NUCL 1 [512295]: Determination of heavy metals and their leaching characteristics in DOE lead-lined hand gloves Sheldon Landsberger1, David Dodoo-Amoo1, Shamsuzzoha Basunia1, and John Macdonald2. (1) Nuclear Engineering Teaching Lab, University of Texas, Pickle Resarch Campus, R-9000, Austin, TX 78712, s.landsberger@mail.utexas.edu, (2) NMT-2, Los Alamos National Lab

Abstract Currently Los Alamos National Laboratory is considering replacing its lead lined gloves with other composite materials to replace the lead waste stream. However, our current neutron activation analysis (NAA) work has shown that the presence of unusual amounts of other heavy metals with the glove matrix. Typically lead cannot be determined using NAA. However, we have successfully employed the Pb-204(n,2n)Pb-203 reaction with the TRIGA reactor since the lead concentrations are so high. We also performed US EPA Toxicity Characteristic Leaching Procedure to determine the leachability for these heavy metals to the environment. These tests are performed under acetic acid conditions to mimic landfill conditions. However, these gloves are often used in conjunction with strong chemical reagents. Thus we propose that additional leaching tests under typical strong acid conditions be undertaken. A complete overview of the analytical procedures will be discussed for these difficult matrices.

NUCL 2 [512328]: Treatment of detection limits and blanks in neutron activation analysis of airborne particulate matter Sheldon Landsberger, Shamsuzzoha Basunia, and Alice Sun, Nuclear Engineering Teaching Lab, University of Texas, Pickle Research Campus R-9000, Austin, TX 78712, s.landsberger@mail.utexas.edu

Abstract It is well known that neutron activation analysis is very well suited to determine many trace elements in airborne particulate matter. However, because of the filter matrix that the samples are collected on, there can be many varying degrees of detection limits coming from analytical procedures and inherent blanks. Thus, a comprehensive evaluation of these limits must be scrutinized to be properly used in source-receptor modeling. Even simple statistical calculations often are severely biased if any zero results are introduced. An overview of a current multielemental data from some 700 samples from the Finnish arctic will be discussed. Included will suggestions for quality and quality control of the results before they are used in any source-receptor modeling.

NUCL 3 [516431]: Determination of I-129 in high activity waste at the

Savannah River Site David P DiPrete1, Cecilia C. DiPrete1, and Charles J. Coleman2. (1) Savannah River Technology Center, Analytical Development, Westinghouse Savannah River Company, Savannah River Technology Center, Aiken, SC 29808, david.diprete@srs.gov, c.diprete@srs.gov, (2) Savannah River Technology Center, Westinghouse Savannah River Company

Abstract I-129 is a fission product with a half life of about 16 million years. It is very mobile in the environment because of its low retention in sub-surface soil. Moreover, the biological hazards of I-129 are enhanced by its affinity for thyroid tissue. For these reasons, I-129 has long been considered a potential problem in the disposal of radioactive waste. Considerable emphasis has been placed on I-129 analyses on numerous waste streams at the Savannah River Site (SRS). Currently the Savannah River Technology Center (SRTC) uses a variation of the silver iodide precipitation method as prescribed for EPA drinking water analyses. The method has been successfully applied to a variety of sample matrices. SRTC waste disposal guidelines require measurements of I-129 to the 10 picocurie/g or ml level on high activity waste tank sludge and salt supernatant samples. The primary beta-emitting radionuclide in the sludge is Sr-90, nominally at an activity of about 1 E10 picocurie/g. The primary beta-emitting radionuclide in the supernatant is Cs-137, nominally at an activity of 1 E10 picocurie/ml. Therefore, for both sludge and supernatant samples, a complete separation of I-129 from high levels of interferring radionuclides is required. The silver iodide precipitation method was successful for sludge, but interferences in the supernatant forced an alternative approach for this matrix. Due to the high dose rate of the samples, the initial radiochemistry was performed remotely in the SRTC shielded cells, followed by further radiochemistry in a conventional radiohood.

NUCL 4 [516960]: Status report on several radiochemical method validation efforts Donivan R. Porterfield1, George H Brooks Jr.2, Donald E Dry3, and Stephanie Boone3. (1) Chemistry Division - Actinide Analytical Chemistry Group, Los Alamos National Laboratory, PO Box 1663; MS E531, Los Alamos, NM 87545, Fax: 505-667-2601, dporterfield@lanl.gov, (2) Chemistry Division - Analytical Chemistry Sciences, Los Alamos National Laboratory, (3) Chemistry Division - Isotope and Nuclear Chemistry, Los Alamos National Laboratory

Abstract This paper will report our progress on three different method validation efforts. The first is a non-destructive approach for actinide solutions being analyzed to meet activity based discard limits (mCi/L to nCi/L). Both sodium iodide and cadmium zinc telluride (CZT) type detectors are being evaluated.

The second is a screening method for aqueous and non-aqueous liquids for alpha activity using the PerkinElmer BetaScout (aka Hidex Triathler) liquid scintillation counter. This is a small form counter, which is capable of alpha beta discrimination.

The third is a method for determination of ppm levels of neptunium-237 in plutonium metal using small-scale solid phase extraction and gamma spectroscopy. This method would utilize the in-grown daughter of americium-243 (neptunium-239) as an internal standard.

The overall goal of each of these three efforts is to serve our client in a better, faster, and cheaper manner where possible.

LAUR 01-6295

NUCL 5 [514224]: 252Cf Neutron activation analysis of high-level processed nuclear tank waste Gary L Troyer1, Mike A. Purcell1, and William I. Winters2. (1) Fluor Hanford, Inc, PO Box 1000/ MSIN T6-50, Richland, WA 99352, Fax: 509-373-1180, gary_l_troyer@rl.gov, (2) Numatec Hanford Corporation

Abstract A basis for production assessment of the vitrification of Hanford nuclear fuel reprocessing wastes will be high precision measurements of the elemental sodium content. However, the chemical analysis of both radioactive and non-radioactive components in nuclear waste can be challenged by high radiation dose rates. The dose rates compromise many analytical techniques as well as pose personnel dosimetry risks. In many cases, reduction of dose rates through dilution compromises the precision and sensitivity for certain key components. The use of neutron activation analysis provides a method of analysis which avoids the need for dilutions or extensive sample preparation. These waste materials also contain trace quantities of fissionable isotopes, which, through neutron activation, can be estimated by delayed neutron counting of fissioned fragments. A recently developed procedure uses a nominal 80 milligram 252Cf neutron source to measure direct process weight per cent sodium samples to approximately one per cent total propagated uncertainty.

NUCL 6 [521977]: Automated radiochemical analysis of total Tc-99 in nuclear waste processing streams Oleg Egorov, Matt O'Hara, and Jay Grate, Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, P7-22, 902 Battelle Blvd, PO Box 999, Richland, WA 99352, oleg.egorov@pnl.gov

Abstract Determination of Tc-99 in nuclear waste processing streams will be required during operation of the Waster Treatment Plant at the Hanford Site. To date there is a lack of analytical methodologies suitable for reliable, rapid, and selective determination of this radionuclide in chemically and radiologically complex matrixes. The research in our laboratory has been directed at the development of a fully automated Tc-99 process monitor instrument based on the radiochemical measurement approach. Technetium-99 quantification is carried out using flow-through solid scintillation detection, after the pertechnetate species are separated from interfering radionuclides. Microwave-assisted sample oxidation is carried prior to chemical separation in order to oxidize all non-pertechnetate species to pertechnetate. Advanced digital fluid handling techniques are used for sample/solutions manipulation and system integration. Performance characteristics of the monitor instrument and analysis of the caustic waste samples from the Hanford site will be discussed.

NUCL 7 [513848]: Development of a combined corrosion and chemistry measurement system D. T. Hobbs1, J. A. Mickalonis2, E. M. Tshishiku1, J. M. Bello3, G. A. Edgemon4, M. T. Terry5, and G. J. Bastiaans6. (1) Savannah River Technology Center, Westinghouse Savannah River Company, 773-A, B-117, Aiken, SC 29808, Fax: 803-725-4704, david.hobbs@srs.gov, (2) Westinghouse Savannah River Company, Savannah River Technology Center, (3) EIC Laboratories, Inc, (4) Hiline Engineering and Fabrication, Inc, (5) Los Alamos National Laboratory, (6) Ames Laboratory Iowa State University

Abstract A combined corrosion and chemistry measurement system has been developed for installation into the Savannah River Site (SRS) high-level nuclear waste tanks. The system features an electrochemical noise probe for the continuous measurement of waste solution corrosivity and a Raman probe for the in-situ determination of key corrosion species including nitrate, nitrite and free hydroxide. This paper will present key design features of the combined probe, results of cold acceptance testing and plans for deployment at the SRS.

NUCL 8 [521927]: In-line ultrasonic sensor for characterization of opaque suspensions N. Dogan1, R. L. Powell1, M. J. McCarthy1, R. Pappas2, D. M. Pfund2, and D. M. Sheen2. (1) University of California, Davis, CA 95616, ndogan@ucdavis.edu, (2) Battelle Pacific Northwest National Laboratory

Abstract This study aims to develop a process sensor, that uses ultrasonics to determine the properties and velocity profiles of fluids undergoing pressure driven flow in a tube. From these profiles and simultaneous pressure drop measurements, the local shear rate and shear stress can be calculated, respectively. Thereby, the viscosity as a function of shear rate can be determined. In many industries, rheological properties of process streams are indicative of other important properties of the materials. Many materials are transported within a process facility by means of flow in a circular pipe and shearing conditions vary dramatically over the pipe cross-section. Shear sensitive materials therefore simultaneously elaborate behavior that reflects both low shear rate and high shear rate properties, which gives the opportunity of calculating shear viscosity at many shear rates. The application of this sensor is being explored using various suspensions. A flow loop was built, which consists of a 50.8mm internal diameter acrylic tube, a positive-displacement pump and pressure transducers. The ultrasound probe with 2.25 MHz basic frequency was placed 5 m from the loop bend and the ratio of the length between pressure transducers to tube diameter was 70. The data acquisition takes less than one second. The experiments with 0.2-0.5 % pulp suspensions showed that this ultrasonic sensor can be used to monitor the flow of opaque, fibrous suspensions.

NUCL 9 [514278]: Evaluation of West Valley Demonstration Project tank 8D-2 samples and radiation profiles Gary L Troyer1, Frederick Damerow2, John Fazio2, Glenn J Bastiaans3, and Michael Grant4. (1) Fluor Hanford, Inc, PO Box 1000/MSIN T6-50, Richland, WA 99352, Fax: 509-373-1180, gary_l_troyer@rl.gov, (2) West Valley Nuclear Services, (3) Ames Laboratory, (4) URS

Abstract This report provides evaluation of various radiological data obtained from in-situ measurements and sample analytical results for West Valley Demonstration Project (WVDP) nuclear waste storage tank 8D-2. The evaluation provides a methodology for inventory estimation and recommendations for technologies to assess progress of tank clean-out. Correlations of various radionuclide concentrations were made to show possibility of projecting marker nuclides such as 154Eu, 60Co, and 137Cs to non-in-situ measurable nuclides. Analytical results were scaled with general radiation dose rate profiles to demonstrate inventory distributions.

NUCL 10 [513869]: Multiple-sensor, long-term monitoring system for environmental contaminants Scott R. Burge, and Russell G. Burge, Burge Environmental, 6100 South Maple Avenue, Suite 114, Tempe, AZ 85283, Fax: 480-345-7633, burgenv@primenet.com

Abstract The automation of environmental monitoring will probably only reach its full potential in terms of cost savings and data reliability if the field methods emulate current laboratory methods and procedures (frequent calibrations, etc.). The deployment of sensors into the environment without the benefit of these methods and procedures will probably never attain full regulatory acceptance. The sampling/analytical instrumentation developed is capable of performing “real-time” organic and inorganic analysis of ground water. It is also capable of performing calibrations and many quality control checks. The present instrumentation is capable of detecting and analyzing Cr (VI) and several organic species (carbon tetrachloride). The instrument uses classical methods (colorimetric analysis) packaged for deployment in the hostile environment encountered within monitoring wells. Sampling and analysis procedures are automated. The paper will present the design, operation and results of a dual-detector instrument.

NUCL 11 [521784]: Antibody-based sensors for hexavalent uranium Diane A. Blake1, Robert C. Blake II2, and Haini Yu1. (1) Tulane/Xavier Center for Bioenvironmental Research, Tulane University Health Sciences Center, 1430 Tulane Avenue, SL-69, New Orleans, LA 70112, Fax: 504-584-2684, blake@tulane.edu, (2) Xavier University of Louisiana

Abstract A portable sensor for U(VI) is under development that employs a monoclonal antibody with specificity for chelated U(VI) and an instrument built by Sapidyne Instruments, Inc. (Boise, ID). In this method, the fluorescently labeled antibody is permitted to equilibrate with soluble metal-chelate complex derived from the environmental sample, then the equilibrium mixture is rapidly passed through a disposable microcolumn that contains an immobilized capture reagent. When the fluorescent signal is plotted versus time, the slope of the line is inversely proportional to the concentration of UO22+ in the original solution. The prototype immunosensor could detect soluble UO22+ at concentrations

from 10 to 100 nM (2.5 to 24 ppb). The maximum CV in the linear portion of the assay was 6.5%. A smaller, handheld version of the immunosensor is presently being tested, and this technology is being extended to include microcolumns and antibodies for the analysis of cadmium, lead, and ethylenediamine tetraacetic acid. Supported by DOE grant (DE-FG02-98ER62704).

NUCL 12 [514907]: DOE waste stream elimination: an overview Dennis L Hjeresen, ACS Green Chemistry Institute, 1155 16th St. N.W, Washington, DC 20036, Fax: 202-872-6206, d_hjeresen@acs.org

Abstract The national security, energy, environmental and science missions of the United States Department of Energy (DOE) require utilization of nearly element of the periodic table. The continued generation of radioactive and hazardous waste streams creates environmental, health, safety, financial, regulatory and social liabilities for the DOE that threaten operational viability. The Science-based Stockpile Stewardship Program depends on a broad set of experiments with nuclear materials to understand aging and materials interactions. The testing of nuclear weapons pits to determine aging effects and processing to recycle the plutonium (Pu) currently use processes such as nitric acid dissolution, anion exchange, pyrochemical processing, alloying, casting, oxidizing, welding, machining, and cleaning. Each step in these processes generates new volumes of low-level, hazardous transuranic (TRU) or mixed radioactive waste. The elimination of waste streams through new science and technology development and implementation would enable the Department to go beyond existing pollution prevention efforts and eliminate these liabilities.

NUCL 13 [510458]: Waste minimization in the INEEL analytical laboratory Rick L. Demmer, V. Jim Johnson, and Jeffrey S. Laug, Bechtel BWXT Idaho, P.O. Box 1625, MS 5218, Idaho Falls, ID 83415, Fax: 208-526-5937, rickd@inel.gov

Abstract The Department of Energy (DOE) has mandated that liquid waste generation at the Idaho Nuclear Technology and Engineering Center (INTEC) on the Idaho National Engineering and Environmental Laboratory (INEEL) site must be cut by 50%. This paper describes the approach applied to waste stream minimization and pollution prevention for the analytical laboratory facilities at the INTEC. Tasks included the identification of individual wastes, preparation of a database of these waste volumes and research of alternative, low waste analytical methods. Metrics were applied based on the amount of samples processed by each method. Finally, these results were used in an evaluation and

comparison of waste volumes with other commercial and DOE laboratories. This approach was validated by an independent review by the DOE National Pollution Prevention Team. Some recommendations and examples are given to support the value of this approach to reduce waste.

NUCL 14 [512196]: Hydrothermal processing for destruction of radioactive halogenated organics Laura A. Worl, NMT-11, Los Alamos National Laboratory, MS-E505, Los Alamos, NM 87545, lworl@lanl.gov, Steven J. Buelow, Chemical Science and Technology, Los Alamos National Laboratory, David Harradine, CST-6, Chemical Reactions, Kinetics and Dynamics Group, Los Alamos National Laboratory, Dallas D. Hill, Engineering Sciences and Applications Division, Energy and Process Engineering, Los Alamos National Laboratory, Rhonda M. McInroy, C-PCS, Los Alamos Naitonal Laboratory, Dennis D. Padilla, Nuclear Materials Technology Division, Actinide Technology Development Group, Los Alamos National Laboratory, and Gary Baca, C-PCS, Los Alamos National Laboratory

Abstract Chemical reactions in high temperature water (hydrothermal processing) allow new avenues for effective waste treatment and elimination. Halogenated hazardous organic liquids containing actinides are a difficult to treat category of transuranic radioactive wastes. These liquids are typically used for degreasing operations or density measurements and can include trichloroethylene and bromobenzene. Hydrothermal processing is proven technology for the destruction of organic based materials and now has the potential to eliminate mixed wastes and other radioactive combustible wastes at DOE facilities. A 20 liter / month full-scale treatment unit was designed, fabricated and tested for nuclear manufacturing needs. The system, based on an ambient pressure, high temperature process, was successfully demonstrated for the destruction of concentrated halogenated organic solutions achieving more than a 99.99% removal of the organic constituent. The effluents are acidic, yet can be neutralized in a post processing step.

NUCL 15 [504744]: Evaluation of ion exchange resins for removing plutonium contamination from uranium materials Alice K. Slemmons, C-AAC, Los Alamos National Laboratory, P.O.Box 1663, Los Alamos, NM 87545, Fax: 505-665-4737, and John R. FitzPatrick, NMT-11, Los Alamos National Laboratory

Abstract Plutonium-contaminated uranium materials are created by various Los Alamos National Laboratory (LANL) processes. To recover the uranium for reuse, the residues must be

cleaned of their plutonium content, such that they contain no more than 0.2 ppm plutonium. Historically, this has been accomplished via solvent extraction. Because the particular process used at LANL has recently become unavailable, there is interest in implementing a new technique to perform the separations.

As part of this effort, the performance of ten commercially-available ion-exchange resins was examined to determine how well suited they are for this particular application. Resins studied include anion and cation exchange resins as well as extraction chromatography materials. Contact studies were performed to evaluate distribution coefficients as contact time, nitric acid molarity, or pH varied. From this data, individual resins were selected for further study of their loading and elution characteristics. The work employed radioanalytical tools to measure the uranium and plutonium content. Results from these studies will be presented and conclusions will be discussed.

NUCL 16 [515251]: Demonstration of a small tank tetraphenylborate precipitation process using Savannah River Site high level nuclear waste Thomas B. Peters1, Mark J. Barnes1, Fernando F. Fondeur1, Sam D. Fink1, Ron W. Blessing2, Rocci E. Norcia3, Karl W. Kennell4, Tony R. Tipton4, and Brian B. Anderson1. (1) Waste Processing Technology, Westinghouse Savannah River Site, 773-42A, Room 128, Aiken, SC 29808, thomas.peters@srs.gov, (2) Shielded Cells, Westinghouse Savannah River Site, (3) Controls, Westinghouse Savannah River Site, (4) Alternate Salt Controls, Westinghouse Savannah River Site

Abstract Experimental efforts have demonstrated the continuous precipitation of cesium from Savannah River Site (SRS) high level nuclear waste using sodium tetraphenylborate (NaTPB). In addition, we examined the removal of strontium and various actinides through sorption on monosodium titanate (MST). The waste used in the experiments represents a mixture from a number of tanks at SRS and includes the same waste source as used in an earlier demonstration. SRS also investigated the use of a specially designed antifoam to prevent hydraulic upsets. This work showed that cesium tetraphenylborate (CsTPB) precipitation will successfully remove cesium from the waste, averaging a decontamination factor of 1.4 million after the equipment reached steady-state operation, including elevated temperature operations. Furthermore, the experiment demonstrated successful actinide and strontium removal, with no process upsets throughout the entire experimental run.

NUCL 17 [522465]: Nuclear forensics and its historical development A.L. Boni, Savannah River Technology Center, Westinghouse Savannah River Company, Aitken, SC 88888, albert.boni@srs.gov

Abstract Nuclear Forensics can be loosely defined as an investigative process using the identification and measurement of radioactive isotopes for the determination of information directly or indirectly related to the material of interest. Radioactive decay since its early discovery provides a unique and very sensitive measure for the identification of ultratrace elements and their isotopes. The rapid development of radioactivity measurement technology during the past 60 years has improved detection sensitivity levels to the one part in 1016. Using ultra-sensitive radioactivity measurement techniques, the measurement of unique trace isotopes, isotopic ratios and interrelated isotope patterns can be detected. It is these isotopic measurements which when applied to the collection of nuclear forensic information led to their application to identification of early atmospheric weapons testing fallout, determination of geological and age history of the earth, atmospheric transport and diffusion, environmental pollution source identification and the origin and history of errant nuclear materials intercepted in nuclear smuggling incidents.

NUCL 18 [522467]: Nuclear forensic analysis of an interdicted HEU sample K. J. Moody1, P. M. Grant2, and I. D. Hutcheon2. (1) Lawrence Livermore National Laboratory, Livermore, CA 94550, (2) Analytical and Nuclear Chemistry Division and Forensic Science Center, Lawrence Livermore National Laboratory

Abstract Nuclear forensic analyses of uranium and plutonium samples are based on comprehensive radioanalytical chemistry, mass spectrometry, and radiation counting. The resulting data are interpreted through first principles and computer modeling. More traditional forensic disciplines rely on measurements of well-defined signature species, with test results compared to established databases built up from prior analyses of known materials. Nuclear forensic analysis has not yet progressed to this point because of the relative youth of the discipline, as well as the classification issues associated with the production of weapons-grade materials. We present the results of a comprehensive investigation of a smuggled sample of highly enriched uranium (HEU) recently interdicted in Bulgaria. Radiochemical age analyses, precision mass spectrometry of actinide signatures, trace element analysis, and particle morphology provided primary information on the questioned specimen to support a law-enforcement investigation of the origin of the sample. Collateral analyses of shielding and packaging materials included forensic efforts in metallurgy, paper analysis, and wax characterization.

NUCL 19 [515148]: Metallurgical review of bullet lead compositional analysis Erik Randich, Forensic Materials International, 927 Creekside Place, Manteca, CA 95336, Fax: 209-825-9711, erandfmi@mediaone.net

Abstract A comparison of the minor and trace element compositions of bullet lead alloys is being used by some forensic examiners to make positive associations between bullets or lead fragments found at a crime scene and bullets linked to a suspect(s). These examiners have concluded that if two or more bullets are analytically indistinguishable in up to six chosen trace and minor elements, then the bullets were manufactured "on or about the same day","came from the same box", or came frome the "same source" of lead. These conclusions are based on the chemical analysis of small, isolated groups of bullets with the assumptins that each "source" or melt of lead alloy is both homogenious and unique. A consideration of the lead refining process (lead smelting) suggests that neither of these assumptions is necessarily correct. Several years of continuous data for two lead alloys produced for .22 caliber ammunition by two different secondary lead smelters is presented to clearly show that multiple, indistinguishable shipments of lead alloy are made to major bullet manufacturers each year. There are even repeats in compositions for production of the same lead alloy from ten years prior. Furthermore, these data show that there are small, in a metallurgical sense, but measurable non-homogeneities in many melts or "sources", demonstrating that bullets with distinguishable compositions can in fact come from the same "source". These results show that the forensic examiner is limited to concluding that two indistinguishable bullets might have come from the same "source", and he has no foundation to say that they did come from the same"source". An understanding of the metallurgy of lead smelting practices and the realities of bullet manufacturing practices is necessary to correctly interpret the analytical chemistry measurements and it logically explains temporally separated compositional matches (dismissed as coincidences) by investigators in the past. The results indicate that any conclusions and pursuant courtroom testimony as to "from the same source" and/or "from the same box" should fail most or all Daubert criteria.

NUCL 20 [522470]: Chemical fingerprinting of California methamphetamine Jerry Massetti, California State Department of Justice, Bureau of Forensic Services, Sacramento, CA 95820, Jerry.Massetti@doj.ca.us

Abstract An effort has begun to evaluate chemical components found in methamphetamine produced at large-scale clandestine methamphetamine laboratories in California. Methamphetamine chemical signatures are studied to find potential indicators of commonness of sample origin, and to establish an index of the range of methamphetamine sample types produced by large-scale California clandestine

methamphetamine operatives. Analytical data generated by this project will be searched by an automated database system. The database will key on diagnostic indicators and chemical component profiles to alert analysts to information having investigative interest, such as emerging manufacturing trends or associations of particular samples with certain operations. The Signature Analysis Project is a component of the California Methamphetamine Strategy (CALMS) program, coordinated within the California State Department of Justice.

NUCL 21 [513105]: A successful approach to forensic “signature” analyses Donald A. Cooper, Special Testing & Research Laboratory, Drug Enforcement Administration, 3650 Concorde Parkway, Suite 200, Chantilly, VA 20151, Fax: 540-338-6969, doncooper@erols.com

Abstract Starting in the early 1970s the Drug Enforcement Administration's Special Testing and Research Laboratory (STRL) began a modest but long term effort to establish analytical techniques for the purpose of determining origin and/or synthesis methods for selected illicit drugs. In the beginning, the focus was heroin, but in the early 1990s, with a reasonably mature "heroin signature" in hand, attention was focused upon cocaine, and more recently, upon selected phenethylamines. These works have evolved into an approach to drug "signature" analysis that is surprisingly uniform, and is an approach that could serve as a general analytical model for the creation of "signature" analytical methods for other drugs and related compounds. The general form of the approach utilized at STRL is discussed, and the criterium necessary for the establishment of a successful analytical signature method is delineated. Several of the "signature" analytical methods utilized at STRL are presented as examples of the approach.

NUCL 22 [522468]: Rapid, on-site sampling and analysis of propellant stabilizers and their decomposition products in any propellant formulation by portable sampling and thin-layer chromatography kits J.S. Haas, Forensic Science Center, L-178, Livermore National Laboratory, Livermore, CA 94550, haas1@llnl.gov

Abstract We have developed sampling methodologies and unique, portable, thin-layer chromatography (TLC) kit hardware for rapid field screening and quantitative assessment of stabilizer content in any propellant formulation. Major advantages of this technology

include simultaneous chromatography of multiple samples and standards, extremely low detection limits, and ease of operation. Once implemented, the new technologies will provide a cost-effective, expedient, and efficient means for low-nanogram detection of all stabilizers and their decomposition products. The technologies are readily applicable to on-site analysis at military or commercial facilities, a variety of emergency and non-emergency scenarios, and situations where public concern is high. The TLC technology, sponsored by the US Army Defense Ammunition Center (DAC), is patented and in the final phases of transition to a commercial partner.

NUCL 23 [491322]: Forensic science research at the U.S. Secret Service Antonio A. Cantu, Forensic Services Division, U.S. Secret Service, 950 H St., NW, Washington, DC 20223, Fax: 202-406-5603

Abstract The U.S. Secret Service forensic science laboratory is among the leading laboratories engaged in research and development to provide new or improved technology for conducting examinations of evidence. Current research includes advances in four areas: questioned document examination, latent print visualization, audio/video enhancement and voice identification. In questioned document examination, three disciplines are being researched: the analysis of inks, papers, and toners to determine their date, link, or source; the computerized examination of handwriting and handprinting to determine their writer; and the examination of suspect identification documents to determine possible links. In latent print visualization, new technology is being developed to improve the detection of the water-soluble (e.g., amines) and water-insoluble (e.g., lipids) components of fingerprint residue. The latter includes advance techniques borrowed from photographic and colloid chemistry. In addition, the USSS is interested in technology capable of remotely detecting deception. The research in all these areas will be discussed.

NUCL 24 [504007]: Provenance and reconstruction using trace evidence David A. Stoney, Director of the McCrone Research Institute, McCrone Research Institute, 2820 S. Michigan Ave, Chicago, IL 60616-3292, Fax: 312-842-1078, dstoney@mcri.org

Abstract Apart from the direct value of trace evidence for comparative associations, trace evidence can also provide a means to infer the provenance of samples or to reconstruct the process that left the traces. These applications are familiar to most trace evidence analysts, and there are striking historical examples. Much of our experience in these areas, however, is anecdotal rather than systematic. This presentation will broadly consider these uses of trace evidence: making inferences of provenance from particle samples and making

inferences from particle characteristics about how or when some event occurred. The overall theme is the organization of this type of examination process. Generally speaking, what types of information can follow from what types of observations? How can we make such observations more systematic and less dependent on prior specific knowledge?

NUCL 25 [522469]: GC-MS and HPLC-ES-MS/MS techniques for the characterization of drugs in aged autopsy tissues B. D. Andresen, and Armando Alcaraz, Forensic Science Center, Lawrence Livermore National Laboratory, L-231, Livermore, CA 94550, x@y.y

Abstract The characterization of questioned autopsy samples for the presence of suspect drugs has led to new analysis protocols developed by the Forensic Science Center at the Lawrence Livermore National Laboratory. The presentation will highlight the history of a homicide investigation that centered on the detection of a neuromuscular blocking agent, a di-quaternary ammonium drug, in aged tissue samples. The development of sensitive procedures, and results from some of the sample sets, are presented to indicate current and future toxicologic analysis activities.

NUCL 26 [521965]: Tritium in the World Trade Center disaster: Its possible sources and fate P. Parekh1, Thomas M Semkow2, L. Husain2, and Gordon J. Wozniak3. (1) Wadsworth Center, New York State Department of Health, Empire State Plaza, Albany, NY 12201, Fax: 518-474-8590, (2) Wadsworth Center, New York State Department of Health and SUNY, Empire State Plaza, Albany, NY 12201-0509, Fax: 518-474-8590, semkow@wadsworth.org, (3) Nuclear Science Division, Lawrence Berkeley National Laboratory

Abstract We have analyzed water for radionuclides, using liquid scintillation counting,from the area of World Trade Center (WTC) in New York City after the September 11th, 2001 terrorist attack. One sample from the WTC sewer, collected on 9/14, contained 0.174+-0.074 (2 sigma) nCi/L of HTO, two split water samples, collected on 9/21 from the basement of WTC Building 6, contained 3.53+-0.17 and 2.83+-0.15 nCi/L, respectively. What could be the sources of tritium at WTC? We present some plausible, but not proven at the time of this writing, scenarios. According to an unconfirmed press report, self-luminous EXIT signs would have been installed at WTC after the previous terrorist attack of 1993. These signs are powered by tritium gas and were probably destroyed in the attack. The EXIT signs contain mostly T2 and up to 10% of HTO. Depending on the

number of the signs present, the total tritium could have been from zero up to as much as thousands of Ci. We have also studied a possible transport and deposition of HTO. Several water and vegetation samples were collected from lower Manhattan, Brooklyn, and Queens, in the direction of prevailing winds after the disaster and analyzed for HTO. No HTO above the background was found, consistent with little or no deposition of HTO, which is corroborated by a lack of rain in the first several days after the disaster. Several possible scenarios and mechanisms of what could have happened are discussed such as dispersion of molecular T2, formation of HTO or other tritiated chemicals in the fire, dissolution of HTO (present in the signs and that formed) in water committed to the site in fire-fighting efforts, as well as the evaporation of HTO and dispersion in the gas phase or on aerosols. It is also possible that the plume from WTC on 9/11 was not intercepted by the downwind sampling sites.

NUCL 27 [513929]: Radioanalytical chemistry in the courtroom J. David Robertson, Department of Chemistry, University of Missouri, 125 Chemistry Building, Columbia, MO 65211, Fax: 573-882-2754, Robertsonjo@missouri.edu

Abstract Two examples of the use of particle-induced X-ray emission (PIXE) analysis to forensic science will be presented. In the first, PIXE was used as a non-destructive method to search for signatures of gunshot residue on clothing. In the second, PIXE was used, again as a non-destructive method, to investigate the authenticity of “ancient” gold coins.

NUCL 28 [516215]: Heavy element production and chemical applications at the Radiochemical Engineering Development Center R. C. Martin, Nuclear Science and Technology Division, Oak Ridge National Laboratory, P. O. Box 2008, MS-6385, 1 Bethel Valley Road, Oak Ridge, TN 37831-6385, Fax: 865-241-2338, martinrc@ornl.gov, D. C. Glasgow, Chemical and Analytical Sciences Division, Oak Ridge National Laboratory, and M. Z. Martin, Environmental Sciences Division, Oak Ridge National Laboratory

Abstract The Radiochemical Engineering Development Center (REDC) at Oak Ridge National Laboratory (ORNL) is the center for heavy-element (transplutonium) production and distribution within the United States. The Transuranium Element Processing Program of the U.S. Department of Energy emphasizes the availability of curium, berkelium, californium, einsteinium, and fermium for basic research and the distribution of californium-252 neutron sources for basic and applied research. Topics to be discussed include the availability of these heavy elements and of other actinides and isotopes from the REDC inventory, custom isotope production at the neighboring High Flux Isotope

Reactor at ORNL, and fast and thermal neutron irradiation experiments at REDC's Californium User Facility for Neutron Science. Several analytical techniques (252Cf-based instrumental neutron activation analysis, laser-induced plasma spectroscopy, and inductively coupled plasma mass spectrometry) have been evaluated for detection of nonradioactive terbium as a surrogate for 252Cf in leak testing of Isotron's NBTTM System miniature medical sources.

NUCL 29 [510654]: Assessing contamination susceptibility using the Tritium-Helium method of age-dating groundwater in the Livermore and Santa Clara valleys of California Gail F. Eaton1, G. Bryant Hudson1, Jean E. Moran1, Brendan P. Dooher2, and H. Wayne Culham1. (1) Analytical and Nuclear Chemistry Division, Lawrence Livermore National Laboratory, P.O. Box 808, L-231, Livermore, CA 94550, Fax: 925-422-3160, eaton3@llnl.gov, (2) Environmental Protection Department, Lawrence Livermore National Laboratory

Abstract The presence of cosmogenic and anthropogenic 3H in recharging water makes it possible to age-date groundwater, since water retains its tritium signature from time of recharge. Using the “Helium In-Growth Method,” which entails removing all dissolved gas from a water sample and then allowing 3He to grow-in from 3H decay (half life 12.43 years), 3He is measured via mass spectrometry. The mean groundwater age is calculated from this result and a measurement of the tritiogenic 3He dissolved in the groundwater. Groundwater from public water supply wells in the Livermore and Santa Clara Valleys was analyzed as part of the California Aquifer Susceptibility project, sponsored by the State of California. 3H-He ages help constrain groundwater flow paths, quantify transport rates of water and associated contaminants, and identify recharge areas. This work was conducted under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory, under contract W-7405-Eng-48.

NUCL 30 [521956]: A research resource providing high specific activity cyclotron produced radionuclides Michael J. Welch, and Deborath W McCarthy, Mallinckrodt Institute of Radiology, Washington University School of Medicine, Division of Radiological Sciences, 510 S. Kingshighway, St. Louis, MO 63110, Fax: 314-362-8399

Abstract Washington University, Department of Radiology has been funded by the National Cancer Institute as a Research Resource in Radionuclide Research. As part of this effort, we have developed production systems for a series of positron emitting radionuclides

including 64Cu, 66Ga, 76Br and 124I. Separations of these nuclides have been developed to provide high specific activity products for collaborative work at Washington University and for shipment to some sixteen other institutions. The techniques to provide the nuclides will be described as well as the applications in medicine and the life sciences.

NUCL 31 [517053]: Interface of Environmental, Bioassay and Radioanalytical Traceability Evaluations Kenneth Inn, Zhichao Lin, Ciara McMahon, and Zhongyu Wu, Ionizing Radiation Division, NIST, 100 Bureau Dr, MS 8462, Gaithersburg, MD 20899-8462, Fax: 301-869-7682, kenneth.inn@nist.gov

Abstract Radiochemistry is the cornerstone for the verification of environmental and bioassay test samples for the NIST traceability evaluation programs. The evaluation programs provides the program participants with a direct test of the traceability of their radioanalytical capabilities by NIST. Because the participants in the evaluation programs depend on absolute confidence in the results of the evaluation to assess their radioanalytical methods for bias from the national physical standard, Bq, NIST must verify the production of the test samples to approximately one percent relative combined standard uncertainty. The production and verification analyses will be described for water, air filter, soil, synthetic urine and synthetic fecal test samples.

NUCL 32 [515427]: Recent progress in the development of extraction chromatographic methods for radionuclide separation and preconcentration Mark L. Dietz, Chemistry Division, Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, IL 60439, Fax: 630-252-7501, mdietz@anl.gov

Abstract The complex and variable nature of many "real world" samples frequently necessitates the incorporation of a separation and preconcentration step into analytical procedures for the determination of radionuclides. Extraction chromatography (EXC), a form of liquid chromatography in which the stationary phase consists of an extractant solution dispersed on an inert support, provides a simple and effective means by which the separation and preconcentration of a variety of radionuclides and their isolation from major sample constituents can be achieved. Recent advances in extractant design, particularly the development of extractants capable of metal ion recognition or strong complex formation in acidic solution, have substantially improved the utility of the method. Advances in support design, particularly the introduction of functionalized supports capable of

enhancing radionuclide retention or the stability of the chromatographic materials, promise to provide further improvements.

NUCL 33 [510428]: Short-lived radiotracers for imaging human enzyme activity: Monoamine Oxidases Joanna S Fowler1, Nora D. Volkow2, Gene-Jack Wang2, and Jean Logan1. (1) Chemistry Department, Brookhaven National Laboratory, Bldg 555, Upton, NY 11973, Fax: 631-344-7902, fowler@bnl.gov, (2) Medical Department, Brookhaven National Laboratory

Abstract It has been more than 70 years since monoamine oxidase (MAO) was discovered and almost 50 years since the first reports of the remarkable effects of MAO inhibitor drugs on mood. Since that time it has been learned that MAO occurs in two subtypes (MAO A and B) that have different substrate and inhibitor specificities and are different gene-products. We have labeled clorgyline and L-deprenyl (suicide inactivators of MAO A and MAO B respectively) with carbon-11 (half-life: 204. min) and with deuterium for imaging enzyme activity in the human brain and recently in peripheral organs using positron emission tomography (PET). The availability of PET methods for measuring MAO A and B has provided the opportunity to facilitate the development of new drugs and to identify factors which influence MAO levels in the human brain including including aging and smoking and their possible implications in health and disease. Supported by United States Department of Energy (Office of Biological and Environmental Research; DE-AC02-98CH10886) and National Institutes of Health (NS15380).

NUCL 34 [521845]: Use of positron emitting tracers as tools in drug development: Some perspectives Bengt Langstrom, Department of Organic Chemistry and Uppsala University PET Centre, Uppsala University, S-751 85 Uppsala, Sweden, bengt.langstrom@pet.uu.se

Abstract The development of new drugs is time-consuming and expensive. Thus new approaches for validating hypotheses on drug mechanisms, for determining efficacy and for planning clinical trials are needed in order to make strategic decisions early in the development process. An important question is whether preclinical information from in vitro studies on gene modified cells or animals are relevant to humans. The use of PET-tracers offers an attractive alternative to characterize drug distribution in the human body. Today there are only a few examples using PET-tracers in drug development. However, there is a significant interest emerging from the drug research field creating a need to advance the development of selective tracer molecules for many new molecular targets along with

high throughput labelling chemistry and efficient bioassays and implementation of the micro dosing concept for early sub- pharmacological applications in humans. In this presentation, examples on new chemistry using 11C-carbon monoxide and its application in screening for new potential tracers and examples of PET technology in applications in the drug development process will be discussed.

NUCL 35 [513764]: New approaches to imaging and therapy of cancer Michael J. Welch, Mallinckrodt Institute of Radiology, Washington University, 510 S. Kingshighway Blvd., Campus Box 8225, St. Louis, MO 63110, Fax: 314-362-8399, welchm@mir.wustl.edu

Abstract At present, the majority of PET scanning in oncology utilizes 2-fluoro-2-deoxyglucose (FDG). It is anticipated that over the next several years new applications of PET in oncology will be introduced into clinical practice. Fluorine-18 ligands have been targeted for the estrogen, androgen and progestin receptors which are important in breast and prostate cancer. It is anticipated that other tracers will be utilized particularly in the evaluation of therapies. Several tracers to measure cellular proliferation are currently under evaluation. Quantification of tumor hypoxia is currently being studied with both fluorine-18 and copper-labeled agents. Several other tracers are being developed to assist in cancer diagnosis. Of particular promise is the carbon-11 acetate which appears to be a measure of tumor lipid synthesis.

NUCL 36 [510668]: Highlights of PET studies on chiral drugs at Brookhaven Yu-Shin Ding, Dept. of Chem, Brookhaven National Laboratory, Bldg.555, Upton, NY 11973, Fax: 631-344-7902, ding@bnl.gov

Abstract A steady, rising flow of single-isomer forms of chiral drugs onto U.S. and world markets is creating an increasing demand for enantiomeric intermediates and enantioselective technologies. A non-invasive imaging method such as Positron Emission Tomography (PET) to determine or discriminate the behavior of individual enantiomers in living systems is therefore crucial in drug development and research. Comparative PET studies in the fields of neuroscience (brain and body) and neuropharmacology that have been carried out at Brookhaven National Laboratory using enantiomers of various labeled drugs and radiotracers are described. These studies using positron-labeled chiral drugs to target various neurotransmitter systems allow us to better understand the mechanisms underlying neurodegenerative disease, substance abuse, normal aging, tumor metastases, and attention-deficit hyperactivity disorder (ADHD).

Supported by DOE/BER under contract DE-AC02-76CH00016.

NUCL 37 [521850]: Imaging drug reinforcement and addiction in the human brain Nora D. Volkow, Gene-Jack Wang, and Joanna S. Fowler, Medical and Chemistry Departments, Brookhaven National Laboratory, Upton, NY 11973, volkow@bnl.gov

Abstract We have used Positron Emission Tomography to investigate the effects of drugs of abuse and the mechanisms underlying drug addiction in the human brain. Because dopamine (DA) is believed to be crucial for the reinforcing effects of drugs of abuse, we have focused our research on the brain dopamine system. We have shown that: (1) a crucial element in reinforcement is the rate dependency at which drugs of abuse change DA concentration in brain; (2) subjects addicted to cocaine, alcohol, heroin and methamphetamine as well as pathologically obese subjects have low dopamine D2 receptor levels suggesting that a deficit in DA D2 receptors results in under-activation of reward circuits in brain facilitating addictive behavior as a compensatory mechanism; (3) non-addicted subjects with high levels of DA D2 receptors report unpleasant responses to psychostimulant drugs whereas subjects with low levels report pleasant responses suggesting that high DA D2 receptor levels protect against drug self administration. Supported by DOE-OBER and NIDA.

NUCL 38 [516267]: Recent developments in radioisotope production with a cyclotron David J Schlyer1, Mahmoud Firouzbakht1, and Joanna S Fowler2. (1) Department of Chemistry, Brookhaven National Laboratory, Building 901, 57 Cornell Ave, Upton, NY 11973, Fax: 631-344-7350, schlyer@bnl.gov, (2) Chemistry, Brookhaven National Laboratory

Abstract Production of medically important radioisotopes is a topic of interest as new centers open which supply these radioisotopes to hospitals to carry out nuclear medicine procedures for diagnosis and therapy. A review of the production of these radioisotopes with a cyclotron or linear accelerator will be given. The development of new targets will be given from a historical perspective using the program at Brookhaven National Laboratory as an example. The targets used for the production of PET radioisotopes, Iodine-123, I-124 will be discussed in detail. Research results on a new water target for the production of F-18 and a cryogenic target for the production of C-11 hydrogen cyanide will be presented. The emphasis will be on the chemistry occurring inside the target during the

irradiation. Mechanisms will be discussed to explain the differences between the products observed from the solid phase reactions and the fluid phase reactions.

NUCL 39 [521846]: State of the art Positron Emission Tomography (PET) Ronald Nutt, CTI PET Systems, Inc, Knoxville, TN, Fax: 865-218-3002, nutt@cti-pet.com

Abstract PET imaging has begun a transition from being a significant research tool to becoming a major medical imaging modality. In the 1970's - 1980's PET was used primarily to study basic functions of the human brain and body, to understand tumor metabolism and to visualize neurotransmitter activity. These areas continue to be investigated. In addition, PET is transitioning into a major clinical imaging modality and is also becoming a significant tool for drug development and for basic research in drugs. This paper will focus on describing the state-of-the-art brain research tomographs, small animal microPET tomographs and clinical whole-body tomographs used in cancer detection and for following the treatment of cancer There will be a special emphasis on the use of lutetium oxyorthosilicate (LSO), a scintillation crystal material that has advanced the development of high-resolution instruments. Projections of clinical PET tomographs for the future and how they may be used in the new world of molecular medicine will be provided.

NUCL 40 [521849]: Radiopharmaceutical Development and Molecular Nuclear Medicine Program Prem C. Srivastava, Medical Sciences, Biological and Environmental Research, Office of Science, U.S. Department of Energy, 19901 Germantown Road, Germantown, MD 20874-1290, prem.srivastava@science.doe.gov

Abstract Radiopharmaceutical and Molecular Nuclear Medicine Research programs are interlinked and involve radioligand synthesis, targeting, in vitro and in vivo biological evaluations, data validation in animal models, and optimization of properties for radiopharmaceutical development. The program has been contributing to molecular tool building for the Nation's biomedical research, and medical applications. The applications include mapping the brain biochemistry as it relates to brain function in neurological and psychiatric disorders, study of fatty acid oxidation and metabolic enzyme deficiencies in cardiac function, imaging genes as they express the disease, and cancer targeting for both radiotracer diagnosis and radionuclide therapy. One of the areas of research emphasis involves direct imaging of wayward gene expression in vivo, in real time, as the DNA sequence implies protein synthesis and function, and expression and the molecular basis

of disease. New efforts by the DOE human genome program are already under way on "Bringing Genomes to Life." It is our hope that our molecular nuclear medicine preparedness on imaging subcellular components in real time, in real concentration, will contribute in a very important way in bringing the genomic pathway to light.

NUCL 41 [515042]: Materials characterization using micro X-ray fluorescence in nuclear applications George J. Havrilla, Chemistry Division, Los Alamos National Laboratory, MS G740, Los Alamos, NM 87545, Fax: 505-665-4737, havrilla@lanl.gov

Abstract Micro X-ray fluorescence (MXRF) offers a powerful capability for materials characterization of both hot (radioactive) and cold samples within the nuclear weapons complex. MXRF can provide not only single point analysis of a spatially resolved point on a specimen; it offers the capability of elemental imaging over large areas that can exceed 10 x 10 cm. Spatially resolved MXRF offers new insights into material composition that cannot be achieved with bulk elemental analysis. Although the spatial resolution attained in conventional MXRF instruments is around 30 micrometers or larger, this is more than sufficient to provide a detailed look into the elemental distribution of a wide array of materials. Radioactive samples in particular offer unique challenges especially when dealing with element associations which can be important in environmental concerns. Specimens include uranium alloy, radioactive waste, polymers, and corrosion.

NUCL 42 [515178]: Quantitative analysis of radioactive materials by X-ray fluorescence Christopher G. Worley, Lisa P. Colletti, and George J. Havrilla, Actinide Analytical Chemistry, Los Alamos National Laboratory, MS G740, Los Alamos, NM 87545, Fax: 505-665-4737, cworley@lanl.gov, havrilla@lanl.gov

Abstract Quantitative analysis of radioactive samples can be a challenging task. This work will demonstrate the usefulness of X-ray fluorescence (XRF) for rapid screening semi-quantitative analysis and high precision and accuracy quantitative analysis of radioactive materials. A semi-quantitative elemental analysis process has been developed for analyzing a wide variety of radioactive samples such as Pu239. Data will be presented demonstrating the value of XRF as a screening tool for identifying major (%) and minor (high ppm to low %) elements in a sample. In addition, the detected elements can be rapidly quantified in a semi-quantitative manner. This is ideal for samples where elemental screening is needed but high precision and accuracy are not necessary. An XRF

method has also been developed to quantify gallium in plutonium metal with high precision and accuracy. Relative errors well below 1% can be achieved, and precision RSD values of 0.5% or better are routinely obtained.

NUCL 43 [522473]: Analysis of oxidation products on aluminum-containing nickel-based superalloys using several x-ray techniques Art R. Jurgensen, David M. Missimer, Kenneth J. Imrich, and Ronny L. Rutherford, Analytical Development Section, Westinghouse Savannah River Company, Bldg. 773-A, Aiken, SC 29808, Fax: 803-725-2756, arthur.jurgensen@srs.gov

Abstract The Defense Waste Processing Facility at the Savannah River Site converts high-level radioactive waste into glass, which is suitable for long-term storage in a geologic repository. One of the major limitations to long-term service life of components in the DWPF melter is the highly corrosive environment encountered in the elevated temperatures regions (~1000° C) above the melt pool. Severe degradation of critical components, made of Inconel 690, has resulted in lost production time. The oxidation resistance at 1000° C of three aluminum-containing nickel-based superalloys, Haynes 214, Inconel 693, and VDM 602CA, is being assessed for this application. Several materials characterization methods, including x-ray diffraction, x-ray fluorescence, electron microprobe, and optical metallography, were used to develop a basic understanding of the surface reactions and kinetics occurring on the surface of these alloys. A comparison of the oxidation resistance of these alloys with Inconel 690 will be presented.

NUCL 44 [515325]: Design and fabrication of the Savannah River Technology Center's new glovebox contained scanning electron microscope Michael E. Summer, Analytical Development Section, Savannah River Technology Center, 773-A Room C-136, Aiken, SC 29803, Fax: 803-725-2756, michael.summer@srs.gov

Abstract

The Savannah River Technology Center has analyzed radioactive and contaminated samples using a glovebox contained scanning electron microscopy for over 16 years. Since then the advances in microscope and detector technology has greatly improved. Electronics and software advancements allow the scanning electron microscope to be controlled by a personal computer. Digitized images, x-ray spectra and x-ray maps can be easily and quickly transferred to the customer via servers. Additional improvements such

as chamber scope and wavelength spectrometry has also been added to the microscope. A comparison of features will be made between the old microscope versus the new microscope. Glovebox Design changes that have been implemented for better operation and maintenance ergonomics will also be presented.

NUCL 45 [516556]: Evaluation of iodide sequestration using silver impregnated activated carbons Steven M. Serkiz1, Erin E. Cumbie2, Jay S. Hoskins3, and Tanju Karanfil3. (1) Waste Processing and Environmental Development, Westinghouse Savannah River Technology Center, Building 773A, Aiken, SC 29808, Fax: 803-725-4704, steven.serkiz@srs.gov, (2) Environmental Engineering and Science Dept, Clemson University, (3) Department of Environmental Engineering and Science, Clemson University

Abstract Iodine-129 (I-129) is a long-lived (t1/2=1.57 x 107 years) radionuclide present in wastes at many nuclear production facilities. One potential strategy to mitigate risk associated with I-129 release in the environment, is to reduce its release rate by the addition of sequestration agents. We investigated the use of a range of silver impregnated activated carbons (SIAC) for this application in a series of adsorption, desorption, and surface characterization studies. A range of SIAC materials including Ag(0) and AgCl materials were evaluated over a range of total silver, pH, and total iodine concentrations. Additionally, selected SIACs were tested on an I-129 contaminated groundwater from the Department of Energy's Savannah River Site. The surface and pore space of the SIAC was examined with scanning electron microscopy (SEM) and energy dispersive x-ray analysis (EDX) after iodide adsorption in an attempt to elucidate the iodide sequestration mechanism(s). Silver iodide precipitates could be identified with SEM, and elemental mapping of the precipitates by EDX showed that the mole ratio of silver to iodide to be approximately 1:1. SIACs performed better than the base activated carbon at medium and high pH conditions and surface characterization of solids reacted at these higher pH values suggests that the sequestration is a result of the formation of a silver iodide precipitate. If the iodide removal mechanism is through the formation of silver iodide, then the exceeding low solubility limit for this precipitate may make this material useful for the long-term control of I-129 migration.

NUCL 46 [516291]: Gas generation over plutonium oxides in the 94-1 Shelf Life Surveillance program Laura A. Worl1, John M. Berg2, David Harradine3, Dallas D. Hill4, Douglas Veirs1, Karen Rau1, J. McFarlan1, and Dennis D. Padilla1. (1) NMT-11, Los Alamos National Laboratory, MS-E505, Los Alamos, NM 87545, lworl@lanl.gov, (2) Nuclear Materials and Technology Division, Los Alamos National Laboratory, (3) C-PCS, Los Alamos

National Lab, (4) Engineering Sciences and Applications Division, Energy and Process Engineering, Los Alamos National Laboratory

Abstract 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 define the behavior of Pu bearing material in sealed containers. Experience with Pu materials has shown that gases generated by catalytic and/or radiolytic processes may accumulate. Of concern are the generation of H2 gas from adsorbed water, the generation of water in the vapor phase at elevated temperatures, and the generation of HCl or Cl2 gases from the radiolysis of chloride salt impurities. The Shelf Life project will monitor gases 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 experimental details and results of the first baseline large-scale container will be discussed.

NUCL 47 [516300]: Analysis of gas constituents from sealed containers of plutonium oxide materials Laura A. Worl1, John M. Berg2, David Harradine3, Thomas Allen4, Karen Rau1, and D. Kirk Veirs5. (1) NMT-11, Los Alamos National Laboratory, MS-E505, Los Alamos, NM 87545, lworl@lanl.gov, (2) Nuclear Materials and Technology Division, Los Alamos National Laboratory, (3) C-PCS, Los Alamos National Lab, (4) NMT-15, Los Alamos National Laboratory, (5) NMT-11: Actinide Technology Development, Nuclear Materials Technology Division, Los Alamos National Laboratory, MS E505, Los Alamos, NM 87545, Fax: (505)665-4394, veirs@lanl.gov

Abstract The safe storage of pure and impure plutonium oxide materials in sealed containers is a current DOE concern. Plutonium oxides adsorb moisture from the atmosphere, and the subsequent radiolytic and/or chemical decomposition of the adsorbed species has been thought to generate pressure inside a sealed container. Eleven sealed containers with ten grams each of plutonium oxide materials have been sampled for gas constituents for up to four years. The sealed materials are representative oxides from the DOE complex and contained less than 0.5 weight percent water. The samples were kept at ambient conditions. The final gas analysis included 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. The detailed results will be presented.

NUCL 48 [489591]: Characterization of legacy plutonium oxide material at Savannah River Site Michael J. Brisson, Analytical Laboratories Dept, Westinghouse Savannah River Co, Savannah River Site MS 704-17F, Aiken, SC 29808, Fax: 803-952-2147, mike.brisson@srs.gov, and Vernon D. Jones, Analytical Laboratories Department, Westinghouse Savannah River Co

Abstract The Savannah River Site (SRS) is located in Aiken, SC and is operated by Westinghouse Savannah River Co. under contract to the U.S. Department of Energy. In 1999, the SRS began a campaign to characterize legacy plutonium oxide material that had been stored for a quarter century at the site's FB-Line facility. This campaign is expected to continue through 2005. The characterization will determine the disposition path for the material (dissolution in a processing facility or repackaging for safe long-term storage). Analytes required include uranium and plutonium isotopes, actinides, moisture content, hydrogen generation, and trace impurities. This presentation describes the techniques used for sample preparation, separation of uranium and plutonium from impurities, analytical methods and instruments used, and method uncertainties based on actual field experience to date.

NUCL 49 [521950]: Rapid actinide column extraction methods for bioassay samples Sherrod L. Maxwell III, and David Fauth, Analytical Laboratories Department, Westinghouse Savannah River Co, Savannah River Site, Aiken, SC 29803, Fax: 803-952-3550, sherrod.maxwell@srs.gov

Abstract A new, rapid separation method to assay actinides in urine samples has been developed at the Westinghouse Savannah River Site (SRS). The new method separates plutonium, neptunium, uranium, americium and strontium-90 with high chemical recovery and excellent thorium removal. The method uses calcium phosphate precipitation and stacked TEVA Resin® and TRU Resin® cartridges to separate and purify the actinides. Plutonium and neptunium are separated on TEVA Resin®, while uranium and americium are simultaneously retained and separated on TRU Resin®. Plutonium-236 tracer can be used to allow simultaneous separation and measurement of both plutonium and neptunium using TEVA Resin®. Strontium-90 can also be separated on SR Resin® by evaporating and redissolving load and rinse solutions collected from the TEVA/TRU column and separating strontium on SR-Resin®. Fast flow rates are achieved by using small particle size resin and a vacuum box separation system that will separate 24 samples at a time. This unique approach can be used with urine samples because iron is not present at significant levels in urine and plutonium reduction is accomplished without

adding iron (II) to the sample. The advantage of this approach is that actinides can be loaded onto two separate resins in a single load step with simultaneous extraction and assay of neptunium and plutonium with high chemical recovery and excellent removal of matrix interferences.

NUCL 50 [516152]: Sequential or simultaneous actinide separation with flow-cell radiation detection Robert A Fjeld1, James E. Roane1, John D. Leyba2, Alena Paulenova1, and Timothy A. DeVol1. (1) Department of Environmental Engineering and Science, Clemson University, 342 Computer Court, Clemson Research Park, Anderson, SC 29625, Fax: 864-656-0672, fjeld@clemson.edu, (2) Canberra Industries, Inc

Abstract Ion chromatography with sequential flow-cell scintillation detection and scintillating extraction chromatography with simultaneous flow-cell scintillation detection were developed for quantification of actinides (at < 10^-6 M) in aqueous solutions. Ion chromatographic separation occurred in an isocratic elution (1 ml/min) with oxalic, diglycolic, and nitric acids. Quantification of the eluted activity was performed with a flow-cell scintillation detection system. An extractive scintillating resin was evaluated for the simultaneous separation, detection, and quantification of actinides in acidic solutions. The extractive scintillating resins were comprised of an inert macroporous polystyrene core impregnated with the organic fluors (diphenyloxazole (PPO) and 1,4-bis-(4-methyl-5-phenyl-2-oxazolyl)benzene (DM-POPOP)) and a selective extraction material (octyl(phenyl)-N, N-diisobutyl-carbamoylmethylphosphine oxide (CMPO) in tri-butyl phosphate). The extractive scintillating resin was packed into an FEP Teflon "column", which was placed into a flow-cell scintillation detection system to obtain real-time pulse height spectra as well as the "whole-column" chromatogram of radioactivity sorbed to the column. The measured concentration of Am(III), Pu(IV, V), and U(VI) in simulated groundwater, a high activity drain tank sample, and dissolved high-level waste tank sludge were compared with expected values and were typically within 25%. The ion chromatography with sequential flow-cell scintillation detection method rapidly separates the actinides with activity of at least 250 Bq. Scintillating extraction chromatography with simultaneous flow-cell scintillation detection method can quantify as little as 2 Bq because of longer count time afforded by "stop-flow" operation, but currently suffers from long-term stability of the resin.

NUCL 51 [514823]: Application of the Triple-to-Double Coincidence Ratio (TDCR) method for the absolute standardization of radionuclides by liquid scintillation counting Brian E Zimmerman1, Ron Colle'1, Jeffrey T Cessna1, Ryszard Broda2, and Philippe

Cassette3. (1) Ionizing Radiation Division, Physics Laboratory, National Institute of Standards and Technology, 100 Bureau Dr, Stop 8462, Gaithersburg, MD 20899, Fax: 301-926-7416, bez@nist.gov, (2) Radioisotope Centre POLATOM, (3) CEA/DIMRI/LNHB

Abstract The Triple-to-Double Coincidence Ratio (TDCR) method is a technique for the absolute determination of contained activity in solutions using liquid scintillation counting. Based on a statistical description of the light emitted from a liquid scintillator and its subsequent detection by phototubes in 2-fold and 3-fold coincidence, it has the advantage of not requiring an external standard to determine the counting efficiency. The National Institute of Standards and Technology (NIST) has recently constructed a TDCR spectrometer primarily for the standardization of nuclides used in nuclear medicine. The details of this new instrument, as well as latest results from standardization studies made with it, will be described.

NUCL 52 [517442]: Radioanalytical techniques to study the partitioning of Pu and other actinides to soils and sediments S. B. Clark, S. Loyland Asbury, H. Kurosaki, and S. LaMont, Chemistry Department, Washington State University, P.O. Box 644630, Pullman, WA 99164-4630, s_clark@wsu.edu

Abstract To develop safe and cost-effective remediation strategies, regulatory agencies need screening tools for assessment at radiologically contaminated sites. Traditionally, total digestions or strong acid leachings are used to complete alpha analysis on soil and sediment samples. While this approach provides total isotopic information for the whole sample, the "environmentally available" fraction of the total activity is not determined. We are developing a combination of radioanalytical techniques that can serve as assessment tools for contaminated sites. These include both batch and flow-through sequential chemical extractions to define the partitioning of U, Pu and the other actinides to the bulk soil or sediment. In addition, we are using fission track analysis and alpha track analysis to determine the microscale distribution of fissionable isotopes within the soil or sediment matrix. Mapping of the microscale distribution of the actinides within the samples will allow in-situ study of individual particles. In this presentation, these methods will be described.

NUCL 53 [521944]: Evolution of extraction chromatography as a meaningful tool in radiochemical analysis Lawrence E. Jassin1, E. Philip Horwitz1, Andrew H. Bond2, Michael J. Fern1, Anil H.

Thakkar1, and Sherrod L. Maxwell III3. (1) Eichrom Technologies, Inc, 8205 S. Cass Ave, Suite 111, Darien, IL 60561, Fax: 630-963-1928, jassin@eichrom.com, (2) PG Research Foundation, (3) Analytical Laboratories Department, Westinghouse Savannah River Co

Abstract Extraction Chromatography (EXC) has developed into a leading technique for separation and preconcentration of radionuclides for analytical purposes. Originally developed as a preparative approach for specific metal separation, EXC involves the coating of an inert support with an organic extractant. This combination delivers the specificity of solvent extraction with the ease of use of resin based methods. The need to establish rapid procedures for routine monitoring of radiation workers at Argonne National Laboratory provided the impetus to expand the role EXC into radio-analytical applications. TRU Resin (for Actinides), UTEVA Resin (Actinides (IV and VI)), TEVA Resin (Actinides (IV), Tc(VII)and Am/ RE separation), Sr Resin (Sr, Pb), Ln Resin (lanthanides, Ra-228) along with other EXC resins now are directly involved in hundreds of thousands of radiochemical analyses annually. Biological, environmental, geochemical, waste and nuclear process samples are routinely analyzed using EXC. The field continues to broaden with new resins and formats to improve on traditional separation methods. As we look to the future, new preparative applications using EXC are also becoming apparent. An overview of EXC technology and applications will be presented.

NUCL 54 [516417]: Development of an efficient method for the analysis of alpha emitters Dale D. Ensor, and Steve Glover, Department of Chemistry, Tennessee Technological University, Box 5055, Cookeville, TN 38505, densor@tntech.edu

Abstract The determination of low levels of alpha-emitting isotopes in water samples and aqueous waste streams generally involves a lengthy and complicated process. The Photon Electron Rejecting Alpha Liquid Scintillation Spectrometer (PERALS®), in combination with extractive scintillators, has been shown to provide an efficient alternative to traditional methods for the detection of these isotopes. The commercially available extractive scintillation cocktail, ALPHAEX®, has been applied to the determination of a number of actinide elements. This cocktail requires oxidation state adjustment and pH control for the successful analyses of these isotopes. The goal of this research was to develop an extractive scintillation cocktail that would extract all the alpha-emitting isotopes from nitric acid concentrations between 0.1M to1.0M. The extractant, P,P'-di(2-ethylhexyl)methanediphosphonic acid, H2DEH[MDP], was combined with a standard toluene-based scintillation cocktail and also in an environmentally friendly cocktail. The results showed excellent extraction efficiencies(> 97%) for tetravalent, trivalent, and hexavalent actinide ions between 0.1M HNO3 and 1.0M HNO3. The use of these

extractive scintillation cocktails for the analyses of Pu(IV), Am(III), Th(IV), UO2(VI), and Ra(II) in water both individually and in mixtures, will be discussed.

NUCL 55 [513793]: Radionuclide separations for providing high specific activity radiolanthanides Cathy Cutler, Keith Bailey, Mary F. Embree, James A. Gawenis, Breanna Ochoa, and Alan R. Ketring, Research Reactor, University of Missouri, Research Park, Columbia, MO 65211, Fax: 573-884-6042, cutlerc@missouri.edu

Abstract Biological targeting agents (e.g., receptor seeking moieties) have been radiolabeled with diagnostic radionuclides (e.g., Tc-99m and In-111) and used successfully to image tumors. These biological probes are being radiolabeled with beta-particle emitting nuclides and evaluated as therapeutic agents. Tumor targeting with a radiolabeled peptide requires high specific activity radionuclides to ensure maximal uptake at the limited number of tumor cell surface receptor sites and minimal radiation doses to the non-target tissues. Three radiolanthanides can be produced in no-carrier added concentrations: Pm-149, Ho-166, and Lu-177 through indirect neutron capture reactions on Nd-148, Dy-164, and Yb-176 respectively. Separating these radionuclides from the target will provide them carrier-free, therefore suitable for developing receptor targeted radiotherapeutic agents. These radiolanthanides exhibit a wide range of half-lives and beta energies and due to their similar chemistry can be used interchangeably using the same or similar radiolabeling techniques. Successes and challenges of these separations will be presented.

NUCL 56 [514727]: Initial characterization of macrobatch three high-level radioactive sludge for the defense waste processing facility N. E. Bibler, R. F. Swingle, C. J. Coleman, T. B. Edwards, and T. L. Fellinger, Savannah River Technology Center, Westinghouse Savannah River Co, Aiken, SC 29808, Fax: 803-725-4704, ned.bibler@srs.gov

Abstract The Defense Waste Processing Facility (DWPF) at Savannah River Site (SRS) immobilizes radioactive sludge slurry at SRS into a durable glass. Currently the DWPF is preparing to receive the third macrobatch of sludge. This macrobatch is ~2E06 liters and is stored in SRS Tank 40. Each macrobatch must be characterized to ensure that it can be processed in the DWPF. Savannah River Technology Center (SRTC) is performing that characterization. Samples were taken from Tank 40 after the sludge was thoroughly mixed. For macrobatch 3, two sets of samples were sent to SRTC. One set was taken after the sludge had been mixed 32 hours and one after 60 hours. To be 95% confident that the two sets had identical compositions, a statistically designed series of sludge

digestions and analyses were performed remotely. Based on measured concentrations of 23 radioactive and nonradioactive elements, the compositions were identical. These two sets were then combined for final characterization. Details will be presented.

NUCL 57 [513723]: Chemical analyses in support of a melter vitrification demonstration with Hanford low activity waste - melter feed, offgas and glass analyses Charles L. Crawford, Jack R. Zamecnik, and Daro M. Ferrara, Immobilization Technology Section, Westinghouse Savannah River Co, Building 773-41A, Rm. 180, Savannah River Technology Section, Aiken, SC 29808, Fax: 803-725-4704, charles.crawford@srs.gov

Abstract The overall objective of this research was to perform a melter vitrification demonstration of Hanford Tank 241-AN-102 (Envelope C) sample in a small-scale continuously-fed melter. Various chemical and radiochemical analyses of the melter feed, the offgas and the product glass were necessary to determine the proper glass former mineral blend and to investigate the overall mass balance of the melter campaign. These studies support a Savannah River Technology Center treatability study of Hanford nuclear waste sponsored by the Department of Energy Hanford River Protection Project. Pretreated waste was analyzed for major metal and radiochemical analytes to determine glass formulation. The melter feed slurry was also analyzed before and during the melter campaign. Offgas analyses included metals and radionuclides by modified EPA SW-846 Method 0060 that is designed for sampling of offgas stacks greater than 4 inches in diameter. The offgas stream was also sampled for fixed gases including combustion gases by GC. Final melter product glass was dissolved and analyzed to determine waste loading and demonstrate radionulcide target specifications in the Low Activity Glass Wasteform.

NUCL 58 [521975]: Characterization of soil organic matter with rapid pyrolysis molecular beam mass spectrometry (py-MBMS) K. A. Magrini, C. M. Hoover, R. J. Evans, M. Looker, and M. F. Davis, Chemistry for Bioenergy Systems Center, National Renewable Energy Laboratory, 1617 Cole Blvd., Golden, CO 80401, Kim_Magrini@nrel.gov

Abstract As interest in the mitigation of greenhouse gas emissions grows, the need for better information on soil organic matter (SOM) also becomes more urgent. Soils are one of the most significant terrestrial carbon sinks, and the anticipated increased use of short rotation woody crops for biomass and bioenergy programs requires that we improve our understanding of the effects of management on soil quality and soil organic carbon pools.

Our objective is to move beyond traditional measures of SOM, using pyrolysis molecular beam mass spectrometry (py-MBMS), for the rapid assessment of SOM. Py-MBMS can quickly provide information on the chemical nature of SOM, allowing the development of SOM quality based on the relative amounts of recent and older SOM pools. Combustion-MBMS provides a rapid assay of total carbon and nitrogen soil contents. Coupling results from both methods provides a basis for assessing the amounts and types of carbon in soils and potentially carbon uptakes over time. We will present the results of this work in applications that include both forest and agricultural management experiments.

NUCL 59 [516372]: Degradation rates of organic resin wastes under subsurface burial conditions based on Arrhenius analyses Kimberly R. Powell, and Daniel I. Kaplan, Savannah River Technology Center, Westinghouse Savannah River Company, 773-43A rm 212, Aiken, SC 29808, Fax: 803-725-1660, kim.powell@srs.gov

Abstract Radioactive resin waste has been generated at the Savannah River Site as a result of groundwater remediation. Key factors in the risk assessment of disposing of these materials in trenches include resin retention of I-129, a long-lived isotope, and the degradation rate of the organic resin itself. In order to estimate the resin degradation rates under subsurface disposal conditions, accelerated thermal-aging experiments were carried out with three types of organic resins. In addition to these Arrhenius-type experiments, soil weathering tests designed to evaluate the microbial contribution to degradation were conducted. Relative rates of degradation as measured in terms of a variety of parameters including elemental analysis, organic carbon, and iodine concentration were compared for anion (Dowex 21K), cation (CG8), and neutral (GT73), resins with, respectively, quaternary ammonium, sulfonate, and thiol functionalities.

NUCL 60 [504930]: Determination of silicon in uranium and plutonium matrices Velma M. Montoya, Alice K. Slemmons, Elmer J. Lujan, and Lav Tandon, C-AAC, Los Alamos National Laboratory, P.O.Box 1663, Los Alamos, NM 87545, Fax: (505)665-4737

Abstract The primary method for determination of silicon in uranium and plutonium matrices by Actinide Analytical Chemistry group at Los Alamos Alamos National Laboratory is by inductively coupled plasma-atomic emission spectroscopy (ICP-AES). To address the need for a secondary method of analysis, the authors have implemented a hetropoly blue

spectrophotometric procedure. Hetropoly blue methods for silicon determination are based on the reduction of molybdosilicic acid to give a characteristic blue species that can be quantified by spectrophotometry. The procedural details of the method will be presented along with comparision results between various analytical techniques in plutonium and non-plutonium matrices. Also, issues such as interfering-elements, required time for color-development, and effects of pH variances were studied. Results from these studies will be included, as will some discussion on detection limits.

NUCL 61 [501138]: Remote determination of silica in highly radioactive defense waste salt solutions by the molybdosilicate colorimetric method Charles J. Coleman, Michael J. Whitaker, John E. Young, Robert Lascola, Mark A. Sanders, and William R. Wilmarth, Savannah River Technology Center, Westinghouse Savannah River Company, Aiken, SC 29808, charles02.coleman@srs.gov

Abstract The Savannah River Site (SRS) has recently had problems with sodium aluminum silicate scale forming in the evaporators used to remove excess process water from the high level radioactive waste tank farm. Several months are required to acid clean the scale from the evaporators, leaving the evaporators unavailable to perform an important process function. To help predict the rate of scale formation, salt solutions that feed the evaporators are analyzed for silica. The molybdosilicate colorimetric method for silica was developed for remote determinations by using fiber optics to couple the light source and photodiode array spectrophotometer outside the shielded cell to the flow cell inside the cell. This remote method has considerable advantages in terms of speed and minimizing radiation dose to personnel versus analyzing the high radiation samples outside the shielded cell. Development of the remote method and its application to high radiation SRS salt solutions will be discussed.

NUCL 62 [519550]: Automation of the radiochemical analysis: From groundwater monitoring to nuclear waste analysis Oleg Egorov1, Matt O'Hara1, and Jay W. Grate2. (1) Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, P7-22, 902 Battelle Blvd, PO Box 999, Richland, WA 99352, oleg.egorov@pnl.gov, (2) EMSL, Pacific Northwest National Laboratory

Abstract Direct, isotope-specific determination of beta- and alpha emitting radionuclides in solutions represents a substantial challenge due to short radiation ranges and energy overlap problems. As the result, in the current analytical practice determination of the key beta and alpha -emitting radionuclides relies on manual radiochemical analysis methods

performed in centralized laboratories. Tedious and costly manual analytical methods are not well suited to support nuclear waste processing and environmental monitoring applications. The research in our laboratories has been directed at the development of chemistry and instrumentation approaches towards automated radiochemical analysis techniques and radionuclide-specific environmental sensing. One aspect of our research is directed at the addressing the fundamental challenges of monitoring of low levels of non-gamma-emitting radionuclides in groundwater. Our overall approach is based on integrating selective separation chemistry and radiation detection within a single functional sensor device. Approaches towards selective sensing of Tc-99 ,Sr-90, and actinides in groundwater will be discussed. Using advanced fluid handling techniques we developed rapid automated separation and analysis procedures for a number of radionuclides of interest in nuclear waste samples using radiometric or mass-spectrometric detection. Determination of actinides and Tc-99 in aged nuclear waste samples will be discussed as examples.

NUCL 63 [521959]: Radioanalytical techniques and the characterization of new separations reagents Kenneth L. Nash1, Renato Chiarizia1, Marian Borkowski1, and Emmanuel Otu2. (1) Chemistry Division, Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, IL 60439, Fax: 630-252-7501, klnash@anl.gov, (2) Division of Natural Sciences, Indiana University Southeast

Abstract The design and synthesis of new extractants or water-soluble complexants for separations applications must be accompanied by an investigation of the separations potential of the new reagents. In our research, the target metal ions for the separations are typically radioactive species, thus our initial characterization of the behavior of the reagents is most often accomplished using radioanalytical techniques. The well-established procedure of "slope analysis" for elucidation of the representative stoichiometry of the extracted complex provides an excellent picture of the chemical processes governing the system at low metal loading. The thermodynamics of the extraction process is often investigated through study of the extraction reaction(s) as a function of temperature. In this presentation, the various techniques that are applied in such studies will be discussed with emphasis on new reagents for actinide and fission product separations. Work performed under the auspices of the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under contract number W-31-109-ENG-38

NUCL 64 [519524]: Realization and applications of collimator-less

gamma-ray imaging systems Kai Vetter, Glenn T. Seaborg Institute, Lawrence Livermore National Laboratory, 7000 East Ave., L-231, Livermore, CA 94550, Fax: 925-422-3160, kvetter@llnl.gov

Abstract Due to advances in manufacturing large and highly segmented semi-conductor detectors along with the availability of fast and high precision digital electronics it is now possible to build efficient gamma-ray imaging systems for gamma-ray energies up to several MeV. These new devices allow to obtain positions and energies of individual gamma-ray interactions and enable the use of "Compton" tracking algorithms not only to determine the scattering sequence of the interactions but also to determine the origin of the incident gamma-rays. The main gain in this approach for localizing and characterizing gamma-ray sources is the increased sensitivity due to the removal of the collimator and therefore significantly increasing the efficiency while maintaining the spatial resolution even of ultra-high resolution collimators. The basic concept of gamma-ray imaging based on tracking and different possible approaches to optimize the sensitivity for different gamma-ray energies will be presented. Applications in nuclear medicine to enhance cancer diagnostic but in particular therapeutic capabilities and in nonproliferation will be discussed. This work is performed under the auspices of the U.S. Department of Energy by the UC Lawrence Livermore National Laboratory under Contract W-7405-Eng-48.

NUCL 65 [511691]: Membrane transport at low ionic strength: Insights from radiochemistry Rebecca M. Chamberlin1, Elizabeth A. Bluhm1, Eve Bauer1, Norman C. Schroeder1, Kent D. Abney2, and Jennifer S. Young3. (1) Chemistry Division, Los Alamos National Laboratory, Los Alamos, NM 87545, rmchamberlin@lanl.gov, (2) Nuclear Materials Technology Division, Los Alamos National Laboratory, (3) Materials Science and Technology Division, Los Alamos National Laboratory

Abstract Cation transport across mesoporous alumina membranes has been studied using radiotracer methods. The high specific activity of gamma-emitting isotopes of Na, Cs, Ca, Sr, Fe, Ln(III) and An(III) elements enables the study of transport and/or sorption of cations in low ionic strength aqueous solutions. In this regime, diffusion of metal ions through the membrane is profoundly influenced by variables such as ion size/charge, pore size, solution pH, and ionic strength. Differences in transport rates can be explained in terms of a Donnan exclusion effect from the positively charged alumina surface.

NUCL 66 [521742]: Alpha-autoradiography: A simple method to monitor the migration of alpha emitters in the environment

Carola A. Laue, and David K Smith, CMS/ANCD, Lawrence Livermore National Laboratory, 7000 East Ave., L-231, Livermore, CA 94550, Fax: 925-422-3160, cal@llnl.gov

Abstract Alpha-autoradiography is a well-established method to map the in-situ distribution of alpha emitters in geologic matrices. The obtained radiographs provide data on the occurrence and spatial distribution of alpha emitters; it is a preferred method to detect discrete alpha emitting particles with extremely high sensitivity. For these reasons, alpha autoradiography is readily applied to studies of the transport of radionuclides in the environment. Our current research focuses on the vertical migration of alpha emitters derived from above-ground nuclear tests through desert soils at the Nevada Test Site. By deploying CR-39 detectors along vertical profiles in the soil horizon, we are able to resolve exact transport pathways. We will compare our data to that previously obtained by chemical, gamma, and autoradiographic analyses to determine the migration behavior of alpha emitters in semi-arid soils over a time period of roughly half a century.

This work was performed under the auspices of the U.S. Department of Energy by University of California Lawrence Livermore National Laboratory under contract No. W-7405-Eng-48.

NUCL 67 [506977]: Determination of isotopic thorium in biological samples using combined alpha spectrometry and radiochemical neutron activation analysis Samuel E Glover, Department of Chemistry, Washington State University, Pullman, WA 99164-4630, glover@wsu.edu

Abstract Thorium is a naturally occuring element with important industrial uses. All of it's isotopes are radioactive. The dosimtrically important isotopes of thorium are alpha emitters whose half-lives span from a few years to many billions of years. Alpha spectrometry has long been used for these determinations, but it has inadequate detection limits for very long-lived radionuclides (e.g. 232Th). Alpha spectrometry does allow the determination 228Th whose short half-life prevents determination using atom counting techniques such as ICP-MS or accelerator mass spectrometry. This discussion will focus on the use of a combined method of alpha spectrometry combined with neutron activation analysis to determine the dosimetrically important isotopes of thorium in biological and environmental samples.

NUCL 68 [510666]: A Study of the Decomposition of Hazardous

Chromium-Amalgam Zheng Chang, Department of Chemistry, Brookhaven National Laboratory *, Bldg 555, Upton, NY 11973-5000, Fax: 631-344-5815, changz@bnl.gov, and Richard L. Hahn, Department of Chemistry, Brookhaven National Laboratory

Abstract Several liters of chromium amalgam, a mixture of metallic chromium and mercury, were produced as a byproduct in studies involving the preparation of an intensely radioactive neutrino calibration source, 51-Cr, for the GALLEX solar neutrino detector. The chromium that was irradiated still contains traces of long-lived radioactive 110m-Ag from silver impurities, even though the bulk 51-Cr has long since decayed away. The amalgam is pyrophoric, posing a fire hazard. Upon standing for a while, the amalgam becomes a silver-colored sticky paste covered with a thick layer of black powder. The black powder, which is composed of metallic Hg and Cr, is found to be very difficult to decompose in normal oxidizing solvents. Also, the powder is fluffy and can become airborne when the amalgam is stirred. All these properties pose problems for the treatment of the Cr amalgam. The decomposition processes of the Cr amalgam were studied, including the composition and chemical properties of the black powder. A procedure was developed, including electrolytic decomposition of the amalgam, electrolytic plating of Cr, and high temperature roasting of the black powder. Furthermore, the process conditions were optimized based on the decomposition rates and recovery percentages. The products of these processes are liquid mercury and either an aqueous solution of trivalent chromium ions or solid chromium metal, all of which are suitable for eventual disposal as chemical waste.

* This research at BNL was sponsored by the Office of High Energy and Nuclear Physics in the Office of Science of the U.S.D.O.E.

NUCL 69 [516537]: In-situ Raman monitoring of head-space gas over plutonium dioxide in long-term storage containers through fiber-optic probes John M. Berg1, Karen C. Rau2, D. Kirk Veirs3, Laura A. Worl2, James T. McFarlan2, and Dallas D. Hill4. (1) Nuclear Materials and Technology Division, Los Alamos National Laboratory, MS E505, Los Alamos, NM 87545, Fax: 505-665-4394, (2) NMT-11, Los Alamos National Laboratory, (3) Nuclear Materials Technology Division and G.T. Seaborg Institute for Transactinium Science, Los Alamos National Laboratory, (4) Engineering Sciences and Applications Division, Energy and Process Engineering, Los Alamos National Laboratory

Abstract Reductions in stockpiles of nuclear weapons increase the need for safe, secure storage of plutonium until its disposition can be decided and carried out. The preferred alternative is to convert plutonium to PuO2 and store it in hermetically sealed containers. Questions

remain about the amount of purification necessary to insure that there is an acceptably small risk of gas generation and container pressurization. We have developed and implemented in-situ Raman spectroscopy through fiber-optic probes as one of a suite of diagnostics in a long-term study to identify and quantify head-space gas changes over several lots of stored PuO2 of varying purity and processing history. We have demonstrated in-situ sensitivity as low as 0.1 kPa for all gases of interest, including nitrogen, oxygen, hydrogen and water vapor. This is a significant improvement over previously demonstrated Raman sensitivity to gases through fiber-optic probes, suggesting broader potential applications in difficult environments.

NUCL 70 [521966]: On-line chemometric analysis of uranium and nitric acid in nuclear processing: practical considerations Robert Lascola, Gary A. Cooper, and Ronald R. Livingston, Westinghouse Savannah River Company, Savannah River Technology Center, Aiken, SC 29808, robert.lascola@srs.gov

Abstract We have previously described an on-line absorption spectrometer used to determine uranium and nitric acid content for the Savannah River Site's uranium solvent extraction process[1]. That instrument is currently used to measure concentrations at several locations where the process stream is well-defined and there is little spectral interference from other stream constituents. Here we discuss several refinements to the chemometric analysis which allow expansion of the spectrometer to more complex streams. Species such as Fe, Al, Hg, Ni, Cr, and various organics may compromise the analysis; we have determined which species are potentially significant, and have reduced the sensitivity of the fits to those species by modifications of the calibration set and mathematical preprocessing. We have also determined a minimum calibration set size for this system. Lessons learned here may be applied to calibrations of other actinide systems, where nuclear safety, worker exposure, and sample disposal are important considerations.

[1] R. Lascola, et al. Abstr. Pap. Am. Chem. Soc. (2000), 220th, NUCL-024.

NUCL 71 [522480]: Laser induced breakdown spectroscopic monitor for in-situ elemental analysis of glass batch mixture Bansai Lal1, Fang-Yu Yueh2, Jagdish P. Singh2, and William G. Ramsey1. (1) Diagnostic Instrumentation & Analysis Laboratory, Mississippi State University, Starkville, MS 39759-7704, bansi@dial.msstate.edu, (2) Diagnostic Instrumentation and Analysis Laboratory, Mississippi State University

Abstract This study deals with the in-situ monitoring of the concentration of the constituents of glass batch mixture so as to conserve energy besides reduction in the wastage of raw material. The monitoring technique used is laser induced breakdown spectroscopy (LIBS) because of its fast response and ease of operation in any real time situation. Glass batch mixture consisting of SiO2, Al2O3, Na2CO3 and CaCO3 has been chosen for investigation. This mixture is used to make window glass that has a typical composition of 71%SiO2, 1%Al2O3, 12%Na2O and 16%CaO. A frequency-doubled pulsed Nd:YAG laser (Continuum Surelite I) is focused on the sample using a 300 mm focal length, UV grade fused silica plano-convex lens which also collects emission from the laser induced spark produced at the focus of the laser beam. The emission from the spark is fed to a spectrometer (2400 l/mm grating, Spex 500M) through an optical fiber. The spectrometer is fitted with a gated 1024-element intensified diode array detector (Princeton Applied Research Model IDAD-1024). EG&G OMAVISION PC software is used for data acquisition and analysis. The effect of the particle size of the mixture on the precision of the data obtained by LIBS and the technique used to handle the powder sample to get reproducible LIBS data are discussed in the paper.

NUCL 72 [522482]: Laser induced breakdown spectroscopy of liquid sample with double pulse excitation V.N. Rai, F.Y. Yueh, and J.P. Singh, Diagnostics Instrumentation and Analysis Laboratory, Mississippi State University, 205 Research Boulevard, Starkville, MS 39759-7704, vnrai@dial.msstate.edu

Abstract Laser Induced Breakdown Spectroscopy (LIBS) of aqueous solution of magnesium studied using double laser pulse excitation is presented. The application of multiple pulses for producing more intense and sustained plasma emission has been found effective in improving the emission from the plasma and as a result the analytical sensitivity of the system. Two Nd:YAG laser converted to second harmonic and delivering ~200 mJ energy in 3-5 ns have been used. The laser beam from both the lasers were made collinear using a thin film polarizer and then focused onto a liquid jet. The spectrum of the emission from the spark plasma was recorded and analyzed. The analysis of the spectrum obtained from the spark plasma shows that LIBS intensity was maximum when the delay between the two laser was kept between 2-3 ms. The first laser vaporizes and pre-ionizes the sample where as the second laser interacts with the expanding laser plasma formed by the first laser beam, which ultimately excites the ions and neutrals present in the first laser produced plasma plume. Nearly five times enhancement in the signal was noted when the lasers were operated at delay of 2 ms in comparison to when the delay between the two lasers was zero. The operational parameters for double pulse LIBS has been optimized to provide better sensitivity of the LIBS system for the analytical purpose. The detailed analytical results for magnesium using double pulse excitation will be presented.

NUCL 73 [522485]: Tailor-made optical fibers as transducers for highly sensitive chemical sensing Shiquan Tao1, Christopher B. Winstead1, J.P. Singh2, and Rajeev Jindal1. (1) Diagnostic Instrumentation and Analysis Laboratory, Mississippi State University, 205 Research Blvd., Starkville, MS 39759, tao@dial.msstate.edu, (2) Diagnostics Instrumentation and Analysis Laboratory, Mississippi State University

Abstract Optical fiber chemical sensors using polymer coatings on the end or surface of an optical fiber are well developed. However, the sensitivity of these sensors is limited by several factors. In this work, a new type of optical fiber chemical sensor is under development. The new sensors use tailored active fiber cores as transducers for chemical sensing. A wet chemical procedure has been developed for making porous sol-gel fibers. The sol-gel fibers made from this process are transparent to ultraviolet, visible and near infrared light. In addition, molecules from the surrounding environment can diffuse into the porous fiber core. Chemical and biochemical reagents can be doped into the fiber core as sensing material. Results for sensing moisture, hydrogen, oxygen and ammonia will be presented.

NUCL 74 [522486]: A water core optical fiber for highly sensitive chromate ion monitoring Shiquan Tao, and Christopher B. Winstead, Diagnostic Instrumentation and Analysis Laboratory, Mississippi State University, 205 Research Blvd., Starkville, MS 39759, tao@dial.msstate.edu

Abstract Ultraviolet/visible absorption spectrometry has been used for many years for metal analysis. The sensitivity of this method depends on the absorption cross section of the analyte and the length of the sample cell. The index of refraction of a recently developed polymeric material is less than that of water, allowing it to act as a water core optical fiber. This water core optical fiber can be used as a long-path sample cell. In this work, a simple technique for monitoring chromate ions in water was developed by using a 2 meter long section of tubing as a flow through sample cell, an ultraviolet wavelength LED as a light source, and a CCD detector. Aqueous solutions containing Cr(VI) were continuously pumped through the micro-tubing. With this simple setup, chromate ions in water can be continuously monitored at a concentration of < 0.8 ppb.

NUCL 75 [522487]: Effect of coatings on evanescent wave fiber–optic

humidity sensor R. Jindal1, S. Tao1, J.P. Singh2, C. Winstead1, and S. Kirthi1. (1) Diagnostic Instrumentation & Analysis Laboratory (DIAL), Mississippi State University, 205 Research Blvd, Starkville, MS 39759, jindal@DIAL.msstate.edu, (2) Diagnostics Instrumentation and Analysis Laboratory, Mississippi State University

Abstract Recently, a fiber-optic relative humidity sensor was realized using evanescent wave absorption of light propagating in the fiber. The cladding was removed from a section of fiber that was subsequently coated with an aqueous solution of polyvinyl acetate (PVA) and CoCl2. PVA serves as a supporting material, while CoCl2 provides an indicator of water concentration. Complexation of CoCl2 with water causes a significant change in the absorption coefficient of the coating. This alters the optical transmission of the fiber since the evanescent wave in the coating is less strongly absorbed when the humidity level increases. The sensor shows good response from a 3% to over 95 % relative humidity range. However, one drawback of the sensor is that the properties of the thin film of PVA and CoCl2 can change when exposed to high humidity or water. In fact, in water the film can dissolve fully. In this study we have tested several coating materials for protecting the thin film. Various coatings of Silicon rubber, Polyimide, and sol-gel were tried. The stability, characterization results, and changes in response time of the coated sensor will be presented.

NUCL 76 [522488]: Monitoring the process of phytoremediation of metal-contaminated soil by near IR reflectance spectroscopy Yi Su, B. B. Maruthi Sridhar, and David L. Monts, Diagnostic Instrumentation & Analysis Laboratory (DIAL), Mississippi State University, 205 Research Blvd, Starkville, MS 39759, su@DIAL.msstate.edu

Abstract This paper outlines the first part of a series of research studies to investigate the potential of using optical remote sensing to monitor some of the DOE sites contaminated by heavy metals. The long-term objective of this project is to detect subsurface contamination by remotely monitoring reflectance spectral signatures of vegetation. The outcome of this research could also be applied to monitor the process of phytoremediation of soils contaminated by heavy metals. In this work, potted plants of Indian mustard (Brassica juncea), a known, well-characterized crop species for heavy metal accumulation, were grown and treated with Zn and Cd at different selected concentration levels. Diffuse reflectance spectra of plant leaves recorded with laboratory illumination and with solar irradiation were used to monitor growth and metal treatment processes. During the first round of phytoremediation experiments, analysis of diffuse reflectance spectra of Brassica juncea plants treated with a “medium” concentration Zn solution (100 millimolar) reveal a spectroscopic feature that is systematically different from the spectra of untreated plants. Analytical results on shoots from the medium Zn treatment plants

show a significant amount of Zn accumulated in the leaves (at the level of approximately 14 g/kg dry shoot weight). The results of spectral data analysis and analytical chemistry tests on harvested plant shoots will be presented in this paper. Further experiments with different plant species and different metal treatments are in progress.

NUCL 77 [522490]: Monitoring of nitrogen and potassium deficiency in plants with photoacoustic spectroscopy Awadhesh K. Rai1, J.P. Singh2, and K.R. Reddy1. (1) Diagnostic Instrumentation and Analysis Laboratory, Mississippi State University, Starkville, MS 39759, singh@dial.msstate.edu, (2) Diagnostics Instrumentation and Analysis Laboratory, Mississippi State University

Abstract The objective of the present study is to explore the feasibility of photoacoustic spectroscopy (PAS) to estimate nitrogen and potassium status of crop plants. We prepared four sets of plant units having deficiencies of N and K. The leaves were collected from every set of samples after different interval of days after treating the nutrients to the plants. The collected leaves were dried at 80 0C and finally granddad as a fine powder. PA spectra of all leaf powder were recorded using single beam PA spectrometer at modulation frequency 36 Hz. PA spectrum of all leaves showed strong band at 675 nm and weak bands at 620 nm and 465nm. Mineral deficiencies decreased leaf chl a and chl b concentration in the leaves resulting in lower absorption spectra. Therefore, PA signal strength of leaves having nitrogen/potassium (N/K) deficiency is lower than the corresponding healthy leaves. Our experimental results reveal that the strengths of the PA signal were high for the leaf sample, which has higher (N/K) concentrations. Thus, the present study clearly demonstrates that PAS technique may be utilized to identify the N/K deficiency in plants.

NUCL 78 [492977]: Challenges and opportunities for interdisciplinary science in targeted radionuclide therapy for cancer Christine L. Hartmann Siantar, Glenn T. Seaborg Institute, Lawrence Livermore National Laboratory, L-231 PO Box 808, Livermore, CA 94550, Fax: 925-422-3160, chs@llnl.gov

Abstract Targeted radionuclide therapy promises to extend the usefulness of radiation from localized tumors to metastatic cancer, by combining radioactive isotopes with tumor-seeking molecules such as monoclonal antibodies and custom-designed synthetic agents. Even though targeted radionuclide therapy has demonstrated much potential, particularly for lymphomas and leukemias, it is still far from optimized and with much work left to be

done for many tumor systems. Major development challenges are selecting patients and optimizing administration, in order to not only cause tumor regression, but to actually cure the patient of widespread cancer. These challenges must be met by an integrated, multidisciplinary science approach that includes better targeting agents, combined with advanced radiation detection, radiation simulations, and radionuclide selection. This presentation provides an overview of the field of targeted radionuclide therapy, summarizes important challenges in radiation detection, simulations, and radioisotope selection, and reviews current approaches, including those being pursued by our group.

NUCL 79 [513901]: Applications of radioanalytical chemistry to Alzheimer’s disease J. David Robertson, Department of Chemistry, University of Missouri, 125 Chemistry Building, Columbia, MO 65211, Fax: 573-882-2754, Robertsonjo@missouri.edu

Abstract Two examples of the use of radioanalytical methods to probe key questions about the pathogenesis of Alzheimer’s disease (AD) will be presented. In the first, micro-beam proton-induced X-ray emission analysis is being used to investigate imbalances of Cu, Fe and Zn in senile plaques (SP) and neurofibrillary tangles (NFT) in AD in light of the fact that these metals can accelerate aggregation of amyloid beta peptide in vitro. In the second, accelerator mass spectrometry and the 14C bomb pulse are being used to determine the average “age” of the physiological structures, plaques and tangles, associated with AD. The time course and defining factors involved in the formation of these pathological features are unknown.

NUCL 80 [515102]: Extraction and Purification of Th-229 for Medical Research Application Miting Du, and Fred Peretz, Nuclear Science and Technology Division, Oak Ridge National Laboratory, MS 6385, Building 7930, P. O. Box 2008, Oak Ridge, TN 37831, Fax: 865-576-6312, yo2@ornl.gov

Abstract Th-229 (alpha, 7300 a) is an important radioisotope, which gives out its invaluble decay daughters of Ac-225 (alpha, 10.0 d) and Bi-213 (alpha, 45.59 m) for medical research applications. Extraction and purification of total 72 mCi (ca. 336 mg) of Th-229 from the storage of Mound U-233 material (kilograms of U-233 and grams of Pu impurities) are carried out at ORNL using a series of ion exchange columns of different dimensions. The separation procedure is described and the processing results of first four batches are present.

NUCL 81 [512573]: Synthesis of Fluoro Thymidine ([18F]FLT) as radiotracer of tumors Datta E. Ponde, Nobuyuki Oyama, Michael J Welch, and Tim J. McCarthy, Division of Radiological Sciences, Mallinckrodt Institute of Radiology, Washington University School of Medicine, 510, S. Kingshighway Boulvard, Saint Louis, MO 63110, Fax: 1-314-362-9940, Ponded@mir.wustl.edu

Abstract Radio labeled thymidine is widely used in biologic research to measure the growth of tissues and tumors, both in cell culture and in vivo. Simple radiosynthesis of fluoro thymidine ([18F]FLT), incorporation into proliferating cells as well as stability to catabolism in vivo makes FLT as important tracer for Positron Emission Tomography (PET). Successful synthesis of FLT was carried out starting from anhydrothymidine. Microwave mediated nucleophilic displacement by fluoride ion followed by controlled acidic hydrolysis gave FLT in high radio purity. Various parameters for high yield product formation and HPLC purification were optimised. microPET imaging of FLT was carried out with mice implanted with CWR22 cell line. Extremely good image of tumor was found 1 hr post injection. Work is under way to understand change in proliferation activity due to cancer therapy using FLT.

NUCL 82 [520564]: Isotopic characterization of depleted uranium contamination by multi-collector high-resolution inductively-coupled plasma mass spectrometry (MC-HR-ICPMS) Bradley K Esser1, Ross Williams1, and Michael Taffet2. (1) ANCD, Lawrence Livermore National Laboratory, 7000 East Ave, L231, Livermore, CA 94550, Fax: 925-422-3160, bkesser@llnl.gov, (2) ERD, Lawrence Livermore National Laboratory

Abstract We have used MC-HR-ICPMS to isotopically characterize depleted uranium contamination at a high explosives test range (Site 300, Lawrence Livermore National Laboratory). Landfill leachates have correlated 235U/238U, 234U/238U, and 236U/238U ratios which may be interpreted as mixing between natural uranium and depleted uranium. The degree of 235U depletion in anthropogenic U varies with landfill and correlates well with the timing of disposal to the landfills and Department of Energy historical records of depleted U composition over the last half century. Isotopic differences in landfill endmembers are used to distinguish landfill source where a groundwater depleted U plume exists with more than one potential source. The ability to precisely characterize 235U, 234U and 236U at environmental levels allows unambiguous attribution of anthropogenic U in contaminated groundwaters. In areas

affected by natural, depleted, and enriched U sources, the use of 4 isotopes will allow the contributions of each component to be quantified.

NUCL 83 [511499]: Plutonium purification via hydroxide precipitation from aqueous chloride solutions Kent D. Abney1, Jennifer L. Alwin1, Keith W. Fife1, Elizabeth A. Bluhm2, Jessica N. Fife2, and Michael R. Cisneros2. (1) Nuclear Materials Technology Division, Los Alamos National Lab, NMT-2, MS-E511, Los Alamos, NM 87545, Fax: 505-665-1780, abney@lanl.gov, (2) Chemistry Division, Los Alamos National Lab

Abstract Current Los Alamos National Laboratory pyrochemical operations use high temperature melts of calcium chloride for the reduction of plutonium oxide to plutonium metal and high temperature melts of sodium chloride and potassium chloride mixtures for the electrorefining purification of plutonium metal. These chloride salts are subsequently dissolved in dilute hydrochloric acid for either solvent extraction or ion exchange recovery of the remaining plutonium and in-growth americium. Aqueous chloride operations generate copious quantities of secondary wastes and are difficult to manage from a materials corrosion perspective. Thus to minimize these problems, a direct hydroxide precipitation process followed by removal of the interstitial chloride would allow for subsequent nitrate-based processing and as such would overcome many of the difficulties of chloride solution handling. Results of the hydroxide precipitation and chloride washing tests will be discussed from the perspective of filterability, washing efficiency, temperature control, and process additives that have been considered.

NUCL 84 [516043]: Tests of a Portable Plutonium Mass Verification System Joel C. Swanson, Tzu-Fang Wang, William Buckley, and Yves X. M. Dardenne, Analytical and Nuclear Chemistry, Lawrence Livermore National Laboratory, 7000 East Avenue, Mail Stop L-232, Livermore, CA 94551, jswanson@llnl.gov

Abstract Lawrence Livermore National Laboratory (LLNL) is developing an instrument, based on established coincidence counting techniques, to yield a semi-portable Pu mass verification solution to the problem of in-vault verification. Commercially available instrumentation is being tested that will enable in-situ verification of Pu masses in sealed containers. The detector assembly includes both neutron and gamma detectors. The device will operate on battery power, and will be mounted on a cart for portability.

For mass verification of plutonium, two types of signal are analyzed. A gamma spectrum is analyzed for isotopic ratios using LLNL's MGAHI code. Neutron count rates and coincidence rates are measured to quantify the spontaneous fission rate within the Pu. Corrections for neutron scattering, alpha-neutron reaction sources, and induced fission rate must be made to establish the necessary accuracy for this analysis. Test results of this system will be presented.

NUCL 85 [505049]: Greg Choppin: a half century in actinide science Darleane C. Hoffman, Nuclear Science Division & Department of Chemistry, Lawrence Berkeley National Laboratory & University of California, Berkeley, 1 Cyclotron Road, MS-70/319, Berkeley, CA 94720, Fax: 510-486-6707, hoffman@lbl.gov

Abstract A brief account of Greg Choppin's introduction to nuclear chemistry, and more specifically, to actinide chemistry, at the Radiation Lab at Berkeley between 1953 and 1956 where he was a co-discoverer of mendelevium (element 101) will be given. This will include his development of alpha-hydroxyisobutyrate as an eluting agent for separation of individual actinides from each other and the subsequent discovery of mendelevium which was separated and chemically identified using this separation technique. From there, Greg Choppin went on to an illustrious teaching and research career at Florida State University in actinide chemistry, the behavior of actinides in the environment, and environmental science.

NUCL 86 [504601]: Choppin’s Études at the NRC Douglas J. Raber, Board on Chemical Sciences & Technology, National Research Council, 2101 Constitution Ave. NW, Washington, DC 20418, Fax: 202-334-2154, draber@nas.edu

Abstract For the last several decades, Dr. Gregory R. Choppin has provided nearly continual service to the National Research Council. Through his work with several different boards and a variety of committees, he has made significant contributions to the scientific community and to the national agenda. This paper will provide an overview and assessment of Dr. Choppin’s contributions and their impact on science policy.

NUCL 87 [489450]: Actinide Research at LLNL Patricia A. Baisden, Chemistry and Materials Science Directorate L-090, Lawrence

Livermore National Laboratory, 7000 East Avenue, Livermore, CA 94550, Fax: 925-422-2979

Abstract Current research on the actinide and transactinide elements within the Chemistry and Materials Science Directorate at the Lawrence Livermore National Laboratory will be discussed. Ongoing efforts that will be described include determining the speciation of actinides within the environment as well as the importance of colloids for their migration, probing the electronic structure of Pu using high resolution photoelectron spectroscopy, understanding radiation damage in Pu via low temperature irradiation and annealing studies, and producing new elements by bombarding actinide targets with light, heavy ions. Future directions for actinide research will also be discussed.

This work was performed under the auspices of the U.S. Department of Energy by the University of California, Lawrence Livermore National Laboratory under Contract No. W-7405-Eng-48.

NUCL 88 [515327]: How come α-hydroxyisobutyric acid is still the best reagent for the separation and analysis of trivalent f-elements? Kenneth L. Nash, Chemistry Division, Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, IL 60439, Fax: 630-252-7501, klnash@anl.gov

Abstract More than 40 years ago, the research team attempting the synthesis of element 101 identified the need for more rapid and selective separations methods. The discovery of the unique behavior of α-hydroxyisobutyric acid as an eluant for cation exchange separations, first reported by Choppin and Silva, satisfied that need. This reagent has proven so successful that it is still the reagent of first choice for isolation of trivalent actinides from mixtures and for liquid chromatographic analysis of trivalent f-elements in general. Following this early career achievement, Professor Choppin has spent the past 40+ years seeking additional similarly brilliant insights. His continued (continuing) investigations have provided many great strides in the advancement of our understanding of the separations, environmental, and solution chemistry of actinides. In this presentation, some of his achievements and insights into the solution chemistry of the actinides (with emphasis on separations) will be discussed. Work performed under the auspices of the U. S. Department of Energy, Office of Science, Office of Basic Energy Sciences under contract number W-31-109-ENG-38 at Argonne National Laboratory

NUCL 89 [516892]: Facilitated transport membranes for selective

separations of actinide metal ions Gordon D. Jarvinen1, Deborah S. Ehler2, Doris K. Ford1, T. Mark McCleskey2, Nancy N. Sauer2, Norman C. Schroeder3, and Jennifer S. Young4. (1) NMT-11, Los Alamos National Laboratory, Mail Stop E505, Los Alamos, NM 87545, Fax: 505-665-4394, gjarvinen@lanl.gov, (2) Chemistry Division, C-SIC, Los Alamos National Lab, (3) Chemistry Division, Los Alamos National Laboratory, (4) Materials Science and Technology Division, Los Alamos National Laboratory

Abstract The selective separation of metal ions using facilitated transport through a membrane has been studied for many years. The poor long-term stability of facilitated transport membranes has limited their industrial application. We are attempting to build more stable membrane systems for facilitated transport by constructing nanoporous structures lined with functional groups that selectively bind to metal ions. For example, thin layers of gold (30-100 nm) were deposited on porous alumina supports producing a gold layer with nanoscale porosity. Reaction of the gold layer with a thiol compound formed a self-assembled monolayer on the gold surface. Using a thiol compound with a terminal phosphoryl group resulted in a monolayer with fixed sites for metal ion binding. The results of recent transport studies with uranium(VI), europium(III), and other metal ions using these membranes will be presented.

NUCL 90 [515877]: Role of organic solvents and characterization of extracted species in the synergistic extraction of lanthanoids(III) Yuko Hasegawa, Department of Chemistry, Science University of Tokyo, Tokyo 162-8601, Japan, Fax: 81-3-3235-2214

Abstract In order to discuss the details of synergistic extraction of lanthanoids(III) with beta-diketones (TTA and pivaloyltrifluoroacetone) and aromatic amines, the residual hydration numbers of lanthanoids(III) in the beta-diketonato chelates and the adducts of the chelates with the amine, and the complexation heat as well as the adduct formation constants have been determined. In addition, the interaction between the donor atom in the amine and the acceptor atom in organic solvents such as H in chloroform has been examined from the IR spectra.

NUCL 91 [491334]: Radiation risks: fiction and facts Jan Rydberg, Chalmers University of Technology, Goteborg, Sweden, rydberg@nc.chalmers.se

Abstract International and most national radiation protection authorities adhere to the LNT (Linear No Threshold) dose-effect relation, which states that there is no radiation dose so small that it is harmless, which means that even the most minute radiation dose increases the risk to develop cancer at a later time (sometimes 5-15 years later), and that the risk increases (approximately) linearly with the radiation dose received. This doctrine forms the bases for the information to the public about radiation risks and produces an opinion which is a big obstacle to increased beneficial use of radiation, whether for medical (therapeutic as well as diagnostic), industrial (energy production, technical applications) or scientific uses; in the medical field the adherence to the doctrine even increases the somatic risks for the patients. However, many scientists now question the scientific bases for the LNT-doctrine and require its modification. This paper illuminates the debate and quotes a large number of contradictory opinions.

NUCL 92 [523253]: Theoretical studies of reaction products of laser-ablated actinide atoms with H2O Jun Li1, Bruce E. Bursten2, Binyong Liang3, and Lester Andrews3. (1) Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, K1-96, P. O. Box 999, Richland, WA 99352, Fax: 509-375-6631, jun.li@pnl.gov, (2) Department of Chemistry, The Ohio State University, (3) Department of Chemistry, University of Virginia

Abstract Understanding of chemical reactivities of actinide atoms toward H2O is of fundamental importance in both actinide chemistry and environmental science. Experimental studies of laser-ablated Th and U atoms with H2O during condensation in excess argon have revealed the formation of a variety of intriguing new actinide complexes, including HThO, HTh(OH)3, OTh(OH)2, H2UO2, H2UO(OH)2, H2AnO, and HAnO(OH) (An=Th, U). In this work, we have performed relativistic DFT and ab initio MP2 and CCSD(T) calculations on these actinide molecules and other possible isomers to elucidate the electronic structures and spectroscopic properties. The good agreement between experimental and calculated vibrational frequencies, relative absorption intensities, and isotopic shifts has provided strong support for the experimental identifications of the proposed species and the infrared absorption assignments.

NUCL 93 [514975]: The Development of Aqueous Thermodynamic Models for Polymerized Silica and Strontium-Silicate Species Valid to High Ionic Strength Andrew R. Felmy1, Herman Cho1, James R Rustad2, and Mason J. Marvin1. (1) The W.R. Wiley Environmental Molecular Sciences Laboratory, The Pacific Northwest

National Laboratory, P.O. Box 999, Richland, WA 99352, ar.felmy@pnl.gov, (2) The W. R. Wiley Environmental Molecular Sciences Laboratory, The Pacific Northwest National Laboratory

Abstract The development of an aqueous thermodynamic model for polymerized silica species is presented which is valid to high ionic strengths and high dissolved silica concentration (~0.1m) at low temperature (22-25°C). The model is based upon the equations of Pitzer and has been parameterized from solubility, electromotive force (emf), and nuclear magnetic resonance (NMR) data. The description of the silica speciation reactions at high dissolved silica and basic conditions (pH >10) required the inclusion of monomeric, dimeric, trimeric (linear, cyclic and substituted), tetrameric (linear and cyclic) and hexameric (prismatic) species. The standard state equilibrium constants for the formation of these species, as well as the necessary Pitzer ion-interaction parameters to describe the ionic strength dependence of the formation reactions were determined. The aqueous phase interaction of divalent Sr with silicate containing solutions was also studied over a range of pH values, dissolved silica and Sr concentrations, and extending to basic solution (0.2M NaOH) at room temperature (22-23 °C). Identification was made of a previously unreported quasi-crystalline tobermorite-like Sr5Si6O16(OH)2.5H2O phase with an equilibrium constant of Log Ksp=-38.0 ± 0.7. The first estimate of the association constant for the species SrH2SiO4(aq) of Log K=2.86 was also made.

NUCL 94 [517740]: Interaction of trivalent actinides with mineral surfaces Thomas Fanghänel, Thorsten Stumpf, and Sylvia Stumpf, Institute of Radiochemistry, Forschungszentrum Rossendorf, P.O. Box 510119, D-01314 Dresden, Germany

Abstract The interaction of actinides with mineral surfaces represents an important mechanism for their retention. We have started a systematic study of the surface reactions of trivalent actinides with various mineral surfaces, like clay minerals, calcite and iron oxide minerals. The present contribution is to provide an overview on this subject. The mechanisms of surface complexation and/or incorporation into the bulk mineral structure of Cm(III) and Eu(III) is studies by Time Resolved Laser Fluorescence Spectroscopy (TRLFS). This high sensitive spectroscopic method enables to identify various surface species and to distinguish between surface sorption and incorporation into the lattice by studying the hydration status of the Cm and Eu species.

NUCL 95 [515810]: Actinide and lanthanide complexation with polyoxometalates in aqueous solutions

Akira Saito, Chemistry Department, Tokyo Gakugei University, Koganei, Tokyo 184-8501, Japan, Fax: 81-42-329-7508, akira@u-gakugei.ac.jp, and Gregory R Choppin, Dept. of Chemistry, Florida State University, Tallahassee, FL 32306, Fax: 850-644-8281, choppin@chem.fsu.edu

Abstract Various polyoxometalate anions can exist as very stable, discrete ionic species in aqueous solutions. They have large ionic sizes, large formal negative charges, unique geometrical structures composed of corner-, edge-, or face-shared MO6 octahedra, and ionic surfaces covered by arrays of oxide ions. Due to these features, polyoxometalates are considered as models for metal oxides and mineral fragments or colloid particles. We have been interested in their function as anionic ligands for metal cations, especially for actinides and lanthanides and have been investigating the interaction as complexation equilibrium in aqueous solutions with the expectation that it will provide insights into the metal cation interaction with particulate matters in natural waters. In this presentation, we will present the experimental results of the determination of stability constants for the systems of various metals and polyoxometalates, and will discuss the nature of the interaction, the factors that affect the stability constants, and the metal binding sites.

NUCL 96 [514347]: Interaction of actinide ions with [NaP5W30O110]14-, [As2W21O69]6-, [P2W18O62]6-, and [P2W17O61]10- Donald E. Wall, Sandia National Laboratories, 4100 National Parks Highway, Carlsbad, NM 88220, dwall@sandia.gov, and Gregory R. Choppin, Chemistry Department, Florida State University

Abstract The thermodynamics of complex formation of Th4+, UO2

2+, NpO2+ and Am3+ with

[NaP5W30O110]14-, [As2W21O69]6-, [P2W18O62]6- and [P2W17O61]10- were examined in 0.1 molar NaCl solution at 25°C. The respective stability constants with [NaP5W30O110]14- are log β101=6.10 ± 0.05, 3.80 ± 0.06, 2.98 ± 0.04, 5.85 ± 0.05; and with [As2W21O69]6- are 9.9 ± 0.1, 6.32 ± 0.04, 4.39 ± 0.03, 10.1 ± 0.1. The log β101 of NpO2

+ with [P2W18O62]6- is < 2 , and with [P2W17O61]10- is 4.81 ± 0.03. The order of the stability constants are: Th4+ > UO2

2+ > Am3+ > NpO2+ when the primary binding sites are tetragonal. The stability

constants follow the order: Th4+ > Am3+ > UO22+ > NpO2

+ when interacting with trigonal or pentagonal binding sites, due to steric effects. Entropy values correlate with the magnitude of dehydration of the metal ion, which depends on the geometry of the binding site.

NUCL 97 [519526]: Potential impact of humic acid solutions on the sorption of some radionuclides Ibrahim Salem Shaban, Department of Chemistry, Clemson University, Clemson, SC 29634, ishaban@clemson.edu, James D. Navratil, Department of Environmental Engineering and Science, Clemson University, and Fedor Macasek, Department of Nuclear Chemistry, Comenius University

Abstract Humic acid solutions of radiocesium, radiostrontium, radioeuropium, and plutonium were investigated to determine its importance in environmental radionuclide mobility. The solubility of humic acid depends on pH, ionic strength and concentration. The humic acid sorption data obtained were treated by various models of sorption isotherms. The three-parameter Sips isotherm of humic acid sorption data appeared to be the most successful for most systems. A comparative study of cesium and strontium with europium(III) and plutonium(IV) on well-defined montmorillonite in the presence of humic acid also verified the "2-sites-2-species" model of radionuclide sorption. Additionally, the high-performance size-exclusion chromatographic behavior of humic acid and its complexes is strongly influenced by the pH and ionic strength of the eluent and by the concentration of humic acid. Strontium was complexed with a low-molecular weight fraction. Cesium followed the very low molecular fraction and no evidence of its interaction with humic acid was found.

NUCL 98 [518206]: Actinide sorption to synthetic and biogenic MnO2 William K. Myers1, Donna Smith1, Matthew Ginder-Vogel1, Sean D. Reilly1, Lynne Soderholm2, S. Skanthakumar2, and Mary P Neu1. (1) Actinide Environmental and Coordination Chemistry, Los Alamos National Laboratory, Mail Stop G739, Los Alamos, NM 87545, mneu@lanl.gov, (2) Chemistry Division, Argonne National Laboratory

Abstract Redox-active transition metal mineral phases and surface coatings may affect the environmental behavior of redox sensitive contaminant metals, including actinide species. As a model of interactions with the natural mineral birnessite, δ-MnO1.7, we are studying the redox and sorption of Pu(IV, V, & VI) and U(VI) species by δ-MnO2. For U(VI) we have determined the sorption capacity of 0.21 moles UO2

2+/mole MnO2 at pH 4.3. We will present Langmuir and pH isotherms for UO2

2+ and U(VI) hydroxo species and compare them with U(VI) sorption by goethite, FeOOH. Environmentally, most manganese minerals are formed via microbiological processes. We have used Pseudomonas Putida MnB1, a manganese oxidizer to obtain 'biogenic MnO2' from Mn2+ in solution. The main characteristics of this material, particle size, surface area, crystallinity, and metal ion sorption capacity, are different from chemically prepared MnO2.

NUCL 99 [516468]: Influence of pH and oxidation state on plutonium transport through a low-carbonate coastal-plain soil Steven M. Serkiz1, Barclay Gibbs2, Robert A. Fjeld2, John T Coates3, and Daniel I. Kaplan4. (1) Waste Processing and Environmental Development, Westinghouse Savannah River Technology Center, Building 773A, Aiken, SC 29808, Fax: 803-725-4704, steven.serkiz@srs.gov, (2) Department of Environmental Engineering and Science, Clemson University, (3) Environmental Engineering and Science, Clemson University, (4) Westinghouse Savannah River Company

Abstract Laboratory-scale studies were conducted on a coastal plain soil from the U. S. Department of Energy's Savannah River Site (SRS) to evaluate the influence of solution pH, redox state, and speciation on the transport of plutonium (Pu). Data from this study show the formation of a more strongly sorbing Pu specie(s) with time and it is postulated that the formation of Pu(IV) by reduction of Pu(V) is the mechanism for the formation of this specie(s). Batch sorption kinetics, run for about three days, showed continual removal of Pu from solution. Breakthrough curves from column tests were characterized by a well defined peak in which the mean retardation factor, R, and a fractional breakthrough that varied systematically with pH. The mean breakthrough fractions and R values of the major Pu peak at pH 3, 5, and 8 were 0.90 at R=1.4, 0.75 at R=8.4, and 0.38 at R=35, respectively. After the passage of the major peak, analysis of the soil confirmed Pu distributions indicative of a wide range of mobilities. Filtration (<0.02mm) analyses showed that the multiple Pu peaks in the breakthrough curves were not attributable to the presence of colloidal phases. Oxidation-state analyses showed the Pu in the major effluent peaks to be Pu(V) for the pH 3 and 5 tests. It is likely that the first effluent peak is the Pu(V)O2+ cation undergoing exchange reactions with the soil surface. Due to detection limit constraints, no oxidation state analyses are available on the pH 8 test as well as the less mobile, low-activity effluent peaks that followed the major peak.

NUCL 100 [515929]: Kinetics of metal-humate interactions Dominic M Jones, Centre for Radiochemistry Research, Manchester University, Department of Chemistry, Oxford Road, Manchester, United Kingdom, Fax: +44-161-275-4598, dominic.m.jones@stud.man.ac.uk, Nick D Bryan, Centre for Radiochemistry Research, University of Manchester, and Malcolm N Jones, School of Biological Sciences, University of Manchester

Abstract Investigations have shown that the migration behaviour of metals cannot be described by a thermodynamic equilibrium approach, but kinetically governed processes need to be included. The aim of this work is to investigate the dissociation kinetics of metals with humic acids. A cation exchange resin was used to scavenge dissociated ions of Eu(III)

complexed with humic acid as a function of pre-equilibration time, metal concentration, ionic strength and humic concentration. Batch experiments, using radioactive tracer quantities of 152Eu were performed. Gamma spectrometry was used to measure the amount of metal dissociated from humic over a period of time. Rates of reaction have been calculated. Zeta potentials have been used to study the changes that occur in a humic colloid under different conditions, for example as functions of pH and ionic strength. They can provide useful structural information on the behaviour of humic substances upon metal ion binding.

NUCL 101 [516103]: Evaluation of a conceptual model for the subsurface transport of plutonium involving surface mediated reduction of Pu(V) to Pu(IV) Robert A Fjeld1, Steve M. Serkiz2, Philip L. McGinnnis1, Alper Elci1, and Daniel I. Kaplan2. (1) Department of Environmental Engineering and Science, Clemson University, 342 Computer Court, Clemson Research Park, Anderson, SC 29625, Fax: 864-656-0672, fjeld@clemson.edu, (2) SRTC, Westinghouse Savannah River Company

Abstract A conceptual model is proposed to explain the transport behavior of plutonium in laboratory columns packed with a sandy coastal soil from the U. S Department of Energy's Savannah River Site. In the experiments, a finite step input of plutonium, predominately in the +5 oxidation state, was introduced into the columns and eluted with a low-carbonate solution of 0.02 M NaClO4 at pH 3, 5, and 8. Total plutonium concentrations were measured in the effluent as a function of time. The elution profiles suggest at least two distinct physical/chemical forms of plutonium, each with a different mobility. To explain the observed behavior, a conceptual model is proposed here which includes [1] equilibrium partitioning (both sorption and desorption) of plutonium (V) and plutonium (IV) between the aqueous and sorbed phases with pH-dependent, oxidation-state specific distribution coefficients and [2] kinetic reduction of plutonium (V) to plutonium (IV) in the sorbed phase. The conceptual model was applied to the column experiments through a one-dimensional advective/dispersive mathematical model, and predictions of the mathematical model were compared with the experimental data. The model provided excellent qualitative predictions of the major features observed in the experiments. It also yielded quantitative estimates of the rate constant for surface mediated reduction of plutonium (V) to plutonium (IV) that were of the same order as those calculated from batch data both for this soil and for goethite.

NUCL 102 [516149]: Influence of redox on soil sorption of metals and radionuclides Daniel I Kaplan, Westinghouse Savannah River Company, 773-43A/215, Aiken, SC

29808, Fax: 803-725-4704, daniel.kaplan@srs.gov, Steven M. Serkiz, Savannah River Development Center, Westinghouse Savannah River Company, Scott McWhorter, SRTC, Westinghouse Savannah River Company, and Kimberly R. Powell, Savannah River Technology Center, Westinghouse Savannah River Company

Abstract Monitored National Attenuation (MNA) is a tool used in environmental remediation that accounts for the ability of natural processes to attenuate or destroy contaminants. Before invoking MNA for a particular contaminant at a particular site, it is necessary to identify and quantify the geochemical processes involved in the attenuation. Lowering redox, especially as it relates to wetlands, has been proposed as an important attenuating process. The objective of this study was to determine the changes in the partitioning of contaminants between the solid and aqueous phases as the redox status of contaminated soils was gradually decreased. Soils from the Savannah River Site contaminated with metals and radionuclides were combined with groundwater and placed in gas and temperature controlled reaction vessels. During the study, pH, Eh, nitrate, ammonium, and conductivity were monitored using in-line microelectrodes placed in a continuously flowing loop through the reaction vessel. Additionally, cation and anion concentrations were monitored from time-discrete samples. Selective extractions were also conducted before and after reduction to characterize the mineral phases that the contaminants were associated with. The ability of these soils to retain contaminants decreased during the early stages of reduction (through to the Fe(III)/Fe(II) couple), likely the result of the dissolution of Mn/Fe/Al-oxyhydroxide coatings. A mechanistic rational for the observed results based on the experimentally measured parameters will be presented.

NUCL 103 [516608]: Greg Choppin’s involvement with the Summer School in Nuclear and Radiochemistry W. Frank Kinard, Department of Chemistry and Biochemistry, College of Charleston, 58 Coming Street Room 310, Charleston, SC 29424, Fax: 843-953-1404, kinardf@cofc.edu, and Patricia A. Baisden, Chemistry and Materials Science Directorate L-090, Lawrence Livermore National Laboratory

Abstract Greg Choppin was a member of the 1977 Committee on Training Nuclear and Radiochemists of the Division of Nuclear Chemistry and Technology that determined that a shortage in scientists trained in nuclear and radiochemical techniques was going to be a national problem in the following decades. As a result of this work, one of Greg’s Ph.D. students, Dr. “Trish” Baisden of LLNL obtained funding to start the nuclear summer school program at San José State University in 1984. In 1989, a second site was added at BNL. Since the founding of the Summer School, Greg has been a great supporter of the program and has presented lectures and interacted with students at the SJSU site. In addition, several of the students in the program have gone on to graduate studies with Greg and have continued their involvement with the program. We will

present information about the history of Greg Choppin’s interaction and support for the summer school program.

NUCL 104 [517031]: Stability and redox behavior of 1:1 and 1:2 Pu(IV)-EDTA and mixed Pu-EDTA-L (L = carbonate or citrate) complexes Hakim Boukhalfa, Structural Inorganic Chemistry, Los Alamos National Laboratory & Duke University, Mail Stop J 514, Los Alamos, NM 87545, Fax: 505 667 9905, hakim@lanl.gov, and Mary P. Neu, Chemistry Division, C-SIC, Los Alamos National Laboratory

Abstract The complexation of plutonium(IV) by ethylenediaminetetra-acetic acid (EDTA) was investigated using cyclic voltammetry (CV), square wave voltammetry (SWV) and potentiometric titration methods. In acidic media and in a 1:1 Pu(IV):EDTA ratio, a Pu- EDTA complex is formed (Logbeta110=26.47), while at higher pHs' Pu-EDTA(OH) (Logbeta11-1=21.81) and Pu(EDTA(OH)2 (Logbeta11-2=14.58) complexes are formed. The speciation of Pu-EDTA complexes in excess EDTA and the formation of ternary complexes Pu(EDTA)L (L=carbonate or citrate) will also be presented. The redox behavior of the Pu-EDTA-L complexes at varying pH was investigated and these results will be discussed.

NUCL 105 [514377]: Thermodynamic model for the solubility of ThO2 (am)in the aqueous Na+ - H+ - OH- - NO3

- - H2O - EDTA and Na+ - H+ - OH- - NO3

- - H2O - citrate systems Yuanxian Xia1, Andrew R. Felmy2, and Nancy J. Hess1. (1) Actinide and Trace Metal Geochemistry Group, Pacific Northwest National Laboratory, P.O. Box 999, Mail Stop P7-50, Richland, WA 99352, Fax: (509)372-1632, Yuanxian.xia@pnl.gov, (2) MS K8-96, Battelle Pacific Northwest Laboratory

Abstract The solubility of ThO2(am) in the aqueous Na+ - H+ - OH- - NO3

- - H2O - EDTA /citrate as a function of pcH (=- log [H+]) in variable NaNO3 (0.5 M to 6.0 M) at a fixed concentration of EDTA/citrate has been determined. The experimental observations can be summarized as follows: 1) in the EDTA system between pcH values 4.2 to 8.2, a stoichiometric 1:1 Th-EDTA complex forms that completely saturates the added chelate concentration, Th concentrations then decrease linearly with increasing pcH at pcH > 9.0; 2) the Th concentrations in high concentrations of NaNO3 (3.0 to 6.0 M) decrease by approximately an order of magnitude compared with in 0.5 M NaNO3 at pcH > 8.2; 3) in citrate system, a stoichiometric 1:3 Th-citrate complex forms between pcH values of 5.0 to 7.5, Th concentrations then decrease linearly with an increase in pcH at pcH > 7.5; 4)

EDTA and citrate can form strong complexes with Th(IV) that extremely enhance the solubility of ThO2(am) by 3-5 orders of magnitude compared with those obtained from in the absence of EDTA or citrate. The impact of EDTA via complexing on the solubility of ThO2(am) is stronger than citrate. The ion-interaction model of Pitzer was used to interpret these solubility data. Thermodynamic analysis indicates the entire speciation is dominated by the dimer Th2(OH)2(EDTA)2

2- in the EDTA system, while in the citrate system the dominant species is Th(Cit)3

5- complex. X-ray absorption near-edge spectroscopy was employed to determine the aqueous Th(IV) species.

NUCL 106 [515038]: Use of Th, U, Np, and Am as oxidation state analogs for Pu in the WIPP actinide chemistry program Nathalie A. Wall, Laurence H. Brush, and Donald E. Wall, Sandia National Laboratories, 4100 National Parks Highway, Carlsbad, NM 88220, Fax: 505-234-0061, nawall@sandia.gov

Abstract The Waste Isolation Pilot Plant, in southeastern New Mexico, is the first deep geological disposal facility for transuranic waste. Performance assessment calculations show that, in the absence of human intrusion, migration of radionuclides through the Salado Formation or through the shaft seal system will not occur. Repository performance models must assume that exploratory drilling intrusions will occur and may release radioactive materials to the surface and subsurface environments. Knowledge of Pu chemistry is important to model repository behavior in response to intrusion scenarios, but factors influencing Pu solubility (e.g. organic ligand complexation) are difficult to measure due to redox lability of Pu. Am(III), Th(IV), Np(V) and U(VI) were used as analogs for Pu(III), Pu(IV), Pu(V) and Pu(VI) in complexation studies with acetate, citrate, oxalate and EDTA. WIPP reviewers have questioned the validity of the analogy. The utility of the oxidation state analogy in high ionic strength solutions is discussed.

NUCL 107 [514136]: Effect of actinide complexation by organic ligands on WIPP performance assessment Donald E. Wall, Sandia National Laboratories, 4100 National Parks Highway, Carlsbad, NM 88220, dwall@sandia.gov

Abstract

The Waste Isolation Pilot Plant (WIPP) is located 42 kilometers east of Carlsbad, New Mexico, at a subsurface depth of 655 meters. A probabilistic approach is used to evaluate alternative isolation scenarios and the uncertainty in physical processes to construct a Complementary Cumulative Distribution Function for radionuclide releases.

The most likely scenario for release of radioactivity to the environment is human intrusion, with brine released from the repository acting as a transport medium. Solubilities calculated with the FMT computer code for An(III), An(IV), An(V) are: 1.2 x 10-7 M, 1.3 x 10-8 M, 2.4 x 10-7 M , respectively, in Salado brine, and 1.4 x 10-8 M, 4.1 x 10-8 M, and 4.8 x 10-7 M, respectively, in Castile brine. The role of acetate, citrate, oxalate, and EDTA on actinide solubilization at high ionic strength, high pH, reducing Eh, and the effect on performance assessment is described.

NUCL 108 [519159]: Stability of Pu(VI) in saturated salt brines and ramification for radioactive waste isolation Wolfgang Runde, Craig E. Van Pelt, Mary P. Neu, and Sean D. Reilly, Chemistry Division, Los Alamos National Laboratory, Mail Stop J514, Los Alamos, NM 87545, Fax: 505-665-4955, runde@lanl.gov

Abstract Formation of hexavalent plutonium is of major concern to the safety assessment of nuclear waste repositories in geological salt formations due to its increased solubility in chloride solutions. We studied the stability of Pu(VI) in complex chloride brines relevant to the WIPP site and compared the results with data reported for concentrated NaCl solutions. The simulated brines used were highly concentrated in NaCl or MgCl2 and sulfate enabling us to study the effect of magnesium on the stability and redox behavior of Pu(VI). Small amounts of hypochlorite and hydrogen peroxide were added to study potential radiolytic conditions and waste degradation effects. The speciation and stability of Pu(VI) in complex brines appeared to be different from that in 5 M NaCl suggesting a matrix effect in complex brines. The long-term stability of Pu(VI) and the applicability of data obtained in pure chloride solutions to model the redox stability of Pu(VI) in complex brines are discussed.

NUCL 109 [516714]: Thermodynamic modeling of cobalt(II), nickel(II) and gadolinium(III) complexation with EDTA at high ionic strength Stefan Lis1, Johan Byegard2, Marian Borkowski3, Robert C. Moore4, and Gregory R. Choppin2. (1) Department of Chemistry, Adam Mickiewicz University, Poznan, Poland, blis@amu.edu.pl, (2) FSU, (3) ANL, (4) S.N.L

Abstract The complexation constants for Co2+ and Ni2+ with EDTA in NaCl media were determined and interpreted using the thermodynamic formalism of Pitzer. The Gd3+ was involved due to its optical properties as a competitor for cobalt and nickel. The slow kinetics of the nickel exchange from EDTA complex was observed. The gadolinium data, however, its charge density is slightly higher can serve as approximation for americium

behavior. A good fit of experimental values was obtained using β(0) and β(1) binary interaction parameters. The Pitzer ion interaction parameters obtained in present work for the WIPP actinide solubility database will be used for thermodynamic evaluation of speciation and solubility calculation in the high ionic strength solutions present in WIPP. This work is supported by the United States Department of Energy under Contract DE-AC04-94AL85000 (Sandia) and under contract AT-8740 (Florida State University).

NUCL 110 [516677]: Synthesis and Characterization of Ruthenium Complexes Containing Alkyl-Substituted β-Diketonate Ligands with Pendant Thiol Groups Aaron R. Northrop, and Kenneth A. Goldsby, Department of Chemistry, The Florida State University, Tallahassee, FL 32306-4390, Fax: 850-644-8281, anorthrp@chem.fsu.edu

Abstract

The recent focus of our research had been the preparation of self-assembled monolayers containing redox-active ruthenium complexes via the thiol-on-gold route. Current work is aimed atype shown in the figure, based on substituted 2,6-bis(N-pyrazolyl)pyridine and β-diketonate ligands. Early studies used substitution of a ligand with a long-chain alkyl thiol at the chloride site to achieve self-assembly on gold surfaces. By moving thethiol group to the β-diketonate, these complexes liberate that site, which could then be used to coordinate ligands providing pH-dependent redox properties and/or potential bridging ligands. In synthesizing such complexes, various advantages and disadvantagcan be associated with coordination of the β-diketonate ligands at different stages in theligand preparation. Synthesis and characterization of the substituted β-diketonate ligands and the subsequent metal complexes will be presented within the context of the differensynthetic strategies and our long-term goals for these complexes.

t target complexes of the

alkyl

es

t

UCL 111 [504557]: Radioisotopes in the biophysical chemistry sity of

Abstract An experiment using radioisotopes is being designed for the biophysical chemistry

Nlaboratory: Kinetics of metal ion exchange in carbonic anhydraseKathryn R. Williams, and Bhavin Adhyaru, Department of Chemistry, UniverFlorida, PO Box 117200, Gainesville, FL 32611-7200, Fax: 352-392-8758, krw@chem.ufl.edu

laboratory, carbonic anhydrase contains zinc(II) as the cofactor. The zinc can be removed and replaced by Mn(II), which dissociates with a half-life of about 10 minutes. Students study the kinetics of dissociation by measuring the uptake of Zn-65 as a function of

which is required of chemistry majors in the biochemistry track. Active

will time.

UCL 112 [516369]: Iminophosphorane complexes of uranium ark Sarsfield1, Francis R Livens1, and Robin J Taylor2. (1) Centre for Radiochemistry

rd Road,

Iminophosphoranes, [N=PR3]-, are closely related to the O=PR3 ligands commonly used ction, and purification, of actinide ions. Despite also being reported to be

o een

NMResearch, The Department of Chemistry, The University of Manchester, OxfoManchester M13 9PL, United Kingdom, Fax: 44 161 275 4598, Mark.J.Sarsfield@man.ac.uk, (2) Research and Technology, BNFL

Abstract

for the extragood π-donor ligands, there have been few reports of uranium iminophosphorano complexes. We report the non-aqueous synthesis of a range of uranyl iminophosphorancomplexes of the general formula [UO2(R3PO)2(R'3PN)2]. These complexes have bcharacterised using a range of techniques, including IR, Raman, UV/vis and multinuclear NMR spectroscopies and by single crystal x-ray diffraction. Structural studies highlightbonding comparisons between P=N and P=O ligands and emphasis is placed on how the uranyl oxygens are affected by the presence of π-donors.

UCL 113 [516280]: Spectroscopic, electrochemical and crystallographic haracterisation of U(VI) and U(V) carbamate complexes

ity of Manchester,

In aqueous solution U(V) readily disproportionates, but can be stabilised in the presence rbonate. Tricarbonato dioxouranate (V), [UO2(CO3)3]5- has been

e U(V) in

R,

NcMark Ogden, Ben Atkins, Iain May, Francis R Livens, and David Collison, Centre for Radiochemistry Research, The Department of Chemistry, The UniversOxford Road, Manchester M13 9PL, United Kingdom, Fax: 44 161 275 4598, mbdxjmdo@mail1.mcc.ac.uk

Abstract

of excess cacharacterised in solution by a range of spectroscopic and electrochemical methods. We have recently discovered that the carbamate anion, H2NCO2

-, can also stabilisaqueous solution, forming tricarbamato dioxouranate (V), [UO2(H2NCO2)3]-. We report the crystal structure of the U(VI) carbamate complex, [UO2(H2NCO2)3]NH4, the electrochemical generation of U(V) in the presence of excess carbamate and the solutionphase characterisation of U(VI) and U(V) carbamate complexes by XAS, 13C NMUV/vis/nIR and Raman spectroscopies.

NUCL 114 [516936]: Synthesis and structural studies of plutonium omplexes containing nitrogen and phosphineoxide donor ligands lejandro E. Enriquez, and Mary P. Neu, Chemistry Division, C-SIC, Los Alamos

ic nitrogen donor ligands. Plutonium compounds containing the bifunctional ligand 2,6-

lphosphino)-methyl]benzene P,P′-dioxide (POPO), a potentially useful

e

cANational Laboratory, Mail Stop J514, Los Alamos, NM 87544, Fax: 505-667-9905

Abstract We present the synthesis of plutonium coordination compounds of polydentate organ

bis[(diphenyextractant for lanthanide/actinide separations, were also prepared. The structural characteristics of mixed nitrate, phosphineoxide Pu complexes will be discussed and thfirst plutonium alkoxide complex, Pu(POPO)(NO3)3(OMe), is reported.

NUCL 115 [515425]: Complexation of Pu(III), Am(III) and Cm(III) with

cetohydroxamic acid ergei I. Sinkov, Radiochemical Processing Laboratory, Pacific Northwest National

d Gregory R. Choppin, Chemistry Department, Florida State

amic acid is being tested extensively over the last years as hydrophilic complex forming agent and reductant for more efficient separations of tetra-, penta- and

ctinides in the advanced PUREX and UREX processes. The design of

tion f-block

onstants

dividual

aSLaboratory, 902 Battelle Blvd., Richland, WA 99352, Fax: 509-372-2156, serguei.sinkov@pnl.gov, anUniversity

Abstract Acetohydrox

hexavalent areprocessing flowsheets of increasing complexity requires knowledge of not only distribution coefficients but more and more involves consideration of speciation processes in the aqueous phase including trivalent actinides. Essentially no informacan be found in the literature concerning complexation chemistry of the trivalent 5metal cations with acetohydroxamic acid, and only one paper reports formation cof some randomly selected trivalent lanthanides with this ligand obtained by potentiometric titration. This presentation will demonstrate the advantage of optical absorbance spectroscopy as the only technique capable of reliable assessment of stability constants for redox sensitive metal cations (Pu(III)).The spectral features of inAn(III)AHAn complexes (n=1-4) resolved by the nonlinear spectra fitting routine SQUAD will be presented. The stability constants obtained for the three consecutive An(III) will be compared with the corresponding values for isoelectronic and ionic radiianalogs from the Ln(III) series.

UCL 116 [519145]: New advances in americium coordination chemistry

Abstract istry differs significantly from that of its actinide neighbours plutonium

m(V)

ined the

ate

NWolfgang Runde, S. D. Conradson, and Mary Neu, Chemistry Division, Los Alamos National Laboratory, Mail Stop J514, Los Alamos, NM 87545, Fax: 505-665-4955, runde@lanl.gov

Americium chemand curium. The stability of higher oxidation states, Am(V) and Am(VI), is significantly reduced compared to Pu(V) and Pu(VI), and americium chemistry is generally determined by the trivalent oxidation state as in Cm(III). In contrast to curium, Aand Am(VI) compounds can be synthesized under strongly oxidizing conditions. However, crystal structures of americium compounds are rare and americium coordination chemistry remains poorly understood. We synthesized a series of compounds with americium in its III, IV, V, and VI oxidation states and determinner coordination environment by using EXAFS spectroscopy. Comparison with analogous U(VI) and Pu(VI) compounds revealed significant differences in ligand association. We will present structural information on Am(III), (V), and (VI) carboncompounds and compare them to the chemical analogues Nd(III) and Cm(III), Np(V), and U(VI) and Pu(VI).

UCL 117 [493058]: A review of the chemistry of berkelium onal

ersity of

Abstract was first produced by alpha-particle bombardment of Am-241. This new

he

has been

nt

m is

.

NDavid E Hobart, Actinide Analytical Chemistry Group, Los Alamos NatiLaboratory, Mail Stop G740, Los Alamos, NM 87545, Fax: 505-665-4737, dhobart@lanl.gov, and Joseph R. Peterson, Department of Chemistry, UnivTennessee, Knoxville, TN 37996, Fax: 865-974-3454, joepete@utk.edu

Element 97 element was named "berkelium" after the city of its discovery in a parallel manner to tnaming of its lanthanide analog, terbium. In the 52 years since the discovery of berkelium, a great deal of knowledge concerning its physicochemical properties acquired. However, because of its relative scarcity and the short half-life of its most available isotope, Bk-249, less is known about berkelium than about its more abundaand longer lived neighbors. Oxidation states of 0, III, and IV are known and studies seeking the elusive II and V states continue. Knowledge of the properties of berkeliuimportant because it is the first member of the second half of the actinide series. Such information should facilitate more accurate extrapolations to the predicted behavior of heavier actinides and transactinides for which experimental studies are severely limitedThis review will emphasize solution and solid state properties. Areas where data are lacking will be noted. Berkelium research results not already in this review will be

requested so that they may be included in the Third Edition of "The Chemistry of the Actinide and Transactinide Elements" to be published by Kluwer Press.

NUCL 118 [512324]: Spectroscopic investigations of the electronic structure of neptunyl ions Mariane P. Wilkerson1, James E. Barefield1, John M. Berg2, Harry J. Dewey1, and Todd A. Hopkins2. (1) Chemistry Division, Los Alamos National Laboratory, MS J565, Los Alamos, NM 87545, Fax: 505-665-4631, mpw@lanl.gov, (2) Nuclear Materials and Technology Division, Los Alamos National Laboratory

Abstract Recent absorption spectroscopic and theoretical investigations of the electronic structure of neptunyl (Np(VI)O2

2+) have reported that f→f transitions lie at relatively low energies (~450-8500 cm-1). With technical improvements in near infrared detectors, we have begun searching for NpO2

2+ f→f luminescence. Dilution of NpO22+ into host matrices has

afforded us the opportunity to study these excited states in the absence of self-quenching. In this paper, a discussion of the vibronic structure of NpO2Cl4

2- in a variety of matrix materials will be presented.

NUCL 119 [514345]: A fluorescence study of uranyl sorption and speciation at clay mineral surface Zheming Wang1, Calvin C. Ainsworth2, Ken Wagnon2, and Alan G Joly1. (1) Environmental Molecular Science Laboratory, Pacific Northwest National Laboratory, 3335 Q Ave., Mail Stop K8-96, Richland, WA 99352, Fax: 509-376-3650, zheming.wang@pnl.gov, (2) Interfacial Geochemistry Group, Pacific Northwest National Laboratory

Abstract Spilling and leakage of large volumes of high-level nuclear wastes stored in tanks at DOE sites caused contamination of the soils and sediments surrounding the tank farms and it is suspected that some of the radionuclides may have reached the level of groundwater. Key to any effective remediation process is the understanding of radionuclide speciation in the soil environment, which ultimately controls the strength of interaction and the rate of migration of the radionuclides. In this project the sorption and speciation of uranyl ion on several well-characterized clay minerals, including montmorillonite, beidellite, illite and vermiculite were studied by luminescence spectroscopy and luminescence lifetime measurements at both ambient and liquid helium temperatures. Analysis of the results clearly indicated the presence of three or more uyanyl bonding environments.

NUCL 120 [515818]: Hydrolysis of uranium(VI) at high temperatures and pressures by time-resolved laser-induced fluorescence spectroscopy Takaumi Kimura, Ryuji Nagaishi, Takuo Ozaki, and Yoshihiro Kitatsuji, Advanced Science Research Center, Japan Atomic Energy Research Institute, Tokai-mura, Ibaraki 319-1195, Japan, Fax: 81-29-282-5935, kimura@analchem.tokai.jaeri.go.jp

Abstract A few experimental studies on uranium(VI) hydrolysis at high temperatures and pressures performed to date are obviously quite insufficient to depict a comprehensive picture of the species and the behavior in a wide variety of hydrothermal conditions. In this study, an optical cell system for spectroscopic speciation of metal ions in hydrothermal solutions was developed and combined with time-resolved laser-induced fluorescence spectroscopy for uranium(VI) speciation. Emission spectra and lifetimes of uranium(VI) in 0.5 M NaClO4 were measured as a function of pH, uranium concentration, temperature, or pressure. The results were compared with speciation calculations at various conditions on the basis of thermodynamic models and data. The emission intensities and lifetimes of uranium(VI) decreased with increasing temperature and pressure. The temperature dependence of the lifetimes obeyed well the Arrhenius law, and the activation energy was characterized for uranyl(VI) ion and some hydroxo complexes.

NUCL 121 [515893]: Measuring uranium-236 in the environment by accelerator mass spectrometry Olivia J Marsden1, Francis R Livens1, J Philip Day2, L Keith Fifield3, and Phillip S Goodall4. (1) Centre for Radiochemistry Research, University of Manchester, Department of Chemistry, University of Manchester, Manchester M13 9PL, England, Fax: +44 161 275 4598, mbdxiojm@stud.man.ac.uk, francis.livens@man.ac.uk, (2) Department of Chemistry, University of Manchester, (3) Department of Nuclear Physics, Australian National University, (4) Research and Technology, BNFL

Abstract The nuclear fuel reprocessing plant at Sellafield in northwest England has been discharging low level liquid radioactive effluents to the Irish Sea under authorisation since the early 1950s. These discharges have included a range of artificial actinide isotopes, and the Irish Sea basin provides an opportunity to study their environmental behaviour. The record of discharges of U-234, 235 and 238 are largely masked by natural uranium whereas U-236 originates solely from the Sellafield discharges. However, U-236

is difficult to measure since it has a low specific activity and is present in only very low concentrations. Here, we have used radiochemical separation and accelerator mass spectrometry to measure U-236 in intertidal sediments. The distribution of U-236 in the sediment profile can be interpreted in terms of the likely historical discharges from Sellafield and suggests that uranium is not remobilised significantly.

NUCL 122 [514667]: Safeguarding nuclear materials: Analysis of Np-237 in spent fuel solutions Alfred Morgenstern, Christos Apostolidis, Herbert Ottmar, and Klaus Mayer, European Commission, Joint Research Centre, Institute for Transuranium Elements, P.O. Box 2340, 76125 Karlsruhe, Germany, Fax: 0049-7247-95199618, morgenstern@itu.fzk.de

Abstract The IAEA Board of Governors has recently recognized the proliferation risk associated with Np-237 and Am-241 and has consequently taken some actions towards a possible control of these alternative nuclear materials (ANM). Presently, efforts are mainly being focused on neptunium since the proliferation risk associated with americium is somewhat lower. For the monitoring of neptunium in spent fuel reprocessing the input solution and the high level liquid waste (HLLW) stream are key measurement points. Already existing safeguards instrumentation, namely X-ray Fluorescence (XRF), affords the quantification of neptunium in the HLLW stream but does not allow direct measurement of neptunium in input solutions. In this study two robust and straightforward methods for the analysis of neptunium in spent fuel solutions will be reported. Based on the use of commercially available UTEVA resin, a rapid, single column extraction chromatographic method that affords the analysis of U, Np, Pu and Am in spent fuel solutions has been developed and implemented on a fully automated robot system. A second, independent method based on the selective extraction of Np and Pu from input solutions using TEVA resin followed by high resolution gamma spectrometric analysis has been developed on synthetic sample solutions and successfully validated on real spent fuel.

NUCL 123 [515905]: Parallel addressing of luminescent lanthanides Stephen Faulkner1, Benjamin P Burton-Pye1, Andrew Beeby2, Simon FitzGerald2, Michael D Ward3, and Phillip S Goodall4. (1) Centre for Radiochemistry Research, Department of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom, Fax: +441612754616, stephen.faulkner@man.ac.uk, mbdxkbpb@stud.man.ac.uk, (2) Department of Chemistry, University of Durham, (3) Department of Chemistry, University of Bristol, (4) Research and Technology, BNFL

Abstract Lanthanide luminescence has been of considerable interest for a number of years,

particularly as a result of the suitability of lanthanide complexes for time resolved imaging and assay. Lanthanide centred emission bands are sharp and have tuneable lifetimes, raising the prospect of addressing several complexes at once. Such an approach is potentially useful in the identification of mixtures in combinatorial synthesis and in parallel analysis of mixtures of ions. We have demonstrated the feasibility of parallel processing for mixtures of complexes which are emissive in the visible and near-IR, using time resolved emission spectroscopy (TRES) and lifetime and intensity analysis to separate signals and generate lifetime resolved spectra.

NUCL 124 [515059]: Electrochemical process for the decontamination of plutonium contaminated uranium surface Ivan Laszak, Mark Jensen, Michael McCoy, and Kenneth Nash, Chemistry Division, Argonne National Laboratory, 9700 South Cass Avenue, bldg 200, Argonne, IL 60439, Fax: 630-252-7501, laszak@anl.gov

Abstract The purpose of this study is to determine a process that may be applied on metallic uranium parts to be decontaminated from plutonium, due to their history in various DOE sites, prior to their recycle at Oak Ridge Y-12 plant. A combination of an electrochemical method (chrono-amperometry) with the use of strong complexing agents (tetrahydrofuran-2,3,4,5-tetracarboxylic acid or 1-hydroxyethane-1,1-diphosphonic acid) in sodium sulfate at low pH leads to very good results: more than 99.5% of the plutonium is removed within two minutes, with an associated loose contamination below the acceptance level required at the Oak Ridge Y-12 plant. Further experiments are currently underway to determine optimal electro-chemical conditions for this process to be highly selective toward plutonium, without dissolving significant amounts of uranium. This work was supported by the United States Department of Energy, Nuclear Materials Focus Area, under contract number W-31-109-ENG-38.

NUCL 125 [516213]: Study of aggregation in the Th(IV)-HNO3/TBP-n-octane extraction system Marian Borkowski, and Renato Chiarizia, Chemistry Division, Argonne National Laboratory, 9700 S. Cass Ave., Argonne, IL 60439, Fax: 630-252-7501, borkowski@anchim.chm.anl.gov

Abstract Little information exists on the morphology of organic phases species immediately before third phase formation. This work reports results from systematic studies of the species formed in 20% TBP in n-octane during Th(IV) and HNO3 extraction. Small-angle

neutron scattering (SANS) measurements on n-octane solutions of TBP indicated modest aggregation of the organic species after HNO3 extraction. Larger aggregates were observed for increasing Th(IV) concentrations in the absence of nitric acid. The largest aggregates were found in the presence of both Th(IV) and HNO3 in the organic phase. These aggregates have an ellipsoidal shape with short and long axes up to 29 Å and 282 Å, respectively. After phase splitting, the light organic phase retains the properties of the original organic phase but the heavy organic phase has a different nature. Work supported by the Office of Basic Energy Science, U.S. Department of Energy, under contract number W-31-109-ENG-38.

NUCL 126 [515472]: Complexation of actinide cations in TBP-nitric acid-water-alkane third phases Mark P. Jensen, Renato Chiarizia, John R. Ferraro, Marian Borkowski, and Kenneth L. Nash, Chemistry Division, Argonne National Laboratory, 9700 S. Cass Ave., Argonne, IL 60439, mjensen@anl.gov

Abstract The formation of third phases in actinide nitrate/nitric acid/water/0.73 M tributylphosphate (20 vol%)/n-alkane systems were studied by distribution measurements, visible and infrared absorption spectroscopy, EXAFS, and scattering techniques to quantify the role of aggregation phenomena in the formation of third phases. The results show that the degree of aggregation changes little with progressive metal loading of the organic phase and that the composition of the actinide inner coordination sphere is invariant before the formation of the third phase. However, the number of nitrate oxygen atoms in the actinide inner coordination sphere undergoes a small but abrupt change upon third phase formation, suggesting that third phase formation is driven more by the solvent system than by the nature of the extracted complexes. This work was supported by the United States Department of Energy, Office of Basic Energy Sciences, under contract number W-31-109-ENG-38.

NUCL 127 [515496]: Contribution of solvent reorganization to the energy of complexation reactions Mark P. Jensen, Chemistry Division, Argonne National Laboratory, 9700 S. Cass Ave., Argonne, IL 60439, mjensen@anl.gov

Abstract This work attempts to measure the fraction of the reaction energy that arises from intrinsic interactions between metal cations and ligands, and how much arises from the rearrangement of solvent molecules when the complex is formed. Isotopic substitution of the solvent has been employed to quantitatively fractionate the enthalpies, entropies, and

free energies of complexation into solvent based and complexation based contributions for the 2,6-pyridinedicarboxylate complexes of a several metal ions. In the case of a transition metal cation like Cu(II) that is prone to form bonds with more covalent character, the contribution of solvation to the enthalpy of complex formation is negligibly small. The energy of metal-ligand bond formation dominates. By contrast, a significant fraction of the complexation enthalpy of 2,6-pyridinedicarboxylic acid comes from solvent rearrangement when complexes with harder cations like Ca(II) or Nd(III) are formed. This work was supported by the United States Department of Energy, Office of Basic Energy Sciences, under contract number W-31-109-ENG-38.

NUCL 128 [515377]: Extraction of trivalent lanthanides and actinides by CMPO-functionalized calix[4]arenes Lætitia H. Delmau, Chemical Sciences Division, Oak Ridge National Laboratory, P.O. BOX 2008 MS 6119, Oak Ridge, TN 37831-6119, Fax: 865-574-4939, delmaulh@ornl.gov

Abstract Complexation of trivalent lanthanides and actinides by different ligands (functionalized calixarenes, particularly) bearing acetamidophosphine oxide groups ("CMPO-like" calixarene) has been studied. These calixarenes exhibited a selective extraction of light lanthanides, showing an obvious cation size effect. Calixarene lower and upper rim substituents take part in extraction and selectivity. Studies involving the improvement of experimental conditions have also been performed. It is possible to strip trivalent cations extracted by "CMPO-like" calixarenes into a very low concentrated nitric acid solution. Chlorinated or alcohol-type diluents are required. Transport experiments using this slightly acidified stripping solution have exhibited separation properties comparable to those observed by liquid-liquid extraction. Nuclear magnetic resonance is an useful spectroscopic method to get structural parameters of complexes in solution. Paramagnetic lanthanide and actinide cations effects on the different nuclei of "CMPO-like" calixarene molecule have been investigated to calculate correlation times and to prove the concept of cation position determination.

The work presented here represents a summary of the author’s graduate work.

The author wants to acknowledge and express her appreciation for the interactions, help, and support she had during her graduate research from Nicole Simon, Jean-François Dozol, Serge Eymard, and Bernard Tournois from the CEA Cadarache, FRANCE, Marie-José Schwing-Weill and Françoise Arnaud-Neu from ECPM Strasbourg, FRANCE, André Thévand and Robert Faure from the University of Aix-Marseille, FRANCE, Philippe Vottéro from CEA Grenoble, FRANCE, Jean-François Desreux from the University of Liège, BELGIUM, Volker Böhmer, Cordula Grüttner, Christian Musigmann, and Abdi Tunayar from the University of Mainz, GERMANY.

NUCL 129 [512860]: Dissolution of Uranium Dioxide in Supercritical Carbon Dioxide Chien M. Wai, Department of Chemistry, University of Idaho, Moscow, ID 83844, cwai@uidaho.edu, and Youichi Enokida, Research Center for Nuclear Materials Recycle, Nagoya University

Abstract Uranium dioxide can be dissolved directly in supercritical carbon dioxide using a CO2 soluble TBP/HNO3/H2O extractant. The extracted uranium complex UO2(NO3)2(TBP)2 has a high solubility in supercritical carbon dioxide (about 0.4 mol/L at 313 K and 20 MPa). Ultrasound application can significantly enhance the dissolution rate of uranium dioxide powders placed on small glass beads in supercritical CO2. The amount of uranium dioxide dissolved in CO2 for a 20-min dynamic extraction at 323 K and 15 MPa can be increased by an order of magnitude with sonification compared to the experiments without sonifacation. This ultrasound-aided process for direct dissolution of uranium dioxide in supercritical CO2 that requires no aqueous solutions and organic solvents may have important applications for reprocessing of spent nuclear fuels and for treatment of certain nuclear wastes.

NUCL 130 [520343]: Lanthanide complexation with ß-diketones and tributylphosphate in critical fluid carbon dioxide Robert V. Fox1, Harry W. Rollins1, Duane D. Ball1, Dean R. Peterman1, and Chen M. Wai2. (1) Idaho National Engineering and Environmental Laboratory, Idaho Falls, ID 83415, (2) Department of Chemistry, Univeristy of Idaho

Abstract Metal complexation reactions occurring between the mono-dentate organophosphate ligand tri-n-butyl phosphate (TBP) and the lanthanide neodymium (Nd) have been investigated in acetonitrile, hexane, and supercritical fluid carbon dioxide. Metal complexation reactions occurring between the bi-dentate ß-diketone ligand thenoyltrifluoroacetone (TTA) and neodymium have also been studied. The synergistic system comprised of TBP and TTA has also been studied in acetonitrile, hexane, and carbon dioxide. Metal-ligand complex stoichiometry and equilibrium constants were calculated for the Nd-TBP and Nd-TTA-TBP systems in acetonitrile, hexane and carbon dioxide. When neodymium nitrate hexahydrate was used as the starting metal salt, complexation with TBP in carbon dioxide yielded a 1:3 metal to TBP complex stoichiometry. That result is expected and mimics Nd:TBP complexation in hexane. However, when neodymium triflate was used as the starting metal salt, complexation with TBP in carbon dioxide yielded a 1:4 metal to TBP complex stoichiometry. Neodymium complexation with the bi-ligand system comprised of TBP and TTA yielded

a complex stoichiometry of 1:3:6 metal to TTA to TBP. This is an unusual complex; however, it is not known if all of the TBP molecules participate as an inner-sphere complex. Neodymium complexation with the bi-ligand TBP/TTA system in hexane and acetonitrile failed to demonstrate a synergistic reaction; whereas, neodymium complexation with TBP/TTA in carbon dioxide clearly demonstrated synergism.

NUCL 131 [522032]: Spectroscopic investigations of the complexation of lanthanide ions by tri-n-butyl phosphate in aqueous acetonitrile Dean R. Peterman, Robert V. Fox, and Harry W. Rollins, Idaho National Engineering and Environmental Laboratory, P.O. Box 1625, Idaho Falls, ID 83415-5218, Fax: 208-526-5937, petedr2@inel.gov

Abstract The complexation of lanthanide metal ions by tri-n-butyl phosphate (TBP) in aqueous acetonitrile has been investigated by absorption and laser-induced lanthanide luminescence spectroscopies. The results of absorption studies using the neodymium nitrate hexahydrate salt indicate the formation a single complex with TBP in aqueous acetonitrile. The stoichiometry of the limiting complex was determined to be 1:2 (metal to TBP) using standard mole-ratio methods. Laser-induced lanthanide luminescence spectroscopy using the europium nitrate hexahydrate salt was performed to characterize further the nature of the metal-TBP complex. The measured europium luminescence decay rate constants point to the formation of an inner-sphere complex in aqueous acetonitrile. While there is no clear shift in the position of the europium 0-0 excitation maxima, the lineshapes of the 0-0 excitation spectra exhibit a marked dependence on TBP concentration. The deconvolution of the europium 0-0 excitation spectra and the determination of stability constants for the Ln(III)-TBP complexes will be discussed.

NUCL 132 [506339]: Actinides in room temperature ionic liquids; old elements – new solvents Richard P. Swatloski1, Ann E. Visser1, James H. Davis Jr.2, and Robin D. Rogers1. (1) Department of Chemistry and Center for Green Manufacturing, The University of Alabama, Tuscaloosa, AL 35487, Fax: 205-348-9104, tubarick@aol.com, (2) Department of Chemistry, University of South Alabama

Abstract Ionic Liquids (ILs) are solvents composed of organic cations with either organic or inorganic anions, which typical have melting points less than 150ºC. The ability to fine-tune an IL can provide one with an extremely efficient Task Specific IL (TSIL), suitable for a wide range of tasks, including selective separations of metal ions. We have successfully demonstrated this concept by the incorporation of traditional extractant

molecules that function to dehydrate metal ions and increase their affinity for the extracting phase. We have employed a well-known actinide extractant, octyl(phenyl)-N,N-diisobutylcarbamoylmethyl phosphine oxide (CMPO), to produce a TSIL that extract UO2

2+, Pu4+, and Am3+ from aqueous solutions. In this presentation, we will discuss the overlap of the more mature chemistry of the actinides with the fledgling field of ionic liquids.

NUCL 133 [516559]: Extraction of Am(III) and Eu(III) from ionic liquids using traditional extractants Dale D. Ensor, Ginger K. Ensor, and Melissa A. Ensor, Department of Chemistry, Tennessee Technological University, Box 5055, Cookeville, TN 38505, densor@tntech.edu

Abstract Ionic liquids have received considerable attention as replacements for the volatile organic phase in liquid-liquid extraction systems. Little attention has been paid to these compounds as replacements for the high temperature molten salt mixtures. The extraction of Eu(III) and Am(III) dissolved in 1-butyl-3-methylimidazolium chloride has been studied using trioctylphosphine oxide and trioctylamine dissolved in dodecane. A separation factor of 15 for Eu(III)/Am(III)was observed for the TOPO system. Results from these measurements and the feasibility of ionic liquids for the use in lanthanide/actinide separations will be discussed.

NUCL 134 [496488]: Chemical thermodynamics of actinides in solution under non-conventional conditions Linfeng Rao, Glenn T. Seaborg Center, Chemical Sciences Division, Lawrence Berkeley National Laboratory, Mailstop 70A-1150, One Cyclotron Road, Berkeley, CA 94720

Abstract The objective of this study is to improve the understanding of chemical thermodynamics governing the coordination chemistry of actinides in non-conventional solution systems. Currently the focus is on the effect of temperature on actinide coordination with organic ligands and the structure/function relationship for the complexation in non-aqueous and aqueous solvents. Variable-temperature potentiometry and calorimetry, and a variety of spectroscopic techniques are used. Studies of the complexation of Nd(III) and U(VI) with acetate at 25 oC to 70 oC indicate that the complexation is endothermic and entropy driven. As the temperature is increased, the complexation becomes more endothermic, but stronger due to increasingly more positive entropy changes. Results obtained by spectroscopy are consistent with the trends in chemical thermodynamics. The complexation of f-elements with alkyl-substituted diamides is studied by non-aqueous

single-phase titration calorimetry and optical spectroscopy. Results suggest that steric effects and ligand basicity may play important roles in the complexation. Application of microcalorimetry to the study of host-guest encapsulations is also presented.

NUCL 135 [496416]: Complexation of uranyl(VI) with acetate in dimethyl sulfoxide PierLuigi Zanonato1, Plinio Di Bernardo1, Arturo Bismondo2, and Linfeng Rao3. (1) Dipartimento di Chimica Inorganica Metallorganica ed Analitica, University of Padova, via Loredan 4, 35131 Padova, Italy, Fax: 39-049-827-5161, (2) Istituto di Chimica e Tecnologie dei Materiali Avanzatidel C.N.R. of Padova, (3) Glenn T. Seaborg Center, Chemical Sciences Division, Lawrence Berkeley National Laboratory, Mailstop 70A-1150, One Cyclotron Road, Berkeley, CA 94720

Abstract The complexation between Uranyl(VI) and acetate ions has been studied in DMSO at 25 oC in an ionic medium of 0.100 mol dm-3 tetrabutyl ammonium perchlorate. Extensive thermodynamic and spectrophotometric studies have shown that uranyl(VI) ion forms three quite strong successive mononuclear complexes with acetate in DMSO. The thermodynamic parameters of the complexes, obtained by potentiometric and calorimetric experiments, show that, notwithstanding the stronger solvation of uranyl ion in DMSO than in water, the complexes are surprisingly more stable in the former solvent. Another remarkable difference between the DMSO and water systems is that the formation of the complexes in DMSO is also enthalpically stabilized. These features can be ascribed to the remarkable role exerted by the acetate ion in the formation of the complexes. Further insight on the coordination sphere of the complexes has been provided by spectroscopic techniques. The comparison with other systems in DMSO (e.g., silver(I)/acetate and uranyl(VI)/amines) is also discussed.

NUCL 136 [494950]: Acoustic Emission Monitoring of Actinide Separation and Recovery Processes Daniel L. Maierhafer1, James D. Navratil1, Major C. Thompson2, and Michael G. Bronikowski3. (1) Environmental Engineering and Science, Clemson University, 342 Computer Court, Anderson, SC 29625, Fax: 864-656-0672, maierhd@clemson.edu, nav@clemson.edu, (2) Actinide Technology Section, Savannah River Technology Center, (3) Actinide Technology Section, Westinghouse Savannah River Company

Abstract Acoustic emission, first studied in the 1930’s during the formation of martensite steel, has been commonly used for structural testing on aircraft, pressure vessels, and bridges. Since 1981, it has been researched as a tool in analytical chemistry to determine the

progress and kinetics of chemical reactions. This paper describes work on the use of acoustic emission as a breakthrough detection scheme in an ion exchange column (IEC). This project, if successful, will maximize the capacity of the IEC, reduce the volume of hazardous and radioactive waste generated by the elution process, and provide a cost effective method to remotely monitor IEC processes.

Preliminary experiments were performed with a batch experimental setup and the following ion exchange resins: The inorganic crystalline-silica titanate (CST), the inorganic mono-sodium titanate (MST), and the organic Reillex HPQ. Non-radioactive cesium nitrate, and strontium nitrate were used with the inorganic resins, and sodium sulfate, was used with the organic resin. Progress of the batch experiments is presented here.

NUCL 137 [516419]: Radiactive waste processing of polyvinyl alcohol fabric materials Heidi L Eichinger1, John T Coates1, and James Navratil2. (1) Environmental Engineering and Science, Clemson University, 342 Computer Court, Anderson, SC 29631, heichin@clemson.edu, (2) Environmental Engineering and science, Clemson University

Abstract Polyvinyl alcohol (PVA) fabric is being evaluated as a substitute for celluosic materials used in glovebox cleaning operations because it can be dissolved and discarded as liquid waste rather than as solid transuranic waste. A substantial cost saving is projected for the use of PVA cloth for rags, mops, etc. The proposed disposal of PVA materials is by dissolving in hot water and oxidation with hydrogen peroxide under ultra-violet irradiation. The decomposition of PVA produces formic and acetic acids, among other products. The oxidized PVA solution would then be introduced to a caustic waste system via basic evaporation. This paper will describe the proposed process and report on the determination of the fate of the oxidized PVA solution under basic evaporation.

NUCL 138 [510502]: Tailoring nanophases for actinide science and nuclear waste disposal James V. Beitz1, L. Fan2, and P Thiyagarajan2. (1) Chemistry Division, Argonne National Laboratory, 9700 S. Cass Ave., Argonne, IL 60439-4831, (2) Intense Pulsed Neutron Source Division, Argonne National Laboratory

Abstract We are exploiting the ability of an ion exchange material termed Diphosil to strongly sorb actinide ions from aqueous solution and then be the basis for creating both f-element

nanophases that are embedded in vitreous silica for fundamental actinide science studies and a nuclear waste form suitable for geologic disposal. Our past work showed that heating metal ion-loaded Diphosil in air can encapsulate and chemically fix sorbed metal ions in phosphate-rich nanophases that are embedded in vitreous silica. We have carried out small angle neutron scattering studies at the Intense Pulsed Neutron Source on lanthanide and actinide ion-loaded Diphosil that had been heated to a series of temperatures. The insight gained as to pore collapse and nanophase formation in heavy metal ion-loaded Diphosil will be presented. This work was performed under the auspices of the Offices of Science and Nuclear Energy, Science, and Technology of the U. S. Department of Energy under contract number W-31-109-ENG-38.

NUCL 139 [495317]: Parameters influencing the formation of post-filtration solids in a Hanford high-level waste simulant Kimberly A. Cole1, John T. Coates1, James D. Navratil1, Christopher J. Bannochie2, and Charles Nash2. (1) Environmental Engineering and Science, Clemson University, 342 Computer Court, Anderson, SC 29625-6510, kcole@clemson.edu, (2) Savannah River Technology Center, Westinghouse Savannah River Company

Abstract The Hanford River Protection Project team has developed a strontium nitrate/sodium permanganate precipitation treatment process for highly complexed nuclear waste. During the initial precipitation process, strontium and transuranic elements in the filtrate are reduced to levels appropriate for further treatment of the waste with ion exchange. Within days of the precipitation reaction, post-filtration solids begin to appear in the filtrate at levels that could impact the efficiency of the ion exchange resin. Experiments were conducted to evaluate the effect of several parameters on the formation of the post-filtrate solids. Light intensity, reaction temperature, permanganate concentration, and sodium hydroxide concentration have been shown to influence the formation of these solids. Additional parameters being investigated include filter pore size, oxidation potential, strontium concentration, and calcium addition.

NUCL 140 [516641]: Chemical behavior of U(VI), Am(III) and Sr(II) in the washing of HLW sludges Alexander Yu. Garnov1, Linfeng Rao1, and Kenneth L. Nash2. (1) Glenn T. Seaborg Center, Chemical Sciences Division, Lawrence Berkeley National Laboratory, Mailstop 70A-1150, One Cyclotron Road, Berkeley, CA 94720, AYGarnov@lbl.gov, (2) Chemistry Division, Argonne National Laboratory

Abstract To understand the behavior of radionuclides during alkaline pretreatment of tank sludges,

simulants were prepared according to the BiPO4, Redox and PUREX processes and incorporated with U-233, U-238, Am-243 or Sr-90. The simulated sludges were washed with solutions of various compositions - acidic, alkaline, or with chelating agents. Spectroscopic techniques including UV/Vis, fluorescence, NMR and EXAFS provided additional information on the speciation. A combination of selective leaching of uranium in the presence of oxalate and malonate and NMR experiments demonstrated the competition between complexation and hydrolysis. Limited experiments with Co-60 radiation were performed to evaluate the effect of radiolysis on the leaching. Preliminary experiments were conducted to study the oxidative leaching of americium from the sludge, using S2O82- as the oxidant. These data help to predict the behavior of radionuclides in sludge washing and improve the washing strategies.

Work performed under the auspices of the U.S. Department of Energy's Environmental Management Science Program under contract numbers DE-AC03-76SF0098 at Lawrence Berkeley National Laboratory and W-31-109-ENG-38 at Argonne National Laboratory.

NUCL 141 [515465]: Optimization of Pu(IV) separation from U(VI) in concentrated solutions by precipitation with oxalate Sergei I. Sinkov, Calvin H. Delegard, and Andrew J. Schmidt, Radiochemical Processing Laboratory, Pacific Northwest National Laboratory, 902 Battelle Blvd., Richland, WA 99352, Fax: 509-372-2156, serguei.sinkov@pnl.gov

Abstract Prior criticality studies at the Plutonium Finishing Plant have left a significant inventory of Pu-bearing solution containing ~80 g Pu/L and 180 g U/L (natural or depleted enrichment) in 2-3 M HNO3. The planned stabilization of these solutions as PuO2 for long-term storage would be optimized if the low-value U did not accompany the Pu. It is well known that the lanthanide and actinide oxalates in their (III) and (IV) oxidation states are excellent precursors to form the respective oxides. Attractively low Pu(IV) oxalate solubilities (on the order of 10s of mg/L), sufficient to achieve efficient removal from moderately concentrated solutions, can be achieved by careful control of the stoichiometric excess of oxalate ion. In contrast, the U(VI) oxalates have solubilities at least 100-times higher. It was proposed that this difference in solubility could be exploited to separate Pu(IV) from U(VI) using oxalate precipitation. Solution volume constraints and plant process simplicity required addition of oxalate as oxalic acid crystal, batch precipitation at room temperature, and minimum digestion times. Tests were performed to optimize the precipitation process (minimum Pu losses to the filtrate and minimum uranium precipitation) in the range 1.1-3.0 M HNO3, oxalate:Pu ratio in the range 2:1 to 3:1, and digestion time from 30 to 90 minutes. The solution concentrations were monitored by spectrophotometry. The importance of the various parameters in achieving process goals will be described.

NUCL 142 [517064]: Freezing of uranyl nitrate-nitric acid solutions Alena Paulenova1, James D. Navratil1, Michael G. Bronikowski2, and Vladimir Paulen3. (1) Department of Environmental Engineering and Science, Clemson University, Clemson Research Park, 342 Computer Court, Anderson, SC 29625, Fax: 864-656-0672, apaulen@clemson.edu, (2) Westinghouse Savannah River Site, (3) Department of Computer Science, Clemson University

Abstract Spent fuel discharged from nuclear reactors contains fission products, uranium and plutonium. Uranium is removed from the PUREX organic phase by back extraction with dilute nitric acid. The behavior of stored solutions at low concentrations of uranium and low temperature conditions was studied. In the reported experiment, uranyl nitrate solutions in 0.5 M nitric acid in the concentration range of 0-100 g/L of uranium were chosen to study concentration-temperature-freezing time dependence. The density and freezing point depression values of uranyl nitrate solutions were determined. The preconcentration factors for frozen solutions as a function of mass of solution and freezing time at a given ambient temperature were determined. Using standard ISO 12441, the computer program was developed to simulate the cooling and freezing processes of stationary liquids in cylindrical containers and the modeling of concentration-temperature-time dependence.

NUCL 143 [516877]: Hydrothermal synthesis of novel uranyl iodates: A comparison of cation effects and structural dimensionality Amanda C Bean1, Thomas E Albrecht-Schmitt2, and Wolfgang H Runde1. (1) C-INC, Los Alamos National Laboratory, Los Alamos, NM 87544, Fax: 505-665-4955, bean@lanl.gov, (2) Department of Chemistry, Auburn University

Abstract Transition and 4f-metal iodates have been of interest in search for compounds with enhanced magnetic and nonlinear optical properties. The anionic iodate ligand can display many different binding modes and can crystallize in non-centrosymmetric space groups. Our research on the hydrothermal synthesis of 5f-element iodates led to a large number of novel U(VI) iodate compounds with different coordination environments and framework dimensionalities. The reaction of UO3 with I2O5 in the presence of a series of metal cations have resulted in the isolation of six new coordination compounds of which three contain new structural motives (*): monoclinic UO2(IO3)2(*), orthorhombic UO2(IO3)2(H2O) (*), triclinic A2[(UO2)3(IO3)4O2] (A=K, Rb, Tl), monoclinic M[(UO2)2(IO3)2O2](H2O) (M=Sr, Ba, Pb), orthorhombic Cs2[(UO2)3Cl2(IO3)(OH)O2]•2H2O(*), and orthorhombic Ag4(UO2)4(IO3)2(IO4)2O2. The latter compound contains the new oxoanion IO4

3- with a stereochemically active lone-pair

at the I(V). The structural variability of these compounds and the versatility of iodate coordination and its effect on the resulting structure and framework will be presented.

NUCL 144 [495264]: Synthesis and Chelation Properties of New Polymers Towards Some Trivalent Lanthanides FAWWAZ I Khalili, DEPARTMENT OF CHEMISTRY, UNIVERSITY OF JORDAN,AMMAN -JORDAN, Amman 11942, Jordan, f_khalili99@yahoo.com

Abstract Some Mannich-type polymers have been prepared through condensation of some phenol derivatives with bifunctional amines.The chelation properties of these polymers towards some trivalent lanthanide metal ions La,Ce,Nd,Sm and Gd have been investigated and the amount of metal ion uptake by these polymers has been determined by EDTA titration.The effect of the counter ion,contact time and pH were also studied.

NUCL 145 [516521]: Reduction of Pu(VI) in an Ion Pac CS5 ion chromatography column Emad H. Borai1, Brian A. Powell2, John T Coates2, and Robert A Fjeld2. (1) Hot Laboratories Center, Egyptian Atomic Energy Authority, Inshas Kalupia, Cairo, Egypt, Fax: 864-656-0672, eborai@clemson.edu, (2) Department of Environmental Engineering and Science, Clemson University

Abstract Studies were conducted to infer the mechanism responsible for reduction of Pu(VI) in an Ion Pac CS5 ion chromatography column. Three possibilities were investigated: pH, the mobile phase complexing agent, and the stationary phase. Batch studies were conducted to determine the stability of Pu(VI) at various pH's for the following mobile phase complexing agents: oxalic acid, a-hydroxy iso-butyric acid (HIBA), Diglycolic (DGA), 2-6 Pyridinedicarboxylic acid (PDCA), and carbonate. Plutonium (VI) was produced by oxidation in 1 M HNO3 + 0.001 M KMnO4 and analyzed by the HDEHP liquid extraction technique. Plutonium (VI) was found to be stable in DGA and carbonate solutions at pH 4.5 and pH 8, respectively. However, when these DGA and carbonate solutions were eluted through an Ion Pac CS5 ion chromatography column, Pu(VI) was reduced to Pu(V). From these tests, it was inferred that the sulfonic acid functional groups in the column are responsible for Pu(VI) reduction.

NUCL 146 [514958]: Radioactive environment contamination and abilities

of the modern radiochemistry in the field of nuclear waste disposal and monitoring Boris F. Myasoedov, Russian Academy of Sciences, V. I. Vernadsky Institute of Geochemistry and Analytical Chemistry, Kosygin str. 19, Moscow, Russia, Fax: 208-526-5937

Abstract Artificial radionuclides have become the constant and unremovable components of biosphere. Such factors as nuclear weapons test, faulty concept of radionuclides dumping into natural water reservoirs, some technological violations and accidents occurred at nuclear power plants and nuclear fuel reprocessing facilities contributed significantly to this condition. Radioecological monitoring, decision making on remediation of polluted areas need detailed information about distribution of radioactive nuclides in the terrestrial and aquatic ecosystems, knowledge about radionuclide occurrence and migration patterns. An overview is given of modern radioecological situation around reprocessing plant “Mayak”, which was constructed more than 40 years ago for the production of plutonium for military purposes. The following problems are considered: lake Karachai, artificial water reservoirs contaminated by radionuclides, solid radioactive waste and their vitrification. Some new approaches, methods and tools developed at Vernadsky Institute for isolation, concentration and determination of radionuclides in environmental samples are discussed.

NUCL 147 [521158]: Carbon dioxide system in natural waters Frank J. Millero, Rosenstiel School of Marine and Atmospheric Science, University of Florida, Rickenbacker Causeway, Miami, FL 33149

Abstract There is now a great interest in understanding the carbon dioxide system in ocean waters. This is largely related to attempts to characterize the mechanism of how 40% of the fossil fuel produced CO2 is added to the oceans. To characterize the CO2 system in natural waters, it is necessary to have reliable thermodynamic constants for the dissociation of carbonic acid. Earlier studies have shown that measurements of the constants are different in artificial and natural seawater. Recent field and laboratory measurements indicate that these differences are due to interactions between the borate and carbonate systems. Ionic interaction models for the carbon dioxide system presently do not predict these interactions due to a lack of experimental measurements. In the present paper, I will review the measurements and ionic interaction models that have been used to understand thermodynamics of the CO2 system in natural waters. The dissociation of carbon acid is also important because it provides carbonate ions that can form strong complexes with divalent and trivalent metals in natural waters. Some of our recent studies on the formation of carbonate complexes with Fe(II) and Mn(II) will be discussed.

NUCL 148 [515803]: Study of hydrolysis and colloid generation of actinides(IV) by laser-induced breakdown detection Jae-Il Kim, Institut fuer Nukleare Entsorgung(INE), Forschungszentrum Karlsruhe (FZK), Postfach 3640, Karlsruhe 76021, Germany, Fax: ++49-7247-824308, kim@ine.fzk.de

Abstract The tetravalent actinide ions are prone to hydrolysis and thus to colloid formation even at acidic pH. Such particular characteristics make a study of the environmental behavior of An(IV) very difficult. This presentation deals with a noble approach to investigate the hydrolysis and colloid fomation of An(IV), which is based on plasma generation by multiphoton excitation on colloids, namely selective dielectric breakdown of solid particles in liquid. Applying the method, the primary hydrolysis and subsequent nucleation of An(IV) have been studied for Th(IV), U(IV), Np(IV) and Pu(IV). Thermodynamic solubilities of An(IV) oxides and hydroxides are derived thereof and a conversion of solid phase in acidic pH is ascertained as well. The study is extended to the appraisal of the chemical interaction of An(IV) with aquatic colloids and hence of their migration behavior.

NUCL 149 [517399]: Research and education in environmental radiochemistry: past, present, and future S. B. Clark, Chemistry Department, Washington State University, P.O. Box 644630, Pullman, WA 99164-4630, s_clark@wsu.edu

Abstract Accidental and/or intentional releases of radioactivity to the environment and decades of storage of radioactive wastes have created a legacy for clean up, and created many challenges for technology development, fundamental research, and educational opportunities. The challenge of defining the fundamental chemistry of the actinides in the environment was realized by Professor Greg Choppin many decades ago, and he has made essential, seminal contributions to our current understanding of these problems. Some of the contributions of Prof. Choppin in this area will be reviewed to define the status of our understanding in this field today. In addition, the influence of Prof. Choppin’s approach to chemical research and education on the current generation of academic radiochemists will be described. Finally, some future challenges that we face in both education and research will be summarized.

NUCL 150 [515651]: Gregory R. Choppin and the speciation of actinides

Heino Nitsche, University of California, Berkeley, Department of Chemistry and Lawrence Berkeley National Laboratory, Glenn T. Seaborg Center, 1 Cyclotron Road, MS 70A-1150, Berkeley, CA 94720, Fax: 510-486-7444, hnitsche@lbl.gov

Abstract Greg Choppin's scientific career covers a wide span of achievements that include the discovery of actinide elements, nuclear waste reprocessing chemistry, and nuclear environmental chemistry, to name only a few.

This talk will present an overview of Professor Choppin's important influence on the field of speciation of actinides in many research areas.

NUCL 151 [520675]: Nuclear science and bone (hydroxylapatite) Andrew J. Tofe, CeraPedics, L.L.C, Lakewood, CO 80228, atofe@cerapedics.com, and Robert C. Moore, Sandia National Laboratory

Abstract It should be recognized that advanced academic training not only enhances technical expertise but also prepares the mind to extrapolate the knowledge for the betterment of mankind. In this presentation, the nuclear expertise gained in Dr. Choppin’s laboratory will be used to illustrate how “out of the box” applications can lead to environmental advances. In wet chemistry development of fission yield curves, the technetium 99m radioisotope allows for normalization of various fission products. Appreciation of the nuclear properties of technetium 99m, combined with the bone seeking properties of bisphosphonates, led to the discovery of the bone scan. Today the bone scan is the most frequent diagnostic procedure in nuclear medicine. The developed understanding of bone and the academic learning of transuranic fission product chemistry led to the utilization of cost-effective bovine-derived hydroxylapatite for environmental sorption and containment of radionuclides. Studies using 10-8 and 10-5 m of strontium, uranium and plutonium showed effective sorption. Containment of long-lived radionuclides is an achievable end-point with bovine-derived hydroxylapatite providing an environmental win through the learnings of nuclear chemistry.

NUCL 152 [515530]: Future trends in nuclear and radiochemistry Gregory R. Choppin, Chemistry Department, Florida State University, Tallahassee, FL 32306-4390, Fax: 850-644-8281, choppin@chem.fsu.edu

Abstract Although nuclear and radiochemistry can be considered mature branches of chemistry one hundred years after the discovery of radioactivity, challenges abound for chemists in

many areas in nuclear science. Global interest in nuclear and radiochemistry encompasses a wide range of difficult tasks including the remediation of contaminated nuclear facilities, limiting nuclear proliferation, providing clean and efficient power to the developed and developing world, the diagnosis and treatment of disease, and the advancement of the biological, physical, earth sciences. Education in nuclear and radiochemistry is vital to the success of these endeavors.