ML20108B027
| ML20108B027 | |
| Person / Time | |
|---|---|
| Site: | Fort Saint Vrain  |
| Issue date: | 12/31/1995 |
| From: | Jerrica Johnson, Miller T, Schleiger T COLORADO STATE UNIV., FORT COLLINS, CO, PUBLIC SERVICE CO. OF COLORADO |
| To: | |
| Shared Package | |
| ML20108B007 | List: |
| References | |
| NUDOCS 9605030121 | |
| Download: ML20108B027 (118) | |
Text
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- PROGRAM SUMV ARY REPORT 1995 COLORADO STATE UNIVERSITY FORT6 COLLINS, COLORADO 80523 9605030121 960429 PDR ADOCK 05000267 R PDR
RADIOLOGICAL ENVIRONMENTAL MONITORING PROGRAM For the Fort St. Vrain Station Operated by the Public Service Co. of Colorado Summary Report for the Period January 1.1995 - December 31.1995 Prepared by: { i 2- OS Jakey E. Johnson.hol'essor Date' Colbfado State University Prepared by: -
/ I!96 Thomas Miller. Lab. Coordinator Dat:
Colorado State University Prepared by: C4# [ d
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Timothy E. Sbhleig6r Lv ' dMh6 IMte Senior llealth Physicist Prepared by: bd/LIMhSI- 'l[Zei[46 Date Frederick @.)lorst Radiation Protection Manager i
l i 1 . Acknowledgments ! i
- Many persons have contributed to this project since its inception in 1970, and it is important to - l acknowledge their efforts. There have been many technicians and graduate students working on this j j project. All have been acknowledged in previous reports, but we here thank them collectively. j a We again thank the citizens from whose farms, homes, and ranches we collect the environmental !
I samples. Without their cooperation the project would not be possible. ; We also wish to acknowledge and thank Mr. Robert Keiss and his associates as well as the - ! Colorado Division of Wildlife, Fort Collins regional office for assisting with the fish collection. Their j 4 i j cooperation, equipment and expertise made the collection possible. 4 The persons in this laboratory working directly on the project during 1995 have been: ; I Roy DePriest Student Employee , Grant Johns Student Employee ( ! i 4 Vaughn Jones Research Associate i Charles Sampier Chief Electronic Technician ; ?
- Gerald M. Ward Professor Emeritus i
/ h ,
UJames E. Johnson L i ' Professor and Project Director . O& ~Y/ # I i Thomas S. Miller i Laboratory Coordinator 1 1 I 1 j 1 l l 4 j ii b
* '
- T =' - " t- e,-- w
1 l - TABLE OF CONTENTS . 4 i Page No. t i t l Acknowledgments ii ; List of Tables iv i
- List of Figures vi l f
i I. INTRODUCTION 1 l-II. SURVEILLANCE DATA FOR 1995 + AND INTERPRETATION OF RESULTS A. External Gamma Exposure Rates 5 ; B. Ambient AirConcentrations 11 , 26 ! C. Radionuclide Concentration in Water D. Milk 62 i E. Food Products 71 t F. Aquatic Pathways 76 I G. Sample Cross-check Program 82
- 11. Summary and Conclusions 90 ,
J III. ENVIRONMENTAL RADIATION SURVEILLANCE l- PROGRAM AND SCHEDULE 105 i l l s 4 iii i l
LIST OF TABLES Page No. II.A.1 Gamma Exposure Rates 7 II.B.1 Concentrations of Long-lived Gross Beta Particulate Activity in Air
- a. First Quarter 13
- b. Second Quarter 14
- c. Third Quarter 15
- d. Fourth Quarter 16 II.B.2 Tritium in Atmospheric Water Vapor
- a. First Quarter 19
- b. Second Quarter 20
- c. Third Quarter 21
- d. Fourth Quarter 22 II.B.3 Tritium Released in Fort St. Vrain Effluents,1995 23 II.B.4 Radiocesium Concentrations in Ambient Air 25 II.C.1 Gross Beta in Drinking Water
- a. First and Second Quarter 28
- b. Third and Fourth Quarter 29 II.C.2 Tritium in Drinking Water
- a. First and Second Quarter 30
- b. Third and Fourth Quarter 31 II.C.3 Radionuclide Concentrations in Bi-weekly Composites of Drinking Water. 32-40 iv
. __ _ . . _ . . . . ~ _ . _ . _ _ _ _ _ _ . _ _ _ . . . . -_ _ ._. _ _.
l i j r i i [ LIST OF TABLES (Continued) ; a
- Page No.
t II.C.4 Tritium in Surface Water 43 , i II.C.5 Radionuclide Concentrations in Surface Water 44-50 i 4 1 3 II.C.6 Radionuclide Ccncentrations in Ground Water -57 + t i i ll.C.7 Tritium in Ground Water 58 l II.C.8 Maximum Permissible Concentrations in Drinking Water 59 ; i II.D.1 Radionuclide Concentrations in Milk 64-69 .i
~ ll.D.2 Tritium in Milk 70.
l !' . II.E.1 Radionuclide Concentrations in Food Products 73
- l' 5
j II.E.2 Radionuclide Concentrations in Beef Samples ;
- a. First Italf 74 i-
! b. Second IIalf .75 1 1 ! II.F.1 Radionuclide Concentrations in Fish 78 i 1 a 5 II.F.2 Radiocesium Concentrations in Sediment from location F-1 !
- a. January through September 79 l
4 1
- b. October through December 80
}' i ilF.3. Radionuclide Concentrations in Sediment from location R-10 81 .! 4 ! 11.G.1 EPA Cross-check Data Summary 84 { s
-4 Ii t
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. ~ . . . . , .-. - , . _ - _ _ . , . _ _ , . _ . . _ . _ __ _, - -
1 i I LIST OF TABLES (Continued) Page No. II.G.2 Tritium Cross-check Analyses on Split Water Samples Determined by Colorado State University and Public Service Company
- a. First and Second Quarter 85 ]
l
- b. Third and Fourth Quarter 86 l li.G.3 Gross Beta Cross-check Analyses on Split Water Samples Determined by Colorado State University and Public Service Company ,
- a. First and Second Quarter 87
- b. Third and Fourth Quarter 88 ;
ll.G.4 Intralaboratory Cross-check Results 89 . 11.11.1 Data Summary 95-99 j i Summary Table of Arithmetic Means and Standard Deviations for I 11.11.2 Selected Sample Types 100-102 II.J.1 Tritium Concentrations in F-16 Well Water
- a. First llalf 103
- b. Second llalf 104 Ill.A.1 Detection Capabilities for Environmental Sample !
Analysis 107 , 1 Ill.C.1 Land-Use Census,1995 110 i i 5 T vi ,
LIST OF FIGURES Page No. Figure II.A.1 Gamma Exposure Rates, 1978-1995 (Facility Area Only) 10 Figure II.B.1 Gross Beta Concentrations in Air 17 Figure ll.C.1 Tritium Concentrations in F-16 Well Water, 1984-1995 60 Figure ll.C.2 Tritium Concentrations in F-16 Well Water 61 Figure 111.B.1 Close-in Sampling Locations 107 Figure Ill.B.2 Adjacent and Reference Sampling Locations 108 Figure III.C.1 Land Use Census,1995 110 vii
l L Introduction to Radiological Environmental Monitoring Program (REMP) Data for the Period January 1,1995 - December 31,1995. During 1995 the environmental monitoring program was concerned only with the decommissioning phase of the Fort St. Vrain Nuclear Station. The operational phase of the reactor ended on August 18,1989. Fuel removal operations were completed by June 10,1992. The spent fuel is stored near by in an Independent Spent Fuel Storage Installation (ISFSI). A complete and detailed listing of radioactivity released by all effluent routes may be found in the Public Service Company of Colorado Annual Efiluent Release Report for 1995 to the U.S. Nuclear Regulatory Commission. When possible in this report, any correlation of radioactivity in
< environmental samples with the effluent release data is discussed. These discussions are presented in the appropriate sample type section and in the summary section, II.H.
Table III. A.2 lists the LLD values achievable by the counting systems used during 1995 on project samples. These values are given for typical sample sizes, counting times and decay times. The LLD is, therefore, an a nriori parameter to indicate the capability of the detection system used. The LLD values in Table Ill.A.2 were calculated as suggested in NUREG-0472. Throughout the report, however, when a sample result is listed as less than a specified value, that value is the calculated minimum detectable concentration (MDC). This approach is analogous to that of Currie (NUREG/CR-4007): the MDC is the same as S, , the critical signal, and the LL.D is equal to Sn, the detectable signal. The MDC value applies to the actual sample size, ) counting time and decay time applicable to that individual sample. It is calculated for each radionuclide as: 1 1
MDC = 2.33 ng EYVe- At Where: o3 = Standard deviation of background count rate 1 E = Counting efficiency, e ds pCi Y = Chemical yield (if any) V = Sample volume (or mass) A = 0.693/ Half-life t = Decay time between sample collection and analysis This calculation method assumes that E, Y, and V are constants and makes no allowance for systematic error. It should be noted that we have not used the notation < MDC for values less than MDC. Rather, we report the result as less than the actual MDC value. Because the MDC is dependent upon variables such as the background count time and sample size, the value will be different for each radionuclide for each sample type and even within sample type. Essentially all radioactivity values measured on this project are near background levels and, more importantly, near the MDC values for each radionuclide and sample type. It has been well-documented that environmental radioactivity values exhibit great inherent variability. This is partly due to sampling and analytical variability, but most importantly due to true environmental or biological variability As a result, the overall variability of the surveillance data is quite large, and it is necessary to use mean values from a rather large sample population size to draw any , conclusions about the absolute radioactivity concentrations in any environmental pathway, i The arithmetic mean for each sample set is listed in Table 11.11.2. All measured values, both l i 2
i l 1 l ? l positive and negative, are used in the calculations of the arithmetic mean. This is the suggested practice by Gilbert (Ifealth Physics 40:377,1984) and the NRC (NUREG/CR-4007). l Many sets of data were compared in this report. The statistical test used was either a "t"-test or a paired "t"-test. If data sets are noted to be significantly different or not significantly different, the confidence for the statement is at the 95% level ((a = 0.05), (1.96c)). ; The Total EfTective Dose Equivalent (TEDE) goal for decommissioning as set by the NRC . I < (NUREG/CR-5512) in 1993 is 10 mrem / year for any member of the general public. This is the whole-body dose rate limit excluding background and medical radiation dose rate. : 4 The maximum permissible dose commitment rate set independently by the EPA 7 (40CFR190) for any specified member of the general pub!!c from any part of the nuclear fuel cycle 1 is 25 mrem / year. , i Dose commitments can be calculated for hypothetical individuals for any mean !
- concentrations noted in unrestricted areas that are significantly above control mean values. ;
i i i 4 i
)
i t 3 2
i The following is the footnote system used in this report.
- a. Sample lost prior to analysis.
- b. Sample missing at site. .
- e. Instrument malfunction. j
- d. Sample lost during analysis.
- e. Insufficient weight or volume for analysis.
- f. Sample unavailable. ;
- g. Analysis in progress. ,
- h. Sample not collected (_ actual reason given). ,
- i. Analytical error (actual reason given). ,
N.A. Not applicable. ; l l I l i l 4
J II. Surveillance Data for January Through December 1995 and Interpretation of Resuhs , 6 A. Extemal Gamma-ray Exposure Rates He average measured gamma-ray exposure rates expressed in mR/ day are given in Table , II.A.I. The values were determined by CaF 2:Dy (TLD-200) dosimeters at each of 41 locations (see i Figure III.B.1). Two TLD chips per package are installed at each site and the mean value is , reported for that site. The mean calculated total exposure is then divided by the number of days that elapsed between pre-exposure and post-exposure annealing to obtain the average daily exposure rate. The TLD devices are changed quarterly at each locadon. Fading during field exposure is minimized by the post-annealing readout procedure. All TLD's are facing north to . l ensure consistent solar heating. The TLD data indicate that the arithmetic mean measured exposure rate (plus 1.96 standard deviations) in the facility area for all of 1995 was 0.41 (0.11) mR/ day. The mean exposure rate was , 0.40 (0.15) mR/ day for the adjacent area and 0.40 (0.14) mR/ day for the reference area. These mean values are not significantly different from each other and not different from the mean values i measured during 1994. : The exposure rate measured at all sites is due to a combination of cxposure from cosmic rays, from natural gamma-ray emitters in the earth's crust and from ground surface deposition of fission products due to previous world-wide fallout. The variation in measured values is due to true variation of the above sources plus the variability due to the measurement method. The purpose of 1 l 5
having two TLD rings around the site is not to measure gamma-rays generated from the facility itself, but to document the presence or absence of gamma-ray emitters deposited upon the ground from the reactor effluent. Since the inception of power production by the reactor, there has been no detectable increase in the extemal exposure rate due to reactor releases. Fallout deposition, trom world-wide fallout, from the Chinese nuclear weapon tests, and from the Chemobyl accident, has been detected in the past. The TLD system is calibrated by exposing chips to a scattered gamma-ray flux produced in a cavity surrounded by uranium mill tailings. This produces a gamma-ray spectrum nearly identical to that from the natural background measured in the site environs. The quality control program includes calibration before readout of each quarterly batch of TLD devices. For comparison purposes, EPA 402/R (Formerly 520/5) Environmental Radiation Data lists very similar background external exposure rate values measured in Denver. There has always been excellent agreement with the results from this program. Figure II.A.1 shows the measured mean exposure rate in the Facility Area from 1978 to 1995. The steady decrease in exposure rate over the period is due to the decay and weathering of i fission product deposition from previous atmospheric weapon tests, l l l l 6
Table II.A.1 Gamma Exposure Rates (mR/ day) 1995 Facility Area 1st Quarter 2nd Quarter 3rd Quarter 4th Quarter F-1 0.39 0.48 0.34 0.37 F-2 0.38 0.50 0.36 0.42 F-3 0.41 0.33 0.49 0.44 F-4 0.40 0.55 0.37 0.43 F-5 0.42 0.43 0.50 0.43 F-6 0.43 0.30 0.38 0.39 F-7 0.41 0.26 0.44 0.40 F-8 0.37 0.52 0.57 0.35 F-9 0.42 0.42 0.40 0.41 F-10 0.37 0.49 0.37 0.44 F-11 0.42 0.42 0.43 0.40 F-12 0.41 0.38 0.45 0.37 F-13 0.39 0.52 0.40 0.43 F-14 0.38 0.23 0.45 0.48 F-15 0.39 0.43 0.36 U.42 F-16 0.40 0.34 0.29 0.47 F-17 0.38 0.45 0.39 0.38 F-18 0.38 0.45 0.44 0.36 X(1.960) 0.40(0.04) 0.42(0.18) 0.41(0.13) 0.41(0.07) l l 7 l l
Table II.A.1 (cont'd) i Adjacent Area ist Quarter 2nd Quarter 3rd Quarter 4th Quarter A- 1 0.38 0.42 0.46 0.45 A-2 0.39 0.49 0.42 0.40 A-3 0.37 0.49 0.51 0.41 A-4 0.37 b 0.40 0.36 A-5 0.37 0.45 0.34 0.33 A-6 0.36 0.34 0.35 0.33 A-7 0.38 0.44 0.35 0.36 A-8 b 0.35 0.41 0.41 A-9 0.39 0.37 0.56 0.42 A-10 0.38 0.47 0.40 0.47 A-11 0.38 0.43 0.41 0.38 A-12 0.43 0.49 0.38 0.34 A-13 0.38 b 0.31 0.37 A-14 0.35 0.26 0.43 0.41 A-15 0.35 0.33 0.28 0.38 A-16 b 0.37 0.36 0.41 A-17 0.36 0.38 0.38 0.40 A-20 0.38 0.45 0.37 0.46 X(1.960) 0.38(0.16) 0.41(0.22) 0.40(0.13) 0.40(0.08) b - sample missing at site 8
Table II.A.1 (cont'd) Reference Area 1st Quarter 2nd Quarter 3rd Quarter 4th Quarter R-1 b 0.36 0.34 0.39 R-2 0.39 0.46 0.39 0.35 R-3 0.41 0.38 0.33 0.43 R-4 0.37 0.45 0.56 0.35 R-7 0.39 0.43 0.38 0.37 X(1.960) 0.39(0.28) 0.42(0.07) 0.40(0.16) 0.38(0.06) b - sample missing at site i 1 9 i
T. Gamma Exposure Rates (mR/ day) i 1978-1995 (Facility Area Only) E i Exposure Rate (m R/ day) O.6 0.5
~
bA 0.4 M -A A ^ bA , w _ pyv - - 0.3
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0.2 0.1 0 o',"""'""""".""i""""""o""m'o""."'o""'"."""""""""'""","."".""""'"">'o"oooo"""," i 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 Year
n, i II.B. Ambient AirConcentrations ~ i 4 i
- l. Gross Beta Activity
?
3 i . i.; . The air concentrations oflong lived particulate gross beta activity measured at the facility ! i and reference sampling sites are listed in Tables II.B.l(a-d) for each quarter of 1995. A-19, while .- l technically in the adjacent zone, is only a few meters from the facility boundary and logically .i 1 t
'should be considered a facility site. It has been termed a facility site since the inception of the ;
- ?
! monitoring program. The reference sites R-3, R-4, and R-11 'were established on January 1,1984 j . j and are sufficiently distant to be considered reference (control) locations. (See Table F-4 in .j f: ODCM). Note that site F-7 is in the predominant wind direction toward Platteville. Platteville is I p the nearest community with the highest D/Q. j 1 The reported concentrations are listed in units of femtocuries per cubic meter of ambient air. , I (fCi/m'), although the measured activity is due to a combination of radionuclides almost all of which are naturally occurring. All air filters are saved for future analysis if warranted due to any - possible accident scenario during decommissioning. l The mean gross beta concentration in air for all facility stations for all of 1995 was 19 !
. fCi/m'. For 1994 the mean value was 28 fCi/m'. The mean concentration for 1995 for all reference 4
i stations was 17 fCi/m'. These measured mean values were statistically significantly lower at the - 95% confidence level. 8 f The gross beta concentrations for 1995 have been added to the plot of air concentrations ! observed since 1973 (Figure II.B.1). In this figure the half-yearly mean values for the facility sites l 8 11
are plotted with the values from the reference sites. The contribution from the Chernobyl accident is dearly evident in 1986. It can be observed that overall mean values of the facility sites are not 1 significantly different from the reference sites. World-wide fallout, principally due to past Chinese atmospheric nuclear weapon tests, is the predominant contributor above background to the measured values over the period shown. There has never been a significant difference observed in gross beta air concentrations between facility and reference sites. Thus, it can be concluded that reactor air effluents of particulate fission products or activation products during operation or decommissioning have not been a source of dose commitment for the Fort St. Vrain environs population. 12
Table II.B.l(a) Concentrations of Long-lived Gross Beta Particulate Activity in Air (fCi/m') 1" Quarter 1995 Collection Facility Reference Dates F-7 F-9 F-16 A-19 R-3 R-4 R-il 01/07 46(1.8)* 42(1.6) 44(1.7) 39(1.6) 17(1.1) 32(1.5) 40(1.6) 01/14 23(1.1) 24(1.1) 24(1.1) 24(1.2) 13(0.88) 13(0.90) 23(I.2) 01/21 18(l.0) 17(0.90) 18(0.9I) 18(l.1) 15(0.92) 14(0.98) 17(l.0) 01/28 30(1.4) 27(1.2) 28(1.2) 31(1.5) 20(1.1) 21(1.2) 22(1.2) 02/04 17(l.0) 16(0.96) 16(0.90) 17(l.1) 15(0.90) 14(0.95) 17(0.97) 02/11 17(0.97) 20(0.97) 18(0.89) 18(1.0) 21(1.1) 16(0.96) 18(0.97) U 02/18 37(1.4) 38(1.4) 38(1.4) 23(1.2) 36(1.4) 21(1.1) 35(1.2) 02/25 26(1.2) 25(1.1) 26(1.1) 26(1.2) 21(1.1) 20(1.1) 21(1.1) 03/04 31(1.2) 28(1.2) 35(1.5) 29(1.3) 27(1.1) 27(1.2) 24(1.1) I 03/11 30(1.2) 35(1.3) 31(1.3) 50(1.7) 31(1.2) 28(1.2) 32(1.2) 03/18 15(1.0) 15(0.97) 15(0.94) 16(1.1) 14(0.94) 12(0.91) 14(0.98) 03/25 17(l.I) 16(l.0) 16(0.99) 18(1.2) 16(0.98) 15(l.1) 16(l.0) X 26 25 27 24 21 19 23 1.960 19 15 12 7 14 13 16 l Max:50 3(1.96o):26(I8) Max:40 5 (1.96o):21(14) l Min:15 n:48 Min:12 n:36 l * - 1.960 (Due to counting statistics)
Table II.B.l(b) Concentrations of Long-lived Gross Beta Particulate Activity in Air (fCi/m 3) , 2"' Quarter 1995 Collection Facility Reference Dates F-7 F-9 F-16 A-19 R-3 R-4 R-11 04/01 19(1.0)" 18(0.93) 18(1.1) 19(1.1) 18(0.97) 16(0.94) 16(0.93) 04'08 24(1.3) 22(1.1) 23(1.1) 25(1.4) 21(1.1) 20(1.1) 20(1.1) 04f15 17(l.0) 14(0.93) 16(l.0) 17(l.1) 15(0.90) 13(0.93) 13(0.96) 04'22 12(0.79) 11(0.7I) 10(0.70) 10(0.85) 11(0.72) 10(0.74) 11(0.73) 04/29 17(0.92) 16(0.84) 17(0.86) 16(0.99) 16(0.86) 15(0.86) 16(0.87) 05/06 11(0.77) 10(0.68) 11(0.72) I1(0.88) 10(0.70) 12(0.94) 12(0.76) 05/12 15(1.0) 13(0.97) 14(0.92) 14(1.1) 12(0.93) 14(0.96) 13(0.96) 05/19 15(0.95) 14(0.87) 14(0.85) 15(1.1) 14(0.95) 12(0.89) 14(0.88) 05/26 25(2.8) 13(0.75) 13(0.74) 12(0.91) 14(0.86) 12(0.78) 13(0.80) 06/02 17(1.4) 13(0.76) 13(0.76) 12(0.94) 13(0.85) 12(0.80) i1(0.75) 06/09 13(0.81) 12(0.75) 13(0.78) 14(1.0) 16(0.97) 13(0.81) 14(0.87) 06/16 19(l.0) 19(0.95) 19(0.96) 20(l.3) 33(l.9) 20(l.1) 19(l.1) 06/23 18(1.0) 18(1.0) 17(1.1) 20(1.2) 25(1.6) 16(1.0) 15(0.98) 06/30 19(0.98) 16(0.84) 19(0.92) 19(1.1) 21(1.1) 20(1.0) 19(0.95) 5 17 15 16 16 17 15 15 i 1.96o 7.9 6.6 7.0 8.3 12.2 6.6 5.8 Max:25 3 (l.96c):16(7.5) Max:33 5 (1.%c):15(8.7) Min:10 n:56 Min:10 n:42 '
* - 1.960 (Due to counting statistics) l
Table II.B.1(c) Concentrations of Long-lived Gross Beta Particulate Activity in Air (fCi/m3 ) 3'* Quarter 1995 1 Collection Facility Reference Dates F-7 F-9 F-16 A-19 R-3 R-4 R-11 07/07 18(0.96)* 17(0.90) 17(0.88) 16(I.1) 19(1.2) 18(0.96) 16(0.89) 07/14 28(1.3) 26(1.2) 27(1.2) 29(1.4) 22(1.3) 25(1.2) 25(1.2) 07/21 23(1,1) 26(1.0) 20(0.98) 18(1.1) 23(1.1) 23(1.1) 21(0.99) 07/28 25(1.2) 23(1.2) 23(1.1) 24(1.3) 27(1.3) 23(1.2) 24(1.2) 08'04 26(1.2) 21(1.1) 22(1.1) 25(1.4) 24(1.3) 24(1.2) 21(1.1) 08/l1 30(1.3) 26(1.2) 28(1.2) 27(1.4) 31(1.3) 28(1.2) 27(1.2) 08/18 29(1.3) 27(1.3) 26(1.1) 17(1.8) 28(1.3) 25(1.2) 24(1.2) OSG6 22(1.0) 17(0.97) 21(0.97) b 21(1.1) 21(1.0) 19(0.97) 09/02 31(1.3) 28(1.3) 28(1.2) 28(1.3) 29(1.4) 28(1.2) 26(1.2) 09'09 23(1.1) 23(1.1) 23(1.1) 22(1.1) 23(1.2) 23(1.1) 21(1.1) 09/16 31(1.3) 29(1.2) 31(1.2) 32(1.3) 31(1.3) 31(1.2) 27(1.2) 09/23 23(l.2) 23(l.1) 13(0.99) 23(1.1) 23(l.1) 20(0.97) 30(l.5) 09/30 28(1.3) 28(1.3) 30(1.1) 29(1.2) 26(1.2) 25(1.2) 26(2.1) X 26 24 24 24 25 22 24 1.96o 7.5 7.4 9.9 9.7 7.2 6.6 7.2 Mas:32 % (l.96c):25(S.8) Max:31 %(1.96c):24(7.1) Min:13 n:51 Min:16 n:39
* - 1.96c (Due to counting statistics) b - Samp e Missing at Site
Table II.B.l(d) Concentrations of Long-lived Gross Beta Particulate Activity in Air (fCi/m3) 4* Quarter 1995 Collection Facility Reference Dates F-7 F-9 F-16 A-19 R-3 R-4 R-l1 10/07 17 (l.07 17 (0.96) 17(0.88) 16 (0.97) 15 (0.98) 16(0.98) 15 (0.91) 10/14 26(1.2) 26(1.2) 26(l.1) 26 (1.2) 25 (13) 2I(1.1) 22 (1.1) 10/20 23 (13) 24 (13) 25 (1.2) 25 (13) 27(1.5) 22 (13) 22 (1.2) 10/27 19(l.0) 20(l.0) 19(0.97) 22 (l.1) 21(l.2) 18 (l.I) 16 (0.94) 11/04 27(1.1) 27(1.1) 28(1.1) 27(1.1) 26 (1.2) 23 (l.2) 23 (1.0) i1/11 25 (~.1) 23 (1.0) 24 (1.0) 24 (1.1) 24 (1.2) 20(1.1) 22 (1.1) 11/18 19 (l.0) 20 (0.96) 21 (0.95) 21(1.1) 18(1.1) 15 (0.98) 18 (0.89) 11/26 27(1.1) 25 (1.1) 28(1.1) 29(1.2) 25 (1.2) 22 (1.0) 21 (1.0) 12/02 21 (1.2) 12 (1.1) 18 (1.1) 19 (1.2) 15 (1.2) 12 (0.98) 14 (1.0) 12/09 24 (1.2) 21(1.1) 22 (1.0) 23 (1.2) 17 (1.1) 20(1.1) 20(1.1) 12/15 27(1.7) 25 (13) 23 (1.2) 25 (1.4) 20(1.4) 17 (1,1) 21 (1.2) i 12/22 b 19 (1.1) 23 (1.2) 29 (1.4) 24 (13) 22 (1.2) 20(1.1) 12/29 b b 38(13) 42(1.6) 28(1.4) 28(1.2) 30(13) X 23 22 24 25 22 20 20 1.96o 6.8 8.1 10 3 11.8 8.5 7.7 7.7 Mat: 42 5 (1.960):9.9(9.0) Max: 30 3(1.96c):8.2(8.0) Min: 12 n:49 Min: 12 n: 39
* - 1.96c (Due to counting statistics) b - Sampic Missing at Site
_ _ _ _ - _ _ - _ _ - - _ _ _ - _ _ _ - - _ - - _ _ _ .__ ._ . - _ _ = _ .-
4 Figure it,H.I Gross Beta Concentrations in Air < 1000 t E *
.N 100 t f v
s u. \
$ 4 ,
b . l V \ lo auuw - -w aa. . 19 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 73 Year
+ Facility Sampling Stations r=48 I
- - Reference Sampling Stations T s4 l
l i 17
- 2. Tritium Activity Atmospheric water vapor samples were collected continuously by passive absorption on silica gel at all seven air sampling stations (four in the facility area and three in the reference area). The specific activity of tritium in water extracted from these weekly samples in 1995 is listed in Tables II.B.2(a-d).
Inspection of Table II.B.2 shows essentially no detectable tritium activity concentrations in any periods during 1995. This was also true in 1994. There was no evidence of release from effluent air pathways. Inhalation is not a significant pathway for
- dose to humans. The milk and food pathway are the only significant source of radiation dose to humans from environmental tritium. See results in sections II.D and II.E for these pathways.
i e i L i 4 4
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)
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i Cp ( 0 0 0 0 0 0 0 0 0 0 0 0 3 3 9 9 8 8 8 9 8 0 9 9 9 r R 4 3 3 3 3 3 3 3 4 3 3 3 o p a V r t e a 9 0 0 0 0 0 0 0 0 0 0 0 0 1 3 9 9 8 8 8 9 8 0 9 9 9 3 3 4 3 3 3 W A
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!ll1 ll
Table II.B.2(b) Tritium in Atmospheric Water Vapor (pCi/L) d 2 Quarter 1995 Collection Facility Reference Dates F-7 F-9 F-16 A-19 R-3 R-4 R-11 04/01 < 390 < 390 < 390 < 390 < 390 < 390 < 390 04J08 < 380 < 380 < 380 < 380 < 380 < 380 < 380 04/15 < 380 < 380 < 380 < 380 < 380 < 380 < 380 04/22 < 380 < 380 < 380 < 380 < 380 < 380 < 380 04/29 < 490 < 490 < 490 < 490 < 490 < 490 < 490 S$ 05/06 < 380 < 380 < 380 < 380 < 380 < 380 410(460)' 05/12 < 370 < 370 < 370 < 370 < 370 < 370 < 370 05/19 < 360 < 360 < 360 < 360 < 360 < 360 < 360 1 05/26 < 370 < 370 < 370 < 370 < 370 < 370 < 370 06/02 < 370 < 370 < 370 < 370 < 370 < 370 < 370 , 06/09 < 370 < 370 < 370 < 370 < 370 < 370 < 370 l 06/16 < 370 < 370 < 370 < 370 < 370 < 370 < 370 06/23 < 370 < 370 < 370 < 370 < 370 < 370 < 370 06/30 < 370 < 370 < 370 < 370 < 370 < 370 < 370
* - 1.960 (Due to counting statistics) l
. . . - - . . . . . - . . . _~ . . . _- .. - _ . - . - _ .
Table II.B.2(c) Tritium in Atmospheric Water Vapor (pCi/L) 3dQuarter 1995 Collection ' Facility Reference Dates F-7 F-9 F-16 A-19 R-3 R-4 R-11 07/07 < 360 480(450)* < 360 1000(450) < 360 < 360 < 360 07/14 < 370 < 370 < 370 < 370 < 370 < 370 < 370 07/21 < 370 < 370 < 370 < 370 < 370 < 370 < 370 07/28 < 37 J < 370 < 370 < 370 < 370 < 370 < 370 08M4 < 370 < 370 < 370 < 370 < 370 < 370 < 370 1 M 08/lI < 380 < 380 < 380 < 380 < 380 < 380 < 380 08/18 < 370 < 370 < 370 < 370 < 370 < 370 < 370 08/26 < 380 < 380 < 380 < 380 < 380 < 380 < 380 l 09/02 < 400 < 400 < 400 < 400 < 400 < 400 < 400 , 09/09 < 390 < 390 < 390 < 390 < 390 < 390 < 390 09/16 480(480) < 400 480(480) < 400 < 400 < 400 < 400 0923 < 390 < 390 450(470) < 390 < 390 < 390 590(470) 09/30 < 370 < 370 < 370 < 370 < 370 < 370 < 370
* - 1.960 (Due to counting statistics) , , , - _ . .m , - - - ,, -- -.,-v~..-m v v, - , , , . - - - -n- =
- _ _ , -- 1 -- - - - - _ = - _ _ , - -_ _ - - _ _
l Table II.B.2(d) Tritium in Atmospheric Water Vapor (pCi/L) 4* Quarter 1995 Collection Facility Reference Dates F-7 F-9 F-16 A-19 R-3 R-4 R-11 10,'07 < 380 < 380 < 380 < 380 < 380 < 380 < 380 10/14 < 390 < 390 < 390 < 390 < 390 < 390 < 390 10/20 < 390 < 390 < 390 < 390 < 390 < 390 < 390 10'27 < 400 < 400 < 400 < 400 < 400 < 400 < 400 1I/04 < 410 < 410 1300(430f 460(430) < 410 < 410 < 410 , O 11/11 < 370 < 370 < 370 < 370 < 370 < 370 < 370 11/18 < 390 < 390 < 390 < 390 < 390 < 390 < 390 1I/26 < 400 < 400 < 400 < 400 < 400 < 400 < 400 12/02 < 430 < 430 < 430 < 430 < 430 < 430 < 430 12/09 < 400 < 400 < 400 < 400 < 400 < 400 < 400 12/15 < 370 < 370 < 370 < 370 < 370 < 370 < 370 12/22 < 380 < 380 < 380 810(450) < 380 < 380 < 380 e 12/29 < 390 < 390 < 390 < 390 < 390 < 390 < 390
* - 1.960 (Due to counting statistics)
Table II.B.3 Tritium Released (Ci) In Fort St. Vrain Effluents,1995 MODE JAN FEB NfAR APR NIAY JUN JUL AUG SEP OCT NOV DEC TOTAL Continuous .2 I .081 .25 .66 .16 .11 .095 .II 1.1 .95 0* O 3.7 Gaseous Stack Batch Liquid .071 .26 0.0 .51 .75 .48 .71 .39 .41 .032 .009 0 3.6 TOTAL .28 .34 .25 1.2 .91 .60 .80 .50 1.5 .98 .009 0 7.4
- October was the final monthly report of tntium released from the shield water system at the Fort St. Vrain Station in accordance with the Tritium Discharge Understanding of October,1992. PSCo initiated liquid efflued releases from the shield water system in June,1993, and has provided monthly tritium release y reports since that time. The Fort St. Vrain decommissionie ; project has progressed to the point that all shield water has been released from the site and the " shield water system has been dismantled. Some liquid efIbent will continue to be released, largely from cleaning and dismantlement activities that remain to be completed; this liquid efIluent will be released in accordance with the controls and requirements in the Fort St. Vrain CDPS Permit and Nuclear Regulatory Commission license.
1 l l l l
- 3. Concentrations of Gamma-rav Emittine Radionuclides in c Ambient Air Table ll.B.4 lists measured ambient air concentrations of Cs-134 and Cs-137 during 1995. These results are from gamma-ray spectrum analyses of weekly air filters composited quarterly from each of the seven air sampling stations. Occasional positive values can be noted. Ilowever, in every case these are very close to the lower limit of detection. The occasional positive values are either measurement system false positives or Cs-137 concentrations ,mssibly due to resuspension of surface soil. The Cs-137 activity in surface soil is due to Chemobyl or previous world-wide fallout which is bound by clay minerals on the surface of undisturbed soil. For the entire year, the mean of the facility stations was not difTerent from the mean of the reference stations (see Table II.H.2).
Although only Cs-134 and Cs-137 are reported, each gamma-ray spectrum is scanned for evidence of peaks from other fission products and activation products. Only gamma-ray activity due to the naturally occurring background radionuclides was observed. During the second quarter of 1986, however, many other fission product and activation product radionuclides were observed due to the Chemobyl accident. Of these only Cs-137 can still be detected, but at steadily decreasing concentrations. Due to the time period since the end of operation, there is no logic in I-131 monitoring and it was discontinued in January 1993. It is worthy to note that I-131, due to facility emuent, was never measured in any environmental sample during the operational phase or since the reactor was permanently shut down in August 1989. < i 24
3 Table II.B.4 Radiocesium Concentrations in Ambient Air. (fCi/m ) 1995 Radio- Facility Reference Collection nuclide Periods F-7 F-9 F-16 A-19 R-3 R-4 R-11 1" Cs-134 < l.8 < 0.66 < l.8 < 0.68 < l.6 < 0.77 < l.7 Quarter Cs-137 < l.8 0.94(1.0)* < l.6 <0.83 < l.8 <0.90 < l.8 to 2"' Cs-134 < l.7 < 0.43 < l.4 0.8(0.94) < l.2 < l.5 < l.3 Quader Cs-137 < l.7 0.7(1.6) < l.3 1.6(0.86) < l.2 < l.4 < l.2 3'd Cs-134 < 0.83 < 0.73 < 0.20 < l.1 1.2(1.0) < 0.80 <0.89 Quarter Cs-137 <0.75 < 0.87 0.63(0.25) 2.0(l.5) < 0.89 < 0.75 < 1.1 4* Cs-134 < 0.60 < 0.47 < 0.36 < l.0 < 0.76 < 0.70 < 0.79 Quarter Cs-137 1.l(0.8) 0.89(0.57) 0.9(0.45) 1.3(l.2) < 0.95 1.2(1.0) < 0.81
* - 1.960 (Due to counting statistics)
II.C. Radionuclide Concentrations in Water
- 1. Drinkine Water Drinking water is sampled weekly and composited biweekly at two locations.
Location R-6 is the water faucet at the Gilcrest Post Oflice in Gilcrest, Colorado, and R-3 is from a water hydrant located on the old CSU dairy farm in Fort Collins. The Gilcrest well is the nearest public water supply that could be afrected by the facility efiluents. R-3 samples are the same as the Fort Collins drinking water supply and serve as a reference location since its source is run-off surface water from the Rocky Mountains to the west. In the past water treatment systems for the two water supplies were very different, however recently Gilerest has adopted treatment practices that more closely correspond to those of Fort Collins. Table II.C.1 shows gross beta concentrations measured in 1995 from each water supply. The mean for the Gilerest site was slightly higher than the Reference site in Fort Collins. This is due to the difTerent supply sources. The city of Gilcrest blends water form two difTerent sources and it does not filter the well supply water as well as Fort Collins and ) l natural radionuclide concentrations due to the suspended solids are responsible for the slightly higher measured concentrations. As can be observed in Table II.H.2, however, the mean for the entire year fbr the Gilcrest site was again lower than that observed prior to 1993. This decrease was due to a changes in treatment practice by the town of Gilcrest. Table ll.C.2 lists measured tritium concentrations in these same two drinking water sources. There is no significant difTerence in the yearly mean tritium concentrations in the two drinking water supplies. The EPA limit for community drinking water systems is 20,000 pCi/L for tritium. 26
The two drinking water supplies were also analyzed biweekly for fission product I and activation product concentrations. A three liter aliquot of the original sample is l
)
counted directly for the other gamma-ray emitters. Inspection of Table II.C.3 reveals occasional positive values of radionuclide concentration, but with the exception of Cs-137, ) these are interpreted to be random variations about the detection limit. The Cs-137 is the residue from the 1986 Chernobyl accident fallout as well as from past world-wide fallout from nuclear weapons testing. I i i 4 i 27 , l 0
Table II.C.l(a) Gross Beta in Drinking Water (pCi/L) 1" and 2"' Quarter 1995 Collection Gilcrest Ft. Collins Dates R-6 R-3 12/31 01/07 1.l(2.2)' O.90(0.58) 01/14 01/21 033(2.I) 0.96(0.58) 01/28 02/M 1.0(23) 0.61(0.57) 02/11 02/18 1.3(2.2) 1.l(0.59) 02/25 03'N 0.40(2.2) 0.73(0.57) 03/11 03/I8 0.49(2.1) 0.6t(0.57)
$ 03/25 M/01 1.l(2.2) 1.0(0.58) 04 S 8 04/15 1.0(2.2) 0.59(0.56) 04/22 M/29 2.6(0.58) 0.87(0.58) 05/06 05/12 1.5(2.2) 0.79(0.57) 05/19 05/26 0.69(2.2) 0.61(0.56) 06/02 06/09 0.49(2.2) 0.89(0.58) 06/16 06/23 0.84(2.2) 1.0(0.58)
* - 1.960 (Due to Counting Statistics)
s ) ) ) ) ) ) ) ) ) ) ) ) i n 7 5 6 5 5 5 8 5 6 5 7 5 6 5 8 5 6 5 9 5 9 5 9 5 l o 3- 0 l 0 0 0 0 0 0 0 ( 0( 0 ( 0 ( 0( ( ( ( ( ( ( ( 8 8 6 0 1 1 1 0 5 5 8 8 C.t R 7 4 4 9 6 7 5 8 5 8 9 8 F 0 0 0 0 0 0 0 0 0 0 0 0 ) L / i Cp ( r t e a W g i n k i n r D * ) ) ) ) ) ) ) ) ) ) ) t ) 2 2 2 2 2 i n s e r6 2 2 2 2 2 2 1 2 2 2 2 3 2 2 2 2
- 2 ( 2
( 2 ( ( ( ( ( ( ( ( ( a icR l ( 4 9 4 6 l. 3 5 1 9 9 4 9 7 2 0 3 9 2 t e G 1 0 1 1 0 0 0 0 1 2 0 1 B s s o r G ) b ( l. C. I I l e b a ) ic s T 1 4 8 2 6 0 4 7 1 6 2 9 0 3 2 i t s n 2 0 I 0 I 3 1 2 7 1 t o / 7 8' .
/
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- 9*
s n 0 0 0 0 i l 0 0 0 0 0 0 0 0 0 0 3 9 2 9 9 9 8 9 9 9 7 7 7 7 6 lo - 3 4 3 3 3 3 3 3 3 3 3 3 3 3 C. R < < < < < < < < < < < < < < t F ) L / i Cp ( r t e a W g i n k i n r ') D t s e 0 0 0 0 0 0 0 0 7 0 9 0 7 0 7 0 7 0 7 0 6 r6 9 2 9 9 9 8 9 n l c R 3 4 3 3 3 3 3 4 ( 3 3 3 3 3 3 i
< < < < < < < 0 9 < < < < < <
iG 5 m i u t i r T ) ( a 2 C. I I l e b a T 7 1 4 8 4 8 1 5 9 2 6 9 3 7 n o 0
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s n i l 0 0 0 0 0 0 0 0 0 0 0 0 l 3 7 7 7 9 8 8 8 7 8 2 8 5 o - 3 3 3 3 3 3 3 3 3 4 3 4 CR . < < < < < < < < < < < < t F ) L / i Cp ( r t e a W g i n k i n r D t s e6 0 0 7 0 7 0 9 0 8 0 8 0 8 0 7 0 8 0 2 0 8 0 5 n lcR r - 7 3 3 3 3 3 3 3 3 3 4 3 4 i iG m i u t i r T ) b ( 2 C. I I l e b a T 1 4 8 2 6 0 4 7 1 6 9 3 n 2 0J l 0 1 3 1 2
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Table II.C.3 Radionuclide Concentrations in Bi-weekly Composite of Drinking Water. (pCi/L) Collection for two weeks ending for two weeks ending for two weeks ending Date 01/07/95 0I/2I/95 02/IIl95 Radionuclide Gilcrest Ft. Collins Gilcrest Ft. Collins Gilcrest Ft. Collins R-6 R-3 R-6 R-3 R-6 R-3 Cs-134 < 2.0 < 1.8 < l.8 < l.9 < 2.0 < 2.4 Cs-137 < 2.5 3.8(2.7)* <23 <23 <2.4 < 3.0 Zr-95 < 4.7 < 4.7 < 4.4 < 4.9 < 5.1 < 5.7 Nb-95 < l.8 < l.7 < 1.7 < l.8 < l.8 < 2.2 Co-58 < l.8 < l.7 < l.7 < l.7 < l.8 < 2.4 d Mn-54 23(2.4) < l.8 < l.9 < l.9 < 2.0 < 2.4 Zn-65 <5.5 < 4.9 < 5.2 < 5.2 <5.4 <73 Fe-59 < 4.7 <43 <43 <5.1 < 4.6 < 5.7 Co-60 < 2.2 < 2.0 <2.0 < 2.1 < 2.2 < 2.6 Ba-140 <3.2 <5.0 < 5.7 <3.1 <3.2 <6.1 La-140 < 3.7 <5.7 < 6.6 < 3.5 <3.7 < 7.0
* - 1.96o (Due to counting statistics)
Table II.C.3 Radionuclide Concentrations in Bi-weekly Composite of Drinking Water. (pCi/L) Collection for two weeks ending for two ueeks ending for two weeks ending Date 02/18,95 03/0495 03/l8/95 Radionuclide Gilcrest Ft. Collins Gilcrest Ft. Collins Gilcrest Ft. Collins R-6 R-3 R-6 R-3 R-6 R-3 Cs-134 < 2.0 < l.9 < l.4 < 2.0 <!! <l.3 Cs-137 < 2.5 3.2(2 9)* 2.l(2.1) 3.3(2.8) 1.9(l.7) 3.9(l.8) Zr-95 < 4.7 < 4.6 <3.3 < 4.6 < 2.7 <3.4 Nb-95 < l.8 < l.7 < l.3 < l.8 < l.2 < l.2 Cc-58 < 2.1 < 2.0 <13 < l.9 < l.1 < l.4 d Mn-54 < 2.0 < 2.0 < l.4 < l.9 <l.1 < l.3 Zn-65 <5.4 < 5.3 < 3.8 < 5.4 < 3.5 <3.9 Fe-59 < 4.7 < 4.6 <3.7 < 4.5 < 2.8 <2.9 Co-60 < 2.1 <2.0 < l.5 < 2.1 < l.1 < l.2 Ba-I40 <3.3 8.5(7.5) < 3.9 <3.1 < l.8 11(7.7) La-140 < 3.8 9.8(8.6) < 4.5 <36 < 2.1 13(8.9)
- 1.96o (Due to counting statistics)
Table II.C.3 Radionuclide Concentrations in Bi-weekly Composite of Drinking Water. (pCi/L) Collection for two weeks ending for two weeks ending for two weeks ending Date 04'01/95 04/15/95 04/29 95 Radionuclide Gi! crest Ft. Collins Gilcrest FL Collins Gilcrest Ft. Collins R-6 R-3 R-6 R-3 R-6 R-3 Cs-134 < 2.0 <l.5 < 2.0 < l.4 < l.2 <2.0 Cs-137 < 2.5 2.2(2.2)' < 2.5 3.9(l.9) 3.9(1.8) 3.2(2.9) Zr-95 < 5.4 < 4.0 < 5.1 <3.1 < 3.0 < 5.0 Nb-95 < l.9 <13 < l.9 1.4(1.6) < l.2 < l.8 Co-58 < 2.1 < l.4 < l.8 < l.2 < l.2 2.4(2.4)
$ Mn-54 2.5(2.5) < l.5 < 2.0 <13 <13 < 2.0 Zn-65 < 5.4 <42 <5.6 <4.0 <3.9 < 5.4 Fe-59 < 4.8 < 3.5 < 4.8 <3.0 <33 < 4.7 CW < 2.2 < l.6 2.4(2.5) < l.3 <l.2 <2.1 Ba-140 <33 < 2.5 < 5.2 < 3.4 <3.2 5.6(6.1)
La-140 <3.8 <2.9 < 6.0 <3.9 <3.7 6.5(7.0)
* - 1.96o (Due to counting statistics)
Table II.C.3 Radionuclide Concentrations in Bi-weekly Composite of Drinking Water. (pCi/L) Collection for two neeks ending for two weeks ending for two weeks ending Date 05/13/95 05/27/95 06/10.95 Radionuclide Gilcrest Ft. Collins Gilcrest Ft. Collins Gilcrest Ft. Collins R-6 R-3 R-6 R-3 R-6 R-3 Cs-134 < 2.0 < 0.81 < 2.0 < l.9 < 2.0 <2.0 Cs-137 < 2.4 1.2(l .2)' < 2.5 < 2.3 < 2.5 < 2.4 Zr-95 < 4.6 < l.7 < 4.7 < 4.3 < 4.8 < 4.6 Nb-95 < l.8 <0.77 < l.8 < l.6 < l.8 <l.8 Co-58 < 2.1 < 0.89 < l.9 <l7 < 2.0 < 1.8
$ Mn-54 < 2.0 < 0.79 < 2.1 < l.9 < 2.0 < 2.0 Zn-65 <5.3 <22 < 5.5 < 4.9 <5.5 <5.4 Fe-59 <4.6 2.8(3.2) < 4.7 < 5.0 <5.5 < 4.9 Co-60 < 2.1 < 0.77 < 2.2 < 2.0 <22 <2.2 Ba-140 < 3.2 4.0(4.7) < 6.9 < 5.1 <3.3 <3.2 La-140 < 3.7 4.6(5.4) < 8.0 < 5.9 < 3.8 <3.7
* - 1.960 (Due to counting statistics)
I
Table II.C.3 Radionuclide Concentrations in Bi-weekly Composite of Drinking Water. (pCi/L) Collection for two weeks ending for two weeks ending for two weeks ending Date 06/24/95 07/08S5 07/22 S 5 Radionuclide Gilcrest Ft. Collins Gilcrest Ft. Collins Gilcrest Ft. Collins R-6 R-3 R-6 R-3 R-6 R-3 Cs-134 < 2.1 <22 < l.1 <23 < l.2 < l.8 Cs-137 < 2.5 < 2.7 <l.3 3.6(3.2)* 2.2(1.8) < 2.2 Zr-95 < 4.8 < 5.2 < 2.6 < 5.2 < 2.9 < 4.2 Nb-95 < l.9 < 2.0 < 0.98 < 2.0 < l.1 < l.6 Co-58 < :.9 < 2.1 < l.0 < 2.1 < l.2 < l.8
$ Mn-54 <2.1 < 2.2 < l.1 <23 13(1.5) < l.8 Zn-65 < 5.5 < 6.0 3.0 < 6.2 <33 < 4.8 Fe-59 < 4.7 < 5.0 <2.5 <53 < 3.4 < 4.2 Co-60 < 2.2 < 2.4 < l.2 < 2.5 <13 < l.9
! Ba-140 <53 5.4(63) <3.0 <3.7 < 2.0 <2.9 La-140 < 6.2 63(7.2) <3.4 <4.2 <23 <33
* - 1.96o (Due to counting statistics) l
Table II.C.3 Radionuclide Concentrations in Bi-weekly Composite of Drinking Water. (pCi/L) ! Collection for two weeks ending for two weeks ending for two weeks ending I Date 07/29.95 08/12/95 08 % 95 Radionuclide Gilcrest Ft. Collins Gilcrest Ft. Collins Gilcrest Ft. Collins R-6 R-3 R-6 R-3 R-6 R-3 Cs-134 < 2.0 < 2.1 < 2.1 1.8(1.4)* < l.2 < 2.2 l Cs-137 3.2(2.9) < 2.5 < 2.5 < l.4 2.9(l.8) < 2.7 ' Zr-95 < 5.1 < 4.8 < 4.7 < 2.7 < 2.9 < 5.I Nb-95 < l.8 < l.9 < l.8 < l.0 < l.1 < 2.0 l Co-58 < l.9 < l.9 < l.8 < l.2 < l.1 < 2.1 d Mn-54 < 2.0 2.2(2.4) 2.6(2.4) < l.2 <13 < 2.2 i Zn-65 <5.5 < 5.7 < 5.6 <3.1 <33 < 5.8 Fe-59 < 4.7 < 4.7 < 4.6 < 2.7 < 2.9 < 5.1 Co-60 < 2.1 < 2.2 < 2.2 < l.2 <13 <23 Ba-140 <3.2 <33 < 7.2 < l.9 <2.0 <3.5 La-140 <3.7 < 3.8 <83 < 2.2 < 23 < 4.1
* - 1.96o (Due to counting statistics)
Table II.C.3 Radionuclide Concentrations in Bi-weekly Composite of Drinking Water. (pCi/L) Collection for two weeks ending for two weeks ending for two weeks ending Date 09'09 S 5 09.23 S 5 10'07/95 Radionuclide Gilcrest Ft. Collins Gilcrest Ft. Collins Gilcrest Ft. Collins R-6 R-3 R-6 R-3 R-6 R-3 Cs-134 < 2.1 < 2.1 < l.6 < 2.1 <13 < l.2 Cs-137 < 2.6 < 2.6 2.2(2.3)' < 2.6 3.l(1.8) 3.4{l.8) Zr-95 < 5.6 < 4.9 < 3.7 < 4.9 < 2.7 <33 Nb-95 < l.9 < l.9 < l .4 < l.9 1.9(1.7) 1.8(1.7) w Co-58 < 2.2 < 2.1 < l.5 < 2.0 < l.1 < l.1 oo Mn-54 < 2.1 < 2.1 < l.6 < 2.1 <13 <13 Zn-65 < 5.9 < 5.7 < 4.4 < 6.0 <3.4 <3.4 Fe-59 < 4.9 < 4.9 < 3.7 < 5.0 8.8(4.8) < 3.0 l Co-60 < 2.2 < 2.2 1.9(2.0) <23 <l.2 <l.1 1 ! Ba-140 <3.4 7.7(8. I) <2.5 < 4.6 <l.9 <2.0 l La-140 < 3.9 8.8(93) < 2.9 <53 < 2.2 <23 l * - 1.960 (Due to counting statistics) l l l l
Table II.C.3 Radionuclide Concentrations in Bi-weekly Composite of Drinking Water. (pCi/L) Collection for two weeks ending for two weeks ending for two ueeks ending Date 102I/95 11/0495 11II8/95 Radionuclide Gilcrest FL Collins Gilcrest Ft. Collins Gilcrest Ft. Collins R-6 R-3 R-6 R-3 R-6 R-3 Cs-134 1.2(1.2)~ 1.2(13) 1.4(1.7) 1.5(1.5) 0.98(1.0) < l.4 Cs-137 < 3.8 2.l(1.8) 3.7(2.1) 1.8(1.9) 2.9(1.2) 3.8(2.0) Zr-95 < 3.5 < 3.3 < 3.4 < 2.9 < l.8 < 3.1 Nb-95 < l.8 < l.6 < l.6 < l.3 2.3(1.2) 1.6(1.9) Co-58 < l.8 < l.6 < l.4 < l.2 < 0.75 < l.3
$ Mn-54 < l.1 < l.4 < l.5 < l.3 < 0.84 1.9(1.7)
Zn-65 < 3.9 < 4.2 < 5.0 <3.3 < 2.5 < 4.0 l Fe-59 <3.5 < 3.8 <3.9 <3.4 4.3(3.2) <3.2 l CMM) < l.3 < l.4 <l.3 < l.2 < 0.77 < l.3 Ba-140 < 2.2 < 2.6 < 2.4 < 3.0 < 3.5 < 5.4 La-140 < 2.9 < 2.9 < 2.8 <3.5 <40 < 6.2
* - 1.960 (Due to counting statistics)
Table II.C.3 Radionuclide Concentrations in Bi-weekly Composite of Drinking Water. (pCi/L) Collection for two weeks ending for tuo weeks ending for two weeks ending Date 12/02 S 5 12/16S 5 12/30 95 Radionuclide Gilcrest Ft. Collins Gilcrest Ft. Collins Gilcrest R. Collins R-6 R-3 R-6 R-3 R-6 R-3 Cs-134 < l.4 < l.4 < 0.98 <l.2 < l.2 < l.4 Cs-137 3.0(2.0)* 22(2.1) 1.2(1.5) 1.5(1.8) 1.4(1.5) 2.0(2.1) Zr-95 <3.0 <3.2 < 2.8 < 2.6 < 2.8 <3.6 Nb-95 2.3(1.7) 2.5(1.6) < 0.94 < l.4 < I.2 < l.7 Co-58 <l.3 < l.2 < 0.88 < l.1 < l.1 < l.3 $ Mn-54 < l.3 1.9(1.7) < l.0 1.4(1.5) < l.6 < l.4 Zn-65 <3.9 <3.9 < 3.0 < 3.9 <3.2 <4.6 Fe-59 <3.7 4.6(4.5) 3.6(4.0) < 3.0 <3.4 4.7(5.0) CW < l.4 < l.3 < 0.95 < l.1 < l.4 < l.4 Ba-140 <2.3 < 2.2 < 5.9 < 4.9 < 4.2 < 2.4 La-140 < 2.6 <2.5 < 6.7 < 5.6 <5.0 <2.7 l
* - 1.960 (Due to counting statistics)
l
\
- 2. Surface Water 1 l
I Surface water is collected from five sites. Since the facility liquid effluent can be directed to either the St. Vrain Creek or the South Platte River, there are upstream and downstream sampling locations on both river courses. Table II.C.4 shows tritium concentrations measured during 1995 at the four surface water sites and the effluent route site. The arithmetic mean value for the two downstream locations in 1995 was not significantly different from the two upstream locations (Table 11.11.2). There were only detectable tritium concentration at A-25, which is the principal effluent route. This can be noted in January, February, July, and October. Table II.C.5 shows measurements of fission product and activation product concentrations in surface water samples collected monthly. There were occasional positive values, but the mean of the downstream sites was not significantly difTerent from the mean of the upstream sites during 1995 for any of the gamma-ray emitting radionuclides measured. This has been the case since the inception of reactor operations at the Fort St. Vrain site. The occasional positive values are either fallout Cs-137, which can be expected, or values close to the uncertainty limits and assumed to be false positives. Using a 95% confidence interval,5% of the values are expected to be high false positives. In addition to the monthly sampling of the South Platte River and St. Vrain Creek, a continuous water sampler collects an aliquot of the effluent stream from the Fann Pond (A-25), at a preset frequency. The sample is dumped after each aliquot into a 5 gallon collection jug. To prevent overflow of the jug in the one week sampling period, the aliquot value and/or the sampling frequency is adjusted. The weekly composites are then combined and analyzed monthly. The results of these samples are shown in Tables II.C.4 and II.C.5. 41 l l
- ._ .-. - . . . . ~. . - . _ - . - - _ . . - - . - .. - . - . . _ . . . . . . _ - .
Periodically throughout the year there was detectable tritium in the Farm Pond overflow (A- ! ! 25) due to decommissioning activities. These concentrations correspond to the effluent release data. These concentrations were much lower than the EPA drinking water limit (20,000 pCi/L). No elevated tritium concentrations were detected, however, at the ! downstream location (R-10) during the entire year. Mean values of the other radionuclides were less than MDC with the exception of Cs-137. The Cs-137 mean in downstream water was not statistically higher than upstream and therefore the activity is concluded to be due to worldwide fallout. The correlation of , the tritium concentrations at A-25 with the effluent release information is good. t f I l l l l l l 42 j
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Table II.C.5 Radionuclide Concentrations In Surface Water (pCi/L) Collection Date: January 14,1995" Downstream Sites Upstream Sites Efiluent Radionuclide St. Vrain S. Platte St. Vrain S. Platte Goosequill F-20 R-10 A-21 F-19 A-25 Cs-134 <20 1. l(13)* < 2.0 <2.2 < 2.5 Cs-137 < 2.5 4.4(l .6) < 2.4 < 2.7 < 4.1 Zr-95 <53 <23 <53 < 5.6 < 5.0 A Nb-95 < l.9 < l.0 < l.8 < 2.0 < 2.6 A Co-58 < 2.0 < 0.97 < l.8 < 2.0 < 2.2 Mn-54 < 2.1 < l.1 < 2.0 < 2.2 < 2.1 i j Zn-65 < 5.5 <33 < 5.5 <63 < 4.4 Fe-59 5.8(6.7) < 2.5 < 4.6 < 5.6 < 5.5 CW < 2.2 < l.0 < 2.2 <23 < 2.0 i Ba-140 < 5.9 < l.8 <33 <3.5 < 3.8 l l La-140 < 6.8 < 2.0 < 3.8 < 4.0 < 3.6 l
* - 1.96o (Due to counting statistics) ** - A-25 collected January 15,1995 l
l l l
Table II.C.5 Radionuclide Concentrations In Surface Water (pCi/L) Collection Date: February 11,1995~ Downstream Sites Upstream Sites Effluent Radionuclide ' St. Vrain S. Platte St. Vrain S. Platte Goosequill F-20 R-10 A-2i F-19 A-25 Cs-134 < 2.0 2.9(2.9T < 2.4 < 2.0 < l.9 Cs-I37 < 2.4 < 3.0 <3.0 3.4(2.9) 3.9(2.7) Zr-95 < 5.1 < 5.7 < 5.7 < 5.1 <43 i Nb-95 < l.8 < 2.1 <23 < l.7 < l.7 . A u Co-58 < l.8 <2.2 < 2.4 <2.0 < l.7 Mn-54 < 2.0 < 2.4 <2.4 < 2.0 < l.9 Zn-65 <5.4 < 6.7 < 7.5 < 5.4 < 4.9 Fe-59 < 4.6 < 5.6 <5.6 < 4.7 < 5.4 Co-60 < 2.0 < 2.7 < 2.7 <2.1 <2.0 Ba-140 < 3.1 < 4.0 <3.9 < 6.0 <3.0 La-140 <3.6 < 4.6 <4.5 < 6.9 <3.4 i
- 1.96o (Due to counting statistics)
"- A-25 collected February 15,1995 1
t i
Table II.C.5 Radionuclide Concentrations In Surface Water (pCi/L) Collection Date: March 11,1995" Downstream Sites Upstream Sites Efiluent Radionuclide St. Vrain S. Platte St. Vrain S. Platte , Goosequill F-20 R-10 A-21 F-19 A-25 Cs-134 < l.5 < l.2 < 2.1 < 2.2 < l.9 Cs-137 3.5(2.2)" 5.6(2.0) 5.2(3.0) 3.7(3.2) 3.5(2.7) Zr-95 < 4.1 < 2.7 < 4.8 < 5.2 <43 Nb-95 < l.4 < l.2 < l.9 < 2.0 <l.7 A
- Co-58 < l.6 < l.1 < l.9 < 2.2 < l.7 Mn-54 1.6(1.9) < l.2 < 2.1 <23 < l.9 Zn-65 < 4.1 < 3.7 < 5.8 < 5.8 < 5.1 Fe-59 <3.5 < 3.1 <4.7 <53 <43 Co-60 < l.6 < l.2 < 2.2 <23 < 2.0 Ba-140 < 5.2 < 2.0 <33 < 6.2 <3.0 La-140 < 6.0 < 2.3 < 3.8 < 7.1 < 3.5
- 1.96o (Due to counting statistics)
" - A-25 collected March 15,1995
Table II.C.5 Radionuclide Concentrations In Surface Water (pCi/L) Collection Date: April 8,1995~ Downstream Sites Upstream Sites Efiluent Radionuclide St. Vrain S. Platte St. Vrain S. Platte Goosequill F-20 R-10 A-21 F-19 A-25 Cs-134 < l.2 <13 < 2.0 < 1.4 < 0.81 Cs-137 23(l.9)* 1.7(l.8) < 2.4 4.2(2.0) 1.4(1.2) Zr-95 <3.1 < 2.6 <53 < 3.0 < 2.2 Nb-95 <13 < l.2 < l.8 < l.4 < 0.75 4 4 Co-58 <l.2 < l.2 < l.8 <13 < 0.74 Mn-54 <13 1.8(1.4) <2.0 < l.4 < 0.82 Zn-65 <3.5 <3.6 <5.4 <5.4 <22 l Fe-59 <33 < 2.9 < 4.7 <33 33(3.4) CM>0 <12 < l.1 < 2.2 <13 < 0.73 Ba-140 < 3.4 < l.9 <33 3.4(3.2) <4.7 La-140 < 4.0 < 2.2 <3.8 3.9(3.6) <5.4
* - 1.96o (Due to counting statistics)
"- A-25 collected April 15,1995 4
. - - . - _ . _ . . _ . - , - - . , - - . . ~ . - . - - . , . . , , .-n------- - , - - , - . - - - - - - - - - -- - - - - + , . - - - - - - ~ - . - - - - - - - - - - - - - ---. ----. ---.- -~~- - -. -- - - - - - - - - -
Table II.C.5 Radionuclide Concentrations In Surface Water (pCi/L) Collection Date: May 12,1995~ Downstream Sites Upstream Sites Efiluent Radionuclide St. Vrain @ S. Platte St. Vrain S. Platte Goosequill F-20 R-10 A-21 F-19 A-25 Cs-134 < 0.60 < l.2 <2.1 <13 <12 4 Cs-137 2.2(0.91)' 33(1.7) < 2.5 2.9(1.9) 2.7(l.7)
- Zr-95 < l.5 <2.7 < 4.9 <3.1 <2.9 Nb-95 <0.58 <l.2 < l.8 <13 1.1
, A Co <0M < l.1 Co-58 <23 <13 <13 Mn-54 0.71(0.74) <13 < 2.2 <13 2.0(1.5) Zn-65 < l.7 < 3.8 < 5.4 < 3.8 <3.7 i Fe-59 < l.8 <3.5 < 6.2 <3.5 <3.6 Co-60 < 0.57 <l.2 <2.2 < l.2 < l.1 Ba-140 < 2.1 <3.8 <93 < 2.1 < l.9 La-140 < 2.4 <43 < 11 < 2.4 <22
* - 1.96o (Due to counting statistics)
" - A-25 collected May 15,1995
. _ _ _ _ _ _ . _ . . _ _ _ _ _ . _ . _ . _ - _ _ _ _ _ _ __ . _ _ ~ __ . -- . - - _ _ _ - . - - ~ - - _ - - . . - _ _ _ _ _ , ~ _ _ . . _ _ . . . . . _ . _ . . , _ . ~ - __
Table II.C.5 Radionuclide Concentrations In Surface Water (pCi/L) Collection Date: June 9,1995" Downstream Sites Upstream Sites Efiluent Radionuclide } St. Vrain S. Platte St. Vrain S. Platte Goosequill F-20 R-10 A-21 F-19 A-25 Cs-134 <13 <23 < 2.0 < l.2 < 13 Cs-137 2.0(l .9)* < 2.8 < 2.5 2.0(l.8) 3.7(1.9) Zr-95 < 2.8 < 5.8 < 4.7 < 2.9 < 2.9 Nb-95 <13 < 2.1 < l.8 < l.2 <13 4 C Co-58 <13 < 2.1 < l.8 <13 < l.4 Mn-54 1.8(:.6) <23 < 2.0 < l.2 <13 Zn-65 < 3.4 < 6.1 <53 <3.4 <3.4 l Fe-59 3.8(43) < 6.0 < 4.7 < 2.9 <3.2 i Co-60 < l.2 < 2.4 <2.2 < l.2 < l.2 Ba-140 <3.9 <3.7 <33 < 2.0 <6.1 La-140 <4.5 <43 <3.8 < 2.4 < 7.0
* - 1.96o (Due to counting statistics) " - A-25 collected June 15,1995
Table II.C.5 Radionuclide Concentrations In Surface Water (pCi/L) Collection Date: July 14,1995" Downstream Sites Upstream Sites Efnuent Radionuclide St. Vrain S. Platte SL Vrain S. Platte Goosequill F-20 R-10 A-21 F-19 A-25 Cs-134 < l.1 < 2.2 < 2.0 <2.0 < 2.5 Cs-137 2.6(l .7)* < 2.7 3.6 (2.9) <2.4 3.9 (3.5) Zr-95 < 2.6 < 5.1 < 4.8 <4.7 < 5.7 Nb-95 < l.1 < l.9 < l.8 < l.8 < 2.2 u o Co-58 < l.1 <2.2 < 2.1 <2.0 <23 Mn-54 < l.2 <2.2 2.6 (2.4) <2.0 < 2.5 Zn-65 <3.2 < 5.8 < 5.5 <53 < 6.7 Fe-59 <33 <5.9 7.6 (6.6) <4.7 <5.5 Co-60 < l.I < 2.5 <2.2 <2.1 < 2.7 Ba-140 <33 <3.6 <33 <3.2 < 9.2 La-140 <3.7 < 4.1 <3.8 < 3.7 < 11
* - 1.960 (Due to counting statistics)
" - A-25 collected July 15,1995
____.- --- - -- - _- -__m__ w__,__. .--v. - .---y w r-eg -,,- e-,ww. yag, y-,- +-y q ar,-- y--. , , --+w. gwy1-- - - --, > e .._.w.. ,...__. ,,
( Table II.C.5 Radionuclide Concentrations In Surface Water (pCi/L) Collection Date: August i1,1995" Downstream Sites Upstream Sites Efiluent Radionuclide St. Vrain S. Platte St. Vrain S. Platte Goosequill F-20 R-10 A-21 F-19 A-25 Cs-134 < 2.2 < l.2 13 (1.6)* <13 < 2.0 Cs-137 < 2.7 3.0 (l.8) 2.8 (l .9) 3.6 (l .9) < 2.5 Zr-95 < 5.1 < 2.7 < 2.9 < 2.9 6.4 (6.6) Nb-95 < 2.0 < l.2 < l.2 <13 < l.9 u
~
Co-58 <23 1.4(13) < l.1 <13 < l.8 Mn-54 2.6 (2.7) 13 (l.4) <l3 <13 < 2.0 Zn-65 < 5.8 < 3.5 <3.1 <33 < 5.5 Fe-59 <63 < 3.0 < 3.9 < 3.6 < 5.8 Co-60 <23 < l.2 < l.2 <13 <23 Ba-140 < 3.6 < l.9 < 4.2 < 4.0 <33 La-140 < 4.1 < 2.2 < 4.8 < 4.6 <3.8
* - 1.06s (Due to counting statistics)
"- A-25 collected August 15,1995
l l l l l Table II.C.5 Radionuclide Concentrations In Surface Water (pCi/L) l Collection Date: September 9,1995" l Downstream Sites I Upstream Shes Efiluent l Radionuclide St. Vrain S. Platte St. Vrain S. Platte Goosequill F-20 R-10 A-21 F-19 A-25 i Cs-134 <l.2 < 2.0 <13 <20 < 2.0 I Cs-137 23 (l .8)' < 2.5 < l.7 < 2.5 4.1 (2.9) l Zr-95 < 2.7 < 5.2 < 2.9 < 4.8 < 4.6 l l Nb-95 < l.1 < l.9 < l.4 < l.8 <2.1 u N Co-58 < l.1 < l.9 <13 < l.9 < l.8 Mn-54 < l.2 <2.1 <13 <2.0 < l.9 Zn-65 < 3.0 < 5.5 < 3.2 <53 <5.3 4 Fe-59 < 2.9 < 4.7 < 3.0 < 4.7 < 4.6 Co-60 < l.1 < 2.2 < l.2 < 2.2 < 2.1 Ba-140 <33 <33 <2.1 83 (6.7) <3.1 La-140 <3.8 < 3.8 < 2.4 9.6 (7.7) < 3.6
* - 1.96o (Due to counting statistics)
" - A-25 collected September 15,1995
Tabic II.C.5 Radionuclide Concentrations In Surface Water (pCUL) Collection Date: October 14,1995" Downstream Sites Upstream Sites Efiluent Radionuclide St. Vrain S. Platte St. Vrain S. Platte Goosequill F-20 R-10 A-21 F-19 A-25 Cs-134 < l.1 < l.2 < l.2 < l.2 < l.1 Cs-137 < l.4 2. l(1.7)' 2.2(1.8) 2.9(1.9) 1.5(1.7) Zr-95 < 2.4 < 3.0 < 3.3 < 3.3 <33 Nb-95 1.5(1.5) 2.3(1.5) < l.4 < l.2 < l.4 t.n W Co-58 < l.2 < l.1 < l.1 < l.1 < l.4 Mn-54 1.2(1.4) < l.1 < l.3 < l.2 2.0(1.5) Zn-65 < 3.0 < 3.1 < 2.9 < 3.6 <3.1 Fe-59 < 3.6 < 2.8 < 4.1 < 3.9 < 2.8 Co-60 < l.1 < l.2 < 1.2 < l.1 < l.1 Ba-140 6.9(63) < l.9 < 6.6 <53 < l.9 La-l40 8.0(7.2) <2.2 < 7.6 < 6.1 < 2.2
* - 1.960 (Due to counting statistics) ** - A-25 collected October 15,1995
4
- Table II.C.5 Radionuclide Concentrations In Surface Water (pCi/L) ;
t i Collection Date: November 11,1995" i I Downstream Sites Upstream Sites Effluent Radionuclide St. Vrain S. Platte St. Vrain S. Platte Goosequill F-20 R-10 A-21 F-19 A-25 Cs-134 < l.0 < l.2 < l.0 < l.2 < l.4 Cs-137 1.6(I .5)' 2.4(1.9) 33(1.5) < l.5 23(2.1) , Zr-95 <23 < 2.7 <23 <3.1 < 3.8 Nb-95 < 199 < l.5 < l.2 2.l(1.7) < l.5 u A Co-58 < l.1 <13 < l.1 <13 <l.6 Mn-54 < l.0 1.4(1.5) < l.1 1.7(1.5) < 1.5 i Zn-65 < 3.1 <3.5 < 2.9 <33 < 4.7 Fe-59 < 2.5 <3.9 <33 <3.9 5.6(5.5) r Co-60 <l.0 < l.2 < 0.95 < l.1 <13 , Ba-140 < l.6 < 2.0 < 5.2 < 2.0 <2.4 La-140 < l.9 <23 < 6.0 <23 < 2.7 i i
* - 1.96o (Due to counting statistics) .
" - A-25 collected November 15,1995 i
Table II.C.5 Radionuclide Concentrations In Surface Water (pCi/L) Collection Date: December 9,1995" Downstrearn Sites Upstream Sites EfIluent Radionuclide St. Vrain S. Platte St. Vrain S. Platte Goosequill F-20 R-10 A-21 F-19 A-25 Cs-134 < 0.59 < 0.46 <13 <l.1 <13 Cs-137 4.7(0.88)' l.7(0.68) 2.9(1.7) 4.6(1.8) 5. l(1.9) Zr-95 <13 < l.0 < 2.7 < 2.5 < 2.8 Nb-95 2.l(0.91) 0.52(0.62) 2.0(1.8) < l.4 2.0(1.9) u '
- Co-58 < 0.54 < 0.42 <l.1 <l.0 <12 Mn-54 < 0.62 < 0.46 < l.2 <l.1 < 13 Zn-65 < 2.1 < l.4 < 3.8 <3.7 < 4.4 Fe-59 < l.9 23(l.6) 4.4(4.9) 3.4(4.2) < 4.1 Co-60 < 0.56 <0.43 <l.1 < l.1 <l.2 Da-140 < 2.8 < 0.73 < l.9 < 5.1 <5.9 La-140 < 3.2 < 0.84 <2.2 < 5.8 < 6.8
* - 1.960 (Due to counting statistics)
"- A-25 collected December 15.1995 1
i
l i i
- 3. Ground Water Ground water is sampled quarterly at two locations. These are et F-16, a well on the l
farm immediately north and the closest to the facility down the hydrological gradient, and at R-5, a well at a personal residence in the town of Milliken. Table II.C.6 lists the measured ! concentrations of fission products and activation products in ground water. The Cs-137 results are not surprising due to residue of Chemobyl fallout. The other occasional results above MDC are assumed to be statistically false positive values. , Table II.C.7 shows tritium concentrations in the same tvell water samples. No > tritium concentrations above the MDC were observed. Figure II.C.1 shows measured l tritium concentrations in the F-16 well from 1984 through 1995. We initiated a weekly sampling of this site beginning early in 1991 and have continued to date. The data for the weekly samples of the F-16 well for 1995 are shown in Table II.J.1 (see Summary section). l Figure II.C.2 is a plot of this data for 1993,1994 and 1995. , For comparison purposes we include Table II.C.8 which lists the Maximum Permissible Concentrations in drinking water from the old 10CFR20. i i i b i l l 1 56
j i i Table II.C.6 Radionuclide Concentrations in Ground Water (pCi/L) 1" 2"' 3'd 4* Radio- Quarter Quarter Quarter Quarter nuclide I-16 R-5 F-16 R-5 F-16 R-5 F-16 R-5 Cs-134 2.6(2.7)* < 1.9 < l.5 1.8(1.4) <23 <23 <13 f 4 , Cs-137 <2.7 <23 4.2(2.2) 3.l(1.6) 4.5(3.4) 9.6(3.4) 4.8(2.0) f Zr-95 < 5.1 < 5.2 < 3.6 < 2.6 < 5.5 <53 < 2.8 f Nb-95 < l.9 < l.7 < l.3 <l.0 < 2.4 < 2.8 < l.7 f Co-58 <23 < l.8 < l.4 12(1.4) < 2.1 < 2.1 < l.2 f l d Mn-54 < 2.2 < l.9 < l.5 < l.1 <23 < 2.4 2.2(1.6) f Zn-65 < 5.9 <53 < 4.2 <3.0 < 8.0 < 10 < 4.1 f Fe-59 < 6.4 < 4.5 <3.5 <3.2 < 5.4 <5.4 <43 f Co-60 < 2.4 2.4(2.5) < l.6 < l.2 < 2.5 < 2.5 <13 f Ba-140 < 3.6 <3.1 <63 < l.8 4.5(5.4) < 4.0 < 2.2 f La-140 <4.1 <3.6 < 7.2 < 2.1 5.2(6.2) < 4.6 <2.5 f
* - 1.96s (Due to counting statistics) f- Sample unavailable (Well pump was frozen all quarter) i . . ., . - - - - . , , -. - -,.-...n . -
n,, .
s I i Table II.C.7 Tritium in Ground Water (pCi/L) i First Quarter 1995 Second Quarter 1995 Third Quarter 1995 Fourth Quarter 1995 Collected: Collected: Collected: Colle..ed: ! February 1I May 12 August 1I November Ii i
,F-16 R-5 F-16 R-5 F-16 R-5 F-16 R-5 t
< 380 < 380 < 370 < 370 < 370 < 370 < 380 f I
w f- Sample Unavailable (Well pump frozen all quarter) . oo t I I I I t I s t I' )
i : l 1 Table II.C.8 Maximum Permissible Concentrations in Drinking Water. (10CFR20, Appendix II, Table 11) Radionuclide Concentration (pCi/L) 6 11-3 3 x 10 1-131 3 x 10 Cs-134 9 x 10' 4 Cs-137 2 x 10 4 Zr-95 6 x 10 Nb-95 1 x 10' Co-58 1 x 10' Mn-54 1 x 10' Zn-65 1 x 10' 4 Fe-59 6 x 10 Co-60 5 x 104 4 fla-140 3 x 10 4 La-140 2 x 10 59
3. T Tritium Concentrations at F-16 Well Water i r o Concentration " (pCi/L) 1993 1994 1995 10000 8 1000 ygi.
.J .k... .s h: -
s _
. ,, y 100
? ? ? ? 9 8 3 ? ? ? ? 3 S O a e u z a & u u O u n h s b Date Collected
Tritium Concentration in F-16 Well Water i 1984-1995 5 L Concentration (pCi/L) t f\ ,-, f \ l\ s ~ e 1000 ' - 1
, \ l \l \ l \ l \l \ l\
4 \ l \ l \ / \ l \l \ f \ l l f \l I / I l il \/ \ R I L4 1
- A I V L ,i jg g j - -
J W ;++s M 100 .,...,.,.. .... ,......... . ...... ,., ,.,..,,, 84 85 86 87 88 89 90 91 92 93 94 95 Year
l m ll.D. Milk
- The dairy food chain is the critical pathway for potential radiation dose commitment around any nuclear facility. This is true for both chronic and acute releases. The critical i individual would be an infant consuming milk produced from cows grazing local pastures.
Milk is the critical pathway for potential dose commitment to humans from environmental 1 l contamination of11-3 and Cs-137. For this reason milk is sampled extensively to document , I - the presence or absence of radioactivity due to the decommissioning operation. l There are no dairies (or personal milk cows) in the facility area which is within a 1.6 7 km radius from the facility. The five dairies in the adjacent area,1.6-8 km radius, were ; j selected as they are located in the highest X/Q areas. The description of these locations can be found in Table F-4 of the ODCM and Figure Ill.B.2. The single reference location dairy, R-8, is 22.5 km Northwest of the facility in the least predominant wind direction. IIerd management practices are similar at all dairy locations. The cows in the milkir.g herd are never on pasture but are under dry-lot management which is typical of the Westem U.S. Table II.D.1 lists the concentrations of all gamma-emitting radionuclides that are investigated in milk samples. Natural-potassium, as measured by K-40, is extremely constant in milk. The mean literature value fbr cow milk is 1.5 g/L K concentrations are homeostatically controlled i and independent of K intake. K-natural is measured in all milk samples as a quality control measure for the other radionuclides determined in the same sample by gamma-ray ; spectrometry. Table ll.D.2 lists measured tritium concentrations in milk. Elevated tritium concentrations in milk due to facility ellluents were not observed during the operational or 62
)
I
' defueling phase, or the decommissioning phase to date. During 1995, only two detectable ;
concentrations were observed. These could easily be a false positive values since the mean of the 5 adjacent sites was not statistically greater than the reference site. This implies that I any tritium from facility effluent is not contributing radiation dose to humans via the milk pathway. Tritium concentrations in milk should respond rapidly to changes in tritium concentrations of the forage water intake or drinking water intake to the cow This is due to the short biological half-life for water in the cow (about three days for the lactating cow). , As noted in previous reports, the reported tritium concentration in milk is the tritium in water extracted from the milk. Contamination of milk samples by any radionuclide due to facility effluents has never been observed during the operational, defueling or decommissioning phases of the Fort St. Vrain Station. 1 ? 1 l 1 I ( 4 63
i t . Table II.D.1 Radionnclide Concentrations in Milk (pCi/L) Location A-6 A-18 . A-23 A-24 A-26 R-8 i Collecuon 01/14 01/14 01/14 01/14 .01/14 Date Cs-134 <23 d < 2.1 <1.9 '< 2.1 <23 ., Cs-137 < 2.8 d <2.8 < 2.4 .3.l(3.1)' 33(3.4) Ba-140 <43 d <3.4 <43 <33 < 4.0 :! La-140 < 4.9 d < 4.0 < 4.9 <3.9 < 4.6 Collection 02/11 02/11 02/11 02/11 02/11 02/11 'l , Date i Cs-134 < 2.2 < 2.1 < 2.1 < 2.0 <2.1 < 2.1 Cs-137 53(3.1) <2.5 < 2.5 < 2.4 < 2.6 < 2.6 I Ba-140 < 3.8 <3.4 <3.4- <4.7 5.8(63) .< 43 ; E La-140 < 4.4 <3.9 < 3.9 < 5.4 6.6(73) <4.9
* - 1.960 (Due to counting statistics)
! d -Sample lost during analysis i r 1 ! i
~
_ . . . , . ~ , - . . - . , . . , - ~ . , - - . . - . _ - - - -.-_-.s -. _ ...._.-...._._-._._.s,4.--.
, . . _ - , . . . . . . . - - - . - . . . . , _ . . . - . - - - . . - - - ~ _ . - - . _ . _ , . . . . _ - - ,
Table H.D.1 Radionuclide Concentrations in Milk (pCi/L) Location A-6 A-18 A-23 A-26 A-28 R-8 Collection 03/I1 03/11 03/11 03/Ii 03/11 03/11 Date Cs-134 <13 < l.5 < 2.0 < 1.0 < 2.4 2.5(2.5)' Cs-137 7.7(2.4) < l.8 < 2.4 6.7(1.9) 3.0(3.4) <2.6 Ba-140 2.2(23) < 2.9 < 4.6 < l.9 < 4.6 < 3.4 La-140 2.5(2.7) < 3.4 <53 <2.1 <53 <3.9 Collection 01V8 04 V8 04/08 04 V8 04 V8 04/08 ' Date Cs-134 < 2.2 < 2.2 < l.9 <l.5 < 2.2 < I.4 Cs-137 <2.6 <2.7 3.0(2.7) <l.9 4.7(3.1) 3.2(23) Ba-140 <3.4 < 4.5 < 4.2 <3.4 < 5.5 < 2.0 m La-140 < 4.0 <5.2 < 4.8 <3.9 < 6.4 <2.2 i Collection 05/12 05/12 05/12 05/12 05/12 05/12 Date Cs-134 < l.5 < l.5 < 0.76 < 2.1 < l.4 < l.2 Cs-137 4.6(2.6) 3.2(2.6) 3.0(1.4) <2.6 2.8(2.7) <1.5 Ba-140 < 2.I <2.1 < l.1 <3.4 <3.6 < 2.0 La-140 <2.4 < 2.4 < l3 <3.9 <42 <23 i
* - 1.960 (Due to counting statistics)
Table II.D.1 Radionuclide Concentrations in Milk (pCi/L) Location A-6 A-18 A-23 A-26 A-28 R-S Collection 06/01 06/01 06uVI 0601 06VI - 06/01 Date Cs-134 < l.4 < l.4 <2.1 < 2.1 < l.5 ~ < 0.76 Cs-137 5.0(2.5)' 4.7(2.5) <2.6 3.l(3.0) 2.6(2.6) 3.2(1.4) Ba-140 <2.7 <2.1 <3.4 < 6.4 < 2.1 < 1.6 La-140 <3.1 < 2.4 <3.9 <73 < 2.4 < l.8 Collection 06/12 06/12 06/12 06/12 06/12 06/12 Date Cs-134 < l.4 < 13 < l.4 < l.5 < l.4 < 2.2 Cs-137 3.0(2.5) 4.4(23) 43(2.6) 42(2.6) < 2.1 < 2.6 Ba-140 3.7(2.8) < 2.0 <3.5 <23 < 2.6 < 4.0 La-140 4.2(33) <23 < 4.0 < 2.6 < 3.0 <4.6 Collection OW23 06/23 06f23 06/23 06/23 06/23 Date Cs-134 < l.6 < l.4 <l.9 < 13 < 0.96 < l.4 Cs-137 2.7(2.8) 3.5(2.5) <23 5.9(23) 1.4(1.4) 5.7(2.5) Ba-140 < 2.2 <2.6 <3.1 < 2.7 < l.5 3.8(3.0) La-140 < 2.5 < 3.0 <3.5 < 3.1 < l.8 43(3.5)
* - 1.960 (Due to counting statistics)
Table II.D.1 Radionuclide Concentrations in Milk (pCi/L) Location A-6 A-18 A-23 A-26 A-28 R-3 Collection 07/14 07/14 07/14 07/14 07/14 07/14 Date Cs-134 < 2.2 <13 < l.4 <1.2 < l.5 <l.6 Cs-137 < 2.7 4.0(2.5)* 2.9(2.6) 3.6(2.1) 4E(2.8) < 2.4 Ba-140 < 4.1 < 2.0 < 2.1 <23 < 3.8 < 2.6 La-140 < 4.8 < 2.4 < 2.4 < 2.7 < 4.4 <3.0 Collection 07/28 07/28 07/28 07/28 07/28 07/28 Date Cs-134 < l.5 < l.5 <22 < l.4 < l.0 < 2.5 Cs-137 4.2(2.7) 6.5(2.7) 4.5(3.2) < 2.0 <13 <3.0
, Ba-140 <23 < 2.9 < 4.5 < 2.6 < l.7 < 4.0 4
La-140 < 2.6 <33 <52 <3.0 < l.9 < 4.6 ! Collection 08/l1 08/l1 08/l1 08/l1 08/l1 08/l1 Date Cs-134 < 2.1 < l.5 < l.2 < l.9 <13 <l.5 Cs-137 < 2.6 <23 4.0(2.1) < 2.4 5.2(23) 6.5(2.6) Ba-140 < 3.4 32(3.5) < l.8 <3.1 <3.2 < 2.1 La-140 <3.9 3.7(4.0) < 2.0 <3.6 < 3.6 < 2.4 ; P
* - 1.960 (Due to counting statistics) r i
Table II.D.1 Radionuclide Concentrations in Milk (pCi/L) Location A-6 A-18 A-23 A-26 A-28 R-8 Collection OS/26 08.26 08/26 08/25 08/26 08/27 Date Cs-134 < l.6 < l.4 < 2.2 < l.4 <2.0 <l.6 Cs-137 4.l(2.7)* 2.5(2.5) 4.1(3.1) 4.8(2.5) <2.4 3.7(2.7) Ba-140 < 2.5 < 2.5 <4.5 2.6(3.2) <3.2 <2.3 La-140 < 2.8 <2.8 <5.1 3.0(3.6) <3.7 <2.7 Collection 09 D9 09.'09 09.09 09 09 09'09 09,D9 Date Cs-134 < 2.2 <2.1 < l.4 < l.2 < 0.76 <13 Cs-137 < 2.6 <2.5 2.9(2.5) < l.5 3.8(13) 3.8(23) , Ba-140 <43 < 4.4 < 2.0 < 2.7 < l.1 < l.9 oo I2-140 < 4.9 <5.0 <23 <3.1 < l.2 <2.2 Collection 09/23 09.23 09:23 09/23 09/23 09/23 Date Cs-134 < 2.1 < l.5 < l.4 <13 < l.1 < 2.1 Cs-13 < 2.5 2.2(2.6) 43(2.5) 2.7(23) 3.9(2.0) < 2.5 Ba-140 <33 <2.5 < 2.0 < 2.4 <l.6 <33 La-140 < 3.8 < 2.8 < 2.4 < 2.8 <l.8 <3.8
* - 1.960 (Due to counting statistics)
Table II.D.1 Radionuclide Concentrations in Milk (pCi/L) Location A-6 A-18 A-23 A-26 A-28 R-8 Collection 10/14 10/14 10/14 10/14 10/14 10!!4 Date Cs-134 < l.5 < l.6 < l.4 < l.5 <l.1 < 0.66 Cs-137 2.3(2.7)* 23(2.8) 2.5(2.5) 2.8(2.6) 1.7(2.0) 1.9(1.2) Ba-140 < 2.6 <23 <3.7 < 2.1 < l.9 < 0.% La-140 <3.0 < 2.6 <43 < 2.4 <22 < l.1 Collection 11/11 11/11 11/11 11/11 11/11 11/11 Date Cs-134 < l.6 < 0.65 < l.5 < l.6 < l.5 < l.6 Cs-137 2.5(2.7) 2.8(1.2) 2.8(2.6) 3.2(3.0) 2.7(2.6) 2.9(2.8) , Ba-140 <23 < 0.95 6.0(5.8) <43 <5.1 8.7(73) c La-140 < 2.7 < l.1 6.9(6.7) < 5.0 <5.8 10(8.4) Collection 12/09 12/09 12/09 12/09 12/09 12/09 Date Cs-134 < l.7 < l.6 < l.6 < l.6 < l.4 1.0(1.2) Cs-137 23(2.9) 3.6(2.9) 32(3.0) 3.l(2.9) 2.7(2.6) 2.6(1.8) Ba-140 < 3.1 < 3.8 < 4.4 5.4(53) 53(4.9) < l.5 La-140 < 3.6 < 4.4 < 5.0 62(6.1) 6.l(5.6) < l.7
* - 1.960 (Due to counting statistics)
Table II.D.2 Tritium in Milk (pCi/L) Collection Adjacent Reference Dates A-6 A-18 A-23 A-24 A-26 A-28 R-8 . 01/14 < 390 < 390 < 390 < 390 < 390 -
< 390 ,
I i 02/11 < 380 < 380 < 380 < 380 520(460)* -
< 380 i 03Il1 < 390 < 390 < 390 f < 390 < 390 < 390 04'08 < 380 < 380 < 380 f I700(340) < 380 540(320) 05/12 < 370 < 370 < 370 f < 370 < 370 370(300) 05/26 < 370 < 370 < 370 f < 370 < 370 < 370 06/12 < 370 < 370 < 370 f < 370 < 370 < 370
$ 06/23 < 370 < 370 < 370 f < 370 . < 370 < 370 07/14 < 370 < 370 < 370 f < 370 < 370 < 370 07/28 < 370 < 370 < 370 f < 370 < 370 < 370 4
08/l1 < 370 < 370 < 370 f < 370 < 370 < 370 O&76 < 380 < 380 < 380 f < 380 < 380 < 380 i 09/09 < 370 < 370 < 370 < 370 ' f < 370 < 370 09/23 < 370 < 370 < 370 f < 370 < 370 < 370 P 10/14 < 380 < 380 < 380 f < 380 < 380 < 380 11/11 < 390 < 390 < 390 < 390 ' f < 390 < 390 12/09 < 430 < 430 < 430 f < 430 < 430 < 430
.l
* - 1.960 Due to counting statistics f- Sample Unavailable - In March Dairy A-24 shut down operations. Dairy A-28 was located to replace A-24.
4
II.E. Food Products Food sampling locations were selected from areas possibly irrigated by surface water downstream of the FSV discharge point or by well water from the aquifer most likely to be contaminated by seepage from the fann pond. The locations of these food product collection sites are described in Table F-4 of the ODCM. One sample of each principal class of food products was collected from these locations. Locations and available produce ollen change due to owner needs, harvest time, harvest size, etc. Each sample was homogenized, without drying, immediately after collection. The sample was then counted by gamma-ray spectroscopy. Table II.E.1 lists the date of collection and the results for the 1995 harvest. One food sample showed low but detectable Cs-137 from past Chemobyl world-wide fallout deposition. The gamma-ray spectra were scanned for other radionuclides, but only the naturally occurring radionuclides were observed, presumably due to surface soil deposits. If Cs-137 was released due to decommissioning, the primary food chain to humans would be through pasture to dairy and beef cattle and to meat and milk. Therefore, in addition to extensive milk sampling, and since beef cattle graze near the effluent routes from the facility, these animals are routinely sampled, slaughtered, and muscle tissue is analyzed for the radionuclides suspected in the effluent. During operation of the reactor, for a significant period (1973-1983) animals were taken quarterly from the pasture and counted in the CSU Whole-Ilody Counter adapted for large animals. No 1-131 or Cs-137 due to plant effluent was ever detected in this herd. In 1992, one animal that grazed the pastures north of the facility, and also had drinking access to the Goosequill ditch, was slaughtered and the tissue analyzed. Tissues 71
i from this animal served as a control for others slaughtered after decommissioning was initiated. l In 1995, two animals were collected for comparison purposes. One animal was removed from pasture on 4/23/95 and another animal was removed 10/08/95. Tables II.E.2a and II.E.2b give the slaughter dates. Each carcass was aged, according to general practice for one week in a cooler Ground meat samples representing the total carcass were mixed and ten random one-kilogram samples of ground beef were packed into one-Liter Marinelli beakers for gamma-ray spectrum analysis. Subsamples of each were taken for tritium analysis. The tritium activity was measured in the water vacuum distilled from each sample. There is evidence of Cs-137 activity in both beef animals but no significant tritium activity. The mean of the Cs-137 activity concentration in the two animals was not statistically difTerent than the control animal slaughtered in 1992. 4 72 , I
Table II.E.1 Radionuclide Concentrations in Food Products (pCi/kg) Collection Date: September 8,1995 Location Food Type Cs-134 Cs-137 A-6 Peppers <4.7 <5.3 A-6 Cantaloupe <5.2 <5.9 A-27 Com <9.1 < 10 A-27 Beets <6.4 < 7.3 A-27 Rhubarb <3.9 7.9(5.3)* A-27 Tomatoes < 5.0 <5.7
- 1.96o (Due to Counting Statistics.)
\
i 1 l l i 73
Table II.E.2(a) Radionuclide Concentrations in Beef Samples Collected on 4/25/95 Radionuclide concentrations in Beef Heef Sample # K-nat Cs-137 11-3 mg/L pCi/kg pCi/L I 1.0 12(7.5)* 650(310) 2 1.0 <5.1 < 370 3 1.1 <3.4 < 370 4 0.97 16(12) < 370 5 1.0 < 6.9 < 370 6 0.98 11(12) 880(320) F 7 1.1 < 6.7 < 370 8 1.0 < 9.6 < 370 9 1.1 9.2(6.1) < 370 10 1.0 < 6.7 < 370 X(l .960) 1.0(0.10) 5.8(l 1) < 370
* - 1.96a (Due to Counting Statistics)
Note: Cow slaughtered 4/25/95. Cow donated by Ben flouston. Animal grazed on pasture north of FSV, and had access to Goosequill Ditch. 1 74
l Table II.E.2(b) Radionuclide Concentrations in Beef Samples Collected on 10/10/95 Radionuclide concentrations in Beef fleef Sample # K-nat Cs-137 11-3 mg/L pCi/kg pCi/L i 1.1 21(7.2)* < 410 2 1.3 12(7.7) < 410 3 0.95 9.0(4.0) < 410 4 1.3 7.8(7.1) < 410 5 1.2 4.8(5.7) < 410 6 1.I 6.2(6.0) < 410 7 0.73 7.2(7.2) < 410 8 0.98 < 6.1 < 410 9 0.82 8.9(7.6) < 410 10 0.99 11(4.9) < 410 X(.I .960) 1.0(0.35) 9.9(9.7) < 410
- - 1.960 (Due to Counting Statistics)
Note: Cow slaughtered 4/25/95. Cow donated by Ben flouston. Animal grazed on pasture north of FSV, and had access to Gomcquill Dit:h. 75
II.F. Aquatic Pathways (Fish & Sediment) Table ll.F.1 shows radionuclide concentrations measured in fish samples collected at F-19, A-25 and R-10 on two dates in 1995. The fish were collected by shocking and netting and the composite sample was homogenized without cleaning and analyzed on a wet weight basis. Detectable Cs-137 activity concentrations were observed in upstream, downstream, and ellluent fish during 1995. Co-60 was detectable in effluent fish during the first half only. The Co-60 activity can only be traced to the decommissioning efTorts. The Cs-137 activity concentrations were approximately the same as observed during 1994. The Cs-137 activity is also attributed to decommissioning effluent. Assuming ICRP-23 consumption of fish the Total Efrective Dose Equivalent . (TEDE) commitments for both Co-60 and Cs-137 to an adult would be: Co-60: 9.5 x 10 4mrem / year Cs-137: 2.2 x 10-2 mrem / year Total: 3.2 x 10 2 mrem / year The above committed dose rate is negligible compared to the appropriate standards or to the naturally occurring background dose rate of approximately 350 mrem / year in the local environs. l Table II.F.2(a-b) shows the measured concentrations of both Cs-137 and Cs-134 in 1 l surface sediment collected at F-1, located at the intersection of the Goosequill and Jay Thomas ditches. There was measurable activity of both Cs-134 and Cs-137 due to the decommissioning effluent. The concentrations observed in 1995 were less thrc observed in previous years and, in no case, did the Cs-137 concentration exceed the NRC guideline of l 15,000 pCi/kg (15 pCi/g). The cesium ions are bound nearly irreversibly by the clay 76
)
i mineral matrix in the sediment and not available for food-chain t,ansport. Table II.F.3 shows the radiocesium concentration in sediment at locations R-10, the ! downstream location. At this site, no Cs-134 or Cs-137 was detected.. Therefore, it can be concluded that Cs-137 due to decomntissioning work did not reach this downstream ! location. i 6 5 l l 1 I I 4 e . i t F 1 i 4 I
. l i <
E i t 1 I L 77
Table II.F.1 Radionuclide Concentrations in Fish (pCi/kg) Collection Date April 4,1995 October 5,1995 Radionuclide Upstream Ellluent Downstream Upstream Efiluent Downstream F-19 A-25 R-10 F-19 A-25 R-10 Cs-134 < 3.0 < l.9 < 5.3 < 2.6 < 4.0 <3.9 Cs-137 7.9(4.2)* 16(2.9) < 5.9 16(3.9) 14(3.6) 18(5.4) Co-58 < 2.7 < l.8 < 4.7 < 2.4 < 4.1 < 3.3 Mn-54 < 2.8 < 2.0 < 5.2 8.l(3.4) < 5.5 <4.1 y Zn-65 < 8.6 < 5.2 < 15 < 11 < 10 < 14 m Fe-59 < 7.9 6.2(6.5) < 14 < 8.4 < 9.2 < 12 Co-60 <3.4 7.2(2.7) < 6.1 < 2.8 < 2.4 < 4.1
- 1.W (Due to Counting Statistics.)
I i l Table II.F.2a Radiocesium Concentrations in Sediment from Location F ! Radionuclide Concentration (pCi/kg) : Collection Date: January 14,1995 , Cs-134 < 22 l l Cs-137 170(35)* Collection Date: February 11,1995 ; Cs-134 31(29) Cs-137 210(38) Collection Date: March 11,1995 , Cs-134 - < 25 i i Cs-137 97(3l) Collection Date: April 8,1995 Cs-134 38(38) ; Cs-137 260(46) t Collection Date: May 12,1995 Cs-134 < 25 Cs-137 84(29) Collection Date: June 9,1995 Cs-134 < 22 , Cs-137 74(29) i Collection Date: July 14,1995 ! Cs-134 77(43) Cs-137 120(71) Collection Date: August 11,1995 l Cs-134 < 25 Cs-137 130(35)
* - 1.96o Due to Counting Statistics !
i 79
Table II.F.2b Radiocesium Concentrations in Sediment from Location F-1 Radionuclide Concentration (pCitg) l Collection Date: September 9,1995 l l Cs-134 < 38 Cs-137 <41 Collection Date: October 14,1995 l Cs-134 < 11 Cs-137 27(24)* Collection Date: November 11,1995 Cs-134 < 25 Cs-137 27(29) Collection Date: December 2,1995 Cs-134 < 13 Cs-l 37 120(36)
- - 1.9M Due to Counting Statistics i
l l l 1 I 1 80
Table II.F.3 Radiocesium Concentrations in Sediment from Location R-10 Radionuclide Concentration (pCi/kg) Collation Date: May 12,1995 Cs-134 < 29 Cs-137 < 29 Collection Date: September 9,1995 Cs-134 < 25 Cs-137 < 27
- - 1.960 Due to Counting Statistics 81
II.G. Sample Cross-check Program To assure both the accuracy and precision of the environmental data obtained from the radiation surveillance program provided for the Fon St. Vrain facility, Colorado State University participates in a number of interlaboratory and intralaboratory quality assurance programs. The U.S. Environmental Protection Agency (EPA) sponsored laboratory intercomparison studies program is the principal cross-check. This involves the analysis of a variety of environmental media containing various levels of radionuclides. The media, type of analysis and frequency of analy sis for the EPA program are summarized below. Medium Analysis (radionuclide) Freauency Water 11-3 Semiannually Water Gross p Annually Water Co-60, Cs-134, Cs-137 Semiannually Air particulate Cs-137, Gross p Annually Milk Cs-137 Annually For each radionuclide analysis of a particular medium, three independent measurements are performed and all results are reported to the EPA. It should be noted that during 1989, the CSU laboratory became certified by the EPA for drinking water analysis. Table II.G.1 gives the EPA cross-check data for 1995. The EPA uses the parameter, Estimated Laboratory Precision (ELP), calculated as one standard deviation for one determination. The nonnalized deviation of our mean from the known is calculated as: CSU mean value - EPA known value o Vn Where:a = standard deviation of the mean of all participating laboratory results 82
r 1 n = number of analyses by our laboratory, normally n=3 The control limit is determined by the mean range of all results and three standard , deviations of the range. If any result exceeds three standard deviations from the mean (warning level), the result is unacceptable. Whenever our mean value falls outside this limit, the calculations are rechecked and the sample reanalyzed if possible. During 1995 all results except one were within the warning level. The result exceeding the warning level has the superscript notation 1 in Table II.G.I. The explanation for the incorrect result is given in Table II.G.I. Table ll.G.2 lists independent results for 11-3 in water samples split between the CSU laboratory and the laboratory at Fort St. Vrain. The comparison between laboratories in general was acceptable. Table 11.G.3 lists the results of gross beta analyses of the split water samples. The procedural differences between the laboratories were previously investigated and minimized. It is concluded that the differences can be attributed only to total analytical uncertainty. Table ll.G.4 shows results of an intralaboratory cross-check program. Replicate samples are independently analyzed. The replicate results are not statistically different and imply that the precision of the methods is acceptable. During 1995 approximately 20% of all laboratory calculations that partly involve techniebn input were recalculated by a ditTerent technician. Only an occasional input or calculation error was detected. This result gives further credence to the laboratory results which are not solely computer calculated and listed. Computer calculations are ollen recalculated by hand and those done during 1995 were all verified to be correct. 83
Table II.G.1 EPA Cross-Check Data Summary,1995. Date Radionuclide CSU Value EPA Value ! E.L.P.
- Normalized Deviation -
from known** WATER, Tritium (pCi/L) Mar 10 'll 6667 7435 744 -1.79 j Aug 04 - 'l1 3966 4872 487 -3.15 j WATER, Beta (pCi/L) Jan 27 Beta 4.67 5.0 5.0 -0. I 2 4 WATER, Gamma (pCi/L) Jun 09 Co-60 28 40 5 -4.04 i Cs-134 49 50 $ -0.12 Cs-137 32 35 5 -0.92 Nov 03 Co-60 55 60 5 -1.50 Cs 134 37 40 5 -0.92 Cs-137 43 49 5 -1.96 5 WATER, Performance (pCi/L) ! Apr 18 Beta 45.3 86.6 10 -7.15' 1 1 4 Cs-134 17 20 5 -0.92 l Cs-137 13 11 5 0.69 ! l i J MILK (pCi/L) l Sep 29 Cs-137 48 50 5 -0.58 l , AIR FILTERS (pCi/ Filter) l i Aug 25 Beta 91 86.6 10 0.69 ! Cs-137 38 25 5 4.50 l '
- E.L.P. = Expected Laboratory Precision.
}. *
- Normalized Deviation = (CSU mean - EPA known)'(oVn);if this value falls i
between upper & lower warning levels, the accura;v is acceptable.
- 1. Too long Beta decay period allowed in lab. l l
. I 1 1 1 84
Table II.G.2 Tritium Cross-check Analyses on Split Water Samples Determined by Colorado State University and Public Service Company during 1995. a) 1" and 2"' Quarters Collection Sample Tritium Concentrations (pCi/L) Date Location CSU PSC Jan 14 , A-25 < 380 < 850 Jan 14 ! A-21 < 380 < 850 Jan 04 E-41 < 380 < 850 Febi1 A-25 510(1100)' 1400(1100) Feb11 A-21 550(650) 1700(1100) Feb 01 E-41 < 380 < 840 Mar 11 A-25 520(390) < 930 Mar 11 A-21 < 380 < 930 J Mar 01 E-41 < 380 < 930 ) l I Apr 08 A-25 410(380) < 900 Apr 08 A-21 < 390 1200(l100) Apr 05 E-41 < 390 < 900 l
\
May 12 A-25 3900(350) 2800(1200) May 12 A-21 < 380 < 940 May 03 E-41 < 370 < 940 Jun 09 A-25 < 370 1200(1100) Jun 09 A-21 < 370 < 840 Jun 06 E-41 < 370 < 840
* - 1.960 (Due to Counting Statistics) 85
1 Tabic II.G.2 Tritium Cross-check Analyses on Split Water Samples Determined by Colorado State University and Public Service Company during 1995. b) 3'd and 4* Quarters Collection Sample Tritium Concentrations (pCi/L) Date Location CSU PSC Jul 14 A-25 860(450)* < 880 Jul 14 A-21 < 390 1800(1100) Jul 12 E-41 23000(670) 23000(1800) Aug11 A-25 < 370 < 860 Aug 11 A-21 < 370 < 860 Aug 09 E-41 < 370 < 860 Sep 09 A-25 < 370 1400(1100) Sep 09 A-21 < 370 < 850 1 Sep1! E-41 < 380 5600(1200) Oct 14 A-25 < 380 1200(1100) ) Oct 14 A-21 < 370 < 860 Oct 04 E-41 < 370 < 860 i Novi1 A-25 < 380 < 850 l Novi1 A-21 < 380 < 850 l Nov 08 E-41 < 380 < 850 l Dec 09 A-25 < 380 < 1400 . Dec 09 A-21 < 380 < 1400 I Dec 13 E-41 < 380 < 1400
* - 1.%c (Due to Counting Statistics) 86
Table II.G.3 Gross Beta Cross-check Analyses on Split Water Samples Determined by Colorado State University and Public Service Company during 1995. a) 1" and 2"' Quarters Collection Sample Gross Beta (pCi/L) Date Location CSU PSC Jan 14 A-25 8.0(5.9)' 9.8(8.5) Jan 14 A-21 7.5(5.8) < 6.4 Jan 04 E-41 7.l(5.8) 11(8.6) Feb11 A-25 9.5(6.0) 5.4(7.2) Febi1 A-21 6.9(5.9) 15(8.3) Feb01 E-41 12(6.1) 12(7.8) Mar 11 A-25 12(6.1) < 6.7 Mar 11 A-21 20(6.4) < 7.0 Mar 01 E-41 7.0(5.8) < 6.8 Apr 08 A-25 9.0(5.9) < 23 Apr 08 A-21 7.1(5.8) < 23 Apr 05 E-41 5.l(5.8) < 23 May 12 A-25 15.7(l1) 19(7.2) l May 12 A-21 8.l(5.9) 11(7.3) May 03 E-41 8.8(5.9) 14(8.0) l Jun 09 A-25 41(7.2) 12(6.9) ) Jun 09 A-21 <4.3 12(6.9) ! l Jun 06 E-41 < 4.8 15(8.2) l
* - 1.960 (Due to Counting Statistics)
I 87
Table II.G.3 Gross Heta Cross-check Analyses on Split Water Samples Determined by Colorado State University and Public Service Company during 1995, b) 3"' and 4"' Quarters Collection Sample Gross Beta (pCi/L) Date Location CSU PSC Jul 14 A-25 58(7.8)* < 12 Jul 14 A-21 <4.5 < 10 Jul12 E-41 19(4.7) 19(5.7) Augi1 A-25 25(6.5) <5.0 Augi1 A-21 9.3(6.0) 13(10) Aug 09 E-41 5.1(5.7) 13(8.7) Sep 09 A-25 44(7.4) < 9.1 Sep 09 A-21 5.6(5.8) 22(5.8) Sep11 E-41 5.3(5.8) 18(5.6) Oct 14 A-25 63(8.0) < 17 Oct 14 A-21 4.0(5.7) < 17 Oct 04 E-41 <4.9 < 18 Novi1 A-25 11(6.1) 15(3.3) Novi1 A-21 4.8(5.8) 14(3.5) Nov 08 E-41 6.0(5.8) 24(3.9) Dec 09 A-25 6.9(6.1) 12(8.7) Dec 09 A-21 13(6.4) 18(l0) Dec 13 E-41 8.4(6.0) 11(9.1)
- 1.960 (Due to Counting Statistics) 88
l i Table II.G.4 Intralaboratory Cross-Check Results (pCi/L). (Replicate Analysis of Same Sample) l^ [ Raimnactade Drinking M ster 1W Quarter 2ndQuarter 3rdQuzter 4thQuaner t A B A B A B A B Cs-134 <20 <22 <20 <l9 < 2.1 < 2.1 1.41.7)* <14 Cs-137 < 2.5 <28 < 2.4 <23 38(3I) < Z.5 37(2I) 42(2.1) Zr-95 <47 <45 <46 <44 <49 <47 <34 < 3.1 Nb-95 <l8 <l5 <l8 <I8 < I .9 < l .8 <16 30(19) Co-58 <21 <19 <21 < l .7 <19 <18 <14 <13 Mn-54 <20 < 2.0 <20 31(23) 32(2.5) 26(24) < l .5 < l .4 2n-65 <54 <54 <53 < 5.2 <$7 <56 <50 <43 Fe-59 <47 <46 <46 <45 <60 <46 <39 <33 Co 60 <21 < l .5 <21 <20 <23 <22 <13 <12
$ Ba-140 <33 <40 < 3.2 < 3.1 < 7.1 <72 <24 <22 tsl40 < 3.8 < 3.5 < 3.7 < 3.5 <82 <82 <28 < 2.5 Csoss Beta <l8 < l .7 < l .8 <l8 <18 <18 < l .8 <18 11-3 < 390 < 410 < 380 < 390 < 380 < 390 < 380 < 390 Rahceuclide Stilk 158 Quarter 2ndQuater 3rdQuarter 4thQuarter .
A B A B A B A B Cs-134 < 2.2 <54 < l .5 < l .4 <19 < 2.3 < l .5 < l .6 Cs-137 53(3I) 9.9(80) 46(26) 56(2.5) <24 < 2.7 3.7(2.6) 79(2.8) Ba-140 <38 < 7.1 <2I < 2.1 <31 7.3(74) <51 87(73) La-140 <44 <8I <24 <24 <36 8.48.5) < 5.8 10(84) 11-3 < 390 < 380 < 380 < 380 < 380 < 380 < 380 < 390
* . I we (thm to c m.s summat
II.II. Summary and Conclusions Table 11.11.1 summarizes the radiation and environmental radioactivity measurements conducted during 1995 in the environs of the Fort St. Vrain facility. The facility is owned and operated by Public Service Company of Colorado and is in the fmal stages of decommissioning. The values for each sample type may be compared to pre-operational and operational periods for this facility, as well as to the values from other U.S. environmental monitoring programs (e.g., EPA 520). It must be emphasized, however, that the mean values in Table 11.11.1 are only the means of the values greater than MDC, the statistically minimum detectable concentration. The range also is given only for detectable measurements. The mean and range values, therefore, are not the true means or ranges if any of the values in the sample population were less than MDC. The calculational methods and the format of Table 11.11.1 is a requirement of the NRC. Inspection of Table 11.11.1 reveals that there were no individual measurements that exceeded the Reporting Level (RL)(see Table F-3 in the ODCM). The Chernobyl world-wide fallout was still observable as Cs-137 in several sample types. Decommissioning activity was observed in Goosequill sediment samples and occasional fish samples. For the category of gross beta concentrations in drinking water, the mean for the Gilcrest well was again significantly greater than for the reference supply located in Fort Collins. The reason for this observation is solely due to the fact that the town of Gilcrest still doesn't completely filter its drinking water supply. The procedure was improved in the last two years but it is sti ll not complete and the activity concentration is still elevated due to naturally occurring radioactive materials from soil and fertilizer contamination. The following conclusions are drawn: i 90
- a. None of the individual fission product or activation product radionuclides measured were significantly i.igher in the Gilcrest drinking water.
- b. Tritium concentrations measured at Gilerest were not statistically greater than those in Fort Collins.
- c. The city of Gilerest does not filter and treat its well water to the same degree as Fort Collins. This has been verified and evidenced by the fact that the gamma-ray-spectra of the suspended solids from Gilcrest water samples show only elevated concentrations of the natural radionuclides. It has been concluded in previous reports that the elevated gross beta concentrations in Gilcrest water are due to elevated concentrations of the naturally occurring U-238, and Th-232 decay products.
For the category of tritium in surface water elevated concentrations were noted at station A-25, the outlet of the Famt pond periodically throughout 1995. A-25 is directly in the principal eflluent route and elevated concentrations should be expected when release is significant. Downstream surface water concentrations of tritium have occasionally been elevated, but there is significant dilution before any human use of this water. During 1995 , 1 1 elevated tritium concentrations were not observed downstream and the mean values for the first and second half of 1995 were not significantly different. Cs-137 was also observed in many environmental samples but is due to the Chemobyl world-wide fallout. The only exception was the elevated Cs-137 in sediment in the liquid effluent pathway. These values, however, are well below NRC guideline values. Tritium concentrations from well water site F-16 do appear to be less than in 1994 I and imply only short temi contamination of the aquifer. Typically lateral water movement in western soils is approximately 30 m/ year. Weekly sampling was initiated in 1991 to 91
observe the movement more closely, but in any case the well at F-16 is not used for drinking water purposes and elevated tritium concentrations have not been observed in any food chain sample. Residents at the F-16 residence purchase bottled water for their primary consumption. Table 11.11.2 presents an additional summary of mean values for selected sample types. The sample types and radionuclides were chosen on the basis of their importance in documenting possible radiation dose to humans. Air and surface water would be the predominant environmental transport routes and drinking water and milk would be the predominant sources of radiation dose if significant radioactivity release from FSV occurred. Table 11.11.2 also allows comparison to the four most recent years of monitoring. All four years were post-operational. The arithmetic means and standard deviations in Table 11.11.2 were calculated for all sample results. It should be repeated that the tabular data presented in the body of this report contain only positive calculated values above the minimum detectable concentration (MDC) levels. Any calculated values less than zero or less than the minimum detectable concentration are listed as less than the actual MDC for that sample analysis. The actual result in all cases was used in the calculation for tha arithmetic mean values for the periods in Table 11.11.2. Therefore, all values, negative as well as positive, were included. This procedure is now generally accepted and gives a proper estimate of the true mean value. Because of this procedure, however, the values listed in Table 11.11.2 cannot be calculated directly from the tabular values in the report. It must be emphasized that while it is true that no sample can contain less than zero radioactivity, due to the landom nature of radioactive decay, it is statistically possible to ob:ain sample count rates less than background and 92
hence a negative result. It is equally true that many sample types do in fact have zero I concentrations of certain radionuclides. Therefore, to obtain the correct mean value from , i the distribution of analytical results, all positive results must be averaged with all negative J results. If the negative results were omitted, the resulting arithmetic mean would be falsely
]
biased high. From the values presented in Tables 11.11.1 and II.IL2 and the tabular data of the report, the following observations and conclusions may be drawn:
- 1. As in every previous report, it was again apparent that for most sample types the variability observed around the mean values was great. This variability is partly due to >
counting statistics and methodological variation, but principally due to true environmental variation (often termed sampling error). It must be recognized and accounted for in analyses of any set of environmental data before meaningful conclusions can be drawn; .
- 2. Tritium was detected in the ellluent pathway periodically throughout 1995.
The release of tritium was indeed much less than in operational years. Since the tritium is released as tritiated water, the dilution by the surrounding hydrosphere is great and 8 i consequently the mean values of downstream surface water were not statistically greater than upstream concentrations. No tritium was detected in ground water or any food samples;
- 3. The Chemobyl world-wide fallout has totally obscured what fission product debris has remained in the FSV environs from the October 1980 Chinese atmospheric nuclear weapon test. The biosphere will contain the Chemobyl fallout, particularly Cs-137, for an equally long period. Nuclear weapon test fallout has, since the inception of the project, been noted to be the predominant source term above natural background. The 93 l
Chemobyl reactor fire debris was superimposed on the weapons test fallout from 1986 to present. It is the variation in fallout deposition, in addition to the variation in naturally occurring radionuclides, that mandates the large number of environmental samples to detect any possible radioactivity due to facility effluents. A simple comparison of pre-operational and operational values is of little value, for most sample types, because the fallout deposition was considerably greater during the pre-operational period due to world-wide fallout;
- 4. The promp' and sensitis e detection of the Chinese weapon test fallout and the Chernobyl fallout in the past assures that the environmental monitoring program was of adequate scope and sensitivity to detect any accidental releases from the FSV decommissioning; and
- 5. Release of decommissioning radioactive waste was evident in the Goosequill sediment. Since this is primaiily Cs-137 in sediment, its transfer to plant and animal food chains will be negligible.
It can be concluded from the data collected by the environmental monitoring program that the radiation dose commitments calculated for the closest human inhabitants or other parts of the nearby ecosystems due to current facility effluents are negligible. i Natural background radiation and the dose commitment from atmospheric fallout are the only known significant sources of radiation dose to the residents of the area. During the current decommissioning phase of the facility it is concluded that this Radiological Environmental Monitoring Program is more than adequate to detect and i quantify any possible routine or accidental release of radioactivity. 94
I Table II.H.I Radiological Environmental Monitoring Program Annual Summary Fort St. Vrain Station, Platteville, Colorado Medium or Type and Total l'acility Locations Adjacent Locations with liighest Annual Mean Reference Number of Pathway Samples Number of Mean (f) Range Locations Mean Name Mean Locations Mean Nonroutine (Unit of Analyses (OIRange Distance & Range (OIRange Reposted measurement) Performed Direction Measurements Direct Radiation TLD(159) 0.41(72/72) 0.40(68/72) F-8 CO 19% 0.45(4/4) 0.40(19/20) 0 (mR/ day) 0.23-0.57 (0.27-0.56) 1.3 km Sec 8 (0.35-0.57) (0.33-0.56) Air. Particulates Gross Beta (360) 19(204/208) - F-7 CR 21 & 34 23(50/52) 17(156/156) 0 (fCi/m3) (10-50) 1.5 km Sec 7 (l1-46) (10-40) Gamma Spectrome. fry 'C Cs-134(28) 0.8(1/16) - R-3 Fort Collins 1.2(1/4) - 0 45.1 km Cs-137(28) 1.1(9/16) - A-19 Ilunter's 1.6(3/4) 1.2(2/12) 0 (0.63-1.6) Cabin (1.3-2.0) 1.7 km Sec 1 Air, Atmospheric 11-3(364) 670(9/208) - A-1911unter's 760(3/52) 500(2/156) 0 Water Vapor (450-1300) Cabin (460-1000) (410-590) (pCi/m3) 1.7 km Sec 1 Drinking Water Gross Beta (52) 1.0(26/26) - R-6 Gilcrest City 1.0(26/26) 0.77(26/26) 0 (pCi/L) (.33-2.6) Water (.33-2.6) (0.46-1.1) 9.3km II-3(52) 590(1/26) - R-6 Gilcrest City 590(t/26) - 0 Water 9.3 km Gamma Spectrometry Drinking Water Cs-l34(52) 1.3(4/26) - R-3 Fort Collins 1.5(2/26) 1.5(2/26) 0 (0.98-1.5) City Water (1.2-1.8) (1.2-1.8) gpg 45.1 km
Tabic II.H.1 Radiological Environmental Monitoring Program Annual Summary Fort St. Vrain Station, Platteville, Colorado Afedium or Ty pe and Total Facility Locations Adjacent Locations with flighest Annual hican Reference Number of Pathway Samples Number of Nican (f) Range Locations hican Name hican Locations hican Nonroutine (Unit of Analyses (f)I Range Distance & Range (f)I Range Reported measurement) Performed Direction hicasurements Drinking Water Cs-137(52) 2.6(13/26) - R-3 Fort Collins 4.2(12/26) 2.8(16'26) 0 (pCi/L) (1.2-3.9) City Water (2.0-6.1) (1.2-3.9) 45.1 km Zr-95(52) - -- - - - 0 Nb-95(52) 2.2(3/26) - R-6 Gilcrest City 2.2(3/26) 1.8(4!26) 0 (l.9-2.3) Water (l .9-2.3) (I .4-2.5) 9.3km , 8 Co-58(52) - R-3 Fort Collins City Water 2.4(1/26) 2.4(1/26) 0 45.1 km . hin-54(52) 2.2(426) - R-6 Gilcrest City 2.2(4/26) 1.9(4/26) 0 (l .3-2.6) Water (l.3-2.6) (l .4-2.2) 9.3 km l Zn-65(52) - - - - - 0 Fe-59(52) 4.6(3/26) - R-6 Gilcrest City 4.6(3/26) 4.0(1/26) 0 (3.6-8.8) Water (3.6-8.8) (2.8-4.7) 9.3 km Co-60(52) 2.2(2/26) - R-6 Gilcrest City 2.2(2/26) 0 (l .9-2.4) Water (I .9-2.4) 9.3km Ba-140(52) - - R-3 Fort Collins 7.0(6/26) 7.0(6/26) O City Water (4.0-1 I) (4.0-1 I) 45.1 km La-140(52) - - R-3 Fort Collins 8.1(6/26) 8.1(6/26) O City Water (4.6-13) (4.6-13)
Table II.H.1 Radiological Environmental Monitoring Program Annual Summary Fort St. Vrain Station, Platteville, Colorado hiedium or Type and Total Facihty Locations Adjacent Locations with liighest Annual hican Reference Number of Pathway Samples Number of Afean (O Range Locations hiean Name h1can Locations hican Nonroutine (Unit of Analyses (f)I Range Distance & Range (OIRange Reported measurement) Performed Direction hicasurements 45.1 km 11-3(6 0) < 390 1200(4/24) A-25 Farm Pond 1200(4'24) < 380 0 (530-1700) 2.2 km Sec I (530-1700) Gamma Spectrometry
~
Surface Water Cs-134(60) 13(1/24) R-10 S. Platte @ 2.0(1/I2) 2.0(1/12) 0 (pCi/L) CO 60 . 10.1 km Surface Water Cs-137(60) 3.0(16/24) 3.4(16/24) A-25 Farm Pond 5 3(4/12) 3.0a 8/12) 0 $ (pCi/L) (1.6-4.7) (1.4-5.2) 2.2 km Sec 1 (3.5-73) (1.7-5.6) Zr-95(60) - 6.4(1/24) A-25 Farm Pond 6.4(1/24) - 0 2.2 km Sec 1 Nb-95(60) 2.l(1/24) 2.0(2/24) F-19 S. Platte 2.l(1/24) 1.4(2/12) 0 1.2 km Sec 4 (0.52-23)
*I3 # I3 Co-58(60) R-10 S. Platte @ 1.4(1/12) 1.4(1/12) O CO 60 10.1 km hin-54(60) 1.7(1/24) 2.2(3/24) A-25 Farm Pond 1.5(3/12) 1.5(3/12) 0 (l .7-2.0) 2.2 km Sec I (l3-2.8) (13-2.8)
Zn-65(60) - - - - - 0 Fe-59(60) 3 4(l/24) 5.2(4/24) A-2I St. Vrain 5.2(4/24) - 0 (33-7.6) Creek (33-7.6) 2.4 km Sec 11 Co-60(60) - - - - - 0 Ha-140(60) 5.9(2/24) - F-19 S. Platte 5.9(2/24) - 0 (3.4-83) 1.2 km Sec 4 (3.4-83)
l Table II.H.1 Radiological Environmental Monitoring Program Annual Summary Fort St. Vrain Station, Platteville, Colorado l hiedium or Type and Total Facility Locations Adjacent Locations with flighest Annual Mean Reference Number of l ! Pathway Samples Number of Mean (O Range Locations Mean Name Mean Locations Mean Nonroutine
- (Unit of Analyses (f)I Range Distance & Range (f)I Range Reported measurement) Performed Direction Measurements La-140(60) 6.8(2/24) -
F-20 St. Vrain 8.0(1/12) 8.0(1/12) 0 (3.9-9.6) Creek 1.5 km See 16 Ground Water 11-3(8) < 370 - - -
< 380 0 (pCi/L)
Gamma Spectrometn-Ground Water Cs-134(7) 2.6(1/4) - F-16 2.6(1/4) 1.8(1/3) 0 (pCi/L) Russel Ranch e 1.5 km Sec 1 oo Cs-137(7) 4.5(3/4) - R-5 Milliken 4.5(3/4) 6.4(2/3) 0 (4.2-4.8) 9.5 km (3.3-3.6) (3.1-9.6) Ground Water Zr-95(7) - - - - - 0 (pCi/L) Nb-95(7) - - - - - 0 Co-58(7) - - R-5 Milliken 1.2(1/3) 1.2(1/3) 0 9.5km Mn-54(7) 2.2(l/4) - F-16 2.2(l/4) - 0 Russel Ranch 1.5 km Sec 1 Zn-65(7) - - - - - 0 Fe-59(7) - - - - - 0 Co-60(7) - - R-5 Milliken 2.4(1/3) 2.4(1/3) 0 9.5km Ba-140(7) 4.5(1/4) - F-16 4.5(1/4) - 0 Russel Ranch
Table II.H.1 Radiological Environmental Monitoring Program Annual Summary Fort St. Vrain Station, Platteville, Colorado hiedium or Type and Total Facility Locations Adjacent Locations with flighest Annual hican Reference Number of Pathway Samples Number of Mean (f) Range Locations Alcan Name Nican Locations hican Nonroutine (Unit of Analy ses (0 1Range Distance & Range (f)I Range Reported measurement) Performed Direction hicaturements 1.5 km Sec I Milk (pCi/L) 11-3(102) - < 330 R-8 Borba Dairy 460(2/17) 460(2/17) 0 23 km (370-540) (370-540) Gamma Spectrometry
~
Milk (pCi/L) Cs-134(102) - R-8 Borba Dairy 1.8(2/17) 1.8(2/17) 0 23 km (l.0-2.5) (I 0-2.5) Cs-137(102) - 3 6(57/85) R-8 Borba Dairy 3.7(10/17) 3.7(10/17) O (l.4-7.7) 23 km (1.9-6.5) (1.9-6.5) e c Ba-140 - 4.3(8/85) R-8 Borba Dairy 6.0(2/17) 6.0(2/17) 0 (2.2-6.0) 23 km (3.8-8.7) (3.8-8.7) La-140 - 4.9(8/85) R-8 Borba Dairy 7.0(2/17) 7.0(2/17) 0 (2.5-6.9) 23 km (4.3-10) (4.3-10) Gamma Spectrometry fu.J Products Cs-134 - - - - - 0 (ptilkg, wet) Cs-137 - 7.9(1/4) A-27 WCR 36 7.9(1/4) - 0 4.3 km Sec 4
Table II.H.2 Summary Table of Arithmetic Means and Standard Deviations for Selected Sample Types 1991 1992 1993 1994 1995 X 1.96o X l.960 Y lh X 1.96o X 1.960 11-3 Atmospheric Water Vapor (pCil) Facility < 9.4 400 980 830 430 130 520 90 420 120 Reference < 80 400 780 530 420 50 630 350 410 110 Gross Beta Air (fCi'm') Facility 29 31 25 15 24 14 28 9.2 19 11 - Reference 25 23 25 12 22 14 24 53 17 9.5 8 I-131 Facility 1.6 13 25 9.0 -' - - - - - Reference 0.52 14 23 6.9 - - - - - - Cs-137 Facility 0.12 0.69 1.0 0.22 1.6 2.9 0.89 0.61 1.1 0.82 Reference 0.98 1.3 1.1 0.40 1.3 23 0.98 0.95 1.2 1.0 11-3 Drinking Water (pCi/L) Gilcrest 30 410 550 90 < 430 50 410 680 590 470 Ft. Collins < 50 350 500 50 < 420 40 < 380 10 < 370 Gross Beta Drinking Water (pCi'L)
' No longer analyze for I-131.
199I I992 1993 1994 1995 X 1.96o X 1.960 X 1.96o X 1.96c K 196c Gilcrest 5.8 2.4 4.3 23 3' 79 2.6 1.7 1.0 1.0 ft. Collins 0.95 035 0.90 031 0.92 0.72 1.2 0.48 0.77 035 I-131 Air (fCi'm') Gilcrest < 0.028 0.16 0.29 0.14 - - - - - - Ft. Collins < 0 022 020 035 0.15 - - - - - - Cs-137 Gilcrest 2.2 1.6 3.4 1.1 3.8 3.1 4.2 23 2.6 1.6 Ft. Collins 1.7 1.2 3.4 0.88 3.4 23 3.7 2.4 2.8 1.8 11-3 Surface Water (pCi'L) k Emuent 1500 2500 770 590 < 420 20 1500 640 590 420 Downstream 6.2 430 990 860 < 420 50 390 550 < 390 - Upstream 20 420 640 0 < 450 200 570 770 < 390 - Cs-137 Emuent 1.7 2.0 3.6 1.4 3.6 2.8 43 23 3.2 2.2 Downstream 23 1.7 3.5 1.2 3.8 2.2 4.5 2.5 2.8 2.2 Upstream 2.0 1.9 3.8 0.89 3.6 23 4.1 2.8 3.5 1.6 11-3 Milk Facility < 130 360 760 590 <430 140 760 660 < 430 - Reference < 110 400 590 90 <420 20 550 450 < 430 - I-131 Facility 0.070 039 <032 0.13 - - - - - - Reference < 0.028 0.24 <037 0.13 - - - - - -
Table II.J.1 Tritium Concentrations in F-16 Well Water for 1995 Date Collected Concentration (pCi/L) 01/07 < 380 01/14 < 380 01/21 < 420 01/28 < 380 02/04 < 390 02/11 < 380 02/18 < 390 02/25 < 390 03/N < 390 03/11 < 390 03/18 < 380 03/25 < 390 G4/01 < 390 G4/08 < 380 04/15 < 390 04/22 < 390 G4/29 < 390 05/06 < 380 05/12 < 370 05/19 < 360 05/26 < 370 06/02 < 370 06/09 < 370 06/16 < 370 06/23 < 370 06/30 < 370 07/07 < 360 07/14 < 370 07/21 < 370 102
i l Table II.J.1 Tritium Concentrations in F-16 Well Water for 1995 ! (cont.) l l D te Collected Concentration (pCi/L) 07/28 < 370 08/04 < 370 08/11 < 370 ; 08/18 < 370 08/26 < 390 i 09/02 < 370 l t 09/16 < 380 ! 09/23 < 390 !
?
09/30 < 380 10/07 < 370 . t 10/14 < 380 [ 10/20 < 370 i 10/28 < 370 11/N < 370 11/11 < 380 , 11/I8 440(500) 11/26 < 420 12/02 < 420 , i 12/09 < 380 [ t 12/15 < 380 , 4 12/22 < 450 12/29 < 450
- 1.96a - Due to counting statistics h
4 i e I i 103 ; i
III. Radiological Environmental Monitoring Program A. Sample Collection and Analysis Schedule Table F-1 in the Offsite Dose Calculation Manual (ODCM) outlines the sampling design, the collection frequency and the type of analysis for all environmental samples. It should be repeated that this schedule was edopted January 1,1984, and while different in certain aspects from the previous schedule, lias as its intent the same objective. That objective is to document the radiation and radioactivity levels in the critical pathways of ; possible dose to humans. Such data is necessary to demonstrate Fort St. Vrain radioactive effluents produce environmental concentrations that are within appropriate environmental protection limits and at the same time are as low as reasonably achievable. During 1995, there were no changes in the sampling program. Iodine-131 analysis was . d.opped at the beginning of 1993 for milk and air samples. The operational phase of the facility ended permanently in August of 1989 and due to the short half-life ofI 131 (8.05 days), there is no longer any inventory of1-131 present. Table Ill.A.1 lists the LLD concentration values for each sample type and l radionuclide measured in this report. These LLD values are the actual values pertinent to the sample sizes, counting yields, and counting times used in the project. Typical decay periods were used in the calculations. It should be noted that the LLD values are in all cases equal to or less than those required by the ODCM. l Table F-3 of the ODCM lists the USNRC reporting level for each sample type and radionuclide. No results exceeded the reporting level in 1995. 104
1 Table F-4 of the ODCM gives the description of each sampling location by number, sector, and distance from the site. Each of these sampling locations (except certain reference locations) can be identified on scale maps (Figures III.B.1 and Ill.B.2). ! Topographical maps showing greater detail, as well as photographs of principal sampling sites are on file in the CSU laboratory. During September 1995 the land-use census was again conducted to determine the locations of the nearest residence, the nearest milk animal, and the nearest garden producing broad leaf vegetation in each of the 16 meteorological sectors around the reactor. These locations are shown in Table Ill.C.I. Figure Ill.C.1 shows these locations in each sector. At the tirne of the 1995 census it was verified that the closest permanent residence in Sector 16 was the critical receptor with regards to mean annual dose commitment and is at the residence at F-16. A few residents in the sampling sectors up to a distance of 8 km from the plant have 1 cows or goats that could be used for personal milk consumption. Ilowever, from direct discussion with these persons, this is not a common practice and all cow milk produced is transported to commercial processors. The milk produced locally is diluted by a large milk shed, processed and distributed over a large area for consumption. Elevated radionuclide concentrations in milk samples due to Fort St. Vrain station effluents have never been detected during either the - donal or decommissioning phases. , 105
TABLE III.A.1 DETECTION CAPABILITIES FOR ENVIRONMENTAL SAMPLE ANALYSIS LOWER LIMIT OF DETECTION (LLD) Analysis W ater Airbome Fish Milk Food Products Sediment (pCil) Particulate (pCikg, wet) (pCil) (pCikg, wet) (pCikg. dry) or Gas (fCi'm') Gross Beta 4 5 N/A N/A N/A N/A 11-3 2000 N/A N/A N/A N/A N/A Cs-134 15 9 130 15 60 150 Cs-137 18 8 150 18 80 180 Mn-54 15 N/A 130 N/A N/A N/A Co-60 15 N/A 130 N/A N/A N/A Zn-65 30 N/A 260 N/A N/A N/A NOTE This list does not mean that only these nuclides are to be detected and reported. Other peaks uhich are measurable and identifiable, together with the above nuclides, shall be identified and reported. __._____.______________m_ _ _ _ _ _ _ _ _ _ . _ _ _ _ . _ _ _- -- - ,- _- -______.___m_
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Table Ill.C.11995 Land Use Census' l Sector Nearest Residence Nearest Garden Nearest Milk Animal 9102 CR 44 " 1 17578 CR 19% l 2 18311 CR 23 19027 CR 23 11258 CR 40 11100 CR 38 " 3 11100 CR 38 . 4 11247 CR 36 11247 CR 36 11777 CR 36 l 5 16543 CR 23 16134 CR 23 16134 CR 23 l 6 16017 CR 23 16017 CR 23 Il585 CR 32 l 7 9999 CR 34 9999 CR 34 15225 CR 21 " 8 15883 CR 21 9 9379 CR 34 9456 CR 34 9033 CR 26 10 9061 CR 34 15449 CR 19 7388 CO 66 6769 CR 32 4513 CR 32 ! i1 8745 CR 34 12 Aristocrat R vich 16202 CR 15 4665 CR 34 I 13 17038 CP 17 17475 CR 17 14 8896 CR 19 17666 CR 17 r 15 18100 CR 19 18995 CR 17 16 17926 CR 19% 17926 CR 19%
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** No milk animals 4
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