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in creator/contributor: "Khalil, H. S."  
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An improved quasistatic option for the DIF3D nodal kinetics code

Description: An improved quasistatic scheme is formulated for solution of the time-dependent DIF3D nodal equations in hexagonal-z geometry. This scheme has been implemented, along with adiabatic and point kinetics solution options, in the DIF3D hexagonal-z nodal kinetics code. The improved quasistatic method is shown to permit significant reduction in computing time, even for transients involving pronounced changes in flux shape. The achievable computing time reduction, in addition to being problem dependen… more
Date: January 1, 1991
Creator: Taiwo, T. A. & Khalil, H. S.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

An improved quasistatic option for the DIF3D nodal kinetics code

Description: An improved quasistatic scheme is formulated for solution of the time-dependent DIF3D nodal equations in hexagonal-z geometry. This scheme has been implemented, along with adiabatic and point kinetics solution options, in the DIF3D hexagonal-z nodal kinetics code. The improved quasistatic method is shown to permit significant reduction in computing time, even for transients involving pronounced changes in flux shape. The achievable computing time reduction, in addition to being problem dependen… more
Date: December 31, 1991
Creator: Taiwo, T. A. & Khalil, H. S.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Analysis of the ATW fuel cycle using the REBUS-3 code system.

Description: Partitioning and transmutation strategies are under study in several countries as a means of reducing the long-term hazards of spent fuel and other high-level nuclear waste. Various reactor and accelerator-driven system concepts have been proposed to transmute the long-lived radioactive nuclei of waste into stable or short-lived species. Among these concepts, the accelerator-driven transmutation of waste (ATW) system has been proposed by LANL for rapid destruction of transuranic actinides and l… more
Date: June 25, 1999
Creator: Khalil, H. S. & Yang, W. S.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Effects of Pb and Bi cross sections on ATW subcriticality predictions.

Description: The accelerator-driven transmutation of waste (ATW) system has been proposed for transmuting the long-lived radioactive nuclei of high-level waste to stable or short-lived species. In recent ATW design concepts, lead-bismuth eutectic (LBE), consisting of 44.5% Pb and 55.5% Bi by weight is used as the spallation target, system coolant, and reflector. Because of the excellent neutron reflection properties of LBE, the subcriticality level of ATW is quite sensitive to the cross sections of lead and… more
Date: June 25, 1999
Creator: Khalil, H. S. & Yang, W. S.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Coupled reactor physics and thermal-hydraulics computations

Description: This paper provides an overview of coupled reactor physics and thermal-hydraulics computations with the SAS-DIF3DK computer code. The assumptions and capabilities of the DIF3D-K nodal diffusion theory spatial kinetics model are presented. Results from DIF3D-K benchmark verification calculations are reported. SAS thermal-hydraulics model assumptions and features are described, and results from a prototypic application are shown. The details of data flow in the coupling of spatial kinetics with t… more
Date: October 1, 1997
Creator: Khalil, H. S.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Direct solution of the mathematical adjoint equations for an interface current nodal formulation

Description: A numerical method for directly computing the mathematical adjoint flux moments and partial currents for the hexagonal-Z geometry interface current nodal formulation in the DIF3D code is described. The new scheme is developed as an alternative to an existing scheme that employs a similarity transformation of the physical adjoint solution to compute the mathematical adjoint. Whereas the existing scheme is rigorous only when the flat transverse-leakage approximation is employed, this new scheme i… more
Date: March 1, 1993
Creator: Taiwo, T. A.; Yang, W. S. & Khalil, H. S.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Analysis of the NEACRP PWR rod ejection benchmark problems with DIF3D-K

Description: Analyses of the NEACRP PWR rod ejection transient benchmark problems with the DIF3D-K nodal kinetics code are presented. The DIF3D-K results are shown to be in generally good agreement with results obtained using other codes, in particular reference results previously generated with the PANTHER code. The sensitivity of the transient results to the DIF3D-K input parameters (such as time step size, radial and axial node sizes, and the mesh structure employed for fuel pin heat conduction calculati… more
Date: March 1, 1994
Creator: Kim, M. H.; Taiwo, T. A. & Khalil, H. S.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Direct solution of the mathematical adjoint equations for an interface current nodal formulation

Description: A numerical method for directly computing the mathematical adjoint flux moments and partial currents for the hexagonal-Z geometry interface current nodal formulation in the DIF3D code is described. The new scheme is developed as an alternative to an existing scheme that employs a similarity transformation of the physical adjoint solution to compute the mathematical adjoint. Whereas the existing scheme is rigorous only when the flat transverse-leakage approximation is employed, this new scheme i… more
Date: January 1, 1993
Creator: Taiwo, T. A.; Yang, W. S. & Khalil, H. S.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Issues and approaches in control for autonomous reactor operation

Description: A capability for autonomous and passively safe operation is one of the goals of the NERI funded development of Generation IV nuclear plants. An approach is described for evaluating the effect of increasing autonomy on safety margins and load behavior and for examining issues that arise with increasing autonomy and their potential impact on performance. The method provides a formal approach to the process of exploiting the innate self-regulating property of a reactor to make it less dependent on… more
Date: July 20, 2000
Creator: Vilim, R. B.; Khalil, H. S. & Wei, T. Y. C.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Validation and application of a physics database for fast reactor fuel cycle analysis

Description: An effort has been made to automate the execution of fast reactor fuel cycle analysis, using EBR-II as a demonstration vehicle, and to validate the analysis results for application to the IFR closed fuel cycle demonstration at EBR-II and its fuel cycle facility. This effort has included: (1) the application of the standard ANL depletion codes to perform core-follow analyses for an extensive series of EBR-II runs, (2) incorporation of the EBR-II data into a physics database, (3) development and … more
Date: March 1, 1994
Creator: McKnight, R. D.; Stillman, J. A.; Toppel, B. J. & Khalil, H. S.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Time-step selection considerations in the analysis of reactor transients with DIF3D-K

Description: The DIF3D-K code solves the three-dimensional, time-dependent multigroup neutron diffusion equations by using a nodal approach for spatial discretization and either the theta method or one of three space-time factorization approaches for temporal integration of the nodal equations. The three space-time factorization options (namely, improved quasistatic, adiabatic and conventional point kinetics) were implemented because of their potential efficiency advantage for the analysis of transients in … more
Date: May 1, 1993
Creator: Taiwo, T. A.; Khalil, H. S.; Cahalan, J. E. & Morris, E. E.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Development of small, fast reactor core designs using lead-based coolant.

Description: A variety of small (100 MWe) fast reactor core designs are developed, these include compact configurations, long-lived (15-year fuel lifetime) cores, and derated, natural circulation designs. Trade studies are described which identify key core design issues for lead-based coolant systems. Performance parameters and reactivity feedback coefficients are compared for lead-bismuth eutectic (LBE) and sodium-cooled cores of consistent design. The results of these studies indicate that the superior ne… more
Date: June 11, 1999
Creator: Cahalan, J. E.; Hill, R. N.; Khalil, H. S. & Wade, D. C.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Development of a parallelization strategy for the VARIANT code

Description: The VARIANT code solves the multigroup steady-state neutron diffusion and transport equation in three-dimensional Cartesian and hexagonal geometries using the variational nodal method. VARIANT consists of four major parts that must be executed sequentially: input handling, calculation of response matrices, solution algorithm (i.e. inner-outer iteration), and output of results. The objective of the parallelization effort was to reduce the overall computing time by distributing the work of the tw… more
Date: 1996-11~
Creator: Hanebutte, U. R.; Khalil, H. S.; Palmiotti, G. & Tatsumi, M.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Preliminary Assessment of Existing Experimental Data for Validation of Reactor Physics Codes and Data for NGNP Design and Analysis.

Description: The Next Generation Nuclear Plant (NGNP), a demonstration reactor and hydrogen production facility proposed for construction at the INEEL, is expected to be a high-temperature gas-cooled reactor (HTGR). Computer codes used in design and safety analysis for the NGNP must be benchmarked against experimental data. The INEEL and ANL have examined information about several past and present experimental and prototypical facilities based on HTGR concepts to assess the potential of these facilities for… more
Date: October 25, 2005
Creator: Terry, W. K.; Jewell, J. K.; Briggs, J. B.; Taiwo, T. A.; Park, W.S. & Khalil, H. S.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Physics studies of higher actinide consumption in an LMR

Description: The core physics aspects of the transuranic burning potential of the Integral Fast Reactor (IFR) are assessed. The actinide behavior in fissile self-sufficient IFR closed cycles of 1200 MWt size is characterized, and the transuranic isotopics and risk potential of the working inventory are compared to those from a once-through LWR. The core neutronic performance effects of rare-earth impurities present in the recycled fuel are addressed. Fuel cycle strategies for burning transuranics from an ex… more
Date: January 1, 1990
Creator: Hill, R. N.; Wade, D. C.; Fujita, E. K. & Khalil, H. S.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Response matrix transport calculations on parallel computers

Description: The response matrix method offers an excellent vehicle for adapting three-dimensional neutron transport methods to parallel computers. Our current thrust is in utilizing the three-dimensional Variational nodal code VARIANT as a point of departure for performing three- dimensional parallel computations on the IBM SPx at Argonne National Laboratory. The code employs a planar red-black iteration with a secondary red-black or four-color iteration within each plane. Speed- up and efficiency results … more
Date: December 1996
Creator: Hanebutte, U. R.; Palmiotti, G.; Khalil, H. S.; Tatsumi, M. & Lewis, E. E.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Enhancement of REBUS-3/DIF3D for Whole-Core Neutronic Analysis of Prismatic Very High Temperature Reactor (VHTR).

Description: Enhancements have been made to the REBUS-3/DIF3D code suite to facilitate its use for the design and analysis of prismatic Very High Temperature Reactors (VHTRs). A new cross section structure, using table-lookup, has been incorporated to account for cross section changes with burnup and fuel and moderator temperatures. For representing these cross section dependencies, three new modules have been developed using FORTRAN 90/95 object-oriented data structures and implemented within the REBUS-3 c… more
Date: October 13, 2006
Creator: Lee, C. H.; Zhong, Z.; Taiwo, T. A.; Yang, W. S.; Khalil, H. S. & Smith, M. A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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