Physical Sciences and Mathematics Commons^™

Vegetation Re-Establishment Of Mojave Desert Plant Communities After 2005-2006 Wildland Fires, E. Cayenne Engel, Scott R. Abella

Fire Science Presentations

Examine biotic and abiotic patterns that determine vegetative regrowth after wildfires to better inform land managers about what to expect after fires and how to manage restoration efforts.

Seeding Effectiveness For Eight Mojave Desert Perennials After A 2005 Wildfire, E. Cayenne Engel, Scott R. Abella, Christina L. Lund

Fire Science Presentations

To assess BLM seeding effectiveness in a mid-elevation burn where pre-burn plant communities were dominated by blackbrush, Joshua trees, and creosote.

Discover Mojave Outdoor World Activity Unit Curriculum, Daphne Sewing, Jennell M. Miller, Allison Brody

Curriculum materials (DM)

This document provides suggested activity outlines for each recreational unit as well as available resources, pertinent contacts, checklists, and activity assessments. Each unit is correlated with the themes identified by the Southern Nevada Agency Partnership Conservation Education and Interpretation Team.

The Discover Mojave Outdoor World program introduces urban youth, ages 8-12, to outdoor recreation and environmental education. The program promotes the belief that outdoor recreation plays an important and positive role in the health and fitness of America’s youth.

The program is patterned after the national Wonderful Outdoor World (WOW) program. WOW introduces urban youth and families to the outdoors …

Learning Science At The Lake: A Successful Partnership Between Formal And Informal Educators, Public Lands Institute

Presentations (DM)

Emphasis on cooperative conservation through:

• Education
• Research
• Community Engagement

Assessing “Discover Mojave”, Year Two: Final Report, Lori Olafson, Gregory Schraw, Michelle L. Weibel

Reports (DM)

Discover Mojave Outdoor World is a hands-on outdoor recreation program for urban, economically disadvantaged youth. In Year One of the program, knowledge, attitude, and performance assessments were developed to document the effectiveness of program events over the duration of the program. Year One findings revealed that knowledge, attitudes, and performance increased substantially as a result of participating in the outdoor recreation events. The assessment plan was modified in Year Two by creating assessments for teachers and parents, as well as a developing a structured interview protocol. Changes were made to existing assessments and two new assessment tools were implemented. Findings …

Decoupling And Disturbance Rejection Control For Target Circulation, Jian Ma, Joon S. Lee, Woosoon Yim

Reactor Campaign (TRP)

In 1998, the Institute of Physics and Power Engineering (IPPE) and Experimental and Development Organization “Gidropress” in Russia, began the design and construction of a prototype lead-bismuth eutectic (LBE) accelerator target, the Target Complex 1 (TC-1), under the International Science and Technology Center (ISTC) project #559 (“Pilot Flow Lead-Bismuth Target of 1 MW Power for Accelerator Driven Systems”) in support of the international efforts to develop accelerator-driven spallation systems for nuclear transmutation and other applications.

During the thermal and engineering test of the TC-1 in 2005 at UNLV, it was observed that the existing control algorithm led to a very …

Modeling And Design Algorithms For Electromagnetic Pumps, Daniel P. Cook

Reactor Campaign (TRP)

Electromagnetic (EM) induction pumps are used in a number of nuclear energy related applications, such as circulation of molten lead-bismuth eutectic alloys in neutron targets, and circulation of liquid sodium metal in Gen IV Sodium-cooled Fast Reactors (SFR). Because EM pumps have no moving parts which can fail, they are considerably more reliable than conventional mechanical pumps for molten metal usage, and thus EM pumps are favored over mechanical pumps even though their pumping efficiency is lower and their initial cost is higher when compared to mechanical pumps of similar flow rates.

The research objectives of this task are:

• A …

University Of Nevada, Las Vegas Transmutation Research Program Annual Report Academic Year 2006-2007, Anthony Hechanova, Rebecca Arbour

Transmutation Research Program Reports (TRP)

It is my pleasure to present the UNLV Transmutation Research Program’s sixth annual report that highlights the academic year 2006-2007. Supporting this document are the many technical reports and theses that have been generated over the past five years.

In the sixth year of our program, we continued to see growth in the Radiochemistry Ph.D. program with a total of 13 students in the third year of the program (we anticipated eight in the program proposal). Since our inception, the program has sponsored to their conclusion 42 M.S. and 4 Ph.D. degrees. The program supported 39 graduate students, 17 undergraduates, …

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

Safeguards Campaign (TRP)

The goal of this project is to evaluate the application of these analytical techniques to the on-line, real-time measurement of the actinide elements in the process streams of a solvent extraction process, with particular attention to the UREX+ and PUREX processes. Based on the experience gained through this effort, engineers will have the information necessary to decide if these technologies should be advanced to the prototype stage and tested at the pilot plant level. Through the experimental work planned as part of this effort, researchers will also develop a better understanding of the chemical interactions of the actinide elements, providing …

Combined Radiation Detection Methods For Assay Of Higher Actinides In Separation Processes, 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 …

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

Transmutation Sciences Materials (TRP)

During the past academic year, this project was focused on the characterization of residual stress in welded specimens consisting of austenitic and martensitic stainless steels using an activation technique based on the Positron Annihilation Spectroscopic (PAS) method. The extent of residual stress was expressed in terms of three line-shape parameters (S-, W- and T-). Further, efforts were made to characterize linear lattice defects such as dislocations in the vicinity of Fusion-Line (FL), Heat-Affected- Zone (HAZ), and the base material of the welded specimens using Transmission Electron Microscopy (TEM). The metallurgical microstructures at these three regions have also been evaluated by …

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 and facilities (e.g., transmutation of nuclear waste, fast reactors, and spallation neutron sources) impose special demands on materials, which must withstand high temperatures, high radiation fields, and chemical corrosion. Proposed schemes for transmuting nuclear waste require a nonmoderating coolant such as lead-bismuth eutectic (LBE). While LBE corrodes most steels, small amounts of oxygen in the LBE greatly reduces the corrosion rate, and could ideally re-grow a damaged oxide layer in-situ. The protective oxide layer would thus be self-healing. However, the fundamental understanding of the role of oxygen and passivating oxide layers is presently incomplete.

During the present …

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 focused on the evaluation of the effects of silicon content on both the corrosion behavior and radiation-induced embrittlement of martensitic stainless steels having compositions similar to that of modified 9Cr-1Mo steel, also known as T91 grade steel. T91 grade steel was selected to be a candidate structural material to contain molten lead-bismuth eutectic (LBE), which can act both as a target material and a coolant during the spallation process. The operating temperature during this process may range from 420-550 °C. Thus, moderate tensile strength of the containment material (T91) is a major requirement.

The beneficial effects of …

Theoretical Modeling Of Protective Oxide Layer Growth In Non-Isothermal Lead Alloy 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 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 apply …

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 to …

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

Transmutation Sciences Physics (TRP)

The specific research objective of this three-year project is to design and conduct accelerator driven experiments, which 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 to calculations …

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 stability of the association of iodine with FCC and NOM products were studied. Product distributions for the various matrices under various reaction conditions were examined in order to maximize the binding of iodine. The recovery of the iodine from the sequestration matrices was also examined, along with the conversion of the iodine to matrices more suitable for geological storage and/or use as transmutation targets.

The following are the specific research objectives and goals:

• Develop bench-scale experimental set-up and procedures for simulating plutonium extraction process (PUREX) head-end vapor phase.
• Develop experimental procedures for evaluating iodine sequestering methods using bench-scale procedures. …

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 major objectives will lead to a creation of framework that combines all the strengths of AMUSE’s complicated calculations, well-established commercial system process package and ISOPro’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 research team from Mechanical Engineering Department at UNLV.

Research accomplishments:

• Integrated the ASPEN-Plus process model with the ISOPro system engineering modeling package, developed by the UNLV team.
• Tested the simplified system process integration using the ISOPro package.
• Generated complete version of the ISOPro package user manual and tutorial. …

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

Separations Campaign (TRP)

The objectives of this project are to use electrochemical techniques to develop a thermodynamic understanding of actinide and lanthanide species in RTIL solution, and to use this data to effectively separate species with very similar chemical properties. In consultation with a national laboratory collaborator, 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. Phase 3 has been partially completed. The tasks have been expanded …

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

Separations Campaign (TRP)

The research objective is to experimentally evaluate the fundamental speciation of Pu and U in the TBP-dodecane-nitric acid- AHA system and the effect of pertechnetate, specifically:

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, 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 …

Criticality Studies For Urex Processes, Denis Beller

Separations Campaign (TRP)

The completion of criticality experiments for mixtures of transuranic actinides (TRU–includes Np, Pu, Am, and Cm) that will be created during the separation of used nuclear fuel may be a requirement in order to construct prototype plants for the Global Nuclear Energy Partnership. In this program and the Advanced Fuel Cycle Research and Development (AFC R&D) program that supports it, economic and environmental methods are being developed to reduce the impact of waste from commercial nuclear fuel cycles.

Recycling of used fuel by chemically separating it into U, fission products, and TRU would be the first step in this new …

F-Element Electrochemistry In Room Temperature Ionic Liquids, David W. Hatchett, Kenneth Czerwinski

Separations Campaign (TRP)

This proposal focuses on f-element electrochemistry in room temperature ionic liquids (RTILs). The ultimate goal is to fully characterize the oxidation/reduction of elements in RTILs to establish the baseline thermodynamic and kinetic data for these systems. The data will be used to critically evaluate the ability to use electrochemical methods for controlled, potential mediated, separation off-elements by electroplating on electrodes surfaces. Factors that will influence the ability to measure the redox processes in f-elements in RTIL solutions and electroplating on electrode surfaces include the structure, solubility, and stability of the target species in these solutions. These factors will be addressed …

Evaluation Of Fundamental Radionuclide Extraction Data For Urex, Kenneth Czerwinski

Separations Campaign (TRP)

The speciation of technetium and actinides in advanced solvent extraction systems is the basis for their manipulation in separations. The ability to understand and predict radionuclide speciation is paramount to successful modeling of proposed separation systems. This project will examine the speciation of radionuclides in different stages of the UREX separation scheme, providing data useful to modeling. The areas to be examined include the speciation of U and Pu with tributylphosphate and the kinetics and thermodynamics of lanthanides and actinides in the TALSPEAK system. The complexation constants of U and Pu with tributylphosphate will be evaluated. In the TALSPEAK system, …

Separation Of Technetium From Uranium And Waste Form Synthesis, Kenneth Czerwinski

Waste Forms Campaign (TRP)

In this project, systematic investigations on the Tc-Zr binary metal system will be evaluated for the first time. The synthesis of metallic Tc as well as its alloys with Zr will be evaluated. In order to provide valuable data to AFC R&D, the thermodynamic equilibrium phases, as well as their performance under repository conditions, will be examined.

Evaluation Of Cs/Sr Waste Form For Long Term Storage And Disposal, Gary Cerefice, Longzhou Ma

Waste Forms Campaign (TRP)

The goal of this project is to examine two potential concerns regarding the long-term performance of a proposed cesium/ strontium waste form. To facilitate long-term storage, up to 300 years, the disposal containers will need to be able to survive for the entire storage interval. The first aspect of the project will explore the potential interaction of the aluminosilicate waste form with the storage canister materials to determine if there is any corrosion or chemical interaction concerns for the storage of the materials.

At the end of the storage interval, most of the 137Cs in the waste form will have …

Farm Water For The North-Eastern And Eastern Wheatbelt Of Western Australia (Zones 2 And 5), Susan Murphy-White

Resource management technical reports

Large proportions of Western Australia's dryland farms suffer from water supply problems in the form of shortages, poor quality or combinations of these two factors ... A regional study for the North-eastern and Eastern Wheatbelt of Western Australia was undertaken. The base data used to develop water supply areas included soil type, landscape units, geology, hydrogeology, native vegetation and existing far water resource infrastructure.

Chemical Analyses In Support Of Yucca Mountain Studies, Harry Reid Center For Environmental Studies, University Of Nevada, Las Vegas

Publications (YM)

Research Objectives:

Provide preparation of injectates, sorption studies and analyses for tracer tests

Provide REE, trace metals, majors and field measurement data from wells of the Nye County Early Warning Drilling Program (NCEWDP)and Inyo County

Other laboratory needs as they arise

Geostatistical And Stochastic Study Of Radionuclide Transport In The Unsaturated Zone At Yucca Mountain, Feng Pan, Ming Ye, Jianting Zhu

Publications (YM)

Motivation: Why Study of Unsaturated Zone?

The unsaturated zone (UZ), where the proposed repository would be located, acts as a critical natural barrier by delaying the arrival of radionuclides at the saturated zone and by reducing radionuclide concentrations in groundwater through dispersion and dilution

Quantitative prediction of radionuclide transport in the unsaturated zone becomes critical for performance assessment and design of the proposed repository of the Yucca Mountain Project

Precipitation Monitoring At Yucca Mountain, Klaus J. Stetzenbach, Amanda Brandt

Publications (YM)

Objectives: Status of the Task to Date
Network Overview/ Equipment
Data Trends
Uses and Collaborative Projects
Spatial Interpolation of YM Rainfall
Storm Event Analysis
Shallow Groundwater Response to Rainfall
UE29a1 Water Level Response to Barometric Pressure Fluctuation