A 3-D hydrodynamic dispersion model for modeling tracer transport in Geothermal Reservoirs (open access)

A 3-D hydrodynamic dispersion model for modeling tracer transport in Geothermal Reservoirs

A 3-D hydrodynamic dispersion model for tracer transport is developed and implemented into the TOUGH2 EOS3 (T2R3D) module. The model formulation incorporates a full dispersion tensor, based on a 3-D velocity field with a 3-D, irregular grid in a heterogeneous geological system. Two different weighting schemes are proposed for spatial average of 3-D velocity fields and concentration gradients to evaluate the mass flux by dispersion and diffusion of a tracer or a radionuclide. This new module of the TOUGH2 code is designed to simulate processes of tracer/radionuclide transport using an irregular, 3-D integral finite difference grid in non-isothermal, three-dimensional, multiphase, porous/fractured subsurface systems. The numerical method for this transport module is based on the integral finite difference scheme, as in the TOUGH2 code. The major assumptions of the tracer transport module are: (a) a tracer or a radionuclide is present and transported only within the liquid phase, (b) transport mechanisms include molecular diffusion and hydrodynamic dispersion in the liquid phase in addition to advection, and (c) first order decay and linear adsorption on rock grains are taken into account. The tracer or radionuclide is introduced as an additional mass component into the standard TOUGH2 formulation, time is discretized fully implicitly, …
Date: January 26, 1998
Creator: Wu, Yu-Shu & Pruess, Karsten
Object Type: Article
System: The UNT Digital Library
Acceptable Knowledge Summary Report for Waste Stream: SR-T001-221F-HET/Drums (open access)

Acceptable Knowledge Summary Report for Waste Stream: SR-T001-221F-HET/Drums

Since beginning operations in 1954, the Savannah River Site FB-Line produced Weapons Grade Plutonium for the United States National Defense Program. The facility mission was mainly to process dilute plutonium solution received from the 221-F Canyon into highly purified plutonium metal. As a result of various activities (maintenance, repair, clean up, etc.) in support of the mission, the facility generated a transuranic heterogeneous debris waste stream. Prior to January 25, 1990, the waste stream was considered suspect mixed transuranic waste (based on potential for inclusion of F-Listed solvent rags/wipes) and is not included in this characterization. Beginning January 25, 1990, Savannah River Site began segregation of rags and wipes containing F-Listed solvents thus creating a mixed transuranic waste stream and a non-mixed transuranic waste stream. This characterization addresses the non-mixed transuranic waste stream packaged in 55-gallon drums after January 25, 1990.Characterization of the waste stream was achieved using knowledge of process operations, facility safety basis documentation, facility specific waste management procedures and storage / disposal records. The report is fully responsive to the requirements of Section 4.0 "Acceptable Knowledge" from the WIPP Transuranic Waste Characterization Quality Assurance Plan, CAO-94-1010, and provides a sound, (and auditable) characterization that satisfies the WIPP …
Date: October 26, 1998
Creator: Lunsford, G.F.
Object Type: Report
System: The UNT Digital Library
ADVANCED TURBINE SYSTEM CONCEPTUAL DESIGN AND PRODUCT DEVELOPMENT (open access)

ADVANCED TURBINE SYSTEM CONCEPTUAL DESIGN AND PRODUCT DEVELOPMENT

None
Date: August 26, 1998
Creator: Mayer, Albrecht H.
Object Type: Report
System: The UNT Digital Library
Alternative Window Schemes for CuInSe2-Based Solar Cells Final Report: 3 November 1995-December 1997 (open access)

Alternative Window Schemes for CuInSe2-Based Solar Cells Final Report: 3 November 1995-December 1997

This work demonstrated high-efficiency CIGS cells based on highly resistive ZnO buffer layers grown by MOCVD. One cell based on NREL CIGS and a ZnO buffer layer exhibited an active-area efficiency of nearly 14%. This result is one of the best efficiencies reported for a ''direct'' ZnO/CIGS cell made with a vacuum process.
Date: October 26, 1998
Creator: Olsen, L.C. (Electronic Materials Laboratory: Washington State University at Tri-Cities)
Object Type: Report
System: The UNT Digital Library
Aluminum hydroxide issue closure package (open access)

Aluminum hydroxide issue closure package

Aluminum hydroxide coatings on fuel elements stored in aluminum canisters in K West Basin were measured in July and August 1998. Good quality data was produced that enabled statistical analysis to determine a bounding value for aluminum hydroxide at a 99% confidence level. The updated bounding value is 10.6 kg per Multi-Canister Overpack (MCO), compared to the previously estimated bounding value of 8 kg/MCO. Thermal analysis using the updated bounding value, shows that the MCO generates oxygen concentrate that are below the lower flammability limits during the 40-year interim storage period and are, therefore, acceptable.
Date: August 26, 1998
Creator: Bergman, T. B.
Object Type: Report
System: The UNT Digital Library
Audit of the US Department of Energy`s consolidated financial statements for fiscal year 1997 (open access)

Audit of the US Department of Energy`s consolidated financial statements for fiscal year 1997

This report contains information on the Office of Inspector General audit of the Department`s Consolidated Statement of Financial Position as of September 30, 1997.
Date: February 26, 1998
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Bunched Beam Echos in the Ags. (open access)

Bunched Beam Echos in the Ags.

Beam echos have been measured at FNAL [3] and CERN [5] in coasting beams. A coherent oscillation introduced by a short RF burst decoheres quickly, but a coherent echo of this oscillation can be observed if the decohered oscillation is ''bounced off'' a second RF burst. In this report we describe first longitudinal echo measurements of bunched beam in the AGS accelerator. We applied a method proposed by Stupakov [1] for transverse beam echos, where the initial oscillation is produced by a dipole kick and is bounced off a quadrupole kick. In the longitudinal case the dipole and quadrupole kicks are produced by a cavities operating at a 90{degree} and 0{degree} phase shift, respectively.
Date: June 26, 1998
Creator: Kewisch, J.
Object Type: Article
System: The UNT Digital Library
COLLIDING CRYSTALLINE BEAMS. (open access)

COLLIDING CRYSTALLINE BEAMS.

The understanding of crystalline beams has advanced to the point where one can now, with reasonable confidence, undertake an analysis of the luminosity of colliding crystalline beams. Such a study is reported here. It is necessary to observe the criteria, previously stated, for the creation and stability of crystalline beams. This requires, firstly, the proper design of a lattice. Secondly, a crystal must be formed, and this can usually be done at various densities. Thirdly, the crystals in a colliding-beam machine are brought into collision. We study all of these processes using the molecular dynamics (MD) method. The work parallels what was done previously, but the new part is to study the crystal-crystal interaction in collision. We initially study the zero-temperature situation. If the beam-beam force (or equivalent tune shift) is too large then overlapping crystals can not be created (rather two spatially separated crystals are formed). However, if the beam-beam force is less than but comparable to that of the space-charge forces between the particles, we find that overlapping crystals can be formed and the beam-beam tune shift can be of the order of unity. Operating at low but non-zero temperature can increase the luminosity by several orders of …
Date: June 26, 1998
Creator: WEI, J.
Object Type: Article
System: The UNT Digital Library
Comparison of General Purpose Heat Source testing with the ANSI N43.6-1977 (R1989) sealed source standard (open access)

Comparison of General Purpose Heat Source testing with the ANSI N43.6-1977 (R1989) sealed source standard

This analysis provides a comparison of the testing of Radioisotope Thermoelectric Generators (RTGs) and RTG components with the testing requirements of ANSI N43.6-1977 (R1989) ``Sealed Radioactive Sources, Categorization``. The purpose of this comparison is to demonstrate that the RTGs meet or exceed the requirements of the ANSI standard, and thus can be excluded from the radioactive inventory of the Chemistry and Metallurgy Research (CMR) building in Los Alamos per Attachment 1 of DOE STD 1027-92. The approach used in this analysis is as follows: (1) describe the ANSI sealed source classification methodology; (2) develop sealed source performance requirements for the RTG and/or RTG components based on criteria from the accident analysis for CMR; (3) compare the existing RTG or RTG component test data to the CMR requirements; and (4) determine the appropriate ANSI classification for the RTG and/or RTG components based on CMR performance requirements. The CMR requirements for treating RTGs as sealed sources are derived from the radiotoxicity of the isotope ({sup 238}P7) and amount (13 kg) of radioactive material contained in the RTG. The accident analysis for the CMR BIO identifies the bounding accidents as wing-wide fire, explosion and earthquake. These accident scenarios set the requirements for RTGs …
Date: March 26, 1998
Creator: Grigsby, C.O.
Object Type: Report
System: The UNT Digital Library
Comprehensive physical models and simulation package for plasma/material interactions during plasma instabilities. (open access)

Comprehensive physical models and simulation package for plasma/material interactions during plasma instabilities.

Damage to plasma-facing components (PFCS) from plasma instabilities remains a major obstacle to a successful tokamak concept. The extent of the damage depends on the detailed physics of the disrupting plasma, as well as on the physics of plasma-material interactions. A comprehensive computer package called High Energy Interaction with General Heterogeneous Target Systems (HEIGHTS) has been developed and consists of several integrated computer models that follow the beginning of a plasma disruption at the scrape-off layer (SOL) through the transport of the eroded debris and splashed target materials to nearby locations as a result of the deposited energy. The package can study, for the first time, plasma-turbulent behavior in the SOL and predict the plasma parameters and conditions at the divertor plate. Full two-dimensional (2-D) comprehensive radiation magnetohydrodynamic (MHD) models are coupled with target thermodynamics and liquid hydrodynamics to evaluate the integrated response of plasma-facing materials. Factors that influence the lifetime of plasma-facing and nearby components, such as loss of vapor-cloud confinement and vapor removal due to MHD effects, damage to nearby components due to intense vapor radiation, melt splashing, and brittle destruction of target materials, are also modeled and discussed.
Date: August 26, 1998
Creator: Hassanein, A.
Object Type: Article
System: The UNT Digital Library
Computer code selection criteria for flow and transport code(s) to be used in undisturbed vadose zone calculations for TWRS environmental analyses (open access)

Computer code selection criteria for flow and transport code(s) to be used in undisturbed vadose zone calculations for TWRS environmental analyses

The Tank Waste Remediation System (TWRS) is responsible for the safe storage, retrieval, and disposal of waste currently being held in 177 underground tanks at the Hanford Site. In order to successfully carry out its mission, TWRS must perform environmental analyses describing the consequences of tank contents leaking from tanks and associated facilities during the storage, retrieval, or closure periods and immobilized low-activity tank waste contaminants leaving disposal facilities. Because of the large size of the facilities and the great depth of the dry zone (known as the vadose zone) underneath the facilities, sophisticated computer codes are needed to model the transport of the tank contents or contaminants. This document presents the code selection criteria for those vadose zone analyses (a subset of the above analyses) where the hydraulic properties of the vadose zone are constant in time the geochemical behavior of the contaminant-soil interaction can be described by simple models, and the geologic or engineered structures are complicated enough to require a two-or three dimensional model. Thus, simple analyses would not need to use the fairly sophisticated codes which would meet the selection criteria in this document. Similarly, those analyses which involve complex chemical modeling (such as those analyses …
Date: January 26, 1998
Creator: Mann, F. M.
Object Type: Report
System: The UNT Digital Library
Concentrator and Space Applications of High-Efficiency Solar Cells-Recent Developments (open access)

Concentrator and Space Applications of High-Efficiency Solar Cells-Recent Developments

GaInP/GaAs cells invented and developed at NREL have achieved world-record efficiencies. We estimate that their production for space applications has grown to > $100 million/yr. Approximately 300 MW/yr of 1000X terrestrial concentrator cells could be fabricated with the existing manufacturing capacity at a cost of about 21{cents}/Wp. A resurgence of interest in terrestrial PV concentrators, together with the strength of the III-V space-solar-cell industry, indicate that III-V cells are also attractive for terrestrial applications.
Date: October 26, 1998
Creator: Kurtz, S. R. & Friedman, D. J.
Object Type: Article
System: The UNT Digital Library
D0 Central Tracking Solenoid Energization, Controls, Interlocks and Quench Protection Operating Procedures (open access)

D0 Central Tracking Solenoid Energization, Controls, Interlocks and Quench Protection Operating Procedures

This procedure is used when it is necessary to operate the solenoid energization, controls, interlocks and quench detection system. Note that a separate procedure exists for operating the solenoid 'cryogenic' systems. Only D0 Control Room Operators or the Project Electrical Engineer are qualified to execute these procedures or operate the solenoid system. This procedure assumes that the operator is familiar with using the Distributed Manufacturing Automation and Control Software (DMACS).
Date: August 26, 1998
Creator: Hance, R.
Object Type: Report
System: The UNT Digital Library
Density functional and neutron diffraction studies of lithium polymer electrolytes. (open access)

Density functional and neutron diffraction studies of lithium polymer electrolytes.

The structure of PEO doped with lithium perchlorate has been determined using neutron diffraction on protonated and deuterated samples. The experiments were done in the liquid state. Preliminary analysis indicates the Li-O distance is about 2.0 {angstrom}. The geometries of a series of gas phase lithium salts [LiCF{sub 3}SO{sub 3}, Li(CF{sub 3}SO{sub 2}){sub 2}N, Li(CF{sub 3}SO{sub 2}){sub 2}CH, LiClO{sub 4}, LiPF{sub 6}, LiAsF{sub 6}] used in polymer electrolytes have been optimized at B3LYP/6-31G(d) density functional level of theory. All local minima have been identified. For the triflate, imide, methanide, and perchlorate anions, the lithium cation is coordinated to two oxygens and have binding energies of ca 141 kcal/mol at the B3LYP/6-311+G(3df,2p)/B3LYP/6-31G* level of theory. For the hexafluoroarsenate and hexafluorophosphate the lithium cation is coordinated to three oxygens and have binding energies of ca. 136 kcal/mol.
Date: June 26, 1998
Creator: Baboul, A. G.
Object Type: Article
System: The UNT Digital Library
The Design Process of Physical Security as Applied to a U.S. Border Point of Entry (open access)

The Design Process of Physical Security as Applied to a U.S. Border Point of Entry

This paper describes the design process of physical security as applied to a U.S. Border Port of Entry (PoE). Included in this paper are descriptions of the elements that compose U.S. border security. The physical security design will describe the various elements that make up the process as well as the considerations that must be taken into account when dealing with system integration of those elements. The distinctions between preventing unlawful entry and exit of illegal contraband will be emphasized.
Date: October 26, 1998
Creator: Wagner, G.G.
Object Type: Article
System: The UNT Digital Library
Detection of Greenhouse-Gas-Induced Climatic Change (open access)

Detection of Greenhouse-Gas-Induced Climatic Change

The objective of this report is to assemble and analyze instrumental climate data and to develop and apply climate models as a basis for (1) detecting greenhouse-gas-induced climatic change, and (2) validation of General Circulation Models.
Date: May 26, 1998
Creator: Jones, P.D. & Wigley, T.M.L.
Object Type: Report
System: The UNT Digital Library
Determination of silica scale deposition rates and thresholds applied toward protection of injection reservoirs. Quarterly progress report, August 1--December 31, 1997 (open access)

Determination of silica scale deposition rates and thresholds applied toward protection of injection reservoirs. Quarterly progress report, August 1--December 31, 1997

Instrumentation and the components required for the probe and reactor assemblies were procured. Probes were fabricated and tested to assess their sensitivity to scaling. In October, the focus was on design and fabrication of the reactors. This required close coordination with welding and machine shop subvendors. Contact was made with the two Nevada power plants where the experimental equipment will be field tested. Each has indicated their support for the project and will accommodate field testing efforts. Lab testing of the components in November determined that a probe sensitivity problem existed. It was decided to request the specification for the materials used by the Costa Rican utility for pipelines and vessels at Miravalles. By building the probe assemblies from these same materials, experimental results would not be subject to the question of whether preferential scaling occurred due to a specific probe material. New probes were manufactured using the same material as the steel pipelines at Miravalles. Electrical problems still existed, however, probably due to the type of excitation used to monitor the scaling effects. Signal conditioning was added between the probe and recorder to convert from direct current to alternating current excitation. This eliminated additional galvanic effects which may have …
Date: January 26, 1998
Creator: Booth, G.M. III
Object Type: Report
System: The UNT Digital Library
Development of an intelligent grinding wheel for in-process monitoring of ceramic grinding. Semi-annual report {number_sign}3 (open access)

Development of an intelligent grinding wheel for in-process monitoring of ceramic grinding. Semi-annual report {number_sign}3

This is the third semi-annual report for the project. The overall objective of this project is to develop sensor-integrated intelligent diamond wheels for grinding of ceramics. Such wheels will be smart enough to monitor and supervise both the wheel preparation and grinding processes without the need to instrument the machine tool. Intelligent wheels will utilize re-useable cores integrated with sensors: to measure the acoustic emission (AE) and grinding force. Signals from the sensors will be transmitted from a rotating wheel to a receiver by telemetry. Wheels will be trained to recognize distinct characteristics associated with truing, dressing and grinding. The technical progress is summarized in this report.
Date: March 26, 1998
Creator: Malkin, S.; Gao, R.; Guo, C.; Varghese, B. & Pathare, S.
Object Type: Report
System: The UNT Digital Library
The dielectric boundary condition for the embedded curved boundary (ECB) method (open access)

The dielectric boundary condition for the embedded curved boundary (ECB) method

A new version of ECB has been completed that allows nonuniform grid spacing and a new dieledric boundary condition. ECB was developed to retain the simplicity and speed of an orthogonal mesh while capturing much of the fidelity of adaptive, unstructured finite element meshes. Codes based on orthogonal meshes are easy to work with and lead to well-posed elliptic and parabolic problems that are comparatively easy to solve. Generally, othogonal mesh representations lead to banded matrices while unstructured representations lead to more complicated sparse matrices. Recent advances in adapting banded linear systems to massively parallel computers reinforce our opinion that iterative field solutions utilizing banded matrix methods will continue to be competitive. Unfortunately, the underlying ``stair-step`` boundary representation in simple orthogonal mesh (and recent Adaptive Mesh Refinement) applications is inadequate. With ECB, the curved boundary is represented by piece-wise-linear representations of curved internal boundaries embedded into the orthogonal mesh- we build better, but not more, coefficients in the vicinity of these boundaries-and we use the surplus free energy on more ambitious physics models. ECB structures are constructed out of the superposition of analytically prescribed building blocks. In 2-D, we presently use a POLY4 (linear boundaries defined by 4 end points), …
Date: January 26, 1998
Creator: Hewwitt, D. W., LLNL
Object Type: Article
System: The UNT Digital Library
The Dissolution and Characterization of Aluminum Clad Oxide Fuel (open access)

The Dissolution and Characterization of Aluminum Clad Oxide Fuel

Laboratory dissolution studies of aluminum clad mixed oxide fuel rods have been conducted using two different F-Canyon decladding and dissolving flowsheets. During the first phase of the experimental program, materials from three different color coded fuel rods were dissolved in caustic and nitric acid solutions. The final phase of the laboratory program involved the dissolution and characterization of materials from three cracked pellet fuel rods using a selected caustic/ nitric acid flowsheet.Laboratory results obtained from the initial dissolution studies identified several inconsistencies and potential problem issues with the behavior of materials from the color coded fuel rods. Based on these findings and influenced by the difficulties introduced by using the RCRA listed mercury during processing, the flowsheet selected for dissolving these aluminum clad fuel rods in F-Canyon dissolvers was the two- step caustic decladding/ nitric acid dissolution flowsheet.The final phase of the experimental program involved testing materials from three cracked pellet fuel rods using the selected flowsheet. Again all aluminum fuel rod components dissolved during the decladding step. However, some uranium and plutonium bearing solids remained with the caustic decladding solution which could be sent to waste. The quantities of uranium and plutonium expected to remain with the caustic solutions …
Date: October 26, 1998
Creator: Gray, J. H.
Object Type: Report
System: The UNT Digital Library
DOE SPENT NUCLEAR FUEL DISPOSAL CONTAINER (open access)

DOE SPENT NUCLEAR FUEL DISPOSAL CONTAINER

The DOE Spent Nuclear Fuel Disposal Container (SNF DC) supports the confinement and isolation of waste within the Engineered Barrier System of the Mined Geologic Disposal System (MGDS). Disposal containers are loaded and sealed in the surface waste handling facilities, transferred to the underground through the access mains, and emplaced in emplacement drifts. The DOE Spent Nuclear Fuel Disposal Container provides long term confinement of DOE SNF waste, and withstands the loading, transfer, emplacement, and retrieval loads and environments. The DOE SNF Disposal Containers provide containment of waste for a designated period of time, and limit radionuclide release thereafter. The disposal containers maintain the waste in a designated configuration, withstand maximum handling and rockfall loads, limit the individual waste canister temperatures after emplacement. The disposal containers also limit the introduction of moderator into the disposal container during the criticality control period, resist corrosion in the expected repository environment, and provide complete or limited containment of waste in the event of an accident. Multiple disposal container designs may be needed to accommodate the expected range of DOE Spent Nuclear Fuel. The disposal container will include outer and inner barrier walls and outer and inner barrier lids. Exterior labels will identify the …
Date: June 26, 1998
Creator: Habashi, F.
Object Type: Report
System: The UNT Digital Library
Elegant impulser developed for flat beam injection (open access)

Elegant impulser developed for flat beam injection

The following report describes the design, construction, and checkout of a high-voltage (HV) impulser built for the heavy ion fusion (HIF) project [1]. The purpose of this impulser is to provide an adjustable diode voltage source of sufficient quality and level to allow the optimization of beam transport and accelerator sections of HIF [2, 3]. An elegant, low-impedance, high-energy storage capacitor circuit has been selected for this application. Circuit parameters of the retrofit to the diode region [4] have been included to provide the controlled rise time. The critical part of this circuit that is common to all candidates is the impedance matching component. The following report provides a description of the implemented circuit, the basic circuit variables for wave shaping, screening techniques revealing the weakest circuit component, and the resulting output of the injector.
Date: May 26, 1998
Creator: Wilson, M. J., LLNL
Object Type: Article
System: The UNT Digital Library
EMITTANCE CONTROL OF A BEAM BY SHAPING THE TRANSVERSE CHARGE DISTRIBUTION, USING A TOMOGRAPHY DIAGNOSTIC. (open access)

EMITTANCE CONTROL OF A BEAM BY SHAPING THE TRANSVERSE CHARGE DISTRIBUTION, USING A TOMOGRAPHY DIAGNOSTIC.

A high-brightness beam is very important for many applications. A diagnostic that measures the multi-dimensional phase-space density-distribution of the electron bunch is a must for obtaining such beams. Measurement of a slice emittance has been achieved [1]. Tomographic reconstruction of phase space was suggested [2] and implemented [3,4] using a single quadrupole scan. In the present work we give special attention to the accuracy of the phase space reconstruction and present an analysis using a transport line with nine focusing magnets and techniques to control the optical functions and phases. This diagnostic, coupled with control of the radial charge distribution of presents an opportunity to improve the beam brightness. Combining the slice emittance and tomography diagnostics lead to an unprecedented visualization of phase space distributions in 5 dimensional phase-space and an opportunity to perform high-order emittance corrections.
Date: June 26, 1998
Creator: Yakimenko, V.
Object Type: Article
System: The UNT Digital Library
Estimating the Uncertainty in Reactivity Accident Neutronic Calculations (open access)

Estimating the Uncertainty in Reactivity Accident Neutronic Calculations

A study of the uncertainty in calculations of the rod ejection accident in a pressurized water reactor is being carried out for the US Nuclear Regulatory Commission. This paper is a progress report on that study. Results are presented for the sensitivity of core energy deposition to the key parameters: ejected rod worth, delayed neutron fraction, Doppler reactivity coefficient, and fuel specific heat. These results can be used in the future to estimate the uncertainty in local fuel enthalpy given some assumptions about the uncertainty in the key parameters. This study is also concerned with the effect of the intra-assembly representation in calculations. The issue is the error that might be present if assembly-average power is calculated, and pin peaking factors from a static calculation are then used to determine local fuel enthalpy. This is being studied with the help of a collaborative effort with Russian and French analysts who are using codes with different intra-assembly representations. The US code being used is PARCS which calculates power on an assembly-average basis. The Russian code being used is BARS which calculates power for individual fuel pins using a heterogeneous representation based on a Green's Function method.
Date: October 26, 1998
Creator: Diamond, D. J.; Yang, C. Y. & Aronson, A. L.
Object Type: Article
System: The UNT Digital Library