[en] The thermochemical equilibrium calculations indicate that at the temperature of a propane--air flame, some volatilization of uranium, plutonium, technetium, and cesium will occur. The expected concentrations of plutonium, technetium, and cesium in the flame will be very low because of the small maximum concentration of these elements in the projected feed materials for the first 30-day test. The quantities volatilized can generally be decreased by operating the flame in a fuel-rich mode, although this will lead to greater carbon monoxide production, which may be more objectionable. The concentrations of chlorine and fluorine, at least at the maximum levels in the projected Vortec feed, are not projected to greatly influence the vaporization rates. Therefore, blending to reduce the concentrations of those elements would most likely not be effective in reducing metal vaporization. Most of the elements vaporized condense by the time the gas cools to 2000 F. These elements would condense either on surfaces near the front of the heat recuperator or on entrained particulates or homogeneously as relatively pure submicron particles. Cesium would be expected to condense at the lower temperatures near the rear of the recuperator, although the expected maximum concentration in the Vortec feed material is extremely low so it should be greatly diluted by other particulates. The elements that condense on other entrained particles will form enriched surface coatings. Particles larger than 10microm or so will be collected in the scrubber. Smaller particles, especially the submicron particles formed from homogeneous nucleation, should be largely collected in the HEPA filter. Deposits formed in the heat recuperator can normally be handled via sootblowing. To reduce handling problems, we suggest that the recuperator be oriented vertically so that the deposits blown off of the heat exchanger fall directly into the molten glass. The large size of the deposits should help to reduce the rate of revaporization, allowing the volatile elements to be removed with the glass. The volatile elements that do not deposit on system surfaces will be concentrated in the smaller particles. Therefore, the HEPA ash will be greatly enriched in these elements. If the HEPA filter is itself sent to a melter, the elements may revaporize and multiply the problems related to metal vaporization significantly. Therefore, the HEPA filters should be disposed of without high-temperature processing. Also, to reduce the formation of these very small particles, it is helpful to include in the feed larger particles to act as condensation nuclei that can then be collected in the scrubber. This can be accomplished by using feed materials with a fraction consisting of particles small enough that they will not be collected in the cyclone in the melter, but large enough that they will easily be collected by the scrubber. This is one advantage that firing bituminous coal has over gas firing; it provides a source of ash particles of the right size range to serve as nucleation sites, but large enough (depending on the coal) so that they can usually be collected efficiently in the scrubber system

[en] The multiple coincidence technique uses 14.1 MeV neutrons to produce (n, multiple-γ) coincidences to detect fissile and fissionable materials. Measurements of n-γ-γ coincidences with targets of depleted uranium (DU), W, and Pb, show that the counting rate for the DU is substantially above that for the non-fissionables. Also, the data involving prompt neutrons and delayed gammas in the DU time spectra provide a signature for fissionables that is distinct from that of non-fissionables

[en] In an extension of the Associated Particle Imaging technique that is used for the detection and imaging of hidden explosives, the present measurements use a beam of tagged 14.1 MeV neutrons in coincidence with two or more gammas to probe for the presence of fissionable materials. We have measured neutron-gamma-gamma coincidences with targets of depleted uranium, tungsten, lead, iron, and carbon and will present results that show the multiple-coincidence counting rate for the depleted uranium is substantially higher than any of the non-fissionable materials. In addition, the presence of coincidences involving delayed particle spectra provides a signature for fissionable materials that is distinct from that for non-fissionable ones. Information from the tagged neutron involved in the coincidence event is used to compute the position of the fissionable material in all three dimensions. The result is an imaging probe for fissionable materials that is compact and portable, and produces relatively low levels of background radiation. Simultaneous measurements on packages of interest for both explosives and fissionable materials are now feasible.

[en] The goal of this task was to work with private industry to refine existing vitrification processes to produce a more stable vitrified product. The initial objectives were to (1) demonstrate a waste vitrification procedure for enhanced stabilization of waste materials and (2) develop a testing protocol to understand the long-term leaching behavior of the stabilized waste form. The testing protocol was expected to be based on a leaching procedure called the synthetic groundwater leaching procedure (SGLP). This task will contribute to the US DOE's identified technical needs in waste characterization, low-level mixed-waste processing, disposition technology, and improved waste forms. The proposed work was to proceed over 4 years in the following steps: literature surveys to aid in the selection and characterization of test mixtures for vitrification, characterization of optimized vitrified test wastes using advanced leaching protocols, and refinement and demonstration of vitrification methods leading to commercialization. For this year, literature surveys were completed, and computer modeling was performed to determine the feasibility of removing heavy metals from a waste during vitrification, thereby reducing the hazardous nature of the vitrified material and possibly producing a commercial metal concentrate. This report describes the following four subtasks: survey of vitrification technologies; survey of cleanup sites; selection and characterization of test mixtures for vitrification and crystallization; and selection of crystallization methods based on thermochemistry modeling

[en] This summary describes experiments to detect and identify fissionable materials using the tagged neutron technique. The objective of this work is to enhance homeland security capability to find fissionable material that may be smuggled inside shipping boxes, containers, or vehicles. The technique distinguishes depleted uranium from lead, steel, and tungsten. Future work involves optimizing the technique to increase the count rate by many orders of magnitude and to build in the additional capability to image hidden fissionable materials. The tagged neutron approach is very different to other techniques based on neutron die-away or photo-fission. This work builds on the development of the Associated Particle Imaging (API) technique at the Special Technologies Laboratory (STL). Similar investigations have been performed by teams at the Oak Ridge National Laboratory (ORNL), the Khlopin Radium Institute in Russia, and by the EURITRACK collaboration in the European Union

[en] Associated particle imaging (API) is a fast-neutron reaction imaging system. An object is illuminated with 14-MeV neutrons and these neutron interaction sites are imaged. The T(d,n)⁴He reaction is used to produce a neutron and an alpha particle which move apart in opposite directions. By detecting the alpha particle, the direction of travel of the neutron is known. When the neutron strikes any material (except hydrogen and helium) it causes the material to emit gamma radiation. If one of the gamma-rays is detected it is then known that a reaction has taken place. By measuring the time between alpha detection and gammadetection, it is known how long the neutron traveled before reacting. By constructing a tally (or histogram) of these reaction sites an image is constructed. By examining the gamma-ray spectra corresponding to each region of space, elemental analysis of that region can be performed. This technique and it's applications are discussed in this paper

[en] A fast-neutron-capture imaging system is being designed. 14.1 MeV neutrons will be produced with a sealed-tube neutron generator (STNG) via the t(d,n)⁴He reaction. The associated alpha particle will be imaged defining the neutron direction. The timing and energy of a neutron-inelastic-scatter gamma ray will define the source-to-target distance and the target isotope. A special sealed-tube neutron generator (STNG) has been designed. The performance of various components of the system has been measured or calculated, and the results are used to predict the overall performance of the system. (orig.)

[en] The Vortec Cyclone Melting System (CMS reg-sign) facility, to be located at the US Department of Energy (DOE) Paducah Gaseous Diffusion Plant, is designed to treat soil contaminated with low levels of heavy metals and radioactive elements, as well as organic waste. To assure that costs of sampling and analysis are contained, Vortec and the DOE Federal Energy Technology Center (FETC) have decided that initially the primary focus of the sampling activities will be on meeting permitting requirements of the state of Kentucky. Therefore, sampling will be limited to the feedstock entering the system, and the glass, flue gas, and water leaving the system. The authors provide suggestions for optional sampling points and procedures in case there is later interest in operations or mass balance data. The permits do not require speciation of the materials in the effluents, only opacity, total radioactivity, total particulate, and total HCl emissions for the gaseous emissions and total radioactivity in the water and solid products. In case future testing to support operations or mass balances is required, the authors include in this document additional information on the analyses of some species of interest. They include heavy metals (RCRA [Resource Conservation and Recovery Act] and Cu and Ni), radionuclides (Th₂₃₀, U₂₃₅, Tc⁹⁹, Cs¹³⁷, and Pu²³⁹), and dioxins/furans

[en] The objective of the Environmental Management program at the Energy and Environmental Research Center (EERC) is to develop, demonstrate, and commercialize technologies that address the environmental management needs of contaminated sites, including characterization, sensors, and monitoring; low-level mixed waste processing; material disposition technology; improved waste forms; in situ containment and remediation; and efficient separation technologies for radioactive wastes. Task 2 is the extraction and analysis of pollutant organics from contaminated solids using off-line supercritical fluid extraction (SFE) and on-line SFE-infrared spectroscopy. Task 3, pyrolysis of plastics, has as its objectives to develop a commercial process to significantly reduce the volume of mixed-plastics-paper-resin waste contaminated with low-level radioactive material; concentrate contaminants in a collectible form; and determine the distribution and form of contaminants after pyrolysis of the mixed waste. Task 4, stabilization of vitrified wastes, has as its objectives to (1) demonstrate a waste vitrification procedure for enhanced stabilization of waste materials and (2) develop a testing protocol to understand the long-term leaching behavior of the stabilized waste form. The primary objective of Task 8, Management and reporting, is coordination of this project with other programs and opportunities. In addition, management oversight will be maintained to ensure that tasks are completed and coordinated as planned and that deliverables are submitted in a timely manner. Accomplishments to date is each task are described. 62 refs

[en] A series of measurements was made to determine the performance of a long, rectangular, polycrystalline, NaI(Tl) scintillator. Using collimated sources of ¹³⁷ and ²²Na, scans were made along the scintillator to measure pulse height and energy resolution as a function of position. The measurements were made using first only one phototube at a time and then with both tubes. Measurements were also made with broad-beam, uncollimated radiation. The data were compiled and analyzed and are presented in both graphical and tabular form