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Transuranic separation using organophophorus extractants adsorbed onto superparamagnetic carriers.

Description: Polymeric coated ferromagnetic carriers with an absorbed layer of octyl(phenyl)-N,N-diisobutylcarbamoylmethylphosphine oxide (CMPO) diluted by tributyl phosphate (TBP) are being evaluated for application in the separation and the recovery of low concentrations of americium, plutonium, and uranium from nuclear waste solutions. Due to their chemical nature, these extractants selectively complex americium and plutonium contaminants onto the particles and the complexed particles can be recovered from the solution using a magnet. Physical and chemical characterization of the extractant-absorbed particles were performed by gamma and liquid scintillation counting, scanning electron microscopic (SEM) micrograph, and other physical measurements. Plutonium, americium, and uranium separations have been performed at various HNO{sub 3} and HCl concentrations. Parameters were studied to determine the limitations and capacity of the process. The status of the chemistry and application of the process to Department of Energy (DOE) remediation efforts for actinide decontamination are discussed.
Date: October 7, 1998
Creator: Nunez, L.
Partner: UNT Libraries Government Documents Department

Application of single ion activity coefficients to determine solvent extraction mechanism for components of high level nuclear waste

Description: The TRUEX solvent extraction process is being developed to remove and concentrate transuranic (TRU) elements from high-level and TRU radioactive wastes currently stored at US Department of Energy sites. Phosphoric acid is one of the chemical species of concern at the Hanford site where bismuth phosphate was used to recover plutonium. The mechanism of phosphoric acid extraction with TRUEX-NPH solvent at 25{degrees}C was determined by phosphoric acid distribution ratios, which were measured by using phosphoric acid radiotracer and a variety of aqueous phases containing different concentrations of nitric acid and nitrate ions. A model was developed for predicting phosphoric acid distribution ratios as a function of the thermodynamic activities of nitrate ion and hydrogen ion. The Generic TRUEX Model (GTM) was used to calculate these activities based on the Bromley method. The derived model supports CMPO and TBP extraction of a phosphoric acid-nitric acid complex and a CMPO-phosphoric acid complex in TRUEX-NPH solvent.
Date: December 31, 1995
Creator: Nunez, L. & Vandegrift, G.F.
Partner: UNT Libraries Government Documents Department

Evaluation of hydroxamic acid in uranium extraction process : literature review.

Description: The Uranium Extraction (UREX) process is being developed for the spent oxide fuel from light water reactors as part of the Accelerator Transmutation of Waste Project. The UREX process is similar to the Plutonium and Uranium Extraction (PUREX) process in that it involves solvent extraction based on a tributyl phosphate extractant. To assure that actinide reduction and complexation are effective, the reductant/complexant aceto-hydroxamic acid is being considered for use in the UREX process. The following literature review describes the solvent extraction, kinetics, oxidation-reduction, and complexation properties of aceto-hydroxamic acid and its derivatives.
Date: May 21, 2001
Creator: Nunez, L. & Vandegrift, G. F.
Partner: UNT Libraries Government Documents Department

Polychlorodibenzo-p-dioxin and polychlorodibenzo-furan removal and destruction.

Description: This report provides a short summary of technologies used to destroy or separate dioxins/furans from environmental samples. It is meant as a resource for developing a technology employing magnetic particles as an engineering vehicle for large-scale, cost-effective destruction of dioxins/furans in fresh waters or sludges/soils.
Date: September 30, 2003
Creator: Patel, S.; Kaminski, M. D. & Nunez, L.
Partner: UNT Libraries Government Documents Department

Review of arsenic removal technologies for contaminated groundwaters.

Description: This review was compiled to summarize the technologies currently being investigated to remove arsenic from drinking waters, with a special focus on developing and third-world countries where the problem is exacerbated by flooding and depressed economic conditions. The reason for compiling this report is to provide background material and a description of competing technologies currently described in the literature for arsenic removal. Based on the sophistication and applicability of current technologies, Argonne National Laboratory may develop an improved method based on magnetic particle technology. Magnetic particle sorbents may afford improved reaction rates, facilitate particle-water separation, and offer reusability. Developing countries like Vietnam and Bangladesh cannot afford expensive, large-scale treatments to remove arsenic from drinking waters to acceptable limits (from 50 ppb to 10 ppb, depending on the country). Low-cost, effective technologies that can be readily available at the household or community level are needed to solve the present crisis. Appropriate technologies should meet certain criteria, including the following: The treatment must be applicable over a wide range of arsenic concentrations; It should be easy to use without running water or electricity; and The materials for the treatment should be cheap and readily available, and/or suitable for reuse. Our review of arsenic removal technologies and procedures indicates that iron filings, ferric salts, granular ferric hydroxide, alumina manganese oxide, Aqua-bind., and Kimberlite tailings are potentially low-cost sorbents that can remove arsenic after simple mixing in a relatively short time. However, all these technologies suffer from significant shortcomings. Ferric salts are cheap and very effective at removing arsenic but the reaction rates are slow. Fixed-bed columns make use of activated alumina and iron-coated sands but do not work well with groundwater having high concentrations of iron because iron precipitates in the presence of air, which could clog and foul the column. Synthetic sorbents ...
Date: May 2, 2003
Creator: Vu, K. B.; Kaminski, M. D. & Nunez, L.
Partner: UNT Libraries Government Documents Department

Radiolysis and hydrolysis of magnetically assisted chemical separation particles

Description: The magnetically assisted chemical separation (MACS) process is designed to separate transuranic (TRU) elements out of high-level waste (HLW) or TRU waste. Magnetic microparticles (1--25 {mu}m) were coated with octyl (phenyl)N,N-diisobutylcarbamoylmethylphosphine oxide (CMPO) dissolved in tributyl phosphate (TBP) and tested for removing TRU elements from acidic nitrate solutions. The particles were contacted with nitric acid solutions and Hanford plutonium finishing plant (PFP) simulant, irradiated with a high intensity {sup 60}Co {gamma}-ray source, and evaluated for effectiveness in removing TRU elements from 2m HNO{sub 3} solutions. The resistance of the coatings and magnetic cores to radiolytic damage and hydrolytic degradation was investigated by irradiating samples of particles suspended in a variety of solutions with doses of up to 5 Mrad. Transmission electron microscopy (TEM), magnetic susceptibility measurements, and physical observations of the particles and suspension solutions were used to assess physical changes to the particles. Processes that affect the surface of the particles dramatically alter the binding sites for TRU in solution. Hydrolysis played a larger role than radiolysis in the degradation of the extraction capacity of the particles.
Date: May 1, 1995
Creator: Buchholz, B.A.; Nunez, L. & Vandegrift, G.F.
Partner: UNT Libraries Government Documents Department

Decontamination of control rod housing from Palisades Nuclear Power Station.

Description: Argonne National Laboratory has developed a novel decontamination solvent for removing oxide scales formed on ferrous metals typical of nuclear reactor piping. The decontamination process is based on the properties of the diphosphonic acids (specifically 1-hydroxyethane-1,1-diphosphonic acid or HEDPA) coupled with strong reducing-agents (e.g., sodium formaldehyde sulfoxylate, SFS, and hydroxylamine nitrate, HAN). To study this solvent further, ANL has solicited actual stainless steel piping material that has been recently removed from an operating nuclear reactor. On March 3, 1999 ANL received segments of control rod housing from Consumers Energy's Palisades Nuclear Plant (Covert, MI) containing radioactive contamination from both neutron activation and surface scale deposits. Palisades Power plant is a PWR type nuclear generating plant. A total of eight segments were received. These segments were from control rod housing that was in service for about 6.5 years. Of the eight pieces that were received two were chosen for our experimentation--small pieces labeled Piece A and Piece B. The wetted surfaces (with the reactor's pressurized water coolant/moderator) of the pieces were covered with as a scale that is best characterized visually as a smooth, shiny, adherent, and black/brown in color type oxide covering. This tenacious oxide could not be scratched or removed except by aggressive mechanical means (e.g., filing, cutting).
Date: May 3, 1999
Creator: Kaminski, M.D.; Nunez, L. & Purohit, A.
Partner: UNT Libraries Government Documents Department

Nondestructive NMR technique for moisture determination in radioactive materials.

Description: This progress report focuses on experimental and computational studies used to evaluate nuclear magnetic resonance (NMR) spectroscopy and magnetic resonance imaging (MRI) for detecting, quantifying, and monitoring hydrogen and other magnetically active nuclei ({sup 3}H, {sup 3}He, {sup 239}Pu, {sup 241}Pu) in Spent nuclear fuels and packaging materials. The detection of moisture by using a toroid cavity NMR imager has been demonstrated in SiO{sub 2} and UO{sub 2} systems. The total moisture was quantified by means of {sup 1}H NMR detection of H{sub 2}O with a sensitivity of 100 ppm. In addition, an MRI technique that was used to determine the moisture distribution also enabled investigators to discriminate between bulk and stationary water sorbed on the particles. This imaging feature is unavailable in any other nondestructive assay (NDA) technique. Following the initial success of this program, the NMR detector volume was scaled up from the original design by a factor of 2000. The capacity of this detector exceeds the size specified by DOE-STD-3013-96.
Date: December 4, 1998
Creator: Aumeier, S.; Gerald, R.E. II; Growney, E.; Nunez, L. & Kaminski, M.
Partner: UNT Libraries Government Documents Department

Removal of VOCs from groundwater using membrane-assisted solvent extraction

Description: A membrane-assisted solvent extraction (MASX) system coupled to a membrane-assisted distillation stripping (MADS) system for use in decontaminating groundwater is discussed. Volatile organic compounds (VOCs) are extracted in the MASX using a sunflower oil solvent. In the MADS, VOCs are stripped from the sunflower oil, and the oil is recycled to the MASX. Thermodynamic data for the sunflower oil-water-VOCs system were experimentally collected. Published membrane-mass transfer results along with these data were used to design the MASX and MADS modules.
Date: January 1, 1992
Creator: Hutter, J.C.; Vandegrift, G.F.; Nunez, L. & Redfield, D.H.
Partner: UNT Libraries Government Documents Department

Removal of VOCs from groundwater using membrane-assisted solvent extraction

Description: A membrane-assisted solvent extraction (MASX) system coupled to a membrane-assisted distillation stripping (MADS) system for use in decontaminating groundwater is discussed. Volatile organic compounds (VOCs) are extracted in the MASX using a sunflower oil solvent. In the MADS, VOCs are stripped from the sunflower oil, and the oil is recycled to the MASX. Thermodynamic data for the sunflower oil-water-VOCs system were experimentally collected. Published membrane-mass transfer results along with these data were used to design the MASX and MADS modules.
Date: November 1, 1992
Creator: Hutter, J. C.; Vandegrift, G. F.; Nunez, L. & Redfield, D. H.
Partner: UNT Libraries Government Documents Department

Comparison of the corrosion behavior of tank 51 sludge-based glass and a nonradioactive homologue glass

Description: We are conducting static dissolution tests with a glass made at the Savannah River Technology Center (SRTC) during a demonstration of the Defense Waste Processing Facility (DWPF) process control for remote vitrification [1]. The glass was made with sludge from Tank 5 1, SRL 202 frit, and added soda. This glass is similar to waste glasses being made in the current DWPF campaign. Parallel tests are being conducted with a nonradioactive glass made at ANL having the same composition as the radioactive glass, except without the radionuclides. The radioactive and nonradioactive glasses are referred to as 5lR and 5lS, respectively. The results of these tests provide information pertinent to assessing the long-term corrosion behavior of DWPF glasses, comparing the corrosion behaviors of radioactive and nonradioactive glasses, and characterizing the disposition of radionuclides as the glass corrodes.
Date: December 31, 1996
Creator: Nunez, L.; Ebert, W.L.; Wolf, S.F. & Bates, J.K.
Partner: UNT Libraries Government Documents Department

Superconducting Open-Gradient Magnetic Separation for the Pretreatment of Radioactive or Mixed Waste Vitrification Feeds

Description: An open-gradient magnetic separation (OGMS) process is being considered to separate deleterious elements from radioactive and mixed waste streams prior to vitrification or stabilization. By physically segregating solid wastes and slurries based on the magnetic properties of the solid constituents, this potentially low-cost process may serve the U.S. Department of Energy (DOE) by reducing the large quantities of glass produced from defense-related high-level waste (HLW). Furthermore, the separation of deleterious elements from low-level waste (LLW) also can reduce the total quantity of waste produced in LLW immobilization activities. Many HLW 'and LLW waste' streams at both Hanford and the Savannah River Site (SRS) include constituents deleterious to the durability of borosilicate glass and the melter many of the constituents also possess paramagnetism. For example, Fe, Cr, Ni, and other transition metals may limit the waste loading and affect the durability of the glass by forming spine1 phases at the high operating temperature used in vitrification. Some magnetic spine1 phases observed in glass formation are magnetite (Fe,O,), chromite (FeCrO,), and others [(Fe, Ni, Mg, Zn, Mn)(Al, Fe, Ti, Cr)O,] as described elsewhere [Bates-1994, Wronkiewicz-1994] Stable spine1 phases can cause segregation between the glass and the crystalline phases. As a consequence of the difference in density, the spine1 phases tend to accumulate at the bottom of the glass melter, which decreases the conductivity and melter lifetime [Sproull-1993]. Crystallization also can affect glass durability [Jantzen-1985, Turcotte- 1979, Buechele-1990] by changing the chemical composition of the matrix glass surrounding the crystals or causing stress at the glass/crystal interface. These are some of the effects that can increase leaching [Jantzen-1985]. A SRS glass that was partially crystallized to contain 10% vol. crystals composed of spinels, nepheline, and acmite phases showed minimal changes in short term leachability [Jantzen-1985, Hench-1982]. However, Jantzen et k > al. found ...
Date: December 31, 1999
Creator: Nunez', L.; Kaminsky', M.D.,; Crawford, C. & Ritter, J.A.
Partner: UNT Libraries Government Documents Department

Review and evaluation of extractants for strontium removal using magnetically assisted chemical separation

Description: A literature review on extractants for strontium removal was initially performed at Northern Illinois University to assess their potential in magnetically assisted chemical separation. A series of potential strontium extractants was systematically evaluated there using radioanalytical methods. Initial experiments were designed to test the uptake of strontium from nitric acid using several samples of magnetic extractant particles that were coated with various crown ether ligands. High partition coefficient (K{sub d}) values for stimulant tank waste were obtained. Further studies demonstrated that the large partitioning was due to uncoated particles.
Date: November 1, 1995
Creator: Bauer, C.B.; Rogers, R.D.; Nunez, L.; Ziemer, M.D.; Pleune, T.T. & Vandegrift, G.F.
Partner: UNT Libraries Government Documents Department

Magnetically assisted chemical separation (MACS) process: Preparation and optimization of particles for removal of transuranic elements

Description: The Magnetically Assisted Chemical Separation (MACS) process combines the selectivity afforded by solvent extractants with magnetic separation by using specially coated magnetic particles to provide a more efficient chemical separation of transuranic (TRU) elements, other radionuclides, and heavy metals from waste streams. Development of the MACS process uses chemical and physical techniques to elucidate the properties of particle coatings and the extent of radiolytic and chemical damage to the particles, and to optimize the stages of loading, extraction, and particle regeneration. This report describes the development of a separation process for TRU elements from various high-level waste streams. Polymer-coated ferromagnetic particles with an adsorbed layer of octyl(phenyl)-N,N-diisobutylcarbamoylmethylphosphine oxide (CMPO) diluted with tributyl phosphate (TBP) were evaluated for use in the separation and recovery of americium and plutonium from nuclear waste solutions. Due to their chemical nature, these extractants selectively complex americium and plutonium contaminants onto the particles, which can then be recovered from the solution by using a magnet. The partition coefficients were larger than those expected based on liquid[liquid extractions, and the extraction proceeded with rapid kinetics. Extractants were stripped from the particles with alcohols and 400-fold volume reductions were achieved. Particles were more sensitive to acid hydrolysis than to radiolysis. Overall, the optimization of a suitable NMCS particle for TRU separation was achieved under simulant conditions, and a MACS unit is currently being designed for an in-lab demonstration.
Date: May 1, 1995
Creator: Nunez, L.; Kaminski, M.; Bradley, C.; Buchholz, B.A.; Aase, S.B.; Tuazon, H.E. et al.
Partner: UNT Libraries Government Documents Department

Superconducting open-gradient magnetic separation for the pretreatment of radioactive or mixed waste vitrification feeds. 1997 annual progress report

Description: 'Vitrification has been selected as a final waste form technology in the US for long-term storage of high-level radioactive wastes (HLW). However, a foreseeable problem during vitrification in some waste feed streams lies in the presence of elements (e.g., transition metals) in the HLW that may cause instabilities in the final glass product. The formation of spinel compounds, such as Fe{sub 3}O{sub 4} and FeCrO{sub 4}, results in glass phase separation and reduces vitrifier lifetime, and durability of the final waste form. A superconducting open gradient magnetic separation (OGMS) system maybe suitable for the removal of the deleterious transition elements (e.g. Fe, Co, and Ni) and other elements (lanthanides) from vitrification feed streams due to their ferromagnetic or paramagnetic nature. The OGMS systems are designed to deflect and collect paramagnetic minerals as they interact with a magnetic field gradient. This system has the potential to reduce the volume of HLW for vitrification and ensure a stable product. In order to design efficient OGMS and High gradient magnetic separation (HGMS) processes, a fundamental understanding of the physical and chemical properties of the waste feed streams is required. Using HLW simulant and radioactive fly ash and sludge samples from the Savannah River Technology Center, Rocky Flats site, and the Hanford reservation, several techniques were used to characterize and predict the separation capability for a superconducting OGMS system.'
Date: October 2, 1997
Creator: Doctor, R.; Nunez, L.; Cicero-Herman, C. A.; Ritter, J. A. & Landsberger, S.
Partner: UNT Libraries Government Documents Department

Preliminary plan for treating mixed waste

Description: A preliminary waste treatment plan was developed for disposing of radioactive inorganic liquid wastes that contain hazardous metals and/or hazardous acid concentrations at Argonne National Laboratory. This plan, which involves neutralization and sulfide precipitation followed by filtration, reduces the concentration of hazardous metals and the acidity so that the filtrate liquid is simply a low-level radioactive waste that can be fed to a low-level waste evaporator.
Date: June 1, 1993
Creator: Vandegrift, G. F.; Conner, C.; Hutter, J. C.; Leonard, R. A.; Nunez, L.; Sedlet, J. et al.
Partner: UNT Libraries Government Documents Department

Basic TRUEX process for Rocky Flats Plant

Description: The Generic TRUEX Model was used to develop a TRUEX process flowsheet for recovering the transuranics (Pu, Am) from a nitrate waste stream at Rocky Flats Plant. The process was designed so that it is relatively insensitive to changes in process feed concentrations and flow rates. Related issues are considered, including solvent losses, feed analysis requirements, safety, and interaction with an evaporator system for nitric acid recycle.
Date: August 1, 1994
Creator: Leonard, R. A.; Chamberlain, D. B.; Dow, J. A.; Farley, S. E.; Nunez, L.; Regalbuto, M. C. et al.
Partner: UNT Libraries Government Documents Department

Development program for magnetically assisted chemical separation: Evaluation of cesium removal from Hanford tank supernatant

Description: Magnetic particles (MAG*SEP{sup SM}) coated with various absorbents were evaluated for the separation and recovery of low concentrations of cesium from nuclear waste solutions. The MAG*SEP{sup SM} particles were coated with (1) clinoptilolite, (2) transylvanian volcanic tuff, (3) resorcinol formaldehyde, and (4) crystalline silico-titanate, and then were contacted with a Hanford supernatant simulant. Particles coated with the crystalline silico-titanate were identified by Bradtec as having the highest capacity for cesium removal under the conditions tested (variation of pH, ionic strength, cesium concentration, and absorbent/solution ratio). The MAG*SEP{sup SM} particles coated with resorcinol formaldehyde had high distribution ratios values and could also be used to remove cesium from Hanford supernant simulant. Gamma irradiation studies were performed on the MAG*SEP{sup SM} particles with a gamma dose equivalent to 100 cycles of use. This irradiation decreased the loading capacity and distribution ratios for the particles by greater than 75%. The particles demonstrated high sensitivity to radiolytic damage due to the degradation of the polymeric regions. These results were supported by optical microscopy measurements. Overall, use of magnetic particles for cesium separation under nuclear waste conditions was found to be marginally effective.
Date: December 1, 1994
Creator: Nunez, L.; Buchholz, B.A.; Ziemer, M.; Dyrkacz, G.; Kaminski, M.; Vandegrift, G.F. et al.
Partner: UNT Libraries Government Documents Department

Magnetically responsive microparticles for targeted drug and radionuclide delivery.

Description: We are currently investigating the use of magnetic particles--polymeric-based spheres containing dispersed magnetic nanocrystalline phases--for the precise delivery of drugs via the human vasculature. According to this review, meticulously prepared magnetic drug targeting holds promise as a safe and effective method of delivering drugs to specific organ, tissue or cellular targets. We have critically examined the wide range of approaches in the design and implementation of magnetic-particle-based drug delivery systems to date, including magnetic particle preparation, drug encapsulation, biostability, biocompatibility, toxicity, magnetic field designs, and clinical trials. However, we strongly believe that there are several limitations with past developments that need to be addressed to enable significant strides in the field. First, particle size has to be carefully chosen. Micrometer-sized magnetic particles are better attracted over a distance than nanometer sized magnetic particles by a constant magnetic field gradient, and particle sizes up to 1 {micro}m show a much better accumulation with no apparent side effects in small animal models, since the smallest blood vessels have an inner diameter of 5-7 {micro}m. Nanometer-sized particles <70 nm will accumulate in organ fenestrations despite an effective surface stabilizer. To be suitable for future human applications, our experimental approach synthesizes the magnetic drug carrier according to specific predefined outcome metrics: monodisperse population in a size range of 100 nm to 1.0 {micro}m, non-toxic, with appropriate magnetic properties, and demonstrating successful in vitro and in vivo tests. Another important variable offering possible improvement is surface polarity, which is expected to prolong particle half-life in circulation and modify biodistribution and stability of drugs in the body. The molecules in the blood that are responsible for enhancing the uptake of particles by the reticuloendothelial system (RES) prefer to associate with hydrophobic surfaces. Accordingly, we will tackle this challenge by modifying the particles with hydrophilic coatings such ...
Date: February 16, 2004
Creator: Kaminski, M. D.; Ghebremeskel, A. N.; Nunez, L.; Kasza, K. E.; Chang, F.; Chien, T.-H. et al.
Partner: UNT Libraries Government Documents Department

Development and demonstration of the TRUEX solvent extraction process

Description: The Generic TRUEX Model (GTM) was developed for use in designing site and feed-specific TRUEX flowsheets and in estimating the space and cost requirements for installing a TRUEX process. This paper discusses data collected in support of the GTM and its use in (1) designing process flowsheets and (2) performing sensitivity analyses. Demonstration of the TRUEX process is underway at Argonne National Laboratory (ANL), where plutonium-containing analytical waste solutions generated at the DOE New Brunswick Laboratory (NBL) are being converted from TRU waste ([approximately]l g Pu/L), with no current means of disposal, to solutions that contain less than 10 nCi of transuranic elements per milliliter of waste solution. Results and implications of this demonstration are discussed in this paper.
Date: January 1, 1993
Creator: Vandegrift, G.F.; Chamberlain, D.B.; Conner, C.; Copple, J.M.; Dow, J.A.; Everson, L. et al.
Partner: UNT Libraries Government Documents Department

Development and demonstration of the TRUEX solvent extraction process

Description: The Generic TRUEX Model (GTM) was developed for use in designing site and feed-specific TRUEX flowsheets and in estimating the space and cost requirements for installing a TRUEX process. This paper discusses data collected in support of the GTM and its use in (1) designing process flowsheets and (2) performing sensitivity analyses. Demonstration of the TRUEX process is underway at Argonne National Laboratory (ANL), where plutonium-containing analytical waste solutions generated at the DOE New Brunswick Laboratory (NBL) are being converted from TRU waste ({approximately}l g Pu/L), with no current means of disposal, to solutions that contain less than 10 nCi of transuranic elements per milliliter of waste solution. Results and implications of this demonstration are discussed in this paper.
Date: March 1, 1993
Creator: Vandegrift, G. F.; Chamberlain, D. B.; Conner, C.; Copple, J. M.; Dow, J. A.; Everson, L. et al.
Partner: UNT Libraries Government Documents Department