States

Qualification of Safety-Related Software in Nuclear Power Plants (open access)

Qualification of Safety-Related Software in Nuclear Power Plants

Digital instrumentation and control systems have the potential of offering significant benefits over traditional analog systems in Nuclear Power Plant safety systems, but there are also significant difficulties in qualifying digital systems to the satisfaction of regulators. Digital systems differ in fundamental ways from analog systems. New methods for safety qualification, which take these differences into account, would ease the regulatory cost and promote use of digital systems. This paper offers a possible method for assisting in the analysis of digital system software, as one step in an improved qualification process.
Date: June 13, 2000
Creator: Johnson, G L
Object Type: Article
System: The UNT Digital Library
Diagnosing Plasma Gradients Using Spectral Line Shapes (open access)

Diagnosing Plasma Gradients Using Spectral Line Shapes

The development of a set of stable implosions using indirectly driven plastic microspheres with argon (0.1 atm) doped deuterium (50 atm) has provided a unique source for testing the plasma spectroscopy of the high energy density imploded core. The core reaches electron densities of > 10{sup 24} cm{sup -3} with temperatures of {approx} 1 keV and has been shown to be reproducible on a shot to shot basis. Moreover, it has been shown that not only the peak temperature and density are consistent, but that the temporal evolution of the mean temperature and density of the final phase of the implosion is also reproducible. These imploding cores provide a unique opportunity to test aspects of plasma spectroscopy that are difficult to study in other plasmas and to develop methods to test stable hydrodynamics. We present experimental results and discuss spectroscopic analysis algorithms to determine consistent temperature and density fits to determine gradients in the plasma.
Date: November 13, 2000
Creator: Back, C. A.; Golovkin, I.; Mancini, R.; Missalla, T.; Landen, O. L.; Lee, R. W. et al.
Object Type: Article
System: The UNT Digital Library
Multigrid algorithms for solving the linear Boltzmann equation using first-order system least-squares finite element methods (open access)

Multigrid algorithms for solving the linear Boltzmann equation using first-order system least-squares finite element methods

Solving the linear Boltzmann equation in neutron scattering phenomena presents many challenges to standard numerical schemes in computational physics. For an SN discretization, the so-called ray effects pollute the numerical solution. This pollution can be viewed mathematically as ''contamination'' from a poorly chosen approximating basis set for the angle component of the discretization-i.e., collocation in angle is equivalent to discretization with delta basis functions, which form a poor approximating basis set. Fortunately, a PN discretization, which uses a better approximating basis set (i.e., spherical harmonics), eliminates these ray effects. Unfortunately, solving for the moments or PN equations is difficult. Moments couple strongly with each other, creating a strongly coupled system of partial differential equations (pde's) ; numerical algorithms for solving such strongly coupled systems are difficult to develop. In this paper, novel algorithms for solving this coupled system are presented. In particular, algorithms for solving the PN discretization of the linear Boltzmann equation using a first-order system least-squares (FOSLS) methodology (c.f. [1]) are presented.
Date: December 13, 2000
Creator: Chang, B. & Lee, B.
Object Type: Article
System: The UNT Digital Library
Preliminary report on self-healing minefield (frogs) concepts and utility in battle (open access)

Preliminary report on self-healing minefield (frogs) concepts and utility in battle

The purpose of this study is to determine battlefield effectiveness of the self-healing minefield (''Frogs'') concept system compared to basecases of the standard AP/AT (anti-personnel/anti-tank) mixed minefield, the AT (anti-tank) pure minefield, and no minefields. This involves tactical modeling where a basecase with and without mines is compared to the concept system. However, it is first necessary to establish system characteristics and behavior of the Frog mine and minefield in order to do the tactical modeling. This initial report provides emerging insights into various minefield parameters in order to allow better program definition early in the conceptual development. In the following sections of this report, we investigate the self-healing minefield's ground pattern and several concepts for movement (''jump'') of a mine. Basic enemy breaching techniques are compared for the different mine movement concepts. These results are then used in the (Joint Conflict and Tactical Simulation) JCATS tactical model to evaluate minefield effects in a combat situation. The three basecases and the Frogs concept are used against a North Korean mechanized rifle battalion and outcomes are compared. Preliminary results indicate: (1) Possible breaching techniques for the self-healing minefield were proposed and compared through simulation modeling. Of these, the best breaching counter …
Date: January 13, 2000
Creator: Greenwalt, R J & Magnoli, D
Object Type: Report
System: The UNT Digital Library
Antiguided Ribbon Laser Concept (open access)

Antiguided Ribbon Laser Concept

We propose a new, robustly scalable technique for phase locking multiple gain cores in a fiber structure based on antiguiding or radiative coupling, rather than the more commonly pursued method of evanescent wave phase locking. Our focus is on a ribbon-like geometry in which a waveguide region contains multiple gain cores arranged in a periodic array. The distinguishing feature of such antiguiding structures is that refractive index of the gain cores is lower than or equal to that of the surrounding waveguide regions. This is just the opposite of evanescently phase locked structures in which the gain cores have higher refractive index than the surrounding regions. The critical design considerations in the structures proposed within are: first that they strongly favor oscillation in a single transverse mode, and second that this strongly favored mode exhibits good intensity uniformity across the entire array of gain cores. We require single mode operation so that a static phase corrector placed in the near field of the ribbon laser's output can optimize the phase across the aperture to achieve a high Strehl ratio in the far field. The requirement that the strongly favored mode exhibit good uniformity across the entire array of gain cores …
Date: December 13, 2000
Creator: Beach, R; Feit, M; Page, R; Brasure, L; Wilcox, R & Payne, S
Object Type: Report
System: The UNT Digital Library
Prompt GRB optical follow-up experiments (open access)

Prompt GRB optical follow-up experiments

Gamma Ray Bursts (GRBs) are brief, randomly located, releases of gamma-ray energy from unknown celestial sources that occur almost daily. The study of GRBs has undergone a revolution in the past three years due to an international effort of follow-up observations of coordinates provided by Beppo/SAX and IPN GRB. These follow-up observations have shown that GRBs are at cosmological distances and interact with surrounding material as described by the fireball model. However, prompt optical counterparts have only been seen in one case and are therefore very rare or much dimmer than the sensitivity of the current instruments. Unlike later time afterglows, prompt optical measurements would provide information on the GRB progenitor. LOTIS is the very first automated and dedicated telescope system that actively utilizes the GRB Coordinates Network (GCN) and it attempts to measure simultaneous optical light curve associated with GRBs. After 3 years of running, LOTIS has responded to 75 GRB triggers. The lack of any optical signal in any of the LOTIS images places numerical limits on the surrounding matter density, and other physical parameters in the environment of the GRB progenitor. This paper presents LOTIS results and describes other prompt GRB follow-up experiments including the Super-LOTIS at …
Date: November 13, 2000
Creator: Park, H. S.; Williams, G.; Ables, E.; Band, D.; Barthelmy, S.; Bionta, R. et al.
Object Type: Article
System: The UNT Digital Library
Numerical simulation of damage and fracture in concrete from shaped charge jets (open access)

Numerical simulation of damage and fracture in concrete from shaped charge jets

This paper addresses numerical simulation of damage and fracture in concrete from the impact and penetration of shaped charge jets. We have modeled the jet penetration process with CALE, a two dimensional arbitrary Lagrange Eulerian hydrocode. We have looked at several constitutive models ranging from simple pressure dependent yield to more complex deviatoric models that include the effects of dilatency. Evaluation of the concrete material models is based on comparison to experimental results of an aluminum lined shaped charge fired against a high strength concrete target at several standoff distances.
Date: September 13, 2000
Creator: Murphy, M J; Baum, D W; Clark, D B; McGuire, E M & Simonson, S C
Object Type: Article
System: The UNT Digital Library
PCMDI analysis of candidate atmospheric models for CCSM (open access)

PCMDI analysis of candidate atmospheric models for CCSM

This report is intended to give a summary analysis of the candidate model configurations under consideration by NCAR for the atmospheric component of next version of the Community Climate System Model (CCSM). Intercomparison results are presented for each of the models available prior to the Atmospheric Model Working Group (AMWG) meeting, December 12-14, 2000. We present four types of figures in this report. The traditional methods of viewing zonal mean surface fields, latitude-longitude maps and zonal mean latitude-height cross sections are straightforward. In each of these cases, we present DJF and JJA climatological averages and a difference from an observational or reanalysis data set. The fourth method of analyzing the candidates' model performance involves the use of ''performance portraits'' and is explained in detail on following pages. As stated by NCAR and the AMWG, the information included in this report should be considered proprietary to NCAR and is not to be cited, consistent with the disclaimer on the AMWG password protected web pages. We deliberately have deferred our conclusions in this printed report to our presentation. Rather, we encourage you to draw your own conclusions based on these figures and other information made available at the AMWG meeting.
Date: December 13, 2000
Creator: Wehner, M. F.; Taylor, K.; Doutriaux, C.; AchutaRao, K.; Gleckler, P.; Hnilo, J. et al.
Object Type: Article
System: The UNT Digital Library
Optimizing Data Recording for the NIF Core Diagnostic X-ray Streak Camera (open access)

Optimizing Data Recording for the NIF Core Diagnostic X-ray Streak Camera

The x-ray streak camera is an important instrument for recording a continuous time history of x-ray emitted from laser target experiments. X-ray streak cameras were used to diagnose experiments in inertially confined fusion and high energy density sciences on the Nova laser. These streak cameras are now used for similar experiments conducted at the OMEGA laser facility, and cameras of this type will be used for experiments on the National Ignition Facility (NIF). The Nova x-ray streak cameras (SSCs) used a sealed optical image intensifier coupled to film to record the streaked x-ray data. In order to develop the core x-ray streak camera for NIF (ref Kimbrough) using a CCD based recording system, we evaluate the performance of the SSCs under a variety of detector configurations. We performed laboratory bench characterization tests of the SSCs to measure the spatial resolution and to evaluate the dynamic range and signal to noise for different configurations of the SSC. We present results of these tests here.
Date: June 13, 2000
Creator: Kalantar, D H; Bell, P M; Perry, T S; Sewall, N; Diamond, C & Piston, K
Object Type: Article
System: The UNT Digital Library
Preliminary safety assessment for an IFE target fabrication facility (open access)

Preliminary safety assessment for an IFE target fabrication facility

We estimate possible ranges of tritium inventories for an inertial fusion energy (IFE) target fabrication facility producing various types of targets and using various production technologies. Target fill is the key subtask in determining the overall tritium inventory for the plant. By segmenting the inventory into multiple, parallel production lines--each with its own fill canister--and including an expansion tank to limit releases, we are able to ensure that a target fabrication facility would meet the accident dose goals of 10 mSv (1 rem) set forth in the Department of Energy's Fusion Safety Standards. For indirect-drive targets, we calculate release fractions for elements from lithium to bismuth and show that nearly all elements meet the dose goal. Our work suggests directions for future R&D that will help reduce total tritium inventories and increase the flexibility of target fabrication facilities.
Date: October 13, 2000
Creator: Latkowski, J F; Reyes, S; Besenbruch, G E & Goodin, D T
Object Type: Article
System: The UNT Digital Library
Statistical error in particle simulations of low mach number flows (open access)

Statistical error in particle simulations of low mach number flows

We present predictions for the statistical error due to finite sampling in the presence of thermal fluctuations in molecular simulation algorithms. The expressions are derived using equilibrium statistical mechanics. The results show that the number of samples needed to adequately resolve the flowfield scales as the inverse square of the Mach number. Agreement of the theory with direct Monte Carlo simulations shows that the use of equilibrium theory is justified.
Date: November 13, 2000
Creator: Hadjiconstantinou, N G & Garcia, A L
Object Type: Article
System: The UNT Digital Library
Development and Characterization of a Single Line of Sight Framing Camera (open access)

Development and Characterization of a Single Line of Sight Framing Camera

We present initial characterization data from a new single line of sight (SLOS) x-ray framing camera. The instrument uses an image dissecting structure inside an electron optic tube to produce up to four simultaneous DC images from a single image incident on the cathode and a microchannel plate based device to provide the temporal gating of those images. A series of gated images have been obtained using a short pulse UV laser source, and the spatial resolution of those images is compared to those obtained using a more traditional MCP based system.
Date: June 13, 2000
Creator: Bradley, D K; Bell, P M; Dymoke-Bradshaw, A K L; Hares, J D; Bahr, R E & Smalyuk, V A
Object Type: Article
System: The UNT Digital Library
Cloud-Resolving Model Intercomparison with the ARM Summer 1997 IOP Data (open access)

Cloud-Resolving Model Intercomparison with the ARM Summer 1997 IOP Data

The Atmospheric Radiation Measurement (ARM) Program's Single Column Model (SCM) working group conducted its intercomparison study of midlatitude summertime continental convection using the July 1995 Intensive Operational Period (IOP) data set (Ghan et al. 2000). Only one cloud-resolving model (CRM) participated in the study. On the other hand, several CRMs participated in the GEWEX (Global Energy and Water-cycle Experiment) Cloud System Study (GCSS) Working Group 4's intercomparison study of tropical deep convection (Krueger and Lazarus 1998; Redelsperger et al. 2000). Both groups decided to have a joint intercomparison project to maximize the resources and advance our understanding of midlatitude continental convection. This joint project compares the cloud-resolving and single-column simulations of summertime continental cumulus convection observed at the Southern Great Plains (SGP) Cloud and Radiation Testbed (CART) site during the ARM Summer 1997 IOP. This paper reports the findings and results of cloud-resolving simulations, while Cederwall et al. (2000) reports the SCM part of the project. Seven CRMs are participating in this project.
Date: March 13, 2000
Creator: Xu, K. M.; Johnson, D. E.; Tao, W. K.; Krueger, S. K.; Khairoutdinov, M.; Randall, D. A. et al.
Object Type: Article
System: The UNT Digital Library
Texas Disease Prevention News, Volume 60, Number 6, March 2000 (open access)

Texas Disease Prevention News, Volume 60, Number 6, March 2000

Newsletter of the Texas Department of Health discussing the news, activities, and events of the organization and other information related to health in Texas.
Date: March 13, 2000
Creator: Texas. Department of Health.
Object Type: Journal/Magazine/Newsletter
System: The Portal to Texas History
Dimensions and Measurements of Debuncher Band 3 and 4 Waveguide-Coax Launchers (open access)

Dimensions and Measurements of Debuncher Band 3 and 4 Waveguide-Coax Launchers

This note is a document about dimensions and measurement results of waveguide-coax launchers (Band 3 and 4) installed on the arrays in debuncher cooling upgrade. Shown in Figure 1 and 5 are schematic drawings of launchers (pick-up) in the cross section along the longitudinal direction (beam direction) of the arrays. The unit in these drawings is inch. Note: although there are upper band and lower band for pickup arrays, the launchers are the same to avoid possible confusion during installation. Launchers for band 3 and 4 kickers were made by Penn-engineering Inc., therefor no schematic drawings are presented in this note. RF Measurements were made on all launchers (port) and printed in hard copies for future reference. Since the measurement results are similar to each other, only a few plots for each type of launcher/band are presented in this document. There are two types of measured S11 parameters. One is the measurement made at the end of design/tuning stage using a launcher and a straight section of band 3 or 4 waveguide terminated with a cone of absorber. I use 'Original' to denote this kind of measurement. As shown in Figure 2, 6, 9 and 12, the original S11 of …
Date: September 13, 2000
Creator: Sun, Ding
Object Type: Report
System: The UNT Digital Library
Design and Simulation Results of Waveguide Bends Used in Debuncher Cooling System (open access)

Design and Simulation Results of Waveguide Bends Used in Debuncher Cooling System

This note is a document about design and simulation results of waveguide bends installed with the arrays in debuncher cooling upgrade. The main feature of these bends is that they are not traditional mitered bends or round bends. Instead, a cylinder is placed in the corner area of the bend. The reason for this design is purely to overcome some practical problems: (1) since these bends are very close to the slotted foil which serves as part of the waveguide array, it is very difficult to make good joint and contact if mitered bends are used, (2) assembly difficulty due to the location of these bends, and (3) limited space requires a compact design. Shown in Figure 1 is a schematic drawing of a bend. Dimensions of bends for each frequency band are listed in Table 1. Shown in Figure 2-5 are the simulation results using HFSS. One of the bends was fabricated with flanges on both ends and measured using a Network Analyzer. The HFSS result was confirmed by the measured data.
Date: September 13, 2000
Creator: Sun, Ding
Object Type: Report
System: The UNT Digital Library
Groundwater Monitoring Plan for the Solid Waste Landfill (open access)

Groundwater Monitoring Plan for the Solid Waste Landfill

This monitoring plan includes well and constituent lists, and summarizes sampling, analytical, and quality control requirements. Changes from the previous monitoring plan include elimination of two radionuclides from the analyte list and some minor changes in the statistical analysis.
Date: October 13, 2000
Creator: Lindberg, Jonathan W. & Chou, Charissa J.
Object Type: Report
System: The UNT Digital Library
Canister Transfer Facility Criticality Calculations (open access)

Canister Transfer Facility Criticality Calculations

The objective of this calculation is to evaluate the criticality risk in the surface facility for design basis events (DBE) involving Department of Energy (DOE) Spent Nuclear Fuel (SNF) standardized canisters (Civilian Radioactive Waste Management System [CRWMS] Management and Operating Contractor [M&O] 2000a). Since some of the canisters will be stored in the surface facility before they are loaded in the waste package (WP), this calculation supports the demonstration of concept viability related to the Surface Facility environment. The scope of this calculation is limited to the consideration of three DOE SNF fuels, specifically Enrico Fermi SNF, Training Research Isotope General Atomic (TRIGA) SNF, and Mixed Oxide (MOX) Fast Flux Test Facility (FFTF) SNF.
Date: October 13, 2000
Creator: Monroe-Rammsy, J. E.
Object Type: Report
System: The UNT Digital Library
ELECTROLUMINESCENT MATERIAL FOR FLAT PANEL DISPLAY (open access)

ELECTROLUMINESCENT MATERIAL FOR FLAT PANEL DISPLAY

The purpose of this Cooperative Research and Development Agreement (CRADA) was to develop a new-generation electroluminescent (EL) material for flat panel displays and related applications by using unique and complementary research capabilities at Oak Ridge National Laboratory and OSRAM Sylvania, Inc. The goal was to produce an EL material with a luminance 10 times greater than conventional EL phosphors. An EL material with this increased luminance would have immediate applications for flat panel display devices (e.g., backlighting for liquid-crystal diodes) and for EL lamp technology. OSRAM Sylvania proposed that increased EL phosphor luminance could be obtained by creating composite EL materials capable of alignment under an applied electric field and capable of concentrating the applied electric field. Oak Ridge National Laboratory used pulsed laser deposition as a method for making these composite EL materials. The materials were evaluated for electroluminescence at laboratory facilities at OSRAM Sylvania, Inc. Many composite structures were thus made and evaluated, and it was observed that a composite structure based on alternating layers of a ferroelectric and a phosphor yielded electroluminescence. An enabling step that was not initially proposed but was conceived during the cooperative effort was found to be crucial to the success of the …
Date: November 13, 2000
Creator: Smith, D.B.
Object Type: Report
System: The UNT Digital Library
ORNL Superconducting Technology Program for Electric Power Systems: Annual Report for FY 1999 (open access)

ORNL Superconducting Technology Program for Electric Power Systems: Annual Report for FY 1999

The Oak Ridge National Laboratory (ORNL) Superconducting Technology Program is conducted as part of a national effort by the U.S. Department of Energy's Office of Energy Efficiency and Renewable Energy to develop the science and technology base needed by U.S. industry for development of electric power applications of high-temperature superconductivity. The two major elements of this program are wire development and applications development. This document describes the major research and development activities for this program together with related accomplishments. The technical progress reported was summarized from recent open literature publications, presentations, and information prepared for the FY 1999 Annual Program Review held July 26-28, 1999. Aspects of ORNL's work that were presented at the International Cryogenic Materials Conference and the Cryogenic Engineering Conference (July 1999) are included in this report, as well. This ORNL program is highly leveraged by the staff and other resources of U.S. industry and universities. In fact, nearly three-fourths of the ORNL effort is devoted to cooperative projects with private companies. Interlaboratory teams are also in place on a number of industry-driven projects. Working group meetings, staff exchanges, and joint publications and presentations ensure that there is technology transfer with U.S. industry. Working together, the collaborative …
Date: June 13, 2000
Creator: Hawsey, R.A.
Object Type: Report
System: The UNT Digital Library
RADIATION ACCESS ZONE AND VENTILATION CONFINEMENT ZONE CRITERIA FOR THE MGR SURFACE FACILITIES (open access)

RADIATION ACCESS ZONE AND VENTILATION CONFINEMENT ZONE CRITERIA FOR THE MGR SURFACE FACILITIES

The objectives of this technical report are to: (1) Establish the criteria for Radiation Access Zone (RAZ) designation. (2) Establish the criteria for the Ventilation Confinement Zone (VCZ) designation. The scope will be to formulate the RAZ and VCZ zoning designation for the Monitored Geologic Repository (MGR) surface facilities and to apply the zoning designations to the current Waste Handling Building (WHB), Waste Treatment Building (WTB), and Carrier Preparation Building (CPB) configurations.
Date: September 13, 2000
Creator: Padula, D. A.
Object Type: Report
System: The UNT Digital Library
The Age Discrimination in Employment Act (ADEA): Overview and Current Legal Developments (open access)

The Age Discrimination in Employment Act (ADEA): Overview and Current Legal Developments

This report provides an overview of the Age Discrimination in Employment Act (ADEA) and discusses current legal and legislative developments.
Date: March 13, 2000
Creator: Jones, Kimberly D.
Object Type: Report
System: The UNT Digital Library
U.S. Space Programs: Civilian, Military, and Commercial (open access)

U.S. Space Programs: Civilian, Military, and Commercial

This report includes information regarding various United States space programs. This information includes issues and budgets related to the space programs
Date: June 13, 2000
Creator: Smith, Marcia S.
Object Type: Report
System: The UNT Digital Library
Electoral Vote Counts in Congress: Survey of Certain Congressional Practices (open access)

Electoral Vote Counts in Congress: Survey of Certain Congressional Practices

This report surveys certain aspects of the historical congressional practice in counting the presidential electoral votes in Congress.
Date: December 13, 2000
Creator: Maskell, Jack; Halstead, T. J. & Welborn, Angie
Object Type: Report
System: The UNT Digital Library