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Sample records for fuel performance codes

  1. Multidimensional Fuel Performance Code: BISON

    Energy Science and Technology Software Center (ESTSC)

    2014-09-03

    BISON is a finite element based nuclear fuel performance code applicable to a variety of fuel forms including light water reactor fuel rods, TRISO fuel particles, and metallic rod and plate fuel (Refs. [a, b, c]). It solves the fully-coupled equations of thermomechanics and species diffusion and includes important fuel physics such as fission gas release and material property degradation with burnup. BISON is based on the MOOSE framework (Ref. [d]) and can therefore efficientlymore » solve problems on 1-, 2- or 3-D meshes using standard workstations or large high performance computers. BISON is also coupled to a MOOSE-based mesoscale phase field material property simulation capability (Refs. [e, f]). As described here, BISON includes the code library named FOX, which was developed concurrent with BISON. FOX contains material and behavioral models that are specific to oxide fuels.« less

  2. Multidimensional Fuel Performance Code: BISON

    SciTech Connect

    2014-09-03

    BISON is a finite element based nuclear fuel performance code applicable to a variety of fuel forms including light water reactor fuel rods, TRISO fuel particles, and metallic rod and plate fuel (Refs. [a, b, c]). It solves the fully-coupled equations of thermomechanics and species diffusion and includes important fuel physics such as fission gas release and material property degradation with burnup. BISON is based on the MOOSE framework (Ref. [d]) and can therefore efficiently solve problems on 1-, 2- or 3-D meshes using standard workstations or large high performance computers. BISON is also coupled to a MOOSE-based mesoscale phase field material property simulation capability (Refs. [e, f]). As described here, BISON includes the code library named FOX, which was developed concurrent with BISON. FOX contains material and behavioral models that are specific to oxide fuels.

  3. Transmutation Fuel Performance Code Conceptual Design

    SciTech Connect

    Gregory K. Miller; Pavel G. Medvedev

    2007-03-01

    One of the objectives of the Global Nuclear Energy Partnership (GNEP) is to facilitate the licensing and operation of Advanced Recycle Reactors (ARRs) for transmutation of the transuranic elements (TRU) present in spent fuel. A fuel performance code will be an essential element in the licensing process ensuring that behavior of the transmutation fuel elements in the reactor is understood and predictable. Even more important in the near term, a fuel performance code will assist substantially in the fuels research and development, design, irradiation testing and interpretation of the post-irradiation examination results.

  4. Transmutation Fuel Performance Code Thermal Model Verification

    SciTech Connect

    Gregory K. Miller; Pavel G. Medvedev

    2007-09-01

    FRAPCON fuel performance code is being modified to be able to model performance of the nuclear fuels of interest to the Global Nuclear Energy Partnership (GNEP). The present report documents the effort for verification of the FRAPCON thermal model. It was found that, with minor modifications, FRAPCON thermal model temperature calculation agrees with that of the commercial software ABAQUS (Version 6.4-4). This report outlines the methodology of the verification, code input, and calculation results.

  5. Verification of the BISON fuel performance code

    SciTech Connect

    D. M. Perez; R. J. Gardner; J. D. Hales; S. R. Novascone; G. Pastore; B. W. Spencer; R. L. Williamson

    2014-09-01

    BISON is a modern finite element-based nuclear fuel performance code that has been under development at Idaho National Labo- ratory (USA) since 2009. The code is applicable to both steady and transient fuel behavior and is used to analyze 1D spherical, 2D axisymmetric, or 3D geometries. BISON has been applied to a variety of fuel forms including LWR fuel rods, TRISO-coated fuel particles, and metallic fuel in both rod and plate geometries. Code validation is currently in progress, principally by comparison to instrumented LWR fuel rods and other well known fuel performance codes. Results from several assessment cases are reported, with emphasis on fuel centerline temperatures at various stages of fuel life, fission gas release, and clad deformation during pellet clad mechanical interaction (PCMI). BISON comparisons to fuel centerline temperature measurements are very good at beginning of life and reasonable at high burnup. Although limited to date, fission gas release comparisons are very good. Comparisons of rod diameter following significant power ramping are also good and demonstrate BISON’s unique ability to model discrete pellet behavior and accurately predict clad ridging from PCMI.

  6. Early User Experience with BISON Fuel Performance Code

    SciTech Connect

    D. M. Perez

    2012-08-01

    Three Fuel Modeling Exercise II (FUMEX II) LWR fuel irradiation experiments were simulated and analyzed using the fuel performance code BISON to demonstrate code utility for modeling of the LWR fuel performance. Comparisons were made against the BISON results and the experimental data for the three assessment cases. The assessment cases reported within this report include IFA-597.3 Rod 8, Riso AN3 and Riso AN4.

  7. An evaluation of the nuclear fuel performance code BISON

    SciTech Connect

    Perez, D. M.; Williamson, R. L.; Novascone, S. R.; Larson, T. K.; Hales, J. D.; Spencer, B. W.; Pastore, G.

    2013-07-01

    BISON is a modern finite-element based nuclear fuel performance code that has been under development at the Idaho National Laboratory (USA) since 2009. The code is applicable to both steady and transient fuel behavior and is used to analyze either 2D axisymmetric or 3D geometries. BISON has been applied to a variety of fuel forms including LWR fuel rods, TRISO-coated fuel particles, and metallic fuel in both rod and plate geometries. Code validation is currently in progress, principally by comparison to instrumented LWR fuel rods and other well known fuel performance codes. Results from several assessment cases are reported, with emphasis on fuel centerline temperatures at various stages of fuel life, fission gas release, and clad deformation during pellet clad mechanical interaction (PCMI). BISON comparisons to fuel centerline temperature measurements are very good at beginning of life and reasonable at high burnup. Although limited to date, fission gas release comparisons are very good. Comparisons of rod diameter following significant power ramping are also good and demonstrate BISON's unique ability to model discrete pellet behavior and accurately predict clad ridging from PCMI. (authors)

  8. Predictive Bias and Sensitivity in NRC Fuel Performance Codes

    SciTech Connect

    Geelhood, Kenneth J.; Luscher, Walter G.; Senor, David J.; Cunningham, Mitchel E.; Lanning, Donald D.; Adkins, Harold E.

    2009-10-01

    The latest versions of the fuel performance codes, FRAPCON-3 and FRAPTRAN were examined to determine if the codes are intrinsically conservative. Each individual model and type of code prediction was examined and compared to the data that was used to develop the model. In addition, a brief literature search was performed to determine if more recent data have become available since the original model development for model comparison.

  9. Code System to Calculate Fuel Rod Thermal Performance.

    Energy Science and Technology Software Center (ESTSC)

    2000-11-27

    Version: 00 GT2R2 is Revision 2 of GAPCON-THERMAL-2 and is used to calculate the thermal behavior of a nuclear fuel rod during normal steady-state operation. The program was developed as a tool for estimating fuel-cladding gap conductances and fuel-stored energy. Models used include power history, fission gas generation and release, fuel relocation and densification, and fuel-cladding gap conductance. The gas release and relocation models can be used to make either best-estimate or conservative predictions. Themore » code is used by the United States Nuclear Regulatory Commission for audit calculations of nuclear fuel thermal performance computer codes.« less

  10. New Mechanical Model for the Transmutation Fuel Performance Code

    SciTech Connect

    Gregory K. Miller

    2008-04-01

    A new mechanical model has been developed for implementation into the TRU fuel performance code. The new model differs from the existing FRAPCON 3 model, which it is intended to replace, in that it will include structural deformations (elasticity, plasticity, and creep) of the fuel. Also, the plasticity algorithm is based on the “plastic strain–total strain” approach, which should allow for more rapid and assured convergence. The model treats three situations relative to interaction between the fuel and cladding: (1) an open gap between the fuel and cladding, such that there is no contact, (2) contact between the fuel and cladding where the contact pressure is below a threshold value, such that axial slippage occurs at the interface, and (3) contact between the fuel and cladding where the contact pressure is above a threshold value, such that axial slippage is prevented at the interface. The first stage of development of the model included only the fuel. In this stage, results obtained from the model were compared with those obtained from finite element analysis using ABAQUS on a problem involving elastic, plastic, and thermal strains. Results from the two analyses showed essentially exact agreement through both loading and unloading of the fuel. After the cladding and fuel/clad contact were added, the model demonstrated expected behavior through all potential phases of fuel/clad interaction, and convergence was achieved without difficulty in all plastic analysis performed. The code is currently in stand alone form. Prior to implementation into the TRU fuel performance code, creep strains will have to be added to the model. The model will also have to be verified against an ABAQUS analysis that involves contact between the fuel and cladding.

  11. Overview of the BISON Multidimensional Fuel Performance Code

    SciTech Connect

    R. L. Williamson; J. D. Hales; S. R. Novascone; B. W. Spencer; D. M. Perez; G. Pastore; R. C. Martineau

    2013-10-01

    BISON is a modern multidimensional multiphysics finite-element based nuclear fuel performance code that has been under development at the Idaho National Laboratory (USA) since 2009. A brief background is provided on the code’s computational framework (MOOSE), governing equations, and material and behavioral models. Ongoing code verification and validation work is outlined, and comparative results are provided for select validation cases. Recent applications are discussed, including specific description of two applications where 3D treatment is important. A summary of future code development and validation activities is given. Numerous references to published work are provided where interested readers can find more complete information.

  12. Current Capabilities of the Fuel Performance Modeling Code PARFUME

    SciTech Connect

    G. K. Miller; D. A. Petti; J. T. Maki; D. L. Knudson

    2004-09-01

    The success of gas reactors depends upon the safety and quality of the coated particle fuel. A fuel performance modeling code (called PARFUME), which simulates the mechanical and physico-chemical behavior of fuel particles during irradiation, is under development at the Idaho National Engineering and Environmental Laboratory. Among current capabilities in the code are: 1) various options for calculating CO production and fission product gas release, 2) a thermal model that calculates a time-dependent temperature profile through a pebble bed sphere or a prismatic block core, as well as through the layers of each analyzed particle, 3) simulation of multi-dimensional particle behavior associated with cracking in the IPyC layer, partial debonding of the IPyC from the SiC, particle asphericity, kernel migration, and thinning of the SiC caused by interaction of fission products with the SiC, 4) two independent methods for determining particle failure probabilities, 5) a model for calculating release-to-birth (R/B) ratios of gaseous fission products, that accounts for particle failures and uranium contamination in the fuel matrix, and 6) the evaluation of an accident condition, where a particle experiences a sudden change in temperature following a period of normal irradiation. This paper presents an overview of the code.

  13. Assessment of MARMOT. A Mesoscale Fuel Performance Code

    SciTech Connect

    Tonks, M. R.; Schwen, D.; Zhang, Y.; Chakraborty, P.; Bai, X.; Fromm, B.; Yu, J.; Teague, M. C.; Andersson, D. A.

    2015-04-01

    MARMOT is the mesoscale fuel performance code under development as part of the US DOE Nuclear Energy Advanced Modeling and Simulation Program. In this report, we provide a high level summary of MARMOT, its capabilities, and its current state of validation. The purpose of MARMOT is to predict the coevolution of microstructure and material properties of nuclear fuel and cladding. It accomplished this using the phase field method coupled to solid mechanics and heat conduction. MARMOT is based on the Multiphysics Object-Oriented Simulation Environment (MOOSE), and much of its basic capability in the areas of the phase field method, mechanics, and heat conduction come directly from MOOSE modules. However, additional capability specific to fuel and cladding is available in MARMOT. While some validation of MARMOT has been completed in the areas of fission gas behavior and grain growth, much more validation needs to be conducted. However, new mesoscale data needs to be obtained in order to complete this validation.

  14. A mechanistic code for intact and defective nuclear fuel element performance

    NASA Astrophysics Data System (ADS)

    Shaheen, Khaled

    During reactor operation, nuclear fuel elements experience an environment featuring high radiation, temperature, and pressure. Predicting in-reactor performance of nuclear fuel elements constitutes a complex multi-physics problem, one that requires numerical codes to be solved. Fuel element performance codes have been developed for different reactor and fuel designs. Most of these codes simulate fuel elements using one-or quasi-two-dimensional geometries, and some codes are only applicable to steady state but not transient behaviour and vice versa. Moreover, while many conceptual and empirical separate-effects models exist for defective fuel behaviour, wherein the sheath is breached allowing coolant ingress and fission gas escape, there have been few attempts to predict defective fuel behaviour in the context of a mechanistic fuel performance code. Therefore, a mechanistic fuel performance code, called FORCE (Fuel Operational peRformance Computations in an Element) is proposed for the time-dependent behaviour of intact and defective CANDU nuclear fuel elements. The code, which is implemented in the COMSOL Multiphysics commercial software package, simulates the fuel, sheath, and fuel-to-sheath gap in a radial-axial geometry. For intact fuel performance, the code couples models for heat transport, fission gas production and diffusion, and structural deformation of the fuel and sheath. The code is extended to defective fuel performance by integrating an adapted version of a previously developed fuel oxidation model, and a model for the release of radioactive fission product gases from the fuel to the coolant. The FORCE code has been verified against the ELESTRES-IST and ELESIM industrial code for its predictions of intact fuel performance. For defective fuel behaviour, the code has been validated against coulometric titration data for oxygen-to-metal ratio in defective fuel elements from commercial reactors, while also being compared to a conceptual oxidation model

  15. Software Design Document for the AMP Nuclear Fuel Performance Code

    SciTech Connect

    Philip, Bobby; Clarno, Kevin T; Cochran, Bill

    2010-03-01

    The purpose of this document is to describe the design of the AMP nuclear fuel performance code. It provides an overview of the decomposition into separable components, an overview of what those components will do, and the strategic basis for the design. The primary components of a computational physics code include a user interface, physics packages, material properties, mathematics solvers, and computational infrastructure. Some capability from established off-the-shelf (OTS) packages will be leveraged in the development of AMP, but the primary physics components will be entirely new. The material properties required by these physics operators include many highly non-linear properties, which will be replicated from FRAPCON and LIFE where applicable, as well as some computationally-intensive operations, such as gap conductance, which depends upon the plenum pressure. Because there is extensive capability in off-the-shelf leadership class computational solvers, AMP will leverage the Trilinos, PETSc, and SUNDIALS packages. The computational infrastructure includes a build system, mesh database, and other building blocks of a computational physics package. The user interface will be developed through a collaborative effort with the Nuclear Energy Advanced Modeling and Simulation (NEAMS) Capability Transfer program element as much as possible and will be discussed in detail in a future document.

  16. Intercode Advanced Fuels and Cladding Comparison Using BISON, FRAPCON, and FEMAXI Fuel Performance Codes

    NASA Astrophysics Data System (ADS)

    Rice, Aaren

    As part of the Department of Energy's Accident Tolerant Fuels (ATF) campaign, new cladding designs and fuel types are being studied in order to help make nuclear energy a safer and more affordable source for power. This study focuses on the implementation and analysis of the SiC cladding and UN, UC, and U3Si2 fuels into three specific nuclear fuel performance codes: BISON, FRAPCON, and FEMAXI. These fuels boast a higher thermal conductivity and uranium density than traditional UO2 fuel which could help lead to longer times in a reactor environment. The SiC cladding has been studied for its reduced production of hydrogen gas during an accident scenario, however the SiC cladding is a known brittle and unyielding material that may fracture during PCMI (Pellet Cladding Mechanical Interaction). This work focuses on steady-state operation with advanced fuel and cladding combinations. By implementing and performing analysis work with these materials, it is possible to better understand some of the mechanical interactions that could be seen as limiting factors. In addition to the analysis of the materials themselves, a further analysis is done on the effects of using a fuel creep model in combination with the SiC cladding. While fuel creep is commonly ignored in the traditional UO2 fuel and Zircaloy cladding systems, fuel creep can be a significant factor in PCMI with SiC.

  17. Assessment of SFR fuel pin performance codes under advanced fuel for minor actinide transmutation

    SciTech Connect

    Bouineau, V.; Lainet, M.; Chauvin, N.; Pelletier, M.

    2013-07-01

    Americium is a strong contributor to the long term radiotoxicity of high activity nuclear waste. Transmutation by irradiation in nuclear reactors of long-lived nuclides like {sup 241}Am is, therefore, an option for the reduction of radiotoxicity and residual power packages as well as the repository area. In the SUPERFACT Experiment four different oxide fuels containing high and low concentrations of {sup 237}Np and {sup 241}Am, representing the homogeneous and heterogeneous in-pile recycling concepts, were irradiated in the PHENIX reactor. The behavior of advanced fuel materials with minor actinide needs to be fully characterized, understood and modeled in order to optimize the design of this kind of fuel elements and to evaluate its performances. This paper assesses the current predictability of fuel performance codes TRANSURANUS and GERMINAL V2 on the basis of post irradiation examinations of the SUPERFACT experiment for pins with low minor actinide content. Their predictions have been compared to measured data in terms of geometrical changes of fuel and cladding, fission gases behavior and actinide and fission product distributions. The results are in good agreement with the experimental results, although improvements are also pointed out for further studies, especially if larger content of minor actinide will be taken into account in the codes. (authors)

  18. Modeling Constituent Redistribution in U-Pu-Zr Metallic Fuel Using the Advanced Fuel Performance Code BISON

    SciTech Connect

    Douglas Porter; Steve Hayes; Various

    2014-06-01

    The Advanced Fuels Campaign (AFC) metallic fuels currently being tested have higher zirconium and plutonium concentrations than those tested in the past in EBR reactors. Current metal fuel performance codes have limitations and deficiencies in predicting AFC fuel performance, particularly in the modeling of constituent distribution. No fully validated code exists due to sparse data and unknown modeling parameters. Our primary objective is to develop an initial analysis tool by incorporating state-of-the-art knowledge, constitutive models and properties of AFC metal fuels into the MOOSE/BISON (1) framework in order to analyze AFC metallic fuel tests.

  19. Advanced Pellet Cladding Interaction Modeling Using the US DOE CASL Fuel Performance Code: Peregrine

    SciTech Connect

    Jason Hales; Various

    2014-06-01

    The US DOE’s Consortium for Advanced Simulation of LWRs (CASL) program has undertaken an effort to enhance and develop modeling and simulation tools for a virtual reactor application, including high fidelity neutronics, fluid flow/thermal hydraulics, and fuel and material behavior. The fuel performance analysis efforts aim to provide 3-dimensional capabilities for single and multiple rods to assess safety margins and the impact of plant operation and fuel rod design on the fuel thermomechanical- chemical behavior, including Pellet-Cladding Interaction (PCI) failures and CRUD-Induced Localized Corrosion (CILC) failures in PWRs. [1-3] The CASL fuel performance code, Peregrine, is an engineering scale code that is built upon the MOOSE/ELK/FOX computational FEM framework, which is also common to the fuel modeling framework, BISON [4,5]. Peregrine uses both 2-D and 3-D geometric fuel rod representations and contains a materials properties and fuel behavior model library for the UO2 and Zircaloy system common to PWR fuel derived from both open literature sources and the FALCON code [6]. The primary purpose of Peregrine is to accurately calculate the thermal, mechanical, and chemical processes active throughout a single fuel rod during operation in a reactor, for both steady state and off-normal conditions.

  20. Advanced Pellet-Cladding Interaction Modeling using the US DOE CASL Fuel Performance Code: Peregrine

    SciTech Connect

    Montgomery, Robert O.; Capps, Nathan A.; Sunderland, Dion J.; Liu, Wenfeng; Hales, Jason; Stanek, Chris; Wirth, Brian D.

    2014-06-15

    The US DOE’s Consortium for Advanced Simulation of LWRs (CASL) program has undertaken an effort to enhance and develop modeling and simulation tools for a virtual reactor application, including high fidelity neutronics, fluid flow/thermal hydraulics, and fuel and material behavior. The fuel performance analysis efforts aim to provide 3-dimensional capabilities for single and multiple rods to assess safety margins and the impact of plant operation and fuel rod design on the fuel thermo-mechanical-chemical behavior, including Pellet-Cladding Interaction (PCI) failures and CRUD-Induced Localized Corrosion (CILC) failures in PWRs. [1-3] The CASL fuel performance code, Peregrine, is an engineering scale code that is built upon the MOOSE/ELK/FOX computational FEM framework, which is also common to the fuel modeling framework, BISON [4,5]. Peregrine uses both 2-D and 3-D geometric fuel rod representations and contains a materials properties and fuel behavior model library for the UO2 and Zircaloy system common to PWR fuel derived from both open literature sources and the FALCON code [6]. The primary purpose of Peregrine is to accurately calculate the thermal, mechanical, and chemical processes active throughout a single fuel rod during operation in a reactor, for both steady state and off-normal conditions.

  1. Validation of the BISON 3D Fuel Performance Code: Temperature Comparisons for Concentrically and Eccentrically Located Fuel Pellets

    SciTech Connect

    J. D. Hales; D. M. Perez; R. L. Williamson; S. R. Novascone; B. W. Spencer

    2013-03-01

    BISON is a modern finite-element based nuclear fuel performance code that has been under development at the Idaho National Laboratory (USA) since 2009. The code is applicable to both steady and transient fuel behaviour and is used to analyse either 2D axisymmetric or 3D geometries. BISON has been applied to a variety of fuel forms including LWR fuel rods, TRISO-coated fuel particles, and metallic fuel in both rod and plate geometries. Code validation is currently in progress, principally by comparison to instrumented LWR fuel rods. Halden IFA experiments constitute a large percentage of the current BISON validation base. The validation emphasis here is centreline temperatures at the beginning of fuel life, with comparisons made to seven rods from the IFA-431 and 432 assemblies. The principal focus is IFA-431 Rod 4, which included concentric and eccentrically located fuel pellets. This experiment provides an opportunity to explore 3D thermomechanical behaviour and assess the 3D simulation capabilities of BISON. Analysis results agree with experimental results showing lower fuel centreline temperatures for eccentric fuel with the peak temperature shifted from the centreline. The comparison confirms with modern 3D analysis tools that the measured temperature difference between concentric and eccentric pellets is not an artefact and provides a quantitative explanation for the difference.

  2. The COPERNIC3 project: how AREVA is successfully developing an advanced global fuel rod performance code

    SciTech Connect

    Garnier, Ch.; Mailhe, P.; Sontheimer, F.; Landskron, H.; Deuble, D.; Arimescu, V.I.; Billaux, M.

    2007-07-01

    Fuel performance is a key factor for minimizing operating costs in nuclear plants. One of the important aspects of fuel performance is fuel rod design, based upon reliable tools able to verify the safety of current fuel solutions, prevent potential issues in new core managements and guide the invention of tomorrow's fuels. AREVA is developing its future global fuel rod code COPERNIC3, which is able to calculate the thermal-mechanical behavior of advanced fuel rods in nuclear plants. Some of the best practices to achieve this goal are described, by reviewing the three pillars of a fuel rod code: the database, the modelling and the computer and numerical aspects. At first, the COPERNIC3 database content is described, accompanied by the tools developed to effectively exploit the data. Then is given an overview of the main modelling aspects, by emphasizing the thermal, fission gas release and mechanical sub-models. In the last part, numerical solutions are detailed in order to increase the computational performance of the code, with a presentation of software configuration management solutions. (authors)

  3. Sensitivity Analysis of FEAST-Metal Fuel Performance Code: Initial Results

    SciTech Connect

    Edelmann, Paul Guy; Williams, Brian J.; Unal, Cetin; Yacout, Abdellatif

    2012-06-27

    This memo documents the completion of the LANL milestone, M3FT-12LA0202041, describing methodologies and initial results using FEAST-Metal. The FEAST-Metal code calculations for this work are being conducted at LANL in support of on-going activities related to sensitivity analysis of fuel performance codes. The objective is to identify important macroscopic parameters of interest to modeling and simulation of metallic fuel performance. This report summarizes our preliminary results for the sensitivity analysis using 6 calibration datasets for metallic fuel developed at ANL for EBR-II experiments. Sensitivity ranking methodology was deployed to narrow down the selected parameters for the current study. There are approximately 84 calibration parameters in the FEAST-Metal code, of which 32 were ultimately used in Phase II of this study. Preliminary results of this sensitivity analysis led to the following ranking of FEAST models for future calibration and improvements: fuel conductivity, fission gas transport/release, fuel creep, and precipitation kinetics. More validation data is needed to validate calibrated parameter distributions for future uncertainty quantification studies with FEAST-Metal. Results of this study also served to point out some code deficiencies and possible errors, and these are being investigated in order to determine root causes and to improve upon the existing code models.

  4. A mono-dimensional nuclear fuel performance analysis code, PUMA, development from a coupled approach

    SciTech Connect

    Cheon, J. S.; Lee, B. O.; Lee, C. B.; Yacout, A. M.

    2013-07-01

    Multidimensional-multi-physical phenomena in nuclear fuels are treated as a set of mono-dimensional-coupled problems which encompass heat, displacement, fuel constituent redistribution, and fission gas release. Rather than uncoupling these coupled equations as in conventional fuel performance analysis codes, efforts are put into to obtain fully coupled solutions by relying on the recent advances of numerical analysis. Through this approach, a new SFR metal fuel performance analysis code, called PUMA (Performance of Uranium Metal fuel rod Analysis code) is under development. Although coupling between temperature and fuel constituent was made easily, the coupling between the mechanical equilibrium equation and a set of stiff kinetics equations for fission gas release is accomplished by introducing one-level Newton scheme through backward differentiation formula. Displacement equations from 1D finite element formulation of the mechanical equilibrium equation are solved simultaneously with stress equation, creep equation, swelling equation, and FGR equations. Calculations was made successfully such that the swelling and the hydrostatic pressure are interrelated each other. (authors)

  5. Analyses with the FSTATE code: fuel performance in destructive in-pile experiments

    SciTech Connect

    Bauer, T.H.; Meek, C.C.

    1982-01-01

    Thermal-mechanical analysis of a fuel pin is an essential part of the evaluation of fuel behavior during hypothetical accident transients. The FSTATE code has been developed to provide this required computational ability in situations lacking azimuthal symmetry about the fuel-pin axis by performing 2-dimensional thermal, mechanical, and fission gas release and redistribution computations for a wide range of possible transient conditions. In this paper recent code developments are described and application is made to in-pile experiments undertaken to study fast-reactor fuel under accident conditions. Three accident simulations, including a fast and slow ramp-rate overpower as well as a loss-of-cooling accident sequence, are used as representative examples, and the interpretation of STATE computations relative to experimental observations is made.

  6. Application of the BISON Fuel Performance Code to the FUMEX-III Coordinated Research Project

    SciTech Connect

    R. L. Williamson; S. R. Novascone

    2012-04-01

    INL recently participated in FUMEX-III, an International Atomic Energy Agency sponsored fuel modeling Coordinated Research Project. A main purpose of FUMEX-III is to compare code predictions to reliable experimental data. During the same time period, the INL initiated development of a new multidimensional (2D and 3D) multiphysics nuclear fuel performance code called BISON. Interactions with international fuel modeling researchers via FUMEX-III played a significant and important role in the BISON evolution, particularly influencing the selection of material and behavioral models which are now included in the code. BISON's ability to model integral fuel rod behavior did not mature until 2011, thus the only FUMEX-III case considered was the Riso3-GE7 experiment, which includes measurements of rod outer diameter following pellet clad mechanical interaction (PCMI) resulting from a power ramp late in fuel life. BISON comparisons to the Riso3-GE7 final rod diameter measurements are quite reasonable. The INL is very interested in participation in the next Fuel Modeling Coordinated Research Project and would like to see the project initiated as soon as possible.

  7. Recent Updates to NRC Fuel Performance Codes and Plans for Future Improvements

    SciTech Connect

    Geelhood, Kenneth J.

    2011-12-31

    FRAPCON-3.4a and FRAPTRAN 1.4 are the most recent versions of the U.S. Nuclear Regulatory Commission (NRC) steady-state and transient fuel performance codes, respectively. These codes have been assessed against separate effects data and integral assessment data and have been determined to provide a best estimate calculation of fuel performance. Recent updates included in FRAPCON-3.4a include updated material properties models, models for new fuel and cladding types, cladding finite element analysis capability, and capability to perform uncertainty analyses and calculate upper tolerance limits for important outputs. Recent updates included in FRAPTRAN 1.4 include: material properties models that are consistent with FRAPCON-3.4a, cladding failure models that are applicable for loss-of coolant-accident and reactivity initiated accident modeling, and updated heat transfer models. This paper briefly describes these code updates and data assessments, highlighting the particularly important improvements and data assessments. This paper also discusses areas of improvements that will be addressed in upcoming code versions.

  8. A Coupling Methodology for Mesoscale-informed Nuclear Fuel Performance Codes

    SciTech Connect

    Michael Tonks; Derek Gaston; Cody Permann; Paul Millett; Glen Hansen; Dieter Wolf

    2010-10-01

    This study proposes an approach for capturing the effect of microstructural evolution on reactor fuel performance by coupling a mesoscale irradiated microstructure model with a finite element fuel performance code. To achieve this, the macroscale system is solved in a parallel, fully coupled, fully-implicit manner using the preconditioned Jacobian-free Newton Krylov (JFNK) method. Within the JFNK solution algorithm, microstructure-influenced material parameters are calculated by the mesoscale model and passed back to the macroscale calculation. Due to the stochastic nature of the mesoscale model, a dynamic fitting technique is implemented to smooth roughness in the calculated material parameters. The proposed methodology is demonstrated on a simple model of a reactor fuel pellet. In the model, INL’s BISON fuel performance code calculates the steady-state temperature profile in a fuel pellet and the microstructure-influenced thermal conductivity is determined with a phase field model of irradiated microstructures. This simple multiscale model demonstrates good nonlinear convergence and near ideal parallel scalability. By capturing the formation of large mesoscale voids in the pellet interior, the multiscale model predicted the irradiation-induced reduction in the thermal conductivity commonly observed in reactors.

  9. Performance evaluation of the R6R018 fuel plate using PLATE code

    SciTech Connect

    Pavel G. Medvedev; Hakan Ozaltun

    2010-03-01

    The paper presents results of performance evaluation of the R6R018 fuel plate using PLATE code. R6R018 is a U-7Mo dispersion type mini-plate with Al-3.5Si matrix irradiated in the RERTR-9B experiment. The design of this plate is prototypical of the planned LEONIDAS irradiation test. Therefore, a detailed performance analysis of this plate is important to confirm acceptable behavior in pile, and to provide baseline and justification for further analysis and testing. Specific results presented in the paper include fuel temperature history, growth of the interaction layer between the U-Mo and the matrix, swelling, growth of the corrosion layer, and degradation of thermal conductivity. The methodology of the analysis will be discussed including the newly developed capability to account for the formation of the interaction layer during fuel fabrication.

  10. Performance of the MTR core with MOX fuel using the MCNP4C2 code.

    PubMed

    Shaaban, Ismail; Albarhoum, Mohamad

    2016-08-01

    The MCNP4C2 code was used to simulate the MTR-22 MW research reactor and perform the neutronic analysis for a new fuel namely: a MOX (U3O8&PuO2) fuel dispersed in an Al matrix for One Neutronic Trap (ONT) and Three Neutronic Traps (TNTs) in its core. Its new characteristics were compared to its original characteristics based on the U3O8-Al fuel. Experimental data for the neutronic parameters including criticality relative to the MTR-22 MW reactor for the original U3O8-Al fuel at nominal power were used to validate the calculated values and were found acceptable. The achieved results seem to confirm that the use of MOX fuel in the MTR-22 MW will not degrade the safe operational conditions of the reactor. In addition, the use of MOX fuel in the MTR-22 MW core leads to reduce the uranium fuel enrichment with (235)U and the amount of loaded (235)U in the core by about 34.84% and 15.21% for the ONT and TNTs cases, respectively. PMID:27213809

  11. KUGEL: a thermal, hydraulic, fuel performance, and gaseous fission product release code for pebble bed reactor core analysis

    SciTech Connect

    Shamasundar, B.I.; Fehrenbach, M.E.

    1981-05-01

    The KUGEL computer code is designed to perform thermal/hydraulic analysis and coated-fuel particle performance calculations for axisymmetric pebble bed reactor (PBR) cores. This computer code was developed as part of a Department of Energy (DOE)-funded study designed to verify the published core performance data on PBRs. The KUGEL code is designed to interface directly with the 2DB code, a two-dimensional neutron diffusion code, to obtain distributions of thermal power, fission rate, fuel burnup, and fast neutron fluence, which are needed for thermal/hydraulic and fuel performance calculations. The code is variably dimensioned so that problem size can be easily varied. An interpolation routine allows variable mesh size to be used between the 2DB output and the two-dimensional thermal/hydraulic calculations.

  12. Roadmap to an Engineering-Scale Nuclear Fuel Performance & Safety Code

    SciTech Connect

    Turner, John A; Clarno, Kevin T; Hansen, Glen A

    2009-09-01

    -development activities. Realizing the full benefits of this approach will likely take some time. However, it is important that the developmental activities for modeling and simulation be tightly coupled with the experimental activities to maximize feedback effects and accelerate both the experimental and analytical elements of the program toward a common objective. The close integration of modeling and simulation and experimental activities is key to developing a useful fuel performance simulation capability, providing a validated design and analysis tool, and understanding the uncertainties within the models and design process. The efforts of this project are integrally connected to the Transmutation Fuels Campaign (TFC), which maintains as a primary objective to formulate, fabricate, and qualify a transuranic-based fuel with added minor actinides for use in future fast reactors. Additional details of the TFC scope can be found in the Transmutation Fuels Campaign Execution Plan. This project is an integral component of the TFC modeling and simulation effort, and this multiyear plan borrowed liberally from the Transmutation Fuels Campaign Modeling and Simulation Roadmap. This document provides the multiyear staged development plan to develop a continuum-level Integrated Performance and Safety Code (IPSC) to predict the behavior of the fuel and cladding during normal reactor operations and anticipated transients up to the point of clad breach.

  13. Assessment of PCMI Simulation Using the Multidimensional Multiphysics BISON Fuel Performance Code

    SciTech Connect

    Stephen R. Novascone; Jason D. Hales; Benjamin W. Spencer; Richard L. Williamson

    2012-09-01

    Since 2008, the Idaho National Laboratory (INL) has been developing a next-generation nuclear fuel performance code called BISON. BISON is built using INL’s Multiphysics Object-Oriented Simulation Environment, or MOOSE. MOOSE is a massively parallel, finite element-based framework to solve systems of coupled non-linear partial differential equations using the Jacobian-FreeNewton Krylov (JFNK) method. MOOSE supports the use of complex two- and three-dimensional meshes and uses implicit time integration, which is important for the widely varied time scales in nuclear fuel simulation. MOOSE’s object-oriented architecture minimizes the programming required to add new physics models. BISON has been applied to various nuclear fuel problems to assess the accuracy of its 2D and 3D capabilities. The benchmark results used in this assessment range from simulation results from other fuel performance codes to measurements from well-known and documented reactor experiments. An example of a well-documented experiment used in this assessment is the Third Risø Fission Gas Project, referred to as “Bump Test GE7”, which was performed on rod ZX115. This experiment was chosen because it allows for an evaluation of several aspects of the code, including fully coupled thermo-mechanics, contact, and several nonlinear material models. Bump Test GE7 consists of a base-irradiation period of a full-length rod in the Quad-Cities-1 BWR for nearly 7 years to a burnup of 4.17% FIMA. The base irradiation test is followed by a “bump test” of a sub-section of the original rod. The bump test takes place in the test reactor DR3 at Risø in a water-cooled HP1 rig under BWR conditions where the power level is increased by about 50% over base irradiation levels in the span of several hours. During base irradiation, the axial power profile is flat. During the bump test, the axial power profile changes so that the bottom half of the rod is at approximately 50% higher power than at the base

  14. Development and verification of NRC`s single-rod fuel performance codes FRAPCON-3 AND FRAPTRAN

    SciTech Connect

    Beyer, C.E.; Cunningham, M.E.; Lanning, D.D.

    1998-03-01

    The FRAPCON and FRAP-T code series, developed in the 1970s and early 1980s, are used by the US Nuclear Regulatory Commission (NRC) to predict fuel performance during steady-state and transient power conditions, respectively. Both code series are now being updated by Pacific Northwest National Laboratory to improve their predictive capabilities at high burnup levels. The newest versions of the codes are called FRAPCON-3 and FRAPTRAN. The updates to fuel property and behavior models are focusing on providing best estimate predictions under steady-state and fast transient power conditions up to extended fuel burnups (> 55 GWd/MTU). Both codes will be assessed against a data base independent of the data base used for code benchmarking and an estimate of code predictive uncertainties will be made based on comparisons to the benchmark and independent data bases.

  15. Assessing the Predictive Capability of the LIFEIV Nuclear Fuel Performance Code using Sequential Calibration

    SciTech Connect

    Stull, Christopher J.; Williams, Brian J.; Unal, Cetin

    2012-07-05

    This report considers the problem of calibrating a numerical model to data from an experimental campaign (or series of experimental tests). The issue is that when an experimental campaign is proposed, only the input parameters associated with each experiment are known (i.e. outputs are not known because the experiments have yet to be conducted). Faced with such a situation, it would be beneficial from the standpoint of resource management to carefully consider the sequence in which the experiments are conducted. In this way, the resources available for experimental tests may be allocated in a way that best 'informs' the calibration of the numerical model. To address this concern, the authors propose decomposing the input design space of the experimental campaign into its principal components. Subsequently, the utility (to be explained) of each experimental test to the principal components of the input design space is used to formulate the sequence in which the experimental tests will be used for model calibration purposes. The results reported herein build on those presented and discussed in [1,2] wherein Verification & Validation and Uncertainty Quantification (VU) capabilities were applied to the nuclear fuel performance code LIFEIV. In addition to the raw results from the sequential calibration studies derived from the above, a description of the data within the context of the Predictive Maturity Index (PMI) will also be provided. The PMI [3,4] is a metric initiated and developed at Los Alamos National Laboratory to quantitatively describe the ability of a numerical model to make predictions in the absence of experimental data, where it is noted that 'predictions in the absence of experimental data' is not synonymous with extrapolation. This simply reflects the fact that resources do not exist such that each and every execution of the numerical model can be compared against experimental data. If such resources existed, the justification for numerical models

  16. Power Histories for Fuel Codes

    SciTech Connect

    Gilbert, E. R.; Rausch, W. N.; Panisko, F. E.

    1982-01-01

    Computations of power history effects on the pre-loss-of-coolant accident (LOCA) conditions of generic pressurized water reactor (PWR) and boiling water reactor (BWR) fuel rods were performed at Pacific Northwest Laboratory using the U.S. Nuclear Regulatory Commission (NRC) code FRAPCON-2. Comparisons were made between cases where the fuel operated at a high ( 11 LOCA-limited") power throughout life (20,000 MWd/MTU) and those where the fuel was at a lower power for most of its burnup and ramped to the high power at 10,000 or 20,000 MWd/MTU burnup. The PWR rod was calculated to have more cladding creepdown during the lower power cases, which resulted in slightly lower centerline temperatures (as much as 100{degrees}C). This result was insensitive to the method used to increase the power during the ramps (i.e., by increasing the average rod power or by changing the peak-to-average (P/A} ratio of the axial power shape). The calculations also indicate that the highest fuel centerline temperatures were reached at startup. The BWR rod, however, demonstrated a substantial dependence on the power history. In this case, the constant high-power rod released considerably more fission gas than the lower power cases (21% versus 0.4%), which resulted in temperature differences of up to 350°C. The hiqhest temperature was reached at end-of-life (EOL) in the constant high-power case.

  17. HIDUTYDRV Code, A Fuel Product Margin Tool

    SciTech Connect

    Krammen, Michael A.; Karoutas, Zeses E.; Grill, Steven F.; Sutharshan, Balendra

    2007-07-01

    HIDUTYDRV is a computer code currently used in core design to model the best estimate steady-state fuel rod corrosion performance for Westinghouse's CE-design 14x14 and 16x16 fuel. The fuel rod oxide thickness, sub-cooled nucleate boiling (referred to as mass evaporation or steaming), and fuel duty indices can be predicted for individual rods or up to every fuel rod in the quarter core at every nuclear fuel management depletion time-step as a function of axial elevation within the core. Best estimate operating margins for fuel components whose performance depends on the local power and thermal hydraulic conditions are candidates for analysis with HIDUTYDRV. HIDUTYDRV development will focus on fuel component parameters associated with known leakers for addressing INPO goals to eliminate fuel leakers by 2010. (authors)

  18. Numerical Prediction of the Performance of Integrated Planar Solid-Oxide Fuel Cells, with Comparisons of Results from Several Codes

    SciTech Connect

    G. L. Hawkes; J. E. O'Brien; B. A. Haberman; A. J. Marquis; C. M. Baca; D. Tripepi; P. Costamagna

    2008-06-01

    A numerical study of the thermal and electrochemical performance of a single-tube Integrated Planar Solid Oxide Fuel Cell (IP-SOFC) has been performed. Results obtained from two finite-volume computational fluid dynamics (CFD) codes FLUENT and SOHAB and from a two-dimensional inhouse developed finite-volume GENOA model are presented and compared. Each tool uses physical and geometric models of differing complexity and comparisons are made to assess their relative merits. Several single-tube simulations were run using each code over a range of operating conditions. The results include polarization curves, distributions of local current density, composition and temperature. Comparisons of these results are discussed, along with their relationship to the respective imbedded phenomenological models for activation losses, fluid flow and mass transport in porous media. In general, agreement between the codes was within 15% for overall parameters such as operating voltage and maximum temperature. The CFD results clearly show the effects of internal structure on the distributions of gas flows and related quantities within the electrochemical cells.

  19. Inter-comparison of Computer Codes for TRISO-based Fuel Micro-Modeling and Performance Assessment

    SciTech Connect

    Brian Boer; Chang Keun Jo; Wen Wu; Abderrafi M. Ougouag; Donald McEachren; Francesco Venneri

    2010-10-01

    The Next Generation Nuclear Plant (NGNP), the Deep Burn Pebble Bed Reactor (DB-PBR) and the Deep Burn Prismatic Block Reactor (DB-PMR) are all based on fuels that use TRISO particles as their fundamental constituent. The TRISO particle properties include very high durability in radiation environments, hence the designs reliance on the TRISO to form the principal barrier to radioactive materials release. This durability forms the basis for the selection of this fuel type for applications such as Deep Bun (DB), which require exposures up to four times those expected for light water reactors. It follows that the study and prediction of the durability of TRISO particles must be carried as part of the safety and overall performance characterization of all the designs mentioned above. Such evaluations have been carried out independently by the performers of the DB project using independently developed codes. These codes, PASTA, PISA and COPA, incorporate models for stress analysis on the various layers of the TRISO particle (and of the intervening matrix material for some of them), model for fission products release and migration then accumulation within the SiC layer of the TRISO particle, just next to the layer, models for free oxygen and CO formation and migration to the same location, models for temperature field modeling within the various layers of the TRISO particle and models for the prediction of failure rates. All these models may be either internal to the code or external. This large number of models and the possibility of different constitutive data and model formulations and the possibility of a variety of solution techniques makes it highly unlikely that the model would give identical results in the modeling of identical situations. The purpose of this paper is to present the results of an inter-comparison between the codes and to identify areas of agreement and areas that need reconciliation. The inter-comparison has been carried out by the cooperating

  20. Multispecies Diffusion Capability For The AMP Nuclear Fuel Performance Code (LANL Milestone M31MS060301 Final Report)

    SciTech Connect

    Dilts, Gary A.

    2012-03-29

    This work addresses only diffusion. The contact solver in AMP was not sufficiently developed this year to attempt treatment of species contact. A cylindrical tensor diffusion coefficient model was added to the AMP code, with the KHHS model [1] implemented into the AMP material library as a specific example. A cylindrical tensor diffusion operator manufactured solution verification example was coded. Before meeting the full text of the milestone task, it remains to: (1) code and run a cylindrical tensor diffusion solver manufactured solution (2) code and run the validation example of [1] (3) document results. These are dependent on developing new capabilities for the AMP code requiring close collaboration with the AMP team at ORNL. The model implemented provides a good intermediate first step toward a general multi-species solver. The multi-species capability of the AMP nuclear fuel code [2] is intended to allow the modeling of radiation-driven redistribution of various elements through solid metal nuclear reactor fuels. The initial model AMP provides for U-Pu-Zr fuels is based on the analysis of the Integral Fast Reactor (IFR) fuel development program experiment X419 post-irradiation data described in [1], referred to here as the KHHS model. This model may be specific to that experiment, but it was thought to provide a good start for the AMP code, because it (1) is formulated at the engineering scale, (2) decouples the species from each other, (3) predetermines the phase boundaries so that reference to a phase diagram is not needed, and (4) one of the authors (Hayes) was the NEAMS Fuels IPSC manager for FY11. The KHHS model is formulated for radial fluxes as little axial redistribution is seen experimentally. As U-Pu-Zr fuel is irradiated, the constituents migrate to form three annular regions. The center region is Zr-enriched and U-depleted, the middle region is Zr-depleted and U-enriched, and the outer region is Zr-enriched and U-depleted. The Pu concentration

  1. Spent fuel pool analysis using TRACE code

    SciTech Connect

    Sanchez-Saez, F.; Carlos, S.; Villanueva, J. F.; Martorell, S.

    2012-07-01

    The storage requirements of Spent Fuel Pools have been analyzed with the purpose to increase their rack capacities. In the past, the thermal limits have been mainly evaluated with conservative codes developed for this purpose, although some works can be found in which a best estimate code is used. The use of best estimate codes is interesting as they provide more realistic calculations and they have the capability of analyzing a wide range of transients that could affect the Spent Fuel Pool. Two of the most representative thermal-hydraulic codes are RELAP-5 and TRAC. Nowadays, TRACE code is being developed to make use of the more favorable characteristics of RELAP-5 and TRAC codes. Among the components coded in TRACE that can be used to construct the model, it is interesting to use the VESSEL component, which has the capacity of reproducing three dimensional phenomena. In this work, a thermal-hydraulic model of the Maine Yankee spent fuel pool using the TRACE code is developed. Such model has been used to perform a licensing calculation and the results obtained have been compared with experimental measurements made at the pool, showing a good agreement between the calculations predicted by TRACE and the experimental data. (authors)

  2. Code System for Spent Fuel Heating Analysis.

    Energy Science and Technology Software Center (ESTSC)

    1999-05-24

    Version 00 SFHA calculates steady-state fuel rod temperatures for hexagon and square-fuel bundles. The code is used to perform sensitivity studies and confirmatory analyses of results submitted by applicants for spent fuel storage licenses. All three modes of heat transfer are considered; radiation, convection, and conduction. Each is modeled separately. SFHA benchmark calculations were made with test data to validate the use of a simple one-dimensional heat transfer model for estimating fuel rod temperatures. Benchmarkmore » results show that SFHA is capable of calculating spent fuel rod temperatures for square and hexagonal fuel bundles under various environments for the consolidated or unconsolidated condition. The program is menu-driven and executes automatically after all required information is entered.« less

  3. IMP: A performance code

    NASA Astrophysics Data System (ADS)

    Dauro, Vincent A., Sr.

    IMP (Integrated Mission Program) is a simulation language and code used to model present and future Earth, Moon, or Mars missions. The profile is user controlled through selection from a large menu of events and maneuvers. A Fehlberg 7/13 Runge-Kutta integrator with error and step size control is used to numerically integrate the differential equations of motion (DEQ) of three spacecraft, a main, a target, and an observer. Through selection, the DEQ's include guided thrust, oblate gravity, atmosphere drag, solar pressure, and Moon gravity effects. Guide parameters for thrust events and performance parameters of velocity changes (Delta-V) and propellant usage (maximum of five systems) are developed as needed. Print, plot, summary, and debug files are output.

  4. HTGR Fuel performance basis

    SciTech Connect

    Shamasundar, B.I.; Stansfield, O.M.; Jensen, D.D.

    1982-05-01

    The safety characteristics of the high-temperature gas-cooled reactor (HTGR) during normal and accident conditions are determined in part by HTGR fuel performance. During normal operation, less than 0.1% fuel failure occurs, primarily from defective particles. This low fuel failure fraction limits circulating activity to acceptable levels. During severe accidents, the radiological consequence is influenced by high-temperature fuel particle behavior. An empirical fuel failure model, supported by recent experimental data, is presented. The onset of significant fuel particle failure occurs at temperatures in excess of 1600/sup 0/C, and complete fuel failure occurs at 2660/sup 0/C. This indicates that the fuel is more retentive at higher temperatures than previously assumed. The more retentive nature of the fuel coupled with the high thermal capacitance of the core results in slow release of fission products from the core during severe accidents.

  5. Model of U3Si2 Fuel System using BISON Fuel Code

    SciTech Connect

    K. E. Metzger; T. W. Knight; R. L. Williamson

    2014-04-01

    This research considers the proposed advanced fuel system: U3Si2 combined with an advanced cladding. U3Si2 has a number of advantageous thermophysical properties, which motivate its use as an accident tolerant fuel. This preliminary model evaluates the behavior of U3Si2 using available thermophysical data to predict the cladding-fuel pellet temperature and stress using the fuel performance code: BISON. The preliminary results obtained from the U3Si2 fuel model describe the mechanism of Pellet-Clad Mechanical Interaction for this system while more extensive testing including creep testing of U3Si2 is planned for improved understanding of thermophysical properties for predicting fuel performance.

  6. Inlet Performance Analysis Code Developed

    NASA Technical Reports Server (NTRS)

    Jules, Kenol; Barnhart, Paul J.

    1998-01-01

    The design characteristics of an inlet very much depend on whether the inlet is to be flown at subsonic, supersonic, or hypersonic speed. Whichever the case, the primary function of an inlet is to deliver free-stream air to the engine face at the highest stagnation pressure possible and with the lowest possible variation in both stagnation pressure and temperature. At high speeds, this is achieved by a system of oblique and/or normal shock waves, and possibly some isentropic compression. For both subsonic and supersonic flight, current design practice indicates that the inlet should deliver the air to the engine face at approximately Mach 0.45. As a result, even for flight in the high subsonic regime, the inlet must retard (or diffuse) the air substantially. Second, the design of an inlet is influenced largely by the compromise between high performance and low weight. This compromise involves tradeoffs between the mission requirements, flight trajectory, airframe aerodynamics, engine performance, and weight-all of which, in turn, influence each other. Therefore, to study the effects of some of these influential factors, the Propulsion System Analysis Office of the NASA Lewis Research Center developed the Inlet Performance Analysis Code (IPAC). This code uses oblique shock and Prandtl-Meyer expansion theory to predict inlet performance. It can be used to predict performance for a given inlet geometric design such as pitot, axisymmetric, and two-dimensional. IPAC also can be used to design preliminary inlet systems and to make subsequent performance analyses. It computes the total pressure, the recovery, the airflow, and the drag coefficients. The pressure recovery includes losses associated with normal and oblique shocks, internal and external friction, the sharp lip, and diffuser components. Flow rate includes captured, engine, spillage, bleed, and bypass flows. The aerodynamic drag calculation includes drags associated with spillage, cowl lip suction, wave, bleed

  7. Handbook of fuel cell performance

    SciTech Connect

    Benjamin, T.G.; Camara, E.H.; Marianowski, L.G.

    1980-05-01

    The intent of this document is to provide a description of fuel cells, their performances and operating conditions, and the relationship between fuel processors and fuel cells. This information will enable fuel cell engineers to know which fuel processing schemes are most compatible with which fuel cells and to predict the performance of a fuel cell integrated with any fuel processor. The data and estimates presented are for the phosphoric acid and molten carbonate fuel cells because they are closer to commercialization than other types of fuel cells. Performance of the cells is shown as a function of operating temperature, pressure, fuel conversion (utilization), and oxidant utilization. The effect of oxidant composition (for example, air versus O/sub 2/) as well as fuel composition is examined because fuels provided by some of the more advanced fuel processing schemes such as coal conversion will contain varying amounts of H/sub 2/, CO, CO/sub 2/, CH/sub 4/, H/sub 2/O, and sulfur and nitrogen compounds. A brief description of fuel cells and their application to industrial, commercial, and residential power generation is given. The electrochemical aspects of fuel cells are reviewed. The phosphoric acid fuel cell is discussed, including how it is affected by operating conditions; and the molten carbonate fuel cell is discussed. The equations developed will help systems engineers to evaluate the application of the phosphoric acid and molten carbonate fuel cells to commercial, utility, and industrial power generation and waste heat utilization. A detailed discussion of fuel cell efficiency, and examples of fuel cell systems are given.

  8. Solid-oxide fuel-cell performance

    SciTech Connect

    Fee, D.C.; Zwick, S.A.; Ackerman, J.P.

    1983-01-01

    Two models have been developed to describe the performance of solid-oxide fuel cells: (1) a cell model which calculates cell performance for various conditions of temperature, current density, and gas composition; and (2) a systems model which performs detailed heat and mass balances around each component in a power plant. The cell model provides insight into the performance tradeoffs in cell design. Further, the cell model provides the basis for predicting fuel cell performance in a power plant environment as necessary for the systems code. Using these two tools, analysis of an atmospheric pressure, natural gas fueled, internally reforming power plant confirms the simplicity and increased efficiency of a solid oxide fuel cell system compared to existing plants.

  9. Identification and Analysis of Critical Gaps in Nuclear Fuel Cycle Codes Required by the SINEMA Program

    SciTech Connect

    Adrian Miron; Joshua Valentine; John Christenson; Majd Hawwari; Santosh Bhatt; Mary Lou Dunzik-Gougar: Michael Lineberry

    2009-10-01

    The current state of the art in nuclear fuel cycle (NFC) modeling is an eclectic mixture of codes with various levels of applicability, flexibility, and availability. In support of the advanced fuel cycle systems analyses, especially those by the Advanced Fuel Cycle Initiative (AFCI), Unviery of Cincinnati in collaboration with Idaho State University carried out a detailed review of the existing codes describing various aspects of the nuclear fuel cycle and identified the research and development needs required for a comprehensive model of the global nuclear energy infrastructure and the associated nuclear fuel cycles. Relevant information obtained on the NFC codes was compiled into a relational database that allows easy access to various codes' properties. Additionally, the research analyzed the gaps in the NFC computer codes with respect to their potential integration into programs that perform comprehensive NFC analysis.

  10. Performance limit analysis of a metallic fuel for Kalimer

    SciTech Connect

    Lee, Byoung Oon; Cheon, J.S.; Lee, C.B.

    2007-07-01

    A metallic fuel is being considered as the fuel for SFR in Korea. The metal fuel development for SFR in Korea started in 2007 in the areas of metal fuel fabrication, cladding materials and fuel performance evaluation. The MACSIS code for a metallic fuel has been developed as a steady-state performance computer code. Present study represents the preliminary parametric results for evaluating the design limits of the metal fuel for SFR in Korea. The operating limits were analyzed by the MACSIS code. The modules of the creep rupture strength for the Mod.HT9 and the barrier cladding were inserted. The strain limits and the CDF limit were analyzed for the HT9, and the Mod.HT9. To apply the concept of a barrier cladding, the burnup limit of the barrier cladding was analyzed. (authors)

  11. Evaluation and validation of criticality codes for fuel dissolver calculations

    SciTech Connect

    Santamarina, A.; Smith, H.J. ); Whitesides, G.E. )

    1991-01-01

    During the past ten years an OECD/NEA Criticality Working Group has examined the validity of criticality safety computational methods. International calculation tools which were shown to be valid in systems for which experimental data existed were demonstrated to be inadequate when extrapolated to fuel dissolver media. The spread of the results in the international calculation amounted to {plus minus} 12,000 pcm in the realistic fuel dissolver exercise n{degrees} 19 proposed by BNFL, and to {plus minus} 25,000 pcm in the benchmark n{degrees} 20 in which fissile material in solid form is surrounded by fissile material in solution. A theoretical study of the main physical parameters involved in fuel dissolution calculations was performed, i.e. range of moderation, variation of pellet size and the fuel double heterogeneity effect. The APOLLO/P{sub IC} method developed to treat latter effect, permits us to supply the actual reactivity variation with pellet dissolution and to propose international reference values. The disagreement among contributors' calculations was analyzed through a neutron balance breakdown, based on three-group microscopic reaction rates solicited from the participants. The results pointed out that fast and resonance nuclear data in criticality codes are not sufficiently reliable. Moreover the neutron balance analysis emphasized the inadequacy of the standard self-shielding formalism (NITAWL in the international SCALE package) to account for {sup 238}U resonance mutual self-shielding in the pellet-fissile liquor interaction. Improvements in the up-dated 1990 contributions, as do recent complementary reference calculations (MCNP, VIM, ultrafine slowing-down CGM calculation), confirm the need to use rigorous self-shielding methods in criticality design-oriented codes. 6 refs., 11 figs., 3 tabs.

  12. National Combustion Code Parallel Performance Enhancements

    NASA Technical Reports Server (NTRS)

    Quealy, Angela; Benyo, Theresa (Technical Monitor)

    2002-01-01

    The National Combustion Code (NCC) is being developed by an industry-government team for the design and analysis of combustion systems. The unstructured grid, reacting flow code uses a distributed memory, message passing model for its parallel implementation. The focus of the present effort has been to improve the performance of the NCC code to meet combustor designer requirements for model accuracy and analysis turnaround time. Improving the performance of this code contributes significantly to the overall reduction in time and cost of the combustor design cycle. This report describes recent parallel processing modifications to NCC that have improved the parallel scalability of the code, enabling a two hour turnaround for a 1.3 million element fully reacting combustion simulation on an SGI Origin 2000.

  13. Performance of code division multiple access systems

    NASA Technical Reports Server (NTRS)

    Weber, C. L.; Huth, G. K.; Batson, B. H.

    1980-01-01

    The performance of code division multiple-access (CDMA) systems is determined using direct sequence spectral spreading. Under relatively ideal conditions, the degradation in system performance as a function of the number of users is shown to have a threshold effect. This basic limitation in the number of users of the system is further limited if the powers are unequal. For two users, system performance as a function of their power ratio also has a threshold effect. System performance as a function of the amount of spectral spreading is determined. The performance of both coded and uncoded systems is predicted.

  14. A GUIDE TO FUEL PERFORMANCE

    SciTech Connect

    LITZKE,W.

    2004-08-01

    Heating oil, as its name implies, is intended for end use heating consumption as its primary application. But its identity in reference name and actual chemical properties may vary based on a number of factors. By name, heating oil is sometimes referred to as gas oil, diesel, No. 2 distillate (middle distillate), or light heating oil. Kerosene, also used as a burner fuel, is a No. 1 distillate. Due to the higher heat content and competitive price in most markets, No. 2 heating oil is primarily used in modern, pressure-atomized burners. Using No. 1 oil for heating has the advantages of better cold-flow properties, lower emissions, and better storage properties. Because it is not nearly as abundant in supply, it is often markedly more expensive than No. 2 heating oil. Given the advanced, low-firing rate burners in use today, the objective is for the fuel to be compatible and achieve combustion performance at the highest achievable efficiency of the heating systems--with minimal service requirements. Among the Oil heat industry's top priorities are improving reliability and reducing service costs associated with fuel performance. Poor fuel quality, fuel degradation, and contamination can cause burner shut-downs resulting in ''no-heat'' calls. Many of these unscheduled service calls are preventable with routine inspection of the fuel and the tank. This manual focuses on No. 2 heating oil--its performance, properties, sampling and testing. Its purpose is to provide the marketer, service manager and technician with the proper guidelines for inspecting the product, maintaining good fuel quality, and the best practices for proper storage. Up-to-date information is also provided on commercially available fuel additives, their appropriate use and limitations.

  15. National Combustion Code: Parallel Implementation and Performance

    NASA Technical Reports Server (NTRS)

    Quealy, A.; Ryder, R.; Norris, A.; Liu, N.-S.

    2000-01-01

    The National Combustion Code (NCC) is being developed by an industry-government team for the design and analysis of combustion systems. CORSAIR-CCD is the current baseline reacting flow solver for NCC. This is a parallel, unstructured grid code which uses a distributed memory, message passing model for its parallel implementation. The focus of the present effort has been to improve the performance of the NCC flow solver to meet combustor designer requirements for model accuracy and analysis turnaround time. Improving the performance of this code contributes significantly to the overall reduction in time and cost of the combustor design cycle. This paper describes the parallel implementation of the NCC flow solver and summarizes its current parallel performance on an SGI Origin 2000. Earlier parallel performance results on an IBM SP-2 are also included. The performance improvements which have enabled a turnaround of less than 15 hours for a 1.3 million element fully reacting combustion simulation are described.

  16. Performance Bounds on Two Concatenated, Interleaved Codes

    NASA Technical Reports Server (NTRS)

    Moision, Bruce; Dolinar, Samuel

    2010-01-01

    A method has been developed of computing bounds on the performance of a code comprised of two linear binary codes generated by two encoders serially concatenated through an interleaver. Originally intended for use in evaluating the performances of some codes proposed for deep-space communication links, the method can also be used in evaluating the performances of short-block-length codes in other applications. The method applies, more specifically, to a communication system in which following processes take place: At the transmitter, the original binary information that one seeks to transmit is first processed by an encoder into an outer code (Co) characterized by, among other things, a pair of numbers (n,k), where n (n > k)is the total number of code bits associated with k information bits and n k bits are used for correcting or at least detecting errors. Next, the outer code is processed through either a block or a convolutional interleaver. In the block interleaver, the words of the outer code are processed in blocks of I words. In the convolutional interleaver, the interleaving operation is performed bit-wise in N rows with delays that are multiples of B bits. The output of the interleaver is processed through a second encoder to obtain an inner code (Ci) characterized by (ni,ki). The output of the inner code is transmitted over an additive-white-Gaussian- noise channel characterized by a symbol signal-to-noise ratio (SNR) Es/No and a bit SNR Eb/No. At the receiver, an inner decoder generates estimates of bits. Depending on whether a block or a convolutional interleaver is used at the transmitter, the sequence of estimated bits is processed through a block or a convolutional de-interleaver, respectively, to obtain estimates of code words. Then the estimates of the code words are processed through an outer decoder, which generates estimates of the original information along with flags indicating which estimates are presumed to be correct and which are found to

  17. Alkaline fuel cell performance investigation

    NASA Technical Reports Server (NTRS)

    Martin, R. E.; Manzo, M. A.

    1988-01-01

    An exploratory experimental fuel cell test program was conducted to investigate the performance characteristics of alkaline laboratory research electrodes. The objective of this work was to establish the effect of temperature, pressure, and concentration upon performance and evaluate candidate cathode configurations having the potential for improved performance. The performance characterization tests provided data to empirically establish the effect of temperature, pressure, and concentration upon performance for cell temperatures up to 300 F and reactant pressures up to 200 psia. Evaluation of five gold alloy cathode catalysts revealed that three doped gold alloys had more than two times the surface areas of reference cathodes and therefore offered the best potential for improved performance.

  18. Alkaline fuel cell performance investigation

    NASA Technical Reports Server (NTRS)

    Martin, R. E.; Manzo, M. A.

    1988-01-01

    An exploratory experimental fuel cell test program was conducted to investigate the performance characteristics of alkaline laboratory research electrodes. The objective of this work was to establish the effect of temperature, pressure, and concentration upon performance and evaluate candidate cathode configurations having the potential for improved performance. The performance characterization tests provided data to empirically establish the effect of temperature, pressure, and concentration upon performance for cell temperatures up to 300 F and reactant pressures up to 200 psia. Evaluation of five gold alloy cathode catalysts revealed that three doped gold alloys had more that two times the surface areas of reference cathodes and therefore offered the best potential for improved performance.

  19. The NMC code: conduct, performance and ethics.

    PubMed

    Goldsmith, Jan

    The Code: Standards of Conduct, Performance and Ethics for Nurses and Midwives is a set of key principles that should underpin the practice of all nurses and midwives, and remind them of their professional responsibilities. It is not just a tool used in fitness-to-practise cases--it should be used to guide daily practice for all nurses and midwives. Alongside other standards, guidance and advice from the NMC, the code should be used to support professional development. PMID:22010552

  20. Enhancing the ABAQUS thermomechanics code to simulate multipellet steady and transient LWR fuel rod behavior

    NASA Astrophysics Data System (ADS)

    Williamson, R. L.

    2011-08-01

    A powerful multidimensional fuels performance analysis capability, applicable to both steady and transient fuel behavior, is developed based on enhancements to the commercially available ABAQUS general-purpose thermomechanics code. Enhanced capabilities are described, including: UO 2 temperature and burnup dependent thermal properties, solid and gaseous fission product swelling, fuel densification, fission gas release, cladding thermal and irradiation creep, cladding irradiation growth, gap heat transfer, and gap/plenum gas behavior during irradiation. This new capability is demonstrated using a 2D axisymmetric analysis of the upper section of a simplified multipellet fuel rod, during both steady and transient operation. Comparisons are made between discrete and smeared-pellet simulations. Computational results demonstrate the importance of a multidimensional, multipellet, fully-coupled thermomechanical approach. Interestingly, many of the inherent deficiencies in existing fuel performance codes (e.g., 1D thermomechanics, loose thermomechanical coupling, separate steady and transient analysis, cumbersome pre- and post-processing) are, in fact, ABAQUS strengths.

  1. Enhancing the ABAQUS Thermomechanics Code to Simulate Steady and Transient Fuel Rod Behavior

    SciTech Connect

    R. L. Williamson; D. A. Knoll

    2009-09-01

    A powerful multidimensional fuels performance capability, applicable to both steady and transient fuel behavior, is developed based on enhancements to the commercially available ABAQUS general-purpose thermomechanics code. Enhanced capabilities are described, including: UO2 temperature and burnup dependent thermal properties, solid and gaseous fission product swelling, fuel densification, fission gas release, cladding thermal and irradiation creep, cladding irradiation growth , gap heat transfer, and gap/plenum gas behavior during irradiation. The various modeling capabilities are demonstrated using a 2D axisymmetric analysis of the upper section of a simplified multi-pellet fuel rod, during both steady and transient operation. Computational results demonstrate the importance of a multidimensional fully-coupled thermomechanics treatment. Interestingly, many of the inherent deficiencies in existing fuel performance codes (e.g., 1D thermomechanics, loose thermo-mechanical coupling, separate steady and transient analysis, cumbersome pre- and post-processing) are, in fact, ABAQUS strengths.

  2. Performance of focused error control codes

    NASA Astrophysics Data System (ADS)

    Alajaji, Fady; Fuja, Thomas

    1994-02-01

    Consider an additive noise channel with inputs and outputs in the field GF(q) where qgreater than 2; every time a symbol is transmitted over such a channel, there are q - 1 different errors that can occur, corresponding to the q - 1 non-zero elements that the channel can add to the transmitted symbol. In many data communication/storage systems, there are some errors that occur much more frequently than others; however, traditional error correcting codes - designed with respect to the Hamming metric - treat each of these q - 1 errors the same. Fuja and Heegard have designed a class of codes, called focused error control codes, that offer different levels of protection against common and uncommon errors; the idea is to define the level of protection in a way based not only on the number of errors, but the kind as well. In this paper, the performance of these codes is analyzed with respect to idealized 'skewed' channels as well as realistic non-binary modulation schemes. It is shown that focused codes, used in conjunction with PSK and QAM signaling, can provide more than 1.0 dB of additional coding gain when compared with Reed-Solomon codes for small blocklengths.

  3. CESAR: A Code for Nuclear Fuel and Waste Characterisation

    SciTech Connect

    Vidal, J.M.; Grouiller, J.P.; Launay, A.; Berthion, Y.; Marc, A.; Toubon, H.

    2006-07-01

    CESAR (Simplified Evolution Code Applied to Reprocessing) is a depletion code developed through a joint program between CEA and COGEMA. In the late 1980's, the first use of this code dealt with nuclear measurement at the Laboratories of the La Hague reprocessing plant. The use of CESAR was then extended to characterizations of all entrance materials and for characterisation, via tracer, of all produced waste. The code can distinguish more than 100 heavy nuclides, 200 fission products and 100 activation products, and it can characterise both the fuel and the structural material of the fuel. CESAR can also make depletion calculations from 3 months to 1 million years of cooling time. Between 2003-2005, the 5. version of the code was developed. The modifications were related to the harmonisation of the code's nuclear data with the JEF2.2 nuclear data file. This paper describes the code and explains the extensive use of this code at the La Hague reprocessing plant and also for prospective studies. The second part focuses on the modifications of the latest version, and describes the application field and the qualification of the code. Many companies and the IAEA use CESAR today. CESAR offers a Graphical User Interface, which is very user-friendly. (authors)

  4. New high burnup fuel models for NRC`s licensing audit code, FRAPCON

    SciTech Connect

    Lanning, D.D.; Beyer, C.E.; Painter, C.L.

    1996-03-01

    Fuel behavior models have recently been updated within the U.S. Nuclear Regulatory Commission steady-state FRAPCON code used for auditing of fuel vendor/utility-codes and analyses. These modeling updates have concentrated on providing a best estimate prediction of steady-state fuel behavior up to the maximum burnup level s of current data (60 to 65 GWd/MTU rod-average). A decade has passed since these models were last updated. Currently, some U.S. utilities and fuel vendors are requesting approval for rod-average burnups greater than 60 GWd/MTU; however, until these recent updates the NRC did not have valid fuel performance models at these higher burnup levels. Pacific Northwest Laboratory (PNL) has reviewed 15 separate effects models within the FRAPCON fuel performance code (References 1 and 2) and identified nine models that needed updating for improved prediction of fuel behavior at high burnup levels. The six separate effects models not updated were the cladding thermal properties, cladding thermal expansion, cladding creepdown, fuel specific heat, fuel thermal expansion and open gap conductance. Comparison of these models to the currently available data indicates that these models still adequately predict the data within data uncertainties. The nine models identified as needing improvement for predicting high-burnup behavior are fission gas release (FGR), fuel thermal conductivity (accounting for both high burnup effects and burnable poison additions), fuel swelling, fuel relocation, radial power distribution, fuel-cladding contact gap conductance, cladding corrosion, cladding mechanical properties and cladding axial growth. Each of the updated models will be described in the following sections and the model predictions will be compared to currently available high burnup data.

  5. Automotive Gas Turbine Power System-Performance Analysis Code

    NASA Technical Reports Server (NTRS)

    Juhasz, Albert J.

    1997-01-01

    An open cycle gas turbine numerical modelling code suitable for thermodynamic performance analysis (i.e. thermal efficiency, specific fuel consumption, cycle state points, working fluid flowrates etc.) of automotive and aircraft powerplant applications has been generated at the NASA Lewis Research Center's Power Technology Division. The use this code can be made available to automotive gas turbine preliminary design efforts, either in its present version, or, assuming that resources can be obtained to incorporate empirical models for component weight and packaging volume, in later version that includes the weight-volume estimator feature. The paper contains a brief discussion of the capabilities of the presently operational version of the code, including a listing of input and output parameters and actual sample output listings.

  6. Fuel Performance Annual Report for 1979

    SciTech Connect

    Tokar, M.; Mailey, W. J.; Cunningham, M. E.

    1981-01-01

    This annual report, the second in a series, provides a brief description of fuel performance in commercial nuclear power plants. Brief summaries are given of fuel surveillance programs, fuel performance problems, and fuel design changes. References to additional, more detailed, information and related NRC evaluation are provided.

  7. Reactor Fuel Isotopics and Code Validation for Nuclear Applications

    SciTech Connect

    Francis, Matthew W.; Weber, Charles F.; Pigni, Marco T.; Gauld, Ian C.

    2015-02-01

    Experimentally measured isotopic concentrations of well characterized spent nuclear fuel (SNF) samples have been collected and analyzed by previous researchers. These sets of experimental data have been used extensively to validate the accuracy of depletion code predictions for given sets of burnups, initial enrichments, and varying power histories for different reactor types. The purpose of this report is to present the diversity of data in a concise manner and summarize the current accuracy of depletion modeling. All calculations performed for this report were done using the Oak Ridge Isotope GENeration (ORIGEN) code, an internationally used irradiation and decay code solver within the SCALE comprehensive modeling and simulation code. The diversity of data given in this report includes key actinides, stable fission products, and radioactive fission products. In general, when using the current ENDF/B-VII.0 nuclear data libraries in SCALE, the major actinides are predicted to within 5% of the measured values. Large improvements were seen for several of the curium isotopes when using improved cross section data found in evaluated nuclear data file ENDF/B-VII.0 as compared to ENDF/B-V-based results. The impact of the flux spectrum on the plutonium isotope concentrations as a function of burnup was also shown. The general accuracy noted for the actinide samples for reactor types with burnups greater than 5,000 MWd/MTU was not observed for the low-burnup Hanford B samples. More work is needed in understanding these large discrepancies. The stable neodymium and samarium isotopes were predicted to within a few percent of the measured values. Large improvements were seen in prediction for a few of the samarium isotopes when using the ENDF/B-VII.0 libraries compared to results obtained with ENDF/B-V libraries. Very accurate predictions were obtained for 133Cs and 153Eu. However, the predicted values for the stable ruthenium and rhodium isotopes varied

  8. BISON and MARMOT Development for Modeling Fast Reactor Fuel Performance

    SciTech Connect

    Gamble, Kyle Allan Lawrence; Williamson, Richard L.; Schwen, Daniel; Zhang, Yongfeng; Novascone, Stephen Rhead; Medvedev, Pavel G.

    2015-09-01

    BISON and MARMOT are two codes under development at the Idaho National Laboratory for engineering scale and lower length scale fuel performance modeling. It is desired to add capabilities for fast reactor applications to these codes. The fast reactor fuel types under consideration are metal (U-Pu-Zr) and oxide (MOX). The cladding types of interest include 316SS, D9, and HT9. The purpose of this report is to outline the proposed plans for code development and provide an overview of the models added to the BISON and MARMOT codes for fast reactor fuel behavior. A brief overview of preliminary discussions on the formation of a bilateral agreement between the Idaho National Laboratory and the National Nuclear Laboratory in the United Kingdom is presented.

  9. Code System for Reactor Physics and Fuel Cycle Simulation.

    Energy Science and Technology Software Center (ESTSC)

    1999-04-21

    Version 00 VSOP94 (Very Superior Old Programs) is a system of codes linked together for the simulation of reactor life histories. It comprises neutron cross section libraries and processing routines, repeated neutron spectrum evaluation, 2-D diffusion calculation based on neutron flux synthesis with depletion and shut-down features, in-core and out-of-pile fuel management, fuel cycle cost analysis, and thermal hydraulics (at present restricted to Pebble Bed HTRs). Various techniques have been employed to accelerate the iterativemore » processes and to optimize the internal data transfer. The code system has been used extensively for comparison studies of reactors, their fuel cycles, and related detailed features. In addition to its use in research and development work for the High Temperature Reactor, the system has been applied successfully to Light Water and Heavy Water Reactors.« less

  10. Code System for Reactor Physics and Fuel Cycle Simulation.

    SciTech Connect

    TEUCHERT, E.

    1999-04-21

    Version 00 VSOP94 (Very Superior Old Programs) is a system of codes linked together for the simulation of reactor life histories. It comprises neutron cross section libraries and processing routines, repeated neutron spectrum evaluation, 2-D diffusion calculation based on neutron flux synthesis with depletion and shut-down features, in-core and out-of-pile fuel management, fuel cycle cost analysis, and thermal hydraulics (at present restricted to Pebble Bed HTRs). Various techniques have been employed to accelerate the iterative processes and to optimize the internal data transfer. The code system has been used extensively for comparison studies of reactors, their fuel cycles, and related detailed features. In addition to its use in research and development work for the High Temperature Reactor, the system has been applied successfully to Light Water and Heavy Water Reactors.

  11. Synthetic fuels handbook: properties, process and performance

    SciTech Connect

    Speight, J.

    2008-07-01

    The handbook is a comprehensive guide to the benefits and trade-offs of numerous alternative fuels, presenting expert analyses of the different properties, processes, and performance characteristics of each fuel. It discusses the concept systems and technology involved in the production of fuels on both industrial and individual scales. Chapters 5 and 7 are of special interest to the coal industry. Contents: Chapter 1. Fuel Sources - Conventional and Non-conventional; Chapter 2. Natural Gas; Chapter 3. Fuels From Petroleum and Heavy Oil; Chapter 4. Fuels From Tar Sand Bitumen; Chapter 5. Fuels From Coal; Chapter 6. Fuels From Oil Shale; Chapter 7. Fuels From Synthesis Gas; Chapter 8. Fuels From Biomass; Chapter 9. Fuels From Crops; Chapter 10. Fuels From Wood; Chapter 11. Fuels From Domestic and Industrial Waste; Chapter 12. Landfill Gas. 3 apps.

  12. Fuel performance: Annual report for 1987

    SciTech Connect

    Bailey, W.J.; Wu, S.

    1989-03-01

    This annual report, the tenth in a series, provides a brief description of fuel performance during 1987 in commercial nuclear power plants and an indication of trends. Brief summaries of fuel design changes, fuel surveillance programs, fuel operating experience, fuel problems, high-burnup fuel experience, and items of general significance are provided. References to more detailed information and related US Nuclear Regulator Commission evaluations are included. 384 refs., 13 figs., 33 tabs.

  13. Fuel performance annual report for 1986

    SciTech Connect

    Bailey, W.J.; Wu, S.

    1988-03-01

    This annual report, the ninth in a series, provides a brief description of fuel performance during 1986 in commercial nuclear power plants and an indication of trends. Brief summaries of fuel design changes, fuel surveillance programs, fuel operating experience, fuel problems, high-burnup fuel experience, and items of general significance are provided. References to more detailed information and related U.S. Nuclear Regulatory Commission evaluations are included. 550 refs., 12 figs., 31 tabs.

  14. Fuel performance annual report for 1988

    SciTech Connect

    Bailey, W.J. ); Wu, S. . Div. of Engineering and Systems Technology)

    1990-03-01

    This annual report, the eleventh in a series, provides a brief description of fuel performance during 1988 in commercial nuclear power plants and an indication of trends. Brief summaries of fuel design changes, fuel surveillance programs, fuel operating experience, fuel problems, high-burnup fuel experience, and items of general significance are provided. References to more detailed information and related US Nuclear Regulatory Commission evaluations are included. 414 refs., 13 figs., 32 tabs.

  15. Fuel performance annual report for 1989

    SciTech Connect

    Bailey, W.J.; Berting, F.M. ); Wu, S. . Div. of Systems Technology)

    1992-06-01

    This annual report, the twelfth in a series, provides a brief description of fuel performance during 1989 in commercial nuclear power plants and an indication of trends. Brief summaries of fuel design changes, fuel surveillance programs, fuel operating experience, fuel problems, high-burnup fuel experience, and items of general significance are provided. References to more detailed information and related US Nuclear Regulatory Commission evaluations are included.

  16. Error Reduction Program. [combustor performance evaluation codes

    NASA Technical Reports Server (NTRS)

    Syed, S. A.; Chiappetta, L. M.; Gosman, A. D.

    1985-01-01

    The details of a study to select, incorporate and evaluate the best available finite difference scheme to reduce numerical error in combustor performance evaluation codes are described. The combustor performance computer programs chosen were the two dimensional and three dimensional versions of Pratt & Whitney's TEACH code. The criteria used to select schemes required that the difference equations mirror the properties of the governing differential equation, be more accurate than the current hybrid difference scheme, be stable and economical, be compatible with TEACH codes, use only modest amounts of additional storage, and be relatively simple. The methods of assessment used in the selection process consisted of examination of the difference equation, evaluation of the properties of the coefficient matrix, Taylor series analysis, and performance on model problems. Five schemes from the literature and three schemes developed during the course of the study were evaluated. This effort resulted in the incorporation of a scheme in 3D-TEACH which is usuallly more accurate than the hybrid differencing method and never less accurate.

  17. Neutronics and Fuel Performance Evaluation of Accident Tolerant Fuel under Normal Operation Conditions

    SciTech Connect

    Xu Wu; Piyush Sabharwall; Jason Hales

    2014-07-01

    This report details the analysis of neutronics and fuel performance analysis for enhanced accident tolerance fuel, with Monte Carlo reactor physics code Serpent and INL’s fuel performance code BISON, respectively. The purpose is to evaluate two of the most promising candidate materials, FeCrAl and Silicon Carbide (SiC), as the fuel cladding under normal operating conditions. Substantial neutron penalty is identified when FeCrAl is used as monolithic cladding for current oxide fuel. From the reactor physics standpoint, application of the FeCrAl alloy as coating layer on surface of zircaloy cladding is possible without increasing fuel enrichment. Meanwhile, SiC brings extra reactivity and the neutron penalty is of no concern. Application of either FeCrAl or SiC could be favorable from the fuel performance standpoint. Detailed comparison between monolithic cladding and hybrid cladding (cladding + coating) is discussed. Hybrid cladding is more practical based on the economics evaluation during the transition from current UO2/zircaloy to Accident Tolerant Fuel (ATF) system. However, a few issues remain to be resolved, such as the creep behavior of FeCrAl, coating spallation, inter diffusion with zirconium, etc. For SiC, its high thermal conductivity, excellent creep resistance, low thermal neutron absorption cross section, irradiation stability (minimal swelling) make it an excellent candidate materials for future nuclear fuel/cladding system.

  18. An Implicit Solution Framework for Reactor Fuel Performance Simulation

    SciTech Connect

    Glen Hansen; Chris Newman; Derek Gaston; Cody Permann

    2009-08-01

    The simulation of nuclear reactor fuel performance involves complex thermomechanical processes between fuel pellets, made of fissile material, and the protective cladding that surrounds the pellets. An important design goal for a fuel is to maximize the life of the cladding thereby allowing the fuel to remain in the reactor for a longer period of time to achieve higher degrees of burnup. This presentation presents an initial approach for modeling the thermomechanical response of reactor fuel, and details of the solution method employed within INL's fuel performance code, BISON. The code employs advanced methods for solving coupled partial differential equation systems that describe multidimensional fuel thermomechanics, heat generation, and oxygen transport within the fuel. This discussion explores the effectiveness of a JFNK-based solution of a problem involving three dimensional fully coupled, nonlinear transient heat conduction and that includes pellet displacement and oxygen diffusion effects. These equations are closed using empirical data that is a function of temperature, density, and oxygen hyperstoichiometry. The method appears quite effective for the fuel pellet / cladding configurations examined, with excellent nonlinear convergence properties exhibited on the combined system. In closing, fully coupled solutions of three dimensional thermomechanics coupled with oxygen diffusion appear quite attractive using the JFNK approach described here, at least for configurations similar to those examined in this report.

  19. FRAPCON-3: Modifications to fuel rod material properties and performance models for high-burnup application

    SciTech Connect

    Lanning, D.D.; Beyer, C.E.; Painter, C.L.

    1997-12-01

    This volume describes the fuel rod material and performance models that were updated for the FRAPCON-3 steady-state fuel rod performance code. The property and performance models were changed to account for behavior at extended burnup levels up to 65 Gwd/MTU. The property and performance models updated were the fission gas release, fuel thermal conductivity, fuel swelling, fuel relocation, radial power distribution, solid-solid contact gap conductance, cladding corrosion and hydriding, cladding mechanical properties, and cladding axial growth. Each updated property and model was compared to well characterized data up to high burnup levels. The installation of these properties and models in the FRAPCON-3 code along with input instructions are provided in Volume 2 of this report and Volume 3 provides a code assessment based on comparison to integral performance data. The updated FRAPCON-3 code is intended to replace the earlier codes FRAPCON-2 and GAPCON-THERMAL-2. 94 refs., 61 figs., 9 tabs.

  20. COBRA-SFS (Spent Fuel Storage): A thermal-hydraulic analysis computer code: Volume 3, Validation assessments

    SciTech Connect

    Lombardo, N.J.; Cuta, J.M.; Michener, T.E.; Rector, D.R.; Wheeler, C.L.

    1986-12-01

    This report presents the results of the COBRA-SFS (Spent Fuel Storage) computer code validation effort. COBRA-SFS, while refined and specialized for spent fuel storage system analyses, is a lumped-volume thermal-hydraulic analysis computer code that predicts temperature and velocity distributions in a wide variety of systems. Through comparisons of code predictions with spent fuel storage system test data, the code's mathematical, physical, and mechanistic models are assessed, and empirical relations defined. The six test cases used to validate the code and code models include single-assembly and multiassembly storage systems under a variety of fill media and system orientations and include unconsolidated and consolidated spent fuel. In its entirety, the test matrix investigates the contributions of convection, conduction, and radiation heat transfer in spent fuel storage systems. To demonstrate the code's performance for a wide variety of storage systems and conditions, comparisons of code predictions with data are made for 14 runs from the experimental data base. The cases selected exercise the important code models and code logic pathways and are representative of the types of simulations required for spent fuel storage system design and licensing safety analyses. For each test, a test description, a summary of the COBRA-SFS computational model, assumptions, and correlations employed are presented. For the cases selected, axial and radial temperature profile comparisons of code predictions with test data are provided, and conclusions drawn concerning the code models and the ability to predict the data and data trends. Comparisons of code predictions with test data demonstrate the ability of COBRA-SFS to successfully predict temperature distributions in unconsolidated or consolidated single and multiassembly spent fuel storage systems.

  1. Thermal-hydraulic/heat transfer code development for sphere-pac-fueled LMFBRs. [COBRA-3SP code

    SciTech Connect

    Morris, D.G.

    1980-06-01

    Sphere-pac fuel has received much attention recently in light of the development of proliferation-resistant fuel cycles for the Fast Breeder Reactor Program in the United States. However, for sphere-pac fuel to be a viable alternative to conventional pellet fuel, a means to analyze the thermal behavior of sphere-pac-fueled pin bundles is needed. To meet this need, a thermal-hydraulic/heat transfer computer code has been developed for sphere-pac-fueled fast breeder reactors. The code, COBRA-3SP, is a modified version of COBRA-3M incorporating a three-region sphere-pac fuel pin model which permits fuel restructuring. With COBRA-3SP, steady-state and transient analysis of sphere-pac-fueled pin bundles is possible. The validity of the sphere-pac fuel pin model has been verified using experimental results of irradiated sphere-pac fuel.

  2. Performance results for a hybrid coding system.

    NASA Technical Reports Server (NTRS)

    Hoffman, L. B.

    1971-01-01

    Results of computer simulation studies of the hybrid pull-up bootstrap decoding algorithm, using a constraint length 24, nonsystematic, rate 1/2 convolutional code for the symmetric channel with both binary and eight-level quantized outputs. Computational performance was used to measure the effect of several decoder parameters and determine practical operating constraints. Results reveal that the track length may be reduced to 500 information bits with small degradation in performance. The optimum number of tracks per block was found to be in the range from 7 to 11. An effective technique was devised to efficiently allocate computational effort and identify reliably decoded data sections. Long simulations indicate that a practical bootstrap decoding configuration has a computational performance about 1.0 dB better than sequential decoding and an output bit error rate about .0000025 near the R sub comp point.

  3. Effects of Fuel Distribution on Detonation Tube Performance

    NASA Technical Reports Server (NTRS)

    Perkins, H. Douglas; Sung, Chih-Jen

    2003-01-01

    A pulse detonation engine uses a series of high frequency intermittent detonation tubes to generate thrust. The process of filling the detonation tube with fuel and air for each cycle may yield non-uniform mixtures. Uniform mixing is commonly assumed when calculating detonation tube thrust performance. In this study, detonation cycles featuring idealized non-uniform Hz/air mixtures were analyzed using a two-dimensional Navier-Stokes computational fluid dynamics code with detailed chemistry. Mixture non-uniformities examined included axial equivalence ratio gradients, transverse equivalence ratio gradients, and partially fueled tubes. Three different average test section equivalence ratios were studied; one stoichiometric, one fuel lean, and one fuel rich. All mixtures were detonable throughout the detonation tube. Various mixtures representing the same average test section equivalence ratio were shown to have specific impulses within 1% of each other, indicating that good fuel/air mixing is not a prerequisite for optimal detonation tube performance under conditions investigated.

  4. Performance of some block codes on a Gaussian channel

    NASA Technical Reports Server (NTRS)

    Baumert, L. D.; Mceliece, R. J.

    1975-01-01

    A technique proposed by Chase (1972) is used to evaluate the performance of several fairly long binary block codes on a wideband additive Gaussian channel. Considerations leading to the use of Chase's technique are discussed. Chase's concepts are first applied to the most powerful practical class of binary codes, the BCH codes with Berlekamp's (1972) decoding algorithm. Chase's algorithm is then described along with proposed selection of candidate codes. Results are presented of applying Chase's algorithm to four binary codes: (23, 12) Golay code, (32, 16) second-order Reed-Muller code, (63, 36) 5-error correcting BCH code, and (95, 39) 9-error correcting shortened BCH code. It is concluded that there are many block codes of length not exceeding 100 with extremely attractive maximum likelihood decoding performance on a Gaussian channel. BCH codes decoded via Berlekamp's binary decoding algorithm and Chase's idea are close to being practical competitors to short-constraint length convolutional codes with Viterbi decoding.

  5. Performance studies of the parallel VIM code

    SciTech Connect

    Shi, B.; Blomquist, R.N.

    1996-05-01

    In this paper, the authors evaluate the performance of the parallel version of the VIM Monte Carlo code on the IBM SPx at the High Performance Computing Research Facility at ANL. Three test problems with contrasting computational characteristics were used to assess effects in performance. A statistical method for estimating the inefficiencies due to load imbalance and communication is also introduced. VIM is a large scale continuous energy Monte Carlo radiation transport program and was parallelized using history partitioning, the master/worker approach, and p4 message passing library. Dynamic load balancing is accomplished when the master processor assigns chunks of histories to workers that have completed a previously assigned task, accommodating variations in the lengths of histories, processor speeds, and worker loads. At the end of each batch (generation), the fission sites and tallies are sent from each worker to the master process, contributing to the parallel inefficiency. All communications are between master and workers, and are serial. The SPx is a scalable 128-node parallel supercomputer with high-performance Omega switches of 63 {micro}sec latency and 35 MBytes/sec bandwidth. For uniform and reproducible performance, they used only the 120 identical regular processors (IBM RS/6000) and excluded the remaining eight planet nodes, which may be loaded by other`s jobs.

  6. FRAPTRAN Fuel Rod Code and its Coupled Transient Analysis with the GENFLO Thermal-Hydraulic Code

    SciTech Connect

    Valtonen, Keijo; Hamalainen, Anitta; Cunningham, Mitchel E. )

    2002-05-01

    The FRAPTRAN computer code has been developed for the U.S. Nuclear Regulatory Commission (NRC) to calculate fuel behavior during power and/or cooling transients at burnup levels up to 65 MWd/kgM. FRAPTRAN has now been assessed and peer reviewed. STUK/VTT have coupled GENFLO to FRAPTRAN for calculations with improved coolant boundary conditions and prepared example calculations to show the effect of improving the coolant boundary conditions.

  7. Evaluation of measured LWR spent fuel composition data for use in code validation

    SciTech Connect

    Hermann, O.W.; DeHart, M.D.; Murphy, B.D.

    1998-02-01

    Burnup credit (BUC) is a concept applied in the criticality safety analysis of spent nuclear fuel in which credit or partial credit is taken for the reduced reactivity worth of the fuel due to both fissile depletion and the buildup of actinides and fission products that act as net neutron absorbers. Typically, a two-step process is applied in BUC analysis: first, depletion calculations are performed to estimate the isotopic content of spent fuel based on its burnup history; second, three-dimensional (3-D) criticality calculations are performed based on specific spent fuel packaging configurations. In seeking licensing approval of any BUC approach (e.g., disposal, transportation, or storage) both of these two computational procedures must be validated. This report was prepared in support of the validation process for depletion methods applied in the analysis of spent fuel from commercial light-water-reactor (LWR) designs. Such validation requires the comparison of computed isotopic compositions with those measured via radiochemical assay to assess the ability of a computer code to predict the contents of spent fuel samples. The purpose of this report is to address the availability and appropriateness of measured data for use in the validation of isotopic depletion methods. Although validation efforts to date at ORNL have been based on calculations using the SAS2H depletion sequence of the SCALE code system, this report has been prepared as an overview of potential sources of validation data independent of the code system used. However, data that are identified as in use in this report refer to earlier validation work performed using SAS2H in support of BUC. This report is the result of a study of available assay data, using the experience gained in spent fuel isotopic validation and with a consideration of the validation issues described earlier. This report recommends the suitability of each set of data for validation work similar in scope to the earlier work.

  8. Modeling and Analysis of FCM UN TRISO Fuel Using the PARFUME Code

    SciTech Connect

    Blaise Collin

    2013-09-01

    The PARFUME (PARticle Fuel ModEl) modeling code was used to assess the overall fuel performance of uranium nitride (UN) tri-structural isotropic (TRISO) ceramic fuel in the frame of the design and development of Fully Ceramic Matrix (FCM) fuel. A specific modeling of a TRISO particle with UN kernel was developed with PARFUME, and its behavior was assessed in irradiation conditions typical of a Light Water Reactor (LWR). The calculations were used to access the dimensional changes of the fuel particle layers and kernel, including the formation of an internal gap. The survivability of the UN TRISO particle was estimated depending on the strain behavior of the constituent materials at high fast fluence and burn-up. For nominal cases, internal gas pressure and representative thermal profiles across the kernel and layers were determined along with stress levels in the pyrolytic carbon (PyC) and silicon carbide (SiC) layers. These parameters were then used to evaluate fuel particle failure probabilities. Results of the study show that the survivability of UN TRISO fuel under LWR irradiation conditions might only be guaranteed if the kernel and PyC swelling rates are limited at high fast fluence and burn-up. These material properties are unknown at the irradiation levels expected to be reached by UN TRISO fuel in LWRs. Therefore, more effort is needed to determine them and positively conclude on the applicability of FCM fuel to LWRs.

  9. A dynamic, dependent type system for nuclear fuel cycle code generation

    SciTech Connect

    Scopatz, A.

    2013-07-01

    The nuclear fuel cycle may be interpreted as a network or graph, thus allowing methods from formal graph theory to be used. Nodes are often idealized as nuclear fuel cycle facilities (reactors, enrichment cascades, deep geologic repositories). With the advent of modern object-oriented programming languages - and fuel cycle simulators implemented in these languages - it is natural to define a class hierarchy of facility types. Bright is a quasi-static simulator, meaning that the number of material passes through a facility is tracked rather than natural time. Bright is implemented as a C++ library that models many canonical components such as reactors, storage facilities, and more. Cyclus is a discrete time simulator, meaning that natural time is tracked through out the simulation. Therefore a robust, dependent type system was developed to enable inter-operability between Bright and Cyclus. This system is capable of representing any fuel cycle facility. Types declared in this system can then be used to automatically generate code which binds a facility implementation to a simulator front end. Facility model wrappers may be used either internally to a fuel cycle simulator or as a mechanism for inter-operating multiple simulators. While such a tool has many potential use cases it has two main purposes: enabling easy performance of code-to-code comparisons and the verification and the validation of user input.

  10. SAFE: A computer code for the steady-state and transient thermal analysis of LMR fuel elements

    SciTech Connect

    Hayes, S.L.

    1993-12-01

    SAFE is a computer code developed for both the steady-state and transient thermal analysis of single LMR fuel elements. The code employs a two-dimensional control-volume based finite difference methodology with fully implicit time marching to calculate the temperatures throughout a fuel element and its associated coolant channel for both the steady-state and transient events. The code makes no structural calculations or predictions whatsoever. It does, however, accept as input structural parameters within the fuel such as the distributions of porosity and fuel composition, as well as heat generation, to allow a thermal analysis to be performed on a user-specified fuel structure. The code was developed with ease of use in mind. An interactive input file generator and material property correlations internal to the code are available to expedite analyses using SAFE. This report serves as a complete design description of the code as well as a user`s manual. A sample calculation made with SAFE is included to highlight some of the code`s features. Complete input and output files for the sample problem are provided.

  11. COBRA-SFS (Spent Fuel Storage): A thermal-hydraulic analysis computer code: Volume 2, User's manual

    SciTech Connect

    Rector, D.R.; Cuta, J.M.; Lombardo, N.J.; Michener, T.E.; Wheeler, C.L.

    1986-11-01

    COBRA-SFS (Spent Fuel Storage) is a general thermal-hydraulic analysis computer code used to predict temperatures and velocities in a wide variety of systems. The code was refined and specialized for spent fuel storage system analyses for the US Department of Energy's Commercial Spent Fuel Management Program. The finite-volume equations governing mass, momentum, and energy conservation are written for an incompressible, single-phase fluid. The flow equations model a wide range of conditions including natural circulation. The energy equations include the effects of solid and fluid conduction, natural convection, and thermal radiation. The COBRA-SFS code is structured to perform both steady-state and transient calculations; however, the transient capability has not yet been validated. This volume contains the input instructions for COBRA-SFS and an auxiliary radiation exchange factor code, RADX-1. It is intended to aid the user in becoming familiar with the capabilities and modeling conventions of the code.

  12. Modeling and analysis of UN TRISO fuel for LWR application using the PARFUME code

    NASA Astrophysics Data System (ADS)

    Collin, Blaise P.

    2014-08-01

    The Idaho National Laboratory (INL) PARFUME (PARticle FUel ModEl) code was used to assess the overall fuel performance of uranium nitride (UN) tristructural isotropic (TRISO) ceramic fuel under irradiation conditions typical of a Light Water Reactor (LWR). The dimensional changes of the fuel particle layers and kernel were calculated, including the formation of an internal gap. The survivability of the UN TRISO particle was estimated depending on the strain behavior of the constituent materials at high fast fluence and burn-up. For nominal cases, internal gas pressure and representative thermal profiles across the kernel and layers were determined along with stress levels in the inner and outer pyrolytic carbon (IPyC/OPyC) and silicon carbide (SiC) layers. These parameters were then used to evaluate fuel particle failure probabilities. Results of the study show that the survivability of UN TRISO fuel under LWR irradiation conditions might only be guaranteed if the kernel and PyC swelling rates are limited at high fast fluence and burn-up. These material properties have large uncertainties at the irradiation levels expected to be reached by UN TRISO fuel in LWRs. Therefore, a large experimental effort would be needed to establish material properties, including kernel and PyC swelling rates, under these conditions before definitive conclusions can be drawn on the behavior of UN TRISO fuel in LWRs.

  13. Modeling and Analysis of UN TRISO Fuel for LWR Application Using the PARFUME Code

    SciTech Connect

    Blaise Collin

    2014-08-01

    The Idaho National Laboraroty (INL) PARFUME (particle fuel model) code was used to assess the overall fuel performance of uranium nitride (UN) tristructural isotropic (TRISO) ceramic fuel under irradiation conditions typical of a Light Water Reactor (LWR). The dimensional changes of the fuel particle layers and kernel were calculated, including the formation of an internal gap. The survivability of the UN TRISO particle was estimated depending on the strain behavior of the constituent materials at high fast fluence and burn up. For nominal cases, internal gas pressure and representative thermal profiles across the kernel and layers were determined along with stress levels in the inner and outer pyrolytic carbon (IPyC/OPyC) and silicon carbide (SiC) layers. These parameters were then used to evaluate fuel particle failure probabilities. Results of the study show that the survivability of UN TRISO fuel under LWR irradiation conditions might only be guaranteed if the kernel and PyC swelling rates are limited at high fast fluence and burn up. These material properties have large uncertainties at the irradiation levels expected to be reached by UN TRISO fuel in LWRs. Therefore, a large experimental effort would be needed to establish material properties, including kernel and PyC swelling rates, under these conditions before definitive conclusions can be drawn on the behavior of UN TRISO fuel in LWRs.

  14. Analysis of fission gas release in LWR fuel using the BISON code

    SciTech Connect

    G. Pastore; J.D. Hales; S.R. Novascone; D.M. Perez; B.W. Spencer; R.L. Williamson

    2013-09-01

    Recent advances in the development of the finite-element based, multidimensional fuel performance code BISON of Idaho National Laboratory are presented. Specifically, the development, implementation and testing of a new model for the analysis of fission gas behavior in LWR-UO2 fuel during irradiation are summarized. While retaining a physics-based description of the relevant mechanisms, the model is characterized by a level of complexity suitable for application to engineering-scale nuclear fuel analysis and consistent with the uncertainties pertaining to some parameters. The treatment includes the fundamental features of fission gas behavior, among which are gas diffusion and precipitation in fuel grains, growth and coalescence of gas bubbles at grain faces, grain growth and grain boundary sweeping effects, thermal, athermal, and transient gas release. The BISON code incorporating the new model is applied to the simulation of irradiation experiments from the OECD/NEA International Fuel Performance Experiments database, also included in the IAEA coordinated research projects FUMEX-II and FUMEX-III. The comparison of the results with the available experimental data at moderate burn-up is presented, pointing out an encouraging predictive accuracy, without any fitting applied to the model parameters.

  15. Analysis of the ATW fuel cycle using the REBUS-3 code system

    SciTech Connect

    Yang, W.S.; Khalil, H.S.

    1999-07-01

    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 the Los Alamos National Laboratory for rapid destruction of transuranic actinides and long-lived fission products ({sup 99}Tc and {sup 129}I). The current reference ATW concept employs a subcritical, liquid-metal-cooled, fast-spectrum nuclear subsystem. Because the discharged fuel is recycled, analysis of ATW nuclear performance requires modeling of the external cycle as well as the in-core fuel management. The fuel cycle analysis of ATW can be performed rigorously using Monte Carlo calculations coupled with detailed depletion calculations. However, the inefficiency of this approach makes it impractical, particularly in view of (a) the large number of fuel cycle calculations needed for design optimization and (b) the need to represent complex in-core and out-of-core fuel cycle operations. To meet the need for design-oriented capabilities, tools previously developed for fast reactor calculations are being adapted for application to ATW. Here, the authors describe the extension and application of the REBUS-3 code to ATW fuel cycle analysis.

  16. Modeling the Integrated Performance of Dispersion and Monolithic U-Mo Based Fuels

    SciTech Connect

    Daniel M. Wachs; Douglas E. Burkes; Steven L. Hayes; Karen Moore; Greg Miller; Gerard Hofman; Yeon Soo Kim

    2006-10-01

    The evaluation and prediction of integrated fuel performance is a critical component of the Reduced Enrichment for Research and Test Reactors (RERTR) program. The PLATE code is the primary tool being developed and used to perform these functions. The code is being modified to incorporate the most recent fuel/matrix interaction correlations as they become available for both aluminum and aluminum/silicon matrices. The code is also being adapted to treat cylindrical and square pin geometries to enhance the validation database by including the results gathered from various international partners. Additional modeling work has been initiated to evaluate the thermal and mechanical performance requirements unique to monolithic fuels during irradiation.

  17. A statistical approach to nuclear fuel design and performance

    NASA Astrophysics Data System (ADS)

    Cunning, Travis Andrew

    As CANDU fuel failures can have significant economic and operational consequences on the Canadian nuclear power industry, it is essential that factors impacting fuel performance are adequately understood. Current industrial practice relies on deterministic safety analysis and the highly conservative "limit of operating envelope" approach, where all parameters are assumed to be at their limits simultaneously. This results in a conservative prediction of event consequences with little consideration given to the high quality and precision of current manufacturing processes. This study employs a novel approach to the prediction of CANDU fuel reliability. Probability distributions are fitted to actual fuel manufacturing datasets provided by Cameco Fuel Manufacturing, Inc. They are used to form input for two industry-standard fuel performance codes: ELESTRES for the steady-state case and ELOCA for the transient case---a hypothesized 80% reactor outlet header break loss of coolant accident. Using a Monte Carlo technique for input generation, 105 independent trials are conducted and probability distributions are fitted to key model output quantities. Comparing model output against recognized industrial acceptance criteria, no fuel failures are predicted for either case. Output distributions are well removed from failure limit values, implying that margin exists in current fuel manufacturing and design. To validate the results and attempt to reduce the simulation burden of the methodology, two dimensional reduction methods are assessed. Using just 36 trials, both methods are able to produce output distributions that agree strongly with those obtained via the brute-force Monte Carlo method, often to a relative discrepancy of less than 0.3% when predicting the first statistical moment, and a relative discrepancy of less than 5% when predicting the second statistical moment. In terms of global sensitivity, pellet density proves to have the greatest impact on fuel performance

  18. On the performance of trellis coded 8PSK with Reed Solomon codes

    NASA Astrophysics Data System (ADS)

    Harada, Yasuo

    Concatenated trellis-coded 8-ary phase shift keying (8PSK) with Reed Solomon (RS) codes is studied over additive white Gaussian noise and Rayleigh fading channels. Trellis coded modulation (TCM) achieves high coding gain without any bandwidth expansion. The basic analysis of its performance is reviewed and confirmed by simulation using a truncated Viterbi decoder. Trellis-coded 8PSK, which has an asymptotic coding gain of 3.6 dB, can be further improved by concatenation with RS codes. By concatenating TCM with an RS code, the bandwidth of the overall system is expanded by the reciprocal of the RS coding rate. Improvement in bit error rate performance is studied for this coding system with various combinations of RS codes. A code with a rate of 0.9 and a good bit error rate performance is chosen for further study for erasure and error decoding. Results suggest the performance can be improved with sufficient reliability of decoded symbols. The reliability of the input symbols to the RS decoder is obtained by a modified Viterbi decoder. Such a decoder is studied and the performance of the bit error rate is shown. To improve performance, a new, modified Viterbi decoder with averaged reliability information is proposed, and the bit error rate improvement is confirmed by computer simulation.

  19. Thermal Conductivity of UO2 Fuel: Predicting Fuel Performance from Simulation

    SciTech Connect

    Phillpot, Simon R.; El-Azab, Anter; Chernatynskiy, Aleksandr; Tulenko, James S.

    2011-08-19

    Recent progress in understanding the thermal-transport properties of UO₂ for fission reactors is reviewed from the perspective of computer simulations. A path to incorporating more accurate materials models into fuel performance codes is outlined. In particular, it is argued that a judiciously integrated program of atomic-level simulations and mesoscale simulations offers the possibility of both better predicting the thermal-transport properties of UO₂ in light-water reactors and enabling the assessment of the thermal performances of novel fuel systems for which extensive experimental databases are not available.

  20. The Modeling of Advanced BWR Fuel Designs with the NRC Fuel Depletion Codes PARCS/PATHS

    DOE PAGESBeta

    Ward, Andrew; Downar, Thomas J.; Xu, Y.; March-Leuba, Jose A; Thurston, Carl; Hudson, Nathanael H.; Ireland, A.; Wysocki, A.

    2015-04-22

    The PATHS (PARCS Advanced Thermal Hydraulic Solver) code was developed at the University of Michigan in support of U.S. Nuclear Regulatory Commission research to solve the steady-state, two-phase, thermal-hydraulic equations for a boiling water reactor (BWR) and to provide thermal-hydraulic feedback for BWR depletion calculations with the neutronics code PARCS (Purdue Advanced Reactor Core Simulator). The simplified solution methodology, including a three-equation drift flux formulation and an optimized iteration scheme, yields very fast run times in comparison to conventional thermal-hydraulic systems codes used in the industry, while still retaining sufficient accuracy for applications such as BWR depletion calculations. Lastly, themore » capability to model advanced BWR fuel designs with part-length fuel rods and heterogeneous axial channel flow geometry has been implemented in PATHS, and the code has been validated against previously benchmarked advanced core simulators as well as BWR plant and experimental data. We describe the modifications to the codes and the results of the validation in this paper.« less

  1. The Modeling of Advanced BWR Fuel Designs with the NRC Fuel Depletion Codes PARCS/PATHS

    SciTech Connect

    Ward, Andrew; Downar, Thomas J.; Xu, Y.; March-Leuba, Jose A; Thurston, Carl; Hudson, Nathanael H.; Ireland, A.; Wysocki, A.

    2015-04-22

    The PATHS (PARCS Advanced Thermal Hydraulic Solver) code was developed at the University of Michigan in support of U.S. Nuclear Regulatory Commission research to solve the steady-state, two-phase, thermal-hydraulic equations for a boiling water reactor (BWR) and to provide thermal-hydraulic feedback for BWR depletion calculations with the neutronics code PARCS (Purdue Advanced Reactor Core Simulator). The simplified solution methodology, including a three-equation drift flux formulation and an optimized iteration scheme, yields very fast run times in comparison to conventional thermal-hydraulic systems codes used in the industry, while still retaining sufficient accuracy for applications such as BWR depletion calculations. Lastly, the capability to model advanced BWR fuel designs with part-length fuel rods and heterogeneous axial channel flow geometry has been implemented in PATHS, and the code has been validated against previously benchmarked advanced core simulators as well as BWR plant and experimental data. We describe the modifications to the codes and the results of the validation in this paper.

  2. Thermomechanical simulation of the DIAMINO irradiation experiment using the LICOS fuel design code

    SciTech Connect

    Bejaoui, S.; Helfer, T.; Brunon, E.; Lambert, T.; Bendotti, S.; Neyroud, C.

    2013-07-01

    Two separate-effect experiments in the HFR and OSIRIS Material Test Reactors (MTRs) are currently under Post- Irradiation Examinations (MARIOS) and under preparation (DIAMINO) respectively. The main goal of these experiments is to investigate gaseous release and swelling of Am-bearing UO2-x fuels as a function of temperature, fuel microstructure and gas production rate. First, a brief description of the MARIOS and DIAMINO irradiations is provided. Then, the innovative experimental in-pile device specifically developed for the DIAMINO experiment is described. Eventually, the thermo-mechanical computations performed using the LICOS code are presented. These simulations support the DIAMINO experimental design and highlight some of the capabilities of the code. (authors)

  3. Alternate-Fueled Combustor-Sector Performance

    NASA Technical Reports Server (NTRS)

    Thomas, Anna E.; Saxena, Nikita T.; Shouse, Dale T.; Neuroth, Craig; Hendricks, Robert C.; Lynch, Amy; Frayne, Charles W.; Stutrud, Jeffrey S.; Corporan, Edwin; Hankins, Terry

    2013-01-01

    In order to realize alternative fueling for military and commercial use, the industry has set forth guidelines that must be met by each fuel. These aviation fueling requirements are outlined in MIL-DTL-83133F(2008) or ASTM D 7566 Annex (2011) standards, and are classified as "drop-in" fuel replacements. This report provides combustor performance data for synthetic-paraffinic-kerosene- (SPK-) type (Fischer-Tropsch (FT)) fuel and blends with JP-8+100, relative to JP-8+100 as baseline fueling. Data were taken at various nominal inlet conditions: 75 psia (0.52 MPa) at 500 degF (533 K), 125 psia (0.86 MPa) at 625 degF (603 K), 175 psia (1.21 MPa) at 725 degF (658 K), and 225 psia (1.55 MPa) at 790 degF (694 K). Combustor performance analysis assessments were made for the change in flame temperatures, combustor efficiency, wall temperatures, and exhaust plane temperatures at 3, 4, and 5 percent combustor pressure drop (DP) for fuel:air ratios (F/A) ranging from 0.010 to 0.025. Significant general trends show lower liner temperatures and higher flame and combustor outlet temperatures with increases in FT fueling relative to JP-8+100 fueling. The latter affects both turbine efficiency and blade and vane lives.

  4. Alternate-Fueled Combustor-Sector Performance

    NASA Technical Reports Server (NTRS)

    Thomas, Anna E.; Saxena, Nikita T.; Shouse, Dale T.; Neuroth, Craig; Hendricks, Robert C.; Lynch, Amy; Frayne, Charles W.; Stutrud, Jeffrey S.; Corporan, Edwin; Hankins, Terry

    2012-01-01

    In order to realize alternative fueling for military and commercial use, the industry has set forth guidelines that must be met by each fuel. These aviation fueling requirements are outlined in MILDTL- 83133F(2008) or ASTM D 7566 Annex (2011) standards, and are classified as drop-in fuel replacements. This paper provides combustor performance data for synthetic-paraffinic-kerosene- (SPK-) type (Fisher-Tropsch (FT)) fuel and blends with JP-8+100, relative to JP-8+100 as baseline fueling. Data were taken at various nominal inlet conditions: 75 psia (0.52 MPa) at 500 F (533 K), 125 psia (0.86 MPa) at 625 F (603 K), 175 psia (1.21 MPa) at 725 F (658 K), and 225 psia (1.55 MPa) at 790 F (694 K). Combustor performance analysis assessments were made for the change in flame temperatures, combustor efficiency, wall temperatures, and exhaust plane temperatures at 3%, 4%, and 5% combustor pressure drop (% delta P) for fuel: air ratios (F/A) ranging from 0.010 to 0.025. Significant general trends show lower liner temperatures and higher flame and combustor outlet temperatures with increases in FT fueling relative to JP-8+100 fueling. The latter affects both turbine efficiency and blade/vane life.

  5. Advanced multiphysics coupling for LWR fuel performance analysis

    SciTech Connect

    Hales, J. D.; Tonks, M. R.; Gleicher, F. N.; Spencer, B. W.; Novascone, S. R.; Williamson, R. L.; Pastore, G.; Perez, D. M.

    2015-10-01

    Even the most basic nuclear fuel analysis is a multiphysics undertaking, as a credible simulation must consider at a minimum coupled heat conduction and mechanical deformation. The need for more realistic fuel modeling under a variety of conditions invariably leads to a desire to include coupling between a more complete set of the physical phenomena influencing fuel behavior, including neutronics, thermal hydraulics, and mechanisms occurring at lower length scales. This paper covers current efforts toward coupled multiphysics LWR fuel modeling in three main areas. The first area covered in this paper concerns thermomechanical coupling. The interaction of these two physics, particularly related to the feedback effect associated with heat transfer and mechanical contact at the fuel/clad gap, provides numerous computational challenges. An outline is provided of an effective approach used to manage the nonlinearities associated with an evolving gap in BISON, a nuclear fuel performance application. A second type of multiphysics coupling described here is that of coupling neutronics with thermomechanical LWR fuel performance. DeCART, a high-fidelity core analysis program based on the method of characteristics, has been coupled to BISON. DeCART provides sub-pin level resolution of the multigroup neutron flux, with resonance treatment, during a depletion or a fast transient simulation. Two-way coupling between these codes was achieved by mapping fission rate density and fast neutron flux fields from DeCART to BISON and the temperature field from BISON to DeCART while employing a Picard iterative algorithm. Finally, the need for multiscale coupling is considered. Fission gas production and evolution significantly impact fuel performance by causing swelling, a reduction in the thermal conductivity, and fission gas release. The mechanisms involved occur at the atomistic and grain scale and are therefore not the domain of a fuel performance code. However, it is possible to use

  6. Advanced multiphysics coupling for LWR fuel performance analysis

    DOE PAGESBeta

    Hales, J. D.; Tonks, M. R.; Gleicher, F. N.; Spencer, B. W.; Novascone, S. R.; Williamson, R. L.; Pastore, G.; Perez, D. M.

    2015-10-01

    Even the most basic nuclear fuel analysis is a multiphysics undertaking, as a credible simulation must consider at a minimum coupled heat conduction and mechanical deformation. The need for more realistic fuel modeling under a variety of conditions invariably leads to a desire to include coupling between a more complete set of the physical phenomena influencing fuel behavior, including neutronics, thermal hydraulics, and mechanisms occurring at lower length scales. This paper covers current efforts toward coupled multiphysics LWR fuel modeling in three main areas. The first area covered in this paper concerns thermomechanical coupling. The interaction of these two physics,more » particularly related to the feedback effect associated with heat transfer and mechanical contact at the fuel/clad gap, provides numerous computational challenges. An outline is provided of an effective approach used to manage the nonlinearities associated with an evolving gap in BISON, a nuclear fuel performance application. A second type of multiphysics coupling described here is that of coupling neutronics with thermomechanical LWR fuel performance. DeCART, a high-fidelity core analysis program based on the method of characteristics, has been coupled to BISON. DeCART provides sub-pin level resolution of the multigroup neutron flux, with resonance treatment, during a depletion or a fast transient simulation. Two-way coupling between these codes was achieved by mapping fission rate density and fast neutron flux fields from DeCART to BISON and the temperature field from BISON to DeCART while employing a Picard iterative algorithm. Finally, the need for multiscale coupling is considered. Fission gas production and evolution significantly impact fuel performance by causing swelling, a reduction in the thermal conductivity, and fission gas release. The mechanisms involved occur at the atomistic and grain scale and are therefore not the domain of a fuel performance code. However, it is

  7. Fuel Performance Experiments and Modeling: Fission Gas Bubble Nucleation and Growth in Alloy Nuclear Fuels

    SciTech Connect

    McDeavitt, Sean; Shao, Lin; Tsvetkov, Pavel; Wirth, Brian; Kennedy, Rory

    2014-04-07

    Advanced fast reactor systems being developed under the DOE's Advanced Fuel Cycle Initiative are designed to destroy TRU isotopes generated in existing and future nuclear energy systems. Over the past 40 years, multiple experiments and demonstrations have been completed using U-Zr, U-Pu-Zr, U-Mo and other metal alloys. As a result, multiple empirical and semi-empirical relationships have been established to develop empirical performance modeling codes. Many mechanistic questions about fission as mobility, bubble coalescience, and gas release have been answered through industrial experience, research, and empirical understanding. The advent of modern computational materials science, however, opens new doors of development such that physics-based multi-scale models may be developed to enable a new generation of predictive fuel performance codes that are not limited by empiricism.

  8. EFFECT OF FUEL IMPURITIES ON FUEL CELL PERFORMANCE AND DURABILITY

    SciTech Connect

    Colon-Mercado, H.

    2010-09-28

    A fuel cell is an electrochemical energy conversion device that produces electricity during the combination of hydrogen and oxygen to produce water. Proton exchange membranes fuel cells are favored for portable applications as well as stationary ones due to their high power density, low operating temperature, and low corrosion of components. In real life operation, the use of pure fuel and oxidant gases results in an impractical system. A more realistic and cost efficient approach is the use of air as an oxidant gas and hydrogen from hydrogen carriers (i.e., ammonia, hydrocarbons, hydrides). However, trace impurities arising from different hydrogen sources and production increases the degradation of the fuel cell. These impurities include carbon monoxide, ammonia, sulfur, hydrocarbons, and halogen compounds. The International Organization for Standardization (ISO) has set maximum limits for trace impurities in the hydrogen stream; however fuel cell data is needed to validate the assumption that at those levels the impurities will cause no degradation. This report summarizes the effect of selected contaminants tested at SRNL at ISO levels. Runs at ISO proposed concentration levels show that model hydrocarbon compound such as tetrahydrofuran can cause serious degradation. However, the degradation is only temporary as when the impurity is removed from the hydrogen stream the performance completely recovers. Other molecules at the ISO concentration levels such as ammonia don't show effects on the fuel cell performance. On the other hand carbon monoxide and perchloroethylene shows major degradation and the system can only be recovered by following recovery procedures.

  9. Thermoelectric pump performance analysis computer code

    NASA Technical Reports Server (NTRS)

    Johnson, J. L.

    1973-01-01

    A computer program is presented that was used to analyze and design dual-throat electromagnetic dc conduction pumps for the 5-kwe ZrH reactor thermoelectric system. In addition to a listing of the code and corresponding identification of symbols, the bases for this analytical model are provided.

  10. Final assessment of MOX fuel performance experiment with Japanese PWR specification fuel in the HBWR

    SciTech Connect

    Fujii, Hajime; Teshima, Hideyuki; Kanasugi, Katsumasa; Kosaka, Yuji; Arakawa, Yasushi

    2007-07-01

    In order to obtain high burn-up MOX fuel irradiation performance data, SBR and MIMAS MOX fuel rods with Pu-fissile enrichment of about 6 wt% had been irradiated in the HBWR from 1995 to 2006. The peak burn-up of MOX pellet achieved 72 GWd/tM. In this test, fuel centerline temperature, rod internal pressure, stack length and cladding length were measured for MOX fuel and UO{sub 2} fuel as reference. MOX fuel temperature is confirmed to have no significant difference in comparison with UO{sub 2}, taking into account of adequate thermal conductivity degradation due to PuO{sub 2} addition and burn-up development. And the measured fuel temperature agrees well with FINE code calculation up to high burn-up region. Fission gas release of MOX is possibly greater than UO{sub 2} based on temperature and pressure assessment. No significant difference is confirmed between SBR and MIMAS MOX on FGR behavior. MOX fuel swelling rate agrees well with solid swelling rate in the literature. Cladding elongation data shows onset of PCMI in high power region. (authors)

  11. Understanding Biodiesel Fuel Quality and Performances

    SciTech Connect

    Weiksner, P. E., J.M. Sr.

    2003-12-12

    The purpose of this paper is to provide the reader with sufficient information to understand Biodiesel fuel quality and the effect various quality parameters have on diesel equipment performance. Biodiesel is produced from vegetable oils, recycled cooking greases and animal fat. The American Society of Testing Material test methods are used as a basis for drawing comparisons between regular diesel fuel and Biodiesel. Failure to control the processes for manufacturing, blending and storage of Biodiesel can lead to performance problems in all types of diesel fueled equipment.

  12. Nitride fuels irradiation performance data base

    SciTech Connect

    Brozak, D.E.; Thomas, J.K.; Peddicord, K.L.

    1987-01-01

    An irradiation performance data base for nitride fuels has been developed from an extensive literature search and review that emphasized uranium nitride, but also included performance data for mixed nitrides ((U,Pu)N) and carbonitrides ((U,Pu)C,N) to increase the quantity and depth of pin data available. This work represents a very extensive effort to systematically collect and organize irradiation data for nitride-based fuels. The data base has many potential applications. First, it can facilitate parametric studies of nitride-based fuels to be performed using a wide range of pin designs and operating conditions. This should aid in the identification of important parameters and design requirements for multimegawatt and SP-100 fuel systems. Secondly, the data base can be used to evaluate fuel performance models. For detailed studies, it can serve as a guide to selecting a small group of pin specimens for extensive characterization. Finally, the data base will serve as an easily accessible and expandable source of irradiation performance information for nitride fuels.

  13. The effects of Reed-Solomon code shortening on the performance of coded telemetry systems

    NASA Technical Reports Server (NTRS)

    Deutsch, L. J.

    1983-01-01

    The theory of Reed-Solomon code shortening in general was developed and the degradation due to shortening in the context of concatenated coding was qualified. It is shown that in the NASA/ESA concatenated system, significant degradations occur only when N 180. A Reed-Solomon code was concatenated with an inner (7, 1/2) convolutional code. Under some circumstances, it would be desirable to use a shorter outer code word length. For example, the format of the data coming from science instruments on board a spacecraft may lend itself naturally to a word length of 200 symbols rather than 223. To accommodate such code word lengths, the Reed-Solomon code can be shortened to an (N, N-32) code where N can be any integer between 33 and 255. Shortening the code, however, changes its performance. On one hand, the amount of redundancy per information symbol increases. Because of this increased redundancy, the amount of energy per information symbol is decreased by code shortening. The overall effect is to degrade the performance of the code.

  14. Codes and Standards Requirements for Deployment of Emerging Fuel Cell Technologies

    SciTech Connect

    Burgess, R.; Buttner, W.; Riykin, C.

    2011-12-01

    The objective of this NREL report is to provide information on codes and standards (of two emerging hydrogen power fuel cell technology markets; forklift trucks and backup power units), that would ease the implementation of emerging fuel cell technologies. This information should help project developers, project engineers, code officials and other interested parties in developing and reviewing permit applications for regulatory compliance.

  15. Finding the key to a better code: code team restructure to improve performance and outcomes.

    PubMed

    Prince, Cynthia R; Hines, Elizabeth J; Chyou, Po-Huang; Heegeman, David J

    2014-09-01

    Code teams respond to acute life threatening changes in a patient's status 24 hours a day, 7 days a week. If any variable, whether a medical skill or non-medical quality, is lacking, the effectiveness of a code team's resuscitation could be hindered. To improve the overall performance of our hospital's code team, we implemented an evidence-based quality improvement restructuring plan. The code team restructure, which occurred over a 3-month period, included a defined number of code team participants, clear identification of team members and their primary responsibilities and position relative to the patient, and initiation of team training events and surprise mock codes (simulations). Team member assessments of the restructured code team and its performance were collected through self-administered electronic questionnaires. Time-to-defibrillation, defined as the time the code was called until the start of defibrillation, was measured for each code using actual time recordings from code summary sheets. Significant improvements in team member confidence in the skills specific to their role and clarity in their role's position were identified. Smaller improvements were seen in team leadership and reduction in the amount of extra talking and noise during a code. The average time-to-defibrillation during real codes decreased each year since the code team restructure. This type of code team restructure resulted in improvements in several areas that impact the functioning of the team, as well as decreased the average time-to-defibrillation, making it beneficial to many, including the team members, medical institution, and patients. PMID:24667218

  16. Fuel accident performance testing for small HTRs

    NASA Astrophysics Data System (ADS)

    Schenk, W.; Pott, G.; Nabielek, H.

    1990-04-01

    Irradiated spherical fuel elements containing 16400 coated UO 2 particles each were heated at temperatures between 1600 and 1800°C and the fission product release was measured. The demonstrated fission product retention at 1600°C establishes the basis for the design of small modular HTRs which inherently limit the temperature to 1600°C by passive means. In addition to this demonstration, the test data show that modern TRISO fuels provide an ample performance margin: release normally sets in at 1800°C; this occurs at 1600°C only with fuels irradiated under conditions which significantly exceed current reactor design requirements.

  17. TEMP: a computer code to calculate fuel pin temperatures during a transient. [LMFBR

    SciTech Connect

    Bard, F E; Christensen, B Y; Gneiting, B C

    1980-04-01

    The computer code TEMP calculates fuel pin temperatures during a transient. It was developed to accommodate temperature calculations in any system of axi-symmetric concentric cylinders. When used to calculate fuel pin temperatures, the code will handle a fuel pin as simple as a solid cylinder or as complex as a central void surrounded by fuel that is broken into three regions by two circumferential cracks. Any fuel situation between these two extremes can be analyzed along with additional cladding, heat sink, coolant or capsule regions surrounding the fuel. The one-region version of the code accurately calculates the solution to two problems having closed-form solutions. The code uses an implicit method, an explicit method and a Crank-Nicolson (implicit-explicit) method.

  18. Metal fuel manufacturing and irradiation performance

    SciTech Connect

    Pedersen, D.R.; Walters, L.C.

    1992-01-01

    The advances in metal fuel by the Integral Fast Reactor Program at Argonne National Laboratory are the subject of this paper. The Integral Fast Reactor (IFR) is an advanced liquid-metal-cooled reactor concept being developed at Argonne National Laboratory. The advances stressed in the paper include fuel irradiation performance, and improved passive safety. The goals and the safety philosophy of the Integral Fast Reactor Program are stressed.

  19. Metal fuel manufacturing and irradiation performance

    SciTech Connect

    Pedersen, D.R.; Walters, L.C.

    1992-06-01

    The advances in metal fuel by the Integral Fast Reactor Program at Argonne National Laboratory are the subject of this paper. The Integral Fast Reactor (IFR) is an advanced liquid-metal-cooled reactor concept being developed at Argonne National Laboratory. The advances stressed in the paper include fuel irradiation performance, and improved passive safety. The goals and the safety philosophy of the Integral Fast Reactor Program are stressed.

  20. Roadmap Toward a Predictive Performance-based Commercial Energy Code

    SciTech Connect

    Rosenberg, Michael I.; Hart, Philip R.

    2014-10-01

    Energy codes have provided significant increases in building efficiency over the last 38 years, since the first national energy model code was published in late 1975. The most commonly used path in energy codes, the prescriptive path, appears to be reaching a point of diminishing returns. The current focus on prescriptive codes has limitations including significant variation in actual energy performance depending on which prescriptive options are chosen, a lack of flexibility for designers and developers, and the inability to handle control optimization that is specific to building type and use. This paper provides a high level review of different options for energy codes, including prescriptive, prescriptive packages, EUI Target, outcome-based, and predictive performance approaches. This paper also explores a next generation commercial energy code approach that places a greater emphasis on performance-based criteria. A vision is outlined to serve as a roadmap for future commercial code development. That vision is based on code development being led by a specific approach to predictive energy performance combined with building specific prescriptive packages that are designed to be both cost-effective and to achieve a desired level of performance. Compliance with this new approach can be achieved by either meeting the performance target as demonstrated by whole building energy modeling, or by choosing one of the prescriptive packages.

  1. IPAC-Inlet Performance Analysis Code

    NASA Technical Reports Server (NTRS)

    Barnhart, Paul J.

    1997-01-01

    A series of analyses have been developed which permit the calculation of the performance of common inlet designs. The methods presented are useful for determining the inlet weight flows, total pressure recovery, and aerodynamic drag coefficients for given inlet geometric designs. Limited geometric input data is required to use this inlet performance prediction methodology. The analyses presented here may also be used to perform inlet preliminary design studies. The calculated inlet performance parameters may be used in subsequent engine cycle analyses or installed engine performance calculations for existing uninstalled engine data.

  2. COBRA-SFS (Spent Fuel Storage): A thermal-hydraulic analysis computer code: Volume 1, Mathematical models and solution method

    SciTech Connect

    Rector, D.R.; Wheeler, C.L.; Lombardo, N.J.

    1986-11-01

    COBRA-SFS (Spent Fuel Storage) is a general thermal-hydraulic analysis computer code used to predict temperatures and velocities in a wide variety of systems. The code was refined and specialized for spent fuel storage system analyses for the US Department of Energy's Commercial Spent Fuel Management Program. The finite-volume equations governing mass, momentum, and energy conservation are written for an incompressible, single-phase fluid. The flow equations model a wide range of conditions including natural circulation. The energy equations include the effects of solid and fluid conduction, natural convection, and thermal radiation. The COBRA-SFS code is structured to perform both steady-state and transient calculations: however, the transient capability has not yet been validated. This volume describes the finite-volume equations and the method used to solve these equations. It is directed toward the user who is interested in gaining a more complete understanding of these methods.

  3. Modeling of the performance of weapons MOX fuel in light water reactors

    SciTech Connect

    Alvis, J.; Bellanger, P.; Medvedev, P.G.; Peddicord, K.L.; Gellene, G.I.

    1999-05-01

    Both the Russian Federation and the US are pursing mixed uranium-plutonium oxide (MOX) fuel in light water reactors (LWRs) for the disposition of excess plutonium from disassembled nuclear warheads. Fuel performance models are used which describe the behavior of MOX fuel during irradiation under typical power reactor conditions. The objective of this project is to perform the analysis of the thermal, mechanical, and chemical behavior of weapons MOX fuel pins under LWR conditions. If fuel performance analysis indicates potential questions, it then becomes imperative to assess the fuel pin design and the proposed operating strategies to reduce the probability of clad failure and the associated release of radioactive fission products into the primary coolant system. Applying the updated code to anticipated fuel and reactor designs, which would be used for weapons MOX fuel in the US, and analyzing the performance of the WWER-100 fuel for Russian weapons plutonium disposition are addressed in this report. The COMETHE code was found to do an excellent job in predicting fuel central temperatures. Also, despite minor predicted differences in thermo-mechanical behavior of MOX and UO{sub 2} fuels, the preliminary estimate indicated that, during normal reactor operations, these deviations remained within limits foreseen by fuel pin design.

  4. Literature review of United States utilities computer codes for calculating actinide isotope content in irradiated fuel

    SciTech Connect

    Horak, W.C.; Lu, Ming-Shih

    1991-12-01

    This paper reviews the accuracy and precision of methods used by United States electric utilities to determine the actinide isotopic and element content of irradiated fuel. After an extensive literature search, three key code suites were selected for review. Two suites of computer codes, CASMO and ARMP, are used for reactor physics calculations; the ORIGEN code is used for spent fuel calculations. They are also the most widely used codes in the nuclear industry throughout the world. Although none of these codes calculate actinide isotopics as their primary variables intended for safeguards applications, accurate calculation of actinide isotopic content is necessary to fulfill their function.

  5. ADS-Demo Fuel Rod Performance: Multivariate Statistical Analysis

    SciTech Connect

    Calabrese, R.; Vettraino, F.; Luzzi, L.

    2004-07-01

    A forward step in the development of Accelerator Driven System (ADS) for the Pu, MA and LLFP transmutation, is the realisation of a 80 MWt ADS-demo (XADS) whose basic objective is the system feasibility demonstration. The XADS is forecasted to adopt the UO{sub 2}-PuO{sub 2} mixed-oxides fuel already experimented in the sodium cooled fast reactors such as the french SPX-1. The present multivariate statistical analysis performed by using the Transuranus Code, was carried out for the Normal Operation at the so-called Enhanced Nominal Conditions (120% nominal reactor power), aimed at verifying that the fuel system complies with the stated design limits, i.e. centerline fuel temperature, cladding temperature and damage, during all the in-reactor lifetime. A statistical input set similar to SPX and PEC fuel case, was adopted. One most relevant assumption in the present calculations was a 30% AISI-316 cladding thickness corrosion at EOL. Relative influence of main fuel rod parameters on fuel centerline temperature was also evaluated. (authors)

  6. Diesel fuel detergent additive performance and assessment

    SciTech Connect

    Vincent, M.W.; Papachristos, M.J.; Williams, D.; Burton, J.

    1994-10-01

    Diesel fuel detergent additives are increasingly linked with high quality automotive diesel fuels. Both in Europe and in the USA, field problems associated with fuel injector coking or fouling have been experienced. In Europe indirect injection (IDI) light duty engines used in passenger cars were affected, while in the USA, a direct injection (DI) engine in heavy duty truck applications experienced field problems. In both cases, a fuel additive detergent performance test has evolved using an engine linked with the original field problem, although engine design modifications employed by the manufacturers have ensured improved operation in service. Increasing awareness of the potential for injector nozzle coking to cause deterioration in engine performance is coupled with a need to meet ever more stringent exhaust emissions legislation. These two requirements indicate that the use of detergency additives will continue to be associated with high quality diesel fuels. The paper examines detergency performance evaluated in a range of IDI and DI engines and correlates performance in the two most widely recognised test engines, namely the Peugeot 1.9 litre IDI, and Cummins L10 DI engines. 17 refs., 18 figs., 5 tabs.

  7. Effects of Fuel Distribution on Detonation Tube Performance

    NASA Technical Reports Server (NTRS)

    Perkins, Hugh Douglas

    2002-01-01

    A pulse detonation engine (PDE) uses a series of high frequency intermittent detonation tubes to generate thrust. The process of filling the detonation tube with fuel and air for each cycle may yield non-uniform mixtures. Lack of mixture uniformity is commonly ignored when calculating detonation tube thrust performance. In this study, detonation cycles featuring idealized non-uniform H2/air mixtures were analyzed using the SPARK two-dimensional Navier-Stokes CFD code with 7-step H2/air reaction mechanism. Mixture non-uniformities examined included axial equivalence ratio gradients, transverse equivalence ratio gradients, and partially fueled tubes. Three different average test section equivalence ratios (phi), stoichiometric (phi = 1.00), fuel lean (phi = 0.90), and fuel rich (phi = 1.10), were studied. All mixtures were detonable throughout the detonation tube. It was found that various mixtures representing the same test section equivalence ratio had specific impulses within 1 percent of each other, indicating that good fuel/air mixing is not a prerequisite for optimal detonation tube performance.

  8. Fuel performance annual report for 1983. Volume 1

    SciTech Connect

    Bailey, W.J.; Dunenfeld, M.S.

    1985-03-01

    This annual report, the sixth in a series, provides a brief description of fuel performance during 1983 in commercial nuclear power plants. Brief summaries of fuel design changes, fuel surveillance programs, fuel operating experience, fuel problems, high-burnup fuel experience, and items of general significance are provided. References to additional, more detailed information and related NRC evaluations are included.

  9. Fuel performance annual report for 1990. Volume 8

    SciTech Connect

    Preble, E.A.; Painter, C.L.; Alvis, J.A.; Berting, F.M.; Beyer, C.E.; Payne, G.A.; Wu, S.L.

    1993-11-01

    This annual report, the thirteenth in a series, provides a brief description of fuel performance during 1990 in commercial nuclear power plants. Brief summaries of fuel design changes, fuel surveillance programs, fuel operating experience and trends, fuel problems high-burnup fuel experience, and items of general significance are provided . References to additional, more detailed information, and related NRC evaluations are included where appropriate.

  10. Performance Analysis of Optical Code Division Multiplex System

    NASA Astrophysics Data System (ADS)

    Kaur, Sandeep; Bhatia, Kamaljit Singh

    2013-12-01

    This paper presents the Pseudo-Orthogonal Code generator for Optical Code Division Multiple Access (OCDMA) system which helps to reduce the need of bandwidth expansion and improve spectral efficiency. In this paper we investigate the performance of multi-user OCDMA system to achieve data rate more than 1 Tbit/s.

  11. Performance of concatenated codes using 8-bit and 10-bit Reed-Solomon codes

    NASA Technical Reports Server (NTRS)

    Pollara, F.; Cheung, K.-M.

    1989-01-01

    The performance improvement of concatenated coding systems using 10-bit instead of 8-bit Reed-Solomon codes is measured by simulation. Three inner convolutional codes are considered: (7,1/2), (15,1/4), and (15,1/6). It is shown that approximately 0.2 dB can be gained at a bit error rate of 10(-6). The loss due to nonideal interleaving is also evaluated. Performance comparisons at very low bit error rates may be relevant for systems using data compression.

  12. NPAC-Nozzle Performance Analysis Code

    NASA Technical Reports Server (NTRS)

    Barnhart, Paul J.

    1997-01-01

    A simple and accurate nozzle performance analysis methodology has been developed. The geometry modeling requirements are minimal and very flexible, thus allowing rapid design evaluations. The solution techniques accurately couple: continuity, momentum, energy, state, and other relations which permit fast and accurate calculations of nozzle gross thrust. The control volume and internal flow analyses are capable of accounting for the effects of: over/under expansion, flow divergence, wall friction, heat transfer, and mass addition/loss across surfaces. The results from the nozzle performance methodology are shown to be in excellent agreement with experimental data for a variety of nozzle designs over a range of operating conditions.

  13. Comparative analysis of isotopic composition of spent fuel from Takahama-3 PWR PIE database using TRIPOLI-PEPIN code

    SciTech Connect

    Lee, Y. K.

    2006-07-01

    Evaluation of isotopic composition of spent nuclear fuel is essential for reactor physics and fuel cycle back-end applications. A TRIPOLI-PEPIN coupled depletion code, TR4PEP, has been developed to meet these requirements. It combines the continuous-energy Monte Carlo transport code, TRIPOLI4.3 [1] and the point depletion code, PEPIN-2 [2], to perform the burnup dependent material data calculation. The depletion calculation flow of TR4PEP code has been presented on a previous study. Its application on PWR UO{sub 2} and MOX spent fuel has been validated against several international numerical benchmarks. Compared to industry standard deterministic cell codes and other Monte Carlo based depletion codes, TR4PEP deep-burn depletion calculations have shown satisfactory results. [3] In addition to the numerical benchmarks, the analysis of available post irradiation examination (PIE) results by TR4PEP is also important The PIE results at fuel assembly level are accessible only from spent fuel reprocessing plant and these data are not easy to use for code validation due to the dissolution of several assemblies in the same time. The PIE results at fuel pellet level depend not only on the method for the isotopic measurements but also on the irradiation environment and history. A free access PIE database on isotopic composition of spent nuclear fuel is obtainable from OECD/NEA. [4] Both PWR and BWR PIE data at fuel pellet level are taken into account in this database but the only 17 x 17 type PWR fuel available in this database is from Takahama-3 PIE results. To validate TR4PEP with Takahama-3 PIE results, two irradiated UO{sub 2} samples, SF95-4 from fuel assembly NT3G23 and SF97-5 from NT3G24, are considered in this study. Both samples have an initial {sup 235}U enrichment of 4.11 wt% and their burnup are respectively 36.69 and 47.03 GWd/t. Comparative analysis of isotopic composition from SF95-4 and SF97-5 including 19 actinides from {sup 234}U to {sup 247}Cm and 18

  14. The Performance of Spent Fuel Casks in Severe Tunnel Fires

    SciTech Connect

    Bajwa, C.S.; Easton, E.P.; Hansen, A.

    2006-07-01

    The Nuclear Regulatory Commission (NRC), working with the National Institute of Standards and Technology (NIST), Pacific Northwest National Laboratory (PNNL), and the National Transportation Safety Board (NTSB), performed analyses to predict the response of various spent fuel transportation cask designs when exposed to a fire similar to that which occurred in the Howard Street railroad tunnel in downtown Baltimore, Maryland on July 18, 2001. The thermal performance of three different spent fuel cask designs (HOLTEC HI-STAR 100, TransNuclear TN-68, and NAC-LWT) was evaluated with the ANSYS{sup R} and COBRA-SFS analysis codes, utilizing boundary conditions for the tunnel fire obtained using NIST's Fire Dynamics Simulator (FDS) code. NRC Staff evaluated the potential for a release of radioactive material from each of the three transportation casks analyzed for the Baltimore tunnel fire scenario. The results of these analyses are described in detail in Spent Fuel Transportation Package Response to the Baltimore Tunnel Fire Scenario, NUREG/CR-6886, published in draft for comment in November 2005. Comments received by the NRC on NUREG/CR-6886 will be addressed in the final version of the report. (authors)

  15. Length-Limited Variable-to-Variable Length Codes for High-Performance Entropy Coding

    SciTech Connect

    Duchaineau, M; Joy, K I; Senecal, J

    2003-11-17

    Arithmetic coding achieves a superior coding rate when encoding a binary source, but its lack of speed makes it an inferior choice when true high-performance encoding is needed. We present our work on a practical implementation of fast entropy coders for binary messages utilizing only bit shifts and table lookups. To limit code table size we limit our code lengths with a type of variable-to-variable (VV) length code created from source string merging. We refer to these codes as ''merged codes''. With merged codes it is possible to achieve a desired level of speed by adjusting the number of bits read from the source at each step. The most efficient merged codes yield a coder with a worst-case inefficiency of 0.4%, relative to the Shannon entropy. Using a hybrid Golomb-VV Bin Coder we are able to achieve a compression ratio that is competitive with other state-of-the-art coders, at a superior throughput.

  16. Length-Limited Variable-to-Variable Length Codes for High-Performance Entropy Coding

    SciTech Connect

    Duchaineau, M; Senecal, J; Joy, K I

    2004-01-05

    Arithmetic coding achieves a superior coding rate when encoding a binary source, but its lack of speed makes it an inferior choice when true high-performance encoding is needed. We present our work on a practical implementation of fast entropy coders for binary messages utilizing only bit shifts and table lookups. To limit code table size we limit our code lengths with a type of variable-to-variable (VV) length code created from source string merging. We refer to these codes as ''merged codes''. With merged codes it is possible to achieve a desired level of speed by adjusting the number of bits read from the source at each step. The most efficient merged codes yield a coder with a worst-case inefficiency of 0.4%, relative to the Shannon entropy. Using a hybrid Golomb-VV Bin Coder we are able to achieve a compression ratio that is competitive with other state-of-the-art coders, at a superior throughput.

  17. Transfer function bounds on the performance of turbo codes

    NASA Technical Reports Server (NTRS)

    Divsalar, D.; Dolinar, S.; Pollara, F.; Mceliece, R. J.

    1995-01-01

    In this article we apply transfer function bounding techniques to obtain upper bounds on the bit-error rate for maximum likelihood decoding of turbo codes constructed with random permutations. These techniques are applied to two turbo codes with constraint length 3 and later extended to other codes. The performance predicted by these bounds is compared with simulation results. The bounds are useful in estimating the 'error floor' that is difficult to measure by simulation, and they provide insight on how to lower this floor. More refined bounds are needed for accurate performance measures at lower signal-to-noise ratios.

  18. Method for improving fuel cell performance

    DOEpatents

    Uribe, Francisco A.; Zawodzinski, Thomas

    2003-10-21

    A method is provided for operating a fuel cell at high voltage for sustained periods of time. The cathode is switched to an output load effective to reduce the cell voltage at a pulse width effective to reverse performance degradation from OH adsorption onto cathode catalyst surfaces. The voltage is stepped to a value of less than about 0.6 V to obtain the improved and sustained performance.

  19. Preserving Envelope Efficiency in Performance Based Code Compliance

    SciTech Connect

    Thornton, Brian A.; Sullivan, Greg P.; Rosenberg, Michael I.; Baechler, Michael C.

    2015-06-20

    The City of Seattle 2012 Energy Code (Seattle 2014), one of the most progressive in the country, is under revision for its 2015 edition. Additionally, city personnel participate in the development of the next generation of the Washington State Energy Code and the International Energy Code. Seattle has pledged carbon neutrality by 2050 including buildings, transportation and other sectors. The United States Department of Energy (DOE), through Pacific Northwest National Laboratory (PNNL) provided technical assistance to Seattle in order to understand the implications of one potential direction for its code development, limiting trade-offs of long-lived building envelope components less stringent than the prescriptive code envelope requirements by using better-than-code but shorter-lived lighting and heating, ventilation, and air-conditioning (HVAC) components through the total building performance modeled energy compliance path. Weaker building envelopes can permanently limit building energy performance even as lighting and HVAC components are upgraded over time, because retrofitting the envelope is less likely and more expensive. Weaker building envelopes may also increase the required size, cost and complexity of HVAC systems and may adversely affect occupant comfort. This report presents the results of this technical assistance. The use of modeled energy code compliance to trade-off envelope components with shorter-lived building components is not unique to Seattle and the lessons and possible solutions described in this report have implications for other jurisdictions and energy codes.

  20. Fuel Performance Calculations for FeCrAl Cladding in BWRs

    SciTech Connect

    George, Nathan; Sweet, Ryan; Maldonado, G. Ivan; Wirth, Brian D.; Powers, Jeffrey J.; Worrall, Andrew

    2015-01-01

    This study expands upon previous neutronics analyses of the reactivity impact of alternate cladding concepts in boiling water reactor (BWR) cores and directs focus toward contrasting fuel performance characteristics of FeCrAl cladding against those of traditional Zircaloy. Using neutronics results from a modern version of the 3D nodal simulator NESTLE, linear power histories were generated and supplied to the BISON-CASL code for fuel performance evaluations. BISON-CASL (formerly Peregrine) expands on material libraries implemented in the BISON fuel performance code and the MOOSE framework by providing proprietary material data. By creating material libraries for Zircaloy and FeCrAl cladding, the thermomechanical behavior of the fuel rod (e.g., strains, centerline fuel temperature, and time to gap closure) were investigated and contrasted.

  1. Thermal-mechanical performance modeling of thorium-plutonium oxide fuel and comparison with on-line irradiation data

    NASA Astrophysics Data System (ADS)

    Insulander Björk, Klara; Kekkonen, Laura

    2015-12-01

    Thorium-plutonium Mixed OXide (Th-MOX) fuel is considered for use in light water reactors fuel due to some inherent benefits over conventional fuel types in terms of neutronic properties. The good material properties of ThO2 also suggest benefits in terms of thermal-mechanical fuel performance, but the use of Th-MOX fuel for commercial power production demands that its thermal-mechanical behavior can be accurately predicted using a well validated fuel performance code. Given the scant operational experience with Th-MOX fuel, no such code is available today. This article describes the first phase of the development of such a code, based on the well-established code FRAPCON 3.4, and in particular the correlations reviewed and chosen for the fuel material properties. The results of fuel temperature calculations with the code in its current state of development are shown and compared with data from a Th-MOX test irradiation campaign which is underway in the Halden research reactor. The results are good for fresh fuel, whereas experimental complications make it difficult to judge the adequacy of the code for simulations of irradiated fuel.

  2. Performance of DBS-Radio using concatenated coding and equalization

    NASA Technical Reports Server (NTRS)

    Gevargiz, J.; Bell, D.; Truong, L.; Vaisnys, A.; Suwitra, K.; Henson, P.

    1995-01-01

    The Direct Broadcast Satellite-Radio (DBS-R) receiver is being developed for operation in a multipath Rayleigh channel. This receiver uses equalization and concatenated coding, in addition to open loop and closed loop architectures for carrier demodulation and symbol synchronization. Performance test results of this receiver are presented in both AWGN and multipath Rayleigh channels. Simulation results show that the performance of the receiver operating in a multipath Rayleigh channel is significantly improved by using equalization. These results show that fractional-symbol equalization offers a performance advantage over full symbol equalization. Also presented is the base-line performance of the DBS-R receiver using concatenated coding and interleaving.

  3. Spent fuel management fee methodology and computer code user's manual.

    SciTech Connect

    Engel, R.L.; White, M.K.

    1982-01-01

    The methodology and computer model described here were developed to analyze the cash flows for the federal government taking title to and managing spent nuclear fuel. The methodology has been used by the US Department of Energy (DOE) to estimate the spent fuel disposal fee that will provide full cost recovery. Although the methodology was designed to analyze interim storage followed by spent fuel disposal, it could be used to calculate a fee for reprocessing spent fuel and disposing of the waste. The methodology consists of two phases. The first phase estimates government expenditures for spent fuel management. The second phase determines the fees that will result in revenues such that the government attains full cost recovery assuming various revenue collection philosophies. These two phases are discussed in detail in subsequent sections of this report. Each of the two phases constitute a computer module, called SPADE (SPent fuel Analysis and Disposal Economics) and FEAN (FEe ANalysis), respectively.

  4. Interim report on fuel cycle neutronics code development.

    SciTech Connect

    Rabiti, C; Smith, M. A.; Kaushik, D.; Yang, W. S.

    2008-05-13

    present good results for an OECD benchmark obtained using the new two-dimensional capability of the MOCFE solver. Additional work on the MOCFE solver is focused on studying the current parallelization algorithms that can be applied to both the two- and three-dimensional implementations such that they are scalable to thousands of processors. The initial research into this topic indicates that, as expected, the current parallelization scheme is not sufficiently scalable for the detailed reactor geometry that it is intended for. As a consequence, we are starting the investigative research to determine the alternatives that are applicable for massively parallel machines. The major development goal in fiscal year 2008 for the PN2ND and SN2ND solvers was to introduce parallelism by angle and energy. The motivation for this is two-fold: (1) reduce the memory burden by picking a simpler preconditioner with reduced matrix storage and (2) improve parallel performance by solving the angular subsystems of the within group equation simultaneously. The solver development in FY2007 focused on using PETSc to solve the within group equation where only spatial parallelization was utilized. Because most homogeneous problems required relatively few spatial degrees of freedom (tens of thousands) the only way to improve the parallelism was to spread the angular moment subsystems across the parallel system. While the coding has been put into place for parallelization by space, angle, and group, we have not optimized any of the solvers and therefore do not give an assessment of the achievement of this work in this report. The immediate task to be completed is to implement and validate Tchebychev acceleration of the fission source iteration algorithm (inverse power method in this work) and optimize both the PN2ND and SN2ND solvers. We further intend to extend the applicability of the UNIC code by adding a first-order discrete ordinates solver termed SN1ST. Upon completion of this work, all memory

  5. Performance of fuel failure detection system for coated particle fuels

    SciTech Connect

    Treada, H.; Ohkawa, H.; Ohlsu, H.; Wakayama, N.; Yoshida, H.

    1985-04-01

    An experimental system was developed for a study of fuel failure detection (FFD) method for coated particle fuels (CPF's) of a high-temperature gas-cooled reactor. Various performance of the FFD-system were examined using a CPF-irradiation rig in the Japan Material Testing Reactor. By experiments, it was made sure that the counting rates of fission products (FP's), released from the CPF's, change with the reactor-power and the fuel-temperature remarkably even during the normal reactor operation. Also, an ability of the selective detection of only short-life FP-nuclides was studied in relation to the travelling time of the sampling gas. The results showed that the contributions of the short-life FP-nuclides such as Kr-89 and Kr-90 are more than 80 percent to the total FP-counting rate at the shortest travelling time of 120 sec. It is concluded that the selective detection of only the short-life FP-nuclides can be realized by controlling the travelling time properly.

  6. The design and performance of the research reactor fuel counter

    SciTech Connect

    Abhold, M.E.; Hsue, S.T.; Menlove, H.O.; Walton, G.; Holt, S.

    1996-09-01

    This paper describes the design features, hardware specifications, and performance characteristics of the Research Reactor Fuel Counter (RRFC) System. The system is an active mode neutron coincidence counter intended to assay material test reactor fuel assemblies under water. The RRFC contains 12 {sup 3}He tubes, each with its own preamplifier, and a single ion chamber. The neutron counting electronics are based on the Los Alamos Portable Shift Register (PSR) and the gamma readout is a manual-range pico-ammeter of Los Alamos design. The RRFC is connected to the surface by a 20-m-long cable bundle. The PSR is controlled by a portable IBM computer running a modified version of the Los Alamos neutron coincidence counting code also called RRFC. There is a manual that describes the RRFC software.

  7. Performance of RS codes in lognormally shadowed Rician channels

    NASA Astrophysics Data System (ADS)

    Trabelsi, Chokri; Yongacoglu, Abbas

    The performance of Reed-Solomon (RS) codes with binary phase shift keying transmission is determined for a class of fading models for land mobile satellite communications. The fading model has the structure of a Rician model except that the line-of-sight component is subjected to a lognormal transformation. By exploiting the statistical characteristics of the multipath fading and shadowing, an effective coding/interleaving scheme is proposed.

  8. Survey of computer codes applicable to waste facility performance evaluations

    SciTech Connect

    Alsharif, M.; Pung, D.L.; Rivera, A.L.; Dole, L.R.

    1988-01-01

    This study is an effort to review existing information that is useful to develop an integrated model for predicting the performance of a radioactive waste facility. A summary description of 162 computer codes is given. The identified computer programs address the performance of waste packages, waste transport and equilibrium geochemistry, hydrological processes in unsaturated and saturated zones, and general waste facility performance assessment. Some programs also deal with thermal analysis, structural analysis, and special purposes. A number of these computer programs are being used by the US Department of Energy, the US Nuclear Regulatory Commission, and their contractors to analyze various aspects of waste package performance. Fifty-five of these codes were identified as being potentially useful on the analysis of low-level radioactive waste facilities located above the water table. The code summaries include authors, identification data, model types, and pertinent references. 14 refs., 5 tabs.

  9. Performance model of molten carbonate fuel cell

    SciTech Connect

    Matsumoto, S.; Sasaki, A.; Urushibata, H.; Tanaka, T. )

    1990-06-01

    A performance model of a molten carbonate fuel cell (MCFC), that is an electrochemical energy conversion device for electric power generation, is discussed. The authors' purpose is to improve the presumptive ability of the MCFC model and to investigate the impact of MCFC characteristics in fuel cell system simulations. Basic data are obtained experimentally by single-cell tests. The authors pay special attention to the MCFC overall characteristics with respect to oxidant composition. A correlation formula based on the experimental data is derived as for the cell voltage, oxygen and carbon dioxide partial pressures. After three types of the MCFC system option are assumed, trade-off studies are made dependant on the performance models.

  10. Modelling fuel cell performance using artificial intelligence

    NASA Astrophysics Data System (ADS)

    Ogaji, S. O. T.; Singh, R.; Pilidis, P.; Diacakis, M.

    Over the last few years, fuel cell technology has been increasing promisingly its share in the generation of stationary power. Numerous pilot projects are operating worldwide, continuously increasing the amount of operating hours either as stand-alone devices or as part of gas turbine combined cycles. An essential tool for the adequate and dynamic analysis of such systems is a software model that enables the user to assess a large number of alternative options in the least possible time. On the other hand, the sphere of application of artificial neural networks has widened covering such endeavours of life such as medicine, finance and unsurprisingly engineering (diagnostics of faults in machines). Artificial neural networks have been described as diagrammatic representation of a mathematical equation that receives values (inputs) and gives out results (outputs). Artificial neural networks systems have the capacity to recognise and associate patterns and because of their inherent design features, they can be applied to linear and non-linear problem domains. In this paper, the performance of the fuel cell is modelled using artificial neural networks. The inputs to the network are variables that are critical to the performance of the fuel cell while the outputs are the result of changes in any one or all of the fuel cell design variables, on its performance. Critical parameters for the cell include the geometrical configuration as well as the operating conditions. For the neural network, various network design parameters such as the network size, training algorithm, activation functions and their causes on the effectiveness of the performance modelling are discussed. Results from the analysis as well as the limitations of the approach are presented and discussed.

  11. Calculation of the Fast Flux Test Facility fuel pin tests with the WIMS-E and MCNP codes

    SciTech Connect

    Schwinkendorf, K.N.; Wittekind, W.D.; Toffer, H.

    1991-10-01

    The Fuel Assembly Area (FAA) at the Fast Flux Test Facility site on the Hanford Site at Richland, Washington currently is being prepared to fabricate mixed oxide fuel (U, Pu) for the FFTF. Calculational tools are required to perform criticality safety analyses for various process locations and to establish safe limits for fissile material handling at the FAA. These codes require validation against experimental data appropriate for the compositions that will be handled. Critical array experiments performed by Bierman provide such data for mixed oxide fuel in the range Pu/(U+Pu) = 22 wt %, and with Pu-240 contents equal to 12 wt %. Both the Monte Carlo Neutron Photon (MCNP) and the Winfrith Improved Multigroup Scheme (WIMS-E) computer codes were used to calculate the neutron multiplication factor for explicit models of the various critical arrays. The W-CACTUS modules within the WIMS-E code system was used to calculate k{infinity} for the explicit array configuration, as well as few-group cross sections that were then used in a three-dimensional diffusion theory code for the calculation of k{sub eff} for the finite array. 10 refs., 15 figs., 7 tabs.

  12. EFFECTS OF FUEL IMPURITIES ON PEM FUEL CELL PERFORMANCE.

    SciTech Connect

    Uribe, F. A.; Zawodzinski, T. A. , Jr.

    2001-01-01

    Power generation with polymer electrolyte membrane fuel cells (PEMFC), particularly those designed for domestic and transportation applications, will likely operate on hydrogen reformed from hydrocarbons. The primary sources of H{sub 2} can be methane (from natural gas), gasoline or diesel fuel. Unfortunately, the reforming process generates impurities that may negatively affect FC performance. The effects of CO impurity have received most of the attention. However, there are other impurities that also may be detrimental to FC: operation. Here we present the effects of ammonia, hydrogen sulfide, methane and ethylene. Two structural domains of the membrane and electrode assembly (MEA) are usually affected by the presence of a harmful impurity. First, the impurity may decrease the ionic conductivity in the catalyst layer or in the bulk membrane. Second, the impurity may chemisorb onto the anode catalyst surface, suppressing the catalyst activity for H{sub 2} oxidation. Catalyst poisoning by CO is the best known example of this kind of effect. Fuel reforming processes [1] generally involve the reaction of a fuel source with air. The simultaneous presence of N{sub 2} and H{sub 2} may generate NH{sub 3} in concentrations of 30 to 90 ppm [1]. The effect of NH{sub 3} on performance depends on the impurity concentration and the time of anode exposure [2]. Higher concentrations result in more rapid performance decreases. If the cell is exposed to ammonia for about 1 hour and then returned to neat H{sub 2}, it will recover its original performance very slowly (about 12 hrs). This behavior is quite different from that of CO, which can be quickly purged from the anode with pure H{sub 2}, resulting in complete performance restoration within a few minutes. Longer exposure times (e.g. >15 hrs) to ammonia result in severe and irreversible losses in performance. It seems that replacement of H{sup +} ions by NH{sub 4}{sup +} ions, first within the anode catalyst layer and then in

  13. High energy-density liquid rocket fuel performance

    NASA Technical Reports Server (NTRS)

    Rapp, Douglas C.

    1990-01-01

    A fuel performance database of liquid hydrocarbons and aluminum-hydrocarbon fuels was compiled using engine parametrics from the Space Transportation Engine Program as a baseline. Propellant performance parameters are introduced. General hydrocarbon fuel performance trends are discussed with respect to hydrogen-to-carbon ratio and heat of formation. Aluminum-hydrocarbon fuel performance is discussed with respect to aluminum metal loading. Hydrocarbon and aluminum-hydrocarbon fuel performance is presented with respect to fuel density, specific impulse and propellant density specific impulse.

  14. High energy-density liquid rocket fuel performance

    NASA Technical Reports Server (NTRS)

    Rapp, Douglas C.

    1990-01-01

    A fuel performance database of liquid hydrocarbons and aluminum-hydrocarbon fuels was compiled using engine parametrics from the Space Transportation Engine Program as a baseline. Propellant performance parameters are introduced. General hydrocarbon fuel performance trends are discussed with respect to hydrogen-to-carbon ratio and heat of formation. Aluminum-hydrocarbon fuel performance is discussed with respect to aluminum metal loading. Hydrocarbon and aluminum-hydrocarbon fuel performance is presented with respect to fuel density, specific impulse, and propellant density specific impulse.

  15. Post irradiation analysis and performance modeling of dispersion and monolithic U-Mo fuels

    SciTech Connect

    Kim, Yeon Soo; Hofman, G.L.; Medvedev, P.G.; Robinson, A.B.; Shevlyakov, G.V.; Ryu, H.J.

    2008-07-15

    We analyzed fission product swelling of post-irradiation U-Mo fuels from the early RERTR tests to the recent RERTR-8 test. We found that the gas bubble swelling of the fuel-swelling model was overestimated. From the recent tests, RERTR-7A and 8, we could also collect a considerable amount of fuel swelling data from monolithic U-Mo fuel plates. The fuel swelling data from the monolithic fuel plates are considered more reliable because the interaction layer growth between the fuel and matrix in dispersion fuel, which obscures fuel swelling, does not exist. The swelling correlation comparison to the Si-added dispersion fuel data and monolithic fuel data suggested that a modification of the existing model was necessary. We also developed an interaction layer growth model for U-Mo/Al dispersion fuel plates with a Si-added matrix. PLATE code calculations with the new PIE data analysis results were performed. The updated versions predict with better accuracies for both monolithic fuel plates and dispersion fuel plates. In this paper, we present the results of fission product swelling characterization. In addition, the interaction layer growth model for U-Mo/Al with a Si-added matrix is presented. (author)

  16. Fuel performance annual report for 1984. Volume 2

    SciTech Connect

    Bailey, W.J.; Dunenfeld, M.S.

    1986-03-01

    This annual report, the seventh in a series, provides a brief description of fuel performance during 1984 in commercial nuclear power plants. Brief summaries of fuel design changes, fuel surveillance programs, fuel operating experience, fuel problems, high-burnup fuel experience, and items of general significance are provided. References to additional, more detailed information and related NRC evaluations are included. 279 refs., 11 figs., 29 tabs.

  17. Development of high performance hybrid rocket fuels

    NASA Astrophysics Data System (ADS)

    Zaseck, Christopher R.

    . In order to examine paraffin/additive combustion in a motor environment, I conducted experiments on well characterized aluminum based additives. In particular, I investigate the influence of aluminum, unpassivated aluminum, milled aluminum/polytetrafluoroethylene (PTFE), and aluminum hydride on the performance of paraffin fuels for hybrid rocket propulsion. I use an optically accessible combustor to examine the performance of the fuel mixtures in terms of characteristic velocity efficiency and regression rate. Each combustor test consumes a 12.7 cm long, 1.9 cm diameter fuel strand under 160 kg/m 2s of oxygen at up to 1.4 MPa. The experimental results indicate that the addition of 5 wt.% 30 mum or 80 nm aluminum to paraffin increases the regression rate by approximately 15% compared to neat paraffin grains. At higher aluminum concentrations and nano-scale particles sizes, the increased melt layer viscosity causes slower regression. Alane and Al/PTFE at 12.5 wt.% increase the regression of paraffin by 21% and 32% respectively. Finally, an aging study indicates that paraffin can protect air and moisture sensitive particles from oxidation. The opposed burner and aluminum/paraffin hybrid rocket experiments show that additives can alter bulk fuel properties, such as viscosity, that regulate entrainment. The general effect of melt layer properties on the entrainment and regression rate of paraffin is not well understood. Improved understanding of how solid additives affect the properties and regression of paraffin is essential to maximize performance. In this document I investigate the effect of melt layer properties on paraffin regression using inert additives. Tests are performed in the optical cylindrical combustor at ˜1 MPa under a gaseous oxygen mass flux of ˜160 kg/m2s. The experiments indicate that the regression rate is proportional to mu0.08rho 0.38kappa0.82. In addition, I explore how to predict fuel viscosity, thermal conductivity, and density prior to testing

  18. CFD Analysis of Coolant Flow in VVER-440 Fuel Assemblies with the Code ANSYS CFX 10.0

    SciTech Connect

    Toth, Sandor; Legradi, Gabor; Aszodi, Attila

    2006-07-01

    From the aspect of planning the power upgrading of nuclear reactors - including the VVER-440 type reactor - it is essential to get to know the flow field in the fuel assembly. For this purpose we have developed models of the fuel assembly of the VVER-440 reactor using the ANSYS CFX 10.0 CFD code. At first a 240 mm long part of a 60 degrees segment of the fuel pin bundle was modelled. Implementing this model a sensitivity study on the appropriate meshing was performed. Based on the development of the above described model, further models were developed: a 960 mm long part of a 60-degree-segment and a full length part (2420 mm) of the fuel pin bundle segment. The calculations were run using constant coolant properties and several turbulence models. The impacts of choosing different turbulence models were investigated. The results of the above-mentioned investigations are presented in this paper. (authors)

  19. COBRA-SFS: A thermal-hydraulic analysis code for spent fuel storage and transportation casks

    SciTech Connect

    Michener, T.E.; Rector, D.R.; Cuta, J.M.; Dodge, R.E.; Enderlin, C.W.

    1995-09-01

    COBRA-SFS is a general thermal-hydraulic analysis computer code for prediction of material temperatures and fluid conditions in a wide variety of systems. The code has been validated for analysis of spent fuel storage systems, as part of the Commercial Spent Fuel Management Program of the US Department of Energy. The code solves finite volume equations representing the conservation equations for mass, moment, and energy for an incompressible single-phase heat transfer fluid. The fluid solution is coupled to a finite volume solution of the conduction equation in the solid structure of the system. This document presents a complete description of Cycle 2 of COBRA-SFS, and consists of three main parts. Part 1 describes the conservation equations, constitutive models, and solution methods used in the code. Part 2 presents the User Manual, with guidance on code applications, and complete input instructions. This part also includes a detailed description of the auxiliary code RADGEN, used to generate grey body view factors required as input for radiative heat transfer modeling in the code. Part 3 describes the code structure, platform dependent coding, and program hierarchy. Installation instructions are also given for the various platform versions of the code that are available.

  20. Integrated Radiation Transport and Nuclear Fuel Performance for Assembly-Level Simulations

    SciTech Connect

    Clarno, Kevin T; Hamilton, Steven P; Philip, Bobby; Berrill, Mark A; Sampath, Rahul S; Allu, Srikanth; Pugmire, Dave; Dilts, Gary; Banfield, James E

    2012-02-01

    The Advanced Multi-Physics (AMP) Nuclear Fuel Performance code (AMPFuel) is focused on predicting the temperature and strain within a nuclear fuel assembly to evaluate the performance and safety of existing and advanced nuclear fuel bundles within existing and advanced nuclear reactors. AMPFuel was extended to include an integrated nuclear fuel assembly capability for (one-way) coupled radiation transport and nuclear fuel assembly thermo-mechanics. This capability is the initial step toward incorporating an improved predictive nuclear fuel assembly modeling capability to accurately account for source-terms and boundary conditions of traditional (single-pin) nuclear fuel performance simulation, such as the neutron flux distribution, coolant conditions, and assembly mechanical stresses. A novel scheme is introduced for transferring the power distribution from the Scale/Denovo (Denovo) radiation transport code (structured, Cartesian mesh with smeared materials within each cell) to AMPFuel (unstructured, hexagonal mesh with a single material within each cell), allowing the use of a relatively coarse spatial mesh (10 million elements) for the radiation transport and a fine spatial mesh (3.3 billion elements) for thermo-mechanics with very little loss of accuracy. In addition, a new nuclear fuel-specific preconditioner was developed to account for the high aspect ratio of each fuel pin (12 feet axially, but 1 4 inches in diameter) with many individual fuel regions (pellets). With this novel capability, AMPFuel was used to model an entire 17 17 pressurized water reactor fuel assembly with many of the features resolved in three dimensions (for thermo-mechanics and/or neutronics), including the fuel, gap, and cladding of each of the 264 fuel pins; the 25 guide tubes; the top and bottom structural regions; and the upper and lower (neutron) reflector regions. The final, full assembly calculation was executed on Jaguar using 40,000 cores in under 10 hours to model over 162

  1. COBRA-SFS CYCLE 3: Code System for Thermal Hydraulic Analysis of Spent Fuel Casks

    Energy Science and Technology Software Center (ESTSC)

    2003-11-01

    COBRA-SFS (Spent Fuel Storage) is a code for thermal-hydraulic analysis of multi-assembly spent fuel storage and transportation systems. It uses a lumped parameter finite difference approach to predict flow and temperature distributions in spent fuel storage systems and fuel assemblies, under forced and natural convection heat transfer conditions. Derived from the COBRA family of codes, which have been extensively evaluated against in-pile and out-of-pile data, COBRA-SFS retains all the important features of the COBRA codesmore » for single phase fluid analysis and extends the range application to include problems with two-dimensional radiative and three-dimensional conductive heat transfer. COBRA-SFS has been used to analyze various single- and multi-assembly spent fuel storage systems containing unconsolidated and consolidated fuel rods, with a variety of fill media, including air, helium and vacuum. Cycle 0 of COBRA-SFS was released in 1986. Subsequent applications of the code led to development of additional capabilities, which resulted in the release of Cycle 1 in February 1989. Since then, the code has undergone an independent technical review as part of a submittal to the Nuclear Regulatory Commission for a generic license to apply the code to spent fuel storage system analysis. Modifications and improvements to the code have been combined to form Cycle 2. Cycle 3., the newest version of COBRA-SFS, has been validated and verified for transient applications, such as a storage cask thermal response to a pool fire.« less

  2. The SECO suite of codes for site Performance Assessment

    SciTech Connect

    Roache, P.J.

    1993-03-01

    Modeling for Performance Assessment of the Waste Isolation Pilot Plant (WIPP ) has led to development of the SECO suite of codes for groundwater flow, particle tracking, and transport. Algorithm and code developments include the following areas: facilitation of grid convergence tests in multiple domains; correct treatment of transmissivity factors for unconfined aquifers; efficient multigrid algorithms; a formulation of brine Darcy flow equations that uses freshwater head as the dependent able; boundary-fitted coordinates; temporal high order particle tracking; an efficient and accurate implicit Finite Volume TVD algorithm for radionuclide transport in (possibly) fractured porous media; accurate calculation of advection via a flux-based modified method of characteristics; and Quality Assurance procedures.

  3. Multi-Zone Liquid Thrust Chamber Performance Code with Domain Decomposition for Parallel Processing

    NASA Technical Reports Server (NTRS)

    Navaz, Homayun K.

    2002-01-01

    Computational Fluid Dynamics (CFD) has considerably evolved in the last decade. There are many computer programs that can perform computations on viscous internal or external flows with chemical reactions. CFD has become a commonly used tool in the design and analysis of gas turbines, ramjet combustors, turbo-machinery, inlet ducts, rocket engines, jet interaction, missile, and ramjet nozzles. One of the problems of interest to NASA has always been the performance prediction for rocket and air-breathing engines. Due to the complexity of flow in these engines it is necessary to resolve the flowfield into a fine mesh to capture quantities like turbulence and heat transfer. However, calculation on a high-resolution grid is associated with a prohibitively increasing computational time that can downgrade the value of the CFD for practical engineering calculations. The Liquid Thrust Chamber Performance (LTCP) code was developed for NASA/MSFC (Marshall Space Flight Center) to perform liquid rocket engine performance calculations. This code is a 2D/axisymmetric full Navier-Stokes (NS) solver with fully coupled finite rate chemistry and Eulerian treatment of liquid fuel and/or oxidizer droplets. One of the advantages of this code has been the resemblance of its input file to the JANNAF (Joint Army Navy NASA Air Force Interagency Propulsion Committee) standard TDK code, and its automatic grid generation for JANNAF defined combustion chamber wall geometry. These options minimize the learning effort for TDK users, and make the code a good candidate for performing engineering calculations. Although the LTCP code was developed for liquid rocket engines, it is a general-purpose code and has been used for solving many engineering problems. However, the single zone formulation of the LTCP has limited the code to be applicable to problems with complex geometry. Furthermore, the computational time becomes prohibitively large for high-resolution problems with chemistry, two

  4. Development of a massively parallel parachute performance prediction code

    SciTech Connect

    Peterson, C.W.; Strickland, J.H.; Wolfe, W.P.; Sundberg, W.D.; McBride, D.D.

    1997-04-01

    The Department of Energy has given Sandia full responsibility for the complete life cycle (cradle to grave) of all nuclear weapon parachutes. Sandia National Laboratories is initiating development of a complete numerical simulation of parachute performance, beginning with parachute deployment and continuing through inflation and steady state descent. The purpose of the parachute performance code is to predict the performance of stockpile weapon parachutes as these parachutes continue to age well beyond their intended service life. A new massively parallel computer will provide unprecedented speed and memory for solving this complex problem, and new software will be written to treat the coupled fluid, structure and trajectory calculations as part of a single code. Verification and validation experiments have been proposed to provide the necessary confidence in the computations.

  5. Performance analysis of a multilevel coded modulation system

    NASA Astrophysics Data System (ADS)

    Kofman, Yosef; Zehavi, Ephraim; Shamai, Shlomo

    1994-02-01

    A modified version of the multilevel coded modulation scheme of Imai & Hirakawa is presented and analyzed. In the transmitter, the outputs of the component codes are bit interleaved prior to mapping into 8-PSK channel signals. A multistage receiver is considered, in which the output amplitudes of the Gaussian channel are soft limited before entering the second and third stage decoders. Upper bounds and Gaussian approximations for the bit error probability of every component code, which take into account errors in previously decoded stages, are presented. Aided by a comprehensive computer simulation, it is demonstrated in a specific example that the addition of the interleaver and soft limiter in the third stage improves its performance by 1.1 dB at a bit error probability of 10(exp -5), and that the multilevel scheme improves on an Ungerboeck's code with the same decoding complexity. The rate selection of the component codes is also considered and a simple selection rule, based on information theoretic arguments, is provided.

  6. The performance of a sequential acquisition system for PN codes

    NASA Astrophysics Data System (ADS)

    Kerr, R. W.; Arakaki, E. M.; Huang, M. Y.

    Direct sequence spread spectrum techniques are being applied in an increasing number of advanced communication systems where anti-jam (AJ), low probability of intercept (LPI), or code division multiple access (CDMA) capabilities are required. In all these systems, rapid acquisition of long PN code is a system necessity. Generally, acquisition of long PN codes is accomplished by correlation measurements of the incoming sequence with a locally generated code sequence. However, instead of utilizing fixed integration times, a sequential acquisition technique could also be used for active correlation, which results in greatly reduced acquisition times. TRW has designed and completed a limited production of 33 spread spectrum receivers for use with the NASA Tracking Data Relay Satellite System (TDRSS). The receivers provide multiple access and ranging capability while simultaneously decreasing the transmitted power flux density to meet CCIR restrictions. This paper presents the analysis, hardware description, and performance of the sequential code acquisition system implemented on these receivers. A unique noise calibration process, which holds the key to successful operation of these receivers, is described in detail.

  7. Fuels Performance: Navigating the Intersection of Fuels and Combustion (Brochure)

    SciTech Connect

    Not Available

    2014-12-01

    Researchers at the National Renewable Energy Laboratory (NREL), the only national laboratory dedicated 100% to renewable energy and energy efficiency, recognize that engine and infrastructure compatibility can make or break the impact of even the most promising fuel. NREL and its industry partners navigate the intersection of fuel chemistry, ignition kinetics, combustion, and emissions, with innovative approaches to engines and fuels that meet drivers' expectations, while minimizing petroleum use and GHGs.

  8. Analysis of Topaz-II thermionic fuel element performance using TFEHX

    SciTech Connect

    Klein, A.C. ); Pawlowski, R.A. )

    1993-01-20

    Data reported by Russian Scientists and engineers for the TOPAZ-II single cell thermionic fuel elments (TFE) is compared with analytical results calculated using the TFEHX computer program in order to benchmark the code. The results of this comparison show good agreement with the TOPAZ-II results over a wide range of power inputs, cesium vapor pressures, and other design variables. Future refinements of the TFEHX methodology should enhance the performance of the code to better predict single cell TFE behavior.

  9. Enhanced thermal conductivity oxide nuclear fuels by co-sintering with BeO: II. Fuel performance and neutronics

    NASA Astrophysics Data System (ADS)

    McCoy, Kevin; Mays, Claude

    2008-04-01

    The fuel rod performance and neutronics of enhanced thermal conductivity oxide (ECO) nuclear fuel with BeO have been compared to those of standard UO 2 fuel. The standards of comparison were that the ECO fuel should have the same infinite neutron-multiplication factor kinf at end of life and provide the same energy extraction per fuel assembly over its lifetime. The BeO displaces some uranium, so equivalence with standard UO 2 fuel was obtained by increasing the burnup and slightly increasing the enrichment. The COPERNIC fuel rod performance code was adapted to account for the effect of BeO on thermal properties. The materials considered were standard UO 2, UO 2 with 4.0 vol.% BeO, and UO 2 with 9.6 vol.% BeO. The smaller amount of BeO was assumed to provide increases in thermal conductivity of 0, 5, or 10%, whereas the larger amount was assumed to provide an increase of 50%. A significant improvement in performance was seen, as evidenced by reduced temperatures, internal rod pressures, and fission gas release, even with modest (5-10%) increases in thermal conductivity. The benefits increased monotonically with increasing thermal conductivity. Improvements in LOCA initialization performance were also seen. A neutronic calculation considered a transition from standard UO 2 fuel to ECO fuel. The calculation indicated that only a small increase in enrichment is required to maintain the kinf at end of life. The smallness of the change was attributed to the neutron-multiplication reaction of Be with fast neutrons and the moderating effect of BeO. Adoption of ECO fuel was predicted to provide a net reduction in uranium cost. Requirements for industrial hygiene were found to be comparable to those for processing of UO 2.

  10. Fuel performance annual report for 1991. Volume 9

    SciTech Connect

    Painter, C.L.; Alvis, J.M.; Beyer, C.E.; Marion, A.L.; Payne, G.A.; Kendrick, E.D.

    1994-08-01

    This report is the fourteenth in a series that provides a compilation of information regarding commercial nuclear fuel performance. The series of annual reports were developed as a result of interest expressed by the public, advising bodies, and the US Nuclear Regulatory Commission (NRC) for public availability of information pertaining to commercial nuclear fuel performance. During 1991, the nuclear industry`s focus regarding fuel continued to be on extending burnup while maintaining fuel rod reliability. Utilities realize that high-burnup fuel reduces the amount of generated spent fuel, reduces fuel costs, reduces operational and maintenance costs, and improves plant capacity factors by extending operating cycles. Brief summaries of fuel operating experience, fuel design changes, fuel surveillance programs, high-burnup experience, problem areas, and items of general significance are provided.

  11. Effects of mixing system and pilot fuel quality on diesel-biogas dual fuel engine performance.

    PubMed

    Bedoya, Iván Darío; Arrieta, Andrés Amell; Cadavid, Francisco Javier

    2009-12-01

    This paper describes results obtained from CI engine performance running on dual fuel mode at fixed engine speed and four loads, varying the mixing system and pilot fuel quality, associated with fuel composition and cetane number. The experiments were carried out on a power generation diesel engine at 1500 m above sea level, with simulated biogas (60% CH(4)-40% CO(2)) as primary fuel, and diesel and palm oil biodiesel as pilot fuels. Dual fuel engine performance using a naturally aspirated mixing system and diesel as pilot fuel was compared with engine performance attained with a supercharged mixing system and biodiesel as pilot fuel. For all loads evaluated, was possible to achieve full diesel substitution using biogas and biodiesel as power sources. Using the supercharged mixing system combined with biodiesel as pilot fuel, thermal efficiency and substitution of pilot fuel were increased, whereas methane and carbon monoxide emissions were reduced. PMID:19683439

  12. Fuel Retrieval Sub Project (FRS) Stuck Fuel Station Performance Test Data Report

    SciTech Connect

    THIELGES, J.R.

    2000-02-23

    This document provides the test data report for Stuck Fuel Station Performance Testing in support of the Fuel Retrieval Sub-Project. The stuck fuel station was designed to provide a means of cutting open a canister barrel to release fuel elements, etc.

  13. Performance of Low-Density Parity-Check Coded Modulation

    NASA Technical Reports Server (NTRS)

    Hamkins, Jon

    2010-01-01

    This paper reports the simulated performance of each of the nine accumulate-repeat-4-jagged-accumulate (AR4JA) low-density parity-check (LDPC) codes [3] when used in conjunction with binary phase-shift-keying (BPSK), quadrature PSK (QPSK), 8-PSK, 16-ary amplitude PSK (16- APSK), and 32-APSK.We also report the performance under various mappings of bits to modulation symbols, 16-APSK and 32-APSK ring scalings, log-likelihood ratio (LLR) approximations, and decoder variations. One of the simple and well-performing LLR approximations can be expressed in a general equation that applies to all of the modulation types.

  14. Performance of concatenated Reed-Solomon/Viterbi channel coding

    NASA Technical Reports Server (NTRS)

    Divsalar, D.; Yuen, J. H.

    1982-01-01

    The concatenated Reed-Solomon (RS)/Viterbi coding system is reviewed. The performance of the system is analyzed and results are derived with a new simple approach. A functional model for the input RS symbol error probability is presented. Based on this new functional model, we compute the performance of a concatenated system in terms of RS word error probability, output RS symbol error probability, bit error probability due to decoding failure, and bit error probability due to decoding error. Finally we analyze the effects of the noisy carrier reference and the slow fading on the system performance.

  15. The development of fuel performance models at the European institute for transuranium elements

    NASA Astrophysics Data System (ADS)

    Lassmann, K.; Ronchi, C.; Small, G. J.

    1989-07-01

    The design and operational performance of fuel rods for nuclear power stations has been the subject of detailed experimental research for over thirty years. In the last two decades the continuous demands for greater economy in conjunction with more stringent safety criteria have led to an increasing reliance on computer simulations. Conditions within a fuel rod must be calculated both for normal operation and for proposed reactor faults. It has thus been necessary to build up a reliable, theoretical understanding of the intricate physical, mechanical and chemical processes occurring under a wide range of conditions to obtain a quantitative insight into the behaviour of the fuel. A prime requirement, which has also proved to be the most taxing, is to predict the conditions under which failure of the cladding might occur, particularly in fuel nearing the end of its useful life. In this paper the general requirements of a fuel performance code are discussed briefly and an account is given of the basic concepts of code construction. An overview is then given of recent progress at the European Institute for Transuranium Elements in the development of a fuel rod performance code for general application and of more detailed mechanistic models for fission product behaviour.

  16. 3D thermo-chemical-mechanical simulation of power ramps with ALCYONE fuel code

    NASA Astrophysics Data System (ADS)

    Baurens, B.; Sercombe, J.; Riglet-Martial, C.; Desgranges, L.; Trotignon, L.; Maugis, P.

    2014-09-01

    This paper presents the coupling of the fuel performance code ALCYONE with the thermochemical code ANGE and its application to Iodine-Stress Corrosion Cracking (I-SCC). The coupling is illustrated by a 3D simulation of a power ramp. The release of chemically active gases (CsI(g), Tex(1

  17. ATES/heat pump simulations performed with ATESSS code

    NASA Astrophysics Data System (ADS)

    Vail, L. W.

    1989-01-01

    Modifications to the Aquifer Thermal Energy Storage System Simulator (ATESSS) allow simulation of aquifer thermal energy storage (ATES)/heat pump systems. The heat pump algorithm requires a coefficient of performance (COP) relationship of the form: COP = COP sub base + alpha (T sub ref minus T sub base). Initial applications of the modified ATES code to synthetic building load data for two sizes of buildings in two U.S. cities showed insignificant performance advantage of a series ATES heat pump system over a conventional groundwater heat pump system. The addition of algorithms for a cooling tower and solar array improved performance slightly. Small values of alpha in the COP relationship are the principal reason for the limited improvement in system performance. Future studies at Pacific Northwest Laboratory (PNL) are planned to investigate methods to increase system performance using alternative system configurations and operations scenarios.

  18. Effects of Non-Uniform Fuel Distribution on Detonation Tube Performance

    NASA Technical Reports Server (NTRS)

    Perkins, H. Douglas; Sung, Chih-Jen

    2003-01-01

    A pulse detonation engine uses a series of high frequency intermittent detonation tubes to generate thrust. The process of filling the detonation tube with fuel and air for each cycle may yield non-uniform mixtures. Uniform mixing is commonly assumed when calculating detonation tube thrust performance. In this study, detonation cycles featuring idealized non-uniform H2/air mixtures were analyzed using a two-dimensional Navier-Stokes computational fluid dynamics code with detailed chemistry. Mixture non-uniformities examined included axial equivalence ratio gradients, transverse equivalence ratio gradients, and partially fueled tubes. Three different average test section equivalence ratios were studied; one stoichiometric, one fuel lean, and one fuel rich. All mixtures were detonable throughout the detonation tube. Various mixtures representing the same average test section equivalence ratio were shown to have specific impulses within 1% of each other, indicating that good fuel/air mixing is not a prerequisite for optimal detonation tube performance under the conditions investigated.

  19. A computer code for performance of spur gears

    NASA Technical Reports Server (NTRS)

    Wang, K. L.; Cheng, H. S.

    1983-01-01

    In spur gears both performance and failure predictions are known to be strongly dependent on the variation of load, lubricant film thickness, and total flash or contact temperature of the contacting point as it moves along the contact path. The need of an accurate tool for predicting these variables has prompted the development of a computer code based on recent findings in EHL and on finite element methods. The analyses and some typical results which to illustrate effects of gear geometry, velocity, load, lubricant viscosity, and surface convective heat transfer coefficient on the performance of spur gears are analyzed.

  20. Tracking performance of symbol synchronizers for Manchester coded data

    NASA Technical Reports Server (NTRS)

    Simon, M. K.; Lindsey, W. C.

    1977-01-01

    The implementation and tracking performance of symbol synchronizers for Manchester coded data is presented with motivation provided by maximum a posteriori (MAP) estimation theory. Certain physically relizable closed-loop structures, readily implemented in practice, are suggested by the theory for uncoded data symbols with arbitrary data transition probabilities. The tracking performance of these loops is optimized and comparisons are made among the various configurations over a wide range of system parameters. Although not the major intent of the paper, the acquisition problem is briefly addressed.

  1. Performance of 2-propanol in direct-oxidation fuel cells

    NASA Astrophysics Data System (ADS)

    Qi, Zhigang; Kaufman, Arthur

    A direct-oxidation fuel cell using 2-propanol as fuel has been evaluated. The cell performance, open circuit voltage (OCV), and alcohol crossover were measured at various alcohol concentration, cell temperature, and air/nitrogen flow rate. The cell shows much higher performance than a direct methanol fuel cell, especially at current densities less than ca. 200 mA/cm 2. This performance is the highest among any direct-liquid-oxidation fuel cells. The cell open circuit voltage can be as much as 0.27 V higher than that of a methanol cell, while the amount of 2-propanol crossing through the membrane can be as low as 1/7 of that of methanol. Therefore, a direct 2-propanol fuel cell can have much higher fuel and fuel cell efficiencies. One problem associated with using 2-propanol as fuel is the anode poisoning by reaction intermediates and a frequent cleaning of the electrode surface is needed.

  2. Performance analysis of LDPC codes on OOK terahertz wireless channels

    NASA Astrophysics Data System (ADS)

    Chun, Liu; Chang, Wang; Jun-Cheng, Cao

    2016-02-01

    Atmospheric absorption, scattering, and scintillation are the major causes to deteriorate the transmission quality of terahertz (THz) wireless communications. An error control coding scheme based on low density parity check (LDPC) codes with soft decision decoding algorithm is proposed to improve the bit-error-rate (BER) performance of an on-off keying (OOK) modulated THz signal through atmospheric channel. The THz wave propagation characteristics and channel model in atmosphere is set up. Numerical simulations validate the great performance of LDPC codes against the atmospheric fading and demonstrate the huge potential in future ultra-high speed beyond Gbps THz communications. Project supported by the National Key Basic Research Program of China (Grant No. 2014CB339803), the National High Technology Research and Development Program of China (Grant No. 2011AA010205), the National Natural Science Foundation of China (Grant Nos. 61131006, 61321492, and 61204135), the Major National Development Project of Scientific Instrument and Equipment (Grant No. 2011YQ150021), the National Science and Technology Major Project (Grant No. 2011ZX02707), the International Collaboration and Innovation Program on High Mobility Materials Engineering of the Chinese Academy of Sciences, and the Shanghai Municipal Commission of Science and Technology (Grant No. 14530711300).

  3. Processing of the GALILEOTM fuel rod code model uncertainties within the AREVA LWR realistic thermal-mechanical analysis methodology

    NASA Astrophysics Data System (ADS)

    Mailhe, P.; Barbier, B.; Garnier, Ch.; Landskron, H.; Sedlacek, R.; Arimescu, I.; Smith, M.; Bellanger, Ph.

    2014-06-01

    The availability of reliable tools and associated methodology able to accurately predict the LWR fuel behavior in all conditions is of great importance for safe and economic fuel usage. For that purpose, AREVA has developed its new global fuel rod performance code GALILEOTM along with its associated realistic thermal-mechanical analysis methodology. This realistic methodology is based on a Monte Carlo type random sampling of all relevant input variables. After having outlined the AREVA realistic methodology, this paper will be focused on the GALILEOTM code benchmarking process on its extended experimental database and the GALILEOTM model uncertainties assessment. The propagation of these model uncertainties through the AREVA realistic methodology is also presented. This GALILEOTM model uncertainties processing is of the utmost importance for accurate fuel design margin evaluation as illustrated on some application examples. With the submittal of Topical Report for GALILEOTM to the U.S. NRC in 2013, GALILEOTM and its methodology are on the way to be industrially used in a wide range of irradiation conditions.

  4. Generating performance portable geoscientific simulation code with Firedrake (Invited)

    NASA Astrophysics Data System (ADS)

    Ham, D. A.; Bercea, G.; Cotter, C. J.; Kelly, P. H.; Loriant, N.; Luporini, F.; McRae, A. T.; Mitchell, L.; Rathgeber, F.

    2013-12-01

    This presentation will demonstrate how a change in simulation programming paradigm can be exploited to deliver sophisticated simulation capability which is far easier to programme than are conventional models, is capable of exploiting different emerging parallel hardware, and is tailored to the specific needs of geoscientific simulation. Geoscientific simulation represents a grand challenge computational task: many of the largest computers in the world are tasked with this field, and the requirements of resolution and complexity of scientists in this field are far from being sated. However, single thread performance has stalled, even sometimes decreased, over the last decade, and has been replaced by ever more parallel systems: both as conventional multicore CPUs and in the emerging world of accelerators. At the same time, the needs of scientists to couple ever-more complex dynamics and parametrisations into their models makes the model development task vastly more complex. The conventional approach of writing code in low level languages such as Fortran or C/C++ and then hand-coding parallelism for different platforms by adding library calls and directives forces the intermingling of the numerical code with its implementation. This results in an almost impossible set of skill requirements for developers, who must simultaneously be domain science experts, numericists, software engineers and parallelisation specialists. Even more critically, it requires code to be essentially rewritten for each emerging hardware platform. Since new platforms are emerging constantly, and since code owners do not usually control the procurement of the supercomputers on which they must run, this represents an unsustainable development load. The Firedrake system, conversely, offers the developer the opportunity to write PDE discretisations in the high-level mathematical language UFL from the FEniCS project (http://fenicsproject.org). Non-PDE model components, such as parametrisations

  5. High Performance Diesel Fueled Cabin Heater

    SciTech Connect

    Butcher, Tom

    2001-08-05

    Recent DOE-OHVT studies show that diesel emissions and fuel consumption can be greatly reduced at truck stops by switching from engine idle to auxiliary-fired heaters. Brookhaven National Laboratory (BNL) has studied high performance diesel burner designs that address the shortcomings of current low fire-rate burners. Initial test results suggest a real opportunity for the development of a truly advanced truck heating system. The BNL approach is to use a low pressure, air-atomized burner derived form burner designs used commonly in gas turbine combustors. This paper reviews the design and test results of the BNL diesel fueled cabin heater. The burner design is covered by U.S. Patent 6,102,687 and was issued to U.S. DOE on August 15, 2000.The development of several novel oil burner applications based on low-pressure air atomization is described. The atomizer used is a pre-filming, air blast nozzle of the type commonly used in gas turbine combustion. The air pressure used can b e as low as 1300 Pa and such pressure can be easily achieved with a fan. Advantages over conventional, pressure-atomized nozzles include ability to operate at low input rates without very small passages and much lower fuel pressure requirements. At very low firing rates the small passage sizes in pressure swirl nozzles lead to poor reliability and this factor has practically constrained these burners to firing rates over 14 kW. Air atomization can be used very effectively at low firing rates to overcome this concern. However, many air atomizer designs require pressures that can be achieved only with a compressor, greatly complicating the burner package and increasing cost. The work described in this paper has been aimed at the practical adaptation of low-pressure air atomization to low input oil burners. The objective of this work is the development of burners that can achieve the benefits of air atomization with air pressures practically achievable with a simple burner fan.

  6. High Performance Fuel Desing for Next Generation Pressurized Water Reactors

    SciTech Connect

    Mujid S. Kazimi; Pavel Hejzlar

    2006-01-31

    The use of internally and externally cooled annular fule rods for high power density Pressurized Water Reactors is assessed. The assessment included steady state and transient thermal conditions, neutronic and fuel management requirements, mechanical vibration issues, fuel performance issues, fuel fabrication methods and econmic assessment. The investigation was donducted by a team from MIT, Westinghouse, Gamma Engineering, Framatome ANP, and AECL. The analyses led to the conclusion that raising the power density by 50% may be possible with this advanced fuel. Even at the 150% power level, the fuel temperature would be a few hundred degrees lower than the current fuel temperatre. Significant economic and safety advantages can be obtained by using this fuel in new reactors. Switching to this type of fuel for existing reactors would yield safety advantages, but the economic return is dependent on the duration of plant shutdown to accommodate higher power production. The main feasiblity issue for the high power performance appears to be the potential for uneven splitting of heat flux between the inner and outer fuel surfaces due to premature closure of the outer fuel-cladding gap. This could be overcome by using a very narrow gap for the inner fuel surface and/or the spraying of a crushable zirconium oxide film at the fuel pellet outer surface. An alternative fuel manufacturing approach using vobropacking was also investigated but appears to yield lower than desirable fuel density.

  7. Validation and Performance Comparison of Numerical Codes for Tsunami Inundation

    NASA Astrophysics Data System (ADS)

    Velioglu, D.; Kian, R.; Yalciner, A. C.; Zaytsev, A.

    2015-12-01

    In inundation zones, tsunami motion turns from wave motion to flow of water. Modelling of this phenomenon is a complex problem since there are many parameters affecting the tsunami flow. In this respect, the performance of numerical codes that analyze tsunami inundation patterns becomes important. The computation of water surface elevation is not sufficient for proper analysis of tsunami behaviour in shallow water zones and on land and hence for the development of mitigation strategies. Velocity and velocity patterns are also crucial parameters and have to be computed at the highest accuracy. There are numerous numerical codes to be used for simulating tsunami inundation. In this study, FLOW 3D and NAMI DANCE codes are selected for validation and performance comparison. Flow 3D simulates linear and nonlinear propagating surface waves as well as long waves by solving three-dimensional Navier-Stokes (3D-NS) equations. FLOW 3D is used specificaly for flood problems. NAMI DANCE uses finite difference computational method to solve linear and nonlinear forms of shallow water equations (NSWE) in long wave problems, specifically tsunamis. In this study, these codes are validated and their performances are compared using two benchmark problems which are discussed in 2015 National Tsunami Hazard Mitigation Program (NTHMP) Annual meeting in Portland, USA. One of the problems is an experiment of a single long-period wave propagating up a piecewise linear slope and onto a small-scale model of the town of Seaside, Oregon. Other benchmark problem is an experiment of a single solitary wave propagating up a triangular shaped shelf with an island feature located at the offshore point of the shelf. The computed water surface elevation and velocity data are compared with the measured data. The comparisons showed that both codes are in fairly good agreement with each other and benchmark data. All results are presented with discussions and comparisons. The research leading to these

  8. SP-100 fuel pin performance: Results from irradiation testing

    SciTech Connect

    Makenas, B.J.; Paxton, D.M.; Vaidyanathan, S.; Hoth, C.W.

    1993-09-01

    A total of 86 experimental fuel pins with various fuel, liner, and cladding candidate materials have been irradiated in the Experimental Breeder Reactor-II (EBR-II) and the Fast Flux Test Facility (FFTF) reactor as part of the SP-100 fuel pin irradiation testing program. Postirradiation examination results from these fuel pin are key in establishing performance correlations and demonstrating the lifetime and safety of the reactor fuel system. This paper provides a brief description of the in-reactor fuel pin tests and presents the most recent irradiation data on the performance of wrought rhenium (Re) liner material and high density UN fuel at goal burnup of 6 atom percent (at. %). It also provides an overview of the significant variety of other fuel/liner/cladding combinations which were irradiated as part of this program and which may be of interest to more advanced efforts.

  9. IRRADIATION PERFORMANCE OF U-Mo MONOLITHIC FUEL

    SciTech Connect

    M.K. Meyer; J. Gan; J.-F. Jue; D.D. Keiser; E. Perez; A. Robinson; D.M. Wachs; N. Woolstenhulme; G.L. Hofman; Y.-S. Kim

    2014-04-01

    High-performance research reactors require fuel that operates at high specific power to high fission density, but at relatively low temperatures. Research reactor fuels are designed for efficient heat rejection, and are composed of assemblies of thin-plates clad in aluminum alloy. The development of low-enriched fuels to replace high-enriched fuels for these reactors requires a substantially increased uranium density in the fuel to offset the decrease in enrichment. Very few fuel phases have been identified that have the required combination of very-high uranium density and stable fuel behavior at high burnup. UMo alloys represent the best known tradeoff in these properties. Testing of aluminum matrix U-Mo aluminum matrix dispersion fuel revealed a pattern of breakaway swelling behavior at intermediate burnup, related to the formation of a molybdenum stabilized high aluminum intermetallic phase that forms during irradiation. In the case of monolithic fuel, this issue was addressed by eliminating, as much as possible, the interfacial area between U-Mo and aluminum. Based on scoping irradiation test data, a fuel plate system composed of solid U-10Mo fuel meat, a zirconium diffusion barrier, and Al6061 cladding was selected for development. Developmental testing of this fuel system indicates that it meets core criteria for fuel qualification, including stable and predictable swelling behavior, mechanical integrity to high burnup, and geometric stability. In addition, the fuel exhibits robust behavior during power-cooling mismatch events under irradiation at high power.

  10. Fuel Properties and Performance of Biodiesel

    Technology Transfer Automated Retrieval System (TEKTRAN)

    When being used as "alternative" diesel fuel, the mono-alkyl esters of vegetable oils or animal fats are referred to as biodiesel. Biodiesel is playing an increasingly important role in the fuel landscape, with production and use growing exponentially and standards established around the world. Co...

  11. Methane fueled engine performance and emissions characteristics

    SciTech Connect

    Swain, M.R.; Adt, R.R.; Bedsworth, K.; Maxwell, R.; Pappas, J.M.; Swain, M.N.

    1983-08-01

    A 1983 Ford 3.8 liter V-6 engine was fueled with methane and tested on an engine dynamometer in order to begin to generate a data base that could be used to estimate emission levels and fuel economy for a driving cycle from a 3-point mini map method. The results showed that, with the proper control of pertinent engine variables, the engine would probably meet the current State of California Emission Standards that have been formulated to account for methane as an unburned hydrocarbon, without having to resort to a catalytic converter, and with Joules fuel consumption comparable, if not better than that for a gasoline-fueled vehicle. Unburned fuel in the exhaust was found to be comprised of between 87 and 96% methane. MBTH total aldehyde emissions were found to vary between 27 and 67 molar ppm.

  12. Performance and fuel-cycle cost comparisons with HEU and LEU fuels

    SciTech Connect

    Matos, J.E.; Daly, T.A.

    1980-01-01

    The objective of this study is a consistent analysis of the performance and fuel cycle costs with HEU (93%) fuel and the various LEU (<20%) fuels that are under development, undergoing irradiation testing of small samples, or in the demonstration phase. All calculations were performed using the generic 10 MW reactor that has been studied extensively by a number of laboratories in the IAEA Guidebook. The conclusion of this study is that there are excellent opportunities for reducing fuel cycle costs in conversions from HEU to LEU if the LEU fuels that are being developed and tested are successful and if all safety considerations allow. The cost reductions described here are the direct result of the longer cycle lengths that can be obtained with increased /sup 235/U loadings. Each reactor is an individual case and fuel cycle economics should, along with safety considerations, be an integral part of choosing the optimal fuel and fuel element design for conversion to LEU.

  13. FRAPCON-2: A Computer Code for the Calculation of Steady State Thermal-Mechanical Behavior of Oxide Fuel Rods

    SciTech Connect

    Berna, G. A; Bohn, M. P.; Rausch, W. N.; Williford, R. E.; Lanning, D. D.

    1981-01-01

    FRAPCON-2 is a FORTRAN IV computer code that calculates the steady state response of light Mater reactor fuel rods during long-term burnup. The code calculates the temperature, pressure, deformation, and tai lure histories of a fuel rod as functions of time-dependent fuel rod power and coolant boundary conditions. The phenomena modeled by the code include (a) heat conduction through the fuel and cladding, (b) cladding elastic and plastic deformation, (c) fuel-cladding mechanical interaction, (d) fission gas release, (e} fuel rod internal gas pressure, (f) heat transfer between fuel and cladding, (g) cladding oxidation, and (h) heat transfer from cladding to coolant. The code contains necessary material properties, water properties, and heat transfer correlations. FRAPCON-2 is programmed for use on the CDC Cyber 175 and 176 computers. The FRAPCON-2 code Is designed to generate initial conditions for transient fuel rod analysis by either the FRAP-T6 computer code or the thermal-hydraulic code, RELAP4/MOD7 Version 2.

  14. An investigation of error characteristics and coding performance

    NASA Technical Reports Server (NTRS)

    Ebel, William J.; Ingels, Frank M.

    1992-01-01

    The performance of forward error correcting coding schemes on errors anticipated for the Earth Observation System (EOS) Ku-band downlink are studied. The EOS transmits picture frame data to the ground via the Telemetry Data Relay Satellite System (TDRSS) to a ground-based receiver at White Sands. Due to unintentional RF interference from other systems operating in the Ku band, the noise at the receiver is non-Gaussian which may result in non-random errors output by the demodulator. That is, the downlink channel cannot be modeled by a simple memoryless Gaussian-noise channel. From previous experience, it is believed that those errors are bursty. The research proceeded by developing a computer based simulation, called Communication Link Error ANalysis (CLEAN), to model the downlink errors, forward error correcting schemes, and interleavers used with TDRSS. To date, the bulk of CLEAN was written, documented, debugged, and verified. The procedures for utilizing CLEAN to investigate code performance were established and are discussed.

  15. Performance of a parallel thermal-hydraulics code TEMPEST

    SciTech Connect

    Fann, G.I.; Trent, D.S.

    1996-11-01

    The authors describe the parallelization of the Tempest thermal-hydraulics code. The serial version of this code is used for production quality 3-D thermal-hydraulics simulations. Good speedup was obtained with a parallel diagonally preconditioned BiCGStab non-symmetric linear solver, using a spatial domain decomposition approach for the semi-iterative pressure-based and mass-conserved algorithm. The test case used here to illustrate the performance of the BiCGStab solver is a 3-D natural convection problem modeled using finite volume discretization in cylindrical coordinates. The BiCGStab solver replaced the LSOR-ADI method for solving the pressure equation in TEMPEST. BiCGStab also solves the coupled thermal energy equation. Scaling performance of 3 problem sizes (221220 nodes, 358120 nodes, and 701220 nodes) are presented. These problems were run on 2 different parallel machines: IBM-SP and SGI PowerChallenge. The largest problem attains a speedup of 68 on an 128 processor IBM-SP. In real terms, this is over 34 times faster than the fastest serial production time using the LSOR-ADI solver.

  16. Numerical Prediction of SERN Performance using WIND code

    NASA Technical Reports Server (NTRS)

    Engblom, W. A.

    2003-01-01

    Computational results are presented for the performance and flow behavior of single-expansion ramp nozzles (SERNs) during overexpanded operation and transonic flight. Three-dimensional Reynolds-Averaged Navier Stokes (RANS) results are obtained for two vehicle configurations, including the NASP Model 5B and ISTAR RBCC (a variant of X-43B) using the WIND code. Numerical predictions for nozzle integrated forces and pitch moments are directly compared to experimental data for the NASP Model 5B, and adequate-to-excellent agreement is found. The sensitivity of SERN performance and separation phenomena to freestream static pressure and Mach number is demonstrated via a matrix of cases for both vehicles. 3-D separation regions are shown to be induced by either lateral (e.g., sidewall) shocks or vertical (e.g., cowl trailing edge) shocks. Finally, the implications of this work to future preliminary design efforts involving SERNs are discussed.

  17. Performance improvement of spectral amplitude coding-optical code division multiple access systems using NAND detection with enhanced double weight code

    NASA Astrophysics Data System (ADS)

    Ahmed, Nasim; Aljunid, Syed Alwee; Ahmad, R. Badlishah; Fadhil, Hilal A.; Rashid, Mohd Abdur

    2012-01-01

    The bit-error rate (BER) performance of the spectral amplitude coding-optical code division multiple access (SACOCDMA) system has been investigated by using NAND subtraction detection technique with enhanced double weight (EDW) code. The EDW code is the enhanced version of double weight (DW) code family where the code weight is any odd number and greater than one with ideal cross-correlation. In order to evaluate the performance of the system, we used mathematical analysis extensively along with the simulation experiment. The evaluation results obtained using the NAND subtraction detection technique was compared with those obtained using the complementary detection technique for the same number of active users. The comparison results revealed that the BER performance of the system using NAND subtraction detection technique has greatly been improved as compared to the complementary technique.

  18. Preliminary TRIGA fuel burn-up evaluation by means of Monte Carlo code and computation based on total energy released during reactor operation

    SciTech Connect

    Borio Di Tigliole, A.; Bruni, J.; Panza, F.; Alloni, D.; Cagnazzo, M.; Magrotti, G.; Manera, S.; Prata, M.; Salvini, A.; Chiesa, D.; Clemenza, M.; Pattavina, L.; Previtali, E.; Sisti, M.; Cammi, A.

    2012-07-01

    Aim of this work was to perform a rough preliminary evaluation of the burn-up of the fuel of TRIGA Mark II research reactor of the Applied Nuclear Energy Laboratory (LENA) of the Univ. of Pavia. In order to achieve this goal a computation of the neutron flux density in each fuel element was performed by means of Monte Carlo code MCNP (Version 4C). The results of the simulations were used to calculate the effective cross sections (fission and capture) inside fuel and, at the end, to evaluate the burn-up and the uranium consumption in each fuel element. The evaluation, showed a fair agreement with the computation for fuel burn-up based on the total energy released during reactor operation. (authors)

  19. Integrated Radiation Transport and Nuclear Fuel Performance for Assembly-Level Simulations

    SciTech Connect

    Hamilton, Steven P; Clarno, Kevin T; Philip, Bobby; Berrill, Mark A; Sampath, Rahul S; Allu, Srikanth

    2012-01-01

    The Advanced Multi-Physics (AMP) Nuclear Fuel Performance code (AMPFuel) is focused on predicting the temperature and strain within a nuclear fuel assembly to evaluate the performance and safety of existing and advanced nuclear fuel bundles within existing and advanced nuclear reactors. AMPFuel was extended to include an integrated nuclear fuel assembly capability for (one-way) coupled radiation transport and nuclear fuel assembly thermo-mechanics. This capability is the initial step toward incorporating an improved predictive nuclear fuel assembly modeling capability to accurately account for source-terms, such as neutron flux distribution, coolant conditions and assembly mechanical stresses, of traditional (single-pin) nuclear fuel performance simulation. A novel scheme is introduced for transferring the power distribution from the Scale/Denovo (Denovo) radiation transport code (structured, Cartesian mesh with smeared materials within each cell) to AMPFuel (unstructured, hexagonal mesh with a single material within each cell), allowing the use of a relatively coarse spatial mesh (10 million elements) for the radiation transport and a fine spatial mesh (3.3 billion elements) for thermo-mechanics with very little loss of accuracy. With this novel capability, AMPFuel was used to model an entire 1717 pressurized water reactor fuel assembly with many of the features resolved in three dimensions (for thermo-mechanics and/or neutronics). A full assembly calculation was executed on Jaguar using 40,000 cores in under 10 hours to model over 160 billion degrees of freedom for 10 loading steps. The single radiation transport calculation required about 50% of the time required to solve the thermo-mechanics with a single loading step, which demonstrates that it is feasible to incorporate, in a single code, a high-fidelity radiation transport capability with a high-fidelity nuclear fuel thermo-mechanics capability and anticipate acceptable computational requirements. The

  20. In-Field Performance Testing of the Fork Detector for Quantitative Spent Fuel Verification

    SciTech Connect

    Gauld, Ian C.; Hu, Jianwei; De Baere, P.; Vaccaro, S.; Schwalbach, P.; Liljenfeldt, Henrik; Tobin, Stephen

    2015-01-01

    Expanding spent fuel dry storage activities worldwide are increasing demands on safeguards authorities that perform inspections. The European Atomic Energy Community (EURATOM) and the International Atomic Energy Agency (IAEA) require measurements to verify declarations when spent fuel is transferred to difficult-to-access locations, such as dry storage casks and the repositories planned in Finland and Sweden. EURATOM makes routine use of the Fork detector to obtain gross gamma and total neutron measurements during spent fuel inspections. Data analysis is performed by modules in the integrated Review and Analysis Program (iRAP) software, developed jointly by EURATOM and the IAEA. Under the framework of the US Department of Energy–EURATOM cooperation agreement, a module for automated Fork detector data analysis has been developed by Oak Ridge National Laboratory (ORNL) using the ORIGEN code from the SCALE code system and implemented in iRAP. EURATOM and ORNL recently performed measurements on 30 spent fuel assemblies at the Swedish Central Interim Storage Facility for Spent Nuclear Fuel (Clab), operated by the Swedish Nuclear Fuel and Waste Management Company (SKB). The measured assemblies represent a broad range of fuel characteristics. Neutron count rates for 15 measured pressurized water reactor assemblies are predicted with an average relative standard deviation of 4.6%, and gamma signals are predicted on average within 2.6% of the measurement. The 15 measured boiling water reactor assemblies exhibit slightly larger deviations of 5.2% for the gamma signals and 5.7% for the neutron count rates, compared to measurements. These findings suggest that with improved analysis of the measurement data, existing instruments can provide increased verification of operator declarations of the spent fuel and thereby also provide greater ability to confirm integrity of an assembly. These results support the application of the Fork detector as a fully quantitative spent fuel

  1. Integrated Fuel-Coolant Interaction (IFCI 7.0) Code User's Manual

    SciTech Connect

    Young, Michael F.

    1999-05-01

    The integrated fuel-coolant interaction (IFCI) computer code is being developed at Sandia National Laboratories to investigate the fuel-coolant interaction (FCI) problem at large scale using a two-dimensional, three-field hydrodynamic framework and physically based models. IFCI will be capable of treating all major FCI processes in an integrated manner. This document is a description of IFCI 7.0. The user's manual describes the hydrodynamic method and physical models used in IFCI 7.0. Appendix A is an input manual provided for the creation of working decks.

  2. Integrated Fuel-Coolant Interaction (IFCI 6.0) code. User`s manual

    SciTech Connect

    Davis, F.J.; Young, M.F.

    1994-04-01

    The integrated Fuel-Coolant interaction (IFCI) computer code is being developed at Sandia National Laboratories to investigate the fuel-coolant interaction (FCI) problem at large scale using a two-dimensional, four-field hydrodynamic framework and physically based models. IFCI will be capable of treating all major FCI processes in an integrated manner. This document is a product of the effort to generate a stand-alone version of IFCI, IFCI 6.0. The User`s Manual describes in detail the hydrodynamic method and physical models used in IFCI 6.0. Appendix A is an input manual, provided for the creation of working decks.

  3. Development of code evaluation criteria for assessing predictive capability and performance

    NASA Technical Reports Server (NTRS)

    Lin, Shyi-Jang; Barson, S. L.; Sindir, M. M.; Prueger, G. H.

    1993-01-01

    Computational Fluid Dynamics (CFD), because of its unique ability to predict complex three-dimensional flows, is being applied with increasing frequency in the aerospace industry. Currently, no consistent code validation procedure is applied within the industry. Such a procedure is needed to increase confidence in CFD and reduce risk in the use of these codes as a design and analysis tool. This final contract report defines classifications for three levels of code validation, directly relating the use of CFD codes to the engineering design cycle. Evaluation criteria by which codes are measured and classified are recommended and discussed. Criteria for selecting experimental data against which CFD results can be compared are outlined. A four phase CFD code validation procedure is described in detail. Finally, the code validation procedure is demonstrated through application of the REACT CFD code to a series of cases culminating in a code to data comparison on the Space Shuttle Main Engine High Pressure Fuel Turbopump Impeller.

  4. Analysis of the IFA-432, IFA-597, and IFA-597 MOX Fuel Performance Experiments by FRAPCON-3.4

    SciTech Connect

    Phillippe, Aaron M; Ott, Larry J; Clarno, Kevin T; Banfield, James E

    2012-08-01

    Validation of advanced nuclear fuel modeling tools requires careful comparison with reliable experimental benchmark data. A comparison to industry-accepted codes, that are well characterized, and regulatory codes is also a useful evaluation tool. In this report, an independent validation of the FRAPCON-3.4 fuel performance code is conducted with respect to three experimental benchmarks, IFA-432, IFA-597, and IFA-597mox. FRAPCON was found to most accurately model the mox rods, to within 2% of the experimental data, depending on the simulation parameters. The IFA-432 and IFA-597 rods were modeled with FRAPCON predicting centerline temperatures different, on average, by 21 percent.

  5. Alternate-Fueled Combustor-Sector Performance: Part A: Combustor Performance Part B: Combustor Emissions

    NASA Technical Reports Server (NTRS)

    Shouse, D. T.; Neuroth, C.; Henricks, R. C.; Lynch, A.; Frayne, C.; Stutrud, J. S.; Corporan, E.; Hankins, T.

    2010-01-01

    Alternate aviation fuels for military or commercial use are required to satisfy MIL-DTL-83133F(2008) or ASTM D 7566 (2010) standards, respectively, and are classified as drop-in fuel replacements. To satisfy legacy issues, blends to 50% alternate fuel with petroleum fuels are certified individually on the basis of feedstock. Adherence to alternate fuels and fuel blends requires smart fueling systems or advanced fuel-flexible systems, including combustors and engines without significant sacrifice in performance or emissions requirements. This paper provides preliminary performance (Part A) and emissions and particulates (Part B) combustor sector data for synthetic-parafinic-kerosene- (SPK-) type fuel and blends with JP-8+100 relative to JP-8+100 as baseline fueling.

  6. Spent fuel metal storage cask performance testing and future spent fuel concrete module performance testing

    SciTech Connect

    McKinnon, M.A.; Creer, J.M.

    1988-10-01

    REA-2023 Gesellshaft fur Nuklear Service (GNS) CASTOR-V/21, Transnuclear TN-24P, and Westinghouse MC-10 metal storage casks, have been performance tested under the guidance of the Pacific Northwest Laboratory to determine their thermal and shielding performance. The REA-2023 cask was tested under Department of Energy (DOE) sponsorship at General Electric's facilities in Morris, Illinois, using BWR spent fuel from the Cooper Reactor. The other three casks were tested under a cooperative agreement between Virginia Power Company and DOE at the Idaho National Engineering Laboratory (INEL) by EGandG Idaho, Inc., using intact spent PWR fuel from the Surry reactors. The Electric Power Research Institute (EPRI) made contributions to both programs. A summary of the various cask designs and the results of the performance tests is presented. The cask designs include: solid and liquid neutron shields; lead, steel, and nodular cast iron gamma shields; stainless steel, aluminum, and copper baskets; and borated materials for criticality control. 4 refs., 8 figs., 6 tabs.

  7. Improving Hearing Performance Using Natural Auditory Coding Strategies

    NASA Astrophysics Data System (ADS)

    Rattay, Frank

    Sound transfer from the human ear to the brain is based on three quite different neural coding principles when the continuous temporal auditory source signal is sent as binary code in excellent quality via 30,000 nerve fibers per ear. Cochlear implants are well-accepted neural prostheses for people with sensory hearing loss, but currently the devices are inspired only by the tonotopic principle. According to this principle, every sound frequency is mapped to a specific place along the cochlea. By electrical stimulation, the frequency content of the acoustic signal is distributed via few contacts of the prosthesis to corresponding places and generates spikes there. In contrast to the natural situation, the artificially evoked information content in the auditory nerve is quite poor, especially because the richness of the temporal fine structure of the neural pattern is replaced by a firing pattern that is strongly synchronized with an artificial cycle duration. Improvement in hearing performance is expected by involving more of the ingenious strategies developed during evolution.

  8. Measurements for liquid rocket engine performance code verification

    NASA Technical Reports Server (NTRS)

    Praharaj, Sarat C.; Palko, Richard L.

    1986-01-01

    The goal of the rocket engine performance code verification tests is to obtain the I sub sp with an accuracy of 0.25% or less. This needs to be done during the sequence of four related tests (two reactive and two hot gas simulation) to best utilize the loss separation technique recommended in this study. In addition to I sub sp, the measurements of the input and output parameters for the codes are needed. This study has shown two things in regard to obtaining the I sub sp uncertainty within the 0.25% target. First, this target is generally not being realized at the present time, and second, the instrumentation and testing technology does exist to obtain this 0.25% uncertainty goal. However, to achieve this goal will require carefully planned, designed, and conducted testing. In addition, the test-stand (or system) dynamics must be evaluated in the pre-test and post-test phases of the design of the experiment and data analysis, respectively always keeping in mind that a .25% overall uncertainty in I sub sp is targeted. A table gives the maximum allowable uncertainty required for obtaining I sub sp with 0.25% uncertainty, the currently-quoted instrument specification, and present test uncertainty for the parameters. In general, it appears that measurement of the mass flow parameter within the required uncertainty may be the most difficult.

  9. Early Experiences Writing Performance Portable OpenMP 4 Codes

    SciTech Connect

    Joubert, Wayne; Hernandez, Oscar R

    2016-01-01

    In this paper, we evaluate the recently available directives in OpenMP 4 to parallelize a computational kernel using both the traditional shared memory approach and the newer accelerator targeting capabilities. In addition, we explore various transformations that attempt to increase application performance portability, and examine the expressiveness and performance implications of using these approaches. For example, we want to understand if the target map directives in OpenMP 4 improve data locality when mapped to a shared memory system, as opposed to the traditional first touch policy approach in traditional OpenMP. To that end, we use recent Cray and Intel compilers to measure the performance variations of a simple application kernel when executed on the OLCF s Titan supercomputer with NVIDIA GPUs and the Beacon system with Intel Xeon Phi accelerators attached. To better understand these trade-offs, we compare our results from traditional OpenMP shared memory implementations to the newer accelerator programming model when it is used to target both the CPU and an attached heterogeneous device. We believe the results and lessons learned as presented in this paper will be useful to the larger user community by providing guidelines that can assist programmers in the development of performance portable code.

  10. On a stochastic approach to a code performance estimation

    NASA Astrophysics Data System (ADS)

    Gorshenin, Andrey K.; Frenkel, Sergey L.; Korolev, Victor Yu.

    2016-06-01

    The main goal of an efficient profiling of software is to minimize the runtime overhead under certain constraints and requirements. The traces built by a profiler during the work, affect the performance of the system itself. One of important aspect of an overhead arises from the randomness of variability in the context in which the application is embedded, e.g., due to possible cache misses, etc. Such uncertainty needs to be taken into account in the design phase. In order to overcome these difficulties we propose to investigate this issue through the analysis of the probability distribution of the difference between profiler's times for the same code. The approximating model is based on the finite normal mixtures within the framework of the method of moving separation of mixtures. We demonstrate some results for the MATLAB profiler using plotting of 3D surfaces by the function surf. The idea can be used for an estimating of a program efficiency.

  11. A new code for predicting the thermo-mechanical and irradiation behavior of metallic fuels in sodium fast reactors

    NASA Astrophysics Data System (ADS)

    Karahan, Aydın; Buongiorno, Jacopo

    2010-01-01

    An engineering code to predict the irradiation behavior of U-Zr and U-Pu-Zr metallic alloy fuel pins and UO2-PuO2 mixed oxide fuel pins in sodium-cooled fast reactors was developed. The code was named Fuel Engineering and Structural analysis Tool (FEAST). FEAST has several modules working in coupled form with an explicit numerical algorithm. These modules describe fission gas release and fuel swelling, fuel chemistry and restructuring, temperature distribution, fuel-clad chemical interaction, and fuel and clad mechanical analysis including transient creep-fracture for the clad. Given the fuel pin geometry, composition and irradiation history, FEAST can analyze fuel and clad thermo-mechanical behavior at both steady-state and design-basis (non-disruptive) transient scenarios. FEAST was written in FORTRAN-90 and has a simple input file similar to that of the LWR fuel code FRAPCON. The metal-fuel version is called FEAST-METAL, and is described in this paper. The oxide-fuel version, FEAST-OXIDE is described in a companion paper. With respect to the old Argonne National Laboratory code LIFE-METAL and other same-generation codes, FEAST-METAL emphasizes more mechanistic, less empirical models, whenever available. Specifically, fission gas release and swelling are modeled with the GRSIS algorithm, which is based on detailed tracking of fission gas bubbles within the metal fuel. Migration of the fuel constituents is modeled by means of thermo-transport theory. Fuel-clad chemical interaction models based on precipitation kinetics were developed for steady-state operation and transients. Finally, a transient intergranular creep-fracture model for the clad, which tracks the nucleation and growth of the cavities at the grain boundaries, was developed for and implemented in the code. Reducing the empiricism in the constitutive models should make it more acceptable to extrapolate FEAST-METAL to new fuel compositions and higher burnup, as envisioned in advanced sodium reactors

  12. Code System to Calculate Radiation Dose Rates Relative to Spent Fuel Shipping Casks.

    Energy Science and Technology Software Center (ESTSC)

    1993-05-20

    Version 00 QBF calculates and plots in a short running time, three dimensional radiation dose rate distributions in the form of contour maps on specified planes resulting from cylindrical sources loaded into vehicles or ships. Shielding effects by steel walls and shielding material layers are taken into account in addition to the shadow effect among casks. This code system identifies the critical points on which to focus when designing the radiation shielding structure and wheremore » each of the spent fuel shipping casks should be stored. The code GRAPH reads the output data file of QBF and plots it using the HGX graphics library. QBF unifies the functions of the SMART and MANYCASK codes included in CCC-482.« less

  13. Code System to Calculate Cross Sections for PWR Fuel Assembly Calculations.

    Energy Science and Technology Software Center (ESTSC)

    1994-11-15

    Version 00 The MARIA System calculates cross sections for PWR fuel assembly calculations. It generates the cross sections library for the diffusion calculations with burnup and feedback effects (CARMEN System, NEA 0649 and RSIC CCC-487) and the k(infinite) and M**2 parameters for the nodal calculations (SIMULA, NEA 0768). MARIA includes three modules. PRELIM generates the input data for the fuel assembly calculation module, for all fuel assembly types in the core and at any conditionmore » of power rate and temperature. WIMS-TRACA is a modified version of the fuel assembly calculation program WIMS-D/4 (NEA 0329 and RSIC CCC-576), which generates the collapsed cross sections versus burn up needed by the CARMEN code (reference cell, boron, xenon, samarium, and light water). POSWIM calculates the transport corrections to the diffusion constant of the absorber materials generated by WIMS-TRACA, to be used directly in the diffusion code when rods or burnable absorber rods are present.« less

  14. Performance Analysis of New Binary User Codes for DS-CDMA Communication

    NASA Astrophysics Data System (ADS)

    Usha, Kamle; Jaya Sankar, Kottareddygari

    2016-03-01

    This paper analyzes new binary spreading codes through correlation properties and also presents their performance over additive white Gaussian noise (AWGN) channel. The proposed codes are constructed using gray and inverse gray codes. In this paper, a n-bit gray code appended by its n-bit inverse gray code to construct the 2n-length binary user codes are discussed. Like Walsh codes, these binary user codes are available in sizes of power of two and additionally code sets of length 6 and their even multiples are also available. The simple construction technique and generation of code sets of different sizes are the salient features of the proposed codes. Walsh codes and gold codes are considered for comparison in this paper as these are popularly used for synchronous and asynchronous multi user communications respectively. In the current work the auto and cross correlation properties of the proposed codes are compared with those of Walsh codes and gold codes. Performance of the proposed binary user codes for both synchronous and asynchronous direct sequence CDMA communication over AWGN channel is also discussed in this paper. The proposed binary user codes are found to be suitable for both synchronous and asynchronous DS-CDMA communication.

  15. Novel proton exchange membrane fuel cell electrodes to improve performance of reversible fuel cell systems

    NASA Astrophysics Data System (ADS)

    Brown, Tim Matthew

    Proton exchange membrane (PEM) fuel cells react fuel and oxidant to directly and efficiently produce electrical power, without the need for combustion, heat engines, or motor-generators. Additionally, PEM fuel cell systems emit zero to virtually zero criteria pollutants and have the ability to reduce CO2 emissions due to their efficient operation, including the production or processing of fuel. A reversible fuel cell (RFC) is one particular application for a PEM fuel cell. In this application the fuel cell is coupled with an electrolyzer and a hydrogen storage tank to complete a system that can store and release electrical energy. These devices can be highly tailored to specific energy storage applications, potentially surpassing the performance of current and future secondary battery technology. Like all PEM applications, RFCs currently suffer from performance and cost limitations. One approach to address these limitations is to improve the cathode performance by engineering more optimal catalyst layer geometry as compared to the microscopically random structure traditionally used. Ideal configurations are examined and computer modeling shows promising performance improvements are possible. Several novel manufacturing methods are used to build and test small PEM fuel cells with novel electrodes. Additionally, a complete, dynamic model of an RFC system is constructed and the performance is simulated using both traditional and novel cathode structures. This work concludes that PEM fuel cell microstructures can be tailored to optimize performance based on design operating conditions. Computer modeling results indicate that novel electrode microstructures can improve fuel cell performance, while experimental results show similar performance gains that bolster the theoretical predictions. A dynamic system model predicts that novel PEM fuel cell electrode structures may enable RFC systems to be more competitive with traditional energy storage technology options.

  16. Will biodiesel fuels derived from algae perform?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The issue of sufficient supply and availability of feedstock is one of the major non-technical issues affecting the widespread commercialization of biodiesel. Another aspect is the food vs. fuel issue that biofuels should not be produced from edible feedstocks. In these connections, lipid-producin...

  17. Rapid screening of biologically modified vegetable oils for fuel performance

    SciTech Connect

    Geller, D.P.; Goodrum, J.W.; Campbell, C.C.

    1999-08-01

    A process for the rapid screening of alternative diesel fuel performance was applied to analogues of genetically modified vegetable oils and a mixture with no. 2 diesel fuel. The oils examined contained 60 to 70% of low molecular weight, short-chain, saturated triglycerides compared to the 1 to 2% found in traditional vegetable oils. These oils have relatively low viscosity that is predicted to enhance their performance as alternative diesel fuels. The screening process utilizes an engine torque test sequence that accelerates the tendency of diesel fuels to coke fuel injectors, a key indicator of fuel performance. The results of the tests were evaluated using a computer vision system for the rapid quantification of injector coking. The results of the screen were compared to those using no. 2 diesel fuel as a baseline. Coke deposition from the modified vegetable oil analogues was not found to be significantly different than deposition from diesel fuel. Suggestions are made to guide further modification of vegetable oil biosynthesis for the production of alternative diesel fuel.

  18. FUEL PERFORMANCE IMPROVEMENT PROGRAM Thermal Conductivity of Sphere-Pac Fuel

    SciTech Connect

    Ades, M. J.

    1981-07-01

    Progress in understanding the thermal conductivity of sphere-pac fuel beds has been made both at Oregon State University and Exxon Nuclear Company supported by the Fuel Performance Improvement Program (FPIP). FPIP is sponsored by the U. S. Department of Energy and is being performed by Consumers Power Company, Exxon Nuclear Company, and Pacific Northwest Laboratory. The purpose of the program is to test and demonstrate improved li9ht water reactor fuel concepts that are more resistant to failure from pellet-cladding interaction during power increases than standard pellet fuel.

  19. The near-field transport code Tullgarn and its use in performance assessment

    SciTech Connect

    Sellin, P.; Kjellbert, N.

    1993-12-31

    The near-field radionuclide migration code Tullgarn has been developed for performance assessment purposes. As a part of the PROPER-code package it has been successfully applied in the SKB 91 safety analysis. THe features and processes included in the code are: (1) Radioactive chain decay; (2) Different canister failure mechanisms (copper corrosion from sulphide attack, steel corrosion, internal overpressure and initially defective canisters); (3) Spent fuel dissolution. The model is based on the assumption that the dissolution rate is proportional to the {alpha}-dose rate; (4) Transport calculations are done with a resistance-network model. Tullgarn calculates the stationary release of radionuclides from a defect in the canister through the buffer and out into a fracture in the rock or up to the damaged zone under the deposition tunnel. Tullgarn can be used as a stand-alone model for near-field release calculations or as a submodel in an integrated assessment. In the SKB 91 analysis, Tullgarn gave the source term to the far-field model.

  20. Engine component improvement program: Performance improvement. [fuel consumption

    NASA Technical Reports Server (NTRS)

    Mcaulay, J. E.

    1979-01-01

    Fuel consumption of commercial aircraft is considered. Fuel saving and retention components for new production and retrofit of JT9D, JT8D, and CF6 engines are reviewed. The manner in which the performance improvement concepts were selected for development and a summary of the current status of each of the 16 selected concepts are discussed.

  1. Low Burnup Inert Matrix Fuels Performance: TRANSURANUS Analysis of the Halden IFA-652 First Irradiation Cycle

    SciTech Connect

    Calabrese, R.; Vettraino, F.; Tverberg, T.

    2006-07-01

    The inert matrix fuels are a promising option to reduce-eliminate worldwide plutonium stockpiles by burning it in LWRs. These fuels, where plutonium is hosted in a U-free inert matrix phase, may reach high burning efficiency while preventing new plutonium build-up under irradiation. A specific investigation on CSZ and thoria inert matrices has been developed by ENEA since several years. In-pile testing on the ENEA-conceived innovative fuels is ongoing in the OECD Halden HBWR since June 2000 (IFA-652 experiment). The registered burnup at the end of 2005 is about 38 MWd.kgU{sub eq}{sup -1} vs. 45 MWd.kgU{sub eq}{sup -1} (40 MWd.kgUOX{sub eq}{sup -1}) target. Fuel pins are equipped with fuel temperature thermocouples, internal pressure transducers and fuel stack elongation sensors, with the task of studying thermal conductivity and its degradation with burnup, densification-swelling behaviour and the FGR. In this paper, the response at low burnup (< 7 MWd.kgU{sub eq}{sup -1}) of CSZ-based fuels loaded in IFA-652, is analysed by means of the TRANSURANUS code. To this purpose, a comprehensive modelling of the above mentioned un-irradiated fuels, mainly relying on the thermophysical characterisation performed at the JRC/ITU-Karlsruhe, has been implemented in a custom TRANSURANUS version (TU-IMF). A comparison of the code predictions vs. the experimental data, aimed at evaluating the early-stage under irradiation phenomena, particularly densification and relocation, has been performed. (authors)

  2. High performance, high density hydrocarbon fuels

    NASA Technical Reports Server (NTRS)

    Frankenfeld, J. W.; Hastings, T. W.; Lieberman, M.; Taylor, W. F.

    1978-01-01

    The fuels were selected from 77 original candidates on the basis of estimated merit index and cost effectiveness. The ten candidates consisted of 3 pure compounds, 4 chemical plant streams and 3 refinery streams. Critical physical and chemical properties of the candidate fuels were measured including heat of combustion, density, and viscosity as a function of temperature, freezing points, vapor pressure, boiling point, thermal stability. The best all around candidate was found to be a chemical plant olefin stream rich in dicyclopentadiene. This material has a high merit index and is available at low cost. Possible problem areas were identified as low temperature flow properties and thermal stability. An economic analysis was carried out to determine the production costs of top candidates. The chemical plant and refinery streams were all less than 44 cent/kg while the pure compounds were greater than 44 cent/kg. A literature survey was conducted on the state of the art of advanced hydrocarbon fuel technology as applied to high energy propellents. Several areas for additional research were identified.

  3. Performance of CVR coatings for PBR fuels

    SciTech Connect

    Adams, J.W.; Barletta, R.E.; Svandrlik, J.; Vanier, P.E.

    1993-12-31

    As part of the component development process for the particle bed reactor (PBR), it is necessary to develop coatings for fuel particles which will be time and temperature stable. These coatings must not only protect the particle from attack by the hydrogen coolant, but must also help to maintain the bed in a coolable geometry and mitigate against fission product release. In order to develop these advanced coatings, a process to produce chemical vapor reaction (CVR) coatings on fuel for PBRs has been developed. The initial screening tests for these coatings consisted of testing in flowing hot hydrogen at one atmosphere. Surrogate fuel particles consisting of pyrolytic graphite coated graphite particles have been heated in flowing hydrogen at constant temperature. The carbon loss from these particles was measured as a function of time. Exposure temperatures ranging from 2,500 to 3,000 K were used and samples were exposed for up to 14 minutes in a cyclical fashion, cooling to room temperature between exposures. The rate of weight loss measured as a function of time is compared to that from other tests of coated materials under similar conditions. Microscopic examination of the coatings before and after exposure was also conducted and these results are presented.

  4. Performance analysis of a cascaded coding scheme with interleaved outer code

    NASA Technical Reports Server (NTRS)

    Lin, S.

    1986-01-01

    A cascaded coding scheme for a random error channel with a bit-error rate is analyzed. In this scheme, the inner code C sub 1 is an (n sub 1, m sub 1l) binary linear block code which is designed for simultaneous error correction and detection. The outer code C sub 2 is a linear block code with symbols from the Galois field GF (2 sup l) which is designed for correcting both symbol errors and erasures, and is interleaved with a degree m sub 1. A procedure for computing the probability of a correct decoding is presented and an upper bound on the probability of a decoding error is derived. The bound provides much better results than the previous bound for a cascaded coding scheme with an interleaved outer code. Example schemes with inner codes ranging from high rates to very low rates are evaluated. Several schemes provide extremely high reliability even for very high bit-error rates say 10 to the -1 to 10 to the -2 power.

  5. Configuration and performance of fuel cell-combined cycle options

    SciTech Connect

    Rath, L.K.; Le, P.H.; Sudhoff, F.A.

    1995-12-31

    The natural gas, indirect-fired, carbonate fuel-cell-bottomed, combined cycle (NG-IFCFC) and the topping natural-gas/solid-oxide fuel-cell combined cycle (NG-SOFCCC) are introduced as novel power-plant systems for the distributed power and on-site markets in the 20-200 mega-watt (MW) size range. The novel NG-IFCFC power-plant system configures the ambient pressure molten-carbonate fuel cell (MCFC) with a gas turbine, air compressor, combustor, and ceramic heat exchanger: The topping solid-oxide fuel-cell (SOFC) combined cycle is not new. The purpose of combining a gas turbine with a fuel cell was to inject pressurized air into a high-pressure fuel cell and to reduce the size, and thereby, to reduce the cost of the fuel cell. Today, the SOFC remains pressurized, but excess chemical energy is combusted and the thermal energy is utilized by the Carnot cycle heat engine to complete the system. ASPEN performance results indicate efficiencies and heat rates for the NG-IFCFC or NG-SOFCCC are better than conventional fuel cell or gas turbine steam-bottomed cycles, but with smaller and less expensive components. Fuel cell and gas turbine systems should not be viewed as competitors, but as an opportunity to expand to markets where neither gas turbines nor fuel cells alone would be commercially viable. Non-attainment areas are the most likely markets.

  6. Performance Evaluation of the Reed Solomon and Low Density Parity Check Codes for Blu-ray Disk Channels

    NASA Astrophysics Data System (ADS)

    Kong, Gyuyeol; Choi, Sooyong

    2010-08-01

    In this paper, we evaluate the performances of the Reed-Solomon (RS) and low density parity check (LDPC) codes in order to propose an efficient coding system for the outer code in high density optical recording channels. Hard decision decoding (HDD) RS code, iterative soft decision decoding (SDD) RS code or LDPC code is used as the outer code and LDPC code is used as the inner code. We compare the bit error rate (BER) performance of each coding system for various code rates, code lengths and burst errors. Simulation results show that the LDPC code has a better BER performance than the HDD RS and iterative SDD RS codes as the outer code in high density optical channels. Therefore, the LDPC code could be more attractive as the outer code than the RS code in high density optical channels.

  7. Performance of Transuranic-Loaded Fully Ceramic Micro-Encapsulated Fuel in LWRs Final Report, Including Void Reactivity Evaluation

    SciTech Connect

    Michael A. Pope; R. Sonat Sen; Brian Boer; Abderrafi M. Ougouag; Gilles Youinou

    2011-09-01

    The current focus of the Deep Burn Project is on once-through burning of transuranics (TRU) in light-water reactors (LWRs). The fuel form is called Fully-Ceramic Micro-encapsulated (FCM) fuel, a concept that borrows the tri-isotropic (TRISO) fuel particle design from high-temperature reactor technology. In the Deep Burn LWR (DB-LWR) concept, these fuel particles are pressed into compacts using SiC matrix material and loaded into fuel pins for use in conventional LWRs. The TRU loading comes from the spent fuel of a conventional LWR after 5 years of cooling. Unit cell and assembly calculations have been performed using the DRAGON-4 code to assess the physics attributes of TRU-only FCM fuel in an LWR lattice. Depletion calculations assuming an infinite lattice condition were performed with calculations of various reactivity coefficients performed at each step. Unit cells and assemblies containing typical UO2 and mixed oxide (MOX) fuel were analyzed in the same way to provide a baseline against which to compare the TRU-only FCM fuel. Then, assembly calculations were performed evaluating the performance of heterogeneous arrangements of TRU-only FCM fuel pins along with UO2 pins.

  8. Performance of miniaturized direct methanol fuel cell (DMFC) devices using micropump for fuel delivery

    NASA Astrophysics Data System (ADS)

    Zhang, Tao; Wang, Qing-Ming

    A fuel cell is a device that can convert chemical energy into electricity directly. Among various types of fuel cells, both polymer electrolyte membrane fuel cells (PEMFCs) and direct methanol fuel cells (DMFCs) can work at low temperature (<80 °C). Therefore, they can be used to supply power for commercial portable electronics such as laptop computers, digital cameras, PDAs and cell phones. The focus of this paper is to investigate the performance of a miniaturized DMFC device using a micropump to deliver fuel. The core of this micropump is a piezoelectric ring-type bending actuator and the associated nozzle/diffuser for directing fuel flow. Based on the experimental measurements, it is found that the performance of the fuel cell can be significantly improved if enough fuel flow is induced by the micropump at anode. Three factors may contribute to the performance enhancement including replenishment of methanol, decrease of diffusion resistance and removal of carbon dioxide. In comparison with conventional mini pumps, the size of the piezoelectric micropump is much smaller and the energy consumption is much lower. Thus, it is very viable and effective to use a piezoelectric valveless micropump for fuel delivery in miniaturized DMFC power systems.

  9. Effects of ambient conditions on fuel cell vehicle performance

    NASA Astrophysics Data System (ADS)

    Haraldsson, K.; Alvfors, P.

    Ambient conditions have considerable impact on the performance of fuel cell hybrid vehicles. Here, the vehicle fuel consumption, the air compressor power demand, the water management system and the heat loads of a fuel cell hybrid sport utility vehicle (SUV) were studied. The simulation results show that the vehicle fuel consumption increases with 10% when the altitude increases from 0 m up to 3000 m to 4.1 L gasoline equivalents/100 km over the New European Drive Cycle (NEDC). The increase is 19% on the more power demanding highway US06 cycle. The air compressor is the major contributor to this fuel consumption increase. Its load-following strategy makes its power demand increase with increasing altitude. Almost 40% of the net power output of the fuel cell system is consumed by the air compressor at the altitude of 3000 m with this load-following strategy and is thus more apparent in the high-power US06 cycle. Changes in ambient air temperature and relative humidity effect on the fuel cell system performance in terms of the water management rather in vehicle fuel consumption. Ambient air temperature and relative humidity have some impact on the vehicle performance mostly seen in the heat and water management of the fuel cell system. While the heat loads of the fuel cell system components vary significantly with increasing ambient temperature, the relative humidity did not have a great impact on the water balance. Overall, dimensioning the compressor and other system components to meet the fuel cell system requirements at the minimum and maximum expected ambient temperatures, in this case 5 and 40 °C, and high altitude, while simultaneously choosing a correct control strategy are important parameters for efficient vehicle power train management.

  10. Performance of concatenated Reed-Solomon trellis-coded modulation over Rician fading channels

    NASA Technical Reports Server (NTRS)

    Moher, Michael L.; Lodge, John H.

    1990-01-01

    A concatenated coding scheme for providing very reliable data over mobile-satellite channels at power levels similar to those used for vocoded speech is described. The outer code is a shorter Reed-Solomon code which provides error detection as well as error correction capabilities. The inner code is a 1-D 8-state trellis code applied independently to both the inphase and quadrature channels. To achieve the full error correction potential of this inner code, the code symbols are multiplexed with a pilot sequence which is used to provide dynamic channel estimation and coherent detection. The implementation structure of this scheme is discussed and its performance is estimated.

  11. GROUND-WATER MODEL TESTING: SYSTEMATIC EVALUATION AND TESTING OF CODE FUNCTIONALITY AND PERFORMANCE

    EPA Science Inventory

    Effective use of ground-water simulation codes as management decision tools requires the establishment of their functionality, performance characteristics, and applicability to the problem at hand. This is accomplished through application of a systematic code-testing protocol and...

  12. Fast Reactor Fuel Type and Reactor Safety Performance

    SciTech Connect

    R. Wigeland; J. Cahalan

    2009-09-01

    Fast Reactor Fuel Type and Reactor Safety Performance R. Wigeland , Idaho National Laboratory J. Cahalan, Argonne National Laboratory The sodium-cooled fast neutron reactor is currently being evaluated for the efficient transmutation of the highly-hazardous, long-lived, transuranic elements that are present in spent nuclear fuel. One of the fundamental choices that will be made is the selection of the fuel type for the fast reactor, whether oxide, metal, carbide, nitride, etc. It is likely that a decision on the fuel type will need to be made before many of the related technologies and facilities can be selected, from fuel fabrication to spent fuel reprocessing. A decision on fuel type should consider all impacts on the fast reactor system, including safety. Past work has demonstrated that the choice of fuel type may have a significant impact on the severity of consequences arising from accidents, especially for severe accidents of low probability. In this paper, the response of sodium-cooled fast reactors is discussed for both oxide and metal fuel types, highlighting the similarities and differences in reactor response and accident consequences. Any fast reactor facility must be designed to be able to successfully prevent, mitigate, or accommodate all consequences of potential events, including accidents. This is typically accomplished by using multiple barriers to the release of radiation, including the cladding on the fuel, the intact primary cooling system, and most visibly the reactor containment building. More recently, this has also included the use of ‘inherent safety’ concepts to reduce or eliminate the potential for serious damage in some cases. Past experience with oxide and metal fuel has demonstrated that both fuel types are suitable for use as fuel in a sodium-cooled fast reactor. However, safety analyses for these two fuel types have also shown that there can be substantial differences in accident consequences due to the neutronic and

  13. Metal Matrix Microencapsulated (M3) fuel neutronics performance in PWRs

    SciTech Connect

    Fratoni, Massimiliano; Terrani, Kurt A

    2012-01-01

    Metal Matrix Microencapsulated (M3) fuel consists of TRISO or BISO coated fuel particles directly dispersed in a matrix of zirconium metal to form a solid rod (Fig. 1). In this integral fuel concept the cladding tube and the failure mechanisms associated with it have been eliminated. In this manner pellet-clad-interactions (PCI), thin tube failure due to oxidation and hydriding, and tube pressurization and burst will be absent. M3 fuel, given the high stiffness of the integral rod design, could as well improve grid-to-rod wear behavior. Overall M3 fuel, compared to existing fuel designs, is expected to provide greatly improved operational performance. Multiple barriers to fission product release (ceramic coating layers in the coated fuel particle and te metal matrix) and the high thermal conductivity zirconium alloy metal matrix contribute to the enhancement in fuel behavior. The discontinuous nature of fissile material encapsulated in coated particles provides additional assistance; for instance if the M3 fuel rod is snapped into multiple pieces, only the limited number of fuel particles at the failure cross section are susceptible to release fission products. This is in contrast to the conventional oxide fuel where the presence of a small opening in the cladding provides the pathway for release of the entire inventory of fission products from the fuel rod. While conventional metal fuels (e.g. U-Zr and U-Mo) are typically expected to experience large swelling under irradiation due to the high degree of damage from fission fragments and introduction of fission gas into the lattice, this is not the case for M3 fuels. The fissile portion of the fuel is contained within the coated particle where enough room is available to accommodate fission gases and kernel swelling. The zirconium metal matrix will not be exposed to fission products and its swelling is known to be very limited when exposed solely to neutrons. Under design basis RIA and LOCA, fuel performance will be

  14. On Codes of Ethics, The Individual and Performance.

    ERIC Educational Resources Information Center

    Lee, Monica

    2003-01-01

    Suggests that codes of ethics do not necessarily promote ethical behavior and do not always provide appropriate guidance on the "ethical" thing to do when an individual is confronted with an ethical situation. Explores concerns in four particular areas in which codes of ethics lapse: reification, time dependence, individual understanding of the…

  15. Environmental performance of green building code and certification systems.

    PubMed

    Suh, Sangwon; Tomar, Shivira; Leighton, Matthew; Kneifel, Joshua

    2014-01-01

    We examined the potential life-cycle environmental impact reduction of three green building code and certification (GBCC) systems: LEED, ASHRAE 189.1, and IgCC. A recently completed whole-building life cycle assessment (LCA) database of NIST was applied to a prototype building model specification by NREL. TRACI 2.0 of EPA was used for life cycle impact assessment (LCIA). The results showed that the baseline building model generates about 18 thousand metric tons CO2-equiv. of greenhouse gases (GHGs) and consumes 6 terajoule (TJ) of primary energy and 328 million liter of water over its life-cycle. Overall, GBCC-compliant building models generated 0% to 25% less environmental impacts than the baseline case (average 14% reduction). The largest reductions were associated with acidification (25%), human health-respiratory (24%), and global warming (GW) (22%), while no reductions were observed for ozone layer depletion (OD) and land use (LU). The performances of the three GBCC-compliant building models measured in life-cycle impact reduction were comparable. A sensitivity analysis showed that the comparative results were reasonably robust, although some results were relatively sensitive to the behavioral parameters, including employee transportation and purchased electricity during the occupancy phase (average sensitivity coefficients 0.26-0.29). PMID:24483287

  16. Fuel type impact at heat exchanger performance

    NASA Astrophysics Data System (ADS)

    Durčanský, Peter; Patsch, Marek; Jandačka, Jozef

    2016-06-01

    Possible solution to the increasing energy consumption in the world may be use of alternative energy sources in micro-cogeneration in combination with increasing energy effectiveness. The use of renewable sources, such as biomass, represents an important contribution to possible solution of this problem. When designing a new heat source it is required to follow a number of technical regulations and recommendations. The proposed combustion furnace is intended for combustion of biomass, either piece, or in the form of wood biomass. But the combustion is not only affected by design of furnace, but also by fuel and its properties.

  17. An investigation of error characteristics and coding performance

    NASA Technical Reports Server (NTRS)

    Ebel, William J.; Ingels, Frank M.

    1993-01-01

    The first year's effort on NASA Grant NAG5-2006 was an investigation to characterize typical errors resulting from the EOS dorn link. The analysis methods developed for this effort were used on test data from a March 1992 White Sands Terminal Test. The effectiveness of a concatenated coding scheme of a Reed Solomon outer code and a convolutional inner code versus a Reed Solomon only code scheme has been investigated as well as the effectiveness of a Periodic Convolutional Interleaver in dispersing errors of certain types. The work effort consisted of development of software that allows simulation studies with the appropriate coding schemes plus either simulated data with errors or actual data with errors. The software program is entitled Communication Link Error Analysis (CLEAN) and models downlink errors, forward error correcting schemes, and interleavers.

  18. Irradiation performance of (Th,Pu)O2 fuel under Pressurized Water Reactor conditions

    NASA Astrophysics Data System (ADS)

    Boer, B.; Lemehov, S.; Wéber, M.; Parthoens, Y.; Gysemans, M.; McGinley, J.; Somers, J.; Verwerft, M.

    2016-04-01

    This paper examines the in-pile safety performance of (Th,Pu)O2 fuel pins under simulated Pressurized Water Reactor (PWR) conditions. Both sol-gel and SOLMAS produced (Th,Pu)O2 fuels at enrichments of 7.9% and 12.8% in Pu/HM have been irradiated at SCK·CEN. The irradiation has been performed under PWR conditions (155 bar, 300 °C) in a dedicated loop of the BR-2 reactor. The loop is instrumented with flow and temperature monitors at inlet and outlet, which allow for an accurate measurement of the deposited enthalpy. Between 2004 and 2006, four fuel segments were irradiated, with on-line recording of centerline temperature and rod pressure of the two instrumented rods and intermittent non-destructive hot-cell investigations of the other two non-instrumented rods. At the end of 2006, the instrumented rods were unloaded for hot-cell investigations. The hot-cell investigations reduced uncertainties in the power history to build a reliable and consistent irradiation history which can be used to assess and validate fuel performance codes. The on-line recorded temperatures of the instrumented rods are presented in this paper and are compared to corresponding calculations on the basis of the power history. One of the non-instrumented rods was re-inserted in the reactor in 2012 and attained a peak burnup level of 37 GWd/tHM by the end of 2014. The combined data set of on-line measurements and post irradiation examinations enables further code validation. In this context, the results of the in-house MACROS code of SCK·CEN have been compared with the experimental results. The code contains dedicated (Th,Pu)O2 models for the calculation of the thermal conductivity as a function of the burnup and models that determine the radial power profile within the pellet.

  19. Prognosis and comparison of performances of composite CERCER and CERMET fuels dedicated to transmutation of TRU in an EFIT ADS

    NASA Astrophysics Data System (ADS)

    Sobolev, V.; Uyttenhove, W.; Thetford, R.; Maschek, W.

    2011-07-01

    The neutronic and thermomechanical performances of two composite fuel systems: CERCER with (Pu,Np,Am,Cm)O 2-x fuel particles in ceramic MgO matrix and CERMET with metallic Mo matrix, selected for transmutation of minor actinides in the European Facility for Industrial Transmutation (EFIT), were analysed aiming at their optimisation. The ALEPH burnup code system, based on MNCPX and ORIGEN codes and JEFF3.1 nuclear data library, and the modern version of the fuel rod performance code TRAFIC were used for this analysis. Because experimental data on the properties of the mixed minor-actinide oxides are scarce, and the in-reactor behaviour of the T91 steel chosen as cladding, as well as of the corrosion protective layer, is still not well-known, a set of "best estimates" provided the properties used in the code. The obtained results indicate that both fuel candidates, CERCER and CERMET, can satisfy the fuel design and safety criteria of EFIT. The residence time for both types of fuel elements can reach about 5 years with the reactivity swing within ±1000 pcm, and about 22% of the loaded MA is transmuted during this period. However, the fuel centreline temperature in the hottest CERCER fuel rod is close to the temperature above which MgO matrix becomes chemically instable. Moreover, a weak PCMI can appear in about 3 years of operation. The CERMET fuel can provide larger safety margins: the fuel temperature is more than 1000 K below the permitted level of 2380 K and the pellet-cladding gap remains open until the end of operation.

  20. Fuel Cycle Performance of Thermal Spectrum Small Modular Reactors

    SciTech Connect

    Worrall, Andrew; Todosow, Michael

    2016-01-01

    Small modular reactors may offer potential benefits, such as enhanced operational flexibility. However, it is vital to understand the holistic impact of small modular reactors on the nuclear fuel cycle and fuel cycle performance. The focus of this paper is on the fuel cycle impacts of light water small modular reactors in a once-through fuel cycle with low-enriched uranium fuel. A key objective of this paper is to describe preliminary reactor core physics and fuel cycle analyses conducted in support of the U.S. Department of Energy Office of Nuclear Energy Fuel Cycle Options Campaign. Challenges with small modular reactors include: increased neutron leakage, fewer assemblies in the core (and therefore fewer degrees of freedom in the core design), complex enrichment and burnable absorber loadings, full power operation with inserted control rods, the potential for frequent load-following operation, and shortened core height. Each of these will impact the achievable discharge burn-up in the reactor and the fuel cycle performance. This paper summarizes the results of an expert elicitation focused on developing a list of the factors relevant to small modular reactor fuel, core, and operation that will impact fuel cycle performance. Preliminary scoping analyses were performed using a regulatory-grade reactor core simulator. The hypothetical light water small modular reactor considered in these preliminary scoping studies is a cartridge type one-batch core with 4.9% enrichment. Some core parameters, such as the size of the reactor and general assembly layout, are similar to an example small modular reactor concept from industry. The high-level issues identified and preliminary scoping calculations in this paper are intended to inform on potential fuel cycle impacts of one-batch thermal spectrum SMRs. In particular, this paper highlights the impact of increased neutron leakage and reduced number of batches on the achievable burn-up of the reactor. Fuel cycle performance

  1. High performance fuel element with end seal

    DOEpatents

    Lee, Gary E.; Zogg, Gordon J.

    1987-01-01

    A nuclear fuel element comprising an elongate block of refractory material having a generally regular polygonal cross section. The block includes parallel, spaced, first and second end surfaces. The first end surface has a peripheral sealing flange formed thereon while the second end surface has a peripheral sealing recess sized to receive the flange. A plurality of longitudinal first coolant passages are positioned inwardly of the flange and recess. Elongate fuel holes are separate from the coolant passages and disposed inwardly of the flange and the recess. The block is further provided with a plurality of peripheral second coolant passages in general alignment with the flange and the recess for flowing coolant. The block also includes two bypasses for each second passage. One bypass intersects the second passage adjacent to but spaced from the first end surface and intersects a first passage, while the other bypass intersects the second passage adjacent to but spaced from the second end surface and intersects a first passage so that coolant flowing through the second passages enters and exits the block through the associated first passages.

  2. Performance Analysis of Wavelength Multiplexed Sac Ocdma Codes in Beat Noise Mitigation in Sac Ocdma Systems

    NASA Astrophysics Data System (ADS)

    Alhassan, A. M.; Badruddin, N.; Saad, N. M.; Aljunid, S. A.

    2013-07-01

    In this paper we investigate the use of wavelength multiplexed spectral amplitude coding (WM SAC) codes in beat noise mitigation in coherent source SAC OCDMA systems. A WM SAC code is a low weight SAC code, where the whole code structure is repeated diagonally (once or more) in the wavelength domain to achieve the same cardinality as a higher weight SAC code. Results show that for highly populated networks, the WM SAC codes provide better performance than SAC codes. However, for small number of active users the situation is reversed. Apart from their promising improvement in performance, these codes are more flexible and impose less complexity on the system design than their SAC counterparts.

  3. The statistical analysis techniques to support the NGNP fuel performance experiments

    NASA Astrophysics Data System (ADS)

    Pham, Binh T.; Einerson, Jeffrey J.

    2013-10-01

    This paper describes the development and application of statistical analysis techniques to support the Advanced Gas Reactor (AGR) experimental program on Next Generation Nuclear Plant (NGNP) fuel performance. The experiments conducted in the Idaho National Laboratory's Advanced Test Reactor employ fuel compacts placed in a graphite cylinder shrouded by a steel capsule. The tests are instrumented with thermocouples embedded in graphite blocks and the target quantity (fuel temperature) is regulated by the He-Ne gas mixture that fills the gap volume. Three techniques for statistical analysis, namely control charting, correlation analysis, and regression analysis, are implemented in the NGNP Data Management and Analysis System for automated processing and qualification of the AGR measured data. The neutronic and thermal code simulation results are used for comparative scrutiny. The ultimate objective of this work includes (a) a multi-faceted system for data monitoring and data accuracy testing, (b) identification of possible modes of diagnostics deterioration and changes in experimental conditions, (c) qualification of data for use in code validation, and (d) identification and use of data trends to support effective control of test conditions with respect to the test target. Analysis results and examples given in the paper show the three statistical analysis techniques providing a complementary capability to warn of thermocouple failures. It also suggests that the regression analysis models relating calculated fuel temperatures and thermocouple readings can enable online regulation of experimental parameters (i.e. gas mixture content), to effectively maintain the fuel temperature within a given range.

  4. The statistical analysis techniques to support the NGNP fuel performance experiments

    SciTech Connect

    Binh T. Pham; Jeffrey J. Einerson

    2013-10-01

    This paper describes the development and application of statistical analysis techniques to support the Advanced Gas Reactor (AGR) experimental program on Next Generation Nuclear Plant (NGNP) fuel performance. The experiments conducted in the Idaho National Laboratory’s Advanced Test Reactor employ fuel compacts placed in a graphite cylinder shrouded by a steel capsule. The tests are instrumented with thermocouples embedded in graphite blocks and the target quantity (fuel temperature) is regulated by the He–Ne gas mixture that fills the gap volume. Three techniques for statistical analysis, namely control charting, correlation analysis, and regression analysis, are implemented in the NGNP Data Management and Analysis System for automated processing and qualification of the AGR measured data. The neutronic and thermal code simulation results are used for comparative scrutiny. The ultimate objective of this work includes (a) a multi-faceted system for data monitoring and data accuracy testing, (b) identification of possible modes of diagnostics deterioration and changes in experimental conditions, (c) qualification of data for use in code validation, and (d) identification and use of data trends to support effective control of test conditions with respect to the test target. Analysis results and examples given in the paper show the three statistical analysis techniques providing a complementary capability to warn of thermocouple failures. It also suggests that the regression analysis models relating calculated fuel temperatures and thermocouple readings can enable online regulation of experimental parameters (i.e. gas mixture content), to effectively maintain the fuel temperature within a given range.

  5. Pedestal Fueling Simulations with a Coupled Kinetic-kinetic Plasma-neutral Transport Code

    SciTech Connect

    D.P. Stotler, C.S. Chang, S.H. Ku, J. Lang and G.Y. Park

    2012-08-29

    A Monte Carlo neutral transport routine, based on DEGAS2, has been coupled to the guiding center ion-electron-neutral neoclassical PIC code XGC0 to provide a realistic treatment of neutral atoms and molecules in the tokamak edge plasma. The DEGAS2 routine allows detailed atomic physics and plasma-material interaction processes to be incorporated into these simulations. The spatial pro le of the neutral particle source used in the DEGAS2 routine is determined from the uxes of XGC0 ions to the material surfaces. The kinetic-kinetic plasma-neutral transport capability is demonstrated with example pedestal fueling simulations.

  6. Theoretical performance of hydrogen-bromine rechargeable SPE fuel cell

    NASA Technical Reports Server (NTRS)

    Savinell, Robert F.; Fritts, S. D.

    1987-01-01

    A mathematical model was formulated to describe the performance of a hydrogen-bromine fuel cell. Porous electrode theory was applied to the carbon felt flow-by electrode and was coupled to theory describing the solid polymer electrolyte (SPE) system. Parametric studies using the numerical solution to this model were performed to determine the effect of kinetic, mass transfer, and design parameters on the performance of the fuel cell. The results indicate that the cell performance is most sensitive to the transport properties of the SPE membrane. The model was also shown to be a useful tool for scale-up studies.

  7. SCALE: A modular code system for performing standardized computer analyses for licensing evaluation: Functional modules F1-F8

    SciTech Connect

    1997-03-01

    This Manual represents Revision 5 of the user documentation for the modular code system referred to as SCALE. The history of the SCALE code system dates back to 1969 when the current Computational Physics and Engineering Division at Oak Ridge National Laboratory (ORNL) began providing the transportation package certification staff at the U.S. Atomic Energy Commission with computational support in the use of the new KENO code for performing criticality safety assessments with the statistical Monte Carlo method. From 1969 to 1976 the certification staff relied on the ORNL staff to assist them in the correct use of codes and data for criticality, shielding, and heat transfer analyses of transportation packages. However, the certification staff learned that, with only occasional use of the codes, it was difficult to become proficient in performing the calculations often needed for an independent safety review. Thus, shortly after the move of the certification staff to the U.S. Nuclear Regulatory Commission (NRC), the NRC staff proposed the development of an easy-to-use analysis system that provided the technical capabilities of the individual modules with which they were familiar. With this proposal, the concept of the Standardized Computer Analyses for Licensing Evaluation (SCALE) code system was born. This volume consists of the section of the manual dealing with eight of the functional modules in the code. Those are: BONAMI - resonance self-shielding by the Bondarenko method; NITAWL-II - SCALE system module for performing resonance shielding and working library production; XSDRNPM - a one-dimensional discrete-ordinates code for transport analysis; XSDOSE - a module for calculating fluxes and dose rates at points outside a shield; KENO IV/S - an improved monte carlo criticality program; COUPLE; ORIGEN-S - SCALE system module to calculate fuel depletion, actinide transmutation, fission product buildup and decay, and associated radiation source terms; ICE.

  8. Bipolar optical pulse coding for performance enhancement in BOTDA sensors.

    PubMed

    Soto, Marcelo A; Le Floch, Sébastien; Thévenaz, Luc

    2013-07-15

    A pump signal based on bipolar pulse coding and single-sideband suppressed-carried (SSB-SC) modulation is proposed for Brillouin optical time-domain analysis (BOTDA) sensors. Making a sequential use of the Brillouin gain and loss spectra, the technique is experimentally validated using bipolar complementary-correlation Golay codes along a 100 km-long fiber and 2 m spatial resolution, fully resolving a 2 m hot-spot at the end of the sensing fiber with no distortion introduced by the decoding algorithm. Experimental results, in good agreement with the theory, indicate that bipolar Golay codes provide a higher signal-to-noise ratio enhancement and stronger robustness to pump depletion in comparison to optimum unipolar pulse codes known for BOTDA sensing. PMID:23938490

  9. Re-evaluation of Spent Nuclear Fuel Assay Data for the Three Mile Island Unit 1 Reactor and Application to Code Validation

    DOE PAGESBeta

    Gauld, Ian C.; Giaquinto, J. M.; Delashmitt, J. S.; Hu, Jianwei; Ilas, Germina; Haverlock, T. J.; Romano, Catherine E.

    2016-01-01

    Destructive radiochemical assay measurements of spent nuclear fuel rod segments from an assembly irradiated in the Three Mile Island unit 1 (TMI-1) pressurized water reactor have been performed at Oak Ridge National Laboratory (ORNL). Assay data are reported for five samples from two fuel rods of the same assembly. The TMI-1 assembly was a 15 X 15 design with an initial enrichment of 4.013 wt% 235U, and the measured samples achieved burnups between 45.5 and 54.5 gigawatt days per metric ton of initial uranium (GWd/t). Measurements were performed mainly using inductively coupled plasma mass spectrometry after elemental separation via highmore » performance liquid chromatography. High precision measurements were achieved using isotope dilution techniques for many of the lanthanides, uranium, and plutonium isotopes. Measurements are reported for more than 50 different isotopes and 16 elements. One of the two TMI-1 fuel rods measured in this work had been measured previously by Argonne National Laboratory (ANL), and these data have been widely used to support code and nuclear data validation. Recently, ORNL provided an important opportunity to independently cross check results against previous measurements performed at ANL. The measured nuclide concentrations are used to validate burnup calculations using the SCALE nuclear systems modeling and simulation code suite. These results show that the new measurements provide reliable benchmark data for computer code validation.« less

  10. Re-evaluation of Spent Nuclear Fuel Assay Data for the Three Mile Island Unit 1 Reactor and Application to Code Validation

    SciTech Connect

    Gauld, Ian C.; Giaquinto, J. M.; Delashmitt, J. S.; Hu, Jianwei; Ilas, Germina; Haverlock, T. J.; Romano, Catherine E.

    2016-01-01

    Destructive radiochemical assay measurements of spent nuclear fuel rod segments from an assembly irradiated in the Three Mile Island unit 1 (TMI-1) pressurized water reactor have been performed at Oak Ridge National Laboratory (ORNL). Assay data are reported for five samples from two fuel rods of the same assembly. The TMI-1 assembly was a 15 X 15 design with an initial enrichment of 4.013 wt% 235U, and the measured samples achieved burnups between 45.5 and 54.5 gigawatt days per metric ton of initial uranium (GWd/t). Measurements were performed mainly using inductively coupled plasma mass spectrometry after elemental separation via high performance liquid chromatography. High precision measurements were achieved using isotope dilution techniques for many of the lanthanides, uranium, and plutonium isotopes. Measurements are reported for more than 50 different isotopes and 16 elements. One of the two TMI-1 fuel rods measured in this work had been measured previously by Argonne National Laboratory (ANL), and these data have been widely used to support code and nuclear data validation. Recently, ORNL provided an important opportunity to independently cross check results against previous measurements performed at ANL. The measured nuclide concentrations are used to validate burnup calculations using the SCALE nuclear systems modeling and simulation code suite. These results show that the new measurements provide reliable benchmark data for computer code validation.

  11. BWR fuel rod performance evaluation program. Final report

    SciTech Connect

    Rowland, T.C.

    1986-05-01

    The joint EPRI/GE fuel performance program, RP510-1, involved thorough preirradiation characterization of fuel used in lead test assemblies, detailed surveillance of their operation, and interim site examinations of the assemblies during reactor outages. The program originally included four GE-5 lead test assemblies operating in the Peach Bottom-2 reactor. The program was later modified to include the pressurized fuel rod test assembly in the Peach Bottom-3 reactor (RP510-2). The program modification also included extending the operation of the Peach Bottom-2 and Peach Bottom-3 lead test assembly fuel beyond normal discharge exposures. Interim site examination results following the first four cycles of operation of the Peach Bottom-2 lead test assemblies up to 35 GWd/MT and the examination of the Peach Bottom-3 pressurized test assembly at 32 GWd/MT are presented in this report. Elements of the examinations included visual examination of the fuel bundles; individual fuel rod visual examinations, rod length measurements, ultrasonic and eddy current nondestructive testing, Zircaloy cladding oxide thickness measurements and fission gas measurements. Channel measurements were made on the PB-2 Lead Test Assemblies after each of the first three operating cycles. All of the bundles were found to be in good condition. Since the pressurized test assembly contained pressurized and nonpressurized fuel rods in symmetric positions, it was possible to make direct comparisons of the fission gas release from pairs of pressurized and nonpressurized fuel rods with identical power histories. With one exception, the release was less from the pressurized fuel rod of each pair. Fuel rod power histories were calculated using new physics methods for all of the fuel rods that were punctured for fission gas release measurements. 28 refs., 41 figs., 16 tabs.

  12. Design and performance of a prototype fuel cell powered vehicle

    SciTech Connect

    Lehman, P.A.; Chamberlin, C.E.

    1996-12-31

    The Schatz Energy Research Center (SERC) is now engaged in the Palm Desert Renewable Hydrogen Transportation System Project. The Project involves a consortium which includes the City of Palm Desert, SERC, the U.S. Department of Energy, the South Coast Air Quality Management District, and Sandia and Lawrence Livermore National Laboratories. Its goal to develop a clean and sustainable transportation system for a community will be accomplished by producing a fleet of fuel cell vehicles, installing a refueling infrastructure utilizing hydrogen generated from solar and wind power, and developing and staffing a fuel cell service and diagnostic center. We will describe details of the project and performance goals for the fuel cell vehicles and associated peripheral systems. In the past year during the first stage in the project, SERC has designed and built a prototype fuel cell powered personal utility vehicle (PUV). These steps included: (1) Designing, building, and testing a 4.0 kW proton exchange membrane (PEM) fuel cell as a power plant for the PUV. (2) Designing, building and testing peripherals including the air delivery, fuel storage/delivery, refueling, water circulation, cooling, and electrical systems. (3) Devising a control algorithm for the fuel cell power plant in the PUV. (4) Designing and building a test bench in which running conditions in the PUV could be simulated and the fuel cell and its peripheral systems tested. (5) Installing an onboard computer and associated electronics into the PUV (6) Assembling and road testing the PUV.

  13. Recent advances in high-performance direct methanol fuel cells

    SciTech Connect

    Narayanan, S.R.; Chun, W.; Valdez, T.I.

    1996-12-31

    Direct methanol fuel cells for portable power applications have been advanced significantly under DARPA- and ARO-sponsored programs over the last five years. A liquid-feed direct methanol fuel cell developed under these programs, employs a proton exchange membrane as electrolyte and operates on aqueous solutions of methanol with air or oxygen as the oxidant. Power densities as high as 320 mW/cm{sup 2} have been demonstrated. Demonstration of five-cell stack based on the liquid-feed concept have been successfully performed by Giner Inc. and the Jet Propulsion Laboratory. Over 2000 hours of life-testing have been completed on these stacks. These fuel cells have been also been demonstrated by USC to operate on alternate fuels such as trimethoxymethane, dimethoxymethane and trioxane. Reduction in the parasitic loss of fuel across the fuel cell, a phenomenon termed as {open_quotes}fuel crossover{close_quotes} has been achieved using polymer membranes developed at USC. As a result efficiencies as high as 40% is considered attainable with this type of fuel cell. The state-of-development has reached a point where it is now been actively considered for stationary, portable and transportation applications. The research and development issues have been the subject of several previous articles and the present article is an attempt to summarize the key advances in this technology.

  14. The Fuel Accident Condition Simulator (FACS) furnace system for high temperature performance testing of VHTR fuel

    SciTech Connect

    Paul A. Demkowicz; David V. Laug; Dawn M. Scates; Edward L. Reber; Lyle G. Roybal; John B. Walter; Jason M. Harp; Robert N. Morris

    2012-10-01

    The AGR-1 irradiation of TRISO-coated particle fuel specimens was recently completed and represents the most successful such irradiation in US history, reaching peak burnups of greater than 19% FIMA with zero failures out of 300,000 particles. An extensive post-irradiation examination (PIE) campaign will be conducted on the AGR-1 fuel in order to characterize the irradiated fuel properties, assess the in-pile fuel performance in terms of coating integrity and fission metals release, and determine the fission product retention behavior during high temperature safety testing. A new furnace system has been designed, built, and tested to perform high temperature accident tests. The Fuel Accident Condition Simulator furnace system is designed to heat fuel specimens at temperatures up to 2000 degrees C in helium while monitoring the release of volatile fission metals (e.g. Cs, Ag, Sr, and Eu), iodine, and fission gases (Kr, Xe). Fission gases released from the fuel to the sweep gas are monitored in real time using dual cryogenic traps fitted with high purity germanium detectors. Condensable fission products are collected on a plate attached to a water-cooled cold finger that can be exchanged periodically without interrupting the test. Analysis of fission products on the condensation plates involves dry gamma counting followed by chemical analysis of selected isotopes. This paper will describe design and operational details of the Fuel Accident Condition Simulator furnace system and the associated fission gas monitoring system, as well as preliminary system calibration results.

  15. Multiple-error-correcting codes for improving the performance of optical matrix-vector processors.

    PubMed

    Neifeld, M A

    1995-04-01

    I examine the use of Reed-Solomon multiple-error-correcting codes for enhancing the performance of optical matrix-vector processors. An optimal code rate of 0.75 is found, and n = 127 block-length codes are seen to increase the optical matrix dimension achievable by a factor of 2.0 for a required system bit-error rate of 10(-15). The optimal codes required for various matrix dimensions are determined. I show that single code word implementations are more efficient than those utilizing multiple code words. PMID:19859320

  16. Soft-decision decoding techniques for linear block codes and their error performance analysis

    NASA Technical Reports Server (NTRS)

    Lin, Shu

    1996-01-01

    The first paper presents a new minimum-weight trellis-based soft-decision iterative decoding algorithm for binary linear block codes. The second paper derives an upper bound on the probability of block error for multilevel concatenated codes (MLCC). The bound evaluates difference in performance for different decompositions of some codes. The third paper investigates the bit error probability code for maximum likelihood decoding of binary linear codes. The fourth and final paper included in this report is concerns itself with the construction of multilevel concatenated block modulation codes using a multilevel concatenation scheme for the frequency non-selective Rayleigh fading channel.

  17. A novel method for performance improvement of optical CDMA system using alterable concatenated code

    NASA Astrophysics Data System (ADS)

    Qiu, Kun; Zhang, Chongfu

    2007-04-01

    A novel method using alterable concatenated code to pre-encode is proposed to reduce the impact of system impairment and multiple access interference (MAI) in optical code division multiple access (OCDMA) system, comprehensive comparisons between different concatenated code type and forward error correcting (FEC) scheme are studied by simulation. In the scheme, we apply concatenated coding to the embedded modulation scheme, and optical orthogonal code (OOC) is employed as address sequence code, an avalanche photodiode (APD) is selected as the system receiver. The bit error rate (BER) performance is derived taking into account the effect of some noises, dispersion power penalty and the MAI. From both theoretical analysis and numerical results, we can show that the proposed system has good performance at a BER of 10 -9 with a gain of 6.4 dB improvement achieved using the concatenated code as the pre-code, and this scheme permits implementation of a cost effective OCDMA system.

  18. Nuclear Energy Advanced Modeling and Simulation (NEAMS) waste Integrated Performance and Safety Codes (IPSC) : gap analysis for high fidelity and performance assessment code development.

    SciTech Connect

    Lee, Joon H.; Siegel, Malcolm Dean; Arguello, Jose Guadalupe, Jr.; Webb, Stephen Walter; Dewers, Thomas A.; Mariner, Paul E.; Edwards, Harold Carter; Fuller, Timothy J.; Freeze, Geoffrey A.; Jove-Colon, Carlos F.; Wang, Yifeng

    2011-03-01

    This report describes a gap analysis performed in the process of developing the Waste Integrated Performance and Safety Codes (IPSC) in support of the U.S. Department of Energy (DOE) Office of Nuclear Energy Advanced Modeling and Simulation (NEAMS) Campaign. The goal of the Waste IPSC is to develop an integrated suite of computational modeling and simulation capabilities to quantitatively assess the long-term performance of waste forms in the engineered and geologic environments of a radioactive waste storage or disposal system. The Waste IPSC will provide this simulation capability (1) for a range of disposal concepts, waste form types, engineered repository designs, and geologic settings, (2) for a range of time scales and distances, (3) with appropriate consideration of the inherent uncertainties, and (4) in accordance with rigorous verification, validation, and software quality requirements. The gap analyses documented in this report were are performed during an initial gap analysis to identify candidate codes and tools to support the development and integration of the Waste IPSC, and during follow-on activities that delved into more detailed assessments of the various codes that were acquired, studied, and tested. The current Waste IPSC strategy is to acquire and integrate the necessary Waste IPSC capabilities wherever feasible, and develop only those capabilities that cannot be acquired or suitably integrated, verified, or validated. The gap analysis indicates that significant capabilities may already exist in the existing THC codes although there is no single code able to fully account for all physical and chemical processes involved in a waste disposal system. Large gaps exist in modeling chemical processes and their couplings with other processes. The coupling of chemical processes with flow transport and mechanical deformation remains challenging. The data for extreme environments (e.g., for elevated temperature and high ionic strength media) that are

  19. 14 CFR 234.8 - Calculation of on-time performance codes.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false Calculation of on-time performance codes. 234.8 Section 234.8 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION... of on-time performance codes. (a) Each reporting carrier shall calculate an on-time performance...

  20. 14 CFR 234.8 - Calculation of on-time performance codes.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Calculation of on-time performance codes. 234.8 Section 234.8 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION... of on-time performance codes. (a) Each reporting carrier shall calculate an on-time performance...

  1. 14 CFR 234.8 - Calculation of on-time performance codes.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 4 2012-01-01 2012-01-01 false Calculation of on-time performance codes. 234.8 Section 234.8 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION... of on-time performance codes. (a) Each reporting carrier shall calculate an on-time performance...

  2. 14 CFR 234.8 - Calculation of on-time performance codes.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 4 2014-01-01 2014-01-01 false Calculation of on-time performance codes. 234.8 Section 234.8 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION... of on-time performance codes. (a) Each reporting carrier shall calculate an on-time performance...

  3. 14 CFR 234.8 - Calculation of on-time performance codes.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 4 2013-01-01 2013-01-01 false Calculation of on-time performance codes. 234.8 Section 234.8 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION... of on-time performance codes. (a) Each reporting carrier shall calculate an on-time performance...

  4. A computer code to estimate accidental fire and radioactive airborne releases in nuclear fuel cycle facilities: User's manual for FIRIN

    SciTech Connect

    Chan, M.K.; Ballinger, M.Y.; Owczarski, P.C.

    1989-02-01

    This manual describes the technical bases and use of the computer code FIRIN. This code was developed to estimate the source term release of smoke and radioactive particles from potential fires in nuclear fuel cycle facilities. FIRIN is a product of a broader study, Fuel Cycle Accident Analysis, which Pacific Northwest Laboratory conducted for the US Nuclear Regulatory Commission. The technical bases of FIRIN consist of a nonradioactive fire source term model, compartment effects modeling, and radioactive source term models. These three elements interact with each other in the code affecting the course of the fire. This report also serves as a complete FIRIN user's manual. Included are the FIRIN code description with methods/algorithms of calculation and subroutines, code operating instructions with input requirements, and output descriptions. 40 refs., 5 figs., 31 tabs.

  5. Fueling Performance: Ketones Enter the Mix.

    PubMed

    Egan, Brendan; D'Agostino, Dominic P

    2016-09-13

    Ketone body metabolites serve as alternative energy substrates during prolonged fasting, calorie restriction, or reduced carbohydrate (CHO) availability. Using a ketone ester supplement, Cox et al. (2016) demonstrate that acute nutritional ketosis alters substrate utilization patterns during exercise, reduces lactate production, and improves time-trial performance in elite cyclists. PMID:27626197

  6. A low-complexity and high performance concatenated coding scheme for high-speed satellite communications

    NASA Technical Reports Server (NTRS)

    Lin, Shu; Rhee, Dojun; Rajpal, Sandeep

    1993-01-01

    This report presents a low-complexity and high performance concatenated coding scheme for high-speed satellite communications. In this proposed scheme, the NASA Standard Reed-Solomon (RS) code over GF(2(exp 8) is used as the outer code and the second-order Reed-Muller (RM) code of Hamming distance 8 is used as the inner code. The RM inner code has a very simple trellis structure and is decoded with the soft-decision Viterbi decoding algorithm. It is shown that the proposed concatenated coding scheme achieves an error performance which is comparable to that of the NASA TDRS concatenated coding scheme in which the NASA Standard rate-1/2 convolutional code of constraint length 7 and d sub free = 10 is used as the inner code. However, the proposed RM inner code has much smaller decoding complexity, less decoding delay, and much higher decoding speed. Consequently, the proposed concatenated coding scheme is suitable for reliable high-speed satellite communications, and it may be considered as an alternate coding scheme for the NASA TDRS system.

  7. A low-complexity and high performance concatenated coding scheme for high-speed satellite communications

    NASA Astrophysics Data System (ADS)

    Lin, Shu; Rhee, Dojun; Rajpal, Sandeep

    1993-02-01

    This report presents a low-complexity and high performance concatenated coding scheme for high-speed satellite communications. In this proposed scheme, the NASA Standard Reed-Solomon (RS) code over GF(2(exp 8) is used as the outer code and the second-order Reed-Muller (RM) code of Hamming distance 8 is used as the inner code. The RM inner code has a very simple trellis structure and is decoded with the soft-decision Viterbi decoding algorithm. It is shown that the proposed concatenated coding scheme achieves an error performance which is comparable to that of the NASA TDRS concatenated coding scheme in which the NASA Standard rate-1/2 convolutional code of constraint length 7 and d sub free = 10 is used as the inner code. However, the proposed RM inner code has much smaller decoding complexity, less decoding delay, and much higher decoding speed. Consequently, the proposed concatenated coding scheme is suitable for reliable high-speed satellite communications, and it may be considered as an alternate coding scheme for the NASA TDRS system.

  8. Model building codes and acoustical performance: Where are we in 2003?

    NASA Astrophysics Data System (ADS)

    Tinianov, Brandon

    2003-10-01

    The proper acoustical design for multi-family dwellings is an important factor in occupant comfort. Key acoustical design practices are often not mandated by the builder or architect, but by the applicable building codes. In early 2003, the three regional/national building codes agreed to join into a single, unified national building code for residential and commercial construction. The scope and governance of these three codes: the Uniform Building Code (ICBO), the National Building Code (BOCA), the Southern Building Code (SBCCI) are reflected in the International Residential Code (IRC) and the International Building Code (IBC) which was developed by the International Code Council (ICC). With the move to a single code body, those concerned with building acoustical performance welcome the benefit of a single minimum standard. Unfortunately, this new minimum performance requirement does not reflect the state of the science for occupant satisfaction. The acoustical requirements of each of these building codes, the timeline of their development and an overview of the state of the science will be presented. Suggestions for revised performance minimums will also be offered for discussion.

  9. Improvements of MCOR: A Monte Carlo depletion code system for fuel assembly reference calculations

    SciTech Connect

    Tippayakul, C.; Ivanov, K.; Misu, S.

    2006-07-01

    This paper presents the improvements of MCOR, a Monte Carlo depletion code system for fuel assembly reference calculations. The improvements of MCOR were initiated by the cooperation between the Penn State Univ. and AREVA NP to enhance the original Penn State Univ. MCOR version in order to be used as a new Monte Carlo depletion analysis tool. Essentially, a new depletion module using KORIGEN is utilized to replace the existing ORIGEN-S depletion module in MCOR. Furthermore, the online burnup cross section generation by the Monte Carlo calculation is implemented in the improved version instead of using the burnup cross section library pre-generated by a transport code. Other code features have also been added to make the new MCOR version easier to use. This paper, in addition, presents the result comparisons of the original and the improved MCOR versions against CASMO-4 and OCTOPUS. It was observed in the comparisons that there were quite significant improvements of the results in terms of k{sub inf}, fission rate distributions and isotopic contents. (authors)

  10. A high performance spectral code for nonlinear MHD stability

    SciTech Connect

    Taylor, M.

    1992-09-01

    A new spectral code, NSTAB, has been developed to do nonlinear stability and equilibrium calculations for the magnetohydrodynamic (MHD) equations in three dimensional toroidal geometries. The code has the resolution to test nonlinear stability by calculating bifurcated equilibria directly. These equilibria consist of weak solutions with current sheets near rational surfaces and other less localized modes. Bifurcated equilibria with a pronounced current sheet where the rotational transform crosses unity are calculated for the International Thermonuclear Experimental Reactor (ITER). Bifurcated solutions with broader resonances are found for the LHD stellarator currently being built in Japan and an optimized configuration like the Wendelstein VII-X proposed for construction in Germany. The code is able to handle the many harmonics required to capture the high mode number of these instabilities. NSTAB builds on the highly successful BETAS code, which applies the spectral method to a flux coordinate formulation of the variational principle associated with the MHD equilibrium equations. However, a new residue condition for the location of the magnetic axis has been developed and implemented. This condition is based on the weak formulation of the equations and imposes no constraints on the inner flux surfaces.

  11. High-alcohol microemulsion fuel performance in a diesel engine

    SciTech Connect

    West, B.H.; Compere, A.L.; Griffith, W.L.

    1990-01-01

    Incidence of methanol use in diesel engines is increasing rapidly due to the potential to reduce both diesel particulate emissions and petroleum consumption. Because simple alcohols and conventional diesel fuel are normally immiscible, most tests to date have used neat to near-neat alcohol, or blends incorporating surfactants or other alcohols. Alcohol's poor ignition quality usually necssitates the use of often expensive cetane enhancers, full-time glow plugs, or spark assist. Reported herein are results of screening tests of clear microemulsion and micellar fuels which contain 10 to 65% C{sub 1}--C{sub 4} alcohol. Ignition performance and NO emissions were measured for clear, stable fuel blends containing alcohols, diesel fuel and additives such as alkyl nitrates, acrylic acids, and several vegetable oil derivatives. Using a diesel engine calibrated with reference fuels, cetane numbers for fifty four blends were estimated. The apparent cetane numbers ranged from around 20 to above 50 with the majority between 30 and 45. Emissions of nitric oxide were measured for a few select fuels and were found to be 10 to 20% lower than No. 2 diesel fuel. 36 refs., 87 figs., 8 tabs.

  12. Feasibility of performing criticality experiments with spent LWR fuel

    SciTech Connect

    Bierman, S.R.

    1988-02-01

    Criticality experiments can be performed with irradiated LWR fuel under very well defined and controlled conditions to provide data sutiable for verifying calculational models. Two facilities currently exist in which such experiments could be performed. Furthermore, the experiments can be performed in a timely manner and for a relatively reasonable cost. It is expected the cost will be greater than those normally incurred for similar experiments with unirradiated fuel because of the handling problems created by the high radiation fields. Although the cost will of course depend on the scoper of the experimental programs, current estimates indicate the costs will be less or comparable to a similar level of effort in other activities with irradiated fuel (e.g., Dry Rod Consolation Project). 2 figs.

  13. Influence of the fuel and dosage on the performance of double-compartment microbial fuel cells.

    PubMed

    Asensio, Y; Fernandez-Marchante, C M; Lobato, J; Cañizares, P; Rodrigo, M A

    2016-08-01

    This manuscript focuses on the evaluation of the use of different types and dosages of fuels in the performance of double-compartment microbial fuel cell equipped with carbon felt electrodes and cationic membrane. Five types of fuels (ethanol, glycerol, acetate, propionate and fructose) have been tested for the same organic load (5,000 mg L(-1) measured as COD) and for one of them (acetate), the range of dosages between 500 and 20,000 mg L(-1) of COD was also studied. Results demonstrate that production of electricity depends strongly on the fuel used. Carboxylic acids are much more efficient than alcohols or fructose for the same organic load and within the range 500-5,000 mg L(-1) of acetate the production of electricity increases linearly with the amount of acetate fed but over these concentrations a change in the population composition may explain a worse performance. PMID:27130968

  14. Electrode Performance in Reversible Solid Oxide Fuel Cells

    SciTech Connect

    Marina, Olga A.; Pederson, Larry R.; Williams, Mark C.; Coffey, Greg W.; Meinhardt, Kerry D.; Nguyen, Carolyn D.; Thomsen, Ed C.

    2007-03-22

    The performance of several negative (fuel) and positive (air) electrode compositions for use in reversible solid oxide fuel cells (SOFC) that are capable of operating both as a fuel cell and as an electrolyzer was investigated in half-cell and full-cell tests. Negative electrode compositions studied were a nickel/zirconia cermet (Ni/YSZ) and lanthanum-substituted strontium titanate/ceria composite, whereas positive electrode compositions examined included mixed ion and electron-conducting lanthanum strontium ferrite (LSF), lanthanum strontium copper ferrite (LSCuF), lanthanum strontium cobalt ferrite (LSCoF), and lanthanum strontium manganite (LSM). While titanate/ceria and Ni/YSZ electrodes performed similarly in the fuel cell mode in half-cell tests, losses associated with electrolysis were lower for the titanate/ceria electrode. Positive electrodes all gave higher losses in the electrolysis mode when compared to the fuel cell mode. This behavior was most apparent for mixed-conducting LSF, LSCuF, and LSCoF electrodes, and discernible but smaller for LSM; observations are consistent with expected trends in the interfacial oxygen vacancy concentration under anodic and cathodic polarization. Full-cell tests conducted for cells with a thin electrolyte (7 um YSZ) similarly showed higher polarization losses in the electrolysis than fuel cell direction.

  15. Single PWR spent fuel assembly heat transfer data for computer code evaluations

    SciTech Connect

    Bates, J.M.

    1986-01-01

    The descriptions and results of two separate heat transfer tests designed to investigate the dry storage of commercial PWR spent fuel assemblies are presented. Presented first are descriptions and selected results from the Fuel Temperature Test performed at the Engine Maintenance and Disassembly facility on the Nevada Test Site. An actual spent fuel assembly from the Turkey Point Unit Number 3 Reactor with a decay heat level of 1.17 KW, was installed vertically in a test stand mounted canister/liner assembly. The boundary temperatures were controlled and the canister backfill gases were alternated between air, helium and vacuum to investigate the primary heat transfer mechanisms of convection, conduction and radiation. The assembly temperature profiles were experimentally measured using installed thermocouple instrumentation. Also presented are the results from the Single Assembly Heat Transfer Test designed and fabricated by Allied General Nuclear Services, under contract to the Department of Energy, and ultimately conducted by the Pacific Northwest Laboratory. For this test, an electrically heated 15 x 15 rod assembly was used to model a single PWR spent fuel assembly. The electrically heated model fuel assembly permitted various ''decay heat'', levels to be tested; 1.0 KW and 0.5 KW were used for these tests. The model fuel assembly was positioned within a prototypic fuel tube and in turn placed within a double-walled sealed cask. The complete test assembly could be positioned at any desired orientation (horizontal, vertical, and 25/sup 0/ from horizontal for the present work) and backfilled as desired (air, helium, or vacuum). Tests were run for all combinations of ''decay heat,'' backfill, and orientation. Boundary conditions were imposed by temperature controlled guard heaters installed on the cask exterior surface.

  16. Performance of a Fuel-Injection Spark-Ignition Engine Using a Hydrogenated Safety Fuel

    NASA Technical Reports Server (NTRS)

    Schey, Oscar W; Young, Alfred W

    1934-01-01

    This report presents the performance of a single-cylinder test engine using a hydrogenated safety fuel. The safety fuel has a flash point of 125 degrees f. (Cleveland open-dup method), which is high enough to remove most of the fire hazard, and an octane number of 95, which permits higher compression ratios to be used than are permissible with most undoped gasolines.

  17. Factors Affecting Polymer Electrolyte Fuel Cells Performance and Reproducibility

    SciTech Connect

    Moller-Holst S.

    1998-11-01

    Development of fuel cells is often based on small-scale laboratory studies. Due to limited time and budgets, a minimum number of cells are usually prepared and tested, thus, conclusions about improved performance are often drawn from studies of a few cells. Generally, statistics showing the significance of an effect are seldom reported. In this work a simple PEM fuel cell electrode optimization experiment is used as an example to illustrate the importance of statistical evaluation of factors affecting cell performance. The use of fractional factorial design of experiments to reduce the number of cells that have to be studied is also addressed.

  18. Spent nuclear fuel storage -- Performance tests and demonstrations

    SciTech Connect

    McKinnon, M.A.; DeLoach, V.A.

    1993-04-01

    This report summarizes the results of heat transfer and shielding performance tests and demonstrations conducted from 1983 through 1992 by or in cooperation with the US Department of Energy (DOE), Office of Commercial Radioactive Waste Management (OCRWM). The performance tests consisted of 6 to 14 runs involving one or two loadings, usually three backfill environments (helium, nitrogen, and vacuum backfills), and one or two storage system orientations. A description of the test plan, spent fuel load patterns, results from temperature and dose rate measurements, and fuel integrity evaluations are contained within the report.

  19. Error-resilient video coding performance analysis of motion JPEG2000 and MPEG-4

    NASA Astrophysics Data System (ADS)

    Dufaux, Frederic; Ebrahimi, Touradj

    2004-01-01

    The new Motion JPEG 2000 standard is providing with some compelling features. It is based on an intra-frame wavelet coding, which makes it very well suited for wireless applications. Indeed, the state-of-the-art wavelet coding scheme achieves very high coding efficiency. In addition, Motion JPEG 2000 is very resilient to transmission errors as frames are coded independently (intra coding). Furthermore, it requires low complexity and introduces minimal coding delay. Finally, it supports very efficient scalability. In this paper, we analyze the performance of Motion JPEG 2000 in error-prone transmission. We compare it to the well-known MPEG-4 video coding scheme, in terms of coding efficiency, error resilience and complexity. We present experimental results which show that Motion JPEG 2000 outperforms MPEG-4 in the presence of transmission errors.

  20. Final report on accident tolerant fuel performance analysis of APMT-Steel Clad/UO₂ fuel and APMT-Steel Clad/UN-U₃Si₅ fuel concepts

    SciTech Connect

    Unal, Cetin; Galloway, Jack D.

    2014-09-12

    In FY2014 our group completed and documented analysis of new Accident Tolerant Fuel (ATF) concepts using BISON. We have modeled the viability of moving from Zircaloy to stainless steel cladding in traditional light water reactors (LWRs). We have explored the reactivity penalty of this change using the MCNP-based burnup code Monteburns, while attempting to minimize this penalty by increasing the fuel pellet radius and decreasing the cladding thickness. Fuel performance simulations using BISON have also been performed to quantify changes to structural integrity resulting from thinner stainless steel claddings. We account for thermal and irradiation creep, fission gas swelling, thermal swelling and fuel relocation in the models for both Zircaloy and stainless steel claddings. Additional models that account for the lower oxidation stainless steel APMT are also invoked where available. Irradiation data for HT9 is used as a fallback in the absence of appropriate models. In this study the isotopic vectors within each natural element are varied to assess potential reactivity gains if advanced enrichment capabilities were levied towards cladding technologies. Recommendations on cladding thicknesses for a robust cladding as well as the constitutive components of a less penalizing composition are provided. In the first section (section 1-3), we present results accepted for publication in the 2014 TOPFUEL conference regarding the APMT/UO₂ ATF concept (J. Galloway & C. Unal, Accident Tolerant and Neutronically Favorable LWR Cladding, Proceedings of WRFPM 2014, Sendai, Japan, Paper No.1000050). Next we discuss our preliminary findings from the thermo-mechanical analysis of UN-U₃Si₅ fuel with APMT clad. In this analysis we used models developed from limited data that need to be updated when the irradiation data from ATF-1 test is available. Initial results indicate a swelling rate less than 1.5% is needed to prevent excessive clad stress.

  1. 14 CFR 234.10 - Voluntary disclosure of on-time performance codes.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false Voluntary disclosure of on-time performance codes. 234.10 Section 234.10 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION... disclosure of on-time performance codes. (a) Any air carrier may determine, in accordance with the...

  2. 14 CFR 234.10 - Voluntary disclosure of on-time performance codes.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Voluntary disclosure of on-time performance codes. 234.10 Section 234.10 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION... disclosure of on-time performance codes. (a) Any air carrier may determine, in accordance with the...

  3. 14 CFR 234.10 - Voluntary disclosure of on-time performance codes.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 4 2013-01-01 2013-01-01 false Voluntary disclosure of on-time performance codes. 234.10 Section 234.10 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION... disclosure of on-time performance codes. (a) Any air carrier may determine, in accordance with the...

  4. 14 CFR 234.10 - Voluntary disclosure of on-time performance codes.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 4 2012-01-01 2012-01-01 false Voluntary disclosure of on-time performance codes. 234.10 Section 234.10 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION... disclosure of on-time performance codes. (a) Any air carrier may determine, in accordance with the...

  5. 14 CFR 234.10 - Voluntary disclosure of on-time performance codes.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 4 2014-01-01 2014-01-01 false Voluntary disclosure of on-time performance codes. 234.10 Section 234.10 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION... disclosure of on-time performance codes. (a) Any air carrier may determine, in accordance with the...

  6. Performance analysis of wavelength/spatial coding system with fixed in-phase code matrices in OCDMA network

    NASA Astrophysics Data System (ADS)

    Tsai, Cheng-Mu; Liang, Tsair-Chun

    2011-12-01

    This paper proposes a wavelength/spatial (W/S) coding system with fixed in-phase code (FIPC) matrix in the optical code-division multiple-access (OCDMA) network. A scheme is presented to form the FIPC matrix which is applied to construct the W/S OCDMA network. The encoder/decoder in the W/S OCDMA network is fully able to eliminate the multiple-access-interference (MAI) at the balanced photo-detectors (PD), according to fixed in-phase cross correlation. The phase-induced intensity noise (PIIN) related to the power square is markedly suppressed in the receiver by spreading the received power into each PD while the net signal power is kept the same. Simulation results show that the W/S OCDMA network based on the FIPC matrices cannot only completely remove the MAI but effectively suppress the PIIN to upgrade the network performance.

  7. Effect of Fuel Additives on Spray Performance of Alternative Jet Fuels

    NASA Astrophysics Data System (ADS)

    Kannaiyan, Kumaran; Sadr, Reza

    2015-11-01

    Role of alternative fuels on reducing the combustion pollutants is gaining momentum in both land and air transport. Recent studies have shown that addition of nanoscale metal particles as fuel additives to liquid fuels have a positive effect not only on their combustion performance but also in reducing the pollutant formation. However, most of those studies are still in the early stages of investigation with the addition of nanoparticles at low weight percentages. Such an addition can affect the hydrodynamic and thermo-physical properties of the fuel. In this study, the near nozzle spray performance of gas-to-liquid jet fuel with and without the addition of alumina nanoparticles are investigated at macro- and microscopic levels using optical diagnostic techniques. At macroscopic level, the addition of nanoparticles is seen to enhance the sheet breakup process when compared to that of the base fuel. Furthermore, the microscopic spray characteristics such as droplet size and velocity are also found to be affected. Although the addition of nanoscale metal particles at low weight percentages does not affect the bulk fluid properties, the atomization process is found to be affected in the near nozzle region. Funded by Qatar National Research Fund.

  8. Use of a commercial heat transfer code to predict horizontally oriented spent fuel rod surface temperatures

    SciTech Connect

    Wix, S.D.; Koski, J.A.

    1993-03-01

    Radioactive spent fuel assemblies are a source of hazardous waste that will have to be dealt with in the near future. It is anticipated that the spent fuel assemblies will be transported to disposal sites in spent fuel transportation casks. In order to design a reliable and safe transportation cask, the maximum cladding temperature of the spent fuel rod arrays must be calculated. A comparison between numerical calculations using commercial thermal analysis software packages and experimental data simulating a horizontally oriented spent fuel rod array was performed. Twelve cases were analyzed using air and helium for the fill gas, with three different heat dissipation levels. The numerically predicted temperatures are higher than the experimental data for all levels of heat dissipation with air as the fill gas. The temperature differences are 4{degree}C and 23{degree}C for the low heat dissipation and high heat dissipation, respectively. The temperature predictions using helium as a fill gas are lower for the low and medium heat dissipation levels, but higher at the high heat dissipation. The temperature differences are 1{degree}C and 6{degree}C for the low and medium heat dissipation, respectively. For the high heat dissipation level, the temperature predictions are 16{degree}C higher than the experimental data. Differences between the predicted and experimental temperatures can be attributed to several factors. These factors include experimental uncertainty in the temperature and heat dissipation measurements, actual convection effects not included in the model, and axial heat flow in the experimental data. This work demonstrates that horizontally oriented spent fuel rod surface temperature predictions can be made using existing commercial software packages. This work also shows that end effects will be increasingly important as the amount of dissipated heat increases.

  9. Results from tight and loose coupled multiphysics in nuclear fuels performance simulations using BISON

    SciTech Connect

    Novascone, S. R.; Spencer, B. W.; Andrs, D.; Williamson, R. L.; Hales, J. D.; Perez, D. M.

    2013-07-01

    The behavior of nuclear fuel in the reactor environment is affected by multiple physics, most notably heat conduction and solid mechanics, which can have a strong influence on each other. To provide credible solutions, a fuel performance simulation code must have the ability to obtain solutions for each of the physics, including coupling between them. Solution strategies for solving systems of coupled equations can be categorized as loosely-coupled, where the individual physics are solved separately, keeping the solutions for the other physics fixed at each iteration, or tightly coupled, where the nonlinear solver simultaneously drives down the residual for each physics, taking into account the coupling between the physics in each nonlinear iteration. In this paper, we compare the performance of loosely and tightly coupled solution algorithms for thermomechanical problems involving coupled thermal and mechanical contact, which is a primary source of interdependence between thermal and mechanical solutions in fuel performance models. The results indicate that loosely-coupled simulations require significantly more nonlinear iterations, and may lead to convergence trouble when the thermal conductivity of the gap is too small. We also apply the tightly coupled solution strategy to a nuclear fuel simulation of an experiment in a test reactor. Studying the results from these simulations indicates that perhaps convergence for either approach may be problem dependent, i.e., there may be problems for which a loose coupled approach converges, where tightly coupled won't converge and vice versa. (authors)

  10. Results from Tight and Loose Coupled Multiphysics in Nuclear Fuels Performance Simulations using BISON

    SciTech Connect

    S. R. Novascone; B. W. Spencer; D. Andrs; R. L. Williamson; J. D. Hales; D. M. Perez

    2013-05-01

    The behavior of nuclear fuel in the reactor environment is affected by multiple physics, most notably heat conduction and solid mechanics, which can have a strong influence on each other. To provide credible solutions, a fuel performance simulation code must have the ability to obtain solutions for each of the physics, including coupling between them. Solution strategies for solving systems of coupled equations can be categorized as loosely-coupled, where the individual physics are solved separately, keeping the solutions for the other physics fixed at each iteration, or tightly coupled, where the nonlinear solver simultaneously drives down the residual for each physics, taking into account the coupling between the physics in each nonlinear iteration. In this paper, we compare the performance of loosely and tightly coupled solution algorithms for thermomechanical problems involving coupled thermal and mechanical contact, which is a primary source of interdependence between thermal and mechanical solutions in fuel performance models. The results indicate that loosely-coupled simulations require significantly more nonlinear iterations, and may lead to convergence trouble when the thermal conductivity of the gap is too small. We also apply the tightly coupled solution strategy to a nuclear fuel simulation of an experiment in a test reactor. Studying the results from these simulations indicates that perhaps convergence for either approach may be problem dependent, i.e., there may be problems for which a loose coupled approach converges, where tightly coupled won’t converge and vice versa.

  11. Atomization and combustion performance of antimisting kerosene and jet fuel

    NASA Technical Reports Server (NTRS)

    Fleeter, R.; Parikh, P.; Sarohia, V.

    1983-01-01

    Combustion performance of antimisting kerosene (AMK) containing FM-9 polymer was investigated at various levels of degradation (restoration of AMK for normal use in a gas turbine engine). To establish the relationship of degradation and atomization to performance in an aircraft gas turbine combustor, sprays formed by the nozzle of a JT8-D combustor with Jet A and AMK at 1 atmosphere (atm) (14.1 lb/square in absolute) pressure and 22 C at several degradation levels were analyzed. A new spray characterization technique based on digital image analysis of high resolution, wide field spray images formed under pulsed ruby laser sheet illumination was developed. Combustion tests were performed for these fuels in a JT8-D single can combustor facility to measure combustion efficiency and the lean extinction limit. Correlation of combustion performance under simulated engine operating conditions with nozzle spray Sauter mean diameter (SMD) measured at 1 atm and 22 C were observed. Fuel spray SMD and hence the combustion efficiency are strongly influenced by fuel degradation level. Use of even the most highly degraded AMK tested (filter ratio = 1.2) resulted in an increase in fuel consumption of 0.08% to 0.20% at engine cruise conditions.

  12. Oxygen - Enemy or Friend for Microbial Fuel Cell Anode Performance?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Until recently, scientists and engineers have held a strong belief that oxygen intrusion into the anode chamber of a bioelectrochemical system (BES) is detrimental to microbial fuel cell (MFC) performance because oxygen acts as an alternate electron acceptor. This would, according to recent beliefs...

  13. Performance of Trasuranic-Loaded Fully Ceramic Micro-Encapsulated Fuel in LWRs Interim Report, Including Void Reactivity Evaluation

    SciTech Connect

    Michael A. Pope; Brian Boer; Gilles Youinou; Abderrafi M. Ougouag

    2011-03-01

    The current focus of the Deep Burn Project is on once-through burning of transuranice (TRU) in light water reactors (LWRs). The fuel form is called Fully-Ceramic Micro-encapsulated (FCM) fuel, a concept that borrows the tri-isotropic (TRISO) fuel particle design from high-temperature reactor technology. In the Deep Burn LWR (DB-LWR) concept, these fuel particles would be pressed into compacts using SiC matrix material and loaded into fuel pins for use in conventional LWRs. The TRU loading comes from the spent fuel of a conventional LWR after 5 years of cooling. Unit cell calculations have been performed using the DRAGON-4 code in order assess the physics attributes of TRU-only FCM fuel in an LWR lattice. Depletion calculations assuming an infinite lattice condition were performed with calculations of various reactivity coefficients performed at each step. Unit cells containing typical UO2 and MOX fuel were analyzed in the same way to provide a baseline against which to compare the TRU-only FCM fuel. Loading of TRU-only FCM fuel into a pin without significant quantities of uranium challenges the design from the standpoint of several key reactivity parameters, particularly void reactivity, and to some degree, the Doppler coefficient. These unit cells, while providing an indication of how a whole core of similar fuel would behave, also provide information of how individual pins of TRU-only FCM fuel would influence the reactivity behavior of a heterogeneous assembly. If these FCM fuel pins are included in a heterogeneous assembly with LEU fuel pins, the overall reactivity behavior would be dominated by the uranium pins while attractive TRU destruction performance of the TRU-only FCM fuel pins may be preserved. A configuration such as this would be similar to CONFU assemblies analyzed in previous studies. Analogous to the plutonium content limits imposed on MOX fuel, some amount of TRU-only FCM pins in an otherwise-uranium fuel assembly may give acceptable reactivity

  14. Code System to Perform Neutronic and Thermal-Hydraulic Subchannel Analysis from Converged Coarse-Mesh Nodal Solutions.

    Energy Science and Technology Software Center (ESTSC)

    2000-06-14

    Version 00 NORMA-FP is an auxiliary program which can perform a neutronic and thermal-hydraulic subchannel analysis, starting from global core calculations carried out by both PSR-471/NORMA or PSR-492/QUARK codes. Detailed flux and power distributions inside homogenized nodes are computed by a two-stage bivariate interpolation method, upon separation of the axial variable for which an analytical solution is adopted. The actual heterogeneous structure of a node is accounted for by fuel rod power factors computed asmore » functions of burnup, burnup-weighted coolant density, and instantaneous coolant density.« less

  15. Method of improving fuel cell performance by removing at least one metal oxide contaminant from a fuel cell electrode

    DOEpatents

    Kim, Yu Seung; Choi, Jong-Ho; Zelenay, Piotr

    2009-08-18

    A method of removing contaminants from a fuel cell catalyst electrode. The method includes providing a getter electrode and a fuel cell catalyst electrode having at least one contaminant to a bath and applying a voltage sufficient to drive the contaminant from the fuel cell catalyst electrode to the getter electrode. Methods of removing contaminants from a membrane electrode assembly of a fuel cell and of improving performance of a fuel cell are also provided.

  16. Overview of the new ASME Performance Test Code for wind turbines

    NASA Technical Reports Server (NTRS)

    Spera, David A.

    1986-01-01

    The principal technical features of the ASME Performance Test Code for wind turbines are presented and such issues as what sizes and types of wind turbines should be included, what the principal measure of performance should be, and how wind speed should be measured are discussed. It is concluded that the present test code is applicable to wind turbine systems of all sizes. The principal measure of performance as defined by this code is net energy output and the primary performance parameter is the 'test energy ratio' which is based on a comparison between the measured and predicted energy output for the test period.

  17. Construction and performance analysis of variable-weight optical orthogonal codes for asynchronous OCDMA systems

    NASA Astrophysics Data System (ADS)

    Li, Chuan-qi; Yang, Meng-jie; Zhang, Xiu-rong; Chen, Mei-juan; He, Dong-dong; Fan, Qing-bin

    2014-07-01

    A construction scheme of variable-weight optical orthogonal codes (VW-OOCs) for asynchronous optical code division multiple access (OCDMA) system is proposed. According to the actual situation, the code family can be obtained by programming in Matlab with the given code weight and corresponding capacity. The formula of bit error rate (BER) is derived by taking account of the effects of shot noise, avalanche photodiode (APD) bulk, thermal noise and surface leakage currents. The OCDMA system with the VW-OOCs is designed and improved. The study shows that the VW-OOCs have excellent performance of BER. Despite of coming from the same code family or not, the codes with larger weight have lower BER compared with the other codes in the same conditions. By taking simulation, the conclusion is consistent with the analysis of BER in theory. And the ideal eye diagrams are obtained by the optical hard limiter.

  18. Bounds on the error performance of coding for nonindependent Rician-fading channels

    NASA Astrophysics Data System (ADS)

    Gagnon, Francois; Haccoun, David

    1992-02-01

    New upper bounds on the error performance of coded systems for Rician channels are presented. The fading channels need not be fully interleaved to obtain meaningful performance results. These bounds hold for coherent, differentially coherent and noncoherent demodulation of binary signals. They provide a useful analytical approach to the evaluation of the error performance of convolutional or block coding and they may be generalized to M-ary signals and trellis modulation. The approach allows for complex bounds using the fine structure of the code, for simpler bounds similar to those on memoryless channels and finally for a random coding bound using the cutoff rate of the channel. The analysis thus permits a step by step evaluation of coded error performances for Rician-fading channels.

  19. Performance of hybrid ball bearings in oil and jet fuel

    SciTech Connect

    Schrader, S.M.; Pfaffenberger, E.E. )

    1992-07-01

    A 308-size hybrid ball bearing, with ceramic balls and steel rings, was tested using a diester oil and gas turbine fuel as lubricants at several speeds and loads. Heat generation data from this test work was then correlated with the heat generation model from a widely used computer code. The ability of this hybrid split inner ring bearing design to endure thrust reversals, which are expected in many turbine applications, was demonstrated. Finally, the bearing was successfully endurance tested in JP-10 fuel for 25 hours at 7560 N axial load and 36,000 rpm. This work has successfully demonstrated the technology necessary to use fuel-lubricated hybrid bearings in limited-life gas turbine engine applications such as missiles, drones, and other unmanned air vehicles (UAVs). In addition, it has provided guidance for use in designing such bearing systems. As a result, the benefits of removing the conventional oil lubricant system, i.e., design simplification and reduced maintenance, can be realized. 6 refs.

  20. Performance of hybrid ball bearings in oil and jet fuel

    NASA Astrophysics Data System (ADS)

    Schrader, Stephen M.; Pfaffenberger, Eugene E.

    1992-07-01

    A 308-size hybrid ball bearing, with ceramic balls and steel rings, was tested using a diester oil and gas turbine fuel as lubricants at several speeds and loads. Heat generation data from this test work was then correlated with the heat generation model from a widely used computer code. The ability of this hybrid split inner ring bearing design to endure thrust reversals, which are expected in many turbine applications, was demonstrated. Finally, the bearing was successfully endurance tested in JP-10 fuel for 25 hours at 7560 N axial load and 36,000 rpm. This work has successfully demonstrated the technology necessary to use fuel-lubricated hybrid bearings in limited-life gas turbine engine applications such as missiles, drones, and other unmanned air vehicles (UAVs). In addition, it has provided guidance for use in designing such bearing systems. As a result, the benefits of removing the conventional oil lubricant system, i.e., design simplification and reduced maintenance, can be realized.

  1. Selection of a numerical unsaturated flow code for tilted capillary barrier performance evaluation

    SciTech Connect

    Webb, S.W.

    1996-09-01

    Capillary barriers consisting of tilted fine-over-coarse layers have been suggested as landfill covers as a means to divert water infiltration away from sensitive underground regions under unsaturated flow conditions, especially for arid and semi-arid regions. Typically, the HELP code is used to evaluate landfill cover performance and design. Unfortunately, due to its simplified treatment of unsaturated flow and its essentially one-dimensional nature, HELP is not adequate to treat the complex multidimensional unsaturated flow processes occurring in a tilted capillary barrier. In order to develop the necessary mechanistic code for the performance evaluation of tilted capillary barriers, an efficient and comprehensive unsaturated flow code needs to be selected for further use and modification. The present study evaluates a number of candidate mechanistic unsaturated flow codes for application to tilted capillary barriers. Factors considered included unsaturated flow modeling, inclusion of evapotranspiration, nodalization flexibility, ease of modification, and numerical efficiency. A number of unsaturated flow codes are available for use with different features and assumptions. The codes chosen for this evaluation are TOUGH2, FEHM, and SWMS{_}2D. All three codes chosen for this evaluation successfully simulated the capillary barrier problem chosen for the code comparison, although FEHM used a reduced grid. The numerical results are a strong function of the numerical weighting scheme. For the same weighting scheme, similar results were obtained from the various codes. Based on the CPU time of the various codes and the code capabilities, the TOUGH2 code has been selected as the appropriate code for tilted capillary barrier performance evaluation, possibly in conjunction with the infiltration, runoff, and evapotranspiration models of HELP. 44 refs.

  2. High performance internal reforming unit for high temperature fuel cells

    DOEpatents

    Ma, Zhiwen; Venkataraman, Ramakrishnan; Novacco, Lawrence J.

    2008-10-07

    A fuel reformer having an enclosure with first and second opposing surfaces, a sidewall connecting the first and second opposing surfaces and an inlet port and an outlet port in the sidewall. A plate assembly supporting a catalyst and baffles are also disposed in the enclosure. A main baffle extends into the enclosure from a point of the sidewall between the inlet and outlet ports. The main baffle cooperates with the enclosure and the plate assembly to establish a path for the flow of fuel gas through the reformer from the inlet port to the outlet port. At least a first directing baffle extends in the enclosure from one of the sidewall and the main baffle and cooperates with the plate assembly and the enclosure to alter the gas flow path. Desired graded catalyst loading pattern has been defined for optimized thermal management for the internal reforming high temperature fuel cells so as to achieve high cell performance.

  3. Toxicological and performance aspects of oxygenated motor vehicle fuels

    SciTech Connect

    1996-12-31

    At the request of the Environmental Protection Agency, the committee reviewed a draft of a federal report that assesses the effects of oxygenated fuels on public health, air quality, fuel economy, engine performance, and water quality. The committee determined that much of the federal report adequately represents what is known about the effects of methyl tertiary-butyl ether (MTBE) -- the most commonly used additive in the federal oxygenated-fuels program -- on health, the environment, and motor vehicles. MTBE, a chemical added to gasoline to reduce carbon monoxide pollution, appears not to pose a substantial human health risk, but more-definitive data are needed to assess short-term health effects and to determine whether this additive is effective in reducing carbon monoxide pollution in cold environments.

  4. High-Performance Java Codes for Computational Fluid Dynamics

    NASA Technical Reports Server (NTRS)

    Riley, Christopher; Chatterjee, Siddhartha; Biswas, Rupak; Biegel, Bryan (Technical Monitor)

    2001-01-01

    The computational science community is reluctant to write large-scale computationally -intensive applications in Java due to concerns over Java's poor performance, despite the claimed software engineering advantages of its object-oriented features. Naive Java implementations of numerical algorithms can perform poorly compared to corresponding Fortran or C implementations. To achieve high performance, Java applications must be designed with good performance as a primary goal. This paper presents the object-oriented design and implementation of two real-world applications from the field of Computational Fluid Dynamics (CFD): a finite-volume fluid flow solver (LAURA, from NASA Langley Research Center), and an unstructured mesh adaptation algorithm (2D_TAG, from NASA Ames Research Center). This work builds on our previous experience with the design of high-performance numerical libraries in Java. We examine the performance of the applications using the currently available Java infrastructure and show that the Java version of the flow solver LAURA performs almost within a factor of 2 of the original procedural version. Our Java version of the mesh adaptation algorithm 2D_TAG performs within a factor of 1.5 of its original procedural version on certain platforms. Our results demonstrate that object-oriented software design principles are not necessarily inimical to high performance.

  5. Design and performance of Huffman sequences in medical ultrasound coded excitation.

    PubMed

    Polpetta, Alessandro; Banelli, Paolo

    2012-04-01

    This paper deals with coded-excitation techniques for ultrasound medical echography. Specifically, linear Huffman coding is proposed as an alternative approach to other widely established techniques, such as complementary Golay coding and linear frequency modulation. The code design is guided by an optimization procedure that boosts the signal-to-noise ratio gain (GSNR) and, interestingly, also makes the code robust in pulsed-Doppler applications. The paper capitalizes on a thorough analytical model that can be used to design any linear coded-excitation system. This model highlights that the performance in frequency-dependent attenuating media mostly depends on the pulse-shaping waveform when the codes are characterized by almost ideal (i.e., Kronecker delta) autocorrelation. In this framework, different pulse shapers and different code lengths are considered to identify coded signals that optimize the contrast resolution at the output of the receiver pulse compression. Computer simulations confirm that the proposed Huffman codes are particularly effective, and that there are scenarios in which they may be preferable to the other established approaches, both in attenuating and non-attenuating media. Specifically, for a single scatterer at 150 mm in a 0.7-dB/(MHz·cm) attenuating medium, the proposed Huffman design achieves a main-to-side lobe ratio (MSR) equal to 65 dB, whereas tapered linear frequency modulation and classical complementary Golay codes achieve 35 and 45 dB, respectively. PMID:22547275

  6. Performance of Reed-Solomon Coded MC-DS-CDMA with Bi-orthogonal Modulation

    NASA Astrophysics Data System (ADS)

    Tanaka, Hirokazu; Jang, Kyung Woon; Yamasaki, Shoichiro; Haseyama, Miki

    In this paper, an error correction scheme suitable for MC-DS-CDMA system with bi-orthogonal modulation is proposed. The input sequence of a bi-orthogonal modulator consists of n - 1 bit code selection bit sequence and 1 bit sign bit sequence. In order to apply an efficient error correction code, the following points should be considered; (1) if the code selection bits can be protected sufficiently, the sign bit error can also be reduced sufficiently, (2) since a code selection bit sequence consists of n - 1 bits, employing a symbol error correcting code is more effective for encoding code selection bits, (3) the complexity of the error correction encoder and decoder implementations should be minimum. Based on these conditions, we propose to employ Reed-Solomon (RS) code for encoding the code selection bits and no error correction code for the sign bit. Additionally, detection algorithm at the bi-orthogonal demodulator is modified for compensating degradations of the sign bit error rate performance. The performance in an Additive White Gaussian Noise (AWGN) channel is evaluated by both theoretical analysis and computer simulations. The performance evaluations by simulations on multi-path fading channels are also shown. It is shown that the proposed scheme has remarkable improvement.

  7. The Statistical Analysis Techniques to Support the NGNP Fuel Performance Experiments

    SciTech Connect

    Bihn T. Pham; Jeffrey J. Einerson

    2010-06-01

    This paper describes the development and application of statistical analysis techniques to support the AGR experimental program on NGNP fuel performance. The experiments conducted in the Idaho National Laboratory’s Advanced Test Reactor employ fuel compacts placed in a graphite cylinder shrouded by a steel capsule. The tests are instrumented with thermocouples embedded in graphite blocks and the target quantity (fuel/graphite temperature) is regulated by the He-Ne gas mixture that fills the gap volume. Three techniques for statistical analysis, namely control charting, correlation analysis, and regression analysis, are implemented in the SAS-based NGNP Data Management and Analysis System (NDMAS) for automated processing and qualification of the AGR measured data. The NDMAS also stores daily neutronic (power) and thermal (heat transfer) code simulation results along with the measurement data, allowing for their combined use and comparative scrutiny. The ultimate objective of this work includes (a) a multi-faceted system for data monitoring and data accuracy testing, (b) identification of possible modes of diagnostics deterioration and changes in experimental conditions, (c) qualification of data for use in code validation, and (d) identification and use of data trends to support effective control of test conditions with respect to the test target. Analysis results and examples given in the paper show the three statistical analysis techniques providing a complementary capability to warn of thermocouple failures. It also suggests that the regression analysis models relating calculated fuel temperatures and thermocouple readings can enable online regulation of experimental parameters (i.e. gas mixture content), to effectively maintain the target quantity (fuel temperature) within a given range.

  8. Limiter-discriminator detection performance of Manchester and NRZ coded FSK

    NASA Technical Reports Server (NTRS)

    Cartier, D. E.

    1977-01-01

    The theory of limiter-discriminator detection of a frequency shift keyed (FSK) carrier is reviewed and this theory is used to predict the bit error probability performance of Manchester coded and nonreturn-to-zero (NRZ) coded data. A major result of the study is that the predetection time bandwidth product BT and the deviation ratio h needed to give optimum performance for Manchester coding are seen to be larger than optimum NRZ FSK. Specifically, BT of about 2 and h of about 1 will result in Manchester performance about 2 dB worse than optimum NRZ.

  9. Improving the performance of BICM-ID and MLC systems with different FEC codes

    NASA Astrophysics Data System (ADS)

    Arafa, T.; Sauer-Greff, W.; Urbansky, R.

    2013-07-01

    In bandwidth limited communication systems, the high data rate transmission with performance close to capacity limits is achieved by applying multilevel modulation schemes in association with powerful forward error correction (FEC) coding, i.e. coded modulation systems. The most important practical approaches to coded modulation systems are multilevel coding with multistage decoding (MLC/MSD) and bit interleaved coded modulation with iterative demapping and decoding (BICM-ID). Multilevel modulation formats such as M-QAM, which can be used as a part of coded modulation systems, have the capability of multilevel protection. Based on this fact, we investigate the methods to improve the performance of BICM-ID using multiple interleavers with different binary channel coding schemes such as convolutional codes, turbo codes and low-density parity-check (LDPC) codes. Moreover, an MLC system with parallel decoding on levels (PDL) at the receiver is considered. In our contribution, we propose to design the individual coding schemes using the extrinsic information transfer (EXIT) charts for individual bit levels in the constellation. Our simulation results show that the BICM-ID systems, taking into account different bit-level protections, can provide an improvement of 0.65 dB, 1.2 dB and 1.5 dB for 256-QAM with turbo, LDPC and convolutional codes, respectively. On the other hand, MLC systems with PDL designed using EXIT charts for individual bit levels can slightly improve the performance and eliminate the error floor compared to the systems with MSD.

  10. DEXTER: A one-dimensional code for calculating thermionic performance of long converters

    NASA Technical Reports Server (NTRS)

    Sawyer, C. D.

    1971-01-01

    A versatile code is described for computing the coupled thermionic electric-thermal performance of long thermionic converters in which the temperature and voltage variations cannot be neglected. The code is capable of accounting for a variety of external electrical connection schemes, coolant flow paths and converter failures by partial shorting. Example problem solutions are included along with a user's manual.

  11. Performance of Adaptive Trellis Coded Modulation Applied to MC-CDMA with Bi-orthogonal Keying

    NASA Astrophysics Data System (ADS)

    Tanaka, Hirokazu; Yamasaki, Shoichiro; Haseyama, Miki

    A Generalized Symbol-rate-increased (GSRI) Pragmatic Adaptive Trellis Coded Modulation (ATCM) is applied to a Multi-carrier CDMA (MC-CDMA) system with bi-orthogonal keying is analyzed. The MC-CDMA considered in this paper is that the input sequence of a bi-orthogonal modulator has code selection bit sequence and sign bit sequence. In [9], an efficient error correction code using Reed-Solomon (RS) code for the code selection bit sequence has been proposed. However, since BPSK is employed for the sign bit modulation, no error correction code is applied to it. In order to realize a high speed wireless system, a multi-level modulation scheme (e.g. MPSK, MQAM, etc.) is desired. In this paper, we investigate the performance of the MC-CDMA with bi-orthogonal keying employing GSRI ATCM. GSRI TC-MPSK can arbitrarily set the bandwidth expansion ratio keeping higher coding gain than the conventional pragmatic TCM scheme. By changing the modulation scheme and the bandwidth expansion ratio (coding rate), this scheme can optimize the performance according to the channel conditions. The performance evaluations by simulations on an AWGN channel and multi-path fading channels are presented. It is shown that the proposed scheme has remarkable throughput performance than that of the conventional scheme.

  12. Use of impedance tagging to monitor fuel cell stack performance

    NASA Astrophysics Data System (ADS)

    Silva, Gregory

    Fuel cells are electrochemical device that are traditionally assembled in stacks to perform meaningful work. Monitoring the state of the stack is vitally important to ensure that it is operating efficiently and that constituent cells are not failing for one of a several common reasons including membrane dehydration, gas diffusion layer flooding, reactant starvation, and physical damage. Current state-of-the-art monitoring systems are costly and require at least one connection per cell on the stack, which introduces reliability concerns for stacks consisting of hundreds of cells. This thesis presents a novel approach for diagnosing problems in a fuel cell stack that attempts to reduce the cost and complexity of monitoring cells in a stack. The proposed solution modifies the electrochemical impedance spectroscopy (EIS) response of each cell in the stack by connecting an electrical tag in parallel with each cell. This approach allows the EIS response of the entire stack to identify and locate problems in the stack. Capacitors were chosen as tags because they do not interfere with normal stack operation and because they can generate distinct stack EIS responses. An experiment was performed in the Center for Automation Technologies an Systems (CATS) fuel cell laboratory at Rensselaer Polytechnic Institute (RPI) to perform EIS measurements on a single cell with and without capacitor tags to investigate the proposed solution. The EIS data collected from this experiment was used to create a fuel cell model to investigate the proposed solution under ideal conditions. This thesis found that, although the concept shows some promise in simulations, significant obstacles to implementing the proposed solution. Observed EIS response when the capacitor tags were connected did not match the expected EIS response. Constraints on the capacitor tags found by the model impose significant manufacturing challenges to the proposed solution. Further development of the proposed solution is

  13. Compression performance of HEVC and its format range and screen content coding extensions

    NASA Astrophysics Data System (ADS)

    Li, Bin; Xu, Jizheng; Sullivan, Gary J.

    2015-09-01

    This paper presents a comparison-based test of the objective compression performance of the High Efficiency Video Coding (HEVC) standard, its format range extensions (RExt), and its draft screen content coding extensions (SCC). The current dominant standard, H.264/MPEG-4 AVC, is used as an anchor reference in the comparison. The conditions used for the comparison tests were designed to reflect relevant application scenarios and to enable a fair comparison to the maximum extent feasible - i.e., using comparable quantization settings, reference frame buffering, intra refresh periods, rate-distortion optimization decision processing, etc. It is noted that such PSNR-based objective comparisons generally provide more conservative estimates of HEVC benefit than are found in subjective studies. The experimental results show that, when compared with H.264/MPEG-4 AVC, HEVC version 1 provides a bit rate savings for equal PSNR of about 23% for all-intra coding, 34% for random access coding, and 38% for low-delay coding. This is consistent with prior studies and the general characterization that HEVC can provide about a bit rate savings of about 50% for equal subjective quality for most applications. The HEVC format range extensions provide a similar bit rate savings of about 13-25% for all-intra coding, 28-33% for random access coding, and 32-38% for low-delay coding at different bit rate ranges. For lossy coding of screen content, the HEVC screen content coding extensions achieve a bit rate savings of about 66%, 63%, and 61% for all-intra coding, random access coding, and low-delay coding, respectively. For lossless coding, the corresponding bit rate savings are about 40%, 33%, and 32%, respectively.

  14. MPI performance evaluation and characterization using a compact application benchmark code

    SciTech Connect

    Worley, P.H.

    1996-06-01

    In this paper the parallel benchmark code PSTSWM is used to evaluate the performance of the vendor-supplied implementations of the MPI message-passing standard on the Intel Paragon, IBM SP2, and Cray Research T3D. This study is meant to complement the performance evaluation of individual MPI commands by providing information on the practical significance of MPI performance on the execution of a communication-intensive application code. In particular, three performance questions are addressed: how important is the communication protocol in determining performance when using MPI, how does MPI performance compare with that of the native communication library, and how efficient are the collective communication routines.

  15. FRAPCON-3: A computer code for the calculation of steady-state, thermal-mechanical behavior of oxide fuel rods for high burnup

    SciTech Connect

    Berna, G.A.; Beyer, G.A.; Davis, K.L.; Lanning, D.D.

    1997-12-01

    FRAPCON-3 is a FORTRAN IV computer code that calculates the steady-state response of light water reactor fuel rods during long-term burnup. The code calculates the temperature, pressure, and deformation of a fuel rod as functions of time-dependent fuel rod power and coolant boundary conditions. The phenomena modeled by the code include (1) heat conduction through the fuel and cladding, (2) cladding elastic and plastic deformation, (3) fuel-cladding mechanical interaction, (4) fission gas release, (5) fuel rod internal gas pressure, (6) heat transfer between fuel and cladding, (7) cladding oxidation, and (8) heat transfer from cladding to coolant. The code contains necessary material properties, water properties, and heat-transfer correlations. The codes` integral predictions of mechanical behavior have not been assessed against a data base, e.g., cladding strain or failure data. Therefore, it is recommended that the code not be used for analyses of cladding stress or strain. FRAPCON-3 is programmed for use on both mainframe computers and UNIX-based workstations such as DEC 5000 or SUN Sparcstation 10. It is also programmed for personal computers with FORTRAN compiler software and at least 8 to 10 megabytes of random access memory (RAM). The FRAPCON-3 code is designed to generate initial conditions for transient fuel rod analysis by the FRAPTRAN computer code (formerly named FRAP-T6).

  16. Performance analysis of multiple interference suppression over asynchronous/synchronous optical code-division multiple-access system based on complementary/prime/shifted coding scheme

    NASA Astrophysics Data System (ADS)

    Nieh, Ta-Chun; Yang, Chao-Chin; Huang, Jen-Fa

    2011-08-01

    A complete complementary/prime/shifted prime (CPS) code family for the optical code-division multiple-access (OCDMA) system is proposed. Based on the ability of complete complementary (CC) code, the multiple-access interference (MAI) can be suppressed and eliminated via spectral amplitude coding (SAC) OCDMA system under asynchronous/synchronous transmission. By utilizing the shifted prime (SP) code in the SAC scheme, the hardware implementation of encoder/decoder can be simplified with a reduced number of optical components, such as arrayed waveguide grating (AWG) and fiber Bragg grating (FBG). This system has a superior performance as compared to previous bipolar-bipolar coding OCDMA systems.

  17. Performance Evaluation of Hybrid SCM/SAC-OCDMA Transmissions System using Dynamic Cyclic Shift Code

    NASA Astrophysics Data System (ADS)

    Abd, Thanaa Hussein; Aljunid, S. A.; Fadhil, Hilal Adnan; Radhi, Ibrahim Fadhil; Saad, N. M.

    2012-12-01

    In this paper, the performance of a hybrid scheme of Subcarrier Multiplexing (SCM) technique in a Spectral Amplitude Coding (SAC) Optical Code Division Multiple Access (CDMA) transmissions system is evaluated. The hybrid system is design using new code family; we call it Dynamic Cyclic Shift (DCS) code. The DCS code design for SAC-OCDMA system to reduce the effect of Multi Access Interference due to it property of low cross-correlation (λC ≤ 1) between code words. In contrast, the SCM scheme shows the ability to increase the data rate of SAC-OCDMA system. Consequently, the hybrid SCM/SAC-OCDMA system could be one promising solution to the high-capacity access network with low cost effective, good flexibility and enhanced security, which makes an attractive candidate for next-generation broadband access network.

  18. The Performance of Current Atmospheric Radiation Codes in Phase I of CIRC

    NASA Technical Reports Server (NTRS)

    Oreopoulos, L.; Mlawer, E.; Shippert, T.; Cole, J.; Fomin, B.; Iacono, M.; Jin, Z.; Li, J.; Manners, J.; Raisanen, P.; Rose, F.; Zhang, Y.; Wilson, M.; Rossow, W.

    2012-01-01

    The Continual Intercomparison of Radiation Codes (CIRC) is intended as an evolving and regularly updated reference source for evaluation of radiative transfer (RT) codes used in Global Climate Models and other atmospheric applications. In our presentation we will discuss our evaluation of the performance of 13 shortwave and 11 longwave RT codes that participated in Phase I of CIRC. CIRC differs from previous intercomparisons in that it relies on an observationally validated catalogue of cases. The seven CIRC Phase I baseline cases, five cloud-free, and two with overcast liquid clouds, are built around observations by the Atmospheric Radiation Measurements (ARM) program that satisfy the goals .of Phase I, namely to examine RT model performance in realistic, yet not overly complex, atmospheric conditions. Besides the seven baseline cases, additional idealized "subcases" are also examined to facilitate interpretation of model errors. We will quantify individual model performance with respect to reference line-by-line calculations, and will also highlight RT code behavior for conditions of doubled CO2 , aspects of utilizing a spectral specification of surface albedo, and the impact of the inclusion of scattering in the thermal infrared. Our analysis suggests that RT codes should work towards improving their calculation of diffuse shortwave flux, shortwave absorption, treatment of spectral surface albedo, and shortwave CO2 forcing. Despite practical difficulties in comparing our results to previous results by the Intercomparison of Radiation Codes in Climate Models (ICRCCM) conducted about 20 years ago, it appears that the current generation of RT codes do indeed perform better than the codes of the ICRCCM era. By enhancing the range of conditions under which participating codes are tested, future CIRC phases will hopefully allow even more rigorous examination of RT code performance.

  19. Advanced Fuels Campaign Light Water Reactor Accident Tolerant Fuel Performance Metrics

    SciTech Connect

    Brad Merrill; Melissa Teague; Robert Youngblood; Larry Ott; Kevin Robb; Michael Todosow; Chris Stanek; Mitchell Farmer; Michael Billone; Robert Montgomery; Nicholas Brown; Shannon Bragg-Sitton

    2014-02-01

    The safe, reliable and economic operation of the nation’s nuclear power reactor fleet has always been a top priority for the United States’ nuclear industry. As a result, continual improvement of technology, including advanced materials and nuclear fuels, remains central to industry’s success. Decades of research combined with continual operation have produced steady advancements in technology and yielded an extensive base of data, experience, and knowledge on light water reactor (LWR) fuel performance under both normal and accident conditions. In 2011, following the Great East Japan Earthquake, resulting tsunami, and subsequent damage to the Fukushima Daiichi nuclear power plant complex, enhancing the accident tolerance of LWRs became a topic of serious discussion. As a result of direction from the U.S. Congress, the U.S. Department of Energy Office of Nuclear Energy (DOE-NE) initiated an Accident Tolerant Fuel (ATF) Development program. The complex multiphysics behavior of LWR nuclear fuel makes defining specific material or design improvements difficult; as such, establishing qualitative attributes is critical to guide the design and development of fuels and cladding with enhanced accident tolerance. This report summarizes a common set of technical evaluation metrics to aid in the optimization and down selection of candidate designs. As used herein, “metrics” describe a set of technical bases by which multiple concepts can be fairly evaluated against a common baseline and against one another. Furthermore, this report describes a proposed technical evaluation methodology that can be applied to assess the ability of each concept to meet performance and safety goals relative to the current UO2 – zirconium alloy system and relative to one another. The resultant ranked evaluation can then inform concept down-selection, such that the most promising accident tolerant fuel design option(s) can continue to be developed for lead test rod or lead test assembly

  20. Performance of PSK modulation with serial concatenated turbo codes through a nonideal satellite channel

    NASA Astrophysics Data System (ADS)

    Shoup, Ryan

    2005-08-01

    Turbo codes and Low Density Parity Check (LDPC) codes are well known to provide Bit Error Rate (BER) performance close to the Shannon capacity limit. Bandwidth constrained satellite channels could potentially benefit by employing higher order PSK modulations. However, employing higher order PSK modulations may not be practical for satellite amplifiers due to the increased power requirements. The excellent performance of serial concatenated turbo codes could be used to maintain satellite amplifier power levels to those relatively close to the Shannon limit. The performance of the system, however, is dependent on the satellite channel, which typically includes phase noise and some degree of nonlinearity in the satellite amplifier. The performance of various waveforms and PSK modulations employing Serial Concatenated Turbo Codes are investigated using a model of a non-ideal satellite channel. The hardware complexity of the serial concatenated turbo decoder at the ground receiver is also considered.

  1. Analysis of sampling and quantization effects on the performance of PN code tracking loops

    NASA Technical Reports Server (NTRS)

    Quirk, K. J.; Srinivasan, M.

    2002-01-01

    Pseudonoise (PN) code tracking loops in direct-sequence spread-spectrum systems are often implemented using digital hardware. Performance degradation due to quantization and sampling effects is not adequately characterized by the traditional analog system feedback loop analysis.

  2. Do Performance-Based Codes Support Universal Design in Architecture?

    PubMed

    Grangaard, Sidse; Frandsen, Anne Kathrine

    2016-01-01

    The research project 'An analysis of the accessibility requirements' studies how Danish architectural firms experience the accessibility requirements of the Danish Building Regulations and it examines their opinions on how future regulative models can support innovative and inclusive design - Universal Design (UD). The empirical material consists of input from six workshops to which all 700 Danish Architectural firms were invited, as well as eight group interviews. The analysis shows that the current prescriptive requirements are criticized for being too homogenous and possibilities for differentiation and zoning are required. Therefore, a majority of professionals are interested in a performance-based model because they think that such a model will support 'accessibility zoning', achieving flexibility because of different levels of accessibility in a building due to its performance. The common understanding of accessibility and UD is directly related to buildings like hospitals and care centers. When the objective is both innovative and inclusive architecture, the request of a performance-based model should be followed up by a knowledge enhancement effort in the building sector. Bloom's taxonomy of educational objectives is suggested as a tool for such a boost. The research project has been financed by the Danish Transport and Construction Agency. PMID:27534292

  3. Performance of direct methanol polymer electrolyte fuel cell

    SciTech Connect

    Shin, Dong Ryul; Jung, Doo Hwan; Lee, Chang Hyeong; Chun, Young Gab

    1996-12-31

    Direct methanol fuel cells (DMFC) using polymer electrolyte membrane are promising candidate for application of portable power sources and transportation applications because they do not require any fuel processing equipment and can be operated at low temperature of 60{degrees}C - 130{degrees}C. Elimination of the fuel processor results in simpler design, higher operation reliability, lower weight volume, and lower capital and operating cost. However, methanol as a fuel is relatively electrochemical inert, so that kinetics of the methanol oxidation is too slow. Platinum and Pt-based binary alloy electrodes have been extensively studied for methanol electro-oxidation in acid electrolyte at ambient and elevated temperatures. Particularly, unsupported carbon Pt-Ru catalyst was found to be superior to the anode of DMFC using a proton exchange membrane electrolyte (Nafion). The objective of this study is to develop the high performance DNTC. This paper summarizes the results from half cell and single cell tests, which focus on the electrode manufacturing process, catalyst selection, and operating conditions of single cell such as methanol concentration, temperature and pressure.

  4. Long-life high performance fuel cell program

    NASA Technical Reports Server (NTRS)

    Martin, R. E.

    1985-01-01

    A multihundred kilowatt Regenerative Fuel Cell for use in a space station is envisioned. Three 0.508 sq ft (471.9 cm) active area multicell stacks were assembled and endurance tested. The long term performance stability of the platinum on carbon catalyst configuration suitability of the lightweight graphite electrolyte reservoir plate, the stability of the free standing butyl bonded potassium titanate matrix structure, and the long life potential of a hybrid polysulfone cell edge frame construction were demonstrated. A 18,000 hour demonstration test of multicell stack to a continuous cyclical load profile was conducted. A total of 12,000 cycles was completed, confirming the ability of the alkaline fuel cell to operate to a load profile simulating Regenerative Fuel Cell operation. An orbiter production hydrogen recirculation pump employed in support of the cyclical load profile test completed 13,000 hours of maintenance free operation. Laboratory endurance tests demonstrated the suitability of the butyl bonded potassium matrix, perforated nickel foil electrode substrates, and carbon ribbed substrate anode for use in the alkaline fuel cell. Corrosion testing of materials at 250 F (121.1 C) in 42% wgt. potassium identified ceria, zirconia, strontium titanate, strontium zirconate and lithium cobaltate as candidate matrix materials.

  5. Direct formic acid microfluidic fuel cell design and performance evolution

    NASA Astrophysics Data System (ADS)

    Moreno-Zuria, A.; Dector, A.; Cuevas-Muñiz, F. M.; Esquivel, J. P.; Sabaté, N.; Ledesma-García, J.; Arriaga, L. G.; Chávez-Ramírez, A. U.

    2014-12-01

    This work reports the evolution of design, fabrication and testing of direct formic acid microfluidic fuel cells (DFAμFFC), the architecture and channel dimensions are miniaturized from a thousand to few cents of micrometers. Three generations of DFAμFFCs are presented, from the initial Y-shape configuration made by a hot pressing technique; evolving into a novel miniaturized fuel cell based on microfabrication technology using SU-8 photoresist as core material; to the last air-breathing μFFC with enhanced performance and built with low cost materials and processes. The three devices were evaluated in acidic media in the presence of formic acid as fuel and oxygen/air as oxidant. Commercial Pt/C (30 wt. % E-TEK) and Pd/C XC-72 (20 wt. %, E-TEK) were used as cathode and anode electrodes respectively. The air-breathing μFFC generation, delivered up to 27.3 mW cm-2 for at least 30 min, which is a competitive power density value at the lowest fuel flow of 200 μL min-1 reported to date.

  6. Advanced Fuels Campaign Light Water Reactor Accident Tolerant Fuel Performance Metrics Executive Summary

    SciTech Connect

    Shannon Bragg-Sitton

    2014-02-01

    Research and development (R&D) activities on advanced, higher performance Light Water Reactor (LWR) fuels have been ongoing for the last few years. Following the unfortunate March 2011 events at the Fukushima Nuclear Power Plant in Japan, the R&D shifted toward enhancing the accident tolerance of LWRs. Qualitative attributes for fuels with enhanced accident tolerance, such as improved reaction kinetics with steam resulting in slower hydrogen generation rate, provide guidance for the design and development of fuels and cladding with enhanced accident tolerance. A common set of technical metrics should be established to aid in the optimization and down selection of candidate designs on a more quantitative basis. “Metrics” describe a set of technical bases by which multiple concepts can be fairly evaluated against a common baseline and against one another. This report describes a proposed technical evaluation methodology that can be applied to evaluate the ability of each concept to meet performance and safety goals relative to the current UO2 – zirconium alloy system and relative to one another. The resultant ranked evaluation can then inform concept down-selection, such that the most promising accident tolerant fuel design option(s) can continue to be developed toward qualification.

  7. Performance analysis of parallel gravitational N-body codes on large GPU clusters

    NASA Astrophysics Data System (ADS)

    Huang, Si-Yi; Spurzem, Rainer; Berczik, Peter

    2016-01-01

    We compare the performance of two very different parallel gravitational N-body codes for astrophysical simulations on large Graphics Processing Unit (GPU) clusters, both of which are pioneers in their own fields as well as on certain mutual scales - NBODY6++ and Bonsai. We carry out benchmarks of the two codes by analyzing their performance, accuracy and efficiency through the modeling of structure decomposition and timing measurements. We find that both codes are heavily optimized to leverage the computational potential of GPUs as their performance has approached half of the maximum single precision performance of the underlying GPU cards. With such performance we predict that a speed-up of 200 - 300 can be achieved when up to 1k processors and GPUs are employed simultaneously. We discuss the quantitative information about comparisons of the two codes, finding that in the same cases Bonsai adopts larger time steps as well as larger relative energy errors than NBODY6++, typically ranging from 10 - 50 times larger, depending on the chosen parameters of the codes. Although the two codes are built for different astrophysical applications, in specified conditions they may overlap in performance at certain physical scales, thus allowing the user to choose either one by fine-tuning parameters accordingly.

  8. ASME PTC 46 -- Acceptance test code for overall plant performance

    SciTech Connect

    Friedman, J.R.; Yost, J.G.

    1999-11-01

    ASME published PTC 46 in 1996 after five years of development. PTC 46 is the first industry standard providing explicit procedures for conducting acceptance tests to determine the overall thermal performance and output of power generating units. It is applicable to any heat cycle power generating unit. This survey paper provides an overview of PTC 46 and discusses how PTC 46 can be used for acceptance testing of new combined cycle and fossil steam power generating units. Several technical papers have been previously presented that provide more detailed information and discussion on the use of PTC 46 in acceptance testing.

  9. DATING: A computer code for determining allowable temperatures for dry storage of spent fuel in inert and nitrogen gases

    SciTech Connect

    Simonen, E.P.; Gilbert, E.R.

    1988-12-01

    The DATING (Determining Allowable Temperatures in Inert and Nitrogen Gases) code can be used to calculate allowable initial temperatures for dry storage of light-water-reactor spent fuel. The calculations are based on the life fraction rule using both measured data and mechanistic equations as reported by Chin et al. (1986). The code is written in FORTRAN and utilizes an efficient numerical integration method for rapid calculations on IBM-compatible personal computers. This report documents the technical basis for the DATING calculations, describes the computational method and code statements, and includes a user's guide with examples. The software for the DATING code is available through the National Energy Software Center operated by Argonne National Laboratory, Argonne, Illinois 60439. 5 refs., 8 figs., 5 tabs.

  10. International Space Station Electric Power System Performance Code-SPACE

    NASA Technical Reports Server (NTRS)

    Hojnicki, Jeffrey; McKissock, David; Fincannon, James; Green, Robert; Kerslake, Thomas; Delleur, Ann; Follo, Jeffrey; Trudell, Jeffrey; Hoffman, David J.; Jannette, Anthony; Rodriguez, Carlos

    2005-01-01

    The System Power Analysis for Capability Evaluation (SPACE) software analyzes and predicts the minute-by-minute state of the International Space Station (ISS) electrical power system (EPS) for upcoming missions as well as EPS power generation capacity as a function of ISS configuration and orbital conditions. In order to complete the Certification of Flight Readiness (CoFR) process in which the mission is certified for flight each ISS System must thoroughly assess every proposed mission to verify that the system will support the planned mission operations; SPACE is the sole tool used to conduct these assessments for the power system capability. SPACE is an integrated power system model that incorporates a variety of modules tied together with integration routines and graphical output. The modules include orbit mechanics, solar array pointing/shadowing/thermal and electrical, battery performance, and power management and distribution performance. These modules are tightly integrated within a flexible architecture featuring data-file-driven configurations, source- or load-driven operation, and event scripting. SPACE also predicts the amount of power available for a given system configuration, spacecraft orientation, solar-array-pointing conditions, orbit, and the like. In the source-driven mode, the model must assure that energy balance is achieved, meaning that energy removed from the batteries must be restored (or balanced) each and every orbit. This entails an optimization scheme to ensure that energy balance is maintained without violating any other constraints.

  11. Performance of a Coded Non-Square Quadrature Amplitude Modulation Scheme over Fading Channels

    NASA Astrophysics Data System (ADS)

    Li, L.; Divsalar, D.; Dolinar, S.

    2004-02-01

    It is shown that a non-square (NS) 2^(2n+1)-ary quadrature amplitude modulation (QAM) can be decomposed into a single-parity-check (SPC) block encoder and a memoryless modulator with independent in-phase (I) and quadrature (Q) symbol mapping. When NS-2^(2n+1)-QAM is concatenated with a forward-error-correcting (FEC) code, iterative demodulation and decoding of the FEC code and the inherent SPC code of NS-2^(2n+1)-QAM exploits the modulation's inherent memory and its independent I- and Q-channel mapping and demapping. The capacity and the bit-/symbol-error-rate (BER/SER) performance of coded and uncoded NS-2^(2n+1)-QAM systems are given for both additive white Gaussian noise (AWGN) channels and Rayleigh fading channels and are compared to those of other conventional 2^(2n+1)-ary systems. Simulation results show that, with iterative demodulation and decoding, coded NS-8QAM outperforms three conventional 8-ary systems by at least 0.65 dB on AWGN channels and by at least 0.57 dB on Rayleigh fading channels at BER = 10^(-5), when the FEC code is a concatenation of (15,11) Hamming codes with rate-1 accumulator codes, while coded NS-32QAM outperforms standard 32QAM by about 0.45 dB on AWGN channels and by about 0.27 dB on Rayleigh fading channels.

  12. The 3D MHD code GOEMHD3 for astrophysical plasmas with large Reynolds numbers. Code description, verification, and computational performance

    NASA Astrophysics Data System (ADS)

    Skála, J.; Baruffa, F.; Büchner, J.; Rampp, M.

    2015-08-01

    Context. The numerical simulation of turbulence and flows in almost ideal astrophysical plasmas with large Reynolds numbers motivates the implementation of magnetohydrodynamical (MHD) computer codes with low resistivity. They need to be computationally efficient and scale well with large numbers of CPU cores, allow obtaining a high grid resolution over large simulation domains, and be easily and modularly extensible, for instance, to new initial and boundary conditions. Aims: Our aims are the implementation, optimization, and verification of a computationally efficient, highly scalable, and easily extensible low-dissipative MHD simulation code for the numerical investigation of the dynamics of astrophysical plasmas with large Reynolds numbers in three dimensions (3D). Methods: The new GOEMHD3 code discretizes the ideal part of the MHD equations using a fast and efficient leap-frog scheme that is second-order accurate in space and time and whose initial and boundary conditions can easily be modified. For the investigation of diffusive and dissipative processes the corresponding terms are discretized by a DuFort-Frankel scheme. To always fulfill the Courant-Friedrichs-Lewy stability criterion, the time step of the code is adapted dynamically. Numerically induced local oscillations are suppressed by explicit, externally controlled diffusion terms. Non-equidistant grids are implemented, which enhance the spatial resolution, where needed. GOEMHD3 is parallelized based on the hybrid MPI-OpenMP programing paradigm, adopting a standard two-dimensional domain-decomposition approach. Results: The ideal part of the equation solver is verified by performing numerical tests of the evolution of the well-understood Kelvin-Helmholtz instability and of Orszag-Tang vortices. The accuracy of solving the (resistive) induction equation is tested by simulating the decay of a cylindrical current column. Furthermore, we show that the computational performance of the code scales very

  13. Research on the transmission performance of turbo codes in DDO-OFDM system

    NASA Astrophysics Data System (ADS)

    Tong, Zheng-rong; Hu, Gui-bin; Cao, Ye; Zhang, Wei-hua

    2015-03-01

    A direct detection optical orthogonal frequency division multiplexing (DDO-OFDM) system using turbo codes is built, and the transmission performance comparison between coded system and uncoded system is analyzed. Three decoding algorithms, which are Log-maximum a posteriori (MAP), Max-Log-MAP and threshold Max-Log-MAP, are used in the turbo coded system. By comparing three decoding algorithms, the system using Max-Log-MAP algorithm has the best bit error rate (BER) performance. At the transmission distance of 240 km, the uncoded system with transmission rate of 30 Gbit/s can get the BER performance at the degree of 8.93×10-3 with optical signal to noise ratio (OSNR) of 24 dB, while the turbo coded system with transmission rate of 50 Gbit/s can achieve it within OSNR of 20 dB.

  14. Generalized Thermohydraulics Module GENFLO for Combining With the PWR Core Melting Model, BWR Recriticality Neutronics Model and Fuel Performance Model

    SciTech Connect

    Miettinen, Jaakko; Hamalainen, Anitta; Pekkarinen, Esko

    2002-07-01

    Thermal hydraulic simulation capability for accident conditions is needed at present in VTT in several programs. Traditional thermal hydraulic models are too heavy for simulation in the analysis tasks, where the main emphasis is the rapid neutron dynamics or the core melting. The GENFLO thermal hydraulic model has been developed at VTT for special applications in the combined codes. The basic field equations in GENFLO are for the phase mass, the mixture momentum and phase energy conservation equations. The phase separation is solved with the drift flux model. The basic variables to be solved are the pressure, void fraction, mixture velocity, gas enthalpy, liquid enthalpy, and concentration of non-condensable gas fractions. The validation of the thermohydraulic solution alone includes large break LOCA reflooding experiments and in specific for the severe accident conditions QUENCH tests. In the recriticality analysis the core neutronics is simulated with a two-dimensional transient neutronics code TWODIM. The recriticality with one rapid prompt peak is expected during a severe accident scenario, where the control rods have been melted and ECCS reflooding is started after the depressurization. The GENFLO module simulates the BWR thermohydraulics in this application. The core melting module has been developed for the real time operator training by using the APROS engineering simulators. The core heatup, oxidation, metal and fuel pellet relocation and corium pool formation into the lower plenum are calculated. In this application the GENFLO model simulates the PWR vessel thermohydraulics. In the fuel performance analysis the fuel rod transient behavior is simulated with the FRAPTRAN code. GENFLO simulates the subchannel around a single fuel rod and delivers the heat transfer on the cladding surface for the FRAPTRAN. The transient boundary conditions for the subchannel are transmitted from the system code for operational transient, loss of coolant accidents and

  15. TRISO Fuel Performance: Modeling, Integration into Mainstream Design Studies, and Application to a Thorium-fueled Fusion-Fission Hybrid Blanket

    SciTech Connect

    Powers, Jeffrey James

    2011-11-30

    This study focused on creating a new tristructural isotropic (TRISO) coated particle fuel performance model and demonstrating the integration of this model into an existing system of neutronics and heat transfer codes, creating a user-friendly option for including fuel performance analysis within system design optimization and system-level trade-off studies. The end product enables both a deeper understanding and better overall system performance of nuclear energy systems limited or greatly impacted by TRISO fuel performance. A thorium-fueled hybrid fusion-fission Laser Inertial Fusion Energy (LIFE) blanket design was used for illustrating the application of this new capability and demonstrated both the importance of integrating fuel performance calculations into mainstream design studies and the impact that this new integrated analysis had on system-level design decisions. A new TRISO fuel performance model named TRIUNE was developed and verified and validated during this work with a novel methodology established for simulating the actual lifetime of a TRISO particle during repeated passes through a pebble bed. In addition, integrated self-consistent calculations were performed for neutronics depletion analysis, heat transfer calculations, and then fuel performance modeling for a full parametric study that encompassed over 80 different design options that went through all three phases of analysis. Lastly, side studies were performed that included a comparison of thorium and depleted uranium (DU) LIFE blankets as well as some uncertainty quantification work to help guide future experimental work by assessing what material properties in TRISO fuel performance modeling are most in need of improvement. A recommended thorium-fueled hybrid LIFE engine design was identified with an initial fuel load of 20MT of thorium, 15% TRISO packing within the graphite fuel pebbles, and a 20cm neutron multiplier layer with beryllium pebbles in flibe molten salt coolant. It operated

  16. Improving performance of DS-CDMA systems using chaotic complex Bernoulli spreading codes

    NASA Astrophysics Data System (ADS)

    Farzan Sabahi, Mohammad; Dehghanfard, Ali

    2014-12-01

    The most important goal of spreading spectrum communication system is to protect communication signals against interference and exploitation of information by unintended listeners. In fact, low probability of detection and low probability of intercept are two important parameters to increase the performance of the system. In Direct Sequence Code Division Multiple Access (DS-CDMA) systems, these properties are achieved by multiplying the data information in spreading sequences. Chaotic sequences, with their particular properties, have numerous applications in constructing spreading codes. Using one-dimensional Bernoulli chaotic sequence as spreading code is proposed in literature previously. The main feature of this sequence is its negative auto-correlation at lag of 1, which with proper design, leads to increase in efficiency of the communication system based on these codes. On the other hand, employing the complex chaotic sequences as spreading sequence also has been discussed in several papers. In this paper, use of two-dimensional Bernoulli chaotic sequences is proposed as spreading codes. The performance of a multi-user synchronous and asynchronous DS-CDMA system will be evaluated by applying these sequences under Additive White Gaussian Noise (AWGN) and fading channel. Simulation results indicate improvement of the performance in comparison with conventional spreading codes like Gold codes as well as similar complex chaotic spreading sequences. Similar to one-dimensional Bernoulli chaotic sequences, the proposed sequences also have negative auto-correlation. Besides, construction of complex sequences with lower average cross-correlation is possible with the proposed method.

  17. Performance of direct formate-peroxide fuel cells

    NASA Astrophysics Data System (ADS)

    Li, Yinshi; Wu, Hao; He, Yaling; Liu, Yue; Jin, Lei

    2015-08-01

    We report the high-performance direct formate-peroxide fuel cells (DFPFCs) that consist of a cation-exchange membrane sandwiched between an alkaline formate anode and an acid peroxide cathode. Much attention has been paid to investigate the effects of different composite parameters and operating parameters, including catalyst loadings at both anode and cathode electrodes, operating temperatures, as well as the concentrations of both formate and electrolyte solutions. It is demonstrated that the optimization of both the electrode composition (anode 2.0 mgPd cm-2, cathode 2.0 mgPt cm-2) and the solution concentration (1.0 M HCOONa-3.0 M NaOH) enables the DFPFC to yield a peak power density as high as 591 mW cm-2 at 60 °C, which is about one times higher than that of state-of-the-art anion-exchange membrane direct formate fuel cells.

  18. TRISO-Fuel Element Performance Modeling for the Hybrid LIFE Engine with Pu Fuel Blanket

    SciTech Connect

    DeMange, P; Marian, J; Caro, M; Caro, A

    2010-02-18

    A TRISO-coated fuel thermo-mechanical performance study is performed for the hybrid LIFE engine to test the viability of TRISO particles to achieve ultra-high burnup of a weapons-grade Pu blanket. Our methodology includes full elastic anisotropy, time and temperature varying material properties for all TRISO layers, and a procedure to remap the elastic solutions in order to achieve fast fluences up to 30 x 10{sup 25} n {center_dot} m{sup -2} (E > 0.18 MeV). In order to model fast fluences in the range of {approx} 7 {approx} 30 x 10{sup 25} n {center_dot} m{sup -2}, for which no data exist, careful scalings and extrapolations of the known TRISO material properties are carried out under a number of potential scenarios. A number of findings can be extracted from our study. First, failure of the internal pyrolytic carbon (PyC) layer occurs within the first two months of operation. Then, the particles behave as BISO-coated particles, with the internal pressure being withstood directly by the SiC layer. Later, after 1.6 years, the remaining PyC crumbles due to void swelling and the fuel particle becomes a single-SiC-layer particle. Unrestrained by the PyC layers, and at the temperatures and fluences in the LIFE engine, the SiC layer maintains reasonably-low tensile stresses until the end-of-life. Second, the PyC creep constant, K, has a striking influence on the fuel performance of TRISO-coated particles, whose stresses scale almost inversely proportional to K. Obtaining more reliable measurements, especially at higher fluences, is an imperative for the fidelity of our models. Finally, varying the geometry of the TRISO-coated fuel particles results in little differences in the scope of fuel performance. The mechanical integrity of 2-cm graphite pebbles that act as fuel matrix has also been studied and it is concluded that they can reliable serve the entire LIFE burnup cycle without failure.

  19. Microstructured Electrolyte Membranes to Improve Fuel Cell Performance

    NASA Astrophysics Data System (ADS)

    Wei, Xue

    Fuel cells, with the advantages of high efficiency, low greenhouse gas emission, and long lifetime are a promising technology for both portable power and stationary power sources. The development of efficient electrolyte membranes with high ionic conductivity, good mechanical durability and dense structure at low cost remains a challenge to the commercialization of fuel cells. This thesis focuses on exploring novel composite polymer membranes and ceramic electrolytes with the microstructure engineered to improve performance in direct methanol fuel cells (DMFCs) and solid oxide fuel cells (SOFCs), respectively. Polymer/particle composite membranes hold promise to meet the demands of DMFCs at lower cost. The structure of composite membranes was controlled by aligning proton conducting particles across the membrane thickness under an applied electric field. The field-induced structural changes caused the membranes to display an enhanced water uptake, proton conductivity, and methanol permeability in comparison to membranes prepared without an applied field. Although both methanol permeability and proton conductivity are enhanced by the applied field, the permeability increase is relatively lower than the proton conductivity improvement, which results in enhanced proton/methanol selectivity and improved DMFC performance. Apatite ceramics are a new class of fast ion conductors being studied as alternative SOFC electrolytes in the intermediate temperature range. An electrochemical/hydrothermal deposition method was developed to grow fully dense apatite membranes containing well-developed crystals with c-axis alignment to promote ion conductivity. Hydroxyapatite seed crystals were first deposited onto a metal substrate electrochemically. Subsequent ion substitution during the hydrothermal growth process promoted the formation of dense, fully crystalline films with microstructure optimal for ion transport. The deposition parameters were systematically investigated, such as

  20. Performance analysis of the word synchronization properties of the outer code in a TDRSS decoder

    NASA Technical Reports Server (NTRS)

    Costello, D. J., Jr.; Lin, S.

    1984-01-01

    A self-synchronizing coding scheme for NASA's TDRSS satellite system is a concatenation of a (2,1,7) inner convolutional code with a (255,223) Reed-Solomon outer code. Both symbol and word synchronization are achieved without requiring that any additional symbols be transmitted. An important parameter which determines the performance of the word sync procedure is the ratio of the decoding failure probability to the undetected error probability. Ideally, the former should be as small as possible compared to the latter when the error correcting capability of the code is exceeded. A computer simulation of a (255,223) Reed-Solomon code as carried out. Results for decoding failure probability and for undetected error probability are tabulated and compared.

  1. Selection of a computer code for Hanford low-level waste engineered-system performance assessment

    SciTech Connect

    McGrail, B.P.; Mahoney, L.A.

    1995-10-01

    Planned performance assessments for the proposed disposal of low-level waste (LLW) glass produced from remediation of wastes stored in underground tanks at Hanford, Washington will require calculations of radionuclide release rates from the subsurface disposal facility. These calculations will be done with the aid of computer codes. Currently available computer codes were ranked in terms of the feature sets implemented in the code that match a set of physical, chemical, numerical, and functional capabilities needed to assess release rates from the engineered system. The needed capabilities were identified from an analysis of the important physical and chemical process expected to affect LLW glass corrosion and the mobility of radionuclides. The highest ranked computer code was found to be the ARES-CT code developed at PNL for the US Department of Energy for evaluation of and land disposal sites.

  2. Performance of CO-OFDM system with RS-Turbo concatenated code

    NASA Astrophysics Data System (ADS)

    Tong, Zheng-rong; Hu, Gui-bin; Cao, Ye; Zhang, Wei-hua

    2015-11-01

    In this paper, the RS-Turbo concatenated code is applied to coherent optical orthogonal frequency division multiplexing (CO-OFDM) system. RS(186,166,8) and Turbo code with code rate of 1/2 are employed for RS-Turbo concatenated code. Two decoding algorithms, which are Max-Log-MAP algorithm and Log-MAP algorithm, are adopted for Turbo decoding, and the iteration Berlekamp-Massey (BM) algorithm is adopted for RS decoding. The simulation results show that the bit error rate ( BER) performance of CO-OFDM system with RS-Turbo concatenated code is significantly improved at high optical signal to noise ratio ( OSNR), and the iteration number is reduced compared with that of the Turbo coded system. Furthermore, when the Max-Log-MAP algorithm is adopted for Turbo decoding, the transmission distance of CO-OFDM system with RS-Turbo concatenated code can reach about 400 km without error, while that of the Turbo coded system can only reach about 240 km when BER is lower than 10-4 order of magnitude.

  3. ATR LEU Fuel and Burnable Absorber Neutronics Performance Optimization by Fuel Meat Thickness Variation

    SciTech Connect

    G. S. Chang

    2007-09-01

    The Advanced Test Reactor (ATR) is a high power density and high neutron flux research reactor operating in the United States. Powered with highly enriched uranium (HEU), the ATR has a maximum thermal power rating of 250 MWth. Because of the large test volumes located in high flux areas, the ATR is an ideal candidate for assessing the feasibility of converting an HEU driven reactor to a low-enriched core. The present work investigates the necessary modifications and evaluates the subsequent operating effects of this conversion. A detailed plate-by-plate MCNP ATR 1/8th core model was developed and validated for a fuel cycle burnup comparison analysis. Using the current HEU U 235 enrichment of 93.0 % as a baseline, an analysis can be performed to determine the low-enriched uranium (LEU) density and U-235 enrichment required in the fuel meat to yield an equivalent K-eff between the HEU core and the LEU core versus effective full power days (EFPD). The MCNP ATR 1/8th core model will be used to optimize the U-235 loading in the LEU core, such that the differences in K-eff and heat flux profile between the HEU and LEU core can be minimized. The depletion methodology MCWO was used to calculate K-eff versus EFPDs in this paper. The MCWO-calculated results for the LEU cases with foil (U-10Mo) types demonstrated adequate excess reactivity such that the K-eff versus EFPDs plot is similar to the reference ATR HEU case. Each HEU fuel element contains 19 fuel plates with a fuel meat thickness of 0.508 mm. In this work, the proposed LEU (U-10Mo) core conversion case with a nominal fuel meat thickness of 0.508 mm and the same U-235 enrichment (15.5 wt%) can be used to optimize the radial heat flux profile by varying the fuel plate thickness from 0.254 to 0.457 mm at the inner 4 fuel plates (1-4) and outer 4 fuel plates (16-19). In addition, a 0.7g of burnable absorber Boron-10 was added in the inner and outer plates to reduce the initial excess reactivity, and the inner/outer heat

  4. ATR LEU fuel and burnable absorber neutronics performance optimization by fuel meat thickness variation

    SciTech Connect

    Chang, G.S.

    2008-07-15

    The Advanced Test Reactor (ATR) is a high power density and high neutron flux research reactor operating in the United States. Powered with highly enriched uranium (HEU), the ATR has a maximum thermal power rating of 250 MWth. Because of the large test volumes located in high flux areas, the ATR is an ideal candidate for assessing the feasibility of converting an HEU driven reactor to a low-enriched core. The present work investigates the necessary modifications and evaluates the subsequent operating effects of this conversion. A detailed plate-by-plate MCNP ATR 1/8th core model was developed and validated for a fuel cycle burnup comparison analysis. Using the current HEU U-235 enrichment of 93.0 % as a baseline, an analysis can be performed to determine the low-enriched uranium (LEU) density and U-235 enrichment required in the fuel meat to yield an equivalent K-eff between the HEU core th and the LEU core versus effective full power days (EFPD). The MCNP ATR 1/8th core model will be used to optimize the U-235 loading in the LEU core, such that the differences in K-eff and heat flux profile between the HEU and LEU core can be minimized. The depletion methodology MCWO was used to calculate K-eff versus EFPDs in this paper. The MCWO-calculated results for the LEU cases with foil (U-10Mo) types demonstrated adequate excess reactivity such that the K-eff versus EFPDs plot is similar to the reference ATR HEU case. Each HEU fuel element contains 19 fuel plates with a fuel meat thickness of 0.508 mm. In this work, the proposed LEU (U-10Mo) core conversion case with a nominal fuel meat thickness of 0.381 mm and the same U-235 enrichment (19.7 wt%) can be used to optimize the radial heat flux profile by varying the fuel meat thickness from 0.191 mm (7.5 mil) to 0.343 mm (13.5 mil) at the inner 4 fuel plates (1-4) and outer 4 fuel plates (16-19). In addition, 0.8g of a burnable absorber, Boron-10, was added in the inner and outer plates to reduce the initial excess

  5. 40 CFR 63.7515 - When must I conduct subsequent performance tests or fuel analyses?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... previous performance test. (f) You must conduct a fuel analysis according to § 63.7521 for each type of... performance tests or fuel analyses? 63.7515 Section 63.7515 Protection of Environment ENVIRONMENTAL PROTECTION... Requirements § 63.7515 When must I conduct subsequent performance tests or fuel analyses? (a) You must...

  6. A Novel Spreading Code Design for E-UTRA Uplink Control Channel and Its Performance

    NASA Astrophysics Data System (ADS)

    Nakao, Seigo; Takata, Tomohumi; Fukuoka, Masaru; Imamura, Daichi; Hiramatsu, Katsuhiko; Miya, Kazuyuki

    Hybrid automatic repeat request (HARQ) is employed for the Evolved Universal Terrestrial Radio Access (E-UTRA) downlink. Each user equipment (UE) sends its ACK/NACK corresponding to the downlink data reception to the base station via a physical uplink control channel (PUCCH). The ACK/NACK signals from the UE are first code spread by the cyclic shift (CS) sequences, and then code spread again by the orthogonal cover (OC) sequences. The ACK/NACK signals from each UE are multiplexed by means of code division multiple access (CDMA), however, it is difficult for the conventional PUCCH code design to satisfy the required bit error rate (BER) of 10-3 [1] in fast-fading environments because of inter-code interference (ICI) among the OC sequences. Therefore, resource management of PUCCH is required depending on the mobility of the UEs to maximize the performance of the ACK/NACK signals and the capacity of PUCCH simultaneously. In this paper, we propose a novel code design for PUCCH, which can suppress the effects of ICI among the OC sequences, and thus can simplify the resource management of PUCCH. The simulation evaluations confirm that the proposed code design can significantly improve the performance of the ACK/NACK signals via PUCCH in fast-fading environments, and any complicated resource management based on the mobility of the UEs are not necessary.

  7. The performance of trellis coded multilevel DPSK on a fading mobile satellite channel

    NASA Technical Reports Server (NTRS)

    Simon, Marvin K.; Divsalar, Dariush

    1987-01-01

    The performance of trellis coded multilevel differential phase-shift-keying (MDPSK) over Rician and Rayleigh fading channels is discussed. For operation at L-Band, this signalling technique leads to a more robust system than the coherent system with dual pilot tone calibration previously proposed for UHF. The results are obtained using a combination of analysis and simulation. The analysis shows that the design criterion for trellis codes to be operated on fading channels with interleaving/deinterleaving is no longer free Euclidean distance. The correct design criterion for optimizing bit error probability of trellis coded MDPSK over fading channels will be presented along with examples illustrating its application.

  8. High-Performance, Low-Complexity Codes Researched for Communication Channels

    NASA Technical Reports Server (NTRS)

    Kwatra, Subhash C.; Jones, Robert E.

    1999-01-01

    NASA Lewis Research Center s Communications Technology Division has an ongoing program in the development of efficient channel coding schemes for satellite communications applications. Through a university grant, as a part of this research, the University of Toledo is investigating the performance of turbocodes, which use parallel concatenation of non-systematic convolutional encoders with an interleaver. The error correcting capacity of these codes is close to the Shannon limit. The research emphasis is on the development of low-complexity, but higher rate (greater than one half), turbocodes and on the iterative decoding of block codes.

  9. Understanding Performance of Parallel Scientific Simulation Codes using Open|SpeedShop

    SciTech Connect

    Ghosh, K K

    2011-11-07

    Conclusions of this presentation are: (1) Open SpeedShop's (OSS) is convenient to use for large, parallel, scientific simulation codes; (2) Large codes benefit from uninstrumented execution; (3) Many experiments can be run in a short time - might need multiple shots e.g. usertime for caller-callee, hwcsamp for HW counters; (4) Decent idea of code's performance is easily obtained; (5) Statistical sampling calls for decent number of samples; and (6) HWC data is very useful for micro-analysis but can be tricky to analyze.

  10. BWR spent fuel storage cask performance test. Volume 2. Pre- and post-test decay heat, heat transfer, and shielding analyses

    SciTech Connect

    Wiles, L.E.; Lombardo, N.J.; Heeb, C.M.; Jenquin, U.P.; Michener, T.E.; Wheeler, C.L.; Creer, J.M.; McCann, R.A.

    1986-06-01

    This report describes the decay heat, heat transfer, and shielding analyses conducted in support of performance testing of a Ridhihalgh, Eggers and Associates REA 2033 boiling water reactor (BWR) spent fuel storage cask. The cask testing program was conducted for the US Department of Energy (DOE) Commercial Spent Fuel Management Program by the Pacific Northwest Laboratory (PNL) and by General Electric at the latters' Morris Operation (GE-MO) as reported in Volume I. The analyses effort consisted of performing pretest calculations to (1) select spent fuel for the test; (2) symmetrically load the spent fuel assemblies in the cask to ensure lateral symmetry of decay heat generation rates; (3) optimally locate temperature and dose rate instrumentation in the cask and spent fuel assemblies; and (4) evaluate the ORIGEN2 (decay heat), HYDRA and COBRA-SFS (heat transfer), and QAD and DOT (shielding) computer codes. The emphasis of this second volume is on the comparison of code predictions to experimental test data in support of the code evaluation process. Code evaluations were accomplished by comparing pretest (actually pre-look, since some predictions were not completed until testing was in progress) predictions with experimental cask testing data reported in Volume I. No attempt was made in this study to compare the two heat transfer codes because results of other evaluations have not been completed, and a comparison based on one data set may lead to erroneous conclusions.

  11. Irradiation performance of HTGR fuel in HFIR experiment HRB-13

    SciTech Connect

    Tiegs, T.N.

    1982-03-01

    Irradiation capsule HRB-13 tested High-Temperature Gas-Cooled Reactor (HTGR) fuel under accelerated conditions in the High Flux Isotope Reactor (HFIR) at ORNL. The ORNL part of the capsule was designed to provide definitive results on how variously misshapen kernels affect the irradiation performance of weak-acid-resin (WAR)-derived fissile fuel particles. Two batches of WAR fissile fuel particles were Triso-coated and shape-separated into four different fractions according to their deviation from spericity, which ranged from 9.6 to 29.7%. The fissile particles were irradiated for 7721 h. Heavy-metal burnups ranged from 80 to 82.5% FIMA (fraction of initial heavy-metal atoms). Fast neutron fluences (>0.18 MeV) ranged from 4.9 x 10/sup 25/ neutrons/m/sup 2/ to 8.5 x 10/sup 25/ neutrons/m/sup 2/. Postirradiation examination showed that the two batches of fissile particles contained chlorine, presumably introduced during deposition of the SiC coating.

  12. Generation IV benchmarking of TRISO fuel performance models under accident conditions. Modeling input data

    SciTech Connect

    Blaise Collin

    2014-09-01

    This document presents the benchmark plan for the calculation of particle fuel performance on safety testing experiments that are representative of operational accidental transients. The benchmark is dedicated to the modeling of fission product release under accident conditions by fuel performance codes from around the world, and the subsequent comparison to post-irradiation experiment (PIE) data from the modeled heating tests. The accident condition benchmark is divided into three parts: the modeling of a simplified benchmark problem to assess potential numerical calculation issues at low fission product release; the modeling of the AGR-1 and HFR-EU1bis safety testing experiments; and, the comparison of the AGR-1 and HFR-EU1bis modeling results with PIE data. The simplified benchmark case, thereafter named NCC (Numerical Calculation Case), is derived from ''Case 5'' of the International Atomic Energy Agency (IAEA) Coordinated Research Program (CRP) on coated particle fuel technology [IAEA 2012]. It is included so participants can evaluate their codes at low fission product release. ''Case 5'' of the IAEA CRP-6 showed large code-to-code discrepancies in the release of fission products, which were attributed to ''effects of the numerical calculation method rather than the physical model''[IAEA 2012]. The NCC is therefore intended to check if these numerical effects subsist. The first two steps imply the involvement of the benchmark participants with a modeling effort following the guidelines and recommendations provided by this document. The third step involves the collection of the modeling results by Idaho National Laboratory (INL) and the comparison of these results with the available PIE data. The objective of this document is to provide all necessary input data to model the benchmark cases, and to give some methodology guidelines and recommendations in order to make all results suitable for comparison with each other. The participants should read this document

  13. Computational Analysis of Dynamic SPK(S8)-JP8 Fueled Combustor-Sector Performance

    NASA Technical Reports Server (NTRS)

    Ryder, R.; Hendricks, Roberts C.; Huber, M. L.; Shouse, D. T.

    2010-01-01

    Civil and military flight tests using blends of synthetic and biomass fueling with jet fuel up to 50:50 are currently considered as "drop-in" fuels. They are fully compatible with aircraft performance, emissions and fueling systems, yet the design and operations of such fueling systems and combustors must be capable of running fuels from a range of feedstock sources. This paper provides Smart Combustor or Fuel Flexible Combustor designers with computational tools, preliminary performance, emissions and particulates combustor sector data. The baseline fuel is kerosene-JP-8+100 (military) or Jet A (civil). Results for synthetic paraffinic kerosene (SPK) fuel blends show little change with respect to baseline performance, yet do show lower emissions. The evolution of a validated combustor design procedure is fundamental to the development of dynamic fueling of combustor systems for gas turbine engines that comply with multiple feedstock sources satisfying both new and legacy systems.

  14. NACA Investigation of Fuel Performance in Piston-Type Engines

    NASA Technical Reports Server (NTRS)

    Barnett, Henry C

    1951-01-01

    This report is a compilation of many of the pertinent research data acquired by the National Advisory Committee for Aeronautics on fuel performance in piston engines. The original data for this compilation are contained in many separate NACA reports which have in the present report been assembled in logical chapters that summarize the main conclusions of the various investigations. Complete details of each investigation are not included in this summary; however, such details may be found, in the original reports cited at the end of each chapter.

  15. 40 CFR 80.166 - Carburetor deposit control performance test and test fuel guidelines.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... test and test fuel guidelines. 80.166 Section 80.166 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) REGULATION OF FUELS AND FUEL ADDITIVES Detergent Gasoline § 80.166 Carburetor deposit control performance test and test fuel guidelines. EPA will use...

  16. PEM fuel cell stack performance using dilute hydrogen mixture. Implications on electrochemical engine system performance and design

    SciTech Connect

    Inbody, M.A.; Vanderborgh, N.E.; Hedstrom, J.C.; Tafoya, J.I.

    1996-12-31

    Onboard fuel processing to generate a hydrogen-rich fuel for PEM fuel cells is being considered as an alternative to stored hydrogen fuel for transportation applications. If successful, this approach, contrasted to operating with onboard hydrogen, utilizes the existing fuels infrastructure and provides required vehicle range. One attractive, commercial liquid fuels option is steam reforming of methanol. However, expanding the liquid methanol infrastructure will take both time and capital. Consequently technology is also being developed to utilize existing transportation fuels, such as gasoline or diesel, to power PEM fuel cell systems. Steam reforming of methanol generates a mixture with a dry gas composition of 75% hydrogen and 25% carbon dioxide. Steam reforming, autothermal reforming, and partial oxidation reforming of C{sub 2} and larger hydrocarbons produces a mixture with a more dilute hydrogen concentration (65%-40%) along with carbon dioxide ({approx}20%) and nitrogen ({approx}10%-40%). Performance of PEM fuel cell stacks on these dilute hydrogen mixtures will affect the overall electrochemical engine system design as well as the overall efficiency. The Los Alamos Fuel Cell Stack Test facility was used to access the performance of a PEM Fuel cell stack over the range of gas compositions chosen to replicate anode feeds from various fuel processing options for hydrocarbon and alcohol fuels. The focus of the experiments was on the anode performance with dilute hydrogen mixtures with carbon dioxide and nitrogen diluents. Performance with other anode feed contaminants, such as carbon monoxide, are not reported here.

  17. Support vector machine to predict diesel engine performance and emission parameters fueled with nano-particles additive to diesel fuel

    NASA Astrophysics Data System (ADS)

    Ghanbari, M.; Najafi, G.; Ghobadian, B.; Mamat, R.; Noor, M. M.; Moosavian, A.

    2015-12-01

    This paper studies the use of adaptive Support Vector Machine (SVM) to predict the performance parameters and exhaust emissions of a diesel engine operating on nanodiesel blended fuels. In order to predict the engine parameters, the whole experimental data were randomly divided into training and testing data. For SVM modelling, different values for radial basis function (RBF) kernel width and penalty parameters (C) were considered and the optimum values were then found. The results demonstrate that SVM is capable of predicting the diesel engine performance and emissions. In the experimental step, Carbon nano tubes (CNT) (40, 80 and 120 ppm) and nano silver particles (40, 80 and 120 ppm) with nanostructure were prepared and added as additive to the diesel fuel. Six cylinders, four-stroke diesel engine was fuelled with these new blended fuels and operated at different engine speeds. Experimental test results indicated the fact that adding nano particles to diesel fuel, increased diesel engine power and torque output. For nano-diesel it was found that the brake specific fuel consumption (bsfc) was decreased compared to the net diesel fuel. The results proved that with increase of nano particles concentrations (from 40 ppm to 120 ppm) in diesel fuel, CO2 emission increased. CO emission in diesel fuel with nano-particles was lower significantly compared to pure diesel fuel. UHC emission with silver nano-diesel blended fuel decreased while with fuels that contains CNT nano particles increased. The trend of NOx emission was inverse compared to the UHC emission. With adding nano particles to the blended fuels, NOx increased compared to the net diesel fuel. The tests revealed that silver & CNT nano particles can be used as additive in diesel fuel to improve complete combustion of the fuel and reduce the exhaust emissions significantly.

  18. Assessment of shielding analysis methods, codes, and data for spent fuel transport/storage applications. [Radiation dose rates from shielded spent fuels and high-level radioactive waste

    SciTech Connect

    Parks, C.V.; Broadhead, B.L.; Hermann, O.W.; Tang, J.S.; Cramer, S.N.; Gauthey, J.C.; Kirk, B.L.; Roussin, R.W.

    1988-07-01

    This report provides a preliminary assessment of the computational tools and existing methods used to obtain radiation dose rates from shielded spent nuclear fuel and high-level radioactive waste (HLW). Particular emphasis is placed on analysis tools and techniques applicable to facilities/equipment designed for the transport or storage of spent nuclear fuel or HLW. Applications to cask transport, storage, and facility handling are considered. The report reviews the analytic techniques for generating appropriate radiation sources, evaluating the radiation transport through the shield, and calculating the dose at a desired point or surface exterior to the shield. Discrete ordinates, Monte Carlo, and point kernel methods for evaluating radiation transport are reviewed, along with existing codes and data that utilize these methods. A literature survey was employed to select a cadre of codes and data libraries to be reviewed. The selection process was based on specific criteria presented in the report. Separate summaries were written for several codes (or family of codes) that provided information on the method of solution, limitations and advantages, availability, data access, ease of use, and known accuracy. For each data library, the summary covers the source of the data, applicability of these data, and known verification efforts. Finally, the report discusses the overall status of spent fuel shielding analysis techniques and attempts to illustrate areas where inaccuracy and/or uncertainty exist. The report notes the advantages and limitations of several analysis procedures and illustrates the importance of using adequate cross-section data sets. Additional work is recommended to enable final selection/validation of analysis tools that will best meet the US Department of Energy's requirements for use in developing a viable HLW management system. 188 refs., 16 figs., 27 tabs.

  19. Performance of asynchronous fiber-optic code division multiple access system based on three-dimensional wavelength/time/space codes and its link analysis.

    PubMed

    Singh, Jaswinder

    2010-03-10

    A novel family of three-dimensional (3-D) wavelength/time/space codes for asynchronous optical code-division-multiple-access (CDMA) systems with "zero" off-peak autocorrelation and "unity" cross correlation is reported. Antipodal signaling and differential detection is employed in the system. A maximum of [(W x T+1) x W] codes are generated for unity cross correlation, where W and T are the number of wavelengths and time chips used in the code and are prime. The conditions for violation of the cross-correlation constraint are discussed. The expressions for number of generated codes are determined for various code dimensions. It is found that the maximum number of codes are generated for S < or = min(W,T), where W and T are prime and S is the number of space channels. The performance of these codes is compared to the earlier reported two-dimensional (2-D)/3-D codes for asynchronous systems. The codes have a code-set-size to code-size ratio greater than W/S. For instance, with a code size of 2065 (59 x 7 x 5), a total of 12,213 users can be supported, and 130 simultaneous users at a bit-error rate (BER) of 10(-9). An arrayed-waveguide-grating-based reconfigurable encoder/decoder design for 2-D implementation for the 3-D codes is presented so that the need for multiple star couplers and fiber ribbons is eliminated. The hardware requirements of the coders used for various modulation/detection schemes are given. The effect of insertion loss in the coders is shown to be significantly reduced with loss compensation by using an amplifier after encoding. An optical CDMA system for four users is simulated and the results presented show the improvement in performance with the use of loss compensation. PMID:20220892

  20. Performance of fuel cell for energy supply of passive house

    NASA Astrophysics Data System (ADS)

    Badea, G.; Felseghi, R. A.; Rǎboacǎ, S. M.; Aşchilean, I.; Mureşan, D.; Naghiu, G.

    2015-12-01

    Hydrogen technology and passive house represent two concepts with a remarkable role for the efficiency and decarbonisation of energy systems in the residential buildings area. Through design and functionality, the passive house can make maximum use of all available energy resources. One of the solutions to supply energy of these types of buildings is the fuel cell, using this technology integrated into a system for generating electricity from renewable primary sources, which take the function of backup power (energy reserve) to cover peak load and meteorological intermittents. In this paper is presented the results of the case study that provide an analysis of the energy, environmental and financial performances regarding energy supply of passive house by power generation systems with fuel cell fed with electrolytic hydrogen produced by harnessing renewable energy sources available. Hybrid systems have been configured and operate in various conditions of use for five differentiated locations according to the main areas of solar irradiation from the Romanian map. Global performance of hybrid systems is directly influenced by the availability of renewable primary energy sources - particular geo-climatic characteristics of the building emplacement.

  1. Performance of fuel cell for energy supply of passive house

    SciTech Connect

    Badea, G.; Felseghi, R. A. Mureşan, D.; Naghiu, G.; Răboacă, S. M.; Aşchilean, I.

    2015-12-23

    Hydrogen technology and passive house represent two concepts with a remarkable role for the efficiency and decarbonisation of energy systems in the residential buildings area. Through design and functionality, the passive house can make maximum use of all available energy resources. One of the solutions to supply energy of these types of buildings is the fuel cell, using this technology integrated into a system for generating electricity from renewable primary sources, which take the function of backup power (energy reserve) to cover peak load and meteorological intermittents. In this paper is presented the results of the case study that provide an analysis of the energy, environmental and financial performances regarding energy supply of passive house by power generation systems with fuel cell fed with electrolytic hydrogen produced by harnessing renewable energy sources available. Hybrid systems have been configured and operate in various conditions of use for five differentiated locations according to the main areas of solar irradiation from the Romanian map. Global performance of hybrid systems is directly influenced by the availability of renewable primary energy sources - particular geo-climatic characteristics of the building emplacement.

  2. A nonlinear model for top fuel dragster dynamic performance assessment

    NASA Astrophysics Data System (ADS)

    Spanos, P. D.; Castillo, D. H.; Kougioumtzoglou, I. A.; Tapia, R. A.

    2012-02-01

    The top fuel dragster is the fastest and quickest vehicle in drag racing. This vehicle is capable of travelling a quarter mile in less than 4.5 s, reaching a final speed in excess of 330 miles per hour. The average power delivered by its engine exceeds 7000 Hp. To analyse and eventually increase the performance of a top fuel dragster, a dynamic model of the vehicle is developed. Longitudinal, vertical, and pitching chassis motions are considered, as well as drive-train dynamics. The aerodynamics of the vehicle, the engine characteristics, and the force due to the combustion gases are incorporated into the model. Further, a simplified model of the traction characteristics of the rear tyres is developed where the traction is calculated as a function of the slip ratio and the velocity. The resulting nonlinear, coupled differential equations of motion are solved using a fourth-order Runge-Kutta numerical integration scheme. Several simulation runs are made to investigate the effects of the aerodynamics and of the engine's initial torque in the performance of the vehicle. The results of the computational simulations are scrutinised by comparisons with data from actual dragster races. Ultimately, the proposed dynamic model of the dragster can be used to improve the aerodynamics, the engine and clutch set-ups of the vehicle, and possibly facilitate the redesign of the dragster.

  3. Irradiation performance of AGR-1 high temperature reactor fuel

    SciTech Connect

    Paul A. Demkowicz; John D. Hunn; Robert N. Morris; Charles A. Baldwin; Philip L. Winston; Jason M. Harp; Scott A. Ploger; Tyler Gerczak; Isabella J. van Rooyen; Fred C. Montgomery; Chinthaka M. Silva

    2014-10-01

    The AGR-1 experiment contained 72 low-enriched uranium oxide/uranium carbide TRISO-coated particle fuel compacts in six capsules irradiated to burnups of 11.2 to 19.5% FIMA, with zero TRISO coating failures detected during the irradiation. The irradiation performance of the fuel–including the extent of fission product release and the evolution of kernel and coating microstructures–was evaluated based on detailed examination of the irradiation capsules, the fuel compacts, and individual particles. Fractional release of 110mAg from the fuel compacts was often significant, with capsule-average values ranging from 0.01 to 0.38. Analysis of silver release from individual compacts indicated that it was primarily dependent on fuel temperature history. Europium and strontium were released in small amounts through intact coatings, but were found to be significantly retained in the outer pyrocrabon and compact matrix. The capsule-average fractional release from the compacts was 1×10 4 to 5×10 4 for 154Eu and 8×10 7 to 3×10 5 for 90Sr. The average 134Cs release from compacts was <3×10 6 when all particles maintained intact SiC. An estimated four particles out of 2.98×105 experienced partial cesium release due to SiC failure during the irradiation, driving 134Cs release in two capsules to approximately 10 5. Identification and characterization of these particles has provided unprecedented insight into the nature and causes of SiC coating failure in high-quality TRISO fuel. In general, changes in coating morphology were found to be dominated by the behavior of the buffer and inner pyrolytic carbon (IPyC), and infrequently observed SiC layer damage was usually related to cracks in the IPyC. Palladium attack of the SiC layer was relatively minor, except for the particles that released cesium during irradiation, where SiC corrosion was found adjacent to IPyC cracks. Palladium, silver, and uranium were found in the SiC layer of irradiated particles, and characterization

  4. Advancements and performance of iterative methods in industrial applications codes on CRAY parallel/vector supercomputers

    SciTech Connect

    Poole, G.; Heroux, M.

    1994-12-31

    This paper will focus on recent work in two widely used industrial applications codes with iterative methods. The ANSYS program, a general purpose finite element code widely used in structural analysis applications, has now added an iterative solver option. Some results are given from real applications comparing performance with the tradition parallel/vector frontal solver used in ANSYS. Discussion of the applicability of iterative solvers as a general purpose solver will include the topics of robustness, as well as memory requirements and CPU performance. The FIDAP program is a widely used CFD code which uses iterative solvers routinely. A brief description of preconditioners used and some performance enhancements for CRAY parallel/vector systems is given. The solution of large-scale applications in structures and CFD includes examples from industry problems solved on CRAY systems.

  5. Low-Complexity, High-Performance Bandwidth Efficient Coding and Coded Modulation Techniques for Satellite and Space Communications

    NASA Technical Reports Server (NTRS)

    Costello, Daniel J., Jr.

    1993-01-01

    The semi-annual progress report for NASA grant NAG5-557 is presented. The report contains three papers concerning bandwidth efficient coding and coded modulation techniques for satellite and space communications.

  6. Multiple trellis coded modulation (MTCM) performance on a fading mobile satellite channel

    NASA Technical Reports Server (NTRS)

    Simon, Marvin K.; Divsalar, Dariush

    1987-01-01

    The author recently introduced the notion of multiple trellis coding, in which more than one channel symbol per trellis branch is transmitted. He showed that on the ideal additive white Gaussian noise (AWGN) channel, the combination of multiple trellis coding with M-ary modulation yields a performance gain with symmetric signal sets comparable to and in some cases better than that previously achieved only with signal constellation asymmetry. The combination of conventional trellis coding with multiple phase-shift-keyed (MPSK) signaling has recently been shown by the author to be a well-suited modulation/coding scheme for transmission over the fading mobile satellite channel. In particular, a rate 2/3 coded 8-PSK scheme operating at 4800 b/s is currently under development for use in NASA's Mobile Satellite Experiment (MSAT-X). The author applies the multiple trellis-coded modulation technique in the same fading mobile satellite environment, extending the analysis results previously found for its performance over the AWGN channel to the MSAT-X channel.

  7. SCALE: A modular code system for performing standardized computer analyses for licensing evaluation

    SciTech Connect

    1997-03-01

    This Manual represents Revision 5 of the user documentation for the modular code system referred to as SCALE. The history of the SCALE code system dates back to 1969 when the current Computational Physics and Engineering Division at Oak Ridge National Laboratory (ORNL) began providing the transportation package certification staff at the U.S. Atomic Energy Commission with computational support in the use of the new KENO code for performing criticality safety assessments with the statistical Monte Carlo method. From 1969 to 1976 the certification staff relied on the ORNL staff to assist them in the correct use of codes and data for criticality, shielding, and heat transfer analyses of transportation packages. However, the certification staff learned that, with only occasional use of the codes, it was difficult to become proficient in performing the calculations often needed for an independent safety review. Thus, shortly after the move of the certification staff to the U.S. Nuclear Regulatory Commission (NRC), the NRC staff proposed the development of an easy-to-use analysis system that provided the technical capabilities of the individual modules with which they were familiar. With this proposal, the concept of the Standardized Computer Analyses for Licensing Evaluation (SCALE) code system was born. This manual covers an array of modules written for the SCALE package, consisting of drivers, system libraries, cross section and materials properties libraries, input/output routines, storage modules, and help files.

  8. A novel multivariate performance optimization method based on sparse coding and hyper-predictor learning.

    PubMed

    Yang, Jiachen; Ding, Zhiyong; Guo, Fei; Wang, Huogen; Hughes, Nick

    2015-11-01

    In this paper, we investigate the problem of optimization of multivariate performance measures, and propose a novel algorithm for it. Different from traditional machine learning methods which optimize simple loss functions to learn prediction function, the problem studied in this paper is how to learn effective hyper-predictor for a tuple of data points, so that a complex loss function corresponding to a multivariate performance measure can be minimized. We propose to present the tuple of data points to a tuple of sparse codes via a dictionary, and then apply a linear function to compare a sparse code against a given candidate class label. To learn the dictionary, sparse codes, and parameter of the linear function, we propose a joint optimization problem. In this problem, the both the reconstruction error and sparsity of sparse code, and the upper bound of the complex loss function are minimized. Moreover, the upper bound of the loss function is approximated by the sparse codes and the linear function parameter. To optimize this problem, we develop an iterative algorithm based on descent gradient methods to learn the sparse codes and hyper-predictor parameter alternately. Experiment results on some benchmark data sets show the advantage of the proposed methods over other state-of-the-art algorithms. PMID:26291045

  9. Using Automated Code Generation to Support High Performance Extended MHD Integration in OpenGGCM

    NASA Astrophysics Data System (ADS)

    Germaschewski, K.; Raeder, J.

    2011-10-01

    Automatic code generation is a technique that takes the specification of an algorithm at a high abstraction level and turns it into a well-tuned computer code. For finite-volume / finite-difference based discretizations, this higher abstraction level can be a stencil computation. At the backend, the code generator features modules which generate optimal code for specific hardware architectures, for example conventional architectures (x86) using SIMD instructions (e.g. SSE2), or heterogeneous architectures like the Cell processor or GPGPUs. The definition of the computation is agnostic to the actual hardware used, as a high-performance implementation tailored to the specific architecture will be generated automatically. The OpenGGCM code, a global magnetosphere model, has been converted to use an automatically generated implementation of its magnetohydrodynamics (MHD) integrator. The new version enables us to take advantage of the Cell processor's computational capability and also shows performance improvements of up to 2.3× on a conventional Intel processor. The code generation approach also facilitated the recent extension of the MHD model to incorporate Hall physics.

  10. Alternate-Fueled Combustor-Sector Performance. Parts A and B; (A) Combustor Performance; (B) Combustor Emissions

    NASA Technical Reports Server (NTRS)

    Shouse, D. T.; Hendricks, R. C.; Lynch, A.; Frayne, C. W.; Stutrud, J. S.; Corporan, E.; Hankins, T.

    2012-01-01

    Alternate aviation fuels for military or commercial use are required to satisfy MIL-DTL-83133F(2008) or ASTM D 7566 (2010) standards, respectively, and are classified as "drop-in" fuel replacements. To satisfy legacy issues, blends to 50% alternate fuel with petroleum fuels are certified individually on the basis of processing and assumed to be feedstock agnostic. Adherence to alternate fuels and fuel blends requires "smart fueling systems" or advanced fuel-flexible systems, including combustors and engines, without significant sacrifice in performance or emissions requirements. This paper provides preliminary performance (Part A) and emissions and particulates (Part B) combustor sector data. The data are for nominal inlet conditions at 225 psia and 800 F (1.551 MPa and 700 K), for synthetic-paraffinic-kerosene- (SPK-) type (Fisher-Tropsch (FT)) fuel and blends with JP-8+100 relative to JP-8+100 as baseline fueling. Assessments are made of the change in combustor efficiency, wall temperatures, emissions, and luminosity with SPK of 0%, 50%, and 100% fueling composition at 3% combustor pressure drop. The performance results (Part A) indicate no quantifiable differences in combustor efficiency, a general trend to lower liner and higher core flow temperatures with increased FT fuel blends. In general, emissions data (Part B) show little differences, but with percent increase in FT-SPK-type fueling, particulate emissions and wall temperatures are less than with baseline JP-8. High-speed photography illustrates both luminosity and combustor dynamic flame characteristics.

  11. Performance analysis of electronic code division multiple access based virtual private networks over passive optical networks

    NASA Astrophysics Data System (ADS)

    Nadarajah, Nishaanthan; Nirmalathas, Ampalavanapillai

    2008-03-01

    A solution for implementing multiple secure virtual private networks over a passive optical network using electronic code division multiple access is proposed and experimentally demonstrated. The multiple virtual private networking capability is experimentally demonstrated with 40 Mb/s data multiplexed with a 640 Mb/s electronic code that is unique to each of the virtual private networks in the passive optical network, and the transmission of the electronically coded data is carried out using Fabry-Perot laser diodes. A theoretical scalability analysis for electronic code division multiple access based virtual private networks over a passive optical network is also carried out to identify the performance limits of the scheme. Several sources of noise such as optical beat interference and multiple access interference that are present in the receiver are considered with different operating system parameters such as transmitted optical power, spectral width of the broadband optical source, and processing gain to study the scalability of the network.

  12. Coding schemes for improving MST radar performance, part 7.1A

    NASA Technical Reports Server (NTRS)

    Bowhill, S. A.

    1984-01-01

    The performance of an mesosphere-stratosphere-troposphere (MST) radar can be characterized by its system sensitivity and its range resolution. The former enables Doppler velocities to be determined even in the presence of very weak structures; the latter permits study of the fine structure within a turbulent region. Coding of transmitted signals has as its aim an increase in the effective radar sensitivity or range resolution without an increase in the peak transmitted power. This is accomplished by spreading the power in the frequency domain, giving better range resolution, without reducing the pulse width. Two basic techniques are used to accomplish this frequency dispersion: (1) using a type of pseudorandom code for the phase or amplitude within a single pulse, or within a finite sequence of pulses; (2) to code the frequency of the transmitted signal in some way. The various possibilities are discussed and are compared with the pulse-coding methods.

  13. PORST: a computer code to analyze the performance of retrofitted steam turbines

    SciTech Connect

    Lee, C.; Hwang, I.T.

    1980-09-01

    The computer code PORST was developed to analyze the performance of a retrofitted steam turbine that is converted from a single generating to a cogenerating unit for purposes of district heating. Two retrofit schemes are considered: one converts a condensing turbine to a backpressure unit; the other allows the crossover extraction of steam between turbine cylinders. The code can analyze the performance of a turbine operating at: (1) valve-wide-open condition before retrofit, (2) partial load before retrofit, (3) valve-wide-open after retrofit, and (4) partial load after retrofit.

  14. Design geometry and design/off-design performance computer codes for compressors and turbines

    NASA Technical Reports Server (NTRS)

    Glassman, Arthur J.

    1995-01-01

    This report summarizes some NASA Lewis (i.e., government owned) computer codes capable of being used for airbreathing propulsion system studies to determine the design geometry and to predict the design/off-design performance of compressors and turbines. These are not CFD codes; velocity-diagram energy and continuity computations are performed fore and aft of the blade rows using meanline, spanline, or streamline analyses. Losses are provided by empirical methods. Both axial-flow and radial-flow configurations are included.

  15. Performance Analysis of Spectral Amplitude Coding Based OCDMA System with Gain and Splitter Mismatch

    NASA Astrophysics Data System (ADS)

    Umrani, Fahim A.; Umrani, A. Waheed; Umrani, Naveed A.; Memon, Kehkashan A.; Kalwar, Imtiaz Hussain

    2013-09-01

    This paper presents the practical analysis of the optical code-division multiple-access (O-CDMA) systems based on perfect difference codes. The work carried out use SNR criterion to select the optimal value of avalanche photodiodes (APD) gain and shows how the mismatch in the splitters and gains of the APD used in the transmitters and receivers of network can degrade the BER performance of the system. The investigations also reveal that higher APD gains are not suitable for such systems even at higher powers. The system performance, with consideration of shot noise, thermal noise, bulk and surface leakage currents is also investigated.

  16. Cumulative hardware distortion effects on coded and uncoded performance via a satellite repeater

    NASA Technical Reports Server (NTRS)

    Benjamin, T.

    1981-01-01

    An analytical investigation is presented of the cumulative impact of numerous hardware-induced distortions on BPSK bit-error-rate performance. Attention is given to 16 user and eight transponder constraints, as well as to the effect of filter bandlimiting. Uncoded and coded performance is evaluated with respect to both NRZ and Manchester signaling formats, and tight upper bounds to coded and uncoded SNR degradation are determined. Computed results based on TDRSS (Tracking and Data Relay Satellite System) specifications are presented as an example.

  17. Thermionic Fuel Element performance: TFE Verification Program. Final test report

    SciTech Connect

    Not Available

    1994-06-01

    The program objective is to demonstrate the technology readiness of a Thermionic Fuel Element (TFE) suitable for use as the basic element in a thermionic reactor with electric power output in the 0.5 to 5.0 MW(e) range, and a full power life of 7 years. A TFE was designed that met the reliability and lifetime requirements for a 2 MW(e) conceptual reactor design. Analysis showed that this TFE could be used over the range of 0.5 to 5 megawatts. This was used as the basis for designing components for test and evaluation. The demonstration of a 7-year component lifetime capability was through the combined use of analytical models and accelerated, confirmatory tests in a fast test reactor. Iterative testing was performed in which the results of one test series led to evolutionary improvements in the next test specimens. The TFE components underwent screening and initial development testing in ex-reactor tests. Several design and materials options were considered for each component. As screening tests permitted, down selection occurred to very specific designs and materials. In parallel with ex-reactor testing, and fast reactor component testing, components were integrated into a TFE and tested in the TRIGA test reactor at GA. Realtime testing of partial length TFEs was used to test support, alignment and interconnective TFE components, and to verify TFE performance in-reactor with integral cesium reservoirs. Realtime testing was also used to verify the relation between TFE performance and fueled emitter swelling, to test the durability of intercell insulation, to check temperature distributions, and to verify the adequacy over time of the fission gas venting channels. Predictions of TFE lifetime rested primarily on the accelerated component testing results, as correlated and extended to realtime by the use of analytical models.

  18. Effect of broad properties fuel on injector performance in a reverse flow combustor

    NASA Technical Reports Server (NTRS)

    Raddlebaugh, S. M.; Norgren, C. T.

    1983-01-01

    The effect of fuel type on the performance of various fuel injectors was investigated in a reverse flow combustor. Combustor performance and emissions are documented for simplex pressure atomizing, spill flow, and airblast fuel injectors using a broad properties fuel and compared with performance using Jet A fuel. Test conditions simulated a range of flight conditions including sea level take off, low and high altitude cruise, as well as a parametric evaluation of the effect of increased combustor loading. The baseline simplex injector produced higher emission levels with corresponding lower combustion efficiency with the broad properties fuel. There was little or not loss in performance by the two advanced concept injectors with the broad properties fuel. The airblast injector proved to be especially insensitive to fuel type.

  19. Impact of broad-specification fuels on future jet aircraft. [engine components and performance

    NASA Technical Reports Server (NTRS)

    Grobman, J. S.

    1978-01-01

    The effects that broad specification fuels have on airframe and engine components were discussed along with the improvements in component technology required to use broad specification fuels without sacrificing performance, reliability, maintainability, or safety.

  20. Development of a Fast Breeder Reactor Fuel Bundle-Duct Interaction Analysis Code - BAMBOO: Analysis Model and Validation by the Out-of-Pile Compression Test

    SciTech Connect

    Uwaba, Tomoyuki; Tanaka, Kosuke

    2001-10-15

    To analyze the wire-wrapped fast breeder reactor (FBR) fuel pin bundle deformation under bundle-duct interaction (BDI) conditions, the Japan Nuclear Cycle Development Institute has developed the BAMBOO computer code. A three-dimensional beam element model is used in this code to calculate fuel pin bowing and cladding oval distortion, which are the dominant deformation mechanisms in a fuel pin bundle. In this work, the property of the cladding oval distortion considering the wire-pitch was evaluated experimentally and introduced in the code analysis.The BAMBOO code was validated in this study by using an out-of-pile bundle compression testing apparatus and comparing these results with the code results. It is concluded that BAMBOO reasonably predicts the pin-to-duct clearances in the compression tests by treating the cladding oval distortion as the suppression mechanism to BDI.

  1. Performance of Four Experimental High-btu-per-gallon Fuels in a Single Turbojet Combustor

    NASA Technical Reports Server (NTRS)

    Jonash, Edmund R; Metzler, Allen; Butze, Helmut F

    1955-01-01

    Performance characteristics of four hydrocarbon fuels having high Btu per gallon were determined in a single turbojet combustor. At simulated low-altitude operating conditions, the fuels with high Btu per gallon generally produced more carbon than did JP-4 and JP-5 fuels. The deposits were reduced appreciably with a fuel-oil additive. At high-altitude conditions, the high Btu-per-gallon fuels gave lower efficiencies than did JP-4 or JP-5 fuels. No attempts were made to improve performance by combustor design modification.

  2. Performance assessment of natural gas and biogas fueled molten carbonate fuel cells in carbon capture configuration

    NASA Astrophysics Data System (ADS)

    Barelli, Linda; Bidini, Gianni; Campanari, Stefano; Discepoli, Gabriele; Spinelli, Maurizio

    2016-07-01

    The ability of MCFCs as carbon dioxide concentrator is an alternative solution among the carbon capture and storage (CCS) technologies to reduce the CO2 emission of an existing plant, providing energy instead of implying penalties. Moreover, the fuel flexibility exhibited by MCFCs increases the interest on such a solution. This paper provides the performance characterization of MCFCs operated in CCS configuration and fed with either natural gas or biogas. Experimental results are referred to a base CCS unit constituted by a MCFC stack fed from a reformer and integrated with an oxycombustor. A comparative analysis is carried out to evaluate the effect of fuel composition on energy efficiency and CO2 capture performance. A higher CO2 removal ability is revealed for the natural feeding case, bringing to a significant reduction in MCFC total area (-11.5%) and to an increase in produced net power (+13%). Moreover, the separated CO2 results in 89% (natural gas) and 86.5% (biogas) of the CO2 globally delivered by the CCS base unit. Further investigation will be carried out to provide a comprehensive assessment of the different solutions eco-efficiency considering also the biogas source and availability.

  3. Performance of the ICAO standard core service modulation and coding techniques

    NASA Technical Reports Server (NTRS)

    Lodge, John; Moher, Michael

    1988-01-01

    Aviation binary phase shift keying (A-BPSK) is described and simulated performance results are given that demonstrate robust performance in the presence of hardlimiting amplifiers. The performance of coherently-detected A-BPSK with rate 1/2 convolutional coding are given. The performance loss due to the Rician fading was shown to be less than 1 dB over the simulated range. A partially coherent detection scheme that does not require carrier phase recovery was described. This scheme exhibits similiar performance to coherent detection, at high bit error rates, while it is superior at lower bit error rates.

  4. Fault-tolerant quantum computation in multiqubit block codes: performance and overhead

    NASA Astrophysics Data System (ADS)

    Brun, Todd

    Fault-tolerant quantum computation requires that quantum information remain encoded in a quantum error-correcting code at all times; that a universal set of logical unitary gates and measurements is available; and that the probability of an uncorrectable error is low for the duration of the computation. Quantum computation can in principle be scaled up to unlimited size if the rate of decoherence is below a threshold. The main constructions that have been studied involve encoding each logical qubit in a separate block (either a concatenated code or a block of the surface code), which typically requires thousands of physical qubits per logical qubit, if not more. To reduce this overhead, we consider using multiqubit codes to achieve much higher storage rates. We estimate performance and overhead for certain families of codes, and ask: how large a quantum computation can be done as a function of the decoherence rate for a fixed size code block? Finally, we consider remaining open questions and limitations to this approach. This work is supported by NSF Grant No. CCF-1421078.

  5. New higher-order Godunov code for modelling performance of two-stage light gas guns

    NASA Technical Reports Server (NTRS)

    Bogdanoff, D. W.; Miller, R. J.

    1995-01-01

    A new quasi-one-dimensional Godunov code for modeling two-stage light gas guns is described. The code is third-order accurate in space and second-order accurate in time. A very accurate Riemann solver is used. Friction and heat transfer to the tube wall for gases and dense media are modeled and a simple nonequilibrium turbulence model is used for gas flows. The code also models gunpowder burn in the first-stage breech. Realistic equations of state (EOS) are used for all media. The code was validated against exact solutions of Riemann's shock-tube problem, impact of dense media slabs at velocities up to 20 km/sec, flow through a supersonic convergent-divergent nozzle and burning of gunpowder in a closed bomb. Excellent validation results were obtained. The code was then used to predict the performance of two light gas guns (1.5 in. and 0.28 in.) in service at the Ames Research Center. The code predictions were compared with measured pressure histories in the powder chamber and pump tube and with measured piston and projectile velocities. Very good agreement between computational fluid dynamics (CFD) predictions and measurements was obtained. Actual powder-burn rates in the gun were found to be considerably higher (60-90 percent) than predicted by the manufacturer and the behavior of the piston upon yielding appears to differ greatly from that suggested by low-strain rate tests.

  6. Performance assessment for the geological disposal of Deep Burn spent fuel using TTBX

    SciTech Connect

    Van den Akker, B.P.; Ahn, J.

    2013-07-01

    The behavior of Deep Burn Modular High Temperature Reactor Spent Fuel (DBSF) is investigated in the Yucca Mountain geological repository (YMR) with respect to the annual dose (Sv/yr) delivered to the Reasonably Maximally Exposed Individual (RMEI) from the transport of radionuclides released from the graphite waste matrix. Transport calculations are performed with a novel computer code, TTBX which is capable of modeling transport pathways that pass through heterogeneous geological formations. TTBX is a multi-region extension of the existing single region TTB transport code. Overall the peak annual dose received by the RMEI is seen to be four orders of magnitude lower than the regulatory threshold for exposure, even under pessimistic scenarios. A number of factors contribute to the favorable performance of DBSF. A reduction of one order of magnitude in the peak annual dose received by the RMEI is observed for every order of magnitude increase in the waste matrix lifetime, highlighting the importance of the waste matrix durability and suggesting graphite's utility as a potential waste matrix for the disposal of high-level waste. Furthermore, we see that by incorporating a higher fidelity far-field model the peak annual dose calculated to be received by the RMEI is reduced by two orders of magnitude. By accounting for the heterogeneities of the far field we have simultaneously removed unnecessary conservatisms and improved the fidelity of the transport model. (authors)

  7. CFD code development for performance evaluation of a pilot-scale FCC riser reactor

    SciTech Connect

    Chang, S.L.; Lottes, S.A.; Zhou, C.Q.; Golchert, B.; Petrick, M.

    1997-09-01

    Fluid Catalytic Cracking (FCC) is an important conversion process for the refining industry. The improvement of FCC technology could have a great impact on the public in general by lowering the cost of transportation fuel. A recent review of the FCC technology development by Bienstock et al. of Exxon indicated that the use of computational fluid dynamics (CFD) simulation can be very effective in the advancement of the technology. Theologos and Markatos used a commercial CFD code to model an FCC riser reactor. National Laboratories of the U.S. Department of Energy (DOE) have accumulated immense CFD expertise over the years for various engineering applications. A recent DOE survey showed that National Laboratories are using their CFD expertise to help the refinery industry improve the FCC technology under DOE`s Cooperative Research and Development Agreement (CRADA). Among them are Los Alamos National Laboratory with Exxon and Amoco and Argonne National Laboratory (ANL) with Chevron and UOP. This abstract briefly describes the current status of ANL`s work. The objectives of the ANL CRADA work are (1) to use a CFD code to simulate FCC riser reactor flow and (2) to evaluate the impacts of operating conditions and design parameters on the product yields. The CFD code used in this work was originally developed for spray combustion simulation in early 1980 at Argonne. It has been successfully applied to diagnosing a number of multi-phase reacting flow problems in a magneto-hydrodynamic power train. A new version of the CFD code developed for the simulation of the FCC riser flow is called Integral CRacKing FLOw (ICRKFLO). The CFD code solves conservation equations of general flow properties for three phases: gaseous species, liquid droplets, and solid particles. General conservation laws are used in conjunction with rate equations governing the mass, momentum, enthalpy, and species for a multi-phase flow with gas species, liquid droplets, and solid particles.

  8. Performance of Pentaborane, Pentaborane - JP-4 Fuel Mixtures, and Trimethylborate Azeotrope Fuel in a Full-scale Turbojet Engine

    NASA Technical Reports Server (NTRS)

    Breitwiesser, Roland; Useller, James W.

    1956-01-01

    This report summarizes the full-scale engine tests of pentaborane, pentaborane - JP-4 fuel mixtures, and trimethylborate azeotrope fuel. The tests were conducted in a full-scale turbojet engine at a simulated altitude of 50,000 feet and Mach number of 0.08. Engine speeds were 90 to 100 percent of rated speed. Pentaborane reduced the the specific fuel consumption to two-thirds that of JP-4 fuel. However, because boron oxide collected in the engine, the performance deteriorated with continued operation of pentaborane in each of the short-duration tests reported.

  9. Performance of Denitrifying Microbial Fuel Cell with Biocathode over Nitrite

    PubMed Central

    Zhao, Huimin; Zhao, Jianqiang; Li, Fenghai; Li, Xiaoling

    2016-01-01

    Microbial fuel cell (MFC) with nitrite as an electron acceptor in cathode provided a new technology for nitrogen removal and electricity production simultaneously. The influences of influent nitrite concentration and external resistance on the performance of denitrifying MFC were investigated. The optimal effectiveness were obtained with the maximum total nitrogen (TN) removal rate of 54.80 ± 0.01 g m−3 d−1. It would be rather desirable for the TN removal than electricity generation at lower external resistance. Denaturing gradient gel electrophoresis suggested that Proteobacteria was the predominant phylum, accounting for 35.72%. Thiobacillus and Afipia might benefit to nitrite removal. The presence of nitrifying Devosia indicated that nitrite was oxidized to nitrate via a biochemical mechanism in the cathode. Ignavibacterium and Anaerolineaceae was found in the cathode as a heterotrophic bacterium with sodium acetate as substrate, which illustrated that sodium acetate in anode was likely permeated through proton exchange membrane to the cathode. PMID:27047462

  10. Progress performance report of clean uses of fossil fuels

    SciTech Connect

    Not Available

    1992-09-01

    A one-year USDOE/EPSCOR Traineeship Grant, entitled ``Clean Uses of Fossil Fuels.`` was awarded to the Kentucky EPSCoR Committee in September 1991 and administered through the the DOE/EPSCoR Subcommittee. Ten Traineeships were awarded to doctoral students who are enrolled or accepted into Graduate Programs at either the University of Kentucky or the University of Louisville. The disciplines of these students include Biology, Chemical Engineering, Chemistry, Geological Sciences, and Physics. The methods used for a statewide proposal solicitation and to award the Traineeships are presented. The review panel and Kentucky DOE/EPSCoR Subcommittee involved in awarding the Traineeships are described. A summary of the proposed research to be performed within these awards is presented, along with a description of the qualifications of the faculty and students who proposed projects. Future efforts to increase participation in Traineeship proposals for the succeeding funding period are outlined.

  11. Progress performance report of clean uses of fossil fuels

    SciTech Connect

    Todd, Jr., Lee T.; Boggess, Ronald J.; Carson, Ronald J.; Falkenberg, Virginia P.; Flanagan, Patrick; Hettinger, Jr., William P.; Kimel, Kris; Kupchella, Charles E.; Magid, Lee J.; McLaughlin, Barbara; Royster, Wimberly C.; Streepey, Judi L.; Wells, James H.; Stencel, John; Derbyshire, Frank J.; Hanley, Thomas R.; Magid, Lee J.; McEllistrem, Marc T.; Riley, John T.; Steffen, Joseph M.

    1992-01-01

    A one-year USDOE/EPSCOR Traineeship Grant, entitled Clean Uses of Fossil Fuels.'' was awarded to the Kentucky EPSCoR Committee in September 1991 and administered through the the DOE/EPSCoR Subcommittee. Ten Traineeships were awarded to doctoral students who are enrolled or accepted into Graduate Programs at either the University of Kentucky or the University of Louisville. The disciplines of these students include Biology, Chemical Engineering, Chemistry, Geological Sciences, and Physics. The methods used for a statewide proposal solicitation and to award the Traineeships are presented. The review panel and Kentucky DOE/EPSCoR Subcommittee involved in awarding the Traineeships are described. A summary of the proposed research to be performed within these awards is presented, along with a description of the qualifications of the faculty and students who proposed projects. Future efforts to increase participation in Traineeship proposals for the succeeding funding period are outlined.

  12. User's manual for the vertical axis wind turbine performance computer code darter

    SciTech Connect

    Klimas, P. C.; French, R. E.

    1980-05-01

    The computer code DARTER (DARrieus, Turbine, Elemental Reynolds number) is an aerodynamic performance/loads prediction scheme based upon the conservation of momentum principle. It is the latest evolution in a sequence which began with a model developed by Templin of NRC, Canada and progressed through the Sandia National Laboratories-developed SIMOSS (SSImple MOmentum, Single Streamtube) and DART (SARrieus Turbine) to DARTER.

  13. 14 CFR 234.9 - Reporting of on-time performance codes.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... deliver, or arrange to have delivered, to each system vendor, as defined in 14 CFR part 255, the on-time... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false Reporting of on-time performance codes. 234.9 Section 234.9 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF...

  14. 14 CFR 234.9 - Reporting of on-time performance codes.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... deliver, or arrange to have delivered, to each system vendor, as defined in 14 CFR part 255, the on-time... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Reporting of on-time performance codes. 234.9 Section 234.9 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF...

  15. 14 CFR 234.9 - Reporting of on-time performance codes.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... deliver, or arrange to have delivered, to each system vendor, as defined in 14 CFR part 255, the on-time... 14 Aeronautics and Space 4 2014-01-01 2014-01-01 false Reporting of on-time performance codes. 234.9 Section 234.9 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF...

  16. 14 CFR 234.9 - Reporting of on-time performance codes.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... deliver, or arrange to have delivered, to each system vendor, as defined in 14 CFR part 255, the on-time... 14 Aeronautics and Space 4 2013-01-01 2013-01-01 false Reporting of on-time performance codes. 234.9 Section 234.9 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF...

  17. 14 CFR 234.9 - Reporting of on-time performance codes.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... deliver, or arrange to have delivered, to each system vendor, as defined in 14 CFR part 255, the on-time... 14 Aeronautics and Space 4 2012-01-01 2012-01-01 false Reporting of on-time performance codes. 234.9 Section 234.9 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF...

  18. Performance of convolutional codes on fading channels typical of planetary entry missions

    NASA Technical Reports Server (NTRS)

    Modestino, J. W.; Mui, S. Y.; Reale, T. J.

    1974-01-01

    The performance of convolutional codes in fading channels typical of the planetary entry channel is examined in detail. The signal fading is due primarily to turbulent atmospheric scattering of the RF signal transmitted from an entry probe through a planetary atmosphere. Short constraint length convolutional codes are considered in conjunction with binary phase-shift keyed modulation and Viterbi maximum likelihood decoding, and for longer constraint length codes sequential decoding utilizing both the Fano and Zigangirov-Jelinek (ZJ) algorithms are considered. Careful consideration is given to the modeling of the channel in terms of a few meaningful parameters which can be correlated closely with theoretical propagation studies. For short constraint length codes the bit error probability performance was investigated as a function of E sub b/N sub o parameterized by the fading channel parameters. For longer constraint length codes the effect was examined of the fading channel parameters on the computational requirements of both the Fano and ZJ algorithms. The effects of simple block interleaving in combatting the memory of the channel is explored, using the analytic approach or digital computer simulation.

  19. Virtual Simulator: An infrastructure for design and performance-prediction of massively parallel codes

    NASA Astrophysics Data System (ADS)

    Perumalla, K.; Fujimoto, R.; Pande, S.; Karimabadi, H.; Driscoll, J.; Omelchenko, Y.

    2005-12-01

    Large parallel/distributed scientific simulations are very complex, and their dynamic behavior is hard to predict. Efficient development of massively parallel codes remains a computational challenge. For example, almost none of the kinetic codes in use in space physics today have dynamic load balancing capability. Here we present a new infrastructure for design and prediction of parallel codes. Performance prediction is useful to analyze, understand and experiment with different partitioning schemes, multiple modeling alternatives and so on, without having to run the application on supercomputers. Instrumentation of the model (with least perturbance to performance) is useful to glean key metrics and understand application-level behavior. Unfortunately, traditional approaches to virtual execution and instrumentation are limited by either slow execution speed or low resolution or both. We present a new framework that provides a high-resolution framework that provides a virtual CPU abstraction (with a full thread context per CPU), yet scales to thousands of virtual CPUs. The tool, called PDES2, presents different levels of modeling interfaces, from general purpose parallel simulations to parallel grid-based particle-in-cell (PIC) codes. The tool itself runs on multiple processors in order to accommodate the high-resolution by distributing the virtual execution across processors. Validation experiments of PIC models in the framework using a 1-D hybrid shock application show close agreement of results from virtual executions with results from actual supercomputer runs. The utility of this tool is further illustrated through an application to a parallel global hybrid code.

  20. Effects of chemical equilibrium on turbine engine performance for various fuels and combustor temperatures

    NASA Technical Reports Server (NTRS)

    Tran, Donald H.; Snyder, Christopher A.

    1992-01-01

    A study was performed to quantify the differences in turbine engine performance with and without the chemical dissociation effects for various fuel types over a range of combustor temperatures. Both turbojet and turbofan engines were studied with hydrocarbon fuels and cryogenic, nonhydrocarbon fuels. Results of the study indicate that accuracy of engine performance decreases when nonhydrocarbon fuels are used, especially at high temperatures where chemical dissociation becomes more significant. For instance, the deviation in net thrust for liquid hydrogen fuel can become as high as 20 percent at 4160 R. This study reveals that computer central processing unit (CPU) time increases significantly when dissociation effects are included in the cycle analysis.

  1. The development of CACTUS : a wind and marine turbine performance simulation code.

    SciTech Connect

    Barone, Matthew Franklin; Murray, Jonathan

    2010-12-01

    CACTUS (Code for Axial and Cross-flow TUrbine Simulation) is a turbine performance simulation code, based on a free wake vortex method, under development at Sandia National Laboratories (SNL) as part of a Department of Energy program to study marine hydrokinetic (MHK) devices. The current effort builds upon work previously done at SNL in the area of vertical axis wind turbine simulation, and aims to add models to handle generic device geometry and physical models specific to the marine environment. An overview of the current state of the project and validation effort is provided.

  2. Improving the performance of tensor matrix vector multiplication in quantum chemistry codes.

    SciTech Connect

    Gropp, W. D.; Kaushik, D. K.; Minkoff, M.; Smith, B. F.

    2008-05-08

    Cumulative reaction probability (CRP) calculations provide a viable computational approach to estimate reaction rate coefficients. However, in order to give meaningful results these calculations should be done in many dimensions (ten to fifteen). This makes CRP codes memory intensive. For this reason, these codes use iterative methods to solve the linear systems, where a good fraction of the execution time is spent on matrix-vector multiplication. In this paper, we discuss the tensor product form of applying the system operator on a vector. This approach shows much better performance and provides huge savings in memory as compared to the explicit sparse representation of the system matrix.

  3. Evaluation of a Cray performance tool using a large hydrodynamics code

    SciTech Connect

    Lord, K.M.; Simmons, M.L.

    1992-06-01

    This paper will discuss one of these automatic tools that has been developed recently by Cray Research, Inc. for use on its parallel supercomputer. The tool is called ATEXPERT; when used in conjunction with the Cray Fortran compiling system, CF77, it produces a parallelized version of a code based on loop-level parallelism, plus information to enable the programmer to optimize the parallelized code and improve performance. The information obtained through the use of the tool is presented in an easy-to-read graphical format, making the digestion of such a large quantity of data relatively easy and thus, improving programmer productivity. In this paper we address the issues that we found when the took a large Los Alamos hydrodynamics code, PUEBLO, that was highly vectorizable, but not parallelized, and using ATEXPERT proceeded to parallelize it. We show that through the advice of ATEXPERT, bottlenecks in the code can be found, leading to improved performance. We also show the dependence of performance on problem size, and finally, we contrast the speedup predicted by ATEXPERT with that measured on a dedicated eight-processor Y-MP.

  4. The effects of receiver tracking phase error on the performance of the concatenated Reed-Solomon Viterbi channel coding system

    NASA Technical Reports Server (NTRS)

    Liu, K. Y.; Woo, K. T.

    1980-01-01

    In connection with attempts to achieve very low error probabilities, Odenwalder (1970) proposed a concatenated coding system using the Viterbi-decoded convolutional codes as the inner code and Reed-Solomon (RS) codes as the outer code. Analytical and experimental results are presented concerning the effects of the receiver tracking phase error on the performance of the concatenated RS/Viterbi channel coding system. On the basis of these results it is concluded that certain problems regarding communication operations on deep-space missions can be alleviated by employing the RS/Viterbi coding system. In one-way communication, an employment of RS/Viterbi coding will also provide greater data protection than the Viterbi-decoded convolutional-only coding system.

  5. A Micropeptide Encoded by a Putative Long Non-coding RNA Regulates Muscle Performance

    PubMed Central

    Anderson, Douglas M.; Anderson, Kelly M.; Chang, Chi-Lun; Makarewich, Catherine A.; Nelson, Benjamin R.; McAnally, John R.; Kasaragod, Prasad; Shelton, John M.; Liou, Jen; Bassel-Duby, Rhonda; Olson, Eric N.

    2015-01-01

    Summary Functional micropeptides can be concealed within RNAs that appear to be non-coding. We discovered a conserved micropeptide, that we named myoregulin (MLN), encoded by a skeletal muscle-specific RNA annotated as a putative long non-coding RNA. MLN shares structural and functional similarity with phospholamban (PLN) and sarcolipin (SLN), which inhibit SERCA, the membrane pump that controls muscle relaxation by regulating Ca2+ uptake into the sarcoplasmic reticulum (SR). MLN interacts directly with SERCA and impedes Ca2+ uptake into the SR. In contrast to PLN and SLN, which are expressed in cardiac and slow skeletal muscle in mice, MLN is robustly expressed in all skeletal muscle. Genetic deletion of MLN in mice enhances Ca2+ handling in skeletal muscle and improves exercise performance. These findings identify MLN as an important regulator of skeletal muscle physiology and highlight the possibility that additional micropeptides are encoded in the many RNAs currently annotated as non-coding. PMID:25640239

  6. Inlet-Compressor Analysis Performed Using Coupled Computational Fluid Dynamics Codes

    NASA Technical Reports Server (NTRS)

    Cole, Gary L.; Suresh, Ambady; Townsend, Scott

    1999-01-01

    A thorough understanding of dynamic interactions between inlets and compressors is extremely important to the design and development of propulsion control systems, particularly for supersonic aircraft such as the High-Speed Civil Transport (HSCT). Computational fluid dynamics (CFD) codes are routinely used to analyze individual propulsion components. By coupling the appropriate CFD component codes, it is possible to investigate inlet-compressor interactions. The objectives of this work were to gain a better understanding of inlet-compressor interaction physics, formulate a more realistic compressor-face boundary condition for time-accurate CFD simulations of inlets, and to take a first step toward the CFD simulation of an entire engine by coupling multidimensional component codes. This work was conducted at the NASA Lewis Research Center by a team of civil servants and support service contractors as part of the High Performance Computing and Communications Program (HPCCP).

  7. Electric field-treated MEAs for improved fuel cell performance

    NASA Astrophysics Data System (ADS)

    Wang, Zhi-Tao; Wang, Yu-Xin; Xu, Li; Gao, Qi-Jun; Wei, Guo-Qiang; Lu, Jun

    In this paper, electric field assisted fabrication of membrane electrode assemblies (MEAs) for fuel cells is proposed, with the aim of improving the electronic and ionic connections in the catalyst layers and increasing the efficiency of catalyst utilization. Anodic and cathodic electrodes have been prepared by the perpendicular application of a low-frequency ac electric field to the catalyst ink spread on the surface of a gas diffusion layer (GDL) while the ink is drying. The thus prepared electrodes were hot-pressed onto a Nafion membrane to form the MEAs. Direct methanol fuel cells (DMFCs) with the electric field-treated MEAs (E-MEA) showed a substantial improvement in performance as compared with common MEAs (C-MEA) without electric field treatment. Under the same operating conditions, the maximum power density of a DMFC was increased from 42.3 to 60.0 mW cm -2 when a C-MEA was replaced by an E-MEA treated with a 5000 V cm -1 and 0.1 Hz ac electric field. Electrochemical impedance spectroscopy (EIS) measurements have shown that the through-plane ohmic resistances in the E-MEAs are lower than that in the C-MEA, while both the electronic and ionic resistances of the catalyst layer in the in-plane direction are higher for the E-MEAs, suggesting the formation of an oriented structure in the catalyst layers under the electric field treatment. EIS measurements have also shown that both the total reaction resistance and the anode reaction resistance in the E-MEAs are lower than in the C-MEA. Based on cyclic voltammetry (CV) data, it has been shown that Pt utilization in the cathode reaches a maximum of 62% for the E-MEA, as opposed to 37% for the C-MEA.

  8. Improvement of BER performance in MIMO-CDMA systems by using initial-phase optimized gold codes

    NASA Astrophysics Data System (ADS)

    Develi, Ibrahim; Filiz, Meryem

    2013-01-01

    This paper describes a new approach to improve the bit error rate (BER) performance of a multiple-input multiple-output code-division multiple-access (MIMO-CDMA) system over quasi-static Rayleigh fading channels. The system considered employs robust space-time successive interference cancellation detectors and initial-phase optimized Gold codes for the improvement. The results clearly indicate that the use of initial-phase optimized Gold codes can significantly improve the BER performance of the system compared to the performance of a multiuser MIMO-CDMA system with conventional nonoptimized Gold codes. Furthermore, this performance improvement is achieved without any increase in system complexity.

  9. Users manual and modeling improvements for axial turbine design and performance computer code TD2-2

    NASA Technical Reports Server (NTRS)

    Glassman, Arthur J.

    1992-01-01

    Computer code TD2 computes design point velocity diagrams and performance for multistage, multishaft, cooled or uncooled, axial flow turbines. This streamline analysis code was recently modified to upgrade modeling related to turbine cooling and to the internal loss correlation. These modifications are presented in this report along with descriptions of the code's expanded input and output. This report serves as the users manual for the upgraded code, which is named TD2-2.

  10. The grout/glass performance assessment code system (GPACS) with verification and benchmarking

    SciTech Connect

    Piepho, M.G.; Sutherland, W.H.; Rittmann, P.D.

    1994-12-01

    GPACS is a computer code system for calculating water flow (unsaturated or saturated), solute transport, and human doses due to the slow release of contaminants from a waste form (in particular grout or glass) through an engineered system and through a vadose zone to an aquifer, well and river. This dual-purpose document is intended to serve as a user`s guide and verification/benchmark document for the Grout/Glass Performance Assessment Code system (GPACS). GPACS can be used for low-level-waste (LLW) Glass Performance Assessment and many other applications including other low-level-waste performance assessments and risk assessments. Based on all the cses presented, GPACS is adequate (verified) for calculating water flow and contaminant transport in unsaturated-zone sediments and for calculating human doses via the groundwater pathway.

  11. Testing and Performance Analysis of the Multichannel Error Correction Code Decoder

    NASA Technical Reports Server (NTRS)

    Soni, Nitin J.

    1996-01-01

    This report provides the test results and performance analysis of the multichannel error correction code decoder (MED) system for a regenerative satellite with asynchronous, frequency-division multiple access (FDMA) uplink channels. It discusses the system performance relative to various critical parameters: the coding length, data pattern, unique word value, unique word threshold, and adjacent-channel interference. Testing was performed under laboratory conditions and used a computer control interface with specifically developed control software to vary these parameters. Needed technologies - the high-speed Bose Chaudhuri-Hocquenghem (BCH) codec from Harris Corporation and the TRW multichannel demultiplexer/demodulator (MCDD) - were fully integrated into the mesh very small aperture terminal (VSAT) onboard processing architecture and were demonstrated.

  12. Using a multifrontal sparse solver in a high performance, finite element code

    NASA Technical Reports Server (NTRS)

    King, Scott D.; Lucas, Robert; Raefsky, Arthur

    1990-01-01

    We consider the performance of the finite element method on a vector supercomputer. The computationally intensive parts of the finite element method are typically the individual element forms and the solution of the global stiffness matrix both of which are vectorized in high performance codes. To further increase throughput, new algorithms are needed. We compare a multifrontal sparse solver to a traditional skyline solver in a finite element code on a vector supercomputer. The multifrontal solver uses the Multiple-Minimum Degree reordering heuristic to reduce the number of operations required to factor a sparse matrix and full matrix computational kernels (e.g., BLAS3) to enhance vector performance. The net result in an order-of-magnitude reduction in run time for a finite element application on one processor of a Cray X-MP.

  13. High performance optical encryption based on computational ghost imaging with QR code and compressive sensing technique

    NASA Astrophysics Data System (ADS)

    Zhao, Shengmei; Wang, Le; Liang, Wenqiang; Cheng, Weiwen; Gong, Longyan

    2015-10-01

    In this paper, we propose a high performance optical encryption (OE) scheme based on computational ghost imaging (GI) with QR code and compressive sensing (CS) technique, named QR-CGI-OE scheme. N random phase screens, generated by Alice, is a secret key and be shared with its authorized user, Bob. The information is first encoded by Alice with QR code, and the QR-coded image is then encrypted with the aid of computational ghost imaging optical system. Here, measurement results from the GI optical system's bucket detector are the encrypted information and be transmitted to Bob. With the key, Bob decrypts the encrypted information to obtain the QR-coded image with GI and CS techniques, and further recovers the information by QR decoding. The experimental and numerical simulated results show that the authorized users can recover completely the original image, whereas the eavesdroppers can not acquire any information about the image even the eavesdropping ratio (ER) is up to 60% at the given measurement times. For the proposed scheme, the number of bits sent from Alice to Bob are reduced considerably and the robustness is enhanced significantly. Meantime, the measurement times in GI system is reduced and the quality of the reconstructed QR-coded image is improved.

  14. Use of FEC coding to improve statistical multiplexing performance for video transport over ATM networks

    NASA Astrophysics Data System (ADS)

    Kurceren, Ragip; Modestino, James W.

    1998-12-01

    The use of forward error-control (FEC) coding, possibly in conjunction with ARQ techniques, has emerged as a promising approach for video transport over ATM networks for cell-loss recovery and/or bit error correction, such as might be required for wireless links. Although FEC provides cell-loss recovery capabilities it also introduces transmission overhead which can possibly cause additional cell losses. A methodology is described to maximize the number of video sources multiplexed at a given quality of service (QoS), measured in terms of decoded cell loss probability, using interlaced FEC codes. The transport channel is modelled as a block interference channel (BIC) and the multiplexer as single server, deterministic service, finite buffer supporting N users. Based upon an information-theoretic characterization of the BIC and large deviation bounds on the buffer overflow probability, the described methodology provides theoretically achievable upper limits on the number of sources multiplexed. Performance of specific coding techniques using interlaced nonbinary Reed-Solomon (RS) codes and binary rate-compatible punctured convolutional (RCPC) codes is illustrated.

  15. Carbon Material Optimized Biocathode for Improving Microbial Fuel Cell Performance

    PubMed Central

    Tursun, Hairti; Liu, Rui; Li, Jing; Abro, Rashid; Wang, Xiaohui; Gao, Yanmei; Li, Yuan

    2016-01-01

    To improve the performance of microbial fuel cells (MFCs), the biocathode electrode material of double-chamber was optimized. Alongside the basic carbon fiber brush, three carbon materials namely graphite granules, activated carbon granules (ACG) and activated carbon powder, were added to the cathode-chambers to improve power generation. The result shows that the addition of carbon materials increased the amount of available electroactive microbes on the electrode surface and thus promote oxygen reduction rate, which improved the generation performance of the MFCs. The Output current (external resistance = 1000 Ω) greatly increased after addition of the three carbon materials and maximum power densities in current stable phase increased by 47.4, 166.1, and 33.5%, respectively. Additionally, coulombic efficiencies of the MFC increased by 16.3, 64.3, and 20.1%, respectively. These results show that MFC when optimized with ACG show better power generation, higher chemical oxygen demands removal rate and coulombic efficiency. PMID:26858695

  16. Carbon Material Optimized Biocathode for Improving Microbial Fuel Cell Performance.

    PubMed

    Tursun, Hairti; Liu, Rui; Li, Jing; Abro, Rashid; Wang, Xiaohui; Gao, Yanmei; Li, Yuan

    2016-01-01

    To improve the performance of microbial fuel cells (MFCs), the biocathode electrode material of double-chamber was optimized. Alongside the basic carbon fiber brush, three carbon materials namely graphite granules, activated carbon granules (ACG) and activated carbon powder, were added to the cathode-chambers to improve power generation. The result shows that the addition of carbon materials increased the amount of available electroactive microbes on the electrode surface and thus promote oxygen reduction rate, which improved the generation performance of the MFCs. The Output current (external resistance = 1000 Ω) greatly increased after addition of the three carbon materials and maximum power densities in current stable phase increased by 47.4, 166.1, and 33.5%, respectively. Additionally, coulombic efficiencies of the MFC increased by 16.3, 64.3, and 20.1%, respectively. These results show that MFC when optimized with ACG show better power generation, higher chemical oxygen demands removal rate and coulombic efficiency. PMID:26858695

  17. Investigating Microbial Fuel Cell Bioanode Performance Under Different Cathode Conditions

    SciTech Connect

    Borole, Abhijeet P; Hamilton, Choo Yieng; Aaron, D; Tsouris, Costas

    2009-01-01

    A compact, three-in-one, flow-through, porous, electrode design with minimal electrode spacing and minimal dead volume was implemented to develop a microbial fuel cell (MFC) with improved anode performance. A biofilm-dominated anode consortium enriched under a multimode, continuous-flow regime was used. The increase in the power density of the MFC was investigated by changing the cathode (type, as well as catholyte strength) to determine whether anode was limiting. The power density obtained with an air-breathing cathode was 56 W/m3 of net anode volume (590 mW/m2) and 203 W/m3 (2160 mW/m2) with a 50-mM ferricyanide- based cathode. Increasing the ferricyanide concentration and ionic strength further increased the power density, reaching 304 W/m3 (3220 mW/m2, with 200 mM ferricyanide and 200 mM buffer concentration). The increasing trend in the power density indicated that the anode was not limiting and that higher power densities could be obtained using cathodes capable of higher rates of oxidation. The internal solution resistance for the MFC was 5 6 X, which supported the improved performance of the anode design. A new parameter defined as the ratio of projected surface area to total anode volume is suggested as a design parameter to relate volumetric and area-based power densities and to enable comparison of various MFC configurations.

  18. Performance Engineering: Understanding and Improving thePerformance of Large-Scale Codes

    SciTech Connect

    Bailey, David H.; Lucas, Robert; Hovland, Paul; Norris, Boyana; Yelick, Kathy; Gunter, Dan; de Supinski, Bronis; Quinlan, Dan; Worley,Pat; Vetter, Jeff; Roth, Phil; Mellor-Crummey, John; Snavely, Allan; Hollingsworth, Jeff; Reed, Dan; Fowler, Rob; Zhang, Ying; Hall, Mary; Chame, Jacque; Dongarra, Jack; Moore, Shirley

    2007-10-01

    Achieving good performance on high-end computing systems is growing ever more challenging due to enormous scale, increasing architectural complexity, and increasing application complexity. To address these challenges in DOE's SciDAC-2 program, the Performance Engineering Research Institute (PERI) has embarked on an ambitious research plan encompassing performance modeling and prediction, automatic performance optimization and performance engineering of high profile applications. The principal new component is a research activity in automatic tuning software, which is spurred by the strong user preference for automatic tools.

  19. Phosphoric acid fuel cell power plant system performance model and computer program

    NASA Technical Reports Server (NTRS)

    Alkasab, K. A.; Lu, C. Y.

    1984-01-01

    A FORTRAN computer program was developed for analyzing the performance of phosphoric acid fuel cell power plant systems. Energy mass and electrochemical analysis in the reformer, the shaft converters, the heat exchangers, and the fuel cell stack were combined to develop a mathematical model for the power plant for both atmospheric and pressurized conditions, and for several commercial fuels.

  20. Performance and fuel-cycle cost analysis of one JANUS 30 conceptual design for several fuel-element-design options

    SciTech Connect

    Nurdin, M.; Matos, J.E.; Freese, K.E.

    1982-01-01

    The performance and fuel cycle costs for a 25 MW, JANUS 30 reactor conceptual design by INTERATOM, Federal Republic of Germany, for BATAN, Republic of Indonesia have been studied using 19.75% enriched uranium in four fuel element design options. All of these fuel element designs have either been proposed by INTERATOM for various reactors or are currently in use with 93% enriched uranium in reactors in the Federal Republic of Germany. Aluminide, oxide, and silicide fuels were studied for selected designs using the range of uranium densities that are either currently qualified or are being developed and demonstrated internationally. To assess the long-term fuel adaptation strategy as well as the present fuel acceptance, reactor performance and annual fuel cycle costs were computed for seventeen cases based on a representative end-of-cycle excess reactivity and duty factor. In addition, a study was made to provide data for evaluating the trade-off between the increased safety associated with thicker cladding and the economic penalty due to increased fuel consumption.

  1. Final Report - Effects of Impurities on Fuel Cell Performance and Durability

    SciTech Connect

    Trent Molter

    2012-08-18

    This program is focused on the experimental determination of the effects of key hydrogen side impurities on the performance of PEM fuel cells. Experimental data has been leveraged to create mathematical models that predict the performance of PEM fuel cells that are exposed to specific impurity streams. These models are validated through laboratory experimentation and utilized to develop novel technologies for mitigating the effects of contamination on fuel cell performance. Results are publicly disseminated through papers, conference presentations, and other means.

  2. 40 CFR 63.11220 - When must I conduct subsequent performance tests or fuel analyses?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... performance tests or fuel analyses? 63.11220 Section 63.11220 Protection of Environment ENVIRONMENTAL... When must I conduct subsequent performance tests or fuel analyses? (a) If your boiler has a heat input... performance (stack) tests according to § 63.11212 on a triennial basis, except as specified in paragraphs...

  3. VINE-A NUMERICAL CODE FOR SIMULATING ASTROPHYSICAL SYSTEMS USING PARTICLES. II. IMPLEMENTATION AND PERFORMANCE CHARACTERISTICS

    SciTech Connect

    Nelson, Andrew F.; Wetzstein, M.; Naab, T.

    2009-10-01

    We continue our presentation of VINE. In this paper, we begin with a description of relevant architectural properties of the serial and shared memory parallel computers on which VINE is intended to run, and describe their influences on the design of the code itself. We continue with a detailed description of a number of optimizations made to the layout of the particle data in memory and to our implementation of a binary tree used to access that data for use in gravitational force calculations and searches for smoothed particle hydrodynamics (SPH) neighbor particles. We describe the modifications to the code necessary to obtain forces efficiently from special purpose 'GRAPE' hardware, the interfaces required to allow transparent substitution of those forces in the code instead of those obtained from the tree, and the modifications necessary to use both tree and GRAPE together as a fused GRAPE/tree combination. We conclude with an extensive series of performance tests, which demonstrate that the code can be run efficiently and without modification in serial on small workstations or in parallel using the OpenMP compiler directives on large-scale, shared memory parallel machines. We analyze the effects of the code optimizations and estimate that they improve its overall performance by more than an order of magnitude over that obtained by many other tree codes. Scaled parallel performance of the gravity and SPH calculations, together the most costly components of most simulations, is nearly linear up to at least 120 processors on moderate sized test problems using the Origin 3000 architecture, and to the maximum machine sizes available to us on several other architectures. At similar accuracy, performance of VINE, used in GRAPE-tree mode, is approximately a factor 2 slower than that of VINE, used in host-only mode. Further optimizations of the GRAPE/host communications could improve the speed by as much as a factor of 3, but have not yet been implemented in VINE

  4. Performance of a parallel code for the Euler equations on hypercube computers

    NASA Technical Reports Server (NTRS)

    Barszcz, Eric; Chan, Tony F.; Jesperson, Dennis C.; Tuminaro, Raymond S.

    1990-01-01

    The performance of hypercubes were evaluated on a computational fluid dynamics problem and the parallel environment issues were considered that must be addressed, such as algorithm changes, implementation choices, programming effort, and programming environment. The evaluation focuses on a widely used fluid dynamics code, FLO52, which solves the two dimensional steady Euler equations describing flow around the airfoil. The code development experience is described, including interacting with the operating system, utilizing the message-passing communication system, and code modifications necessary to increase parallel efficiency. Results from two hypercube parallel computers (a 16-node iPSC/2, and a 512-node NCUBE/ten) are discussed and compared. In addition, a mathematical model of the execution time was developed as a function of several machine and algorithm parameters. This model accurately predicts the actual run times obtained and is used to explore the performance of the code in interesting but yet physically realizable regions of the parameter space. Based on this model, predictions about future hypercubes are made.

  5. High Performance Fuel Cell and Electrolyzer Membrane Electrode Assemblies (MEAs) for Space Energy Storage Systems

    NASA Technical Reports Server (NTRS)

    Valdez, Thomas I.; Billings, Keith J.; Kisor, Adam; Bennett, William R.; Jakupca, Ian J.; Burke, Kenneth; Hoberecht, Mark A.

    2012-01-01

    Regenerative fuel cells provide a pathway to energy storage system development that are game changers for NASA missions. The fuel cell/ electrolysis MEA performance requirements 0.92 V/ 1.44 V at 200 mA/cm2 can be met. Fuel Cell MEAs have been incorporated into advanced NFT stacks. Electrolyzer stack development in progress. Fuel Cell MEA performance is a strong function of membrane selection, membrane selection will be driven by durability requirements. Electrolyzer MEA performance is catalysts driven, catalyst selection will be driven by durability requirements. Round Trip Efficiency, based on a cell performance, is approximately 65%.

  6. Effects of fuel nozzle design on performance of an experimental annular combustor using natural gas fuel

    NASA Technical Reports Server (NTRS)

    Wear, J. D.; Schultz, D. F.

    1972-01-01

    Tests of various fuel nozzles were conducted with natural gas fuel in a full-annulus combustor. The nozzles were designed to provide either axial, angled, or radial fuel injection. Each fuel nozzle was evaluated by measuring combustion efficiency at relatively severe combustor operating conditions. Combustor blowout and altitude ignition tests were also used to evaluate nozzle designs. Results indicate that angled injection gave higher combustion efficiency, less tendency toward combustion instability, and altitude relight characteristics equal to or superior to those of the other fuel nozzles that were tested.

  7. An in-pile testing program to study the performance characteristics of coated particle fuels

    SciTech Connect

    Wright, S.A. )

    1993-01-15

    Sandia National Laboratories is actively involved in testing coated particle nuclear fuels for the Space Nuclear Thermal Propulsion (SNTP) program managed by Phillips Laboratory. The testing program integrates the results of numerous in-pile and out-of-pile tests with modeling efforts to qualify fuel and fuel elements for the SNTP program. This paper briefly describes the capabilities of the Annular Core Research Reactor (in which the experiments are performed), the major in-pile tests, and the models used to determine the performance characteristics of the fuel and fuel elements.

  8. An in-pile testing program to study the performance characteristics of coated particle fuels

    SciTech Connect

    Wright, S.A.

    1992-01-01

    Sandia National Laboratories is actively involved in testing coated particle nuclear fuels for the Space Nuclear Thermal Propulsion (SNTP) program managed by Phillips Laboratory. The testing program integrates the results of numerous in-pile and out-of-pile tests with modeling efforts to qualify fuel and fuel elements for the SNTP program. This paper briefly describes the capabilities of the Annular Core Research Reactor (in which the experiments are performed), the major in-pile tests, and the models used to determine the performance characteristics of the fuel and fuel elements. 6 refs.

  9. Some methods for achieving more efficient performance of fuel assemblies

    NASA Astrophysics Data System (ADS)

    Boltenko, E. A.

    2014-07-01

    More efficient operation of reactor plant fuel assemblies can be achieved through the use of new technical solutions aimed at obtaining more uniform distribution of coolant over the fuel assembly section, more intense heat removal on convex heat-transfer surfaces, and higher values of departure from nucleate boiling ratio (DNBR). Technical solutions using which it is possible to obtain more intense heat removal on convex heat-transfer surfaces and higher DNBR values in reactor plant fuel assemblies are considered. An alternative heat removal arrangement is described using which it is possible to obtain a significantly higher power density in a reactor plant and essentially lower maximal fuel rod temperature.

  10. Performance of breached LMFBR fuel pins during continued operation

    SciTech Connect

    Lambert, J.D.B.; Strain, R.V.; Gross, K.C.; Hofman, G.L.; Colburn, R.P.; Adamson, M.G.; Ukai, S.

    1985-01-01

    Four EBR-II tests were used to scope the behavior of breached mixed-oxide pins. After release of stored fission gas, delayed-neutron signals were large and easily detected, although not readily correlated with exposed fuel area. No problems were met during reactor operation or fuel handling. Fuel-sodium reaction caused only narrow breaches which released minute amounts of fuel and fission products; the reaction product appeared dense and non-friable. These initial results indicated LMFBR oxide pins could have considerable potential for operating in the breached mode.

  11. Effect of carbon coating on scuffing performance in diesel fuels

    SciTech Connect

    Ajayi, O. O.; Alzoubi, M. F.; Erdemir, A.; Fenske, G. R.

    2000-06-29

    Low-sulfur and low-aromatic diesel fuels are being introduced in order to reduce various types of emissions in diesel engines to levels in compliance with current and impending US federal regulations. The low lubricity of these fuels, however, poses major reliability and durability problems for fuel injection components that depend on diesel fuel for their lubrication. In the present study, the authors evaluated the scuff resistance of surfaces in regular diesel fuel containing 500 ppm sulfur and in Fischer-Tropsch synthetic diesel fuel containing no sulfur or aromatics. Tests were conducted with the high frequency reciprocating test rig (HFRR) using 52100 steel balls and H-13 tool-steel flats with and without Argonne's special carbon coatings. Test results showed that the sulfur-containing fuels provide about 20% higher scuffing resistance than does fuel without sulfur. Use of the carbon coating on the flat increased scuffing resistance in both regular and synthetic fuels by about ten times, as measured by the contact severity index at scuffing. Scuffing failure in tests conducted with coated surfaces did not occur until the coating had been removed by the two distinct mechanisms of spalling and wear.

  12. Irradiation performance of HTGR fuel rods in HFIR experiments HRB-11 and -12

    SciTech Connect

    Homan, F.J.; Tiegs, T.N.; Kania, M.J.; Long, E.L. Jr.; Thoms, K.R.; Robbins, J.M.; Wagner, P.

    1980-06-01

    Capsules HRB-11 and -12 were irradiated in support of development of weak-acid-resin-derived recycle fuel for the high-enriched uranium (HEU) fuel cycle for the HTGR. Fissil fuel particles with initial oxygen-to-metal ratios between 1.0 and 1.7 performed acceptably to full burnup for HEU fuel. Particles with ratios below 1.0 showed excessive chemical interaction between rare earth fission products and the SiC layer.

  13. Summary of Code Barriers:Summary of Code and Standard Barriers to the Implementation of High Performance Home Systems Designs

    SciTech Connect

    2009-12-01

    Building codes serve to ensure minimum requirements for safety, durability, and energy efficiency of homes.To enable innovation and to support continual improvement, building codes are updated on a 2-3 year basis to (1) include new methods of and/or materials for construction and (2), where needed, revise the current methods of construction to better meet the intent of the code. This report discusses issues of wind pressure resistance in walls with exterior rigid foam sheathing installed directly over framing members.

  14. The coupling of the neutron transport application RATTLESNAKE to the nuclear fuels performance application BISON under the MOOSE framework

    SciTech Connect

    Gleicher, Frederick N.; Williamson, Richard L.; Ortensi, Javier; Wang, Yaqi; Spencer, Benjamin W.; Novascone, Stephen R.; Hales, Jason D.; Martineau, Richard C.

    2014-10-01

    The MOOSE neutron transport application RATTLESNAKE was coupled to the fuels performance application BISON to provide a higher fidelity tool for fuel performance simulation. This project is motivated by the desire to couple a high fidelity core analysis program (based on the self-adjoint angular flux equations) to a high fidelity fuel performance program, both of which can simulate on unstructured meshes. RATTLESNAKE solves self-adjoint angular flux transport equation and provides a sub-pin level resolution of the multigroup neutron flux with resonance treatment during burnup or a fast transient. BISON solves the coupled thermomechanical equations for the fuel on a sub-millimeter scale. Both applications are able to solve their respective systems on aligned and unaligned unstructured finite element meshes. The power density and local burnup was transferred from RATTLESNAKE to BISON with the MOOSE Multiapp transfer system. Multiple depletion cases were run with one-way data transfer from RATTLESNAKE to BISON. The eigenvalues are shown to agree well with values obtained from the lattice physics code DRAGON. The one-way data transfer of power density is shown to agree with the power density obtained from an internal Lassman-style model in BISON.

  15. Performance of low smeared density sodium-cooled fast reactor metal fuel

    SciTech Connect

    Porter, D. L.; H. J. M. Chichester; Medvedev, P. G.; Hayes, S. L.; Teague, M. C.

    2015-06-17

    An experiment was performed in the Experimental Breeder Rector-II (EBR-II) in the 1990s to show that metallic fast reactor fuel could be used in reactors with a single, once-through core. To prove the long duration, high burnup, high neutron exposure capability an experiment where the fuel pin was designed with a very large fission gas plenum and very low fuel smeared density (SD). The experiment, X496, operated to only 8.3 at. % burnup because the EBR-II reactor was scheduled for shut-down at that time. Many of the examinations of the fuel pins only funded recently with the resurgence of reactor designs using very high-burnup fuel. The results showed that, despite the low smeared density of 59% the fuel swelled radially to contact the cladding, fission gas release appeared to be slightly higher than demonstrated in conventional 75%SD fuel tests and axial growth was about the same as 75% SD fuel. There were axial positions in some of the fuel pins which showed evidence of fuel restructuring and an absence of fission products with low metaling points and gaseous precursors (Cs and Rb). Lastly, a model to investigate whether these areas may have overheated due to a loss of bond sodium indicates that it is a possible explanation for the fuel restructuring and something to be considered for fuel performance modeling of low SD fuel.

  16. Performance of low smeared density sodium-cooled fast reactor metal fuel

    NASA Astrophysics Data System (ADS)

    Porter, D. L.; Chichester, H. J. M.; Medvedev, P. G.; Hayes, S. L.; Teague, M. C.

    2015-10-01

    An experiment was performed in the Experimental Breeder Rector-II (EBR-II) in the 1990s to show that metallic fast reactor fuel could be used in reactors with a single, once-through core. To prove the long duration, high burnup, high neutron exposure capability an experiment where the fuel pin was designed with a very large fission gas plenum and very low fuel smeared density (SD). The experiment, X496, operated to only 8.3 at.% burnup because the EBR-II reactor was scheduled for shut-down at that time. Many of the examinations of the fuel pins only funded recently with the resurgence of reactor designs using very high-burnup fuel. The results showed that, despite the low smeared density of 59% the fuel swelled radially to contact the cladding, fission gas release appeared to be slightly higher than demonstrated in conventional 75%SD fuel tests and axial growth was about the same as 75% SD fuel. There were axial positions in some of the fuel pins which showed evidence of fuel restructuring and an absence of fission products with low melting points and gaseous precursors (Cs and Rb). A model to investigate whether these areas may have overheated due to a loss of bond sodium indicates that it is a possible explanation for the fuel restructuring and something to be considered for fuel performance modeling of low SD fuel.

  17. Performance of Low Smeared Density Sodium-cooled Fast Reactor Metal Fuel

    SciTech Connect

    Porter, D. L.; H. J. M. Chichester; Medvedev, P. G.; Hayes, S. L.; Teague, M. C.

    2015-10-01

    An experiment was performed in the Experimental Breeder Rector-II (EBR-II) in the 1990s to show that metallic fast reactor fuel could be used in reactors with a single, once-through core. To prove the long duration, high burnup, high neutron exposure capability an experiment where the fuel pin was designed with a very large fission gas plenum and very low fuel smeared density (SD). The experiment, X496, operated to only 8.3 at. % burnup because the EBR-II reactor was scheduled for shut-down at that time. Many of the examinations of the fuel pins only funded recently with the resurgence of reactor designs using very high-burnup fuel. The results showed that, despite the low smeared density of 59% the fuel swelled radially to contact the cladding, fission gas release appeared to be slightly higher than demonstrated in conventional 75%SD fuel tests and axial growth was about the same as 75% SD fuel. There were axial positions in some of the fuel pins which showed evidence of fuel restructuring and an absence of fission products with low metaling points and gaseous precursors (Cs and Rb). A model to investigate whether these areas may have overheated due to a loss of bond sodium indicates that it is a possible explanation for the fuel restructuring and something to be considered for fuel performance modeling of low SD fuel.

  18. Performance of low smeared density sodium-cooled fast reactor metal fuel

    DOE PAGESBeta

    Porter, D. L.; H. J. M. Chichester; Medvedev, P. G.; Hayes, S. L.; Teague, M. C.

    2015-06-17

    An experiment was performed in the Experimental Breeder Rector-II (EBR-II) in the 1990s to show that metallic fast reactor fuel could be used in reactors with a single, once-through core. To prove the long duration, high burnup, high neutron exposure capability an experiment where the fuel pin was designed with a very large fission gas plenum and very low fuel smeared density (SD). The experiment, X496, operated to only 8.3 at. % burnup because the EBR-II reactor was scheduled for shut-down at that time. Many of the examinations of the fuel pins only funded recently with the resurgence of reactormore » designs using very high-burnup fuel. The results showed that, despite the low smeared density of 59% the fuel swelled radially to contact the cladding, fission gas release appeared to be slightly higher than demonstrated in conventional 75%SD fuel tests and axial growth was about the same as 75% SD fuel. There were axial positions in some of the fuel pins which showed evidence of fuel restructuring and an absence of fission products with low metaling points and gaseous precursors (Cs and Rb). Lastly, a model to investigate whether these areas may have overheated due to a loss of bond sodium indicates that it is a possible explanation for the fuel restructuring and something to be considered for fuel performance modeling of low SD fuel.« less

  19. Performance Evaluation and Optimization of Diesel Fuel Properties and Chemistry in an HCCI Engine

    SciTech Connect

    Bunting, Bruce G; Eaton, Scott J; Crawford, Robert W

    2009-01-01

    The nine CRC fuels for advanced combustion engines (FACE fuels) have been evaluated in a simple, premixed HCCI engine under varying conditions of fuel rate, air-fuel ratio, and intake temperature. Engine performance was found to vary mainly as a function of combustion phasing as affected by fuel cetane and engine control variables. The data was modeled using statistical techniques involving eigenvector representation of the fuel properties and engine control variables, to define engine response and allow optimization across the fuels for best fuel efficiency. In general, the independent manipulation of intake temperature and air-fuel ratio provided some opportunity for improving combustion efficiency of a specific fuel beyond the direct effect of targeting the optimum combustion phasing of the engine (near 5 CAD ATDC). High cetane fuels suffer performance loss due to easier ignition, resulting in lower intake temperatures, which increase HC and CO emissions and result in the need for more advanced combustion phasing. The FACE fuels also varied in T90 temperature and % aromatics, independent of cetane number. T90 temperature was found to have an effect on engine performance when combined with high centane, but % aromatics did not, when evaluated independently of cetane and T90.

  20. 2-D Time-Dependent Fuel Element, Thermal Analysis Code System.

    Energy Science and Technology Software Center (ESTSC)

    2001-09-24

    Version 00 WREM-TOODEE2 is a two dimensional, time-dependent, fuel-element thermal analysis program. Its primary purpose is to evaluate fuel-element thermal response during post-LOCA refill and reflood in a pressurized water reactor (PWR). TOODEE2 calculations are carried out in a two-dimensional mesh region defined in slab or cylindrical geometry by orthogonal grid lines. Coordinates which form order pairs are labeled x-y in slab geometry, and those in cylindrical geometry are labeled r-z for the axisymmetric casemore » and r-theta for the polar case. Conduction and radiation are the only heat transfer mechanisms assumed within the boundaries of the mesh region. Convective and boiling heat transfer mechanisms are assumed at the boundaries. The program numerically solves the two-dimensional, time-dependent, heat conduction equation within the mesh region. KEYWORDS: FUEL MANAGEMENT; HEAT TRANSFER; LOCA; PWR« less

  1. The impact of pulsed RFI on the coded BER performance of the nonlinear satellite communication channel

    NASA Technical Reports Server (NTRS)

    Weinberg, A.

    1980-01-01

    Communication links from low orbiting spacecraft to a central ground station, via satellite repeater, may be susceptible to significant performance degradation if high-level, pulsed radio frequency interference (RFI) must be contended with. The present paper examines the coded bit error rate (BER) performance of a communication system in which BPSK modulation is employed, pulsed CW or pulsed noise RFI is present, and the transponder contains a nonlinearity characterized by arbitrary AM/AM and AM/PM characteristics. A major result of this paper is an analytic method for determining soft decision statistics of the receiver demodulator output, in which pulsed RFI effects are accounted for. It is demonstrated that this result can be analytically applied to the approximate determination of the BER at the output of a Viterbi decoder, when convolutional coding is employed.

  2. Perform Thermodynamics Measurements on Fuel Cycle Case Study Systems

    SciTech Connect

    Leigh R. Martin

    2014-09-01

    This document was prepared to meet FCR&D level 3 milestone M3FT-14IN0304022, “Perform Thermodynamics Measurements on Fuel Cycle Case Study Systems.” This work was carried out under the auspices of the Thermodynamics and Kinetics FCR&D work package. This document reports preliminary work in support of determining the thermodynamic parameters for the ALSEP process. The ALSEP process is a mixed extractant system comprised of a cation exchanger 2-ethylhexyl-phosphonic acid mono-2-ethylhexyl ester (HEH[EHP]) and a neutral solvating extractant N,N,N’,N’-tetraoctyldiglycolamide (TODGA). The extractant combination produces complex organic phase chemistry that is challenging for traditional measurement techniques. To neutralize the complexity, temperature dependent solvent extraction experiments were conducted with neat TODGA and scaled down concentrations of the ALSEP formulation to determine the enthalpies of extraction for the two conditions. A full set of thermodynamic data for Eu, Am, and Cm extraction by TODGA from 3.0 M HNO3 is reported. These data are compared to previous extraction results from a 1.0 M HNO3 aqueous medium, and a short discussion of the mixed HEH[EHP]/TODGA system results is offered.

  3. Performance Characteristics of the Methane Fueled Rocket Nozzles

    NASA Astrophysics Data System (ADS)

    Ito, Takashi; Miyajima, Hiroshi

    Performance of the methane fueled rocket nozzles are numerically investigated using computational fluid dynamics approach. A simple set of chemical reactions and kinetics for methane/oxygen nozzle flow is proposed. The chamber pressure, mixture ratio and size of the nozzle are parametrically changed to study the influence of characteristic rocket engine design parameters on nozzle losses. The amount of dissociation is high when the chamber pressure is low and the kinetic loss becomes dominant compared to the other nozzle losses. The peak specific impulse is achieved at a higher mixture ratio region as the chamber pressure increases. The chemical non-equilibrium flow appears mainly at down stream region of the nozzle throat. The influence of the chemical non-equilibrium effect decreases as the chamber pressure increases. Supersonic chemically reactive gas stays longer in the nozzle as the size of the nozzle become larger and the amount of recombination increases which decreases the kinetic loss. When the chamber pressure is high, the kinetic loss becomes small and the effect of the size of nozzle also becomes small.

  4. Performance of HT9 clad metallic fuel at high temperature

    SciTech Connect

    Pahl, R.G.; Lahm, C.E.; Hayes, S.L.

    1992-12-01

    Steady-state testing of HT9 clad metallic fuel at high temperatures was initiated in EBR-II in November of 1987. At that time U-10 wt. % Zr fuel clad with the low-swelling ferritic/martensitic alloy HT9 was being considered as driver fuel options for both EBR-II and FFTF. The objective of the X447 test described here was to determine the lifetime of HT9 cladding when operated with metallic fuel at beginning of life inside wall temperatures approaching {approximately}660{degree}C. Though stress-temperature design limits for HT9 preclude its use for high burnup applications under these conditions due to excessive thermal creep, the X447 test was carried out to obtain data on high temperature breach phenomena involving metallic fuel since little data existed in that area.

  5. Performance of HT9 clad metallic fuel at high temperature

    SciTech Connect

    Pahl, R.G.; Lahm, C.E.; Hayes, S.L.

    1992-01-01

    Steady-state testing of HT9 clad metallic fuel at high temperatures was initiated in EBR-II in November of 1987. At that time U-10 wt. % Zr fuel clad with the low-swelling ferritic/martensitic alloy HT9 was being considered as driver fuel options for both EBR-II and FFTF. The objective of the X447 test described here was to determine the lifetime of HT9 cladding when operated with metallic fuel at beginning of life inside wall temperatures approaching [approximately]660[degree]C. Though stress-temperature design limits for HT9 preclude its use for high burnup applications under these conditions due to excessive thermal creep, the X447 test was carried out to obtain data on high temperature breach phenomena involving metallic fuel since little data existed in that area.

  6. Effect of fuel vapor concentrations on combustor emissions and performance

    NASA Technical Reports Server (NTRS)

    Norgren, C. T.; Ingebo, R. D.

    1973-01-01

    Effects of fuel vaporization on the exhaust emission levels of oxides of nitrogen, carbon monoxide, total hydrocarbons, and smoke number were obtained in an experimental turbojet combustor segment. Two different fuel injectors were used in which liquid ASTM A-1 jet fuel and vapor propane fuel were independently controlled to simulate varying degrees of vaporization. Tests were conducted over a range of inlet-air temperatures from 478 to 700 K, pressures from 4 to 20 atm, and combustor reference velocities from 15.3 to 27.4 m/sec. Converting from liquid to complete vapor fuel resulted in oxides of nitrogen reductions of as much as 22 percent and smoke number reductions up to 51 percent. Supplement data are also presented on flame emissivity, flame temperature, and primary-zone liner wall temperatures.

  7. FUEL PERFORMANCE IMPROVEMENT PROGRAM Power-Ramp Testing and Postirradiation Examination of PCI- Resistant LWR Fuel Rod Designs

    SciTech Connect

    Barner, J. O.; Guenther, R. J.

    1982-09-01

    This report describes the power-ramp testing results from 10 fuel rods irradiated in the Halden Boiling Water Reactor (HBWR), Halden, Norway. Tne work is part of the Fuel Performance Improvement Program (FPIP), which is sponsored by the U.S. Department of Energy (DUE) and is conducted through the joint efforts of Consumers Power Company, Exxon Nuclear Company, lnc., and Pacific Northwest Laboratory. The objective of the FPlP is to identify and demonstrate fuel concepts with improved pellet-cladding interaction (PCl) behavior that will be capable of extended burnup. The postirradiation examination results obtained from one nonramped rod are also presented. The power-ramping behavior of three basic fuel rod types--rods with annular-pellet fuel, sphere-pac fuel, and dished-pellet (reference) fuel--are compared in terms of mechanisms known to promote PCl failures. The effects of graphite coating on the inside cladding surface and helium pressurization in rods witn annular fuel are also evaluated .

  8. Nuclear Energy Advanced Modeling and Simulation Waste Integrated Performance and Safety Codes (NEAMS Waste IPSC).

    SciTech Connect

    Schultz, Peter Andrew

    2011-12-01

    The objective of the U.S. Department of Energy Office of Nuclear Energy Advanced Modeling and Simulation Waste Integrated Performance and Safety Codes (NEAMS Waste IPSC) is to provide an integrated suite of computational modeling and simulation (M&S) capabilities to quantitatively assess the long-term performance of waste forms in the engineered and geologic environments of a radioactive-waste storage facility or disposal repository. Achieving the objective of modeling the performance of a disposal scenario requires describing processes involved in waste form degradation and radionuclide release at the subcontinuum scale, beginning with mechanistic descriptions of chemical reactions and chemical kinetics at the atomic scale, and upscaling into effective, validated constitutive models for input to high-fidelity continuum scale codes for coupled multiphysics simulations of release and transport. Verification and validation (V&V) is required throughout the system to establish evidence-based metrics for the level of confidence in M&S codes and capabilities, including at the subcontiunuum scale and the constitutive models they inform or generate. This Report outlines the nature of the V&V challenge at the subcontinuum scale, an approach to incorporate V&V concepts into subcontinuum scale modeling and simulation (M&S), and a plan to incrementally incorporate effective V&V into subcontinuum scale M&S destined for use in the NEAMS Waste IPSC work flow to meet requirements of quantitative confidence in the constitutive models informed by subcontinuum scale phenomena.

  9. High-performance computational fluid dynamics: a custom-code approach

    NASA Astrophysics Data System (ADS)

    Fannon, James; Loiseau, Jean-Christophe; Valluri, Prashant; Bethune, Iain; Náraigh, Lennon Ó.

    2016-07-01

    We introduce a modified and simplified version of the pre-existing fully parallelized three-dimensional Navier–Stokes flow solver known as TPLS. We demonstrate how the simplified version can be used as a pedagogical tool for the study of computational fluid dynamics (CFDs) and parallel computing. TPLS is at its heart a two-phase flow solver, and uses calls to a range of external libraries to accelerate its performance. However, in the present context we narrow the focus of the study to basic hydrodynamics and parallel computing techniques, and the code is therefore simplified and modified to simulate pressure-driven single-phase flow in a channel, using only relatively simple Fortran 90 code with MPI parallelization, but no calls to any other external libraries. The modified code is analysed in order to both validate its accuracy and investigate its scalability up to 1000 CPU cores. Simulations are performed for several benchmark cases in pressure-driven channel flow, including a turbulent simulation, wherein the turbulence is incorporated via the large-eddy simulation technique. The work may be of use to advanced undergraduate and graduate students as an introductory study in CFDs, while also providing insight for those interested in more general aspects of high-performance computing.

  10. Performance and Application of Parallel OVERFLOW Codes on Distributed and Shared Memory Platforms

    NASA Technical Reports Server (NTRS)

    Djomehri, M. Jahed; Rizk, Yehia M.

    1999-01-01

    The presentation discusses recent studies on the performance of the two parallel versions of the aerodynamics CFD code, OVERFLOW_MPI and _MLP. Developed at NASA Ames, the serial version, OVERFLOW, is a multidimensional Navier-Stokes flow solver based on overset (Chimera) grid technology. The code has recently been parallelized in two ways. One is based on the explicit message-passing interface (MPI) across processors and uses the _MPI communication package. This approach is primarily suited for distributed memory systems and workstation clusters. The second, termed the multi-level parallel (MLP) method, is simple and uses shared memory for all communications. The _MLP code is suitable on distributed-shared memory systems. For both methods, the message passing takes place across the processors or processes at the advancement of each time step. This procedure is, in effect, the Chimera boundary conditions update, which is done in an explicit "Jacobi" style. In contrast, the update in the serial code is done in more of the "Gauss-Sidel" fashion. The programming efforts for the _MPI code is more complicated than for the _MLP code; the former requires modification of the outer and some inner shells of the serial code, whereas the latter focuses only on the outer shell of the code. The _MPI version offers a great deal of flexibility in distributing grid zones across a specified number of processors in order to achieve load balancing. The approach is capable of partitioning zones across multiple processors or sending each zone and/or cluster of several zones into a single processor. The message passing across the processors consists of Chimera boundary and/or an overlap of "halo" boundary points for each partitioned zone. The MLP version is a new coarse-grain parallel concept at the zonal and intra-zonal levels. A grouping strategy is used to distribute zones into several groups forming sub-processes which will run in parallel. The total volume of grid points in each

  11. Performance characterization and transmission schemes for instantly decodable network coding in wireless broadcast

    NASA Astrophysics Data System (ADS)

    Yu, Mingchao; Sadeghi, Parastoo; Aboutorab, Neda

    2015-12-01

    We consider broadcasting a block of packets to multiple wireless receivers under random packet erasures using instantly decodable network coding (IDNC). The sender first broadcasts each packet uncoded once, then generates coded packets according to receivers' feedback about their missing packets. We focus on strict IDNC (S-IDNC), where each coded packet includes at most one missing packet of every receiver. But, we will also study its relation with generalized IDNC (G-IDNC), where this condition is relaxed. We characterize two fundamental performance limits of S-IDNC: (1) the number of transmissions to complete the broadcast, which measures throughput and (2) average packet decoding delay, which measures how fast each packet is decoded at each receiver on average. We derive a closed-form expression for the expected minimum number of transmissions in terms of the number of packets and receivers and the erasure probability. We prove that it is NP-hard to minimize the average packet decoding delay of S-IDNC. We also prove that the graph models of S- and G-IDNC share the same chromatic number. Next, we design efficient S-IDNC transmission schemes and coding algorithms with full/intermittent receiver feedback. We present simulation results to corroborate the developed theory and compare our schemes with existing ones.

  12. Performance, durability and low temperature evaluation of sunflower oil as a diesel fuel extender

    SciTech Connect

    Baranescu, R.A.; Lusco, J.J.

    1982-01-01

    The paper presents the results of a research project to evaluate performance and durability of direct injection turbocharged diesel engines using sunflower oil and blends thereof. Alcaline refined sunflower oil and three different blends of sunflower oil and diesel fuel were comparatively tested against No. 2 diesel fuel for: physical and chemical characteristics, fuel injection system performance, short term engine performance, propensity to nozzle deposits buildup, limited durability operation and low temperature starting capability. Results are presented for the various phases of the project and correlations between the fuel characteristics and engine accept-ability are discussed. 19 figures, 2 tables.

  13. NUCRAC: a code for the estimation of adversary-action consequences in the nuclear power fuel cycle

    SciTech Connect

    Kaul, D.C.; Ritzman, R.L.; Roberts, J.A.; Sachs, E.S.

    1986-02-01

    A program sponsored by the Nuclear Regulatory Commission (NRC) and designed to estimate the potential consequences of adversary actions in the nuclear power fuel cycle has been completed. So that the results of this consequence analysis would be comparable to that of the reactor Safety Study (RSS), the methodology described in the RSS and implemented in the Calculation of Reactor Accident Consequences (CRAC) code served as the baseline for consequence evaluation in this study. Four portions of the RSS methodology were modified for use in this study: the atmospheric dispersion model, the inhalation dose factors, the criterion for early mortality from lung dose, and the model for chronic pathways to man. Implementation of these modifications to the CRAC code resulted in the preparation and application of a revised code termed NUCRAC. These modifications are described in detail. Detailed instructions for the operation of NUCRAC are presented in the form of a user-manual. Inputs and outputs for an example calculation are also presented.

  14. 2004 DOE Hydrogen, Fuel Cells & Infrastructure Technologies Program Review Presentation COST AND PERFORMANCE ENHANCEMENTS FOR A PEM FUEL CELL TURBOCOMPRESSOR

    SciTech Connect

    Mark K. Gee

    2004-04-01

    The objective is to assist the Department of Energy in the development of a low cost, reliable and high performance air compressor/expander. Technical Objective 1: Perform a turbocompressor systems PEM fuel cell trade study to determine the enhanced turbocompressor approach. Technical Objective 2: Using the results from technical objective 1, an enhanced turbocompressor will be fabricated. The design may be modified to match the flow requirements of a selected fuel cell system developer. Technical Objective 3: Design a cost and performance enhanced compact motor and motor controller. Technical Objective 4: Turbocompressor/motor controller development.

  15. Effects of fuel-injector design on ultra-lean combustion performance

    NASA Technical Reports Server (NTRS)

    Anderson, D. N.

    1981-01-01

    Emissions data were obtained for six fuel injector configurations tested with ultra lean combustion. Fuel injectors included three multiple source designs and three configurations using a single air assist injector. Only the multiple source fuel injectors provided acceptable emissions. Values of 16g CO/kg fuel, 1.9g HC/kg fuel, and 19.g NO2/kg fuel were obtained for the combustion temperature range of 1450 to 1700 K for both a high blockage 19 source injector and a low blockage 41 source injector. It was shown that high fuel injector pressure drop may not be required to achieve low emissions performance at high inlet air temperature when the fuel is well dispersed in the airstream.

  16. Development of an Integrated Performance Model for TRISO-Coated Gas Reactor Particle Fuel

    SciTech Connect

    Petti, David Andrew; Miller, Gregory Kent; Martin, David George; Maki, John Thomas

    2005-05-01

    The success of gas reactors depends upon the safety and quality of the coated particle fuel. The understanding and evaluation of this fuel requires development of an integrated mechanistic fuel performance model that fully describes the mechanical and physico-chemical behavior of the fuel particle under irradiation. Such a model, called PARFUME (PARticle Fuel ModEl), is being developed at the Idaho National Engineering and Environmental Laboratory. PARFUME is based on multi-dimensional finite element modeling of TRISO-coated gas reactor fuel. The goal is to represent all potential failure mechanisms and to incorporate the statistical nature of the fuel. The model is currently focused on carbide, oxide nd oxycarbide uranium fuel kernels, while the coating layers are the classical IPyC/SiC/OPyC. This paper reviews the current status of the mechanical aspects of the model and presents results of calculations for irradiations from the New Production Modular High Temperature Gas Reactor program.

  17. Fuel performance improvement program. Semiannual progress report, April-September 1980

    SciTech Connect

    Crouthamel, C E; Freshley, M D

    1980-10-01

    Progress on the Fuel Performance Improvement Program's fuel test and demonstration irradiations is reported for the period April-September, 1980. Included are results of out-of-reactor experiments with zircaloy cladding on the iodine assisted stress corrosion cracking mechanism. Preliminary results from the first eight ramp tests performed in the Halden Boiling Water Reactor are reported. The status of demonstration fuel irradiations in the Big Rock Point Reactor is described.

  18. Performance Evaluation of a High Bandwidth Liquid Fuel Modulation Valve for Active Combustion Control

    NASA Technical Reports Server (NTRS)

    Saus, Joseph R.; DeLaat, John C.; Chang, Clarence T.; Vrnak, Daniel R.

    2012-01-01

    At the NASA Glenn Research Center, a characterization rig was designed and constructed for the purpose of evaluating high bandwidth liquid fuel modulation devices to determine their suitability for active combustion control research. Incorporated into the rig s design are features that approximate conditions similar to those that would be encountered by a candidate device if it were installed on an actual combustion research rig. The characterized dynamic performance measures obtained through testing in the rig are planned to be accurate indicators of expected performance in an actual combustion testing environment. To evaluate how well the characterization rig predicts fuel modulator dynamic performance, characterization rig data was compared with performance data for a fuel modulator candidate when the candidate was in operation during combustion testing. Specifically, the nominal and off-nominal performance data for a magnetostrictive-actuated proportional fuel modulation valve is described. Valve performance data were collected with the characterization rig configured to emulate two different combustion rig fuel feed systems. Fuel mass flows and pressures, fuel feed line lengths, and fuel injector orifice size was approximated in the characterization rig. Valve performance data were also collected with the valve modulating the fuel into the two combustor rigs. Comparison of the predicted and actual valve performance data show that when the valve is operated near its design condition the characterization rig can appropriately predict the installed performance of the valve. Improvements to the characterization rig and accompanying modeling activities are underway to more accurately predict performance, especially for the devices under development to modulate fuel into the much smaller fuel injectors anticipated in future lean-burning low-emissions aircraft engine combustors.

  19. The WISGSK: A computer code for the prediction of a multistage axial compressor performance with water ingestion

    NASA Technical Reports Server (NTRS)

    Tsuchiya, T.; Murthy, S. N. B.

    1982-01-01

    A computer code is presented for the prediction of off-design axial flow compressor performance with water ingestion. Four processes were considered to account for the aero-thermo-mechanical interactions during operation with air-water droplet mixture flow: (1) blade performance change, (2) centrifuging of water droplets, (3) heat and mass transfer process between the gaseous and the liquid phases and (4) droplet size redistribution due to break-up. Stage and compressor performance are obtained by a stage stacking procedure using representative veocity diagrams at a rotor inlet and outlet mean radii. The Code has options for performance estimation with (1) mixtures of gas and (2) gas-water droplet mixtures, and therefore can take into account the humidity present in ambient conditions. A test case illustrates the method of using the Code. The Code follows closely the methodology and architecture of the NASA-STGSTK Code for the estimation of axial-flow compressor performance with air flow.

  20. Codes & standards research, development & demonstration Roadmap

    SciTech Connect

    None, None

    2008-07-22

    This Roadmap is a guide to the Research, Development & Demonstration activities that will provide data required for SDOs to develop performance-based codes and standards for a commercial hydrogen fueled transportation sector in the U.S.

  1. Used Nuclear Fuel Loading and Structural Performance Under Normal Conditions of Transport- Demonstration of Approach and Results on Used Fuel Performance Characterization

    SciTech Connect

    Adkins, Harold; Geelhood, Ken; Koeppel, Brian; Coleman, Justin; Bignell, John; Flores, Gregg; Wang, Jy-An; Sanborn, Scott; Spears, Robert; Klymyshyn, Nick

    2013-09-30

    This document addresses Oak Ridge National Laboratory milestone M2FT-13OR0822015 Demonstration of Approach and Results on Used Nuclear Fuel Performance Characterization. This report provides results of the initial demonstration of the modeling capability developed to perform preliminary deterministic evaluations of moderate-to-high burnup used nuclear fuel (UNF) mechanical performance under normal conditions of storage (NCS) and normal conditions of transport (NCT) conditions. This report also provides results from the sensitivity studies that have been performed. Finally, discussion on the long-term goals and objectives of this initiative are provided.

  2. Diesel Fuel Sulfur Effects on the Performance of Lean NOx Catalysts

    SciTech Connect

    Ren, Shouxian

    2000-08-20

    Evaluate the effects of diesel fuel sulfur on the performance of low temperature and high temperature Lean-NOx Catalysts. Evaluate the effects of up to 250 hours of aging on the performance of the Lean-NOx Catalysts with different fuel sulfur contents.

  3. Chloride contamination effects on proton exchange membrane fuel cell performance and durability

    NASA Astrophysics Data System (ADS)

    Li, Hui; Wang, Haijiang; Qian, Weimin; Zhang, Shengsheng; Wessel, Silvia; Cheng, Tommy T. H.; Shen, Jun; Wu, Shaohong

    2011-08-01

    Chlorine is a major fuel contaminant when by-product hydrogen from the chlor-alkali industry is used as the fuel for proton exchange membrane (PEM) fuel cells. Understanding the effects of chlorine contamination on fuel cell performance and durability is essential to address fuel cell applications for the automotive and stationary markets. This paper reports our findings of chloride contamination effects on PEM fuel cell performance and durability, as our first step in understanding the effects of chlorine contamination. Fuel cell contamination tests were conducted by injecting ppm levels of contaminant into the fuel cell from either the fuel stream or the air stream. In situ and ex situ diagnosis were performed to investigate the contamination mechanisms. The results show that cell voltage during chloride contamination is characterized by an initial sudden drop followed by a plateau, regardless of which side the contaminant is introduced into the fuel cell. The drop in cell performance is predominantly due to increased cathode charge transfer resistance as a result of electrochemical catalyst surface area (ECSA) loss attributable to the blocking of active sites by Cl- and enhanced Pt dissolution.

  4. Optimizing performance of superscalar codes for a single Cray X1MSP processor

    SciTech Connect

    Shan, Hongzhang; Strohmaier, Erich; Oliker, Leonid

    2004-06-08

    The growing gap between sustained and peak performance for full-scale complex scientific applications on conventional supercomputers is a major concern in high performance computing. The recently-released vector-based Cray X1 offers to bridge this gap for many demanding scientific applications. However, this unique architecture contains both data caches and multi-streaming processing units, and the optimal programming methodology is still under investigation. In this paper we investigate Cray X1 code optimization for a suite of computational kernels originally designed for superscalar processors. For our study, we select four applications from the SPLASH2 application suite (1-D FFT,Radix, Ocean, and Nbody), two kernels from the NAS benchmark suite (3-DFFT and CG), and a matrix-matrix multiplication kernel. Results show that for many cases, the addition of vectorization compiler directives results faster runtimes. However, to achieve a significant performance improvement via increased vector length, it is often necessary to restructure the program at the source level sometimes leading to algorithmic level transformations. Additionally, memory bank conflicts may result in substantial performance losses. These conflicts can often be exacerbated when optimizing code for increased vector lengths, and must be explicitly minimized. Finally, we investigate the relationship of the X1 data caches on overall performance.

  5. Osiris: A Modern, High-Performance, Coupled, Multi-Physics Code For Nuclear Reactor Core Analysis

    SciTech Connect

    Procassini, R J; Chand, K K; Clouse, C J; Ferencz, R M; Grandy, J M; Henshaw, W D; Kramer, K J; Parsons, I D

    2007-02-26

    To meet the simulation needs of the GNEP program, LLNL is leveraging a suite of high-performance codes to be used in the development of a multi-physics tool for modeling nuclear reactor cores. The Osiris code project, which began last summer, is employing modern computational science techniques in the development of the individual physics modules and the coupling framework. Initial development is focused on coupling thermal-hydraulics and neutral-particle transport, while later phases of the project will add thermal-structural mechanics and isotope depletion. Osiris will be applicable to the design of existing and future reactor systems through the use of first-principles, coupled physics models with fine-scale spatial resolution in three dimensions and fine-scale particle-energy resolution. Our intent is to replace an existing set of legacy, serial codes which require significant approximations and assumptions, with an integrated, coupled code that permits the design of a reactor core using a first-principles physics approach on a wide range of computing platforms, including the world's most powerful parallel computers. A key research activity of this effort deals with the efficient and scalable coupling of physics modules which utilize rather disparate mesh topologies. Our approach allows each code module to use a mesh topology and resolution that is optimal for the physics being solved, and employs a mesh-mapping and data-transfer module to effect the coupling. Additional research is planned in the area of scalable, parallel thermal-hydraulics, high-spatial-accuracy depletion and coupled-physics simulation using Monte Carlo transport.

  6. Fuel Performance Improvement Program. Semiannual progress report, October 1979-March 1980. [PWR; BWR

    SciTech Connect

    Not Available

    1980-04-01

    Progress on the Fuel Performance Improvement Program's fuel design tests and demonstration irradiations for October 1979 through March 1980 is reported. Included are the results of out-of-reactor experiments with Zircaloy cladding using a device that simulates the interaction between fuel and cladding. Also included are reports on the irradiation of the advanced LWR fuel designs in the Halden Boiling Water Reactor and in Consumers Power Company's Big Rock Point Reactor. The establishment of the technical bases and licensing requirements for the advanced fuel concepts are also described.

  7. Fuel cell/gas turbine system performance studies

    SciTech Connect

    Lee, G.T.; Sudhoff, F.A.

    1996-12-31

    Because of the synergistic effects (higher efficiencies, lower emissions) of combining a fuel cell and a gas turbine into a power generation system, many potential system configurations were studied. This work is focused on novel power plant systems by combining gas turbines, solid oxide fuel cells, and a high-temperature heat exchanger; these systems are ideal for the distributed power and on- site markets in the 1-5 MW size range.

  8. Vegetable oils: Precombustion characteristics and performance as diesel fuels

    SciTech Connect

    Bagby, M.O.

    1986-03-01

    Vegetable oils show technical promise as alternative fuels for diesel engines and have good potential as emergency fuels. Realistically, vegetable oils cause a number of problems when used in direct-injection diesel engines, generally attributable to inefficient combustion. At least partially responsible for poor combustion of neat vegetable oils are their high viscosity and non-volatility. To improve combustion several somewhat empirical approaches involving both chemical and physical modifications have been investigated by endurance tests in a variety of engines. Using the EMA 200 h engine screening test, several fuels show technical promise. These include methyl, ethyl, and butyl esters; high-oleic oils:diesel blend (1:3); diesel:soybean oil:butanol:cetane improver (33:33:33:1); and microemulsion fuels (diesel:soybean oil:190 proff ethanol:butanol, 50:25:5:20) and (soybean oil:methanol:2-octanol:cetane improver, 53:13:33:1). Using a pressure vessel, fuel injection system, and high speed motion picture camera, fuel injection characteristics of vegetable oils, e.g., soybean, sunflower, cottonseed, and peanut, have been observed in a quiescent nitrogen atmosphere at 480/sup 0/C and 4.1MPa. Their injection and atomization characteristics are markedly different from those of petroleum derived diesel fuels. Heating the vegetable oils to lower their viscosities increased spray penetration rate, reduced spray cone angles, and resulted in spray characteristics resembling those of diesel fuel. Significant chemical changes occurred following injection. Samples collected at about 400 microseconds after the injection event consisted of appreciable quantities of C/sub 4/-C/sub 16/ hydrocarbons, and free carboxyl groups were present.

  9. Formulation, Implementation and Validation of a Two-Fluid model in a Fuel Cell CFD Code

    SciTech Connect

    Kunal Jain, Vernon Cole, Sanjiv Kumar and N. Vaidya

    2008-11-01

    Water management is one of the main challenges in PEM Fuel Cells. While water is essential for membrane electrical conductivity, excess liquid water leads to ooding of catalyst layers. Despite the fact that accurate prediction of two-phase transport is key for optimal water management, understanding of the two-phase transport in fuel cells is relatively poor. Wang et. al. [1], [2] have studied the two-phase transport in the channel and diffusion layer separately using a multiphase mixture model. The model fails to accurately predict saturation values for high humidity inlet streams. Nguyen et. al. [3] developed a two-dimensional, two-phase, isothermal, isobaric, steady state model of the catalyst and gas diffusion layers. The model neglects any liquid in the channel. Djilali et. al. [4] developed a three-dimensional two-phase multicomponent model. The model is an improvement over previous models, but neglects drag between the liquid and the gas phases in the channel. In this work, we present a comprehensive two- fluid model relevant to fuel cells. Models for two-phase transport through Channel, Gas Diffusion Layer (GDL) and Channel-GDL interface, are discussed. In the channel, the gas and liquid pressures are assumed to be same. The surface tension effects in the channel are incorporated using the continuum surface force (CSF) model. The force at the surface is expressed as a volumetric body force and added as a source to the momentum equation. In the GDL, the gas and liquid are assumed to be at different pressures. The difference in the pressures (capillary pressure) is calculated using an empirical correlations. At the Channel-GDL interface, the wall adhesion affects need to be taken into account. SIMPLE-type methods recast the continuity equation into a pressure-correction equation, the solution of which then provides corrections for velocities and pressures. However, in the two-fluid model, the presence of two phasic continuity equations gives more freedom and

  10. A modified PN code tracking loop - Its performance analysis and comparative evaluation

    NASA Astrophysics Data System (ADS)

    Yost, R. A.; Boyd, R. W.

    1982-05-01

    A modified PN code tracking loop (MCTL) has been reported by Yost and Boyd (1980). The MCTL makes it possible to reduce the hardware complexity of a noncoherent delay lock loop in multiple data rate applications. The MCTL utilizes the on-time or data channel as the reference. This concept eliminates the need for the traditional loop's sum channel (early signal plus late signal) and, hence, the hardware associated with that channel. This saving may be substantial if the channel were to be optimized for a number of different data rates. With the elimination of an entire IF channel, the MCTL complexity is nearly equivalent to the dithering loop for PN code tracking considered by Hartmann (1974). However, the MCTL does not suffer the loss in tracking performance (with respect to the traditional loop) that the dithering loop experiences.

  11. TRISO-fuel element thermo-mechanical performance modeling for the hybrid LIFE engine with Pu fuel blanket

    NASA Astrophysics Data System (ADS)

    DeMange, P.; Marian, J.; Caro, M.; Caro, A.

    2010-10-01

    A TRISO-coated fuel thermo-mechanical performance study is performed for the fusion-fission hybrid Laser Inertial Fusion Engine (LIFE) to test the viability of TRISO particles to achieve ultra-high burn-up of Pu or transuranic spent nuclear fuel blankets. Our methodology includes full elastic anisotropy, time and temperature varying material properties, and multilayer capabilities. In order to achieve fast fluences up to 30 × 10 25 n m -2 ( E > 0.18 MeV), judicious extrapolations across several orders of magnitude of existing material databases have been carried out. The results of our study indicate that failure of the pyrolytic carbon (PyC) layers occurs within the first 2 years of operation. The particles then behave as a single-SiC-layer particle and the SiC layer maintains reasonably-low tensile stresses until the end-of-life. It is also found that the PyC creep constant, K, has a striking influence on the fuel performance of TRISO-coated particles, whose stresses scale almost inversely proportional to K. Conversely, varying the geometry of the TRISO-coated fuel particles results in little differences in terms of fuel performance.

  12. An overview of the geochemical code MINTEQ: Applications to performance assessment for low-level wastes

    SciTech Connect

    Peterson, S.R.; Opitz, B.E.; Graham, M.J.; Eary, L.E.

    1987-03-01

    The MINTEQ geochemical computer code, developed at the Pacific Northwest Laboratory (PNL), integrates many of the capabilities of its two immediate predecessors, MINEQL and WATEQ3. The MINTEQ code will be used in the Special Waste Form Lysimeters-Arid program to perform the calculations necessary to simulate (model) the contact of low-level waste solutions with heterogeneous sediments of the interaction of ground water with solidified low-level wastes. The code can calculate ion speciation/solubilitya, adsorption, oxidation-reduction, gas phase equilibria, and precipitation/dissolution of solid phases. Under the Special Waste Form Lysimeters-Arid program, the composition of effluents (leachates) from column and batch experiments, using laboratory-scale waste forms, will be used to develop a geochemical model of the interaction of ground water with commercial, solidified low-level wastes. The wastes being evaluated include power-reactor waste streams that have been solidified in cement, vinyl ester-styrene, and bitumen. The thermodynamic database for the code was upgraded preparatory to performing the geochemical modeling. Thermodynamic data for solid phases and aqueous species containing Sb, Ce, Cs, or Co were added to the MINTEQ database. The need to add these data was identified from the characterization of the waste streams. The geochemical model developed from the laboratory data will then be applied to predict the release from a field-lysimeter facility that contains full-scale waste samples. The contaminant concentrations migrating from the waste forms predicted using MINTEQ will be compared to the long-term lysimeter data. This comparison will constitute a partial field validation of the geochemical model.

  13. Performance Spec. for Fuel Drying and Canister Inerting System for PWR Core 2 Blanket Fuel Assemblies Stored within Shipping Port Spent Fuel Canisters

    SciTech Connect

    JOHNSON, D.M.

    2000-03-14

    This specification establishes the performance requirements and basic design requirements imposed on the fuel drying and canister inerting system for Shippingport Pressurized Water Reactor (PWR) Core 2 blanket fuel assemblies (BFAs) stored within Shippingport spent fuel (SSFCs) canisters (fuel drying and canister inerting system). This fuel drying and canister inerting system is a component of the U.S. Department of Energy, Richland Operations Office (RL) Spent Nuclear Fuels Project at the Hanford Site. The fuel drying and canister inerting system provides for removing water and establishing an inert environment for Shippingport PWR Core 2 BFAs stored within SSFCs. A policy established by the U.S. Department of Energy (DOE) states that new SNF facilities (this is interpreted to include structures, systems and components) shall achieve nuclear safety equivalence to comparable U.S. Nuclear Regulatory Commission (NRC)-licensed facilities. This will be accomplished in part by applying appropriate NRC requirements for comparable NRC-licensed facilities to the fuel drying and canister inerting system, in addition to applicable DOE regulations and orders.

  14. Advanced fuels modeling: Evaluating the steady-state performance of carbide fuel in helium-cooled reactors using FRAPCON 3.4

    NASA Astrophysics Data System (ADS)

    Hallman, Luther, Jr.

    Uranium carbide (UC) has long been considered a potential alternative to uranium dioxide (UO2) fuel, especially in the context of Gen IV gas-cooled reactors. It has shown promise because of its high uranium density, good irradiation stability, and especially high thermal conductivity. Despite its many benefits, UC is known to swell at a rate twice that of UO2. However, the swelling phenomenon is not well understood, and we are limited to a weak empirical understanding of the swelling mechanism. One suggested cladding for UC is silicon carbide (SiC), a ceramic that demonstrates a number of desirable properties. Among them are an increased corrosion resistance, high mechanical strength, and irradiation stability. However, with increased temperatures, SiC exhibits an extremely brittle nature. The brittle behavior of SiC is not fully understood and thus it is unknown how SiC would respond to the added stress of a swelling UC fuel. To better understand the interaction between these advanced materials, each has been implemented into FRAPCON, the preferred fuel performance code of the Nuclear Regulatory Commission (NRC); additionally, the material properties for a helium coolant have been incorporated. The implementation of UC within FRAPCON required the development of material models that described not only the thermophysical properties of UC, such as thermal conductivity and thermal expansion, but also models for the swelling, densification, and fission gas release associated with the fuel's irradiation behavior. This research is intended to supplement ongoing analysis of the performance and behavior of uranium carbide and silicon carbide in a helium-cooled reactor.

  15. Reforming petroleum-based fuels for fuel cell vehicles : composition-performance relationships.

    SciTech Connect

    Kopasz, J. P.; Miller, L. E.; Ahmed, S.; Devlin, P. R.; Pacheco, M.

    2001-12-04

    Onboard reforming of petroleum-based fuels, such as gasoline, may help ease the introduction of fuel cell vehicles to the marketplace. Although gasoline can be reformed, it is optimized to meet the demands of ICEs. This optimization includes blending to increase the octane number and addition of oxygenates and detergents to control emissions. The requirements for a fuel for onboard reforming to hydrogen are quite different than those for combustion. Factors such as octane number and flame speed are not important; however, factors such as hydrogen density, catalyst-fuel interactions, and possible catalyst poisoning become paramount. In order to identify what factors are important in a hydrocarbon fuel for reforming to hydrogen and what factors are detrimental, we have begun a program to test various components of gasoline and blends of components under autothermal reforming conditions. The results indicate that fuel composition can have a large effect on reforming behavior. Components which may be beneficial for ICEs for their octane enhancing value were detrimental to reforming. Fuels with high aromatic and naphthenic content were more difficult to reform. Aromatics were also found to have an impact on the kinetics for reforming of paraffins. The effects of sulfur impurities were dependent on the catalyst. Sulfur was detrimental for Ni, Co, and Ru catalysts. Sulfur was beneficial for reforming with Pt catalysts, however, the effect was dependent on the sulfur concentration.

  16. Solid amine-boranes as high performance hypergolic hybrid rocket fuels

    NASA Astrophysics Data System (ADS)

    Pfeil, Mark A.

    Hypergolic hybrid rockets have the potential of providing systems that are simple, reliable, have high performance, and allow for energy management. Such a propulsion system can be applied to fields that need a single tactical motor with flexible mission requirements of either high speed to target or extended loitering. They also provide the possibility for alternative fast response dynamic altitude control systems if ignition delays are sufficiently short. Amines are the traditional fuel of choice when selecting a hypergolic combination as these tend to react readily with both nitric acid and dinitrogen tertroxide based oxidizers. It has been found that the addition of a borane adduct to an amine fuel tends to reduce the ignition delay by up to an order of magnitude with white fuming nitric acid (WFNA). The borane addition has resulted in fuels with very short ignition delays between 2-10 ms - the fastest times for an amine based fuel reacting with nitric acid based oxidizers. The incorporation of these amine-boranes, specifically ethylenediamine bisborane (EDBB), into various fuel binders has also been found to result in ignition delays between 3-10 ms - the fastest times again for amine based fuels. It was found that the addition of a borane to an amine increased theoretical performance of the amine resulting in high performance fuels. The amine-borane/fuel binder combinations also produced higher theoretical performance values than previously used hypergolic hybrid rockets. Some of the theoretical values are on par or higher than the current toxic liquid hypergolic fuels, making amine boranes an attractive replacement. The higher performing amine-borane/fuel binder combinations also have higher performance values than the traditional rocket fuels, excluding liquid hydrogen. Thus, amine-borane based fuels have the potential to influence various area in the rocket field. An EDBB/ferrocene/epoxy fuel was tested in a hypergolic hybrid with pure nitric acid as the

  17. New features and applications of PRESTO, a computer code for the performance of regenerative, superheated steam turbine cycles

    NASA Technical Reports Server (NTRS)

    Choo, Y. K.; Staiger, P. J.

    1982-01-01

    The code was designed to analyze performance at valves-wide-open design flow. The code can model conventional steam cycles as well as cycles that include such special features as process steam extraction and induction and feedwater heating by external heat sources. Convenience features and extensions to the special features were incorporated into the PRESTO code. The features are described, and detailed examples illustrating the use of both the original and the special features are given.

  18. Development of a Fast Breeder Reactor Fuel Bundle Deformation Analysis Code - BAMBOO: Development of a Pin Dispersion Model and Verification by the Out-of-Pile Compression Test

    SciTech Connect

    Uwaba, Tomoyuki; Ito, Masahiro; Ukai, Shigeharu

    2004-02-15

    To analyze the wire-wrapped fast breeder reactor fuel pin bundle deformation under bundle/duct interaction conditions, the Japan Nuclear Cycle Development Institute has developed the BAMBOO computer code. This code uses the three-dimensional beam element to calculate fuel pin bowing and cladding oval distortion as the primary deformation mechanisms in a fuel pin bundle. The pin dispersion, which is disarrangement of pins in a bundle and would occur during irradiation, was modeled in this code to evaluate its effect on bundle deformation. By applying the contact analysis method commonly used in the finite element method, this model considers the contact conditions at various axial positions as well as the nodal points and can analyze the irregular arrangement of fuel pins with the deviation of the wire configuration.The dispersion model was introduced in the BAMBOO code and verified by using the results of the out-of-pile compression test of the bundle, where the dispersion was caused by the deviation of the wire position. And the effect of the dispersion on the bundle deformation was evaluated based on the analysis results of the code.

  19. Performance testing of the upgraded uranium isotopics multi-group analysis code MGAU

    NASA Astrophysics Data System (ADS)

    Berlizov, A. N.; Gunnink, R.; Zsigrai, J.; Nguyen, C. T.; Tryshyn, V. V.

    2007-06-01

    The paper describes recent developments of the MGAU (Multi-Group Analysis for Uranium) method, which resulted in the creation of an upgraded version 4.0 of the MGAU code. The major improvements concerned the procedure of the intrinsic efficiency calibration, particularly in the 120-205 keV region. The results of the tests carried out with the use of certified reference uranium isotopic materials SRM 969 and CRM 146 showed a significantly improved performance of the upgraded MGAU code for the accurate characterization of 235U and 234U abundances. The relative systematic biases of the abundances measured were evaluated not to exceed 1% and 3% over the concentration intervals 0.32-93.2 and 0.002-0.98 mass% for 235U and 234U, respectively. The influence of an up to 4-5 mm steel equivalent absorber and sample thickness on the measurement results was found to be much smaller than in previous versions of the code.

  20. Fuel properties effect on the performance of a small high temperature rise combustor

    NASA Technical Reports Server (NTRS)

    Acosta, Waldo A.; Beckel, Stephen A.

    1989-01-01

    The performance of an advanced small high temperature rise combustor was experimentally determined at NASA-Lewis. The combustor was designed to meet the requirements of advanced high temperature, high pressure ratio turboshaft engines. The combustor featured an advanced fuel injector and an advanced segmented liner design. The full size combustor was evaluated at power conditions ranging from idle to maximum power. The effect of broad fuel properties was studied by evaluating the combustor with three different fuels. The fuels used were JP-5, a blend of Diesel Fuel Marine/Home Heating Oil, and a blend of Suntec C/Home Heating Oil. The fuel properties effect on the performance of the combustion in terms of pattern factor, liner temperatures, and exhaust emissions are documented.

  1. Performance of Cladding on MOX Fuel with Low 240Pu/239Pu Ratio

    SciTech Connect

    McCoy, Kevin; Blanpain, Patrick; Morris, Robert Noel

    2014-01-01

    The U.S. Department of Energy has decided to dispose of a portion of its surplus plutonium by reconstituting it into mixed oxide (MOX) fuel and irradiating it in commercial power reactors. As part of fuel qualification, four lead assemblies were manufactured and irradiated to a maximum fuel rod average burnup of 47.3 MWd/kg heavy metal. This was the world s first commercial irradiation of MOX fuel with a 240Pu/239Pu ratio less than 0.10. Five fuel rods with varying burnups and plutonium contents were selected from one of the assemblies and shipped to Oak Ridge National Laboratory for hot cell examination. This paper discusses the results of those examinations with emphasis on cladding performance. Exams relevant to the cladding included visual and eddy current exams, profilometry, microscopy, hydrogen analysis, gallium analysis, and mechanical testing. There was no discernible effect of the type of MOX fuel on the performance of the cladding.

  2. Cold temperature diesel performance/combustion with Canadian low ignition quality fuels

    SciTech Connect

    Neill, W.S.; Wolf, W.M.; Webster, G.D.

    1986-01-01

    Three Canadian tar sands derived experimental diesel fuels with cetane numbers (CN) of 36, 31 and 26 and a reference fuel with a 47 CN were tested in a Deutz F1L511D, single cylinder, 4 stroke, naturally aspirated, diesel engine. Tests were performed with intake and cooling air temperatures of 0/sup 0/C and -12/sup 0/C over the entire engine operating range. Performance and combustion behaviour with the 36 CN fuel was marginally acceptable at 0/sup 0/C and unacceptable at -12/sup 0/C. High maximum combustion pressures and rates of combustion pressure rise were encountered at the low engine speed, high load condition with the experimental fuels. Poor combustion behaviour was also experienced with the two low CN fuels at light loads. Operation of this engine configuration with the 31 and 26 CN fuels is not recommended at 0/sup 0/C and lower intake air temperatures.

  3. Durability and performance optimization of cathode materials for fuel cells

    NASA Astrophysics Data System (ADS)

    Colon-Mercado, Hector Rafael

    The primary objective of this dissertation is to develop an accelerated durability test (ADT) for the evaluation of cathode materials for fuel cells. The work has been divided in two main categories, namely high temperature fuel cells with emphasis on the Molten Carbonate Fuel Cell (MCFC) cathode current collector corrosion problems and low temperature fuel cells in particular Polymer Electrolyte Fuel Cell (PEMFC) cathode catalyst corrosion. The high operating temperature of MCFC has given it benefits over other fuel cells. These include higher efficiencies (>50%), faster electrode kinetics, etc. At 650°C, the theoretical open circuit voltage is established, providing low electrode overpotentials without requiring any noble metal catalysts and permitting high electrochemical efficiency. The waste heat is generated at sufficiently high temperatures to make it useful as a co-product. However, in order to commercialize the MCFC, a lifetime of 40,000 hours of operation must be achieved. The major limiting factor in the MCFC is the corrosion of cathode materials, which include cathode electrode and cathode current collector. In the first part of this dissertation the corrosion characteristics of bare, heat-treated and cobalt coated titanium alloys were studied using an ADT and compared with that of state of the art current collector material, SS 316. PEMFCs are the best choice for a wide range of portable, stationary and automotive applications because of their high power density and relatively low-temperature operation. However, a major impediment in the commercialization of the fuel cell technology is the cost involved due to the large amount of platinum electrocatalyst used in the cathode catalyst. In an effort to increase the power and decrease the cathode cost in polymer electrolyte fuel cell (PEMFC) systems, Pt-alloy catalysts were developed to increase its activity and stability. Extensive research has been conducted in the area of new alloy development and

  4. Improving the detection task performance of a LWIR imaging system through the use of wavefront coding

    NASA Astrophysics Data System (ADS)

    Gross, Kevin A.; Kubala, Kenny

    2007-04-01

    In a traditional optical system the imaging performance is maximized at a single point in the operational space. This characteristic leads to maximizing the probability of detection if the object is on axis, at the designed conjugate, with the designed operational temperature and if the system components are manufactured without error in form and alignment. Due to the many factors that influence the system's image quality the probability of detection will decrease away from this peak value. An infrared imaging system is presented that statistically creates a higher probability of detection over the complete operational space for the Hotelling observer. The system is enabled through the use of wavefront coding, a computational imaging technology in which optics, mechanics, detection and signal processing are combined to enable LWIR imaging systems to be realized with detection task performance that is difficult or impossible to obtain in the optical domain alone. The basic principles of statistical decision theory will be presented along with a specific example of how wavefront coding technology can enable improved performance and reduced sensitivity to some of the fundamental constraints inherent in LWIR systems.

  5. Enhancing the performance of the light field microscope using wavefront coding

    PubMed Central

    Cohen, Noy; Yang, Samuel; Andalman, Aaron; Broxton, Michael; Grosenick, Logan; Deisseroth, Karl; Horowitz, Mark; Levoy, Marc

    2014-01-01

    Light field microscopy has been proposed as a new high-speed volumetric computational imaging method that enables reconstruction of 3-D volumes from captured projections of the 4-D light field. Recently, a detailed physical optics model of the light field microscope has been derived, which led to the development of a deconvolution algorithm that reconstructs 3-D volumes with high spatial resolution. However, the spatial resolution of the reconstructions has been shown to be non-uniform across depth, with some z planes showing high resolution and others, particularly at the center of the imaged volume, showing very low resolution. In this paper, we enhance the performance of the light field microscope using wavefront coding techniques. By including phase masks in the optical path of the microscope we are able to address this non-uniform resolution limitation. We have also found that superior control over the performance of the light field microscope can be achieved by using two phase masks rather than one, placed at the objective’s back focal plane and at the microscope’s native image plane. We present an extended optical model for our wavefront coded light field microscope and develop a performance metric based on Fisher information, which we use to choose adequate phase masks parameters. We validate our approach using both simulated data and experimental resolution measurements of a USAF 1951 resolution target; and demonstrate the utility for biological applications with in vivo volumetric calcium imaging of larval zebrafish brain. PMID:25322056

  6. Enhancing the performance of the light field microscope using wavefront coding.

    PubMed

    Cohen, Noy; Yang, Samuel; Andalman, Aaron; Broxton, Michael; Grosenick, Logan; Deisseroth, Karl; Horowitz, Mark; Levoy, Marc

    2014-10-01

    Light field microscopy has been proposed as a new high-speed volumetric computational imaging method that enables reconstruction of 3-D volumes from captured projections of the 4-D light field. Recently, a detailed physical optics model of the light field microscope has been derived, which led to the development of a deconvolution algorithm that reconstructs 3-D volumes with high spatial resolution. However, the spatial resolution of the reconstructions has been shown to be non-uniform across depth, with some z planes showing high resolution and others, particularly at the center of the imaged volume, showing very low resolution. In this paper, we enhance the performance of the light field microscope using wavefront coding techniques. By including phase masks in the optical path of the microscope we are able to address this non-uniform resolution limitation. We have also found that superior control over the performance of the light field microscope can be achieved by using two phase masks rather than one, placed at the objective's back focal plane and at the microscope's native image plane. We present an extended optical model for our wavefront coded light field microscope and develop a performance metric based on Fisher information, which we use to choose adequate phase masks parameters. We validate our approach using both simulated data and experimental resolution measurements of a USAF 1951 resolution target; and demonstrate the utility for biological applications with in vivo volumetric calcium imaging of larval zebrafish brain. PMID:25322056

  7. Performance and optimization of direct implicit time integration schemes for use in electrostatic particle simulation codes

    SciTech Connect

    Procassini, R.J.; Birdsall, C.K.; Morse, E.C.; Cohen, B.I.

    1988-01-01

    Implicit time integration schemes allow for the use of larger time steps than conventional explicit methods, thereby extending the applicability of kinetic particle simulation methods. This paper will describe a study of the performance and optimization of two such direct implicit schemes, which are used to follow the trajectories of charged particles in an electrostatic, particle-in-cell plasma simulation code. The direct implicit method that was used for this study is an alternative to the moment-equation implicit method. 10 refs., 7 figs., 4 tabs.

  8. The VELOPT code for estimating performance of a Fabry-Perot velocimeter

    SciTech Connect

    Goosman, D.R.

    1992-04-09

    The VELOPT code calculates an estimate of the performance of a Fabry- Perot (FP) velocimeter. The code is a macro-driven, Symphony spreadsheet written for an IBM PC. VELOPT is designed to be used in conjunction with the POWER codes, which estimate the amount of light entering a collection fiber and the ratio of collected light to light leaving the laser fiber. In this model a velocimeter system, single- frequency laser output illuminates a moving test surface through a lens. Reflected light from the test surface is concentrated by a lens into an optical collection fiber. The collected light is presented to a mode scrambler, a cylinder lens, a filter, and then to a striped Fabry-Perot interferometer (FPI). Light leaving the FPI is imaged via spherical lenses and one mirror onto the slit of an electronic streak camera. The image is intensified within the camera, and then is recorded on film. VELOPT takes 47 user inputs that describe the FP velocimeter system. The primary outputs from the code include the following estimates for each of the first four fringes: Energy per unit area reaching the film; optical density expected on both Polaroid 667 and TMAX3200 films; velocity and time resolution; and statistical smoothness of the streak records. Twenty-six other secondary output quantities for each fringe are also calculated. The finesse limitation due to the finite size of the mirrors is calculated in detail by the routine WALKOFF, which is internal to VELOPT. An estimate of the reduction in effective fill time of the FPI due to the finite spatial resolution of the streak camera is also calculated by VELPOPT.

  9. The VELOPT code for estimating performance of a Fabry-Perot velocimeter

    NASA Astrophysics Data System (ADS)

    Goosman, D. R.

    1992-04-01

    The VELOPT code calculates an estimate of the performance of a Fabry-Perot (FP) velocimeter. The code is a macro-driven, Symphony spreadsheet written for an IBM PC. VELOPT is designed to be used in conjunction with the POWER codes, which estimate the amount of light entering a collection fiber and the ratio of collected light to light leaving the laser fiber. In this model a velocimeter system, single-frequency laser output illuminates a moving test surface through a lens. Reflected light from the test surface is concentrated by a lens into an optical collection fiber. The collected light is presented to a mode scrambler, a cylinder lens, a filter, and then to a striped Fabry-Perot interferometer (FPI). Light leaving the FPI is imaged via spherical lenses and one mirror onto the slit of an electronic streak camera. The image is intensified within the camera, and then is recorded on film. VELOPT takes 47 user inputs that describe the FP velocimeter system. The primary outputs from the code include the following estimates for each of the first four fringes: Energy per unit area reaching the film; optical density expected on both Polaroid 667 and TMAX3200 films; velocity and time resolution; and statistical smoothness of the streak records. Twenty-six other secondary output quantities for each fringe are also calculated. The finesse limitation due to the finite size of the mirrors is calculated in detail by the routine WALKOFF, which is internal to VELOPT. An estimate of the reduction in effective fill time of the FPI due to the finite spatial resolution of the streak camera is also calculated by VELPOPT.

  10. On the performance of Trellis coded modulation with octal phase shift keying over the TDRSS channel

    NASA Technical Reports Server (NTRS)

    Osborne, William P.; Wolcott, Ted J.; Kopp, Brian T.; Ross, Michael

    1993-01-01

    As the National Aeronautics and Space Administration moves into the 21st century with programs like Space Station Freedom, a manned mission to Mars, and the new Landsat mission, transmission demands on the Tracking and Data Relay Satellite System (TDRSS) will very likely exceed the available bandwidth. The Manual Lujan, Jr. Center for Space Telemetering and Telecommunications Systems (CSTTS) at New Mexico State University (NMSU) is studying techniques for increasing the data rate capabilities of TDRSS. These techniques include the use of advanced bandwidth efficient modulation formats to increase the data rate that can be sustained in a TDRSS transponder and the use of lossless bandwidth compression of the data to be transmitted to lower the data rate required from the user spacecraft. Based upon current technology the most promising bandwidth efficient modulation technique is Trellis Coded Modulation (TCM) operating with Octal Phase shift Keying (8PSK). Trellis Coded Modulation coding with 8PSK carrier modulation has the capability to increase the data rate which can be transmitted through the TDRSS spacecraft by a factor of 2 to 2.5 times that available with todays coded QPSK systems with only a small penalty in link performance relative to the existing systems. However, before NASA can safely employ TCM coding it is necessary to prove that this complex format can perform on the real TDRSS link as it does in labs and simulation studies. This proof-of-concept test over a live satellite channel was the objective of the construction and testing performed under this task of the NMSU NASA grant referenced above. In conjunction with NASA, NMSU's CSTTS has constructed a system to test a new candidate TDRSS modulation scheme, TCM 8PSK, that can enhance the information throughput of the TDRSS spacecraft. The test system for this project which was constructed over a period of 18 months by NMSU consisted of two racks of commercial and univeristy-designed and -built

  11. Performance and emissions characteristics of a naturally aspirated diesel engine with vegetable oil fuels - 2

    SciTech Connect

    Humke, A.L.; Barsic, N.J.

    1981-01-01

    A naturally aspirated, direct injected diesel engine was used to evaluate the performance and emissions characteristics of a crude soybean oil, a 50 percent (by volume) mixture of crude soybean oil and no. 2 diesel fuel, and a degummed soybean oil. The data were compared with previous tests conducted on the same engine using diesel fuel, crude sunflower oil and a 50 percent mixture of crude sunflower oil and diesel fuel. 18 refs.

  12. Construction and performance research on variable-length codes for multirate OCDMA multimedia networks

    NASA Astrophysics Data System (ADS)

    Li, Chuan-qi; Yang, Meng-jie; Luo, De-jun; Lu, Ye; Kong, Yi-pu; Zhang, Dong-chuang

    2014-09-01

    A new kind of variable-length codes with good correlation properties for the multirate asynchronous optical code division multiple access (OCDMA) multimedia networks is proposed, called non-repetition interval (NRI) codes. The NRI codes can be constructed by structuring the interval-sets with no repetition, and the code length depends on the number of users and the code weight. According to the structural characteristics of NRI codes, the formula of bit error rate (BER) is derived. Compared with other variable-length codes, the NRI codes have lower BER. A multirate OCDMA multimedia simulation system is designed and built, the longer codes are assigned to the users who need slow speed, while the shorter codes are assigned to the users who need high speed. It can be obtained by analyzing the eye diagram that the user with slower speed has lower BER, and the conclusion is the same as the actual demand in multimedia data transport.

  13. Effect of fuel cycle length on plant performance and cost

    SciTech Connect

    O`Donnell, E.P.

    1996-08-01

    As competitive pressures increase in the utility industry, many nuclear units are moving to longer fuel cycles in order to increase capacity factors and lower cost. This paper reviews recent experience with longer cycle operation for both GPU Nuclear and the industry as a whole.

  14. Microbial Fuel Cell Performance with a Pressurized Cathode Chamber

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Microbial fuel cell (MFC) power densities are often constrained by the oxygen reduction reaction rate on the cathode electrode. One important factor for this is the normally low solubility of oxygen in the aqueous cathode solution creating mass transport limitations, which hinder oxygen reduction a...

  15. PERFORMANCE AND COST EVALUATION OF BIOREMEDIATION TECHNIQUES FOR FUEL SPILLS

    EPA Science Inventory

    Soils and ground water beneath the U.S. Coast Guard Air Station at Traverse City, MI, have been contaminated with separate spills of aviation gasoline and JP-4 jet fuel. Contamination from both plumes has affected a shallow water table aquifer consisting of a medium grained sand....

  16. SiC-CMC-Zircaloy-4 Nuclear Fuel Cladding Performance during 4-Point Tubular Bend Testing

    SciTech Connect

    IJ van Rooyen; WR Lloyd; TL Trowbridge; SR Novascone; KM Wendt; SM Bragg-Sitton

    2013-09-01

    The U.S. Department of Energy Office of Nuclear Energy (DOE NE) established the Light Water Reactor Sustainability (LWRS) program to develop technologies and other solutions to improve the reliability, sustain the safety, and extend the life of current reactors. The Advanced LWR Nuclear Fuel Development Pathway in the LWRS program encompasses strategic research focused on improving reactor core economics and safety margins through the development of an advanced fuel cladding system. Recent investigations of potential options for “accident tolerant” nuclear fuel systems point to the potential benefits of silicon carbide (SiC) cladding. One of the proposed SiC-based fuel cladding designs being investigated incorporates a SiC ceramic matrix composite (CMC) as a structural material supplementing an internal Zircaloy-4 (Zr-4) liner tube, referred to as the hybrid clad design. Characterization of the advanced cladding designs will include a number of out-of-pile (nonnuclear) tests, followed by in-pile irradiation testing of the most promising designs. One of the out-of-pile characterization tests provides measurement of the mechanical properties of the cladding tube using four point bend testing. Although the material properties of the different subsystems (materials) will be determined separately, in this paper we present results of 4-point bending tests performed on fully assembled hybrid cladding tube mock-ups, an assembled Zr-4 cladding tube mock-up as a standard and initial testing results on bare SiC-CMC sleeves to assist in defining design parameters. The hybrid mock-up samples incorporated SiC-CMC sleeves fabricated with 7 polymer impregnation and pyrolysis (PIP) cycles. To provide comparative information; both 1- and 2-ply braided SiC-CMC sleeves were used in this development study. Preliminary stress simulations were performed using the BISON nuclear fuel performance code to show the stress distribution differences for varying lengths between loading points

  17. Orbiter fuel cell performance constraints. STS/OPS Pratt Whitney fuel cells. Operating limits for mission planning

    NASA Technical Reports Server (NTRS)

    Kolkhorst, H. E.

    1980-01-01

    The orbiter fuel cell powerplant (FCP) performance constraints listed in the Shuttle Operational Data Book (SODB) were analyzed using the shuttle environmental control requirements evaluation tool. The effects of FCP lifetime, coolant loops, and FCP voltage output were considered. Results indicate that the FCP limits defined in the SODB are not valid.

  18. Performance evaluation of two-stage fuel cycle from SFR to PWR

    SciTech Connect

    Fei, T.; Hoffman, E.A.; Kim, T.K.; Taiwo, T.A.

    2013-07-01

    One potential fuel cycle option being considered is a two-stage fuel cycle system involving the continuous recycle of transuranics in a fast reactor and the use of bred plutonium in a thermal reactor. The first stage is a Sodium-cooled Fast Reactor (SFR) fuel cycle with metallic U-TRU-Zr fuel. The SFRs need to have a breeding ratio greater than 1.0 in order to produce fissile material for use in the second stage. The second stage is a PWR fuel cycle with uranium and plutonium mixed oxide fuel based on the design and performance of the current state-of-the-art commercial PWRs with an average discharge burnup of 50 MWd/kgHM. This paper evaluates the possibility of this fuel cycle option and discusses its fuel cycle performance characteristics. The study focuses on an equilibrium stage of the fuel cycle. Results indicate that, in order to avoid a positive coolant void reactivity feedback in the stage-2 PWR, the reactor requires high quality of plutonium from the first stage and minor actinides in the discharge fuel of the PWR needs to be separated and sent back to the stage-1 SFR. The electricity-sharing ratio between the 2 stages is 87.0% (SFR) to 13.0% (PWR) for a TRU inventory ratio (the mass of TRU in the discharge fuel divided by the mass of TRU in the fresh fuel) of 1.06. A sensitivity study indicated that by increasing the TRU inventory ratio to 1.13, The electricity generation fraction of stage-2 PWR is increased to 28.9%. The two-stage fuel cycle system considered in this study was found to provide a high uranium utilization (>80%). (authors)

  19. An experimental study of the concatenated Reed-Solomon/Viterbi channel coding system performance and its impact on space communications

    NASA Technical Reports Server (NTRS)

    Liu, K. Y.; Lee, J. J.

    1981-01-01

    The need for efficient space communication at very low bit error probabilities to the specification and implementation of a concatenated coding system using an interleaved Reed-Solomon code as the outer code and a Viterbi-decoded convolutional code as the inner code. Experimental results of this channel coding system are presented under an emulated S-band uplink and X-band downlink two-way space communication channel, where both uplink and downlink have strong carrier power. This work was performed under the NASA End-to-End Data Systems program at JPL. Test results verify that at a bit error probability of 10 to the -6 power or less, this concatenated coding system does provide a coding gain of 2.5 dB or more over the Viterbi-decoded convolutional-only coding system. These tests also show that a desirable interleaving depth for the Reed-Solomon outer code is 8 or more. The impact of this "virtually" error-free space communication link on the transmission of images is discussed and examples of simulation results are given.

  20. Performance Modeling and Measurement of Parallelized Code for Distributed Shared Memory Multiprocessors

    NASA Technical Reports Server (NTRS)

    Waheed, Abdul; Yan, Jerry

    1998-01-01

    This paper presents a model to evaluate the performance and overhead of parallelizing sequential code using compiler directives for multiprocessing on distributed shared memory (DSM) systems. With increasing popularity of shared address space architectures, it is essential to understand their performance impact on programs that benefit from shared memory multiprocessing. We present a simple model to characterize the performance of programs that are parallelized using compiler directives for shared memory multiprocessing. We parallelized the sequential implementation of NAS benchmarks using native Fortran77 compiler directives for an Origin2000, which is a DSM system based on a cache-coherent Non Uniform Memory Access (ccNUMA) architecture. We report measurement based performance of these parallelized benchmarks from four perspectives: efficacy of parallelization process; scalability; parallelization overhead; and comparison with hand-parallelized and -optimized version of the same benchmarks. Our results indicate that sequential programs can conveniently be parallelized for DSM systems using compiler directives but realizing performance gains as predicted by the performance model depends primarily on minimizing architecture-specific data locality overhead.