&EPA United States Environmental Protection Agency Environmental Monitoring Systems Laboratory P.O. Box 93478 Las Vegas NV 89193-3478 EPA 600/4-91/031 November 1991 Research and Development Environmental Monitoring Report Radiation Monitoring On and Around the Tatum Salt Dome, Lamar County, Mississippi April 1991 1238mPB91 rpt ------- Radiation Monitoring On and Around the Tatum Salt Dome, Lamar County, Mississippi April 1991 by D. J. Thome* S. H. Faller C. A. Fontana C. F. Costa Environmental Protection Agency P.O. Box 93478 Las Vegas, NV 89193-3478 prepared for the U.S. DOE under Interagency Agreement DE-A108-86NV10522 ENVIRONMENTAL MONITORING SYSTEMS LABORATORY OFFICE OF RESEARCH AND DEVELOPMENT U.S. ENVIRONMENTAL PROTECTION AGENCY LAS VEGAS, NV 89193-3478 1238mPB91.rpt ------- NOTICE The information in this document has been funded wholly or in part by the United States Environ- mental Protection Agency through Interagency Agreement DE-A108-91NV10963 from the United States Department of Energy. It has been subject to the Agency's peer and administrative review, and it has been approved for publication as an EPA document. Mention of trade names or commercial products does not constitute endorsement or recommendation for use. ------- ABSTRACT In 1964, and again in 1966 a nuclear explosive was detonated approximately 2700 feet underground in the Tatum Salt Dome located in Lamar County, Mississippi. Drilling and cleanup activities have resulted in tritium contamination in close proximity to the surface ground zero. The Long-Term Hydrological Monitoring Program conducted by the U.S. Environmental Protection Agency consists of annual water sampling on and around the Tatum Salt Dome. In 1991, in addition to water sampling, a gamma-ray characterization study was conducted. As in past years no radioactive materials from the Tatum Salt Dome were detected in any water samples collected offsite. The highest tritium concentration found in water collected in the offsite area was 48 pCi/1. This is from natural sources and is 0.24 percent of the National Interim Primary Drinking Water Regulations (40CFR141) which places the maximum level of tritium in drinking water to be 20,000 pCi/1. The highest tritium concentration found onsite was 14,000 pCi/1. This concentration was detected in water samples collected in two wells, Well HMH-1 and Well HMH-2. These wells are both less than 10 feet deep and they are located very near to the surface ground zero. The water from these wells is not available to the public nor suitable for drinking due to its brackishness. The gamma-ray characterization study consisted of eight locations onsite and four offsite. The study showed good agreement between exposure rates derived from in-situ gamma-ray spectrometry and those measured with a pressurized ion chamber in all locations surveyed. Variabilities of gamma flux contributed by radionuclides in the soil were small with the exception of 137Cs, which was lower than expected in all onsite locations. The 137Cs is the result of global fallout from atmospheric nuclear testing. in ------- CONTENTS Page Abstract iii Figures vii Acknowledgments viii Introduction 1 History 1 Monitoring Results: Historical Summary 1 Calendar Year 1991 Monitoring Results 5 Water 5 Sample Analysis Procedures 8 Water Analysis Results 8 Gamma-Ray Characterization Study 11 Gamma-Ray Characterization Results 11 Conclusion 12 References 13 Appendices 1 Abbreviations 14 2 Glossary of Terms 15 3 Summary of Analytical Procedures 16 4 Results for Water Samples Collected in April 1991 17 5 Exposure Rate Inventories at all Survey Locations 24 6 Soil Sample Study 25 ------- FIGURES Figure Number Page 1 General site location 2 2 Topographic map of the Tatum Dome Test Area showing the Surface Ground Zero and outline of Salt Dome at 2,700 feet below land surface 3 3 Test cavity and aquifers 4 4 Plots of tritium concentrations vs. time 6 5 Locations in the vicinity of surface ground zero sampled and monitored in 1991 9 6 Offsite locations sampled in 1991 10 VI ------- ACKNOWLEDGMENTS The authors would like to acknowledge Mr. M.G. Davis for his dedication to quality and his tireless work in the design and execution of the sampling effort. We also want to thank Ms. D.J. Chaloud for her suggestions, editorial expertise, and for bringing this document to fruition. VII ------- INTRODUCTION Under an Interagency Agreement with the U.S. Department of Energy (DOE), the Environmental Monitoring Systems Laboratory (EMSL-LV) of the U.S. Environmental Protection Agency (EPA) located in Las Vegas, NV, conducts a Long-Term Hydro- logical Monitoring Program (LTHMP) to measure radioactivity concentrations in water sources near the sites of underground nuclear explosions. The results of the LTHMP provide assurance that radio- active materials from the tests have not migrated into drinking water supplies. This report presents the results for the samples collected in April 1991, on and around the Tatum Salt Dome, in Lamar County, Mississippi. History Project Dribble, consisting of two nuclear ex- plosions, and Project Miracle Play, consisting of two non-nuclear gas explosions, were conducted in the Tatum Salt Dome, near Baxterville, Lamar County, Mississippi, between 1964 and 1970. The general area is depicted in Figure 1. This area is called the Tatum Dome Test Area (Figure 2) and contains approximately 1470 acres located in Sections 11,12, 13 and 14, Township 2 North, Range 16 West. Event Date Name 10-22-64 Salmon Nuclear 12-03-66 Sterling Nuclear 02-02-69 Diode Tube Gas 04-19-70 Humid Water Gas Yield 5.3 0.38 0.32 0.32 These tests were part of the Vela Uniform program of the U.S. Atomic Energy Commission (now the DOE). The purpose of the tests was to study the decoupling principle, i.e., to measure and evalu- ate the phenomena of seismic waves that are induced from the explosions as compared to those that occur naturally from earthquakes. The first explosion, the Salmon Event, created a cavity in the Tatum Salt Dome that was used for the other three explosions. The top of the cavity is 1,160 feet (360 m) below the top of the salt dome. The top of the salt dome is another 1,500 feet (460 m) below the land surface (Figure 3). At the Project Dribble site, disposal of drilling muds and fluids near surface ground zero (SGZ) resulted in onsite contamination of shallow ground water and the surficial aquifer with tritium (3H). The shallow ground water, between 4 and 10 feet (1.2 and 3 m) deep, and the surficial aquifer that is approxi- mately 30 feet (9 m) below the surface both consist of non-potable water. Tritium contamination has also been detected in the potable water Local Aquifer which is 200 feet (62 m) deep. The 3H appears to be migrating down the exterior of the sampling well (HM-L) casing from the surficial aquifer above. Well HM-L is located very close to the SGZ and the well casing penetrates the contaminated surficial aquifer. No contamination has been detected in a second Local Aquifer sampling well (HM-L2), located down gra- dient from HM-L. All 3H contamination is less than the concentration specified in the National Interim Primary Drinking Water Regulations (40CFR141). There is no indication from ground and surface water monitoring that any radioactivity is presently escaping from the test cavity. Following each explosive event, the near-offsite area was closely monitored by the U.S. Public Health Service (PHS). The radiological monitoring became the responsibility of EPA at its inception in 1970. The EPA radiological monitoring is a continuing responsibility. From 1964 to the present, neither the EPA nor the PHS has detected any contamination offsite resulting from the Tatum Dome experiments. Monitoring Results: Historical Summary After site cleanup activities in 1971-72 the LTHMP was instituted. In this program, all potable aquifers, many individual wells, public water sup- plies, and some surface waters in the Tatum Salt Dome area have been sampled and analyzed for ------- Prentiss •***_ Monticello Brookhaven Seminary Bassfield A f Moselle Eatonyille Runnelstown Bunker sumrall Hill Columbia ^ Cheraw Purvis Talowah Beaumont Brooklyn Tylertown- I Pinebur w MISSISSIPPI I Baxterville 7 \ ^Lumberton LOUISIANA I / Varnado ^ / — Major Highway (•) Test Site, SGZ Figure 1. General site location. ------- All tritium contamination found within this circle with radius of 1400 feet (430m) DRIBBLE SITE BOUNDARY T W _0> 1 CM X 2 Q. Q. CO I approx. 1 1/2 miles Baxterville M^_ N SCALE IN FEET 1000 2000 3000 4000 5000 _m 500 1000 SCALE IN METERS 1238GR90NRD-2 Figure 2. Topographic map of the Tatum Dome Test Area showing the Surface Ground Zero and outline of Salt Dome at 2,700 feet (830 m) below land surface. ------- I 3 w a i s I i /Well HT-2 Surficlal Aquifer ^Anhydrite 1160' ^ STA.1A ps-1 Salt Stock PS-1W PS-2W Test Cavity* Highly Radioactive Zone Recrystalized Melt Puddle SANDSTONE Ground Surface Local Aquifer Aquifer 1 iifT Aquifer 2A Aquifer 2B Aquifer 3A Caprock Aquifer •!•!•!•!•!•!•!•!•* Aquifer4 i|i|i|;|i!i!i!Ji|1 Aquifers *The test cavity contains fission and activation products from the detonations plus 10,770 cubic yards of radioactive, contaminated soils and 1,305,000 gallons of contaminated fluids and water from surface cleanup. 1238GR90-3nnJ ------- tritium and for any detectable gamma-emitting ra- dioisotopes. A special study was conducted in 1977-78 because of irregularities in tritium results in onsite samplings from a pond near SGZ (Half Moon Creek Overflow). To determine the source and extent of contamination, a grid design was used to locate 171 shallow holes that were drilled into the surface ground water. From the tritium results of the samples collected from these holes, a set of LTHMP holes was selected and added to the LTHMP sampling design. Tritium levels in the surface ground water have shown large fluctuations due to local rainfall. In general the concentrations continue to decrease. Decreasing trends, representative of those sampling wells with the highest tritium concentrations, from the Local Aquifer (HM-L), the Surficial Aquifer (HM-S) and the surface ground water (HMH-1, HMH-2, HMH- 5) are shown in Figure 4. Concern regarding possible health effects at- tributable to the two nuclear detonations conducted in the Tatum Salt Dome caused EPA to increase the scope of the radiological monitoring activities in 1990 to include the following: a. Urine samples from nearby residents. b. Vegetables and soil samples from local gardens. c. Water samples from additional residen- tial wells. d. Milk samples from goats and cows. e. Atmospheric moisture monitoring. f. Atmospheric paniculate monitoring. g. Deer, turkey, catfish, and turtle from the vicinity of SGZ. h. Soil, sediment, and vegetation sampling in the vicinity of SGZ. i. Water samples for non-radiological analysis (volatile organics, semi-volatile organics, pesticides, and heavy metals). j. Cow tissue samples. k. Goat tissue samples. 1. Five additional onsite shallow ground- water monitoring holes. For 1990, in all of the offsite samples, including human bioassay, no radioactive materials from the Tatum Dome Test Area were detected. Tritium contamination was detected in some water samples taken close to SGZ but the concentrations met the EPA criteria for drinking water. No other radioac- tive material above background was detected in any sample. All tritium contamination was detected within a 1,400-foot (430m) radius of SGZ. The analysis of water samples taken in the vicinity of SGZ for nonradioactive hazardous materials revealed very low level concentrations of a few organic chemical contaminants of unknown origin. No health effects would be expected from the contaminants at the concentrations found. The 1990 study is described in the EPA report, "Onsite and Offsite Environmental Monitoring Re- port: Radiation Monitoring Around Tatum Salt Dome, Lamar County, Mississippi, April 1990 (Thome et al., 1990). All analytical data resulting from the LTHMP and other radiological monitoring programs are published annually in EPA's "Offsite Environmental Monitoring Report: Radiation Moni- toring Around United States Nuclear Test Areas,...." These reports have been published each calendar year since the tests were conducted. Calendar Year 1991 Monitoring Results In April 1991, EMSL-LV conducted sampling on and around Tatum Salt Dome. In addition to the routine monitoring, a gamma-ray characterization of the Tatum Dome Test Area was performed. The locations of all sampling and gamma-ray measure- ment sites are shown in Figures 5 and 6. Sampling also included three locations in Columbia, MS, not shown in Figure 6. The sampling results are dis- cussed in the following sections. Water Much emphasis is placed on tritium analysis of ground-water samples. Following an underground nuclear test most of the radioactive materials that are created decay away very quickly. Most of those remaining are captured in the molten rock created by the explosion and in the surrounding rock itself. Tritium, which is naturally occurring and is also a product of nuclear explosions, is a radioactive form of hydrogen. It becomes incorporated in water molecules and moves with the ground-water flow. For this reason, tritium is used as an indicator of the migration of radioactive materials created from nuclear explosions. In April 1991, the HMH holes were sampled and then pumped dry. On the following day tritium samples were again collected. Also, according to standard procedure, one HM well (Well HM-3) was pumped steadily and five samples collected at one- naif hour intervals. The other HM wells were pumped steadily and two samples collected at one-half hour intervals. Two samples were taken on successive days from Half Moon Creek, Half Moon Creek Overflow, and the Pond West of GZ. All other locations were sampled once. Additional water samples were collected at the request of nine resi- dents. ------- Tritium in Water, Well HMH-1 Tatum Dome Test Area -J o Q. s—' c o to I_ 'c OJ £ O o ouuuuu " 450000 - 400000 - 350000 - 300000 - . . 250000 - i 200000 ' . 150000 - 100000 ' 50000 - n - q \ \ \ \ b \ t : i 1 t i i 1 i i •— i \ D"""" *s^n * •' ^» • '' x*» \ p-'' *n— . 0, i f ^^ * S *\ b— -a— --d' H""1-3 1978 1979 1980 19811982 1983 1984 1985 1986 1987 19881989 1990 1991 1992 Year o o O 250000 200000 ' O 150000 ' a. o "• 100000 - 50000 - Tritium in Water, Well HMH-2 Tatum Dome Test Area a.. -n—-a,. a—-a 0 1978 1979 1980 19811982 1983 1984 1985 1986 1987 19881989 1990 1991 1992 Figure 4. Plots of tritium concentrations vs. time. ------- Tritium in Water, Well HM-L Tatum Dome Test Area J- u a. c o co c 1 o O auuu 2800- 2600- 2400- 2200- 2000- 1800- 1600- 1400" 1200- 1000- p \ \ *^ » \ D \ -P n \ .'' *• P'' b -o-" "T dv P-... "P 0 P P \ i .--n 1 / p p p-- c) / cr' , *-* 0 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 Year (Depth = 200') 30000 25000 O 20000 o. c .2 15000- CO 0) u c o o 10000- 5000- Tritium in Water, Well HM-S Tatum Dome Test Area "•n. '"a 0 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 Year (Depth = 30') Figure 4. (Continued) ------- Tritium in Water, Well HMH-5 Tatum Dome Test Area 2* ri O a. c .0 "eo C 0) c O O 19000 : 18000 • 17000 : 16000 : 15000 : HOOO : 13000 : 12000 : tiooo : 1,0000 : 9000 : Booo : 7000 : 6000 • 5000 : 4000 : 3000 : 2000 : 1000 • .n. X p* ^ ff \ 'a P n / '-*"•--.. n / N\ / '» ' » ( 1 1 * 1 1 ' ~*n i « / *% ' * / < / > -u ', • • d \ / d n 0 1978 1979 1980 1981 1982 19831984 19851986 1987 1988 1989 1990 1991 1992 Year 1041GR91-4A Figure 4. (Continued) Sample Analysis Procedures The procedures for analyzing samples collected for this report were described by Johns et al. (EPA 1979) and are summarized in Appendix 3. These include gamma spectral analysis and radionuclide analysis for strontium, tritium, and plutonium. The EPA procedures are based on standard methodology for given analytical procedures. Two methods for tritium analysis were performed—conventional and electrolytic enrichment. The samples were initially analyzed by the conventional method. If the tritium result was less than 700 pCi/I, the sample was then analyzed by the electrolytic enrichment method which lowers the Minimum Detectable Concentration (MDC) from approximately 300 pCi/1 to 10 pCi/1. In the data tables (Appendix 4), results obtained using the conventional method are denoted by "3H" and results obtained by electrolytic enrichment are de- noted by "3H+". Sample results are corrected for the background radioactivity in the laboratory. Occa- sionally, negative results are obtained for extremely low level samples due to slight fluctuations in the background or analytical variability. Water Analysis Results No gamma-emitting radioactive materials were detected. The highest tritium concentration above the MDC in water collected from the offsite area was 48 pCi/L. This is from natural sources and it is 0.24 percent of the National Interim Primary Drinking Water Regulations (40CFR141) that places the maximum level of tritium in drinking water to be 20,000 pCi/L. The water samples from Wells HMH- 1 and HMH-2 both had the highest tritium concen- tration, 14,000 pCi/L, which is 70 percent of the drinking water regulation. Wells HMH-1 andHMH- 2 are located near SGZ and the water is not accessible to the public nor suitable for drinking due to its brackishness. In addition to the tritium and gamma spectroscopy analyses, water samples from locations sampled for the first time were analyzed for '"Sr, 238Pu and 239+24°pu. All of the water sample results are shown in Appendix 4. . Strontium-90, 238Pu, and 239+24opu were not detected at levels above the MDCs of approximately 3 pCi/L, 0.05 pCi/L and 0.004 pCi/ L, respectively. ------- HMH-16 Decontamiation Pad HMH-6 Water Lilies xx —HMH-4 200 Location/water sample Survey Location N [WellHT-2C 'HT-2 1238GR90NRD-5 Figure 5. Locations in the vicinity of surface ground zero sampled and monitored in 1991. ------- 3 (Q 3 0> o 0) s •o (O to Little Creek #1 T.S. Saucier - Yancy Saucier - erman Gipson — Lower Little Creek GIN Ray's Crawfish Pond Hugh Gipson r-Willie Surge I r~Joe Burge Hattiesburg • A ©CD©® Young s Dairy M u Salt Dome Timber Co. Donald Beach A.C. Mills ujRoy Mills B. Chambliss R. King Anderson's Pond v)©(u)B.R. Anderson Dennis • Saucier Hulon Lowe Tatum Hunting Club Howard Smith Rita Moree Sylvester Graham Lee L. Saul P.T. Lee H. Anderson ( J.R. Nobles G.W. Anderson© Noble's Pond Rita Smith Purvis Well * *13 Regina Anderson ,.,„ . . W. Daniels Noble's Quail House Ray Daniels Daniel's Well #2 • Location/water sample 0 Vegetation I) Soil Goat u) Urine 5) Milk * Non-Rad Water Sample A Atmospheric Tritium Lumberton i W 'u ------- Gamma-Ray Characterization Study This study was undertaken to inventory the amounts of surficial gamma-ray emitting radioactive materials and to determine the gamma-ray exposure rates on and around the Tatum Dome Test Area. Field measurements and soil core sampling were conducted at eight sites on the Tatum Dome Test Area and four locations in the surrounding areas. The locations of the eight sites located near SGZ are shown in Figure 5. The remaining four sites are the B.R. Anderson residence near the Tatum Dome Test Area, Purvis Elementary School lawn, Purvis High School lawn and the Hattiesburg Fire Station #4 dirt lot. Gamma-ray spectra were collected in the field with a high-purity germanium detector (HpGe) and a desktop multi-channel analyzer. Power was sup- plied to the electronics by aportable gasoline-powered generator. The spectra were later interpreted by the methods described in Beck et al. (1972) and Heifer and Miller (1988). During the data collection time, pressurized ion chamber measurements were made around the individual sites and at the exact location of the HpGe detector to determine the overall exposure rates. In addition, soil core samples were taken from the sites to determine the distribution of radionuclides with depth. The samples were separated into depth intervals of 0-2.5 cm, 2.5-5.0 cm, and 5.0-15.0 cm and packaged for shipment to the EMSL-LV labora- tory, where they were prepared and analyzed. Gamma-Hay Characterization Results Appendix 5 lists the (one meter above ground) dose rates measured in this study. Under the head- ings of "Total" and "PIC" are listed the sum of all nuclide and cosmic-ray contributions, and the pres- surized ion chamber readings at the same locations for comparison. Under the heading of "Other PIC Readings" are given the readings taken in the vicinity of each site. In addition to the pressurized ion chamber readings listed, the following locations were surveyed: south bank of Half Moon Creek Overflow (5.5 u.R/hr), 20 m southeast of the surface ground zero (SGZ) monument (5.9 |J-R/hr), 40 m southeast of SGZ monument (5.7 ^iR/hr), 120 m southeast of SGZ monument on access road (7.0 jiR/ hr), near Well HMH-11 approximately 40 m south- east of SGZ monument (6.1 uJR/hr), and inside REECo Pit near sampling location B (6.4 |iR/hr). The gamma-ray contribution sums and the pressurized ion chamber readings at all surveyed locations are in good agreement. In most cases the summed value is slightly less than the pressurized ion chamber value probably due to attenuation of radiation by surrounding trees (Miller et al. 1990). Appendix 6 lists the 137Cs inventories calcu- lated for each site surveyed with the germanium detector. The table shows the depth distribution parameter expressed as 3/p (Miller and Heifer 1985), 137Cs activity per unit area, and the MDC. No other manmade radionuclides were detected. The 137Cs inventories at all onsite locations are much lower than those at offsite locations where the surveys were taken on lawns. This is expected because dense grass cover is known to strongly retain deposited global fallout (Beck 1979), and the onsite locations were generally bare or partially covered. Also, all of the onsite surveys were made at locations where covering material was put down in remedial clean-up opera- tions. The presence of sand or gravel and the lack of humus causes a reduction of 137Cs retention and promotes a deeper dispersion of the cesium that remains, resulting in the low values of 3/p . 11 ------- CONCLUSION Njo radioactive materials from the Tatum Dome Test Area were detected in any of the offsite water samples. Onsite, tritium was the only radioactive contaminant detected. The tritium contamination was found in brackish water collected from shallow wells located near SGZ. Although this water is not available to the public nor fit for human consumption because of its brackishness, the tritium concentra- tions are well below those defined in the EPA Na- tional Interim Primary Drinking Water Regulations (40CFR141). The gamma-ray characterization study showed good agreement between the exposure rates derived from in-situ gamma-ray spectrometry and those measured with a pressurized ion chamber in all of the locations surveyed. Variabilities of flux contributed from radionuclides in the soil were small, with the exception of 137Cs fallout, which was lower than expected on all onsite locations. The 137Cs inventories on cultivated lawns were the highest measured in this study, but were within the range observed at other locations with similar annual precipitation. Vertical distributions of 137Cs in soil cores were found to be extended, likely because of the large amount of precipitation and the characteristics of the soil used as backfill during cleanup and decommission operations. No other manmade gamma-emitting nuclides were detected in laboratory analyses of soils or in spectra collected at any locations. A comparison of the open-field pressurized ion chamber measurements in this study showed no significant difference in gamma-ray flux at onsite and offsite locations. 12 ------- REFERENCES 1. A Guide for Environmental Radiological Sur- veillance at U.S. Dept. of Energy Installations, July 1981, Office of Operational Safety Report, U.S. DOE(DOE/EP-0023). 2. Beck, H. L. 1979. The natural radiation background of Utah - Preliminary report on radio- nuclides in soils in populated areas. New York: U.S. Department of Energy, Environmental Measure- ments Laboratory; EML-362. 3. Beck, H. L., J., De Campo, C. V., Gogolak. 1972. In Situ Ge(Li) and Nal(Tl) gamma-ray spec- trometry. New York: U.S. Department of energy, Environmental Measurements Laboratory; HASL- 258. 4. Federal Register, Vol. 41, title 40, Part 141, July 9, 1976, National Interim Primary Drinking Water Regulations. 5. Heifer, I. K., and K. M., Miller. 1988. Cali- bration factors for Ge detectors used for field spec- trometry. Health Physics 55:15-29. 6. Johns, F. 1979. Radiochemical and Analytical Procedures for Analysis of Environmental Samples. U.S. EPA, (EMSL-LV-0539-17-1979). 7. Lowder, W. M. and H. L., Beck. 1966. Cos- mic-ray ionization in the lower atmosphere. J. Geophys. Research 71:4661-4668. 8. Miller, K. M. and I. K., Heifer. 1985. In situ measurements of 137Cs inventory in natural terrain. In: Proceedings of the Health Physics Society mid- year topical symposium; (6-10 January); Colorado Springs, CO: Central Rocky Mountain chapter of the Health Physics society; 1985:243-251. 9. Miller, K. M., J. L., Kuiper, and I. K., Heifer. 1990.137Cs fallout depth distributions in forest ver- sus field sites: implications for external gamma dose rates. J. Environ. Radioactivity 12:23-47. 10. Shleien, B. and M. Terpilak. 1984. The Health Physics and Radiological Health Handbook. Nucleon Lectern Associates. 11. Thome", D. J., C. F., Fontana, and C. F., Costa. 1990. Onsite and offsite environmental monitoring report: radiation monitoring around Tatum Salt Dome, Lamar county, Mississippi. Las Vegas, NV: U.S. Environmental Protection Agency, Environmental Monitoring systems Laboratory; EPA/600/4-91/005. 13 ------- Appendix 1 Abbreviations cm centimeter = 1/100 meter = 0.39 inch DOE U.S. Department of Energy 24IAm EMSL-LV Environmental Monitoring Systems 3H Laboratory - Las Vegas 3H+ EPA U.S. Environmental Protection Agency ^Co FDA U.S. Food and Drug Administration 137Cs HpGe High purity germanium detector ^Sr keV kilo electron volts = thousand electron 238Pu VOltS 239+240^ kT kiloton (TNT equivalent) LTHMP Long-Term Hydrological Monitoring Program HMH-1 L liter thru 16 m meter HM-L, MDC minimum detectable concentration HM-L2 MeV mega electron volts = million electron HM-S volts mL milliliter = one thousandth of a liter HM-1 NIST National Institute of Science and Technology HM-2a ppb parts per billion pCi/L picocuries per liter = 10~12 curies per HM-2b liter = 1/1,000,000,000,000 curies per liter HM-3 pCi/g picocuries per gram = 10'12 curies per gram HT-2c, 4,5 PHS U.S. Public Health Service SGZ surface ground zero Americium-241 tritium enriched tritium cobalt-60 cesium-137 strontium-90 plutonium-238 plutonium-239 andplutonium-240 (in- dividual isotope not distinguished in analysis) Hydrological Monitoring Hole Hydrological Monitoring Well - Local Aquifer Hydrological Monitoring Well - Surficial Aquifer Hydrological Monitoring Well - Aquifer 1 Hydrological Monitoring Well - Aquifer 2a Hydrological Monitoring Well - Aquifer 2b Hydrological Monitoring Well - Aquifer 3 Hydrological Test Hole 14 ------- Appendix 2 Glossary of Terms Background Radiation The radiation in man's natural environment, including cosmic rays and radiation from natural- occurring radioactive elements, both outside and inside the bodies of humans and animals. It is also called natural radiation. The usually quoted average individual exposure from background radiation is 125 millirem per year in mid-latitudes at sea level (Shleien and Terpilak 1984). Curie (Ci) The basic unit used to describe the rate of radioactive disintegration. The curie is equal to 37 billion disintegrations per second, which is ap- proximately the rate of decay of 1 gram of radium; named for Marie and Pierre Curie, who discovered radium in 1898. Isotope One of two or more atoms with the same number of protons, but different numbers of neutrons in their nuclei. Thus 12C, 13C, and I4C are isotopes of the element carbon, the numbers denoting the ap- proximate atomic weights. Isotopes have very nearly the same chemical properties, but often different physical properties (for example 12C and 13C are stable, I4C is radioactive). Minimum Detectable Concentration (MDC) The smallest amount of radioactivity that can be reliably detected with a probability of Type I and Type II errors at 5 percent each (DOE 1981). Offsite All areas exclusive of the Tatum Dome Test Area. Onsite In this report refers to the area within the Tatum Dome Test Area. Shallow ground water Water found near the soil surface, caused by rain water saturation of the soil. This shallow ground water is not an aquifer. Surficial Aquifer The ground-water layer located closest to the surface, generally at a depth of approximately 30 feet at SGZ. Tritium A radioactive isotope of hydrogen that decays by beta emission. Its half-life is about 12.5 years. Type I Error The statistical error of accepting the presence of radioactivity when none is present. Type II Error 15 ------- APPENDIX 3 SUMMARY OF ANALYTICAL PROCEDURES TYPE OF ANALYSIS ANALYTICAL EQUIPMENT COUNTING PERIOD (MIN) ANALYTICAL PROCEDURES SAMPLE SIZE APPROXIMATE DETECTION LIMIT* IG or Ge(Li) Gamma Spectrometryb IG or GE(Li) detector calibrated at 0.5 keV/channel (0.04 to 2 MeV range) individual detector efficiencies ranging from 15% to 35%. Individual air filters, 30 min; 100 min for milk, water, sus-pended solids. Radionuclide concen- tration quantified from gamma spectral data by on-line computer program. Radionu- clides in air filter com- posite samples are identified only. 3.5 L for liquids and vegetables. Generally 5 pCi/L for most common fallout radionuclides in routine milk and water samples in a simple spectrum. Low background thin-window, gas- flow, proportional counter. 50 Chemical separation by ion exchange. Separated sample counted succes- sively; activity calculated by simul-taneous solution of equations. LOLformilkor water; 0.1 to 1 kg for tissue. 2pCi/L 3H Automatic liquid scintillation counter with output printer. 300 Sample prepared by distillation. 4 ml for water; 10 ml for urine; 50 g for tissue. 300to700pCi/L 3H+ (Enrichment) Automatic liquid scintillation counter with output printer. 300 Sample concentrated by electrolysis followed by distillation. 250 ml for water. 10 pCi/L 238,239+240pu /^ha spectrometer with silicon surface barrier detectors operated in vacuum chambers. 1000 to 4000 Water sample or acid- digested filter or tissue samples separated by ion exchange, electroplated on stainless steel planchet. 1.0L for water; 0.1 to1 kg for tissue. In water samples 0.08 pCi/L for ^Pu, and 0.05 pCi/L for 239*240Pu. For tissue samples, 0.05 pCi per total sample for all isotopes. The detection limit is defined as the smallest amount of radioactivity that can be reliably detected, i.e., probability of Type I and Type II error at 5% each. Gamma spectrometry using either an intrinsic germanium (IG), or lithium-drifted germanium diode (Ge(Li)) detector. 16 ------- APPENDIX 4 RESULTS FOR WATER SAMPLES COLLECTED IN APRIL, 1991 SAMPLE LOCATION COLLECTION DATE 1991 CONCENTRATION ± 2 S.D. IN pCI/L (MINIMUM DETECTABLE CONCENTRATION [MDC]) "°Sr 2MPu Anderson, Billy Ray 04/22 Anderson Pond 04/22 Anderson, Regina 04/22 Anderson, Robert Harvey 04/22 Anderson, Robert Lowell 04/22 04/22 Burge, Joe 04/22 Chambliss, B. 04/23 Daniels, Webster, Jr. 04/22 Daniels - Well #2 04/22 Half Moon Creek Half Moon Creek Overflow Hudson Quail House Jr. Green Creek Kelly Gertrude King, Rhonda 04/21 04/22 04/21 04/22 04/23 04/23 04/22 04/22 Baxterville, MS 19±5* (7.7) 13 ±6* (9.8) 18±6* (10) 16 ±5* (7.4) 14+5* (7.5) 26 ±6* (9.9) 18 ±7* (11) -4 ±5.5 (9.1) 14±6* (10) 24 ±5* (7.1) 19 ±5* (8.3) 31 ±7* (10) 120 ±7* (8.9) 280 ±8* (10) 48 ±8* (12) Not Sampled - Could not locate sampling point -3.6 ±4.4 (7.3) 20 ±6* (10) (Continued) 17 ------- APPENDIX 4 Continued RESULTS FOR WATER SAMPLES COLLECTED IN APRIL, 1991 SAMPLE COLLECTION LOCATION DATE 1991 Lee.P.T. i Little Creek #1 Lowe, M. Lower Little Creek #2 Mills, A. C. Mills, Roy Nobles Pond Noble, W.H., Jr. Pond West of GZ Ready, R. C. REECo Pit Drainage-A REECo Pit Drainage-B REECo Pit Drainage-C Salt Dome Hunting Club Salt Dome Timber Co. Saucier, Dennis 04/22 04/23 04/23 04/23 04/22 04/22 04/22 04/22 04/21 04/22 04/22 04/24 04/24 04/24 04/24 04/22 04/22 CONCENTRATION ± 2 S.D. IN pCI/L (MINIMUM DETECTABLE CONCENTRATION [MDC]) 3H 3H+ MSr ""Pu *wMopu Baxterville,MS(Cont.) 44±6* (9.1) 21 ±7* (12) Not sampled - On City Water 20 ±6* (9.8) 0.50 ±4.6 (7.5) 20 ±5* (7.3) 21 ±7* (11) 36 ±7* (11) 8.9 ±5.8 (9.4) 9.9 ±7.6 (12) 37 ±5* (7.4) 20 ±6* (9.8) 240 ±11* (15) 290+8* (10) 33 ±8* (13) 26 ±6* (9.4) 40 ±6* (9.9) (Continued) 18 ------- APPENDIX 4 Continued RESULTS FOR WATER SAMPLES COLLECTED IN APRIL, 1991 CONCENTRATION ± 2 S.D. IN pCI/L (MINIMUM DETECTABLE CONCENTRATION [MDC]) SAMPLE COLLECTION LOCATION DATE 1991 3H 3H+ *>Sr ""Pu 2~»s«pu Saucier, Talmadge S. Saucier, Wilma & Yancy Smith, Rita Well Ascot 2 Well City Well E-7 Well HM-1 Well HM-2A Well HM-2B Well HM-3 Well HM-L 04/23 04/23 04/22 04/23 04/23 04/23 04/22 04/22 04/22 04/22 04/22 04/22 04/22 04/22 04/22 04/22 04/22 04/22 04/22 04/22 Baxterville, MS(Cont.) 28 ±6* (9.2) 1.1 ±6.7 (11) Not Sampled - No One Home Not Sampled - No Access 33 ±6* (9.7) 8.5 ±6 (9.7) 1.9 ±5.4 (8.9) 0 + 5 (8.3) -2.9 ±5.2 (8.6) -2.8 ±5.7 (9.4) -0.63 ±6.67 (11) -1.2 + 5 (8.3) -0.1 9 ±5.93 (9.8) -4.1 ±5.4 (8-9) 2±5 (8.1) -0.19 ±6.18 (10) -2.5 ±7 (12) 1300 ±280* (450) 890 ±280* (450) 850 ±13* (12) (Continued) 19 ------- APPENDIX 4 Continued RESULTS FOR WATER SAMPLES COLLECTED IN APRIL, 1991 SAMPLE LOCATION COLLECTION DATE 1991 >H CONCENTRATION ± 2 S.D. IN pCI/L (MINIMUM DETECTABLE CONCENTRATION [MDC]) "°Sr Baxterville,MS(Cont.) Well HM-L2 i Well HM-S Well HMH-1 Well HMH-2 Well HMH-3 Well HMH4 Well HMH-5 WellHMH-6 Well HMH-7 Well HMH-8 04/22 04/22 04/21 04/23 04/23 04/21 04/22 04/21 04/22 04/21 04/22 04/21 04/22 04/21 04/22 04/21 04/22 04/21 04/22 04/21 04/22 7500 ±340* (450) 7600 ±340* (450) 7400 ±340* (450) 5000 ±320* (450) 14,000 ±390* (450) 7200+340* (450) 14,000 ±400* (450) _ 2200 ±290* (450) 2700 ±300* (450) 0.91 ±5.76 (9.5) -3.4 ±7.2 (12) 41 ±7* (11) 44 ±5* (8.2) 18±6* (10) 14 + 6* (8.8) 210 ±8* (10) 170 ±7* (8.7) Not Sampled - Under Water 16 ±6* (10) 22 ±5* (8) 20 ------- APPENDIX 4 Continued RESULTS FOR WATER SAMPLES COLLECTED IN APRIL, 1991 CONCENTRATION ± 2 S.D. IN pCI/L (MINIMUM DETECTABLE CONCENTRATION [MDC]) SAMPLE LOCATION Well HMH-9 Well HMH-10 WellHMH-11 WellHMH-12 Well HMH-13 Well HMH-14 Well HMH-15 WellHMH-16 Well HT-2C Well HT-4 Well HT-5 COLLECTION DATE 1991 3H 3H+ "Sr 04/21 04/22 04/21 04/22 04/21 04/22 04/21 04/22 04/21 04/22 04/21 04/22 04/21 04/22 04/21 04/22 04/23 04/23 04/23 Baxterville,MS,(Cont.) 130 ±8* (11) 150 ±7* (9.4) 91 ±8* (11) 35 ±7* (10) 22 ±5* (7.5) 21 ±7* (11) 16 ±6* (10) 17 ±5* (8.2) 18±6* (10) 19±7* (11) 16 ±6* (8.9) 11 ±6* (10) 18 ±6* (10) 8.9 ±5* (8.2) 31 ±6* (8.8) 38 ±6* (8.6) 18 ±7* (12) 7.6 ±6 (9.8) 4.216.5 (11) 2MB it 23ft+240B|] (Continued) 21 ------- APPENDIX 4 Continued RESULTS FOR WATER SAMPLES COLLECTED IN APRIL, 1991 CONCENTRATION ± 2 S.D. IN pCI/L (MINIMUM DETECTABLE CONCENTRATION [MDC]) SAMPLE COLLECTION LOCATION DATE 1991 3H Dennis, Buddy Dennis, Marvin Well 64B City Anderson, G. W. Anderson, Lee L. Beach, Donald Bond, Bradley K. Cox, Eddie Daniels, Ray Gil Ray's Crawfish Pond Gipson, Herman Graham, Sylvester Moree, Rita - House Well Powell, Shannon Rushing, Debra Saul, Lee L. 04/23 04/23 04/23 04/22 04/22 04/22 04/22 04/24 04/22 04/23 04/22 04/23 04/23 04/22 04/24 04/23 3H+ Columbia, MS 14 ±4* (6.7) 26 ±6* (8.7) 17 ±6* (10) Lumberton, MS 27 ±5* (8.2) 26 ±7* (11) 28 ±6* (9.3) 36 ±7* (11) 27 ±5* (7.7) 13 ±5* (8.6) 21 ±5* (7.3) -2.616.7 (11) 4.8 ±4.5 (7.4) 18 ±6* (9.5) 34 ±7* (10) -1.3 ±6.5 (11) •°Sr ^Pu 0.21 ±0.63 0.0048± 0.0096 (1.4) 0.36 ±0.61 0± 0.0094 (1.4) 0.27 ±0.60 -0.0027± 0.0121 (1.4) No sample - residents moved, -0.088 ± 0.71 3 -0.0039± 0.0079 (1.5) 0.077 ±0.573 0± 0.0066 (1.3) 0.51 ±0.60 0± 0.0065 (1-3) 0.93 ±0.63 0.01 6 ±0.032 (1.4) 231*240pu 0± 0.0068 0± 0.0094 0.0054 ±0.01 08 well down -0.0020 ±0.0039 0± 0.0066 0.0068 ±0.01 21 -0.0080 ±0.01 60 (Continued) 22 ------- APPENDIX 4 Continued RESULTS FOR WATER SAMPLES COLLECTED IN APRIL, 1991 SAMPLE COLLECTION LOCATION DATE 1991 Smith, Howard 04/23 Smith, Howard - Pond 04/23 Well 2 City 04/23 Burge, Willie Ray & Graco 04/22 City Supply 04/22 Gil, Ray -House Well 04/22 CONCENTRATION ± 2 S.D. IN pCI/L (MINIMUM DETECTABLE CONCENTRATION [MDC]} 3H ^ .«* ^ _pu Lumberton, MS, (Cont.) 0.073 ±4.598 (7-6) 18 ±5* 0.44 ±0.59 0 ±0.011 0.0075 ±0.0151 (7.7) (1.4) 4.7 ±5.9 (9.6) Purvis, MS 15 ±5* (7.7) 6.4+5.8 (9.4) 2.6+6.2 (10) * Concentration is greater than the minimum detectable concentration (MDC). Where gamma spectral analysis was performed, only collection dates are shown. 23 ------- APPENDIX 5 EXPOSURE RATE INVENTORIES AT ALL SURVEY LOCATIONS (Other pic readings taken near the location are also given.) A discussion of uncertainties is given in the following section. COSMIC WK ONSITE (1 ) Surface Ground Zero (12m northwest of monument) (2) Postshot No. 1 Slush Pit (3) WellHT-2 (4) WellHT-2M (5) Decontamination Pad (20 m north of beaver pond) (6) REECoPitA (7) REECoPitB (8) REECoPitC OFFsrre (9) B. R. Anderson Residence (lawn 30 m west of house) (1 0) Purvis Elementary School (lawn 100 m southwest of school) (11) Purvis High School (lawn 150 m north of school) (1 2) Hattiesburg Fire Station #4 Lot (13) Hattiesburg Hotel Room 3.6 3.6 3.6 3.6 3.6 3.6 3.6 3.6 3.7 3.7 3.7 3.6 3.6 0.2 0.4 0.3 0.6 0.2 0.4 0.5 0.4 0.5 0.3 0.4 0.2 1.0 Th 0.9 1.6 1.2 1.5 0.9 1.5 1.7 1.5 1.3 0.9 1.1 0.8 1.8 U 1.1 1.0 0.8 1.1 0.8 1.0 1.1 0.9 1.4 0.9 0.9 0.9 1.6 EXPOSURE RATE friR/HR) Rn "Be 1"Cs TOTAL 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 — „ 0.01 0.01 0.01 0.01 ._ 0.01 0.01 0.01 0.01 0.01 0.01 — 0.02* 0.02 0.03 0.06 0.01* 0.03 0.01 0.02 0.1 0.2 0.1 0.1* ™ 5.9 6.7 6.0 7.0 5.6 6.6 7.0 6.5 7.1 6.1 6.3 5.7 8.0 PIC 6.0 7.0 6.9 7.2 7.0 6.5 6.7 6.7 8.0 6.7 6.4 6.4 6.6 OTHER PIC READING 6.2, 7.2, 6.4, 6.8, 7.1, 7.2, 6.6, 7.0, 7.0, 6.8, 6.3, 6.0, 5.9, 6.1 6.5, 6.1 6.8, 6.4 7.5, 6.8 6.0, 6.4 7.3, 6.8 6.0, 6.4 6.6, 6.9 6.7, 7.2 6.4, 6.8 6.7, 6.5 6.5, 6.3 *—• 'Assuming <*/p = 0.5 (no cores taken) 24 ------- APPENDIX 6 SOIL SAMPLE STUDY IN-SITU SPECTROMETRY «/p" (mCi/km2) MDC ONSITE (1) Surface Ground Zero (12m northwest of monument) 0.05a 10.611.5 (5.2) (2) Post Shot No. 1. Slush Pit 0.081b 7.311.0 (5.4) (15m east of monument) (3) WellHT-2 0.13 7.811.7 (3.8) (4) WellHT-2M 0.060 25.213.5 (7.7) (5) Decontamination Pad 0.05a 6.512.1 (4.1) (6) REECoPitA 0.17 7.911.7 (3.7) (7) REECoPitB 0.10 4.710.2 (4.7) (8) REECoPitC 0.032° 15.514.2 (10.7) OFFSITE (9) B.R. Anderson Residence 0.065 42.613.7 (7.3) (10) Purvis Elementary School 0.068 89.113.5 (7.8) (11) Purvis High School 0.052 56.814.6 (8.4) (12) Hattiesburg Fire Station #4 Lot 0.05a 4.412.2 (5.8) 'Estimated value. ''Derived from result of combined six core samples. c Derived from result of one core sample (all others derived from combined three core samples). "x/p = x Corresponds to surficial deposition, <*/p = 0 corresponds to uniform distribution 25 ------- |