Long wavelength GaN blue laser (400-490nm) development (open access)

Long wavelength GaN blue laser (400-490nm) development

Room temperature (RT) pulsed operation of blue nitride based multi-quantum well (MQW) laser diodes grown on c-plane sapphire substrates was achieved. Atmospheric pressure MOCVD was used to grow the active region of the device which consisted of a 10 pair In{sub 0.21}Ga{sub 0.79}N (2.5nm)/In{sub 0.07}Ga{sub 0.93}N (5nm) InGaN MQW. The threshold current density was reduced by a factor of 2 from 10 kA/cm{sup 2} for laser diodes grown on sapphire substrates to 4.8 kA/cm{sub 2} for laser diodes grown on lateral epitaxial overgrowth (LEO) GaN on sapphire. Lasing wavelengths as long as 425nm were obtained. LEDs with emission wavelengths as long as 500nm were obtained by increasing the Indium content. These results show that a reduction in nonradiative recombination from a reduced dislocation density leads to a higher internal quantum efficiency. Further research on GaN based laser diodes is needed to extend the wavelength to 490nm which is required for numerous bio-detection applications. The GaN blue lasers will be used to stimulate fluorescence in special dye molecules when the dyes are attached to specific molecules or microorganisms. Fluorescein is one commonly used dye molecule for chemical and biological warfare agent detection, and its optimal excitation wavelength is 490 nm. InGaN …
Date: October 26, 2000
Creator: DenBaars, S. P.; Abare, A.; Sink, K.; Kozodoy, P.; Hansen, M.; Bowers, J. et al.
System: The UNT Digital Library
National Ignition Facility monthly status report--April 2000 (open access)

National Ignition Facility monthly status report--April 2000

The Project provides for the design, procurement, construction, assembly, installation, and acceptance testing of the National Ignition Facility (NIF), an experimental inertial confinement fusion facility intended to achieve controlled thermonuclear fusion in the laboratory by imploding a small capsule containing a mixture of the hydrogen isotopes, deuterium and tritium. The NIF will be constructed at the Lawrence Livermore National Laboratory (LLNL), Livermore, California as determined by the Record of Decision made on December 19, 1996, as a part of the Stockpile Stewardship and Management Programmatic Environmental Impact Statement (SSM PEIS). Safety: On Saturday April 29, 2000, while preparing the Ringer crane for operation at the NIF site, a mechanical malfunction was observed by the operator. He stopped work and consulted with line management. They agreed with the operator's assessment, and with the Livermore Emergency Duty Officer, implemented a precautionary evacuation of the area around the crane. DOE was notified of the situation. The crane was then placed in a safe condition. A crane maintenance vendor is inspecting the crane and a management team headed by the Beampath Infrastructure System Associate Project Manager is reviewing the documentation, crane history, and repairs to ensure that the crane is fully safe before reuse. …
Date: May 26, 2000
Creator: Moses, Edward
System: The UNT Digital Library
Thermal Decomposition of Radiation-Damaged Polystyrene (open access)

Thermal Decomposition of Radiation-Damaged Polystyrene

The radiation-damaged polystyrene (given the identification name of 'polycube') was fabricated by mixing high-density polystyrene material ("Dylene Fines # 100") with plutonium and uranium oxides. The polycubes were used in the 1960s for criticality studies during processing of spent nuclear fuel. The polycubes have since been stored for almost 40 years at the Hanford Plutonium Finishing Plant (PFP) after failure of two processes to reclaim the plutonium and uranium oxides from the polystyrene matrix. Thermal decomposition products from this highly cross-linked polystyrene matrix were characterized using Gas Chromatograph/Mass Spectroscopy (GC/MS) system coupled to a horizontal furnace. The decomposition studies were performed in air and helium atmospheres at about 773 K. The volatile and semi-volatile organic products for the radiation-damaged polystyrene were different compared to virgin polystyrene. The differences were in the number of organic species generated and their concentrations. In the inert (i.e., helium) atmosphere, the major volatile organic products identified (in order of decreasing concentrations) were styrene, benzene, toluene, ethylbenzene, xylene, nathphalene, propane, .alpha.-methylbenzene, indene and 1,2,3-trimethylbenzene. But in air, the major volatile organic species identified changed slightly. Concentrations of the organic species in the inert atmosphere were significantly higher than those for the air atmosphere processing. Overall, 38 …
Date: September 26, 2000
Creator: Abrefah, John & Klinger, George S.
System: The UNT Digital Library
Review of Waste Retrieval Sluicing System Operations and Data for Tanks 241-C-106 and 241-AY-102 (open access)

Review of Waste Retrieval Sluicing System Operations and Data for Tanks 241-C-106 and 241-AY-102

Sluicing operations were performed to retrieve high-heat sludge from single-shell tank 241-C-106 and transfer it to double-shell tank 241-AY-102 using the Waste Retrieval Sluicing System. This eliminated the high-heat safety issue for C-106 and demonstrated a technology for retrieval of single-shell tank waste. Both AY-102 and C-106 were monitored during the waste transfer operations, providing a clear picture of general trends in each tank. Specific issues addressed were evaluation of the data for evidence of flammable gas accumulation in AY-102 and thermal performance of AY-102 under the increasing heat load.
Date: September 26, 2000
Creator: Cuta, Judith M.; Carothers, Kelly G.; Damschen, Dennis W.; Kuhn, William L.; Lechelt, Jeanne A.; Sathyanarayana, Kurabalakota et al.
System: The UNT Digital Library
Description of Work for Drilling at the 183-DR Site in Support of the In Situ Gaseous Reduction Test (open access)

Description of Work for Drilling at the 183-DR Site in Support of the In Situ Gaseous Reduction Test

In Situ Gaseous Reduction is a technology currently being developed by DOE for the remediation of soil waste sites contaminated with hexavalent chromium. Prior work suggests that a candidate for application of this approach is the 183-DR site at Hanford. However, deep vadose zone drilling is needed to verify the presence of a hexavalent chromium source and to determine the concentration levels and spatial distribution of contamination. This document presents the requirements associated with drilling one to two vadose zone boreholes at the 183-DR site to obtain this information. If hexavalent chromium is determined to be present at levels of at least 10 ppm in the vadose zone in one of the initial boreholes, this hole will be completed for gas injection and six additional gas extraction boreholes will be drilled and completed. This network will be used as a flowcell for performing a gas treatment test at the site.
Date: June 26, 2000
Creator: Thornton, Edward C.; Olsen, Khris B. & Schalla, Ronald
System: The UNT Digital Library
Review of Upscaling Methods for Describing Unsaturated Flow (open access)

Review of Upscaling Methods for Describing Unsaturated Flow

Representing samll-scale features can be a challenge when one wants to model unsaturated flow in large domains. In this report, the various upscaling techniques are reviewed. The following upscaling methods have been identified from the literature: stochastic methods, renormalization methods, volume averaging and homogenization methods. In addition, a final technique, full resolution numerical modeling, is also discussed.
Date: September 26, 2000
Creator: Wood, Brian D.
System: The UNT Digital Library
Estimating Worker Risk Levels Using Accident/Incident Data (open access)

Estimating Worker Risk Levels Using Accident/Incident Data

The purpose of the work described in this report was to identify methods that are currently being used in the Department of Energy (DOE) complex to identify and control hazards/risks in the workplace, evaluate them in terms of their effectiveness in reducing risk to the workers, and to develop a preliminary method that could be used to predict the relative risks to workers performing proposed tasks using some of the current methodology. This report describes some of the performance indicators (i.e., safety metrics) that are currently being used to track relative levels of workplace safety in the DOE complex, how these fit into an Integrated Safety Management (ISM) system, some strengths and weaknesses of using a statistically based set of indicators, and methods to evaluate them. Also discussed are methods used to reduce risk to the workers and some of the techniques that appear to be working in the process of establishing a condition of continuous improvement. The results of these methods will be used in future work involved with the determination of modifying factors for a more complex model. The preliminary method to predict the relative risk level to workers during an extended future time period is based on …
Date: September 26, 2000
Creator: Kenoyer, Judson L.; Stenner, Robert D.; Andrews, William B.; Scherpelz, Robert I. & Aaberg, Rosanne L.
System: The UNT Digital Library
Abstraction of Seepage into Drifts (open access)

Abstraction of Seepage into Drifts

A total-system performance assessment (TSPA) for a potential nuclear-waste repository requires an estimate of the amount of water that might contact waste. This paper describes the model used for part of that estimation in a recent TSPA for the Yucca Mountain site. The discussion is limited to estimation of how much water might enter emplacement drifts; additional considerations related to flow within the drifts, and how much water might actually contact waste, are not addressed here. The unsaturated zone at Yucca Mountain is being considered for the potential repository, and a drift opening in unsaturated rock tends to act as a capillary barrier and divert much of the percolating water around it. For TSPA, the important questions regarding seepage are how many waste packages might be subjected to water flow and how much flow those packages might see. Because of heterogeneity of the rock and uncertainty about the future (how the climate will evolve, etc.), it is not possible to predict seepage amounts or locations with certainty. Thus, seepage is treated as a stochastic quantity in TSPA simulations, with the magnitude and spatial distribution of seepage sampled from uncertainty distributions. The distillation of the essential components of process modeling into …
Date: September 26, 2000
Creator: Wilson, M. L. & Ho, C. K.
System: The UNT Digital Library
Strategy for Characterizing Transuranics and Technetium Contamination in Depleted UF{sub 6} Cylinders (open access)

Strategy for Characterizing Transuranics and Technetium Contamination in Depleted UF{sub 6} Cylinders

This report summarizes results of a study performed to develop a strategy for characterization of low levels of radioactive contaminants [plutonium (Pu), neptunium (Np), americium (Am), and technetium (Tc)] in depleted uranium hexafluoride (DUF{sub 6}) cylinders at the gaseous diffusion plants in Oak Ridge, Tennessee; Paducah, Kentucky; and Piketon, Ohio. In these gaseous diffusion plants, this radioactivity came from enriching recycled uranium (the so-called ''reactor returns'') from Savannah River, South Carolina, and Hanford, Washington, reactors. Results of this study will be used to support a request for proposals to design, build, and operate facilities to convert the DUF{sub 6} to more chemically stable forms. These facilities would need to be designed to handle any transuranic contaminants that might be present in order to (1) protect the workers' health and safety and (2) protect the public and the environment.
Date: October 26, 2000
Creator: Hightower, J.R.
System: The UNT Digital Library
Dose Rate Calculations for Rotary Mode Core Sampling Exhauster (open access)

Dose Rate Calculations for Rotary Mode Core Sampling Exhauster

This document provides the calculated estimated dose rates for three external locations on the Rotary Mode Core Sampling (RMCS) exhauster HEPA filter housing, per the request of Characterization Field Engineering.
Date: October 26, 2000
Creator: FOUST, D.J.
System: The UNT Digital Library
Perfluoro(Methylcyclohexane) Tracer Tagging Test and Demonstration (open access)

Perfluoro(Methylcyclohexane) Tracer Tagging Test and Demonstration

On February 14 and 15, 2000, a demonstration of current perfluorocarbon tagging technology and the future potential of these methods was held at Oak Ridge National Laboratory (ORNL). The demonstration consisted of a brief technical discussion followed by a laboratory demonstration. The laboratory demonstrations included the detection of letters, parcels, briefcases and lockers containing perfluorocarbon-tagged papers. Discrimination between tagged and non-tagged items and between three perfluorocarbon tags was demonstrated along with the detection of perfluorocarbon in a background of non-fluorinated volatile organic solvent. All demonstrations involved real-time detection using a direct sampling ion trap mass spectrometer. The technical results obtained at ORNL during and in preparation for the demonstration are presented in Appendix 1 to assist Tracer Detection Technology Corp. in further evaluating their position on development and marketing of perfluorocarbon tracer technology.
Date: September 26, 2000
Creator: Sigman, M.E.
System: The UNT Digital Library
Industrial Assessment Center Program Impact Evaluation (open access)

Industrial Assessment Center Program Impact Evaluation

This report presents the results of an evaluation of the U.S. Department of Energy's Industrial Assessment Center (IAC) Program. The purpose of this program is to conduct energy, waste, and productivity assessments for small to medium-sized industrial firms. Assessments are conducted by 30 university-based industrial assessment centers. The purpose of this project was to evaluate energy and cost savings attributable to the assessments, the trained alumni, and the Websites sponsored by this program. How IAC assessments, alumni, and Web-based information may influence industrial energy efficiency decision making was also studied. It is concluded that appreciable energy and cost savings may be attributed to the IAC Program and that the IAC Program has resulted in more active and improved energy-efficiency decision making by industrial firms.
Date: January 26, 2000
Creator: Martin, M.A.
System: The UNT Digital Library
Desorption Kinetics of H2O from Cab-O-Sil-M-7D and Hi-Sil-233 Silica Particles (open access)

Desorption Kinetics of H2O from Cab-O-Sil-M-7D and Hi-Sil-233 Silica Particles

Temperature programmed desorption (TPD) was performed at temperatures up to 850K on Cab-O-Sil-M-7D and Hi-Sil-233 silica particles. Physisorbed water molecules on both types of silica had activation energies in the range of 9-14.5 kcal/mol. However, the activation energies of desorption for chemisorbed water varied from {approx} 19 kcal/mol to > 59 kcal/mol for Cab-O-Sil-M-7D, and {approx} 23-37 kcal/mol for Hi-Sil-233. Our results suggest that physisorbed water can be effectively pumped away at room temperature (or preferably at 320 K) in a matter of hours. Chemisorbed water with high activation energies of desorption (>30 kcal/mol) will not escape the silica surfaces in 100 years even at 320 K, while a significant amount of the chemisorbed water with medium activation energies (19-26 kcal/mol) will leave the silica surfaces in that time span. Most of the chemisorbed water with activation energies < 30 kcal/mol can be pumped away in a matter of days in a good vacuum environment at 500 K. We had previously measured about 0.1-0.4 wt. % of water in M9787 polysiloxane formulations containing {approx} 21% Cab-O-Sil-M-7D and {approx} 4% Hi-Sil-233. Comparing present results with these formulations, we conclude that absorbed H{sub 2}O and Si-OH bonds on the silica surfaces are …
Date: January 26, 2000
Creator: Dinh, L.; Balooch, M. & LeMay, J.D.
System: The UNT Digital Library
ASSEMBLY TRANSFER SYSTEM DESCRIPTION DOCUMENT (open access)

ASSEMBLY TRANSFER SYSTEM DESCRIPTION DOCUMENT

The Assembly Transfer System (ATS) receives, cools, and opens rail and truck transportation casks from the Carrier/Cask Handling System (CCHS). The system unloads transportation casks consisting of bare Spent Nuclear Fuel (SNF) assemblies, single element canisters, and Dual Purpose Canisters (DPCs). For casks containing DPCs, the system opens the DPCs and unloads the SNF. The system stages the assemblies, transfer assemblies to and from fuel-blending inventory pools, loads them into Disposal Containers (DCs), temporarily seals and inerts the DC, decontaminates the DC and transfers it to the Disposal Container Handling System. The system also prepares empty casks and DPCs for off-site shipment. Two identical Assembly Transfer System lines are provided in the Waste Handling Building (WHB). Each line operates independently to handle the waste transfer throughput and to support maintenance operations. Each system line primarily consists of wet and dry handling areas. The wet handling area includes a cask transport system, cask and DPC preparation system, and a wet assembly handling system. The basket transport system forms the transition between the wet and dry handling areas. The dry handling area includes the dry assembly handling system, assembly drying system, DC preparation system, and DC transport system. Both the wet and …
Date: June 26, 2000
Creator: Gorpani, B.
System: The UNT Digital Library
Cold Vacuum Drying (CVD) OCRWM Loop Error Determination (open access)

Cold Vacuum Drying (CVD) OCRWM Loop Error Determination

Characterization is specifically identified by the Richland Operations Office (RL) for the Office of Civilian Radioactive Waste Management (OCRWM) of the US Department of Energy (DOE), as requiring application of the requirements in the Quality Assurance Requirements and Description (QARD) (RW-0333P DOE 1997a). Those analyses that provide information that is necessary for repository acceptance require application of the QARD. The cold vacuum drying (CVD) project identified the loops that measure, display, and record multi-canister overpack (MCO) vacuum pressure and Tempered Water (TW) temperature data as providing OCRWM data per Application of the Office of Civilian Radioactive Waste Management (OCRWM) Quality Assurance Requirements to the Hanford Spent Nuclear Fuel Project HNF-SD-SNF-RPT-007. Vacuum pressure transmitters (PT 1*08, 1*10) and TW temperature transmitters (TIT-3*05, 3*12) are used to verify drying and to determine the water content within the MCO after CVD.
Date: July 26, 2000
Creator: PHILIPP, B.L.
System: The UNT Digital Library
Determination of Secondary Encasement Pipe Design Pressure (open access)

Determination of Secondary Encasement Pipe Design Pressure

This document published results of iterative calculations for maximum tank farm transfer secondary pipe (encasement) pressure upon failure of the primary pipe. The maximum pressure was calculated from a primary pipe guillotine break. Results show encasement pipeline design or testing pressures can be significantly lower than primary pipe pressure criteria.
Date: October 26, 2000
Creator: TEDESCHI, A.R.
System: The UNT Digital Library
PFP Commercial Grade Food Pack Cans for Plutonium Handling and Storage Critical Characteristics (open access)

PFP Commercial Grade Food Pack Cans for Plutonium Handling and Storage Critical Characteristics

This document specifies the critical characteristics for containers procured for Plutonium Finishing Plant's (PFP's) Vault Operations system as required by HNF-PRO-268 and HNF-PRO-1819. These are the minimum specifications that the equipment must meet in order to perform its safety function.
Date: October 26, 2000
Creator: BONADIE, E.P.
System: The UNT Digital Library
Planning Document for Spent Nuclear Fuel (SNF) Cleanliness Inspection Process (OCRWM) (open access)

Planning Document for Spent Nuclear Fuel (SNF) Cleanliness Inspection Process (OCRWM)

The Fuel Retrieval System (FRS) Process Validation Procedure (Stegen 2000) requires that a specified quantity of fuel processed through the Primary Cleaning Machine (PCM) be inspected for cleanliness during initial operational and process validation testing. Specifically these inspections are performed to confirm that the PCM adequately cleans the fuel elements of canister sludge. The results of these inspections will be used to demonstrate that residual quantities of canister particulate on fuel elements loaded into Multi-Canister Overpacks (MCOs) are within projected levels used to establish safety basis limits (Sloughter 2000). The fuel inspections performed as part of the validation process will be conducted during the Hot Operations portion of the Phased Startup Initiative (PSI) of the Fuel Retrieval and Integrated Water Treatment Systems (Pajunen 2000). Hot Operations testing constitutes Phases 3 and 4 of PSI. The fuel assemblies in all candidate canisters will be thoroughly inspected during these test phases (highly degraded fuel assemblies that qualify as scrap are exempt from inspection). During subsequent production operation of the FRS, only periodic inspections for cleanliness will be performed and documented. This document describes the specific processes and techniques that will be applied in performing the cleanliness inspections, and the methodology used to …
Date: June 26, 2000
Creator: Pitner, A. L.
System: The UNT Digital Library
Double Shell Tank (DST) Maintenance and Recovery Subsystem Definition Report (open access)

Double Shell Tank (DST) Maintenance and Recovery Subsystem Definition Report

The description of the Double-Shell Tank (DST) Maintenance and Recovery Subsystem presented in this document was developed to establish its boundaries. The DST Maintenance and Recovery Subsystem consists of new and existing equipment and facilities used to provide tank farm operators logistic support and problem resolution for the DST System during operations. This support will include evaluating equipment status, performing preventive and corrective maintenance, developing work packages, managing spares and consumables, supplying tooling, and training maintenance and operations personnel.
Date: July 26, 2000
Creator: Smith, E. A.
System: The UNT Digital Library
Software development guidelines for Visual Basic and SQL Server (open access)

Software development guidelines for Visual Basic and SQL Server

Development Guidelines are programming directions that focus not on the logic of the program but on its physical structure and appearance. These directions make the code easier to read, understand, and maintain. These guidelines are put in place to create a consistent set of conventions to follow that will standardize the development process. With these guidelines in place the readability and understanding others have when reviewing the code is greatly enhanced. Use these guidelines as a general rule when writing any set of logical statements. Development Guidelines are put into place in an effort to standardize the structure and style of the development process. They are not intended to limit or channel the developer's own creativity and flexibility. These guidelines will cover general development syntax, organization and documentation. The general information covers the high level areas of development, no matter what the environment. This guide will detail specific Visual Basic guidelines, following the same standard naming conventions set by Microsoft, with some minor additions. The guideline will finish with conventions specific to a Database or Microsoft's SQL Server specific environment.
Date: July 26, 2000
Creator: IBSEN, T.G.
System: The UNT Digital Library
Explosive Effectiveness Capability (ExEC) (open access)

Explosive Effectiveness Capability (ExEC)

Gaining accurate predictions of damage inflicted by high explosive devices is vital in order to minimize collateral damage effects on a target. ExEC provides a means for conducting very detailed analysis of weapons effects on targets for advanced mission planning purposes. ExEC is composed of a suite of high fidelity physics codes, which have been used for decades by the nuclear weapons laboratories for assessing high explosive, thermal, and structural effects. The ExEC capability should not be confused with the fast running empirical codes MEA and MEVA, which are good for fast scoping analysis. MEA and MEVA rely on look-up tables or simple approximations to quickly obtain a rough estimate of weapon damage on a target. In contrast, the ExEC capability provides a much higher fidelity damage prediction and a limitless number of target configurations by solving the time dependent conservation equations for mass, momentum, and energy, in order to directly simulate the interaction of a weapon with a target component. In contrast, MEA/MEVA must be calibrated for every different weapon type and target. ExEC has produced accurate simulations for weapon disablement, shape charge penetration, sympathetic detonation, fragment damage effects, and blast effects. For example, ExEC was used to look …
Date: July 26, 2000
Creator: Nakafuji, G.; Daily, L. & Leake, J.
System: The UNT Digital Library
Diesel Generator Control Panel Components Wiring and Terminals (open access)

Diesel Generator Control Panel Components Wiring and Terminals

None
Date: April 26, 2000
Creator: Van Katwijk, C.
System: The UNT Digital Library
Engineering-Economic Analyses of Automotive Fuel Economy Potential in the United States (open access)

Engineering-Economic Analyses of Automotive Fuel Economy Potential in the United States

Over the past 25 years more than 20 major studies have examined the technological potential to improve the fuel economy of passenger cars and light trucks in the US. The majority has used technology/cost analysis, a combination of analytical methods from the disciplines of economics and automotive engineering. In this paper they describe the key elements of this methodology, discuss critical issues responsible for the often widely divergent estimates produced by different studies, review the history of its use, and present results from six recent assessments. Whereas early studies tended to confine their scope to the potential of proven technology over a 10-year time period, more recent studies have focused on advanced technologies, raising questions about how best to include the likelihood of technological change. The paper concludes with recommendations for further research.
Date: January 26, 2000
Creator: Greene, D. L.
System: The UNT Digital Library
Design Criteria for Bagless Transfer System (BTS) Packaging System (open access)

Design Criteria for Bagless Transfer System (BTS) Packaging System

This document provides the criteria for the design and installation of a Bagless Transfer System (BTS); Blend, Sieve and Balance Equipment; and Supercritical Fluid Extraction System (SFE). The project consists of 3 major modules: (1) Bagless Transfer System (BTS) Module; (2) Blend, Sieve and Balance Equipment; and (3) Supercritical Fluid Extraction (SFE) Module.
Date: April 26, 2000
Creator: RISENMAY, H.R.
System: The UNT Digital Library