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An Evaluation of Activated Bismuth Isotopes in Environmental Samples From the Former Western Pacific Proving Grounds

Description: {sup 207}Bi (t{sub 1/2}=32.2 y) was generated by activation of weapons material during a few ''clean'' nuclear tests at the U.S. Western Pacific Proving Grounds of Enewetak and Bikini Atolls. The radionuclides first appeared in the Enewetak environment during 1958 and in the environment of Bikini during 1956. Crater sediments from Bikini with high levels of {sup 207}Bi were analyzed by gamma spectrometry in an attempt to determine the relative concentrations of {sup 208}Bi (t{sup 1/2} = 3.68 x 10{sup 5} y). The bismuth isotopes were probably generated during the ''clean'', 9.3 Mt Poplar test held on 7/12/58. The atom ratio of {sup 208}Bi to {sup 207}Bi (R value) ranges from {approx}12 to over 200 in sections of core sediments from the largest nuclear crater at Bikini atoll. The presence of bismuth in the device is suggested to account for R values in excess of 10.
Date: March 21, 2000
Creator: Robison, W.L.; Brunk, J.A. & Jokela, T.A.
Partner: UNT Libraries Government Documents Department

Radiation measurements of uranium ingots from the electrometallurgical treatment of spent fuel.

Description: Radiation measurements and gamma spectroscopy analyses were made on numerous uranium ingots produced during the treatment of Experimental Breeder Reactor-II (EBR-II) spent nuclear fuel. The objective of these measurements was to provide background data for shielding concerns and potential process optimization. The uranium ingots resulted from the processing of both driver and blanket fuel by the electrometallurgical treatment process. The observed variation in the measurements was traced to the levels of certain fission product residues that remained in the uranium ingots produced during spent fuel treatment. A minor process change to hold the material at an elevated temperature for a specified length of time was found to significantly reduce concentrations of high-activity fission products and, thus the radiation field.
Date: March 24, 2003
Creator: Westphal, B. R.; Liaw, J. R.; Krsul, J. R.; Maddison, D. W. & Jensen, B. A.
Partner: UNT Libraries Government Documents Department

Origin of the 871-keV gamma ray and the ``oxide'' attribute

Description: This work concludes the investigation of the oxide attribute of current interest for the characterization of stored plutonium. Originally it was believed that the presence of oxide could be ascertained by measurement of the 871-keV line in a high-resolution gamma-ray spectrum. However, recent work has suggested that the 871-keV gamma ray in plutonium oxide arises from the reaction {sup 14}N({alpha},p){sup 17}O rather than the inelastic scattering reaction {sup 17}O({alpha},{alpha}{prime}){sup 17}O*. This conclusion, though initially surprising, was obtained during efforts to determine the relative importance of americium and plutonium alpha-particle decay for the production of the 871-keV gamma ray. Several questions were raised by previous experiments: What role, if any does {sup 17}O have in the generation of the 871-keV gamma ray? How does sufficient nitrogen come to be present in plutonium oxide? Under what conditions is the 871-keV gamma ray measurable in plutonium oxide? This paper describes the answers to these questions.
Date: March 22, 2000
Creator: Peurrung, AJ; Arthur, RJ; Geelhood, BD; Scheele, RD; Elovich, RJ & Pratt, SL
Partner: UNT Libraries Government Documents Department

Cadium-Zinc-Telluride (CZT) Gamma Ray Spectrometry

Description: This report describes CZT crystals and their use in large arrays for generation of gamma ray spectra. Laboratory spectra will be shown together with spectra accumulated by various battery powered portable instruments (see Appendix A). One of these portable instruments was specifically constructed to minimize power consumption and yet provide reasonable isotope identification capability. Detailed data will be presented covering gamma energy resolution, gamma peak shapes, system background, and detector efficiency. Nearly all data were taken with very small crystals of CZT; cubes 5 mm on a side. A few spectra will be presented from cylindrical crystals of about the same size (see Appendix A). The small crystal size leads to low counting rates and extended counting times for reliable isotope identification. We have addressed this problem by using arrays of CZT crystals, initially two crystals and, at present, arrays of eight crystals. Data will be shown relating spectral parameters for these two arrays. System MDA is one way of combining resolution, efficiency, and background that will enable direct comparison of various detector types for individual isotope identification. We have calculated the MDA for an early dual crystal array and the current eight crystal array. Data derived from each array will be presented. In addition, it is possible to extrapolate the MDA methodology to much larger arrays. A 32-crystal array is under construction and extrapolations to 256 and 1024 crystals are considered possible. Estimated MDA values for these larger arrays are also presented. Several 8-crystal arrays have been constructed and versions have been incorporated into portable instruments. Descriptions of these small instruments are given covering physical size, weight, and general configuration. These instruments have been tested for shock and temperature effects and data will be presented on the results of these tests. The MDA concept will also allow extrapolation to ...
Date: September 1, 2001
Creator: Quam, William
Partner: UNT Libraries Government Documents Department


Description: Calorimetry has been used for accountability measurements of nuclear material in the US. Its high accuracy, insensitivity to matrix effects, and measurement traceability to National Institute of Standards and Technology have made it the primary accountability assay technique for plutonium (Pu) and tritium in the Department of Energy complex. A measurement of Pu isotopic composition by gamma-ray spectroscopy is required to transform the calorimeter measurement into grams Pu. The favorable calorimetry attributes allow it to be used for verification measurements, for production of secondary standards, for bias correction of other faster nondestructive (NDA) methods, or to resolve anomalous measurement results. Presented in this paper are (1) a brief overview of calorimeter advantages and disadvantages, (2) a description of projected large volume calorimeters suitable for waste measurements, and (3) a new technique, direct measurement of transuranic TRU waste alpha-decay activity through calorimetry alone.
Date: August 2000
Creator: Rudy, C.; Bracken, D. S.; Smith, M. K. & Schanfein, M. J.
Partner: UNT Libraries Government Documents Department

Neutron-Induced Partial Gamma-Ray Cross-Section Measurements with GEANIE at LANSCE/WNR

Description: GEANIE is the first large-scale Ge detector array used in conjunction with a high-energy neutron spallation source. GEANIE consists of eleven Compton-suppressed planar detectors, nine suppressed and six unsuppressed co-axial detectors. Spallation neutrons are provided by the LANSCE/WNR facility, and reaction neutron energies are determined via time-of-flight. neutron flux is monitored in-beam with a fission chamber. GEANIE at LANSCE/WNR currently emphasizes the measurement of partial gamma-ray cross sections as a function of neutron energy. Absolute cross section measurements require a complete understanding of array performance. Important effects include intrinsic detector efficiency, beam and detector geometry corrections, target attenuation, and deadtime. Measurements and calculations of these effects will be presented for the specific cases of iron and actinide targets. The use of radioactive targets incurs a large deadtime penalty. In order to increase data throughput they are making plans to move to a triggerless data acquisition system. These modifications and other improvements to the electronics for better timing will be discussed.
Date: January 10, 2000
Creator: McNabb, D.P.; Becker, J.A.; Archer, D.; Bernstein, L.A.; Garrett, P.E.; McGrath, C.A. et al.
Partner: UNT Libraries Government Documents Department

Preparation of Pure Plutonium Metal Standards for Nondestructive Assay

Description: To calibrate neutron coincidence and neutron multiplicity counters for passive assay of plutonium, certain detector parameters must be determined. When one is using small plutonium metal samples, biases can be introduced from non-zero multiplication and impurities. This paper describes preparing small, pure plutonium metal standards with well-known geometries to enable accurate multiplication corrections and with acceptably low levels of impurities. To minimize multiplication, these standards are designed as 2-cm-diameter foils with varying thicknesses and masses of 1.4, 3.6, and 7.2 g plutonium. These standards will significantly improve characterization and calibration of neutron coincidence and multiplicity counters. They can also be equally useful for gamma-ray spectrometry and calorimetry. Five sets will be made: four for other US Department of Energy plutonium facilities, and one set to remain at Los Alamos. We will also describe other nondestructive assay standards that are planned for the next few years.
Date: November 1, 2000
Creator: Hsue, S. -T.; Stewart, J. E. & Krick, M. S.
Partner: UNT Libraries Government Documents Department

Determination of 243Am in 244Cm by Gamma Spectroscopy

Description: Gamma spectroscopy with a high resolution Ge(Li) detector is used to determine 243Am by its 74.7-keV gamma transition in solutions containing much higher specific activities of other actinides and fission products. The method is well suited for analytical control of curium process steps because of its simplicity, speed and reliability. This paper discusses the study results.
Date: August 29, 2001
Creator: Wakat, M.A.
Partner: UNT Libraries Government Documents Department

Achieving Higher Accuracy in the Gamma-Ray Spectrocopic Assay of Holdup

Description: Gamma-ray spectroscopy is an important technique for the measurement of quantities of nuclear material holdup in processing equipment. Because the equipment in large facilities dedicated to uranium isotopic enrichment, uranium/plutonium scrap recovery or various stages of fuel fabrication is extensive, the total holdup may be large by its distribution alone, even if deposit thicknesses are small. Good accountability practices require unbiased measurements with uncertainties that are as small as possible. This paper describes new procedures for use with traditional holdup analysis methods based on gamma-ray spectroscopy. The procedures address the two sources of bias inherent in traditional gamma-ray measurements of holdup. Holdup measurements are performed with collimated, shielded gamma-ray detectors. The measurement distance is chosen to simplify the deposit geometry to that of a point, line or area. The quantitative holdup result is based on the net count rate of a representative gamma ray. This rate is corrected for contributions from room background and for attenuation by the process equipment. Traditional holdup measurements assume that the width of the point or line deposit is very small compared to the measurement distance, and that the self-attenuation effects can be neglected. Because each point or line deposit has a finite width and because self-attenuation affects all measurements, bias is incurred in both assumptions. In both cases the bias is negative, explaining the systematically low results of gamma-ray holdup measurements. The new procedures correct for bias that arises from both the finite-source effects and the gamma-ray self-attenuation. The procedures used to correct for both of these effects apply to the generalized geometries. One common empirical parameter is used for both corrections. It self-consistently limits the total error incurred (from uncertain knowledge of this parameter) in the combined correction process, so that it is compelling to use these procedures. The algorithms and the procedures ...
Date: September 1, 2000
Creator: Russo, P.A.; Wenz, T.R.; Smith, S.E. & Harris, J.F.
Partner: UNT Libraries Government Documents Department

X-ray and Gamma-ray Spectroscopy of Solids under Pressure

Description: This report describes our recent synchrotrons x-ray absorption fine structure (XAFS) measurements on a number of systems that undergo pressure induced changes in local structure at high pressure. The reader should also refer to the accompanying renewal proposal for a more in-depth discussion of the general scope of this program, and its relevance to condensed matter science. We merely state that the methods here are aimed at using XAFS to probe the various phenomena that are caused by high pressure, especially including various structural, and/or electronic, changes or transitions. Our general technique is based upon a pressure cell which utilizes scintered boron carbide anvils, since diamond anvils generally produce Bragg glitches which spoil the high quality XAFS necessary for precision structural measurements. Sample pressure is determined at the beam-line by measuring and analyzing, via XAFS, the compression of some cubic material contained within the sample chamber. Recently we have extended this work to 77 K using helium gas for the applied force, rather than hydraulic oil. This report period has been productive. The increased flux available at the Stanford Synchrotrons Radiation Laboratory (SSRL) has permitted our going to smaller beams, on the order of 300 pm in diameter, for precision probing of the sample region. At the same time we have received ample amounts of beam time at SSRL, in part because of the high rating of our latest user proposal. We also were invited to share some of the beam time at the National Synchrotron Light Source (NSLS) assigned to the group of our collaborator, E. A. Stern. Below we describe in some detail our recent work. Some of the pending papers are reports on systems that have been under study for some time and have been described in past progress reports and, as such, need not be described ...
Date: March 1, 2000
Partner: UNT Libraries Government Documents Department

The deployment of an innovative real-time radiological soil characterization system

Description: Fluor Fernald Inc., in conjunction with partners from Argonne National Laboratory, the Department of Energy's Environmental Measurements Laboratory, and Idaho National Engineering and Environmental Laboratory, has developed a program for characterizing radiological contaminants in soil in real time. The soil characterization system in use at the Fernald Environmental Management Project (FEMP) for over three years combines gamma ray spectrometry equipment with other technologies to produce a system that can scan large areas of ground and produce color coded maps which display quantitative information regarding isotopic contamination patterns. Software running on a battery powered lap-top computer, is used to control acquisition of gamma spectral data to link the spectral Information with precise detector position measurements from Global Positioning System (GPS) satellites, and to control transmission of data to a central station or van via a wireless Ethernet link where Surfer6 mapping software is used to produce maps showing the position and amount of each target analyte. Either sodium iodide (NaI) gamma ray detectors mounted on three different vehicles for mobile measurements or stationary tripod-mounted hyper-pure germanium (HPGe) detectors can be used in this system to radiologically characterize soil. The operational and performance characteristics, as well as the strengths and limitations of each of these units, will be described. The isotopic information generated by this system can be made available to remediation project mangers within an hour after the completion of a scan to aid in determination of excavation footprints, segregation of contaminated soil and verification of contamination removal. The immediate availability of radiological characterization data made possible by this real-time scanning system has allowed Fluor Fernald to accelerate remediation schedules and reduce costs by avoiding excavation delays and expensive and time consuming laboratory analyses. Obtaining actual radiological characterization data from a much greater percentage of the soil under characterization than would ...
Date: September 29, 2000
Creator: Allen, David; Danahy, Raymond; Laird, Gregory; Seiller, Dale; White, Joan & Janke, Robert
Partner: UNT Libraries Government Documents Department

Gamma-Ray Spectrometric Characterization of Overpacked CC104/107 RH-TRU Wastes: Surrogate Tests

Description: Development of the gamma-ray spectrometric technique termed GSAK (Gamma-Ray Spectrometry with Acceptable Knowledge) for the characterization of CC104/107 remote-handled transuranic (RH-TRU) wastes continued this year. Proof-of-principle measurements have been completed on the surrogate RH-TRU waste drums configured earlier this year. The GSAK technique uses conventional gamma-ray spectrometry to quantify the detectable fission product content of overpacked RH-TRU drums. These results are then coupled with the inventory report to characterize the waste drum content. The inventory report is based on process knowledge of the waste drum loading and calculations of the isotopic distribution in the spent fuel examined to generate the drummed wastes. Three RH-TRU surrogate drums were configured with encapsulated EBR-II driver fuel rod segments arranged in the surrogate drum assemblies. Segment-specific inventory calculations initially specified the radionuclide content of the fuel segments and thus the surrogate drums. Radiochemical assays performed on representative fuel element segments identified a problem in the accuracy of some of the fission and activation product inventory values and provided a basis for adjustment of the specified surrogate drum inventories. The three waste drum surrogates, contained within their 8.9 cm (3.5 inch) thick steel overpacks, were analyzed by gamma-ray spectrometry at the TREAT facility at Argonne National Laboratory-West. Seven fission and activation product radionuclides ({sup 54}Mn, {sup 60}Co, {sup 125}Sb, {sup 134}Cs, {sup 137}Cs, {sup 144}CePr, and {sup 154}Eu) were reliably detected. The gamma-ray spectral accuracy was very good. In all cases, a two-sigma error bar constructed about the measured value included the actual drum activity.
Date: May 1, 2000
Creator: Hartwell, J. K.; Klann, R. T. & McIlwain, M. E.
Partner: UNT Libraries Government Documents Department


Description: This report describes a system for handling and radioassay of lead, consisting of a robot, a conveyor, and a gamma spectrometer. The report also presents a cost-benefit analysis of options: radioassay and recycling lead vs. disposal as waste.
Date: January 1, 2001
Creator: M.A. Ebadian, Ph.D.; Dua, S.K.; Roelant, David & Kumar, Sachin
Partner: UNT Libraries Government Documents Department

[Three-dimensional position-sensitive germanium detectors]. Annual report for EMSP Project Number 65015

Description: This study focuses on the radioactive materials characterization needs of DOE's decontamination and decommissioning effort. Gamma-ray imaging and spectroscopy together form a potentially powerful tool for the passive, non-destructive and non-intrusive identification and spatial mapping of contaminated structures. Germanium position-sensitive gamma-ray detectors offer the advantage of excellent energy resolution required for clear isotopic identification combined with potentially high spatial resolution. The authors propose a program of research to develop three-dimensional position-sensitive germanium detectors with the ultimate goal of improving image resolution without cameras. With the addition of depth-of-interaction sensing to conventional two-dimensional position-sensitive detectors, they will be able to greatly reduce the image degradation effects caused by Compton scattering and parallax, thereby increasing the resolving power of the detectors. The technology developed will form the basis for the design and fabrication of future high-performance gamma-ray imaging cameras.
Date: February 25, 2000
Creator: Amman, Mark & Luke, Paul
Partner: UNT Libraries Government Documents Department

Closure Report for Corrective Action Unit 240: Area 25 Vehicle Washdown Nevada Test Site, Nevada

Description: The Area 25 Vehicle Washdown, Corrective Action Unit (CAU) 240, was clean-closed following the approved Corrective Action Decision Document closure alternative and in accordance with the Federal Facility Agreement and Consent Order (FFACO, 1996). The CAU consists of thee Corrective Action Sites (CASs): 25-07-01 - Vehicle Washdown Area (Propellant Pad); 25-07-02 - Vehicle Washdown Area (F and J Roads Pad); and 25-07-03 - Vehicle Washdown Station (RADSAFE Pad). Characterization activities indicated that only CAS 25-07-02 (F and J Roads Pad) contained constituents of concern (COCs) above action levels and required remediation. The COCs detected were Total Petroleum Hydrocarbons (TPH) as diesel, cesium-137, and strontium-90. The F and J Roads Pad may have been used for the decontamination of vehicles and possibly disassembled engine and reactor parts from Test Cell C. Activities occurred there during the 1960s through early 1970s. The F and J Roads Pad consisted of a 9- by 5-meter (m) (30- by 15-foot [ft]) concrete pad and a 14- by 13-m (46-by 43-ft) gravel sump. The clean-closure corrective action consisted of excavation, disposal, verification sampling, backfilling, and regrading. Closure activities began on August 21, 2000, and ended on September 19, 2000. Waste disposal activities were completed on December 12, 2000. A total of 172 cubic meters (223 cubic yards) of impacted soil was excavated and disposed. The concrete pad was also removed and disposed. Verification samples were collected from the bottom and sidewalls of the excavation and analyzed for TPH diesel and 20-minute gamma spectroscopy. The sample results indicated that all impacted soil above remediation standards was removed. The closure was completed following the approved Corrective Action Plan. All impacted waste was disposed in the Area 6 Hydrocarbon Landfill. All non-impacted debris was disposed in the Area 9 Construction Landfill and the Area 23 Sanitary Landfill.
Date: March 1, 2001
Creator: Gustafason, D. L.
Partner: UNT Libraries Government Documents Department

Measurement uncertainties and minimum detectable concentrations for the in situ NaI gamma spectroscopy systems used at the Fernald site.

Description: This report determines the uncertainties associated with measurements made by using the mobile gamma-ray spectrometers deployed at the U.S. Department of Energy's Fernald Closure Project to characterize soil contaminated with {sup 238}U, {sup 226}Ra, and {sup 232}Th. It also examines minimum detectable concentrations (MDCs) for these instruments. The spectrometers use sodium iodide (NaI) detectors and are mounted on a variety of platforms that allow access to all areas of the site, including deep excavations. They are utilized for surveying large areas to obtain distribution patterns for radionuclides in soil, determining whether activity concentrations exceed action levels for hot spots, and determining if the concentration of total uranium exceeds the allowable level for Fernald's on-site disposal facility. Soil cleanup levels at Fernald are 82 parts per million (ppm) for total uranium (27.3 pCi/g for {sup 238}U), 1.7 pCi/g for {sup 226}Ra, and 1.5 pCi/g for {sup 232}Th. The waste acceptance criterion (WAC) for total uranium for the disposal facility is 1030 ppm. Uncertainties associated with counting, efficiency calibration, the calibration pad and sources used, the vertical distribution of contaminants in soil, the use of moisture corrections, and the use of corrections to account for the loss of radon from soil are examined. (Loss of radon is an important process because measurement of {sup 226}Ra relies on emissions from progeny of {sup 226}Ra and because {sup 222}Rn is an intermediate, highly mobile decay product.) The importance of each source of uncertainty depends on the radionuclide of interest and level of contamination. The combined relative uncertainty (relative standard deviation) in measurements of dry-weight concentrations near three times the cleanup levels (the action levels for hot spots) is about 30% for 4-second measurements of {sup 238}U, 40% for {sup 226}Ra, and 20% for {sup 232}Th. (Measurement uncertainties for {sup 226}Ra are elevated because of ...
Date: July 20, 2004
Creator: Davis, M. J.
Partner: UNT Libraries Government Documents Department

Measurement of cross sections for the 63Cu(alpha,gamma)67Ga reaction from 5.9-8.7 MeV

Description: We have measured cross sections for the 63Cu(alpha,gamma)67Ga reaction in the 5.9-8.7 MeV energy range using an activation technique. Natural Cu foils were bombarded with alpha beams from the 88 Cyclotron at Lawrence Berkeley National Laboratory (LBNL). Activated foils were counted using gamma spectrometry system at LBNL's Low Background Facility. The 63Cu(alpha,gamma)67Ga cross-sections were determined and compared with the latest NON-SMOKER theoretical values. Experimental cross sections were found to be in agreement with theoretical values.
Date: September 23, 2004
Creator: Basunia, M. Shamsuzzoha; Norman, Eric B.; Shugart, Howard A.; Smith, Alan R.; Dolinski, Michelle J. & Quiter, Brian J.
Partner: UNT Libraries Government Documents Department

Gamma Ray Imaging for Environmental Remediation

Description: This program is the development of germanium strip detectors for environmental remediation. It is a collaboration between the Naval Research Laboratory and Lawrence Berkeley National Lab. The goal is to develop detectors that are simultaneously capable of excellent spectroscopy and imaging of gamma radiation.
Date: November 12, 2004
Creator: Philips, B.F.; Johnson, R.A. Kroeger: J.D. Kurfess: W.N.; Wulf, E.A. & Novikova, E. I.
Partner: UNT Libraries Government Documents Department

University Reactor Sharing Program

Description: Research projects supported by the program include items such as dating geological material and producing high current super conducting magnets. The funding continues to give small colleges and universities the valuable opportunity to use the NSC for teaching courses in nuclear processes; specifically neutron activation analysis and gamma spectroscopy. The Reactor Sharing Program has supported the construction of a Fast Neutron Flux Irradiator for users at New Mexico Institute of Mining and Technology and the University of Houston. This device has been characterized and has been found to have near optimum neutron fluxes for A39/Ar 40 dating. Institution final reports and publications resulting from the use of these funds are on file at the Nuclear Science Center.
Date: February 24, 2004
Creator: Reese, W.D.
Partner: UNT Libraries Government Documents Department

Generalization of the FRAM's Bias

Description: The Fixed-Energy Response-Function Analysis with Multiple Efficiency (FRAM) code was developed at Los Alamos National Laboratory to measure the gamma-ray spectrometry of the isotopic composition of plutonium, uranium, and other actinides. Its reported uncertainties of the results come from the propagation of the statistics in the peak areas only. No systematic error components are included in the reported uncertainties. We have done several studies and found that the FRAM's statistical precision can be reasonably represented by its reported uncertainties. The FRAM's biases or systematic uncertainties can come from a variety of sources and can be difficult to determine. We carefully examined the FRAM analytical results of the archival plutonium data and of the data specifically acquired for this isotopic uncertainty analysis project and found the relationship between the bias and other parameters. We worked out the equations representing the biases of the measured isotopes from each measurement using the internal parameters in the spectrum such as peak resolution and shape, region of analysis, and burnup (for plutonium) or enrichment (for uranium).
Date: October 1, 2005
Creator: Vo, Duc T.
Partner: UNT Libraries Government Documents Department


Description: Global warming is promoted by anthropogenic CO{sub 2} emissions into the atmosphere, while at the same time it is partially mitigated by carbon sequestration by terrestrial ecosystems. However, improvement in the understanding and monitoring of below ground carbon processes is essential for evaluating strategies for carbon sequestration including quantification of carbon stores for credits. A system for non-destructive in situ carbon monitoring in soil, based on inelastic neutron scattering (INS), is described. The system can be operated in stationary or scanning mode and measures soil to depth of approximately 30 cm. There is a good agreement between results obtained from INS and standard chemical analysis of soil cores collected from the same study site.
Date: May 5, 2003
Partner: UNT Libraries Government Documents Department


Description: As of October 2001, approximately 7,000 yd{sup 3} of stockpiled soil, contaminated to varying degrees with radioactive materials and heavy metals, remained at Brookhaven National Laboratory (BNL) after the remediation of the BNL Chemical/Animal/Glass Pits disposal area. During the 1997 removal action, the more hazardous/radioactive materials were segregated, along with, chemical liquids and solids, animal carcasses, intact gas cylinders, and a large quantity of metal and glass debris. Nearly all of these materials have been disposed of. In order to ensure that all debris was removed and to characterize the large quantity of heterogeneous soil, BNL initiated an extended sorting, segregation, and characterization project, co-funded by the BNL Environmental Management Directorate and the DOE EM Office of Science and Technology Accelerated Site Technology Deployment (ASTD) program. Project objectives were to remove any non-conforming items, and to assure that mercury and radioactive contaminant levels were within acceptable limits for disposal as low-level radioactive waste. Sorting and segregation were conducted simultaneously. Large stockpiles, ranging from 150 to 1,200 yd{sup 3}, were subdivided into manageable 20 yd{sup 3} ''subpiles'' after powered vibratory screening. The 1/2 inch screen removed gravel and almost all non-conforming items, which were separated for further characterization. Soil that passed through the screen was also visually inspected before being moved to a subpile. Eight samples plus QA duplicates were collected from each subpile for chemical analysis, and a 1-Liter jar of material for gamma spectroscopy. A field lab equipped for chemical analysis and gamma spectroscopy was set up in a trailer close by the stockpile site. Chemical analysis included X-ray fluorescence (XRF) to screen for high (>260 ppm) total mercury concentrations, and modified Toxicity Characteristic Leaching Procedure (TCLP) tests to verify that the soils were not RCRA hazardous. The modified (1/10th scale) TCLP tests minimized secondary (leachate) waste and maximized ...
Date: February 23, 2003
Partner: UNT Libraries Government Documents Department