Detailed Reaction Kinetics for CFD Modeling of Nuclear Fuel Pellet Coating for High Temperature Gas-Cooled Reactors (open access)

Detailed Reaction Kinetics for CFD Modeling of Nuclear Fuel Pellet Coating for High Temperature Gas-Cooled Reactors

The research project was related to the Advanced Fuel Cycle Initiative and was in direct alignment with advancing knowledge in the area of Nuclear Fuel Development related to the use of TRISO fuels for high-temperature reactors. The importance of properly coating nuclear fuel pellets received a renewed interest for the safe production of nuclear power to help meet the energy requirements of the United States. High-temperature gas-cooled nuclear reactors use fuel in the form of coated uranium particles, and it is the coating process that was of importance to this project. The coating process requires four coating layers to retain radioactive fission products from escaping into the environment. The first layer consists of porous carbon and serves as a buffer layer to attenuate the fission and accommodate the fuel kernel swelling. The second (inner) layer is of pyrocarbon and provides protection from fission products and supports the third layer, which is silicon carbide. The final (outer) layer is also pyrocarbon and provides a bonding surface and protective barrier for the entire pellet. The coating procedures for the silicon carbide and the outer pyrocarbon layers require knowledge of the detailed kinetics of the reaction processes in the gas phase and at …
Date: November 29, 2008
Creator: Battaglia, Francine
Object Type: Report
System: The UNT Digital Library
Bahrain: Reform, Security, and U.S. Policy (open access)

Bahrain: Reform, Security, and U.S. Policy

This report is about a free trade agreement between the United States and Bahrain.
Date: November 29, 2007
Creator: Katzman, Kenneth
Object Type: Report
System: The UNT Digital Library
CH Packaging Operations Manual (open access)

CH Packaging Operations Manual

This procedure provides instructions forassembling the following CH packaging payload: Drum payload assembly Standard Waste Box (SWB) assembly Ten-Drum Overpack (TDOP)
Date: November 29, 2007
Creator: Westinghouse TRU Solutions LLC
Object Type: Report
System: The UNT Digital Library
Climate Change: Science Update 2007 (open access)

Climate Change: Science Update 2007

This report summarizes highlights of new scientific research and assessments released in 2007 related to global warming.
Date: November 29, 2007
Creator: Leggett, Jane A.
Object Type: Report
System: The UNT Digital Library
Dislocation-Radiation Obstacle Interactions: Developing Improved Mechanical Property Constitutive Models (open access)

Dislocation-Radiation Obstacle Interactions: Developing Improved Mechanical Property Constitutive Models

Radiation damage to structural and cladding materials, including austenitic stainless steels, ferritic steels, and zirconium alloys, in nuclear reactor environments results in significant mechanical property degradation, including yield strength increases, severe ductility losses and flow localization, which impacts reliability and performance. Generation IV and advanced fuel cycle concepts under consideration will require the development of advanced structural materials, which will operate in increasingly hostile environments. The development of predictive models is required to assess the performance and response of materials in extreme Gen IV reactor operating conditions (temperature, stress, and pressure), to decrease the time to rapidly assess the properties of new materials and insert them into technological applications (Gen IV and Advanced Fuel Cycle Operations).
Date: November 29, 2007
Creator: WIrth, B.D. & Robertson, Ian M.
Object Type: Report
System: The UNT Digital Library
Excessive CEO Pay: Background and Policy Approaches (open access)

Excessive CEO Pay: Background and Policy Approaches

This report provides Background and Policy Approaches about Excessive CEO Pay where average pay for non-management workers has stagnated after adjustment for inflation, falling slightly since the early 1970's.
Date: November 29, 2007
Creator: Shorter, Gary; Jickling, Mark & Raab, Alison
Object Type: Report
System: The UNT Digital Library
Extreme Ultraviolet Imaging of Electron Heated Targets in Petawatt Laser Experiments (open access)

Extreme Ultraviolet Imaging of Electron Heated Targets in Petawatt Laser Experiments

The study of the transport of electrons, and the flow of energy into a solid target or dense plasma, is instrumental in the development of fast ignition inertial confinement fusion. An extreme ultraviolet (XUV) imaging diagnostic at 256 eV and 68 eV provides information about heating and energy deposition within petawatt laser-irradiated targets. XUV images of several irradiated solid targets are presented.
Date: November 29, 2007
Creator: Ma, T.; MacPhee, A.; Key, M.; Akli, K.; Mackinnon, A.; Chen, C. et al.
Object Type: Article
System: The UNT Digital Library
FRACTIONAL CRYSALLIZATION LABORATORY TESTS WITH SIMULATED TANK WASTE (open access)

FRACTIONAL CRYSALLIZATION LABORATORY TESTS WITH SIMULATED TANK WASTE

Results are presented for several simulated waste tests related to development of the fractional crystallization process. Product salt dissolution rates were measured to support pilot plant equipment design. Evaporation tests were performed to evaluate the effects of organics on slurry behavior and to determine optimum antifoam addition levels. A loss-of-power test was performed to support pilot plant accident scenario analysis. Envelope limit tests were done to address variations in feed composition.
Date: November 29, 2007
Creator: DL, HERTING
Object Type: Report
System: The UNT Digital Library
Going to Conference in the Senate (open access)

Going to Conference in the Senate

This report discusses these steps and how they are taken on the Senate floor.
Date: November 29, 2007
Creator: Rybicki, Elizabeth
Object Type: Report
System: The UNT Digital Library
Ground Water Level Measurements in Selected Boreholes Near the Site of the Proposed Repository (open access)

Ground Water Level Measurements in Selected Boreholes Near the Site of the Proposed Repository

The Harry Reid Center for Environmental Studies (HRC) at the University of Nevada, Las Vegas (UNLV) acquired quarterly and continuous data on water levels from approximately 26 boreholes that comprise a periodic monitoring network (Table 1) between October 2003 and September 2007. During this period we continued to observe and analyze short and long-term ground water level trends in periodically monitored boreholes. In this report we summarize and discuss four key findings derived from analysis of water level data acquired during this period: 1. Rapid ground water level rise after storm events in Forty Mile Canyon; 2. Seismically-induced ground water level fluctuations; 3. A sample of synoptic observations and barometric influences on short term fluctuations; and 4. Long term ground water level trends observed from mid-2001 through late-2005.
Date: November 29, 2007
Creator: Page, H. Scott
Object Type: Report
System: The UNT Digital Library
Inertial Fusion Energy's Role in Developing the Market for High Power Laser Diodes (open access)

Inertial Fusion Energy's Role in Developing the Market for High Power Laser Diodes

Production-cost models for high-power laser-diodes indicate systems of 10GW peak power coupled with facilitization of semi-conductor manufacturing capacity could yield costs below $0.02/Watt. This is sufficient to make IFE competitive with other nuclear power technologies.
Date: November 29, 2007
Creator: Ladran, A. L.; Ault, E. R.; Beach, R. J.; Campbell, J. H.; Erlandson, A. C.; Felker, A. J. et al.
Object Type: Article
System: The UNT Digital Library
Keck Observations of the 2002-2003 Jovian Ring Plane Crossing (open access)

Keck Observations of the 2002-2003 Jovian Ring Plane Crossing

We present new observations of Jupiter's ring system at a wavelength of 2.2 {micro}m obtained with the 10-m W. M. Keck telescopes on three nights during a ring plane crossing: UT 19 December 2002, and 22 and 26 January 2003. We used conventional imaging, plus adaptive optics on the last night. Here we present detailed radial profiles of the main ring, halo and gossamer rings, and interpret the data together with information extracted from radio observations of Jupiter's synchrotron radiation. The main ring is confined to a 800-km-wide annulus between 128,200 and 129,000 km, with a {approx} 5000 km extension on the inside. The normal optical depth is 8 x 10{sup -6}, 15% of which is provided by bodies with radii a {approx}> 5 cm. These bodies are as red as Metis. Half the optical depth, {tau} {approx} 4 x 10{sup -6}, is attributed to micron-sized dust, and the remaining {tau} {approx} 3 x 10{sup -6} to grains tens to hundreds of {micro}m in size. The inward extension consists of micron-sized (a {approx}< 10 {micro}m) dust, which probably migrates inward under Poynting-Robertson drag. The inner limit of this extension falls near the 3:2 Lorentz resonance (at orbital radius r = …
Date: November 29, 2007
Creator: de Pater, I.; Showalter, M. R. & Macintosh, B. A.
Object Type: Article
System: The UNT Digital Library
Major Leadership Election Contests in the House of Representatives, 94th - 110th Congresses (open access)

Major Leadership Election Contests in the House of Representatives, 94th - 110th Congresses

None
Date: November 29, 2007
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Private Pensions: Low Defined Contribution Plan Savings May Pose Challenges to Retirement Security, Especially for Many Low-Income Workers (open access)

Private Pensions: Low Defined Contribution Plan Savings May Pose Challenges to Retirement Security, Especially for Many Low-Income Workers

A letter report issued by the Government Accountability Office with an abstract that begins "Over the last 25 years, pension coverage has shifted primarily from "traditional" defined benefit (DB) plans, in which workers accrue benefits based on years of service and earnings, toward defined contribution (DC) plans, in which participants accumulate retirement balances in individual accounts. DC plans provide greater portability of benefits, but shift the responsibility of saving for retirement from employers to employees. This report addresses the following issues: (1) What percentage of workers participate in DC plans, and how much have they saved in them? (2) How much are workers likely to have saved in DC plans over their careers and to what degree do key individual decisions and plan features affect plan saving? (3) What options have been recently proposed to increase DC plan coverage, participation, and savings? GAO analyzed data from the Federal Reserve Board's 2004 Survey of Consumer Finances (SCF), the latest available, utilized a computer simulation model to project DC plan balances at retirement, reviewed academic studies, and interviewed experts."
Date: November 29, 2007
Creator: United States. Government Accountability Office.
Object Type: Report
System: The UNT Digital Library
SALT CORE SAMPLING EVOLUTION AT THE SAVANNAH RIVER SITE (open access)

SALT CORE SAMPLING EVOLUTION AT THE SAVANNAH RIVER SITE

The Savannah River Site (SRS), a Department of Energy (DOE) facility, has over 30 million gallons of legacy waste from its many years of processing nuclear materials. The majority of waste is stored in 49 buried tanks. Available underground piping is the primary and desired pathway to transfer waste from one tank to another until the waste is delivered to the glass plant, DWPF, or the grout plant, Saltstone. Prior to moving the material, the tank contents need to be evaluated to ensure the correct destination for the waste is chosen. Access ports are available in each tank top in a number of locations and sizes to be used to obtain samples of the waste for analysis. Material consistencies vary for each tank with the majority of waste to be processed being radioactive salts and sludge. The following paper describes the progression of equipment and techniques developed to obtain core samples of salt and solid sludge at SRS.
Date: November 29, 2007
Creator: Nance, T; Daniel Krementz, D & William Cheng, W
Object Type: Article
System: The UNT Digital Library
Senate Conferees: Their Selection and Authority (open access)

Senate Conferees: Their Selection and Authority

None
Date: November 29, 2007
Creator: unknown
Object Type: Report
System: The UNT Digital Library
SYSTEMATIC STUDIES OF HEAVY ION COLLISIONS TO SEARCH FOR QUARK-GLUON PLASMA (open access)

SYSTEMATIC STUDIES OF HEAVY ION COLLISIONS TO SEARCH FOR QUARK-GLUON PLASMA

This is the final technical report for DOE Outstanding Junior Investigator (OJI) Award, 'Systematic Studies of Heavy Ion Collisions to Search for Quark-Gluon Plasma', grant DE-FG02-02ER41219, Principal Investigator (PI) Fuqiang Wang. The research under the grant was divided into two phases. The first concentrated on systematic studies of soft hadron production at low transverse momentum (p{sub T}), in particular the production of (anti-)baryon and strangeness in heavy ion collisions at RHIC energies. The second concentrated on measurements of di-hadron and multi-hadron jet-correlations and investigations of medium response to jets. The research was conducted at the Relativistic Heavy-Ion Collider (RHIC) at BNL with the Solenoidal Tracker At RHIC (STAR) experiment. The total grant is $214,000. The grant established a PC farm solely used for this research. The PC farm consists of 8 nodes with a total of 16 CPUs and 3 disk servers of total 2 TB shared storage. The current balance of the grant is $19,985. The positive balance is because an initial purchase of $22,600 for the PC farm came out of the PI's start-up fund due to the lateness of the award. The PC farm is an integral part of the Purdue Physics Department's computer cluster. The grant …
Date: November 29, 2007
Creator: Wang, Fuqiang
Object Type: Report
System: The UNT Digital Library
TREATABILITY TEST FOR REMOVING TECHNETIUM-99 FROM 200-ZP-1 GROUNDWATER HANFORD SITE (open access)

TREATABILITY TEST FOR REMOVING TECHNETIUM-99 FROM 200-ZP-1 GROUNDWATER HANFORD SITE

The 200-ZP-1 Groundwater Operable Unit (OU) is one of two groundwater OUs located within the 200 West groundwater aggregate area of the Hanford Site. The primary risk-driving contaminants within the 200-ZP-1 OU include carbon tetrachloride and technetium-99 (Tc-99). A pump-and-treat system for this OU was initially installed in 1995 to control the 0.002 kg/m{sup 3} (2000 {micro}g/L) contour of the carbon tetrachloride plume. Carbon tetrachloride is removed from groundwater with the assistance of an air-stripping tower. Ten extraction wells and three injection wells operate at a combined rate of approximately 0.017m{sup 3}/s (17.03 L/s). In 2005, groundwater from two of the extraction wells (299-W15-765 and 299-W15-44) began to show concentrations greater than twice the maximum contaminant level (MCL) of Tc-99 (33,309 beq/m{sup 3} or 900 pCi/L). The Tc-99 groundwater concentrations from all ten of the extraction wells when mixed were more than one-half of the MCL and were slowly increasing. If concentrations continued to rise and the water remained untreated for Tc-99, there was concern that the water re-injected into the aquifer could exceed the MCL standard. Multiple treatment technologies were reviewed for selectively removing Tc-99 from the groundwater. Of the treatment technologies, only ion exchange was determined to be …
Date: November 29, 2007
Creator: SW, PETERSEN; AC, TORTOSO; WS, ELLIOTT & ME, BYRNES
Object Type: Article
System: The UNT Digital Library
TREATABILITY TEST PLAN FOR DEEP VADOSE ZONE REMEDIATION AT THE HANFORD SITE CENTRAL PLATEAU (open access)

TREATABILITY TEST PLAN FOR DEEP VADOSE ZONE REMEDIATION AT THE HANFORD SITE CENTRAL PLATEAU

A treatability test plan has been prepared to address options for remediating portions of the deep vadose zone beneath a portion of the U.S. Department of Energy's (DOE's) Hanford Site. The vadose zone is the region of the subsurface that extends from the ground surface to the water table. The overriding objective of the treatability test plan is to recommend specific remediation technologies and laboratory and field tests to support the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 and Resource Conservation and Recovery Act of 1976 remedial decision-making process in the Central Plateau of the Hanford Site. Most of the technologies considered involve removing water from the vadose zone or immobilizing the contaminants to reduce the risk of contaminating groundwater. A multi-element approach to initial treatability testing is recommended, with the goal of providing the information needed to evaluate candidate technologies. The proposed tests focus on mitigating two contaminants--uranium and technetium. Specific technologies are recommended for testing at areas that may affect groundwater in the future, but a strategy to test other technologies is also presented.
Date: November 29, 2007
Creator: SW, PETERSEN; JG, MORSE; MJ, TRUEX & GV, LAST
Object Type: Article
System: The UNT Digital Library
Two-photon Photo-emission of Ultrathin Film PTCDA Morphologies on Ag(111) (open access)

Two-photon Photo-emission of Ultrathin Film PTCDA Morphologies on Ag(111)

Morphology- and layer-dependent electronic structure and dynamics at the PTCDA/Ag(111) interface have been studied with angle-resolved two-photon photoemission. In Stranski-Krastanov growth modes, the exposed wetting layer inhibited the evolution of the vacuum level and valence band to bulk values. For layer-by-layer growth, we observed the transition of electron structure from monolayer to bulk values within eight monolayers. Effective masses and lifetimes of the conduction band and the n=1 image potential state were measured to be larger for disordered layers. The effective mass was interpreted in the context of charge mobility measurements.
Date: November 29, 2007
Creator: Yang, Aram; Yang, Aram; Shipman, Steven T.; Garrett-Roe, Sean; Johns, James; Strader, Matt et al.
Object Type: Article
System: The UNT Digital Library
20-MW Magnicon for ILC (open access)

20-MW Magnicon for ILC

The 1.3 GHz RF power to drive ILC is now planned to be supplied by 600-1200, 10-MW peak power multi-beam klystrons. In this project, a conceptual design for 1.3 GHz magnicons with 20 MW peak power was developed as an alternative to the klystrons, with the possibility of cutting in half the numbers of high-power tubes and associated components. Design of a conventional magnicon is described, using TM110 modes in all cavities, as well as design of a modified magnicon with a TE111 mode output cavity. The latter has the advantage of much lower surface fields than the TM110 mode, with no loss of output power or electronic efficiency.
Date: November 29, 2006
Creator: Hirshfield, Jay L.
Object Type: Report
System: The UNT Digital Library
A Cassette Based System for Hydrogen Storage and Delivery (open access)

A Cassette Based System for Hydrogen Storage and Delivery

A hydrogen storage system is described and evaluated. This is based upon a cassette, that is a container for managing hydrogen storage materials. The container is designed to be safe, modular, adaptable to different chemistries, inexpensive, and transportable. A second module receives the cassette and provides the necessary infrastructure to deliver hydrogen from the cassette according to enduser requirements. The modular concept has a number of advantages over approaches that are all in one stand alone systems. The advantages of a cassette based system are discussed, along with results from model and laboratory testing.
Date: November 29, 2006
Creator: E., Britton Wayne
Object Type: Report
System: The UNT Digital Library
Central Energy System Modernization at Fort Jackson, South Carolina (open access)

Central Energy System Modernization at Fort Jackson, South Carolina

An evaluation of technology options was conducted for the central energy systems at Fort Jackson, South Carolina. There were two objectives in conducting this study. From a broader viewpoint, the Army would like to develop a systematic approach to management of its central energy systems and selected Fort Jackson for this ''pilot'' study for a prospective Central Energy System Modernization Program. From a site-specific perspective, the objective was to identify the lowest life-cycle cost energy supply option(s) at Fort Jackson for buildings currently served by central boilers and chillers. This study was co-funded by the Army's Southeast Region and the U.S. Department of Energy's Federal Energy Management Program.
Date: November 29, 2006
Creator: Brown, Daryl R.; Chvala, William D. & Dirks, James A.
Object Type: Report
System: The UNT Digital Library
Chemical reaction rates using the semiclassical Van-Vleck initialvalue representation (open access)

Chemical reaction rates using the semiclassical Van-Vleck initialvalue representation

A semiclassical IVR formulation using the Van-Vleck propagator has been used to calculate the flux correlation function and thereby reaction rate constants. This Van-Vleck formulation of the flux-flux correlation function is computationally as simple as the classical Wigner model. However unlike the latter, it has the ability to capture quantum interference/coherence effects. Classical trajectories are evolved starting from the dividing surface that separates reactants and products, and are evolved negatively in time. This formulation has been tested on model problems ranging from the Eckart barrier, double well to the collinear H + H{sub 2}.
Date: November 29, 2006
Creator: Venkataraman, Charulatha & Miller, William H.
Object Type: Article
System: The UNT Digital Library