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Feasibility studies of in-situ coal gasification in the Warrior coal field. Quarterly report

Description: Support studies for in-situ gasification involved design and construction of a laboratory combustor, measurement of the physical and chemical properties of coke, experiments with the shrinking core combustion model, and calculations of in-situ combustion in thin seams and a review of the in-situ gasification experiments at Gorgas, Alabama. (LTN)
Date: October 1, 1978
Creator: G.W., Douglas & McKinley, M.D.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department

Feasibility studies of in-situ coal gasification in the Warrior coal field. Quarterly report

Description: Because of high internal temperatures, the external temperature has no effect upon the reaction rate of coke particles with air for temperatures above 750/sup 0/K. Reactions could not be initiated below that temperature. Chemical reaction rate was not found to be a rate-controlling step: both extra-particle and intra-particle diffusion are important and limit the rate of oxidation. The observed values of k/sub c/, the extra-particle mass transfer coefficient were found to be in good agreement with the correlation of Ranz and Marshall. The effective diffusivity, D/sub e/, of the ash layer was not affected by changes in temperature, oxygen concentration, gas flow rate, and particle size. The observed value of D/sub e/ was 0.69 cm/sup 2//sec with a standard deviation of 0.04. Experiments with bench-scale combustors, measurements of the thermal conductivity of coke and of the reactivity of coke at 500/sup 0/C made from Alabama coals are also discussed. (LTN)
Date: June 1, 1979
Creator: G.W., Douglas & McKinley, M.D.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department

Feasibility studies of in-situ coal gasification in the Warrior coal field. Quarterly report

Description: Studies in support of in-situ gasification involved experiments in bench-scale combustors where three parameters were varied independently: initial fuel bed temperature, applied air flow and water vapor influx rate. Methods for measuring the thermal conductivity of solids at high temperatures were evaluated and measurements of the thermal conductivity and thermal diffusivity were made over a temperature range for several samples of coke. (LTN)
Date: January 1, 1980
Creator: G.W., Douglas & McKinley, M.D.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department

Feasibility studies of in-situ coal gasification in the Warrior coal field. Quarterly report

Description: Laboratory studies on a research combustor were used in an attempt to determine the length of oxidation and reduction zones. Unfortunately the buoyant effects of the heated gases caused the burn to proceed along the upper portion of the horizontal combustor. This made the interpretation of uncertain value. Methods of measuring the thermal conductivity and chemical reactivity of coke are discussed. A bibliography of the physical and chemical properties of coke is appended. (LTN)
Date: March 1, 1979
Creator: Douglas, G.W. & McKinley, M.D.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department

Feasibility studies of in-situ coal gasification in the Warrior coal field. Quarterly report

Description: Studies in support of in-situ gasification involved bench-scale combustor experiments using forward combustion and coke as a fuel. Measurements of the thermal conductivity, thermal diffusivity and reactivity were made on several cokes over a range of temperatures. (LTN)
Date: October 1, 1979
Creator: Douglas, G.W. & McKinley, M.D.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department

Radiographic Capabilities of the MERCURY Monte Carlo Code

Description: MERCURY is a modern, parallel, general-purpose Monte Carlo code being developed at the Lawrence Livermore National Laboratory. Recently, a radiographic capability has been added. MERCURY can create a source of diagnostic, virtual particles that are aimed at pixels in an image tally. This new feature is compared to the radiography code, HADES, for verification and timing. Comparisons for accuracy were made using the French Test Object and for timing were made by tracking through an unstructured mesh. In addition, self consistency tests were run in MERCURY for the British Test Object and scattering test problem. MERCURY and HADES were found to agree to the precision of the input data. HADES appears to run around eight times faster than the MERCURY in the timing study. Profiling the MERCURY code has turned up several differences in the algorithms which account for this. These differences will be addressed in a future release of MERCURY.
Date: April 7, 2008
Creator: McKinley, M. S. & von Wittenau, A.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department

Accurate and efficient radiation transport in optically thick media -- by means of the Symbolic Implicit Monte Carlo method in the difference formulation

Description: The equations of radiation transport for thermal photons are notoriously difficult to solve in thick media without resorting to asymptotic approximations such as the diffusion limit. One source of this difficulty is that in thick, absorbing media thermal emission is almost completely balanced by strong absorption. In a previous publication [SB03], the photon transport equation was written in terms of the deviation of the specific intensity from the local equilibrium field. We called the new form of the equations the difference formulation. The difference formulation is rigorously equivalent to the original transport equation. It is particularly advantageous in thick media, where the radiation field approaches local equilibrium and the deviations from the Planck distribution are small. The difference formulation for photon transport also clarifies the diffusion limit. In this paper, the transport equation is solved by the Symbolic Implicit Monte Carlo (SIMC) method and a comparison is made between the standard formulation and the difference formulation. The SIMC method is easily adapted to the derivative source terms of the difference formulation, and a remarkable reduction in noise is obtained when the difference formulation is applied to problems involving thick media.
Date: March 30, 2005
Creator: Szoke, A; Brooks, E D; McKinley, M & Daffin, F
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department

Response Matrix Solution Using Boundary Condition Perturbation Theory for the Diffusion Approximation

Description: A second-order response matrix method is developed for solving the diffusion equation in a coarse-mesh grid. In this method, the problem domain is divided into a grid of coarse meshes (nodes) of the size of a fuel assembly. Then, by using the fact that all nodes have the same eigenvalue, an equation is developed for the node interface current to flux ratio. The fine-mesh solution in the domain is then obtained by evaluating perturbation expressions for the core eigenvalue and the flux with the node interface current to flux ratios and the precomputed Green's functions for the unique assemblies in the system. The Green's functions and the perturbation expressions for the eigenvalue and flux are based on a high-order boundary condition perturbation method developed recently. Two example problems are used to assess the accuracy of the new method.
Date: June 26, 2002
Creator: McKinley, M.S. & Rahnema, F.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department

H2O[underscore]TREAT users' manual: An aid for evaluating water treatment requirements for aquifer thermal energy storage systems

Description: This manual addresses the use of a public-domain software package developed to aid engineers in the desip of water treatment systems for aquifer thermal energy storage (ATES). The software, H20[underscore]TREAT, which runs in the DOS or UNIX Environment, was developed by the Pacific Northwest Laboratory and targeted to engineers possessing limited or no experience in geochemistry. To do this, the software provides guidance on geochemical phenomena that can cause problems in ATES systems (i.e., the formation of scale in heat exchangers, clogging of wells, corrosion in piping and heat exchangers, and degradation of aquifer materials causing a reduction in permeability). Preventing such problems frequently requires the use of water treatment systems. Because individual water treatment methods vary in cost, effectiveness, environmental impact, corrosion potential, and acceptability to regulators, proper evaluation of treatment options is required to determine the feasibility of ATES systems. The software is available for DOS- and UNIX-based computers. It uses a recently revised geochemical model, MINTEQ, to calculate the saturation indices of selected carbonate, oxide, and hydroxide minerals based on water chemistry and temperature data provided by the user. The saturation index of a specific mineral defines the point at which that mineral is oversaturated and hence may precipitate at the specified temperature. Cost calculations are not performed by the software; however, treatment capacity requirements are provided. Treatments include Na and H ion exchanger, fluidized-bed heat exchanger or pellet reactors, and CO[sub 2] injection. The H2O[underscore]TREAT software also provides the user with warning of geochemical problems that must be addressed, such as Fe and Mn oxide precipitation, SiO[sub 2] precipitation at high temperatures, corrosion, and clay swelling and dispersion.
Date: February 1, 1993
Creator: Vail, L.W.; Jenne, E.A.; Zipperer, J.P. & McKinley, M.I.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department

A common sense approach to consequence analysis at a large DOE site

Description: The primary objective of the Probabilistic Safety Assessment (PSA) at the U. S. Department of Energy (DOE) Savannah River Site (SRS) is to quantify health and economic risks posed by K Reactor operation to the nearby offsite and onsite areas from highly unlikely severe accidents. The overall risk analyses have also been instrumental as defensible bases for analyzing existing safety margins of the restart configuration; determining component, human action, and engineering system vulnerabilities; comparing measures of risk to DOE and commercial guidelines; and prioritizing risk-significant improvements. The key final phase of these probabilistic risk calculations, a third level of analysis or Level 3 PSA, requires the determination of the conditional consequences to onsite workers and the DOE reservation facilities, given low-probability, postulated fuel-melting accidents with accompanying atmospheric releases have occurred. A modified version of the commercial reactor-based MACCS 1.5 code, MACCS/ON, is used in the context of the SRS PSA to perform the consequence determinations. The updated code is applicable to other large DOE sites for risk analyses of facility operations, and is compatible with proposed modifications planned by code developers, Sandia National Laboratories.
Date: January 1, 1992
Creator: O'Kula, K.R.; McKinley, M.S. & East, J.M.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department

A common sense approach to consequence analysis at a large DOE site. Revision 1

Description: The primary objective of the Probabilistic Safety Assessment (PSA) at the U. S. Department of Energy (DOE) Savannah River Site (SRS) is to quantify health and economic risks posed by K Reactor operation to the nearby offsite and onsite areas from highly unlikely severe accidents. The overall risk analyses have also been instrumental as defensible bases for analyzing existing safety margins of the restart configuration; determining component, human action, and engineering system vulnerabilities; comparing measures of risk to DOE and commercial guidelines; and prioritizing risk-significant improvements. The key final phase of these probabilistic risk calculations, a third level of analysis or Level 3 PSA, requires the determination of the conditional consequences to onsite workers and the DOE reservation facilities, given low-probability, postulated fuel-melting accidents with accompanying atmospheric releases have occurred. A modified version of the commercial reactor-based MACCS 1.5 code, MACCS/ON, is used in the context of the SRS PSA to perform the consequence determinations. The updated code is applicable to other large DOE sites for risk analyses of facility operations, and is compatible with proposed modifications planned by code developers, Sandia National Laboratories.
Date: December 31, 1992
Creator: O`Kula, K. R.; McKinley, M. S. & East, J. M.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department

H2O{underscore}TREAT users` manual: An aid for evaluating water treatment requirements for aquifer thermal energy storage systems

Description: This manual addresses the use of a public-domain software package developed to aid engineers in the desip of water treatment systems for aquifer thermal energy storage (ATES). The software, H20{underscore}TREAT, which runs in the DOS or UNIX Environment, was developed by the Pacific Northwest Laboratory and targeted to engineers possessing limited or no experience in geochemistry. To do this, the software provides guidance on geochemical phenomena that can cause problems in ATES systems (i.e., the formation of scale in heat exchangers, clogging of wells, corrosion in piping and heat exchangers, and degradation of aquifer materials causing a reduction in permeability). Preventing such problems frequently requires the use of water treatment systems. Because individual water treatment methods vary in cost, effectiveness, environmental impact, corrosion potential, and acceptability to regulators, proper evaluation of treatment options is required to determine the feasibility of ATES systems. The software is available for DOS- and UNIX-based computers. It uses a recently revised geochemical model, MINTEQ, to calculate the saturation indices of selected carbonate, oxide, and hydroxide minerals based on water chemistry and temperature data provided by the user. The saturation index of a specific mineral defines the point at which that mineral is oversaturated and hence may precipitate at the specified temperature. Cost calculations are not performed by the software; however, treatment capacity requirements are provided. Treatments include Na and H ion exchanger, fluidized-bed heat exchanger or pellet reactors, and CO{sub 2} injection. The H2O{underscore}TREAT software also provides the user with warning of geochemical problems that must be addressed, such as Fe and Mn oxide precipitation, SiO{sub 2} precipitation at high temperatures, corrosion, and clay swelling and dispersion.
Date: February 1, 1993
Creator: Vail, L. W.; Jenne, E. A.; Zipperer, J. P. & McKinley, M. I.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department

New Capabilities in Mercury: A Modern, Monte Carlo Particle Transport Code

Description: The new physics, algorithmic and computer science capabilities of the Mercury general-purpose Monte Carlo particle transport code are discussed. The new physics and algorithmic features include in-line energy deposition and isotopic depletion, significant enhancements to the tally and source capabilities, diagnostic ray-traced particles, support for multi-region hybrid (mesh and combinatorial geometry) systems, and a probability of initiation method. Computer science enhancements include a second method of dynamically load-balancing parallel calculations, improved methods for visualizing 3-D combinatorial geometries and initial implementation of an in-line visualization capabilities.
Date: March 8, 2007
Creator: Procassini, R J; Cullen, D E; Greenman, G M; Hagmann, C A; Kramer, K J; McKinley, M S et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department

Update on the Development and Validation of MERCURY: A Modern, Monte Carlo Particle Transport Code

Description: An update on the development and validation of the MERCURY Monte Carlo particle transport code is presented. MERCURY is a modern, parallel, general-purpose Monte Carlo code being developed at the Lawrence Livermore National Laboratory. During the past year, several major algorithm enhancements have been completed. These include the addition of particle trackers for 3-D combinatorial geometry (CG), 1-D radial meshes, 2-D quadrilateral unstructured meshes, as well as a feature known as templates for defining recursive, repeated structures in CG. New physics capabilities include an elastic-scattering neutron thermalization model, support for continuous energy cross sections and S ({alpha}, {beta}) molecular bound scattering. Each of these new physics features has been validated through code-to-code comparisons with another Monte Carlo transport code. Several important computer science features have been developed, including an extensible input-parameter parser based upon the XML data description language, and a dynamic load-balance methodology for efficient parallel calculations. This paper discusses the recent work in each of these areas, and describes a plan for future extensions that are required to meet the needs of our ever expanding user base.
Date: June 6, 2005
Creator: Procassini, R J; Taylor, J M; McKinley, M S; Greenman, G M; Cullen, D E; O'Brien, M J et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department