Sensitivity and uncertainty analysis of a polyurethane foam decomposition model (open access)

Sensitivity and uncertainty analysis of a polyurethane foam decomposition model

Sensitivity/uncertainty analyses are not commonly performed on complex, finite-element engineering models because the analyses are time consuming, CPU intensive, nontrivial exercises that can lead to deceptive results. To illustrate these ideas, an analytical sensitivity/uncertainty analysis is used to determine the standard deviation and the primary factors affecting the burn velocity of polyurethane foam exposed to firelike radiative boundary conditions. The complex, finite element model has 25 input parameters that include chemistry, polymer structure, and thermophysical properties. The response variable was selected as the steady-state burn velocity calculated as the derivative of the burn front location versus time. The standard deviation of the burn velocity was determined by taking numerical derivatives of the response variable with respect to each of the 25 input parameters. Since the response variable is also a derivative, the standard deviation is essentially determined from a second derivative that is extremely sensitive to numerical noise. To minimize the numerical noise, 50-micron elements and approximately 1-msec time steps were required to obtain stable uncertainty results. The primary effect variable was shown to be the emissivity of the foam.
Date: March 14, 2000
Creator: Hobbs, Michael L. & Robinson, David G.
Object Type: Article
System: The UNT Digital Library
The impact of brannerite on the release of plutonium and gadolinium during the corrosion of zirconolite-rich titanate ceramics (open access)

The impact of brannerite on the release of plutonium and gadolinium during the corrosion of zirconolite-rich titanate ceramics

Titanate ceramics have been selected as the preferred waste form for the immobilization of excess plutonium. Corrosion tests are underway to try to understand the long-term behavior of this material. In this paper, results from PCT-B static dissolution tests are used to provide an explanation of the observed corrosion behavior of a zirconolite-based ceramic. Two important observations are made. First, Ca is released at a constant rate [7 x 10{sup {minus}5} g/(m{sup 2} day)] in PCT-B tests for up to two years. Second, the release rates for Pu and Gd increase with time (up to two years) in PCT-B tests. The first observation suggests that the ceramics continue to corrode at a low rate for at least two years in PCT-B tests. The second observation suggests that the release rates of Pu and Gd are controlled by some process or processes that do not affect the release rate of other elements. Evidence indicates that this is due to the preferential dissolution of brannerite from the ceramic.
Date: March 14, 2000
Creator: Chamberlain, D. B.; Hash, M. C.; Basco, J. K.; Bakel, A. J.; Metz, C. J.; Wolf, S. F. et al.
Object Type: Article
System: The UNT Digital Library
TEM investigation of U{sup 6+} and Re{sup 7+} reduction by Desulfovibrio desulfuricans, a sulfate-reducing bacterium (open access)

TEM investigation of U{sup 6+} and Re{sup 7+} reduction by Desulfovibrio desulfuricans, a sulfate-reducing bacterium

Uranium and its fission product Tc in aerobic environment will be in the forms of UO{sub 2}{sup 2+} and TcO{sub 4}{sup {minus}}. Reduced forms of tetravalent U and Tc are sparingly soluble. As determined by transmission electron microscopy, the reduction of uranyl acetate by immobilized cells of Desulfovibrio desulfuricans results in the production of black uraninite nanocrystals precipitated outside the cell. Some nanocrystals are associated with outer membranes of the cell as revealed from cross sections of these metabolic active sulfate-reducing bacteria. The nanocrystals have an average diameter of 5 nm and have anhedral shape. The reduction of Re{sup 7+} by cells of Desulfovibrio desulfuricans is fast in media containing H{sub 2} an electron donor, and slow in media containing lactic acid. It is proposed that the cytochrome in these cells has an important role in the reduction of uranyl and Re{sup 7+} is (a chemical analogue for Tc{sup 7+}) through transferring an electron from molecular hydrogen or lactic acid to the oxyions of UO{sub 2}{sup 2+} and TcO{sub 4}{sup {minus}}.
Date: March 14, 2000
Creator: Xu, Huifang; Barton, Larry L.; Choudhury, Keka; Zhang, Pengchu & Wang, Yifeng
Object Type: Article
System: The UNT Digital Library
Growth of compaction bands: A new deformation mode for porous rock (open access)

Growth of compaction bands: A new deformation mode for porous rock

Compaction bands are thin, tabular zones of grain breakage and reduced porosity that are found in sandstones. These structures may form due to tectonic stresses or as a result of local stresses induced during production of fluids from wells, resulting in barriers to fluid (oil, gas, water) movement in sandstone reservoirs. To gain insight into the formation of compaction bands the authors have produced them in the laboratory. Acoustic emission locations were used to define and track the thickness of compaction bands throughout the stress history during axisymmetric compression experiments. Narrow zones of intense acoustic emission, demarcating the boundaries between the uncompacted and compacted regions were found to develop. Unexpectedly, these boundaries moved at velocities related to the fractional porosity reduction across the boundary and to the imposed specimen compression stress. This appears to be a previously unrecognized, fundamental mode of deformation of a porous, granular material subjected to compressive loading with significant implications for the production of hydrocarbons.
Date: March 14, 2000
Creator: OLSSON,WILLIAM A. & HOLCOMB,DAVID J.
Object Type: Article
System: The UNT Digital Library
Assessing the disturbed rock zone (DRZ) around a 655 meter vertical shaft in salt using ultrasonic waves: An update (open access)

Assessing the disturbed rock zone (DRZ) around a 655 meter vertical shaft in salt using ultrasonic waves: An update

An array of ultrasonic transducers was constructed consisting of three identical arrays at various depths in an air intake shaft at the Waste Isolation Pilot Plant (WIPP). Each array consists of transducers permanently installed in three holes arranged in an L shape. An active array, created by appropriate arrangement of the transducers and selection of transmitter-receiver pairs, allows the measurement of transmitted signal velocities and amplitudes (for attenuation studies) along 216 paths parallel, perpendicular and tangential to the shaft walls. Transducer positions were carefully surveyed, allowing absolute velocity measurements. Installation occurred over a period of about two years beginning in early 1989, with nearly continuous operation since that time, resulting in a rare, if not unique, record of the spatial and temporal variability of damage development around an underground opening. This paper reports results from the last two years of operation, updating the results reported by Holcomb, 1999. Results will be related to the damage, due to microcracking, required to produce the observed changes. It is expected that the results will be useful to other studies of the long-term deformation characteristics of salt.
Date: March 14, 2000
Creator: HARDY,ROBERT D. & HOLCOMB,DAVID J.
Object Type: Article
System: The UNT Digital Library
Thermodynamic stability of actinide pyrochlore minerals in deep geologic repository environments (open access)

Thermodynamic stability of actinide pyrochlore minerals in deep geologic repository environments

Crystalline phases of pyrochlore (e.g., CaPuTi{sub 2}O{sub 7}, CaUTi{sub 2}O{sub 7}) have been proposed as a durable ceramic waste form for disposal of high level radioactive wastes including surplus weapons-usable plutonium. In this paper, the authors use a linear free energy relationship to predict the Gibbs free energies of formation of pyrochlore phases (CaMTi{sub 2}O{sub 7}). The Pu-pyrochlore phase is predicted to be stable with respect to PuO{sub 2}, CaTiO{sub 3}, and TiO{sub 2} at room temperatures. Pu-pyrochlore is expected to be stable in a geologic repository where silica and carbonate components are absent or limited. The authors suggest that a repository in a salt formation be an ideal environment for disposal of high level, pyrochlore-based ceramic wastes. In such environment, adding CaO as a backfill will make pyrochlore minerals thermodynamically stable and therefore effectively prevent actinide release from these mineral phases.
Date: March 14, 2000
Creator: Wang, Yifeng & Xu, Huifang
Object Type: Article
System: The UNT Digital Library
Complexants for actinide element coordination and immobilization (open access)

Complexants for actinide element coordination and immobilization

The goal of this project is to develop inorganic metal oxide clusters known as polyoxoanions (POAs) as complexants for the immobilization of actinide (An) ions from high-level waste (HLW). A diverse array of rugged isopolyoxoanions, [M{sub x}O{sub y}]{sup z{minus}}, and heteropolyoxoanions, [X{sub a}M{sub b}O{sub c}]{sup d{minus}}, comprised of M = V, Mo, W and X = Si, P polyhedra will be investigated for their ability to incarcerate An ions. The research combines two objectives--An-POA coordination and An-POA containment. The first involves the synthesis, isolation, and characterization of POAs that can selectively bind An ions to form stable An-POA complexes in alkaline and acidic solutions. The second involves investigations of the thermochemistry of the An-POA complexes under vitrification conditions germane to the formation of proposed HLW forms, such as borosilicate glass. The approach is envisioned to provide two levels of An encapsulation for maximum stability and durability as well as the potential to incorporate higher levels of An ions (particularly Pu) in waste forms than now possible. Such versatility bodes well for the potential application of POAs as An complexants in technology of significance to the environmental management of HLW. This report summarizes work performed since the commencement of the project …
Date: March 14, 2000
Creator: Antonio, M.R.; Soderholm, L.; Williams, C.W. & Francesconi, L.C.
Object Type: Report
System: The UNT Digital Library
Oxidative alteration of spent fuel in a silica-rich environment: SEM/AEM investigation and geochemical modeling (open access)

Oxidative alteration of spent fuel in a silica-rich environment: SEM/AEM investigation and geochemical modeling

Correctly identifying the possible alteration products and accurately predicting their occurrence in a repository-relevant environment are the key for the source-term calculation in a repository performance assessment. Uraninite in uranium deposits has long been used as a natural analog to spent fuel in a repository because of their chemical and structural similarity. In this paper, a SEM/AEM investigation has been conducted on a partially alternated uraninite sample from a uranium ore deposit of Shinkolobwe of Congo. The mineral formation sequences were identified: uraninite {yields} uranyl hydrates {yields} uranyl silicates {yields} Ca-uranyl silicates or uraninite {yields} uranyl silicates {yields} Ca-uranyl silicates. Reaction-path calculations were conducted for the oxidative dissolution of spent fuel in a representative Yucca Mountain groundwater. The predicted sequence is in general consistent with the SEM observations. The calculations also show that uranium carbonate minerals are unlikely to become major solubility-controlling mineral phases in a Yucca Mountain environment. Some discrepancies between model predictions and field observations are observed. Those discrepancies may result from poorly constrained thermodynamic data for uranyl silicate minerals.
Date: March 14, 2000
Creator: Wang, Yifeng & Xu, Huifang
Object Type: Article
System: The UNT Digital Library
Criticality control in shipments of fissile materials (open access)

Criticality control in shipments of fissile materials

This paper describes a procedure for finite-array criticality analysis to ensure criticality safety of shipments of fissile materials in US DOE-certified packages. After the procedure has been performed, one can obtain the minimum transport index and determine the maximum number of fissile packages allowable in a shipment that meets the 10 CFR 71 criticality safety requirements.
Date: March 14, 2000
Creator: Liaw, J. R. & Liu, Y. Y.
Object Type: Article
System: The UNT Digital Library
Remedial investigation report for J-Field, Aberdeen Proving Ground, Maryland. Volume 1: Remedial investigation results (open access)

Remedial investigation report for J-Field, Aberdeen Proving Ground, Maryland. Volume 1: Remedial investigation results

This report presents the results of the remedial investigation (RI) conducted at J-Field in the Edgewood Area of Aberdeen Proving Ground (APG), a U.S. Army installation located in Harford County, Maryland. Since 1917, activities in the Edgewood Area have included the development, manufacture, and testing of chemical agents and munitions and the subsequent destruction of these materials at J-Field by open burning and open detonation. These activities have raised concerns about environmental contamination at J-Field. This RI was conducted by the Environmental Conservation and Restoration Division, Directorate of Safety, Health and Environmental Division of APG, pursuant to requirements outlined under the Comprehensive Environmental Response, Compensation, and Liability Act, as amended (CERCLA). The RI was accomplished according to the procedures developed by the U.S. Environmental Protection Agency (EPA 1988). The RI provides a comprehensive evaluation of the site conditions, nature of contaminants present, extent of contamination, potential release mechanisms and migration pathways, affected populations, and risks to human health and the environment. This information will be used as the basis for the design and implementation of remedial actions to be performed during the remedial action phase, which will follow the feasibility study (FS) for J-Field.
Date: March 14, 2000
Creator: Yuen, C. R.; Martino, L. E.; Biang, R. P.; Chang, Y. S.; Dolak, D.; Van Lonkhuyzen, R. A. et al.
Object Type: Report
System: The UNT Digital Library
Ultrasonic Imaging for Poling Uniformity Measurements in PZT Ceramic Elements (open access)

Ultrasonic Imaging for Poling Uniformity Measurements in PZT Ceramic Elements

This report summarizes the results of a project sponsored by Honeywell Corporation (formerly AlliedSignal Inc.) Federal Manufacturing and Technologies/Kansas City (FM and T/KC) and conducted jointly with the University of Missouri, Rolla, titled ''Ultrasonic Imaging for Poling Uniformity Measurements in PZT Ceramic Elements.'' In this three-month research project, a series of experiments was performed on soft and hard lead-zirconate-titanate (PZT) structures to determine the effectiveness of ultrasonic measurements as a nondestructive method of evaluating poling quality and uniformity. The study revealed that acoustic velocity correlates well with the degree of poling of PZT structures, as predicted by elastic theory. Additionally, time-of-flight (TOF) imaging was shown to be an ideal tool for viewing the spatial distribution of poled material and of material affected by the electric field beyond the edge of electroded regions. Finally, the effectiveness of ultrasonic methods for flaw detection and evaluation of PZT/stainless steel bonds was also demonstrated.
Date: March 14, 2000
Creator: Jamieson, E. E.
Object Type: Report
System: The UNT Digital Library
Charm Results on CP Violation and Mixing (open access)

Charm Results on CP Violation and Mixing

The most recent results on CP violation and mixing in the charm system are reviewed as a guide to the future. While no surprising results are reported so far, charm provides a unique window to physics beyond the Standard Model. The results reported here come from four sources, ALEPH at LEP, E791 and FOCUS/E831 at Fermilab, and CLEO II.V at CESR. Results beyond these sources may be expected as a byproduct of B-motivated experiments.
Date: March 14, 2000
Creator: Appel, J. A.
Object Type: Article
System: The UNT Digital Library
Criticality safety requirements for transporting EBR-II fuel bottles stored at INTEC (open access)

Criticality safety requirements for transporting EBR-II fuel bottles stored at INTEC

Two carrier/shipping cask options are being developed to transport bottles of EBR-II fuel elements stored at INTEC. Some fuel bottles are intact, but some have developed leaks. Reactivity control requirements to maintain subcriticality during the hypothetical transport accident have been examined for both transport options for intact and leaking bottles. Poison rods, poison sleeves, and dummy filler bottles were considered; several possible poison materials and several possible dummy filler materials were studied. The minimum number of poison rods or dummy filler bottles has been determined for each carrier for transport of intact and leaking bottles.
Date: March 14, 2000
Creator: Lell, R. M. & Pope, C. L.
Object Type: Article
System: The UNT Digital Library
Hands-free operation of a small mobile robot (open access)

Hands-free operation of a small mobile robot

The Intelligent Systems and Robotics Center of Sandia National laboratories has an ongoing research program in advanced user interfaces. As part of this research, promising new transduction devices, particularly hands-free devices, are being explored for the control of mobile and floor-mounted robotic systems. Brainwave control has been successfully demonstrated by other researchers in a variety of fields. In the research described here, Sandia developed and demonstrated a proof-of-concept brainwave-controlled mobile robot system. Preliminary results were encouraging. Additional work required to turn this into a reliable. fieldable system for mobile robotic control is identified. Used in conjunction with other controls, brainwave control could be an effective control method in certain circumstances.
Date: March 14, 2000
Creator: Amai, Wendy A.; Fahrenholtz,Jill C. & Leger, Chris L.
Object Type: Article
System: The UNT Digital Library
Variation of equivalence ratio and element ratios in low-pressure premixed flames of aliphatic fuels (open access)

Variation of equivalence ratio and element ratios in low-pressure premixed flames of aliphatic fuels

In previously published work it was found that the element ratios (such as C/O, H/O, H/C) and the equivalence ratio all varied in the flame zone of a low-pressure premixed fuel-rich benzene/oxygen/argon laminar flat flame. These variations were seen from analyses of both the data and detailed kinetic modeling. In the present work, seven additional flames were analyzed in the same manner, including five flames with a single hydrocarbon fuel (methane, acetylene, ethylene, allene, and propene) and two flames with a mixture of fuels (acetylene/allene, hydrogen/allene). All the flames had argon as the diluent, with pressures between 20 and 37.5 Torr, equivalence ratios between 1.6 and 2.5, cold gas velocities between 42 and 126 cm/sec. All of these flames showed variations in the element ratios and equivalence ratios. Furthermore, these variations changed in a consistent pattern with respect to the molecular weight of the fuel. In the flame zone, the percent change in the H/O, C/O and equivalence ratios increased with increasing molecular weight of the fuel, except for the hydrogen/allene flame in which the C/O ratio first increases, then decreases in the flame zone. Also, unlike all the other hydrocarbon flames, the C/O ratio decreases below its inlet value …
Date: March 14, 2000
Creator: Pope, C. J. & Miller, J. A.
Object Type: Article
System: The UNT Digital Library
Final Report: Adaptive Numerical Algorithms for Partial Differential Equations, May 1, 1994 - April 30, 1998 (open access)

Final Report: Adaptive Numerical Algorithms for Partial Differential Equations, May 1, 1994 - April 30, 1998

None
Date: March 14, 2000
Creator: Colella, Phillip
Object Type: Report
System: The UNT Digital Library
Renewable Energy: An Overview (open access)

Renewable Energy: An Overview

This fact sheet provides an introduction to renewable energy technologies: hydropower, bioenergy, geothermal energy, solar energy, wind energy, hydrogen, and ocean energy.
Date: March 14, 2001
Creator: Tromly, K.
Object Type: Book
System: The UNT Digital Library
Advanced Thermal Barrier Coating System Development. Technical progress report (open access)

Advanced Thermal Barrier Coating System Development. Technical progress report

The objectives of the program are to provide an improved TBC system with increased temperature capability and improved reliability relative to current state of the art TBC systems. The development of such a coating system is essential to the ATS engine meeting its objectives. The base program consists of three phases: Phase I: Program Planning--Complete Phase II: Development--Complete Phase III: Selected Specimen--Bench Test Work was performed on the Phase II final report and on Ill of the program during the reporting period.
Date: March 14, 2000
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Effect of Internal Alpha Radiation on Borosilicate Glass Containing Simulated Radioactive Waste (open access)

Effect of Internal Alpha Radiation on Borosilicate Glass Containing Simulated Radioactive Waste

To evaluate borosilicate glass as a matrix for long-term storage of radioactive waste, samples containing 45 wt. percent simulated waste along with 0.5 wt. percent 244Cm or 1 wt. percent 238Pu as alpha particle emitters were synthesized. A glass containing 238Pu without simulated waste was also made. Effects of internal alpha radiolysis from 244Cm and 238Pu on physical stability, leachability, and dilatation of the glasses were examined. Results confirm that glass may be a desirable matrix for fixing SRP radioactive waste for long-term storage. Internal alpha radiolysis and helium accumulation in the small samples did not significantly damage the glass. Actual values for helium solubility and permeability would be necessary, however, to determine whether helium accumulation might eventually damage larger glass monoliths during long-term storage.
Date: March 14, 2001
Creator: Bibler, N.E.
Object Type: Article
System: The UNT Digital Library
Reducing Emissions of Volatile Organic Compounds - Final Report - 08/15/1997 - 02/14/2001 (open access)

Reducing Emissions of Volatile Organic Compounds - Final Report - 08/15/1997 - 02/14/2001

The overall objective of this research was to determine if the shallow suspended growth reactor (SSGR) could provide sufficient treatment performance of organic and reduced sulfur (TRS) compounds, at 50 C to meet the EPA ''cluster rule'' regulatory limits. The biodegradation of a mixture of organic compounds that could be present in pulp and paper high volume low concentration gas streams was evaluated at 50 C in a bench-scale SSGR. The removal of methanol was followed in particular, and was mathematically modeled to evaluate the effect of process design and operating parameters on methanol removal. Additional tests were performed to obtain mass transfer and biodegradation kinetic parameters for the model. The acclimation of microbial populations capable of degrading TRS compounds from various seed sources was studied in batch reactors at 30 and 50 C. The degradation of TRS compounds in bench-scale SSGR was studied at 20-50 C. Also, the biodegradation kinetic and mass transfer coefficients for alpha-terpinene and gamma-terpinene were studied. Finally, a pilot plant was constructed and operated at Simpson pulp and paper mill in Tacoma, WA.
Date: March 14, 2001
Creator: Stensel, H. David & Strand, Stuart E.
Object Type: Report
System: The UNT Digital Library
Tc-99 Analysis with Picogram Sensitivity by a Resin-Bead Mass-Spectrometric Isotope-Dilution Technique (open access)

Tc-99 Analysis with Picogram Sensitivity by a Resin-Bead Mass-Spectrometric Isotope-Dilution Technique

This paper describes an improved isotope-dilution mass-spectrometric procedure. Important improvements are a highly selective (yet non-critical) isolation scheme devised primarily from the work of Maeck, et al. and a significant increase in the mass spectrometric ionization efficiency for technetium obtained by analyzing the technetium absorbed on individual anion exchange resin beads.
Date: March 14, 2001
Creator: Anderson, T. J.
Object Type: Article
System: The UNT Digital Library
WABASH RIVER INTEGRATED METHANOL AND POWER PRODUCTION FROM CLEAN COAL TECHNOLOGIES (IMPPCCT) (open access)

WABASH RIVER INTEGRATED METHANOL AND POWER PRODUCTION FROM CLEAN COAL TECHNOLOGIES (IMPPCCT)

The Wabash River Integrated Methanol and Power Production from Clean Coal Technologies (IMPPCCT) project is evaluating integrated electrical power generation and methanol production through clean coal technologies. The project is conducted by a multi-industry team lead by Gasification Engineering Corporation (GEC), a company of Global Energy Inc., and supported by Air Products and Chemicals, Inc., Dow Chemical Company, Dow Corning Corporation, Methanex Corporation, and Siemens Westinghouse Power Corporation. Three project phases are planned for execution over several years, including: (1) Feasibility study and conceptual design for an integrated demonstration facility, and for fence-line commercial embodiment plants (CEP) operated at Dow Chemical or Dow Corning chemical plant locations (2) Research, development, and testing to define any technology gaps or critical design and integration issues (3) Engineering design and financing plan to install an integrated commercial demonstration facility at the existing Wabash River Energy Limited (WREL) plant in West Terre Haute, Indiana.
Date: March 14, 2003
Creator: Tsang, Albert
Object Type: Report
System: The UNT Digital Library
OZONE TREATMENT OF SOLUBLE ORGANICS IN PRODUCED WATER (open access)

OZONE TREATMENT OF SOLUBLE ORGANICS IN PRODUCED WATER

This project was an extension of previous research to improve the applicability of ozonation and will help address the petroleum-industry problem of treating produced water containing soluble organics. The goal of this project was to maximize oxidation of hexane-extractable organics during a single-pass operation. The project investigated: (1) oxidant production by electrochemical and sonochemical methods, (2) increasing the mass transfer rate in the reactor by forming microbubbles during ozone injection into the produced water, and (3) using ultraviolet irradiation to enhance the reaction if needed. Several types of methodologies for treatment of soluble organics in synthetic and actual produced waters have been performed. The technologies tested may be categorized as follows: (1) Destruction via sonochemical oxidation at different pH, salt concentration, ultraviolet irradiation, and ferrous iron concentrations. (2) Destruction via ozonation at different pH, salt concentration, hydrogen peroxide concentrations, ultraviolet irradiation, temperature, and reactor configurations.
Date: March 14, 2002
Creator: Klasson, KT
Object Type: Report
System: The UNT Digital Library
Gunite and Associated Tanks Waste Conditioning System: Description and Operational Summary (open access)

Gunite and Associated Tanks Waste Conditioning System: Description and Operational Summary

The purpose of this report is to describe and document the function, operational performance, problems encountered, lessons-learned, and overall assessment of the performance of the waste conditioning system (WCS) in the Gunite{trademark} and Associated Tanks (GAAT) remediation project at the Oak Ridge National Laboratory (ORNL). The GAAT are located in the main plant area of ORNL in the North and South Tank Farms. These tanks were constructed in 1943 as part of the Manhattan Project during World War II. Each tank in the South Tank Farm (STF) has a 50-ft inside diameter and a capacity of {approx}170,000 gal. Each Gunite tank in the North Tank Farm (NTF) has a 25-ft inside diameter with a capacity of {approx}44,000 gal. The GAAT were designed to receive radioactive and chemical wastes from ORNL processes. The tanks were constructed of Gunite, which is created by pneumatically spraying concrete over a wire mesh. Following construction, the site was backfilled so the domes of the tanks were covered with {approx}6 ft of earth. The STF tanks (W-5, -6, -7, -8, -9, and -10) are set in a 2 x 3 array with an east-west axis. The two GAAT in the NTF are on the north side …
Date: March 14, 2002
Creator: Emison, JA
Object Type: Report
System: The UNT Digital Library