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Use of high gradient magnetic separation for actinide application

Description: Decontamination of materials such as soils or waste water that contain radioactive isotopes, heavy metals, or hazardous components is a subject of great interest. Magnetic separation is a physical separation process that segregates materials on the basis of magnetic susceptibility. Because the process relies on physical properties, separations can be achieved while producing a minimum of secondary waste. Most traditional physical separation processes effectively treat particles larger than 70 microns. In many situations, the radioactive contaminants are found concentrated in the fine particle size fraction of less than 20 microns. For effective decontamination of the fine particle size fraction most current operations resort to chemical dissolution methods for treatment. High gradient magnetic separation (HGMS) is able to effectively treat particles from 90 to {approximately}0.1 micron in diameter. The technology is currently used on the 60 ton per hour scale in the kaolin clay industry. When the field gradient is of sufficiently high intensity, paramagnetic particles can be physically captured and separated from extraneous nonmagnetic material. Because all actinide compounds are paramagnetic, magnetic separation of actinide containing mixtures is feasible. The advent of reliable superconducting magnets also makes magnetic separation of weakly paramagnetic species attractive. HGMS work at Los Alamos National Laboratory (LANL) is being developed for soil remediation, waste water treatment and treatment of actinide chemical processing residues. LANL and Lockheed Environmental Systems and Technologies Company (LESAT) have worked on a co-operative research and development agreement (CRADA) to develop HGMS for radioactive soil decontamination. The program is designed to transfer HGMS from the laboratory and other industries for the commercial treatment of radioactive contaminated materials. 9 refs., 2 figs., 2 tabs.
Date: August 1, 1996
Creator: Avens, L.R.; Worl, L.A. & Padilla, D.D.
Partner: UNT Libraries Government Documents Department

Metrology and quality assurance from surveillance of gas compositions over PuO[sub 2]

Description: Until the late 1980s, a primary mission of the Department of Energy (DOE) has been the production of nuclear materials for nuclear weapons. Termination of the Cold War in 1989 and the subsequent nuclear weapons treaties dramatically decreased the inventory needs for nuclear weapons. These activities resulted in the consolidation of nuclear material inventories and activities, generating substantial amounts of surplus nuclear materials ranging from plutonium metal and pure oxides to impure plutonium residues. Packaging and storage of these materials in physically and environmentally safe configurations for significant time periods were required. In 1993 the Defense Nuclear Facility Safety Board (DNFSB) and the DOE Office of Nuclear Safety examined the storage of metal and oxides at the Rocky Flats Plant that ultimately resulted in recommendation 94-1, calling for a standard to define the processing and storage of plutonium bearing materials. This recommendation generated a standard for storage of plutonium metals and oxides, DOE-STD-3013-2000, which is now in its fourth revision. The current DOE 3013 Standard is limited to metal and oxides, which contain greater than 30 weight percent plutonium and uranium. The 3013 Standard requires that the oxide be calcined to 950 C for two hours in an oxidizing environment. Before packaging, the oxide is required to have less than 0.5 weight percent moisture. Up to five kilograms of the stabilized oxide material is subsequently sealed in a set of two-nested welded stainless steel container, which must have a power less than 19 Watts.
Date: January 1, 2002
Creator: Worl, L. A. (Laura A.); French, Catherine A. & Kreyer, L. S. (Lawrence S.)
Partner: UNT Libraries Government Documents Department

Enzymatic degradation of plutonium-contaminated cellulose products

Description: Enzyme solutions produced for commercial purposes unrelated to waste management have the potential for reducing the volume of wastes in streams containing cellulose, lipid and protein materials. For example, the authors have shown that cellulases used in denim production and in detergent formulations are able to digest cellulose-containing sorbents and other cellulose-based wastes contaminated either with crude oil or with radionuclides. This presentation describes the use of one such enzyme preparation (Rapidase{trademark}) for the degradation of cotton sorbents intentionally contaminated with low levels of plutonium. This is part of a feasibility study to determine if such treatments have a role in reducing the volume of low level and transuranic wastes to minimize the amount of radionuclide-contaminated waste that must be disposed of in secured storage areas.
Date: March 1, 1999
Creator: Heintz, C.E.; Rainwater, K.A.; Swift, L.M.; Barnes, D.L.; Worl, L. & Avens, L.
Partner: UNT Libraries Government Documents Department

Enzymatic degradation of plutonium-contaminated cellulose products

Description: Enzyme solutions produced for commercial purposes unrelated to waste management have the potential for reducing the volume of wastes in streams containing cellulose, lipid and protein materials. For example, the authors have shown previously that cellulases used in denim production and in detergent formulations are able to digest cellulose-containing sorbents and other cellulose-based wastes contaminated either with crude oil or with uranium. This presentation describes the use of one such enzyme preparation (Rapidase{trademark}, manufactured by Genencor, Rochester, NY) for the degradation of cotton sorbents intentionally contaminated with low levels of plutonium. This is part of a feasibility study to determine if such treatments have a role in reducing the volume of low level and transuranic wastes to minimize the amount of radionuclide-contaminated waste destined for costly disposal options.
Date: June 1, 1999
Creator: Heintz, C.E.; Rainwater, K.A.; Swift, L.M.; Barnes, D.L. & Worl, L.A.
Partner: UNT Libraries Government Documents Department

Selective separation of ultra-fine particles by magnetophoresis

Description: The selective and-specific extraction of species of interest fiom local environmental and other sample sources are importaut fbr scientific research, industrial processes, and environmental applications. A novel process for selective separation of ultrafine particles using 'magnetophoresis' is investigated. The principle of this process is that the direction and velocity of particle movement in a magnetic field are determined by magnetic, gravitational, and drag fbrces. By controlling these fbrces, one is able to control the migration rates of different species and then magnetically fiactionate mixtures of species into discrete groups. This study demonstrated for the fist time the selective separation of various species, such as iron (111) oxide, cupric (11) oxide, samarium (In) oxide, and cerium (III) oxide, by magnetophoresis. To better understand this phenomenon, a fbrce-balance model was developed that provides a good interpretation of the experimental results.
Date: January 1, 2002
Creator: Ying, T. (Tung-yu); Prenger, F. Coyne; Wingo, R. M. (Robert M.) & Worl, L. A. (Laura A.)
Partner: UNT Libraries Government Documents Department

Magnetic Separation for Nuclear Material Detection and Surveillance

Description: A high performance superconducting magnet is being developed for particle retrieval from field collected samples. Results show that maximum separation effectiveness is obtained when the matrix fiber diameter approaches the diameter of the particles to be captured. Experimentally, the authors obtained a single particle capture limit with 0.8{micro}m PuO{sub 2} particles with dodecane as a carrier fluid. The development of new matrix materials is being pursued through the controlled corrosion of stainless steel wool, or the deposition of nickel dendrites on the existing stainless steel matrix material. They have also derived a model from a continuity equation that uses empirically determined capture cross section values. This enables the prediction of high gradient magnetic separator performance for a variety of materials and applications. The model can be used to optimize the capture cross section and thus increase the capture efficiency.
Date: August 1, 1998
Creator: Worl, L.A.; Devlin, D.; Hill, D.; Padilla, D. & Prenger, F.C.
Partner: UNT Libraries Government Documents Department

Hydrothermal processing of radioactive combustible waste

Description: Hydrothermal processing has been demonstrated for the treatment of radioactive combustible materials for the US Department of Energy. A hydrothermal processing system was designed, built and tested for operation in a plutonium glovebox. Presented here are results from the study of the hydrothermal oxidation of plutonium and americium contaminated organic wastes. Experiments show the destruction of the organic component to CO{sub 2} and H{sub 2}O, with 30 wt.% H{sub 2}O{sub 2} as an oxidant, at 540 C and 46.2 MPa. The majority of the actinide component forms insoluble products that are easily separated by filtration. A titanium liner in the reactor and heat exchanger provide corrosion resistance for the oxidation of chlorinated organics. The treatment of solid material is accomplished by particle size reduction and the addition of a viscosity enhancing agent to generate a homogeneous pumpable mixture.
Date: September 1, 1998
Creator: Worl, L. A.; Buelow, S. J.; Harradine, D.; Le, L.; Padilla, D. D. & Roberts, J. H.
Partner: UNT Libraries Government Documents Department

Analysis of gas constituents from sealed containers of plutonium oxide materials.

Description: The safe storage of pure and impure plutonium oxide materials in sealed containers is a current Department of Energy (DOE) concern. Plutonium oxides sorb moisture from the atmosphere, and the subsequent radiolytic and/or chemical decomposition of the water has been thought to generate excessive hydrogen pressures inside sealed containers. Eleven sealed containers with ten grams each of plutonium oxide materials have been studied for up to four years. The sealed materials were representative materials from the DOE complex and contain less than 0.5 weight percent water. The samples were kept at ambient conditions. We report the final gas analysis of the headspace gas of these containers using gas chromatography, mass spectrometry and Raman spectroscopy. The results show that none of the containers have pressurized significantly, and that hydrogen was not generated in significant quantities.
Date: January 1, 2002
Creator: Worl, L. A. (Laura A.); Veirs, D. K. (Douglas Kirk); Allen, Tom; Berg, J. M. (John M.); Harradine, D. M. (David M.) & Padilla, D. D. (Dennis D.)
Partner: UNT Libraries Government Documents Department

Gas generation over plutonium oxides in the 94-1 shelf-life surveillance program.

Description: The Department of Energy (DOE) is embarking upon a program to store large quantities of plutonium-bearing materials for up to fifty years. The Los Alamos National Laboratory Shelf Life Project was established to bound the behavior of plutonium-bearing material meeting the DOE 3013 Standard. The shelf life study monitors temperature, pressure and gas composition over oxide materials in a limited number of large-scale 3013 inner containers and in many small-scale containers. For the large-scale study, baseline plutonium oxides, oxides exposed to high-humidity atmospheres, and oxides containing chloride salt impurities are planned. The first large-scale container represents a baseline and contains dry plutonium oxide prepared according to the 3013 Standard. This container has been observed for pressure, temperature and gas compositional changes for less than a year. Results indicate that no detectable changes in pressure and gas composition are observed.
Date: January 1, 2002
Creator: Berg, J. M. (John M.); Harradine, D. M. (David M.); Hill, D. D. (Dallas D.); McFarlan, James T.; Padilla, D. D. (Dennis D.); Prenger, F. Coyne et al.
Partner: UNT Libraries Government Documents Department

Integration of advanced nuclear materials separation processes

Description: This is the final report of a two-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). This project has examined the fundamental chemistry of plutonium that affects the integration of hydrothermal technology into nuclear materials processing operations. Chemical reactions in high temperature water allow new avenues for waste treatment and radionuclide separation.Successful implementation of hydrothermal technology offers the potential to effective treat many types of radioactive waste, reduce the storage hazards and disposal costs, and minimize the generation of secondary waste streams. The focus has been on the chemistry of plutonium(VI) in solution with carbonate since these are expected to be important species in the effluent from hydrothermal oxidation of Pu-containing organic wastes. The authors investigated the structure, solubility, and stability of the key plutonium complexes. Installation and testing of flow and batch hydrothermal reactors in the Plutonium Facility was accomplished. Preliminary testing with Pu-contaminated organic solutions gave effluent solutions that readily met discard requirements. A new effort in FY 1998 will build on these promising initial results.
Date: December 31, 1998
Creator: Jarvinen, G.D.; Worl, L.A.; Padilla, D.D.; Berg, J.M.; Neu, M.P.; Reilly, S.D. et al.
Partner: UNT Libraries Government Documents Department

Introducing equipment and plutonium glove box modifications for monitoring gas generation over plutonium oxide materials.

Description: DOE is embarking on a program to store large quantities of Pu-bearing materials for up to fifty years. Materials for long-term storage are metals and oxides that are stabilized and packaged according to the DOE storage standard. Experience with PuO, materials has shown that gases generated by catalytic and/or radiolytic processes may accumulate. Of concern are the generation of H, gas from adsorbed water and the generation of HCI or CI, gases from the radiolysis of chloride-containing salts. We have designed instrumented storage containers that mimic the inner storage can specified in the standard. The containers and surveillance equipment are interfaced with a plutonium glovebox and are designed to allow the gas composition and pressure to be monitored over time. The surveillance activities and glovebox interfaces include Raman fiber optic probes, a gas analysis sampling port, corrosion monitors, and pressure and temperature feedthrus. Data collection for these containers is automated in order to reduce worker exposure. The equipment design and glovebox modifications are presented.
Date: January 1, 2002
Creator: Padilla, D. D. (Dennis D.); Berg, J. M. (John M.); Carrillo, A. G. (Alejandro G.); Montoya, A. R. (Adam R.); Morris, J. S. (John S.); Veirs, D. K. (Douglas Kirk) et al.
Partner: UNT Libraries Government Documents Department

Gas generation by pure and impure plutonium oxide materials in sealed containers.

Description: The Department of Energy (DOE) standard, DOE-STD-3013-2000, establishes criteria for stabilizing, packaging, and long term safe storage of plutonium-bearing materials at DOE facilities . The Standard applies to oxide or metal that contains at least 30 weight percent plutonium plus uranium. For oxide material a maximum of 5 kg of material is packaged in a nested set of two individually welded containers and the requirements include material stabilization at 950 C, 0 .5 weight percent moisture content or less, and less than nineteen watts of power per sealed container . The welded containers ensure that any gas generated due to radiolysis will be retained within the container . Although the 3013 package provides for a robust storage system, its long-term safety performance has not been demonstrated . To ensure failures do not occur while the sealed containers are being stored for up to 50 years, a DOE complex-wide integrated surveillance program has been established to measure the gas generation rates of these materials. At Los Alamos National Laboratory (LANL), the shelf life project monitors gases over oxide materials in a limited number of large-scale 3013 inner containers charged with 5 kg of material and in many small-scale containers with 10 gram samples taken from site-wide representative materials actually being stored . The small-scale containers allow more sample types and conditions to be studied. This information provides invaluable, defensible results for assuring safe long-term storage of these materials in sealed containers . Initial results on gas generation are presented.
Date: January 1, 2003
Creator: Berg, J. M. (John M.); McFarlan, James T.; Padilla, D. D. (Dennis D.); Veirs, D. K. (Douglas Kirk); Worl, L. A. (Laura A.); Harradine, D. M. (David M.) et al.
Partner: UNT Libraries Government Documents Department