Enhanced Waste Tank Level Model (open access)

Enhanced Waste Tank Level Model

'With the increased sensitivity of waste-level measurements in the H-Area Tanks and with periods of isolation, when no mass transfer occurred for certain tanks, waste-level changes have been recorded with are unexplained.'
Date: June 24, 1999
Creator: Duignan, M.R.
Object Type: Report
System: The UNT Digital Library
Validation Testing of the Nitric Acid Dissolution Step Within the K Basin Sludge Pretreatment Process (open access)

Validation Testing of the Nitric Acid Dissolution Step Within the K Basin Sludge Pretreatment Process

No abstract is available for this document at this time.
Date: February 24, 1999
Creator: Schmidt, Andrew J.; Delegard, Calvin H.; Silvers, Kurt L.; Bredt, Paul R.; Carlson, Clark D.; Hoppe, Eric W. et al.
Object Type: Report
System: The UNT Digital Library
Generalized b-spline subdivision-surface wavelets and lossless compression (open access)

Generalized b-spline subdivision-surface wavelets and lossless compression

We present a new construction of wavelets on arbitrary two-manifold topology for geometry compression. The constructed wavelets generalize symmetric tensor product wavelets with associated B-spline scaling functions to irregular polygonal base mesh domains. The wavelets and scaling functions are tensor products almost everywhere, except in the neighborhoods of some extraordinary points (points of valence unequal four) in the base mesh that defines the topology. The compression of arbitrary polygonal meshes representing isosurfaces of scalar-valued trivariate functions is a primary application. The main contribution of this paper is the generalization of lifted symmetric tensor product B-spline wavelets to two-manifold geometries. Surfaces composed of B-spline patches can easily be converted to this scheme. We present a lossless compression method for geometries with or without associated functions like color, texture, or normals. The new wavelet transform is highly efficient and can represent surfaces at any level of resolution with high degrees of continuity, except at a finite number of extraordinary points in the base mesh. In the neighborhoods of these points detail can be added to the surface to approximate any degree of continuity.
Date: November 24, 1999
Creator: Bertram, M; Duchaineau, M A; Hamann, B & Joy, K I
Object Type: Article
System: The UNT Digital Library
A Modular Computer Code for Simulating Reactive Multi-Species Transport in 3-Dimensional Groundwater Systems (open access)

A Modular Computer Code for Simulating Reactive Multi-Species Transport in 3-Dimensional Groundwater Systems

No abstract is available for this document at this time.
Date: June 24, 1999
Creator: Clement, Thangadurai P.
Object Type: Report
System: The UNT Digital Library
SUBURFACE SHIELDING-SPECIFIC SOURCE TERM EVALUATION (open access)

SUBURFACE SHIELDING-SPECIFIC SOURCE TERM EVALUATION

The purpose of this work is to provide supporting calculations for determination of the radiation source terms specific to subsurface shielding design and analysis. These calculations are not intended to provide the absolute values of the source terms, which are under the charter of the Waste Package Operations (WPO) Group. Rather, the calculations focus on evaluation of the various combinations of fuel enrichment, burnup and cooling time for a given decay heat output, consistent with the waste package (WP) thermal design basis. The objective is to determine the worst-case combination of the fuel characteristics (enrichment, burnup and cooling time) which would give the maximum radiation fields for subsurface shielding considerations. The calculations are limited to PWR fuel only, since the WP design is currently evolving with thinner walls and a reduced heat load as compared to the viability assessment (VA) reference design. The results for PWR fuel will provide a comparable indication of the trend for BWR fuel, as their characteristics are similar. The source term development for defense high-level waste and other spent nuclear fuel (SNF) is the responsibility of the WPO Group, and therefore, is not included this work. This work includes the following items responsive to the …
Date: August 24, 1999
Creator: Su, S.
Object Type: Report
System: The UNT Digital Library
RIP Input Tables from WAPDEG for LA Design Selection: Enhanced Design Alternative II-3 (open access)

RIP Input Tables from WAPDEG for LA Design Selection: Enhanced Design Alternative II-3

The purpose of this calculation is to document (1) the Waste Package Degradation (WAPDEG) version 3.09 (CRWMS M&O 1998b. ''Software Routine Report for WAPDEG'' (Version 3.09)) simulations used to analyze degradation and failure of 2-cm thick titanium grade 7 corrosion resistant material (CRM) drip shields (that are placed over waste packages composed of a 2-cm thick Alloy 22 corrosion resistant material (CRM) as the outer barrier and an unspecified material to provide structural support as the inner barrier) as well as degradation and failure of the waste packages themselves, and (2) post-processing of these results into tables of drip shield/waste package degradation time histories suitable for use as input into the Integrated Probabilistic Simulator for Environmental Systems (RIP) version 5.19.01 (Golder Associates 1998) computer code. This calculation supports Performance Assessment analysis of the License Application Design Selection (LADS) Enhanced Design Alternative (EDA) II-3. The aging period in the EDA II design (CRWMS M&O 1999f. ''Design Input Request for LADS Phase II EDA Evaluations'', Item 1 Row 9 Column 3) was replaced in the case of EDA II-3 with 25 years preclosure ventilation, leading to a total of 50 years preclosure ventilation. The waste packages are line loaded in the repository …
Date: August 24, 1999
Creator: Monib, A.M.
Object Type: Report
System: The UNT Digital Library
Thermal Fusing Model of Conducting Particle Composites (open access)

Thermal Fusing Model of Conducting Particle Composites

Composites of carbon black particles in polyethylene are known to exhibit an unusually rapid increase in resistivity as the applied field is increased, making this material useful in automatically resettable fuses. In this application the composite is in series with the circuit it is protecting: at low applied voltages this circuit is the load, but at high applied voltages the composite becomes the load, limiting the current to the circuit. We present a simple model of this behavior in terms of a network of nonlinear conductors. Each conductor has a conductance that depends on its instantaneous Joule heating. It is shown that in the fusing regime, where the current through the composite decreases with increasing voltage, an plate-like dissipation instability develops normal to the applied field. Experimental evidence of this phenomena is described.
Date: June 24, 1999
Creator: Martin, James E.
Object Type: Article
System: The UNT Digital Library
FANTM: The First Article NIF Test Module for the Laser Power Conditioning System (open access)

FANTM: The First Article NIF Test Module for the Laser Power Conditioning System

Designing and developing the 1.7 to 2. 1-MJ Power Conditioning System (PCS) that powers the flashlamps for the National Ignition Facility (NIF), currently being constructed at Lawrence Livermore National Labs (LLNL), is one of several responsibilities assumed by Sandia National Labs (SNL) in support of the NIF Project. The test facility that has evolved over the last three years to satisfy the project requirements is called FANTM. It was built at SNL and has operated for about 17,000 shots to demonstrate component performance expectations over the lifetime of NIF. A few modules similar to the one shown in Fig. 1 will be used initially in the amplifier test phase of the project. The final till NIF system will require 192 of them (48 in each of four capacitor bays). This paper briefly summarizes the final design of the FANTM facility and compares its performance with the predictions of circuit simulations for both normal operation and fault-mode response. Applying both the measured and modeled power pulse waveforms as input to a physics-based, semi-empirical amplifier gain code indicates that the 20-capacitor PCS can satisfy the NIF requirement for an average gain coefficient of 5.00 %/cm and can exceed 5.20%/cm with 24 capacitors.
Date: June 24, 1999
Creator: Hammon, Jud; Harjes, Henry C.; Moore, William B.S.; Smith, David L. & Wilson, J. Michael
Object Type: Article
System: The UNT Digital Library
Final state interaction phase in B decays (open access)

Final state interaction phase in B decays

From an estimate of the meson-meson inelastic scattering at 5 GeV it is concluded that a typical strong phase in B decays to two mesons is of order of 20{sup o}. For a particular final state an estimate of the phase depends on whether that state is more or less probable as a final state compared to those states to which it is connected by the strong interaction S matrix.
Date: March 24, 1999
Creator: Suzuki, Mahiko & Wolfenstein, Lincoln
Object Type: Article
System: The UNT Digital Library
Anisotropic Magnetism in Field-Structured Composites (open access)

Anisotropic Magnetism in Field-Structured Composites

Magnetic field-structured-composites (FSCs) are made by structuring magnetic particle suspensions in uniaxial or biaxial (e.g. rotating) magnetic fields, while polymerizing the suspending resin. A uniaxial field produces chain-like particle structures, and a biaxial field produces sheet-like particle structures. In either case, these anisotropic structures affect the measured magnetic hysteresis loops, with the magnetic remanence and susceptibility increased significantly along the axis of the structuring field, and decreased slightly orthogonal to the structuring field, relative to the unstructured particle composite. The coercivity is essentially unaffected by structuring. We present data for FSCs of magnetically soft particles, and demonstrate that the altered magnetism can be accounted for by considering the large local fields that occur in FSCs. FSCS of magnetically hard particles show unexpectedly large anisotropies in the remanence, and this is due to the local field effects in combination with the large crystalline anisotropy of this material.
Date: June 24, 1999
Creator: Anderson, Robert A.; Martin, James E.; Odinek, Judy & Venturini, Eugene
Object Type: Article
System: The UNT Digital Library
Nonlinear Interlayer Tunneling in a Double Electron Layer Structure (open access)

Nonlinear Interlayer Tunneling in a Double Electron Layer Structure

None
Date: June 24, 1999
Creator: Lyo, S.K.
Object Type: Article
System: The UNT Digital Library
Use of Surfactant Micelles to Control the Structural Phase of Nanosize Iron Clusters (open access)

Use of Surfactant Micelles to Control the Structural Phase of Nanosize Iron Clusters

None
Date: June 24, 1999
Creator: Provencio, P. P. & Wilcoxon, J. P.
Object Type: Article
System: The UNT Digital Library
Review of Subcritical Source-Driven Noise Analysis Measurements (open access)

Review of Subcritical Source-Driven Noise Analysis Measurements

Subcritical source-driven noise measurements are simultaneous Rossi-{alpha} and randomly pulsed neutron measurements that provide measured quantities that can be related to the subcritical neutron multiplication factor. In fact, subcritical source-driven noise measurements should be performed in lieu of Rossi-{alpha} measurements because of the additional information that is obtained from noise measurements such as the spectral ratio and the coherence functions. The basic understanding of source-driven noise analysis measurements can be developed from a point reactor kinetics model to demonstrate how the measured quantities relate to the subcritical neutron multiplication factor. More elaborate models can also be developed using a generalized stochastic model. These measurements can be simulated using Monte Carlo codes to determine the subcritical neutron multiplication factor or to determine the sensitivity of calculations to nuclear cross section data. The interpretation of the measurement using a Monte Carlo method is based on a perturbation model for the relationship between the spectral ratio and the subcritical neutron multiplication factor. The subcritical source-driven noise measurement has advantages over other subcritical measurement methods in that reference measurements at delayed critical are not required for interpreting the measurements. Therefore, benchmark or in-situ subcritical measurements can be performed outside a critical experiment facility. Furthermore, …
Date: November 24, 1999
Creator: Valentine, T.E.
Object Type: Report
System: The UNT Digital Library
Performance Characteristics of an Extended Throat Flow Nozzle for the Measurement of High Void Fraction Multi-Phase Flows (open access)

Performance Characteristics of an Extended Throat Flow Nozzle for the Measurement of High Void Fraction Multi-Phase Flows

An extended throat flow nozzle has been examined as a device for the measurement of very high void fraction multi-phase flows. Due to its greater density and partial contact with the wall, the equilibrium velocity of the liquid phase appreciably lags that of the lighter gas phase. The two phases are strongly coupled resulting in pressure drops across the contraction and in the extended throat that are significantly different than those experienced in single-phase flow. Information about the mass flow rates of the two phases can be extracted from the measured pressure drops. The performance of an extended throat flow nozzle has been evaluated under multi-phase conditions using natural gas and hydrocarbon liquids at 400 and 500 psi. Two hydrocarbon solvents were used as the test liquids, Isopar M (sp=0.79) and Aromatic 100 (sp=0.87). These data are compared to prior air-water data at nominally 15 psi. The high and low pressure data were found to be consistent, confirming that the temperature, pressure, and size scaling of the extended throat venturi are correctly represented. This consistency allows different sized devices to be applied under different fluid conditions (temperature, pressure, gas and liquid phase composition, etc) with confidence.
Date: March 24, 1999
Creator: Fincke, James R. (INEEL), Ronnenkamp, C.; Kruse, D.; Krogue, J. & Householder, D. (Perry Equipment Corporation)
Object Type: Article
System: The UNT Digital Library
Project W-211 initial tank retrieval systems year 2000 compliance assessment project plan (open access)

Project W-211 initial tank retrieval systems year 2000 compliance assessment project plan

This assessment describes the potential Year 2000 (Y2K) problems and describes the methods for achieving Y2K Compliance for Project W-211, Initial Tank Retrieval Systems (ITRS). The purpose of this assessment is to give an overview of the project. This document will not be updated and any dates contained in this document are estimates and may change. The scope of project W-211 is to provide systems for retrieval of radioactive wastes from ten double-shell tanks (DST). systems will be installed in tanks 102-AP, 104-AP, 105-AN, 104-AN, 102-AZ, 101-AW, 103-AN, 107-AN, 102-AY, and 102-SY. The current tank selection and sequence supports phase I feed delivery to privatized processing plants. A detailed description of system dates, functions, interfaces, potential Y2K problems, and date resolutions can not be described since the project is in the definitive design phase. This assessment will describe the methods, protocols, and practices to assure that equipment and systems do not have Y2K problems.
Date: August 24, 1999
Creator: BUSSELL, J.H.
Object Type: Report
System: The UNT Digital Library
Texas Bi-Fuel Liquefied Petroleum Gas Pickup Study: Final Report (open access)

Texas Bi-Fuel Liquefied Petroleum Gas Pickup Study: Final Report

Alternative fuels may be an effective means for decreasing America's dependence on imported oil; creating new jobs; and reducing emissions of greenhouse gases, exhaust toxics, and ozone-forming hydrocarbons. However, data regarding in-use fuel economy and maintenance characteristics of alternative fuel vehicles (AFVs) have been limited in availability. This study was undertaken to compare the operating and maintenance characteristics of bi-fuel vehicles (which use liquefied petroleum gas, or propane, as the primary fuel) to those of nominally identical gasoline vehicles. In Texas, liquefied petroleum gas is one of the most widely used alternative fuels. The largest fleet in Texas, operated by the Texas Department of Transportation (TxDOT), has hundred of bi-fuel (LPG and gasoline) vehicles operating in normal daily service. The project was conducted over a 2-year period, including 18 months (April 1997-September 1998) of data collection on operations, maintenance, and fuel consumption of the vehicles under study. This report summarizes the project and its results.
Date: May 24, 1999
Creator: Huang, Y.; Matthews, R. D. & Popova, E. T.
Object Type: Report
System: The UNT Digital Library
Transformation Mechanism and Kinetics for the Pressure-Induced Phase Transition in Shocked CdS (open access)

Transformation Mechanism and Kinetics for the Pressure-Induced Phase Transition in Shocked CdS

The pressure-induced phase transition in CdS was investigated using picosecond time-resolved electronic spectroscopy in plate impact shock wave experiments. Real-time changes in the electronic spectra were observed, with 100 ps time resolution, in single crystals of CdS shocked along the c and a axes to peak stresses between 35 and 90 kbar (above the phase transition stress of approximately 30 kbar measured in continuum studies). When shocked to stresses above approximately 50 kbar along the crystal c axis and 60 to 70 kbar along the crystal a axis, the crystals undergo a very rapid change in electronic structure, indicating that significant structural changes occur within the first 100 ps. These results, along with previous ns continuum measurements, make a strong case for a metastable state during the phase transition in shocked CdS. Ab-initio periodic Hartree-Fock calculations (with DFT correlation corrections) were employed to examine the compression of CdS and to determine a possible lattice structure for the proposed metastable structure. These results, along with details of the transformation kinetics and orientational dependence, will be discussed. Work supported by ONR.
Date: June 24, 1999
Creator: Gupta, Y.M.; Knudson, M.D. & Kunz, A.B.
Object Type: Article
System: The UNT Digital Library
Large-Scale Eigenvalue Calculations for Stability Analysis of Steady Flows on Massively Parallel Computers (open access)

Large-Scale Eigenvalue Calculations for Stability Analysis of Steady Flows on Massively Parallel Computers

None
Date: June 24, 1999
Creator: Lehoucq, Richard B. & Salinger, Andrew G.
Object Type: Article
System: The UNT Digital Library
NRC-BNL Benchmark Program on Evaluation of Methods for Seismic Analysis of Coupled Systems (open access)

NRC-BNL Benchmark Program on Evaluation of Methods for Seismic Analysis of Coupled Systems

A NRC-BNL benchmark program for evaluation of state-of-the-art analysis methods and computer programs for seismic analysis of coupled structures with non-classical damping is described. The program includes a series of benchmarking problems designed to investigate various aspects of complexities, applications and limitations associated with methods for analysis of non-classically damped structures. Discussions are provided on the benchmarking process, benchmark structural models, and the evaluation approach, as well as benchmarking ground rules. It is expected that the findings and insights, as well as recommendations from this program will be useful in developing new acceptance criteria and providing guidance for future regulatory activities involving licensing applications of these alternate methods to coupled systems.
Date: March 24, 1999
Creator: Chokshi, N.; DeGrassi, G. & Xu, J.
Object Type: Article
System: The UNT Digital Library
PARTICLE TRANSPORT AND DEPOSITION IN THE HOT-GAS FILTER AT WILSONVILLE (open access)

PARTICLE TRANSPORT AND DEPOSITION IN THE HOT-GAS FILTER AT WILSONVILLE

Particle transport and deposition in the Wilsonville hot-gas filter vessel is studied. The filter vessel contains a total of 72 filters, which are arranged in two tiers. These are modeled by six upper and one lower cylindrical effective filters. An unstructured grid of 312,797 cells generated by GAMBIT is used in the simulations. The Reynolds stress model of FLUENT{trademark} (version 5.0) code is used for evaluating the gas mean velocities and root mean-square fluctuation velocities in the vessel. The particle equation of motion includes the drag, the gravitational and the lift forces. The turbulent instantaneous fluctuation velocity is simulated by a filtered Gaussian white-noise model provided by the FLUENT code. The particle deposition patterns are evaluated, and the effect of particle size is studied. The effect of turbulent dispersion, the lift force and the gravitational force are analyzed. The results show that the deposition pattern depends on particle size. Turbulent dispersion plays an important role in transport and deposition of particles. Lift and gravitational forces affect the motion of large particles, but has no effect on small particles.
Date: June 24, 1999
Creator: Ahmadi, Goodarz
Object Type: Report
System: The UNT Digital Library
NIF diagnostic damage and design issues (open access)

NIF diagnostic damage and design issues

The NIF target environment is evaluated with respect to target and diagnostic debris and with respect to instrument survivability in the presence of target debris and radiation. Quantitative estimates are arrived at by extrapolating from Nova and Omega experience using simple scaling arguments. Specifically, we evaluate the closest distance of approach of various components of DIM-based diagnostics such as target mounted pinhole arrays, open detectors, filters, x-ray optics, and spectrometers. We also include constraints on achieving adequate signal-to-noise on x-ray diagnostics. Four of the most important conclusions are as follows: (1) The required full NIF stand-off distance for heavily filtered detectors (e.g. multi-keV x-ray and particle detectors) as determined by concerns of diagnostic debris and diagnostic survivability to debris and radiation is no more than 100 cm. (2) Target mounted pinhole arrays and slits mounted a few cm from chamber center at NIF will survive long enough to record data and should be an acceptable source of shrapnel debris. (3) DIM-based instrument stand-off distances are compatible with achieving the same photon statistics (or better with ongoing improvements in detector resolution and noise) than available with current Nova and Omega SIM- or TIM-based instrumentation. Section II reviews target and diagnostic debris …
Date: June 24, 1999
Creator: Landen, N
Object Type: Report
System: The UNT Digital Library
A Database of Herbaceous Vegetation Responses to Elevated Atmospheric CO{sub 2} (open access)

A Database of Herbaceous Vegetation Responses to Elevated Atmospheric CO{sub 2}

To perform a statistically rigorous meta-analysis of research results on the response by herbaceous vegetation to increased atmospheric CO{sub 2} levels, a multiparameter database of responses was compiled from the published literature. Seventy-eight independent CO{sub 2}-enrichment studies, covering 53 species and 26 response parameters, reported mean response, sample size, and variance of the response (either as standard deviation or standard error). An additional 43 studies, covering 25 species and 6 response parameters, did not report variances. This numeric data package accompanies the Carbon Dioxide Information Analysis Center's (CDIAC's) NDP-072, which provides similar information for woody vegetation. This numeric data package contains a 30-field data set of CO{sub 2}-exposure experiment responses by herbaceous plants (as both a flat ASCII file and a spreadsheet file), files listing the references to the CO{sub 2}-exposure experiments and specific comments relevant to the data in the data sets, and this documentation file (which includes SAS{reg_sign} and Fortran codes to read the ASCII data file). The data files and this documentation are available without charge on a variety of media and via the Internet from CDIAC.
Date: November 24, 1999
Creator: Jones, M.H.
Object Type: Report
System: The UNT Digital Library
Portable Exhauster Position Paper (open access)

Portable Exhauster Position Paper

This document identifies the tasks that are involved in preparing the ''standby'' portable exhauster (POR05 skid C) to support Interim Stabilization's schedule for saltwell pumping.
Date: September 24, 1999
Creator: KRISKOVICH, J.R.
Object Type: Report
System: The UNT Digital Library
High intensity physics with a table-top 20 TW laser system (open access)

High intensity physics with a table-top 20 TW laser system

The purpose of this project was to develop a high peak power laser system (100 TW) and begin initial high intensity experiments that exploit its short pulse width (30 fs) and high repetition rate (1 - 10 Hz). Such a laser system presents unique capabilities such as permitting ultrafast time-resolved plasma physics experiments by probing the plasma with the 30 fs laser pulse. The high repetition rate also allows detailed, systematic studies of phenomena, not possible with large, single shot laser systems. During the previous year we have made good progress on the development of the laser. We have demonstrated the production of pulses up to the 5 TW level at 10 Hz and have installed an additional amplifier to take the system to 20 TW. We have pulse compressed the pulses to 30 fs and have developed a number of diagnostics to characterize the laser prepulse. During this year we have also activated a target chamber to begin plasma physics experiments in gas jet targets.
Date: February 24, 1999
Creator: Ditmire, T & Perry, M D
Object Type: Report
System: The UNT Digital Library