United States Environmental Monitoring EPA 600/R-93/141 Environmental Protection Systems Laboratory January 1992 Agency P .O. Box 93478 Las Vegas NV 89193-3478 Research and Development - _______ EPA Offsite Environmental Monitoring Report: Radiation Monitoring Around United States Nuclear Test Areas Calendar Year 1991 ------- Available to DOE and DOE contractors from the Office of Scientific and Technical Information, P.O. Box 62, Oak ridge, TN 39831; prices available from (615) 576-8401 Available to the public from the National Technical Information Service, U.S. Department of Commerve, 5285 Port Royal Road, Springfield, VA 22161 Price Code: Printed Copy of Microfiche AOl Front and back cover: Community Monitor Station (front) and Whole Body Laboratory (back), Craig A. Tsosle Environmental Monitonng Systems Laboratory-Las Vegas, Nevada ------- Offsite Environmental Monitoring Report: Radiation Monitoring Around United States Nuclear Test Areas, Calendar Year 1991 Contributors: D.J. Chaloud, B.B. Dicey, A.A. Mullen, A.C. Neale, A.R. Sparks, C.A. Fontana, L.D. Carroll, W.G. Phillips, D.D. Smith, D.J. Thome and Nuclear Radiation Assessment Division Prepared for: U.S. Department of Energy under Interagency Agreement Number DE-A108-86-NV10522 ENVIRONMENTAL MONITORING SYSTEMS LABORATORY OFFICE OF RESEARCH AND DEVELOPMENT U.S. ENVIRONMENTAL PROTECTION AGENCY LAS VEGAS, NV 89193-3478 ------- Notice This report has been reviewed in accordance with the U.S. Environmental Protection Agency s peer and administrative review policies and approved for publication. Mention of trade names or commercial products does not constitute endorsement or recommendation for use. II ------- Abstract This report describes the Offsite Radiation Safety Program conducted during 1991 by the Environmental Protection Agency’s (EPA’s) Environmental Monitoring Systems Laboratory-Las Vegas. This laboratory operates an environmental radiation monitoring program in the region surrounding the Nevada Test Site (NTS) and at former test sites in Alaska, Colorado, Mississippi, Nevada, and New Mexico. The surveillance program is designed to measure levels and trends of radioactivity, if present, in the environment surrounding testing areas to ascertain whether current radiation levels and associated doses to the general public are in compliance with existing radiation protection standards. The surveillance program additionally has the responsibility to take action to protect the health and well being of the public in the event of any accidental release of radioactive contaminants. Offsite levels of radiation and radioactivity are assessed by sampling ,water, and air; by deploying thermoluminescent dosimeters (TLDs) and using pressurized ion chambers (PlCs); and by biological monitoring of animals, food crops, and humans. Personnel with mobile monitoring equipment are placed in areas downwind from the test site prior to each nuclear weapons test to implement protective actions, provide immediate radiation monitoring, and obtain environmental samples rapidly after any occurrence of radioactMty release. Comparison of the measurements and sample analysis results with background levels and with appropriate standards and regulations indicated that there was no radioactivity detected offsite by the various EPA monitoring networks and no exposure above natural background to the population living in the vicinity of the NTS that could be attributed to current NTS activities. Annual and long-term (10 year) trends were evaluated in the Noble Gas, Tritium, Milk Surveillance, Biomonitonng, TLD, PlC networks, and the Long- Term Hydrological Monitoring Program. All evaluated data were consistent with previous data history. No radiation directly attributable to current NTS activities was detected in any samples. Monitoring network data indicate the greatest population exposure came from naturally occurring background radiation, which yielded an average exposure of 123 mremfyr. Worldwide fallout accounted for about 0.05 mrernlyr. Calculation of potential dose to off site residents based on onsite source emission measurements provided by the Department of Energy (DOE) resulted in a maximum calculated dose of 0.009 mremlyr. These were insignificant contributors to total exposure as compared to natural background. III ------- Contents Notice Abstract iii Figures ix Tables xi Abbreviations, Acronyms, Units of Measure, and Conversions xii List of Elements xiv Acknowledgements xvi SECTION 1 1 Introduction 1 1.1 Program Description 1 1.2 Report Description 2 SECTION 2 2 Description of the Nevada Test Site 5 2.1 Location 5 2.2 Climate 5 2.3 Hydrology 7 2.4 Land Use Of Nevada Test Site Region 9 2.5 Population Distribution 9 SECTION 3 3 External Ambient Gamma Monitoring 17 3.1 Thermoluminescent Dosimetry Network 17 3.1.1 Design 17 3.1.2 Procedures 19 3.1.3 Results of TLD Monitoring 19 3.1.4 Quality Assurance/Quality Control 22 3.1.5 Data Management 23 3.2 Pressurized Ion Chambers 24 3.2.1 Network Design 24 3.2.2 Procedures 24 3.2.3 Results 26 3.2.4 Quality Assurance/Quality Control 28 3.3 Comparison of TLD Results to PlC Measurements 32 SECTiON 4 4 Atmospheric Monitoring 4.1 Air Surveillance Network 33 4.1.1 Design 33 4.1.2 Procedures 33 4.1.3 Results 36 4.2 Tritium In Atmospheric Moisture ... 43 4.2.1 Design 43 4.2.2 Procedures 43 4.2.3 Results 43 V ------- Contents (continued) 4.3 Noble Gas Sampling Network 45 4.3.1 Design 45 4.3.2 Procedures 46 4.3.3 Results 47 4.4 Quality Assurance/Quality Control 47 SECTION 5 5.0 Foodstuffs 51 5.1 Milk Surveillance Network 51 5.1.1 Design 51 5.1.2 Procedures 53 5.1.3 Results 53 5.1.4 Quality Assurance/Control 55 5.2 Animal Investigation Program 55 5.2.1 Network Design 55 5.2.2 Sample Collection and Analysis Procedures 55 5.2.4 Sample Results for Bighom Sheep 57 5.2.5 Sample Results for Mule Deer 58 5.2.6 Sample Results for Cattle 60 5.2.7 Sample Results for the Mountain Lion 62 5.2.8 Quality Assurance 62 5.3 Fruits And Vegetables Monitoring 63 5.3.1 Network Design 63 5.3.2 Sample Collection and Analysis Procedures 63 5.3.3 Quality Assurance 64 5.3.4 Sample Results 64 SECTION 6 6.0 Internal 6.1 Dosimetry Network Design 67 67 6.2 Procedures 67 6.3 Results 69 6.4 Quality Assurance/Quality Control 70 SECTION 7 7.0 Long-Term Hydrological Monitoring Program 71 7.1 Network Design 71 7.1 .1 Sampling Locations 71 7.1.2 Sampling and Analysis Procedures 72 7.1.3 Quality Assurance/Quality Control Samples 72 7.1.4 Data Management and Analysis 73 7.2 Nevada Test Site Monitoring 73 7.3 Offsite Monitoring In The Vicinity Of The Nevada Test S te 76 7.4 Hydrological Monitoring At Other United States Nuclear Weapons Testing Locations 78 7.4.1 Project FAULTLESS 80 7.4.2 Project SHOAL 80 vi ------- Contents (continued) 7.4.3 Project RULISON 83 7.4.4 Project RIO BLANCO 85 7.4.5 Project GNOME 85 7.4.6 Project GASBUGGY 86 7.4.7 Project DRIBBLE 92 7.4.8 Amchitka Island, Alaska 97 7.5 Summary 97 SECTION 8 8. Dose Assessment 103 8.1 Estimated Dose From Nevada Test Site Activity Data 103 8.2 Estimated Dose From ORSP Monitoring Network Data 103 8.3 Dose from Background Radiation 108 8.4 Summary 108 SECTION 9 9.0 Weapons Test and Liquefied Gaseous Fuels Spills Facility Support 109 9.1 Weapons Tests Support 109 9.2 Liquefied Gaseous Fuels Spills Test Facility Support 110 SECTION 10 10. Public Information and Community Assistance Programs 111 10.1 Community Radiation Monitoring Program 111 10.2 Town Hall Meetings 111 10.3 Nevada Test Site Tours 112 SECTION 11 11 Quality Assurance 113 11.1 Policy 113 11.2 Data Quality Objectives 113 11.2.1 Representativeness, Comparability, and Completeness Objectives 113 11.2.2 Precision and Accuracy Objectives of Radioanalytical Analyses 114 11.2.3 Quality of Exposure Estimates 114 11.3 Data Validation 114 11.4 Quality Assessment Of 1991 Data 116 11.4.1 Completeness 116 11.4.2 Precision 117 11.4.3 Accuracy 121 11.4.4 Comparability 124 11.4.5 Representativeness 125 SECTION 12 12. Sample Analysis Procedures 129 vii ------- Contents ( nu SECTION 13 13. Radiation Protection Standards For External and Internal Exposure 131 13.1 Dose Equivalent Commitment 131 132 Concentration Guides 131 13.3 U.S. Environmental Protection Agency Drinking Water Guide 131 SECTION 14 14 Summary and Conclusions 133 14.1 Thermoluminescent Dosimetry Program 133 142 Pressurized Ion Charther Network 133 14.3 Air Surveillance Network 133 14.4 Tritium In Atmospheric Moisture 133 14.5 Noble Gas Sampling Network 134 14.6 Foodstuffs 134 14.7 Internal Exposure Monitoring 134 14.8 Long-Term Hydrological Monitoring Program 135 References 137 Glossaiyof Terms 141 AppendixA 145 Appendix B 165 AppendtxC 175 Append ixD 197 Appendix E 205 Appendix F 225 vi” ------- Figures Number Page 1. Typical mid-latitude steppe climatological zone in Nevada 5 2. Location of the Nevada Test Site 6 3. Ground water flow systems around the Nevada Test Site 8 4. General land use within 180 miles (300 km) of the Nevada Test Site 10 5. Population of Arizona, California, Nevada, and Utah counties near the Nevada Test Site. .. 11 6. Distribution of family milk cows and goats, by county 13 7. Distribution of dairy cows, by county 14 8. Distribution of beef cattle, by county 15 9. Distribution of sheep, by county 16 10. Locations monitored with thermoluminescent dosimeters 18 11. Typical personnel thermoluminescent dosimeter 19 12. Illustration of a Panasonic UD 710 Dosimeter Reader 20 13. Thermoluminescent Dosimetry exposures at all fixed environmental stations, 1981 - 1991 21 14. Distribution of personnel exposures compared to associated reference background 22 15. Locations of Pressurized Ion Chamber network stations 25 16. Pressurized Ion Chamber Network, including remote automatic weather stations operated by the Bureau of Land Management 26 17. Pressurized ion chamber, gamma-rate recorder remote processor unit, with chart recorder, digital readout, and telemetry antenna with solar panel 27 18. Distribution of weekly averages from the Pressurized Ion Chamber Data. Figure shows minimum, 25th percentile, mean, median, 75th pementile, and maximum values 30 19. Weekly averages from Austin, Nevada, January 1988 to December 1991 31 20. Weekly averages from Twin Springs, Nevada, January 1988 to December 1991 31 21. Comparison of Thermoluminescent Dosimetry Data to Pressurized Ion Chamber Data 32 22. Air Surveillance Network stations, 1991 34 23. Standby Air Surveillance Network stations, 1991 35 24. Distribution of gross beta values from air surveillance network stations, 1989. Figure shows minimum, 25th percentile, mean, median, 75th percentile, and maximum values 38 25. Distribution of gross beta values from air surveillance network stations, 1990. Figure shows minimum, 25th percentile, mean, median, 75th percentile, and maximum values 39 26. Distribution of gross beta values from air surveillance network stations, 1991. Figure shows minimum, 25th percentile, mean, median, 75th percentile, and maximum values 40 27. Distribution of the mean quarterly gross beta averages for seven stations surrounding the NTS 41 28. Distribution of the mean quarterly gross beta averages from standby stations in the midwest region 41 29. Distribution of the mean quarterly gross beta averages from standby stations in the mountain region 42 30. Distribution of the mean quarterly gross beta averages from standby stations in the western region 42 31. Oftsite noble gas and tritium surveillance network sampling locations, 1991 44 32. Distribution of HTO data, 1991. Figure shows minimum, 25th percentile, mean, median, 75th percentile, and maximum values 46 33. Distribution of krypton data from routine sampling stations, 1991. Figure shows minimum, 25th percentile, mean, median, 75th percentile, and maximum values 49 34. Annual network average krypton 85 concentrations 49 ix ------- Figures (continued) Number Page 35. Milk Surveillance Network stations, 1991 52 36. Standby Milk Surveillance Network stations, 1991 54 37. Collection sites for animal samples 56 38. Average Strontium levels in bighom sheep, deer, and cattle, 1956 - 1991 59 39. Location of families in the Ottsite Internal Dosimetry Program 68 40. Long-Term Hydrological Monitoring Program sampling locations on the Nevada Test Site. .. 75 41. Tritium results ± standard deviation for Nevada Test Site Test Well B, January 1976 through December 1991 76 42. Long-Term Hydrological Monitoring Program sampling locations near the Nevada Test Site. 77 43. Tritium results ± 1 standard deviation for Specie Springs, January 1972 through December 1991 78 44. Tritium results ± 1 standard deviation for Adaven Springs, January 1975 through December 1991 79 45. Tritium results ± 1 standard deviation for Lake Mead Intake, January 1982 through December 1991 79 46. Long-Term Hydrological Monitoring Program sampling locations for Project FAULTLESS. .. 81 47. Long-Term Hydrological Monitoring Program sampling locations for Project SHOAL 82 48. Tritium results ± 1 standard deviation for Smith/James Spring, January 1986 through December 1991 83 49. Long-Term Hydrological Monitoring Program sampling locations for Project RULISON 84 50. Tritium results ± 1 standard deviation for Lee Hayward Ranch, January 1972 through December 1991 86 51. Long-Term Hydrological Monitoring Program sampling locations for Project RIO BLANCO. . 87 52a. Tritium results for Fawn Creek - 6800 ft upstream of surface ground zero, January 1976 through December 1991 88 52b. Tritium results for Fawn Creek - 500 ft downstream of surface ground zero, January 1976 through December 1991 88 53. Long-Term Hydrological Monitoring Program Sampling Locations for Project GNOME 89 54a. Tritium results plotted with normal tritium decay curve for Gnome Well DD-1, January 1980 through December 1991 90 54b. Tritium results ± 1 standard deviation plotted with normal tritium decay curve for Gnome Well LRL-7, January 1980 through December 1991 90 54c. Tritium results plotted with normal tritium decay curve for Gnome USGS Well 4, January 1972 through December 1991 91 544 Tritium results plotted with normal tritium decay curve for Gnome USGS Well 8, January 1972 through December 1991 91 55. Long-Term Hydrological monitoring Program sampling locations for Project GASBUGGY. .. 93 56. Tritium results for Gasbuggy Well EPNG 10-36, January 1972 through December 1991. ... 94 57. Long-Term Hydrological Monitoring Program sampling locations for Project DRIBBLE-near ground zero 95 58. Long-Term Hydrological Monitoring Program sampling locations for Project DRIBBLE-towns and residences 96 59. Amchitka Island and Background sampling location for the Long-Term Hydrological Monitoring Program 98 60. Long-Term Hydrological Monitoring Program sampling locations for Projects MILROW and LONGSHOT 99 61. Long-Term Hydrological Monitoring Program sampling locations for Project CANNIKIN. ... 100 62. Precision results for conventional method tritium in water 119 63. Precision results for enriched method tritium in water 119 64. Precision results for beta in air 120 65. Precision results for 23 °Pu in air 120 66. Precision results for Kr in noble gas 121 x ------- Tables 1. Characteristics of Climatic Types in Nevada (from Houghton et al. 1975) 7 2. Weeks for which there were no Pressurized Ion Chamber Data collected for given stations .. 28 3. Summary of weekly Gamma Exposure Rates as measured by Pressurized Ion Chambers, 1991 29 4. Gross Beta results for the Air Surveillance Network, 1991 37 5. Atmospheric Tritium Results, 1991 45 6. Noble Gas Sampling Network - Kr and 1 Xe Results, 1991 48 7. Summary of Radionuclides Detected in Milk Samples 53 8. Radioriuclide Concentrations in Desert Bighom Sheep Samples taken in Winter 1990 58 9. Summarized Radiochemical Results for animal Samples, 1991 61 10. Detectable Plutonium Concentrations in Vegetables, 1991 64 11. Inoperative and Closed LTHMP Wells 74 12. NTS Radionuclide Emissions, 1991 104 13. Summary of Committed Effective Dose Equivalents from NTS Operations during 1991 .... 105 14. Concentrations from Monitoring Networks, 1991 106 15. Dose Calculations from the Monitoring Networks 107 16. Data Completeness of Offsite Radiological Safety Program Networks 117 17. Overall Precision of Analysis 122 18. Accuracy of Analysis from EPA lntercompatison Studies 123 19. Accuracy of Analysis from DOE Intemomparison Study 125 20. Comparability of Analysis from EPA Intercomparison Studies 126 21. Summary of Analytical Procedures 129 22. Routine Monitoring Guides 132 xi ------- Abbreviations, Acronyms, Units of Measure, and Conversions ABBREVIATIONS and ACRONYMS — As Low as Reasonably Achievable — Annual Limit on Intake — Air Surveillance Network — American National Standards Institute — Bureau of Land Management — Bottle Mannequin Absorber -- Committed Effective Dose Equivalent — Code of Federal Regulations — Concentration Gukle — Community Monitoring Station — Control Point One — Derived Air Concentration U.S. Department of Energy Department of Energy, Laboratory Accreditation Program -- data quality objective — Desert Research Institute -- Environmental Monitoring Laboratory — Environmental Monitoring Systems Laboratory, Las Vegas — U.S. Environmental Protection Agency — Food and Drug Administration — lithium-drifted germanium detector — Geostationary Operational Environmental Satellite — tritiated water — International Commission on Radiological Protection — intrinsic germanium -- liter LCL — lower control limit LTHMP — Long-Term Hydrological Monitoring Program LWL -- lower working limit MCD -- minimum detectable concentration -- mean sea level -- Milk Surveillance Network — National Council of Radiation Protection and Measurement NIST -- National Institute of Standards and Technology NGTSN -- Noble Gas and Tntium Surveillance Network NPDWR -- National Primary Drinking -- Water Regulation NTS -- Nevada Test Site NRD -- Nuclear Radiation Assessment DMsion -- Offstte Radiological Safety Program -- pressurized ion chamber -- quality assurance -- Quality Assurance Management Staff -- quality control -- Remote Automatic Weather Station -- reference correction factor -- Science Applications International Corporation -- standard deviation -- Standby Milk Surveillance Network -- standard operating procedure -- sample tracking data management system -- thermoluminescent dosimeter -- upper control limit -- U.S. Geological Survey -- upper working limit ALARA ALl ASN ANSI BLM BOMAB CEDE CFR CG CMS CP-1 DAC DOE DOELAP -- MSL MSN NCRP DQO DRI EML EMSL-LV EPA FDA Ge(Li) GOES HTO ICRP ORSP PlC QA QAMS QC RAWS RCF SAIC S.D. SMSN SOP STDMS TW UCL USGS UWL XII ------- Abbreviations, Acronyms, Units of Measure, and Conversions (continued) UNITS OF MEASURE -- Becquerel, one disintegration per second -- coulomb -- degrees centigrade -- curie -- centimeter, 1/100 meter -- electron volt -- degrees Fahrenheit --gram hour -- one thousand electron volts -- kilogram, 1000 grams - - kilometer, 1000 meters -- liter -- pound -- meter -- one million electron volts -- milligram, i0 3 gram -- minute —— milliliter, 1 0 liter PREFIXES CONVERSIONS -- month -- milliroentgen, 1 0 roentgen -— millirem 1 0 rem -- millisievert 1 if 3 sievert -- picocurie, 1 012 curie -- quarter -- roentgen -- unit of absorbed dose, 100 ergs/g -- dose equivalent, the rad adjusted for biological effect -- sievert, equivalent to 100 rem -- week -- year -- microcurie, 1 0 curie -- microroentgen, 1 06 roentgen -- percent -- plus or minus -- less than -- equals -- approximately equals ji micro = 106 m miNi = k kilo = i0 3 Multiply i Concentrations pCVmL i0 9 jiCilmL 1012 SI Units pC L pCi/m 3 Bq C Ci cm eV 9 hr keV kg km L lb m meV mg mm mL mo mA mrem mSv pCi qtr R rad rem Sv wk yr % + a atto = 10.18 f femto = 1016 p pico = 10.12 n nano = i0 To Obtain rad 102 Gray (Gy=1 Joule/kg) rem 1 -2 Sievert (Sv) pCi 3.7 x 102 Becquerel (Bq) mR/yr 2.6 x i0 ’ Coulomb (0)/kg-yr x l i ’ ------- List of Elements ATOMIC ATOMIC NUMBER SYMBOL NAME NUMBER SYMBOL NAME 1 H hydrogen 47 Ag silver 2 He helium 48 Cd cadmium 3 Li lithium 49 In indium 4 Be beryllium 50 Sn tin 5 B boron 51 Sb antimony 6 C carbon 52 Te tellurium 7 N nitrogen 53 I iodine 8 0 oxygen 54 Xe xenon 9 F fluorine 55 Cs cesium 10 Ne neon 56 Ba barium 11 Na sodium 57 La lanthanum 12 Mg magnesium 58 Ce cerium 13 Al aluminum 59 Pr praseodymium 14 Si silicon 60 Nd neodymium 15 P phosphorus 41 Pm promethium 16 S sulfur 62 Sm samarium 17 CI chlorine 63 Eu europium 18 Ar argon 64 Gd gadolinium 19 K potassium 65 Th terbium 20 Ca calcium 66 Dy dysprosium 21 Sc scandium 67 Ho holmium 22 Ti titanium 68 Er erbium 23 V vanadium 69 Tm thulium 24 Cr chromium 70 Yb ytterbium 25 Mn manganese 71 Lu lutetium 26 Fe iron 72 Hf hafnium 27 Co cobalt 73 Ta tantalum 28 Ni nickel 74 W tungsten 29 Cu copper 75 Re rhenium 30 Zn zinc 76 Os osmium 31 Ga gallium 77 Ir iridium 32 Ge germanium 78 Pt platinum 33 As arsenic 79 Au gold 34 Se selenium 80 Hg mercury 35 Br bromine 81 TI thallium 36 Kr krypton 82 Pb lead 37 Rb rubidium 83 Bi bismuth 38 Sr strontium 84 Po polonium 39 Y yttrium 85 At astatine 40 Zr zirconium 86 Rn radon 41 Nb niobium 87 Fr francium 42 Mo molybdenum 88 Ra radium 43 Tc technetium 89 Ac actinium 44 Ru ruthenium 90 Th thorium 45 Rh rhodium 91 Pa protactinium 46 Pd palladium 92 U uranium xi v ------- List of Elements (continued) ATOMIC NUMBER SYMBOL NAME neptunium plutonium americium curium berkelium californium einsteinium fermium mendelevium nobelium lawrencium 93 94 95 96 97 98 99 100 101 102 103 Np Pu Am Cm Bk Cf ES Fm Md No Lr xv ------- Acknowledgements External peer reviews were provided by N.E. Cooper, Desert Research Institute (Las Vegas, Nevada); J. Chapman, Desert Research Institute (Las Vegas, Nevada); F.H. Au, U.S. Department of Energy, (Las Vegas, Nevada) and V.E. Niemann, U.S. Department of Energy, (Las Vegas, Nevada). Internal reviewers, in addition to the authors, included T.M. Grady, and A.R. Sparks, U.S. Environmental Protection Agency (Las Vegas, Nevada). The contributions of these reviewers in production of this final version of the 1991 annual report are gratefully acknowledged. The authors would like to thank Paul J. Weeden for his advice and assistance in the coordination and preparation of this report. We also want to thank the Field Monitoring Branch for collecting samples, maintaining the equipment, and interlacing with oftsite residents; and the Radioanalysis Branch for analyzing the samples. Appreciation is also extended to P.O. Cobb, U.S. Environmental Protection Agency (Las Vegas, Nevada), for his preparation of graphs, and to T.L. Mouck, U.S. Environmental Protection Agency (Las Vegas, Nevada), for desktop publishing support. xvi ------- 1 Introduction The U.S. Atomic Energy Commission used the Nevada Test Site (NTS), between January 1951 and January 1975, for conducting nuclear weapons tests, nuclear rocket engine development, nuclear medicine studies, and for other nuclear and non- nuclear experiments. Beginning in mid-January 1975, these activities became the responsibility of the U.S. Energy Research and Development Administration. Two years later this organization was merged with other energy-related agencies to form the U.S. Department of Energy (DOE). Atmospheric weapons tests were conducted periodically at the NTS from January 1951 through October 1958, followed by a test moratonum which was in effect until September 1961. Since then all nuclear detonations at the NTS have been con- ducted underground, with the expectation of con- tainment, except the above-ground and shallow underground tests of Operation Sunbeam and in cratering experiments conducted under the Plow- share program between 1962 and 1968. Prior to 1954, an offsite radiation surveillance program was performed by personnel from the Los Alamos Scientific Laboratory and the U.S. Army. Beginning in 1954, and continuing through 1970, this program was conducted by the U.S. Public Health Service (PHS). When the U.S. Environ- mental Protection Agency (EPA) was formed in December 1970, certain radiation responsibilities from several federal agencies were transferred to it, including the Offsite Radiological Safety Program (ORSP) of the PHS. Since 1970, the EPA, Envi- ronmental Monitoring Systems Laboratory-Las Vegas (EMSL-LV) has conducted the ORSP, both in Nevada and at other U.S. nuclear test sites, under interagency agreements (lAGs) with the DOE or its predecessor agencies. Since 1954, the three major objectives of the ORSP have been: Measuring and documenting levels and trends of environmental radiation or radio- active contaminants in the vicinity of atomic testing areas. • Verifying compliance with applicable radiation protection standards, guidelines, and regulations. • Assuring the health and safety of the people living near the NTS. Offsite levels of radiation and radioactivity are assessed by gamma-ray measurements using pressurized ion chambers (PlCs) and thermolumi- nescent dosimeters (TLDs); by sampling air, water, milk, food crops, other vegetation, soil, animals; and by human exposure and biological assay procedures. Before each nuclear test at the NTS, EPA radiation monitoring technicians are stationed in off site areas most likely to be affected by an airborne release of radioactive material. These technicians use trucks equipped with radiation detectors, samplers, and supplies and are directed by two-way radio from the control center at the NTS. 1.1 Program Description The EPA, EMSL-LV, Nuclear Radiation Assess- ment Division (NRD) provides scientific and technical support to the DOE’s nuclear weapons testing program at the NTS and other nuclear testing sites through an lAG. The primary objec- tive of EPA’s activities is protection of the health and safety of the offsite resident population. This objective is accomplished through monitoring and documentation environmental levels of radiation in the areas around the NTS, monitoring of people in the offsite area, calculating committed effective radiation dose to the most potentially exposed of the offsite population, maintaining emergency response capabilities, and fostering community involvement and education in radiation-related issues. Emergency response capabilities are maintained in readiness for each nuclear weapons test conduct- ed at the NTS. Monitoring technicians are de- ployed for each test and senior EPA personnel serve on the Test Controller’s Scientific Advisory Panel. Tests are only conducted when meteoro- logical conditions are such that any release would be carried towards sparsely populated, controllable 1 ------- areas. Should a release occur, EPA monitoring technicians would deploy mobile monitoring instru- ments, assist state and local officials in implement- ing protective actions, and collect samples for prompt analysis. Hours before each test, Weather Service Nuclear Support Office personnel and, if requested, an instrumented aircraft gather meteo- rological data for use by the Test Controllers Advisory Panel in judging the safety of executing the test. A second aircraft carries radiation detec- tors. In the unlikely event of a significant release of radioactivity following a nuclear weapons test, the equipment on the aircraft would enable rapid sampling and analysis of a radioactive cloud. Data gathered by the aircraft are used to assist in deploying field monitoring technicians to downwind areas, to help determine appropriate protective actions, and to perform radiation monitoring and environmental sampling (EPA, 1 988a). The lAG also requires EPA monitoring technicians to conduct monitoring during tests conducted at the Liquefied Gaseous Fuels Spill Test Facility (LGFS- TF) located on the NTS. These spills involve non- radioactive hazardous materials. Environmental radiation levels are continuously monitored and documented through an extensive environmental surveillance program conducted by EPA in the offsite areas surrounding the NTS. This program is an outgrowth of environmental surveillance activities conducted by the PHS before 1970. The original PHS surveillance program, initiated in 1954, was limited to offsite surveillance during testing activities. Since 1954, the program has grown and evolved to its present configuration. Many historical sampling locations have been retained, resulting in a continuous data record of three decades or longer. The ORSP consists of several networks to monitor concentrations of radioactive materials (radioiso- topes) in air, atmospheric moisture, milk, local foodstuffs and surface and groundwater. Ambient radiation levels are continuously monitored at selected locations using PlCs and TLDs. Atmo- spheric monitoring includes air samplers, noble gas samplers, and atmospheric moisture (tritium-in-air) samplers. Milk, wildlife, domestic animals, arid fruits and vegetables are routinely sampled and analyzed. Some residents in the offsite areas participate in TLD and internal dosimetry networks. Groundwater on and in the vicinity of the NTS is monitored in the Long-Term Hydrological Monitor- ing Program (LTHMP); additional monitoring of surface and groundwater is conducted under the LTHMP at sites of previous nuclear weapons tests in Alaska, Colorado, Nevada, New Mexico, and Mississippi. Results obtained from these networks are used to calculate an annual radiation dose to the offsite residents. Another function of the ORSP is to conduct dairy animal and human population censuses. This type of information would be necessary in the unlikely event of a release from the NTS. A dairy animal and population census is continuously updated for areas within 240 miles north and east, and 125 miles south and west of the Control Point One (CP-1). The location of CP-1 is shown in Figures 3 and 6, Chapter 2. The remainder of the Nevada counties and the western-most Utah counties are scheduled for dairy animal and population census updates every other year. The next complete census is scheduled for Fall 1992. The locations of processing plants and commercial dairy herds in Idaho and the remainder of Utah are obtained from the milk and food sections of the respective state governments. Community information programs are an integral component of the EPA activities. Town hall meet- ings or presentations are held at the request of various civic groups. These meetings and presen- tations provide a forum for increasing public aware- ness of NTS activities, disseminating radiation monitoring results, and addressing concerns of residents related to environmental radiation and possible health effects. In addition, tours of the NTS are arranged for interested parties. In nine- teen of the communities around the NTS, Commu- nity Radiation Monitoring Program (CRMP) stations have been established. The CRMP stations are established in prominent locations in the oftsite communities and include samplers for several of the surveillance networks (PlC, TLD, and air samplers; many also include noble gas and tritium- in-air samplers). At each CRMP, a local resident serves as the station manager. The CRMP is a collaborative effort of EPA EMSL-LV, the Desert Research Institute (DRI), the University of Utah, and DOE. 1.2 Report Description Beginning with operation Upshot-Knothole in 1953, a report summarizing the monitoring data obtained from each test series was published by the U.S. Public Health Service. For the reactor tests in 2 ------- 1959 and the weapons and Plowshare tests in 1962, data were published only for the tests in which detectable amounts of radioactivity were measured in an offsite area. Publication of the summary data for each six-month period was initiated in 1964. In 1971, the Atomic Energy Commission implemented a requirement (AEC71), subsequently incorporated into Department of Energy Order 5484.1 (D0E85), that each agency or contractor involved in major nuclear activities provide an annual comprehensive radiological monitoring report. in 1988, DOE Order 5484.1 was superseded by the General Environmental Protec- tion Program Requirements (Order 5400.1) of the DOE (DOE, 1988). Each annual report summanz- es the radiation monitoring activities of the EPA in the vicinity of the NTS and at former nuclear testing areas in the United States. This report summarizes those activities for calendar year 1991. Chapter 2 of this report contains a physical de- scnption of the NTS and the surrounding areas. Chapter 3 discusses the external ambient gamma monitoring networks including the TLD Network, the PlC network and a comparison of the two monitoring technologies. Chapter 4 discusses the atmospheric monitoring networks including the Air Surveillance Network, the Tritium in Atmospheric Moisture Network, and the Noble Gas Sampling Network. Chapter 5 addresses foodstuffs that could be consumed by residents living close to the NTS. This includes the Milk Surveillance Network, the Animal Investigation Program, and a discussion of fruits and vegetables. Chapter 6 discusses the internal Dosimetry Program. The LTHMP is discussed in Chapter 7. Each of the monitoring network sections includes a description of the network design, a discussion of the procedures, a presentation of the results, and a section on quality assurance/quality control methods. Chapter 8 contains a calculation of potential radiation dose to residents living in the off-site area. Chapter 9 contains a discussion of the support the ORSP provides for weapons testing and liquified gaseous fuels spill tests. Chapter 10 describes the CRMP and lists the town hall meetings and NTS tours conducted in 1991. A detailed description of the Quality Assurance (QA) program including a discussion of data quality objectives and of QA data analysis is provided in Chapter 11. Chapter 12 contains a discussion of the sample analysis procedures. Chapter 13 contains radiation protec- tion standards for external and internal exposure. Chapter 14 contains the summary and conclusions. Although written to meet the terms of the lAG between the EPA and the DOE as well as the requirements of DOE Order 5400.1, this report also should be of interest and use to the citizens of Nevada, Utah, and California. State, federal, and local agencies involved in protecting the environ- ment and the health and well-being of the public, and individuals and organizations concerned with environmental quality and the possible release of radioactive contaminants into the biosphere, also may find the contents of this report of interest. 3 ------- 2 Description of the Nevada Test Site The principal activity at the NTS is the testing of nuclear devices to aid in the development of nuclear weapons, proof testing of weapons, and weapons safety and effects studies. The major activity of the EPA’s ORSP is radiation monitoring around the NTS. This section provides an over- view of the climate, geology and hydrology, and land uses in this generally arid and sparsely populated area of the southwestern UniteJ States (Figure 1). The information included should pro- vide an understanding of the environment in which nuclear testing and monitoring activities take place, the reasons for the location of instrumentation, the weather extremes to which both people and equip- ment are subjected, and the distances traveled by field monitoring technicians in collecting samples and maintaining equipment. 2.1 Location The NTS is located in Nye County, NV, with its southeast corner about 54 miles (90 km) northwest of Las Vegas (Figure 2). It occupies an area of about 1,350 square miles (3,750 square km), varies from 28 to 35 miles (46 to 58 km) in width (east-west) and from 49 to 55 miles (82 to 92 km) in length (north-south). This area consists of large basins or flats about 2,970 to 3,900 feet (900 to 1,200 m) above mean sea level (MSL) surrounded by mountain ranges rising from 5,940 to 7,590 feet (1,800 to 2,300 m) above MSL. The NTS is surrounded on three sides by exclusion areas, collectively named the Nellis Air Force Base Range Complex, which provides a buffer zone between the test areas and privately owned lands. This buffer zone varies from 14 to 62 miles (24 to 104 km) between the test area and land that is open to the public. In the unlikely event of an atmospheric release of radioactivity (venting), two to more than six hours would elapse, depending on wind speed and direction, before any release of airborne radioactivity would reach private lands. 2.2 Climate The climate of the NTS and surrounding area is variable, due to its wide range in attitude and its rugged terrain. Most of Nevada has a semi-arid climate characterized as mid-latitude steppe. Throughout the year, there is insufficient water to support the growth of common food crops without irrigation. . . ,. . T:; : ’ e1 J mid-latitude steppe climatological zone in Nevada. $ 4’ - 5 ------- I I I 0 50 100 Scale In Kilometers Scale in Miles 0 50 100 I I _________________ Figure 2. Location of the Nevada Test Site. 150 6 ------- Climate may be classified by the types of vegeta- tion indigenous to an area. According to Nevada Weather and Climate (Houghton et at., 1975), this method of classification developed by KOppen is further subdivided on the basis of ‘...seasonal distribution of rainfall and the degree of summer heat or winter cold. Table 1 summarizes the characteristics of climatic types for Nevada. According to Quiring (Quiring, 1968), the NTS average annual precipitation ranges from about 4 inches (10 cm) at the lower elevations to around 10 inches (25 cm) at the higher elevations. During the winter months, the plateaus may be snow- covered for a period of several days or weeks. Snow is uncommon on the flats. Temperatures vary considerably with elevation, slope, and local air currents. The average daily temperature ranges at the lower altitudes are around 50 to 25°F (10 to -4°C) in January and 95 to 55°F (35 to 13°C) in July, with extremes of 120°F (49°C) and -15°F (- 26°C). Corresponding temperatures on the pla- teaus are 35 to 25°F (2 to -4°C) in January and 80 to 65°F (27 to 18°C) in July with extremes of 115°F (46°C) and -30°F (-34°C). The wind direction, as measured on a 98 ft (30 m) tower at an observation station approximately 7 miles (11 km) north-northwest of CP-1, is predomi- nantly northerly except during the months of May through August when winds from the south-south- west predominate (Quiring, 1968). Because of the prevalent mountain/valley winds in the basins, south to southwest winds predominate during daylight hours of most months. During the winter months, southerly winds predominate slightly over northerly winds for a few hours during the warmest part of the day. These wind patterns may be quite different at other locations on the NTS because of local terrain effects and differences in elevation. 2.3 Hydrology Two major hydrologic systems shown in Figure 3 exist on the NTS (U.S. Energy Research and Development Administration, 1977). Ground water in the northwestern part of the NTS or in the Pahute Mesa area flows at a rate of 6.6 to 600 feet (2 to 180 m) per year to the south and southwest toward the Ash Meadows discharge area in the Amargosa Desert. Ground water to the east of the Table 1. Characteristics of Climatic Types in Nevada (from Houghton et al. 1975) Moan Climate Type Annual Temperature °F (°C) Winter Summer Precipitation inches (cm) TotaJ Snowfall Percent Dominant of Vegetation Area Alpine tundra 0 to 15 (-18 to -9) 40 to 50 (4 to 10) 15 to 45 (38 to 114) Medium to heavy Alpine meadows — Humid continental 10 to 30 (- l2to-1) 50 to 70 (lOto2l) 25 to 45 (64to114) Heavy Pine-fir forest 1 Subhumid continental 10 to 30 (-12 to -1) 50 to 70 (10 to 21) 12 to 25 (30 to 64) Moderate Pine or scrub 15 woodland Mid-latitude steppe 20 to 40 (-7 to 4) 65 to 80 (18 to 27) 16 to 15 (15 to 38) Light to moderate Sagebrush, grass, 57 scrub Mid-latitude desert 20 to 40 (-7 to 4) 65 to 80 (18 to 27) 3 to 8 (8 to 20) Light Greasewood, 20 shadscale Low-latitude desert 40 to 50 (-4 to 10) 80 to 90 (27 to 32) 2 to 10 (5 to 25) Neghgible Creosote bush 7 * Limits of annual precipitation oveilap because of variations in temperature which affect the water balance. 7 ------- r Flow Direction — — Ground Water System Boundaries SilentCanyon Cakiera Timber Mountain 1 I I I I. II UU 0 10 20 I 30 I I I I I 20 I 30 40 0 Figure 3. Ground water flow systems around the Nevada Test Site. LOCATION MAP / I 51 Pahute Mesa Ground Water System * N / Ash Meadows Ground Water System / Mercury Indian Springs Death ‘ ‘i Valley Jct. / C!ySta,. / Pahrump 8 ------- NTS moves from north to south at a rate of not less than 6.6 feet (2 m) nor greater than 730 feet (220 m) per year. Carbon-14 analyses of this eastern ground water indicate that the lower velocity is nearer the true value. At Mercury Valley in the extreme southern part of the NTS, the eastern ground water flow shifts to the southwest, toward the Ash Meadows discharge area. 2.4 Land Use Of Nevada Test Site Region Figure 4 is a map of the off-NTS area showing a wide variety of land uses, such as farming, mining, grazing, camping, fishing, and hunting within a 180-mile (300 1cm) radius of the NTS operations control center, located at CP-1 (the location of CP- I is shown on Figures 3 and 6). West of the NTS, elevations range from 280 feet (85 m) below MSL in Death Valley to 14,600 feet (4,420 m) above MSL in the Sierra Nevada Range. Portions of two major agricultural valleys (the Owens and San Joaquin) are included. The areas south of the NTS are more uniform since the Mojave Desert ecosystem (mid-latitude desert) comprises most of this portion of Nevada, California, and Arizona. The areas east of the NTS are primarily mid- latitude steppe with some of the older river valleys, such as the Virgin River Valley and the Moapa Valley, supporting irrigation for small-scale but intensive farming of a variety of crops. Grazing is also common in this area, particularly to the north- east. The area north of the NTS is also mid- latitude steppe, where the major agricultural activity is grazing of cattle and sheep. Minor agriculture, primarily the growing of alfalfa hay, is found in this portion of Nevada within 180 miles (3001cm) of the CP-1. Many of the residents have access to locally grown fruits and vegetables. Recreational areas lie in all directions around the NTS (Figure 4) and are used for such activities as hunting, fishing, and camping. In general, the camping and fishing sites to the northwest, north, and northeast of the NTS are closed during winter months. Camping and fishing locations to the southeast, south, and southwest are utilized throughout the year. The peak of the hunting season is from September through January. 2.5 Population Distribution Knowledge of population densities and spatial distribution of farm animals is necessary to assess protective measures required in the event of an accidental release of radioactivity at the NTS. Figure 5 shows the current population of counties surrounding the NTS based on 1990 Bureau of Census (BOO) count (BOO, 1990). Excluding Clark County, the major population center (approxi- mately 741,459 in 1990), the population density of counties adjacent to the NTS is about 0.7 persons per square mile (0.4 persons per square kilometer). For comparison, the population density of the 48 contiguous states was 70.3 persons per square mile (27 persons per square kilometer) (BOC, 1990). The estimated average population density for Nevada in 1980 was 1.1 persons per square mile (0.4 persons per square kilometer) (BOC, 1986). The oftsite area within 48 miles (80 km) of CP-i (the primary area in which the dose commitment must be determined for the purpose of this report) is predominantly rural. Several small communities are located in the area, the largest being in Pah- rump Valley. Pahrump, a growing rural community with a population of 7,425 (BOC, 1990), is located 48 miles (80 1cm) south of the NTS C P-i. The small residential community of Crystal, Nevada, also located in the Pahrump Valley, is several miles north of the town of Pahrump. The location of Crystal, Nevada, is shown in Figure 3. The Amargosa farm area, which has a population of about 950, is located 30 miles (50 km) southwest of C P.1. The largest town in the near offsite area is Beatty, which has a population of about 1,500 and is located approximately 39 miles (65 km) to the west of CP-1. The Mojave Desert of California, which includes Death Valley National Monument, lies along the southwestern border of Nevada. The National Park Service (NPS) estimated that the population within the Monument boundaries ranges from a minimum of 200 permanent residents during the summer months to as many as 5,000 tourists including campers on any particular day during the major holiday periods in the winter months, and as many as 30,000 during 1)eath Valley Days in the month of November (NPS, 1990). The next largest town and contiguous populated area, about 40 square miles (about 111 square km) in the Mojave Desert, Barstow, California, located 159 miles (265 9 ------- & I — S — I U i Camping & Recreational Areas Hunting Fishing Mines Oil Fields 0 S Is m MMS 50 0 50 100 ScsIe W i KLn em Figure 4. General land use within 180 miles (300 km) of the Nevada Test Site. LIJ(E TAHOE I I I I I I I I 1 I I I I I I I I I I I I I I 1 I ARIZONA $ N Lace Havasu 100 150 10 ------- I I I Ii Figure 5. Population of Arizona, California, Nevada, and Utah counties near the Nevada Test Site. Humboft 12,844 I U — U NEVADA i I I i I 1 I Elko 33,530 Box Elder 36,485 Douglas 27,637 Esmeralda L344 $ N Scale r Miles 50 100 6 s’o i6o Scale Kilometers 150 San Bernardino 1418,380 11 ------- km) south-southwest of the NTS, with a 1990 population of 21,472. The largest populated area is the Ridgecrest, California area, which has a population of 27,725 and is located 114 miles (190 km) southwest of the NTS. The Owens Valley, where numerous small towns are located, lies 30 miles (50 km) west of Death Valley. The largest town in the Owens Valley is Bishop, California, located 135 miles (225 km) west-northwest of the NTS, with a population of 3,475 (BOC, 1990). The extreme southwestern region of Utah is more developed than the adjacent pail of Nevada. The largest community is St. George, located 132 miles (220 km) east of the NTS, with a 1990 population of 28,502. The next largest town, Cedar City, with a population of 13,443, is located 168 miles (280 km) east-northeast of the NTS (BOC, 1990). The extreme northwestern region of Arizona is mostly range land except for that portion in the Lake Mead Recreation Area. In addition, several small communities lie along the Colorado River. The largest towns in the area are Bullhead City, 99 miles (165 km) south-southeast of the NTS, with a 1990 population of 21,951 and Kingman, located 168 miles (280 km) southeast of the NTS, with a population of 12,722 (BOC, 1990). Figures 6 through 9 show the most recent esti- mates of the domestic animal populations in the counties near the NTS. Domestic animal numbers are updated through interim survey as part of routine monitoring and by resurvey periodically. The numbers given in Figure 6, showing distnbu- tion of family milk cows and goats, are determined from these interim surveys. The numbers in Fig- ures 7 to 9 were compiled for Nevada and Utah from the Nevada Agricultural Statistics 1992 report (Nevada Agricultural Statistics Service, 1992) and from the 1992 Utah Agricultural Statistics report (Utah Agricultural Statistics Service, 1992). The numbers in Figures 7 to 9 pertaining to counties in California were received verbally from personnel at the California Agricultural Statistics Service. 12 ------- 00 Cows (00) Goats Scale in Miles 50 50 100 150 Scale in Kilometers Figure 6. Distribution of fami’y milk cows and goats, by county. Washoe — . — I — I — I — I — I I — S — U —. NEVADA UTAH I Elko 85(0) Box Elder 11(0) Lyon 5(32) ARIZONA San Bernardino 16(37) 4 N 0 100 13 ------- All * counties total 2,700. Individual county values not published to avoid disclosure of indrvidual operations . Figure 7. Distribution of dairy cows, by county. 14 ------- Figure 8. Distribution of beef cattle, by county. Washoe — I I — I — I I — I — I — I — UI NEVADA UTAH I I Elko 180,000 Box Elder 29,000 Lyon 44,000 ARIZONA San Bernardino 6,200 4 N 0 50 100 150 Scale in Kilometers 0 Scale in Miles 50 100 15 ------- * counties total I 9,800. IndMdual county values n published to avoid disclosure of individual operations. Figure 9. Distribution of sheep, by county. 16 ------- 3 External Ambient Gamma Monitoring External ambient gamma radiation is measured by the Thermoluminescent Dosimetry (TLD) network and also by the Pressurized Ion Chamber (PlC) network. The primary function of the two networks is to detect changes in ambient gamma radiation. In the absence of man’s activities (e.g., nuclear testing), ambient gamma radiation rates naturally differ among locations as rates vary with altitude (cosmic radiation) and with radioactivity in the soil (terrestrial radiation). Ambient gamma radiation will also vary slightly at a location due to weather patterns. 3.1 Thermoluminescent Dosimetry Network The TLD network is designed primarily to measure total ambient gamma exposures at fixed locations. A secondary function of the network is the mea- surement of exposures to specific individuals living within and outside estimated fallout zones from past atmospheric nuclear tests at the Nevada Test Site (offsite residents). Measuring environmental ambient gamma exposures at fixed locations provides a reproducible index which can then easily be correlated to the maximum exposure an individual would have received were he continu- ously present at that location. Monitoring of indi- viduals makes possible an estimate of individual exposures and helps to confirm the validity of correlating fixed-site ambient gamma measure- ments to projected individual exposures. Since 1987, environmental and personnel monitor- ing for ambient gamma exposures has been accomplished using the Panasonic ILD system. This system provides tissue equivalence for per- sonnel TLDs which facilitates correlating individual measured exposures with the absorbed biological dose equivalent. During 1991, the EMSL-LV TLD Laboratory was awarded accreditation as a processor of personnel TLDs by the Department of Energy Laboratory Accreditation Program (DOELAP). This accredita- tion was the culmination of a process extending over a period of approximately one year. The accreditation process began with three rounds of blind exposures to a variety of radiation types and levels ranging from occupational levels through the accident range and included both “pur& and mixed radiation fields. The purpose of these blind expo- sures was to test the accuracy, precision, and long-term consistency of overall laboratory perfor- mance. The performance testing phase was followed by a rigorous on-site appraisal of laborato- ry operations, procedures, and quality control both from the perspective of routine operations and to ensure that operations as conducted were appro- priate to the overall EMSL-LV radiation safety management mission. 3.1.1 Design During 1991, 130 offsite stations (excluding the Nevada Low Level Waste Site station) encircling the NTS and 72 offsite residents were monitored by the TLD program. Locations monitored in 1991 are shown in Figure 10. This network allows estimation of average background exposures as well as detection of any increases. The personnel TLDs are sensitive to beta, gamma, neutron, and to low and high energy x-ray radia- tions. All personnel exposures are presumed to be due to gamma or high energy x-ray radiation. Exposures of this type are numerically equivalent to absorbed dose. The TLDs used to monitor fixed environmental stations are sensitive only to gamma and high-energy x-ray radiations. The personnel TLDs are provided in holders which are designed to be worn on the front of an individ- ual’s body, between the neck and the waist. When worn in this manner, the TLD may be used to estimate not only ambient gamma radiation expo- sure but to characterize the absorbed radiation dose an individual may have received. Figure 11 illustrates a typical personnel TLD holder as it would be issued to a monitored individual. TLDs issued to individuals are normally deployed and collected monthly. Each fixed environmental station has a custom designed holder that can hold from one to four TLDs. Normal operations involve packaging two TLDs in a heat-sealed bag to provide protection from the environmental elements and placing the dosimeter packet into the fixed station holder. Fixed environmental monitoring TLDs are normally 17 ------- A Locations monitored with both personnel - and fixed station TLDs. (40) Figure 10. Locations monitored with thermoluminescent dosimeters. FLocatbons monitored with fixed station TLDs. (130)1 18 ------- deployed for a period of approximately three months (one calendar quarter). 3.1.2 Procedures The EPA TLD program utilizes the Panasonic Model UD-802 and UD-814 thermoluminescent dosimeters and Model UD-71 OA automatic dosime- ter reader. Monitoring of offsite personnel is accomplished with the Panasonic UD-802 dosimeter/UD-874A hanger combination. This dosimeter badge con- tains two elements of Li 2 B 4 O 7 :Cu and two of CaSO 4 :Tm phosphors. The use of different filtra- tion elements makes possible a close estimation of the type of radiation to which the dosimeter was exposed, data that are essential to assess the absorbed dose equivalent for the indMdual wearing the dosimeter. Monitoring of offsite environmental stations is accomplished with the Panasonic UD- 814 dosimeter. This dosimeter contains a single element of Li 2 B 4 O 7 :Cu and three replicate CaSO 4 :Tm elements. The first element is filtered by 17 mg/cm 2 of plastic and the remaining three are filtered by 1,020 mg/cm 2 of plastic and lead. The use of three replicate phosphors provides greater precision of the measurement. The Panasonic Model UD-71 OA automatic dosime- ter reader consists of a badge transport and insertion mechanism, a heat source, a carbon-14 ( 14 C) activated reference light source, a light measurement system, and a microprocessor controller. Up to 500 TLDs may be loaded in 50- dosimeter magazines into the automatic sample changer attached to each reader. Each magazine is automatically advanced to admit dosimeters into the reading mechanism. In the mechanism, the dosimeter portion containing the four phosphors is withdrawn from the holder. Each element is then heated and its light output measured. When all four elements have been read, the card is re- inserted into its holder, the holder is returned to the magazine, and the process is repeated for the next dosimeter. Figure 12 illustrates the general mech- anism of the dosimeter reader. 3.1.3 Results of TLD Monitoring A portion of the 1991 TLD data are not included in this report due to a data retrieval problem with the network software. The problem affects only the ability to retrieve data, not the quality of the data reported. The measurement period dates given in t-igure 71. iypicai personnei rnermoiuminescenr aos,mewr. 19 ------- Slide Remover Figure 12. Illustration of a Panasonic UD 710 Dosimeter Reader. the tables in this section indicate which data are not included. The 1992 report wilt include all 1991 data that are not presented in this report. As stated above, the primary function of the fixed environmental station TLDs is to characterize background gamma radiation fiekis. Daily expo- sure rates are obtained by dividing the total expo- sure from each TLD by the number of days in the monitoring period. Annual adjusted ambient gamma exposures at fixed stations (mR in one year) are calculated by multiplying the mean daily rate for each individual station by 365.25. Individu- al measurements can be compared to historical data to evaluate whether that measurement vanes significantly from the historical background for that location. Annual exposures measured at fixed environmental TLD stations during 1991 ranged from 47 to 377 mR, with a median of 87 mR. Results obtained at each of the fixed environmental stations monitored with TLDs are summarized in Appendix A, Table A- 1. The data are presented alphabetically by state. During 1991, the maximum net annual exposure of 377 mR was measured at Warm Springs, Nevada, located east of Tonopah on Highway 6. This exposure, at Warm Springs #2, was determined to be due to elevated levels of naturally occurring radioactive material present in a hot springs-fed stream adjacent to the monitoring location. Radia- lion levels measured in a nearby parking lot (Warm Springs #1) indicated an annual net exposure of 116 mA. A detailed evaluation of the Warm Springs #1 and Warm Springs #2 monitoring locations was included in the 1989 Annual Report (EPA9O). These values represent gross ambient gamma radiation levels measured at the respective locations. Element Slide Reference Light Source — Dosimeter Element — Lamp Photomultiplier ID Code Reading Unit Z Dimeter Holder Magazine 20 ------- Figure 13 shows 10 yearS of TLD exposure data expressedas annual means of a1 1 stations. The figure shOws the mean ± two standard deviations. The iange of exposures observed at fixed environ- mental monitoring locations during 1991 was similar to that observed in the previous ten years. The range Of exposures was consistent with that expected from background radiation in the United States with the exception of Warm Springs #2, discussed above. For eaôh resident participating in the TLD Network, the measured eXposUre oan be compared to an associated reference background. An average for all offsite station TLDs is hOtan appropriate refer- ence background because environmental ambient radiation levels vary markedly with natural radioac- tivity in the soil, altitude, and other factors. There- fore, results obtained at the fixed environmental station closest to that individual are the most appropriate reference point. Daily dose rates are obtained by dMding the total dose from each TLD by the number of days in the monitoring period. Annual adjusted ambient gamma doses to person- nel (mrem in one year) are calculated by multiply- ing the mean daily rate for each individual by 365.25. Of the. 72 individuals monitored, 52 (73.2%) re- ceived exposures varying from the associated reference background location by less than 20 mR in one year. Sixty-eight of the 72(94.4%) received exposures varyng from associated reference background by less than 50 rnR in one year. In no case did any individual or cumulative exposure exceed regulatory or as low as reasonably achiev- able (ALARA) investigation limits. The distribution of personnel exposures as compared to associated reference background exposures is shown in Figure 14. The results of offsite personnel TLD monitoring for 1991 are summarized in Appendix A, Table A-2. Annual equivalent doses ranged from 31 mrem in an individual from St. George, Utah to 167 mrern in an individual from Stone Cabin Ranch, Nevàda The median value was 76. Absorbed radiation doseto personnel is calculated at three depths in tissue: 17mg/cm 2 , 300mg/cm 2 , and 1 ,000mg/cm2. These are by convention referred to as ushallowu 5 eye, 5 and “deep.” Appen- dix A, Table A-2 lists the deep absorbed dose equivalent in mrem because this is most represen- tative of the dose to the whole body, including the dose to blood forming organs. Figure 13 Thermoluminescent Dosimetty exposures at all fixed environmental stations, 1981 - 1991. 200 Ten-Year- TLD Exposures at Fixed 1981 Env I ronmenta Stations - 1991 i50 0 L a, >‘ E LOB 50 - 0 I I I I I I I I i981 i902 i9B3 i904 LEBS i906 i907 Source: Mnual EPA Off site Environneutal lonitoring Reports Bulb TLDs used prior to i974: Uarsbav i974 - i987: Panasonic since LOB? ‘gee 1989 LOgO i99i 21 ------- 3.1.4 Quality Assurance/Quality Control During 1991, two cabbration instruments were available to support the program. One uses a panoramic style irradiator containing a Cs source which delivers an exposure rate of approxirT tely 87 mR/hour at 100 cm from the source. The other is a 10 Ci well-type 1 ° Cs irradiator, delivering approximatety 60 mR/minute at 100 cm. Expo- sures given to irradiated control TLDs are moni- tored using Victoreen model #570 or Victoreen Radocon-lil electrometers with appropriate ioniza- tion chambers having calibrations traceable to the National Institute of Standards and Technology (NIST). The ionization chamber is placed in the center of the radiation field. The exposure rates of both irradiators have been confirmed by measure- ment using precision electrometers and ionization chambers having calibrations traceable to NIST. Panasonic UD-800 dosimeters exposed by these irradiators are used to calibrate the TLD readers and to verify TLD reader linearity. Control dosime- ters of the same type as field dosimeters (UD-802 or UD-81 4) are exposed and read together with the field dosimeters. This provides daily on-line pro- cess quality control checks in the form of irradiated controls. Each magazine containing TLDs to be read nor- mally contains three irradiated control TLDs that have been exposed to a nominal 200 mR at least 24 hours prior to the reading. After the irradiated controls have been read, the ratio of recorded exposure to delivered exposure is calculated and recorded for each of the four elements of the dosimeter. This ratio is applied to all raw element readings from held and unirradiated control dosim- eters to automatically compensate for reader variations. Personnel Exposures Compared to Associated Reference Background < 20 mR (73.2%) ). 50 m (5.6%) 41 - 50 iT (5.6%) 31 - 40 ir (7.0%) mr I n one year above associated reference back oufld Distribution of 21 - 30 mR (9.5%) Figure 14 Distribution of personnel exposures con ared to associated reference background. 22 ------- Prior to being placed in service, element correction factors (ECFs) are determined for all dosimeters. Whenever a dosimeter is read, the mean of the three most recent ECF determinations is applied to each element to compensate for normal variability (caused primarily by the TLD manufacturing pro- cess) in individual dosimeter response. In addition to irradiated controls, each group of field dosimeters normally contains three transit and three unirradiated background dosimeters. Thus, each magazine of 50 dosimeters may contain up to nine QC dosimeters. Field dosimeters receive exposure while in transit as well as while deployed at the monitoring location. To determine the field exposure, it is necessary to estimate this additional exposure, which is designated “transit exposure”. Transit control dosimeters are shipped with each batch of field dosimeters. Exposures received while in storage are determined by using unirradiated background dosimeters. Unirradiated background dosimeters are held in shielded stor- age at the EPA TLD processing laboratory. The exposure while in transit is estimated by taking the difference between the exposures measured on transit dosimeters and those measured on unirradi- ated background dosimeters. The exposure to unirradiated background dosimeters is essentially due only to the cosmic ray component of the local natural background radiation. Likely sources of transit exposure include shipments of medical and other radloisotopes in the mail and natural terrestri- al and cosmic radiation. An assessment of TLD data quality is based on the presumption that exposures measured at an individual fixed location will remain substantially constant over an extended period of time. A number of factors will combine to affect the certain- ty of measurements. The total uncertainty of the reported exposures is a combination of random and systematic components of uncertainty. The random component is primarily the statistical uncertainty in the reading of the TLD elements themselves. Based on repeated known exposures, this random uncertainty for the calcium sulfate elements used to determine exposure at fixed environmental stations is estimated to be approxi- mately ± 3 to 5%. There are also several system- atic components of exposure uncertainty, including energy-directional response, fading, calibration, and exposures received while in storage. These uncertainties are estimated according to estab- lished statistical methods for propagation of uncer- tainty. A study conducted by the Nuclear Regulatory Commission (NRC-1991) indicated an average total net field exposure uncertainty across fixed environmental station TLDs deployed for a period of 90 days of 21.1% relative standard deviation (RSD). A review of fixed environmental station TLD results obtained by the EPA network in 1991 showed an average of 21.6 % RSD across all stations, virtually identical to the results reported by NRC. Also, the NRC reported an average net field exposure of 22.8 mR in 90 days. Results ob- served in the EPA monitoring network averaged 21.6 mR when adjusted to the same length moni- toring period. Net field exposure uncertainty for exposures at the occupational and accident range of 30 mR to 500 R would be significantly lower when compared to natural background or transit exposure levels. Accuracy of the overall TLD deployment and processing cycle has been evaluated via the DOELAP accreditation process. This process concluded that procedures and practices utilized by the EPA EMSL-LV TLD Laboratory are adequate to detect exposures to individuals greater than 3 mrem above background at the 95% confidence level. This is referred to as the lower limit of detectability. Tests using dosimeters exposed to known radiation levels both in-house and by external organizations have confirmed that the TLD readers exhibit linear performance from the lower limit of detectability through the accident range (500 reds). 3.1.5 Data Management The TLD data base resides on a Digital Equipment Corporation (DEC). MicroVAX II, directly connected to the two Panasonic TLD readers. Samples are tracked using field data cards and an issue data base tracking system incorporated into the reader control software. Two major software packages are utilized by the TLD network. The first, a proprietary package written and supported by International Science Associates (ISA), controls the TLD readers, tracks dosimeter performance, completes necessary calculations to determine absorbed dose equivalent, performs automated QNQC functions, and generates raw data files and reports. The second software package, locally developed, maintains privacy act information and the identifying data, generates reports in a number of predefined formats, and provides archival stor- age of TLD results dating to 1971. 23 ------- 3.2 Pressurized Ion Chambers The Pressurized Ion Chamber (PlC) network continuously measures ambient gamma radiation exposure rates, and because of its sensitivity, may detect low-level exposures not detected by other monitoring methods. 3.2.1 Network Design Excluding the Nevada Low Level Waste Site, 29 Pressurized Ion Chambers (PIGs) are stationed in communities around the NTS. The PlCs provide near real-time estimates of gamma exposure rates. The locations of the PlCs are shown in Figure 15 Nineteen of the PICs are located at Community Radiation Monitoring Program Stations (CAMPS), which are discussed in Section 10.1. To expand the network, EPA added PICs to ten of the Remote Automatic Weather Stations (RAWS) in the spring of 1991. The RAWS are owned and operated by the Bureau of Land Management and the U.S. Forest Service and are maintained by the Boise Interagency Fire Center. The locations of all the PlCs, including the RAWS PICs, are shown in Figure 16. Two PlCs were relocated during 1991. The PlC at Holloway’s Ranch (near Scotty’s Junction, NV) was relocated about one-half mile to Terrell’s Ranch on June 24, 1991. The results discussion in Section 3.2.3 combines the results from Holloway’s and Terrell’s Ranches and refers to the station as Terreirs Ranch. The station in St. George, Utah was relocated on September 4,1991 approximate- ly one-halt mile from the high school to Dixie College. 3.2.2 Procedures The network utilizes Reuter-Stokes models 1011, 1012, and 1013 PlCs. The PlC is a spherical shell filled with argon gas to a pressure 25 times that of atmospheric. In the center of the chamber is a spherical electrode with a charge opposite to the outer shell. When gamma radiation penetrates the sphere, ionization of the gas occurs and the ions are collected by the center electrode. The electri- cal current generated is measured, and the intensi- ty of the radiation field is determined from the magnitude of this current. Figure 17 shows a typical PlC unit in the field. Data are retrieved from the PlCs shortly after measurements are made. The near real-time telemetry-based data retrieval is achieved by the connection of each PlC to a Data Collection Plat- form (DCP) which collects and transmits the data. Gamma exposure measurements are transmitted via the Geostationary Operational Environmental Satellite (GOES) directly to a receiver earth station at the NTS and from there to the EMSL-LV by dedicated telephone line. Each station routinely transmits data every four hours (i.e., 4-hour aver- age, 1-minute maximum, and 1-minute minimum values) unless the gamma exposure rate exceeds the currently established threshold of 50 p .RJhr. When the 50 RR/hr is exceeded for two consecu- tive 1-minute samples, the system goes into the alarm mode and transmits a string of nine consec- utive 1-minute values every 2 to 15 minutes. Additionally, the location and status (i.e., routine or alarm mode) of each station are shown on a map display in the Control-Point-One (CP-1) control room at the NTS and at the EMSL-LV. Thus, the PIG network is able to provide immediate docu- mentation of radioactive cloud passage in the unlikely event of an accidental release from the NTS. Parameters affecting the physical status of the station equipment are also transmitted along with exposure rates. This allows staff in EMSL-LV to identify equipment problems (e.g., low battery,) with the PICs soon after they occur. All data transmitted via the telemetry system are stored on a DEC microVAX II computer which is managed by Los Alamos National Laboratory. In addition to telemetry retrieval, PlC data are also recorded on both magnetic tapes and hard-copy strip charts at 27 of the 29 EPA stations and on magnetic cards for the other two EPA stations. The magnetic tapes and cards, which are collected weekly, provide a backup to the telemetry data and are also useful for investigating anomalies because the data are recorded in smaller increments of time (5 minute averages). Summarized data from the 5- minute averages are stored on a personal comput- er in dBASE files. Raw 5-minute averages are stored in ASCII files on floppy diskettes. The PICs also contain a liquid crystal display, permitting interested persons to monitor current readings. The data are evaluated weekly by EMSL-LV personnel. Trends and anomalies are investigated and equipment problems are identified and correct- ed. Weekly averages are stored in Lotus files on 24 ------- • • I — — I I — I U — I — I — I — I —, NEVADA UTAH 1 • I I I i I Lake 1 f PVRAMIO LAKE I City 1 — I I Austln• I •Ely De lta• — I I I Stone Cabin Rn. • Miltord I I . Piochel Twin Springs Rn. UI ICteS Rn. I I I I U Complex I • Caliente • C0d T City I TerreU’s Rn.I I I I • St. George Bey — . — . — . — ..d •4 I ARIZONA AmargosaV Furnace CreekU I Amargosa Center j MEAD $ N Scale in Miles __________ o so ioo I . Community Monitoring Stations (19) p” o 50 100 150 • Other PlC Locations (10) ____________________________________________ Scale in Kilometers Figure 15 Locations of Pressurized Ion Chamber network stations. Tonopah -I Indian ShoshoneS 25 ------- $ N Scale m Miles 0 100 300 I i . 100 300 500 Scale in Kilometers • EPA PICS(29) o BLM PICS (10) Figure 16. Pressurized Ion Chanter Network, including remote automatic weather stations operated by the Bureau of Land Management. a PC. These weekly averages are compiled from the 4-hour averages from the telemetry data when available and from the 5-minute averages from the magnetic tapes or cards when the telemetry data are unavailable. Computer-generated reports of the PlC weekly average data are issued weekly for posting at each station. These reports indicate the current week s average gamma exposure rate, the previous week s and year’s averages, and the maximum and minimum background levels in the U.S. 3.2.3 Results The Pressurized Ion Chamber data presented in this section are based on weekly averages of gamma exposure rates from each station. Weekly averages were compiled for every station, for every week during 1991 with the exception of the weeks listed in Table 2. Data were unavailable during these weeks due to equipment failure. Data are not presented for the RAWS PICs. The RAWS data are not yet processed and maintained with the data from the other stations. Data from the RAWS will be included in future reports. Table 3 contains the number of weekly averages available from each station and the mean, standard deviation, minimum, maximum, and median of the weekly averages. The mean ranged from 5.9 j.tR/hr at Las Vegas, NV to 17.6 pR/hr at Stone Cabin Ranch, NV. For each station, this table also shows the total mRlyr (calculated based on mean of the weekly averages) and the average gamma exposure rate from 1990. Total mR/yr measured 7 0 26 ------- I :i Figure 17. Pressurized ion chamber (left), gamma-rate recorder remote processor unit (right), with chart recorder, digital readout, and telemetry antenna with solar panel (top center). - a’ I r a ’ 27 ------- Table 2. Weeks for which there were no Pressur- ized Ion Chamber Data collected for given stations. Station Week Ending Austin June 6 June 26 July 2 Furnace Creek June 26 July 2 Salt Lake City December 4 St. George September 11 December 4 Shoshone November 13 TerreWs Ranch January 16 December 17 Uhalde’s Ranch October 1 by this network ranged from 52 mR/yr at Las Vegas, Nevada, to 154 mR/yr at Stone Cabin Ranch, Nevada. U.S. background, levels of envi- ronmental gamma exposure rates (from the com- bined effects of terrestrial and cosmic sources) vary between 49 and 247 mR/yr (Committee on the Biological Effects of Ionizing Radiation, 1980). The annual exposure levels observed at each PlC station are well within the U.S. background levels. The PlC data from 1991 are consistent with data from previous years. The greatest difference in averages between 1990 and 1991 was seen at Gokifield, NV. This was probably because the sensor unit, which was exchanged in February of 1992, was slightly underestimating the gamma exposure rate. The 1992 exposure rates at Gold- field are expected to resemble the levels seen in 1990. Figure 18 shows the distribution of the weekly averages from each station arranged by ascending means (represented in figure by filled circles). The left and right edges of the box on the graph repre- sent the 25th and 75th percentiles of the distribu- tion of the weekly averages (i.e., 50% of the data falls within this region). The vertical line drawn inside the box represents the 50th percentile or the median value. The horizontal lines extend from the box to the minimum and maximum values. The data from Austin, NV show the greatest amount of variability. The variability seen at Austin is probably due to seasonal differences in gamma exposure rates which have historically been seen at this station. Weekly averages reported for Austin from January 1988 to December 1991 are given in Figure 19. The figure shows a consistent decrease in gamma exposure rates during the winter months. This trend is possibly due to snow cover shielding radiation from the ground or to frozen ground preventing radon emanation from the soil. In contrast to the Austin data, Figure 20 shows increasing gamma exposure rates during the winter months at Twin Springs, NV. The reason for the increasing gamma exposure rates during winter months is currently under investigation. Time series graphs for all the EPA stations are given in Appendix A, Figure A-i. 3.2.4 Quality Assurance/Quality Control Several measures are taken to ensure that the PlC data are of acceptable quality: • The PICs are calibrated at least once every two years and usually once a year. The DOE requires that the PICs be calibrated every two years. However, the calibration is usually done annually. • Radiation monitoring technicians place a radioactive source of a known exposure on the PlCs weekly to check the performance of the units. • Source check calibration and background exposure rate data are evaluated weekly and compared to historical values. • Data transmitted via the telemetry system are compared to the magnetic tape data on a weekly basis to check that both systems are reporting the same numbers. Whenev- er weekly averages from the two sets of numbers are not in agreement, the cause of the discrepancy is investigated and corrected. 28 ------- Table 3. Summary of weekly Gamma Exposure Rates as Measured by Pressurized Ion Chambers, 1991 Number Gamma Exposure Rate (pR/br) 1990 of Weekly Station Averages Mean Std. Mean mR/yr (pR/hr) Dev. Minimum Maximum Median Alamo, NV 52 13.4 0.39 12.9 14.1 13.3 118 13 Amargosa Center, NV 52 11.0 0.16 10.0 11.4 11.0 96 11 Amargosa Valley, NV 52 14.0 0.24 13.2 14.5 14.0 122 14 Austin, NV 49 17.4 2.19 12.4 20.0 18.1 152 19 Beatty, NV 52 16.3 0.38 15.6 17.0 16.0 142 17 Caliente, NV 52 14.3 0.29 13.7 15.1 14.4 126 14 Cedar City, UT 52 10.6 0.43 9.9 11.4 10.8 93 10 Complex I, NV 52 15.9 0.42 15.1 16.6 16.0 139 16 Delta, UT 52 11.9 0.33 11.0 12.4 12.0 104 11 Ely. NV 52 12.3 0.57 11.2 13.3 12.4 108 13 Furnace Creek, CA 50 10.1 0.26 9.8 11.0 10.0 89 10 Goldfield, NV 52 12.8 0.52 11.7 14.0 12.8 112 15 Indian Springs, NV 52 8.7 0.38 8.0 9.7 8.8 76 9 Las Vegas, NV 52 5.9 0.23 5.0 6.2 6.0 52 6 Medlins Ranch, NV 52 15.8 0.33 15.0 16.5 16.0 139 16 Mitford, UT 52 17.4 0.49 15.8 18.2 17.4 152 17 Nya la,NV 52 12.4 0.39 11.7 13.4 12.5 109 13 Overton, NV 52 8.9 0.31 8.2 9.6 9.0 78 9 Pahrump, NV 52 7.9 0.27 7.0 8.1 8.0 69 8 Pioche, NV 52 11.8 0.35 11.0 12.5 12.0 104 12 Rachel, NV 52 15.9 1.23 13.7 18.0 16.2 139 16 Salt Lake City, UT 51 10.9 0.48 10.0 13.1 11.0 96 11 Shoshone, CA 51 11.8 0.40 11.0 12.9 11.8 103 12 St. George, UT 50 8.9 0.44 7.6 9.8 9.0 78 9 Stone Cabin Ranch, NV 52 17.6 0.66 16.3 18.8 17.4 154 17 Terrets Ranch, NV 50 15.2 0.43 14.2 16.0 15.1 133 NA Tonopah, NV 52 16.7 0.39 15.7 17.4 16.8 146 16 Twin Springs, NV 52 16.7 0.64 15.4 18.3 16.8 146 17 Uhaldes Ranch, NV 51 17.0 0.38 16.0 17.8 17.0 149 17 Note: Multiply pR / br by 2.6 x icr ’° to obtain Ckg 1 h’. NA = Not available. 29 ------- LasVegas,NV- ‘ Pahrump, NV - Indian Springs, NV Overton, NV• St. George, UT Furnace Creek, CA Cedar City, UT• Salt Lake City, UT• Amargosa Center, NV ‘ • ‘ Pioche, NV ‘—51— i Shoshone, CA - Delta, UT - Ely, NV - Nyala. NV Goldfield, NV- Alamo, NV ‘ - E l i- ’ Amargosa Valley, NV ‘ 4 Caliente, NV• Terrell’s Ranch ,NV Medlins Ranch, NV Complex I, NV• Rachel, NV Beatty, NV Tonopah, NV - Twin Springs, NV - Uhaldes Ranch, NV - Austin, NV - Milford, UT - Stone Cabin Ranch, NV - 4 8 12 16 20 Weekly Gamma Rate Average (uR/Hr) Figure 18. Distribution of weekly averages from the Pressurized Ion Chamber Data. Figure shows minimum, 25th percentile, mean, median, 75th percentile, and maximum values. 30 ------- Austin, NV 8° 0 D 0 ObW88 0 0 0 t o 0 0 0-o 0 0 ob Week Ending Date Figure 19. Weekly averages from Austin, Nevada, January 1988 to December 1991. Mn Spdngs, NV II 0 OliWB8 01iW89 1,V1 1 O 01 101 191 01 101192 Week Ending Date Figure 20. Weekly averages from Twin Springs, Nevada, Januaiy 1988 to December 1991. 18 I 0 00 0 0 ‘5’ 0 16 00 0 8 U 0 0 0 14 12 oV O lm9 01iV1190 01101 192 18 16 10 31 ------- A data quality assessment of the PIG data is given in Sectk)n 11, Quality Assurance. 3.3 Comparison of TLD Results to PlC Measurements When calculated TLD exposures are compared with results obtained from colI ated PIGs (see Figure 21), a uniform under-response of TLDs was noted. This difference, which has been observed in previous years, is attributed primarily to the differing energy response of the two systems. The PICs have a greater sensitivity to lower energy gamma radiation than the TLDs and hence will normally record a higher apparent exposure. This difference is attnbuted to three pnrnaiy factors: (1) PIGs are more sensitive to lower energy gamma radiation than are the TLDs. A review of manufacturer’s specifications for the PlC and RD systems shows their responses to be close to linear above approximately 80 and above approximately 150 keV, respectively; and (2) The PIG units are calibrated by the manufacturer against °Co, while the TLDs are calibrated using 137 Cs. No adjustment is made to account for the differing energies at which the two sys- tems are calibrated. (3) The PIG is an exposure rate measuring device, sampling every five seconds, while the TLD as an integrating dosime- ter is analyzed approximately once each quarter. Some reduction in TLD results may be due to a small amount of loss due to normal fading (studies by Pana- sonic have shown this loss to be mini- mal over the sampling period used). A soc-month fade study was conducted by the EMSL-LV RD Laboratory. This study confirmed that, over the normal sampling period, fading is negligible. Although these known systematic differences occur, both the RD and PIG networks serve as valuable components of an overall environmental radiation monitoring program, each with unique capabilities. Figure 21. Con iarison of Thermoluminescent Dosimetiy Data to Pressurized Ion Chamber Data TLD - PlC Correlation Co-located Fixed Environmental Stations (1991) L C > 0 C 0 a. 9, * * I I * * w * SO I 0 30 40 50 SO 10 50 TLD - mR t Itn rs ton in.I)51$ (V • AX • PlC - C1.1023 5 X TLO) • In on. yw a I 90 100 In one year 110 120 130 140 32 ------- 4 Atmospheric Monitoring The inhalation of radioactive airborne particles can be a major pathway for human exposure to radia- tion. The atmospheric monitoring networks are designed to detect environmental radiation from NTS and non-NTS activities. Data from atmo- spheric monitoring can determine the concentration and source of airborne radioactivity and can project the fallout patterns and durations of exposure to man. Atmospheric monitoring networks include the Air Surveillance, Noble Gas, and Atmospheric Moisture (Tritium-in-Air) networks. The atmospheric monitoring networks were de- signed to monitor the areas within 350 kilometers (210 miles) of the NTS. These continuously operating networks are supplemented by standby networks which cover the contiguous states west of the Mississippi River. Many of the data collected from the atmospheric monitoring networks fall below the minimum detect- able concentration (MDC). Averages of data presented in this chapter were calculated including measured results below MDCs. All of the data collected from the atmospheric monitoring networks reside on a VAX computer in the Sample Tracking Data Management System (S1DMS). 4.1 Air Surveillance Network 4.1.1 Design In 1991, the Air Surveillance Network (ASN) consisted of 33 continuously operating sampling stations located in areas surrounding the NTS (see Figure 22 for sampling locations). Complementing the ASN, the Standby Air Surveillance Network (SASN) consisted of 76 samplers located in contig- uous states west of the Mississippi River (see Figure 23 for standby station locations). Each state had at least one standby sampler which was operated continuously for one week each quarter by local residents or state and municipal health department personnel. Locations of stations were dependent upon the availability of electrical power and the willingness of a local resident to operate the equipment at stations distant from the NTS. Changes to the ASN during 1991 included the relocation of the Scotty’s Junction station from Holloway’s Ranch approximately one-halt mile to Terrell’s Ranch on June 24. This station, the Amargosa Valley Community Center Station (Amargosa Valley, Nevada), and the G. L. Coffer- Fleur-de-Lis Ranch (Beatty, Nevada) were reas- signed to the Yucca Mountain Project ASN on December 1, 1991. High-volume air samplers were also installed and operated in May at Amar- gosa Valley, Nevada and from May 28 through July 8 at Rachel, Nevada. The high volume air sam- plers were evaluated as part of a special study. The results from the high-volume air samplers are presented in conjunction with the results from the routine air samplers. The air sampler at each station was equipped to collect particulate radionuclides on fiber prefilters and gaseous radioiodines in charcoal cartridges. Prefitters and charcoal cartridges collected from all ASN and prefitters collected trom all SASN stations received complete analyses at EMSL-LV. Char- coal cartridges are collected from the SASN sta- tions and would be available for analyses should the need arise. 4.1.2 Procedures At each ASN station, samples of airborne particu- lates are collected as air is drawn through 5 cm (2.1 in) diameter, glass-fiber filters (prefilters) at a flow rate of about 80 m 3 (2800 ft 3 ) per day. Filters are exchanged after sampler operation periods of about one week (approximately 560 m 3 or 20,000 ft 3 ). Activated charcoal cartridges placed directly behind the filters to collect gaseous radioiodines are exchanged at the same time as the filters. Duplicate air samples were obtained weekly from various stations. Four air samplers, which are identical to the ASN station samplers, were rotated between ASN stations for three to four week periods. The results of the duplicate field sample analyses are given in Chapter 11 as part of the data quality assessment. The samplers used at the standby stations are identical to those used at the continuously operat- ing stations. Results were not provided for Oregon 33 ------- . . s I • — $ — — U — U — I u p — I NEVADA TJTAH • I i I I I I I Ipyp I Lake’ I .LN I CftYl • I I I Austh• I I SEly De lta• I BIueEVeRn. I i Sbne I •MIIford I Cabin Rn. Nyala Sr - I Tonopah ____ . . . . rrR Springs Rn. Ploche I I - •HIko •CalIente •Cedarclty I •PJano 1 1 Sco s • I •St.George I I — — — — — Id ARIZONA Fumace reek. I Ama9osa Cen r Death Va ey Jtxlcthn 4 N Scab W Mile. 100 • Community Monitoring Stations (19) _______________ • Other Air Samphng Stations (14) 0 _______________________________________ Scala ii KiIcme ere Figure 22. Air Surveillance Network stations, 1991. Ind n1 Shoehone 0 34 ------- Canada AStandby AJr Surveillance Network Stations (76) Scale in Miles 0 100 300 500 1.11111.11 , Ii I 100 300 500 700 Scale in Kilometers Figure 23. Standby Air Surveillance Network stations, 1991. 35 ------- for the 1991 second quarter because the two SASN samplers in this state were not operated. At EMSL-LV, both the prefliters and the charcoal cartridges are initially analyzed by high resolution gamma spectrometry. Each of the prelilters is then analyzed for gross beta activity. Gross beta analysis is performed on the pref liters 7 to 14 days after sarr le collection to allow time for the decay of naturally occurring radon-thoron daughter prod- ucts. Gross beta analysis is used to detect trends in atmospheric radioactivity since it is more sensi- tive than gamma spectrometry for this purpose. Selected pref liters are then composited (combined) and analyzed for plutonium isotopes. Details of the analytical procedures are provided in Chapter 12. In 1991, prefitters from five ASN stations were composited monthly: Alamo, Amargosa Valley, Las Vegas, and Rachel, Nevada; and Salt Lake City, Utah. Prefliters from Alamo were composited for plutonium analysis beginning in January 1991 because this station is located in the prevailing downwind direction from areas on the NTS under- going or scheduled for remediation activities. Plutonium analysis Will no longer be performed on the prefilters from Salt Lake City effective January 1992. For the thirteen states which contain two SASN stations, the prefilters from the two stations are composited quarterly. These states are Arizona, California, Colorado, Idaho, Missouri, Montana, New Mexico, North Dakota, Oregon, Texas, Utah, Washington and Wyoming. 4.1.3 Results The majority of all ASN and SASN prefilters and cartridges analyzed by gamma spectrometry were gamma-spectrum negligible (i.e., no gamma emitting radionuclkies were detected). Naturally occurring 7 Be averaging 0.23 X 1012 CVmL was the only radionuclide occasionally detected. The pnnc aI means of 7 Be production is from spallation (splitting) of 160 and 14 N by cosmic rays in the atmosphere. As in previous years, the majority of the gross beta results exceeded the MDC. Gross beta results for the ASN and the SASN are summarized in Table 4 and Appendix B, Table B-i respectively. The average gross beta activity in 1991 (calculated as an average of the average activity from each station) was 0.01 76 X 10 2 pCi/mL. As a compari- son, the 1990 average was 0.0224 X 10.12 .tCVmL. Figures 24, 25, and 26 show the distribution of the gross beta values from each ASN station for 1989, 1990, and 1991 respectively. The stations are ordered by ascending means of the data values. The mean values are represented by the filled circles (black dots). The left and right edges of the box on the graph represent the 25th and 75th percentiles of the distribution of the values (i.e., 50% of the data falls within this region). The vertical line drawn inside the box represents the 50th percentile or the median value. The horizon- tal lines extend from the box to the minimum and maximum values. The averages of the quarterly gross beta values from the SASN stations, ar- ranged by ascending values, are shown in Appen- dix B, Figure B-i. Figure 27 shows the distribution of the mean monthly gross beta averages from 1989 through 1991 for Alamo, Amargosa Valley, Beatty, Gold- field, Indian Springs, Rachel, and Tonopah, Neva- da combined. The distribution of the data is presented by the same conventions as in Figure 24. These stations were selected for the graph as they are located in close proximity to the NTS. The figure indicates little change in regional gross beta activity over the last several years. The mean quarterly gross beta averages for the SASN sta- tions divided into three regions are provided in Figures 28, 29, and 30. The Mid-West region included Louisiana, Texas, Arkansas, Oklahoma, Missouri, Kansas, Iowa, Nebraska, Minnesota, South and North Dakota. The Mountain region included New Mexico, Arizona, Colorado, Utah, Wyoming, Idaho and Montana. The Western region included California, Nevada, Washington and Oregon. The gross beta data from 1991 are consistent with data from previous years. The 23 Pu and 23 240 Pu results from January through December 1991 for the ASN and the SASN are listed in Appendix B, Table B-2. The collection date associated with the results refers to the collection date of the last (most recent) sample induded in the composite. The plutonium results from four of the samples exceeded the MDC. Two of these were very close to the MDC: Pu results from Las Vegas, Nevada for February 25; and 2 Pu results from Logan and Vernal, Utah for June 27, 1991. The other two values- exceeding the MDC were the 2 ’°Pu results from the high- 36 ------- Table 4. Gross Beta results for the Air Surveillance Network, 1991 Gross Beta Concentration Number x 1 012 j .tCiIrnL of days Sampling Location Sampled ’ Maximum Minimum Mean Std. 0ev. Death Valley Junction, CA 365 0.036 0.004 0.017 0.009 Furnace Creek, CA 365 0.100 0.003 0.026 0.019 Shoshone, CA 365 0.056 0.005 0.019 0.010 Alamo, NV 365 0.027 -0.011 0.015 0.006 Amargosa Valley, NV 364 0.036 0.007 0.017 0.007 Amargosa Valley Community Center, NV 336 0.042 0.004 0.019 0.008 Austin, NV 365 0.035 0.001 0.014 0.007 Beatty, NV 359 0.036 0.008 0.018 0.006 Beatty, NV Coffer-Fleur-de-Lis Ranch 335 0.032 0.001 0.013 0.007 Caliente, NV 365 0.039 0.002 0.018 0.007 Clark Station, NV Stone Cabin Ranch 365 0.033 0.006 0.016 0.006 Currant, NV Blue Eagle Ranch 365 0.050 0.006 0.018 0.009 Ely, NV 365 0.023 0.004 0.014 0.004 Goldfield, NV 358 0.032 0.007 0.017 0.006 Groom Lake, NV 345 0.033 0.006 0.017 0.006 Hiko, NV 358 0.032 0.003 0.017 0.006 Indian Springs, NV 365 0.037 0.009 0.019 0.006 Las Vegas, NV 360 0.100 0.008 0.022 0.014 Nyaia, NV 358 0.041 0.007 0.013 0.007 Overton, NV 365 0.042 0.008 0.021 0.009 Pahrump, NV 365 0.043 0.005 0.018 0.008 Pioche, NV 364 0.036 0.005 0.017 0.005 Rachel, NV 365 0.053 0.005 0.019 0.009 Scotty’s Junction, NV Holloway’s Ranch 175 0.039 0.006 0.018 0.008 Scotty’s Junction, NV Terreirs Ranch 161 0.037 0.003 0.022 0.008 Sunnyside, NV 365 0.040 0.002 0.015 0.008 Tonopah, NV 365 0.027 0.006 0.015 0.005 Tonopah Test Range, NV 365 0.039 0.000 0.016 0.008 Twin Springs, NV Fallini’s Ranch 365 0.104 0.010 0.022 0.015 Cedar City, UT 365 0.034 0.007 0.016 0.006 Delta, UT 365 0.066 0.010 0.021 0.012 Milford, UT 365 0.059 0.003 0.021 0.011 St. George, UT 364 0.043 0.005 0.019 0.009 Salt Lake City, UT 365 0.037 0.008 0.017 0.006 (9 ) .tCWmL = pCWm 3 ; multiply tCWmL result by 0.037 to obtain BqIm 3 . (b) Days sampled are determined from filter change dates. Station moved to Terrell’s Ranch on June 24, 1991. Station moved from Holloway’s Ranch on June 24, 1991. 37 ------- Routine Air Sampling Stations - 1989 Nyala, NV Ely, NV TTR, NV• Stone Cabin Ranch, NV Sunnyside, NV Blue Eagle Ranch, NV - Twin Springs, NV - Pioche, NV - Rachel, NV - Goldfield, NV - Amargosa Valley, NV - Austin, NV Pahrump, NV Tonopah, NV’ Caliente, NV Groom Lake, NV• Beatty, NV Cedar City, UT Hiko, NV• Indian Springs, NV• Salt Lake City, UT Shoshone, CA• Alamo, NV• Overton, NV Las Vegas, NV - Holloway’s Ranch, NV Death Valley Jct., CA - Milford, UT- St. George, UT- Delta, UT - Furnace Creek, CA - -0.02 I I I E TJ Beta in Air (1.OE-12 iJCifmI) Figure 24. Distribution of givss beta values from air surveillance network stations, 1989. Figure shows minimum, 25th percentile, mean, median, 75th percentile, and maximum values. E J I - I J•] I I 11.1 Il .1 0.02 0.06 0.10 0.14 38 ------- Routine Air Sampling Stations - 1990 Nyala,NV [ I:] Coffer Ranch, NV CedarCity,UT- [ J Stone Cabin Ranch, NV - Sunnyside, NV• Blue Eagle Ranch, NV - TTR,NV- I EIJ Groom Lake, NV - Tonopah, NV• Amargosa Valley, NV - I LIJ I Austin, NV - Ely, NV - Death Valley Jct., CA - Rachel, NV 1+J I Pahrump, NV - Goldfield, NV - Indian Springs, NV - Pioche, NV - Hiko, NV- Salt Lake City, UT - Twin Springs, NV - I St. George, UT - I Amargosa Center, NV - ____ ______ Holloway’s Ranch, NV - Beatty, NV - Shoshone, CA - I I I . I I Caliente, NV - Milford, UT Las Vegas, NV - Alamo,NV- I Overton, NV - Delta, UT - Furnace Creek, CA - I -0.02 0.02 0.06 0.10 0.14 Beta in Air (1.OE-12 pCVml) Figure 25. Distribution of gross beta values from air surveillance network stations, 1990. Figure shows minimum, 25th percentile, mean, median, 75th percentile, and maximum values. 39 ------- Routine Air Sampling Stations - 1991 Coffer Ranch, NV - Nyala, NV - Ely, NV - Austin, NV - Sunnyside, NV - Alamo, NV- Tonopah, NV - TTR, NV Stone Cabin Ranch, NV• Cedar City, UT Pioche, NV Hiko, NV• Death Valley Jct., CA• Amargosa Valley, NV• Groom Lake, NV• Goldfield, NV• Salt Lake City, UT• ‘— [ 1)---——’ Holloway’s Ranch, NV Caliente, NV• Pahrump, NV- Blue Eagle Ranch, NV• Beatty, NV- Rachel, NV - Indian Springs, NV- Amargosa Center, NV - Shoshone, CA - St. George, UT - Overton, NV - Delta,UT- ‘—O+ Milford, UT - Las Vegas, NV - I—D: I Terrell’s Ranch, NV - Twin Spnngs, NV - HL J I Furnace Creek, CA - -0.02 0.02 0.06 0.10 0.14 Beta in Air (1.OE-12 iCVmI) Figure 26. Distribution of gross beta values from air sua’veillance network stations, 1991. Figure shows minimum, 25th percentile, mean, median, 75th percentile, and maximum values. 40 ------- 0.10 !0.08 0.06 1 01/01/89 01 / 01/90 01/01 191 01101192 Sample Collection Date Figure 27. Distribution of the mean quarterly gross beta averages for seven stations surrounding the NTS. 0.10 0 ( \1 1 w 0.04 J0.02 0 (Y i 01/01/89 01/01/90 01101/91 01/01/92 Sample Collection Date Figure 28. Distribution of the mean quarterly gross beta averages from standby stations in the midwest region. 41 ------- 0.10 0• c%J 1 w q. 0.04 Jo.o2 0.00 . 01/01 9 01/01/90 01/01/91 01/01/92 Sample Collection Date Figure 29. Distribution of the mean quarterly gross beta averages from standby stations in the mountain region. 0.10 0• c J 1 w q. ; 0.04 0.02 0.00 . 01/01/89 01/01/90 01/01/91 01 /01/92 Sample Collection Date Figure 30. Distribution of the mean quarterly gross beta averages from standby stations in the western region. 42 ------- volume air samples collected from Amargosa Valley on May 28; and from Rachel, Nevada on July 8, 1991. The MDCs associated with the high- volume air samples are very low compared to the MDCs associated with the routine air samplers because of the larger volume of air collected. Equipment problems (e.g., motor failure at high temperatures) with the high-volume samplers precluded any further high-volume sampling. The use of other, more durable high-volume samplers is currently being investigated. The plutonium results from 1991 are consistent with data from previous years. 4.2 Tritium In Atmospheric Moisture 4.2.1 Design At the beginning of 1991, the tritium network consisted of 20 continuously operated and two standby stations. A number of changes were made to the tritium network in 1991: the station at Pioche, Nevada, was discontinued November 12; a new station at Fallini’s Ranch, Twin Springs, Nevada, was activated November 19; and the St. George, Utah, sampler was relocated September 4 from the high school to Dixie Junior College. The following six stations were converted from routine to standby status effective with their last sampling collection periods in November, 1991: Shoshone, California; Salt Lake City and Cedar City, Utah; and Austin, Ely, and Caliente, Nevada. The two standby stations (Delta and Milford, Utah,) were not activated during 1991. Figure 31 shows the locations of the tritium network sampling stations in conjunction with the noble gas sampling network stations. 4.2.2 Procedures A column filled with molecular sieve pellets is used to collect moisture from the air. Approximately 6 m 3 (212 ft 3 ) of air is drawn through the column during a typical 7-day sampling period. The water absorbed in the pellets is recovered and measured and the concentration of 3 H is determined by liquid scintillation counting. The volume of recovered water and the 3 H concentration is then used to calculate the concentration of HTO, the vapor form of tritium. HTO is the most common form of tritium encountered in the environment. 4.2.3 Results Of the 957 samples collected in 1991, 23 were of insufficient volume to permit analysis. Six of the 934 analyses performed exceeded the MDC. Three of these six results were very close to the MDC: Shoshone, California for January 28 through February 4 was 1.70 X 1 012 l.tC /mL with a two sigma value of 1.02 and an MDC of 1.64; Gold- field, Nevada for June 18 through June 26 was 4.53 X 10.12 p CVmL with a two sigma value of 2.43 and an MDC of 3.91; Rachel, Nevada for June 17 through June 24 was 2.43 X 1 012 .tCVmL with a two sigma value of 1.38 and an MDC of 2.22. Of the other three results above MDC, one sample was collected from the Salt Lake City, Utah, station for the week of March 11 through March 18 and had a result of 10.2 X 10 2 l.LCVmL with a two sigma value of 2.57 and an MDC of 3.99. This station is adjacent to the engineering nuclear reactor complex. A telephone conversation with personnel at the reactor complex verified that tritium was present at the time of sample collection. The two other results above MDC were from samples collected from the Las Vegas. Nevada, station for the weeks of June 24 through July 1 and July 19 through July 22. These samples had results of 15.0 X 10.12 p .CVmL with a two sigma value of 6.78 and an MDC of 10.80, and 8.46 X 10 12 xCiImL with a two sigma value of 4.07 and an MDC of 4.07 respectively. The highest value of 15.0 x 10.12 tCi/mL is approximately 0.01% of the concentration guide. This station is adjacent to the EPA Radioanalysis Laboratory. The HTO average concentration for the Las Vegas, Nevada, station was 1.69 X 10.12 CVmL as compared to the 1990 average of 0.42 X 10 12 RC1ImL. (Note: Averages include results which are less than MDC). The overall HTO network average concentration, including values below MDC, was 0.496 X 10.12 pCi/mL as compared to the 1990 average of 0.591 X 10.12 .tCi/mL. The HTO data are summarized in Table 5. The distribution of the HTO data from each station is shown in Figure 32. The graph is presented using the same conventions as in Figure 24. The 1991 tritiurn data appear to be consistent with data from previous years. 43 ------- NEVADA I UTAH c y 1 I I I 100 I I I 0 50 100 150 Scale I K ometers *PYRAM1 LNcE Au • •EIy Defta• b opah 1 n £ • M tord •Aiano •Cedarc lty I St George $ N oehoneI ARIZONA MEAD • Both Noble Gas and Tritium (18) A Tritium only (1) • Standby Noble Gas and Trltium (2) V Tritium, Standby Noble Gas (1) 0 Scale m Mb a 50 Figure 31. Offsite noble gas and tritium suriei!Iance netsvrk sanpling locations, 1991. 44 ------- 4.3 Noble Gas Sampling Network 4.3.1 Design At the beginning of 1991, the Noble Gas Sampling Network consisted of 16 continuously operated and three standby stations. Noble gas samplers were added to the Amargosa Valley Community Center and to the Twin Springs, NV (Fallini’s Ranch), Station in May of 1991, increasing the number of routinely operated stations to 18. Samples were collected approximately once a week from the Table 5. Atmospheric Tritium Results, 1991 routinely operated stations and between 1 and 4 times during the year from the standby stations. Samples collected were analyzed for 85 Kr and 1 Xe. The locations of the noble gas sampling stations are shown in Figure 31. Noble gases may be released into the atmosphere from research and power reactor facilities, fuel reprocessing facilities, and from nuclear testing. Noble gases may also be released during drill- backs and tunnel purgings which take place after nuclear tests. Environmental levels of the xenons, with their very short half-lives, are normally below 10.12 p.Ci/mL = pCi /rn 3 ; multiply j.tCiImL result by 0.037 to obtain BqIm 3 . Percent of the Concentration Mean Std. Dev. Guide ‘ The concentration guide referenced is calculated from the dose conversion factors for inhalation as listed in DOE Order 5400.5 (DOE, 1988b), adjusting to 10 mrem effective dose equivalent as required by 40 CFR 61 (CFR, 1989) for nonoccupational exposure to radionuclides in air. Concentration guides are listed in Chapter 13. Number of Samples Sampling Location Analyzed Concentration (1012 iCVmL) Maximum Minimum Shoshone, CA 45 2.9 -4.6 0.12 1.51 <0.01 Alamo, NV 52 7.2 -4.3 0.79 2.24 <0.01 Amargosa Center, NV 51 6.1 -9.2 0.47 2.20 <0.01 Amargosa Valley, NV 49 2.7 -3.0 0.27 1.24 <0.01 Austin, NV 46 4.0 -2.0 0.50 1.26 <0.01 Beatty, NV 51 3.8 -1.0 0.60 1.07 <0.01 Caliente, NV 46 9.7 -10.2 0.42 3.27 <0.01 Ely, NV 45 4.4 - 4.3 0.50 1.74 <0.01 Goidlield, NV 53 14.3 -7.0 0.42 2.98 <0.01 Indian Springs, NV 48 9.2 -3.7 0.86 2.37 <0.01 Las Vegas, NV 53 15.0 -2.9 1.69 2.92 <0.01 Overton, NV 53 2.8 -3.9 0.40 1.34 <0.01 Pahrump, NV 52 5.9 -3.0 0.26 1.67 <0.01 Pioche, NV 46 8.4 -3.1 0.61 2.14 <0.01 Rachel, NV 50 2.4 -4.6 0.40 1.21 <0.01 Tonopah, NV 52 11.6 -6.1 0.79 2.95 <0.01 Twin Springs, NV 6 2.2 -1.6 0.14 1.63 <0.01 Cedar City, UT 45 3.9 -7.0 0.11 1.68 <0.01 St. George, UT 51 5.2 -2.6 0.36 1.59 <0.01 Salt Lake City, UT 41 10.2 -3.3 0.97 2.16 <0.01 45 ------- Cedar City, UT Shoshone, CA Twin Springs, NV Pahrump, NV• Amargosa Valley, NV• St. George, UT Overton, NV• Rachel, NV Caliente, NV• Goldfield, NV Amargosa Center, NV Ely, NV Austin, NV - Beatty, NV Pioche, NV• Alamo, NV Tonopah, NV• Indian Springs, NV• Salt Lake City, UT Las Vegas, NV - -15 Figure 32. Distribution of HTO data, 1991. percentile, and maximum values. the MDC. Krypton-85 disperses more or less uniformly over the entire globe because of its half- life, 10.7 years, and the lack of significant sinks (NCRP, 1975). For these reasons, Kr results are expected to be above the MDC. A number of changes were made to the network during 1991 in addition to installing noble gas samplers at two stations. In November, the fol- lowing five stations were converted from routine to standby status: Austin, Caliente, and Ely, Nevada; Shoshone, California; and Cedar City, Utah. All of the existing noble gas samplers, used since 1974, were replaced with newly designed samplers during 1991. The first replacement was completed at the Las Vegas station in March. After a suc- cessful evaluation period, replacement was initiated at the remaining stations in May. An essential part of the development included comparison testing of the old and new model systems to ensure data HI H Tritium in Air Moisture (1.OE-12 uCi/mi) Figure shows minimum, 25th percentile, mean, median, 75th comparability. The results of the comparison testing are discussed in Section 11.4.4. 4.3.2 Procedures Noble gas samples are collected by compressing air into storage tanks (bottles). Air is continuously sampled over a 7-day period, collecting approxi- mately 0.6 m 3 (21.2 ft 3 ) of air. The tanks are returned to the Radioanalysis Laboratory for analysis. The old noble gas samplers consisted of a two-bottle system; both bottles were filled simul- taneously during the entire sampling period (i.e., one bottle was a duplicate of the other). The new noble gas samplers consist of a four-bottle system. One bottle is filled over the entire sampling period. The other three bottles are filled consecutively over the same sampling period in 56-hour increments. The bottle containing the sample from the entire I F- I ( } ___ I I I __ 101 I I ___ I I I I I I -10 -5 0 5 10 15 46 ------- sampling penod is the only sample which is rou- tinely analyzed. If xenons or abnormally high levels of Kr were detected in this sample, then the other three samples would be analyzed. For the analysis, samples are condensed at liquid nitrogen temperature. Gas chromatography is then used to separate the vanous radionuclides. The radioactive gases are dissolved in liquid scintillation ‘cockLails, then counted to determine activity. 4.3.3 Results Table 6 summarizes the Kr and Xe results for all routine and standby sampling locations. The table contains the number of samples analyzed and the minimum, maximum, mean, and standard deviation of the concentrations measured at each station. The number of samples analyzed is frequently less than 52 because samples are occasionally lost in analysis, lost due to equipment failure, or the sample volume collected is insuffi- cient to permit analysis. Some of the data losses were due to problems experienced with the new noble gas samplers. These pnblems are dis- cussed further in Section 11. All of the Kr results exceeded the MDC and were within the range anticipated. Activities ranged from 20.5 to 32.3 pCi/rn 3 . This activity range is virtually identical to that observed in 1990. All of the 1 Xe results were below the MDC. The MDC for 1 Xe varied but was generally about 14 pCi/rn 3 . Figure 33 shows the distribution of the Kr data from each routine sampling location arranged by as- cending means. Those stations for which the status changed from routine to standby in Novem- ber are included in the graph as they were routine- ly sampled throughout the majority of the year. The graph is presented using the same conven- tions as in Figure 24. The graph shows that Kr results are very consistent among stations. Figure 34 shows the annual average Kr value from 1972 through 1991. The graph shows that the levels of Kr have remained consistent over the past sever- al years. The results for 1 Xe are not graphed as all the values were below the MDC. 4.4 Quality Assurance/ Quality Control General quality assurance/quality control guidelines for the atmospheric monitoring networks are as follows: • Maintaining a current calibration decal on all field sampling and laboratory instru- ments. • Maintaining a file of calibration records, control charts, and log books. • Assigning unique sample numbers. • Obtaining laboratory supervisor approval of all analytical results before they are entered into the permanent data base. • Maintaining files of QA data, which includes raw analytical data, intermediate calcula- tions, and review reports. • Performing analysis of blanks to verify that method interferences caused by contami- nants in solvents, reagents, glassware, and other sample processing hardware are known and minimized. • Estimating analytical accuracy with perfor- mance evaluation samples. For the gamma analysis of fiber filters, spiked samples should be within ± 10% of the known value. Gross beta analysis should be within ± 20%. Plutonium analysis of internal spikes should produce results within ± 20% of the known value. For the noble gases, spiked samples should be within ± 20% of the known value. • Estimating precision of laboratory analytical techniques and total precision for the entire system (both analytical and sampling error) using replicates. Field duplicate air sam- ples as well as internal laboratory replicates are analyzed for the ASN. Only internal laboratory replicates are analyzed for the noble gas and the HTO samples. • Determining bias (the difference between the value obtained and the true or refer- ence value) by participating in intercom- parison studies. Further discussion of the QA program and the data quality assessment is given in Chapter 11. 47 ------- Table 6. Noble Gas Sampling Network - Kr and 1 Xe Results, 1991 Station Name # of Samples Minimum Maximum Mean Std. Dev. Kr Concentration (pCi/rn 3 ) Alamo, NV 44 22.4 30.7 26.26 1.99 Amargosa Center, NV 24a 24.0 31.0 27.46 2.16 Amargosa Valley, NV 42 23.5 30.2 26.55 1.73 Austin, NV 32 ” 22.3 30.9 26.52 2.25 Beatty, NV 52 22.2 30.9 26.32 1.92 Caliente, NV 37 b 21.9 29.7 25.85 1.85 Cedar City, (if 33 b 22.4 29.2 25.96 1.82 Delta, UT 4° 25.0 30.0 27.28 1.92 Ely, NV 38 b 21.3 31.1 26.30 2.03 Goldfield, NV 51 22.6 31.1 26.99 1.96 Indian Springs, NV 48 20.8 31.0 26.78 2.02 Las Vegas, NV 45 22.3 31.0 26.83 1.98 Milford, UT 3° 22.5 28.3 26.17 3.19 Overton, NV 53 21.2 32.3 26.44 2.08 Pahrump, NV 46 21.3 30.7 26.50 2.14 Rachel, NV 45 21.6 30.5 26.82 1.95 Salt Lake City, UT 1° 23.8 23.8 23.80 N/A Shoshone, CA 20.5 28.9 25.86 2.00 St. George, UT 46 21.1 30.2 26.16 2.26 Tonopah, NV 46 20.9 30.6 26.22 2.15 Twin Springs, NV 28a 21.5 30.1 26.76 1.90 1 Xe Concentration (pCi/rn 3 ) Alamo, NV 45 -12.40 12.70 -1.14 5.65 Amargosa Center, NV 26 -13.00 16.00 -2.37 6.51 Amargosa Valley. NV 41 - 7.29 4.10 -1.36 3.03 Austin, NV 32 b -19.20 9.50 -2.06 6.02 Beatty, NV 52 -13.60 7.06 -0.88 4.33 Cahente, NV 37b -20.90 13.40 -2.51 7.21 Cedar City, UT 33 b -13.90 5.52 -2.23 4.97 Delta, UT 4° 6.2 10 8.50 1.46 Ely, NV -18.90 12.40 -1.39 6.64 Goldfleld, NV 51 -11.40 9.75 -0.86 4.26 Indian Springs, NV 49 -6.88 5.29 -0.64 3.12 Las Vegas, NV 47 -7.55 13.90 -0.84 3.71 Milford, UT 3° -6.68 8.93 -1.15 8.74 Overton, NV 53 -9.70 13.40 -1.48 4.30 Pahrump, NV 47 -7.88 4.30 -1.42 3.14 Rachel, NV 46 -15.00 15.00 -1.08 5.72 Salt Lake City. UT 1 C -1.63 -1.63 -1.63 N/A Shoshone, CA 39” -9.18 3.81 -1.48 3.44 St. George, UT 49 -12.40 14.40 -2.16 4.49 Tonopah, NV 46 -13.80 7.20 -1.41 4.64 Twin Springs, NV 2T -15.30 5.91 -2.56 5.72 * Installed in May 1991 b Standby status as of November 1991 S_ S ns 48 ------- Cailente, NV Shoshone, CA - Cedar city, 1ff- St Geoige, UT Tonopah, NV Alamo, NV Ely, NV• Beatty, NV Overton, NV• Pahrump, NV• Austin, NV• A.margosa Vailey, NV Twin Spnngs, NV Indian Springs, NV Rachel, NV• Las Vegas, NV• Goldfield, NV• Amargosa Center, NV• Kr-85 (pCi/m3) Figure 33. Distribution of kiypton data from routine sampling stations, 1991. Figure shows minimum, 25th percentile, mean, median, 75th percentile, and maximum values. — --------- I I 22.5 25.0 20.0 27.5 30.0 32.5 45. 40’ 35.. • • • • •. .. 15. 10. 5. 0• I I 1970 1975 1980 1985 1990 1995 Figure 34. Annual network average kiypton 85 concentrations . 49 ------- 5.0 Foodstuffs Ingestion is one of the critical transport pathways for radionuclides to humans. Food crops may absorb radionuclides from the soil in which they are grown. Radionuclides may be found on the surface of fruits and vegetables from atmospheric deposition, resuspension, or in particles of soil adhering to vegetable surfaces. Weather patterns, especially precipitation, can affect soil inventories of radionuclides. Grazing animals ingest radio- nuclides which may have been deposited on forage grasses and, while grazing, ingest soil which may contain radionuclides. Certain organs in the grazing animal, such as liver and muscle, may bioaccumulate radionuclides. These radionuclides are transported to humans by consumption of meat and meat products. In the case of milk cattle, ingested radionuclides may be transferred to milk. This is particularly true of radioiodine isotopes, which, when consumed by children, can cause significant impairment of thyroid function. Water is another significant ingestion transport pathway of radionuclides to humans. To monitor the ingestion pathways, milk surveil- lance and biomonitonng networks are operated within the Offsite Radiological Safely Program (ORSP). Drinking water is monitored under the Long-Term Hydrological Monitoring Program (LTHMP), discussed in Chapter 7. The Milk Surveillance Network (MSN) includes commercial dairies and family-owned milk cows and goats representing the major rnilksheds within 180 miles (300 km) of the NTS. The MSN is supplemented by the Standby Milk Surveillance Network (SMSN) which includes all states west of the Mississippi. The biomonitoring network includes the animal investigation program and monitoring of radio- nuclides in locally grown fruits and vegetables. The biomonitonng network also includes special studies, such as collection and analysis of forage and grains. No such special studies were conduct- ed in 1991. 51 Milk Surveillance Network Milk is particularly important in assessing levels of radioactivity in a given area and, especially, the exposure of the population as a result of ingesting milk or milk products. It is one of the most univer- sally consumed foodstuffs and certain radionuclid- es are readily traceable through the food chain from feed or forage to the consumer. Because dairy animals consume vegetation representing a large area of ground cover and because many radionuclides are transferred to milk, analysis of milk samples may yield information on the deposi- tion of small amounts of radionuclides over a relatively large area. Accordingly, milk is closely monitored by EMSL-LV through the MSN and the SMSN. 5.1.1 Design As in other networks, MSN collection locations are distributed around the NTS in those places that have family dairy cows or goats or where commer- cial dairies exist. MSN stations are located within a 180 mile radius of the NTS. Figure 35 shows the 23 MSN stations for which milk was collected in 1991. Samples from these stations were collected monthly. Samples were not collected from the Susie Scott and the Jane Frayne ranches near Goldfield, Nevada in 1991 because the goats were dry. These two ranches will remain in the MSN. Three ranches were deleted from the network during 1991: McKays Ranch, Ely, Nevada (deleted in January); Twin Springs Ranch, Warm Springs, Nevada (deleted in December); and Blue Jay Springs Ranch, Blue Jay, Nevada (deleted in September). Of these three ranches, only Blue Jay Springs Ranch provided milk in 1991. Four MSN stations were added to the network in 1991: John Deer (in March) and Bar-B-Cue (in July) Ranches, Amargosa Valley, Nevada; Karen Harper property (in October), Tonopah, Nevada; and Bradshaw’s Ranch (in November), Duckwater, Nevada. The SMSN consists of 115 dairies or processing plants located in all states west of the Mississippi River and is activated annually to monitor trends and ensure proper operation of the network in case of an emergency. The SMSN is activated by a written request for samples from EMSL-LV. The request is sent to the five federal Food and Drug Administration (FDA) regional offices covering the western states and to state representatives for each state. The FDA regulates 51 ------- I_I NEVADA UTAH I I I I I I ! I Austi,• rgRn.• - DcJ t&. Bradshaw Rn. • Harbecke Rn. M zon,e Rn. • undO Shoehone Curmnt R.Horsley e •BlueEagleRn. I usJaySprmgsRn.• - Tonopah Wami •Nyaia i KHaiper Springs SharpeRn. I Lemon Rn. DYOf June Cox Rn.U I Cedar City I. Brown Rn. Ca lIente • B 1hInlS Dairy - David Hafen I :. . . . — . — . • Hafen Dairy ARIZONA • Mesq nte L. Marshall Rn. MEAD —I John Deer Pahnimp Pahiump Dairy • Inyokem • Cedarsage Farm Figure 35. Milk Surielilance Network stations, 1991. 4 N s I, i , ss 50 100 C— DaN Rn. •Hu*Iey • Desert View Daisy 0 6 s’o i i o S he m IGkdn eIs • Milk Sampling Locations • Nearest Town NOTE: When sanpling location occurred in city or town, the san ling location syn ol was used for showing both town and sanpling location. 52 ------- the dairy industry. The state representatives are responsible for the collection, the preservation, and the shipment of the samples to EMSL-LV for analysis. The locations of the SMSN stations are shown in Figure 36. Six stations in Texas were added to the SMSN during 1991. Prior to 1991, Texas had not been part of the SMSN. Samples were not received from the Lompoc, California SMSN station in 1991. 5.1.2 Procedures Raw milk is collected in 1-gallon (3.8 L) collapsible Cubitainers and preserved with formaldehyde. Routine sampling is conducted monthly for the MSN and annually for the SMSN, or whenever local or worldwide radiation events suggest possi- ble radiation concerns, such as the Chernobyl incident or nuclear testing by foreign nations. All samples are analyzed by high resolution gam- ma spectroscopy to detect gamma-emitting radio- nuclides. One sample per quarter from each MSN location and the annual samples from two of the SMSN locations in each western state (excluding Nevada) are evaluated by radiochemical analysis. These samples are analyzed for 3 H by liquid scintillation counting and for Sr and 90 Sr by radiochemical purification and beta counting. 5.1.3 Results For both MSN and SMSN samples, only naturally occurring 40 K averaging 2.17 gm(L was detected by gamma spectroscopy. Appendix C, Table C-i contains the 3 H, Sr, and 90 Sr quarterly results for the MSN samples. The 3 H, Sr, and 90 Sr results for the SMSN are provided in Appendix C, Table C-2. A list of the SMSN station samples which received gamma spectroscopy analysis only is provided in Appendix C, Table C-3. The majority of the 3 H, Sr, and 90 Sr results were below the MDC. Table 7 summarizes the number of values which exceeded the MDC for 3 H, Sr, and 90 Sr analysis for 1991 and compares them to the 1990 data for both MSN and SMSN stations. The values exceeding the MDC are also annotated in the tables listing the data in Appendix C. For the MSN, one sample result from the June Cox Ranch, Caliente, Nevada and one from the Harbe- cke Ranch, Shoshone, Nevada exceeded the MDC for 3 H. For both of these results, the MDC falls Table 7. Summary of Radionuclides Detected in Milk Samples # of Stations Radio- Avg. Conc. with results nuclide Year (pCVL) > MDC Milk Surveillance Network 3 H 1990 129 0 1991 152 2 Sr 1990 0.179 0 1991 0.303 1 90 Sr 1990 0.585 4 1991 0.546 4 Standby Milk Surveillance Network 3 H 1990 159 1 1991 153 1 Sr 1990 -0.161 0 1991 0.420 3 90 Sr 1990 1.324 17 1991 1.236 17 within or very close to one standard deviation of the analysis indicating the result is within expected statistical variation. For Sr, one result from the David Hafen Ranch, Ivens, Utah was the only value which exceeded the MDC. The MDC for this result was also within one standard deviation of the analysis result. For 90 Sr results, two samples from the Harbecke Ranch, Shoshone, Nevada and two samples from the Karen Harper Ranch, Tonopah, Nevada exceeded the MDC. Values above MDC have been observed at the Harbecke Ranch in previous years. The higher values have generally occurred during the summer months, indicating those values may be associated with feeding patterns during those months. The Karen Harper Ranch has not been sampled in previous years so there is no historical record from that ranch. One 3 H result, three Sr results, and 17 90 Sr results were above the MDC for samples from the SMSN stations. This is consistent with the number of values exceeding the MDC in 1990. Time series of the 90 Sr and H data for 1982 through 1991 are provided in Appendix C, Figures C-i and C-2 for those MSN stations for which there are historical data. The graphs show the result, the standard deviation, and the MDC for each analysis. The distribution of the past ten 53 ------- Figure 36. StancThy Milk Suriei!lance Network stations, 1991. 54 • St cby Mdk SurvesI Network Stabon Scale m Mies o ioo 300 • I I II I 100 300 500 700 Scale m KIom ers ------- years of 9 °Sr and 3 H data for the SASN stations are provided in Appendix C, Figures C-3 to C-a The stations were divided into three regions for the graphs: the Mid-West region including Louisiana, Texas, Arkansas, Illinois, Oklahoma, Missouri, Kansas, Iowa, Nebraska, Minnesota, South and North Dakota; the Mountain region including New Mexico. Arizona, Colorado, Utah, Wyoming, Idaho and Montana; and the Western region including California, Nevada, Washington and Oregon. It should be noted that the data presented in these graphs include many values which are below the MDC. Values below the MDC were reported as measured. In conclusion, the MSN and SMSN data are con- sistent with previous years and are not indicative of increasing or decreasing trends. No radioactivity directly related to current NTS activities was evident. 51.4 Quality Assurance/Control Procedures for the operation, maintenance and calibration of laboratory counting equipment, the control and statistical analysis of the sample and the data review and records are documented in approved SOP’s. External and internal comparison studies were performed and field and internal duplicate samples obtained for precision and accuracy assessments. Analytical results are reviewed for completeness and comparability. Trends are identified and potential risks to humans and the environment are determined based on the data. The data quality assessment is given in Chapter 11. 5.2 Animal Investigation Program The primary purpose of the animal investigation program is monitoring of the ingestion transport pathway to humans. Therefore, animals which are likely to be consumed by humans are targeted by the program. These are bighom sheep, mule deer, and beef cattle. Occasionally, other animals are analyzed. In 1991, tissue samples from a moun- tain lion shot in Area 12 of the NTS were analyzed. A veterinarian retained through EPA EMSL-LV investigates any claims of damage to animals caused by radiation. No such claims were re- ceived in 1991. 5.2.1 Network Design The objective of the animal investigation program is to determine whether there is any potential for radionuclides to reach humans through the inges- tion pathway. To that end, the program is based upon what is considered to be a worst-case sce- nario. Mule deer are migratory; the ranges of the herds which inhabit the NTS include lands outside the federal exclusionary area in which hunting is permitted. Therefore, it is theoretically possible for a resident to consume meat from a deer which had become contaminated with radionuclides during its inhabitation of the NTS. During the years of atmospheric testing, fission products were carried outside the boundaries of the NTS and deposited in the otfsite area. Longer-lived radionuclides, particularly plutonium and strontium isotopes, are still detected in soil in the area. Some of these radionuclides may be ingested by animals residing in those areas. Cattle are purchased from ranches where atmospheric tests are known to have depos- ited radionuclides. The continued monitoring of bighom sheep provides a long-term history for examination of radioactivity trends in large grazing animals. The collected animals are not selected to be representative of average radionuclide levels in animals residing in the offsite area, nor are they designed to be necessarily representative of the herd from which they are drawn. However, selec- tion is not random. There is an inherent nonran- dom selection in hunting and the ranchers select the cattle to be sold. Because the program is not statistically based, no conclusions can or should be drawn regarding average concentrations of radio- nuclides in animals in the offsite area, nor should any conclusions be drawn regarding average radionuclide ingestion by humans. The collection sites for the bighom sheep, deer, and cattle ana- lyzed in 1991 are shown in Figure 37. 5.2.2 Sample Collection and Analysis Procedures During the bighorn sheep season in November and December, licensed hunters in Nevada are asked to donate one leg bone and one kidney from each bighom sheep taken. The location where the sheep was taken and any other available informa- tion are recorded on the field data form. The bone and kidney samples are weighed, sealed in labeled sample bags, and stored in a controlled freezer 55 ------- Tonopah S Nyala Goldfield Mule Deer (1991) Cattle (1991) Numbers below or within symbol, represents the ai*nai identification numbers. City Smt. 5 Tempiute 1 Coyote Hiko JHancock Smt. Rn. AlElJflO I DESERT NATIONAL WILDUFE RANGE 0 0 Bighom Sheep (winter 1990) Baker Figure 37. Collection sites for animal samples. 56 ------- until processing takes place. Weights are recorded on the field data form. After completion of the hunting season, a subset of the samples is select- ed to represent areas around the NTS. The kidney is divided into two samples. One kidney sample is delivered to the EPA EMSL-LV Radioanalysis Laboratory for analysis of gamma-emitting radio- nuclides. The second kidney sample and all bone samples are shipped in a single batch to a contract laboratory for ashing. Upon completion of ashing, both the kidney and the bone samples are ana- lyzed for plutonium isotopes and the bone samples are additionally analyzed for strontium. All results are reported in units of pCi/g of ash. The ash weight to wet weight ratios (percent ash) are also reported, to permit conversion of radionuclide activity to a wet weight basis for use in dose calculations. Each year, attempts are made to collect four mule deer from the NTS, on a one per quarter schedule. if a deer is killed on the road, that animal is used. If road kills are not available, a deer is hunted by personnel with a special permit to carry weapons on the NTS. The deer is usually dressed in the field, with precautions taken to minimize risk of contamination. The location of the deer, weight, sex, condition, and other information are recorded on a field data form. Organs are removed, weighed, and sealed in labeled sample bags. Soft tissue organs, including lung, liver, muscle, and rumen contents are divided into two samples, one for analysis of gamma-emitting radionuclides and one which is ashed prior to analysis for plutonium isotopes. Thyroid and fetus (when available), because of their small size, are analyzed only for gamma-emitting radionuclides. Samples of blood are analyzed for gamma-emitting radionuclides and tritium. Bone samples are ashed and analyzed for plutonium isotopes and strontium. The samples requiring ashing are shipped in a single batch each quarter to a contract laboratory. Analyses are completed in the EPA EMSL-LV Radioanalysis Laboratory. Results for ashed samples are report- ed in units of pCVg ash; the percent ash is also reported to permit conversion to wet weight activity for calculation of dose assessments. Four cattle are purchased from ranches in the off site area around the NTS each spring and another four are purchased each fall. Generally, two adult cattle and two calves are acquired in each purchase. The facility at the old EPA farm on the NTS is used for the slaughter. This facility is designed to minimize risk of contamination. As with the bighorn sheep and mule deer, sampling information and sample weights are recorded on a field data form and samples are sealed in labeled sample bags. Samples of blood and soft tissues (lung, muscle, liver, thyroid, and kidney) are ana- lyzed for gamma-emitting radionuclides; blood is also analyzed for tritium activity. A second kidney sample and bone samples are sent to a contract laboratory for ashing. Ashed kidney samples are analyzed for plutonium isotopes; bone ash samples are analyzed for plutonium isotopes and strontium. On occasion, other animals become available for analysis. Such was the case when a mountain lion which had been menacing the NTS Area 12 camp was shot in March 1991. As with the other ani- mals, selected soft tissue and blood samples were analyzed for gamma-emitting radionuclides and blood samples were additionally analyzed for tritium. Selected soft tissue and bone samples were ashed by a contract laboratory and analyzed for plutonium isotopes; bone samples were addi- tionally analyzed for strontium. 5.2.4 Sample Results for Bighorn Sheep Licensed hunters in Nevada donated a kidney and leg bone from bighorn sheep collected in Novem- ber and December of 1990. From these, a subset was selected representing areas around the NTS. The kidney samples were analyzed for gamma- emitting radionuclides and for tritium. The bone samples were ashed prior to analysis of 9 °Sr, Pu, and 2 Pu. The results obtained from analysis of bighorn sheep bone and kidney are shown in Table 8. The numbers in the first column of the table refer to the numbered sample locations shown in Figure 37. Other than naturally occurring °K, neither gamma-emitting radionuclides nor tritium were detected at activities greater than the MDC in any of the kidney samples. All of the bone tissue samples, however, yielded 90 Sr activities greater than the MDC of the analysis. The range and median values for 90 Sr, shown in Table 9 and in Table 10, were similar to those obtained last year. The average 90 Sr levels found in animal bone ash since 1956 are shown in Figure 38. None of the bone samples yielded Pu results greater than the MDC of the analysis and only one sample (Bighom sheep No. 5) yielded a 240 Pu result greater than the MDC. This animal was collected in Area 287, south of Searchlight, Neva- da. Medians and ranges of plutonium isotopes, 57 ------- Table 8. Radionuclide Concentrations in Desert Bighom Sheep Samples taken in Winter 1990 Bone Bone Bone Kidney’ B i om °°Sr Pu 240 Pu 3 H Sheep Concentration Concentration Concentration Concentration Identifi- Percent ± 1 s ± 1 $ ± 1 s ± 1 s cation # Ash pCifg Ash) (lO 4 pCWg Mh)° ’ (lO 4 pCVg Ash) (pCVL) 1 33 1.8 ± 0.1 .13 ± 0.9 0.7 ± 1.5 -50 ± 140 2 34 l.7 ± 0.1 0.0 ± 0.6 0.4 ± 0.7 130 ± 140 3 32 * () ± 0.2 -1.3 ± 1.8 0.6 ± 1.4 -30 ± 140 4 27 1.2 ± 0.2 1.0 ± 1.3 0.0 ± 1.0 30 ± 140 5 30 2.0 ± 0.2 -0.4 ± 0.4 4.5 ± 1.6 220 ± 140 6 36 0.5 ± 0.1 0.0 ± 1.1 -1.0 ± 0.8 100 ±140 7 33 *1.1 ± 0.1 0.6 ± 2.1 -0.6 ± 1.1 170 ±140 8 34 *1.4 ± 0.1 0.7 ± 1.7 0.7 ± 1.7 -80 ± 140 9 32 1.2 ± 0.1 -1.1 ± 1.1 4.5 ± 2.8 60 ±140 10 36 1.0 ± 0.1 0.8 ± 1.0 -0.4 ± 0.7 110 ± 140 11 34 *1.2 ± 0.1 -0.4 ± 0.4 -0.4 ± 0.4 -10 ± 140 12 35 *1.9 ± 0.1 -0.6 ± 1.8 -0.6 ± 1.0 -50 ± 140 13 34 *1.7 ± 0.1 0.0 ± 1.0 2.5 ± 1.5 NC 14 Bone sample not collected -30 ± 140 15 Bone sample not collected -10 ± 140 16 Bone sample not collected 150 ± 140 Median 34 1.4 0.0 0.4 30 Range 27to36 0.5to2.0 -1.3to l.0 -1.Oto4.5 -80to220 given in Table 9 and in Table 9, were similar to those obtained in the previous year. 5.2.5 Sample Results for Mule Deer One mule deer was obtained, either by hunting or road kill, each quarter from areas on the NTS. Collection sites are shown on Figure 37, numbered by quarter of collection. Blood samples were analyzed for gamma-emitting radionuclides and tritium. Soft tissue samples (lung, muscle, liver, thyroid, rumen contents, and fetus, when available) were analyzed for gamma-emitting radionuclides. Additionally, samples of soft tissues and bones were ashed and then analyzed for plutonium isotopes; ashed bone samples were also analyzed for 90 Sr. Samples of thyroid and fetus tissue were not ashed due to their small size. The mule deer collected in the first quarter of 1991 was a pregnant female in poor condition obtained by hunting in Area 12. Analysis of blood, soft tissue, and bone samples indicated the animal had been contaminated by radioactivity, as shown in Appendix C, Table C-4. No gamma-emitting radionuclides other than naturally occurring 40 K were detected in soft tissues; however, °Pu was detected in all of the ashed soft tissue sam- ples, ranging from 0.008 ± 0.003 pCi/g ash in the liver sample to 1.2 ± 0.1 Pci/g ash in the muscle sample. Concentrations of Pu greater than the MDC of the analysis were also obtained in the lung and rumen contents samples. The bone sample also yielded 0.9 ± 0.2 pCi/g ash of 90 Sr. The tritium activity in the blood sample was 420,000 ± 1000 pCi/L, indicating the animal probably drank from the NTS Area 12 ponds. The area 12 con- tainment ponds are catchment basins which con- tain impounded waters from tunnel test areas. All active containment ponds are restricted access areas posted with radiological warning signs. The mule deer collected in the second quarter also showed indications of contamination (see Appendix C, Table C.4). This animal was obtained as a road kill in the southeast portion of the NTS (see Figure 37). Although the blood sample was negative for (a) (C) NC Aqueous portion of the ki ey tissue. To convert pCi/g to Bq/kg, multiply the concentration by 37. To convert pCi/I to Bq’I, multiply the concentration by 0.037. = Not collected. = greater than minimum detectable concentration. 58 ------- 40 Bighorn Sheep C) 0 C ) 20 0 E 18 C 2 1461211 157 14 13 19 19 121417181924 192014161313 0 55 57 59 61 63 65 67 69 71 73 75 77 79 81 83 85 87 89 91 Year * Number of samples prior to 1969 not available Figure 38. Average Strontium levels in bighom sheep, deer, and cattle, 1956 - 1991. Deer 40 30 20- 10 - 5 0 C l ) a) C ‘Jill 2 U) 0 Number of samples prior to 1969 not available Figure 38. Continued. - [ T 6 57676434 435444 00 0 • __ 55 57 59 61 63 65 67 69 71 73 75 77 79 81 83 85 87 89 91 Year 59 ------- Cattle 40 30 20 10 0 C-) 0 . . Co C I Figure 38Continueii. tritium and no gamma-emitting radknuctides other than °1( were found in the soft tissue samples, all of the ashed soft tissue samples contained 23 °Pu at concentrations greater than the MDC of the analysis. The °Pu actwities in ashed soft tissues ranged from 0.09 ± 0.01 pCifg ash in the rumen contents to 0.8 ± 0.1 pCifg ash in the muscle sample. In addition, Pu was detected at activities greater than the MDC of the analysis in the lung and liver samples. The bone sample results were less than the analysis MDC for pluto- nium isotopes and 0.5 ± 0.1 pCi/g ash for 90 Sr. The other two mule deer, obtained in the third and fourth quarters of 1991, yielded results less than the analysis MDC for most analyses, with the exceptions of a tritium activity of 1000 ± 150 pCi/L in the bkxxi sample from mule deer No.3, a Pu activity of 0.012 ± 0.002 pCifg ash in the rumen contents of mule deer No. 4, and greater-than- MDC 2 °Pu activities in the rumen contents of both animals. Mule deer No. 3 was collected in Area 12, and may have drunk from the Area 12 ponds. Mule deer No. 4 was obtained near Echo Peak on the NTS. The medians and ranges of the 1991 mule deer analyses, presented in Table 10, are similar to those reported for mule deer collected in 1990 for bone tissue analyses and 238 Pu analyses in all tissues. The average Sr levels found in animal bone ash since 1955 are shown in Figure 38. Marked differences between years are observed in the medians of tritium activity in blood and °Pu in ashed soft tissues. These differences are due to the fact that two contaminated animals were collected in 1991. In past years, none or, at most, one of the mule deer have shown evidence of radioactive contamination and, thus, a contaminat- ed sample had no impact on the median. 5.2.6 Sample Results for Cattle Four cattle were purchased from the Courtney Dahi ranch in Delamar Valley (near Alamo, Nevada) in the spring of 1991 and another four were pur- chased from the William Agee ranch near Rachel, Nevada in the fall of 1991. Figure 37 shows the locations of these ranches. Both adult and juvenile cattle were purchased. The animals were slaugh- tered and necropsied at the EPA farm facility on the NTS. Blood and soft tissues (lung, muscle, liver, thyroid, and kidney) were analyzed for gamma-emitting radionuclides; blood was also analyzed for tritium activity. Samples of kidney 13 12 12121213 121212 3 14 6 8 55 57 59 61 63 65 67 69 71 73 75 77 79 81 83 85 87 89 91 Year ¶4un er of sw 1es pdor b 1969 not ava lab e 60 ------- Table 9. Summarized Radiochemical Results for Animal Samples 1991 Number % ash 90 Sr Median 238 Pu Median 240 Pu Median of Median Range Range Range 3 H Median Range (pCi /I..) 241 (120 to 360) Sample Cattle Blood Cattle Liver Deer Muscle Deer Lung Deer Liver Deer Rumen Content Deer Blood Deer Bone Cattle Bone Sheep Bone Sheep Kidney Mt. Lion Muscle Mt. Lion Bone Mt. Lion Blood 8 8 1.3 (1.0 to 1.4) 2.4 (-0.0001 to 60) 35 (-0.0001 to 3400) 4 1.0 (1.0 to 1.1) 7.2 (-1.1 to 18) 402 (-0.7 to 1200) 4 1.0 (0.gtol.0) 1.3 (- l7to lO) 10.7 (-0.8to350) 4 1.3 (0.9 to 1.4) 2.4 (0.7 to 6.0) 5.2 (2.2 to 170) 4 3.9 (1.7to21) 5.0 (2.Otol2) 73 (l7to 110) 33 (30 to 35) 0.7 (0.5 to 0.9) 0.5 (-0.7 to 2.1) 0.7 (-0.0002 to 5.9) 34 (19 to 47) 0.8 (0.3 to 1.3) -0.5 (-3.1 to 0.7) 0.0 (-0.7 to 5.1) 34 (27 to 26) 1.4 (0.5 to 2.0) -0.0001 (-1.3 to 1.0) 0.4 (-1.0 to 4.5) 4 4 8 13 15 1 1 1 504 (-28 to 420,000) 30 (-80 to 220) 2.6 71,300 1.2 20 1.1 -3.0 1.1 18 -3.3 61 ------- and bone were ashed and analyzed for plutonium isotopes; bone samples were also analyzed for °Sr. Duplicate kidney and bone samples from one animal in each group of four were prepared and analyzed. All four of the cattle purchased from the Courtney DahI ranch (Bovine 1 to 4) yielded detectable concentrations of 90 Sr in bone ash samples, rang- ing from 0.29 ± 0.04 pCVg ash to 1.00 ± 0.07 pCVg ash, as shown in Appendix C, Table C-5. None of the four cattle purchased from the WilFiam Agee ranch yielded concentrations of Sr greater than the MDC; however, the MDC of the analysis was higher for these analyses (approximately 1.4 pCi/g ash as compared to approximately 0.13 pCVg ash for the spring samples) 1 . The average Sr levels found in animal bone ash since 1956 are shown in Figure 38. All of the liver ash samples, with the exception of the sample from Bovine No.4, yielded greater-than-MDC concentrations of °Pu, ranging from 0.015 ±0.007 pCi/g ash to 3.4 ± 0.2 pCifg ash 2 . Bovine No. 4 was a young calf, ap- proximately seven months in age and still receiving milk as a part of its diet. Absorbed plutonium is concentrated in the liver of cattle ingesting plutoni- um oxide (EPA 1980). The only bone ash sample with a ° °Pu result greater than the MDC of the analysis was in the sample from Bovine No.6, with a value of 0.005 ± 0.002 pCi/g ash. Medians and ranges, given in Table 10, are similar to those reported for animals collected in 1990, with the exception of cattle liver. The 1991 cattle liver median is greater than the upper end of the range in 1990. It should be noted that in 1990, cattle were purchased from the Ages Ranch and the Medlins Ranch and not from the Courtney Dahl Ranch. An investigation was conducted of all procedures from sampling through data reporting. No evidence of uniform contamination could be found, either in sample preparation or analysis. Resutts of QAIQC samples analyzed with the animal tissue samples were within specified control limits, with the exception of the duplicate pair discussed in the preceding footnote. The possibili- ty of sample contamination occurring during the ashing process could not be ruled out, although other tissues and mule deer samples submitted for ashing in the same batch yielded results similar to those obtained in previous years, and any source of contamination would have to have affected two different batches of cattle samples submitted at different times. Prior to 1991, plutonium analyses of ashed tissue samples were completed by a contract laboratory. Analysis of samples collected in 1991 was completed by the EPA EMSL-LV Radioanalysis Laboratory. Although the methods used by the two laboratories are similar and should produce comparable data, the possibility of labora- tory bias cannot be eliminated. This possibility is unlikely, however, since medians and ranges for other tissues and other animal types were similar for 1990 and 1991 data. 5.2.7 Sample Results for the Mountain Lion A mountain lion which had been menacing the Area 12 camp was killed by an NTS-authorized hunter in the spring of 1991. Kidney, lung, muscle, blood, and liver samples were analyzed for gam- ma-emitting radionuclides; only naturally occurring 40 K was detected. A blood sample analyzed for tritium activity yielded a result of 71,300 ± 400 pCi/I.., indicating the animal probably drank from the Area 12 ponds. Muscle and bone samples were ashed and analyzed for plutonium isotopes; the bone sample was also analyzed for Results are given in Table 10. The only results greater than the MDC of the analysis were 90 Sr in bone, with a result of 1.09 ± 0.07 pCi/g ash, and 2 °Pu in muscle, with a result of 0.018 ± 0.009 pCi/g ash. 5.2.8 Quality Assurance Standard operating procedures (SOPs) detail sample collection, preparation, storage, analysis, and data review procedures to ensure comparabili- ty among operators. Field personnel complete a standardized necropsy protocol form to ensure that all relevant information is recorded, such as date and location of collection, history and condition of the animals and tissues, and sample weights and assigned identification numbers. Standardized forms accompany each shipment of samples sent to the contract laboratory for ashing and are also used for analyses conducted in the Radioanalysis Laboratory. All information entered into the data base management system by Sample Control and the radioanalysis chemists is checked and verified by the Group Leader and assigned media expert. An estimate of system precision is obtained from results of duplicate samples. Matrix spike samples are used to verify analytical accuracy. Matrix blank samples monitor any contamination resulting from sample preparation and analysis. The entire 62 ------- sample set analyzed in any given year is quite small (usually four or five sample batches) and, as a consequence, the quality assurance/quality control (QAIQC) sample results set contains fewer values than is considered minimal for statistical uses. Therefore, the results of QA/QC samples are considered to provide only an indication or estimate of true precision and accuracy. This is considered adequate because the animal investiga- tion program itself is not statistically based. Prior to 1991, analyses of animal tissue samples were performed by a contract laboratory. The EPA EMSL-LV Radioanalysis Laboratory assumed responsibility for sample analysis beginning with the results contained in this report. The change of laboratories raised concerns about comparability of analyses, so a special QA review was conducted. The procedures used by each laboratory are comparable, as are results of matrix spike sam- ples. Generally, the result ranges obtained in 1991 were similar to those obtained in previous years when samples were analyzed by the contract laboratory. Finally, results of QAIQC samples, with the exception of one routine-duplicate pair, were within established control limits. Although a direct comparability study was not undertaken (i.e., analysis of replicate samples by both laboratoi ies), the results of the QA review indicate the data obtained for 1991 analyses are comparable to data obtained in previous years. The QA review also resulted in recommendations for some changes in the animal investigation program to be implemented in 1992. These recommendations included preparation of a large stock of matrix spike and blank sample material and addition of a system blank. The single stock of matrix spike sample material will permit an additional estimate of precision, in this case analyt- ical precision, to be obtained. The system blank will be a bone sample known to contain no detect- able concentrations of radionuclides (with the possible exception of strontium) processed with each tissue sample batch to provide a check of possible contamination during the ashing and sample preparation processes. 5.3 Fruits And Vegetables Monitoring Another possible pathway of radionuclide ingestion is through produce: fruits, vegetables, and grains. Commercial farming, other than alfalfa, is not a major industry in the offsite area around the NTS. Therefore, monitoring is limited to fruits and vege- tables grown in local gardens for family consump- tion. In the event of a release of radioactivity from the NTS, monitoring of produce would be extended to include alfalfa, forage grasses, and feed grain supplies. No such extensive monitoring was required in 1991. 5.3.1 Network Design Like the animal investigation program, fruit and vegetable monitoring is based on a worst-case scenario. Local residents living in areas known to have received fallout from past atmospheric testing are asked to donate produce from their family gardens. These areas which received fallout are also the areas in the preferred downwind direction during current underground testing. As sample collection is not statistically based, no inference should be drawn regarding the representativeness of the sampled materials to concentrations of radionuclides in produce as a whole, nor should any conclusions be drawn regarding the average consumption of radionuclides from produce. 53.2 Sample Collection and Analysis Procedures Sample collection is a strictly voluntary contribution by the offsite residents. Sampling is done only once per year, in the late summer. Fruits and vegetables harvested at that time generally include root crops (onions, carrots, potatoes), melons and squash, and some leafy vegetables (e.g., cab- bage). A unique sample number is assigned and pertinent information, such as date and place of collection, is recorded on the sample collection tag. Following receipt in Sample Control, the available information is entered into the sample tracking data management system (STDMS). Processing of the samples includes washing the material as it would be washed by residents prior to eating or cooking. This washing procedure introduces an element of variability, as the thor- oughness of washing varies by individual. Pota- toes and carrots are not peeled. Further process- ing generally includes cutting the material into small pieces and/or blending in a mixer or food processor. Splits are prepared for analysis of gamma-emitting radionuclides and tritium. Other sample splits are ashed and analyzed for 90 Sr, Pu, and 240 Pu. 63 ------- 5.3.3 Quality Assurance The fruits and vegetables are considered to be a batch within the animal investigation program. The same QAFQC samples are used, including matrix- spikes and matrix blanks (NOTE: animal bone ash is the matrix). If sufficient material is received, at least one of the san les may be analyzed in duplicate, however, in many years not enough of any one type of material is received from any one source to permit preparation of replicates. As with the animal investigation program, the QA/OC samples provide only an estimate or indication of the analytical precision and accuracy. 5.3.4 Sample Results In the fall of 1991, fifteen samples of locally grown fruits and vegetables were donated by offsite residents in Utah, Arizona, and Nevada. Fruits and vegetables sampled included cabbage, canta- loupes, zucchini and summer squash, onions, carrots, beets, and potatoes. All samples were analyzed for gamma-emitting radionuclides and only naturally occurring 40 K was detected. All samples were also analyzed for tritium; no results greater than the MDC of the analysis were ob- tained. Ashed samples were analyzed for 90 Sr, 2 Pu, and 2 ’ 40 Pu. None of the 90 Sr results were greater than the MDC of the analysis. Concentra- tions of 238 Pu greater than the analysis MDC were found in two samples, both from Fallis Ranch near Rachel, Nevada, and concentrations of 2 °Pu greater than the analysis MDC were found in seven samples. These results are given in Table 10. No consistent correlations of greater-than- MDC results with sample location or with vegetable mode of growth (i.e., surface crops as opposed to root crops) were evident. Table 10. Detectable Plutonium Concentrations in Vegetable 1991 Vegetable Collection Location ° 240 Pu ± la (pCVg) ash 240 Pu MDC Pu ± la (pCi/g) ash 238 Pu MDC Onions Beaver Dam, AZ (Meddibow Farms) 0.004 ± 0.002 0.002 Zucchini Squash Enterprise, UT (Dewai J Terry) 0.006 ± 0.003 0.005 Summer Squash Rachel, NV 0.029 ± 0.006 0.005 0.008 ± 0.003 0.005 (Yellow) (Fallis Ranch) Summer Squash Rachel, NV (Penoyer Farms) 0.010 ± 0.005 0.008 Potatoes Rachel, NV (Fallis Ranch) 0.051 ± 0.005 0.002 0.008 ±0.002 0.003 Beets Rachel, NV (Penoyer Farms) 0.007± 0.003 0.005 Red and Green St. George, UT 0.002 ±0.001 0.002 Cabbage (Jeff Layne) MDC = minimum detectable concentration. 64 ------- 1. Reanalysis was conducted on the Agee Ranch samples due to the high MDC. The high MDC was the result of 1 g rather than 10 g of sample being used in the first analysis. The reanalysis results were nearly identical to those obtained in the first analysis. All were above the MDC, which was about 0.7 pCilg ash for the second analysis. 2. The highest result obtained in Bovine No. 2, 3.4 pCifg ash, is suspect. A duplicate sample prepared from the same liver yielded a greater-than-MDC result of 0.04 ± 0.01 pCiIg ash for 2 °Pu. Additionally, this sample yielded the only 238 Pu result greater than the MDC of the analysis, a result of 0.059 ± 0.007 pCi/g ash, while the duplicate sample Pu result was less than the MDC. Repeated analyses yielded similar results. However, an investigation of the sample could not identify a sourte of contamination. Additionally, the possibility of differing activities in separate liver lobes could not be ruled out as a possible explanation for the observed difference in analytical results. Therefore, the value cannot be invalidated, but should be regarded as suspect. 65 ------- 6.0 Internal Dosimetry Internal exposure is caused by ingested, absorbed, or inhaled radionuclides that remain in the body either temporarily or for longer periods of time because of storage in tissues. At EMSL-LV, two methods are used to detect body burdens: whole- body counting and urinalysis. These two methods constitute the Internal Dosimetry Program. 61 Network Design The Internal Dosimetry Program consists of two components, the Offsite Internal Dosimetry Pro- gram and the Radiological Safety Program. The Offsite Internal Dosimetry Program is designed to: (1) measure radionuclide body burdens in a representative number of families who reside in areas that were subjected to fallout during the early years of nuclear weapons tests, and (2) provide a biological monitoring system for present nuclear testing activities. A few families who reside in areas not affected by such fallout were selected for comparative study. Members of the general public concerned about possible exposure to radio- nudides are also counted periodically as a public service. The Radiological Safety Program is designed to assess internal exposure for EPA employees, DOE contractor employees, and, by special request, for employees of companies or government agencies who may have had an accidental exposure to radioactive material. The Ottsite Internal Dosimetry Program was initiated in December 1970 to determine levels of radionuclides in some of the families residing in communities and ranches surrounding the NTS. For these families, biannual counting is performed in the spring and fall of each year. This program started with 34 families (142 individuals). In 1991, 15 of these families (35 individuals) were still active in the program. When the CAMP network was started in 1981, the families of the station manag- ers interested in participating were added to the program. As additional station managers joined the program, the number of families in the program in 1991 has increased to 58. Although there are 58 families in the program, only 34 of them actually patticqated in 1991. These families are counted in the winter and summer of each year. The number of individuals participating in the program varies as children leave home to attend school or obtain employment. The geographical locations of the participating families are shown in Figure 39. Although most families are able to come into the laboratory as scheduled, some are unable to participate in a particular year due to distance, weather, or family commitments. All families currently in residence would presumably be avail- able following any accidental release of radioactivi- ty. Individuals with potential for occupational exposure are counted at the request of their employers as part of the Radiological Safety Program. Counting is done routinely for DOE contractors. EPA per- sonnel in radiation programs or who work with radioactive materials undergo a whole body count and a urinalysis annually. 6.2 Procedures The whole-body counting facility has been main- tained at EMSL-LV since 1966 and is equipped to determine the identity and quantity of gamma- emitting radionuclides that may have been inhaled, absorbed, or ingested. Routine examinations consist of a 2,000 second count in each of the two shielded examination vaults. In one vault, a single intrinsic germanium coaxial detector positioned over an adjustable chair allows detection of gamma radiation with energies ranging from 60 keV to 2.0 meV in the whole body. The other vault contains an adjustable chair with six intrinsic germanium semi-planar detectors mounted above the chest area. The semi-planar array is designed for detection of gamma and X-ray emitting radio- nuclides with energy ranges from 10 to 300 keV. Specially designed software allows individual detector spectra to be analyzed to obtain a summation of left- or right-lung arrays and of the total lung area. This provides much greater sensitivity for the transuranic radionuclides while still maintaining the ability to pinpoint “hot spots.” Custom-designed detector mounts allow maximum flexibility for the placement of detectors in various configurations for skull, knee, ankle, or other geometries. Individuals travel to EMSL-LV where a whole-body count and a lung count of each person are per- formed. A urine sample is collected for 3 H analy- 67 ------- I_ I — u • £ & _ NEVADA - UTAH i i I I I I I I I I Lakes a city 1 I I LAKE I I I — I AUSI IflOO •McGiU OODelta OOSBy - I I •Lis d I Rotmd MtOO I 00 Milford •B1ueEa eRn. a SSSNyaIa • I I Tonopah 2) Maven 0 oche I I Q•CedarCity I Cahente . 0 I 00 St. George I I • — U — U ARIZONA 5 100 10 0 Scale in Kilometers • Offsite Family Monitored in 1991 o Not Monitored in 1991 Beats —‘ Amargosa r 0 4 N Scale w Miles 50 100 iSpnngs Shoshoneq, L Figure 39. Location of families in me Qffs,te Internal Dosimetry Program. 68 ------- sis. Not all participants of the Radiological Safety Program submit urine samples for 3 H analysis. Results of the whole-body and lung counts are available before the Offsite Internal Dosimetry Program participants leave the facility and are discussed with the subjects. Results of the urine 3 H analysis are submitted later if the result is abnormal. At 1 8-month intervals, a physical exam, heafth history, and the following are performed: a complete urinalysis, complete blood count, serolo- gy, chest x-ray (3-year intervals), sight screening, audiogram, vital capacity, EKG (for individuals over 40 years old), and thyroid panel. The individual is then examined by a physician. The results of the examination can be requested for use by the individual’s family physician. 6.3 Results During 1991, a total of 2,800 gamma spectra were obtained from whole-body counting of 350 persons (including those individuals who were counted twice). One hundred and six of the counts were on participants of the Off site Internal Dosimetry Program. All spectra were representative of normal background and showed only naturally occurring 40 K. No transuranic radionuclides were detected in any lung-counting data. No internal exposure above applicable regulatory limits was detected in either occupationally exposed individu- als or members of the general public who partici- pated in the Internal Dosimetry Program at EMSL- LV. Bioassay results for the Offsite Internal Dosimetry Program showed that the concentration of tritium in single urine samples collected at random periods of time (i.e., whenever the individual was able to come to EMSL-LV) varied from below the MDC average value of 2.7 x i0 p .CVmL to 3.8 x i0 iCLImL. The average value for 98 samples analyzed for tritium in urine was 8.9 x 10.8 j . CiImL. The bioassay results for the Offsite Internal Dosimetry Program are listed in Appendix D, Table 1. Two values were slightly above the MDC. The MDCs for these values were within one standard deviation of the result. The highest value of 3.8 x i0 p.Ci/mL is only 0.01 percent of the annual limit of intake for the general public. As no accidental or planned releases from NTS were reported in 1991, no additional bioassay sampling was performed. As reported in previous years, medical examinations of the offsite families revealed a generally healthy population. The blood examina- tions and thyroid profiles showed no symptoms which could be attributed to past or present NTS testing operations. Of the 87 bioassay samples obtained from individu- als with potential for occupational exposure, five were over the MDC. The MDCs for all of these results were within one standard deviation of the result. The highest value, 3.6 x 1 o7 j.tCVmL is less than 0.001 percent of the annual limit for occupa- tionally exposed individuals. The bioassay results for occupationally exposed individuals are given in Appendix D, Table 2. Some members of the general public request whole body counts because they are concerned about possible radiation exposure. Such was the case of two men using heavy equipment in the vicinity of a mine thought to have a high percent- age of thorium in the ore. One of the men had returned home from work after dark and removed a fluorescent tube from the trunk of his car. The tube glowed when he picked it up by the end. He thought the glowing was caused by radiation in his body. He had demonstrated this to his partner and other people who all became convinced that he was contaminated. He brought the tube with him to EMSL-LV, along with a soil sample. It was easy to demonstrate how the tube would glow from a static charge. He had inadvertently rubbed the tube across the carpet in his truck and upon his trousers, causing the tube to glow. The soil did not contain enough thorium to be detectible. Although the incident that caused their anxiety was easily explained scientifically, they were concerned enough to seek assistance and relieved that they were not contaminated. Another man was referred to EMSL-LV by his employer after his wife became upset when she learned he had been checking equipment on the NTS during a nuclear event. Although he had been working in the vicinity, he was not in the exclusion zone and was a number of miles away from the event. He had not been notified by his employer of the pending event and became con- cerned when his wife heard that there had been an event. When he was counted, no internally depos- ited radioactive material was detected. No release of radioactivity had occurred and he had actually been in his car headed off the site at the time of the event. 69 ------- Numerous employees of DOE contractors were counted as part of the Radiological Safety Pro- gram. AN of these were routine counts with the exception of two employees who were flown in after separate incidents. One was a mechanic who had been working on forldifts. The forklifts had been contaminated with uranium prior to procure- mént from excess property. No uranium or other radionuclides, except naturally occurring potassi- um, were detected. The minimum detectible activity (MDA) for U in the lungs is 1.8 tCi and for U, is 0.12 tCi. The other person was in- volved in a filter incident at Rocky Flats, a DOE facility in Colorado. He had been given chelation therapy after having a positive nasal swipe. Subsequent urine samples had tested positive for Pu and 241 Am. He had been counted at Rocky Flats but had requested another count by someone else to verify the negative results. Lung and whole body counts at this facility detected no radio- nuclides other than naturally occurring 40 K. The MDA for his chestwall thickness is 0.35 l.tCi of 241 Am. The annual limit of intake (ALl) for 241 Am is 5.4 tCi. 6.4 Quality Assurance/Quality Control Quality Assurance procedures consist of daily equipment operations checks using QA software obtained specifically for this program. Some of the parameters monitored daily include energy calibra- tion of each detector using a NIST-traceable point source to check for zero, gain shift, and resolution over a wide range of energies. A background measurement is also taken once or twice daily depending on the count schedule. The whole-body detector efficiency is calibrated annually using a Bottle Mannequin Absorber (BOMAB) phantom containing a NIST-tiaceable mixed radionuclide source. The lung counter is also calibrated annually with a male realistic lung phantom. A separate set of efficiency calibration data is kept for each combination of sample shape(organ geometry. The following MDAs were calculated following recalibration of the lung counting system in Febru- ary, 1992: Am, 0.2 .tCi; 238 Pu, 18 p .Ci; and Pu, 130 tCi. There were no significant differences from previous MDA’s. These were calculated for a standard chestwall thickness of 3 cm. The MDAs for the whole-body counting system for 1991 were as follows: 60 Co, 10 nCi; 137 Cs, 14 nCi; Cs- 134, 11 nCi; ar 1311 13 nCi. All efficiency curves are generated by the vendor- supplied whole-body counting and lung counting software. Daily performance and background routines are completed. QA software is used to monitor the systems by performing out-of-range tests for predetermined parameters. Results are plotted and reports are generated daily and month- ly. All data are stored in the computer. Replicate counting of the standard BOMAB phantom pro- vides a measure of consistency. Replicate counts of blind intercalibration phantoms and of people counted previously in other facilities provide addi- tional measurements of precision and accuracy. Verification and validation are completed before results are entered into a data base. Calculation of internal dose is done utilizing software based on the International Commission on Radiological Protection (ICRP) methodology (ICRP, 1979). Dose calculation is verified using ICRP and Nation- al Council of Radiation Protection and Measure- ment (NCRP) guidelines (NCRP, 1989). Preven- tive maintenance and repair of analytical equip- ment are done by the vendor service represents- live. Data are retained permanently. Subject confidentiality and data security are maintained through well-established procedures. EPA whole- body counting technicians participate in DOE and EPA QA training programs. 70 ------- 7.0 Long-Term Hydrological Monitoring Program One of the concerns of underground nuclear weapons testing is the possibility of radionudide contamination of groundwaters. Underground nuclear weapons tests are currently conducted only on the Nevada Test Site (NTS). Between 1961 and 1973, eleven tests were conducted in eight other locations in the United States. The initial ground and surface water monitoring program was established by the U.S. Public Heath Service (USPHS) in the early 1 950s. Pretest and posttest monitoring for the locations off the NTS were conducted by USPHS, the U.S. Geological Survey (USGS), and Teledyne Isotopes, Inc. In 1972, the Long-Term Hydrological Monitoring Program (LTHMP) was established by the Nevada Opera- tions Office (NV) of the Atomic Energy Commission (AEC), a predecessor agency to DOE. Through an interagency agreement between AEC (later DOE) and EPA, responsibility for operation of the LTHMP was assigned to the U.S. EPA’s Environmental Monitoring Systems Laboratory in Las Vegas, Nevada (EMSL-LV). The LThMP is only one component of the total surface and ground water monltoiing program conducted under the auspices of DOE/NV. Under the LTHMP, routine monitoring is conducted of specific wells on the NTS and of wells, springs, and surface waters in the offsite area around the NTS. In addition, LTHMP sampling is conducted at the eight other locations in the U.S. where nuclear weapons tests have been conducted. These locations include sites in Nevada, Colorado, New Mexico, Mississippi, and Alaska. 7.1 Network Design The LTHMP was instituted because AEC (later DOE /NV) acknowledged its responsibility for obtaining and disseminating data acquired from all locations where nuclear devices have been tested. The three objectives originally established for the LTHMP were to: • Assure public safety. • Inform the public, news media, and scientific community about any radiologi- cal contamination. • Document compliance with existing fed- eral, state, and local antipollution require- ments. Another objective which has been incorporated into the LThMP is to, where possible, detect trends in radionuclide activities which may be indicative of migration from the test cavity. The primary radionuclide analyzed in the LTHMP is tritium. As a product of nuclear weapons testing, high levels of tritium are found in test cavities. Because tritium can be incorporated into water molecules, it is expected to be the first radionuclide to migrate from a test cavity. Therefore, tntium serves as an indicator of radionuclide migration. Atmospheric tritium may also be deposited into water, primarily by precipitation scavenging. Tritium arising from this source is primarily found in surface waters, surficial aquifers, and springs closely connected to surf icial aquifers. 7.1.1 Sampling Locations In order to meet the objective of assuring public safety, monitoring is conducted of drinking water supply wells and springs around the NTS and in the vicinity of surface ground zero (SGZ) at the other locations. The majority of these sampling sites are privately owned and participation in the LTHMP is voluntary. Municipal drinking water supplies are also represented. Regardless of the number of individuals served by a particular water supply, the National Primary Drinking Water Regu- lation 1 (NPDWR) pertaining to radioactivity is used as the compliance standard. 2 All of the nuclear weapons tested at locations other than the NTS were emplaced at depths of greater than 1200 feet. Nuclear weapons tested on the NTS are also emplaced at great depths, with the exception of some shallow underground tests conducted in the early 1 960s. Most of the drinking water supply wells tap shallow aquifers and, consequently, do not represent groundwater in the geologic strata containing the test cavities. There- fore, wherever possible, deep wells are included in the monitoring program. These wells include some which were specifically drilled soon after a nuclear test to monitor activities in or near the test cavity 71 ------- and others which can be considered only as targets of opportunity; e.g., existing wells for which sampling permission has been obtained. Most of the deep wells tap nonpotable water sources. Monitoring design standards, such as those in the Resource Conservation and Recovery Act (RCRA), did not become available until long after the LTHMP deep wells had been drilled. Cost has delayed emplacement of new wells, although a program to drill more than 90 new wells on the NTS was initiated in 1990. The sampling locations not associated with the NTS are defined by DOE as inactive hazardous waste sites and, therefore, exempt from the RCRA monitoring design require- ments. 7.1.2 Sampling and Analysis Procedures At nearly all LTHMP locations, the standard operat- ing procedure is to collect three samples from each source. Two samples are collected in 500-mL glass bottles to be analyzed for tritium. The results from analysis of one of these samples are reported while the other sample serves as a backup in case of loss or as a duplicate sample. The third sample is collected in a 3 .8-L plastic container (Cubitainer) for gamma spectroscopy analysis. At LTHMP sites other than the NTS and vicinity, two Cubitainer samples are collected. One is analyzed by gamma spectrometry and the other is stored as a backup or for duplicate analysis. At a few locations, because of limited source of water supply, only 500-nt samples for tritium analysis are collected. For wells with operating pumps, the samples are collected at the nearest convenient outlet. If the well has no pump, a truck-mounted sampling rig is used. With this rig it is possible to collect three- liter samples from wells as deep as 1800 meters. At each sample collection site, the pH, conductivity, water temperature, and sampling depth are mea- sured when the sample is collected. The first time samples are collected from a well, Sr, 90 Sr, Ra, and plutonium and uranium iso- topes are determined by radiochemistry as time permits. Prior to 1979. the first samples from a new location were analyzed for 15 stable elements; anions, nitrates, amrnoniacal nitrogen, silica; uranium, plutonium and strontium isotopes; and Ra. Most of these analyses can still be complet- ed by special request. At least one of the 3.8-L samples from each site is analyzed by gamma spectrosoopy. One of the 500-mi. samples from each site is analyzed for tritium. Two tritium analysis methods are em- ployed in the LTHMP: the standard or convention- al method and an enrichment method developed by EMSL-LV. In the enrichment method, the sample is concentrated, resulting in an MDC of approximately 7 to 10 pCVL, as compared to the MDC for the conventional method of approximately 250 to 700 pCi&. Most of the LTHMP samples are analyzed by the enrichment method, unless past years’ data have indicated activities are within the detectable range of the conventional method. Additionally, semiannually sampled wells on and in the vicinity of the NTS are analyzed once per year by the enrichment method and once per year by the conventional method. 7.1.3 Quality Assurance/Quality Control Samples Sample collection and analysis procedures are described in standard operating procedures (SOPs). Data base management and data analy- sis activities are described in the Quality Assur- ance Plan (EPA, 1992). Use of standardized procedures ensures comparability of operations and data among monitoring locations and across temporal intervals. Annual data quality assessments of precision, accuracy, and comparability are based on the results of quality assurance/quality control samples. The data quality assessment results for 1991 are given in Section 11.0. Overall system precision is estimated from the results of field duplicates. A field duplicate is a second sample collected from a sampling location immediately following collection of the routine sample using identical procedures. Field duplicates are collected from sampling locations on the NTS and in the vicinity of the NTS according to a schedule established by the LTHMP Technical Leader. Generally, all samples from the other locations are collected in duplicate; the second sample may be used as a duplicate or may be used as a replacement for the routine sample, if necessary. Accuracy is estimated from results of intercompari- son study samples. These intercomparison study samples are spiked samples (i.e., a water sample to which a known amount of particular radio- nuclide(s) have been added). lntercomparison 72 ------- study programs managed by EMSL-LV and DOEs Environmental Monitoring Laboratory (EML) both include water matrix samples. The EMSL-LV intercomparison study samples are also used as an estimate of comparability. Generally, sixty to more than 100 laboratories participate in a given intercomparison study. Results for each laboratory are reported, as are pooled results (mean, stan- dard deviation). Comparison of the Radioanalysis Laboratory to the mean for all laboratories provides an estimate of the comparability of results. In addition to the above-described QA/QC samples which are used in annual data quality assess- ments, the Radloanalysis Laboratory employs a nurther of internal QC samples and procedures to ensure data quality on a day-to-day basis. Internal QC samples include blanks, regular calibrations, matrix spike samples, and duplicate analyses (gamma spectroscopy only). If results of these internal QC samples fall outside prescribed control limits, corrective actions are implemented; analysis is stopped until the cause of the discrepant data is found and resolved. 7.1.4 Data Management and Analysis In the spring of 1991, the LTHMP was selected as the pilot program to test the use of bar code sample labels. Bar code labels were prepared prior to each sampling excursion, based on the sampling schedule prepared by the LTHMP Tech- nical Leader. Upon receipt of samples in Sample Control, the bar code label was read and the information transferred into the Sample Tracking Data Management System (STDMS), along with information from the field data card. This pilot program was extremely successful and is being continued for the LTHMP and expanded to other monitoring networks. Analysis data were entered into STDMS after they had been generated and reviewed by the analyst and Group Leader. Special software written in Fortran (referred to as “Chemistry Programs”) is used for a majority of the radiochemical data reduction. The Chemistry Programs are used for calculating final data such as activity per unit volume, MDC and 2-sigma error terms. All hand- entered data were checked for transcription errors. Once data had been entered and checked, they were transferred from a “review” data base to a permanent data base, i.e., further changes may be made only by authorized personnel. On a periodic basis, the assigned media expert reviewed the data base and checked for complete- ness of sample collection, transcription errors, completion of analysis of samples and QA/QC samples, and accuracy of information input. All discrepancies were resolved and corrected. Once the data base was complete for a given location, time series plots were generated. Any discemable trends were discussed at an annual data review attended by management and scientific personnel. Another data review of the LTHMP was held with DOE and Desert Research Institute (DRI) hydrolo- gy personnel. The time series plots which indicat- ed consistent data trends are included as figures in the subsections which follow. The filled circles on the time series plots represent the result values, the error bars indicate ± one standard deviation of the analysis, and the (x) represents the MDC value. 7.2 Nevada Test Site Monitoring The present makeup of the LTHMP for the NTS onsite network is displayed in Figure 40. The onsile network includes sample locations on the NTS or immediately outside its borders on federally owned land. In 1991, samples were collected monthly from 14 onsite wells and semiannually from 15 others. An additional five wells could not be sampled at any time in 1991 and one well became inoperative midway through 1991. These are listed in Table 11. Two new wells were added in 1991; Well 6 located in the immediate offsite area near wells 3, 4, and 5 and Well UE6D located in Area 6. Well 6 has been sampled monthly, beginning in September. Radionuclide analysis completed on the first sample collected from this well indicated detectable activities of U, U, and U. These results were: 1.6 ± 0.2 pCVL of U, 0.063 ± 0.027 pCVL of 5 U, and 0.51 ± 0.08 pCi/L of U. Attempts were made to sample Well UE6D in March and September, but it was not possible to collect a sample due to insufficient water in the well. All LTHMP samples are analyzed for gross gamma and tritium. All of the gross gamma results were negligible. Of the samples collected semiannually, one sample is analyzed for tritium by the conven- tional method and the other is analyzed by the 73 ------- T to 11. Inoperative and Closed LTHMP Wells Well IdentWication Sampling Schedule Last Sampled Well 2 monthly December 1990 Well 5B semiannually July 1988 Well 20 monthly April 1991 Well A monthly October 1988 Well U3CN-5 monthly December 1981 Well UE7NS semiannually September 1987 enrichment method. Al) of the monthly samples are analyzed for tritium by the enrichment method. None of the samples analyzed by the conventional tritium method in 1991 exceeded the MDC. The greatest tritium activity measured in the LTHMP NTS sampling network in 1991 was 156±3 pCiIL in the September sample from Well UE18T. This activity is 0.8 percent of the NPDWR. Twelve of the fourteen onsite wells sampled on a monthly basis did not exhibit trilium activihes exceeding the MDC of the enrichment analysis at any time during 1991. These included Well 6, added to the sampling directory in September 1991, and Well J-1 2 which has never yielded a detectable tritium activity; the remaining wells have been sampled for a period of years and have only on rare occasions exhibited tritium activity at detectable levels (greater than appràximately 7 to 10 pCVL). Five of the 15 other wells sampled semiannually also did not exhibit tritium activity greater than the MDC of the enrichment method. Like the monthly sampled wells, these five wells have rarely exhibited detectable tritium activity using the enrichment analysis method. Another three of the semiannually sampled wells were only analyzed by the conventional method in 1991, with all results less than the MDC. Of these, Well UE6E had shown tritium activities of 33 to 48 pC in 1989 and 1990, Test Well 7 had only been sampled twice, in 1989 and 1991. with both sam- ples analyzed by the conventional method. Well UE4T was sampled for the first time in 1991. Tritium activities greater than the MDC of the enrichment method were observed only in Test Well B and Well C in the monthly sampled sites. Test WeliBaveraged ll5pCi/Lforl99l (rangeof 99 to 128 pCi/L); the long-term trend for this site indicates the tritium activity is decreasing, as shown in Figure 41. The average for Well C for 1991 was 23 pCVL (range 9 to 62 pCi/L); the sampling history indicates a slightly decreasing trend consistent with tritium decay. Tritium activities greater than the MDC of the enrichment method were also found in Well C-i, Test Well D, and wells HTH-1, UE15D, UE16D, UE16F, and UE18T in the semiannually sampled sites. The 1991 tritium activity for Well C-i was 22 ± 4 pCVL and was the first time a result greater than the MDC had been obtained since 1983, although the long-term sampling history indicates greater-than-MDC tritium activities have occasion- ally been observed. The result for Test Well 0 was 7.6 ± 2.3 pCi/L, which was only slightly greater than the MDC of 7.4 pCVL. Like Well C-i, Test Well D results had not exceeded the MDC of the tritium enrichment analysis since 1983, although greater-than-MDC results had occasionally been obtained in the years prior to 1983. Both of the samples collected from Well HTH-1 were analyzed by the enrichment method. The June sample was below the MDC and the December sample was 35 ± 2 pCi/L. Sampling of this well was initiated in 1989; tritium activity in the June 1990 sample was similar to that observed in the December 1991 sample, although the number of data points is insufficient to discern any trend. The May 1991 tritium result for Well UE16D was 31 ± 3 pCVL and was the first time that this well has displayed a detectable tritium activity since sampling began in 1982. The second sample from Well UE16D, collected in November 1991, was also analyzed for tritium by the enrichment method with a result less than the MDC. Both samples collected from Well UE16F in 1991 were analyzed for tritium by the enrichment method, yielding results greater than the MDC. The May 1991 sample showed tritium activity of 11 ± 3 pCVL and tritium activity in the November 1991 sample was 10±2 pCi/L. These were the first detectable tritium activities observed at Well UE16F since sampling began in 1989. The sample collected in April from Well UE15D yielded 74 ------- FIgure 40. Long-Term Hydmiogical Monitoring Program sampling locations on the Nevada Test Site. Well 3 Well 4 Well U Well 6 I 110 Scale hi Kilometers = Water Sampling Location = Not Sampled this year 75 ------- NIS Test Well B 400 300 200 100 0 JAN72 JAN76 JAN88 JAN92 Figure 41. Tritium results ± standard deviation for Nevada Test Site Test Well B, Januaty 1976 through Decenter 1991. The X indicates the MDC value. JAN80 S JAN84 Sample COlleCtiOn Date atritiumactivityof76±3pCi&;thesarrpling history for this well indicates high variability in tritium activity, ranging from below the MDC to greater than 100 pCVL. Sampling at Well UE18T has only been conducted since 1989, thus, only three analyses of tritium by the ennchment method have been completed. The 1991 result was 156± 3 pCi/L, the highest tritium activity measured in any of the LTHMP samples from the NTS onsite net- work in 1991. This result is approximately 0.8 percent of the NPDWR. Analytical results for all samples are provided in Appendix E. 7.3 Offsite Monitoring In The Vicinity Of The Nevada Test Site The monitoring sites located in the otfsite area around the NTS are shown in Figure 42. Most of the sampling locations represent drinking water sources for rural reskients in the offsite area and public drinking water supplies in most of the com- munities in the area. The sampling sites include 22 wells, seven springs, and two surface water sites. Twenty-nine of the locations are routinely sampled every month. Samples are collected each month for gamma spectroscopy analysis. The remaining two sites, Penoyer Well 13 and Penoyer Wells 7 and 8, are in operation only part of the year; samples are collected whenever the wells are in operation. All of the gross gamma results were negligible. Samples for tritium analysis are collect- ed on a semiannual basis. One of these semian- nual tritium analyses is done by the conventional tritium analysis method, the other is analyzed by the enrichment method. Few of the sites have yielded detectable tritium levels (greater than approximately 7 to 10 pCi/L) over the last decade. Only three sites have evi- denced detectable tritium activity on a relatively consistent basis. These three sites are Lake Mead + + V , S . . • •. • 76 ------- U Sharp’s Ranch U Tonopah City Well • Adaven Springs • Twin Springs Rn. Beatty Well Figure 42. 4 ’ Specie . Nickell’s Rn. Amargosa Valley Well 15S/50E-l8cdc F ffbankS • Springs % •Well 18S/51lE-7db \ •Johnnie Mine Shoshone Spr ings $ N Scale in Miles 0 10 20 30 40 • , I I I I I U U I 0 10 20 30 40 50 60 Scale in Kilometers • = Water Sampling Location • Crystal Pool • Spring 17S150E-l4cac • Calvada Well LOCATiON MAP • Crystal Springs U Alamo C ityWeH4 Las Vegas Well 28 U Lake Mead Intake U • Union Carbide Well Penoyer (4) Well 7 & 8 Well 13 SpicerU Road D Goss Springs Coffers 11S/48-t 12S/47E-ldbdU Springs Sewer Co. Well 1 Long-Term Hydrological Monitoring Program sampling locations near the Nevada Test Site. 77 ------- Intake (Boulder City, NV), Adaven Springs (Ada- yen, NV), and Specie Springs (Beatty, NV). In all three cases, the tritium activity has been generally decreasing over time. The 1991 sample results for Specie Springs were less than the MDC, as shown in Figure 43. In 1991, only four of the samples analyzed for tritium by the enrichment method yielded detect- able tritium activities. These were the January sample from Maven Spring, the February sample from Shoshone Springs, CA, and two samples from the Lake Mead Intake collected in September and October. The Adaven Spring result of 27±4 pCi/L (0.1 percent of the NPDWR) was consistent with the generally decreasing trend observed at this site, as shown in Figure 44. Tritium has occasion- ally been observed at detectable activities in Shoshone Springs, CA, samples, but a consistent trend is not evident. The 1991 result was 33±3 pC &, which is less than 0.2 percent of the NPDWR. The results for the Lake Mead Intake were 69±3 pCi/L and 65±2 pCi/L for September and October, respectively. These results, which are 0.3 percent of the NPDWR, were greater than results obtained in 1990, as indicated in Figure 45. This surface water site may be impacted by rainfall containing scavenged atmospheric tritium to a greater extent than the well and spring sites in the offsite network. Analytical results for all samples are contained in Appendix E. 7.4 Hydrological Monitoring At Other United States Nuclear Weapons Testing Locations In addition to the groundwater monitoring conduct- ed on and in the vicinity of the NTS, monitoring is conducted under the LTHMP at sites of past nuclear weapons testing in other parts of the U.S. 9O 80 70 Specie Springs : :+ : : Sample Collection Date Figure 43. Tritium results ± 1 standard deviation for Specie Springs, January 1972 through December 1991. The x indicates the MDC value. E 60 50 40 30 20 10 0 —10 x x S.. 44 XX . JAN72 JAN76 JAN80 JAN84 JAN88 JAN92 78 ------- Maven Sp ngs 600 500 400 200 100 . S . S. . . . . 0 JAN72 JAN76 JAN80 JAN84 JAN88 JAN92 Sample Collection Date Figure 44. Tritium results for Adaven Springs, January 1975 through December 1991. The x indicates the MDC value. Error bars are within circles. L e Mead Intake 300 I 200 I 100 p. a ) J ( X 0 01)01 ) 90 01)01/84 01/01/88 01)01)92 Sample Collection Date Figure 45. Tritium results ± 1 standard deviation for Lake Mead Intake, January 1982 through December 1991. The x indicates the MDC value. 79 ------- Annual sampling of surface and ground waters Is conducted at the Projects SHOAL and FAULT- LESS sites in Nevada, the Projects GASBUGGY and GNOME sites in New Mexico, the Projects RUL 1SON and RIO BLANCO sites in Colorado, and the Project DRIBBLE site in Mississçpi. Additionally, sampling is conducted every two years on Amchitka Island, Alaska, site of Projects CANNIKIN, LONG SHOT, and MILROW. The primary purposes of this portion of the LTHMP are to ensure the safety of public drinking water sup- plies and, where suitable sampling points are available, to monitor any migration of radionuclides from the test cavity. The following subsections summarize results of sampling conducted in 1991; analytical results for all samples are provided in Appendix E. The sampling procedure is the same as that used for sites on the NTS and offsite areas (described in Section 7.12), with the exception that two 3.8-L samples are collected in Cubitainers. The second sample serves as a backup or as a duplicate sample. Because of the variability noted in past years in samples obtained from the shallow moni- toring wells near Project DRIBBLE ground zero (GZ), the sampling procedure was modified. A second sample is taken after pumping for a speci- fied period of time or after the well has been pumped dry and permitted to refill with water. Both samples are analyzed. The second samples may be more representative of formation water, where- as the lirst samples may be more indicative of recent area rainfall. The gross gamma results for all the projects discussed in the following sections were negligible with the exception of Project GNOME. The results for Project GNOME are discussed in Section 7.4.5. 7.4.1 Project FAULTLESS Project FAULTLESS was a calibration test con- ducted on January 19, 1968, in a sparsely populat- ed area near Blue Jay Maintenance Station, Nevada. The test had a yield of less than 1 megaton and was designed to test the behavior of seismic waves and to determine the usefulness of the site for high-yield tests. The emplacement depth was 3200 ft. A surface crater was created, but as an irregular block along local faults rather than as a saucer-shaped depression. The area is characterized by basin and range topography, with alkivium overlaying tuffaceous sediments. The working point of the test was in tuft. The ground- water flow is generally from the highlands to the valley and through the valley to Twin Springs Ranch and Railroad Valley (Chapman and Hokett, 1991). Sampling was conducted on March 19, 1991. Sampling locations are shown in Figure 46. Routine sampling locations include one spring and five wells of varying depths. All of the sampling locations are being used as, or are suitable for, drinking water supplies. At least two wells (HTH-1 and HTH-2) are positioned to intercept cavity migration, should it occur (Chapman and Hokett, 1991). All samples yielded negligible gamma spectra and tritium activities were less than the MDC and less than 0.01 percent of the NPDWR. These results are consistent with results obtained in previous years. The consistently below-MDC results for tritium indicate that, to date, migration into the sampled wells has not occurred and no event-related radiation has entered area dnnking water supplies. 7.4.2 Project SHOAL Project SHOAL, a 12 kiloton test emplaced at 1200 ft, was conducted on October 26, 1963, in a sparsely populated area near Frenchman Station, Nevada. The test, a part of the Vela Uniform Program, was designed to investigate detection of a nuclear detonation in an active earthquake zone. The working point was in granite and no surface crater was created. Samples were collected on Februaiyl2and 13, 1991. Fiveofthesixroutine sampling locations shown in Figure 47 were sam- pled. No sample was collected from Well H-3 because the pump was not operational. The routine sampling locations include one spring, one windmill, and four wells of varying depths. At least one location, Well HS-1, should intercept cavity migration, should it occur (Chapman and Hokett, 1991). A tritium result of 67±3 pCWL was detect- ed in the water sample from Smith/James Spring; all of the remaining samples yielded tritium results less than the MDC. The result for Smith/James Springs is consistent with values obtained in previous years, as shown in Figure 48. It is unlike- ly that the tritium source is the Project SHOAL cavity; the most probable source is assumed to be rainwater infiltration. The 1991 tritium results are 0.3 percent of the NPDWR for Smith/James Spring and less than 0.01 percent of the NPDWR for the remaining sampling locations. 80 ------- / I I I r I I Hot Creek T Ranch ; I I I 1 I I I I I I I I I 4 I I N I I I I I I I I I I . Jim Bias Well (Blue Jay Splings) 0 Surface Ground Zero U Water Sampling Locations / HTH 2 HTh 1 I I J ‘I — I I / I I / I I ‘4 Six-Mile Well Blue Jay Maintenance Station Figure 46. Long-Term Hydrological Scale in Miles _ i _ j 1 Scale in lometers Monitoring Program sampling locations for Project FAULTLESS. 81 ------- Flowing Wells H-3D Hunrs station• 0 NHS-1 • Smith/James Spring CHURCHILL COUNTY I — — — — — — — — — — — — — — — — — — — — — MINERAL COUNTY 0 Surface Groind Zero • Water Sampling Locations 0 N Sampled This Year Figure 47. Long-Term Hydrologk a! Monitoring Program sampling locations for Project SHOAL. • Spnn Windmill S. N LOCATION MAP Scale in Miles o 5 I I I o 5 10 15 Scale in IGlometers 10 CHURCHILL COUNTY 82 ------- 7.4.3 Project RULISON Cosponsored by AEC and Austral Oil Co. under the Plowshare Program, Project RULISON was designed to stimulate natural gas recovery in the Mesa Verde formation. The test, conducted near Rifle, Colorado on September 10, 1969, consisted of a 43 kiloton nuclear explosive emplaced at 8426 ft depth. Production testing began in 1970 and was completed in April 1971. Cleanup was initiat- ed in 1972 and wells were plugged in 1976. Some surface contamination resulted from decontamina- tion of dnlling equipment and fallout from gas flaring. Soil was removed during the cleanup operations. Sampling was completed on June 11, 1991, with the collection of nine samples in the area of Grand Valley and Rulison, CO. Routine sampling loca- tions, depicted in Figure 49, include the Grand Valley municipal drinking water supply springs, water supply wells for five local ranches, and three sites in the vicinity of SGZ, including one test well. a surface-discharge spring, and a surface sampling location on Battlement Creek. An analysis of the sampling locations performed by DRI indicated that none of the sampling locations are likely to detect migration of radionuclides from the test cavity (Chapman and Hokett, 1991). Most of the sam- pling locations draw water from the surf Icial aquifer, composed of Quatemary deposits. This aquifer is separated from the test cavity aby great thickness- es of low permeability formations, making transport of contamination through the geologic medium unlikely” (Chapman and Hokett, 1991). Migration up the emplacement hole or drillback well is also thought to be unlikely due to a zone of low pres- sure at 7200 feet (Chapman and Hokett, 1991). Tritium has never been observed in measurable concentrations in the Grand Valley City Springs. All of the remaining sampling sites show detectable levels of tritium, which have exhibited a decreasing trend over the last two decades. The range of Sample Collection Date SmitWJames Spiing 90— 80 70 60 . 40 30 20 10 01/01/86 + 1 1 1 x x 01/01/88 01/01/90 01/01/92 Figure 48. Tritium results ± 1 standard deviation for SmitWJames Spring, January 1986 through December 1991. The x indicates the MDC value. 83 ------- Rifle do cRanch — Hayward Ranch Ut Battlement Creek Gardner CER Ranch Test Well LOCATiON MAP Surface Grouna Zero U Water Samplmg Locations Scale in Ml$es 0 5 — — — — — — 0 8 Scale in Klome is Potter Ranch Grand C y / , Spring 0 $ N Figure 49. Long-Term Hydrobgical Monitoring Program sampling locations for Project RULISON. 84 ------- tritium activity in the 1991 samples was 56 ± 3 pCi/L at Battlement Creek to 187 ± 4 pCiIL at Lee Hayward Ranch. These values are 0.3 to 0.9 percent of the NPDWR. Tritium results for all samples are provided in Appendix E. An analysis by DRI indicated that most of the sampling loca- tions draw water from the surf icial aquifer which is unlikely to become contaminated by any radio- nuclides arising from the Project RULISON cavity (Chapman and Hokett, 1991). Figure 50 displays data for the last 20 years for Lee Hayward Ranch. The low value obtained in 1990 was attributed to analytical bias and was observed consistently for all Project RULISON sampling locations. 7.4.4 Project RIO BLANCO Like Project RULISON, Project RIO BLANCO was a joint government-industry test designed to stimu- late natural gas flow conducted under the Plow- share Program. The test was conducted on May 17, 1973, at a location between Rifle and Meeker, Colorado. Three explosives with a total yield of 90 kt were emplaced in a 7000 ft hole. The explo- sives were emplaced at 5838, 6229, and 6689 ft depths in the Ft. Union and Mesa Verde forma- tions. Production testing continued to 1976; tritiated water produced during testing was injected to 5600 ft in a nearby gas well. Cleanup and restoration activities were completed by November 1976. Sampling was completed on June 12 and 13, 1991, with the collection of thirteen samples. One routine sampling location, Brennan Windmill, was not sampled because the windmill was inoperative. The sampling sites, shown in Figure 51, include two shallow domestic water supply wells, six surface water sites along Fawn Creek, three springs, and three monitoring wells located near the cavity. At least two of the monitoring wells (wells RB-D-01 and RB-D-03) are suitable for monitoring possible cavity migration. All of the springs had tritium activities of approximately 60 pCi/L (range 60 to 62 pCi/L). These values are 0.3 percent of the NPDWR. Of two shallow domestic wells located near the Project RIO BLANCO site, one could not be sampled in 1991 and the other yielded no detectable tritium activity. All of the sampling sites along Fawn Creek yielded tritium activities of approximately 30 pCi/L (range 27 to 34 pCi/L), equivalent to 0.1 to 0.2 percent of the NPDWR. There is no statistically significant differ- ence observed between results for sites located upstream and downstream of the cavity area. Figures 52a and 52b depict tritium data for two Fawn Creek sites, one located more than a mile upstream of surface ground zero and the other located 500 ft downstream of surface ground zero. The three monitoring wells all yielded no detectable tritium activity, indicating that migration from the test cavity has not occurred. Tritium analysis results for each sample are contained in Appendix E. 7.4.5 Project GNOME Project GNOME, conducted on December 10, 1961, near Carlsbad, New Mexico, was a multipur- pose test conducted in a salt formation. A slightly more than three kiloton nuclear explosive was emplaced at 1216 ft depth in the Salado salt formation. Oil and gas are produced from the geologic units below the working point. The overlying Rustler formation contains three water- bearing zones: brine located at the boundary of the Rustler and Salado formations, the Culebra Dolomite which is used for domestic and stock supplies, and the Magenta Dolomite which is above the zone of saturation (Chapman and Hokett, 1991). The groundwater flow is generally to the west and southwest. Radioactive gases were unexpectedly vented during the test. In 1963, USGS conducted a tracer study invoMng injection of 20 Ci tritium, 10 Ci 137 Cs, 10 Ci 90 Sr, and 4 Ci 1311 in the Culebra Dolomite zone; wells USGS 4 and 8 were used for this tracer study. During remediation activities in 1968-69, contaminated material was placed in test cavity and shaft up to within seven ft of the sur- face. More material was slurried into the cavity and drifts in 1979. There is a potential for dis- charge of this slurry to the Culebra Dolomite and to Rustler-Salado brine. This potential may increase as the salt around the cavity will compress, forcing contamination upward and distorting and cracking the concrete stem and grout. Sampling in the area of Project GNOME was completed between June 22 and 25, 1991. A total of 11 samples were collected from routine sam- pling locations in Carlsbad, Loving, and Malaga, NM. One location, Well 1 at the Pecos Pumping Station, was not sampled because access could not be obtained. The routine sampling sites, depicted in Figure 53, include nine monitoring wells in the vicinity of surface GZ, the municipal supplies 85 ------- Lee Hayward Ranch 500 400 1300 200 100 0 01/01112 01/01176 01/01 , 0 01/01/84 Sample Collection Date 01/01/88 01/01/92 Figure 50. Tritium results ± 1 standard deviation for Lee Hayward Ranch, Janualy 1972 through December 1991. The x indicates the MDC value. at Loving and Carlsbad, NM, and the Pecos River Pumping Station well. As in previous years, the municipal water supplies indicated no detectable tritium activity. An analysis by DRI (Chapman and Hokett, 1991) indicates the Loving and Carlsbad municipal supply wells, located on the opposite side of the Pecos River from the Project GNOME site, are not connected hydrologically to the site and, therefore, can not become contaminated by Project GNOME radionuolides. Tritium results greater than the MDC were detected in water samples from six of the nine sampling locations in the immediate vicinity of GZ. In addi- lion to tritium, detectable concentrations of ‘ 37 Cs and 90 Sr were observed in Well DD-1 which sam- ples water in the test cavity, Well LRL-7 which samples a sidedrift, and wells USGS 4 and 8, which were used in the radionuclide tracer study conducted by USGS. The remaining two wells with detectable tritium concentrations were PHS wells 6 and 8, with results of 41 ± 3 pCiit and 13 ± 3 pCi/I.., respectively. These values are 0.2 and less than 0.1 peJtent, respectively, of the NPDWR. In all cases, the tritium activities exhibit a decreasing trend, as shown in Figures 54a, 54b, 54c and 54d. The figures show the normal tritium decay curve as well as the tritium values. No tritium was detected in the remaining Pioject GNOME samples, includ- ing USGS Well 1, which the DRI analysis (Chap- man and Hokett, 1991) indicated is positioned to possibly detect cavity migration, should it occur. 7.4.6 Project GASBUGGY Project GASBUGGY, like Project RULISON, was a Plowshare Program test cosponsored by the U.S. government and El Paso Natural Gas. Conducted near Gobernador, New Mexico on December 10, 1967, the test was designed to stimulate a low productivity natural gas reservoir. A nuclear explosive with a 29-kt yield was emplaced at a depth of 4240 ft in the Lewis Shale formation, with the resultant cavity extending into the overlying a a . . X X 86 ------- Fawn Cr. No. 3 0 Scale In Miles 0 5 Scale ui Kilometers 8 RIO BLANCO COUNTY GARFiELD COUNTY 0 Surface Ground Zero • Water Sampling Locations o Not Sampled This Year £ LOCATION MAP Figure 51. N Monitoring Program sampling locations for Project RIO BLANCO. 87 ------- Fawn Creek — 6800 ft. Upstream 130 + 120 110 1 + + 80 70 + 4 60 50 + 40 30 20 x 10 x n __________________________________ OliOl/76 01)01/80 01/01/84 01/01/88 01)01192 Sample Collection Date Figure 52a. Tritium results for Fawn Creek - 6800 ft upstream of surface ground zero, January 1976 through December 1991. Fawn Creek — 500 It. Downstream 140 130 + 120 110 100 90 80 + 70 +‘ 4 60 50 40 30 44 20 x 10 x A _____________________________________________________________ 01/01/76 01/01/80 01101/84 01/01/88 01/01192 Sample Collection Date Figure 52b. Tritium results for Fawn Creek - 500 ft downstream of surface ground zero, January 1976 through December 1991. 88 ------- • DD-1 U jU LRL-7 U UPHSWe II8 PHS Well 10 0 Pecos River Pumping Station Well 1 10 0 5 10 15 Scale in Kilometers EDDY COUNTY MAP Carlsbad C y U Well 7 U Loving City Well 2 USGS Wells 48 U. Carlsbad 4 N PHSWeII9 U PHS Well 6U 0 Surface Ground Zero U Water Sampling Locations 0 Not Sampled This Year 0 Scaie in iviiie 5 Figure 53. Long-Term Hydrological Monitoring Program Sampling Locations for Project GNOME. 89 ------- 1.70E +08 1.60E + 08 1.50E+ 08 1.40E+08 1.30E+08 1.20E+08 1.1OE -F 08 1.OOE+08 9.OOE +07 8 ,0 0E+07 01/01/80 Gnome. Well DD—1 T 1thim vs Nomial Tritium Decay Figure 548. Tritium results plotted with normal trftium decay curve for Gnome Well DO-i, January 1980 through December 1991. Gnome, Well LRL- 7 Tritium vs Noanai Tr tium Decay 01/01/84 01101/88 Sample Collection Date Figure 54b. Tnt/urn results ± 1 standard deviation plotted with normal tnitium decay curve for Gnome Well LRL-7, Januaiy 1980 through December 1991. The x indicates the MDC value. 01/01/84 01/01 /88 Sample Collection Date . 01 / 01192 ww 30000 20000 10000 x X x n 01/01/92 90 ------- Gnome 1 USGS Vi ll 4 Trttkni vs Normal Trftlumn Decay 1200000 • 800000 . 01/01172 01/01/76 01/01/80 01/01/84 01/01/88 01/01/82 Sample Collection Date Figure 54c. Tritium results plotted with normal tritium decay cuive for Gnome USGS Well 4, January 1972 through December 1991. The x indicates the MDC value. Gnome, USGS Well 8 TñthJT vs Nom aI Tritlum Decay 1600000 I 1200000 • • 800000 TTTTT 01/01/72 01/01/76 01/01/80 01/01/84 01/01/88 01/01/82 Sample Collection Date Figure 54d. Tritium results plotted with normal tritium decay cuive for Gnome USGS Well 8, January 1972 through December 1991. The x indicates the MDC value. 91 ------- Painted Cliffs Sandstone. Neither of these forma- tions are major water producers. Production testing was completed in 1976 and restoration activities were completed in July 1978. The principal aquifers are the Ojo Alamo Sand- stone, an aquifer containing nonpotable water located above the test cavity, and the San Jose formation and Nacimiento formation, both surficial aquifers containing potable water. The flow regime of the San Juan Basin is not well known, although it is likely that the Op Alamo Sandstone discharg- es to the San Juan River 50 miles northwest of the Gasbuggy site. Hydrologic gradients in the vicinity are downward, but upward gas migration is possi- We (Chapman and Hokett, 1991). Thirteen samples were collected between June 17 to 19, 1991. Well 300.3.32.343 (North) has been removed and, therefore, has been deleted from the routine sampling location directory. A sample was collected from the Old School House Well at the request of the State of New Mexico. This was intended to be a one-time sample only, but the site is being considered for addition to the routine sampling directory due to its location in the proba- We downgradient direction from the test cavity. The routine sampling locations include seven wells, one windmill, three springs, and Iwo surface water sites, depicted in Figure 55. The two surface water sampling sites yielded Iritium activities of 40 ± 2 pCi/L and 46 ± 2 pCi/L; these values may be indicative of concentrations in rainfall and are 02 percent of the NPDWR. The three springs yielded tritium activities ranging from 48±3 pCi/I to 71 ± 3 pCifL, which is 0.2 to 0.4 percent of the NPDWR. Tritium activities in shallow wells varied from less than the MDC to 50± 2 pCi/I, which is less than 0.1 to 0.3 percent of the NPDWR. Well EPNG 10-36, a former gas well located 435 ft northwest of the test cavity with a sampling depth of approximately 3600 ft, yielded a tritium activity of 484 ± 4 pCi/I in 1991. Prior to 1984, all tntium activities measured in this well were less than 45 pCi/L, a value which may be considered the back- ground activity for this location. In 1984 arid every year since then, with the exception of 1987, tritium activities have been between 100 and 560 pCifL, with wide variability sometimes noted between consecutive years. In each of the last three years, the activity in this well has approximately doubled, as shown in Figure 56. The proximity of the well to the test cavity suggests the possibility that the increased activity may be indicative of migration from the test cavity into the Ojo Alamo Sandstone groundwater. Communication between the Ojo Alamo Sandstone and the test cavity has been documented (Power and Bowman 1970) and is probably due to concrete failure. It is also TM un likely but remotely possibl& that fracturing around the test cavity extends to the Ojo Alamo Sandstone (DOE, 1986). Representatives of DOE, DRI, and EPA are currently working on a sampling plan for this well to further investigate the increased activi- ty. 7.4.7 Project DRIBBLE Project DRIBBLE was comprised of four explosive tests, two nuclear and two gas, conducted in the Tatum Salt Dome area of Mississippi under the Vela Uniform Program. The purpose of Project DRIBBLE was to study the effects of decoupling on seismic signals produced by explosives tests. The first test, SALMON, was a nuclear device with a yield of about 5 kt, detonated on October 22, 1964, at a depth of 2710 ft. This test created the cavity used for the subsequent tests, including STER- LING, a nuclear test conducted on December 3, 1966, with a yield of about 380 tons, and the two gas explosions, DIODE TUBE, conducted on February 2,1969, and HUMID WATER, conducted on April 19, 1970. The ground surface and shallow groundwater aquifers were contaminated by dis- posal of drilling muds and fluids in surface pits. The radioactive contamination was primarily limited to the unsaturated zone and upper aquifers con- taining nonpotable water. Shallow wells, labeled HMH wells on Figure 57 have been added to the area near surface GZ to monitor this contamina- tion. In addition to the monitoring wells surround- ing GZ, extensive sampling is conducted in the nearby offsite area. Most private drinking water supply wells are included, as shown in Figure 58. Sampling on and in the vicinity of the Tatum Salt Dome was conducted between April 21 and 24, 1991. A total of 104 samples were collected; eight of these were from new sampling locations in Columbia and Lumberton, MS. Eight routine sampling locations were not sampled. In two cases, the residents (Rita Smith arid Donald Beach) have moved and the well is not in opera- tion. These sampling locations will not be sampled again unless new residents reopen the well. Another resident (M. Lowe) switched to rural water and is no longer using a well, thus eliminating the need to sample at this location. The other five 92 ------- To O Schod House Well Cedar Springs U Cave Springs U Amotd Ranch U N [ o • Surface Ground Zero Water Sampling Locations Scale in Miles Scale in Kilometers Lu Aiior1 MAP Bixier Ranch U To Blanco & U Pond N.ot Well 30.3.32.343N Bubbling Springs U La Jara Creek EPNG Well 10-36 Windmill 2 . Jicarilla Well 1 Lower Burro U Canyon 4 U Well 28.3.33.233 (South) 0 5 0 8 RIO ARRIBA COUNTY Figure 55. Long-Term Hydrological monitoring Program sampling locations for Project GASBUGGY. 93 ------- E 600 500 400 Gasbuggy Well EPNG 10-36 Figure 56. Tritium results for Gasbuggy Well EPNG 10-36, Januaiy 1972 through December 1991. samples were not taken this year either because the site was inaccessible due to local flooding or because the resident was not home. Of the 47 samples collected from offsite sampling locations, tritium activities ranged from less than the MDC to 48 ± 4 pCi/L, equivalent to less than 0.01 to 0.2 percent of the NPDWR. The results do not exceed the natural tritium activity expected in rainwater in the area. Results for each sample are provided in Appendix E. Uranium-238 was detect- ed at concentrations greater than the MDC in three of the water samples collected from the eight new sampling locations and U was greater than the MDC in one sample. The highest U was 0.0705 ± 0.0191 pCi/L and the highest U was 0.0537 ± 0.0163 pCi/L, both in the water sample collected from the pond on the Howard Smith properly in Lumberton, MS. These activities are extremely low and probably of natural origin. Due to the high rainfall in the area, the normal sampling procedure is modified for the shallow onsite wells. Following collection of a first sample, the well is pumped for a set period of time and permitted to refill and a second sample is collected. The second samples are thought to be more representative of the formation water. Thirty-two locations were sampled in the vicinity of GZ; 23 of these yielded tritium activities greater than the MDC in either the first or second sample. Overall, tritium activities ranged from less than the MDC to 1.44 x 1 o ± 1.95 x 102 pCi/L. The locations where the highest tritium activities were measured gener- ally correspond to areas of known contamination. None of the samples indicate any migration of radionuclides from the test cavity. Results for all samples are provided in Appendix E. Results of sampling related to Project DRIBBLE are dis- cussed in greater detail in Onsite and Offsite Environmental Monitoring Report: Radiation Monitoring around Tatum Salt Dome, Lamar County, Mississippi, Apr11 1991 (Thomé et al, in press). 300 200 100 0 -100 01/01/72 . . . . . . . •.•• . . XXX 01It 1/76 01/01/80 01/01/84 Sample Collection Date 01/01/88 01/01/92 94 ------- Well HT-4 0 Suriace Ground Zero 0 Water Samphng Locations o Not Sampled This Year 0 100 HMH-10 O ow • •HMH-9 I HMH-7D Well HT-5 4 N Scale in Miles 300 Scale in Kilometers LAMAR COUNTY LOCATiON MAP Figure 57. Long-Term Hydrological Monitoring Program sampling locations for Project DRIBBLE-near ground zero. 95 ------- • B. Dennis • PA. Dennis • Cokrnbla City Utle Creek 11 Wel 648 Lee Anderson T.S. Saucier Yancy Saucier Herman G son Lcmsr Little Creek *2 th Pond Timber Co ro Surface Ground Zero • Water SaTtpllng Locations o Not Sampled This Year Sc s in PMes 0 1 2 3 $ I I 01 2 34 Scale Wi Kiloreelers IA n COUNTY LOCATION MAP Figure 58. Long-Term HydroIogk a! Monitoring Program sampling bcations for Project DRIBBLE- towns and residences. 96 ------- 7.4.8 Amchitka Island, Alaska Three nuclear detonations were conducted on Amchitka Island in the Aleutian Island chain of Alaska. Project LONG SHOT, conducted on October 29, 1965, was an 85-kt yield test em- placed at 2359 ft depth. It was a Vela Uniform Program test, designed to investigate the travel times of seismic waves. Project MILROW, con- ducted on October 2, 1969, was an approximately 1-Mt ‘calibration test’ of seismic and environmental response to the detonation of large-yield nuclear explosives. The emplacement depth of Project MILROW was 3990 ft. Project CANNIKIN, con- ducted on November 6, 1971, was a proof test of the Spartan antiballistic missile warhead with a less than 5-Mt yield emplaced at 5875 ft depth. Project LONG SHOT resulted in some surface contamina- tion, even though the chimney did not extend to the surface. Amchitka Island is composed of several hundred feet of permeable tundra overlaying tertiary vol- canics. The groundwater system consists of a freshwater lens floating on seawater estimates of the depth to the saline freshwater-interface range from 3900 to 5250 ft (Chapman and Hokett, 1991). It is likely that any migration from the test cavities would discharge to the nearest salt water body, Project MILROW to the Pacific Ocean and Projects LONG SHOT and CANNIKIN to the Bering Sea (Chapman and Hokett, 1991). The sampling locations on Arnchitka Island are shallow wells and surface sampling sites. Therefore, the monitoring network for Amchitka Island is restricted to monitor- ing of surface contamination and drinking water supplies. Sampling on Amchitka Island, AK, was conducted between September 21 and 24, 1991. Four loca- tions were sampled for the first time. These four new sampling sites are Constantine Spring Pump House, RX-Site Pump House, TX-Site Springs, and TX-Site Water Tank (House). Of the routine sampling locations, nine were not sampled. Army Well 3 and the Site D Hydrological Exploratory Hole are plugged and, therefore, are being elimi- nated from the routine sampling directory. The Site E Hydrological Exploratory Hole was not sampled due to the presence of oil in the hole. Five EPA wells were not sampled because the wells were in the lake (flooded); these were EPA wells 9, 12, 16, 17, and 19. Another well, EPA 4, was dry. In addition, two sampling locations were deleted from the routine sampling directory prior to the initiation of sampling. These were the Decon Pump and Decon Sump which were eliminated because past data indicates no potential for detec- tion of radioactive contaminants. Background sampling locations are shown in Figure 59, for Projects LONG SHOT and MILROW in Figure 60, and for Project CANNIKIN in Figure 61. Sample results are consistent with the sampling history for the area. Samples collected from the four new sampling locations yielded gross alpha and gross beta results greater than the MDC for those scans. The highest values were 2.9 ± 0.7 pCi/L alpha and 7.3 ± 0.8 pCi/L beta for the Con- stantine Spring Pump House. In general, while most samples contain tritium concentrations detect- able by the enrichment method of analysis (mini- mum detectable concentration approximately 7 to 10 pCiIL), the levels are extremely low and contin- ue to evidence the decreasing trend observed throughout the sampling history. With the excep- tion of five of the Project LONG SHOT sampling locations, all tritium results were less than 50 pCi/L. Samples from the three Mud Pits and the stream east of LONG SHOT yielded tritium activi- ties of approximately 225 pCi/L (range 190 ± 3 pCi/L to 282 ± 3 pCi/L). Of these, only the stream east of LONG SHOT has the potential to be used as drinking water. The measured 3 H activity for this site was 190 ± 3 pCLIL, which is less than 1 percent of the NPDWR. Well GZ No. 1, located in or near the Project LONG SHOT cavity, had a tritium activity of 1128 ± 99 pCi/L. All of these sampling locations have shown a decreasing trend over time. Analytical results for all samples are contained in Appendix E. 7.5 Summary None of the domestic water supplies monitored in the LThMP in 1991 yielded tritium activities of any health concern. The greatest tritium activity mea- sured in any water body which has potential to be a drinking water supply was less than one percent of the NPDWRs. In general, surface water and spring samples yielded tritium activities greater than those observed in shallow domestic wells in the same area. This is probably due to scavenging of atmospheric tritium by precipitation. Where suitable monitoring wells exist, there were no indications that migration from any test cavity is affecting any domestic water supply. 97 ------- BERING 5ff A Rx - Site Pump Hou Duck Cove C Milr BASE CAMP AREA - . 0 t ‘ o t : ‘ :: : . t.:::c.... :.A. y $ 10 1 $ome1 rs I LI [ [ 111 tIWUU ... KfrL 1 af FoIiTf CONSTANT iNE • Water Sampling Locations o Not Sampled This Year 0 SCale in Miles 1 I PACIFIC Iii 0 1 Scale in Kilometers Figure 59. Amchitka Island and Background sarrqling location for the Long-Term Hydrological Monitoring Program. 98 0 Surlaco Zb; • Water Sampling Locations 0 Not Sampled This Year ------- Scale In 600 200 Feet Scale In Meters 1200 400 MILROW 0 Scale hi Feet 300 E l 100 Scale in Meters Figure 60. Long-Term Hydrological Monitoring Program sampling locations for Projects MILROW and LONGSHOT. * N 0 0 Heart Lake Surface Ground Zero / U Water Sampling Locations 0 Not Sampled This Year Surface Ground Zero U 0 Water Sampling Locations Streams Long Shot Pond 3 0 99 ------- j Surface Ground Zero • Water Sampling Locations Figure 61. Long-Term Hydrological Monitoring Program sampling locations for Project CANNIKIN. Lake DK-45 Army Well 2 U Well 4 V HTH-3 Scale In Miles 1 Scale in Klkxneters 100 ------- In most cases, monitonng wells also yielded no radionuclide activity above the MDC. Exceptions include wells into test cavities, wells monitonng known areas of contamination, and one well at GASBUGGY. Known areas of contamination exist at Project GNOME where USGS conducted a tracer study experiment, some areas onsite at Project DRIBBLE, and a few surface areas near Project LONG SHOT. The 1991 results for these monitoring wells are consistent with decreasing trends observed over time. Monitoring well EPNG 10-36 at Project GASBUGGY was a notable exception to wells evidencing decreasing trends. This well is a former gas well located 435 feet northwest of SGZ. The sampling depth of this well is approximately 3600 ft in the Ojo Alamo Sand- stone, an aquifer containing nonpotable water. The tritium activity in 1991 was 484 ± 4 pCiIL, approximately 10 times the historic background activity. An increase in tritium activity was first observed in 1984, seventeen years after the test was conducted. In every year since then, with the exception of 1987, tritium activities have been between 100 and 560 pCi/L, with wide variability sometimes noted between consecutive years. The proximity of the well to the test cavity suggests the possibility that the increased activity may be indicative of migration from the test cavity. 1. The NPDWR states that the sum of all beta/gamma emitter concentrations in drinking water cannot lead to a dose exceeding 4 mrern/year, assuming a person were to drink two liters per day for a year (40 CFR 141). Assuming tritium to be the only radioactive contaminant yields a maximum allowable concentration of 2 x 10’ pCi/L. 2. The NPDWR applies only to public systems with at least 15 hookups or 25 users. Although many of the drinking water supplies monitored in the LTHMP serve fewer users and are therefore exempt, the regulations provide a frame of reference for any observed radionuclide activity. 101 ------- 8. Dose Assessment There are four pathways of possible radiation exposure to the population of Nevada that were monitored by EPA’s offsite monitoring networks during 1991. The four pathways were: • Background radiation due to natural sourc- es such as cosmic radiation, natural radio- activity in soil, and 7 Be in air. • Worldwide distributions of radioactivity, such as Sr in milk, Kr in air, and plu- tonium in soil. • Operational releases of radioactivity from the NTS, including those from drilback and purging activities. • Radioactivity that was accumulated in migratory game animals during their resi- dence on the NTS. 8.1 Estimated Dose From Nevada Test Site Activity Data The estimated Committed Effective Dose Equiva- lent (CEDE) to the offsite population due to NTS activities was based on the total release of air- borne radioactivity from the NTS in 1991. Onsite source emission measurements, as provided by DOE, are listed in Table 12. Because no radio- activity of recent NTS origin was detectable oftsite by the various EPA monitoring networks, no mea- surable exposure to the population living around the NTS was expected from the sources listed in Table 12. To confirm this expectation, a calcula- tion of estimated dose from NTS effluent estimates was performed using EPA’s CAP88-PC model (EPA 1992). A population totaling 21,752 individu- als living within a radius of 80 km (50 ml) of any of the sources was included in the calculation. Excluding Clark County, the population density of counties adjacent to the NTS is about 0.7 persons per square mile (0.4 persons per square kilometer) (BOC, 1990). Section 2.5 of this report details the population distribution in areas surrounding the NTS. The results of the model indicated that a hypothetical individual with the maximum calcu- lated dose from airborne NTS radioactivity would have been continuously present at Spnngdale, Nevada, 72 kilometers (45 miles) west of CP-1. The maximum possible dose to that indMdual was 8.6 x 1 0 mrem (8.6 x 1 mSv). Data from the PlC monitoring network indicated a 1991 dose of 143 mrem from background gamma radiation occurring in the Beatty area near Spnngdale. The collective population dose within 80 km (50 mi) from the airborne emission sources was calculated to be 4.2 x 102 person-rem (4.2 x io person-Sv). Activity concentrations in air that would cause these calculated doses are too small to be detect- ed by the offsite monitoring network. Table 13 summarizes the annual contributions to the CEDEs due to 1991 NTS operations as calculated by use of CAP88-PC and the released radionuclides listed in Table 12. Input data for the CAP88-PC model include me- teorological data from Weather Service Nuclear Support Office (WSNSO) and effluent release data reported to DOE by organizations conducting operations at the NTS. The effluent release data are known to be estimates and the meteorological data are mesoscale; e.g., representative of an area approximately 40 km (25 mi) or less around the point of collection. However, these data are considered sufficient for model input, primarily because the model itself is not designed for com- plex terrain such as that on and around the NTS. Errors introduced by the use of the effluent and meteorological data are small compared to the errors inherent in the model. Results obtained by using the CAP88-PC model are considered esti- mates only of the dose to offsite residents. 8.2 Estimated Dose From ORSP Monitoring Network Data Potential CEDEs to individuals may be estimated from the concentrations measured by the EPA monitoring networks during 1991. Actual results obtained in analysis are used; the majority of which are less than the reported MDC. Precision and accuracy DQOs are, by necessity, less stringent for values near the MDC and consequently, confi- dence intervals around the input data are broad. Table 14 and Table 15 describes the concentra- 103 ------- Tthl. 12. NTS Radionuclide Emissions 1991 Airborne Effluent Releases Curies Event or Facility Name (Airborne Releases) ‘H “Ar “Ar “‘Kr “Xe “Xe “Xe 133)( “Xe ‘ ‘i Area 5, RWMS 5.OxlO t Area 3. LUBBOCK 8.3x10 ’ Area 12. P Tunnel 1.4x10 ’ 4.5x10’ 2.1x1O 6.6x10 4 6. 10 5.2x10 4 7.0x10 4 2.7x10’ 3.8x10 4 Area 19. BEXAR 5.0x10’ 1.0x10 TOTAL 5.0x1O ’ 4.5x10’ 2.1x10’ 6.6x10 4 6.6x10 ’ 5.2x10 4 7.0x10 4 8.5x10’ 3.8x10’ 1.OxlO 4 Lkp.ld Effluent Releases Cuhes Containment end Redo- nnc ds on (RNM) Ponds Gross Beta ‘H ‘°Sr “'CS ““Pu “ “ ‘ “°Pu Area 5, U50RNM2S 1.2 x 102 Area 6. Decordwnlnation Pad Pond 2.6 x i0 4 1.8 x i0 1.0 x 106 2.7 x 1O 3.0 x 1(1 ’ Area 12. ETunnel 1.9 x 10’ 5.0 x 10’ 1.1 x 10’ 2.7 x i0 4 1.7 x 10’ 1.4 x iO ’ Area 12, N Tunnel 1.3 x 10’ 1.9 x 10’ 1.8 x i0 4 1.4 x 10’ Area 12,TT u nnel 3.7 x 10’ 1.7 x 10’ 4.4 x 10’ 1.0 x 10’ 7.7 X 10’ 1.3 x i0 TOTAL 4.0 x 10’ 1.8 x 10’ 5.6 x iO 1.3 x 10’ 2.7 x 1(1’ 2.7 x 10’ Mtit ly by 3.7 x 10 i0 Bq. ‘ Enwonmenlal monltoring in Area 20 detected an average “'Kr o(8 pCi/rn’ above the network average. Probably due Po seepage as source temi is indeterminate. A person standng at the sampler location all year would have received a dose of only 2.7 x 10’ mrem. 104 ------- Table 13. Summary of Committed Effective Dose Equivalents from NTS Operations during 1991 Maximum CEDE at NTS Boundary Maximum CEDE to an lndividual CoDective CEDE to Population within 80 km of the NTS Sources Dose 9.4 x 10 mrem (9.4 x 10 mSv) 8.6 ± 0.8 x 10 mrem (8.6 x 10 mSv) 4.2 x 10 person-rem (4.2 x 10 person-Sv) Location Site boundary 42 km WSW of NTS Area 12 Springdale, NV, 56 km WSW of NTS Area 12 21,700 people within 80 km of NTS Sources NESHAP* Standard 10 mrem per year (0.1 mSv per yr) 10 mrem per year (0.1 mSv per yr) ----- Percentage of NESHAP* 9.4 x 10 8.6 x 102 Background 143 mrem (1.4 mSv) 143 mrem (1.4 mSv) 1660 person-rem (16.6 person Sv) Percentage of Background 6.6 x 10 6 x 10 2.5 x 10 (a) The maximum boundary CEDE is to a hypothetical individual who remains in the open continuously during the year at the NTS boundary located 42 km WSW from the Area 12 tunnel ponds. (b) The maximum individual CEDE is to a person outside the NTS boundary at a residence where the highest dose-rate occurs using NTS effluents listed in Table 13. (c) Maximum CEDEs are calculated using CAP88-PC (Version 1.0). The calculations assume all tritiated water input to the area 12 containment ponds was evaporated. * National Emmission Standards for Hazardous Air Pollutants. tions from the monitoring networks used in the calculation of potential CEDEs. The dose to an individual then is estimated from the concentrations given in Table 14 and Table 15 by using the assumptions and dose conversion factors described below. The dose conversion factors assume continuous presence at a fixed location and no loss of radioactivity in meat and vegetables through storage and cooking. • Adult respiration rate = 8400 m 3 /yr (ICRP 1975). • Milk intake for a normal child = 164 LJyr (ICRP 1975). • Consumption of beef liver = 0.5 lblwk (11.5 kglyr). • An average deer has 100 lb (45 kg) of meat. • Water consumption = 2 L/day (ICRP 1975). • Fresh vegetable consumption = 516 glday (1.1 lb/day) for a four-month growing season (ICRP 1975). The Committed Effective Dose Equivalent (CEDE) conversion factors are derived from EPA-52W1-88-02o (Federal Guidance Report No. 11). Those used are: • 3 H: 6.4 x 1 0 mremlpCi (ingestion or inhala- tion). • 9 °Sr: 1.4 xl 0 mrerrt/pCi (ingestion). • Kr: 1.5 x 1 Cr 5 mrerrt/yr per pCi/rn 3 (submer- sion). • 240 Pu: 5.0 x 10 mrenVpCi (ingestion). 3.1 x 10.1 mrernlpCi (inhalation). 105 ------- Table 14. Concentrations from Monftonng Networks 1991 Medium Radionuclide Concentration Comment Animals Beef Liver °Pu 4.4 x 10.2 pCi/g (1.6 xl 0 Bqfg) Concentrations are the maximum concentrations observed for each animal tissue type. Deer Muscle °Pu 1.2 x 10.2 pCVg (4.4 x 10. ’ Bq/g) Deer Blood 3 H 4.2 x iø pCi/ I. Deer Liver ‘ ° 240 Pu 2.2 x 1 0 pCilg (8.2 x 1 Bqfg) Milk 90 Sr 0.6 pCi/L (2.2 x 10.2 BqIL) Concentration is the average of all strontium results from network. 3 H 152 pCi/L (5.6 Bq/L) Concentration is the average of all tritium results from network. Drinking Water 3 H 3.4 pCi/I. Concentration is the average of results from Coffer’s, Spicer’s, Younghans’ and Beatty City wells, all of which are near Springdale, Nevada. Vegetables Potatoes 23 2 °Pu 6 x 1 0 pCi/g Concentrations are from vegetables from Rachel; all other vegetables ranged from Summer Squash 23 °Pu 2 x 10.’ pCVg approximately 4 x 1 0 to 1 x 10.’ pCiIg. Air 3 H 0.5 pCi/rn 3 (1.8 x 10.2 Bq/m 3 ) Concentration is the average of all tritium results from network. ‘ Kr 26.4 pCi/rn 3 (1 Bqlm 3 ) Concentration is the average of all krypton results from network. 23 ’°Pu 1.1 x 1 0 pCi/rn 3 (4 x 1 0 Bqfm 3 ) Concentration is the highest result from High-volume sampler at Amargosa Valley station. Used as it is the highest detectable result near Springdale, Nevada. 106 ------- Table 15. Dose Calculations from the Monitoring Networks Route of Medium Exposure Radionuclide Calculation Dose (CEDE) Milk Ingestion 90 Sr (0.6 pCi/L) x (164 L/yr) x (1.4 x 1 0 mrem/pCi) 1.38 x 1 o 2 mremlyr 3 H (152 pCLIL) x (164 L/yr) x (6.4 x 108 mremlpCi) 1.6 x 1 0 mremlyr Total from milk consumption 1.5 x 1 02 mrerrtlyr Water Ingestion 3 H (3.4 pCi/L) x (730 L/yr) x (6.4 x 10.8 mrern/PCi) 1.6 x 1 0 mrem/yr Animals (Beef Liver) Ingestion 2 °Pu (4.4 x 10.2 pcvg) x (11.5 x glyr) x (5.0 x ici mremlpCi) 2.5 x 102 mremfyr Vegetables (at Rachel) Ingestion 240 Pu (6 x 10 pCi/g) x(6.2x 10 g/yr) x (5.0 x i0 mrernlpCi) 2 x 10 mrern/yr Vegetables (other Ingestion locations) °Pu (1 x 10 pCi/g) x (6.2 x 1 glyr) x (5.0 x i(i mrem/pCi) 3 x 10 mremlyr Air Submersion Kr (26.4 pCi/rn 3 ) x (1.5 x 1 0 mrem/yr per pCi/rn 3 ) 4.0 x 10 mrem/yr Air Inhalation °Pu (1.1 x 106 pCi/rn 3 ) x (8400 m 3 fyr) x (3.1 x i0 mrern/pCi) 2.9 x 10 a mrem/yr Inhalation & Absorption 3 H (0.5 pCi/rn 3 ) x (8400 m 3 /yr) x (6.4 x 10 mrernlpCi) x 1.5 4.0 x i0 mremlyr Total from inhalation and absorp tion of air 3.3 x 1 o mremlyr 107 ------- As an example calculation, the following is the result of breathing background levels of tritium in air: (0.5 pCVm 3 ) x (8400 m 3 /yr) x (6.4 x 10 mrem/pCi) = 2.7 x 10 mremfyr. OR (concentration) x (volume/unit time) x (CEDE conversion factors) = CEDE However, in calculating the inhalation CEDE from 3 H, the value is increased by 50% to account for absorption through the skin. The total dose in one year, therefore, is 4.0 x 1 4 mrem. Dose calcula- tions from the monitoring networks are given in Table 16. The individual CEDEs from the various pathways can be added together for a total of 5 x 1 .2 mrem including the vegetables from Rachel. Total CEDEs can be calculated based on different combinations of data. If an individual were inter- ested in just one area for example, the concentra- tions from those stations closest to that area could be substituted into the equation. The highest measured concentrations of radio- nuclides in tissue occurred in deer collected on the NTS. The highest deer muscle sample measured 1.2 x 1 if 2 pCifg of 23 °Pu. In the event that one such deer were collected and eaten by a resident in an offsite area, the consumer’s dose can be estimated. Assuming 45 kg (100 Ib) of meat with these plutonium concentrations, the CEDE from plutonium would be: • (1.2 x 1 ci 2 pCi/g) x (45 x 1 o g) x (5 x 1 mrem/pCi) = 2.7 x 10.2 mrem. The tritium concentration in the blood of the same mule deer was 4.2 x iO pCi/L. If one asumes that the 3 H concentration in tissue equals that of the blood and that the density of tissue equals that of blood, i.e. 1 g/ml, then 45 kg of tissue equals 45 liters. The CEDE from tritium would be: • (4.2xlO 5 pCi/L)x(45L)x (6.4 x 10 mren /pCi) = 1.2 mrem The sumof thedosesfrom ° Puand 3 H is 1.2 mrem showing that the total is completely dominat- ed by the 3 H concentration. 8.3 Dose from Background Radiation In addition to external radiation exposure due to cosmic rays and gamma radiation from naturally occurring radionuclides in soil (e.g., 40 K, uranium and thorium daughters), there is a contribution from 7 Be that is formed in the atmosphere by cosmic ray interactions with oxygen and nitrogen. The annual average 7 Be concentration measured by the oftsite surveillance network was 0.23 pCVm 3 . With a dose conversion factor for inhalation of 3.2 x 1 o mremlpCi, this equates to a dose of 6 x 1 0 mrem. This is a negligible quantity when compared with the PlC network measurements that vary from 52 to 154 mR/year, depending on location. 8.4 Summary The extensive offsite environmental surveillance system operated around the NTS by EPA EMSL-LV measured no radiological exposures that could be attributed to recent NTS operations. Calculation with the CAP88-PC model resulted in a maximum inhalation dose of 8.6 x 1 0 mrem (8.6 x 1 0 mSv) to a hypothetical resident of Spnngdale, NV, 72 kilometers (45 miles) west of the NTS C P-I. The calculated dose to this individu- al from worldwide distributions of radioactivity as measured from surveillance networks was 5 x 1(12 mrem (including vegetables from Rachel). If this individual were to additionally collect and consume an NTS deer such as the one discussed above, the estimated CEDE would increase by another 1.2 mrem to a total possible CEDE of slightly over 1.2 mrem. All of these maximum dose estimates are approximately 1% of the International Commission on Radiation Protection (ICRP) recommendation of an annual effective dose equivalent not to exceed 100 mrernfyr (ICRP 1985). The calculated popula- tion dose (collective committed effective dose equivalent) to the approximately 21,752 residents living within 80 km (50 mi.) of each of the NTS airborne emission sources was 4.2 x 10.2 person-rem (4.2 x 1 o- person-sievert). Data from the PlC gamma monitoring indicated a 1991 dose of 143 mrem from background radiation occurring in the Beatty area near Spnngdale. The 143 mrem background value is derived from an average PlC field measurement of 16.3 hR/hr. The 1.2 mrem CEDE calculated from the monitoring networks discussed above is a negligible amount compared to the background dose of 143 mrem. Both the NTS and worldwide distributions contrib- ute a negligible amount of exposure compared to natural background. 108 ------- 90 Weapons Test and Liquefied Gaseous Fuels Spills Facility Support The EPA participates in the execution of every nuclear test conducted at the NTS. For each test, the EPA performs a pre-test census of the offsite area population, is directly involved in the nuclear test itself, and is prepared to take protective ac- tions in the event they are necessary. The EPA also provides offsite safety monitoring in support of chemical spill tests conducted at the Liquified Gaseous Fuels Spill Test Facility (LGFSTF) on the NTS. For each test, the EPA performs a pre-test inspection of the routes to sampling locations, is directly involved with the test itself, and collects samples. 9.1 Weapons Tests Support Two days prior to each nuclear test, mobile teams of radiation monitoring technicians are dispatched to the counties surrounding the NTS. These technicians perform a census of the off site areas to determine the locations and numbers of residents, work crews, and domestic animal herds. This information would be essential to providing protec- tive actions in the event of a radiation release from a test. Additionally, the technicians monitor the seasonal population such as hunters and shep- herds to ensure that they too can be notified if necessary. After the census is completed, the information is presented by the EPA to the Test Controllers Science Advisory Panel. Senior EPA personnel serve as members of the Test Controller’s Science Advisory Panel to provide advice on possible public and environmental impact of each test and on feasible protective actions in the event that an accidental release of radioactivity should occur. At the time of each test, approximately 20 radiation monitoring technicians are positioned in the downwind areas of the test. Each technician is equipped with a variety of radiation survey instru- ments, dosimeters, portable air samplers, and supplies for collecting environmental samples. The technicians are in constant radio contact with CP-1 which enables them to provide monitoring informa- tion and to receive operational instructions from the EPA staff. In the unlikely occurrence of any release of radioactivity, the technicians are pre- pared to initiate all manner of protective actions to assure the health and safety of those people in the offsite areas. They are also prepared to conduct a radiological monitoring and sampling program to document the radiation levels in the environment. The radiological safety criteria, or protective action guides, used by the EPA are based on those specified in NVO-176 (EPA, 1991a). If an underground nuclear test is expected to cause detectable ground motion offsite, EPA monitoring technicians are stationed at locations where hazardous situations might occur, such as underground mines. At these locations, occupants are notified of potential hazards so they can take precautionary measures. Miners, for example, are brought above ground before such a test. Remedial actions that EPA could recommend or implement to reduce exposures include: evacua- tion, shelter, access control, livestock feeding practices control, milk control, and food and water control. Which action would be appropriate de- pends largely upon the type of accident and the magnitude of the projected exposures and doses, the response time available for carrying out the action, and local constraints associated with a specific site. An important factor affecting the effectiveness of the remedial actions is the degree of credibility EPA personnel maintain with offsite residents. Credibility is created and maintained by routine personal contacts made with local officials and law enforcement personnel as well as with the ranch- ers, miners, and others living in the offsite areas close to the NTS. To determine the feasible remedial actions for an area, EPA uses its best judgment based on experi- ence gained during atmospheric tests and from those tests conducted in the 1 960s that contami- nated offsite areas. No remedial actions have been necessary since 1970, so there is no recent experience by which to test this judgment. Howev- er, through routine contact with offsite residents and through continuing population and road sur- veys, EPA maintains a sense of the degree to 109 ------- which it could implement remedial actions and the kind of cooperation that would be provided by officials and residents of the area. During 1991, EMSL-LV personnel were deployed for all nuclear tests conducted at the NTS, none of which released radioactivity that could be detected off site. 9.2 Liquefied Gaseous Fuels Spills Test Facility Support The EPA provides offsite safety monitoring in support of chemical spill tests conducted at the LGFSTF on the NTS. This is one of the few non- nuclear related activities conducted at the NTS. A scientist from the EPA is a member of the Spill Test Advisory Panel for each test. For each test, the EPA also conducts monitoring in the downwind direction at the boundary of the NTS. Prior to the initial test of any given series of tests, and during operational trials by the spill sponsors, an EPA technician inspects the unmaintained jeep- trail routes to the predetermined sampling location to assure ready access. Since each test is contin- gent on compatible technical and ambient condi- tions, including wind direction and speed, the technician remains at the Test Facility Control Center until the Advisory Panel authorizes initiation of the test. The EPA Advisory Panel representa- tive then dispatches the technician to the sampling location, as close as accessible to the downwind trajectory. When the spill test is in progress, the EPA representative, in coordination with the Advi- sory Panel meteorologist, determines the travel time of gases from the spill to the sampling loca- tion of the monitor. The EPA representative then gives the technician specific clock time(s) to collect gas samples. Samples are collected using a Model 31 Drager hand pump into which is inserted a Drager tube for the type of chemical gases to be detected. The technician remains at the sampling location until the Advisory Panel determines that further offsite monitoring is no longer required for that day’s testing. Testing during 1991 occurred on May 1, and May 7, and involved hydrogen fluoride (HF) protective suit evaluations. The tests were conducted by the Lawrence Livermore National Laboratory. The EPA monitor was positioned approximately 4.7 km (3.5 miles) downwind of the point of release, at the border between NTS and Air Force property. The results of air monitoring indicated that HF was not detected at the NTS boundary. In addition, no odors attributable to test chemicals were noted by field monitoring personnel. 110 ------- 10. Public Information and Community Assistance Programs In addition to its many monitoring and data anal- ysis activities, the EPA EMSL-LV conducts a comprehensive program designed to provide information and assistance to individual citizens, organizations, and local government agencies in communities near the NTS. Activities in 1991 included: participation in public hearings, town halla meetings, continued support of the Commu- nity Radiation Monitoring Program (CAMP) and a variety of tours, lectures, and presentations. 10.1 Community Radiation Monitoring Program Beginning in 1981, DOE and EPA established a network of CAMP stations in the offsite areas to perform radiological sampling and monitoring to increase public awareness, and to disseminate the results of radiation monitoring activities to the public. These stations continued operation in 1991. The DOE, through an interagency agree- ment with EPA, sponsors the program. The EPA provides technical and scientific direction, main- tains the instrumentation and sampling equipment, analyzes the collected samples, and interprets and reports the data. The Desert Research Institute of the University of Nevada System administers the program by hiring the local station managers and alternates, securing rights-of-way and utility meters, and by providing QA checks of the data. The University of Utah provides in-depth training for station managers and alternates twice a year on issues related to nuclear science, radiological health, and radiation monitoring. In each commu- nity, EPA and DRI work with civic leaders to select and hire a local manager and an alternate. When- ever possible, they choose residents with some scientific training, such as a high school or univer- sity science teacher. All of the 19 CRMP stations contain one each of the samplers for the Air, Noble Gas, and Tritium networks discussed in the previous chapters. Each station also contains a TLD and a PlC with a recorder for immediate readout of external gamma exposure, and a recording barograph. Figure 3.9 shows the layout of the equipment at a typical CRMP. At Milford and Delta the atmospheric moisture samplers for tritium analysis were on standby and the noble gas samplers were placed on standby following installation in July 1991. All the equipment is mounted on a stand at a promi- nent location in each community so the residents are aware of the surveillance and, if interested, can have ready access to the PlC and barometric data. The locations of the CAMP stations are shown in Figure 3.7, Chapter 3. The data from these sta- tions were discussed in Chapters 3 and 4. Computer-generated reports for each station are issued weekly. These reports indicate the current weekly average gamma exposure rate as mea- sured by the PIGs, the average over the previous week, and the average for the previous year. For comparison these reports additionally show the maximum and minimum background concentrations in the U.S. These reports are distributed to each CAMP station for public display. 10.2 Town Hall Meetings Ninety-four town hall meetings have been conduct- ed since 1982. These meetings provide an opportunity for the public to meet directly with EPA, DOE, and DRI personnel, ask questions, and express their concerns regarding nuclear testing. During a typical meeting, the procedures used and the safeguards in place during every nuclear test are described. The EPA’s radiological monitoring and surveillance networks are explained and the proposed High Level Waste Repository at Yucca Mountain is discussed. Similar presentations and presentations devoted solely to EPA’s ORSP were presented to various groups such as chambers of commerce, schools, Rotary clubs and professional workshops. A town meeting was held in Baxterville, Mississippi to explain the results of EPA’s annual monitoring on and around the Tatum Dome Nuclear Test Area located in Lamar County, Mississippi. The Tatum Dome Nuclear Test Area was the site of two nuclear and two non-nuclear experimental detona- tions conducted in the Tatum Salt Dome between 1964 and 1970. This meeting was held in re- sponse to concerns expressed by residents about 111 ------- 10.3 Nevada Test Site Tours possible health effects originating from the Tatum Dome site. The locations of the 1991 meetings were as follows: Location Date Las Vegas, NV - Gilbert Sixth Grade Center Las Vegas, NV - Clark County Science Teachers Boise, ID - Workshop on Low-Level Radiation Ely, NV - Chamber of Commerce Denver, CO - Radiation Monitoring Workshop Overton, NV - Rotary Club Baxterville, MS To complement the town hall meetings and to familiarize citizens with both the DOE testing program at the NTS and the Environmental Radiological Monitoring Program conducted by EPA, tours of the NTS are arranged for business and community leaders and individuals from towns around the NTS, as well as for government employees and for the news media. During 1991, the following tours were sponsored by the EPA: EPA Program Headquarters Director and Staff EPA Regional Directors, Office of Pesticides & Toxic Substances EPA Headquarters Office of The Comptroller EPA Headquarters Staff Residents of Rachel, NV NRD Employees EPA Employees and Dependents 01/91 03/91 05/91 08/91 11/91 12191 12/91 02/07/91 o oa gi oa i 0 04/91 06/18 & 19/91 10/22 & 23/91 1 29 / 91 112 ------- 11 Quality Assurance 11.1 Policy One of the major goals of the U.S. Environmental Protection Agency (EPA) is to ensure that all EPA decisions which are dependent on environmental data are supported by data of known quality. Agency policy initiated by the Administrator in memoranda of May 30, 1979, and June 14, 1979, requires participation in a centrally managed Quality Assurance (QA) Program by all EPA Laboratories, Program Offices, Regional Offices, and those monitoring and measurement efforts supported or mandated through contracts, regula- tions, or other formalized agreements. Further, by EPA Order 5360.1, Agency policy requires partici- pation in a QA Program by all EPA organizational units involved in environmental data collection. The QA policies and requirements of EPA’s Envi- ronmental Monitoring Systems Laboratory in Las Vegas (EMSL-LV) are summarized in the Quality Assurance Program P/an (EPA, 1987). Policies and requirements specific to the Offsfte Radiologi- cal Safety Program (ORSP) are documented in the Quality Assurance Program Plan for the Nuclear Radiation Assessment Division Offsite Radiation Safety Program (EPA, 1992). The requirements of these documents establish a framework for consis- tency in the continuing application of quality assur- ance standards and implementing procedures in support of the ORSP. Administrative and technical implementing procedures based on these QA requirements are maintained in appropriate manu- als or are described in standard operating proce- dures (SOPs). It is NRD policy that personnel adhere to the requirements of the QA Plan and all SOPs applicable to their duties to ensure that all environmental radiation monitoring data collected by the EPA EMSL-LV in support of the ORSP are of adequate quality and properly documented for use by the DOE, EPA, and other interested parties. 11.2 Data Quality Objectives Data quality objectives (DQOs) are statements of the quality of data a decision maker needs to ensure that a decision based on that data is defensible. Data quality objectives are defined in terms of representativeness, comparability, com- pleteness, precision, and accuracy. Representa- tiveness and comparability are generally qualitative assessments while completeness, precision, and accuracy may be quantitatively assessed. In the ORSP, representativeness, comparability, and completeness objectives are defined for each monitoring network. Precision and accuracy are defined for each analysis type or radionuclide. Achieved data quality is monitored continuously through internal QC checks and procedures. In addition to the internal quality control procedures, NRD participates in external intercomparison programs. One such intercomparison program is managed and operated by a group within EPA EMSL-LV. These external performance audits are conducted as described in and according to the schedule contained in “Environmental Radioactivity Laboratory Intercomparison Studies Program” (EPA, 1991). The analytical laboratory also partici- pates in the DOE Environmental Measurements Laboratory (EML) Quality Assurance Program in which real or synthetic environmental samples that have been prepared and thoroughly analyzed are distributed to participating laboratories. External external systems and performance audits are conducted for the TLD network as part of the certification requirements for DOE’s Laboratory Accreditation Program (DOELAP) (DOE, 1 986a, DOE 1 986b). These external intercomparison and audit programs are used to monitor analysis accuracy. 112.1 Rep resentativeness, Comparability, and Completeness Objectives Representativeness is defined as “the degree to which the data accurately and precisely represent a characteristic of a parameter, variation of a property, a process characteristic, or an operation condition” (Stanley and Vemer, 1985). In the ORSP, representativeness may be considered to be the degree to which the collected samples represent the radionuclide activity concentrations in the offsite environment. Collection of samples representative of all possible pathways to human exposure as well as direct measurement of offsite 113 ------- resident exposure through the TLD and internal dosimetry monitoring programs provides assurance of the representativeness of the calculated expo- sures. Comparability is defined as ‘the confidence with which one data set can be compared to another’ (Stanley and Vemer, 1985). Comparability of data is assured by use of SOPs for sample collectkrn, handling, and analysis; use of standard reporting units; and use of standardized procedures for data analysis and interpretation. In addition, another aspect of comparability is examined through long term companson and trend analysis of various radionuclide activity concentrations, RD and PIG data. Use of SOPs, maintained under a document control system, is an important component of comparability, ensuring that all personnel conform to a unified, consistent set of procedures. Completeness is defined as ‘a measure of the amount of data collected from a measurement process compared to the amount that was expect- ed to be obtained under the conditions of measure- ment’ (Stanley and Vemer, 1985). Data may be lost due to instrument malfunction, sample destruc- tion, loss in shipping or analysis, analytical error, or unavailability of sarrples. Additional data values may be deleted due to unacceptable precision, accuracy, or detection limit or as the result of application of statistical outlier tests. The com- pleteness objective for all networks except the LTHMP is 90%. The completeness objective for the LTHMP is 80%; a lower objective has been established because dry wells or access restric- tions occasionally preclude sample collection. 11.2.2 Precision and Accuracy Objectives of Radioanalytical Analyses Measurements of sample volumes should be accurate to ±5% for aqueous samples (water and milk) and to ± 10% for air and soil samples. The sensitivity of radiochemical and gamma spectro- metric analyses must allow no more than a 5 percent risk of either a false negative or false positive value. Precision to a 95% confidence interval, monitored through analysis of duplicate and blind samples, must be within ± 10% for activities greater than 10 times the minimum detectable concentration (MDC) and ± 30% for activities greater than the MDC but less than 10 times the MDC. There are no precision require- ments for activity concentrations below the MDC, which by definition, cannot be distinguished from background at the 95% confidence interval. Control limits for accuracy, monitored with matrix spike samples, are required to be no greater than ± 20% for all gross alpha, gross beta, and gamma sn etrometric analyses, depending upon the media At concentrations greater than 10 times the MDC, precision is required to be within ± 10% for: • Conventional Tritium Analyses • Uranium • Thorium (all media) • Strontium and within ± 20% for: • Enriched Tritium Analyses • Strontium (in milk) • Noble Gases • Plutonium. At concentrations less than 10 times the MDC, both precision and accuracy are expressed in absolute units, not to exceed 30% of the MDC for all analyses and all media types. 11.2.3 Quality of Exposure Estimates The allowable uncertainty of the effective dose equivalent to any human receptor is ± 0.1 mrem annually. This uncertainty objective is based solely upon the precision and accuracy of the data produced from the surveillance networks and does not apply to uncertainties in the model used, effluent release data received from DOE, or dose conversion factors. Generally, effective dose equivalents must have an accuracy (bias) of no greater than 50% for annual exposures greater than or equal to I mrem but less than 5 mrem and no greater than 10% for annual exposures greater than or equal to 5 mrem. 11.3 Data Validation Data validation is defined as ‘A systematic process for reviewing a body of data against a set of criteria to provide assurance that the data are adequate for their intended use. Data validation consists of data editing, screening, checking, auditing, verification, certification, and review’ 114 ------- (Stanley et al, 1983). Data validation procedures are documented in SOPs. All data are reviewed and checked at various steps in the collection, analysis, and reporting processes. The first level of data review consists of sample tracking; e.g., that all samples planned to be collected are collected or reasons for noncollection are documented, that all collected samples are delivered to Sample Control and are entered into the appropriate data base management system, and that all entered information is accurate. Next, analytical data are reviewed by the analyst and by the laboratory supervisor. Checks at this stage include verifying that all samples received from Sample Control have been analyzed or reasons for nonanalysis have been documented, that data are ‘reasonable TM (e.g., within expected range), and that instrumentation operational checks indicate the analysis instrument is within permissible toleranc- es. Discrepancies indicating collection instrument malfunction are reported to the Field Operations Branch. Analytical discrepancies are resolved; individual samples or sample batches may be reanalyzed it required. Raw data are reviewed by a designated media expert. A number of checks are made at this level, including: 1. Completeness - all samples scheduled to be collected have, in fact, been collected and analyzed or the data base contains documentation explaining the reasons for noncollection or nonanalysis. 2. Transcription errors - checks are made of all manually entered information to ensure that the information contained in the data base is accurate. 3. Quality control data - field and analytical duplicate, audit sample, and matrix blank data are checked to ensure the collection and analytical processes are within speci- fied QC tolerances. 4. Analysis schedules - lists of samples awaiting analysis are generated and checked against normal analysis sched- ules to identify backlogs in analysis or data entry. 5. Unidentified malfunctions - sample results and diagnostic graphics of sample results are reviewed for reasonableness. Condi- tions indicative of instrument malfunction are reported to Field and/or Laboratory Operations. Once the data base has been finalized, the data are compared to the DQOs. Completeness, accuracy, and precision statistics are calculated. The achieved quality of the data is reported annu- ally, at a minimum. If data fail to meet one or more of the established DQOs, the data may still be used in data analysis; however, the data and any interpretive results are to be qualified. All sample results exceeding the traditional-natural background activity range are investigated. If data are found to be associated with a nonenviron- mental condition, such as a check of the instru- ment using a calibration source, the data are flagged and are not included in calculations of averages, etc. Only data verified to be associated with a nonenvironmental condition are flagged; all other data are used in calculation of averages and other statistics, even if the condition is traced to a source other than the NTS (for example, higher- than-normal activities were observed for several radionuclides following the Chemobyl accident). When activities exceeding the expected range are observed for one network, the data for the other networks at the same location are checked. For example, higher-than-normal-range PlC values are compared to data obtained by the air, noble gas, TLD, and tritium-in-air samplers at the same location. Data are also compared to previous years’ data for the same location using trend analysis techniques. Other statistical procedures may be employed as warranted to permit interpretation of current data as compared to past data. Trend analysis is made possible due to the length of the sampling history which, in some cases, is 30 years or longer. Data from the off site networks are used, along with NTS source emission estimates prepared by DOE, to calculate or estimate annual committed effective dose equivalents to offsite residents. Surveillance network data are the primary tools for the dose calculations. Additionally, EPA’s CAP88-PC model (EPA, 1992) is used with local meteorological data to predict doses to oftsite residents from NTS source term estimates. An assessment of the uncertainty of the dose estimate is made and reported with the estimate. 115 ------- 114 Quality Assessment Of 1991 Data Data quality assessment is associated with the regular QA and QC practices within the radio- analytical laboratory. The analytical quality control plan, documented in SOPs, describes specific procedures used to demonstrate that data are within prescribed requirements for accuracy and precalon. Duplicate samples are collected or prepared and anatyzed in the exact manner as the regular samples for that particular type of analysis. Data obtained from duplicate analyses are used for determining the degree of precision for each individual analysis. Accuracy is assessed by comparison of data from spiked samples with the trues or accepted values. Spiked samples are either in-house laboratory blanks spiked with known amounts of radionuclides, or QC samples prepared by other organizations in which data are compared between several laboratories and as- sessed for accuracy. On a quarterly and annual basis, achieved data quality statistics are compled. This data quality assessment is performed as part of the process of data validation, described in Section 11.3. The following subsections describe the achieved data quality for 1991. 11.4,1 Completeness Completeness is calculated as: %C= (X)xlOO = p 7t n Gt9flOSS V = nur, of ineesumments judged va/k n k,tal number of measurements The percent completeness of the 1991 data are given in Table 16. Reasons for sample loss include instrument malfunction, inability to gain site access, monitoring technician error, or laboratory error. A number of the families who normally participate in the Internal Dosimetry Network were unable to part4ate in 1991 due to scheduling difficulties. As a consequence, the completeness objective of 90 percent was not achieved and some areas were not well represented. In 1992, efforts will be made to increase the level of participation. The achieved completeness of over 93 percent for the LTHMP exceeds the DQO of 80 percent; however, it the wells which have been shut down by DOE are included, the achieved completeness drops to 75 percent for the LThMP overall and 54 percent for sites sampled on the NTS. The completeness achieved overall in the ASN was 99.3 percent. There were no data gaps for twenty three stations (100 percent completeness). All of the ASN stations had data recoveries greater than 90 percent for 1991, exceeding the DQO of 90 percent completeness. The achieved complete- ness for plutonium isotopes in air was 97.2 per- cent, greater than the DQO of 90 percent. All but three sites achieved a 100 percent recovery. The standby stations in Oregon failed to collect sam- ples in the second quarter and one composite sample from Amargosa Valley was lost in the process of chemical analysis. The achieved completeness for the noble gas network overall was less than the DQO of 90 percent. A new model of sampler was installed at each station in the spring of 1991. These new units exhibited a number of malfunctions in the first several months of operation, resufting in low sample recovery. The only stations to meet or exceed the 90 percent DQO on an individual basis were Beatty, Goldfield, Indian Springs, and Overton, Nevada. The standby station at Delta, Utah achieved a 100 percent recovery for the 26 days it was in operation. Due to sample loss in the Radioanalysis Laboratory, the achieved recovery for the St. George, Utah station was greater than 90 percent for 1 Xe, but less than 90 percent for Kr. Completeness was less than 75 percent for noble gases at Austin and Amargosa Valley Com- munity Center, Nevada and Milford and Salt Lake City, Utah; consequently, the samples cannot be considered representative of activities at these sites for 1991. Each of the tritium-in-air stations achieved sample recoveries of greater than the 90 percent DQO. Completeness was 100 percent at eight stations: Shoshone, California and Austin, Caliente, Las Vegas, Overton, Pahrump, Pioche, and Twin Springs, Nevada. The tritium-in-air sampler was installed at Twin Springs in November; therefore, even though sample recovery was 100 percent for 116 ------- Table 16. Data Completeness of Oftsite Radiological Safety Program Networks No. of Sampling T Network Locations otal Samples Possible Valid Samples Collected Percent Completeness LTHMP 256a 466 436 93.6a Air Surveillance 33 18 ( 23 °Pu) 11 722 daysb 109 11,640 106 99.3 97.2 Noble Gas 21 6133 days 1 ’ 5243 ( Kr) 5309 ( 1 Xe) 85.5 ( Kr) 86.6 ( Xe) Tritium in Air 20 6670 daysb 6460 96.9 Milk Surveillance 25 277 223 80.5 Animal Investigation 3 12° 12 100.0 PlC 29 1508 weeksd 1496 99.2 • Does not include wells which have been shut down by DOE (see Section 7.2) 1’ Continuous samplers with samples collected at intervals of approximately one week. Days used as units to account for differences in sample interval length. Includes four mule deer from the Nevada Test Site and four cows from each of two locations. Does not include bighom sheep, fruits and vegetables, and other animals which are samples of opportunity. the period of operation, the activities cannot be considered to be representative of all of 1991. Overall completeness for the MSN was 80.5 percent. Samples were obtained every month (i.e., 100 percent recovery) from 14 of the 25 sampling locations. Another two sites had an achieved completeness of greater than the DQO of 90 percent. Three of the family-owned cow or goat sampling locations yielded no samples in 1991 (i.e., 0 percent completeness) and another two had an achieved completeness of 50 percent or less. In the majority of the cases, samples could not be collected because the cow or goat was unable to produce milk. In the Animal Investigation program, one mule deer is harvested each quarter from the NTS. Four cows are purchased in the spring and another four are purchased in the fall from ranches in the offsite area around the NTS. Overall completeness for 1991 was 100 percent. Hunters in the state of Nevada donate the kidney and one leg bone from bighom sheep harvested during the winter hunting season and offsite residents donated locally grown fruits and vegetables. Because these are voluntary contributions, no expected number of samples can be determined for estimation of completeness. Occasionally, road kills or other animals from the NTS are included in the Animal Investigation program, such as the mountain lion obtained by hunting in 1991. These targets of opportunitya are not included in calculation of percent complete- ness. Completeness for the PlC network can be quanti- fied by the number of weeks for which there are average gamma exposure rates recorded for the 29 PlCs. Completeness would be 100% if there were 1,508 (29 stations multiplied by 52 weeks) recorded weekly averages. Using this method, the PlC data is 99.2% complete. The stations for which data were unavailable for specific weeks are listed in Section 3.2. 11.4.2 Precision Precision is monitored through analysis of duplicate samples. Field duplicates (e.g., a second sample 117 ------- collected immediately after the routine sample) are collected in the LTHMP and Milk Surveillance networks. Two TLDs, each with three KlenticaI phosphors, are deployed to each fixed station, providing a total of six replicates. Noble gas samples are split to provide duplicate samples for analysis. Animal tissue, vegetable, arid human urine samples are also split after processing. A second air sampler is collocated with the routine sampler to provide a field duplicate. A total of four samplers are used; these second samplers are moved to various site locations throughout the year. In lieu of field duplicates, precision for the PICs is determined by the variance of measure- ments over a specific time interval when only background activities are being measured. Preci- sion may also be determined for repeated analyses of laboratory spiked samples. These OC samples are generally not blind to the analyst; e.g., the analyst both recognizes the sample as a OC sample and knows the expected (theoretical) activity of the sample. Precision is expressed as percent relative standard deviation (%RSD), also known as coefficient of variation, and is calculated by: %ASD=( )x1OO For duplicate sample pairs, the standard deviation is equal to the absolute value of the difference between the analytical results. The precision or %RSD is not reported for duplicate pairs in which one or both results are less than the MDC of the analysis. For most analyses, the DOOs for preci- sion are defined for two ranges: values greater than or equal to the MDC but less than 10 times the MDC and values equal to or greater than 10 times the MDC. Figure 62 displays %RSDs for LTHMP field and spiked sample duplicate pairs analyzed by the conventional tritium method. Three field duplicate pair %RSDs are not included in the figure; these three pairs had means of 5046; 98,470; and 144,650 pCi/L and %RSDs of 12.3, 0.3, and 02 percent, respectively. All pairs yielded %RSDs of less than 20 percent. Only three pairs were greater than 10 times the MDC; the %RSDs for these pairs were less than 2 percent. These results are better than the DOOs of 30 percent for values equal to or greater than the MDC but less than 10 times the MDC and 10 percent for values equal to or greater than 10 times the MDC. Figure 63 displays %RSDs for duplicate pairs analyzed by the enriched tritium method. Only three %RSDs exceeded the DQO of 30 percent for values great- erthanorequaltothe MDC but tessthan lOtimes the MDC and all of the duplicate pairs greater than or equal to 10 times the MDC yielded %RSDs less than the DQO of 20 percent. Two pairs with means of 836 and 521 pCVL and %RSDs of 1.0 and 5.2 percent, respectively, are not shown in the figure. In the ASN, field duplicate pairs are analyzed for gross alpha and gross beta and laboratory spiked sample pairs are analyzed for °Pu. Gross alpha analysis was initiated late in the year and only 7 sets of duplicates were analyzed, only one of which was greater than or equal to 10 times the MDC. The %RSDs were generally less than 30 percent, although there are an insufficient number of points to draw definitive conclusions regarding achieved precision. As shown in Figure 64, gross beta analyses yielded %RSDs ranging from less than one percent to greater than 95 percent for duplicate pairs greater than or equal to the MDC but less than 10 times the MDC. With the excep- tion of one pair, all of the %RSDs for pairs greater than 10 times the MDC were less than 20 percent. All of the spiked sample pairs analyzed for °Pu were greater than or equal to 10 times the MDC. All %RSDs were less than the DQO of 20 percent, as shown in Figure 65. All of the noble gas sample splits analyzed for Kr had activities greater than or equal to the MDC but less than 10 times the MDC. All %RSDs were less than 20 percent, better than the DQO of 30 percent for sample pairs in this activity range. The %RSDs for Kr are shown in Figure 66. Only four of the duplicate pairs analyzed in the tritium-in-air network yielded results greater than the MDC. The %RSDs for these were all less than 20 percent, but the number of points is insufficient to draw definitive conclusions regarding achieved precision. None of the duplicate pairs from the MSN analyzed for tritium yielded results greater than the MDC. Similarly, because only four animal tissue duplicate pairs were analyzed, insufficient information was available to determine achieved precision. Precision for the PlC data was estimated by the agreement between continuous background gam- ma radiation measurements for given periods of 118 ------- J40 o A 1000 Mean 01 ç) P91r ReeuE ( I() I I ooo a £4I a > — — Figure 62. Precision results for conventional method tritium in water. 80 J40. J 0 A Mean ol ( Ic1e F ir Aoeulls (p04.) F I I I 000 AAA 1 .>— mx Figure 63. Precision results for enriched method tritium in water. 119 ------- 100• 80 80 40 0 0 00 0 0 0 0 0 0 o o0 : 0 0 D 0 OO 0.04 Moim ci R i n— I aao a>mX ooo a,- & a(mX I Figure 64. Precision results for beta in air. 100 1 ____ o , • . c3 LI 0 I aoa a,1..mX ] Figure 65. Precision results for °Pu in air. 5 . 0 I I I I 0 0 0.05 120 ------- 100. 80• 40 0 0 DO C l U i D QD 0 Me i c E pficate Pal Resits ( V -3) I aaa a>- a <’mx I time. Although this method does not provide an independent assessment of precision (e.g., not derived from a second collocated PlC), it is a justifiable estimation of precision because back- ground radiation levels at each station are relative- ty stable. Precision between the 4-hour averages transmitted from each PlC location are examined weekly and are used as a tool to identify equip- ment problems. The precision between weeks for 1991 is expressed as percent relative standard deviation (%RSD) or coefficient of variation. The %RSD can be calculated for each station by dividing the standard deviation of the weekly averages by the mean of the weekly averages (standard deviations and means of the PlC data are given in Section 3.2). The %RSD for each PlC station in 1991 was less than 5% except the Austin and Rachel stations. The Austin PlC had a be- tween-week %RSD of 13% and the Rachel station had a between-week %RSD of 8%. The variability in the Austin PlC is probably due to seasonal differences. The variability in the PlC at Rachel is possibly due to seasonal differences but could also be partially due to equipment problems. The variability in the Rachel PlC is currently under investigation. In addition to examination of %RSDs for individual duplicate pairs, an overall precision estimate was determined by calculating the pooled standard deviation. To convert to a unitless value, the pooled standard deviation was divided by the grand mean and muttiplied by 100 to yield a %RSD. Table 17 presents the pooled data and estimates of overall precision. With the exception of gross alpha, the achieved precision is essentially equal to or better than the DQO for the analysis and activity range. The achieved precision for gross alpha is based on a limited number of duplicate pairs analyzed in the last quarter of 1991. 11.4.3 Accuracy The accuracy of all analyses is controlled through the use of approved or NIST-traceable standards in instrument calibrations. Internal checks of instrument accuracy may be periodically per- formed, using spiked and blank matrix samples. 60 I I I Figure 66. Precision results for UKr in noble gas. 0 1 — 24 26 0 0 D 27 121 ------- Table 17. Overall Precision of Analysis Network Analysis Sample Type Range n Pooled Std. Dev. %RSD LTHMP Cony. Tritium Enrich. Tritium Enrich. Tritium Enrich. Tritium Spiked Spiked Spiked Field >MDC,<10 x MDC >MDC,<10 x MDC >lOx MDC >lOx MDC 47 8 20 18 226.62 11.21 6.97 9.98 5.6 14.1 7.0 5.6 Air Surveil- lance Gross Alpha Gross Beta Gross Beta °Pu Field Field Field Spiked >MDC,<10 x MDC >MDC,clO x MDC >lOx MDC >lOx MDC 6 113 6 9 0.001 0.003 0.006 0.295 39.9 22.4 22.0 6.8 Noble Gas Kr Split >MDC,<10 x MDC 33 2.49 9.4 Tritium in Air HTO Split >MDC,<10 x MDC 4 0.83 10.7 These internal QC procedures are the only control of accuracy for whole body and lung counts, animal and vegetable samples, and PICs in 1991. The whole body counting facility participates in inter1aborato y comparison studies when available through the DOE intercomparison committee. Spiked calbration phantoms are periodically exchanged throughout the DOE whole body count- ing facilities. No intercompanson phantoms were exchanged during 1991. For spectroscopic and radiochemical analyses, an independent measure- ment of accuracy is provided by participation in inteitomparison studies using samples of known activities. The EPA EMSL-LV Radioanalysis Laboratory participates in two such intercorr arison studies. An independent verification of the accura- cy of the TLDs is achieved through participation in DOELbIP. In the EPA EMSL-LV Intercomparison Study program, samples of known activities of selected radionuclides are sent to participating laboratories on a set schedule throughout the year. Water, milk, and air fitters are used as the matrices for these samples. Resutts from all participating laboratories are compiled and statistics computed comparing each laboratory 3 s results to the known value and to the average of all laboratones. The comparison to the known value provides an inde- pendent assessment of accuracy for each partici- pating laboratory. Comparison of results among all participating laboratories provides a measure of comparability, discussed in Section 11.4.4. Ap- proximately 70 to 190 laboratories participate in any given intercompansori study. In Table 18, results for radionuclides commonly measured in the ORSP are given. Results for all intercompan- son studies are provided in Appendix F. Accuracy, as percent difference or percent bias, is calculated by: %BL4S ( CmCS ) x 100 %BIAS = p nt bias Cm = IflG6SW Xfl flt1 tbf7 Ca = knowiif th ,,etk .sI a ncentiath n In most cases, the achieved accuracy was well within the established DOOs for the analysis. In general, these DQOs are ± 20 percent for values greater than ten times the MDC and ± 30 percent for results greater than the MDC but less than ten times the MDC. The DQO was exceeded for one alpha intercompanson sample in water and one in air, one beta intercomparison sample in air, one 131 Cs intercompanson sample in water, one Sr intercompanson sample in water and one in milk, and one total potassium intercomparison sample in milk. The other intercomparison study in which the EPA EMSL-LV Radioanalysis Laboratory participates is the semiannual DOE QA Program conducted by EML in New York, NY. Approximately 20 laborato- ties participate in this intercomparison study pro- 122 ------- Table 18. Accuracy of Analysis from EPA Intercompanson Studies Known Value Lab Average Percent Nuclide Month (pCi/L)a (p( j/lL)a Bias Water lntercompanson Studies Alpha April (PE) 54.0 67.33 24.7 Alpha Sept 10.0 9.00 -10.0 Alpha Oct (PE) 82.0 97.67 19.1 Beta Sept 20.0 20.00 0.0 Beta Oct (PE) 65.0 61.67 -5.1 Feb 8.0 8.33 4.1 137 Cs April (PE) 25.0 20.00 -20.0 Oct 10.0 10.33 3.3 137 Cs Oct (PE) 11.0 12.00 9.1 3 H Feb 4418.0 4613.00 4.4 Oct 2452.0 2499.33 1.9 Sr April (PE) 28.0 22.33 -20.2 Sr May 39.0 34.33 -12.0 Sr Sept 49.0 39.67 -19.0 Sr Oct (PE) 10.0 8.33 -16.7 90 Sr April (PE) 26.0 23.33 -10.3 Sr May 24.0 24.00 0.0 Sr Sept 25.0 23.67 -5.3 90 Sr Oct (PE) 10.0 10.33 3.3 U (Nat) Mar 7.6 7.67 0.9 U (Nat) April (PE) 29.8 30.30 1.7 U (Nat) July 14.2 14.43 1.6 U (Nat) Oct (PE) 13.5 13.17 -2.4 U (Nat) Nov 24.9 23.97 -3.7 Aug 19.4 18.23 -6.0 Air Intercompanson Studies Alpha Mar 5.0 6.00 20.0 Alpha Aug 10.0 14.00 40.0 Beta Mar 31.0 36.67 18.3 Beta Aug 62.0 80.33 29.6 Milk lntercorr arison Studies Sr Apr 32.0 29.67 -7.3 Sr Apr 23.0 18.67 -18.8 Sr Sept 25.0 22.33 -10.7 Sr Sept 16.0 12.67 -20.8 90 Sr Apr 32.0 32.00 0.0 Sr Apr 23.0 19.67 -14.5 90 Sr Sept 25.0 25.33 1.3 Sr Sept 20.0 18.00 -10.0 Continued 123 ------- Table 18. Continued. Nuclide Month Known Value Lab Average (pCi/L) (pcj L)a Percent Bias Milk lnteivonparison Studies K K K K (tot) (tot) (tot) (tot) Apr Apr Sept Sept 1650.0 1212.67 1550.0 1587.33 1740.0 1710.67 1700.0 1754.67 -26.5 2.4 -1.7 3.2 a Values were obtained from the individual intemompanson study reports and are reported with the significant figures included in those reports. PE = performance evaluation study gram, although each laboratory receives only its own results and the EML value. The EML result is assumed to represent the known or true activity concentration. Results for radionuclides commonly analyzed in the ORSP are given in Table 19; results for all analyses are given in Appendix F. In all cases, the EPA results differed from the EML known activities by a percent bias of less than ±10 percent. These results are well within the estab- lished DQO. In addition to use of irradiated control samples in the processing of TLDs, DOELAP monitors accura- cy, precision, and bias as part of the accreditation program. As with the intercompanson studies, dosimeters receiving a known type and level exposure are submitted as single blind samples. The designation ‘single blind’ indicates the analyst recognizes the sample as being other than a routine sample, but does not know the radiation type or level to which the dosimeter has been exposed except that dosimeters are identified as having been exposed in either the ‘protection range’ or the ‘accident range’. Individual results are not provided to the participant laboratories by DOELAP until the conclusion of the third round of performance testing in each test cycle. Issuance of the accreditation certificate indicates acceptable accuracy, precision, and bias and successful completion of a comprehensive onsite review by independent DOELAP Site Assessors. 11.4,4 Comparability ing in each intercomparison study. A grand aver- age is computed for all values, excluding outliers. A normalized deviation statistic compares each laboratory’s result (mean of three replicates) to the known value and to the grand average. If the value of this statistic (in multiples of standard normal deviate, unitless) lies between control limits of -3 and +3, the accuracy (deviation from known value) or comparability (deviation from grand average) is within normal statistical variation. Table 20 displays data from the 1991 intercompari- son studies for the variables most commonly measured in the ORSP. The complete data set for all variables is presented in Appendix F. Of the commonly measured variables, there were three instances in which the Radioanalysis Laboratory results deviated from the grand average by more than three standard normal deviate units. These were the April intercomparison sample for total potassium in milk, the August sample for beta emitters on an air filter, and the September water intercomparison sample containing Sr. The first two of these also exceeded the DQO for accuracy (see Section 11.4.3, above). The third sample, Sr in water, was within the DQO for accuracy. Apart from these three, all of the normalized deviations from the grand average were within the statistical control limit range of -3 to +3. This indicates acceptable comparability of the Radio- analysis Laboratory with the 69 to 207 laboratories participating in the EPA Intercomparison Study Program. The EPA Intercomparison Study reports (EPA, 1991) provide results for all laboratories participat- 124 ------- Table 19. Accuracy of analysis from DOE Intercomparison Study Nuclkie Month EML (Known) EPA Value Lab Average (pCi/L) (pCi/L)a Percent Bias Water Intercomparison Studies Cs 137 3 H Sr U (Nat) °Pu Mar Sept Sept Sept Sept Sept 169 163 46.0 48.3 100 102 10.1 9.93 0.940 0.949 0.510 0.480 -3.5 5.0 2.0 -1.7 1.0 -5.9 Air Intemomparison Studies 7 Be 7 Be °Pu °Pu Mar Sept Sept Sept 53.0 47.8 53.8 56.4 0.084 0.087 Vegetation Intercompanson Studies 0.365 0.359 Soil lntercomparison Studies -9.8 4.8 3.6 -1.6 °Pu Sept 7.35 7.22 -1.8 a Values were obtained from the Environmental Measurements Laboratory (EML) and reported with the significant figures provided by EML. 11.4.5 Representativeness Representativeness cannot be evaluated quantita- tively. Rather, it is a qualitative assessment of the ability of the sample to model the objectives of the program. The primary objective of the ORSP is to protect the health and safety of the offsite resi- dents. Therefore, the DQO of representativeness is met if the samples are representative of the radiation exposure of the resident population. Monitoring stations are located in resident popula- tion centers. Siteing criteria specific to radiation sensors are not available for many of the instru- ments used. Existing siteing criteria developed for other pollutants are applied to the ORSP sensors as available. For example, siteing criteria for the placement of air sampler inlets are contained in Prevention of Significant Deterioration guidance documents (EPA, 1976). Inlets for the air samplers at the ORSP stations have been evaluated against these criteria and, in most cases, meet the siteing requirements. Guidance or requirements for handling, shipping, and storage of radioactivity samples are followed in program operations and documented in SOPs. Standard analytical method- ology is used and guidance on the holding times for samples, sample processing, and results calculations are followed and documented in SOPs. In the LTHMP, the primary objectives are protec- tion of drinking water supplies and monitoring of any potential cavity migration. Sampling locations are primary ‘targets of opportunity’, i.e., the sam- pling locations are primarily wells developed for other purposes than radioactivity monitoring. Guidance or requirements developed for CERCLA and RCRA regarding the number and location of monitoring wells has not been applied to the LTHMP sampling sites. In spite of these limita- tions, the samples are representative of the first objective, protection of drinking water supplies. At all of the LTHMP monitoring areas, including on 125 ------- Table 20. Comparability of Analysis from EPA lnteroonpanson Studies No. of EPA Lab Grand Normalized Ratio EPA Paitk çating Average Average Deviation from Lab Averag& Nuclide Month Laboratories (pCi / I.) (pCi&) Grand Average Grand Average Water lntercon arison Studies Alpha April (PE) 179 67.33 49.71 2.18 1.35 Alpha Sept 207 9.00 10.36 -0.47 0.87 Alpha O (PE) 187 97.67 75.57 1.82 1.29 Beta Sept 207 20.00 20.30 -0.10 0.99 Beta O (PE) 187 61.67 55.53 1.06 1.11 ‘ Cs Feb 151 8.33 9.06 -0.25 0.92 April (PE) 179 20.00 25.49 -1.90 0.78 137 Cs 162 10.33 10.86 -0.18 0.95 137 Cs Od (PE) 187 12.00 12.45 -0.15 0.96 3 H Feb 150 4613.00 4437.60 0.69 1.04 3 H 166 2499.00 2532.00 -0.16 0.99 Sr April (PE) 179 22.33 25.74 -1.18 0.87 Sr May 104 34.33 37.43 -1.07 0.92 Sr Sept 69 39.67 49.57 3 43* 0.80 Sr Od (PE) 187 8.33 9.79 -0.51 0.85 90 Sr April (PE) 179 23.33 23.61 -0.10 0.99 °°Sr May 104 24.00 28.85 0.05 0.83 90 Sr Sept 69 23.67 24.72 -0.46 0.96 Sr Od (PE) 187 10.33 10.09 0.08 1.02 U (Nat) Mar 117 7.67 7.30 0.21 1.05 U (Nat) April (PE) 179 30.30 28.88 0.82 1.05 U (Nat) July 127 14.43 13.38 0.61 1.08 U (Nat) Od (PE) 187 13.17 13.25 -0.05 0.99 U (Nat) Nov 90 23.97 23.76 0.12 1.01 Aug 61 18.23 19.22 -0.90 0.95 Air Intercomparison Studies Alpha Mar 185 6.00 6.25 -0.09 0.96 Alpha Aug 179 14.00 12.21 0.62 1.15 Beta Mar 185 36.67 32.19 1.55 1.14 Beta Aug 179 80.33 64.66 5 43* 1.24 Milk Intettomparison Studies °Sr Apr 96 29.67 27.07 0.90 1.10 Sr Apr 104 18.67 23.14 -1.55 0.81 eaSr Sept 95 22.33 20.95 0.48 1.07 °Sr Sept 98 12.67 13.53 -0.30 0.94 90 8r Apr 96 32.00 28.02 1.38 1.14 Sr Apr 104 19.67 22.33 -0.92 0.88 Continued 126 ------- Table 20. Continued. Nuclide Month No. of Participating Laboratories EPA Lab Grand Normalized Average Average Deviation from (pCi/L) (pCi/L) Grand Average Ratio EPA Lab AvgJ Grand Avg. Milk Intercompanson Studies Sr Sept 95 25.33 21.09 1.47 1.20 Sr Sept 98 18.00 17.57 0.15 1.02 K (tot) Apr 96 1212.70 1653.00 .9.19* 0.73 K (tot) Apr 104 1587.00 1548.00 0.86 1.03 K (tot) Sept 95 1710.70 1667.00 0.86 1.03 K (tot) Sept 98 1754.70 1713.60 0.84 1.02 a Values were obtained from the individual intercompanson study reports and are reported with the significant figures included in those reports. performance evaluation study. natural. = outside control limits. and around the NTS, all potentially impacted drinking water supplies are monitored, as are many supply sources with virtually no potential to be impacted by radioactivity resulting from past or present nuclear weapons testing. The sampling network at some locations is not optimal for achiev- ing the second objective, monitoring of any migra- lion of radionuclides from the test cavities. An evaluation conducted by DRI describes, in detail, the monitoring locations for each LTHMP location and the strengths and weaknesses of each moni- toring network (Chapman and Hokett, 1991). This evaluation is cited in the discussion of the LThMP data in Chapter 7. PE = (Nat) = 127 ------- 12. Sample Analysis Procedures The procedures for analyzing samples collected for this report are descnbed in Radiochemical and Analytical Procedures for Analysis of Environmental Samples (Johns, 1979) and are summarized in Table 21. These include gamma Table 21.. Summary of Analytical Procedures analysis, gross beta on air filters, strontium, tritium, plutonium, and noble gas analyses. These procedures outline standard methods used to perform given analytical procedures. Type of Analytical Counting Analytical Sample Approximate Analysis Equipment Period (mm) Procedures Size Detection Limita HpGe HpGe Air charcoal Rackonuclide concen- 560 m 3 for air For routine milk and Gamma” detector- cartridges and tration quantified from filters and water generally, 5 x calibrated at individual air gamma spectral data charcoal car- 10 ’ tCVmL (1.85 x 0.5 key! filters, 30; 100 by online computer tridges; 3.5 L 10’ Bq/L) for most channel for milk, water, program. for milk common fallout ratio- (0.04 to 2 suspended and water. nuclides in a simple meV range) solids, spectrum. Filters for individual LTHMP suspended detector solIds, 6 x iCY’ tCii iL effiolencies (a22x 101 Bq/L). Air ranging from 15 to 35%. filters and charcoal cartñdges ,0.04x iCY’ 2 CWmL(i.48x iCY’ BqJm 3 ). Gross alpha and beta on Low-level end windows, gas 30 Samples are counted after decay 560 m’ 8.0 x i c r” p( fl [ (3.0 x iCY’ Bq/m ’) air filters flow pro- portional counter with a 5-cm diameter window. of naturally occumng rationuctides. b 25x 10 15 pCWrt (9.25 x iCY’ Bq/m ’) Low background thin-window, gas-flow, proportional counter. 50 Chemical separation by ion exchange. Separated sample counted succes- aivety; activity calcu- lated by simulta- neous solution of equations. 1.0 L for milk or water. 0.1 to 1 kg for tissue. “Sr=5 x io iiCilmL (1.85 x 10 ’l Bq/L) ‘°Sr=2x 10 LCVmL (7.4 x 1 .2 Bq/1..) ‘H Automatic liquid scintillation counter with output printer. 300 Sample prepared by distillation. 5 to 10 mL for water. 300 to 700 x 10’ CiImL (11-26 BqIL)c Continued 129 ------- Table 21. Continued. Type of Analysis Analytical Equçment Counting Period (mm) Analytical Procedures Sample Size Approximate Detection Umit’ ‘H Automatic liquid scinl lafion counter with output printer. 300 Sample prepared by distilation. 5 to 10 mL for water. 300 to 700 x 10” j.tCikriL (11-26 BqtL)c ‘H Enrichment Automatic 300 Sample concen- 250 mL for 10 xlO ” tCihnL (LTHMP liquid trated by electmlyes water. (3.7 x 10 Bq/L) samples) scintillation counter with output printer. folowed by dleb5at ion. ‘ “Pu Alpha spectrometer with silicon surface barrier detectors operatedin vacuum chambers, 1.000 Water sample or add-digested filter or tissue samples separated by ion exchange, electro- plated on stainless stee lptanchet. 1.0 1 for water, 0.1 to 1 kg for tissue; 5,000 to 10,000 m’ for air. Pu =O.08 x 10” .tCiImL (2.9 x 10” Bq/L), “ ° Pu=0.04 x 10” JLC nL (1.5 x 10’ Bq&) for water. For tissue samples, 0. O4pC i(1.5x10 ” Sq) per total sample for all isotopes; 5 x 10 17 to lOx 10 ’ tCiknL(1.9x 10” to 3.7 x iO ” Bqkn’) for plutonium on air filters. Kr. Xe, Xe Automatic liquid san- tiltation counter th output printer. 200 Separation by gas chromatography; dissolved in toluene cocktail for counting. 0.4 to 1.Om’ for air. Kr, Xe, Xe4x 10.12 iCi/mL (1.5 x 10.1 Bq/m’) . The detection lwnit is defined as the smallest amount of radioactivity that can be reliably detected, i.e., probability of Type I and Type I I error at 5 percent each (00E81). ‘ Gaimrsa spectrometry using a h4 purity inthnsic germanium (HpGe) detector. Depending on sample type. 130 ------- 13. Radiation Protection Standards For External and Internal Exposure Design and operation of the ORSP are based on requirements and guidelines contained in 13.1 Dose Equivalent Commitment For stochastic effects in members of the public, the following limits are used: Effective Dose mrem/yr Dose Equivalenta mSv/yr Occasional annual exposuresb 500 5 Prolonged period of exposure 100 1 . Includes both effective dose equivalent from external radiation and committed effective dose equivalent from ingested and inhaled radionuctides. b Occasional exposure implies exposure over a few years with the provision that over a lifetime the average exposure does not exceed 100 mrem (1 mSv) per year (ICRP, 1983). 13.2 Concentration Guides ICRP-30 (ICRP, 1979) lists Derived Air Concentra- tions (DAC) and Annual Limit on Intake (ALl). The ALl is the secondary limit and can be used with assumed breathing rates and ingested volumes to calculate concentration guides. The concentration guides (CGs) in Table 22 were derived in this manner and yield the committed effective dose equivalent (50 year) of 100 mrem/yr for members of the public. 13.3 U.S. Environmental Protection Agency Drinking Water Guide In 40 CFR 141 (CFR, 1988), the EPA set allowable concentrations for continuous controlled releases of radionuclides to drinking water sources. Any single or combination of beta and gamma emitters should not lead to exposures exceeding 4 mrenVyr. For tritium, this is 2.0 x 1 o xCVmL (740 Bq/L) and for 90 Sr is 8 x 1 o tCVmL (0.3 Bq/L). applicable legislation and literature. A summary of applicable regulations and guidelines follows. 131 ------- Table 22. Routine Monitoring Gu des RD (Prsors el) RD (Station) PlC weekly Sampirig Sample Count Concentrations MDC Nuclide Frequency Locations Size Time Gu ide t MDC (%CG) Air Surveillance Network 7 Be 1/wk Zr 1/wk Nb 1/wk • Mo l/wk 1/wk “I 1/wic ‘ Te 1/wk 127 Cs 1/wk i/wk 1/wk 1/wk Ce l/wk NPU 1/mo Gross Beta 1/wk ‘H l/wk rKr 1/vv lc “Xe 1/wk “'Xe 1/wk (ASN) all all all all all all all all all all all all all all 19 16 16 16 m ’ 560 560 560 560 560 560 560 560 560 560 560 560 2400 560 5 0.4 0.4 0.4 Uters 1 0.25 1700 12 110 110 58 4 17 12 120 120 52 1.2 5 x iO 2x10 2 4.6x 10’ 2.2x 10’ 1.8x 10’ 2.3x io Minutes 30 30 30 30 30 30 30 30 30 30 30 30 1000 30 150 200 200 200 Minutes 300 300 RCI/mL 4.7x io 3 x 10 ° 3 x 10 ’ 3 x i0 ’ 1.5x 10 1 x 10.10 5 x 10.10 3 x 10.10 3 x 10 ° 3 x iO ° 1.4x 10.0 3 x 10” I x 10.14 5 x i0 1.2x i c y 7 6.2x iO- 4.9 x i0 1 6.2 x iO mBq/m 3 17 4.1 1.8 1.5 1.8 1.8 1.8 1.8 4.8 2.6 3.0 12 1.Sx 10.0 0.11 148 148 370 370 Water Suiveillaice Network ( LThMP)b all all 740 i .tCi /mL 2x10 ’ 12 1 x iO ’ 4x 10.2 2 x 10’ 2 x 10 3 x 1O 4 x 10.0 1 x 10.2 2 x 10.2 4 x iO ’ 2 x iCY’ 6 x 10 ’ 1.0 0.32 6 x 10’ 3 x 10.0 6 x iCY’ 2 x 10.0 2 x 102 1.8 5 x 10.2 1.1 9.2 10 2.6 0.04 0.035 0.035 0.05 0.05 <0.2 0.01 0.44 0.2 0.02 0.18 ‘H 1/mo 1/mo (enñched thtium) “Sr 1st time eoSr 1st time Cs 1/mo “‘Ra 1st time 1st time 1st time 1st time “Pu isttime “ 3 °Pu 1st time Gamma 1/mo MIUC Surveillance Network ‘H 1/mo l/mo 1/mo “Sr 1/mo “Sr 1/mo all 1 50 16 all 1 50 0.8 2.2x10 4 all 1 100 3.3 8.8x iø all 1 1000 1.4 3.9x i0 all 1 1000 8.2 2.2 x i0 7 all 1 1000 10 2.8x10 4 all 1 1000 10 2.8x10 4 all 1 1000 6.2 1.7x 10 4 all 1 1000 4.1 1.1 x iO all 3.5 30 — - ( MSN ) all all all all all 0.18 0.074 0.33 0.037 0.0035 0.0035 0.0035 0.003 0.002 0.18 12 0.18 0.33 0.18 0.074 Liters 3.5 3.5 3.5 3.5 3.5 Minutes 300 100 100 50 50 Doalmetry Networks 12x 10’ 41 160 820 40 j .iC i/mL 3 x 10 1 x 10’ 4 x 10’ 2 x 10’ 1 x 10 1/mo 1/quarter Locations Number Exposure Guide 72 1 l O OmR 130 3to6 29 Continuous ! MDC(%CG ) 3.Olmrem 2 — 5. l0mrem 2 br ALl and DAC values from ICRP-30 moc fied to 1 mSv annual effective dose equivalent for continuous exposure. To and I data corrected to 2g thyroid, greater milk u take, and smaller volume of air breathed annually (1 year-old infant). b For tri um, Sr. and Cs the concentration guide is based on Drinking Water Regs, (4 mrern/yr) (CFR, 1988). 132 ------- 14 Summary and Conclusions The primary functions of the ORSP are to conduct routine environmental monitoring for radioactive materials in areas potentialiy impacted by nuclear tests and, when necessary, to irr lement actions to protect the public from radiation exposure. Com- ponents of the ORSP include surveillance networks for air, noble gas, atmospheric tritium, and milk; biomonitoring of meat, game animals, and vegeta- bles; exposure monitoring by thermoluminescent dosimetry, pressurized ion chambers, and whole body counting; and long-term hydrological monitor- ing of wells and surface waters. In 1991, data from all networks and monitonng activities indicat- ed no radiation directly attributable to current activities conducted at the NTS. Therefore, there was no need for any protective actions to be taken. The following sections summarize the ORSP activities for 1991. 14.1 Thermoluminescent Dosimetry Program In 1991, external exposure was monitored by a network of thermoluminescent dosimeters (TLDs) at 130 fixed locations surrounding the NTS and by TLDs worn by 72 offsite residents. No apparent net exposures were related to NTS activities. As discussed in Section 3.1, regulatory or ALARA investigation limits were not exceeded for any individual or cumulative exposure. The range of exposures was similar to those observed in other areas of the U.S. 14.2 Pressurized Ion Chamber Network The Pressurized Ion Chamber (PlC) network measures ambient gamma radiation exposure rates. The 29 PICs deployed around the NTS in 1991 showed no unexplained deviations from background levels. The maximum annual expo- sure of 154 mR/yr was measured at Stone Cabin Ranch, Nevada; the minimum of 52 mRJyr was recorded at Las Vegas, Nevada. As discussed in Section 3.2 these values are within the U.S. back- ground range and are consistent with previous years’ trends. 14.3 Air Surveillance Network In 1991, the Air Surveillance Network (ASN) consisted of 33 continuously operating sampling locations surrounding the NTS. These stations were complemented by 76 standby stations which were operated at least one week each quarter. At least one standby sampler is located in each state west of the Mississippi River. In the majority of cases, no gamma emitting radionuclides were detected by gamma spectrome- try (i.e., the results were gamma-spectrum negligi- ble). Naturally occurring 7 Be was the only radio- nuclide occasionally detected. As in previous years, the majority of the gross beta results exceeded the MDC. The plutonium results from four of the composite samples exceeded the MDC in 1991. Two of these were very close to the MDC: 238 Pu results from Las Vegas, Nevada and 238 Pu results from Logan and Vernal, Utah. The other two values exceeding the MDC were the 9 °Pu results from the high-volume air samples collected from Amargosa Valley and from Rachel, Nevada. Operation of the Air Sampling Network and the data results were discussed in Section 4.1. 14.4 Tritium In Atmospheric Moisture At the beginning of 1991, the tritium network consisted of 20 continuously operating and two standby stations. Several changes were made to the network in 1991. These are discussed in Section 4.2.1. Of the 957 samples collected in 1991, 23 were of insufficient volume to permit analysis, and six of the results exceeded the MDC. Three of these six results, from Shoshone, Gold- field, and Rachel, Nevada were very close to the MDC. Of the other three values above MDC, one was from Salt Lake City, Utah and the other two were from Las Vegas, Nevada. The operation of the tritium samplers and the data results are discussed in Section 4.2. 133 ------- 14.5 Noble Gas Sampling Network At the beginning of 1991, Noble Gas Sampling Network (NGSN) consisted of 16 routinely operated and three standby stations. Several changes were made to the network in 1991. These are dis- cussed in Section 4.3.1. Samples collected were analyzed for Kr and 133 Xe. As in previous years, all of the results for 1 Xe were below the MDC. All of the Kr were above the MDC and were within the range anticipated from sampling background levels. 14,6 Foodstuffs Milk samples were collected from 23 Milk Surveil- lance Network (MSN) and 115 Standby Milk Surveillance Network (SMSN) stations in. 1991. For both MSN and SMSN samples, only naturally occurring 40 K averaging 2.17 grn/L was detected by gamma spectroscopy. The majority of the 3 H, Sr, and °Sr results were below the MDC. For the MSN, one sample result from the June Cox Ranch, Caliente, Nevada and one from the Harbecke Ranch, Shoshone, Nevada exceeded the MDC for 3 H. For both of these results, the MDC falls within or very close to one standard deviation of the analysis indicating the result is within expected statistical variation. For Sr, one result from the David Hat en Ranch, Ivins, Utah was the only value which exceeded the MDC. The MDC for this result was also within one standard deviation of the analysis result. For Sr results, two samples from the Harbecke Ranch, Shoshone, Nevada and two samples from the Karen Harper Ranch, Tonopah, Nevada exceeded the MDC. Values above MDC have been observed at the Harbecke Ranch in previous years. The higher values have generally occurred during the summer months, indicating those values may be associated with feeding patterns during those months. The Karen Harper Ranch has not been sampled in previous years so there is no historical record from that ranch. One 3 H result, three Sr results, and 17 90 Sr results were above the MDC for samples from the SMSN stations. This is consistent with the number of values exceeding the MDC in 1990. Sampling under the animal investigation program in 1991 showed detectable concentrations of tritium in two mule deer collected from the NTS and detectable concentrations of 23 2 °Pu were found in one or more tissues from each of the four mule deer collected. The mountain lion collected on the NTS also evidenced detectable concentrations of tritium, °Pu, and 90 Sr. All but one of the cattle liver samples yielded detectable concentrations of °Pu. Only one bighom sheep bone yielded a concentration of 2 °Pu greater than the MDC of the analysis. Strontium-90 was detected in all of the bone samples for each species. No gamma- emitting radionuclides other than naturally occur- ring 40 K were detected in any tissue sample. Medians and ranges of radionuclides in bighom sheep tissues and all analyzed cattle tissues except liver were generally similar to those ob- tained in previous years. Cattle liver yielded higher concentrations of radionuclides than noted in previous years. While ranges of radionuclide concentrations in mule deer were similar to those obtained in previous years, the medians were higher. This is attributed to collection of two (out of four) animals with evidence of radioactive contamination. As the objective of the animal investigation program is to detect worst-case conditions, the results indicate that the component of possible radionuclide ingestion from meat is small (see Chapter 8, Dose Assessment). Fifteen samples of locally grown fruits and vegeta- bles were collected in the fall of 1991. No gamma- emitting radionuclides were detected apart from naturally occurring 40 K. Two samples from the same location yielded detectable concentrations of Pu and concentrations of 3 Pu greater than the analysis MDC were found in seven samples. No correlation between radionuclide concentration and mode of growth (i.e., surface crops as op- posed to root crops) was evident. The observed plutonium may be contained in the fruit or vegeta- ble material or may be contained in soil or dust adhering to the vegetable surface. In the latter case, residents could reduce the potential for radionuclide ingestion by thorough washing of vegetables prior to eating and peeling of potatoes and carrots. The worst-case dose that could potentially result from eating these fruits and vegetables is discussed in Chapter 8, Dose As- sessment. 14.7 Internal Dosimetry Internal deposition of radioactive material is as- sessed by whole body counting using a single intrinsic coaxial germanium detector, lung counting using six intrinsic germanium semiplanar detectors, 134 ------- and bioassay using radiochemical procedures. During 1991, a total of 2,800 gamma spectra was obtained from whole-body counting of 350 persons (including those individuals who were counted twice). One hundred and six of the counts were on participants of the Otfsite Internal Dosimetry Pro- gram. All spectra were representative of normal background and showed only naturally occurring ‘°K. No transuranic radionuclides were detected in any lung-counting data. No internal exposure above applicable regulatory limits was detected in either occupationally exposed individuals or mem- bers of the general public who participated in the Internal Dosimetry Program at EMSL-LV. Bioassay results for the Offsite Internal Dosimetry Program showed that the concentration of tritium in single urine samples collected at random periods of time (i.e., whenever the individual was able to come to EMSL-LV) varied from below the MDC average value of 2.7 x 1 0 ’ tCiImL (10 BqIL) to 3.8 x iO j .tCiImL (14 BqIL). Two values were slightly above the MDC. This can be accounted for by random statistical fluctuation. The highest value of 3.8 x j 7 pCIImL (14 Bq/L) is only 0.01 percent of the annual limit of intake for the general public. As no accidental or planned releases from NTS were reported in 1991, no additional bioassay sampling was performed. As reported in previous years, medical examinations of the offsite families re- vealed a generally healthy population. The blood examinations and thyroid profiles showed no symptoms which could be attributed to past or present NTS testing operations. 14.8 Long-Term Hydrological Monitoring Program The Long-Term Hydrological Monitoring Program is discussed in detail in Chapter 7. None of the domestic water supplies monitored in the LTHMP in 1991 yielded tritium activities of any health concern. The greatest tritium activity measured in any water body which has potential to be a drink- ing water supply was less than one percent of the Interim Primary Drinking Water Regulation. In general, surface water and spring samples yielded tritium activities greater than those observed in shallow domestic wells in the same area. This is probably due to scavenging of atmospheric tritium by precipitation. There were no indications that migration from any test cavity is affecting any domestic water supply. In most cases, monitoring wells also yielded no detectable radionuclide activity. Exceptions include wells into test cavities and wells monitoring known areas of contamination. Known areas of contami- nation exist at Project GNOME where USGS conducted a tracer study experiment, some areas onsite at Project DRIBBLE, and a few surface areas near Project LONG SHOT. The 1991 results for these monitoring wells are consistent with decreasing trends observed over time. Monitoring well EPNG 10-36 at Project GAS- BUGGY was a notable exception to wells evidenc- ing decreasing trends. This well is a former gas well located 435 feet northwest of SGZ. The sampling depth of this well is approximately 3600 ft in the Ojo Alamo Sandstone, a nonpotable aquifer. The tritium activity in 1991 was 484 ± 4 pCi/L, approximately 10 times the historic back- ground activity. An increase in tntium activity was first observed in 1984, seventeen years after the test was conducted. In every year since then, with the exception of 1987, tritium activities have been between 100 and 560 pCi/L, with wide variability sometimes noted between consecutive years. The proximity of the well to the test cavity suggests the possibility that the increased activity may be indicative of migration from the test cavity. 135 ------- References U.S. Atomic Energy Commission, 1971. Effluent and Environmental Monitoring and Reporting. j j U.S. Atomic Energy Commission Manual, Chapter 0513. U.S. Atomic Energy Commission, Washington, D.C. American National Standards Institute, 1975. ANSI Standard N545--1975. American National Standards Institute, New York, NY. l6pp. Committee on the Biological Effects of Ionizing Radiation, 1980. The Effects on Populations of Exposure to Low Levels of Ionizing Radiation. National Academy Press, Washington, D.C. Code of Federal Regulations, 1988. Drinking Water Regulations, Title 40, part 141, Washington D.C. Code of Federal Regulations, 1989. 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Onsite and Offsite Environmental Monitoring Report: Radiation Monitoring around Tatum Salt Dome, Lamar County, Mississippi April 1991. U.S. Environmental Protection Agency, Office of Research and Development, Las Vegas, Nevada. U.S. Department of Energy. 1986. Long-Term Monitoring Program, Project GASBUGGY, Rio Arnba County, New Mexico. NVO-277. U.S. Department of Energy, Nevada Operations Office, Las Vegas, Nevada. 24 pp. U.S. Environmental Protection Agency. In preparation. Quality Assurance Program Plan for the Nuclear Radiation Assessment Division Offsite Radiation Safety Program. U.S. Environmental Protection Agency, Office of Research and Development, Las Vegas, Nevada. Internal document. 37 pp. U.S. Department of Energy. 1986. Handbook for the Department of Energy Laboratory Accreditation Program for Personnel Dosimetry Systems. DOE/EH-0026. U.S. Department of Energy, Assistant Secretary for Environment, Safety, and Health, 38 pp. U.S. Department of Energy. 1986. DOE Laboratory Accreditation Program for Personnel Dosimetry Systems. DOE/EH-0027. U.S. Department of Energy, Assistant Secretary for Environment, Safety, and Health, 36 pp. 139 ------- Glossary of Terms Definitions of terms given here are modified from the U.S. Nuclear Regulatory Commisskn Glossary of terms (NRC81). The radiation in man’s natural envi- ronment, including cosmic rays and radiation from the naturally radioac- tive elements, both outside and inside the bodies of humans and animals. It is also called natural radiation. The usually quoted aver- age indMdual exposure from back- ground radiation is 125 millirem per year in midlatitudes at sea level. beoquerel A unit, in the International System (Ba) of Units, of measurement of radio- activity equal to one nuclear trans- formation per second. beta A charged particle emitted from a particle (B) nucleus during radioactive decay, with a mass equal to 1/837 that of a proton. A positively charged beta particle is called a positron. Large amounts of beta radiation may cause skin bums, and beta emitters are harmful if they enter the body. Beta particles are easily stopped by a thin sheet of metal or plastic. blind A spiked sample, the composition samples of which is unknown to the techni- cian, which has been introduced into the laboratory as a separate sample. These samples are used for the verification of analytical ac- curacy. Approximately one percent of the sample load shall be blind samples. cosmic Penetrating ionizing radiation, both radiation particulate and electromagnetic, originating in space. Secondary cosmic rays, formed by interactions in the earth’s atmosphere, account for about 45 to 50 millirem of the 125 millirem background radiation that an average individual receives in a year. coulomb (C) Unit of electrical charge in the MKSA system of units. A coulomb is a quantity of a charge equal to one ampere-second. curie (Ci) The basic unit used to describe the rate of radioactive disintegration. The curie is equal to 37 billion disin- tegrations per second, which is approximately the rate of decay of 1 gram of radium; named for Marie and Pierre Curie, who discovered radium in 1898. dosimeter A portable instrument for measuring and registering the total accumulat- ed dose to ionizing radiation. duplicate A second aliquot of a sample which is approximately equal in mass or volume to the first ahquot and is analyzed for the sample parame- ters. The laboratory performs dupli- cate analyses to evaluate the preci- sion of an analysis. The time in which half the atoms of a particular radioactive substance disintegrate to another nuclear form. Measured halt-lives vary from mil- lionths of a second to billions of years. Also called physical hall-life. ionization The process of creating ions (charged particles) by adding one or more electrons to, or removing one or more electrons from, atoms or molecules. High temperatures, electrical discharges, nuclear radia- tion, and x-rays can cause ioniza- tion. ionization An instrument that detects and chamber measures ionizing radiation by mea- suring the electrical current that flows when radiation ionizes gas in a chamber. background radiation halt-life 141 ------- One of two or more atoms with the same number of protons, but differ- ent numbers of neutrons in their nuclei. Thus, ‘ 2 C, 3 C and 14 C are isotopes of the element carbon, the numbers denoting the approximate atomic weights. Isotopes have very nearly the same chemical proper- ties, but often different physical properties (for example, 12 C and 14 C are radioactive). An aliquot of a sample which is spiked with a known concentration of the analyte of interest. The pur- pose of analyzing this type of sam- pie is to evaluate to the effect of the sample matrix upon the analytical methodology. A method blank is a volume of de- mineralized water for lk uid samples, or an appropriate solid matrix for soil/sediment samples, carried through the entire analytical proce- dure. The volume or weight of the blank must be approximately equal to the volume or weight of the sam- ple processed. Analysis of the blank verifies that method interfer- ences caused by contaminants in solvents, reagents, glassware, and other sample processing hardware are known and minimized. The smallest amount of radio- actMty that can be reliably detected with a probability of Type I and Type II error at five percent each (DOE8I). noble gas A gaseous element that does not readily enter into chemical combina- tion with other elements. An inert personnel The determination of the degree of monitoring radioactive contamination on individ- uals using survey meters, or the determination of radiation dosage received by means of internal or external dosimetry methods. picocurie (pCi)One tnllionth part of a curie. The factor by which the absorbed dose is to be muftiplied to obtain a quantity that expresses, on a com- mon scale for all ionizing radiations, the biological damage to exposed persons. It is used because some types of radiation, such as alpha particles, are more biologically dam- aging than other types. Acronym for radiation absorbed dose. The basic unit of absorbed dose of radiation. A dose of one rad means the absorption of 100 ergs (a small but measurable amount of energy) per gram of absorbing material. radioisotope An unstable isotope of an element that decays or disintegrates sponta- neously, emitting radiation. radionuclide A radioisotope. Acronym of roentgen equivalent man. The unit of dose of any ioniz- ing radiation that produces the same biological effect as a unit of absorbed dose of ordinary X-rays. (See quality factor.) A unit of exposure to ionizing radia- tion. It is that amount of gamma or X-rays required to produce ions carrying one electrostatic unit of electrical charge in one cubic centi- meter of dry air under standard conditions. Named after Wilhelm Roentgen, German scientist who discovered X-rays in 1895. The combination of phosphor, photomultiplier tube, and associated counter electronic circuits for count- ing light emissions produced in the phosphor by ionizing radiation. quality factor rad matrix spike method blank minimum detectable (MDC) millirem (mrem) milliroentgen (mR) rem roentgen (A) scintillation (dectector or counter) A one-thousandth part of a rem. (See rem.) A one-thousandth part of a roentgen. (See roentgen.) gas. 142 ------- A unit, in the International System of Units (SI), of dose equivalent which is equal to one joule per kilogram (1 Sv equals 100 rem). A radioactive isotope of hydrogen that decays by beta emission. It’s half-life is about 12.5 years. A prepared sample of known con- centration of a purchased standard reference material. These samples are analyzed in triplicate and the results are used to verify accuracy and precision of the procedure. Penetrating electromagnetic radia- tion (photon) having a wavelength that is much shorter than that of visible light. These rays are usually produced by excitation of the elec- tron field around certain nuclei. In nuclear reactions, it is customary to refer to photons originating in the nucleus as gamma rays, and to those originating in the electron field of the atom as X-rays. These rays are sometimes called roentgen rays after their discoverer, Wilhelm K. Roentgen. Sieved (Sv) terrestrial The portion of natural radiation radiation (background) that is emitted by naturally occurring radioactive mate- rials in the earth. verification/ reference standard X-rays tritium 143 ------- Appendix A Table A-i: Offsite Station TLD Results, 1991 Table A-2: Offsite Personnel TLD Results, 1991 Figure A-i: Weekly averages of Pressunzed Ion Chamber Data by Station, January 1988 to December 1991 145 ------- Table A-i. Offsite Station TLD Results, 1991 Start End # Number of Data Equ iv. Exposure (mR/day) Rate Annual Equiv. Station Number Date Date Days Points Mm. Max. Ave. Exp. (mA)b Arizona Colorado City 008STA230 10/30/90 11/12/91 378 4 0.17 0.19 0.18 65 Jacob’s Lake 008STA452 10/30/90 11/12/91 378 4 0.25 0.28 0.26 96 Page 008STA708 10/31/90 11/12/91 378 4 0.13 0.16 0.15 55 California Baker 005STA035 11)01/90 11/19/91 378 4 0.23 0.30 0.26 95 Barstow 005STA045 11)01/90 11/19/91 378 4 0.28 0.37 0.32 119 Bishop 0058TA095 11)03/90 11/20/91 378 4 0.26 0.36 0.31 111 Death Valley Jct. 005STA290 01)09/91 07)03/91 378 2 0.12 0.21 0.16 60 Furnace Creek 005STA340 01/09/91 07/02/91 378 2 0.07 0.18 0.13 47 Independence 005STA445 11/02/90 11/20/91 378 4 0.23 0.32 0.28 101 Lone Pine 005STA545 11/02/90 11/20/91 378 4 0.23 0.33 0.28 103 Mammoth Geothermal 005STA576 11/03/90 11/20/91 378 4 0.26 0.38 0.32 117 Mammoth Lakes 005STA575 11)03/90 11/20/91 378 4 0.19 0.38 0.30 109 Olancha OO5STA700 11/02/90 11/20/91 378 4 0.22 0.31 0.26 94 Ridgecrest 005STA765 11/02/90 11/20/91 378 4 0.23 0.33 0.27 98 Shoshone 005STA855 11/01/90 11/19/91 378 4 0.20 0.28 0.22 81 Valley Crest 005STA920 01/09/91 04/02/91 83 2 0.06 0.13 0.10 35 Nevada Alamo OO2STAO15 10/30/90 11/12/91 378 3 0.21 0.28 0.23 86 Amargosa Center 007STA825 01/14/91 07)03/91 378 2 0.15 0.30 0.22 82 Amargosa Valley 007STA490 01/14/91 07/01/91 378 2 0.16 0.26 0.21 75 American Borate OO7STA91O 01/14/91 07)02/91 378 2 0.16 0.31 0.24 87 Atlanta Mine 002STA023 12/04/90 08/28/91 378 2 0.27 0.28 0.27 99 Austin 006STA025 11/07/90 11/18/91 378 4 0.30 0.43 0.36 132 Battle Mountain 005STA055 11/28/90 12/10/91 378 4 0.15 0.28 0.22 80 Beatty 007STA065 01/09/91 07)01/91 378 2 0.17 0.29 0.23 83 Blue Eagle Ranch OO3STA1O6 01)08/91 10)09/91 378 3 0.02 0.30 0.16 60 Blue Jay 004.STA115 01)08/91 10/09/91 378 3 0.19 0.45 0.33 120 Cactus Springs OO7STAI4O 11/01/90 11/18/91 378 4 0.14 0.21 0.17 61 Caliente 002STA155 10/29/90 11/12/91 378 3 0.19 0.26 0.22 82 Carp OO2STA16O 10/29/90 11/15/91 378 3 0.14 0.23 0.18 65 Cherry Creek OO9STA21O 12/05/90 08/28/91 378 2 0.32 0.34 0.33 120 Clark Station 004STA215 01/08/91 10/09/91 378 3 0.15 0.38 0.28 102 Coaldale 006STA220 11/06/90 11/13/91 378 4 0.19 0.31 0.27 98 Complex I 003STA240 10/31/90 11/15/91 378 3 0.22 0.29 0.25 93 Corn Creek 001STA295 11/01/90 11/18/91 378 4 0.11 0.19 0.14 50 Cortez/Hwy 278 009STA298 03/12/91 12/10/91 378 3 0.27 0.49 0.41 149 Coyote Summit 004STA230 10/30/90 11/15/91 378 3 0.24 0.37 0.31 113 Crescent Valley 009STA233 11/28/90 12/10/91 378 4 0.14 0.35 0.22 81 Currant 003STA245 01/08/91 10/09/91 378 3 0.14 0.33 0.26 95 Cume 005STA275 12)05190 08/28/91 378 2 0.33 0.34 0.34 122 Diablo Mtc. Sta. OO4STA300 01/03/91 10/08/91 378 3 0.21 0.40 0.33 120 Duckwater 003STA305 01)08/91 10)09/91 378 3 0.13 0.29 0.23 84 El n 002STA315 10/29/90 11/15191 378 3 0.27 0.34 0.29 107 Elko 005STA320 11/27/90 12/10/91 378 4 0.14 0.35 0.21 75 Ely 003STA326 12/05/90 08/27/91 378 2 0.23 0.25 0.24 86 Eureka 006STA333 01/15/91 1 9/91 378 2 0.22 0.31 0.27 97 Fallon 009STA335 11/29/90 12/12/91 378 4 0.13 0.31 0.19 70 Flying Diamond 003STA338 10/31/90 11/15/91 378 3 0.14 0.22 0.17 64 Gabbs 006STA350 11/06/90 11/13/91 378 4 0.11 0.22 0.18 65 Geyser Ranch 003STA370 12)04/90 08/27/91 378 3 0.11 0.30 0.22 82 Continued 146 ------- Table A-i. Continued. Start End C Number of Data Equi v. Exposure (mF llday) Rate Annual Equiv. Station Number Date Date Days Points Mm. Max. Ave. Exp. (mR)b Gokifleld 006STA380 11/13/90 11/13191 378 4 0.18 0.31 0.25 91 Groom Lake OO4STA400 11/14 /90 10/09/91 378 2 0.06 0.28 0.17 61 Hancock Summit 004STA420 11/01/90 11/15/91 378 3 0.33 0.45 0.37 136 Hiko 002STA430 10/30/90 11/16191 378 3 0.14 0.19 0.17 61 Hot Creek Ranch 004STA440 01/08191 10/09/91 378 3 0.13 0.25 0.21 75 Indan Spnngs 007STA450 11/01/90 11/18191 378 4 0.14 0.25 0.19 70 lone 01 1STA452 11/06/90 11/13/91 378 3 0.24 0.31 0.28 104 Kirkeby Ranch 003STA390 12/04/90 08/27/91 378 2 0.18 0.23 0.21 75 Koynes Ranch 004STA460 11/01/90 11/15/91 378 3 0.18 0.31 0.24 89 Las Vegas Apts. 001STA472 01/02/91 07/02/91 378 2 0.15 0.17 0.16 58 Las Vegas UNLV 001STA485 01/02/91 07/02/91 378 2 0.08 0.13 0.10 37 Las Vegas USD1 OO1STA48O 01/02/91 07/02/91 378 2 0.12 0.19 0.15 55 Uda OO6STA500 11/13/90 11/13/91 378 4 0.18 0.31 0.26 95 Lovelock 009STA548 11/28/90 12/11/91 378 4 0.15 0.27 0.19 68 Lund 003STA555 12/06/90 08/29/91 378 2 0.21 0.26 0.23 85 Manhattan 006STA585 11/07/90 11/14/91 378 4 0.25 0.45 0.34 123 Medlin’s Ranch 004STA943 11/01/90 11/15/91 378 3 0.23 0.35 0.28 104 Mesquite OO1STA615 10/29/90 11/15/91 378 4 0.12 0.16 0.14 51 Mina 006STA620 11/06190 11/13/91 378 4 0.16 0.29 0.24 86 Moapa 002STA757 10/29/90 11/12/91 378 4 0.17 0.21 0.20 72 MIn Meadows Ranch 0046TA185 01/03/91 10109/91 378 3 0.13 0.19 0.16 58 Nash Ranch 003STA655 10/30/90 11/16191 378 3 0.16 0.24 0.19 71 Nyala 004.STA69O 01/03/91 10/08/91 378 3 0.08 0.25 0.18 66 Overton OO1STA7O5 10/29/90 11/20/91 378 4 0.13 0.15 0.15 54 Pahiump 007STA720 11/01/90 11/19/91 378 4 0.11 0.18 0.14 49 Penoyer Farms 004STA670 10131/90 11/15/91 378 3 0.24 0.36 0.28 104 Pine Creek Ranch 004STA730 10/31/90 11/15/91 378 3 0.27 0.35 0.30 111 Pioche 002STA740 10/29/90 11/12/91 378 3 0.17 0.19 0.18 66 Queen City Summit 004STA750 01/03/91 10/08/91 378 3 0.24 0.41 0.33 121 Rachel 004STA773 ‘10/31/90 11/15/91 378 3 0.24 0.29 0.26 95 Reed Ranch 004STA760 01/03/91 10/08/91 378 2 0.34 0.35 0.35 127 Reno 009STA757 11/29/90 12/11/91 378 4 0.14 0.33 0.20 71 Round Mountain 006STA775 11/07/90 11/14/91 378 4 0.21 0.35 0.30 108 Ruby Valley 009STA788 11/27/90 12/10/91 378 4 0.24 0.47 0.31 112 So. Desert Corr. 007STA860 11/01/90 11/18191 378 4 0.12 0.20 0.14 53 Shun OO9STASO5 11/29/90 12/12/91 378 4 0.22 0.47 0.29 107 Silver Peak 005STA857 11/13/90 08/22/91 378 4 0.16 0.20 0.19 70 Spnngda le 007STA885 01110/91 04/03/91 83 2 0.17 0.31 0.24 88 Steward Ranch 003STA912 12 ,04/90 03/04/91 90 2 0.29 0.33 0.31 113 Stone Cabin Ranch 004STA915 01103/91 04)02/91 89 3 0.14 0.33 0.26 94 Sunnyside 003STA930 12/06/90 03/06/91 90 2 0.13 0.16 0.14 53 Temptute 004STA940 11101/90 02/05/91 96 3 0.26 0.31 0.28 104 Tonopah Test Range 006STA947 01/02/91 04/10/91 98 3 0.24 0.50 0.36 130 Tonopah 006STA945 11/07/90 02/07/91 92 4 0.29 0.32 0.31 113 Twin Springs Ranch 004STA955 01/03/91 04/01/91 68 3 0.09 0.40 0.26 95 Uhalde’s Ranch OO4STAOIO 10/31/90 02/05/91 97 3 0.26 0.32 0.29 106 Warm Springs #1 004STA975 01/03/91 04/02/91 89 3 0.20 0.39 0.32 116 Warm Springs #2 004STA977 01/03/91 04/02/91 89 3 0.94 1.15 1.04 378 Wells 005STA985 11/27/90 03/12/91 105 4 0.17 0.36 0.23 84 Winnemucca 009STA998 11/28/90 03/1 3191 105 4 0.12 0.37 0.21 76 Young’s Ranch OO6STA9BO 08/22/90 02/06/91 168 4 0.07 0.26 0.21 75 Continued 147 ------- Table A-i. Continued. Station Number Start Date End Date # Days Number of Data Points Equiv. Mm. Exposure (mR/day) Max. Rate Ave. Annual Equiv. Exp. (mR)b U Boumder O1OSTA116 12105/90 12/11/91 378 4 0.18 0.29 0.23 85 Bryce Canyon O1OSTA118 1205190 12/11/91 378 4 0.18 0.24 0.21 77 Cedar City OO1STA200 11/28/90 12109/91 378 4 0.16 0.23 0.19 71 Delta 011STA295 01/30/91 01109/92 378 3 0.15 0.34 0.22 81 Duchesne O11STA3O3 01/29/91 01i07/92 378 3 0.12 0.27 0.18 66 Enterprise 001STA325 11/27/90 1209/91 378 4 0.26 0.39 0.32 116 Ferron 008STA337 01/29/91 01107/92 378 3 0.12 0.30 0.18 67 Garrison 003STA360 12105/90 08/28/91 378 2 0.22 0.22 0.22 80 GrantsvWe 011STA393 01/30/91 01i0W92 378 3 0.15 0.29 0.20 73 Green River 0088TA395 08107/90 11/12/91 378 4 0.04 0.21 0.15 54 Gunnieon 0088TA405 12 ,06/90 12/10/91 378 4 0.13 0.16 0.15 54 lbapah 009STA443 12105/90 08/28/91 378 2 0.24 0.34 0.29 106 Kanab 008STA453 10/30/90 11/12/91 378 4 0.11 0.17 0.14 52 Loa O1OSTA52O 12105(90 12/11/91 378 4 0.28 0.39 0.33 122 Logan O11STA53O 01/10/91 07105/91 378 2 0.15 0.24 0.20 72 Lund O1OSTAS6O 11/28/90 12/09/91 378 4 0.25 0.34 0.28 104 Milford OO1STA62O 12104/90 12/10/91 378 4 0.28 0.37 0.32 118 MOntiCe llO 008STA650 10/31/90 11/13(91 378 4 0.22 0.23 0.23 83 Nephi O11STA66O 12 0&90 12/10/91 378 4 0.13 0.18 0.16 58 Parowan 010STA725 12 ,04/90 12/12/91 378 4 0.18 0.20 0.19 70 Price 011STA743 01/29/91 01107/92 378 3 0.15 0.30 0.20 74 Provo 011STA745 01/29/91 0108/92 378 3 0.13 0.23 0.18 65 SaitLaice City OO1STA800 01/30(91 01108/92 378 3 0.12 0.21 0.17 61 St. George 001STA795 11/28/90 03101/91 93 4 0.12 0.14 0.12 45 Trout Creak 0098TA948 12105/90 0&0S ( 91 90 2 0.20 0.23 0.21 78 Vernal 011STA973 01/29/91 04109/91 70 3 0.13 0.29 0.19 71 Vernon 011STA974 01/30/91 04/10(91 70 3 0.17 0.33 0.22 82 Wendover 005STA990 11/27/90 03/12(91 105 4 0.10 0.30 0.17 64 Wilow Spr. Lodge 01 1STA997 01/30/91 04/10/91 70 3 0.13 0.26 0.18 66 UNIV - University of Neveda, Las Vegas USD1 - United States Depailment of Interior Daly exposure rates are obtained by vidIng the total exposure from each TLD by the number of days in tho measurement period. b Annual exposures are calculated by muIt iying average daily exposure rate by 365.25. 148 ------- Table A-2. Offsite Personnel TLD Results, 1991 California 304 Death Valley Jct. 359 Death Valley Jct 60 Shoshone 404 Shoshone Nevada 22 Alamo 427 Alamo 380 Amargosa Center 426 Amargosa Valley 329 Austin 21 Beatty 38 Beatty 358 Beatty 429 Beatty 9 Blue Eagle Ranch 2 Caliente 336 Caliente 10 Complex 1 11 Complex 1 56 Corn Creek 14 Coyote Summit 15 Coyote Summit 47 Ely 44 Ely 302 Gabbs 7 Goldfield 19 GoIdlield 40 Goldfleld 424 Terrell’s Ranch 232 Hiko 3 Hot Creek Ranch 6 Indan Springs 37 Indan Springs 405 Indan Springs 381 lone 300 Koyne’s Ranch 49 Las Vegas UNLV 25 Las Vegas USD1 297 Las Vegas USD1 326 Las Vegas USD1 376 Las Vegas USD1 377 Las Vegas USD1 398 Las Vegas USD1 399 Las Vegas USD1 402 Las Vegas USD1 403 Las Vegas USD1 423 Las Vegas USD1 428 Las Vegas USD1 379 Manhattan 307 Mina 18 Nyala OO2STAO15 01/03/91 08105/91 214 OO2STAO15 01103/91 OM)6/91 215 007STA825 01103/91 07102/91 180 012YCA023 01103/91 0702/91 180 006STA025 01/16/91 07/09/91 174 007STA065 01/10/91 07102191 173 007STA065 01109/91 07/01/91 173 007STA065 01/11/91 07102/91 172 007STA065 02/12/91 07 ,02/91 140 OO3STA1O6 01108/91 07/16/91 189 002STA155 01 / 02191 08 ,06/91 216 002STA155 01,02/91 08101/91 211 003STA240 01103/91 08106/91 215 003STA240 01103/91 08106/91 215 001 STA295 01102191 08/31/91 241 004STA230 01104/91 08/13/91 221 004STA230 01104/91 08/13/91 221 003STA326 01102/91 07/12/91 191 003STA326 07/10/91 08106/91 27 006STA350 01/15/91 07/10/91 176 0068TA380 01/17/91 07/11/91 175 006STA380 01/17/91 07/11/91 175 006STA380 01/17/91 07/11/91 175 O12YCA81O 01/10/91 07102/91 173 002STA430 01104/91 08/06/91 214 004STA440 01/09/91 07/16/91 188 007STA450 01/07/91 07108/91 182 007STA450 0 1,07/91 07108/91 182 007STA450 01107/91 07,08/91 182 011STA452 01/15/91 07/10/91 176 004STA460 01103/91 08/06/91 215 001STA485 01/31/90 04/02/91 426 OO1STA48O 01102/91 08/31/91 241 OO1STA48O 01102191 08/31/91 241 OO1STA48O 01/02/91 05/02/91 120 OO1STA48O 01102/91 07/31/91 210 001STA480 01102191 08/31/91 241 OO1STA48O 01/02/91 08/31/91 241 OO1STA48O 01/02/91 08/31/91 241 OO1STA48O 01/02/91 08/31/91 241 001 STA48O 01/02/91 08/31/91 241 OO1STA48O 08/01/91 08/31/91 30 OO1STA48O 01103/91 08/31/91 240 006STA585 01/16/91 07/09/91 174 0068TA620 01/15/91 07/10/91 176 004STA690 01/03/91 07/16/91 194 ODOSIMETER NOT RETURNED 8 0.02 0.44 0.24 87 6 0.09 0.46 0.32 116 6 0.02 0.30 0.18 67 6 0.07 0.33 0.18 64 Continued Person Background Start End # Number of Data Equiv. Deep Dose Rate Annual (mrem/day) Equiv. ID. Location Station # Date Date Days Points Mm. Max. Av4)ose (mrem)b 005STA290 01/09/91 07103/91 175 005STA290 01/10/91 07/11/91 182 005STA855 01/08/91 07,08/91 181 005STA855 01/08/91 07/08/91 181 6 0.18 0.55 6 0.06 0.43 6 0.14 0.52 6 0.10 0.68 7 0.03 0.18 7 0.05 0.39 6 0.18 0.57 6 0.24 0.56 6 0.19 0.57 6 0.09 0.44 6 0.21 0.41 6 0.15 0.42 5 0.03 0.35 6 0.11 0.31 7 0.21 0.36 7 0.05 0.27 7 0.11 0.50 7 0.07 0.36 8 0.04 0.26 7 0.12 0.36 7 0.04 0.34 6 0.06 0.30 1 0.18 0.18 6 0.04 0.39 6 0.07 0.76 6 0.04 0.39 6 0.10 0.28 5 0.05 0.52 7 0.03 0.19 6 0.12 0.29 6 0.04 0.52 6 0.04 0.44 6 0.06 0.24 6 0.10 0.50 7 0.05 0.46 3 0.03 0.24 8 0.02 0.19 8 0.04 0.20 4 0.11 0.19 7 0.03 0.44 8 0.03 0.22 8 0.04 0.40 8 0.00 0.35 8 0.04 0.32 8 0.04 0.27 0.36 0.21 0.29 0.34 0.10 0.18 0.30 0.37 0.30 0.29 0.28 0.30 0.21 0.22 0.32 0.16 0.30 0.19 0.15 0.22 0.18 0.18 0.18 0.22 0.35 0.21 0.18 0.29 0.13 0.20 0.20 0.18 0.15 0.28 0.17 0.11 0.09 0.11 0.14 0.14 0.10 0.26 0.20 0.15 0.15 133 76 105 123 38 66 114 135 111 105 102 111 78 79 117 58 110 69 59 81 65 67 66 79 127 76 66 105 46 73 72 64 54 102 64 39 34 39 50 50 36 94 72 56 56 149 ------- Table A-2. Continued. Person LD. Background Location Station # Start Date End Date # Days Number of Data Points Equiv. ( Mm. Deep Do mrem/day) Max. so Rate Annual Equiv. Avd)ose (mrem)b 299 Round Mountain 006STA775 01/16191 07i09/91 174 6 0.09 0.57 0.29 107 341 Silver Peak 005STA857 01/17/91 07/10191 174 6 0.05 0.57 0.31 112 29 Stone Cabin Ranch 004STA915 01103/91 07/16/91 194 6 0.24 0.68 0.46 167 42 Tonopah 006STA945 01/17/91 07/11191 175 6 0.09 0.54 0.30 110 339 Tonopah 006STA945 01/17/91 07/10/91 174 6 0.16 0.50 0.31 113 348 Overton OO1STA7O5 01102/91 08101/91 211 7 0.18 0.29 0.23 83 372 Pahrump 007STA720 01103191 07101/91 179 6 0.05 0.22 0.15 55 410 Pahrump 007STA720 01108/91 07108/91 181 6 0.03 0.58 0.26 94 411 Pahiump 007STA720 01108/91 07108/91 181 6 0.03 0.44 0.26 96 248 Penoyer Farms 0048TA670 01103/91 08106/91 215 7 0.16 0.38 0.22 82 293 Pioche 002STA740 01102/91 08105/91 215 7 0.03 0.39 0.15 56 264 Rachel 004STA773 01104191 08106/91 214 7 0.13 0.31 0.25 92 334 Rachel 004STA773 01103191 08106/91 215 7 0.16 0.26 0.20 75 443 Rachel 0048TA773 07/10191 08106/91 27 1 0.09 0.09 0.09 32 370 Tw n Springs Ranch 004STA955 01103/91 07/16/91 194 6 0.21 0.39 0.32 118 U 44 Cedar City OO1STA200 01102/91 08101/91 211 7 0.09 0.39 0.20 71 344 Delta 01 1STA295 01102/91 08106191 216 7 0.08 0.19 0.15 54 345 Delta 011STA295 01102/91 08106191 216 7 0.09 0.50 0.25 90 346 Milford OO1STA62O 01102/91 08105(91 215 7 0.15 0.34 0.24 89 347 Mllford OO1STA62O 01102/91 08105/91 215 7 0.08 0.61 0.39 143 52 Salt Lake City OO1STA800 01102/91 08106(91 216 7 0.06 0.26 0.17 63 45 St. George 001STA795 01102/91 0&02/91 212 7 0.03 0.14 0.08 31 USD1 - United States Department of Interior UNLV - University of Nevada, Las Vegas Daly dose rates are obtained by dvic*ng the toW dose from each TLD by the number of days in the measurement period. b Annual doses are calculated by multiplying average daily dose rate by 36525. 150 ------- Aiamo, NV 2O . 18 16 a-- < 12 10. . O1X)1/88 01/01/89 01 / 01i90 01IO1 1 01/01 192 Week Endng Date knargosa Cente NV 15- 13 11 < 7, 01 / 01/88 01/01/89 01/01190 01/01191 01/01192 Week Ending Date Figure A-i. Weekty averages of Pressurized Ion Chamber data, by station, January, 1988 to December, 1991. 151 ------- fr ri&gosa Valley NV d 18 16 14 - < 12 10 O1 t O 14 1 Oh/01 2 Week Endkig Date Beat N t: J14 I < 12. 10 1 119O 01 101 191 01101192 Week Endi g Date Figure A-i. Continued. 152 ------- Caliente, NV Ced City, UT 01 / 01/90 01/01/91 Week Ending Date 18 16 I p 14 0 12 10 01/01/88 01/01/89 01/01 ,90 01/01/91 01/01/92 Week Endmg Date I p 15 13 11 9. 5 01/01/88 Figure A-i. Continued. 01/01/89 01/01/92 153 ------- Complex I, NV 20 . 18 00 16 o fo E ( 14 o 12 10. 01/01/88 01/01/89 01/01,90 01/01 1 W/01 2 Week Ending Date DeIta Jr 15 . 13 0 .3 11 0 E 9. 5 01/01/88 01/01/89 01/01/91 01/01/92 Week Ending Date Figure A-i. Continued. 154 ------- By,NV 15 ‘Hi I 01/01/88 01/01/89 01/01190 01/01/91 01/01/92 Week Ending Date Furnace Creek, CA 15 — . 13 11 I: 5 01/01/88 01/01/89 01 101/90 01/01/91 01/01/92 Week Ending Date Figure A-i. Continued. 155 ------- Go d, NV 18 01101/88 01 1 01/89 01101190 01)01191 01)01192 Week Endmg Date id n Sprngs, NV 15 13 iii 5. 01101/88 01)01/89 01/01191 01)01192 Week Ending Date Figure A-I. Continued. 156 ------- Las gas, NV 10• . 8 6 ___ p < 2 0 01/01/88 01/01/89 01/01/90 01/01/91 01/01/92 Week Ending Date Medlins Ranch, NV 20 18 < 12 10 . 01/01/88 01/01/89 01/01/90 01/01/91 01/01/92 Week Ending Date Figure A-i. Continued. 157 ------- Millord, UT 20 ( 14 I < 12 10 01/01/88 01/01/89 01/01190 01/01/91 01/01/92 Week Endng Date Nya NV 15 0 . 11. 0 a: §3 < T 5 01/01/88 01jO1/89 01/01/91 01/01)92 Week Ending Date Figure A-i. Continued. 158 ------- Overton, NV 01/01/88 01/01/89 01101 / 90 01/01/91 15• 13 11 5 15 13 11 9 7 5 01101/88 Week Ending Date Pahrump, NV 01/01/92 Figure A-i. Continued. Week Ending Date c i p ( ci p 01/01/89 01101/90 01/01/91 01/01/92 159 ------- oche, NW OW1/88 01/01/89 01 / 01 190 01/01/91 4 a 0 01/01/89 Week Ending Date Rache NW Figure A-i. Continued. Week Endmg Date I I I 15 13 11. 9, 7, 5 20• 18 16 14 12 10 01 / 01/92 a 00 I D o 0 0 0 01/01/88 01 101 1 90 01/01/91 01/01/92 160 ------- Satt Leke aty, UT 15 13 o 0 0 % 0 __ m E 9 0 7. 5. O1 1/88 O1iW89 O1A)1i90 O1 , )1/91 O1/O1 2 Week Ending Date Shoshone, CA 15 13 0¼ 11 0 E 9. 5 O1 1/88 01101/89 01 1 0W0 01101 191 01/01 /92 Week Ending Date Figure A-i. Continued. 161 ------- St. George, UT b 0 vgo Week Ending Date Stone Cabin ich, NV O1 1i9O Week Endmg Date O1iti1 1 01/01 /92 Figure A-i. Continued. 15 13 11 t 9 7 5 01/01/88 01 / 01i91 01/01/92 18 16 t < 12 U 10 01/01/88 01/0V89 162 ------- Terrels Reich, NV 01/01/88 01/01 )90 01/01/91 01/01 ) 92 Week Endlig Date Tonop i, NV 01/01 ) 90 01/01)91 01/01)92 Figure A-i. Continued. Week Endrig Date 18 12 10 18 16 !14 c i I a a 16 14 12 0 10 01/01/88 163 ------- Uh des F ich, W 0 R (4’ 00 0 o o 0 0 0 01 1 01/88 ovoii i 0 Rgure A-i. ContiAued. Week D e . 18 16 <12 10• 01M, 2 164 ------- Appendix B Atmospheric Monitoring Tables And Figures Table B-i Gross Beta Results for the Standby Air Surveillance Network, 1991 Table B-2 Plutonium Results for the Air Surveillance Network, 1991 Figure B-i Distribution of gross beta values from Standby Air Surveillance Network stations, 1991 165 ------- Table B-i. Gross Beta Results for the Standby Air Surveillance Network, 1991 Gross Beta Concentration Number x 10.12 CVmL of days Sampling Location Sampled Maximum Minimum Mean Std. Dev. Globe, AZ 30 0.025 0.013 0.017 0.006 Kingman, AZ 28 0.033 0.006 0.019 0.011 Tuscon, AZ 29 0.029 0.022 0.026 0.004 Winslow, AZ 28 0.039 0.009 0.024 0.013 Yuma, AZ 37 0.028 0.006 0.016 0.008 Little Rock, AR 33 0.018 0.008 0.013 0.004 Alturas, CA 21 0.018 0.005 0.010 0.007 Baker, CA 31 0.048 0.019 0.031 0.013 Bishop, CA 36 0.045 0.014 0.013 0.013 Chico, CA 27 0.018 0.010 0.014 0.004 Indlo, CA 21 0.039 0.020 0.027 0.010 Lone Pine, CA 8 0.011 0.011 0.011 0.000 Needles, CA 21 0.011 0.006 0.008 0.002 Ridgecrest, CA 27 0.041 0.005 0.024 0.015 Santa Rosa, CA 28 0.017 0.005 0.009 0.006 Cortez, CO 35 0.025 0.017 0.022 0.004 Denver, CO 27 0.037 0.015 0.025 0.010 Grand Junction, CO 34 0.088 0.012 0.033 0.037 Mountain Home, ID 27 0.031 0.003 0.014 0.013 Nampa, ID 28 0.010 0.000 0.007 0.005 Pocatello, ID 21 0.012 0.009 0.010 0.001 Fort Dodge. IA 28 0.034 0.016 0.023 0.008 Iowa City, IA 21 0.031 0.014 0.024 0.009 Dodge City, KS 28 0.022 0.011 0.016 0.006 Monroe, LA 28 0.024 0.018 0.021 0.003 Minneapolis, MN 20 0.026 0.017 0.022 0.004 Clayton, MO 29 0.021 0.008 0.016 0.006 Joplin, MO 28 0.018 0.008 0.014 0.005 St. Joseph, MO 28 0.020 0.016 0.018 0.002 Great Falls, MT 35 0.019 0.007 0.013 0.005 Kalispell, MT 28 0.029 0.009 0.017 0.009 Miles City, MT 21 0.029 0.015 0.020 0.008 North Platte, NE 14 0.024 0.021 0.022 0.002 Battle Mountain, NV 26 0.050 0.012 0.027 0.017 Blue Jay, NV 29 0.033 0.015 0.023 0.008 Clark Station, NV 29 0.034 0.003 0.018 0.013 Angle Worm Ranch, NV 29 0.036 0.014 0.024 0.010 Curne Maint. Station, NV 30 0.028 0.006 0.018 0.011 Duckwater, NV 29 0.024 0.010 0.019 0.007 Elko, NV 29 0.029 0.008 0.018 0.009 Continued 166 ------- Table B-i. Continued Gross Beta Concentration Number x 10.12 iCVmL of days Sampling Location SampIed ’ Maximum Minimum Mean Std. Dev. Eureka, NV 20 0.016 0.001 0.007 0.009 Fallon, NV 35 0.068 0.011 0.028 0.023 Geyser Ranch, NV 26 0.017 0.010 0.014 0.003 Lovelock, NV 29 0.060 0.001 0.021 0.027 Lund, NV 21 0.018 0.007 0.013 0.006 Mesquite, NV 20 0.010 0.006 0.008 0.002 Reno, NV 28 0.043 0.004 0.021 0.017 Round Mountain, NV 29 0.019 0.012 0.016 0.003 Uhalde Ranch, NV 56 0.040 0.007 0.016 0.010 Wells, NV 23 0.038 0.010 0.020 0.015 Winnemucca, NV 29 0.050 0.012 0.025 0.017 Albuquerque, NM 35 0.025 0.010 0.016 0.006 Carlsbad, NM 27 0.012 0.004 0.008 0.003 Shiprock, NM 36 0.039 0.006 0.019 0.012 Bismarck, ND 28 0.024 0.015 0.019 0.004 Fargo, ND 27 0.026 0.013 0.020 0.006 Williston, ND 21 0.029 0.023 0.026 0.003 Muskogee, OK 21 0.019 0.014 0.016 0.003 Bums, OR 21 0.011 0.009 0.010 0.001 Mediord, OR 20 0.035 0.008 0.019 0.014 Rapid City, SD 21 0.012 0.010 0.011 0.001 Amarillo, TX 37 0.022 0.013 0.018 0.004 Austin, TX 29 0.027 0.011 0.019 0.008 Midland, TX 28 0.010 0.003 0.006 0.003 Tyler, TX 31 0.022 0.013 0.017 0.004 Biyce Canyon, UT 46 0.016 0.000 0.009 0.007 Enterprise, UT 35 0.029 0.015 0.019 0.006 Garrison, UT 28 0.040 0.014 0.022 0.012 Logan, UT 29 0.017 0.007 0.013 0.005 Parowan, UT 21 0.018 0.009 0.014 0.005 Vernal, UT 35 0.050 0.011 0.021 0.016 Wendover, UT 28 0.029 0.006 0.018 0.011 Seattle, WA 37 0.007 0.003 0.005 0.017 Spokane, WA 31 0.036 0.004 0.016 0.014 Rock Springs, WY 41 0.021 0.012 0.016 0.003 Worland, WV 29 0.018 0.009 0.014 0.004 ) 10.12 CVmL = pCWm 3 ; multiply CVmL result by 0.037 to obtain Bq/m 3 . Number of days sampled is determined by filter change dates. 167 ------- Table B-2. Plutonium Results for the Air and Standby Air Surveillance Networks, 1991 Composite Collection Concentration ± is (MDC) Pu °Pu Sampling Location Date x 1 0 18 pCi/mL x 10.18 .tCVmL Arizona (Winslow & Tucson) 02105/91 -23 ± 14 (62) 0 ± 11 (36) 05/06f91 -35 ± 20 (95) -12 ± 20 (77) 08/30/91 -16 ± 13 (61) -9.2 ± 9.2 (43) 10/18191 0 ± 3.7 (12) 7.8 ± 5.8 (12) Californ ia (Bishop & Ridgecrest) 02113/91 -12 ± 15 (55) 12 ± 12 (28) 05/15/91 0 ± 8.2 (27) 0 ± 8.2 (27) 09/11191 -7 ± 5 (23) 11 ± 7.9 (16) 12/25/91 6.6 ± 6.6 (18) 0 ± 3.1 (10) C o (Denver & Cortez) 01/25/91 -11 ± 11 (50) 11 ± 19 (50) 05/24/91 14 ± 11 (22) -9.6 ± 9.6 (39) 09/15/91 7.3 ± 15 (4.8) 0 ± 5.2 (17) 10/24/91 -11 ± ii (43) 3.8 ± 8.5 (25) Idaho (Nampa & Mountain Home) 01/27/91 -9.4 ± 9.4 (44) -9.4 ± 9.4 (44) 04124/91 -5.1 ± 8.8 (33) -5.1 ± 5.1 (24) 07/22/91 14 ± 17 (47) 7.1 ± 12 (33) 10/20/91 0 ± 8.6 (28) 0 ± 6.1 (20) Missouri (Clayton & Joplin) 01/30/91 7.1 ± 19 (57) 14 ± 14 (33) 05/31/91 -4.5 ± 10 (36) 9 ± 11 (30) 09/15/91 -6.5 ± 7.9 (30) -3.2 ± 3.2 (15) 10/31/91 4.4 ± 7.6 (20) 13 ± 9.8 (20) Mo ana (Great Falls & Miles City) 01131/91 -17 ± 21 (79) -8.4 ± 8.4 (39) 05/24/91 5.4 ± 9.3 (25) -5.4 ± 5.3 (25) 09/05/91 0 ± 11 (35) 4.3 ± 7.5 (20) 10/31/91 -6.5 ± 4.6 (21) 6.5 ± 6.5 (15) Alamo, Nevada 01/28191 1.5 ± 3.5 (10) 1.5 ± 2.7 (7.2) 02/25/91 -1.5 ± 2.1 (7.7) 2.2 ± 2 (4.9) 03/25/91 -5.2 ± 2.6 (12) 0 ± 1.8 (6.1) 04/29/91 -0.8 ± 0.8 (3.9) -0.8 ± 1.4 (5.5) 05/27/91 -0.8 ± 0.8 (3.9) 0.8 ± 1.4 (3.9) 06124/91 0 ± 1.8 (5.8) -1.3 ± 1.3 (5.8) 07/29/91 0 ± 2.3 (7.4) 1.6 ± 2.8 (7.4) Continued 168 ------- Table B-2. Continued Composite Sampling Location Collection Date Con centration ± is (MDC) Pu x 1018 CWmL x °Pu 10 8 iCi/mL 08/26/91 -1.5 ± 2.6 (9.9) 0 ± 2.1 (7.0) 09/30/91 -2.3 ± 1.6 (7.4) 1.1 ± 1.9 (5.2) 10/28/91 0 ± 5.2 (1.7) 0 ± 3.0 (9.9) 11/25/91 0 ± 9.0 (29) 0 ± 5.2 (17) 12/30/91 -1.7 ± 3.0 (11) 0 ± 2.4 (8) Amargosa Valley, Nevada 01/27/91 -3.1 ± 3.1 (14) 0 ± 4.4 (14) 02124191 2.6 ± 5.8 (17) 0 ± 3.7 (12) 03131/91 -25 ± 19 (78) 0 ± 12 (39) 04/28/91 3.9 ± 4.7 (13) 1.9 ± 3.4 (9) 05/26/91 -3.4 ± 7.6 (27) 3.4 ± 5.9 (22) 05/28/91(Hi Vol) -0.1 ± 0.1 (0.4) *1.1 ± 0.3 (0.4) 06/30/91 0 ± 3.3 (11) 7.1 ± 5.3 (11) 07/29/91 -3.9 ± 6.7 (26) 0 ± 5.5 (18) 08/25/91 -3.0 ± 5.3 (20) -3.0 ± 3.1 (14) 09/29/91 -1.8 ± 3.2 (12) -1.8 ± 1.8 (8.5) 10/27/91 SAMPLE LOST 11/24/91 9.9 ± 6.1 (12) 0 ± 3.5 (12) 12/30/91 -1.2 ± 2.8 (10) -1.2 ± 1.2 (5.8) Las Vegas, Nevada 01 /28/91 0 ± 9.2 (30) 3.3 ± 5.7 (15) 02/25/91 *17 ± 8.1 (16) 0 ± 3.4 (11) 03/25/91 4.2 ± 4.2 (9.8) 0 ± 3 (9.8) 04129/91 -1.8 ± 4.1 (15) 1.8 ± 4.1 (12) 05/27/91 -2.5 ± 2.5 (12) -2.5 ± 2.5 (12) 06/24/91 10 ± 6.2 (12) -2.5 ± 5.6 (20) 07/29/91 -4.6 ± 5.6 (20) 4.6 ± 3.5 (7.2) 08/26(91 0 ± 14 (46) -4.9 ± 5.0 (25) 09/30/91 -1.9 ± 1.9 (7.6) -0.9 ± 0.9 (4.4) 10/28/91 -2.3 ± 2.3 (11) 0 ± 3.3 (11) 11/25/91 -2.3 ± 3.9 (15) -2.3 ± 2.3 (11) 12/30/91 -1.6 ± 1.6 (7.4) 0 ± 2.2 (7.4) Rachel, Nevada 01/28/91 -2.6 ± 2.6 (12) 0 ± 3.6 (12) 02/25/91 7.8 ± 6.2 (16) -2 ± 2 (9.1) 03/25/91 -3 ± 2.3 (9.4) 1 ± 1.7 (4.7) 04/29/91 4.3 ± 3.2 (6.6) -4.3 ± 2.5 (11) 05/28/91 0 ± 4.1 (13) 4.1 ± 4.1 (9.5) 06/24/91 -3 ± 6.8 (25) 0 ± 6.1 (20) 07/08/91(Hi Vol) 0.3 ± 0.3 (0.6) *74 ± 1.1 (0.6) 07/29/91 -2.1 ± 5.7 (20) -2.1 ± 2.1 (9.9) 08/26/91 -11 ± 6.5 (30) 0 ± 5.3 (17) 09/30/91 1.9 ± 3.3 (8.9) 0 ± 2.7 (8.9) Continued 169 ------- Tabte B-2. Continued Composite Sampling Location Collection Datett Con centration ± is (MDC) Pu x 10.18 pCL’mL x °Pu 10.18 pCi/mL 10/28/91 0 ± 3.9 (13) -2.0 ± 2.0 (9.2) 11/24/91 1.7 ± 2.9 (7.7) -1.7 ± 1.7 (7.7) 12/30/91 -3.8 ± 4.6 (17) 2.5 ± 3.1 (8.4) New Mexico (Albuquerque & Carlsbad) 03/22/91 -8.4 ± 6.3 (26) 0 ± 3.9 (13) 06/28/91 35 ± 22 (41) -27 ± 15 (71) 09/03(91 -3.2 ± 7.2 (26) -3.2 ± 3.2 (15) 10/30(91 -4.2 ± 4.2 (19) 0 ± 5.9 (19) North Dakota (Bismarck & Fargo) 03/12/91 5.9 ± 13 (39) 12 ± 12 (28) 06/27/91 0 ± 7.7 (26) 7.8 ± 7.8 (18) 09/22/91 -3.5 ± 3.5 (16) -3.5 ± 3.5 (16) 10/31/91 -15 ± 10 (40) 3.0 ± 6.8 (20) Oregon (Bums & Medtord) 02/11/91 -12 ± 8.4 (39) 0 ± 8.4 (28) 09/16/91 -3.8 ± 2.7 (12) 0 ± 2.7 (8.8) 10/16/91 33 ± 25 (52) 11 ± 19 (52) Texas (Austin & Amarillo) 03/15/91 -3.2 ± 5.5 (21) -3.2 ± 3.2 (15) 06/28/91 10 ± 17 (47) 0 ± 14 (47) 09/07/91 -6.0 ± 4.3 (20) -3.0 ± 3 (14) 10/18191 -14 ± 10 (40) -7.0 ± 5.0 (23) Utah (Logan & Vernal) 03/11/91 -15 ± 12 (48) -5.1 ± 5.2 (24) 06(27/91 *21 ± 11 (19) -8.3 ± 8.3 (34) 09/09/91 -22 ± 26 (96) 0 ± 10 (34) 10/24/91 -14 ± 9.8 (45) -6.9 ± 6.9 (32) Salt Lake City, Utah 01128191 3.7 ± 5.2 (15) 0 ± 2.6 (8.6) 02/25/91 -1.1 ± 2.8 (9.9) 0 ± 1.5 (5) 03/25/91 -2 ± 2 (9.1) 0 ± 2.8 (9.1) 04/29/91 0 ± 2.5 (8.1) 0 ± 2.5 (8.1) 05/31/91 2.9 ± 5 (13) -5.7 ± 5.8 (23) 06/28191 0 ± 4.1 (14) 2.1 ± 3.6 (9.6) 07/26/91 -13 ± 8.4 (33) 2.5 ± 4.4 (12) 08/30(91 8.4 ± 7.5 (18) 0 ± 4.0 (13) 09/27/91 -13 ± 6.6 (31) 3.3 ± 5.7 (15) 10/25/91 -5.2 ± 5.2 (20) -1.7 ± 3.0 (11) Continued 170 ------- Table B-2. Continued Composite Sampling Location Collectkn Date Concentra tion ± is (MDC) x 238 Pu 1018 CVmL x 2 Pu 1018 tCVmL 11/29/91 12/27/91 -6.6 -2.2 ± 4.7 (22) ± 2.2 (10) 0 -2.2 ± 4.7 (15) ± 2.2 (10) Washington (Seattle & Spokane) 03/22/91 06/29/91 08/26191 11/15/91 -5.5 70 0 0 ± 9.5 (36) ± 44 (82) ± 6.8 (22) ± 6.7 (22) -5.5 0 3.4 0 ± 5.5 (26) ± 41 (142) ± 5.9 (16) ± 6.7 (22) Wyoming (Worland & Rock Springs) 03/30/91 05/13/91 09/14/91 10/31/91 8.7 8.1 -5.0 -5.4 ± 20 (57) ± 18 (53) ± 6.1 (23) ± 9.3 (35) 8.7 8.1 0 -5.4 ± 15 (41) ± 14 (38) ± 3.5 (12) ± 5.4 (25) MDC = minimum detectable concentration. Collection date of the last (most recent) sample included in the composite. * Concentration is greater than the MDC. 171 ------- Seattle, WA • Midland, TX S Eureka, NV Nampa, ID Mesquite, NV• Carlsbad, NM - S Needles, CA - Bryce Canyon, UT• • Santa Rosa, CA - Pocatello, ID - Burns, OR• S Afturas, CA - Lone Pine, CA - Rapid City, SD - Great Falls, MT • Lund, NV - Logan, UT • Little Rock, AR• S Geyser Ranch, NV• Chico, CA• S Worland, WY • Mountain Home, ID Parowan, UT Joplin, M0 S Round Mountain, NV 0.000 0.007 0.014 0.021 0.028 0.035 Beta in Air (1.OE-12 )iCiIml) Figure B-i. Distribution of gross beta values from standby air suivei!lance network stations - 1991. 172 ------- Spokane, WA - • Yuma, AZ- Uhalde Ranch, NV• Clayton, MO• Albuquerque, NM Muskogee, OK • Dodge City, KS Rock Springs, WY - Globe, AZ - Kalispell, MT - Tyler, TX- St. Joseph, MO• • Currie, NV Amarillo, TX• Clark Station, NV • Wendover, UT Phillips 66, Elko, NV - • Kingman, AZ - Duckwater, NV - Bismarck, ND - Austin, TX- Enterprise, UT- • Medford, OR• Shiprock, NM S Miles City, MT I I I —- 0.000 0.007 0.014 0.021 0.028 0.035 Beta in Air (1.OE-12 jCiIml) Figure B-i. Continued. 173 ------- Fargo, ND• Wells, NV• • Reno, NV• Monroe, LA Vernal, UT Lovelock, NV• Cortez, CO Minneapolis, MN North Platte, NE Garrison, UT• Blue Jay, NV• Fort Dodge, IA Angle Worm Ranch, NV Winslow, AZ Ridgecrest, CA Iowa City, IA Winnemucca, NV • Denver, CO Tuscon, AZ Williston, ND - Battle Mountain, NV - Indio, CA - Fallon, NV - S Bishop, CA - Baker, CA - Grand Junction, CO - 0.000 0.007 0.014 0.021 0.028 0.035 Beta in Air (1 .OE-12 pCVmI) Figure 6-1. Continued. 174 ------- Appendix C Table C-i: Milk Surveillance Network results, 1991 Table C-2: Standby Milk Surveillance Network results, 1991 Table C-3: Sampling location and collection date for Standby Milk Surveillance Network samples receMng gamma spectroscopy analysis only. Table C-4: Radionuclide Results for Mule Deer Table C-5: Radionuclide Results for Cattle Figure C-i: Time series of strontium results for Milk Surveillance Network stations. Figure C-2: Time series of tritium results for Milk Surveillance Network stations. Figure C-3: Time series of strontium results for Standby Milk Surveillance Network stations, midwestern region. Figure C-4: Time series of strontium results for Standby Milk Surveillance Network stations, mountain region. Figure C-5: Time series of strontium results for Standby Milk Surveillance Network stations, western region. Figure C-6: Time series of tritium results for Standby Milk Surveillance Network stations, mid-western region. Figure C-7: Time series of tritium results for Standby Milk Surveillance Network stations, mountain region. Figure C-8: Time series of tritium results for Standby Milk Surveillance Network stations, western region. Note: The mid-west region referred to in Figures C-3 and C-6 indudes Louisiana, Texas, Arkansas, Illinois, Oklahoma, Missouri, Kansas, Iowa, Nebraska, Minnesota, and South and North Dakota. The mountain region referred to in Figures C-4 and C-i includes New Mexico, Arizona, Colorado, Utah, Wyoming, Idaho, and Montana. The western region referred to in Figures C-5 and C-B includes California, Nevada, Washington and Oregon. 175 ------- Table C-i. Milk Surveillance Network Results, 1991 113 ± 94 (306) -31 ±108 (356) Dud ter, NV Bradshaw’s Ranch 11/20 114 ± 109 (355) 0.13 ± 0.84 (1.1) 0.66 ± 0.38 (1.4) COHGCtiOU Concentration ± is (MDC) ‘H Sr 90 Sr San lr g Location Date (10 CiImL) (10 4 j.tCUmL) (1O 4 iCi/mL) Benton, CA Irene Brown Ranch 01t03 04/24 07/10 1Q24 188 44 180 88 ± 116 ± 90 ± 95 ± 111 (379) (297) (308) (363) N/A N/A 0.050 ± N/A 0.85 (1.2) 2.4 ± 0.59 ± 0.16 ± 0.25 ± 0.94 0.35 0.34 0.33 (2.6) (1.4) (1.4) (1.4) Hirddey, CA Desert View Deny 01)03 04/24 07/10 1W23 170 86 0 178 ± 114 ± 92 ± 93 ± 110 (372) (301) (306) (358) N/A N/A N/A N/A 0.76 ± 0.39 ± -0.62 ± 0.11 ± 0.49 0.33 0.32 0.32 (1.6) (1.4) (1.4) (1.4) Inyokem, CA Cedarsage Farm O1R)3 04/24 07/10 1Q23 81 197 207 173 ± 113 ± 94 ± 94 ± 114 (370) (304) (303) (372) N/A N/A N/A N/A 0.32 ± 0.19 ± 0.081 ± -0.080 ± 0.42 0.33 0.34 0.32 (1.5) (1.4) (1.4) (1.4) Alano, NV Cortney DaI d Ranch 02)06 08)06 11)01 183 152 352 ± 116 ± 119 ± 116 (379) (389) (372) N/A N/A N/A -0.57 ± -0.14 ± 0.29 ± 0.35 0.52 0.34 (1.4) (1.9) (1.5) Amargosa Valley, NV Bar-B-Cue Ranch 0&05 11/15 190 213 ± 117 ± 111 (383) (360) N/A -0.78 ± 0.95 (1.5) 0.067 ± 0.37 ± 0.39 0.39 (1.6) (1.6) Amargosa Valley, NV John Deer Ranch 03)06 06/13 09 (12 236 -40 120 ± 113 ± 90 ± 111 (367) (299) (364) 0.15 ± N/A N /A 2.50 (3.3) 0.77 ± 0.88 ± 0.26 ± 0.72 0.42 0.30 (2.4) (1.6) (1.3) Auatin, NV Young’s Ranch Blue Jay, NV Blue Jay SprIngs Jim Bias Ranch 06)05 09/17 12/10 05(15 06)05 09)04 8.5 113 230 153 177 -20 ± 90 ± 108 ± 84 ± 94 ± 93 ± 111 (298) (352) (270) (306) (300) (367) N/A N/A 0.066 ± N/A N/A N/A 0.60 (0.9) 0.61 ± 0.16 ± 0.63 ± 0.18 ± 0.58 ± 0.64 ± 0.32 0.32 0.34 0.34 0.35 0.32 (1.3) (1.3) (1.4) (1.4) (1.4) (1.3) Ca ente, NV kine Cox Ranch 02)07 05)01 O&V7 11)01 217 100 208 409 ± 120 ± 93 ± 121 ± 115 (390) (306) (392) (368) N/A N/A N/A N/A 0.27 ± -0.77 ± 0.42 ± 0.22 ± 0.36 0.96 0.31 0.40 (1.5) (3.2) (1.3) (1.6) Currant, NV Blue Ea e Ranch 06)05 09/18 N/A N/A 0.51 ± 0.78 ± 0.39 0.31 (1.4) (1.3) Currant, NV Mananie Ranch 06/12 09)09 12/10 154 103 143 ± 87 ± 112 ± 83 (282) (366) (270) 0.92 ± N/A N/A 0.86 (1.2) 0.86 ± 1.2 ± 1.1 ± 0.36 0.36 0.36 (1.3) (1.3) (1.3) Dyer, NV 03/13 21 ± 113 (371) 0.66 ± 1.03 (1.4) 0.55 ± 0.38 (1.4) Ozel Lemon 06)04 09/10 219 201 ± ± 97 110 (314) (356) N/A N/A 0.52 0.19 ± ± 0.31 0.34 (1.3) (1.4) Continued 176 ------- Table C-i. Continued MDC = minimum detectable concentration. Multiply tCi/mL by 3.7 x iO to obtain Bq/L NJA = Sample not analyzed. = Concentration is greater than the 0.85 ± 1.20 (1.6) 0.74 ± 0.41 N/A 1.1 ± 0.38 Collection Concentration ± is (MDC) 3 H Sr 90 Sr Sampling Location Date (10 4 Ci/mL) (1 0 4 l.tCVmL) (1 CY° iCVmL) Logar,dale, NV 02 ,04 241 ± 112 (363) N/A 0.072 ± 0.51 (1.8) Leonard Marshall 05/01 -88 ± 89 (295) N/A -0.31 ± 0.42 (1.6) 08/01 192 ± 92 (299) N/A 0.091 ± 0.37 (1.5) 11,01 301 ± 113 (365) N/A 0.54 ± 0.35 (1.4) Lund, NV 02 / 06 205 ± 115 (372) N/A 0.29 ± 0.43 (1.5) Ronald Horstey Ranch 05/07 08 106 11,01 179 -6 233 ± 94 ± 95 ± 112 (306) (314) (363) N/A N/A N/A 0.047 0.37 0.65 ± ± ± 0.60 0.33 0.37 (2.2) (1.3) (1.5) Mesquite, NV 01,04 62 ± 115 (376) N/A 1.2 ± 0.56 (1.9) Hafen Dairy 04/05 07,01 10,01 120 256 80 ± 115 ± 94 ± 114 (377) (302) (374) -0.054 -0.035 ± ± N/A 0.60 0.87 (0.98) 0.23 (1.3) 0.30 0.66 ± ± ± 0.32 0.32 0.37 (1.4) (1.4) (1.4) Moapa, NV 01/04 323 ± 119 (384) N/A 1.3 ± 0.99 (3) Rockview Daines,lnc 04/05 07/01 10/01 -37 -28 153 ± 113 ± 92 ± 111 (374) (303) (362) -0.33 0.21 ± ± N/A 0.77 0.89 (1.2) 0.87 (1.3) 0.46 0.11 ± ± ± 0.40 0.33 0.34 (1.5) (1.4) (1.5) Nyala, NV 03/05 103 ± 116 (379) (1.5) Sharp’s Ranch 06 / 04 09/10 12/03 -4.3 294 199 ± 91 ± 115 ± 85 (301) (371) (275) -0.14 N/A ± 0.68 0.38 (0.97) 0.79 ± ± 0.34 0.34 (1.4) (1.4) (1.3) Pahrump, NV 01/02 182 ± 114 (371) N/A 0.71 ± 0.39 (1.4) Pahrump Dairy 04/23 07,09 10/21 70 36 93 ± 91 ± 89 ± 106 (299) (293) (347) N/A N/A N/A 0.31 0.44 0.59 ± ± ± 0.41 0.31 0.37 (1.5) (1.4) (1.5) Shoshone, NV 02/06 246 ± 117 (379) N/A 1.1 ± 0.55 (1.6) Harbecke Ranch 05/01 08/06 11/01 77 297 475 ± 94 ± 95 ± 112 (308) (305) (358) N/A N/A N/A 1.2 *2.6 2.0 ± ± ± 0.51 0.43 0.48 (1.6) (1.3) (1.5) Tonopah, NV 10/24 340 ± 126 (406) N/A •2.5 ± 0.43 (1.3) Karen Harper Ranch 12/10 241 ± 86 (277) 0.62 ± 0.71 (0.65) .1.6 ± 0.40 (1.3) Cedar City, UT Brent Jones Dairy 01/03 04/05 07/01 10 / 02 144 97 46 165 ± 117 ± 112 ± 93 ± 114 (381) (367) (305) (372) 0.19 N/A ± N/A N/A 0.73 1.0 (1.0) 0.72 0.71 0.56 ± ± ± ± 0.47 0.37 0.35 0.32 (1.7) (1.4) (1.4) (1.3) Ivins, UT 01/03 237 ± 112 (364) N/A 0.24 ± 0.48 (1.6) David Hafen Ranch 04/05 07/01 10,02 344 -40 239 ± 131 ± 91 ± 113 (422) (299) (366) 0.69 *2.0 ± ± N/A 0.63 1.0 (0.97) 0.20 ± (1.4) -0.23 ± -0.056 ± 0.33 0.36 0.31 (1.4) (1.4) (1.4) 177 ------- Table C-2. Standby Milk Surveillance Network Results, 1991 Concentration ± is (MDC)” Collection Sr °°Sr Sampling Location Date (10°i.LCLImL) (10 4 #iCi/mL) (i0 4 j . CiImL) Taylor, AZ Sunrise Deny 07/17 228 ± 114 (369) 0.69 ± 0.81 (1.2) 0.049 ± 0.37 (1.5) Tucson, AZ Univ Of Ari na 07/25 232 ± 115 (375) -0.42 ± 0.68 (1.1) 0.33 ± 0.30 (1.3) Little Roclç AR Borden’s 06/04 62 ± 92 (302) N/A 2.3 ± 0.42 (1.4) Russelville, AR Arkansas Tech Univ 06125 72 ± 91 (299) N/A 2.0 ± 0.43 (1.3) Bakersfield, CA Favorite Foods, Inc 07/15 179 ± 89 (289) 0.21 ± 0.69 (1.2) -0.21 ± 0.31 (1.4) Ortand, CA Meadow Glen Cheese 08/21 124 ± 115 (377) N /A -0.011 ± 0.31 (1.3) Redding, CA Mccall’s Dairy Prod 08112 67 ± 113 (371) N/A 0.53 ± 0.33 (1.3) W ows, CA Glenn Milk Prodocers 08/21 227 ± 113 (367) N/A 1.1 ± 0.33 (1.3) Deft CO Meadow Gold Dairy 08/07 131 ± 119 (389) N/A 0.089 ± 0.34 (1.4) Denver, CO Safeway Dairy Rant 0 20 293 ± 96 (307) N/A 0.22 ± 0.38 (1.4) Qtincy. IL Prairie Farms Dairy 06/05 94 ± 96 (316) 0.42 ± 1.0 (1.3) 1.4 ± 0.39 (1.3) Boise, ID MeadowGo ldDaiñes 08/05 134 ± 116 (377) 0.081 ± 0.79 (1.1) 0.78 ± 0.38 (1.4) ldtho Falls, ID Reed’s Dairy 08/29 130 ± 109 (357) N/A 1.1 ± 0.34 (1.3) Dubuque, L’. Swiss Valley Farms 06/05 19 ± 92 (303) 2.67 ± 1.2 (1.3) 1.34 ± 0.43 (1.3) Ellis, KS Mid-America Dairymen 06/05 2.8 ± 92 (303) 0.063 ± 1.1 (1.3) 1.3 ± 0.38 (1.3) Sabetha, KS Mid-America Dairymen 06/11 228 ± 94 (306) N/A 1.8 ± 0.41 (1.4) Baton Rouge, LA Borden’s 08/19 209 ± 114 (371) N/A 3.1 ± 0.48 (1.3) Monroe, LA Borden’s Dairy 09/17 101 ± 109 (357) N/A 1.7 ± 0.42 (1.5) Continued 178 ------- Table C-2. Continued Concentration ± is (MDC) Collection Ii Sr 90 Sr Sampling Location Date (1 0 4 .tCVmL) (1 0 CVmL) ’ (1 0 9 .tCVmL) New Orleans, LA Brown’s Velvet Dry 12/11 190 ± B6 (277) N/A 1.3 ± 0.40 (1.4) Fosston, MN Land 0’ Lakes Inc 06/19 234 ± 97 (313) N/A *2.7 ± 0.51 (1.3) Rochester. MN Assoc Milk Prod Inc 06/06 174 ± 94 (306) 0.56 ± 1.1 (1.3) 1.1 ± 0.38 (1.3) Aurora, MO Mid-Amenca Dairy Inc 07/31 200 ± 117 (381) *1.14 ± 0.97 (1.1) 2.3 ± 0.46 (t4) Chillicotha, MO Mid-America Dairymen 06/20 113 ± 95 (310) N /A •2.4 ± 0.44 (1.3) Bilkngs, MT Meadow Gold Dairy 11/15 404 ± 114 (366) -1.6 ± 0.95 (1.1) 2.6 ± 0.39 (1.3) Great Falls, MT Meadow Gold Dairy 06/26 149 ± 110 (357) N/A 1.1 ± 0.37 (1.3) Norfollç NE Gillette Dairy 06/17 60 ± 92 (302) N/A *1.5 ± 0.43 (1.4) North Platte, NE Mid-America Dairymen 06/27 147 ± 95 (308) N/A 0.94 ± 0.42 (1.3) Albuqerque, NM Borden’s Valley Gold 08X)8 211 ± 112 (365) 0.35 ± 0.74 (0.97) 0.64 ± 0.37 (1.4) La Plata, NM River Edge Dairy 08/16 345 ± 116 (372) N/A 0.55 ± 0.33 (1.4) Bismarck, ND Biidgeman Creamery 07/31 42 ± 111 (364) 0.13 ± 0.95 (1.1) 2.3 ± 0.44 (1.4) Grand Forks, ND Minnesota Dairy 08/14 89 ± 112 (367) N/A 0.33 ± 0.37 (1.4) Enid, OK AMPI Goldspot Div 06/12 167 ± 96 (314) N/A 2.0 ± 0.43 (1.4) McAlester, OK Jackie Brannon Corp 06/20 151 ± 97 (317) N/A *1.5 ± 0.43 (1.3) Medford, OR Dairygold Famis 08A)7 165 ± 111 (361) 0.36 ± 0.73 (1.0) 0.36 ± 0.36 (1.4) Salem, OR Curly’s Dairy 08/20 204 ± 118 (384) N/A 0.95 ± 0.33 (1.3) Tillamook, OR Tillamook Creamery 06/19 165 ± lii (361) N/A 1.1 ± 0.36 (1.3) Continued 179 ------- Table C-2. Continued Co ncentration ± is (MDC) Collection 3 H San ling Location Date (i0 4 &tCiImL) Sr (10 iCWmL) 90 Sr (10 CiImL) Rapid City, SD Gillette Dairy 0&V8 269 ± 115 (371) N/A 1.3 ± 0.39 (1.4) Sioux Fails, SD Lakeside Dairy 12/31 116 ± 88 (288) N/A 0.92 ± 0.39 (1.4) Glen Rose, TX Daftan Family Dairy 06/13 -4.5 ± 92 (304) N/A 1.0 ± 0.36 (1.4) Sulphur Springs, TX Tommy Potts Dairy 08R)5 109 ± 113 (370) 1.2 ± 1.0 (1.0) 2.8 ± 0.51 (1.4) Wu dthorsI TX Uoyd Wolf Dairy OM)7 23 ± 90 (296) N/A 0.91 ± 0.33 (1.3) Beaver, UT Cache Valley Dairy 05/22 96 ± 96 (314) N/A 1.2 ± 0.36 (1.4) Provo, UT BYU Dairy Proó.icts 05/20 144 ± 94 (306) N/A 0.80 ± 0.35 (1.3) Seattle, WA Darigold Inc 09/16 60 ± 109 (356) N/A 0.24 ± 0.35 (1.4) Spokane, WA Darigold Inc 11/12 223 ± 112 (363) N/A 1.7 ± 0.39 (1.3) Cheyeme, WY Daily Gold Foods 06/11 110 ± 91 (297) N/A 1.4 ± 0.38 (1.4) Sheridan, WI Mycland Daijy 05/10 292 ± 97 (313) N/A 1.2 ± 0.35 (1.3) MDC = mininum detectable concentration. Muftply iCWmLby3.7x10 7 toobtainBq/L N /A = Sample not analyzed. = Concentration is greater than the MDC. 180 ------- Table C-3. Sampling Location and Collection Date for Standby Milk Surveillance Network Samples ReceMng Gamma Spectroscopy Analysis Only. Collection Collection Sampling Location Date Sampling Location Date Duncan, AZ Ruston, LA Lunt Dairy 07/24 LA Tech Univ Dairy 09/19 Tempe, AZ Shreveport, LA United Dairymen of AZ 07/24 Foremost Dairy 12/18 Batesviile, AR Fergus Falls, MN Hilts Valley Foods 06125 Mid-America Dairymen 06125 Fayetteville, AR Browerville, MN University of Arkansas 06/20 Land 0’ Lakes, Inc. 06117 Helendale, CA Nicollet, MN Osterkamp Dairy No. 2 07/16 Doug Schultz Farm 06127 Chino, CA Jackson, MO CA Inst. for Men 07/23 Mid-America Dairymen Inc 06/06 Fembridge, CA Jefferson City, MO Humboldt Creamery Assn 07/19 Central Dairy Co 06/11 Fresno, CA Bozeman, MT CA State Univ Creamery 07/15 Country Classic-DBA-Dang 09/11 Hottville, CA Kalispell, MT Schaftner & Son Dairy 07/23 Equity Supply Co 09/11 Manteca, CA Omaha, NE A & J Foods, Inc 07/23 Roberts Dairy 06/19 Modesto, CA Marshall Green 07/31 Foster Farms, Jersey Dairy 07/22 Chappell, NE Petaluma, CA Leprino Foods 11/20 Point Reyes Seashore Dairy 07117 Superior, NE San Jose, CA Mid-America Dairymen 06/11 Marquez Bros Mexican Cheese 07/17 Logandale, NV San Luis Obispo, CA Nevada Dairy 09/17 Cal Poly Univ Dairy 07/19 Reno, NV Saugus, CA Model Dairy 07I10 Wayside Honor Ranch 07/26 Yerington, NV Cresent City, CA Valley Dairy 07/24 Rumiano Cheese Co 07/17 Fargo, ND Soledad, CA Case Clay Creamery 07/30 Correction Training Nds. 07/12 Minot, ND Tracy, CA Bridgemen Creamery 08/15 Deuel Voc Inst 07/10 Claremore, OK Manchester, CA Swan Bros Dairy 07/10 Point Arema Dairies 07/17 Stillwater, OK Colorado Springs, CO OK State Univ Dairy 06/05 Sinton Dairy CO 05/13 Grants Pass, OR Greeley, CO Valley Ot Rouge Dairy 12/03 Meadow Gold Dairy 05/28 Junction City, OR Lockmead Farms Inc 09/16 Continued 181 ------- Table C-3. Continued Sampling Location Collection Date Sampling Location Collection Date Ft Collins, CO Poudre Valley Creamery 05/22 Klamath Falls, OR Caidwell, ID Klamath Dairy Product 08/08 Dairymens Creamery 08/08 North Powder, OR Association Elmer Hill Dairy 08/05 Pocatello, ID Myrtle Point, OR Rowland’s Meadowgokl 08/19 Safeway Stores Inc 08/05 Dairy Portland, OR Twin Falls, ID Dangold Farms 12/24 Triangle Young’s Dairy 08/30 Redmond, OR Kimballion, IA Assoc. Milk Pro. lnc(AMPI) 06/05 Eberhaid’s Creamery Inc Ethan, SD 08/27 Lake Mills, IA Ethan Dairy Products 11/04 Lake Mills Co-op Creamery 06/24 Volga, SD Lemars, IA Land O’Lakes Inc 08/08 Wells Dairy 06/12 Canyon, TX Manhattan, KS West Texas State Dairy 06/17 Kansas State University 06/17 Corpus Christi, TX Lafayette, LA Peoples Baptist Churth 06/05 Borden’s 08/20 Fabens, TX New Orleans, LA Island Dairy-El Paso Ct 06/07 Walker Roamer Dairy 12/11 Richfield, UT Riverton, WY Ideal Dairy 05/22 Western Dairymen’s Co-op 05/10 Smithfield, UT Thayne, WY Cache Valley Dairy 05/28 Western Dairymen’s Co-op 05/13 Moses Lake, WA Safeway Stores Inc 11/12 182 ------- Continued Table C-4. Radionuc ljde resufts for Mule Deer Animal Tissue % Ash Radionuclide Mule blood 3 H Deer #la lung 1.0 Pu 2 °Pu Result ± is (MDC) Units liver 1.4 muscle 1.1 238 Pu 23 °Pu 238 Pu bone 30 238 Pu 23 °Pu Sr 21 238 Pu 23 °Pu rumen content blood lung Mule Deer #2 0.9 3 H 238 Pu 23 °Pu liver 0.9 *42E+5 ± 1.1 E+3 (5.6E+2) pCi/L *1 .7E-3 *1 .7E-2 ± ± 9.OE-4 2.6E-3 (1 .6E-3) (1 .6E-3) pCi/g ash 1.3E-2 *1 .2E+0 ± ± 7.OE-3 9.5E-2 (1.7E-2) (7.OE-3) pCilg ash 2.4E-3 *8 0E3 ± ± 2.7E-3 2.8E-3 (7.4E-3) (3.7E-3) pCi/g ash 2.1E-3 *59E3 *88E1 ± ± ± 1.3E-3 1.8E-3 1.7E-1 (2.8E-3) (2.8E-3) (3.9E-1) pCilg ash *69E..3 *57E2 ± ± 1 .6E-3 4.7E-3 (1 .5E-3) (1 .5E-3) pCilg ash •2.BE+1 ± 1 .4E+2 (4.6E+2) pCi/ I.. *loE..2 *35E1 ± ± 2.2E-3 1 .7E-2 (2.OE-3) (2.OE-3) pCilg ash 1.BE-2 *80E1 ± ± 1.1E-2 7.5E-2 (2.3E-2) (2.3E-2) pCi/g ash *6oE..3 *17E1 ± ± 1 .7E-3 1.1E-2 (1 .9E-3) (1.9E-3) pCi/g ash 9.2E-4 -1 .8E-7 t 4.8E-1 ± ± ± 2.1E-3 1 .9E-3 5.5E-2 (6.OE-3) (6.OE-3) (1 .3E-1) pCVg ash 2.OE-3 *88E2 ± ± 1.4E-3 6.5E-3 (3.8E-3) (1 .6E-3) pCilg ash *1 .OE+3 ± 1 .5E+2 (4.6E+2) -1 .7E-2 4.3E-3 ± ± 1 .4E-2 7.5E-3 (5.3E-2) (2.OE-2) -1.1E-3 3.2E-3 ± ± 1.1E-3 2.4E-3 (4.9E-3) (4.9E-3) 7.3E-4 2.2E-3 ± ± 1 .3E-3 1.7E-3 (3.4E-3) (3.4E-3) muscle 1.0 bone 34 90 Sr rumen 1.7 content blood lung Mule Deer #3 1.0 238 Pu °Pu muscle 1.0 238 Pu 23 °Pu liver 1.3 Pu 23 °Pu pCi/L pCiIg ash pCi/g ash pCi/g ash 183 ------- wmen content a Contaminated animal. Resuft is greater than MDC. Table C-4. Continued. Animal Tissue % Ash Radionuclide Result ± is (MDC) Units bone 31 Pu 3 ’°Pu 90 Sr -1 .4E-7 7.1E-4 5.2E-1 ± ± ± 1 .4E-3 1.3E-3 4.7E-1 (4.7E-3) (3.3E-3) (1 .5E+0) pCi/g ash rumen content 1.7 Pu °Pu 3.1 E-3 *1 .7E-2 ± ± 2.4E-3 4.6E-3 (4.9E-3) (4.9E-3) pCi/g ash Mule Deer #4 blood lung 1.0 3 H Pu 2 °Pu 1 .3E+1 8.3E-4 -8.3E-4 ± ± ± 1 .4E+2 2.5E-3 8.5E-4 (4.6E+2) (7.8E-3) (3.9E-3) pCi/L pCilg ash muscle 1.0 Pu °Pu 1.4E-3 -6.7E-4 ± ± 1.9E-3 7.OE-4 (5.4E-3) (3.1 E-3) pCu/g ash liver 1.3 Pu 3 ’°Pu 2.3E-3 2.3E-3 ± ± 2.6E-3 1 .8E-3 (7.3E-3) (3.6E-3) pCi/g ash bone 35 Pu 238 Pu Sr -6.9E-4 6.9E-4 9.5E-1 ± ± ± 1 .6E-3 1 .2E-3 4.2E-1 (5.6E-3) (3.2E-3) (1.4E+0) pCu/g ash 6.1 Pu 3 °Pu 1.2E-2 *1.1E 1 ± ± 2.2E-3 7.OE-3 (2.3E-3) (1.7E-3) pCi/g ash 184 ------- Table C-5. Radionuclide results for Cattle Animal Tissue % Ash Radionuclide Result ± is (MDC) Units Bovine #1 blood liver 1.3 3 H 238 Pu 2 °Pu 1 .2E+2 9.4E-4 *31 E-2 ± ± ± 1.1 E÷2 1 .1E-3 3.4E-3 (3.6E+2) (2.9E-3) (1 .5E-3) pCi/L pCi/g ash bone 35 238 Pu 3 °Pu 90 Sr -3.1E-3 -3.1 E-7 *9.9E i ± ± ± 4.5E-3 3.2E-3 7 .OE-2 (l.6E-2) (1 .OE-2) (i.3E-1) pCi/g ash Bovine #2 blood liver 1.3 3 H 238 Pu 23 40 Pu 2.2E+2 *59E2 *34E ± ± ± 1.1 E+2 6.5E-3 1 .5E-1 (3.4E+2) (6.2E-3) (2.5E-3) pCiIL pCi/g ash bone 41 238 Pu °Pu 90 Sr 7.3E-4 -7.3E-4 *29E1 ± ± ± 1 .7E-3 i.3E-3 4.3E-2 (4.BE-3) (4.8E-3) (1.2E-1) pCVg ash Bovine #3 blood liver 1.3 3 H 228 Pu 23 °Pu 3.6E+2 2.4E-3 *1 .3E-1 ± ± ± 1 .2E+2 1 .8E-3 1 .2E-2 (3.9E+2) (3.7E-3) (3.7E-3) pCi/L pCi/g ash hock 32 238 Pu 3 °Pu 9 °Sr -5.3E-4 5.3E-4 1.1E-1 ± ± ± 5.5E-4 9.OE-4 5.5E-2 (2.5E-3) (2.5E-3) (1.2E-1) pCiIg ash Bovine #4 blood liver 1.2 3 H Pu °Pu 2.8E+2 -1 .OE-7 -i .OE-7 ± ± ± i.1E÷2 1 .5E-3 i .5E-3 (3.4E+2) (4.8E-3) (4.8E-3) pCi/L pCiIg ash bone 19 Pu 23 °Pu 90 Sr -8.3E-8 -8.3E-8 *38E1 ± ± ± 8.5E-4 8.5E-4 5.5E-2 (2.7E-3) (2.7E-3) (1.4E-i) pCi/g ash Bovine #5 blood liver 1.3 3 H Pu °Pu 2.4E+2 3.6E-3 *20E2 ± ± ± 1 .2E+2 2.5E-3 4.5E-3 (3.7E+2) (5.8E-3) (4.1E-3) pCi/ I pCi/g ash bone 45 Pu °Pu 90 Sr -i.iE-3 -5.4E-4 i .3E+O ± ± ± i.9E-3 5.5E-4 4.8E-1 (6.7E-3) (2.5E-3) (1 .6E+O) pCVg ash Continued 165 ------- Table C-S. Continued. Animal Tissue % Ash Radionuclide Result ± is (MDC) Units Bovine #6 blood liver 1.4 3 H Pu 2 °Pu 1 .6E+2 2.4E-3 *1 .5E-2 ± 1.1 E+2 ± 4.3E-3 ± 7.OE-3 (3.6E+2) (1.1 E-2) (1.1 E-2) pCi/L pCi/g ash bone 26 Pu ° 2 °Pu Sr -4.OE-4 *5.1 E-3 9.7E-1 ± 4.OE-4 ± 1 .6E-3 ± 3.1 E-1 (1.8E-3) (1 .8E-3) (1 .2E+0) pCi/g ash Bovine #7 blood liver 1.0 3 H Pu ° °Pu 2.5E+2 3.4E-3 *47E2 ± 1 .2E+2 ± 3.2E-3 ± 7.OE-3 (3.8E+2) (9.OE-3) (5.7E-3) pCi/L pCi/g ash bone 26 Pu 2 °Pu 90 Sr 4.8E-4 1 .9E-3 8.OE-1 ± 1.1 E-3 ± 1 .2E-3 ± 4.2E-1 (3.2E-3) (2.2E-3) (1.6E-.-0) pCi/g ash Bovine #8 blood liver 1.4 3 H Pu 240 Pu 2.5E+2 1 .9E-3 *3.9E 2 ± 1.2E+2 ± 1 .9E-3 ± 6.5E-3 (3 .7E+2) (4.3E-3) (6.1 E-3) pCi/L pCi/g ash bone 47 Pu ‘ 3 ’°Pu °°Sr -1 .2E-3 -6.OE-4 4.3E-1 ± 1 .5E-3 ± 6.OE-4 ± 3.6E-1 (5.6E-3) (2.8E-3) (1 .5E+0) pCi/g ash * Result is greater than MDC. 186 ------- Station = Blue Eagle Ranch, Currant, W JAN82 JAN84 JAN86 JAN88 JAN90 Sample Collection Date Station = Brent Jones Daity, Cedar City UT 6 5 IL JAN82 JAN84 JAN86 JAN88 JAN90 JAN92 Sample Collection Date Figure C-i. lime series of strontium results for Milk Surveillance Network stations. 187 X . X 6 5 4 3 2 S I X X 0 0 ) - C E S 1 X S • X S X . . i S —1 XX H . —3 JAN92 X X X X x X XXX ‘S 5 • X *XX XII S S ------- Station=Cedarsage Fam , ir icem, i- 6 5, — x 0 X : x XX xX X x x .... . JAN82 JAN84 JAN86 JAN88 JAN90 JAN92 Sample Collection Date Sta on=Courtney Dahl R ch, Alamo, NV 6 5. X 0) 3• X X x>S< Xx (x X JAN82 JAN84 JAN86 JAN88 JAN90 JAN92 Sample Collection Date Figure C-i. Continued. 188 ------- on=Dav,d Haten Ranch, Mns UT 6 5 Ii + i x xXXX _ +4 4 —2 —3 JAN82 JAN84 JAN86 JAN88 JAN90 JAN92 Sam Ie Colledion Date Station = Desert fi Dairy, Hk ckIe CA 6 5 a a I x X’, -2 T X I x lxx XXX XXX U - i —2 —3 JAN82 JAN84 JAN86 JAN90 JAN92 Samp C on Date Figure C-i. Continued. 189 ------- anon = Helen Dairy, Mesquite, NV 6 5 0 c3 xXIxxx JAN82 JAN84 JAN86 JAN88 JAN92 Sample CoHec ion Date Station=Habecke F nch, Shoshone, NV 6 . 5 .- __ x 4 XXX .x I X I 1.. S EO Ui. —2 —3 JAN82 JAN84 JAN86 JAN88 JAN90 JAN92 Sample Collection Date Figure C-i. Continued. 190 ------- Stat,on= Irene Br n Ranch, Benton, GA 6 5. Cr 3 x x X X)(X )()< JAN82 JAN84 JAN86 JAN88 JAN90 JAN92 Sample COlleCtiOn Date Station =Jun B s Ranch, Blue J , NV 6 5 Cr 3 xxx? 4 x 30 U i —2 3. JAN82 JAN84 JAN86 JAN88 JAN90 JAN92 Sample ColleCtion Date Figure C-i. Continued. 191 ------- Satkr =John Deer Ranch, Miargosa Valley, NV 6 X x C) ) 3 x x x x X x x x . 1 4 I4 . .. I _q. JAN82 JAN84 JAN86 JAN88 JAN90 JAN92 San le C on Deta Station =kine CcE Ranch, Caherle, NV 6 5 _ X S X X 3 X x I X X 2 r x x X • X - X • IX C • S •• S X 1:1? . . . S • E 0 1_ —2 —3.. JAN82 JAN84 JAN88 JAN90 JAN92 S ple C on Da Figu,e C-i. Continued. 192 ------- Station= Leonard Marshall, Logandale, NV 6 x 5. x • xX XX < X)(>< I 4144444444+441 JAN82 JAN54 JAN86 JAN55 JAN90 JAN92 Sample COlleCtiOn Date Stalion = Manzonie Ranch, Currant, NV 6 X 5 X • x X>< c3 o ., X cE. X XX S •XX xJxXXXx ix • • • I .c • > • I •• •• Ui, —2 —3. JAN82 JAN84 JAN86 JAN88 JAN90 JAN92 Sample Collection Date Figure C-i. Continued. 193 ------- Station=Paharnp Dairy Pahiurnp, NV JAN84 JAN86 JAN88 Sample Collection Date Station=Ozel Lemon, Dyei NV x X XX X X X JAN90 JAN92 Figure C-i. Continue’i. Sample Collection Date 0 0) Li 0 C E I 0) C E I 6 5. 4. 3. 2 1• —1 —2 —3, JAN82 6 5 4 3 2 1 0 —1 —2 —3 JAN82 X X X X ‘ x X S X x •S Iif1 I S S JAN84 JAN86 JAN88 JAN90 JAN92 194 ------- Station=Rockv w Denies, Inc., Moapa, NV U 5 X x x 4. 0 x 3 X x I x 2 X X x X xxxTxxx x .xx f .x x • i . •s ç ••. 0 • ... # . -1. —2 . —3 JAN82 JAN84 JAN86 JAN88 JAN90 JAN92 Sample Collection Date Station =Ronalcl Horsley Ranch, Luid, NV 6 5. x O 3 X xxxx xxx xX 1. E 0 C l , —2 —3 JAN82 JAN84 JAN86 JAN88 JAN90 JAN92 Sample COlleCtiOn Date Figure C-i. Continued. 195 ------- Station = Sharp’s Ranch, Nyala, NV 6 5 x X 4 X X X X X X X XXX X 2 ( xx XX)j XXIxx X• ••J 1 x x • • S. • i.... 0 . • —1 , —2 S —3 JAN84 JAN86 JAN88 JAN90 JAN92 1 0’ U i —2 —3 JAN82 Figure C-i. Continued. Sample CoIIec ion Date Station =Yotng’s Ranch, Austin, NV . JAN84 JAN86 JAN88 JAN90 Sample Coilection Date C-) 0) C E I 6 + X 3 X XX X x X 2 X X X S S S 5—, x XX X S. ‘ •.• S • • X’ S I . JAN92 196 ------- Appendix D Table D-1. Trftium in Urine, Ottsite Internal Dosimetry NetWOrk, 1991 Table D-2. Tritium in Urine, Radiological Safety Program, 1991 197 ------- Table D-1. Tritium in Urine, Oftsite Internal Dosimetry Network, 1991 Collection Concentration ± is Sampling Location Date (1 0 pCi/mL) (a) (MDC) Alamo, NV 12111/90 111 ± 64 (209) 12/11/90 99 ± 64 (208) 12/16 190 82 ± 63 (206) 12116190 8 ± 63 (206) 12/16/90 24 ± 62 (205) 12116190 88 ± 63 (206) 12/16190 103 ± 63 (204) Amargosa Farm Area, NV 07/23191 -14 ± 91 (301) Beatly, NV 02/07/91 225 ± 96 (311) 02107/9 1 246 ± 96 (311) 03115/91 -56 ± 90 (298) 03/15/91 175 ± 91 (295) 03119/91 77 ± 92 (302) 03119/91 -50 ± 90 (298) 03128/91 218 ± 91 (294) 03128/91 144 ± 92 (299) 03/28/91 111 ± 91 (296) 03/29/91 28 ± 89 (294) 03/29/91 115 ± 91 (297) 03/29/91 208 ± 93 (302) 03/29/91 168 ± 92 (298) 08/13191 69 ± 76 (249) 08/13/91 26 ± 75 (247) 08113191 -90 ± 75 (248) 12/17/91 60 ± 63 (206) 12/17/91 24 ± 62 (204) 12/23191 39 ± 62 (204) 12/23/91 23 ± 62 (205) 12/23191 26 ± 62 (202) 12/23191 48 ± 62 (204) 12/23/91 20 ± 63 (207) 12/23/91 23 ± 62 (205) Currant, NV Blue Eagle Ranch 02115191 153 ± 96 (313) 02/15/91 -23 ± 94 (311) Ely, NV 06/05/91 136 ± 88 (287) 06/05/91 47 ± 88 (289) 12/12/91 131 ± 64 (206) 1211 2/91 144 ± 64 (206) Continued 198 ------- Table D-1. Continued Collection Concentration ± is Sampling Location Date (i0 pCi/mL) > (MDC) Gokffield, NV 04/10191 95 ± 90 (295) 04/10/91 -69 ± 88 (291) 04/10/91 88 ± 88 (288) Henderson, NV 03/13/91 127 ± 97 (315) 03/13/91 77 ± 96 (316) Indian Springs, NV 06/25/91 -14 ± 90 (297) 06125/91 74 ± 97 (319) 08/28/91 -19 ± 75 (248) 08/28/91 -57 ± 74 (245) 08/28/91 19 ± 76 (250) Nyala, NV 01/11/91 126 ± 103 (337) 01/11/91 -30 ± 103 (339) 01/18/91 55 ± 88 (290) 07/18/91 105 ± 95 (310) 07/13/91 -36 ± 92 (305) 07/18/91 42 ± 92 (302) Overton, NV 01/04/91 161 ± 104 (340) 01/04/91 83 ± 102 (333) 01/04/91 166 ± 103 (335) 01/04/91 187 ± 102 (330) 01/04/91 81 ± 102 (335) 01104191 232 ± 102 (332) 05/08/91 86 ± 88 (286) 05/08/91 *375 ± 97 (311) 05/08/91 134 ± 88 (287) 05/08/91 28 ± 88 (289) 05/08191 152 ± 90 (293) 12/18191 56 ± 63 (207) 12/18/91 -78 ± 62 (205) 12118/91 10 ± 62 (205) 12/18191 114 ± 63 (206) 12/18/91 32 ± 62 (205) Pahrump, NV 03/13/91 166 ± 97 (315) 08/02191 -88 ± 90 (297) 08/02/91 -93 ± 90 (300) 08/02/91 -66 ± 91 (301) 08/02/91 79 ± 92 (300) Pioche, NV 04/05/91 81 ± 91 (289) 04/05/91 4 ± 88 (289) Continued 199 ------- Table D-1. Continued Sampling Location Collection Date Concentration ± is (10 pCi/mL) (MDC) 04/05/91 04/05/91 05/04/91 09/25/91 09/25/91 09/25/91 09/25/91 09/25/91 10/15/91 10/15/91 12 ± 89 -45 ± 87 112 ± 90 109 ± 85 21 ± 84 181 ± 87 121 ± 86 116 ± 85 58 ± 87 164 ± 92 (294) (289) (293) (279) (278) (282) (218) (278) (284) (300) Rachel. NV 04/22/91 04/22/91 04/22/91 04/22/91 04/22/91 09/10/91 78 ± 88 357 ± 91 201 ± 88 289 ± 90 260 ± 89 11 ± 76 (288) (293) (285) (289) (285) (249) Cedar City, UT 12/13191 12/13191 12/13/91 12/13/91 12/13(91 108 ± 63 148 ± 64 79 ± 68 92 ± 64 93 ± 63 (204) (206) (222) (208) (206) Multiply by 0.037 to obtaui Bq/L. * Concentration is greater than the minimum detectable activity (MDC). 200 ------- Table D-2. Tritium in Urine, Radiological Safety Program 1991 Collection Concentration ± is Organi- zation Sampling Location Date (10 pCiImL) (MDC) Ust Riverside, Ca 06/18/91 -12 ± 83 (274) DRI Boulder City, NV 07/03/91 241 ± 84 (272) EPA Beatty, NV 04/19/91 128 ± 90 (294) ARCATA Carson City, NV 07/30/91 58 ± 76 (248) NDEP Hawthorne, NV 12/06 191 30 ± 63 (208) DRI Henderson, NV 06/28/91 -121 ± 81 (270) EPA 07/17/91 152 ± 73 (236) NDEP 09/13/91 119 ± 77 (252) DRI 09/18/91 -26 ± 76 (250) EPA Indian Springs, NV 07/i 1/91 25 ± 80 (263) USGS Las Vegas, NV 01 /09/91 69 ± 90 (294) EPA 01/09/91 227 ± 92 (299) EPA 01 /09/91 36 ± 90 (294) EPA 01 /09/91 71 ± 90 (294) EPA 01/10/91 98 ± 86 (282) EPA 01/10/91 84 ± 87 (286) REECo 01/10191 75 ± 90 (294) EPA 01/10/91 32 ± 90 (296) EPA 01/14/91 84 ± 95 (310) EPA 01/14191 40 ± 92 (301) EPA 01/15/91 -0.98 ± 88 (291) EPA 01/15/91 94 ± 89 (291) EPA 01 /1 6191 3.9 ± 88 (290) EPA 01/16191 177 ± 103 (334) ERC 01/17/91 63 ± 89 (291) EPA 01/17/91 *305 ± 91 (291) EPA 02/04/91 41 ± 94 (308) EPA 02/05/91 287 ± 97 (313) DRI 02/06191 273 ± 96 (309) EPA 02/06/91 285 ± 96 (311) EPA 02/14/91 *359 ± 92 (295) RSN 02/22/91 88 ± 92 (300) EPA 02/27/91 20 ± 90 (297) DRI 02/27/91 112 ± 92 (300) DRI 03127/91 67 ± 90 (296) EPA 04/09/91 138 ± 88 (286) SAIC 04/09/91 18 ± 88 (288) WEC 04/09/91 175 ± 89 (289) SAIC Continued 201 ------- Table D-2. Continued Organi- Collection Concentration ± is zation Sampling Location Date (1 o pCiImL) (MDC) List 04/10/91 59 ± 87 (286) WEC 04/10/91 63 ± 88 (287) SAIC 04/12/91 -4 ± 88 (290) EPA 04/15/91 -14 ± 88 (291) DRI 04/29/91 -46 ± 89 (295) DRI 06/11/91 254 ± 89 (288) EG&G 06/17/91 303 ± 98 (316) DRI 06/17/91 -42 ± 92 (303) DRI 06/17/91 101 ± 93 (304) DRI 06/18/91 *311 ± 94 (301) DRI 07/02/91 -31 ± 84 (276) DRI 07/02/91 -59 ± 84 (278) DAt 07/02/91 208 ± 82 (263) DAt 07/02/91 183 ± 84 (271) DRI 07/03 191 73 ± 81 (266) EPA 07/i 1/91 97 ± 80 (261) USGS 07/i 1/91 148 ± 82 (268) USGS 07/11/91 109 ± 76 (249) USGS 07/16/91 109 ± 81 (263) NDEP 07/16/91 192 ± 83 (267) NDEP 07/17/91 185 ± 80 (260) NDEP 08/07/91 227 ± 93 (301) EG&G 08/07/91 24 ± 91 (299) SAIC 08/08/91 43 ± 74 (244) NSHD 08/16/91 *267 ± 77 (248) DAt 08/19/91 -75 ± 74 (246) DRI 08/19/91 83 ± 75 (246) DRI 08/19/91 200 ± 76 (246) DRI 08/21/91 -12 ± 82 (270) KAFB 08/30/91 -23 ± 75 (248) DRI 09/06/91 55 ± 77 (253) DRI 09/06/91 -102 ± 74 (248) DAt 09/09/91 265 ± 83 (266) DRI 09/09/91 -48 ± 76 (252) DRI 09/23/91 -79 ± 75 (249) DRI 09/27/91 87 ± 88 (289) DAt 10/01/91 143 ± 86 (279) EPA 10/01/91 -65 ± 82 (271) DRI 10/03/91 554 ± 89 (279) EG&G 11/05/91 245 ± 87 (279) EPA 11/08/91 •337 ± 87 (279) DRI 12/05191 21 ± 63 (209) EPA 12/09/91 52 ± 63 (205) DRI 12/09/91 83 ± 63 (206) DRI 12/18/91 11 ± 63 (206) DAt Continued 202 ------- Table D-2. Continued Organi- Collection Concentration ± is zation Sampling Location Date (10° pCi/mL) (a (MDC) List Mercury, NV 08/28f91 -12 ± 77 (253) DRI 09/16 (91 -134 ± 78 (261) DRI NTS, NV Camp Mercury 08/19/91 87 ± 75 (246) NTS Reno, NV 06/25/91 203 ± 85 (274) DRI * Concentration is greater than the minimum detectable concentration (MDC). Mutiply by 0.037 to obtain Bq/L. 203 ------- Appendix E Table 1. Long-Term Hydrological Monitoring Program 1991 Analytical Results for Nevada Test Site Locations Sampled Monthly Table 2. Long-Term Hydrological Monitoring Program 1991 Analytical Results for Nevada Test Site Locations Sampled Semiannually Table 3. Long-Term Hydrological Monitoring Program 1991 Analytical Results for Locations in the Vicinity of the Nevada Test Site Table 4. Long-Term Hydrological Monitoring Program 1991 Analytical Results for Project FAULTLESS Table 5. Long-Term Hydrological Monitoring Program 1991 Analytical Results for Project SHOAL Table 6. Long-Term Hydrological Monitoring Program 1991 Analytical Results for Project RULISON Table 7. Long-Term Hydrological Monitoring Program 1991 Analytical Results for Project RIO BLANCO Table B. Long-Term Hydrological Monitoring Program 1991 Analytical Results for Project GNOME Table 9. Long-Term Hydrological Monitoring Program 1991 Analytical Results for Project GASBUGGY Table 10. Long-Term Hydrological Monitoring Program 1991 Analytical Results for Project DRIBBLE Table 11. Long-Term Hydrological Monitoring Program 1991 Analytical Results for Amchitka Island, Alaska 205 ------- Table E-i. Long-Term Hydrological Monitoring Program 1991 Analytical Results for Nevada Test Site Locations Sampled Monthly Sampling Collection Concentration ± is Tritium MDC Percent of Concentration Location Date (pCi/L) (pCVL) Gukie Remarks Well 1 Army 01/03 0.40 ± 3.26* 10.7 NA 02/05 0.82 ± 2.63* 8.65 NA 03/13 —2.2 ± 3.6* 11.9 NA 04/08 —1.9 ± 33* 11.0 NA 05/08 1.4 ± 2.9* 9.5 NA 06/03 4.3 ± 34* 11.2 NA 07/09 -2.6 ± 1.9* 6.4 NA 08/06 —2.9 ± 1.7* 5.7 NA 09/04 —0.25 ± 2.32* 7.66 NA 10/07 —2.9 ± 1.6* 5.3 NA 11/13 —2.1 ± 1.8* 6.0 NA 12/09 0.94 ± 1.63 5.33 NA Well 2- Well Shut Down Throughout 1991. Last sampled December 1990. We 1 13 01/22 1.7 ± 2.7* 9.0 NA 02113 3.8 ± 3Q* 9.9 NA 03/08 —2.6 ± 39* 12.8 NA 04/03 2.5 ± 3.0* 9.8 NA 05/02 7.6 ± 2.7* 8.7 NA 06/05 —2.1 ± 3.0* 10.0 NA 07/08 —0.37 ± 1.68* 5.53 NA 08114 0.0 ± 1.8* 5.9 NA 09/10 3.3 ± 2.6* 8.4 NA 10/17 0.99 ± 1.67* 5.47 NA 11/21 1.5 ± 1.3* 4.2 NA 12/12 2.2 ± 1.9* 6.2 NA Well 4 01/22 5.8 ± 3•3* 10.6 NA 02/13 4.8 ± 2.9* 9.4 NA 03/08 —2.1 ± 2.9 9.5 NA 04/03 —2.5 ± 2.9* 9.6 NA 05/02 3.4 ± 2.6* 8.5 NA 06/05 —0.45 ± 3.17* 10.5 NA 07/08 Not Sampled - Well Down 08/14 —3.8 ± 1.7* 5.6 NA 09/10 0.0 ± 2.4 7.9 NA 10/17 1.0 ± 2.4* 8.0 NA 11/21 —2.1 ± 1.8* 5.9 NA 12/12 2.5 ± 2.1 6.9 NA Continued 206 ------- Table E-i. Continued Sampling Collection Concentration ± is Tritium MDC Percent of Concentration Location Date (pCi/L) (pCi/L) Guide Remarks Well 4 CP-1 01/03 —1.4 ± 2.8* 9.1 NA 02/05 4.9 ± 2.4* 8.0 NA 03/13 3.9 ± 3.1* 10.4 NA 04/08 3.0 ± 2.4* 8.0 NA 05/08 1.4 ± 2.5* 8.1 NA 06/03 —3.6 ± 2.3* 7.7 NA 07/09 0.56 ± 1.68* 5.51 NA 08/06 —4.6 ± 1.6* 5.5 NA 09/04 —0.88 ± 2.28* 7.54 NA 10/07 —2.5 ± 2.1* 6.9 NA 11/13 —2.0 ± 1.7* 5.7 NA 12/09 —1.1 ± 1.9* 6.1 NA Well 5 01/22 —5.6 ± 2.9* 9.6 NA 02/13 1.0 ± 3.0* 9.7 NA 03/08 —1.3 ± 3.1* 10.4 NA 04/03 —1.8 ± 3.1* 10.2 NA 05/02 4.2 ± 2.9* 9.6 NA 06/05 2.9 ± 2.9* 9.6 NA 07/08 —0.92 ± 1.72* 5.70 NA 08/14 —1.6 ± 1.4* 4.7 NA 09/10 0.81 ± 2.57* 8.46 NA 10/18 4.0 ± 2.7* 8.9 NA 11/21 2.2 ± 1.8* 6.0 NA 12/12 1.8 ± 1.5* 5.0 NA Well 5C 01/03 2.1 ± 3.0* 9.8 NA 02/05 2.6 ± 2.3* 7.5 NA 03/13 2.0 ± 3.2* 10.6 NA 04/08 3.7 ± 2.9* 9.6 NA 05/08 34 ± 2.0* 6.6 NA 06/03 —2.1 ± 2.3* 7.6 NA 07/09 0.58 ± 1.74* 5.70 NA 08/06 0.0 ± 1.6* 5.2 NA 09/04 —1.2 ± 2.0* 6.6 NA 10/07 —0.94 ± 1.56* 5.16 NA 11/13 —2.7 ± 1.5* 5.2 NA 12/09 0.0 ± 1.9* 6.2 NA Well 6 09/10 —1.9 ± 1.7* 5.6 NA (a), New Sampling Location 10/17 —0.68 ± 2.72* 8.98 NA 11/21 1.9 ± 1.6* 5.1 NA 12/12 —2.2 ± 1.8* 6.1 NA Continued 207 ------- Table E-i - Continued Sampling Collection Concentration ± is Tritium MDC Percent of Concentration Location Date (pCWL) (pCi/L) Guide Remarks Well 8 01/03 —0.61 ± 2.46* 8.11 NA 02/05 3.5 ± 2.6* 8.5 NA 03/13 —8.7 ± 35* 11.7 NA 04/08 —2.2 ± 33* 10.8 NA 05/08 —0.73 ± 1 93* 6.37 NA 06/03 3.1 ± 2.3’ 7.5 NA 07/09 2.8 ± 1.8* 5.8 NA 08/06 —2.3 ± 1.4* 4.6 NA 09/03 1.1 ± 2.0* 6.5 NA 10/07 0.0 ± 1.5’ 5.0 NA 11/13 —0.36 ± 2.52’ 8.29 NA 12/09 1.4 ± 2.4* 7.7 NA Well 20 01/03 —0.71 ± 2.29* 755 NA 02/05 0.94 ± 1.90* 6.22 NA 03/13 1.5 ± 2.6’ 8.5 NA 04/08 2.3 ± 2.9* 9.6 NA Well Shut Down Remainder of 1991 Well A - Well Shut Down Throughout 1991. Last Sampled October 1988. Well B Test 01/02 128 ± 4 10 0.6 02/06 106 ± 3 8 0.5 03/13 Not Collected - Punp Locked 04/08 121 ± 3 9 0.6 05/09 120 ± 3 8 0.6 06(04 99 ±3 7 0.5 07/10 110 ± 3 6 0.5 08/07 124 ± 3 6 0.6 09/17 120 ± 3 9 0.0 10/08 Not Sampled - Road Closed 11/12 115 ± 2 5 0.6 12/10 106 ± 3 6 0.5 Well C 01/03 11 ± 3 9 0.1 02/05 20 ±2 8 0.1 03113 34 ± 4 11 0.2 04/08 62 ±3 8 0.3 05/08 47 ± 3 9 0.2 06/03 15 ± 3 9 0.1 07/09 17 ± 3 8 0.1 08/06 15 ± 2 6 0.1 09/03 12 ± 2 7 0.1 10/07 8.7 ± 1.9 6.0 <0.1 11/13 16 ± 2 6 0.1 12/09 19 ± 2 6 0.1 Continued 208 ------- Table E-1. Continued Well J-12 Sampling Collection Concentration ± is Tritium MDC Percent of Concentration Location Date (pCi/L) (pCi/i..) Guide Remarks Well J-13 Well UE19C 01/03 0.20 ± 3.27* 10.8 NA 02/05 —0.08 ± 2.41* 7.94 NA 03/13 —3.1 ± 3•3* 11.0 NA 04/08 2.4 ± 2.8* 9.1 NA 05/08 3.9 ± 35* 11.6 NA 06/03 4.3 ± 3.4k 11.2 NA 07/09 1.9 ± 2.2* 7.1 NA 08/06 0.0 ± 1.7* 5.5 NA 09/04 —1.0 ± 1.8* 5.9 NA 10/07 —2.0 ± 1.6* 5.4 NA 11/13 0.0 ± 1.5* 5.0 NA 12/09 1.3 ± 2.2* 7.2 NA 01/03 3.4 ± 3.0* 9.8 NA 02/05 2.1 ± 33* 10.8 NA 03/13 —1.9 ± 3.1* 10.4 NA 04/08 2.3 ± 3.1* 10.1 NA 05/08 Not Sampled - Well Down 06/03 —2.1 ± 3.0* 9.9 NA 07/09 —0.38 ± 1.72* 5.67 NA 08/06 —3.5 ± 1.6* 5.3 NA 09/04 1.2 ± 2.9* 9.6 NA 10/07 3.4 ± 2.5* 8.1 NA 11/13 0.0 ± 1.4* 4.5 NA 12/09 0.0 ± 1.7* 5.6 NA 01/03 3.5 ± 2.6* 8.6 NA 02/05 2.9 ± 2.8* 9.3 NA 03/13 0.42 ± 2.70* 8.89 NA 04/08 2.8 ± 35* 11.5 NA 05/08 —0.99 ± 2.87* 9.47 NA 06/03 —1.8 ± 2.8* 9.2 NA 07/09 —1.7 ± 1.6* 5.2 NA 08/06 0.0 ± 1 •5* 5.0 NA 09/03 —0.31 ± 2.24* 7.38 NA 10/07 1.7 ± 2.7* 8.8 NA 11/13 1.1 ± 1.9* 6.3 NA 12/09 0.0 ± 1.5* 5.0 NA = Concentration is less than the minimum detectable concentration (MDC). NA = Not applicable. Percent of concentration guide is not applicable either because the tntium result is less than the MDC or because the water is know to be nonpotable. (a) = Adcitional analyses greater than MDC: Analysis Alpha Beta U U U Result 8.7 19 1.6 0.063 0.51 1 sigma 1.8 2 0.2 0.027 0.08 MDC 3.7 5 0.1 0.042 0.08 Urnts pCi/L pCi/L pCiIL pCLIL pCVL 209 ------- Table E-2. Long-Term Hydrological Monitoring Program 1991 Analytical Results for Nevada Test Site Locations Sampled Semiannually Sampling Collection Concentration ± is Tritium MDC Percent of Concentration Location Date (pCi/L) (pC ) Gukie Remarks Well 5B - Well Shut Down, Last Sampled July 1988. Well 6A Army 04/09 Not Sampled - Generator Down 07/il 1.8 ± .7 5.7 NA Hit Bottom at 1062’ Well 7 Test 01/02 Not Sampled - Road Blocked 07/il —109 ± 125* 414 NA Well C-i 04/08 22 ± 4 ii 0.1 10/07 108 ± 94* 309 NA Well D Test 01/02 7.6 ± 2.3 7.4 NA 07/10 0 ± 126* 414 NA Well HTH-i 06/04 0.88 ± 2.23* 7.32 NA 12/16 35 ± 2 6 NA Well U3CN-5 - Well Shut Down Throughout 1991. Last sampled Decenter 1981. Well UE1C 01/02 0.94 ± 2.34* 7.67 NA 07/10 146 ± 126* 414 NA Well UE-4T 02/13 Not Sampled - Road Closed 09/17 423 ± 132* 430 NA Well UE5C 03/13 6.7 ± 3.0* 9.7 NA 09/04 256 ± 132* 430 NA 10/07 —98 ± 93* 309 NA Well UE-60 03113 Not Sampled - Instruments in Hole 09/10 Not Sampled - Insufficient Water Well UE6E 03/13 Not Sampled - No Access 09117 303 ± 132* 430 NA Well UE7NS - Well shut down throughout 1991. Last sampled September 1987. Well UE15D 04/08 76 ± 3 10 0.4 10/07 Not Sampled - Well Down Well UE16D 05/08 31 ± 3 9 0.2 11/13 0.0 ± 1.6* 54 NA Continued 210 ------- Table E-2. Continued Sampling Location Collection Date Concentration ± is Tritium (pCi/L) MDC (pCi/L) Percent of Concentration Guide Remarks Well UE-16F 05/09 11/14 11 ± 3 9.9 ± 1.7 9 5.4 0.1 <0.1 Well UE-17A 05/09 11/14 —4.3 ± 2.7k 2.8 ± 1.6* 9.1 5.1 NA NA Well UEI8R 06/04 12/16 —3.2 ± 2.6* —1.2 ± 2.1* 8.6 6.8 NA NA Well UE-18T 09/17 12/16 156 ± 3 Not Sampled- Road 7 Out 0.8 * = Concentration is less than the minimum detectable concentration (MDC). NA = Not apphcable. Percent of concentration guide is not applicable either because the tritium result is less than the MDC or because the water is know to be nonpotable. 211 ------- Table E-3. Long-Term Hydrological Monitoring Program 1991 Analytical Results for Locations in the Vicinity of the Nevada Test Site Concentration ± is Percent of Sampling Collection Tritium MDC Concentration Location Date (pC ) (pCi/L) Guide Amargosa Valley, NV Well Mary Nickelrs 02/04 0.67 ± 2.40* 7.91 NA 06/11 0.97 ± 2.42* 7.97 NA 08/12 206 ± 131* 430 NA Shoshone, CA Shoshone Spring 02/05 33 ± 3 9 0.2 08/05 314 ± 132* 430 NA Adaven, NV Adaven Spring 01/03 27 ± 4 13 0.1 07/02 0 ± 126* 414 NA 08/06 339 ± 132* 430 NA Alamo, NV City Well 4 01/28 5.0 ± 2.4* 7 9 NA 07/03 109 ± 126* 414 NA Ash Meadows, NV Crystal Pool 05/10 —2.8 ± 2.8* 93 NA 11/19 80 ± 73* 239 NA Fairbanks Springs 05/10 0.39 ± 2.80* 9.23 NA 11/14 0 ± 73* 239 NA Spring-17S-50E-14CAC 06111 -0.91 ± 2.28* 7.54 NA 12/02 218 ± 126* 413 NA Well 188-51 E-7DB 05/10 2.9 ± 2.9* 9.6 NA 11/19 40 ± 73* 239 NA Beatty, NV Specie Springs 01/10 —445 ± 145* 487 NA 07/12 1.8 ± 1.7* 5.5 NA Tolicha Peak 03/06 0 ± 137* 451 NA 08/07 0.90 ± 1.64* 5.36 NA Well 11S-48-1 DD Coffers 01/10 —145 ± 147* 487 NA 07/11 0.93 ± 1.76 5.78 NA Well 12S-47E-7DBD City 07/02 0.98 ± 1.84* 6.04 NA Continued 212 ------- Table E-3. Continued Collection Concentration ± is Tritium MDC Percent of Concentration Date (pCi/L) (pCi/L) Guide Location Beatty, NV (continued) Well Road D Spk ers 02/19 08/07 7.7 0.0 ± ± 3.2* 1.7* Younghans Ranch (House) 06112 12/04 4.2 146 ± ± 2.6* 126* Boulder City, NV Lake Mead Intake Clark Station, NV Well 6 TTR 03/11 09/05 10/08 02/12 08/08 39 69 65 47 0.0 ± ± ± ± ± 137* 3 2 138* 1.6* Hiko, NV Crystal Springs 07/01 08/07 36 267 ± ± 126* 132* Indian Springs, NV Well 1 Sewer Company 03/04 09/03 156 —2.5 ± ± 138* 3.0* Well 2 US Air Force 03/04 09/03 12 —3.3 ± ± 137k 2.9* Johnnie, NV Johnnie Mine Well 03/19 09/03 —66 1.7 ± ± 137* 1.5* Las Vegas, NV Well 28 Water District 03/11 09/06 39 0.89 ± ± 137* 1.58* Lathrop Wells, NV City 15S-50E-18CDC 04/05 10/01 2.6 134 ± 3.0* 94* Nyala, NV Sharp’s Ranch 02/05 08/08 -231 2.7 ± ± 137* 1.6* Oasis Valley, NV Goss Springs 08/07 0.84 ± 1.58* 10.3 5.7 8.4 413 451 10 6 456 5.4 414 430 451 9.9 451 9.5 451 4.9 451 5.17 9.9 309 456 5.3 5.18 NA NA NA NA NA 0.3 0.3 NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA Continued 213 ------- Table E-3. Continued Concentration ± is Percent of Sampling Collection Tritium MDC Concentration Location Date (pCVL) (pCi/L) Guide Pahrump, NV Calvada Well 08/05 267 ± 132* 430 NA Rachel, NV Wells 7 & 8 Penoyer 05107 —127 ± 132* 437 NA 10/02 0.62 ± 2.4r 8.14 NA Well 13 Penoyer 04/23 85 ± 135* 442 NA 05/07 85 ± 133* 6.9 NA Well Penoyer Culinary 04/01 —72 ± 134* 442 NA 10/02 —3.8 ± 2.1* 6.9 NA 10/02 1.0 ± 2.8* 9.3 NA Tempiute, NV Union Carbide Well 02/06 20 ± 138* 456 NA 09/11 0.89 ± 1.58* 5.20 NA Tonopah, NV City Well 03/05 -90 ± 137* 451 NA 09/04 —0.91 ± 3.19* 10.5 NA Warm Springs, NV Twin Spnngs Ranch 04/03 No Sample Collected 10/01 -5.0 ± 2.0* 6.8 NA * = Concentration is less than the minimum detectable concentration (MDC). NA = Not applicable. Percent of concentration guide is not applicable either because the tntium result is less than the MDC or because the water is know to be nonpotable. Table E-4. Long-Term Hydrological Monitoring Program 1991 Analytical Results for Project FAULTLESS Concentration ± is Percent of Sampling Collection Tritium MDC Concentration Location Date (pCVL) (pCi/L) Guide Blue Jay, NV Hot Creek Ranch Spring 03/19 5.0 ± 3.0* 9.7 NA Maintenance Station 03/19 -2.4 ± 3.0* 9.8 NA Well Bias 03/19 0.8 ± 2.6* 8.7 NA Well HTH-1 03/19 -6.2 ± 3•4* 11.3 NA Well HTH-2 03/19 -6.7 ± 3 3* 10.9 NA Well Six Mile 03/19 -6.1 ± 3•5* 11.7 NA * = Concentration is less than the minimum detectable concentration (MDC). NA = Not applicable. Percent of concentration guide is riot applicable either because the tritium result is less than the MDC or because the water is know to be nonpotable. 214 ------- Table E-5. Long-Term Hydrological Monitoring Program 1991 Analytical Results for Project SHOAL Sampling Location Collection Date Concentration ± is Tritium (pCi/L) P MDC Con (pCi/L) ercent of centration Guide Frenchmen Station, NV Hunt’s Station 02/12 —2.3 ± 2.7* 8.8 NA Smith/James Sprgs 02/13 67 ± 3 10 0.3 Spring Windmill 02/12 0.0 ± 3 3* 10.9 NA Well Flowing 02/12 —1.7± 3.0* 9.8 NA Well H-3 02/13 Not Sampled - Pump Inoperative Well HS-1 02/13 —1.4 ± 2.5* 8.3 NA * = Concentration is less than the minimum detectable concentration (MDC). NA = Not applicable. Percent of concentration guide is not applicable either because the tritium result is less than the MDC or because the water is known to be nonpotable. Table E-6. Long-Term Hydrological Monitoring Program 1991 Analytical Results for Project RULISON Sampling Location Collection Date Concentration Tritium (pCi/L) is MDC (pCi/L) Percent of Concentration Guide Rulison, CO Lee Hayward Ranch 06/11 187 ± 4 10 0.9 Potter Ranch 06/11 119 ± 4 11 0.6 Robert Searcy Ranch 06/11 63 ± 4 11 0.3 Felix Sefcovic Ranch 06/11 133 ± 4 10 0.7 Grand Valley, CO Battlement Creek 06/11 56 ± 3 9 0.3 City Springs 06/11 0.78 ± 3.12* 10.3 NA Albert Gardner Ranch 06/11 113 ± 4 10 0.6 Spring 300 ‘Id. N of GZ 06/11 57 ± 3 7 0.3 Well CER Test 06/11 57 ± 2.1 6 0.3 * = Concentration is less than the minimum detectable concentration (MDC). NA = Not applicable. Percent of concentration guide is not applicable either because the tritium result is less than the MDC or because the water is know to be nonpotable. 215 ------- Table E-7. Long-Term Hydrological Monitoring Program 1991 Analytical Results for Project RIO BLANCO Sampling Collection Location Date Concentration ± is Percent of Tritium MDC Concentration (pCi/L) (pCi/L) Guide Rio Blanco, CO B-i Equity Camp 06/13 60 ± 3 9 0.3 Brennan Windmill 06/12 Not Sampled - Windmill Inoperative CER No.1 Black Sulfur 06/13 60 ± 3 9 0.3 CER No.4 Black Sulfur 06/13 62 ± 3 9 0.3 Fawn Creek 1 06/12 27 ± 2 6 0.1 Fawn Creek 3 06/12 30 ± 3 9 0.1 Fawn Creek 500 Ft Upstream 06/12 29 ± 2 6 0.1 Fawn Creek 500 Ft Downstream 06/12 34 ± 2 7 0.2 Fawn Creek 6800 Ft Upsteam 06/12 34 ± 2 7 0.2 Fawn Creek 8400 Ft Downstream 06/12 30 ± 2 7 0.1 Johnson Artesian Well 06/12 -0.94 ± 2.08* 6.88 NA Well RB-D-01 06/13 -0.30 ± 3.01* 9.92 NA Well RB-D-03 06/13 0.93 ± 3.12* 10.3 NA Well RB-S-03 06/13 2.9 ± 2.8* 9.2 NA * = Concentration is less than the minimum detectable concentration (MDC). NA = Not applicable. Percent of concentration guide is not applicable either because the tritium result is less than the MDC or because the water is Iciow to be nonpotable. 216 ------- Table E-8. Long-Term Hydrological Monitoring Program 1991 Analytical Results for Project GNOME Sampling Location Collection Date Concentration ± is Tritium MDC (pCi/L) (pCi/L) Percent o Concentrat Guide f ion Remarks Malaga, NM Well 1 Pecos Pumping Station Well DD-1 Well LRL-7 Well PHS 6 06/24 06/25 06125 06/22 Not Sampled - No Access 8.8E+07± 3.5E÷05 4.1E05 9329 ± 165 414 41 ± 4 11 NA NA 0.2 (a) (b) Well PHS 8 06/22 13 ± 3 10 0.1 Windmill Down - Stock Tank From Well PHS 9 06/22 —1.1 ± 2.9* 9.6 NA Windmill Down - Stock Tank From Well PHS 10 06/22 2.0 ± 3•5* 11.6 NA Well USGS 1 06/25 —1.3 ± 3•5* 11.5 NA Well USGS 4 06/25 148,300 ± 443 414 NA (c) Well USGS 8 06/25 98,580 ± 368 414 NA (d) Carlsbad, NM Well 7 City 06/24 3.1 ± 3.6* 11.7 NA Loving, NM Well 2 City 06/22 4.8 ± 3.2* 10.6 NA * = Concentration is less than the minimum detectable concentration (MDC). NA = Not applicable. Percent of concentration guide is not applicable either because the tritium result is less than the MDC or because the water is know to be nonpotable. (a,b ,c,d) = Additional analyses greater than MDC: Analysis Result 1 sigma 778,000 15300 6050 1265 NA 2720 MDC Units (a) 137 Cs °Sr pCi/L pCi/L (b) 137 Cs Sr 243 5.9 9 4.3 NA 1.3 pCIIL pCi/L (c) 137 Cs °°Sr 15 6080 3 49 NA 13 pCi / i.. pCi/L (d) 137 Cs Sr 52 4470 5 43 NA 13 pCi/L pCi/L 217 ------- Table E-9. Long-Term Hydrological Monitoring Program 1991 Analytical Results for Project GASBUGGY Sarrçling Location Collection Date Concentration ± is Tritium (pCLIL) MDC (pCi/L) Percent o Concentrat Gukie f ion Remarks Gobemador, NM Arnold Ranch 06/18 7.1 ± 1.7 5.5 <0.1 Bixier Ranch 06118 13 ± 2 6 0.1 Sample from house Bthbling Springs 06/18 48 ± 2 7 0.2 Cave Springs 06/16 56 ± 2 5 0.3 Cedar Springs 06/16 71 ± 2 6 0.4 La Jam Creek 06/19 40 ± 2 6 0.2 Lower Burro Canyon 06119 42 ± 2 5 0.2 Old School House Well 06/17 4.9 ± 1.9* 6.0 NA (a), New Sampling Location Pond N of Well 30.3.32.343 06/18 46 ± 2 6 0.2 Well EPNG 10-36 06/16 484 ± 4 5 NA Well Jicanila 1 06/19 25 ± 2 5 0.1 Sample from stock tank Well 28.3.33.233 (South) 06119 50 ± 2 6 0.2 Well 30.3.32.343 (North) 06/18 Welt Removed Windmill 2 06(19 0.94± 1.78* 5.83 NA = Concentration is less than the minimum detectable concentration (MDC). NA = Not applicable. Percent of concentration guide is not applicable either because the tritium result is less than the MDC or because the water is know to be nonpotable. (a) = Additional analyses greater than MDC: Analysis Result 1 sigma MDC Units 1.12 0.08 0.05 pCi& 0.39 0.04 0.04 pCi/L 218 ------- Table E-10. Long-Term Hydrological Monitoring Program 1991 Analytical Resufts for Project DRIBBLE Sampling Collection Concentration ± is Tritium MDC Percent of Concentration Location Date (pCi/L) (pCLIL) Guide Remarks ONSITE SAMPLING LOCATIONS Baxtervifle, MS Halt Moon Creek 04121 19 ± 3 8 0.1 Pre Sample 04/22 31 ± 3 10 0.1 Post Sample Halt Moon Creek Overflow 04/21 118 ± 3 9 0.6 Pre Sample 04/22 280 ± 4 10 1.4 Post Sample Pond West Of GZ 04/21 8.9 ± 2.9* 9.4 NA Pre Sample 04/22 9.9 ± 3.8* 12.4 NA Post Sample REECO Pit Drainage-A 04/24 20 ± 3 10 0.1 REECO Pit Drainage-B 04/24 242 ± 5 15 1.2 REECO Pit Drainage-C 04124 288 ± 4 10 1.4 Well E-7 04/23 8.5 ± 3.0* 9.7 NA Well HM-1 04/22 1.9 ± 2.7k 8.9 NA Pre Sample 04/22 0.0 ± 2.5* 8.3 NA Post Sample Well HM-2A 04/22 —2.9 ± 2.6 8.6 NA Pre Sample 04/22 —0.63± 333* 11.0 NA Post Sample Well HM-2B 04/22 —1.2 ± 2.5* 8.3 NA Pre Sample 04/22 —0.19± 2.9T 9.77 NA Post Sample Well HM-3 04/22 —4.1 ± 2.7k 8.9 NA Pre Sample 04/22 —2.5 ± 3 5* 11.5 NA Post Sample Well HM-L 04/22 1282 ±141 442 NA Pre Sample 04/22 848 ± 7 12 NA Post Sample Well HM-L2 04/22 0.91 ± 2.88* 9.47 NA Pre Sample 04/22 —3.4 ± 3.6* 12.0 NA Post Sample Well HM-S 04/21 7530 ±169 442 NA Pre Sample 04/23 7644 ±170 442 NA Post Sample Well HMH-1 04/21 4962 ±158 442 NA Pre Sample 04/22 13,740 ± 193 442 NA Post Sample Well HMH-2 04/21 7246 ±168 442 NA Pre Sample 04/22 14,380 ±196 442 NA Post Sample Well HMH-3 04/21 41 ± 3 11 NA Pre Sample 04/22 44 ± 3 8 NA Post Sample Well HMH-4 04/21 14 ± 3 9 NA Post Sample 04/21 18 ± 3 10 NA Pre Sample Well HMH-5 04/21 2229 ±145 442 NA Pre Sample 04/22 2737 ±148 442 NA Post Sample Well HMH-6 04/21 213 ± 4 10 NA Pre Sample 04/22 166 ± 3 9 NA Post Sample Well HMH-7 04/21 Not Sampled - Well Under Water 04/22 Not Sampled - Well Under Water Continued 219 ------- Table E-1O. Continued Sampling Collection Concentration ± is Tritium MDC Percent of Concentration Location Date (pCi /I) (pCi/L) Guide Remarks ONSITE SAMPLING LOCATIONS (Continued) Baxterville, MS (Continued) Well HMH-8 04/21 16 ± 3 10 NA Pre Sample 04/22 22 ± 3 8 NA Post Sample Well HMH-9 04/21 128 ± 4 11 NA Pre Sample 04/22 147 ± 4 9 NA Post Sample Well HMH-10 04/21 91 ± 4 11 NA Pre Sample 04/22 35 ± 3 10 NA Post Sample Well HMH-1 1 04/21 22 ± 2 7 NA Pre Sample 04/22 21 ± 3 11 NA Post Sample Well HMH-12 04/21 16 ± 3 10 NA Pre Sample 04/22 17 ± 3 8 NA Post Sample Well HMH-i3 04/21 18 ± 3 10 NA Pre Sample 04/22 19 ± 3 11 NA Post Sample Well HMH-i4 04/21 16 ± 3 9 NA Pre Sample 04/22 11 ± 3 10 NA Post Sample Well HMH-15 04/21 18 ± 3 10 NA Pre Sample 04/22 8.9 ± 2.5 8.2 NA Post Sample Well HMH-16 04/21 31 ± 3 9 NA Pre Sample 04/22 38 ± 3 9 NA Post Sample Well HT-2C 04/23 18 ± 4 12 NA Well HT-4 04/23 7.6 ± 3.0* 9.8 NA Well HT-5 04/23 4.2 ± 3.3 10.7 NA OFFSITE SAMPLING LOCATIONS Baxterville, MS Little Creek #1 04/23 21 ± 4 12 0.1 Lower Little Creek #2 04/23 20 ± 3 10 0.1 Salt Dome Hunting Club 04/24 33 ± 4 13 0.2 Salt Dome Timber Co. 04/22 26 ± 3 9 0.1 Anderson Pond 04/22 13 ± 3 10 0.1 Anderson, Billy Ray 04/22 19 ± 2 8 0.1 Anderson, Regina 04/22 18 ± 3 10 0.1 Anderson, Robert Harvey 04/22 16 ± 2 7 0.1 Anderson, Rcbert Lowell 04/22 14 ± 2 7 0.1 04/22 26 ± 3 10 0.1 Burge, Joe 04/22 18 ± 3 11 0.1 Chambliss, B. 04/23 -4.0 ± 2.T 9.1 NA Daniels, Ray 04/22 27 ± 2 8 0.1 Continued 220 ------- Table E-1O. Continued Sampling Collection Concentration ± is Tritium MDC Percent of Concentration Location Date (pCIIL) (pCi/L) Guide Remarks OFFSITE SAMPLING LOCATIONS (Continued) Baxterville, MS (Continued) Daniels, Webster Jr. 04/22 14 ± 3 10 0.1 Daniels Fish Pond Well #2 04/22 24 ± 2 7 0.1 Kelly Gertrude 04/22 —3.6 ± 2.2* 7.3 NA King, Rhonda 04/22 20 ± 3 10 0.1 Lee, P. T. 04/22 44 ± 3 9 0.2 Lowe, M. 04/23 Not Sampled - Now On Rural Water Mills, A. C. 04/22 0.50± 2.30* 7.55 NA Mills, Roy 04/22 20 ± 2 7 0.1 Nobles Pond 04/22 21 ± 3 11 0.1 Noble’s Quail House 04/23 48 ± 4 12 0.2 Noble, W. H., Jr. 04/22 36 ± 3 11 0.2 Ready, R. C. 04/22 37 ± 2 7 0.2 Saucier, Dennis 04/22 40 ± 3 10 0.2 Saucier, Talmadge S. 04/23 28 ± 3 9 0.1 Saucier, Wilma/Yancy 04/23 1.1 ± 3.3’ 11.0 NA Smith, Rita 04122 Not Sampled - Moved, Well Down Well Ascot 2 04/23 Not Sampled - Well In Water City Well 04/23 33 ± 3 10 0.2 Columbia, MS Dennis, Buddy 04/23 14 ± 2 7 0.1 Dennis, Marvin 04/23 26 ± 3 9 0.1 (a) City Well MB 04/23 17 ± 3 10 0.1 Lumberton, MS Anderson, G. W. 04/22 27 ± 3 8 0.1 Anderson, Lee L. 04/22 26 ± 3 11 0.1 Bond, Bradley K. 04/22 28 ± 3 9 0.1 Cox, Eddie 04/24 36 ± 3 11 0.2 (b) Gil Ray’s Crawfish Pond 04/23 13 ± 3 9 0.1 Gipson, Herman 04/22 21 ± 2 7 0.1 Graham, Sylvester 04/23 —2.6 ± 3•3* 11.0 NA Moree, Rita-House Well 04/23 4.8 ± 2.3’ 7.4 NA Beach, Donald 04/22 Not Sampled - Moved, Well Down Powers, Sharon 04/22 18 ± 3 9 0.1 Rushing, Debra 04/24 34 ± 3 10 0.2 Saul, Lee L. 04/23 —1.3 ± 3.3’ 10.8 NA Smith, Howard 04/23 0.07± 2.30* 7.57 NA Smith, Howard-Pond 04/23 18 ± 2 8 0.1 (c) Well 2 City 04/23 4.7 ± 2.9’ 9.6 NA Continued 221 ------- Table E-l0. Continued Sampling Location Concentration ± is Percent of Collection Tritium MDC Concentration Date (pCi/L) (pCiIL) Guide Remarks OFFSITE SAMPLING LOCATIONS (Continued) Purvis, MS Burge Willie Ray and City Supply Gil, Ray-House Well Grace 04/22 15 ± 2 8 0.i 04/22 6.4 ± 2.9* 9.4 04/22 2.6 ± 3.1* 10.1 NA * = Concentration is less than the minimum detectable concentration (MDC). NA = Not applicable. Percent of concentration guide is not applicable either because the tritium result is less than the MDC or because the water is known to be nonpotable. (a,b,c) = Additional analyses greater than MDC: Analysis Result 1 siin MDC Units (a) tJ 0.035 0.019 0.033 pCi/L (b) U 0.022 0.011 0.017 pCi/i (c) ‘U 0.054 0.019 0.044 pCi/I 0.071 0.016 0.016 pCi/I 222 ------- Table E-i 1. Long-Term Hydrological Monitonng Program 1991 Analytical Results for Amchitka Island, Alaska Sampling Collection Concentration ± is Tritium MDC Percent of Concentration Location Date (pCi/L) (pCi/L) Guide Remarks BACKGROUND SITES Clevenger Lake Constantine Spring Constantine Spnng-Pump House RX-Site Pump House TX-Site Springs TX-Site Water Tank House Duck Cove Creek Jones Lake Site D Hydro Exploratory Hole Site E Hydro Exploratory Hole Well 1 Army Well 2 Army Well 3 Army Weli 4 Army 25 ±3 9 0.1 42 ±3 8 0.2 39 ±2 5 0.2 18 ±2 5 0.1 24 ±2 6 0.1 23 ±2 6 0.1 19 ±3 8 0.1 18 ±2 6 0.1 Not Sampled - Hole Plugged Not Sampled - Oil in Hole 28 ±2 6 16 ±2 5 Not Sampled - Hole 35 ±2 6 (a) (b) (c) (d) (e) 09/2 1 09/21 09/2 1 09/24 09/24 09/24 09/23 09/21 09/23 09/23 09/21 09/23 09/22 09/23 0.1 0.1 Plugged 0.2 PROJECT CANNIKIN Cannikin Lake (North End) Cannikin Lake (South End) DK-45 Lake 09/21 20 ± 2 09/21 24 ± 2 09/23 23 ± 3 6 6 9 0.1 0.1 0.1 Ice Box Lake 09/21 22 ± 2 6 0.1 Pit South of Cannikin GZ 09/21 19 ± 2 6 0.1 Well HTH-3 09/21 28 ± 2 5 0.1 White Alice Creek 09/21 18 ± 2 8 0.1 PROJECT LONG SHOT Long Shot Pond 1 Long Shot Pond 2 Long Shot Pond 3 Mud Pit No.1 Mud Pit No.2 Mud Pit No.3 Reed Pond Stream East-Longshot Well EPA-i Well GZ No.1 Well GZ No.2 Well WL-1 Well WL-2 09/22 14 ± 3 09/22 21 ± 3 09/22 27 ± 3 09/22 192 ± 3 09/22 243 ± 3 09/22 282 ± 3 09/22 23 ± 2 09/23 190 ± 3 09/22 17 ± 3 09/23 1128 ±99 09/23 65 ± 2 09/22 17 ± 2 09/22 78 ± 2 9 9 9 5 5 5 6 6 9 309 6 6 5 0.1 0.1 0.1 NA NA NA 0.1 1.0 0.1 NA 0.3 0.1 0.4 Continued 223 ------- Table E-1 1. Continued Sampling Location Concentration ± is Collection Tritium MDC Date (pCi/L) (pCi/L) Percent of Concentration Guide Remarks PROJECT MILROW Clevenger Creek 09/22 22 ± 2 7 0.1 Heart Lake 09/22 15 ± 2 6 0.1 WellW-2 09/22 18 ± 2 7 0.1 We IIW-3 09/22 16 ±3 9 0.1 Well W-4 09/22 Not Sampled - Well Dry Well W-5 09/22 15 ± 2 7 0.1 WeU W6 09/22 17 ± 2 8 0.1 Well W-7 09/22 19 ± 3 9 0.1 WellW-8 09/22 20 ±2 6 0.1 Well W-9 09/22 Not Sampled - Well In Water Well W-1 0 09/22 22 ± 2 6 0.1 Well W-1 1 09/22 44 ± 3 9 0.2 Well W-12 09/22 Not Sampled - Well In Stream Well W-13 09/22 29 ± 2 6 0.1 Well W-14 09/22 19 ± 2 6 0.1 Well W-15 09/22 18 ± 2 5 0.1 Well W-16 09/22 Not Sampled - Well In Water Well W-1 7 09/22 Not Sampled - Well In Water Well W-1 8 09/22 27 ± 2 6 0.1 Well W-19 09/22 Not Sampled - Well In Water * = Concentration is less than the minimum detectable concentration (MDC). NA = Not applicable. Pement of concentration guide is not applicable either because the tritium result is less than the MDC or because the water is know to be nonpotable. (a,b,c,d,e) = Additional analyses greater than MDC: Analysis Result 1 sigma MDC Units (a) Beta 7.0 0.74 1.9 pCi/L (b) Alpha 2.9 0.70 1.5 pCi/L Beta 7.3 0.75 1.9 pCi/L (c) Alpha 1.3 0.34 0.8 pCi/L Beta 2.6 0.36 1.0 pCi/L (d) Alpha 1.7 0.37 0.7 pCi& Beta 3 0.34 0.8 pCi/i.. (e) Alpha 1.4 0.36 0.8 pCi/L Beta 7.2 0.45 0.9 pCi/L 224 ------- Appendix F Table F-i. Accuracy of Analysis from EPA lntercompanson Studies. Table F-2. Accuracy of Analysis from DOE Intercompanson Studies. Table F-3. Comparability of Analysis from Intercornparison Studies. 225 ------- Table F-i. Accuracy of Analysis from EPA Intercomparison Studies Known Value Lab Average Percent Nuclide Month pCL/L)a ( pcuL)e Bias Water Intercomparison Studies Alpha Jan 5.0 ND Alpha April (PE) 54.0 67.33 24.7 Alpha May 24.0 ND Alpha Sept 10.0 9.00 -10.0 Alpha Oct (PE) 82.0 97.67 19.1 Beta Jan 5.0 ND Beta April (PE) 115.0 ND Beta May 46.0 ND Beta Sept 20.0 20.00 0.0 Beta Oct (PE) 65.0 61.67 -5.1 60 Co Feb 40.0 36.67 -8.3 Co June 10.0 ND Co Oct 29.0 28.67 -1.1 e Co Oct (PE) 20.0 19.67 -1.6 Zn Feb 149.0 141.33 -5.1 Zn June 108.0 ND Zn Oct 73.0 75.67 3.7 Ru Feb 186.0 174.33 -6.3 1 Ru June 149.0 ND 106 Ru Oct 199.0 180.67 -9.2 Cs Feb 8.0 7.33 -8.4 134i April (PE) 24.0 18.67 -22.2 134 June 15.0 ND 134 Cs Oct 10.0 10.0 0.0 134 Cs Oct (PE) 10.0 9.33 -6.7 137 Cs Feb 8.0 8.33 4.1 131 Cs April (PE) 25.0 20.00 -20.0 137 Cs June 14.0 ND 137 Cs Oct 10.0 10.33 3.3 131 Cs Oct (PE) 11.0 12.00 9.1 133o Feb 75.0 74.67 -0.4 June 62.0 ND Oct 98.0 90.33 -7.8 3 H Feb 4418.0 4613.00 4.4 3 H Oct 2452.0 2499.33 1.9 1311 Feb 75.0 81.67 8.9 1311 Aug 20.0 21.33 6.6 Ra Mar 31.8 31.60 -0.6 Ra April (PE) 8.0 8.10 1.2 Ra July 15.9 ND Ra Oct (PE) 22.0 ND Continued 226 ------- Table F-i. Continued. Known Value Lab Average Percent Nuclide Month (pCi/L) 8 (pCi/L)a Bias Water Intercompanson Studies 226 Ra Nov 6.5 ND Mar 21.1 ND Ra April (PE) 15.2 11.33 -25.5 228 Ra July 16.7 ND Ra Oct (PE) 22.2 ND Nov 8.1 ND Sr April (PE) 28.0 22.33 -20.2 Sr May 39.0 34.33 -12.0 Sr Sept 49.0 39.67 -19.0 Sr Oct (PE) 10.0 8.33 -16.7 90 Sr April (PE) 26.0 23.33 -10.3 90 Sr May 24.0 24.00 0.0 °Sr Sept 25.0 23.67 -5.3 °Sr Oct (PE) 10.0 10.33 3.3 U (Nat) Mar 7.6 7.67 0.9 U (Nat) April (PE) 29.8 30.30 1.7 U (Nat) July 14.2 14.43 1.6 U (Nat) Oct (PE) 13.5 13.17 -2.4 U (Nat) Nov 24.9 23.97 -3.7 Pu Aug 19.4 18.23 -6.0 Air Intercomparison Studies Alpha Mar 25.0 ND Alpha Mar 5.0 6.00 20.0 Alpha Aug 25.0 ND Alpha Aug 10.0 14.00 40.0 Beta Mar 124.0 ND Beta Mar 31.0 36.67 18.3 Beta Aug 92.0 ND Beta Aug 62.0 80.33 29.6 90 Sr Mar 40.0 ND °Sr Mar 10.0 11.0 10.0 90 Sr Aug 30.0 29.33 -2.2 90 Sr Aug 20.0 18.67 -6.6 137 Cs Mar 40.0 42.33 5.8 137 Cs Mar 10.0 10.67 6.7 137 Cs Aug 30.0 31.33 4.4 137 CS Aug 20.0 22.33 11.6 Milk lntercomparisofl Studies Sr Apr 32.0 29.67 -7.3 Sr Apr 23.0 18.67 -18.8 Continued 227 ------- Tabte F-i. Continued Nuclide Month Known Value Lab Avetage (p( j/ [ )a ( p( j&)a Pen ent Bias Milk lnteroorr arison Studies Sr Sr 90 Sr Sept Sept Apr 25.0 22.33 16.0 12.67 32.0 32.00 -10.7 -20.8 0.0 °°Sr Apr 23.0 19.67 -14.5 Sr °°Sr Sept Sept 25.0 25.33 20.0 18.00 1.3 -10.0 1811 1811 Apr Apr 60.0 59.33 99.0 98.00 -1.1 -1.0 1811 Sept 108.0 108.33 0.3 131J Cs Cs 137 Cs Sept Apr Apr Sept 58.0 63.33 49.0 45.33 24.0 25.33 30.0 31.67 9.2 -7.5 5.5 5.6 137 Sept 20.0 20.33 1.6 K(tot) Apr 1650.0 1212.67 -26.5 K (tot) Apr 1550.0 1587.33 2.4 K (tot) Sept 1740.0 1710.67 -1.7 K (tot) Sept 1700.0 1754.67 3.2 a Values were obtained from the individual study reports and are reported with the significant figures included in those repoits. PE = performance evaluation study. ND = not detected. 228 ------- Table F-2. Accuracy of Analysis from DOE Intercomparison Studies Nuclide Month EML Value (pCi/L)e EPA Value (pCi/L)a Percent Bias Water Intercomparison Studies 1 ”Ce Mar 35.1 39.2 11.7 1M Ce Sept 226 214 -5.3 ‘Co Mar 230 214 -7.0 57 Co Sept 166 174 4.8 °Co Mar 201 191 -5.0 60 Co Sept 291 294 1.0 Mar 169 163 3.5 131 Cs Sept 46.0 48.3 5.0 3 H Sept 100 102 2.0 54 Mn Mar 213 206 -3.3 Mn Sept 103 104 1.0 90 Sr Sept 10.1 9.93 -1.7 U (Nat) Sept 0.940 0.949 1.0 Pu Sept 0.510 0.480 -5.9 Air lntercomparison Studies 7 Be Mar 53.0 47.8 -9.8 7 Be Sept 53.8 56.4 4.8 1 Ce Mar 52.2 52.9 1.3 1 ”Ce Sept 50.8 56.0 10.2 Co Mar 5.82 5.44 -6.5 Co Sept 16.6 19.3 16.3 60 Co Mar 5.14 4.92 -4.3 Co Sept 23.0 24.5 6.5 Mar 4.53 4.70 3.7 137 Cs Sept 28.0 30.1 7.5 54 Mn Mar 4.80 4.85 1.0 54 Mn Sept 24.3 26.4 8.6 Pu Sept 0.084 0.087 3.6 Vegetation Intercomparison Studies Sept 0.365 0.359 -1.6 Soil Intercomparison Studies Pu Sept 7.35 7.22 -1.8 a Values were obtained from the Environmental Measurements Laboratory (EML) and reported with the significant figures provided by EML. Nat = natural. 229 ------- Table F-3. Corr arability of Anatysis from 1ntercon arison Studiesa No. of EPA Lab Grand Normalized Ratk, EPA Participating Average Average Deviation from Lab Average/ Nuclide Month Laboratories (pCiiL) (pC ) Grand Average Grand Average Water lnterconparison Studies Alpha Jan 198 ND 5.69 NA Alpha April (PE) 179 67.33 49.71 2.18 1.35 Alpha May 209 ND 20.94 NA Alpha Sept 207 9.00 10.36 -0.47 0.87 Alpha Oct (PE) 187 97.67 75.57 1.82 1.29 Beta Jan 198 ND 6.60 NA Beta April (PE) 179 ND 108.60 NA Beta May 209 ND 44.73 NA Beta Sept 207 20.00 20.30 -0.10 0.99 Beta Oct (PE) 187 61.67 55.53 1.06 1.11 °Co Feb 151 36.67 40.04 -1.17 0.92 Co June 159 ND 10.69 NA Co Oct 162 28.67 29.83 -0.40 0.96 eoCo Oct (PE) 187 19.67 20.22 -0.19 0.97 Zn Feb 151 141.33 149.71 -0.97 0.94 ‘Zn June 159 ND 109.54 NA *Zn Oct 162 75.67 74.57 0.27 1.01 Ru Feb 151 174.33 191.83 -1.60 0.91 1 Ru June 159 ND 141.48 NA Oct 162 180.67 194.21 -1.17 0.93 134 Cs Feb 151 7.33 8.09 -0.26 0.91 1 Cs April (PE) 179 18.67 22.96 -1.49 0.81 ‘ Cs June 159 ND 14.2 NA Oct 162 10.0 9.93 0.02 1.01 1 Cs Oct (PE) 187 9.33 9.58 -0.08 0.97 137 Cs Feb 151 8.33 9.06 -0.25 0.92 1 Cs April (PE) 179 20.00 25.49 -1.90 0.78 137 Cs June 159 ND 15.37 NA 137 Cs Oct 162 10.33 10.86 -0.18 0.95 137 Cs Oct (PE) 187 12.00 12.45 -0.15 0.96 ‘ 33 8a Feb 151 74.67 74.14 0.11 1.01 133o June 159 ND 61.37 NA Oct 162 90.33 95.56 -0.91 0.95 3 H Feb 150 4613.00 4437.54 0.69 1.04 Oct 166 2499.33 2531.91 -0.16 0.99 1311 Feb 120 81.67 77.00 1.01 1.06 1311 Aug 113 21.33 20.96 0.11 1.02 Ra Mar 115 31.60 29.45 0.77 1.07 Ra April (PE) 179 8.10 7.72 0.55 1.05 Ra July 120 ND 15.34 NA Ra Oct (PE) 187 ND 21.57 NA Nov 121 ND 6.38 NA Ra Mar 115 ND 19.14 NA Ra April (PE) 179 11.33 14.01 -1.22 0.81 Contintued 230 ------- Table F-3. Continueie No. of EPA Lab Grand Normalized Ratio EPA Participating Average Average Deviation from Lab Average/ Nuclide Month Laboratories (pCi/L) (pCi/L) Grand Average Grand Average Water lntercornparison Studies (Continued) 228 Ra July 120 ND 1563 NA Oct (PE) 187 ND 21.12 NA 228 Ra Nov 121 ND 8.19 NA Sr April (PE) 179 22.33 25.74 -1.18 0.87 Sr May 104 34.33 37.43 -1.07 0.92 Sr Sept 69 39.67 49.57 .3•43* 0.80 Sr Oct (PE) 187 8.33 9.79 -0.51 0.85 90 Sr April (PE) 179 23.33 23.61 -0.10 0.99 90 Sr May 104 24.00 28.85 0.05 0.83 90 Sr Sept 69 23.67 24.72 -0.46 0.96 90 Sr Oct (PE) 187 10.33 10.09 0.08 1.02 U (Nat) Mar 117 7.67 7.30 0.21 1.05 U (Nat) April (PE) 179 30.30 28.88 0.82 1.05 U (Nat) July 127 14.43 13.38 0.61 1.08 U (Nat) Oct (PE) 187 13.17 13.25 -0.05 0.99 U (Nat) Nov 90 23.97 23.76 0.12 1.01 Pu Aug 61 18.23 19.22 -0.90 0.95 Air Intercomparison Studies Alpha Mar 165 ND 29.73 NA Alpha Mar 185 6.00 6.25 -0.09 0.96 Alpha Aug 172 ND 28.33 NA Alpha Aug 179 14.00 12.21 0.62 1.15 Beta Mar 165 ND 130.11 NA Beta Mar 185 36.67 32.19 1.55 1.14 Beta Aug 172 ND 95.54 NA Beta Aug 179 80.33 64.66 5 43* 1.24 9 °Sr Mar 165 ND 39.3 NA 90 Sr Mar 185 11.0 9.69 1.51 1.14 °Sr Aug 172 29.33 29.11 0.08 1.01 90 Sr Aug 179 18.67 19.45 -0.27 0.96 137 Cs Mar 165 42.33 44.61 -0.79 0.95 137 Cs Mar 185 10.67 11.56 -0.31 0.92 137 Cs Aug 172 31.33 32.48 -0.40 0.96 1 Cs Aug 179 22.33 22.70 -0.13 0.98 Milk lntercomparison Studies Sr Apr 96 29.67 27.07 0.90 1.10 Sr Apr 104 18.67 23.14 -1.55 0.81 Sr Sept 95 22.33 20.95 0.48 1.07 Sr Sept 98 12.67 13.53 -0.30 0.94 Sr Apr 96 32.00 28.02 1.38 1.14 Continued 231 ------- Table F-3. Continueda No. of EPA Lab Grand Normalized Ratio EPA Participating Average Average Deviation from Lab Average! Nuclide Month Laboratories (pCi/L) (pCVL) Grand Average Grand Average Milk Intercomparison Studies (Continued) 90 5r Apr 104 19.67 22.33 -0.92 0.88 90 6r Sept 95 25.33 21.09 1.47 1.20 Sr Sept 98 18.00 17.57 0.15 1.02 1311 Apr 96 59.33 61.17 -0.53 0.97 Apr 104 98.00 98.49 -0.09 1.00 1311 Sept 95 108.33 108.56 -0.04 1.00 1311 Sept 98 63.33 58.88 1.29 1.08 137 Cs Apr 96 45.33 51.35 -2.08 0.88 137 Cs Apr 104 25.33 24.65 0.24 1.03 137 Cs Sept 95 31.67 31.35 0.11 1.01 137 Cs Sept 98 20.33 21.47 -0.39 0.95 K (tot) Apr 96 1212.67 1653.09 .9.19* 0.73 K (tot) Apr 104 1587.33 1548.38 0.86 1.03 K (tot) Sept 95 1710.67 1667.46 0.86 1.03 K (tot) Sept 98 1754.67 1713.52 0.84 1.02 1 Values were obtained from the individual intercor, arison study reports and are reported with the significant figures included in those reports. PE = performance evaluation study. (Nat) = natural. ND = not detected. NA = not applicable. * = outside control limits. 232 ------- |