177 Matching Results

Search Results

Advanced search parameters have been applied.

Particle characterization: July--September, 1970

Description: The effect of particle size, shape and surface on the behavior of a powder is continually being studied. In quality control of a powder, seldom is a given parameter known well enough to predict accurately overall behavior of a powder. Therefore, many particle parameters must be evaluated to determine the influencing factors, including width, length/width ratio, volume, surface area, reentrant surface, bulk density, compressibility, surface roughness, pore volume, degree of sphericity, etc., and their relation to extrudability, pressability, firing performance, etc. Determining these things is called powder or particle characterization.
Date: 1970
Creator: Duncan, A. A.
Partner: UNT Libraries Government Documents Department

Radioactive wastes dispersed in stabilized ash cements

Description: One of the most widely-used methods for the solidification/stabilization of low-level radwaste is by incorporation into Type-I/II ordinary portland cement (OPC). Treating of OPC with supercritical fluid carbon dioxide (SCCO{sub 2}) has been shown to significantly increase the density, while simultaneously decreasing porosity. In addition, the process significantly reduces the hydrogenous content, reducing the likelihood of radiolytic decomposition reactions. This, in turn, permits increased actinide loadings with a concomitant reduction in disposable waste volume. In this article, the authors discuss the combined use of fly-ash-modified OPC and its treatment with SCCO{sub 2} to further enhance immobilization properties. They begin with a brief summary of current cement immobilization technology in order to delineate the areas of concern. Next, supercritical fluids are described, as they relate to these areas of concern. In the subsequent section, they present an outline of results on the application of SCCO{sub 2} to OPC, and its effectiveness in addressing these problem areas. Lastly, in the final section, they proffer their thoughts on why they believe, based on the OPC results, that the incorporation of fly ash into OPC, followed by supercritical fluid treatment, can produce highly efficient wasteforms.
Date: December 31, 1997
Creator: Rubin, J.B.; Taylor, C.M.V.; Sivils, L.D. & Carey, J.W.
Partner: UNT Libraries Government Documents Department

Thermodynamic properties of pulverized coal during rapid heating devolatilization processes

Description: The thermodynamic properties of coal under conditions of rapid heating have been determined using a combination of UTRC facilities including a proprietary rapid heating rate differential thermal analyzer (RHR-DTA), a microbomb calorimeter (MBC), an entrained flow reactor (EFR), an elemental analyzer (EA), and a FT-IR. The total heat of devolatilization, was measured for a HVA bituminous coal (PSOC 1451D, Pittsburgh No. 8) and a LV bituminous coal (PSOC 1516D, Lower Kittaning). For the HVA coal, the contributions of each of the following components to the overall heat of devolatilization were measured: the specific heat of coal/char during devolatilization, the heat of thermal decomposition of the coal, the specific heat capacity of tars, and the heat of vaporization of tars. Morphological characterization of coal and char samples was performed at the University of Pittsburgh using a PC-based image analysis system, BET apparatus, helium pcynometer, and mercury porosimeter. The bulk density, true density, CO{sub 2} surface area, pore volume distribution, and particle size distribution as a function of extent of reaction are reported for both the HVA and LV coal. Analyses of the data were performed to obtain the fractal dimension of the particles as well as estimates for the external surface area. The morphological data together with the thermodynamic data obtained in this investigation provides a complete database for a set of common, well characterized coal and char samples. This database can be used to improve the prediction of particle temperatures in coal devolatilization models. Such models are used both to obtain kinetic rates from fundamental studies and in predicting furnace performance with comprehensive coal combustion codes. Recommendations for heat capacity functions and heats of devolatilization for the HVA and LV coals are given. Results of sample particle temperature calculations using the recommended thermodynamic properties are provided.
Date: July 1, 1994
Creator: Proscia, W.M.; Freihaut, J.D.; Rastogi, S. & Klinzing, G.E.
Partner: UNT Libraries Government Documents Department

Compaction Stress in Fine Powders

Description: A vexing feature in granular materials compaction is density extrema interior to a compacted shape. Such inhomogeneities can lead to weaknesses and loss of dimensional control in ceramic parts, unpredictable dissolution of pharmaceuticals, and undesirable stress concentration in load-bearing soil. As an example, the centerline density in a cylindrical compact often does not decrease monotonically from the pressure source but exhibits local maxima and minima. Two lines of thought in the literature predict, respectively, diffusive and wavelike propagation of stress. Here, a general memory function approach has been formulated that unifies these previous treatments as special cases; by analyzing a convenient intermediate case, the telegrapher's equation, one sees that local density maxima arise via semidiffusive stress waves reflecting from the die walls and adding constructively at the centerline.
Date: April 1, 1999
Creator: Hurd, A.J.; Kenkre, V.M.; Pease, E.A. & Scott, J.E.
Partner: UNT Libraries Government Documents Department

Accelerated alpha radiation damage in a ceramic waste form, interim results

Description: Interim results are presented on the alpha-decay damage study of a {sup 238}Pu-loaded ceramic waste form (CWF). The waste form was developed to immobilize fission products and transuranic species accumulated from the electrometallurgical treatment of spent nuclear fuel. To evaluate the effects of {alpha}-decay damage on the waste form the {sup 238}Pu-loaded material was analyzed by (1) x-ray diffraction (XRD), (2) microstructure characterization by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) with energy and wavelength dispersive spectroscopy (EDS/WDS) and electron diffraction, (3) bulk density measurements and (4) waste form durability, performed by the product consistency test (PCT). While the predominate phase of plutonium in the CWF, PuO{sub 2}, shows the expected unit cell expansion due to {alpha}-decay damage, currently no significant change has occurred to the macro- or microstructure of the material. The major phase of the waste form is sodalite and contains very little Pu, although the exact amount is unknown. Interestingly, measurement of the sodalite phase unit cell is also showing very slight expansion; again, presumably from {alpha}-decay damage.
Date: November 11, 1999
Creator: Frank, S. M.; Johnson, S. G.; Moschetti, T. L.; O'Holleran, T. P.; Sinkler, W.; Esh, D. et al.
Partner: UNT Libraries Government Documents Department

Characterization of hydrogeologic units using matrix properties, Yucca Mountain, Nevada

Description: Determination of the suitability of Yucca Mountain, in southern Nevada, as a geologic repository for high-level radioactive waste requires the use of numerical flow and transport models. Input for these models includes parameters that describe hydrologic properties and the initial and boundary conditions for all rock materials within the unsaturated zone, as well as some of the upper rocks in the saturated zone. There are 30 hydrogeologic units in the unsaturated zone, and each unit is defined by limited ranges where a discrete volume of rock contains similar hydrogeologic properties. These hydrogeologic units can be easily located in space by using three-dimensional lithostratigraphic models based on relationships of the properties with the lithostratigraphy. Physical properties of bulk density, porosity, and particle density; flow properties of saturated hydraulic conductivity and moisture-retention characteristics; and the state variables (variables describing the current state of field conditions) of saturation and water potential were determined for each unit. Units were defined using (1) a data base developed from 4,892 rock samples collected from the coring of 23 shallow and 8 deep boreholes, (2) described lithostratigraphic boundaries and corresponding relations to porosity, (3) recognition of transition zones with pronounced changes in properties over short vertical distances, (4) characterization of the influence of mineral alteration on hydrologic properties such as permeability and moisture-retention characteristics, and (5) a statistical analysis to evaluate where boundaries should be adjusted to minimize the variance within layers. This study describes the correlation of hydrologic properties to porosity, a property that is well related to the lithostratigraphy and depositional and cooling history of the volcanic deposits and can, therefore, be modeled to be distributed laterally.
Date: September 1, 1998
Creator: Flint, L.E.
Partner: UNT Libraries Government Documents Department

Steam chemical reactivity of plasma-sprayed beryllium

Description: Plasma-spraying with the potential for in-situ repair makes beryllium a primary candidate for plasma facing and structural components in experimental magnetic fusion machines. Deposits with good thermal conductivity and resistance to thermal cycling have been produced with low pressure plasma-spraying (LPPS). A concern during a potential accident with steam ingress is the amount of hydrogen produced by the reactions of steam with hot components. In this study the authors measure the reaction rates of various deposits produced by LPPS with steam from 350 C to above 1,000 C. They correlate these reaction rates with measurements of density, open porosity and BET surface areas. They find the reactivity to be largely dependent upon effective surface area. Promising results were obtained below 600 C from a 94% theoretical dense (TD) deposit with a BET specific surface area of 0.085 m{sup 2}/g. Although reaction rates were higher than those for dense consolidated beryllium they were substantially lower, i.e., about two orders of magnitude, than those obtained from previously tested lower density plasma-sprayed deposits.
Date: July 1, 1998
Creator: Anderl, R.A.; Pawelko, R.J.; Smolik, G.R. & Castro, R.G.
Partner: UNT Libraries Government Documents Department

Phase II of the demonstration of the Koppelman series C process. Topical report, February 1995--February 1996

Description: A pilot plant using the Koppelman Series C Process was designed, constructed, and operated near Gillette, Wyoming, as part of Phase I of this project. Construction was completed in late fall of 1993, and the shakedown was completed in early 1994. The initial series of tests performed to prove the process and to characterize the effluents was conducted during the first half of 1994. The results of those tests are described in the final report for Phase I. This report describes the activities conducted during Phase II of the project the objective of which was to move the process, which was proven during Phase I, a step closer to commercialization. Specifically, the work was planned to lower the cost of the process by developing a high-capacity processor, increasing the already high efficiency of the process by using a feed coal preheated, increasing the bulk density of the product by using mixed particle size extrudate, and preparing a preliminary scoping design for the water treatment plant for a 500,000 ton per year commercial plant.
Date: December 31, 1998
Creator: Merriam, N.
Partner: UNT Libraries Government Documents Department

Effective porosity and density of carbonate rocks (Maynardville Limestone and Copper Ridge Dolomite) within Bear Creek Valley on the Oak Ridge Reservation based on modern petrophysical techniques

Description: The purpose of this study is to provide quantitative data on effective porosity of carbonate rock from the Maynardville Limestone and Copper Ridge Dolomite within Bear Creek Valley based on modern petrophysical techniques. The data will be useful for groundwater-flow and contaminant-flow modeling in the vicinity of the Y-12 Plant on the Oak Ridge Reservation (ORR). Furthermore, the data provides needed information on the amount of interconnected pore space potentially available for operation of matrix diffusion as a transport process within the fractured carbonate rock. A second aspect of this study is to compare effective porosity data based on modern petrophysical techniques to effective porosity data determined earlier by Goldstrand et al. (1995) with a different technique. An added bonus of the study is quantitative data on the bulk density and grain density of dolostone and limestone of the Maynardville Limestone and Copper Ridge Dolomite which might find use for geophysical modeling on the ORR.
Date: February 1, 1997
Creator: Dorsch, J.
Partner: UNT Libraries Government Documents Department

Buried waste containment system materials. Final Report

Description: This report describes the results of a test program to validate the application of a latex-modified cement formulation for use with the Buried Waste Containment System (BWCS) process during a proof of principle (POP) demonstration. The test program included three objectives. One objective was to validate the barrier material mix formulation to be used with the BWCS equipment. A basic mix formula for initial trials was supplied by the cement and latex vendors. The suitability of the material for BWCS application was verified by laboratory testing at the Idaho National Engineering and Environmental Laboratory (INEEL). A second objective was to determine if the POP BWCS material emplacement process adversely affected the barrier material properties. This objective was met by measuring and comparing properties of material prepared in the INEEL Materials Testing Laboratory (MTL) with identical properties of material produced by the BWCS field tests. These measurements included hydraulic conductivity to determine if the material met the US Environmental Protection Agency (EPA) requirements for barriers used for hazardous waste sites, petrographic analysis to allow an assessment of barrier material separation and segregation during emplacement, and a set of mechanical property tests typical of concrete characterization. The third objective was to measure the hydraulic properties of barrier material containing a stop-start joint to determine if such a feature would meet the EPA requirements for hazardous waste site barriers.
Date: October 1, 1997
Creator: Weidner, J.R. & Shaw, P.G.
Partner: UNT Libraries Government Documents Department

Application of cathodic arc deposited amorphous hard carbon films to the head/disk tribology

Description: Amorphous hard carbon films deposited by filtered cathodic arc deposition exhibit very high hardness and elastic modulus, high mass density, low coefficient of friction, and the films are very smooth. All these properties are beneficial to applications of these films for the head/disk interface tribology. The properties of cathodic arc deposited amorphous carbon films are summarized, and they are compared to sputter deposited, hydrogenated (CH{sub x}), and nitrogenated (CN{sub x}) carbon films which are the present choice for hard disk and slider coatings. New developments in cathodic arc coaters are discussed which are of interest to the disk drive industry. Experiments on the nanotribology, mass density and hardness, corrosion behavior, and tribochemical behavior of cathodic arc films are reported. A number of applications of cathodic arc deposited films to hard disk and slider coatings are described. It is shown that their tribological performance is considerably better compared to CH{sub x} and CN{sub x} films.
Date: April 1998
Creator: Anders, S.; Bhatia, C. S.; Fong, W.; Lo, R. Y. & Bogy, D. B.
Partner: UNT Libraries Government Documents Department

Large-scale dynamic compaction demonstration using WIPP salt: Fielding and preliminary results

Description: Reconsolidation of crushed rock salt is a phenomenon of great interest to programs studying isolation of hazardous materials in natural salt geologic settings. Of particular interest is the potential for disaggregated salt to be restored to nearly an impermeable state. For example, reconsolidated crushed salt is proposed as a major shaft seal component for the Waste Isolation Pilot Plant (WIPP) Project. The concept for a permanent shaft seal component of the WIPP repository is to densely compact crushed salt in the four shafts; an effective seal will then be developed as the surrounding salt creeps into the shafts, further consolidating the crushed salt. Fundamental information on placement density and permeability is required to ensure attainment of the design function. The work reported here is the first large-scale compaction demonstration to provide information on initial salt properties applicable to design, construction, and performance expectations. The shaft seals must function for 10,000 years. Over this period a crushed salt mass will become less permeable as it is compressed by creep closure of salt surrounding the shaft. These facts preclude the possibility of conducting a full-scale, real-time field test. Because permanent seals taking advantage of salt reconsolidation have never been constructed, performance measurements have not been made on an appropriately large scale. An understanding of potential construction methods, achievable initial density and permeability, and performance of reconsolidated salt over time is required for seal design and performance assessment. This report discusses fielding and operations of a nearly full-scale dynamic compaction of mine-run WIPP salt, and presents preliminary density and in situ (in place) gas permeability results.
Date: October 1, 1995
Creator: Ahrens, E.H. & Hansen, F.D.
Partner: UNT Libraries Government Documents Department


Description: Task Objectives: (1) Support the shakedown of the commercial plant. The plant, which was completed in early 1997, uses the Series C process, which was proven at the pilot-plant scale during Phase I of this project. (2) Improve the Series C process for future plants by completing construction and testing a pilot-scale coal-in-shell processor. This high-throughput, low-cost variation of the process will greatly reduce the cost of future plants using the Series C process. (3) Continue testing the use of foreign coal and high-sulfur US coals to increase the size of the market for the product from the Series C process. (4) Continue work to increase the bulk density of the product by pelletizing. (5) Conduct tests using the Series C Process to upgrade wastes from processing coal and also test upgrading biomass. Quarter Objectives--Continue to support the startup activities of the commercial plant. Support the conduct of bench-scale tests and tests using the Series C pilot plant. Undertake a series of studies to characterize coal. These characterizations could be of use to KFx in developing its commercial processes. The areas studied include a literature review of dust control methods for processed coal; pyrophoricity studies of pyrolized coal; distribution of metals distribution in a swelled coal product; coal briquetting of a KFx product; pretreatment of a feed coal to reduce the sodium content of the ash; and a literature review on techniques to reduce air toxics in the KFx process.
Date: July 1, 1998
Partner: UNT Libraries Government Documents Department

Methodology for uncertainty estimation of Hanford tank chemical and radionuclide inventories and concentrations

Description: The exact physical and chemical nature of 55 million gallons of toxic waste held in 177 underground waste tanks at the Hanford Site is not known with sufficient detail to support the safety, retrieval, and immobilization missions presented to Hanford. The Hanford Best Basis team has made point estimates of the inventories in each tank. The purpose of this study is to estimate probability distributions for each of the 71 analytes and 177 tanks that the Hanford Best Basis team has made point estimates for. This will enable uncertainty intervals to be calculated for the Best Basis inventories and should facilitate the safety, retrieval, and immobilization missions. Section 2 of this document describes the overall approach used to estimate tank inventory uncertainties. Three major components are considered in this approach: chemical concentration, density, and waste volume. Section 2 also describes the two different methods used to evaluate the tank wastes in terms of sludges and in terms of supernatant or saltcakes. Sections 3 and 4 describe in detail the methodology to assess the probability distributions for each of the three components, as well as the data sources for implementation. The conclusions are given in Section 5.
Date: February 1, 1998
Creator: Chen, G.; Ferryman, T. A. & Remund, K. M.
Partner: UNT Libraries Government Documents Department

Effects of Microstructural Variables on the Shock Wave Response of PZT 95/5

Description: The particular lead zirconate/titanate composition PZT 95/5-2Nb was identified many years ago as a promising ferroelectric ceramic for use in shock-driven pulsed power supplies. The bulk density and the corresponding porous microstructure of this material can be varied by adding different types and quantities of organic pore formers prior to bisque firing and sintering. Early studies showed that the porous microstructure could have a significant effect on power supply performance, with only a relatively narrow range of densities providing acceptable shock wave response. However, relatively few studies were performed over the years to characterize the shock response of this material, yielding few insights on how microstructural features actually influence the constitutive mechanical, electrical, and phase-transition properties. The goal of the current work was to address these issues through comparative shock wave experiments on PZT 95/5-2Nb materials having different porous microstructures. A gas-gun facility was used to generate uniaxial-strain shock waves in test materials under carefully controlled impact conditions. Reverse-impact experiments were conducted to obtain basic Hugoniot data, and transmitted-wave experiments were conducted to examine both constitutive mechanical properties and shock-driven electrical currents. The present work benefited from a recent study in which a baseline material with a particular microstructure had been examined in detail. This study identified a complex mechanical behavior governed by anomalous compressibility and incomplete phase transformation at low shock amplitudes, and by a relatively slow yielding process at high shock amplitudes. Depoling currents are reduced at low shock stresses due to the incomplete transformation, and are reduced further in the presence of a strong electrical field. At high shock stresses, depoling currents are driven by a wave structure governed by the threshold for dynamic yielding. This wave structure is insensitive to the final wave amplitude, resulting in depoling currents that do not increase with shock amplitude for ...
Date: February 1, 2003
Partner: UNT Libraries Government Documents Department

Tank 41H Post-Dissolution Saltcake Core and Supernate SampleAnalysis

Description: This report provides analyses of the samples from Tank 41H. The characterization also includes supernate samples pulled from the surface (347 inch) and 250 inch levels of the salt supernate. The three saltcake samples (HTF-E-03-145, 146, and 147) were filled to nearly their capacity with saltcake and free liquid, with an average saltcake bulk density of 2.06 g/cm3. The undrained saltcake from the bottom of the middle sample (HTF-E-03-146) had a water content of 4.1 percentage weight, a 137Cs activity of 0.14 Ci per gallon of saltcake, and an alpha content of 1.4E+4 pCi/g. The undrained saltcake from the bottom of the bottom sample (HTF-E-03-147) had a water content of 8.5 percentage weight, a 137Cs activity of 0.17 Ci per gallon of saltcake, and an alpha content of 3.0E+4 pCi/g. Interstitial liquid drained from the middle sample (HTF-E-03-146) had a density of 1.43 g/cm3, a soluble solids content of 45.4 percentage weight, a 137Cs activity of 0.78 Ci per gallon of interstitial liquid, a nd an alpha content of 1.1E+4 pCi/mL. An analysis of material from the top of the top sample (HTF-E-03-145) is provided in support of Nuclear Criticality Safety Evaluations. The as-received saltcake and the residual insoluble solids had a uranium-235 enrichment of approximately 12.2 per cent. Characterization focused on providing information on fissile radionuclides, potential neutron poisons, and other potential diluents. Supernate samples pulled from the surface and from the 250 in. levels of the C1 and C3 risers yielded information on the vertical and lateral tank supernate homogeneity. The 137Cs content of these Tank 41H samples averaged 0.56 Ci/gal for the C3 riser and 0.65 Ci/gal for the C1 riser. The 238Pu content of the four unfiltered samples ranged from 1.41E+4 pCi/mL to 2.21E+4 pCi/mL. Scanning electron microscopy of saltcake from sample HTF-E-03-146 revealed several features ...
Date: July 7, 2004
Partner: UNT Libraries Government Documents Department


Description: The 2002-2003 Department of Energy plantings amounted to 164 acres containing 111,520 tree seedlings in eastern and western Kentucky. Data gathered on these trees included an inventory to determine survival of all planted species. A sub-sample of seedlings was selected to assess the height and diameter of individual species of seedlings established. Additional efforts involved collection of soil sample and litter samples, analysis of herbaceous ground cover from vegetation clip plots and leaf area on each tree species, and development of tissue collections. All areas were sampled for penetration resistance, penetration depth (or depth to refusal), and bulk density at various depths. Rain fall events and flow rates were recorded. The water quality of runoff samples involved the determination of total and settleable solids and particle size distribution. A study was initiated that will focus on the colonization of small mammals from forest edges to various areas located on reclaimed surface mines. This effort will provide a better understanding of the role small mammals and birds have in the establishment of plant communities on mine lands that will be useful in developing and improving reclamation techniques.
Date: October 30, 2003
Creator: Graves, Donald H.; Barton, Christopher; Sweigard, Richard & Warner, Richard
Partner: UNT Libraries Government Documents Department

A Benchmarking Analysis for Five Radionuclide Vadose Zone Models (Chain, Multimed{_}DP, Fectuz, Hydrus, and Chain 2D) in Soil Screening Level Calculations

Description: Five vadose zone models with different degrees of complexity (CHAIN, MULTIMED{_}DP, FECTUZ, HYDRUS, and CHAIN 2D) were selected for use in radionuclide soil screening level (SSL) calculations. A benchmarking analysis between the models was conducted for a radionuclide ({sup 99}Tc) release scenario at the Las Cruces Trench Site in New Mexico. Sensitivity of three model outputs to the input parameters were evaluated and compared among the models. The three outputs were peak contaminant concentrations, time to peak concentrations at the water table, and time to exceed the contaminants maximum critical level at a representative receptor well. Model parameters investigated include soil properties such as bulk density, water content, soil water retention parameters and hydraulic conductivity. Chemical properties examined include distribution coefficient, radionuclide half-life, dispersion coefficient, and molecular diffusion. Other soil characteristics, such as recharge rate, also were examined. Model sensitivity was quantified in the form of sensitivity and relative sensitivity coefficients. Relative sensitivities were used to compare the sensitivities of different parameters. The analysis indicates that soil water content, recharge rate, saturated soil water content, and soil retention parameter, {beta}, have a great influence on model outputs. In general, the results of sensitivities and relative sensitivities using five models are similar for a specific scenario. Slight differences were observed in predicted peak contaminant concentrations due to different mathematical treatment among models. The results of benchmarking and sensitivity analysis would facilitate the model selection and application of the model in SSL calculations.
Date: February 26, 2002
Creator: Chen, J-S.; Drake, R.; Lin, Z. & Jewett, D. G.
Partner: UNT Libraries Government Documents Department

Production of New Biomass/Waste-Containing Solid Fuels

Description: CQ Inc. and its industry partners--PBS Coals, Inc. (Friedens, Pennsylvania), American Fiber Resources (Fairmont, West Virginia), Allegheny Energy Supply (Williamsport, Maryland), and the Heritage Research Group (Indianapolis, Indiana)--addressed the objectives of the Department of Energy and industry to produce economical, new solid fuels from coal, biomass, and waste materials that reduce emissions from coal-fired boilers. This project builds on the team's commercial experience in composite fuels for energy production. The electric utility industry is interested in the use of biomass and wastes as fuel to reduce both emissions and fuel costs. In addition to these benefits, utilities also recognize the business advantage of consuming the waste byproducts of customers both to retain customers and to improve the public image of the industry. Unfortunately, biomass and waste byproducts can be troublesome fuels because of low bulk density, high moisture content, variable composition, handling and feeding problems, and inadequate information about combustion and emissions characteristics. Current methods of co-firing biomass and wastes either use a separate fuel receiving, storage, and boiler feed system, or mass burn the biomass by simply mixing it with coal on the storage pile. For biomass or biomass-containing composite fuels to be extensively used in the U.S., especially in the steam market, a lower cost method of producing these fuels must be developed that is applicable to a variety of combinations of biomass, wastes, and coal; economically competitive with current fuels; and provides environmental benefits compared with coal. During Phase I of this project (January 1999 to July 2000), several biomass/waste materials were evaluated for potential use in a composite fuel. As a result of that work and the team's commercial experience in composite fuels for energy production, paper mill sludge and coal were selected for further evaluation and demonstration in Phase II. In Phase II (June 2001 ...
Date: September 23, 2005
Creator: Shirey, Glenn A. & Akers, David J.
Partner: UNT Libraries Government Documents Department


Description: This calculation determines the release of residual radioactivity (including H-3, C-14, Co-60, Ni-63, Sr-90, and Cs-137), from subsurface structures filled with concrete debris at the Yankee Nuclear Power Station. Analyses were performed to assess the rate of release from the source of contamination and the resulting dose in the groundwater pathway. Two mechanisms were considered, diffusive release from the concrete structures (walls and floors) that remain intact and sorption onto concrete backfill placed within these structures. RESRAD was used to calculate the predicted maximum dose assuming a unit loading of 1 pCi/g on the intact structures. To the extent possible, the same assumptions in the soil DCGL calculations performed for Yankee Atomic were used in the calculation. However, modifications to some input parameter values were needed to represent the geometry of the subsurface facilities, flow through these facilities, and releases from the backfill and intact structures. Input parameters specific to these calculations included the leach rate, disposal geometry, pumping rate, porosity and bulk density. The dose results for a unit loading of 1 pCi/g on intact structures showed that Sr-90 had the highest dose (3.67E-02 mrem/yr).
Date: September 30, 2004
Creator: SULLIVAN, T.
Partner: UNT Libraries Government Documents Department

Tank 241-BY-112, cores 174 and 177 analytical results for the final report

Description: Results from bulk density tests ranged from 1.03 g/mL to 1.86 g/mL. The highest bulk density result of 1.86 g/mL was used to calculate the solid total alpha activity notification limit for this tank (33.1 uCi/g), Total Alpha (AT) Analysis. Attachment 2 contains the Data Verification and Deliverable (DVD) Summary Report for AT analyses. This report summarizes results from AT analyses and provides data qualifiers and total propagated uncertainty (TPU) values for results. The TPU values are based on the uncertainties inherent in each step of the analysis process. They may be used as an additional reference to determine reasonable RPD values which may be used to accept valid data that do not meet the TSAP acceptance criteria. A report guide is provided with the report to assist in understanding this summary report.
Date: May 6, 1997
Creator: Nuzum, J. L.
Partner: UNT Libraries Government Documents Department

[Dynamic enhanced recovery technologies]. Quarterly technical report, August 1992--October 1993

Description: This paper has presented the investigation of the mechanism of geopressure occurrence, the transition of elastic properties from the hydrostatic pressured formation to the geopressured formation, and finally, a novel seismic amplitude analysis technique to map the top-of-geopresure surface. The successful application of our new technique to the Pleistocene, offshore Louisiana, Gulf of Mexico has again demonstrated that seismic attributes analyses are of importantance in the hydrocarbon exploration. There are three parts in this paper corresponding to the above discussed topics: Part I discusses mechanisms of geopressuring, and the effects of changing porosity, pressure, and fluid saturation on the elastic properties; Part II investigates the controlling factors in the geopressure transition zone, their seismic responses, and theoretical derivations of our new prediction method; and Part III demonstrates the application of the proposed method to the Pleistocene, Offshore Louisiana, Gulf of Mexico, the prediction discrpepancy between the seismic predicted top-of-geopressure and that dericed from 145 well logs, and finally, the importance of this hydrodynamic surface.
Date: October 15, 1993
Creator: Anderson, R. N.
Partner: UNT Libraries Government Documents Department

Monolithic Nickel (II) Oxide Aerogels Using an Organic Epoxide: The Importance of the Counter Ion

Description: The synthesis and characterization of nickel (II) oxide aerogel materials prepared using the epoxide addition method is described. The addition of the organic epoxide propylene oxide to an ethanolic solution of NiCl{sub 2} 6H{sub 2}O resulted in the formation of an opaque light green monolithic gel and subsequent drying with supercritical CO{sub 2} gave a monolithic aerogel material of the same color. This material has been characterized using powder X-ray diffraction, electron microscopy, elemental analysis, and nitrogen adsorption/desorption analysis. The results indicate that the nickel (II) oxide aerogel has very low bulk density (98 kg/m{sup 3} ({approx}98 %porous)), high surface area (413 m{sup 2}/g), and has a particulate-type aerogel microstructure made up of very fine spherical particles with an open porous network. By comparison, a precipitate of Ni{sub 3}(NO{sub 3}){sub 2}(OH){sub 4} is obtained when the same preparation is attempted with the common Ni(NO{sub 3}){sub 2} 6H{sub 2}O salt as the precursor. The implications of the difference of reactivity of the two different precursors are discussed in the context of the mechanism of gel formation via the epoxide addition method. The synthesis of nickel (II) oxide aerogel, using the epoxide addition method, is especially unique in our experience. It is our first example of the successful preparation of a metal oxide aerogel using a metal divalent metal ion and may have implications for the application of this method to the preparation of aerogels or nanoparticles of other divalent metal oxides. To our knowledge this is the first report of a monolithic pure nickel (II) oxide aerogel materials.
Date: January 13, 2004
Creator: Gash, A E; Satcher, J H & Simpson, R L
Partner: UNT Libraries Government Documents Department

Excess Foundry Sand Characterization and Experimental Investigation in Controlled Low-Strength Material and Hot-Mixing Asphalt

Description: This report provides technical data regarding the reuse of excess foundry sand. The report addresses three topics: a statistically sound evaluation of the characterization of foundry sand, a laboratory investigation to qualify excess foundry sand as a major component in controlled low-strength material (CLSM), and the identification of the best methods for using foundry sand as a replacement for natural aggregates for construction purposes, specifically in asphalt paving materials. The survival analysis statistical technique was used to characterize foundry sand over a full spectrum of general chemical parameters, metallic elements, and organic compounds regarding bulk analysis and leachate characterization. Not limited to characterization and environmental impact, foundry sand was evaluated by factor analyses, which contributes to proper selection of factor and maximization of the reuse marketplace for foundry sand. Regarding the integration of foundry sand into CLSM, excavatable CLSM and structural CLSM containing different types of excess foundry sands were investigated through laboratory experiments. Foundry sand was approved to constitute a major component in CLSM. Regarding the integration of foundry sand into asphalt paving materials, the optimum asphalt content was determined for each mixture, as well as the bulk density, maximum density, asphalt absorption, and air voids at Nini, Ndes, and Nmax. It was found that foundry sands can be used as an aggregate in hot-mix asphalt production, but each sand should be evaluated individually. Foundry sands tend to lower the strength of mixtures and also may make them more susceptible to moisture damage. Finally, traditional anti-stripping additives may decrease the moisture sensitivity of a mixture containing foundry sand, but not to the level allowed by most highway agencies.
Date: October 15, 2004
Creator: Paul J. Tikalsky, Hussain U. Bahia, An Deng and Thomas Snyder
Partner: UNT Libraries Government Documents Department