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Synthesis of Actinide Materials for the Study of Basic Actinide Science and Rapid Separation of Fission Products

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Synthesis of Actinide Materials for the Study of Basic Actinide Science and Rapid Separation of Fission Products UNLV Theses, Dissertations, Professional Papers, and Capstones 12-1-2017 Synthesis of Actinide Materials for the Study of Basic Actinide Science and Rapid Separation of Fission Products Jacquelyn M. Dorhout University of Nevada, Las Vegas Follow this and additional works at: https://digitalscholarship.unlv.edu/thesesdissertations Part of the Chemistry Commons Repository Citation Dorhout, Jacquelyn M., "Synthesis of Actinide Materials for the Study of Basic Actinide Science and Rapid Separation of Fission Products" (2017). UNLV Theses, Dissertations, Professional Papers, and Capstones. 3125. http://dx.doi.org/10.34917/11889685 This Dissertation is protected by copyright and/or related rights. It has been brought to you by Digital Scholarship@UNLV with permission from the rights-holder(s). You are free to use this Dissertation in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s) directly, unless additional rights are indicated by a Creative Commons license in the record and/or on the work itself. This Dissertation has been accepted for inclusion in UNLV Theses, Dissertations, Professional Papers, and Capstones by an authorized administrator of Digital Scholarship@UNLV. For more information, please contact [email protected]. SYNTHESIS OF ACTINIDE MATERIALS FOR THE STUDY OF BASIC ACTINIDE SCIENCE AND RAPID SEPARATION OF FISSION PRODUCTS By Jacquelyn M. Dorhout Bachelor of Science – Chemistry University of Massachusetts Amherst 2012 A dissertation submitted in partial fulfillment of the requirements for the Doctor of Philosophy – Radiochemistry Department of Chemistry and Biochemistry College of Sciences The Graduate College University of Nevada, Las Vegas December 2017 Copyright by Jacquelyn M. Dorhout, 2018 All Rights Reserved Dissertation Approval The Graduate College The University of Nevada, Las Vegas September 29, 2017 This dissertation prepared by Jacquelyn M. Dorhout entitled SYNTHESIS OF ACTINIDE MATERIALS FOR THE STUDY OF BASIC ACTINIDE SCIENCE AND RAPID SEPARATION OF FISSION PRODUCTS is approved in partial fulfillment of the requirements for the degree of Doctor of Philosophy – Radiochemistry Department of Chemistry and Biochemistry Kenneth R. Czerwinski, Ph.D. Kathryn Hausbeck Korgan, Ph.D. Examination Committee Chair Graduate College Interim Dean Ralf Sudowe, Ph.D. Examination Committee Member Paul Forster, Ph.D. Examination Committee Member Jaqueline L. Kiplinger, Ph.D. Graduate College Faculty Representative ii Abstract This dissertation covers several distinct projects relating to the fields of nuclear forensics and basic actinide science. Post-detonation nuclear forensics, in particular, the study of fission products resulting from a nuclear device to determine device attributes and information, often depends on the comparison of fission products to a library of known ratios. The expansion of this library is imperative as technology advances. Rapid separation of fission products from a target material, without the need to dissolve the target, is an important technique to develop to improve the library and provide a means to develop samples and standards for testing separations. Several materials were studied as a proof-of-concept that fission products can be extracted from a solid target, including microparticulate (< 10 µm diameter) dUO2, porous metal organic frameworks (MOFs) synthesized from depleted uranium (dU), and other organic- based frameworks containing dU. The targets were irradiated with fast neutrons from one of two different neutron sources, contacted with dilute acids to facilitate the separation of fission products, and analyzed via gamma spectroscopy for separation yields. The results indicate that smaller particle sizes of dUO2 in contact with the secondary matrix KBr yield higher separation yields than particles without a secondary matrix. It was also discovered that using 0.1 M HNO3 as a contact acid leads to the dissolution of the target material. Lower concentrations of acid were used for future experiments. In the case of the MOFs, a larger pore size in the framework leads to higher separation yields when contacted with 0.01 M HNO3. Different types of frameworks also yield different results. The second portion of this dissertation describes efforts to better understand electronic structure and bonding of the actinide metals in various environments. One project involved studying thorium and uranium bonding with the soft-donor chalcogenides, specifically sulfur. Results from these studies include the synthesis and characterization of the novel (C5Me5)2Th(SMe)2 complex; the synthesis of (C5Me5)2ThS5 by myriad routes, indicating the product is a thermodynamic sink; and evidence that sulfur is inserted iii into the thorium-carbon bond of (C5Me5)2ThMe2 to form the pentasulfide. The second project involved unique activation of the strong carbon-halide bonds present in benzyl-halides mediated by a uranium- (2,2’-bipyridine) complex. The resultant products include a series of uranium-halide bonds from fluoride to iodide, and the addition of the benzyl group to the bipyridine ring. Studies of the mechanism indicate that the benzyl group is added first to the 6 position of the ring before migrating to its final place at the 4 position. The final project utilized a novel gold-tetrazolate complex that can be tailored to add high- nitrogen ligands to actinides in a facile and safe way. This transfer ligand was used to synthesize new uranium-tetrazolate species. A brief exploration into using the transfer ligand to add tetrazolates to lanthanides was also done. All resultant compounds from each of these projects was studied by NMR, IR, and UV-Vis-NIR spectroscopies, electrochemistry, and X-ray crystallography. iv Acknowledgements There are several groups of people and funding agencies that have made this research possible. First and foremost is my committee – my thesis advisor Dr. Ken Czerwinski whose energy and excitement makes everything seem possible; Dr. Ralf Sudowe who has helped with the gamma analysis; Dr. Paul Forster who first taught me how hydrothermal synthesis works; Dr. Jaqueline Kiplinger who allowed me to move to New Mexico and try something completely new; and Dr. Alexander Barzilov for serving as my outside committee member. There are also several UNLV graduate students, post-docs, and staff members that have helped me along the way – Dr. William Kerlin, Dr. Daniel Lowe, Lucas Boron-Brenner, and Rebecca Springs aided in the gamma spectroscopy of a number of samples; Julie Bertoia and Trevor Low who kept the labs running and operational; Wendee Johns who kept the radiochemistry program running; Dr. Dan Koury and Dr. Thomas Hartmann who served as users; Dr. Frederick Poineau, Daniel Mast, AJ Swift, Katherine Thornock, and others in the radiochemistry program who have helped with aspects of this project along the way. I would also like to acknowledge the LANL contingent – Drs. David Morris, Kent Abney, Nick Travia, Alex Lichtscheidl, Karla Erickson, Stephen Cope, David Baumann, and Ross Beattie for helpful discussions; Dr. Brian Scott for his crystallographic genius; and Dr. Todd Bredeweg for his help with the irradiations. Thank you to Dr. Marisa Monreal for her insight into Chapter 6; a project that she started. Thank you to Dr. Kevin Browne for his precursor work on Chapter 7, including the synthesis and crystal structure of (Ph3P)Au- methyltetrazolate. Thank you to Dr. Justin Pagano for helpful discussions, crystal structure solving, and talking me off various ledges. Thank you to Dr. George Stanley (LSU) for computational expertise and helpful discussions. Thank you to my father, Dr. Peter Dorhout, for the use of chalcogenide materials he synthesized at LANL several years ago. v A big thank you goes to the people who made the irradiations possible – our colleagues at LANL, LLNL, and PNNL for allowing us to piggyback on their runs; the irradiation technicians at the DAF for actually doing the irradiations for us; and the radiation safety staff at UNLV (Brian Rowsell, Al Ogurek, and Reggie Stewart) for their help shipping and receiving my samples. Thank you also to my family and friends (particularly my parents, my sister Kate, and Jaimie Daum) who have kept me sane throughout this process. Without you, I may have never finished. Many funding agencies were involved in this thesis project, including the DOE office of science, the Development of a Synthetic Debris for Nuclear Forensics (Prime Contract No. DE-AC52-06NA25946), the LANL G.T. Seaborg Institute for Transactinium Science, and the DHS. Department of Homeland Security Disclaimer This material is based upon work supported by the U.S. Department of Homeland Security under Grant Award Number 2012-DN-130-NF0001. The views and conclusions contained in this document are those of the author and should not be interpreted as representing the official policies, either expressed or implied, of the U.S. Department of Homeland Security. LA-UR-17-30783 vi This work is dedicated to my parents Dr. Peter Dorhout and Carolyn Dorhout for their invaluable support vii Table of Contents Abstract ........................................................................................................................................................ iii Acknowledgements ....................................................................................................................................... v List of Tables ..............................................................................................................................................
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