TECHNICAL NOTE OKP/EAD 76 .1 RADIOACTIVE ISOTOPIC CHARACTERIZATION OF THE ENVIRONMENT NEAR WISCASSET, MAINE USING PRE AND POST-OPERATIONAL SURVEYS IN THE VICINITY OF THE MAINE YANKEE NUCLEAR REACTOR U.S. ENVIRONMENTAL PROTECTION AGENCY Office of Radiation Programs ------- RADIOACTIVE ISOTOPIC CHARACTERIZATION OF THE ENVIRONMENT NEAR WISCASSET, MAINE USING PRE- AND POST-OPERATIONAL SURVEYS IN THE VICINITY OF THE MAINE YANKEE NUCLEAR REACTOR. MAY 1976 ENVIRONMENTAL ANALYSIS DIVISION OFFICE OF RADIATION PROGRAMS U.S. ENVIRONMENTAL PROTECTION AGENCY WASHINGTON, D.C. 20460 THIS WORK WAS PERFORMED UNDER ENVIRONMENTAL PROTECTION AGENCY CONTRACT NUMBER 68-01-2654 BY THE UNIVERSITY OF MAINE, ORONO, MAINE, UNDER THE DIRECTION OF DR. C. T. HESS, DR. C. W. SMITH, C. H. CHURCHILL AND G. F. BURKE. ------- PREFACE The Office of Radiation Programs is concerned with the evaluation of radiation exposure to man and his environs. Nuclear power plants release radioactive materials to the environment from normal operations which become a potential source of exposure to the population. The Environmental Analysis Division has responsibilities for evaluating the environmental and public health impacts resulting from such releases. This study was performed on contract to this Division by the University of Maine for the purpose of isotopic •characterization of environmental radioactivity outside the plant site boundary of the Maine Yankee Pressurized Water Nuclear Power Reactor during 1973. It compares the pre- operational survey with the postoperational survey to determine the amount of contamination resulting from operations of this power reactor. loyd L. Gal pin Director Environmental Analysis Division Office of Radiation Programs ------- RADIOACTIVE ISOTOPIC CHARACTERIZATION OF THE ENVIRONMENT NEAR WISCASSET, MAINE USING PRE- AND POST-OPERATIONAL SURVEYS IN THE VICINITY OF THE MAINE YANKEE NUCLEAR REACTOR ABSTRACT A comparison of identical surveys of the pre- and post-operational environmental radioactivity is made for the vicinity of the Maine Yankee Atomic Power Reactor, Wiscasset, Maine. Radionuclides are measured in laboratory samples of soil, sediment, well water, surface water, estua- rine water, air particulate, air moisture, and precipitation. Field measurements of gamma-ray emitting radionuclides and high pressure ion chamber measurements are also presented. The changes in radionuclide concentration and dose are evaluated using the Maine Yankee Environmental Impact Statement. The most significant changes occur for radionuclides in soils and sediments. Details of the distribution of sediment radio- nuclides near the outflow of the reactor in Bailey Cove are presented with dose estimates of 10.6 mrem/year at the sites of greatest specific activity. Radionuclides in the water were mainly natural 2^Rn ancj daughters. Tritium concentrations were at minimum detectable level. Air particulate showed traces of ^Be and ^^ZrNb at fallout levels which were not significantly different from the preoperational levels. High pressure ion chamber dose rates ranged from 8.9 to 12.6 uR/hr at the 12 measured sites. Time variations of radionuclide content were measured for oysters cultured in the reactor effluent and associated sediments. Doses calculated for ingestion of radionuclides by consumption of oysters would be 0.27 mrem/yr for 58Co and 0.004 mrem/yr for 54Mn. ------- FORWARD This report presents the procedures and results of an environmental radioactivity survey in the vicinity of the Maine Yankee Atomic Power Plant (a 855 MWE pressurized water reactor) 6.4 km south southwest of Wiscasset, Maine on Bailey Point. Prior to the operation of this facility measurements of environmental radioactivity were made (1972) on samples of soil, sediment, well water, surface water, estuarine water, air particulate, air moisture, and precipitation. The procedures and results of that survey were reported in "Radiation Data and Reports", volume 15, number 2, February 1974. The post-operational survey (1974) represents the follow-up survey to the pre-operational survey referenced above. The study design employs the same techniques, environmental media, and sampling sites as the pre-operational survey. The objective of this dual survey is to assess changes in environmental radioactivity. ------- ACKNOWLEDGMENTS The work reported here represents a cooperative effort by several institutions and facilities. Essential to this study was the work of the staff of the Eastern Environmental Radiation Facility, Montgomery, Alabama for off-site laboratory measurements, with special thanks to Mrs. Ann B. Strong, Mr. Charles Phillips and Mr. Thomas Reavey. We gratefully acknowledge the participation by the Ira C. Darling Center for Oceanographic Research, University of Maine in the estuarine aspects of this study, the transect study of Bailey Cove and the aquaculture of the oysters for the uptake modeling, with special thanks to Mr. A. H. Price and Dr. H. Hidu. Cooperation and assistance by the Maine Yankee Atomic Electric Company, with special thanks to Mr. V. Thompson, was gratefully appreciated. We acknowledge the use and cooperation of the University of Maine Physics Department, Computer Center and Office of Grant Support. The information included in this report as Appendix D was part of a study funded by the National Oceanic and Atmospheric Administration. We appreciate their willingness to have this material included in this report. We are especially grateful for the useful discussions throughout this study with Mr. C. L. Weaver of EPA's Office of Radiation Programs and for the assistance of Mr. Charles Robbins of the Environmental Analysis Division who coordinated the publication of this report. Dr. C. T. Hess Dr. C. W. Smith University of Maine ------- TABLE OF CONTENTS SECTION 1. INTRODUCTION 1 Purpose of this Study 1.1 Goals for this Study 1.2 Study Design 1-3 2. EXPERIMENTAL PROCEDURES AND ANALYSIS 2 Radionuclides in the Soil and Sediment 2.1 Laboratory Soil and Sediment Measurements and their Analysis 2.11 Field Soil and Sediment Measurements and their Analysis. . . 2.12 Discussion of Soil and Sediment Analysis 2.13 Sediment Transect Survey and Analysis 2.14 Radionuclides in the Water 2.2 Field Water Measurements 2.21 Laboratory Water Measurements and Analysis 2.22 Tritium in the Water, Air Moisture and Precipitation .... 2.23 Discussion of Tritium Measurements 2.24 Radionuclides in the Air Particulate 2.3 Laboratory Air Particulate Measurements and Analysis .... 2.31 Field Air Particulate Measurements and Analysis 2.32 High Pressure Ion Chamber Measurements 2.4 3. APPENDICES 3 Liquid and Gaseous Effluent Inventory A Prescan Results B Gamma Ray Dose Calculations C A Model for Radionuclides in Oysters and Associated Sediments . D Pre-Operational Laboratory Water Gamma-ray Analysis of the Dissolved Component ------- 1. INTRODUCTION 1.1 Purpose of the Study This study consists of a pre-operational (1972) and post-operational (1974) environmental radioactivity survey in the vicinity of the Maine Yankee Nuclear Power Reactor (6.4 km S.S.W. of Wiscasset, Maine on Bailey Point, See Fig. 1). The study measures any changes in the radionuclide content of the soil, estuarine sediment, estuary, well, and surface water, air moisture precipitation, and air particulate for this region. The study identifies the pathways in these environmental media which tend to collect or reconcentrate radionucl ides and the regions in which reconcen- tration occurs. 1.2 Goals for this Study A. To broadly survey several environmental media (soil, sediment, water, air moisture and air particulate) for changes in radionuclide content (nuclide by nuclide rather than gross activity) resulting from the operation and refueling of the Maine Yankee Nuclear Power Reactor. B. To compare observed changes with the Maine Yankee Semi-annual Report of Release of Radioactive Materials^ ' and with predictions of (2) the Maine Yankee Environmental Impact Statement '. C. To examine in detail the largest change observed in the study. ------- -2- 1.3 Study Design Studies of pressurized water reactors as outlined by Kahn^ , Rowe^ and LentsdT5^ et.al. are based on a combination of knowledge of radio- nuclide releases, use of very sensitive environmental measurements and a carefully planned pre-operational survey. This study similarly employs these features. A nuclide by nuclide comparison of a pre-operational and post-operational survey of several environmental media forms the overall structure of this study. Field and laboratory measurements of primarily gamma-ray emitting radionuclides were used to determine which of the radionuclides listed in the Semi-annual Report of Release of Radioactive Materials are being retained in the environment in the vicinity of the reactor. Tritium, gross beta and gross alpha measurements, along with high pressure ion chamber measurements also were employed. The major radionuclide in the liquid effluent is tritium and the major radionucl ides in the gaseous effluent is 133Xe and tritium. Several other radionuclides in trace amounts (See Appendix A) are also released in the liquid and gaseous effluents. To achieve both the sensitivity and diversity of measurements to cover this broad survey this study utilized the facilities of the Eastern Environmental Radiation Facility, Montgomery, Alabama for laboratory measure- ments for the post-operational survey, the Northeastern Radiological Health Laboratory, Woburn, Massachusetts for laboratory measurements for the pre- operations survey and the University of Maine, Department of Physics for the field measurements and some laboratory measurements for both surveys The two surveys employ the same sampling sites and as far as possible the same or similar instrumentation. Details of each measurement are presented ------- -3- in the following sections along with the experimental results. Post- operational and pre-operational results are presented in tables in each section. Comparisons are made, changes are discussed and conclusions are presented in each section. The largest change was observed for sediments in the Bailey Cove estuary and is presented as Section 2.14 Sediment Transect Survey and Analysis. ------- -4- 2.1 RADIONUCLIDES IN THE SOIL AND SEDIMENT 2.11 Laboratory Soil and Sediment Measurements and Their Analysis Soil samples were collected at the following sites: (Foxbird Island, 0,1 km, S.; Eaton Farm, 0.4 km, W.; Bailey Farm, 0.8 km, N.E.; Young's Creek, 1.0 km, N.; Knight Cemetary, 1.1 km, E.; Westport Fire- house , 1.8 km, S.; Chewonki Neck (Camp), 1.9 km, S.W.; Cowseagan Narrows, 3.2 km, N.E. and Bluff Head, 4.0 km, S.S.W., see map). Sediment samples were collected at Foxbird Island, 0.1 km, S, on the outfall side of the causeway and at Murphy's Corner, 2.8 km, S.W. Soil samples were collected using a disc-cutter sampler which would cut a cylindrical soil sample 15 cm in diameter by 15 cm deep. Four soil samples this size, each centered at the corner of a square grid 25 cm on an edge were collected at each of the nine sites. The four soil samples including surface vegetation were mixed and the root mats pulverized. The sample was then screened and all material smaller than 5 mm retained. The sample was then dried at 110°C for 24 hours. In the case of the sediment samples, the top two centimeters were collected. These samples were screened and dried in an identical manner. In each case the samples were divided and a dry kilogram of the sample material was shipped to the Eastern Environ- mental Radiation Facility, Montgomery, Alabama for gamma-ray analysis using a Ge(Li) detector and on-line computer-analyzer. Analysis was carried out by hand using the Compton continuum subtraction method^ '. All samples were counted for a nominal 900 minutes (with a nominal 10 persent dead time) with a 2048 channel analysis. The results of the analysis are listed in Table I. The results of the pre-operational analysis are listed in Table II. ------- TABLE I POST-OPERATIONAL LABORATORY SOIL AND SEDIMENT GAMMA-RAY ANALYSIS SAMPLE IDENTIFICATION LOCATION Foxbird Island Eaton Farm Bailey Farm Young's Creek Knight Cemetery Westport Fi rehouse Chewonki Neck(Camp) Cowseagan Narrows Bluff Head Foxbird Island Murphy's DATE COLLECTED 8/14/74 8/14/74 8/14/74 8/14/74 8/14/74 8/14/74 8/14/74 8/14/74 8/14/74 8/14/74 8/14/74 DATE COUNTED 11/16/74 11/18/74 11/20/74 11/18/74 11/19/74 11/17/74 11/14/74 11/15/74 11/19/74 11/15/74 11/20/74 TYPE soil soil soil tidal marsh soil soil soil soil soil soil tidal marsh sediment tidal flat sediment THORIUM SERIES 228Ac pCi/kg ±2a 900 ±90 1100 ±120 1100 ±150 1100 ±120 1700 ±225 800 ±90 900 ±90 1000 ±70 1200 ±48 900 ±300 900 ±90 URANIUM SERIES 21l)Bi pCi/kg ±2a 700 ±200 1100 ±120 1100 ±170 800 ±70 1300 ±180 800 ±100 700 ±80 1000 ±100 1600 ±80 900 ±270 800 ±72 OTHER NATURAL 40K pCi/kg ±2a 7300 ±950 17400 ±1200 17600 ±1300 19400 ±780 11300 ±1300 11800 ±700 15100 ±600 14300 ±570 13300 ±530 20500 ±1600 18000 ±500 RADIONUCLIDES 137Cs pCi/kg ±2a 4600 ±180 2500 ±130 1800 ±100 700 ±50 4000 ±160 3200 ±100 1500 ±50 1300 ±50 1200 ±50 1000 ±130 500 ±35 13"CS DCi/kg ±2o < 35 < 35 < 35 < 35 < 35 < 35 < 35 < 35 < 35 1000 ±130 < 35 58Co DCi/kg ±2a < 25 < 25 < 25 < 25 < 25 < 25 < 25 < 25 < 25 21000 ±400 < 25 6°CO 3Ci/kg ±2a < 30 < 30 < 30 < 30 < 30 < 30 < 30 < 30 < 30 2420 ±250 < 30 51»Mn pCi/kg ±2a < 15 < 15 < 15 < 15 < 15 < 15 < 15 < 15 < 15 450 ±100 < 15 en i All measurements based on dry weight ------- TABLE II PRE-OPERATIONAL LABORATORY SOIL AND SEDIMENT GAMMA-F SAMPLE IDENTIFICATION LOCATION :oxbird Island Eaton Farm 3a i 1 ey Farm Young's Creek (night Cemetery Jestport Fi rehouse ^hewonki Neck(Camp) Cowseagan Narrows Bluff Head Foxbird Island Murphy's Corner DATE COLLECTED 6/29/72 6/12/72 6/12/72 6/12/72 6/12/72 6/12/72 6/12/72 6/13/72 6/12/72 6/29/72 7/3/72 DATE COUNTED 7/20/72 7/17/72 7/12/72 7/14/72 6/26/72 6/21/72 7/20/72 7/24/72 6/22/72 7/28/72 7/27/72 TYPE soil soil soil tidal marsh soil soil soil soil soil soil tidal marsh sediment tidal flat sediment THORIUM SERIES 228Ac pCi/kg ±2a 1200 ±100 340 ±120 1240 ±300 880 ±250 1210 ±200 1000 ±350 1100 ±250 300 ±300 660 ±300 250 ±130 1660 ±280 URANIUM SERIES 21 "Si pCi/kg ±2a 700 ±90 630 ±70 810 ±150 1075 ±120 700 ±80 920 ±120 1370 ±300 730 ±180 1100 ±180 500 ±180 740 ±120 OTHER NATURAL 40K pCi/kg ±2a 14000 ±1000 14900 ±400 14600 ±1300 18200 ±400 11200 ±1200 11800 ±900 13200 ±1200 13400 ±1250 11300 ±1240 15000 ±350 15200 ±1200 U\Y ANALYSIS RADIONUCLIDES i3?Cs pCi/kg . ±2a 940 ±85 870 ±45 1670 ±110 800 ±80 4960 ±110 1110 ±85 3340 ±130 2620 ±130 2030 ±110 350 ±32 450 ±80 131(Cs pCi/kg ±2a < 30 < 15 < 30 < 30 < 30 < 30 < 30 < 30 < 30 < 15 < 30 58Co pCi/kg ±2a < 25 < 12 < 25 < 25 < 25 < 25 < 25 < 25 < 25 < 12 < 25 60Co pCi/kg ±2o < 30 < 15 < 30 < 30 < 30 < 30 < 30 < 30 < 30 < 15 < 30 5"Mn pCi/kg ±2a < 20 < 10 < 20 < 20 < 20 < 20 < 20 < 20 < 20 < 10 < 20 I cr> ------- -7- The Thorium series as represented by 228Ac is found to be the same (±2a) as the pre-operational measurements with significant changes only at Eaton Farm soil. At present there is no obvious explanation of the difference. The Uranium series as represented by 21/+Bi is found, in all cases, to be the same (±2a) as pre-operational measurements. The concentration of 1+0K is found to be the same (±2a) for all cases except Foxbird Island soil and Foxbird Island sediment. In the case of Foxbird Island soil, a decrease is observed and for Foxbird Island sediment, increase is observed. 137Cs is observed to be the same (±2o) in all cases except Foxbird Island soil, Eaton Farm soil, Westport Firehouse soil, Chewonki Neck soil, Bluff Head soil, and Foxbird Island sediment. Finally, 134Cs, 58Co, 60Co and 5ltMn are all found to be present in Foxbird Island sediment. These four isotopes were not present in the sediment at the time of the pre-operational study. This change is not in agreement with the Maine Yankee Environmental (2) Impact Statement . Specifically, page V-15, states - "Recreational and other uses of shorelines and waters near the plant will be permitted by the Applicant. Therefore, direct exposure to radiation from nuclides in the waters of the bay will be experienced. The individual receiving the highest radiation dose would probably be one who earns his livelihood by digging blood and sand worms in the mud flats in the vicinity of the reactor dis- charge. For this calculation, concentrations of radionuclides deposited on the mud flats were assumed to result from undiluted effluent water. Such a person was also postulated to be exposed to the mud flats for 2000 hr/yr. Based on these assumptions, the dose to the total body from radionuclides associated with the mud would be about 6 mrem per year for the individual receiving maximum exposure. Nearly all this exposure is from 13ttCs and 137Cs deposited on the mud flats where the worms are harvested. The exposure to the hands of the worm diggers would be somewhat higher than their total- ------- -8- body exposure since they sift through the mud while harvesting the worms." We find that over (0.92) of the exposure will come from 54Mn, 58Co and 60Co with the remaining portion (.08) coming from 13ttCs and 137Cs. Furthermore, high pressure ion chamber measurements at Foxbird Island and Murphy's Corner show an increase of the intensity over sediment. At Foxbird Island, for example, this change in intensity is 5.3 (6.58)calc microrem per hour which comes to a dose change (for the 2000 hr/yr worm digger) of 10.6 (13.6)calc millirem per year. See Section 2.4 High Pressure Ion Chamber for details of these measurements. The range and extend of radio- nuclides in the sediment are presented in greater detail in Section 2.14 Sediment Transect Survey and Analysis. ------- -9- 2.12 Field Soil and Sediment Measurements and their Analysis As prescribed by our pre-scans of soil samples described in 2.11 radionuclides in the soil were measured in the field at the following, six locations. (Foxbird Island, 0.1 km, S.; Eaton Farm, 0.4 km, W.; Bailey Farm, 0.8 km, N.E.; Westport Firehouse, 1.8 km, S.; Chewonki Neck (Camp), 1.9 km, S.W.. On-site sediment measurements were taken at low tide at Murphy's Corner, 2.9 km, S.W. the location of a tidal mud flat of commercial importance to the local blood worm industry and Foxbird Island the site of the outflow. A portable multichannel analyzer system with a 5 cm by 5 cm Nal(Tl) detector was employed. The portable multichannel analyzer system consisted of a Northern Scientific, Inc. NS-710 multichannel analyzer powered by a Cornel 1-Dubilier Powercon sine wave inverted Model 12ESW25 and a 12 v.d.c., 96 amp-hour battery. The detector, a 5 cm by 5 cm Nal(Tl) crystal was an integral crystal-photomultiplier assembly by Teledyne Isotopes, Inc., Model S-88-I with 8.4 percent resolution at the 137Cs photo-peak. It was powered by a Northern Scientific, Inc. high voltage battery power pack NS-308 with a matched cable-base assembly NS-309. The detector was connected to the multichannel analyzer with 50 m of coaxial cable (RG-59). A 100 Ib. lead shield consisted of a cylinder 28 cm high, and 18 cm in diameter with a 6 cm diameter concentric hole the full length of the cylinder. The detector was housed in this shield for each on-site measurement. The shield was placed on the ground, the detector lowered into the shield and a 3 cm thick lead cap covered the upper end of the shield. The lower end of the shield was open to the soil so that the circular face of the detector was placed on the ground (a 1/8 inch insulating layer of plywood was used to protect the crystal from thermal shock). All ------- -10- field soil and sediment gamma-ray spectra were taken using this top shielded 2 IT geometry^7) It is felt that this geometry has two advantages: (i) it is reproducible and (ii) it is without bias in that it samples the soil in a nondestructive non-mixed manner. All field soil and sediment spectra were taken on one quarter memory (512 channels) for 4000 seconds. At the end of 4 runs the multichannel analyzer was returned to the University of Maine, Physics Department and the memory outputted into a model KSR-33 teletype. The teletype provided a listing of the counts in each channel and a punched paper tape. The punched paper tapes were converted into cards and the gamma spectra analyzed at the University of Maine Computer Center. The least squares method was used to obtain the best estimates of the amounts of each radionuclide present in each sample and an evaluation of the errors of these results. The computer program used was the Oak Ridge National Laboratory spectrum fitting program, Alpha-M^9' It employs the least squares method to analyze the data for which a "best fit" is mathematically computed such that the sum of the squares of the deviations between the actual spectra and the. "best fit" is minimized. The program also uses automatic gain shift and automatic threshold shift routines to optimize the fit. The program works with a library of standard spectra from which it synthesizes the "best fit" spectra. The library used for the analysis of the soil and sediment on-site spectra was composed of standard spectra for k°K, 137Cs, the 232Th series, 13l+Cs, 58Co, 60Co, and the 238U series. Output from the program consists of the estimated amount of each standard spectra needed to synthesize the sample spectrum, the estimated error in the amount used for each library standard, the gain shift (if any) used to match the spectrum to the standards, the threshold or zero shift (if any) used to match the spectrum to the standards, the residuals for each channel and a listing of suspicious channels whose residuals lie outside two standard deviations. ------- -11- In all cases convergence was obtained in less than 20 iterations. The results of the analysis are listed in Table III. Table IV lists results from the pre-operation survey. One can see that in general all spectra contained Lf°K, and the natural decay series for 232Th and 238U. A significant amount of 137Cs, a non- natural isotope, is contained in all spectra. The field measurements at Foxbird Island tidal mud flats indicates 58Co, and 60Co at this site. Comparison of the levels of natural isotopes 232Th, 238U and 40K and 137Cs which is partly due to fallout are similar to pre-operational levels: with the exception of the Foxbird Island measurement which had more 238U, 232Th and less 137Cs, and may be due to disturbances done by nearby construction of a diffuser for the reactor. Eaton Farm also shows more 238U series and is not explained. Measurements at Foxbird Island and Murphy's Corner show 58Co and 60Co. 60Co was also measured at Bailey Farm and Knight Cemetery while 58Co was measured at Eaton Farm. These cobalt isotopes were not present at the time of the pre-operational study. Measurements at Foxbird Island indicate 238U and 232Th has increased and 137Cs decreased as compared to the pre-operational study. These changes in these three isotopes were probably caused by the extensive dust due to construction dredging trucking and back filling with estuarine sediment during construction of the diffuser channel and head basin. ------- TABLE III POST-OPERATIONAL FIELD SOIL AND SEDIMENT GAMMA-RAY ANALYSIS LOCATION :oxbird Island iaton Farm Jailey -arm Knight Cemetery Murphy's Corner Foxbird Island DATE MEASURED 8/24/74 8/22/74 8/22/74 8/22/74 8/22/74 8/24/74 TYPE soil soil soil soil sedi- ment sedi - ment 232Th pCi/kg ±2a 2000 ±70 2300 ±80 2100 ±95 3100 ±80 1300 ±40 1500 ±60 238u pCi/kg ±2a 1250 ±120 1300 ±120 1000 ±130 660 ±120 280 ±50 580 ±80 •fOK pCi/kg ±2a 17400 ±750 24700 ±740 18600 ±880 23200 ±790 11000 ±370 16500 ±470 137Cs pCi/kg ±2a 3800 ±230 2800 ±260 3380 ±370 6900 ±310 590 ±130 1400 ±200 58Co pCi/kg ±2a < 30 210 ±30 < 30 < 30 180 ±30 730 ±20 6°Co pCi/kg ±2a 150 ±90 < 75 60 ±90 150 ±80 70 ±40 100 ±70 IN} I ------- TABLE IV PRE-OPERATIONAL FIELD SOIL AND SEDIMENT GAMMA-RAY ANALYSIS -OCATION :oxbird Island iaton Farm Bailey Farm Young's Creek Knight Cemetery destport Fi rehouse Chewonki Neck (Camp) Cowseagan Narrows Bluff Head Murphy ' s Corner DATE MEASURED 6/29/72 6/26/72 6/27/72 6/27/72 6/27/72 6/27/72 6/26/72 6/27/72 6/28/72 7/3/72 TYPE soil soil soil soil soil soil soil soil soil sediment THORIUM SERIES pCi/kg 1600 ±100 2400 ±100 2000 ±100 1600 ±400 3100 ±300 1500 ±100 1900 ±100 1700 ±100 2000 ±100 1400 ±100 URANIUM SERIES pCi/kg 600 ±100 700 ±100 800 ±200 600 ±200 600 ±200 500 ±100 500 ±150 500 ±100 800 ±300 400 ±200 if oK pCi/kg 14000 ±3500 21000 ±5000 16000 ±6000 14000 ±9000 20000 ±6000 14000 ±3000 20000 ±4000 15000 ±3000 16000 ±5000 9000 ±4000 i3?Cs pCi/kg 3590 ±800 5600 ±2700 3300 ±600 4000 ±1400 9500 ±1600 7600 ±2000 5000 ±1100 5400 ±800 6300 ±1400 7000 ±1900 58Co pCi/kg < 30 < 30 < 30 < 30 < 30 < 30 < 30 < 30 < 30 < 30 6°CO pCi/kg < 75 < 75 < 75 < 75 < 75 c 75 < 75 < 75 < 75 < 75 ------- -14- 2.14 Sediment Transect Survey and Analysis As a result of the high readings for the pre-scan and in situ gamma-ray measurements of sediment from Foxbird Island and as a result of suggestions from our collaborator Mr. Charles Phillips of Eastern Environmental Radiation Facility, Montgomery, Alabama, we decided to make a survey along tidal transects of the sediments in Bailey Cove. Using the cooperative efforts of the Ira C. Darling Center for marine research and members of the bloodwoorm research project, under the direction of Marine Biologist A. H. Price, 50 samples of estuarine sediments were collected at 50 ft. transects in Baily Cove adjacent to the outflow of the reactor. The locations of the sites are shown in Figure 2. These sediments were counted for 5000 sec. using the University of Maine, Physics Department's Ge(Li) detector and low background shield. Results of the determination of the concentration of gamma-ray emitting isotopes in the sediment is shown in pCi/kg. Figures 3 and 4 illustrate activity maps for 58Co and 60Co, respectively. It should be noted that the highest levels of radioactivity are for the outflow site (29) and for the upper reaches of the cove. The constant picocurie lines seem to follow the flow of water out of the cove at low tide and into the upper cove at high tide and thus suggest that the isotopes are transported by the outflow water and reconcentrated into the sediments. This reconcentration is consistent with a diffusion theory for fallout radionuclides in sediments as suggested by Lerman and with chemical precipitation of 58Co in the effluent of reactors as suggested by Fukui . Comparison of the average flow velocities of the water from the outflow suggests sedimentation as another mechanism which reconcentrates the nuclides. Some indication of ------- 15 Figure 2, Site Locations for Sediment Transect Bailey Cove 175 meters ------- (K V-/IOO 1780s 3160 5620 3, Activity Map 58Co(pCi/kg) n Sediment, Bailey Cove 175 meters ------- 17 Figure 4, Activity Map for 60Co(pCi/kg) in Sediment, Bailey Cove 175 meters ------- -18- this may be seen in the reduced level of nuclides along the most direct channel of the outflow. The radionuclides 13ifCs, 137Cs, and 60Co bear this out by having similar behavior to the 58Co. Since the Maine Yankee (2) Environmental Impact Statement ' does not specify range or distribution guidelines or estimates no comparison is made. However, implicit in the I 10) modelv ' upon which the dose calculations were based is an assumption of uniform distribution of effluent discharge. This is not the case in the vicinity of Maine Yankee as shown by this transect survey in Bailey Cove. One radioactive particle containing 7700 pCi of 60Co was observed in the sediment transect #19 and had a total activity (58Co, 530 pCi: l+6Sc, 670 pCi: 54Mn, 120 pCi) of more than 9000 pCi in a mass less than 20 y grams. Photographs and x-rays powder patterns were made and it was found to be cubic cobalt, alpha iron, nickel, alpha and gamma manganese and possibly chromium and vanadium. This stainless steel like composition suggests reactor origin. The particle was also checked for the oxides, chlorides, nitrates, sulphates and hydroxides of these metals with negative results(13). ------- -19- 2.2 RADIONUCLIDES IN THE WATER 2.21 Field Hater Measurements Based upon the data obtained during the pre-operational field water measurements, the post-operational measurements showed no detectable amount of gamma activity above background. It is felt that field measurement of in-situ water with portable multichannel analyzer-detector equipment is significantly less sensitive than laboratory measurement and yields no additional information. Laboratory measurement, with the advantages larger detectors and massive shielding together with the practicality of longer measuring time, outweighs the advantages of preserving temperature, particulate and salinity gradients as is done in the laboratory water measurement. 2.22 Laboratory Water Measurements and Their Analysis Water samples were collected at the following seven sites Foxbird Island, 0.1 km, S.; Eaton Farm, 0.4 km, W.; Bailey Farm, 0.8 km, N.E.; Young's Creek, 1.0 km, N.; Chewonki Neck (Camp), 1.9 km, S.W.; Cowseagan Narrows, 3.2 km, N.E.; and Bluff Head, 4.0 km, S.S.W., see map Figure 1. Each water sample was separated,by filtering the dissolved and the un- dissolved solids into two components. This separation was done in the field at the time of collection. The water was filtered using a Millipore high pressure filtering unit. A Milipore 90 mm filter holder was loaded with a Whatman No. 1 paper filter, a Millipore AP3207500 spacer, a Millipore SCWP09025 cellulose ester 8.0y filter, a Mi Hi pore AP3207500 spacer and a Millipore HAWP09025 cellulose ester 0.45y filter for each water sample. Ten liters of water from each site was filtered using the above arrangement. ------- -20- The filtered water (dissolved component) was placed in one gallon plastic shipping containers to which 40 ml of nitric acid was added to stabilize the sample. Prior to acidification a 50 ml sample from each site was placed in a plastic bottle for tritium analysis, (see section 2.23). The dissolved component, (one gallon samples) and the undissolved component (filters) were sent to the Eastern Environmental Radiation Facility, Montgomery, Alabama for gamma-ray analysis. The dissolved component was gamma-ray analyzed using a Nal(Tl) detector and 3.5 liter Marinelli beaker geometry in a massive shield. The results of this analysis show no detectable gamma activity in the dissolved component. (See Appendix E for pre-operational laboratory dissolved water component). The undissolved component was analyzed in the following manner. The filters were weighed before use. After use they were dried and reweighed to determine the amount of undissolved material. The filters were sent to the Eastern Environmental Radiation Facility, Montgomery, Alabama for gamma-ray analysis. The three filters for each site were first measured for gross alpha and gross beta activity and then counted in a 40 ml Nal(Il) well-crystal 10 cm x 13 cm with 3 cm deep well. The results of these measurements are presented in Table V. Table VI lists the results for the pre-operational survey. ------- TABLE V POST-OPERATIONAL LABORATORY WATER MEASUREMENT UNDISSOLVED COMPONENT (FILTER) COLLECTED 8/14/74 LOCATION Foxbird Island Eaton Farm Bailey Farm Long Ledge Creek (Young's Creek) Chewonki Neck (Camp) Cowseagan Narrows Bluff Head WATER TYPE estuarine well well surface well estuarine estuarine SAMPLE MASS (GRAMS) 0.165 ± 0.015 0.005 ± 0.015 0.002 ± 0.015 0.621 ± 0.045 0.005 ± 0.015 0.122 ± 0.015 0.149 ± 0.015 GROSS ALPHA pCi/10 liters ±2a ND 18.9 ± 85% 60.7 ± 33% 2.1 ± 59% 6.2 ± 66% ND ND GROSS BETA pCi/10 liters ±2a 1.4 ± 81% 2.6 ± 39% 21.1 ± 22% 4.8 ± 59% 1.6 ± 57% 1.3 ± 69% ND GROSS GAMMA pCi/10 liters ±2a ND ND ND ND ND ND ND I no ------- TABLE VI PRE-OPERATIONAL LABORATORY WATER MEASUREMENT UNDISSOLVED COMPONENT (FILTER) COLLECTED 6/13/72 LOCATION Foxbird Island Eaton Farm Bailey Farm Long Ledge Creek (Young's Creek) Chewonki Neck Camp Cowseagan Narrows Bluff Head WATER TYPE estuarine well wel 1 surface well estuarine estuarine SAMPLE MASS (GRAMS) 0.131 ± 0.005 0.000 ± 0.005 0.007 ± 0.005 0.045 ± 0.005 0.002 ± 0.005 0.114 ± 0.005 0.163 ± 0.005 228Ac < 45 < 45 200 ±45 < 45 < 45 < 45 < 45 212Bi 100 ±20 < 10 < 10 < 10 < 10 < 10 < 10 20871 < 25 < 25 < 25 < 25 < 25 30 ±25 70 ±25 214pb < 10 30 ±25 < 10 < 10 < 10 < 10 < 10 2i^B1 < 10 < 10 < 10 < 10 < 10 < 10 < 10 "°K < 25 < 25 < 25 < 25 < 25 < 25 < 25 I ro ro ------- -23- 2,22 Discussion of the Water Gamma-Ray Analysis Several observations can be made from the data in Table V. The well water in this region of Maine contains considerable dissolved 222Rn. This is due primarily to leaching from uranium oxide in the pegmatite deposits in the area. This is also reflected in the alpha and beta activity in the well water from the sites measured (Eaton Farm, Bailey Farm and to some extent Chewonki Neck Camp). Irr general the water measurements at all sites show no significant change from the pre-operational survey shown in Table VI and, with the exception of the well water, have typical activities for this type of environmental media. The specific activity of the undissolved component in the estuarine water is of the same magnitude as the specific activity in the estuarine sediments. The specific activity of the well water samples was about two orders of magnitude greater but from the pre- operational survey this is known to be of natural origin. 2.23 Tritium in the Water, Air Moisture and Precipitation 2.231 Tritium in the Water Tritium in the water was measured in samples collected at the following seven locations, Foxbird Island, 0.1 km, S.; Eaton Farm, 0.4 km, W.; Bailey Farm, 0.8 km, N.E.; Young's Creek, 1.0 km, N.; Chewonki Neck (Camp) 1.9 km, S.W.; Cowseagan Narrows, 3.2 km, N.E. and Bluff Head, 4.0 km, S.S.W.; (see Fig. 1). Each water sample was filtered as described in section 2.2. A 50 milliliter sample from each site was sent to the Eastern Environmental Radiation Facility, Montgomery, Alabama for tritium analysis using the direct counting liquid scintillation method. The samples were counted in a low background chamber. The results of these post-operational measurements are presented in Table VII. Pre-operational measurements are presented in Table VIII. ------- -24- TABLE VII POST-OPERATIONAL TRITIUM IN WATER LOCATION Foxbird Island Eaton Farm Bailey Farm Long Ledge Creek (Young's Creek) Chewonki Neck (Camp) Cowseagan Narrows Bluff Head DATE COLLECTED 8/15/74 8/15/74 8/15/74 8/15/74 8/15/74 8/15/74 8/15/74 TYPE estuarine well well surface well estuarine estuarine ACTIVITY nCi/l±2a 0.2 ± 0.2 <0.2 0.2 ± 0.2 0.3 ± 0.2 0.2 ± 0.2 < 0.2 < 0.2 INTERPRETED RESULT at m.d.l . below m.d.l . at m.d.l . above m.d.l . at m.d.l . below m.d.l . below m.d.l . The minimum detectable level (m.d.l.) for the analysis of tritium is 0.2 nCi/1. ------- -25- TABLE VIII PRE-OPERATIONAL TRITIUM IN WATER LOCATION Foxbird Island Eaton Farm Bailey Farm Young's Creek Chewonki Neck(Camp) Cowseagan Narrows Bluff Head DATE COLLECTED 6/13/72 6/13/72 6/13/72 6/13/72 6/13/72 6/13/72 6/13/72 TYPE estuarine well well surface well estuarine estuarine ACTIVITY nCi/l±2a 0.39 ± 0.2 0.40 ± 0.2 0.34 ± 0.2 0.14 ± 0.2 0.30 ± 0.2 0.09 ± 0.2 0.40 ± 0.2 INTERPRETED RESULT zero zero zero zero zero zero zero ------- -26- TABLE IX POST-OPERATIONAL TRITIUM IN AIR MOISTURE LOCATION Eaton Farm Bailey Farm Westport Fi rehouse DATE COLLECTED 8/27/74 8/27/74 8/27/74 WATER QUALITY MEASURED 32.8 ml 33.0 ml 25.4 ml AIR VOLUME 1280 1 1990 1 1730 1 MEASURED RESULTS ±2o nCi/1 WATER < 0.2 < 0.2 < 0.2 INTERPRETED RESULTS nCi/1 zero zero zero TABLE X PRE-OPERATIONAL TRITIUM IN AIR MOISTURE LOCATION Eaton Farm Bailey Farm Westport Fi rehouse DATE COLLECTED 6/29/72 6/15/72 6/27/72 WATER QUALITY MEASURED 33.7 ml 33,1 ml 33.4 ml AIR VOLUME 2502.7 1 2000.0 1 2500.0 1 MEASURED RESULTS ±2a nCi/1 WATER 0.60 ± 0.2 19.1 ± 0.2 0.60 ± 0.2 INTERPRETED RESULTS nCi/1 0.6 19.1 0.6 ------- -27- TABLE XI POST-OPERATIONAL TRITIUM IN PRECIPITATION LOCATION Eaton Farm Bailey Farm Knight Cemetery DATE COLLECTED 8/27/74 8/27/74 4/9/74 TYPE RAIN RAIN SNOW MEASURED RESULTS nCi/l±2a < 0.2 0.3 ± 0.2 < 0.2 INTERPRETED RESULTS nCi/1 zero 0.3 zero TABLE XII PRE-OPERATIONAL TRITIUM IN PRECIPITATION LOCATION Eaton Farm Bailey Farm Knight Cemetery Westport Fi rehouse DATE COLLECTED 6/30/72 6/30/72 3/11/72 3/11/72 TYPE RAIN RAIN SNOW SNOW MEASURED RESULTS nCi/U2a 0.40 ± 0.2 1.10 ± 0.2 0.26 ± 0.2 0.17 ± 0.2 INTERPRETED RESULTS nCi/1 zero 1.1 zero zero ------- -28- 2.232 Tritium in the Air Moisture Tritium in the air moisture was measured in samples collected at the following three sites, Eaton Farm, 0.4 km, W.; Bailey Farm, 0.8 km, N.E.; and Westport Firehouse, 1.8 km, S. Air moisture samples were collected by drawing nominally 2000 liters of air through a plastic cylinder (8 cm (14 } diameter by 24 cm long) containing a desiccantv ' . The desiccant used was indicator type Dryrite. The cylinder of desiccant was weighed before the air was pulled through and weighed afterward to insure the collection of between twenty and thirty milliliters of air moisture. Nominal collection time was between two and four hours depending on the relative humidity. The desiccant cylinders were sealed and sent to the Eastern Environmental Radiation Facility in Montgomery, Alabama for tritium analysis. Water was exchanged with the desiccant moisture in a closed system. The resulting samples were processed for liquid scintillation tritium analysis in the usual way. The results of these measurements indicate the level for tritium in the air moisture was below the minimum detectable level of 0.2 nCi/1 at all locations sampled on the data sampled (8/27/74). 2.233 Tritium in Precipitation Tritium in precipitation was measured in two snow samples collected at Knight Cemetery, l.l km, E. on April 9, 1974 and rain samples collected at Eaton Farm, 0.4 km, W. and Bailey Farm, 0.8 km, N.E. on August 27, 1974. These samples were filtered in the same manner used for the water samples. (See section 2.22) Fifty mi 11iliter samples were sent to the Eastern Environmental Radiation Facility, Montgomery, Alabama for tritium analysis using the liquid scintillation method. (See section 2.231) The results ------- -29- of the analysis of tritium activity in the rain at Eaton Farm showed it to be below the minimum detectable level of 0.2 nCi/liter and the level at Bailey Farm to be 0.3 ± 0.2 nCi/liter, greater than the minimum detectable level. Tritium activity in the snow samples was below the minimum detectable level. 2.24 Discussion of Tritium Measurements The purpose of tritium measurements in this study is to document typical values for the HTO component in water, air moisture and precipitation In general the results of tritium analysis indicate no significant change. There is no evidence of an accumulation of tritium in the interchangeable environmental reservoirs such as wells, surface water or the Montsweag Bay (2) estuary. Even though the Maine Yankee Environmental Impact Statement^ lists a bioaccumulation factor of 1 for tritium, the authors feel that in light of the fact that tritium is one of the major radionuclide in the liquid and gaseous effluent, that tritium monitoring should be carried out on a regularly scheduled basis for a period of one half life (12.5 years) in order to check for possible long term accumulation. The only significant correlation between the pre-operational survey for tritium and the post-operational survey is that the rain samples at the Bailey Farm location contain tritium above the minimum detectable level. The large amount of tritium in the air moisture observed on 6/15/72 in the pre- operational survey was not observed in the post-operational study. ------- -30- 2.3 Radionuclides in Air Particulates 2.31 Field Air Particulate Measurements and Analysis Radionuclides in air participates were measured at three sites: Eaton Farm, Bailey Farm and Westport Firehouse. A Staplex large volume air sampler was used in conjunction with a 20.5 cm (8 1/16 inch) by 25.4 cm (10 inch) filter holder. Nuclear Associates, Inc. fiberglass 3 filters number 08-780 were used. Approximately 3400 ft of air were filtered at each site. The filter was folded three times (8 layers) and placed on the circular surface of the Nal(Tl) detector assemble used for the soil and sediment field measurements, and covered with a 3 cm lead shield. All air particulate field data were counted as soon after collection as possible (normally within a few minutes) on quarter memory (512 channels) for 2000 seconds. The multichannel analyzer was outputted on the teletype. Qualitative analysis shows that the bulk of the activity was due to daughters of 222Rn and 220Rn. After a period of 24 hours the activity of particulate on the filters was found to be long halflife radon daughters. 2.32 Laboratory Air Particulate Measurements Air particulates for laboratory analysis were also collected at these same sites (Easton Farm, Bailey Farm, Westport Firehouse). A Millipore pump type XX6000000 was used to pull air through a 47 mm diameter Mi Hi pore absolute aerosol 0.8 urn filter, type AAWP4700. The throughput of this system was metered for all runs and a calibrated gas flow meter, American Meter Company Model 10-300-PR1264. The meter, pump, and filter holder were housed in an instrument box with a rubber hose from the filter holder to the outside. A nominal sampling time was 100 hours, with a nominal sampling ------- -31- volume being 200,000 liters. The filters were weighed before and after collection. They were packaged carefully in separate plastic boxes and sent to the Eastern Environmental Radiation Facility; Montgomery, Alabama, for gamma-ray analysis. Each sample was counted for gamma-rays in the 40 ml Nal(Tl) well-counter which is 11 cm x 15 cm and has a 3 cm well. The results of these measurements are given in Table XIII. The gross- alpha measurements were counted in an internal proportional counter and the gross-beta measurements were counted in a low background beta counter. The results of these measurements are also given in Table XIII. The pre-operational measurements are listed in Table XIV. ------- -32- Discussion of the Air Participate Results The short term field air particulate collections and measurements reveal the presence of 220Rn and 222Rn as the most important source of activity, essentially identical to the pre-operational study of 1972. Large volume laboratory air particulate measurements as presented in TABLES XIII and XIV show no significant changes. 2.4 High Pressure Ion Chamber 2.41 High Pressure Ion Chamber Measurements High pressure ion chamber measurements had been carried out in 1971 by Wesley R. Van Pelt of Environmental Analysis, Inc. for Maine Yankee. Due to the relevance for population dose calculations and for comparison with the gamma-ray field studies, high pressure ion chamber measurements were carried out in collaboration with Mr. Charles Phillips of the Eastern Environmental Radiation Facility, Montgomery, Alabama. Both studies employed calibrated Reuter Stokes high pressure ion chambers. In the present study the ion chamber was RSS-111 (Reuter Stokes environmental monitor), with Rustrak Recorder. The monitor was placed 1 meter above the surface at 11 soil sites and 2 sediment sites. The soil sites were Foxbird Island, 0.1 km, S.; Eaton Farm, 0.4 km, W.; Bailey Farm, 0.8 km, N.E.; Young's Creek, 1.0 km, N.; Knight Cemetery, 1.1 km, E.; Westport Firehouse, 1.8 km, S.; Chewonki Neck (Camp) 1.9 km, S.W.; Cowseagan Narrows, 3.2 km, N.E.; Bluff Head, 4.0, S.S.W.; Cromwells 1.0 km, E.; and sediment sites Foxbird Island, 0,1 km, S.; and Murphy's Corner, 2.8 km, S.W.. The results of these measurements are shown in Table XV. Table XV lists high pressure ion chamber measurements of dose rate (yR/hr) for the post-operational and (15) pre-operational surveys. The most significant change occured at the ------- -33- Foxbird Island (sediment) site at 42 percent increase in dose rate was measured. The last column lists post-operational calculated dose rate based upon laboratory measurement of specific activity for all significant gamma emitting radionuclides observed. The method used, due to Beck, is (16) discussed in Appendix C ------- -34- TABLE XIII POST-OPERATIONAL AIR PARTICULATE ANALYSIS .OCATION Bailey Farm Eaton Farm Westport Fi rehouse COLLECTION DATE 8/19/74 8/22/74 8/27/74 AIR VOLUME LITERS 166,230 197,350 191,960 PARTICULATE MASS (GRAMS) 0.016 ± 0.001 0.004 ± 0.001 0.005 ± 0.001 a-ACTIVITY pCi/FILTER ±2a 5.3 ± 68% 6.0 ± 70% 7.7 ± 55% 8- ACTIVITY pCi/FILTER ±2a 29.3 ± 73% 25.4 ± 10% 4.4 ± 11% Y-ACTIVITY pCi/FILTER ±2o 34 ± 37% (7Be) 4 ± 18% (95ZrNb) NONE TABLE XIV PRE-OPERATIONAL AIR PARTICULATE ANALYSIS .OCATION Bailey Farm Eaton Farm Westport Fi rehouse COLLECTION DATE 6/19/72 7/5/72 6/29/72 AIR VOLUME LITERS 97,740 86,730 101,810 PARTICULATE MASS (GRAMS) 0.002 ± 0.001 0.001 ± 0.001 0.004 ± 0.001 Y-ACTIVITY ZrNb <15 pCi ZrNb < 5 pCi <15 pCi Y-ACTIVITY (7Be) <200 pCi < 50 pCi <200 pCi ------- TABLE XV COMBINED PRE-OPERATIONAL AND POST-OPERATIONAL HIGH PRESSURE ION CHAMBER MEASUREMENTS SITE NAME (measured over soil unless otherwise noted) Foxbird Island Eaton Farm Bailey Farm Young's Creek Knight Cemetery Westport Fi rehouse Chewonki Neck Camp Cowseagan Narrows Bluff Head Foxbird Island (sediment) Murphy's Corner (sediment) Cromwells POST-OPERATIONAL MEASUREMENTS DATE 8/24/74 8/22/74 8/22/74 8/22/74 8/22/74 8/22/74 8/22/74 8/22/74 8/22/74 8/24/74 8/22/74 8/22/74 POST-OPERATIONAL DOSE RATE uR/hr 10.1 10.2 9.7 9.7 11.2 9.5 9.9 10.2 10.8 12.6 8.9 9.1 PRE-OPERATIONAL MEASUREMENTS DATE - 9/20/71 9/20/71 - - 9/21/71 - - - 9/21/71 9/21/71 - PRE-OPERATIONAL DOSE RATE pR/h'r - 9.5 9.5 - - 11.4 - - - 7.3 7.91 - POST-OPERATIONAL CALCULATED DOSE RATE (pR/hr) 8.9 12.0 12.0 11.7 13.0 9.6 10.2 10.9 12.3 14.51 10.8 - ------- -36- APPENDIX A LIQUID EFFLUENT INVENTORY IN CURIES TABLE XVI 140BaLa 133! 131! 133Xe 135Xe 137Cs 13-,Cs 60Co 58Co 5ICr 5"Mn 103Ru 9°Sr "Mo 95Zr 95Nb 59 Fe 97Zr UN i33mXe "Co 89Sr 3H JULY-DEC 72 NDA NDA 4.12 x 10"3 1.49 x 10"3 NDA NDA NDA 2.04 x 10"4 5.48 x 10"3 NDA 8.06 x 10"4 NDA LOST 1.5 x 10"5 - - 1.5 x 10"5 1.34 x 10"3 - 9.22 JAN-JUNE 73 NDA NDA 1.62 x 10"3 7.05 x 10"2 NDA NDA NDA 3.34 x 10"3 6.56 x 10'2 2.68 x 10"2 1.12 x 10~2 NDA NDA NDA 3.1 x 10"3 2.9 x 10"3 5.95 x 10"3 - - - - 75.67 JULY-DEC 73 NDA NDA 4.12 x 10"3 1.49 x 10"3 NDA NDA NDA 2.04 x 10"4 5.48 x 10"3 NDA 8.06 x 10'4 NDA LOST 1.50 x 10"5 . 1.5 x 10"5 - - - - 771. 9 JAN-JUNE 74 6.09 x 10"5 2.93 x 10"3 2.76 x 10"1 11.7 7.78 x 10"3 6.15 x 10"3 2.53 x 10~3 5.41 x 10"3 2.17 x 10~2 3.78 x 10~2 1.99 x 10"3 NDA 1.40 x 10"5 2.30 x 10"3 1.54 x 10"3 2.62 x 10"3 _ - 6.48 x 10"5 9.38 x 10"6 - 115 JULY-DEC 74 NDA 8.20 x 10"2 1.04 x 10~2 NDA 9.81 x Kf1 7.31 x 10"1 1.46 x 10"2 2.60 x 10"1 _ NDA - NDA _ _ 1.19 x 10"3 _ - - NDA 2.94 x 10"5 104 6.09 x 10"& 2.93 x 10"3 0.37 11.78 7.78 x 10"3 9.9 x 10"1 7.3 x 10"1 2.3 x 10"2 3.58 x 10"1 4.04 x 10"1 1.48 x 10"2 NDA 1.40 x 10"5 2.33 x 10"3 4.64 x 10"3 5.52 x 10"3 7.14 x 10"3 3.0 x 10'5 1.34 x 10"3 6.48 x 10"5 9.38 x 10"6 2.94 x 10"5 3.81 x 102 ------- -37- TABLE XVI GASEOUS EFFLUENT INVENTORY IN CURIES 137Cs 140BaLa 90Sr 13l)Cs 89Sr 58Co 6°Co 5l*Mrr 110Ag "Co "Mo 131! 133! 135! 85Kr 133Xe 88 Kr 87 Kr 138Xe 35mXe 41 Ar 33mXe 3imXe 88 Rb 85mKr i35Xe 51Cr 95Nb OCT-DEC 72 NDA NDA NDA NDA _ - - 1.71 x 10"6 NDA NDA 2.05 NDA NDA NDA NDA NDA 7.1 x 10"2 - - NDA _ _ - JAN-JUNE 73 NDA NDA NDA NDA 3.9 x 10"6 - - - - 9.39 x 10"6 NDA NDA 6.3 x 10"3 6.36 NDA NDA NDA NDA NDA - 8.9 x 10"2 NDA NDA _ - JULY-DEC 73 NUA NDA NDA NDA 8.91 x 10"5 - - - - 1.62 x 10"3 3.28 x 10'4 NDA 1.505 151.56 NDA NDA NDA NDA 1.00 x 10'1 - NDA - NDA 1.27 x 10"1 - - JAN-JUNE 74 3.51 x 10"5 NDA 1.37 x 10"5 2.3 x 10"5 5.1 x 10"6 2.2 x 10"8 2.9 x 10"6 6.58 x 10'2 3.00 x 10"2 5.79 x 10"3 3.50 x 102 3.81 x 103 NDA NDA NDA NDA NDA 4.91 x 101 NOA NDA 1.90 x 102 8.4 x 10"6 1.78 x 10'6 JULY-DEC 74 NDA NDA _ NDA 3.32 x 10"4 1.72 x 10"4 NDA NDA 2.10 x 10"5 2.90 x 10"6 4.98 x 10"2 1.48 x 10"3 NDA 4.36 x 102 2.41 x 103 NDA NDA NDA NDA NDA 3.30 7.78 x 101 NDA B.50 x 10"1 - - ------- -38- APPENDIX B PRE-SCAN RESULTS The purpose of a pre-scan is to determine the optimum locations for the field studies. For this reason, the pre-scan was planned to take place early in the field studies and to provide usable results during the first week of the study. As is mentioned in section 2.11 of off-site soil measurements and their analysis, gamma-ray pre-scans were taken on kilogram samples from nine soil and two sediment sites. Samples were counted for 5000 seconds using the University of Maine Department of Physics Ge(Li) detector with low background shield. The lists of counts were then compared with lists of counts taken on pre-operational samples, collected in 1972. The examination of these lists provided the information for choosing the field locations. Later, punched tapes of these spectra were analyzed at the University of Maine Computer Center. The results of these analysis are shown in Table XVIII. Radionuclide concentrations are shown in picocuries per kilogram of sample. The first five columns of this table contain concentrations of natural isotopes: 228Ac, 208T1 of the Thorium series, 214Pb, 214Bi of the Urnaium series, and 1+0K. The remaining columns of concentrations are of man-made fallout or reactor origin. Trace amounts of 46Sc or 65Zn were observed at Foxbird Island, Eaton Farm, Bailey Farm, Young's Creek, Knight Cemetery, Bluff Head, and Murphy's Corner, but could not be quantitatively determined due to interference from 21l+Bi. The radionuclides 95Nb-95Zr (200 pCi/kg) were observed at Foxbird Island, Bailey Farm, Young's Creek, Knight Cemetery, Westport Firehouse, Bluff Head, Murphy's Corner and Foxbird Island sediment, and 131I (300 pCi/kg) may have been observed in Murphy's Corner sediment. Errors are quoted under each number and represent ±lo. The site which showed largest amounts of man-made radionuclides was ------- -39- Foxbird Island (sediment). There was on archival pre-scan result for this sample and Murphy's Corner sediment since there were no archival samples. In all other cases, pre-operational and post-operation samples were available and results are given in pairs in the table. Dashes in the table mean that results were below the minimum detectable limit. As a result of studying the pre-scan results (using the original lists) we selected for field studies: Foxbird Island soil and sediment, Eaton Farm, Bailey Farm, Knight Cemetery, soils and Murphy's Corner sediment. ------- TABLE XVIII PRE-SCAN RADIONUCLIDES pCi/kg ± lo LOCATION Foxbird Island Eaton Farm Bailey Farm Young's Creek Knight Cemetery Westport Firehouse Chewonki Neck Camp Cowseagan Narrows Bluff Head Murphy Corner Foxbird Island DATE OF COLLECTION 6/29/72 8/14/74 6/12/72 8/14/74 6/12/72 8/14/74 6/12/72 8/14/74 6/12/72 8/14/74 6/12/72 8/14/74 6/12/72 8/14/74 6/13/72 8/14/74 6/12/72 8/14/74 8/14/74 8/14/74 DATE OF MEASUREMENT 8/15/73 8/17/74 8/14/73 8/19/74 8/14/73 8/17/74 8/16/73 8/19/74 9/21/73 8/17/74 8/17/73 8/19/74 9/19/73 8/20/74 8/17/73 8/19/74 8/21/73 8/17/74 8/20/74 8/20/74 TYPE soil soil soil soil soil soil tidal marsh soil tidal marsh soil soil soil soil soil soil soil soil soil soil Sed. Sed. 228Ac 600 ±400 600 ±400 1100 ±200 1300 ±300 1400 ±300 700 ±200 1200 ±200 1400 ±300 2400 ±400 1700 ±500 1100 ±200 400 ±200 1300 ±300 600 ±200 700 ±300 1000 ±200 1900 ±300 1300 ±300 1100 ±200 600 ±100 208T1 600 ±200 1400 ±200 1200 ±200 1600 ±200 700 ±200 1400 ±200 1800 ±300 1600 ±200 1400 ±200 800 ±200 1100 ±200 1300 ±300 700 ±200 900 ±300 1100 ±200 1100 ±200 1500 ±200 1100 ±200 1400 ±300 2mpb 1000 ±100 700 ±500 1100 ±200 1400 ±200 2000 ±200 1000 ±100 1600 ±200 1000 ±100 1600 ±200 1400 ±200 1700 ±200 1200 ±200 1500 ±200 800 ±100 1600 ±200 1700 ±200 2000 ±200 1300 ±200 1300 ±200 ±37°0°0 21"Bi 700 ±200 700 ±200 900 ' ±100 800 ±200 900 ±100 800 ±100 800 ±100 800 ±200 1400 ±300 1100 ±200 1000 ±100 700 ±200 1200 ±200 600 ±200 800 ±200 700 ±100 1600 ±200 1100 ±200 1000 ±200 2000 ±200 4°K 11000 ±1000 10000 ±1000 15000 ±1200 15000 ±1200 17000 ±1400 15000 ±1200 18000 ±1100 14000 ±1300 13000 ±1400 10000 ±1200 10000 ±900 11000 ±1300 16000 ±1400 10000 ±1200 17000 ±1700 10000 ±1000 12000 ±1100 12000 ±1100 12000 ±1000 8000 ±900 137Cs 800 ±100 5400 ±400 1900 ±100 1900 ±100 1300 ±100 1800 ±100 500 ±100 800 ±100 6200 ±300 3600 ±200 1300 ±100 2200 ±200 5000 ±300 1700 ±100 4000 ±200 2500 ±200 1800 ±200 400 ±200 910 ±100 58Co - - - 80 ±50 - 50 ±50 - 120 ±64 80 ±50 100 ±40 19000 ±400 60,, Co 60 ±30 - - - 70 ±50 60 ±50 40 ±50 30 ±20 160 ±70 90 ±44 40 ±50 30 ±50 : 20 ±30 ±8l88 u,cs 200 ±60 600 ±80 4dO ±70 200 ±60 300 ±60 100 ±100 300 ±60 300 ±60 600 ±80 300 ±60 300 ±60 100 ±30 300 ±60 200 ±60 81 ±20 100 ±30 400 ±70 400 ±70 1000 ±80 5"Mn - 20 ±30 - - - - - 25 ±30 20 ±30 - 200 ±60 o I ------- -41- APPENDIX C Calculation of Dose Rate at One Meter from Gamma-Ray Emitting Soils and Sediments Calculation of gamma-ray dose rate due to a plane source such as soil or sediment is of practical importance. The factors for conversion from the isotope concentration of the plane medium to dose at one meter above the surface for 40K, 137Cs, 60Co, 232Th-series and 238U-series are found in a paper due to Beclo1 '17). Two new factors, using Beck's Table 7 and branching ratios from the literature, are calculated for 58Co and 134Cs. These eight factors are presented in Table XIX. Dose Calculations for eleven sites are presented in Table XV. The cosmic ray contribution is included using ionization chamber data gathered by W. Van Pelt^15' over water in 1971. ------- -42- TABLE XIX Factors for Computation of Dose Rate at 1 Meter due to Gamma-Ray Emitting Radionuclides in Soil and Sediment Isotope Natural / Man Made 40K 238U-Series 232Th-Series 137Cs 58Co 60Co 54Mn 131tCs Factor (yR/h per pCi/g) 0.179 1.82 2.82 (pR/h per mCi/km ) X10"3 4.29 7.25 18.0 6.3 11.4 ------- -43- TABLE XX POST-OPERATIONAL LABORATORY RESULTS USED IN CALCULATION OF DOSE RATE (uR/h) 1 METER ABOVE GROUND LOCATION Foxblrd Island (soil) Eaton ' s Farm (soil) Bailey's Farm Young's Creek (soil) Knight Cemetery (soil) Westport Fi rehouse (soil) Chewonki Neck (Camp) (So'il) Cowseagan Narrows (soil) Bluff Head (soil) Foxbird Island (sed.) Murphy's Corner (sed.) "°K 1.30 3.14 3.15 3.47 2.02 2.11 2.70 2.55 2.38 3.67 3.22 238U-series 1.24 2.00 2.00 1.45 2.36 1.45 1.27 1.82 2.91 1.64 1.45 232Th--series 2.53 3.10 3.10 3.10 4.79 2.25 2.53 2.82 3.38 2.54 2.53 137Cs .22 .12 .05 .03 .19 .15 .07 .06 .06 .06 .02 TOTAL GAMMA-RAY DOSE RATE 5.29 8.36 8.30 8.05 9.36 5.96 6.57 7.25 8.73 7.91 7.20 COSMIC RAY* 3.60 3.60 3.60 3.60 3.60 3.60 3.60 3.60 3.60 3.60 3.60 GRAND TOTAL1" 8,89 11.96 11.90 11.65 12.96 9.56 10.17 10.85 12.33 14.45 10.80 *Taken over water in 1971 by W. Van Pelt Deluding 13ltCs, 58Co, 60Co and 5l+Mn (2.93yR/h) ------- -44- APPENDIX D A Model for Radionuclides in Oysters and Associated Sediments* INTRODUCTION The variation of the concentration of gamma-ray emitting radionuclides has been observed and modeled in a stable population of American oysters (C. virginica), and associated estuarine sediments during 12 months at four sites in the Montsweag Estuary in the effluent of the Maine Yankee Nuclear Power Reactor and at a control site in the Damariscotta Estuary. Gamma- ray peaks have been observed at 0.810 MeV (58Co), 1.173 and 1.332 MeV (60Co), 1.732 (40K), 0.835 MeV (54Mn), 0.765 MeV (95Nb), 0.238 MeV (212Pb), and 0.662 MeV (137Cs) using a Ge(Li) detector. The concentration of the most abundant man-made isotopes 58Co, 60Co, and 54Mn have been compared at selected sites with a mathematical model for the accumulation and loss of these nuclides by the oysters and sediments. PREVIOUS WORK Radionuclide accumulation and loss have been studied in oysters by Seymour^18', Jefferies and Preston^19', Naidu and Seymour^20', Nelson and Seymour^ , Wolf^ , Lowman, Rice and Richards^^'; and radionuclide accumulation has been studied in sediments by Heft, Phillips, Ralston, and Steel^ ', Noshkin and Bowen^ ' and Lentsch, et. al.^ ' among others. Models, field studies and laboratory studies of accumulation and depuration have been undertaken for radionuclides in reactor effluent for 137Cs and 60Co in the marine clam, Harrison^ '; 58Co in the mussel, Mytilus edulis, Shimizu et. al.^28' ; Teleost and Elasmobranch fish, Pentreath^29', and for several organisms by Lowman, et. al. . *This work was supported in part by a grant from the National Oceanic and Atmospheric Administration, number 04-3-158-63. ------- -45- Mathematical models for accumulation of radionuclides, are usually based on a constant source of radionuclides, a condition which is generally convenient and applicable for laboratory studies however, must provide for the time variation of the sources of radionuclides since in the case of nuclear reactors the liquid, radionuclide effluents are usually released according to some schedule with waiting periods between releases, as discussed by Heft et.al.^2 '. This variation of source intensity can be included in the mathematical model by driving the first order linear differential equation for accumulation and decay with a time varying function representing the release schedule^1'. This model corresponds mathematically to an impulsively driven relaxator with characteristic relaxation times for the various mechansims of accumulation and decay. EXPERIMENTAL DESIGN Five groups of American oysters were grown: 4 Montsweag Estuary locations (intake of the reactor SI, outflow of the reactor S2, upper cove S3 and 0.58 km, N., Long Ledge S4, 1.29 km. S.) and at a control site located on the Damariscotta Estuary S5. At approximately two month intervals, the live oysters were removed from their trays, and transported to the Ge(Li) detector enclosed in a low background shield. Approximately 1 liter of live oysters were counted for 5000 seconds and the resulting data were (8) computer processed using the Compton continuum subtraction method . After counting, the oysters were returned to their original locations. The concentrations of radionuclides were determined using standard techniques to calibrate the multichannel analyzer-detector-shield system. ------- -46- Seven sediment sites were chosen (intake sediment Ml, outflow M2, Upper cove M3, Long Ledge M4, Murphy Corner, M5, 2.98 km S.W., Oak Island M6, 2.90 km S.W., and Bluff Head M7, 4.39 km S.W.) At approximately two month intervals, 2 Kg sediment samples were collected at each of the sites and gamma-ray analyzed in the same manner as the oysters. THEORY The uptake of radionuclides may be described by a first order linear differential equation dN where -rr is the rate of increase in atoms of nuclide N, AN is the rate of dt loss due to radioactive decay, and R(t) is the rate of introduction of nuclides from an external source (i.e. the nuclear reactor release schedule) Depuration is included by writing a term XpN which describes the ("Biological Decay") observed experimentally by Seymour^ '. -+ AN + ApN = R(t). 2) The solution to Eq. 1 may be written N = e"U\ eUR(t) dt + ce"Xt. 3) We assume that releases of nuclides are made on a sequence of m times, {t., tp, t_, .......... t } and the amount of nuclide released is given by a function f(t) which for times greater than or equal to t, but less than t? is given by f 6(t-tJ, and for times greater than or equal to t? but less than t,. by f,<5(t-t,J and so on up to times greater than .t . The fraction o L. C- rn of the nuclide which was released and is retained is given by U, so that for the accumulation N(t) ------- -47- N(t) = e-At C Ve extf (t_ } + J ! ! o e-At (JV eAtV(t-tJ U d t + c e~ t. 5) If U. is a constant ratio of retention for all time, we can construct a table of functions for the times between the release time. o < t < t1 N(t) = ce"At t, < t < t, N(t) = Uf^-^*-*^ + ce'At t2 < t < t3 N(t) = Uf2e'A(t-t2) + U^e'^-V + ce'At These equations may be interpreted as a gradual decay of isotopes from the release-time until the next release-time. Sudden increases occur at each release-time. Graphs of two typical cases are shown in Fig. 5, which shows the results for a half life (58Co) comparable to two release intervals, as well as a half life (50Co) comparable to 60 release intervals. OYSTER RESULTS The concentration expressed in pCi of the radionuclide 58Co is shown per gram of oysters in Fig. 6. The broken lines represent the experimental values for this isotope in the four Montsweag Estuary sites and the Damari- scotta Estuary control site from June 73 through July 74. The theoretical results are shown with a solid line from May 73 through June 74. The same peak found in the theory is evident at the outflow, Long Ledge and intake sites and a small increase may be seen in the control site in October. The best agreement occurs (comparison may be made) between the outflow site and the theory. It is evident that the oysters show a faster decrease in activity in Dec. 73 through Feb. 74 than that predicted by theory. This may be ------- -48- 140 n o o UJ CE n o 120- 40- FEB APR JUN AUG OCT DEC FEB TIME IN MONTHS 1973- 1974 APR JUN Figure 5, Calculated Accumulation of 58Co and 60Co as a Function of Time The solid line shows the theoretical accumulation of 58Co in millicuries versus month of year from Feb. 1973 through July, 1973. The dashed line shows the theoretical accumulation of60Co in millicuries versus month of the year from Feb. 1973 through June, 1974. ------- -49- AUG OCT DEC FEB APR AUG OCT DEC FEB APR JUN TIME IN MONTHS (1973-1974) AUG Figure 6. Calculated and Measured Accumulation of 58Co as a Function of Time The upper half shows the radionuclide 58Co in oysters at site SI (intake) triangle and dot-dash, site S2 (outflow) square and dash, site S3 (Upper cove) circle and dot-dash, site S4 (Long Ledge) triangle and dot, SC (control site) hexagon dash-dot-dot, and theoretical curve for outflow site with filled circle and solid line, versus time in montns, for the years 1973-1974. The lower half shows the radionuclides 58Co in sediments at sediments sites Ml (intake) with triangle dash-dat, M2 (outflow) with square dash, M3 (Upper cove) circle dash-dot, M4 (Long ledge) with triangle dot and theoretical curve for outflow site with cricle solid line versus time in months from Aug. 1973-July, 1974; ------- -50- explained as the depuration of isotopes from the oysters during these months. The concentration of the radionuclide 51tMn for the outflow site was found to be practically flat during this time and compare favorably with theory within statistical errors in the measurement. In addition to the 58Co and 54Mn results, small amounts of 60Co are observed in Oct. 73 at the outflow, Jan. 74 at Long Ledge and Oct. 73 and Jan. 74 at Upper Cove. Small amounts of 5ttMn is also observed on July 73, Dec. 73 and Jan. 74 at Long Ledge and Jan. 74 at the control site. The naturally occurring isotope t*°K is observed at all sites for all measurements and its variation is correlated with variation in the salinity. SEDIMENT RESULTS The concentration expressed in pCi of 58Co per gram of sediments is shown in Fig. 6. The broken lines represent the experimental values for this isotope in four Montsweag Estuary sites from Sept. 73 through July 74. The solid line represents the theory for the time from Aug. 73 through June 74. The best comparison can be made fro the outflow site which has the largest concentration and shows a broad peak in the months Sept. 73 through Jan. 74. The decrease of 58Co during Jan - Feb. 74, is more rapid than theory predicts and represents depuration due to loss of radioactivity from the sediments. The other sites had a factor of 10 less isotope than this site, and insufficient data for further conclusions. The radionuclides tt°K, 58Co, 60Co, 54Mn observed in the outflow sediment may be averaged, and compared. These radionuclides are expressed in picocuries/gram of sediment and are averaged for monthly values for the time period Aug. 73 - March 74. The average values in order of decreasing concentration are 40K, 5.7 pCi/gm, 58Co, 4.9 pCi/gm, 60Co, 0.8 pCi/gm, ------- -51- and 54Mn, 0.2 pCi/gm. All of these isotopes have maximum values in the month of Nov. 73. Most of the isotopes show a decrease in the month of Dec. 73 which is correlated with a salinity drop in the estuary. The decreases in both 60Co and 5ttMn may be interpreted as the combined effect of radioactive decay and depuration. The effective depuration rate for the outflow sediment during this time was 150 ± 30 days for 60Co. The depuration rate for the 51+Mn is 180 ± 50 days. The radionuclides 95Nb, 212Pb, 137Cs in the outflow sediment may also be averaged and compared. In order of decreasing concentration, these are 95Nb, 0.8 pCi/gm, 212Pb, 0.4 pCi/gm and 137Cs, 0.2 pCi/gm. These radio- nuclides show a maximum during the month of Nov. 73 for 95Nb and March 74 for the 212Pb and 137Cs. Since the initial values of 212Pb, 137Cs and 95Nb95Zr in soil and sediments measured prior to the plant operations were large, comparison with theory is not attempted for these nuclides. The sediment sites, M5 M6, and M7 showed only lf°K, 212Pb and 137Cs. DETERMINATION OF UPTAKE RATIO U Since theory and experiment seem to agree, it is possible to divide the radionuclide in oysters or sediments (Fig. 6) by the calculated accumulation (Fig. 5) to form an uptake ratio U. The values for U indicate that most of the radioactivity is concentrated in the region of outflow, decreasing rapidly with distance. There is also variation of concentration from radionuclide to radionuclide with 58Co strongest, 60Co weaker and 54Mn weakest for both sediments and oysters. ------- -52- SUMMARY OF APPENDIX D Oysters have been grown in the effluent of a nuclear reactor and have been used in a longitudinal study of radionuclide uptake and depuration The radionuclides 58Co, 60Co and 54Mn have been observed experimentally in the oysters and associated sediments. At selected sites, the variation of radionuclides in both oysters and sediments was found to be in good agreement with predictions of a mathematical model, which incorporates radioactive decay and a time dependent driving source of radionuclides due to the liquid effluent release from the reactor. Values for an average uptake ratio U, are then calculated for selected sites. Maximum values of 58Co of 800 pCi/kg results in an annual dose rate of 0.27 mrem/year; Maximum values of 51tMn of 12 pCi/kg results in an annual dose rate of 0.004 mrem/year. ------- -53- PRE-OPERATIONAL LABORATORY WATER GAMMA-RAY ANALYSIS OF THE DISSOLVED COMPONENT APPENDIX E TABLE XXI LOCATION Foxbird Island Eaton Farm Bailey Farm Young's Creek Chewonki Neck(Camp) Cowseagan Narrows Bluff Head TYPE estuarine well well surface well estuarine estuarine DATE COLLECTED 6/13/72 /13/72 6/13/72 6/13/72 6/13/72 6/13/72 6/13/72 6/13/72 6/13/72 DATE COUNTED 6/22/72 6/22/72 6/22/72 6/29/72 6/22/72 6/22/72 6/27/72 6/22/72 6/22/72 40K gm/l±2a 0.18 ±0.06 <0.10 <0.10 <0.10 <0.10 <0.10 <0.10 0.19 ±0.06 0.16 ±0.06 137Cs pCi/l±2o <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 222Rn pCi/l±2a <4.0 <4.0 81.0 ± 13.0 <4.0 <4.0 98.2 ± 19.2 <4.0 <4.0 <4.0 (All samples were counted for 50 minutes in a 3.5 liter Marinelli beaker geometry) ------- -54- REFERENCES 1. Maine Yankee Atomic Power Company Wiscassett, Maine, "Semi-Annual Report of Release of Radioactive Materials", 1972-1975. 2. Maine Yankee Atomic Power Company, Wiscassett, Maine, "Maine Yankee Environmental Impact Statement", 1974. 3. Kahn, B., "Radionuclides in the Environment at Nuclear Power Stations", AEC Proceedings CONF-710501-P1, 30-36 (1971). 4. Rowe, W. D., U. S. Environmental Protection Agency Office of Radiation Programs, "Environmental Radioactivity Surveillance Guide" ORP/SID 72-2 (1972). 5. Lentsch, J. W., et. al., "Stable Manganese and Manganese-54 Distributions in the Physical and Biological Components of the Hudson River Estuary", in AEC Proceedings Conf-710501-Pl, 752-768 (1971). 6. Hess, C. T., C. W. Smith, H. Kelley, F. C. Rock, "A Radioactive Isotopic Characterization of the Environment Near Wiscassett, Maine: A Pre- Operational Survey in the Vicinity of the Maine Yankee Nuclear Reactor", Rad. Data. Rep. 15_, 39-52 (1974). 7. Hess, C. T., C. W. Smith, "Calibration Method for In-Situ Environmental Radiation Measurements Using Top Shielded 2-n Geometry." Bull. Am. Phys. Soc. Series II, JL8_, 242 (1973). 8. CoveTl, D. F. Anal. Chem. 3l_, 1785 (1959). 9. Schonfeld, E., "Alpha-A Computer Program for the Determination of Radioisotopes by Least Squares Resolution of the Gamma-Ray Spectra", ORNL-3810 (July, 1965). 10. Lerman, A., "Time to Chemical Steady-States in Lakes and Oceans, in: Non-Equilibrium Processes in Natural Water Systems, J. D. Hem. Symp. Chair., Amer. Chem. Soc. Adv. Chem. Ser. 106: 30-76 (1971). 11. Fukai, R., C. N. Murray, "Environmental Behavior of Radiocobalt and Radiosilver Released for Nuclear Power Stations into Aquati.c Systems", IAEA-SM-172/42, 217-241 (1973). 12. Freke, A. M., "A Model for the Approximate Calculation of Safe Rates of Discharge of Radioactive Wastes into Marine Environments", Health Physics 13, 743-758 (1967). 13. Cutshall, N., C. Osterberg, "Radioactive Particle in Sediment from the Columbia River", Sci. 144, 536-537 (1964). 14. Cochran, J. A., D. G. Smith, P. J. Magno, B. Shlein, "An Investigation of Airborne Radioactive Effluent from an Operating Nuclear Fuel Reprocessing Plant". BRH/NERHL 70-3, p. 26, (1970). ------- -55- 15. Van Pelt, W. R., "Environmental Radiation Survey for Maine Yankee Atomic Electric Company", Westboro, Massachusetts, (1971). 16. Beck, H. L., "The Physics of Environmental Gamma Radiation Fields". Second International Symposium on the Natural Radiation Environment, Houston, Texas, (1972). 17. Beck, H. L., J. De Campo, C. Gogolak, "In Situ Ge (Li) and Nal(tl) Gamma-Ray Spectrometry", HASL-258 (1972"T 18. Seymour, A. H., "Accumulation and Loss of Zinc-65 by Oysters in a Natural Environment in Disposal of Radioactive Wastes into Seas, Oceans and Surface Waters", Int. Atomic. Eng. Agency, Vienna 605-619 (1966). 19. Jefferies, D. F., and A. Preston, "Summary of Field Studies in the United Kingdom", in Proc. Seminar on Marine Radioecology, Paris CONF-681225, 67-71 (1969). 20. Naidu, J. R., and A. H. Seymour, "Accumulation of Zinc by Oysters in Willapa Bay, Washington", in Proc. Symp. on Mollusca, II Mar. Biol. Assoc. India, Symp. Ser. 3, p. 463-474 (1969). 21. Nelson, V. A., A. H. Seymour, "Oyster Research with Selected Radio- nuclides a Review of Selected Literature", Proc. Nat. Shellfish Assoc. 62_, 89-94 (1972). 22. Wolf, D. A. "Levels of Stable Zn and 65Zn in Crassostrea virginica from North Carolina", J. Fish, Res. Bd. Canada, 27_, 47=57 (1970). 23. Lowman, F., T. R. Rice, F. A. Richards, "Accumulation and' Re- distriubtion of Radionuclides by Marine Organisms in Radioactivity in the Marine Environment, National Acad. of Sciences, Washington, UTT:(1971). 24. Heft, R. E., W. A. Phillips, H. R. Ralston, W. S. Steel, "Radionuclide Transport Studies in the Humbolt Bay Marine Environment" IAEA-SM-158/26, 595, (1973). 25. Noshkin, V. E., V. T. Bowen, "Concentrations and Distributions of Long-lived Fallout Radionuclides in Open Ocean Sediments in "Radioactive Contamination of the Marine Environment" IAEA, Vianna, (1973). 26. Lentsch, J. W., et. al., Ibid. 27. Harrison, F. L., "Accumulation and Loss of Cobalt and Caesium by the Marine Clam Mia arenaria under Laboratory and Field Conditions" IAEA- SM- 158/28 45TT1973). 28. Shimizu, M., T. Kajihara, I.Suyama, Y. Hiyama, "Uptake of 58Co by Mussel Mytilus edulis, J. Radiat. Res., 12, 17 (1971). ------- -56- 29. Pentreath, R. J., "Roles of Food and Water in the Accumulation of Radionuclides by Marine Telost and Elasmobranch Fish" IAEA-SM-158/26 421 (1973). 30. Lowman, R., T. R. Rice, F- A. Richards, Ibid. GPO 904-363 ------- |