Paragenesis and Geochronology of the Nopal I Uranium Deposit, Mexico (open access)

Paragenesis and Geochronology of the Nopal I Uranium Deposit, Mexico

Uranium deposits can, by analogy, provide important information on the long-term performance of radioactive waste forms and radioactive waste repositories. Their complex mineralogy and variable elemental and isotopic compositions can provide important information, provided that analyses are obtained on the scale of several micrometers. Here, we present a structural model of the Nopal I deposit as well as petrography at the nanoscale coupled with preliminary U-Th-Pb ages and O isotopic compositions of uranium-rich minerals obtained by Secondary Ion Mass Spectrometry (SIMS). This multi-technique approach promises to provide ''natural system'' data on the corrosion rate of uraninite, the natural analogue of spent nuclear fuel.
Date: February 14, 2007
Creator: Fayek, M. & Ren, M.
Object Type: Report
System: The UNT Digital Library
The Effect of Magnetic Field on HTS Leads What Happens when thePower Fails at RAL? (open access)

The Effect of Magnetic Field on HTS Leads What Happens when thePower Fails at RAL?

The key to being able to operate the MICE superconducting solenoids on small coolers is the use of high temperature superconducting (HTS) leads between the first stage of the cooler and the magnet, which operates at around 4.2 K. Because MICE magnets are not shielded, all of the MICE magnets have a stray magnetic field in the region where the coolers and the HTS leads are located. The behavior of the HTS leads in a magnetic field depends strongly on the HTS material used for the leads and the temperature of the cooler first stage temperature. The HTS leads can be specified to operate at the maximum current for the magnet. This report shows how the HTS leads can be specified for use the MICE magnets. MICE magnets take from 1.3 hours (the tracker solenoids) to 3.7 hours (the coupling magnet) to charge to the highest projected operating currents. If the power fails, the cooler and the upper ends of the HTS leads warm up. The question is how one can discharge the magnet to protect the HTS leads without quenching the MICE magnets. This report describes a method that one can use to protect the HTS leads in the …
Date: February 14, 2007
Creator: Green, Michael A.
Object Type: Report
System: The UNT Digital Library
RECENT PROCESS IMPROVEMENTS TO INCREASE HLW THROUGHPUT AT THE DWPF (open access)

RECENT PROCESS IMPROVEMENTS TO INCREASE HLW THROUGHPUT AT THE DWPF

The Savannah River Site's (SRS) Defense Waste Processing Facility (DWPF), the world's largest operating high level waste (HLW) vitrification plant, began stabilizing about 35 million gallons of SRS liquid radioactive waste by-product in 1996. The DWPF has since filled over 2000 canisters with about 4000 pounds of radioactive glass in each canister. In the past few years there have been several process and equipment improvements at the DWPF to increase the rate at which the waste can be stabilized. These improvements have either directly increased waste processing rates or have desensitized the process and therefore minimized process upsets and thus downtime. These improvements, which include glass former optimization, increased waste loading of the glass, the melter heated bellows liner, and glass surge protection software, will be discussed in this paper.
Date: February 14, 2007
Creator: Herman, C
Object Type: Report
System: The UNT Digital Library
Real-Time Ellipsometry-Based Transmission Ultrasound Imaging (open access)

Real-Time Ellipsometry-Based Transmission Ultrasound Imaging

Ultrasonic imaging is a valuable tool for non-destructive evaluation and medical diagnosis. Reflection mode is exclusively used for medical imaging, and is most frequently used for nondestructive evaluation (NDE) because of the relative speed of acquisition. Reflection mode imaging is qualitative, yielding little information about material properties, and usually only about material interfaces. Transmission imaging can be used in 3D reconstructions to yield quantitative information: sound speed and attenuation. Unfortunately, traditional scanning methods of acquiring transmission data are very slow, requiring on the order of 20 minutes per image. The sensing of acoustic pressure fields as optical images can significantly speed data acquisition. An entire 2D acoustic pressure field can be acquired in under a second. The speed of data acquisition for a 2D view makes it feasible to obtain multiple views of an object. With multiple views, 3D reconstruction becomes possible. A fast, compact (no big magnets or accelerators), inexpensive, 3D imaging technology that uses no ionizing radiation could be a boon to the NDE and medical communities. 2D transmission images could be examined in real time to give the ultrasonic equivalent of a fluoroscope, or accumulated in such a way as to acquire phase and amplitude data over …
Date: February 14, 2007
Creator: Kallman, J. S.; Poco, J. F. & Ashby, A. E.
Object Type: Report
System: The UNT Digital Library
Structural Defects in Laterally Overgrown GaN Layers Grown onNon-polar Substrates (open access)

Structural Defects in Laterally Overgrown GaN Layers Grown onNon-polar Substrates

Transmission electron microscopy was used to study defects in lateral epitaxial layers of GaN which were overgrown on a template of a-plane (11{und 2}0) GaN grown on (1{und 1}02) r-plane Al2O3. A high density of basal stacking faults is formed in these layers because the c-planes of wurtzite structure are arranged along the growth direction. Density of these faults is decreasing at least by two orders of magnitude lower in the wings compared to the seed areas. Prismatic stacking faults and threading dislocations are also observed, but their densities drastically decrease in the wings. The wings grow with opposite polarities and the Ga-wing width is at least 6 times larger than N-wing and coalescence is rather difficult. Some tilt and twist was detected using Large Angle Convergent Beam Electron Diffraction.
Date: February 14, 2007
Creator: Liliental-Weber, Z.; Ni, X. & Morkoc, H.
Object Type: Article
System: The UNT Digital Library
Development of the Low Swirl Injector for Fuel-Flexible Gas Turbines (open access)

Development of the Low Swirl Injector for Fuel-Flexible Gas Turbines

Industrial gas turbines are primarily fueled with natural gas. However, changes in fuel cost and availability, and a desire to control carbon dioxide emissions, are creating pressure to utilize other fuels. There is an increased interest in the use of fuels from coal gasification, such as syngas and hydrogen, and renewable fuels, such as biogas and biodiesel. Current turbine fuel injectors have had years of development to optimize their performance with natural gas. The new fuels appearing on the horizon can have combustion properties that differ substantially from natural gas. Factors such as turbulent flame speed, heat content, autoignition characteristics, and range of flammability must be considered when evaluating injector performance. The low swirl injector utilizes a unique flame stabilization mechanism and is under development for gas turbine applications. Its design and mode of operation allow it to operate effectively over a wide range of conditions. Studies conducted at LBNL indicate that the LSI can operate on fuels with a wide range of flame speeds, including hydrogen. It can also utilize low heat content fuels, such as biogas and syngas. We will discuss the low swirl injector operating parameters, and how the LSC performs with various alternative fuels.
Date: February 14, 2007
Creator: Littlejohn, D.; Cheng, R.K.; Nazeer,W.A. & Smith, K.O
Object Type: Article
System: The UNT Digital Library
Hydrologic Data and Evaluation for Model Validation Wells, MV-1, MV-2, and MV-3 near the Project Shoal Area (open access)

Hydrologic Data and Evaluation for Model Validation Wells, MV-1, MV-2, and MV-3 near the Project Shoal Area

In 2006, a drilling campaign was conducted at the Project Shoal Area (PSA) to provide information for model validation, emplace long-term monitoring wells, and develop baseline geochemistry for long term hydrologic monitoring. Water levels were monitored in the vicinity of the drilling, in the existing wells HC-1 and HC-6, as well as in the newly drilled wells, MV-1, MV-2 and MV-3 and their associated piezometers. Periodic water level measurements were also made in existing wells HC-2, HC-3, HC-4, HC-5 and HC-7. A lithium bromide chemical tracer was added to drilling fluids during the installation of the monitoring and validation (MV) wells and piezometers. The zones of interest were the fractured, jointed and faulted horizons within a granitic body. These horizons generally have moderate hydraulic conductivities. As a result, the wells and their shallower piezometers required strenuous purging and development to remove introduced drilling fluids as evidenced by bromide concentrations. After airlift and surging well development procedures, the wells were pumped continuously until the bromide concentration was less then 1 milligram per liter (mg/L). Water quality samples were collected after the well development was completed. Tritium scans were preformed before other analyses to ensure the absence of high levels of radioactivity. …
Date: February 14, 2007
Creator: Lyles, B.; Oberlander, P.; Gillespie, D.; Donithan, D.; Chapman, J. & Healey, J.
Object Type: Report
System: The UNT Digital Library
HANFORD DST THERMAL & SEISMIC PROJECT DYTRAN ANALYSIS OF SEISMICALLY INDUCED FLUID STRUCTURE INTERACTION IN A HANFORD DOUBLE SHELL PRIMARY TANK (open access)

HANFORD DST THERMAL & SEISMIC PROJECT DYTRAN ANALYSIS OF SEISMICALLY INDUCED FLUID STRUCTURE INTERACTION IN A HANFORD DOUBLE SHELL PRIMARY TANK

Revision 0A of this document contains new Appendices C and D. Appendix C contains a re-analysis of the rigid and flexible tanks at the 460 in. liquid level and was motivated by recommendations from a Project Review held on March 20-21, 2006 (Rinker et al Appendix E of RPP-RPT-28968 Rev 1). Appendix D contains the benchmark solutions in support of the analyses in Appendix C.
Date: February 14, 2007
Creator: Mackey, T. C.; Rinker, M. W. & Abatt, F. G.
Object Type: Report
System: The UNT Digital Library
Real-Time Temperature Measurement in a Vacuum Degasser Using Optical Pyrometry (open access)

Real-Time Temperature Measurement in a Vacuum Degasser Using Optical Pyrometry

The objective of the research was the development of a fiber-coupled, optical pyrometer for continuous temperature measurement in a vacuum degasser that reduces process time, enhances process control, and eliminates manual or robot-operated thermocouples. Through the live testing performed at US Steel's Edgar Thompson Works, the challenges associated with making optical temperature measurements in a vacuum chamber were identified. As a result of these challenges it was determined that continuous temperature monitoring in RH-type degassers was not a viable alternative to standard immersion thermocouples. The project was not successful.
Date: February 14, 2007
Creator: Metrix, Michel Bonin - Process; Metrix, Peter Hues - Process; Metals, William Federoff - US Steel Nichloas Rymarchyk - Berry & Metals, Todd Smith - Berry
Object Type: Report
System: The UNT Digital Library
Isotope-Geochmical Evidence For Uranium Retardation in Zeolitized Tuffs at Yucca Mountain, Nevada, USA (open access)

Isotope-Geochmical Evidence For Uranium Retardation in Zeolitized Tuffs at Yucca Mountain, Nevada, USA

Retardation of radionuclides by sorption on minerals in the rocks along downgradient groundwater flow paths is a positive attribute of the natural barrier at Yucca Mountain, Nevada, the site of a proposed high-level nuclear waste repository. Alteration of volcanic glass in nonwelded tuffs beneath the proposed repository horizon produced thick, widespread zones of zeolite- and clay-rich rocks with high sorptive capacities. The high sorptive capacity of these rocks is enhanced by the large surface area of tabular to fibrous mineral forms, which is about 10 times larger in zeolitic tuffs than in devitrified tuffs and about 30 times larger than in vitric tuffs. The alteration of glass to zeolites, however, was accompanied by expansion that reduced the matrix porosity and permeability. Because water would then flow mainly through fractures, the overall effectiveness of radionuclide retardation in the zeolitized matrix actually may be decreased relative to unaltered vitric tuff. Isotope ratios in the decay chain of {sup 238}U are sensitive indicators of long-term water-rock interaction. In systems older than about 1 m.y. that remain closed to mass transfer, decay products of {sup 238}U are in secular radioactive equilibrium where {sup 234}U/{sup 238}U activity ratios (AR) are unity. However, water-rock interaction along …
Date: February 14, 2007
Creator: Neymark, L. A. & Paces, J. B.
Object Type: Report
System: The UNT Digital Library
Intercellular Genomics of Subsurface Microbial Colonies (open access)

Intercellular Genomics of Subsurface Microbial Colonies

This report summarizes progress in the second year of this project. The objective is to develop methods and software to predict the spatial configuration, properties and temporal evolution of microbial colonies in the subsurface. To accomplish this, we integrate models of intracellular processes, cell-host medium exchange and reaction-transport dynamics on the colony scale. At the conclusion of the project, we aim to have the foundations of a predictive mathematical model and software that captures the three scales of these systems – the intracellular, pore, and colony wide spatial scales. In the second year of the project, we refined our transcriptional regulatory network discovery (TRND) approach that utilizes gene expression data along with phylogenic similarity and gene ontology analyses and applied it successfully to E.coli, human B cells, and Geobacter sulfurreducens. We have developed a new Web interface, GeoGen, which is tailored to the reconstruction of microbial TRNs and solely focuses on Geobacter as one of DOE’s high priority microbes. Our developments are designed such that the frameworks for the TRND and GeoGen can readily be used for other microbes of interest to the DOE. In the context of modeling a single bacterium, we are actively pursuing both steady-state and kinetic …
Date: February 14, 2007
Creator: Ortoleva, Peter; Tuncay, Kagan; Gannon, Dennis & Meile, Christof
Object Type: Report
System: The UNT Digital Library
Nuclear Probing of Dense Plasmas (open access)

Nuclear Probing of Dense Plasmas

The object of inertial confinement fusion (ICF) is to compress a fuel capsule to a state with high enough density and temperature to ignite, starting a self-sustaining fusion burn that consumes much of the fuel and releases a large amount of energy. The national ICF research program is trying to reach this goal, especially through experiments at the OMEGA laser facility of the University of Rochester Laboratory of Laser Energetics (LLE), planned experiments at the National Ignition Facility (NIF) under construction at the Lawrence Livermore National Laboratory (LLNL), and experimental and theoretical work at other national laboratories. The work by MIT reported here has played several important roles in this national program. First, the development of new and improved charged-particle-based plasma diagnostics has allowed the gathering of new and unique diagnostic information about the implosions of fuel capsules in ICF experiments, providing new means for evaluating experiments and for studying capsule implosion dynamics. Proton spectrometers have become the standard for evaluating the mass assembly in compressed capsules in experiments at OMEGA; the measured energy downshift of either primary or secondary D3He fusion protons to determines the areal density, or ?R, of imploded capsules. The Proton Temporal Diagnostic measures the time …
Date: February 14, 2007
Creator: Petrasso, Richard
Object Type: Report
System: The UNT Digital Library
Nuclear Probing of Dense Plasmas and Implosion Physics at OMEGA, Z, OMEGA with EP and the NIF (open access)

Nuclear Probing of Dense Plasmas and Implosion Physics at OMEGA, Z, OMEGA with EP and the NIF

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Date: February 14, 2007
Creator: Petrasso, Richard
Object Type: Report
System: The UNT Digital Library
Parametic Study of the current limit within a single driver-scaletransport beam line of an induction Linac for Heavy Ion Fusion (open access)

Parametic Study of the current limit within a single driver-scaletransport beam line of an induction Linac for Heavy Ion Fusion

The High Current Experiment (HCX) at Lawrence Berkeley National Laboratory is part of the US program that explores heavy-ion beam as the driver option for fusion energy production in an Inertial Fusion Energy (IFE) plant. The HCX is a beam transport experiment at a scale representative of the low-energy end of an induction linear accelerator driver. The primary mission of this experiment is to investigate aperture fill factors acceptable for the transport of space-charge-dominated heavy-ion beams at high intensity (line charge density {approx}0.2 {micro}C/m) over long pulse durations (4 {micro}s) in alternating gradient focusing lattices of electrostatic or magnetic quadrupoles. This experiment is testing transport issues resulting from nonlinear space-charge effects and collective modes, beam centroid alignment and steering, envelope matching, image charges and focusing field nonlinearities, halo and, electron and gas cloud effects. We present the results for a coasting 1 MeV K{sup +} ion beam transported through ten electrostatic quadrupoles. The measurements cover two different fill factor studies (60% and 80% of the clear aperture radius) for which the transverse phase-space of the beam was characterized in detail, along with beam energy measurements and the first halo measurements. Electrostatic quadrupole transport at high beam fill factor ({approx}80%) is …
Date: February 14, 2007
Creator: Prost, Lionel Robert
Object Type: Thesis or Dissertation
System: The UNT Digital Library
2006 Annual Operations Report for INTEC Operable Unit 3-13, Group 1, Tank Farm Interim Action (open access)

2006 Annual Operations Report for INTEC Operable Unit 3-13, Group 1, Tank Farm Interim Action

This annual operations report describes the requirements followed and activities conducted to inspect, monitor, and maintain the items installed during performance of the Waste Area Group 3, Operable Unit 3-13, Group 1, Tank Farm Interim Action, at the Idaho Nuclear Technology and Engineering Center. This report covers the time period from January 1 through December 31, 2006, and describes inspection and monitoring activities for the surface-sealed areas within the tank farm, concrete-lined ditches and culverts in and around the tank farm, the lift station, and the lined evaporation pond. These activities are intended to assure that the interim action is functioning adequately to meet the objectives stated in the Operable Unit 3-13, Record of Decision for the Group 1, Tank Farm Interim Action (DOE/ID-10660) as described in the Group 1 Remedial Design/Remedial Action Work Plan (DOE/ID-10772).
Date: February 14, 2007
Creator: Shanklin, D. E.
Object Type: Report
System: The UNT Digital Library
Tensile and Creep-Rupture Evaluation of a New Heat of Haynes Alloy 25 (open access)

Tensile and Creep-Rupture Evaluation of a New Heat of Haynes Alloy 25

From 1999 to 2006, a program was undertaken within the Materials Science and Technology Division, formerly the Metals and Ceramics Division, of Oak Ridge National Laboratory to characterize the tensile and creep-rupture properties of a newly produced heat of Haynes alloy 25 (L-605). Tensile properties from room temperature to 1100 C were evaluated for base material and welded joints aged up to 12,000 hours at 675 C. Creep and creep-rupture tests were conducted on base metal and cross-weldments from 650 to 950 C. Pressurized tubular creep tests were conducted to evaluate multiaxial creep-rupture response of the material. Over 800,000 hours of creep test data were generated during the test program with the longest rupture tests extending beyond 38,000 hours, and the longest creep-rate experiments exceeding 40,000 hours.
Date: February 14, 2007
Creator: Shingledecker, J. P.; Glanton, D. B.; Martin, R. L.; Sparks, B. L. & Swindeman, R. W.
Object Type: Report
System: The UNT Digital Library
HANFORD DOUBLE SHELL TANK (DST) THERMAL & SEISMIC PROJECT BUCKLING EVALUATION METHODS & RESULTS FOR THE PRIMARY TANKS (open access)

HANFORD DOUBLE SHELL TANK (DST) THERMAL & SEISMIC PROJECT BUCKLING EVALUATION METHODS & RESULTS FOR THE PRIMARY TANKS

This report documents a detailed buckling evaluation of the primary tanks in the Hanford double-shell waste tanks (DSTs), which is part of a comprehensive structural review for the Double-Shell Tank Integrity Project. This work also provides information on tank integrity that specifically responds to concerns raised by the Office of Environment, Safety, and Health (ES&H) Oversight (EH-22) during a review of work performed on the double-shell tank farms and the operation of the aging waste facility (AWF) primary tank ventilation system. The current buckling review focuses on the following tasks: (1) Evaluate the potential for progressive I-bolt failure and the appropriateness of the safety factors that were used for evaluating local and global buckling. The analysis will specifically answer the following questions: (a) Can the EH-22 scenario develop if the vacuum is limited to -6.6-inch water gage (w.g.) by a relief valve? (b) What is the appropriate factor of safety required to protect against buckling if the EH-22 scenario can develop? (c) What is the appropriate factor of safety required to protect against buckling if the EH-22 scenario cannot develop? (2) Develop influence functions to estimate the axial stresses in the primary tanks for all reasonable combinations of tank loads, …
Date: February 14, 2007
Creator: TC, MACKEY; KI, JOHNSON; JE, DEIBLER; SP, PILLI; MW, RINKER & NK, KARRI
Object Type: Report
System: The UNT Digital Library