. The disintegration rate of the atmospheric radioactivity is continuously recorded at each station and radiotelemetered into the plant. These stations will detect any significant airborne release from BFNP.
Air filters are collected weekly and analyzed for gross beta activity. No analyses are performed until 3 days after sample collec-tion. The'onthly results are combined for each station to obtain a semiannual average. The average semiannual concentrations for the stations in each group of monitors (local, perimeter, and remote) are combined to yield a semiannual average for each group. These data are presented in table 2.
With reference to table 3, which contains the maximum permissible concentrations (MPC) recommended by 10 CFR 20 for nonoc-cupational exposure, it is seen that the maximum beta concentration is 0.42 percent MPC.
Rainwater is collected and analyzed for gross beta'ctivity, specific gamma-emitting isotopes, and radiostrontium. For the gross beta analysis, a maximum of 500 ml of the sample is boiled to dryness and counted. A gamma scan is performed on a 3.5-liter monthly sample and the results averaged by group location as was done with the air filter data. The strontium isotopes are separated chemically ahd counted in a low background system. The results are shown in table 4. The highest value reported for beta actgvity is 0.76 percent MPC for drinking water.
The gummed acetate that is us'ed to collect heavy particle fallout is changed monthly. The sample is ashed and counted for gross beta activity. The results are given in table 5.
Charcoal filters are collected and analyzed for radioiodine.
The filter is counted in a single channel analyzer system. The data are shown in table 6, where the highest, value reported is 0.03 percent MPC for X.
Table 2 RADIOACTIVITY IN AIR Ci/meter Specific Radionuclides in No. of Nonvolatile Beta* Composite Samples Location ~Sam les Max. Mfa. ~Av (Avera e)
Local Northwest 26 0. 176 0. 012 0. 037 '"'44C ;008 + .004 51C ND LM-4BF 26 0. 274 0. 015 0. 042 131I ND 103>106R .012 + .003 North 26 0. 109 0. 009 0. 029 134CS ND 137C ND Northeast 26 0. 135 0. 015 0. 035 "Zr-"'Nb ND Co ND Avera e: 0. 036 '4Mn ND Zn ND SOC ND 140B 140L .008 + .003 "Sr ND 09S ND Perimeter Rogersville, 26 0.084 0: 012 0. 028 '4'44C ND AL "Cr ND Athens, AL 26 0.085 0. 014 0. 032 131I ND 103 > IOGR .014 + .004 Decatur, AL 26 0.162 0.016 0. 034 1 34(. ND
'37C .001 + .0002 Courtland, AL 26 0.076 0.011 '.028 "'Zr-"Nb ssG
.001 + .0001 ND Avera e: 0. 031 '"Mn ND Zn ND 00Co ND 140B 140L .009 + .0004 "Sr ND "Sr ND
- Sensitivity 0.004 ND Not detectable
10 Table 2 (Continued)
Specific Radionuclides in No. of Nonvolatile Beta* Composite Samples Location ~Sam lea Max. Mia. ~Av (Avera e)
Remote Muscle Shoals, AL 26 0.260 0. 014 0. 042 14lp144 Ce ND 51C .002 + .001 ~
Lawrenceburg, TN 26 0.423 ND 0. 058 131T ND 103~106Ru .010 + .003 Fayetteville, TN 26 0.241 0.043 1 34( ND 137Cs ND Cullman, AL 26 0. 13'7 0.012 0. 033 3 Zr- Nb ND 58Co ND Avera e: 0.044 '"Mn, ND Zn ND 60( ND 1 OB 1
.012 + .003 SOS ND 89Sr ND
- Sensitivity 0.004 ND Not detectabl'e
Table 3 MAXIMUM PERMISSIBLE CONCENTRATIONS FOR NONOCCUPATIONAL EXPOSURE In Mater In Air
~cz/1
~cz/m'00 Alpha 30 Nonvolatile beta 3,000 Tritium 3,000,000 200,000 137G 20,000 500 108$ 106R 200 10$ 000 144C 10,000 200 95Z 95Nb 60,000 1,000 1soBa 1woLa 20,000 1,000 181I 300 100 "Zn 100,000 2,000
'"Mn 100,000 1,000 "Co 30,000 300 09Sr 3,000 300 "Sr 300 30 "Cr 2,000,000 80$ 000 18"CS 9,000 400 "Co 90,000 2,000
12 Table 4 RAIN '
~Cf /11 ter .
Special No. of Nonvolatile Beta* Radionuclides Location ~Sam les (Avera e)
Local 141 %144Ce Northwest 13. 7 ND 4.2 1.6 + 0.6 61Gr ND LM-4BF 4.5 "2.7, 131I 0.6 + 0.2 103 s 106Ru 1 34C 0.5 + 0.4, North 10. 4 3.6 ~<
0.9 + 0.2 137CS 0.4 +, 0.2 Northeast 6.1 2.6 9'Zr-"Nb 0.9 + 0.3=
S8G + 0.3 0.5 Avera e: 3.3 '4Mn 0.4 + 0.3
".zn 1.7 + 0.6 60( 4.5 + -0.4 140Ba 140La 5.0 + 0.5 "Sr 0-2 + 0.1 89Sr 0.5 + 0.1 3H*A ND Perimeter Rogersville, AL 7.5 ND 2.4 0.9 + 0.6 5 1(.r 2.8 + 1.4 Athens, AL 22.9 7.1 131I 3.8'41t144G 103>>106Ru ND ND Decatur, AL . 5,4 2.'8 134CS + 0.2 0.7 137Cs 0.6 + 0.2 Courtland, AL 6 4.6 ND 2.7 "Zr-"'Nb. 0.7 + 0.2 s + 0.4 Go 0.6 Avera e: '4Mn 0.7 + 0.4 "zn 1.4 + 0.6 60Co 6.1 + 0.4 4.3 + 0.5
". Sr 0.1 + 0.06=
89 Sr 0.6 + 0.1 H ND
- Sensitivity 1.6
- Sensitivity 400 ND . Not detectable
13 Table 4 (Continued)
Specific No. of Nonvolatile Beta* Radionuclides Location ~Sam les (Avera e)
Remote 141 s 144Ce 1.8 + 0.7 Muscle Shoals, AL 12. 2 3.4 slCr ND Lawrenceburg, TN 6 9;5 'ND 2.8 131T 0.4 + 0.1 103>106Ru ND Fayetteville, TN 6.5 2. 134Cs 0.7 + 0.2 7'.
137Cs 1 3 + 0.3 Cullman, AL 8.2 "Zr.-"Nb, 0.8 + 0.3 4'.1 Co 0.2 + 0.04 Avera e: '4Mn 0.6 + 0.4 6SZn 1.3 + 0.6 60C 4.1 + 0.3 140Ba 140 5.1 + 1.1 "Sr 0.5 + 0.1 00Sr 0,3 + 0.1 3Ha* ND
- Sensitivity 1.6
- Sensitivity 400 ND - Not detectable
'4 Table 5 TOTAL FALLOUT DEPOSITED mCi/kilometer No. of Nonvolatile Beta*
Location ~Sam les Max. Min. ~Av .
Local Northwest 0.24 0.07 '.12 LM-4BF 0.19 0.08 0.12 North 0.23 '.07 0.12 Northeast 0.26 0. 09 ; 0.16 Avera e:' 0. 13 Perimeter Rogersville, AL, 0. 19 0. 05 0. 10 Athens, AL 0. 22 0. 08 0. 15 Decatur, AL 0.23 0.08 . -.
0.15 Courtland, AL 0.21 0.09 0.13
'Avera e: 0.13 Remote Muscle Shoals, AL 0. 24, 0.13 0.16 Lawrenceburg, TN 6 0.06 0.09 Fayetteville, TN 0. 17 0. 07 0. 09 Cullman, AL 0.22 0.07 '.11 Avera e: 0. 11
- Sensitivity 0. Ol
Table 6 CHARCOAL FILTERS I
No. of Radioiodine*
Location ~Sam les Max. Min. ~Av .
Local Northwest 26 0. 023 .
ND ND LM-4BF 26 ND North 26 0. 026 ND ND Northeast 26 0. 026 ND ND Avera e:
Perimeter Rogersville, AL 26 0.022 ND ND Athens, AL 26 ND ND Decatur, AL 26 0. 023 Courtland, AL 26 ND Avera e:
Remote Muscle Shoals, AL 26 Lawrenceburg, TN 26 ND Fayetteville, TN 26 Cullman, AL 26 0. 022 Avera e:
+Sensitivity 0.022 ND Not detectable
17 Terrestrial Monitorin Milk Milk is collected from five farms within a 10-mile radius of the plant (see figure 3). Raw milk is'analyzed weekly foi ~I, and monthly for gamma-emitting isotopes and for radiostrontium. The average results for each farm are shown in table 7. So that any relationship between fallout on pastureland and the presence of radionuclides in milk might be seen, pasturage is also sampled at the five farms.
A cow census was completed in December 1975. It. was determined that, there are no dairy farms nearer the plant than the nearest farm being sampled.
Ve etation In addition to the pasturage samples mentioned previously, vegetation samples are collected near each monitoring station in the network to determine possible plant uptake of radioactive materials from the soil or from foliar deposition. Table 8 gives the results obtained from the laboratory analyses. The data for the specific radionuclide analysis.'of vegetation are averaged for the four prin-cipal locations local, perimeter, remote-control, and farm.
Soil Soil samples are collected near each monitoring station in order that any relationship between the amount of radioactive material found in vegetation and that in soil might be established. The averages for specific analyses are obtained in the same fashion as those for vegetation. The results are given in table 9.
War er Domestic water supplies, obtained from surface streams and wells, are sampled and analyzed. Well water is obtained from seven private supplies within a 10-mile radius of the plant. The results of analyses of well water are shown in table 10 and indicate that the maximum beta concentration is '0.31 percent MPC. Table ll indicates the results of samples taken from public water supplies. The maximum beta concentration is 0.37 percent MPC. The specific isotopic con-centrations reported are averages for each station for the semiannual period.
Environmental Gamma Radiation Levels Thermoluminescent dosimeters (TLD's) are placed at nine stations around the plant near the plant boundary and at the perimeter and remote air monitors to determine the gamma exposure rates at these locations. The TLD's are changed every 3 months.
The quarterly gamma radiation levels determined from these TLD's are given in table 12.
18 Figuie 3 MILK tlttIIQKING NETWORK At hons gS 72 Clement School I moo Roid
.Roog 2 to Rlploy Jones
, Cro s sr oads good 3p
'phoo le~net 3:
eee foft Y Ppg~ Qt QNI Co no~
.ALA. 20
- 1. Farm 8
- 2. Farm ll
- 3. Farm l,
- 4. Farm T Bo Farm Bf Scale: 1" ~ 1.5 mtlcn
19 Poultr and Food Cro s Poultry and food crops raised in the vicinity of Browns Ferry Nuclear Plant are sampled as they become available during the growing season. During this sampling, period samples, of toma-toes and'soybeans were coll'ected and analyzed for ~ross beta,
'pecific gamma-emitting radionuclides, Sr, and Sr. The results are given. in table 13.
Table 7
~CA/lltet No. of "'r.*
Location ~Sam les Max a Mla. ~Av . Cs 140B 100La "Sr 89 Sr Raw Milk Farm B (6)** 1.0 ND 4.5 1301.3 3.1 . 8.9 0.2 Farm Bi 27 (6) ND 6.8 1215.8 1.8 3.9 Farm H 27 (6) 5 5*** ND 5.7 1245.2 3.6 4.2 0.4 Farm L 27 (6) 0.6 ND 3.9 1244.1 1.0 6.6 0.7 Farm T 27 (6) ND 8..9 1227 1 '112 6.7 0.5 Avera e: 6.0 1246 ..7 2.1 6.1 0.6 I
- Chemical separation. of, iodine: Sensitivity for
.E '0.5 at time of, sample colle'ction.
- I"analysis weekly: (gamma scan and. "Sr, Sr analyses pCi/1 monthly.)
- This value represents one isolated occurrence. All other values for this station were less than the sensitivity of the analysis.
,ND. Not detectable s
21 Table 8 VEGETATION Cl/ D Wei ht)
No. of Alpha* Nonvolatile Specific Radionuclides Location ~Sam lea ~Av .) Beta'* (Av . (Avera e)
Local 141 ~144C Northwest 9.0 ND 51Cr 0.7 + 0.2 LM-4BF 5.1 131I'03~lobRu 0.2 + 0.02 1.6 '+ 0.1 North 2 7.5 134C ND
'"Cs 0.1 +,0.03 Northeast
'.9 "Zr-"5Nb ND Co ND Average: 7.4 54Mn ND
."zn ND 60C ND 140Ba 140La 0.7 + 0.04 90S 0.4 + 0.01 8
Sr ND Perimeter 11.8 141 144Ce 0.2 + O.l Rogersville, AL ND ~
51Cr 1.3 + 0.3 Athens, AL ND 7.4 131I 0.4 + 0.03 10 3 t 106Ru +'0".2 2.6 Decatur, AL 2 12.2 134Cs ND 137C O.l + 0.04 Courtland, AL 2 9.7 "Zr-"Nb 'D 58C ND Avera e: 10.3 54mn ND Zn ND 60C ND 140B 140 0.6 + 0.05 90S 0.3 + 0.01 89S ND
- Sensitivity 0.1
- Sensitivity 0.1 ND - Not detectable
22 Table 8 (Continued)
No. of Alpha* Nonvolatile Specific Radionuclides Location ~>>am les (Avera e)
Remote and Control Muscle Shoals, AL 11.9 141>>144Ce 0 0.05 "Cr 0.8 + 0.2 Lavrenceburg, TN 16.8 131'03>>106Ru 0.2 + 0.02 2.2 + 0.1 Fayetteville, TN 14.1 134Cs ND 137CS 0.1 + 0.03 Cullman, AL 7.8 "zr-96Nb ND "Co ND Avera e: 12.7 64Mn ND Zn ND "Co ND 140Ba 140La 0.5 + 0.03 90Sr 0 7 + 0.01 BBSr ND Nonvolatile Beta Max. Miri. ~AV ~
F,armarm Bi 26. 9 12<<3 12.7 141>>144Ce ND SiG 0.5 + 0.02 Farm B 19. 2 12. 2 8.8 1 31'03>>106R 0.1 + 0.01 1.6 + 0.05 Farm H 30.8 13.0 11.6 134C ND 137cs ,ND Farm L 25. 8 9.9 13.0 "Zr-96Nb ND 6BCo ND Farm T 28.1 12.7 9.4 '4Mn ND "zn ND Avera e: 60Co ND
'40Ba-'"'La 0.3 + 0.01 90S 0.3 + 0.01 0"Sr ND
- Sensitivity 0.1
- Sensitivity 0.1 ND Not Detectable
23 Table 9 SOIL Ci/ . Dr Wei ht No. of Nonvolatile Beta* Specific Radionuclides Location ~Sam lee (Avera e)
Local
- 12. 9 141 144 Northwest ND 51 ND LM-4BF 13.7 131I ND 103rl06R ND North 12.3 134Cs ND 137C 0.7 + 0.1 Northeast 13.9 ,
36Zr-"Nb 0.1 + 0.04 Co ND, Avera e:
13.2 '4Mn 'n ND ND 60C ND 140B 140L + 0.'03
.'.'2 Perimeter Rogersville, AL '12. 5 '4 " '44C 0 7 + 0.1 "Cr ND Athens, AL 2 10. 5 131I 103s106Ru 0.3 + 0.1 Decatur, AL lle6 134C ,ND 137( 1.3 + 0.1 "
'Zr-"'Nb' 0.1 + 0.02 Courtland, AL 7.0 Co ND Avera e: 10.4 '4Mn 66zn "
., ND "Co ND 140B 1 0.1 + 0. 02 Remote Muscle Shoals, AL ll.8 141~144Ce 61Cr 0.7 ~ + 0.2 ND Lawrenceburg, TN 2 13.0 131I ND 1 03' Q6Ru 0.4 0.1 Fayetteville, TN 10.7 134Cs ND 137Cs 2.2 0.1 Cullman, AL 7.8, 36zr-36Nb ND 66Co ND Avera e, 10.8 64Mn ND 66zn ND 6oCo 1 40La 1 4oBa '.1 ND 0.02
- Sensitivity 0.15 ND - Not detectable
Table 10 PRIVATE WELL WATER
~Ci/liter No. of Nonvolatile Beta* S ecific Radionuclides Avera e Location ~tat les Nin. ~Av . Ct Cr Ru Cs Cs Zr- hb Co Hn Zn Co Ba-Fern B 3.2 hD, ND ND 1.4i0.6 ED 1.4f 0. 7 1, 1+0.8 5. 5'l. 2 4.5+1.0 Fara Bi 9.4 3.3 4.9 ND 0.5+0.4 0.9i0.6 ED 0.7t0.6 1.7il.2 7.1+0.7 3.8 0.6 Farm 8 3.3 1.4 2.4 2.2t1.7 ND 1.3t0.5 ND ND 6.3+1.0 3.0f1.0 Fam L ND ND ND ND ND 0.7-'0.5 0.6 0.5 2.0-'ltO 5.2-0.7 . 2.1+0.6 Fare T 2.9 ND 0.6+0.'4 ND ND 2.710.9 4.9-'0.8 3.2 0.5 Residence BT 1.3 O. 4tO. 3 l. 6+0. 6 ND 5.6t0.6 . 3.8-'0.9 Residence BK 1.6i1.4 0.850.4 1.1t0.6 0. 4+0. 2 0.7-0.6 1.9-0.9 4.7-0.6 2.8 0.5 AveraBe: ND 0.5%0.3 ND ND ND 0.2+0.1 0.4%Oil 0.7t0.2 OCIXOcl 0.4+O.l 1.3t0.3 5.6t0.4 3.3+0.3 aSensitivity 1.6 ND Not detectable
Table 11 PUBLIC WATER Ci liter ho. of Nonvolatile Betae S eciffc Radionuc s Location Saalcs ?fax. Nin. ~Av Cr Zr- Nb Ba- La H*e Wilson Dan 2 1.9 hD ND ND 8. 2i1. 6 1. 8 f1. 1 Colbert SP 2 ND ND ND 1.6i0.9 3.8i1.3 3.4il.l 4.0i0.9 Cle=ents School 2 ND ND ND 7.0i2.8 3.6il.o 6.8il. 1 Athens 2 hD hD hD ND ND '.8i1.7 2.8i1.0 Courtland 2 ND hD ND I.lio.5 5.5i1.5 7.1i1.4 HD Tovn Creeh 2 ND ND hD ND 1.7il 4 4.2i1.2 3e2ils7 Trfnfty 2 hD hD hD 4.7i1.0 2o9iOe9 Decatur 6 8.5 ND 2.9 Oo810.5 0.6i0.3 0.7i0.6 HD 1.8i1.2 4.5i0.7 3.9i0.5 Sheffield (Nuscle 6 4.4 1.8 2 9 0.540.4 0.7i0.4 1.7i0.7 3.8i0.7 3.6i0.5 Shoals)
Wheeler Dam 6 3.3 1.6 2.3 1. 3i0.4 1.3i0.8 2.2i1.5 6.0i0.9 3.4i0.6 ND
~ion Payer Co. 6 11.2 HD 3.7 0.5i0.3 1.4i0.6 ~ Io3iOa5 3,1i1,6 3,7i0.7 5.0iO.S Wei hted Avera e: 1.9 0.3io.l 0. i0. 0.8iO.
- 0. i0.1 ND ND 1.8i0.2 4.8i0.2 4.0i0.1 ND
- Sensitivity 1.6 eaSensitivity 400 HD Not detectable
26 "
Table 12 ENVIRONMENTAL GAMMA RADIATION LEVELS Environmental Gamma
~aar ter Location I ~l Radiation Levels July-September 1975 On-Site (9)+
Maximum 0.031 69.0 Minimum 0. 012, 26. 4 Average** 0. 021+0. 015 45. 1+32. 2 Of f-Site (8)
Maximum 0. 030 65. 2 Minimum 0. 010 20. 3 Average 0.019+0.016 42.1+35.4 October-December 1975 On-Site (9)
Maximum 0. 014 31.5 Minimum 0. 012 25.4 Average 0. 014+0. 002 29.6+4.0 Off-Site (8)
Maximum 0. 018 40.3 Minimum 0. 010 23.0 Average 0.014+0.005 29.8+11.8
- Number of stations (three TLD's at each station)
- Allaverages reported +2a
27 Table 13 POULTRY AND FOOD CROPS Ci/K Wet wei ht) Ci/ (Dr wei ht)
Tomatoes So beans Athens Plant Area Muscle Shoals Gross beta* 1033.2+7.1 22.0+0.2 20.8+0.2 Specific Radionuclides 141~144Ce 0.1+0.07(
5 1Cr 0.2+0. 1 1311 8. 0+5. 5 103~106Ru 1 34CS 9.4+5.1 0. 1+0. 05 137CS 8. 4+6. 9 "Zr-"Nb 58Co ND
'4Mn Zn 60C 16.1+6.9 40K 1981.6+162.2 15. 1+0. 4 15. 1+0. 7 140'40 14.5+5.5 "Sr 8.6+1.5 0.1+0.02" 0. 2+0. 02 89S ND
- Sensitivity 0.1 (pCi/g, dry weight)
ND - Not detectable
29 Reservoir Monitorin Samples are collected quarterly along seven cross sections in Wheeler Reservoir at Tennessee River miles 277.98, 283.94,, 288.78, 291.76, 293; 70, 295.87, and 307.52 as detailed in table 14. Samples collected for radiological analysis include plankton from three of these cross sections and bottom fauna and sediment from four cross
. sections. The locations of these cross sections are shown on the accompanying map (figure 4) and conform to sediment ranges estab-lished and surveyed by the Data Services Branch, TVA. Station 307.52 is located 13.5 miles upstream from the plant diffuser outfall and was selected as a control station.
Samples of water, net plankton, sediment, Asiatic clams, and two species of fish collected quarterly (plankton in only two quarters) are analyzed for radioactivity. Gamma and gross beta activity. are determined in water (dissolved'nd total activity),
net plankton, sediment, shells and flesh of clams, flesh of a com-mercial and a game fish species, and also in the whole, body of the commercial species. The Sr and Sr contents are determined in all samples where sufficient quantities are available. The. activity of 12 gamma-emitting radionuclides is determined with a multichannel gamma spectrometer. The Sr and Sr contents are determined by appropriate radiochemical techniques.
Water From five of the seven cross sections a total of 15 water samples is collected quarterly for determination of total and dis-solved radioactivity. The locations and depths for sampling are shown in table 14. Results are displayed in tables 15 and 16. Samples from all horizontal locations and depths at each river mile cross section are composited quarterly for tritium analysis. Water samples are also collected monthly at the point of plant discharge to the Tennessee River and at a point on the Elk River. These samples are a part of the quality control program. From the data in table 17, the maximum average beta concentration is 0.12 percent of MPC for, samples collected at these two locations.
Fish Radiological monitoring for fish is accomplished by analysis of composite samples of adult fish taken from each of three contiguous reservoirs Wilson, Wheeler, and Guntersville. No permanent sampling stations have been established within each reservoir; this reflects the movement of fish species 'within reservoirs as determined by TVA data from the Browns Ferry Nuclear Plant preoperational monitoring program.
Two species, white crappie and smallmouth buffalo, are collected repre-senting both commercial and game species. Sufficient fish are collected in 'each reservoir .to yield 250 to 300 grams oven-dry weight for analytical purposes. All samples are collected quarterly and analyzed for gamma,
30 gross alpha, gross beta activity, 89 Sr, and 90 Sr. The composite samples contain approximately the same quantity of flesh from each fish. For each composite a subsample of material is drawn for countin'g. Results are given in table 18.
Plankton As indicated in table 14, net plankton (all phytoplankton and zooplankton caught with a 100 p mesh net) is collected for radio-logical analyses at each of three stations by vertical tows with a net. At least 50 grams (wet weight) of material is necessary '-meter for analytical accuracy. Collection of this amount will probably be practical only during the period April to September (spring and summer quarters) because of seasonal variability in plankton abundance.
Samples are analyzed for gross beta'activity and, when quantities are sufficient, for gamma activity and Sr and Sr content. Results are shown in table 19.
Sediment Sediment samples are collected from Ponar dredge hauls89 made for bottom fauna. Gamma and gross beta radioactivity and Sr and Sr content are determined quarterly in composite samples col-"
lected from each of four stations. Locations of these stations are shown in table 14. Results are shown in table 20.
Bottom Fauna The flesh and shells of Asiatic clams collected from the cross sections at four stations (table 14) are analyzed for gamma and gross beta activity at quarterly intervals. The 89 Sr and'r
, 90 contents are determined on the shells, and on the flesh when suf-ficient amounts were available. A 50-gram (wet weight) sample provides sufficient activity for count% g. Results are given in table 21.
Table 14 SAMPLING SCHEDULE RESERVOIR MONITORING Biolo ical Sam les Water Sam les Zooplankton, Distance From Tennessee River Chlorophyll, Benthic Left Bank Depths Mile) Fauna* Sediment* Fish** Feet Percent (Meters) 277.98 2 '
283.94 3600 40 7100 78 288.78 291.76 5000 60 1 7000 84 1, 5 293.70 6800 65 1 9200 88 1, 5 295.87 4000 44 7500 .- 82 .
307.52 1800 24 .
1, 5 2800 37 1
- Replicate samples
~Gill net and/or electroshocker will be used for collection. Samples of fish are collected from Guntersville, Wheeler, and Wilson Reservoirs.
32 Figure 4 R ESERVOlR MONlTORING NETNORK Bk River MIHEELER DAM mile 274.90 mile 277.98-Rogersville 0
mile 29l.76 Athens 0
B.F. NUCLEAR PLANT mile 295.87 ile 288.78 rnite 266.94 0
Cour tfand rrtile 295.70 Decatur mlle 307.52 Scale of Miles 0
Table 1S RIVER RATER Dissolved Activit Ci liter T8 Dep tb Cross Nonvolatile River No. of Nor is. in Alpha** Bc tasse 8 ecific Radionuclides Nile '~San les Locst Iona Haters ~ARE Ce Cr I Ru Ca -
Cs Zr- Nb Co Mn En Co Ba- ta Sr e 283.94 2 40 2.2 ND "10e 283.94 2 78 1.8 HD ND ND ND '.8i0.8 Se7tle3 2.6t1.0 1.4=0.5 283.94 2 10 1.7 ND ND ND ND ND 4,7i1,2 2.8i0.9 2.0r0.6 291.76 2 hD ND ND ND .
ND'D
- 2. 7r1.4 S.SI0.9 ND 1.0c0.5 291,76 2 4,9 3.&1.8 HD ND ND HD 0 7i0.4 2. 3i2. 0 5,0i0,8 2. Si0. 7 291.76 2 S'il ND ND = hD 5.0tl.l 2.9i0.8 0 6'0 S 293.70 2 65 2.5 4,4t1.0 2.2t0.6 1.$ t0.3 0.9-0.5 293.70 2 88 2.8 3.0tl.6 6.4r1.4 ND .c:0.5 293.70 2 88 3+0 4.8j1.3 1.910.7 ND l.atO.S 295.87 2 44 1 ND 2.5 ND ND ND hD ND ~ ND ND 4.L1.3 4.Sil.l ND 0. 6-0 ~ 5 295.87 2 '44 5 hD 2.6 I.l~0.6 ~
. hD 4.0il.l ND ND 2.6il.l 3.810.8 3.9i0.8 ND '.2~0.5 29$ 87 2 82 1 hD 3.4 ND ND ND 5.9tl ~ 2 3,2il.l 0,8i0.4 ND 307.52 2 -24 1 ND 2+4 ND, 1,2tOa6 ND 8,4t2 ~ 7 2.5t0.9 3.9tOo9 ND ., I.Li0.5 ~
307.52 2 24 5 ND 3ol ND " ND HD ND ND 10,4i2.0 2.ltO'9 ND ITALO.S
-307 52 37 I ND 4.0 HD ND = ND ND 3.6tl 0 2.3t0.8 MD " 0.7tO.S Avere e: ND 0 2i0.1 ND ND 0.2t0.07 0 08t0.04 0. 0.0 ND O,OSi0.03 0.9t0.2 4.4t0. "
3.0!0.2 .EeO.OS I. ~ O.I apercent of distance across river frnn left bank Iookfn8 dovnstregs esSensitivity 1.2
~ ee8ensitivity 1.6 ND Not detectabls
Table 16 RIVER WATER Total Activit Ci liter Ta Depth Croae Noavolatfle River No. of Borfa. in Alpha*a Sctaece 8 cciffc Radfonuclfdea Avera e)
UIlc ~II I I II ~II . ~A Ce Cr I Ru Ce Nb Co . Mn Za Co Ra La Sr cg 8~ 'e 83.94 2 40 1 3.0 2e3f3o3 ND ND ND ND ND 8.2tl.6 7.Oil.0 0.$ r0.4 0.4t0.3 1o3.94 78 1 1.2 2.8 33,5t21,0 2,3t1.4 ND l.5611. 1 3. It1. 6 ND ND 1,2t2,7 4 't1.4 17.5E4.8 ND 0.6t0.4 183.94 2 78. 10 3.6 2.1f 0.9 1 4fO 6 OeltOo4 ND ND 4 'f2 7~ 3.4fl,Q 2,9rl.Q 0.7t0.4 291. 76 ND le Of Oi7 ND ND 40f1 4 ND OoSfO.C 0.3r0.2 r
291.76 84 ~ 1 302 1.4+1 9 ND ND ND 3.2f1.4 16.6 4.1 0.5:0.4 291.76 3,8 ND 2e Sf 0.6 ND lo3f0.6 2 'fl.S 2.7aI.Q 2,4t0.6 ND 0.7-0.4 293.70 65 1.4 5.0 hD ND 1.9f 1.1 ND ND ND 3.7tl.4 22.8t4.0 O.S!0.3 0 7.0.3 293.70 88 ND 2.8 ND ND 1.2i0.8 ND 6,2f2,0 3.8fl,2 I.3f0.8 0.3t0.2 0.7t0.3 293.70 3.6 10.91 6.5 ND II611,4 ND 3I1 f0.7 ND ND ~ 2.5f2.0 8.4f1.8 4.2rf.d 0.7t0.4 29$ 87 ND ',3tl ~ 1 3.1t2.5 2.$ f1.0 2 3<0.9 0.7%.4 29$ .87 2 44 4.0 ND ND ND 1.5f0 8 lo9f0.7 ND 4 2f1.2 1.0r0.5 0.5Ã.4 295 ~ 87 2 82 ND 4.7 ND = 48t2 8 ND ND 6aSfS 0 10alf2 4 71 StSeS O.SH).4 307 52 2 .
24 2' 0+9fOe2 ND . 2,7f1,6 2.7f1.0 4.2fO'8 02r04 'D 307+52 2 24 S ND i 3eO ND ND 4,$ f2.2 Zali0.8 3.3i0.7, ND
/
307.'S2 2 37 1 4.9 2.2t0.9 ND, ND 2.6fi.9 .6.9f2.0 .13,5i8.$ 112j0.7 Averc el I.fLO $ 2. l. 0.4%0.2 0,4 0.1 0. 0.1 0.'3f0.07 0.08t0.0$ 2f0.08 2.7rOl6 4.4f0.4 11.6rOl9 0.3h):CS 0.4 %.0.
cpcrcent of diataace acroea river froa left bank lookfnS dounatreaa ecicaaftfvfty 1.2
~ ecSereftfvfty 1.6
+ceclenaitfvfty 400 ND - Not detectable
35 Table 17 RIVER WATER
~ci/laptev No. of Alpha+ Nonvolatile Beta** Specific Radionuclides Location ~Sam les ~(Av . Max. Min. ~Av . Avera e)
'tlocation Browns Ferry discharge 6 ND 27 17 23 141 slCr 131Z
~ 144Ce 1
ND ND 4+0.6 103t106R ND 1 34Cs ND 137C ND 9sZr-"Nb.'o ND
'. ND "Mn ND 652 , ND.
60Co 6.0+0.9 140B 140L 4.2+0. 8 90Sr 0.9+0. 2 0
Sr 0,5&.2 3H*** ND Elk River 3;5 'D'. 2.9 141y144Ce ND slCr ND 131I. ND 103>106R ND 134CS 137C
- l. 6+0. 7
- 1. 421. 1 9sZr-"sNb ND "Co ND ND "Zn ND 60Co 4.4+1.0 140B 140L "Sr 3.2+0.8'.4+0.2 89S 0.5+0.2 H'k** ND Avera ei. Avera e: 2.6
- Sensitivity 1.2
- Sensitivity 1.6
- ~Sensitivity 400 ND Not detectable
Table 18 PISH D Mef hr Cross Cross Locatfoo No. of hlpha* Betae* 5c if' 4l ill(
~ll 1r Tyl f tt h ~sl ~(A g ~A Cr I Ru Ce Cs Zr- hb Co Ho Zu C 5-Cuatersvfllc Saallsouth Buffalo (Vhole)
ND 7.44 ND ND ND ND O.li0.03 ND ND ND ND hD'D 0.2i0.03 Nn Ssallaouch Buffalo ND 10.80 ND 0.3i0.1 ND ND ND 0+2i0.04 hD ND ND ND ND ND hD Nn (Flesh)
Shits Crappie 9.73 0.3in.l ND ND ND ND ND ND ND (Flesh)
Wheeler Saalltouth Buf fslo ND 7.14 Nn 0. 3in. 2 ND ND ND ND ND hD ND ND ND O.li0.02 0.3i0.02
(@hole)
Scallaouth Buffalo ND PeBS Nn O.SCOel ND ND Nn Nn Nn Nn hn hn hn Nn (Flesh) white Crappie ND 10. 31 ND ND ND 0.2i0.03 ND . hD hD ND ND ND ÃD Nn (Plash)
Mllson Scalloouth Buffalo hD 7 ~ 16 Ooltne03 ND ND ND hD ND Nn ND 0 IIO.OZ Nn (hhole)
Sk I)south Buffalo (Plash) 8,37 ND hD Oalina04 ~ ND hn ND ND ND 'D
%hite Crappie (Flesh)
ND 11,18 0 3i0,1 ND a'D ND Oo3ina04 ND Nn ND ND ND hD Nn aSeasftfvfcy 0,02 saSeuslcivfcy 0.03 ND Not detectable
37 Table 19 PLANKTON Ci/ Dr Wei ht Gross Gross Tennessee No. of Alpha* Beta** Specific River Mile ~Sam les ~(Av . '~Av~ Radionuclides***
277.98 l. 99 21. 53 291.76 5."41 30. 88 307.52 5.37 27.87 Avera e: 4.26 26.76
- Sensitivity 0.03
,+*Sensitivity 0.04
+*+Sample size not sufficient to perform specific isotopic analysis.
Table 20 SEDIMENT Ci/ D Wei ht TN River Mile 277.98 288.78 293.70 307.32 ~Avera e No. of Samples Gross Alpha* (Avg.) 3.6 4.0 3.3 4.4 3.8 Nonvolatile Beta** (Avg,) 21.8 21. 6 17. 6 20. 2 20. 3 Specific Radionuclides (Average)
ND 51(r 131I 103'106Ru 0. 4+0. 2 0. 5+0. 2 0. 4+0. 2 0. 3+0. 2 0. 4+0. 1 134CS 137Cs 4. 6+0. 2 2. 9+0. 1 4. 3+0. 2, l. 2+0. 1 3. 3+0. 08 Zr- Nb 0:2+0.07 0.2+0.07 0.1+0.06 0.1+0.06 0.2+0.03 56Co
'4Mn 0.2+0.09 0.2+0.1 0.2+0.07 0.2+0.08 0.2+0.04 Zll 60( ND ND
" Ba-'4 La 0.3+0.06 0.3+0.05 0.2+0.05 0.3+0.07 0. 3+0. 03
"'Sr 0.1+0.05 0.3+0.06 0.2+0.05 0.3+0.06 0. 2+0. 03 89S 0.4+0.08 0.06+0.05 0.2+0. 05 0.4+0.08 0.3+0.03 777Sensitivity 0. 11
- Sensitivity 0. 15 ND Not detectable
39 Table 21 CLAM Ci/ Dr Hei ht Clam Shell TN River Mile 277. 98 288. 78 293. 70 307.52 ~Aveve e No. of Samples Gross Alpha* (Avg.) '0.3 0.5 0.6 1.5 0. 73 Nonvolatile Beta** 6. 84 6. 73 6. 74 9. 34 7.41 (Average)
Specific Radio-nuclides (Avg.)
141~ 144 Ce 0. 4+0. 1 0.3+0.05 0.4+O.l ND 0. 3+0. 04 Cr ND 131 103% 106 Ru ND 0. 2+0. 1 0. 2+0. 1 0. 1+0. 04 134 Cs 137 Cs 0. 1+0. 04 0. 1+0. 03 0. 1+0. 04 0. 1+0. 02 Zr- Nb Co Mn 0.1+0.07 Zn 60 Co ND 140 Ba- 1%0 La 0. 120. 02 0.2+0.03 0. 1+0. 01 "Sr 3. 7+0. 2 4. 1+0. 2 3. 1+0. 2 4.6+0.2 3.9+0.1 09 Sr ND
- Sensitivity 0. 11
- Sensitivity - 0.14 ND - Not detectable
40 Table 21 (Continued)
CLAM Ci/ Dr Wei ht Clam Flesh TN River Mile 277.98 288.78 293.70 307.32 ~Avera e No. of Samples Gross Alpha* (Avg.) 0.7 0.2 0.4 1.7 0.8 Nonvolatile Beta** 4. 03 1.54 1.29 2.25 2. 28 (Average)
Specific Radio-nuclides (Avg.)
141>> 144( e
- 3. 9+1. 7 0. 8+0. 2 l. 79+. 2 1.6%.5 5 1Cr 25. 0+6. 8 2.3%.9 5. 3+Q. 0 8. 2+3. 8 131Z 2. 9+0. 5 0. 5+0. 1 0. 3+0. 1 0. 3&e 1 1. Oi0. 1 103>> 106Ru 2. 0+1. 7 0. 8+0. 4 0.7%.4 134(s 1. 6+0. 3 0. 3+0. 1 0. 3+0. 1 0. 3+0. 1 0.6.1 1 37Cs 0. 9+0. 4 0. 5+0. 2 4+0. 2 0. 5+0. 1 9 5Zr- Nb 0. 1+0. 06 0. 4+0; 2 0. 8+0. 3 0. 3+0. 1 58Co
- 0. 3+0. 2 0. 1+0. 05 6 5Zn 0. 2+0. 1 1. 3+0. 5 0. 4+0. 1 60(o 1.8+0.3 0. 6+0. 1 0. 4+0. 1 1. 1+0. 2 l. 0+0. 1 140Ba 140La 3. 1+0. 6 1. 0+0. 2 1. 3+0. 2 2. 0+0. 3 1. 9+0. 2 "Sr NA NA 89Sr NA NA
- Sensitivity 0.03
- +Sensitivity 0.04 NA - Not analyzed ND Not detectable
ualit Control A quality control program has been established with the Alabama Department of Public Health Environmental Health Administra-tion Laboratory and the Eastern Environmental Radiation Facility, Environmental Protection Agency, Montgomery, Alabama. Samples of air, water, milk, and vegetation collected around the BFNP are forwarded to these laboratories for analysis; and results are exchanged for comparison.
Data Anal sis Data measured at each indicator and control station were averaged for the 6-month reporting period. In order to describe the distribution of control station data, a mean, st'andard 'deviation, and 3-sigma value were calculated. Me can expect, with 99 percent con-fidence, that background concentrations would be distributed within these limits. This provides us the basis for. comparing control and indicator data. If the indicator data fall within the limits defined for control data, we can say, with 99 percent confidence, that the indicator data were not significantly affected by the nuclear plant.
If the, data do not fall within the limits, we will perform further analyses to determine if the difference is attributable to the nuclear plant.
Conclusions, A vast majority of'he indicator station data were found to be within the distribution defined by the control station data. One anomalous value which was observed is discussed below. The Alpha-M least squares computer program identified concentrations slightly exceeding the limits of the control station data for a small number of radionuclides in samples from indicator stations. Many of these values may be discounted because the error reported by the Alpha-M program was greater than the calculated concentration. The remaining isolated elevated concentrations may be the result of fallout, computer program artifacts, or analytical errors. The same type of isolated high values occurred in the control station data and m'ay be attributed to the same sources.
Analysis of the rainwater sample taken at60 the Athens, Alabama, sampling station on August 4 indicated a Co concentration of 33.5+2.8 pCi/1. Concentrations of Co reported for rainwater taken at all other stations ranged from 0.8+1.6 to 5.7+1.8 pCi/l.
Rainwater collected at the Athens, Alabama, station from August 4-19 was sampled on August 19. Analysis of this sample revealed no signif'cant levels of radionuclides in the sample.'
42 Routine analysis of particulate filters from the turbine and reactor building exhausts during the month of July indicated higher than normal levels of Co. At no time did these concen-trations exceed reportable levels.
The general movement of thunderstorms in the area is from the plant area toward the Athens area. .A large number of thunderstorms occurred during the month of July. Approximately 8 inches of rainfall were measured at Athens during the month.
It is concluded from the above data that Co released from Browns Ferry probably was caught up by a passing storm cloud and washed out in the Athens area. The result of the second sample indicates that the phenomenon was probably unique and not recurring. These results were reported to the NRC on September 3, 1975. The occurrence represented no hazard to the public since the concentration reported is only O.l,percent of the 10CFR20 limits.