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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

Heat load limits for TRU drums on pads

Description: Some of the Trans-Uranic (TRU) waste generated at SRS is packaged in 55 gallon, galvanized steel drums and stored on concrete pads that are exposed to the weather. It was necessary to compute how much heat can be generated by the waste in these drums without exceeding the temperature limits of the contents of the drum. This report documents the calculation of heat load limits for the drum, which depend on the temperature limits of the contents of the drum. The applicable temperature limits for the contents of the drum are the melting temperature of the polyethylene liner, 284 {+-} 8 F, the combustion temperature of paper, 450 F and the decomposition temperature of anionic resin, 190 F. One part of the analysis leading to the heat load limits was the collection of weather records on solar flux, wind speed and air temperature. Another part of the task was an experimental measurement of two important properties of the drum lid, the emittance and the absorptance. As used here, emittance is the rate at which an object emits infrared thermal radiation divided by the rate at which a perfect black body at the same temperature emits thermal radiation. Absorptance is the rate at which an object absorbs solar radiation divided by the rate at which a perfect black body absorbs radiation. For nine locations on each of eight typical weathered drum lids the measured emittance ranged from 0.73 {+-} 0.05 to 1.00 {+-} 0.07 (95% confidence level) and the average emittance for the eight lids was 0.85. For the eight drum lids the measured absorptance ranged from 0.64 {+-} 0.07 to 0.79 {+-} 0.07 with an average absorptance for the eight lids of 0.739.
Date: August 1, 1993
Creator: Steimke, J. L. & McKinley, M. S.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department

High-Order Boundary Condition Perturbation Theory for the Neutron Transport Equation

Description: First-order boundary condition perturbation theory is extended to nth-order in transport theory for eigenvalue problems. In particular, using an unperturbed (known) solution, formalisms are developed to determine the solution to the neutron transport equation when the boundary condition of the system is perturbed. The new method requires the computation of an adjoint Green's function. The numerical solution of this function is discussed. Finally, four numerical examples are provided to verify the validity of the formalisms presented.
Date: September 19, 2001
Creator: McKinley, M S & Rahnema, F
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department

NADS - Nuclear And Atomic Data System

Description: We have developed NADS (Nuclear and Atomic Data System), a web-based graphical interface for viewing pointwise and grouped cross-sections and distributions. Our implementation is a client / server model. The client is a Java applet that displays the graphical interface, which has interactive 2-D, 3-D, and 4-D plots and tables. The server, which can serve and perform computations the data, has been implemented in Python using the FUDGE package developed by Bret Beck at LLNL. Computational capabilities include algebraic manipulation of nuclear evaluated data in databases such as LLNL's ENDL-99, ENDF/B-V and ENDF/B-VI as well as user data. Processed data used in LLNL's transport codes are accessible as well. NADS is available from http://nuclear.llnl.gov/
Date: September 17, 2004
Creator: McKinley, M S; Beck, B & McNabb, D
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

Effects of Spatial Variations in Packing Fraction of Reactor Physics Parameters in Pebble-Bed Reactors

Description: The well-known spatial variation of packing fraction near the outer boundary of a pebble-bed reactor core is cited. The ramifications of this variation are explored with the MCNP computer code. It is found that the variation has negligible effects on the global reactor physics parameters extracted from the MCNP calculations for use in analysis by diffusion-theory codes, but for local reaction rates the effects of the variation are naturally important. Included is some preliminary work in using first-order perturbation theory for estimating the effect of the spatial variation of packing fraction on the core eigenvalue and the fission density distribution.
Date: June 11, 2003
Creator: Terry, W K; Ougouag, A M; Rahnema, F & Mckinley, M S
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. 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

Advantages of Analytical Transformations in Monte Carlo Methods for Radiation Transport

Description: Monte Carlo methods for radiation transport typically attempt to solve an integral by directly sampling analog or weighted particles, which are treated as physical entities. Improvements to the methods involve better sampling, probability games or physical intuition about the problem. We show that significant improvements can be achieved by recasting the equations with an analytical transform to solve for new, non-physical entities or fields. This paper looks at one such transform, the difference formulation for thermal photon transport, showing a significant advantage for Monte Carlo solution of the equations for time dependent transport. Other related areas are discussed that may also realize significant benefits from similar analytical transformations.
Date: December 13, 2004
Creator: McKinley, M. S.; Brooks, E. D., III & Daffin, F.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department

Comparison of Implicit and Symbolic Implicit Monte Carlo Line Transport with Frequency Weight Vector Extension

Description: We compare the Implicit Monte Carlo (IMC) technique to the Symbolic IMC (SIMC) technique, with and without weight vectors in frequency space, for time-dependent line transport in the presence of collisional pumping. We examine the efficiency and accuracy of the IMC and SIMC methods for test problems involving the evolution of a collisionally pumped trapping problem to its steady-state, the surface heating of a cold medium by a beam, and the diffusion of energy from a localized region that is collisionally pumped. The importance of spatial biasing and teleportation for problems involving high opacity is demonstrated. Our numerical solution, along with its associated teleportation error, is checked against theoretical calculations for the last example.
Date: December 3, 2002
Creator: McKinley, M S; Brooks III, E D & Szoke, A
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department

Comparison of Implicit and Symbolic Implicit Monte Carlo Line Transport With Frequency Weight Vector Extension

Description: We compare the Implicit Monte Carlo (IMC) technique to the Symbolic IMC (SIMC) technique, with and without weight vectors in frequency space, for time-dependent line transport in the presence of collisional pumping. We examine the efficiency and accuracy of the IMC and SIMC methods for examples involving the evolution of a collisionally pumped trapping problem to steady-state, the surface heating of cold media by a beam, and the diffusion of energy from a localized region that is collisionally pumped. The importance of spatial biasing and teleportation for problems involving high opacity is demonstrated. Our numerical solution, along with its associated teleportation error, is checked against theoretical calculations for the last example.
Date: March 20, 2002
Creator: McKinley, M S; Brooks III, E D & Szoke, A
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department

NADS: A Web Applet for Manipulation and Graphical Viewing of Nuclear Data

Description: We have developed a program called NADS (Nuclear and Atomic Data System) which provides a web-based, user-friendly interface for viewing nuclear data. NADS uses a client/server model. The client is a Java applet that runs in a web browser. The server is a Python code that delivers pointwise data to the applet per user request and then plots the data. The data is also stored in tables for viewing and modifying. NADS can display 2-D, 3-D and 4-D (time sliced) data in a powerful, user-friendly environment. Currently, evaluated nuclear data are available from ENDF/B-V, ENDF/B-VI, JENDL, JEF and Lawrence Livermore National Laboratory's ENDL databases. LLNL's ENDL database has data for neutron, gamma and charged particles as projectiles. In addition to displaying and saving data, NADS has the capability to perform computations with the data. NADS is accessible over the Internet at http://nuclear.llnl.gov/.
Date: November 30, 2004
Creator: McKinley, M S; Beck, B R & McNabb, D P
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department

An Evaluation of the Difference Formulation for Photon Transport in a Two Level System

Description: In this paper we extend the difference formulation for radiation transport to the case of a single atomic line. We examine the accuracy, performance and stability of the difference formulation within the framework of the Symbolic Implicit Monte Carlo method. The difference formulation, introduced for thermal radiation by some of the authors, has the unique property that the transport equation is written in terms that become small for thick systems. We find that the difference formulation has a significant advantage over the standard formulation for a thick system. The correct treatment of the line profile, however, requires that the difference formulation in the core of the line be mixed with the standard formulation in the wings and this may limit the advantage of the method. We bypass this problem by using the gray approximation. We develop three Monte Carlo solution methods based on different degrees of implicitness for the treatment of the source terms, and we find only conditional stability unless the source terms are treated fully implicitly.
Date: May 20, 2004
Creator: Daffin, F D; McKinley, M S; Brooks, E D & Szoke, A
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department

An Evaluation of the Difference Formulation for Photon Transport in a Two Level System

Description: In this paper we extend the difference formulation for radiation transport to the case of a single atomic line. We examine the accuracy, performance and stability of the difference formulation within the framework of the Symbolic Implicit Monte Carlo method. The difference formulation, introduced for thermal radiation by some of the authors, has the unique property that the transport equation is written in terms that become small for thick systems. We find that the difference formulation has a significant advantage over the standard formulation for a thick system. The correct treatment of the line profile, however, requires that the difference formulation in the core of the line be mixed with the standard formulation in the wings, and this may limit the advantage of the method. We bypass this problem by using the gray approximation. We develop three Monte Carlo solution methods based on different degrees of implicitness for the treatment of the source terms, and we find only conditional stability unless the source terms are treated fully implicitly.
Date: March 2, 2005
Creator: Daffin, F C; McKinley, M S; Brooks, E D & Szoke, A
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department