Physical Sciences and Mathematics Commons^™

Red Rock Desert Learning Center & Wild Horse And Burro Facility: Fact Sheet, Red Rock Desert Learning Center

Oliver Ranch Project

Overview and questions about Red Rock Canyon Desert Learning Center and Wild Horse and Burro Facility.

Red Rock Desert Learning Center & Wild Horse And Burro Facility: Frequently Asked Questions, Red Rock Desert Learning Center

Oliver Ranch Project

The mission of the Red Rock Desert Learning Center is to instill stewardship and respect by increasing knowledge and understanding of the Mojave Desert ecosystems and cultures through a unique experiential discovery program.

Dissolution, Reactor, And Environmental Behavior Of Zro2-Mgo Inert Fuel Matrix: Neutronic Evaluation Of Zro2-Mgo Inert Fuels, E. Fridman, A. Galperin, E. Shwageraus

Fuels Campaign (TRP)

Various fuel cycle concepts for plutonium incineration in existing PWR loaded with Inert Matrix Fuel (IMF), in which uranium is replaced by neutron-transparent inert matrix material, are currently under investigation at BGU. Some of the studied designs include ZrO₂-based IMF with annular fuel geometry and ZrO₂-MgO based IMF with the relative amount of MgO varied from 30v/o to 70v/o. These concepts are analyzed via detailed three-dimensional full core simulation of existing PWR including thermal-hydraulic feedback. The whole core simulations are carried out with the SILWER code. The SILWER code, which is a part of the ELCOS …

Decoupling And Disturbance Rejection Control For Target Circulation Loop, Xiuju Tan

Reactor Campaign (TRP)

The primary objective is to modify the existing control algorithm of the pilot target circuit (TC-1) loop to achieve precise temperature control. Safety concerns, the alarm system, and a user-friendly design are the secondary objectives.

The decoupling and active disturbance rejection controls are the effective control scheme in this special multivariable control process to TC-1 loop.

The research objectives are:

• To identify the interacting terms between heater inputs and target temperature outputs in each zone experimentally,

• To design of decoupling and active disturbance rejection control (ADRC),

• To monitor system through internet based remote monitoring, automatic alarming and …

Magnetohydrodynamic Simulation Of Electromagnetic Pump In Tc-1, Lillian J. Ratliff

Reactor Campaign (TRP)

The pilot molten lead-bismuth target circuit (TC-1) in university of Nevada Las Vegas (UNLV) was designed for beam power of 1 MW accelerator driven system (ADS). The TC-1 is a liquid lead-bismuth eutectic (LBE) circulation loop. Circulation of the liquid alloy is driven by an annular linear induction pump (ALIP). Experimental measurements of system parameters have yielded a surprisingly low pump efficiency of less than 1%. A numerical study of the pump efficiency is being conducted to determine which operational parameters are responsible for this low efficiency and to give insight into future EM pump design. The numerical study will …

Investigation Of Optical Spectroscopy Techniques For On-Line Materials Accountability In The Solvent Extraction Process, Gary Cerefice, Kenneth Czerwinski

Safeguards Campaign (TRP)

The long-term goal of this project is the evaluation of optical spectroscopy-based techniques for the on-line, real-time determination of actinide element concentrations in fuel recycling plant process streams. To generate the information necessary to evaluate the potential of these systems, initial experiments will focus on determining the detection limits for UV/Vis and LFS will be measured for the actinide elements under chemical conditions representative of the process streams for the UREX+ process. The system will then be systematically explored to examine the impact of acid concentration, nitrate concentration, redox potential, diluent concentration, ligand concentration, and contaminant/ fission product concentration on …

Optical Spectroscopy: Quarterly Report: 01/01/06 – 03/31/06, Harry Reid Center For Environmental Studies. Nuclear Science And Technology Division

Safeguards Campaign (TRP)

Progress report for the quarter: laser system alignment finished, site visit scheduled for final spectrometer configuration; initial studies on UO2 2+/NO3 -/H+ completed; preliminary data regression in progress; preliminary work on uranyl/AHA and organic/aqueous interface systems started.

Combined Radiation Detection Methods For Assay Of Higher Actinides In Separation Processes (Afci), Denis Beller, Warnick Kernan

Safeguards Campaign (TRP)

The ultimate objective of this project is to develop technology to detect and accurately measure quantities of higher actinides in processing systems without taking frequent samples. These systems include used fuel receipt, separations batches, and pipelines. A variety of measurements may be combined to calculate flow rates of actinide elements with a to-be-determined precision. Nuclear and decay characteristics of materials during processing will be acquired, conceptual designs of monitoring systems will be developed, radiation transport studies will be conducted to develop an understanding of operational regimes, and experiments will be performed to confirm performance. Radiation transport and scoping studies will …

Developing A Sensing System For The Measurement Of Oxygen Concentration In Liquid Pb-Bi Eutectic, Yingtao Jiang, Bingmei Fu

Transmutation Sciences Materials (TRP)

The research objectives of this project were as follows:

• To generate calibration curves of voltage versus oxygen concentration for the YSZ oxygen sensor system under various temperatures in liquid LBE.
• To determine the sensor characteristics of the YSZ sensor system.
• To determine oxygen dissolving rates in LBE under different temperatures in vitro.
• To study the effects of unwanted electrical conductivity, contributed by the mobility of the electrons at high temperatures, for more accurate oxygen measurement.
• To study alternative and promising oxygen measuring methods.

Fundamental And Applied Experimental Investigations Of Corrosion Of Steel By Lbe Under Controlled Conditions: Kinetics, Chemistry Morphology, And Surface Preparation, John Farley, Allen L. Johnson, Dale L. Perry

Transmutation Sciences Materials (TRP)

Advanced nuclear processes such as the transmutation of nuclear waste, fast reactors, liquid-metal-cooled reactors, and spallation neutron sources require advanced materials systems to contain them. The required structural materials must be stable in the presence of nonmoderating coolants. A prime candidate for such a coolant is Lead Bismuth Eutectic (LBE). Materials in these systems must be able to tolerate high neutron fluxes, high temperatures, and chemical corrosion. Unfortunately, LBE corrodes stainless steel.

The corrosive behaviors of structural materials in LBE are not well understood. The Russians have over 80 reactor-years experience with LBE coolant in their Alpha-class submarine reactors. The …

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)

This task is primarily focused on the evaluation of the effect of Si content on the susceptibility of modified 9Cr-1Mo-0.24V steel to stress corrosion cracking (SCC) and localized cracking in both molten lead-bismuth eutectic (LBE) and an aqueous solution of acidic pH.

Further, significant efforts are in progress to characterize the deformation mechanism of modified T91 grade steel as a function of temperature and strain rate. Simultaneously, surface analyses of the tested materials are ongoing using state-of-the-art techniques including scanning electron microscopy (SEM) and transmission electron microscopy (TEM).

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

Transmutation Sciences Materials (TRP)

The goal of this research project is to provide a basic understanding of the protective oxide layer behaviors and to develop oxide layer growth models of steels in non-isothermal lead alloys (lead or lead-bismuth eutectic) coolant systems. Precise studies and simulations of all hydrodynamics with thermal conditions encountered in practical coolant loop systems by use of different flowing conditions in the laboratory are difficult and expensive, if not impossible. Therefore it is important and necessary to develop theoretical models to predict the protective oxide layer behaviors at the design stage of a practical lead-alloy coolant system, to properly interpret and …

Corrosion Barrier Development For Lbe Corrosion Resistance: Quarterly Report (April 2006), Biswajit Das

Transmutation Sciences Materials (TRP)

As reported in the last quarterly report, synthesis of Cr nanowires was found to be problematic in terms of uniform coverage. Hence Ni was identified as the alternative metal to form the nanowires. The purpose of the metal nanowires is to provide structural integrity to the nanoporous alumina, as well as a second defense mechanism against corrosion by oxidizing in case the top alumina layer is compromised. Nickel was selected due to its established electrochemical synthesis procedure. While Ni can provide very good structural integrity to the porous alumina, one potential problem is its higher dissolution rate in LBE. However, …

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

Transmutation Sciences Materials (TRP)

Advanced transmutation systems require structural materials that are able to withstand high neutron fluxes, high thermal cycling, and high resistance to chemical corrosion. The current candidate materials for such structures are ferritic and ferritic-martensitic steels due to their strong resistance to swelling, good microstructural stability under irradiation, and the retention of adequate ductility at typical reactor operating temperatures.

In parallel, lead bismuth eutectic (LBE) has emerged as a potential spallation target material for efficient production of neutrons, as well as a coolant in the accelerator system. While LBE has excellent properties as a nuclear coolant, it is also highly corrosive …

Development Of Dose Coefficients For Radionuclides Produced In Spallation Targets, Phillip W. Patton, Mark Rudin

Transmutation Sciences Physics (TRP)

Dose coefficients permit simple determination of radiation dose associated with various exposure scenarios, and ultimately permit radiation safety personnel to assess the health risks to workers in a nuclear facility. Specifically, radiation safety personnel use dose coefficients to determine the radiation dose incurred to a tissue or organ system from a given exposure. These parameters are often expressed in terms of Annual Limits on Intake (ALIs) and Derived Air Concentrations (DACs).

The research consortium comprised of representatives from several universities and national laboratories has successfully generated internal and external dose conversion coefficients for twenty radionuclides produced in spallation neutron sources. …

Reactor Physics Studies For The Afci Reactor-Accelerator Coupling Experiments (Race) Project, Denis Beller

Transmutation Sciences Physics (TRP)

The specific research objective of this three-year project is to design and conduct an accelerator driven experiment. This experiment will help demonstrate in the U.S. the ability to design, compute, and conduct ADSS experiments; and to predict and measure source importance, coupling efficiency, sub-critical reactor kinetics and source-driven transients. In addition, databases will be created for both steady state and transient ADSS experiments for the nuclear community to develop and test new computational codes and methods, and the importance of a driving neutron source in various regions of different subcritical assemblies will be mapped. Experiments will be conducted and compared …

Immobilization Of Fission Iodine By Reaction With A Fullerene Containing Carbon Compound And Insoluble Natural Matrix, Spencer M. Steinberg, Gary Cerefice, David W. Emerson

Separations Campaign (TRP)

The recovery of iodine released during the processing of used nuclear fuel poses a significant challenge to the transmutation of nuclear waste. Iodine-129, a long-lived fission product formed by both commercial nuclear power generation and nuclear weapons production, is released when reprocessing nuclear fuel. Since iodine can be concentrated in the human thyroid, any uncontrolled release of iodine may result in an increased rate of thyroid cancer in the exposed population. For this reason, recovery of iodine is important for implementing any nuclear transmutation strategy.

The stability of the association of iodine with FCC and NOM products are studied. Product …

Evaluation Of Fluorapatite As A Waste-Form Material, Dennis W. Lindle, Oliver Hemmers, Dale L. Perry

Separations Campaign (TRP)

Argonne National Laboratory has proposed a new extraction procedure to handle TRISO-coated fuels, the Fluoride Extraction Process, or FLEX. The FLEX process is designed to separate the uranium in the fuel from the actinides and most fission products by taking advantage of the unique properties of uranium hexafluoride (UF₆). In the FLEX process, the used TRISO fuel is reacted with zirconium fluoride salt, forming UF₆ and the fluoride salts of the actinides and fission products. At process temperatures, the UF₆ volatizes into a gas, and is released from the molten salt mixture. This leaves behind the …

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

Separations Campaign (TRP)

The overall goal of this project is the creation of a framework that combines all the strengths of AMUSE’s complicated calculations, well-established commercial system process packages, and TRPSEMPro’s flexible parameter optimization modules. Development of the process simulation code can be done using the solvent extraction process at Argonne National Laboratory in collaboration with the UNLV Nevada Center for Advanced Computational Methods.

The major objectives are the following:

• Develop a framework for simulating the Spent Fuel Treatment Facility (SFTF) process using AMUSE code, commercial process package, such as ASPEN-PLUS, and system engineering model.
• Develop a middleware package that can communicate between …

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

Separations Campaign (TRP)

The objective of this project is to use electrochemical techniques to develop a thermodynamic understanding of actinide and lanthanide species in aqueous solution and use this data to effectively separate species with very similar chemical properties. In consultation with a national laboratory collaborators, electrochemical methods and materials will be evaluated and used to exploit the thermodynamic differences between similar chemical species enhancing the ability to selectively target and sequester individual species from mixtures. This project is in its third year and has successfully completed Phases 1 and 2.

The following were specific goals for this year:

• To develop a fundamental …

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

Separations Campaign (TRP)

The research objectives of this project are as follows:

• To determine the influence of nitrate on the speciation of U and Pu in the TBP-dodecane-nitric acid system. The aqueous and organic speciation of U and Pu are examined as a function of the nitric acid concentration, nitrate concentration (by the addition of NaNO₃), actinide ion concentration, temperature, and time.
• To determine the speciation of U and Pu with AHA in the presence and absence of TBP-dodecane organic phase. The aqueous and organic speciation of U and Pu are evaluated as a function of AHA concentration, metal ion concentration, …

Uncertainty, Climate Change And Nuclear Power, David M. Hassenzahl

Public Policy and Leadership Faculty Publications

Long time-horizon environmental risks with potential for global impacts have increased in visibility over the past several decades. Such issues as climate change, the nuclear fuel cycle, persistent synthetic chemicals, and stratospheric ozone depletion share some characteristics, including intergenerational impacts, strongly decoupled incidence of risks and benefits, substantial decision stakes and extreme uncertainty. What is not well understood are the similarities and differences among sources and implications of uncertainty among these global environmental threats, especially those associate with current and future human behavior. This describes the uncertainties associated with managing two global concerns: the nuclear (fission) fuel cycle and anthropogenic …

Isothermal Titration Calorimetry And Transmission Electron Microscopy Of Main-Chain Viologen Polymer Containing Bromide As Counerions, Pradip K. Bhowmik, Marcos A. Cheney, Haesook Han, Longzhou Ma

Transmission Electron Microscope

Polyelectrolytes are an important class of macromolecules that contain dissociable ionic groups. When introduced into polar solvent, usually the universal solvent water, dissociation takes place so that electrically charged macromolecule is suspended in solution. The electrostatic interaction is operative between ionized groups inside the macromolecule, between the macromolecules, between the counterions, and between the macromolecule and counterion. Since this interaction is characterized by its long-range nature, the solution exhibits various interesting properties including the polyelectrolyte behavior very different from solutions of neutral polymers.

Interaction Between Metal Fission Products And Triso Coating Materials: A Study Of Chemical Bonding And Interdiffusion: 1st Quarterly Report, 2006, Clemens Heske

Fuels Campaign (TRP)

This project is devoted to an in-depth study of the chemical and electronic impact of metal fission products on the coating layers in TRISO nuclear fuel. In particular, there is a focus on the investigation of Pd, Cs, and Ag and their interface formation with SiC and carbon-based substrates. A variety of surface and near-surface bulk sensitive probes that investigate the occupied and unoccupied electronic states of the substrate and the metal overlayer have been utilized. By a controlled and stepwise deposition of the metal overlayer, it is possible to gain substantial insight into the formation of interfaces and their …

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

Fuels Campaign (TRP)

The safe and effective manufacturing of actinide-bearing fuels for any transmutation strategy requires that the entire manufacturing process be contained within a shielded hot cell environment. To ensure that the fabrication process is feasible, the entire process must be designed for remote operation. The equipment must be reliable enough to perform over several decades, and also easy to maintain or repair remotely. The facility must also be designed to facilitate its own decontamination and decommissioning. In addition to these design factors, the potential viability of any fuel fabrication process will also be impacted by a number of variables, such as …

Solution-Based Synthesis Of Nitride Fuels, Kenneth Czerwinski, Thomas Hartmann

Fuels Campaign (TRP)

A wide variety of fuel concepts are considered for advanced reactor technology including metals, metal oxides or metal nitrides as solid solutions or composite materials. Nitride fuels have appropriate properties for advanced fuels including high thermal conductivity, thermal stability, solid-state solubility of actinides, fissile metal density, and suitable neutronic properties. A drawback of nitride fuels involves their synthesis. A key parameter for preparing oxide fuels is the precipitation step in the sol-gel process. For nitride fuels, the current synthetic route is carbothermic reduction from the oxide to the nitride. This process step is based on solid phase reactions and for …

Sauger Population Ecology In Three Missouri River Mainstem Reservoirs, Brian D. S. Graeb

Electronic Theses and Dissertations

Sauger Sander canadensis populations have experienced widespread declines across much of their range. Factors suspected to contribute to these declines include hybridization, exploitation, loss of spawning areas, and general habitat alterations associated with regulated rivers. Several sauger populations within the Missouri River basin are also experiencing similar declines, particularly in the headwaters of Montana, and the lower basin states of Nebraska and Missouri. However, sauger populations in many of the reservoirs in South Dakota (between Montana and the lower basin) have relatively stable populations. Given the paucity of information on factors influencing sauger population ecology in general, and Missouri River …

Thermal And Flame Properties Of Polyethylene And Polypropylene Nanocomposites Based On An Oligomerically–Modified Clay, Jinguo Zhang, David D. Jiang, Charles A. Wilkie

Chemistry Faculty Research and Publications

An oligomerically-modified clay was made using a surfactant which is the ammonium salt of an oligomer. The newly modified clay contains 37.5% inorganic clay and 62.5% oligomer. Polyethylene and polypropylene nanocomposites were made by melt blending the polymer with the oligomerically-modified clay in a Brabender mixer at various clay loadings. The structure of the nanocomposites was characterized by X-ray diffraction and transmission electron microscopy. Mechanical testing showed that the polyethylene nanocomposites had an enhanced Young's modulus and slightly decreased elongation, while the changes for polypropylene nanocomposites are small compared with the virgin polymers. The thermal stability and flame properties were …

Temporal Processing In The Exponential Integrate-And-Fire Model Is Nonlinear, Joanna R. Wares, Todd W. Troyer

Department of Math & Statistics Faculty Publications

The exponential integrate-and-fire (EIF) model was introduced by Fourcaud-Trocme et al. (2003) as an extension of the standard leaky integrate-and-fire model (LIF). Here, the nonlinearity in the EIF model’s temporal response to square-wave inputs is investigated. Comparing the time course of onset and offset responses revealed that offset responses have a steeper initial slope, but a slower approach to equilibrium. A linear systems analysis performed for these square-wave inputs indicates that at frequencies above ~40 Hz, gain was slightly smaller for square-wave inputs, but phase did not change significantly relative to simulations in which the corresponding sinusoids were presented in …

Salinity Controls Phytoplankton Response To Nutrient Enrichment In The Great Salt Lake, Utah, Usa, Amy M. Marcarelli, Wayne A. Wurtsbaugh, O. Griset

Watershed Sciences Faculty Publications

To examine how salinity and nutrient supply interact to control phytoplankton community composition, nutrient limitation, and dinitrogen (N2) fixation rates in the Great Salt Lake (Utah, USA), we conducted a series of bioassay experiments with plankton from both Gilbert Bay, where salinities are near 160 g·L–1, and Farmington Bay, where salinities range from 10 to 90 g·L–1. Six-day nutrient addition bioassay experiments showed that the extant phyto plankton communities in both bays were limited by nitrogen (N). However, in 28- to 30-day factorial bioassay experiments in which both salinities and nutrient supply were manipulated, phosphorus stimulated chlorophyll a as much …