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Summary  

A novel device for collecting, concentrating and separating airborne particles in situ is under development through a collaborative effort between Savannah River Technology Center (SRTC) and Oak Ridge National Laboratory (ORNL). This work entails coupling an Aerosol-to-Liquid Particle Extraction System (ALPES) to an electrochemically modulated separation (EMS) cell. The ALPES collects and concentrates airborne particles into a liquid,1 and the EMS cell separates species based on their affinity for a charged target surface.2 Preliminary data indicates substantial sensitivity enhancement may be realized by interfacing these devices. The system will allow for rapid field analysis of radionuclides while providing reductions in labor, cost, and turnaround time compared to standard radiometric techniques.

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Abstract  

The performance of several commercially available portable radiation spectrometers containing small NaI(Tl) scintillation detectors has been studied. These devices are used by field inspection personnel to detect and identify illicit radioactive materials. The detection and identification of enriched uranium is an important deterrent to undeclared nuclear proliferation and nuclear terrorism. This study was conducted using a variety of shielded and unshielded uranium sources in a simulated maritime environment. The results indicate adequate identification capability for various uranium enrichments using the manufacturer’s spectral analysis firmware. More sophisticated methods for analyzing the spectra can be applied to these short field measurements to determine the isotopic enrichment.

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Abstract  

A small, unmanned aerial vehicle (UAV) equipped with sensors for physical and chemical measurements of remote environments, is described. A miniature helicopter airframe is used as a platform for sensor testing and development. The sensor output is integrated with the flight control system for real-time, interactive, data acquisition and analysis. Pre-programmed flight missions will be flown with several sensors to demonstrate the cost-effective surveillance capabilities of this new technology.

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Abstract  

The performance of four types of - and X-ray radiation detectors for environmental applications was evaluated in the 10–450 keV energy range. Two cadmium zinc telluride (CdZnTe) room temperature semiconductor detectors were evaluated along with a cryogenically cooled semiconductor detector and two different types of scintillation detectors. The energy resolution, absolute peak detection efficiency and peak-to-background ratio of each of the detectors were calculated and intercompared. The advantages and disadvantages of environmental applications of each detector, along with their performance results, are summarized.

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The relative abundance and nature of associations between symbiotic species can be affected by abiotic conditions with consequences for population dynamics. We investigated the effects of temperature on the community of mites and fungi associated with the southern pine beetle, Dendroctonus frontalis , an important pest of pine forests in the southern United States. First, we determined whether the growth rates of mutualistic and antagonistic fungi associated with D. frontalis differed in their responses to temperature. Second, we tested the effects of temperature on the abundance of, and interactions among, fungi, mites and beetles within D. frontalis -infested trees. Fungi differed in their growth responses to temperature, resulting in changes in fungal-beetle associations. Mite species associated with D. frontalis also differed in their responses to temperature, resulting in different mite communities associated with bark beetle progeny. The effects of temperature on beetle reproduction could not be assessed because of high wood borer density, but inter-relations among surviving beetles, mites and fungi were altered by temperature. Results support the hypothesis that temperature can produce direct and indirect effects on the web of mutualistic and antagonistic relationships within the community of D. frontalis and their symbiotic mites and fungi.

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Abstract  

A number of nuclear technologies developed and applied at the Savannah River Site in support of nuclear weapons material production and environmental remediation can be applied to problems in law enforcement. Techniques and equipment for high-sensitivity analyses of samples are available to identify and quantify trace elements and establish origins and histories of forensic evidence removed from crime scenes. While some of these capabilities are available at local crime laboratories, state-of-the-art equipment and breakthroughs in analytical techniques are continually being developed at DOE laboratories. Extensive experience with the handling of radioactive samples at the DOE labs minimizes the chances of cross-contamination of evidence received from law enforcement. In addition to high-sensitivity analyses, many of the field techniques developed for use in a nuclear facility can assist law enforcement personnel in detecting illicit materials and operations, in retrieving of pertinent evidence and in surveying crime scenes. Some of these tools include chemical sniffers, hand-held detectors, thermal imaging, etc. In addition, mobile laboratories can be deployed to a crime scene to provide field screening of potential evidence. A variety of portable sensors can be deployed on vehicle, aerial, surface or submersible platforms to assist in the location of pertinent evidence or illicit operations. Several specific nuclear technologies available to law enforcement and their potential uses are discussed.

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Abstract  

A portable, field rugged, sampling and analysis system has been developed for the rapid screening of aqueous samples during scoping and remediation studies. Using field portable equipment, water is pumped through ion selective solid phase extraction (SPE) disks, at a flow rate of 150-250 ml/min, and counted for the radionuclide of interest in the field using portable detectors. SPE disks are currently available to selectively concentrate 99Tc, 90Sr, radiocesium (134Cs and 137Cs) and radium isotopes. In the field the radiocesium concentration is determined by gamma-spectrometry, 90Sr and 99Tc are determined by beta-counting. A one-liter sample can be processed and ready for counting within ten minutes. Using a 5-minute counting time, a detection limit of <50 pCi/l for 99Tc or 90Sr and ~50 pCi/l for 137Cs has been achieved. Up to 10 liters of water have been processed for the analysis of 99Tc and 137Cs when lower limits of detection were required. The sampling and analysis system has been field tested at the Savannah River Site (SRS), Aiken SC, and the Hanford Site, Richland WA. The SRS H-area tank farm storm water runoff system was analyzed for 90Sr and 137Cs. Groundwater from the SX tank farm at the Hanford Site was analyzed for 137Cs and 99Tc. Groundwater from seeps below the 100-H area at Hanford was analyzed for 90Sr and 99Tc.

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Journal of Radioanalytical and Nuclear Chemistry
Authors:
K. Hofstetter
,
D. Beals
,
D. Odell
,
R. Eakle
,
R. Huffman
, and
L. Harpring

Abstract  

A simple, inexpensive instrument for measuring radiation fields in otherwise inaccessible locations has been developed. The RadRope consists of a series of radiation detectors inside a flexible sheath and connected to a data readout device to alert the operator to unexpected radiation fields at a remote location. The instrument is designed for use in a maritime environment and will assist inspection personnel in detecting potential illicit radioactive materials or radiological/nuclear weapons of mass destruction.

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Abstract  

Researchers from the Savannah River Technology Center, the Center for Applied Isotope Studies (CAIS) and Sampling Systems have developed a prototype Field Deployable Tritium Analysis System (FDTAS) for near-real-time measurements of environmental levels of tritium in ground and surface water. The device consists of a modified liquid scintillation counter coupled to an automatic sampler which incorporates on-line water purification. The FDTAS has been field tested at several Savannah River Site locations and has produced results comparable to laboratory analyses for low concentrations of tritium. Figures of merit obtained in the field include an average tritium background count rate of 1.5 counts per minute (cpm), tritium detection efficiency of ≈25%, and a detection limit of <10 Bq/l for a 100 minute count.

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