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The use of selective extraction chromatographic columns as an alternative to solvent extraction for the separation of uranium followed by the use of Arsenazo III as a calorimetric reagent for uranium determination

Description: The use of U/TEVA{reg_sign} Spec columns as an alternative to solvent extraction for separation of uranium prior to its determination by various techniques (calorimetric, phosphorescence, and mass spectroscopy) was investigated. U/TEVA{reg_sign} Spec columns have several advantages over the widely used 4-methyl-2-pentanone solvent extraction method. Among the advantages are: (1) no hazardous liquid organic waste, that creates regulatory waste disposal problems, is generated; (2) a clean separation of U from Zr, F, and fission products is obtained; (3) the sample preparation time is reduced; and (4) the exposure of analysts to ionizing radiation is reduced because the entire procedure may be performed in a hot cell using remote operations. This study also investigated the use of Arsenazo III (1,8-dihydroxynapthalene-3,6-disulfonic acid-2,7-bis [<-azo-2>-phenylarsonic acid]) as a calorimetric reagent to determine uranium concentrations over a wide range in waste streams and product streams at the Idaho Chemical Processing Plant. Process and waste stream samples were passed through a U/TEVA{reg_sign} Spec column to selectively remove the uranium. The uranium bearing fraction is compatible with the pH range for color development with Arsenazo III. Arsenazo III may be added to the uranium fraction, at a 3:1 mole ratio (Arsenazo:Uranium) at the high end of the method (10 {mu}/mL). Arsenazo III forms a highly stable complex with uranium. Stability tests from this and other studies show that the colored complex of Arsenazo III with U(VI) forms within one minute and remains stable for several hours. The complex with U(VI) varies in color with pH. However, with excess reagent, the color is varying shades of purple. Since the samples were passed through a highly selective extraction chromatographic column prior to adding the calorimetric reagent, no interferences were observed.
Date: October 1, 1994
Creator: Miller, C. J. & Del Mastro, J. R.
Partner: UNT Libraries Government Documents Department

Test plan for demonstrating plutonium extraction from 10-L solutions using EIChrom extraction chromatographic resins

Description: Corrosive plutonium solutions stored in 10-L containers at the Plutonium Finishing Plant must be treated to convert the plutonium to a safe, solid form for storage and to remove the americium so that radiation exposure can be reduced. Extraction chromatographic resins will be tested for separating plutonium from these solutions in the laboratory. Separation parameters will be developed during the testing for large scale processing of the 10-L solutions and solutions of similar composition. Use of chromatographic resins will allow plutonium separation with minimum of chemical addition to the feed and without the need for plutonium valence adjustment. The separated plutonium will be calcined to plutonium oxide by direct solution calcination.
Date: August 15, 1994
Creator: Barney, G. S.
Partner: UNT Libraries Government Documents Department

Rapid, Quantitative Analysis of Americium, Curium and Plutonium Isotopes in Hanford Samples Using Extraction Chromatography and Precipitation Plating

Description: Recently developed methods for the rapid, quantitative analysis of americium (Am), curium (Cm), and plutonium (Pu) isotopes in Hanford soil, sludge, and waste-tank samples are described. After dissolution, dilutions are made as necessary based on alpha-energy analysis of a small aliquot of the original solution. isotopic tracers are then added and Am-Cm and Pu are separated by extraction chromatography, coprecipitated with neodymium fluoride, and counted. Examples of alpha spectra are given, and results obtained for Hanford sludge samples are presented.
Date: April 1, 1994
Creator: Kaye, J. H.; Strebin, R. S. & Orr, R. D.
Partner: UNT Libraries Government Documents Department

Measurement of actinides and strontium-90 in high activity waste

Description: The reliable measurement of trace radionuclides in high activity waste is important to support waste processing activities at SRS (F and H Area Waste Tanks, Extended Sludge Processing (ESP) and In-Tank precipitation (ITP) processing). Separation techniques are needed to remove high levels of gamma activity and alpha/beta interferences prior to analytical measurement. Using new extraction chromatographic resins from EiChrom Industries, Inc., the SRS Central Laboratory has developed new high speed separation methods that enable measurement of neptunium, thorium, uranium, plutonium, americium and strontium-90 in high activity waste solutions. Small particle size resin and applied vacuum are used to reduce analysis times and enhance column performance. Extraction chromatographic resins are easy to use and eliminate the generation of contaminated liquid organic waste.
Date: August 1, 1994
Creator: Maxwell, S. L. III & Nelson, M. R.
Partner: UNT Libraries Government Documents Department

Improved accountability method for measuring enriched uranium in H-Canyon dissolver solution at the Savannah River Site

Description: At the Savannah River Site (SRS), accountability measurement of enriched uranium dissolved in H-Canyon is performed using isotope dilution mass spectrometry (IDMS). In the IDMS analytical method, a known quantity of uranium{sup 233} is added to the sample solution containing enriched uranium and fission products. The resulting uranium mixture must first be purified using a separation technique in the shielded analytical(``hot``) cells to lower radioactivity levels by removing fission products. Following this purification, the sample is analyzed by mass spectrometry to determine the total uranium content and isotopic abundance. The magnitude of the response of each uranium isotope in the sample solution and the response of the U{sup 233} spike is measured. By ratioing these responses, relative to the known quantity of the U{sup 233} spike, the uranium content can be determined. A hexane solvent extraction technique, used for years at SRS to remove fission products prior to the mass spectrometry analysis of uranium, has several problems. The hexone method is tedious, requires additional sample clean-up after the purified sample is removed from the shielded cells and requires the use of Resource Conservation and Recovery Act (RCRA)-listed hazardous materials (hexone and chromium compounds). A new high speed separation method that enables a rapid removal of fission products in a shielded cells environment has been developed by the SRS Central Laboratory to replace the hexone method. The new high speed column extraction chromatography technique employs applied vacuum and columns containing tri (2-ethyl-hexyl) phosphate (TEHP) solvent coated on a small particle inert support (SM-7 Bio Beads). The new separation is rapid, user friendly, eliminates the use of the RCA-listed hazardous chemicals and reduces the amount of solid waste generated by the separation method. 2 tabs. 4 figs.
Date: August 1, 1992
Creator: Maxwell, S. L. III; Satkowski, J. & Mahannah, R. N.
Partner: UNT Libraries Government Documents Department

Evaluation of solid-based separation materials for the pretreatment of radioactive wastes

Description: Separation science will play an important role in pretreating nuclear wastes stored at various US Department of Energy Sites. The application of separation processes offers potential economic and environmental benefits with regards to remediating these sites. For example, at the Hanford Site, the sizeable volume of radioactive wastes stored in underground tanks could be partitioned into a small volume of high-level waste (HLW) and a relatively large volume of low-level waste (LLW). After waste separation, only the smaller volume of HLW would require costly vitrification and geologic disposal. Furthermore, the quality of the remaining LLW form (e.g., grout) would be improved due to the lower inventory of radionuclides present in the LLW stream. This report investigates extraction chromatography as a possible separation process for Hanford wastes.
Date: May 1, 1993
Creator: Lumetta, G. J.; Wagner, M. J.; Wester, D. W. & Morrey, J. R.
Partner: UNT Libraries Government Documents Department

Separation techniques for the clean-up of radioactive mixed waste for ICP-AES/ICP-MS analysis

Description: Two separation techniques were investigated for the clean-up of typical radioactive mixed waste samples requiring elemental analysis by Inductively Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES) or Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). These measurements frequently involve regulatory or compliance criteria which include the determination of elements on the EPA Target Analyte List (TAL). These samples usually consist of both an aqueous phase and a solid phase which is mostly an inorganic sludge. Frequently, samples taken from the waste tanks contain high levels of uranium and thorium which can cause spectral interferences in ICP-AES or ICP-MS analysis. The removal of these interferences is necessary to determine the presence of the EPA TAL elements in the sample. Two clean-up methods were studied on simulated aqueous waste samples containing the EPA TAL elements. The first method studied was a classical procedure based upon liquid-liquid extraction using tri-n- octylphosphine oxide (TOPO) dissolved in cyclohexane. The second method investigated was based on more recently developed techniques using extraction chromatography; specifically the use of a commercially available Eichrom TRU{center_dot}Spec{trademark} column. Literature on these two methods indicates the efficient removal of uranium and thorium from properly prepared samples and provides considerable qualitative information on the extraction behavior of many other elements. However, there is a lack of quantitative data on the extraction behavior of elements on the EPA Target Analyte List. Experimental studies on these two methods consisted of determining whether any of the analytes were extracted by these methods and the recoveries obtained. Both methods produced similar results; the EPA target analytes were only slightly or not extracted. Advantages and disadvantages of each method were evaluated and found to be comparable.
Date: March 17, 1993
Creator: Swafford, A. M. & Keller, J. M.
Partner: UNT Libraries Government Documents Department

Extraction chromatography of neodymium by an organophosphorous extractant supported on various polymeric resins

Description: Fifteen resins coated with dihexyl-N,N-diethylcarbamoylmethyl phosphonate (CMP) were studied for their extraction of neodymium (Nd) in 4.0 and 7.0 M nitric acid. Resin properties, such as chemical composition and physical morphology, which can influence Nd extraction as well as subsequent resin regeneration (Nd stripping), were identified. Hydrophilic or polar resins coated with CMP efficiently extracted the Nd. Resins initially washed free of residual monomer and solvent before CMP coating outperformed their untreated counterparts. The macroporous styrene-divinylbenzene hydrophobic resins that were high in surface area were less effective supports compared with hydrophilic microporous Aurorez, polybenzimidazole (PBI) and macroporous Amberlite polyacrylic resins. Only one resin, Duolite C-467, showed no measurable improvement in Nd extraction with CMP coating. CMP-coated Aurorez PBI, a microporous and hydrophilic polymeric resin with an average surface area, showed the best overall efficiency for Nd removal and resin regeneration.
Date: April 1, 1993
Creator: Takigawa, D. Y.
Partner: UNT Libraries Government Documents Department

Removal of plutonium and Americium from hydrochloric acid waste streams using extraction chromatography

Description: Extraction chromatography is under development as a method to lower actinide activity levels in hydrochloric acid (HCl) effluent streams. Successful application of this technique for radioactive liquid waste treatment would provide a low activity feedstream for HCl recycle, reduce the loss of radioactivity to the environment in aqueous effluents, and lower the quantity and improve the form of solid waste generated. The extraction of plutonium and americium from HCl solutions was examined for several commercial and laboratory-produced sorbed resin materials. Polymer beads were coated with n-octyl(phenyl)-N,N-diisobutylcarbamoyl- methylphosphine oxide (CMPO) and either tributyl phosphate (TBP), or diamyl amylphosphonate (DAAP). Distribution coefficients for Pu and Am were measured by contact studies in 1-10 M HCl, while varying REDOX conditions, actinide loading levels, and resin formulations. Flow experiments were run to evaluate actinide loading and elution under varied conditions. Significant differences in the actinide distribution coefficients in contact experiments, and in actinide retention in flow experiments were observed as a function of resin formulation.
Date: January 1, 1995
Creator: Schulte, L. D.; FitzPatrick, J. R.; Salazar, R. R.; Schake, B. S. & Martinez, B. T.
Partner: UNT Libraries Government Documents Department

Chemistry Research and Development. Progress Report, July 1977--April 1978

Description: The following studies are reported on: calorimetry and thermodynamics of nuclear materials; actinide recovery and purification; optimization of the cation exchange process for recovering americium and plutonium from molten salt extraction residues; decontamination of soil; secondary actinide recovery; evaluation of tributyl phosphate-impregnated sorbent for plutonium-uranium separations; comparison of cation exchange recovery of actinides from the NaCl--KCl--MgCl/sub 2/ and CaCl/sub 2/--KCl--MgCl/sub 2/ systems; combined anion exchange-bidentate organophosphorous extraction process for molten salt extraction residues; recovery of actinides from combustible wastes; actinide recovery and recycle preparation for waste streams; processing Leco crucible residues containing a tin accelerator; dissolution of refractory residues in hydrochloric acid; metal distillation; induction-heated, tilt-pour furnace; plutonium from backlog salts; and plutonium peroxide precipitation process. (LK)
Date: November 8, 1978
Creator: Miner, F. J.
Partner: UNT Libraries Government Documents Department

Separation techniques for the clean-up of radioactive mixed waste for ICP-AES/ICP-MS analysis

Description: Two separation techniques were investigated for the clean-up of typical radioactive mixed waste samples requiring elemental analysis by Inductively Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES) or Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). These measurements frequently involve regulatory or compliance criteria which include the determination of elements on the EPA Target Analyte List (TAL). These samples usually consist of both an aqueous phase and a solid phase which is mostly an inorganic sludge. Frequently, samples taken from the waste tanks contain high levels of uranium and thorium which can cause spectral interferences in ICP-AES or ICP-MS analysis. The removal of these interferences is necessary to determine the presence of the EPA TAL elements in the sample. Two clean-up methods were studied on simulated aqueous waste samples containing the EPA TAL elements. The first method studied was a classical procedure based upon liquid-liquid extraction using tri-n- octylphosphine oxide (TOPO) dissolved in cyclohexane. The second method investigated was based on more recently developed techniques using extraction chromatography; specifically the use of a commercially available Eichrom TRU[center dot]Spec[trademark] column. Literature on these two methods indicates the efficient removal of uranium and thorium from properly prepared samples and provides considerable qualitative information on the extraction behavior of many other elements. However, there is a lack of quantitative data on the extraction behavior of elements on the EPA Target Analyte List. Experimental studies on these two methods consisted of determining whether any of the analytes were extracted by these methods and the recoveries obtained. Both methods produced similar results; the EPA target analytes were only slightly or not extracted. Advantages and disadvantages of each method were evaluated and found to be comparable.
Date: March 17, 1993
Creator: Swafford, A.M. & Keller, J.M.
Partner: UNT Libraries Government Documents Department

Tributyl phosphate impregnated sorbent for plutonium--uranium separation

Description: Extraction, or reverse-phase partition chromatography, as used mostly for analytical separations, employs an organic solvent extractant as a stationary phase on an inert support material. This technique has the advantage of utilizing the versatility of solvent extraction systems with the less expensive operation of ion exchange equipment. Bayer AG Lewatit OC-1023, a tributyl phosphate impregnated sorbent developed for extraction chromatography, was evaluated for the separation of uranium and plutonium from mixed actinide residues at Rocky Flats. Uranium breakthrough capacity and eluion behavior were determined for the OC-1023. Uranium breakthrough capacity results show that the support has a high capacity for uranium from 10 g/l uranium and 25 g/l plutonium-2.5 g/l uranium feeds. The total uranium capacity of the support under these conditions was determined to range from about 53 to 65% of the theoretical TBP capacity. The uranium elution results show that the uranium can be eluted with a minimum of eluant.
Date: March 31, 1978
Creator: Alford, C.E. & Navratil, J.D.
Partner: UNT Libraries Government Documents Department

Comparison between CMPO and DHDECMP for alpha decontamination of radioactive liquid waste

Description: Ion exchange is the major method used at Los Alamos to recover and purify plutonium from a variety of different contaminants. During this process, a high-acid (5-7M), low-activity stream is produced that presently is concentrated by evaporation, then cemented for long-term disposal. Our goal is to remove and concentrate the radioactive elements so that the remainder can be treated as low-level'' or regular industrial waste. Solvent extraction with neutral bifunctional extractants, such as DHDECMP and CMPO, has been chosen as the process to be developed. Experimental work has shown that both extractants effectively remove actinides to below the required limits, but that CMPO was much more difficult to strip. In addition, studies of plutonium and americium removal using a wide variety of ion exchangers and supported extractants including DHDECMP, CMPO, and TOPO will be reviewed. 22 refs., 10 figs., 3 tabs.
Date: January 1, 1990
Creator: Muscatello, A. C.; Yarbro, S .L. & Marsh, S. F.
Partner: UNT Libraries Government Documents Department

Actinide removal from nitric acid waste streams

Description: Actinide separations research at the Rocky Flats Plant (RFP) has found ways to significantly improve plutonium secondary recovery and americium removal from nitric acid waste streams generated by plutonium purification operations. Capacity and breakthrough studies show anion exchange with Dowex 1x4 (50 to 100 mesh) to be superior for secondary recovery of plutonium. Extraction chromatography with TOPO(tri-n-octyl-phosphine oxide) on XAD-4 removes the final traces of plutonium, including hydrolytic polymer. Partial neutralization and solid supported liquid membrane transfer removes americium for sorption on discardable inorganic ion exchangers, potentially allowing for non-TRU waste disposal.
Date: January 1, 1986
Creator: Muscatello, A.C. & Navratil, J.D.
Partner: UNT Libraries Government Documents Department

Radiochemistry of uranium, neptunium and plutonium: an updating

Description: This report presents some procedures used in the radiochemical isolation, purification and/or analysis of uranium, neptunium, and plutonium. In this update of the procedures, we have not attempted to discuss the developments in the chemistry of U, Np, and Pu but have restricted the report to the newer procedures, most of which have resulted from the increased emphasis in environmental concern which requires analysis of extremely small amounts of the actinide element in quite complex matrices. The final section of this report describes several schemes for isolation of actinides by oxidation state.
Date: February 1, 1986
Creator: Roberts, R. A.; Choppin, G. R. & Wild, J. F.
Partner: UNT Libraries Government Documents Department

Applications of DHDECMP extraction chromatography to nuclear analytical chemistry

Description: Dihexyl-N,N-diethylcarbamylmethylenephosphonate (DHDECMP) is a highly selective extractant for actinides and lanthanides. This reagent, extensively studied for process-scale operations, also has valuable analytical applications. Extraction chromatographic columns of DHDECMP, supported on inert, porous, polymer beads effectively separate most metallic impurity elements from the retained inner transition elements. The retained elements can be separated into individual fractions of (1) lanthanides, (2) americium, (3) plutonium, and (4) uranium by mixed-solvent anion exchange.
Date: January 1, 1981
Creator: Marsh, S.F. & Simi, O.R.
Partner: UNT Libraries Government Documents Department

Chemistry research and development. Progress report, November 1978-April 1979

Description: The status of the following studies is given: calorimetry and thermodynamics of nuclear materials; americium recovery and purification; optimization of the cation exchange process for recovering americium and plutonium from molten net extraction residues; evaluation and comparison of bidentate extractants and methods for actinide recovery; a combined anion exchange-bidontate organophosphorus extraction process for molten salt extraction residues; a combined anion exchange-extraction chromatography technique for secondary recovery; plutonium recovery in the Advanced Size Reduction Facility; decontamination of Rocky Flats soil; separating lead and calcium from americium by chromate and oxalate precipitation; demonstration of the pyroredox process in the induction-heated, tilt-pour furnace; process development for recovery of americium from vacuum melt furnace crucibles; plutonium peroxide precipitation process; and a comparative study of annular and Raschig ring-filled tanks.
Date: October 5, 1979
Creator: Miner, F. J.
Partner: UNT Libraries Government Documents Department

Rapid separation of individual rare-earth elements from fission products

Description: A microprocessor-controlled radiochemical separation system has been developed to rapidly separate rare-earth elements from gross fission products. The system is composed of two high performance liquid chromatography columns coupled in series by a stream-splitting injection valve. The first column separates the rare-earth group by extraction chromatography using dihexyldiethylcarbamylmethylenephosphonate (DHDECMP) adsorbed on Vydac C/sub 8/ resin. The second column isolates the individual rare-earth elements by cation exchange using Aminex A-9 resin with ..cap alpha..-hydroxyisobutyric acid (..cap alpha..-HIBA) as the eluent. With this system, fission-product rare-earth isotopes with half-lives as short as three minutes have been studied.
Date: January 1, 1980
Creator: Baker, J.D.; Gehrke, R.J.; Greenwood, R.C. & Meikrantz, D.H.
Partner: UNT Libraries Government Documents Department

Evaluation of extraction chromatography for americium recovery

Description: Extraction, or reverse-phase partition chromatography, as used mostly for analytical separations, employs an organic solvent extractant as a stationary phase on an inert support material. This technique, which has the advantage of utilizing the versatility of solvent extraction systems with the less expensive operation of ion exchange equipment, was evaluated for a process to recover low level concentrations of americium from acidic process waste streams at Rocky Flats. The bidentate organophosphorous extractant DHDECMP (dihexyl-N, N-diethylcarbamylmethylene phosphonate) was used as the stationary phase since it was shown to effectively scavenge americium from acidic waste streams without significantly extracting impurity ions. Over 30 support materials were evaluated for DHDECMP capacity and for their ability to retain the extractant. Of the supports tested, the Amberlite XAD macroreticular sorbents were found to have the highest DHDECMP capacity. Amberlite XAD-4 beads retained the extractant significantly better than the other supports evaluated. Thus, this solvent was tested for americium breakthrough capacity and compared to the theoretical capacity.
Date: March 23, 1977
Creator: Alford, C. E. & Navratil, J. D.
Partner: UNT Libraries Government Documents Department

Chemical research at Rocky Flats

Description: An overview of the research projects in the Chemical Research group will be given. The work involves actinide waste and processing chemistry, separations chemistry, radiation studies, and calorimetry and thermodynamics. Details will be given of the actinide separations research, including work with macroreticular anion exchangers and bidentate organophosphorus extractants.
Date: February 27, 1978
Creator: Navratil, J. D.
Partner: UNT Libraries Government Documents Department

Actinide production in /sup 136/Xe bombardments of /sup 249/Cf

Description: The production cross sections for the actinide products from /sup 136/Xe bombardments of /sup 249/Cf at energies 1.02, 1.09, and 1.16 times the Coulomb barrier were determined. Fractions of the individual actinide elements were chemically separated from recoil catcher foils. The production cross sections of the actinide products were determined by measuring the radiations emitted from the nuclides within the chemical fractions. The chemical separation techniques used in this work are described in detail, and a description of the data analysis procedure is included. The actinide production cross section distributions from these /sup 136/Xe + /sup 249/Cf bombardments are compared with the production cross section distributions from other heavy ion bombardments of actinide targets, with emphasis on the comparison with the /sup 136/Xe + /sup 248/Cm reaction. A technique for modeling the final actinide cross section distributions has been developed and is presented. In this model, the initial (before deexcitation) cross section distribution with respect to the separation energy of a dinuclear complex and with respect to the Z of the target-like fragment is given by an empirical procedure. It is then assumed that the N/Z equilibration in the dinuclear complex occurs by the transfer of neutrons between the two participants in the dinuclear complex. The neutrons and the excitation energy are statistically distributed between the two fragments using a simple Fermi gas level density formalism. The resulting target-like fragment initial cross section distribution with respect to Z, N, and excitation energy is then allowed to deexcite by emission of neutrons in competition with fission. The result is a final cross section distribution with respect to Z and N for the actinide products. 68 refs., 33 figs., 6 tabs.
Date: August 1, 1985
Creator: Gregorich, K.E.
Partner: UNT Libraries Government Documents Department