Physical Sciences and Mathematics Commons^™

Nearest-Neighbor-Atom Core-Hole Transfer In Isolated Molecules, Renaud Guillemin, Oliver Hemmers, D. Rolles, S. W. Yu, A. Wolska, I. Tran, A. C. Hudson, J. Baker, Dennis W. Lindle

Environmental Studies Faculty Publications

A new phenomenon sensitive only to next-door-neighbor atoms in isolated molecules is demonstrated using angle-resolved photoemission of site-selective core electrons. Evidence for this interatomic core-to-core electron interaction is observable only by measuring nondipolar angular distributions of photoelectrons. In essence, the phenomenon acts as a very fine atomic-scale sensor of nearest-neighbor elemental identity.

Afci Quarterly Input – Unlv April Through June, 2004, Harry Reid Center For Environmental Studies. Nuclear Science And Technology Division

Transmutation Research Program Reports (TRP)

Quarterly report highlighting research projects and objectives of the Transmutation Research Program at the Nuclear Science & Technology Division, Harry Reid Research Center.

The University of Nevada, Las Vegas supports the AFCI through research and development of technologies for economic and environmentally sound refinement of spent nuclear fuel. The UNLV program has four components: infrastructure, international collaboration, student-based research, and management and program support.

Point Load Strength Testing Of Irregular Rock Fragments Of Welded Tuff, Jaak J.K. Daemen, George Danko, Amy J. Smiecinski

Publications (YM)

Yucca Mountain is composed of a thick sequence of variably welded and nonwelded ashflow tuffs (Rautman and Engstrom, 1996). The understanding of the rock mechanical properties is useful for characterizing the mechanical stability of the potential repository and for estimating the amount of ground support needed in underground construction (Sweetkind et al, 2003). According to Brook (1993), knowledge of lump point load strength is helpful because it can help in estimating the compressive strength. Lump point load testing is one basic mechanical characterization test to support the study of long term drift stability at the potential High Level Waste repository …

Evaluation Of Fluorapatite As A Waste-Form Material: Third Quarter Report, March 1- May 31, 2004, Dennis W. Lindle, Oliver Hemmers

Separations Campaign (TRP)

Fluorapatite, fluorinated calcium phosphate, has been identified as a potential matrix for the entombment of the zirconium fluoride fission product waste stream from the proposed FLEX process. If the efficacy of fluorapatite-based waste-storage can be demonstrated, then new and potentially more-efficient options for handling and separating high-level wastes, based on fluoride-salt extraction, will become feasible. This proposal will develop a dual-path research project to develop a process to fabricate a synthetic fluorapatite waste form for the ZrF₄, FP waste stream, characterize the waste form, examine its performance under environmental conditions, and correlate the behavior of the waste form …

Modeling Corrosion In Oxygen Controlled Lbe Systems With Coupling Of Chemical Kinetics And Hydrodynamics-Task V: Third Quarterly Report 03/01/2004-05/31/2004, Samir Moujaes, Yitung Chen

Transmutation Sciences Materials (TRP)

The Lead-Bismuth eutectic (LBE) has been determined from previous experimental studies by the Russians and the European scientific community to be a potential material that can be used as a spallation target and coolant for the TRP proposed application. Properly controlling the oxygen content in LBE can drastically reduce the LBE corrosion to structural steels. However, existing knowledge of material corrosion performance was obtained from point-wise testing with only very sparse experimental data. Scientists have noticed that the concentration of oxygen dissolved in the liquid alloy could control the corrosion rate of steels exposed to Pb or Pb-Bi. At high …

Parks & Trails Partnership, Margaret N. Rees, Nancy Flagg, David Frommer

Presentations (PLI)

• UNLV is committed to demonstrating how the traditional values of higher education can be adapted to the conditions and needs of individuals and communities in the 21st century.
• Key macrothemes of the university’s strategic plan include Economic Development, Preservation of History & Culture, and Community Outreach & Collaboration.
• In keeping with these macrothemes, UNLV is embarking on several partnerships with the BLM and related agencies to provide a wide array of research, technical assistance, education, and service support on projects funded through the SNPLMA.
• UNLV is a research extensive university with academic departments and research centers and institutes that embrace …

Oliver Ranch Core Group Meeting: May 18, 2004, Red Rock Desert Learning Center

Reports (RRLC)

1. Where have we been and where are we going?
2. Line and Space Report
3. Committee Reports
4. Future Core Group Meetings

Evaluating The Effectiveness Of Simulation-Based Instruction About Water Resources In Las Vegas, Stephanie Fincher

UNLV Theses, Dissertations, Professional Papers, and Capstones

This study compared the effectiveness of simulation-based instruction to traditional teacher-directed instruction about water resource management in Las Vegas. Subjects, undergraduate students recruited from Psychology and Environmental Studies departments, participated in one of two treatments. All participants were given a pretest prior to instruction, a post-test immediately following instruction, and a retention-test 4 weeks after instruction. Evaluation instruments provided overall scores, gauged student learning in topic areas and different question difficulty-levels as well as attitudes toward the environment and water management. The treatments differed only in how students interacted with the system after receiving background information on Las Vegas valley’s …

Electrochemical Separation Of Curium And Americium, David W. Hatchett, Kenneth Czerwinski

Separations Campaign (TRP)

The objective of this project is to develop a method for the separation of Am from Cm based on electrochemical techniques. Electrochemical systems that allow the thermodynamics of actinide and lanthanide complexes to be systematically evaluated and tuned will be examined. The influence of complex formation on the ability to selectively isolate a given species electrochemically will be evaluated. Metal-ligand complex formation provides a useful derivation technique to increase solubility in solution environments that favor precipitation. In addition, the thermodynamic properties of a complex relative to the isolated species may be shifted to more suitably measurable electrochemical separation regimes. Electrochemical …

Fundamental Chemistry Of U And Pu In The Tbp-Dodecane-Nitric Acid System, Kenneth Czerwinski, Byron Bennett

Separations Campaign (TRP)

The speciation of hexavalent U and tetravalent Pu will be examined in the TBP-dodecane-nitric acid systems. This topic is chosen based on data needs for separation modeling identified by the AFCI. Emphasis will be placed on studying the influence of nitrate and acetohydroxamic acid on U and Pu speciation as well as conditions where a third phase forms in the organic phase. The organic phase will be 30% TBP in dodecane. Equal volumes of aqueous and organic phase will be used. The speciation of the actinides in the aqueous and organic phase will be determined by a number of different …

Development Of Nanostructure Based Corrosion-Barrier Coatings On Steel For Transmutation Applications, Biswajit Das

Transmutation Sciences Materials (TRP)

The objective of this project is to develop a novel nanostructure based coating technology that will provide significantly improved corrosion resistance for steel in LBE at elevated temperatures (500 - 600^oC), as well as provide long-term reliability under thermal cycling. The nanostructure based coatings will consist of a layer of nanoporous alumina with the pores filled with an oxidizing metal such as Cr, followed by a capping layer of alumina. Alumina, which is a robust anti-corrosion material, provides corrosion resistance at elevated temperatures. The Cr serves two purposes: (1) it acts as a solid filler material for the …

Design Concepts And Process Analysis For Transmuter Fuel Manufacturing, Georg F. Mauer

Fuels Campaign (TRP)

This proposal addresses the subject heading ‘Transmutation Fuel Development’ in the 2004 research topic list of the UNLV Transmutation Research Program (TRP) and DOE Advanced Fuel Cycle Initiative (AFCI). The large-scale deployment of remote fabrication and refabrication processes (with a capacity of approx. 100 metric tons of Minor Actinides (MA) annually) will be required for all transmutation scenarios. The objective of this project is the design, analysis, and evaluation of manufacturing processes for transmuter fuel fabrication. Fabrication processes for different fuel types differ in terms of equipment types, throughput, and cost. The evaluation of the fabrication processes will create a …

Effect Of Silicon Content On The Corrosion Resistance And Radiation-Induced Embrittlement Of Materials For Advanced Heavy Liquid Metal Nuclear Systems, Ajit K. Roy

Transmutation Sciences Materials (TRP)

The purpose of this collaborative research project involving the University of Nevada Las Vegas (UNLV), Los Alamos National Laboratory (LANL) and Idaho State University (ISU) is to evaluate the effect of silicon (Si) content on the corrosion behavior and radiation-induced embrittlement of martensitic stainless steels having chemical compositions similar to that of the modified 9Cr-1Mo 2 steel. Recent studies at LANL involving Alloy EP-823 of different Si content have demonstrated that increased Si content in this alloy may enhance the corrosion resistance in molten lead-bismuth-eutectic (LBE). Since very little data exists in the open literature on the beneficial effect of …

A Long Baseline Laser Strainmeter For The Exploratory Studies Facility At Yucca Mountain, Frank K. Wyatt, James N. Brune, Drew Coleman, Don Baepler, Amy J. Smiecinski

Publications (YM)

This Scientific Investigation Plan (SIP), for work under the second Department of Energy/University and Community College System of Nevada (DOE/UCCSN) Cooperative Agreement (10/01/03), DEFC28- 04RW12232, is intended to cover the laser strainmeter operation and monitoring task being conducted by the University of California, San Diego (UCSD), under the oversight of the Nevada Seismological Laboratory of the University of Nevada-Reno (NSL/UNR). UCSD has carried out the design, engineering, and installation of the east-west laser strainmeter (LSM) currently in place in the Exploratory Studies Facility (ESF) at Yucca Mountain.

Chemical Analyses For Alcove 8/Niche 3 Tracer Studies, Jeanette Daniels, Klaus J. Stetzenbach, Drew Coleman, Don Baepler, Amy J. Smiecinski

Publications (YM)

The objective of this task “Analytical Support For Tracer Studies in Alcove 8 / Niche 3” is to provide chemical analyses for the tracer studies at Alcove 8 / Niche 3 in the Exploratory Studies Facilities (ESF). This analytical support includes developing procedures for measuring tracer concentrations and then performing the tracer (and other background constituent) analyses for the water samples generated from each Alcove 8 / Niche 3 tracer test. These tracer tests are part of the Flow and Seepage Testing in Alcove 8/Niche 3 (TWP-NBS-HS-000004 REV 00). The overall goal of this study is to quantify large scale …

A Study Of Invasive Species Cover Near Roads In A Red Rock Canyon Blackbrush Community, Christopher Keough

UNLV Theses, Dissertations, Professional Papers, and Capstones

The monitoring of Mojave Desert plant communities during and following disturbance is an important process that could provide invaluable information about disturbance/recovery regimes in similar arid environments across the globe. Blackbrush communities are of particular interest because of their low replacement rate, which makes them highly susceptible to disturbance. Roads in the Mojave Desert have been associated with soil compaction resulting in a lack of vegetation as well as an increase in invasive species cover in the immediate proximity. To investigate these statements, eight fifty-foot line transects were established in each of three plot types (perpendicular to dirt roads, perpendicular …

Habitat Preferences Of Four Species Of Lizards Found At The Las Vegas Springs Preserve, Scott Garncarz

UNLV Theses, Dissertations, Professional Papers, and Capstones

Developing an understanding of the habitat usage of reptiles is important when trying to develop a management or restoration plan that is compatible with what is known of the reptile species that are being investigated. There are many lizard species found in the Mojave Desert, but there are only four known to inhabit the Las Vegas Springs Preserve (LVSP) in Las Vegas, Nevada. In the LVSP, sites are going to be restored with native Mojave Desert vegetation. Since there are many habitat types in the Mojave Desert, we must determine which types would be best suited for the four species …

Inside Unlv, Gian Galassi, Andy Grossman, Donna Mcaleer, Jennifer Vaughan, Carol C. Harter, Ronald Yasbin

Inside UNLV

No abstract provided.

Design And Simulation Of An Induction Skull Melting System, Taide Tan

UNLV Theses, Dissertations, Professional Papers, and Capstones

Incorporating volatile actinides, mainly americium into a metallic fuel pin (MFP) has been a serious problem due to americium’s high vapor pressure. An Induction Skull Melting (ISM) system was identified by Argonne National Laboratory (ANL) as a potential furnace design to cast MFPs. Through the development of the ISM system, the nuclear waste feedstock can be melted and injected into the mold for fabricating MFPs in the advanced nuclear fuel cycles. The main phenomena in this system include: induction melting process, casting process and mass transfer process of americium. Issues related to ISM system design for casting MFPs are discussed …

Investigation And Calculation Of Dose Coefficients For Radionuclides Produced In A Spallation Neutron Source Using The Ensdf And Nubase Nuclear Databases, Yayun Song

UNLV Theses, Dissertations, Professional Papers, and Capstones

Dose coefficients are useful for risk assessment during the design and siting of accelerator-driven nuclear facilities including the Spallation Neutron Source. There are seventy-two radionuclides with half-lives equal to or greater than one minute that will be produced by the spallation of a mercury target for which no published dose coefficients exist. Out of these seventy-two, twenty-four currently have conflicting published nuclear data in the Evaluated Nuclear Structure Data Files (ENSDF) and the NUBASE data files. In this research these twenty-four radionuclides have been studied. Because of missing ENSDF records, internal and external dose coefficients were determined for only six …

Immobilization Of Fission Iodine By Reaction With A Fullerene Containing Carbon Compound And Insoluble Natural Organic Matrix, Spencer M. Steinberg

Separations Campaign (TRP)

The recovery of iodine released during the processing of used nuclear fuel poses a significant challenge to the transmutation of radioactive iodine. During the first two years of this program the use of Fullerene Containing Carbon (FCC) compounds and Natural Organic Matter (NOM) as potential sorbents for iodine release from the reprocessing of nuclear fuel was examined. This work also included the development of bench-scale testing capabilities at UNLV to allow the testing of the FCC and NOM materials in a simulated process off-gas environment. In the final year of the project we will complete studies of FCC and NOM …

Development Of Integrated Process Simulation System Model For Spent Fuel Treatment Facility (Sftf) Design, Yitung Chen, Sean Hsieh

Separations Campaign (TRP)

The Advanced Fuel Cycle Initiative (AFCI) and Transmutation Research Program-University Participation Program (TRP-UPP) supported by Department of Energy of the United States have been developing many important technologies for the transmutation of nuclear waste to address long-term disposal issues. While successfully embedding AMUSE module into a dedicated System Engineering Model (TRPSEMPro), developed by the Nevada Center for Advanced Computational Methods (NCACM) at the University of Nevada-Las Vegas collaborating with Argonne National Laboratory (ANL), ANL is interested in further simulating the Light Water Reactor (LWR) Spent Fuel Treatment Facility (SFTF) combining commercial process simulation and analysis packages and core calculation of …

Theoretical Modeling Of Protective Oxide Layer Growth In Non-Isothermal Lead-Alloys Coolant Systems, Yitung Chen, Jinsuo Zhang, Jichun Li

Transmutation Sciences Materials (TRP)

The goal of the proposed research project is to provide basic understanding of the protective oxide layer behaviors and to develop oxide layer growth models of steels in non-isothermal leadalloys (lead or lead-bismuth eutectic) coolant systems. It is widely recognized that the corrosiveness of the lead-alloys is a critical obstacle and challenge for which it can be safely used or applied in the nuclear coolant systems. Active oxygen control technique can promote the formation of the “self-healing” oxide films on the structural material surface, drastically reducing steel corrosion and coolant contamination. Many experiments of steels exposed to flowing leadalloys have …

Use Of Positron Annihilation Spectroscopy For Stress-Strain Measurements, Ajit K. Roy

Transmutation Sciences Materials (TRP)

The purpose of this collaborative research project involving the University of Nevada Las Vegas (UNLV) and Idaho State University (ISU) is to evaluate the feasibility of determining residual stresses of welded, bent (three-point-bend), and cold-worked engineering materials using a new nondestructive technique based on positron annihilation spectroscopy (PAS). The proposed technique is to use γ-rays from a small MeV electron linear accelerator (Linac) to generate positrons inside the test sample via 2 pair production. This method can be used for materials characterization and investigation of defects in thick samples that usually cannot be accomplished by conventional positron technique or other …

Defining Soil Type And Habitat Characteristics Of The Arctomecon Californica, Philip S. Childers

UNLV Theses, Dissertations, Professional Papers, and Capstones

A. californica can be considered a rare endemic species, which is believed to be restricted by unique soil relationships. These relationships make the species vulnerable to anthropogenic habitat disturbance. Although A. californica is listed as critically endangered by the state of Nevada, further research is needed before the species can be listed as federally endangered or threatened. This study used primary observational data and secondary GIS compatible data to characterize A. californica habitat. Representative sampling techniques were used to select observations from derived soil types. Although a majority of A. californica populations were found to occur in gypsic soil types, …

The Effects Of Off-Road Vehicle Use In Desert Tortoise (Gopherus Agassizii) Habitats, Brent D. Clark

UNLV Theses, Dissertations, Professional Papers, and Capstones

The desert tortoise (Gopherus agassizii) populations have been in decline and have been placed on the endangered species list. No single factor is ultimately responsible for the tortoise decline. It is a combination of events that collectively have a negative impact. I chose to focus my study on only one factor, off-road vehicles. By evaluating the damage done to the terrain by off-road vehicles, a better understanding of their impact on the tortoise populations can be assessed and protective measures taken.

The amount of available vegetation does not seem to play a role in their decisions of which plants to …

Time Dependent Mechanical Behavior Of Welded Tuff, Jaak J.K. Daemen, George Danko, Amy J. Smiecinski

Publications (YM)

This part of the Technical Report includes four types of experimental studies: strain rate dependence, uniaxial creep, Brazilian (Indirect splitting) tensile strength and uniaxial compressive strength. These are presented in four chapters. One hundred twenty one specimens have been tested in uniaxial compression. Ninety three of these are included in the strain rate dependence study, presented in Chapter 2. Uniaxial compression strain rates range from about 10~8 to 10~2 s~l. Results of twenty eight tests are presented in Chapter 5, which describes uniaxial compression testing of specimens containing major lithophysal cavities. Fourteen specimens have been tested in uniaxial creep, presented …

Preparation Studies For Secondary Electron Emission Experiments On Superconducting Niobium, Anoop George, Robert A. Schill Jr.

Transmutation Sciences Materials (TRP)

Accelerator driven transmutation of waste is one complementary approach to deal with spent nuclear fuel as compared to permanent storage. High-energy protons generated by a particle accelerator collide with a heavy metal target producing neutrons. Long-lived radioactive isotopes interacting with the neutrons transmute into shorter-lived isotopes. To generate the high-energy protons efficiently, linear accelerators use multi-cell superconducting radio frequency (RF) cavities made of niobium. Superconducting niobium cavities have several advantages, including small power dissipation. The high electromagnetic fields present in these cavities may result in undesired field emission from surface imperfections with the probability of generating an avalanche of secondary …

Converting Low-Level Mixed Waste Into Transuranic Waste For Geologic Disposal At Wipp: A Cost Analysis, Helen R. Neill, Robert H. Neill

Public Policy and Leadership Faculty Publications

The Department of Energy (DOE) has approximately 43,000 cubic meters of mixed-low-level waste (MLLW) with alpha emitting concentrations of 10 to 100 nanocuries per gram (nCi/g) generated from the nations defense programs requiring radioactive waste disposal [1]. DOE has decided to commingle MLLW containers with transuranic (TRU) waste containers in larger containers such that the average concentration in the larger container would qualify as TRU waste for deep geologic disposal at the Waste Isolation Pilot Plant (WIPP). Since Congress has exempted the WIPP mixed TRU waste from the Resource Conservation and Recovery Act (RCRA) [2] requirement to treat the waste …

The Electrochemical Separation Of Curium And Americium: Quaterly Report January - March 2004, David W. Hatchett, Kenneth Czerwinski

Separations Campaign (TRP)

This research report outlines the current status and progress associated with the electrochemical separation of Curium and Americium.

Data collection and analysis of the Ce³⁺/Ce⁴⁺ redox couple in various supporting electrolytes has continued. All electrolyte systems were investigated at Pt, Au, and Glassy Carbon working electrodes. Analysis of these data was accomplished by performing appropriate background subtractions to reveal net peaks due to Ce redox behavior. Successful identification of the Ce redox couple was achieved with all electrolyte/electrode systems, although a decline in peak resolution was observed with increasing acid concentration. Optimal conditions in this experiment were …