A variety of systems have now been described for use in surveying sites for anthropogenic radiological contamination. Virtually all of these include use of sodium iodide detectors and register detection data with global positioning satellite data. This paper demonstrates how lanthanum bromide detectors can be used to augment existing field surveys in a manner to reduce uncertainty in areas of low count rates and to discriminate between depleted uranium and naturally occurring uranium. The survey system described is equipped with large (20 × 20 × 100 cm) sodium iodide (Alpha Spectra) and 7.5 × 7.5 cm lanthanum bromide (Saint Gobain) detectors. Additional radiological detection equipment (DigiBase) was obtained from ORTEC with survey data collected in the List Mode. Data collected in surveys were then used to generate digital maps using GeoSoft’s Oasis Montaj. Software has been developed to automatically identify areas of increased count rates using user-defined thresholds. This software can collect the count data for the masked area and generate a composite spectrum that can be compared to a reference spectrum believed to represent an uncontaminated area. Ratios of counts attributed to protactinium-234m (Pa-234m) are compared to counts attributed to Bismuth-214 (Bi-214) for both the composite filed survey spectrum and the reference spectrum. Soil samples have been collected from selected sites over a range of soil and geology types for the purpose of collecting data comparing high purity germanium (HPGe) detector and lanthanum bromide (LaBr) detector spectra. These samples have come from areas believed to be devoid of depleted uranium contamination and from areas expected to have higher concentrations of naturally occurring uranium. A library of HPGe and LaBr spectra have been collected comparing: (1) background soil samples with, (2) spectra from the same samples that have been doped with half the remediation threshold activity of depleted uranium, and (3) the remediation threshold activity of depleted uranium. Ratios of the Pa-234m:Bi-214 for both HPGe and LaBr detectors are provided in this paper. This process can be repeated for any site of interest. Background soil samples can be obtained prior to surveying and an equivalent library of spectral ratios generated. Field data from three different sites will be used to show how LaBr detectors can be effectively used as an infield HPGe surrogate for rapid discrimination between DU contamination and areas of high naturally occurring uranium. Areas of maps of questionable contamination are selected and composite LaBr spectra are generated along with Pa-234m:Bi-214 ratio. This is compared to library data to determine the approximate activity of DU present. All areas suspected of DU contamination can also be selected and excluded from the remainder of map data. A composite spectrum from the areas believed to be uncontaminated can be generated and spectral ratios compared library data for clearance purposes.

The contents of this report are not to be used for advertising, publication, or promotional purposes. Citation of trade names does not constitute an official endorsement or approval of the use of such commercial products. All product names and trademarks cited are the property of their respective owners. The findings of this report are not to be construed as an official Department of the Army position unless so designated by other authorized documents. DESTROY THIS REPORT WHEN NO LONGER NEEDED. DO NOT RETURN IT TO THE ORIGINATOR.DISCLAIMER: The contents of this report are not to be used for advertising, publication, or promotional purposes. Citation of trade names does not constitute an official endorsement or approval of the use of such commercial products. All product names and trademarks cited are the property of their respective owners. The findings of this report are not to be construed as an official Department of the Army position unless so designated by other authorized documents.

Researchers from the Mississippi State University Institute for Clean Energy Technology (MSU-ICET) and the U.S. Army Engineer Research and Development Center (ERDC) have identified procedures and methodologies for identifying leaching solutions to assist in the removal of depleted uranium (DU) oxides from contaminated soils. They developed a benchscale leach system to optimize leaching procedures and methodologies. This study identified that a 2 molar (M) acetic-acid solution with a 15% (v/v) 0.3 M hydroxylamine hydrochloride solution could remove approximately 70% of the uranium in the soil sample. Pretreating the soil with 3 M hydrochloric acid improved leaching efficiency to approximately 90%. The MSU-ICET research team developed the preliminary design of a mobile leaching system based on the hydrochloric-acid pretreatment followed by 2 M acetic acid / 15% (v/v) 0.3 M hydroxylamine hydrochloride leaching method. The trailer heap leach system is designed to be used on-site, eliminating the need for additional transport of radioactive, contaminated soils. This will reduce the risk of radioactive exposure for personnel and will eliminate potentially serious transportation accidents. DISCLAIMER:The contents of this report are not to be used for advertising, publication, or promotional purposes. Citation of trade names does not constitute an official endorsement or approval of the use of such commercial products. All product names and trademarks cited are the property of their respective owners. The findings of this report are not to be construed as an official Department of the Army position unless so designated by other authorized documents.DESTROY THIS REPORT WHEN NO LONGER NEEDED. DO NOT RETURN IT TO THE ORIGINATOR. DISCLAIMER:The contents of this report are not to be used for advertising, publication, or promotional purposes. Citation of trade names does not constitute an official endorsement or approval of the use of such commercial products. All product names and trademarks cited are the property of their respective owners. The findings of this report are not to be construed as an official Department of the Army position unless so designated by other authorized documents.

This paper describes an integrated detection system that has been developed to conduct radiological surveys of sites suspected of contamination of materials such as depleted uranium. This system utilizes cerium activated lanthanum bromide and thallium activated sodium iodide gamma detectors and can be easily adapted to include units for detecting neutrons. The detection system includes software controlling the collection of radiological spectra and GPS data. Two different platforms are described for conducting surveys, a modified zero turn radius (ZTR) mower and a three-wheeled cart that is manually pushed. The detection system software controlling data collection has components that facilitate completing a gridless survey on user specified spacings. Another package confirms that all data quality activities (calibrations, etc.) are conducted prior to beginning the survey and also reviews data to identify areas that have been missed for which data quality falls below user designated parameters. Advanced digital signal processing algorithms are used to enhance the interpretation of spectra for conducting background subtractions and for mapping. Data from radiation detection instruments and GPS antennae are merged and made compatible with mapping using Geosoft Oasis montaj software. A summary of system performance during field-testing is included in the paper. This includes survey rate, detection limits, duty cycle, supporting ancillary equipment/material, and manpower requirements. The rate of false positives and false negatives is discussed with the benefits of surveys conducted using synergetic detection systems such as electromagnetic induction imaging.

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