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Summary report on transportation of nuclear fuel materials in Japan : transportation infrastructure, threats identified in open literature, and physical protection regulations

Cochran, John R.

This report summarizes the results of three detailed studies of the physical protection systems for the protection of nuclear materials transport in Japan, with an emphasis on the transportation of mixed oxide fuel materials1. The Japanese infrastructure for transporting nuclear fuel materials is addressed in the first section. The second section of this report presents a summary of baseline data from the open literature on the threats of sabotage and theft during the transport of nuclear fuel materials in Japan. The third section summarizes a review of current International Atomic Energy Agency, Japanese and United States guidelines and regulations concerning the physical protection for the transportation of nuclear fuel materials.

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TYPE SAND Report YEAR 2008
DOIOSTI

Studies of a lattice model of water confined in a slit pore

Proposed for publication in an invited special edition of the Journal of Physical Chemistry.

Van Swol, Frank

We describe an extension of the Bell-Salt lattice model of water to the study of water confined in a slit pore. Wall-fluid interactions are chosen to be qualitatively representative of water interacting with a graphite surface. We have calculated the bulk vapor-liquid phase coexistence for the model through direct Monte Carlo simulations of the vapor-liquid interface. Adsorption and desorption isotherms in the slit pore were calculated using grand canonical ensemble Monte Carlo simulations. In addition, the thermodynamic conditions of vapor-liquid equilibrium for the confined fluid were determined. Our results are consistent with recent calculations for off-lattice models of confined water that show metastable vapor states of confined water persisting beyond the bulk saturation conditions, except for the narrowest pores. The results are similarly consistent with recent experiments on water adsorption in graphitized carbon black.

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TYPE Journal Article YEAR 2008
OSTI

Characterization of differentiated quiescent and nonquiescent cells in yeast stationary-phase cultures

Molecular Biology of the Cell

Aragon, Anthony D.; Rodriguez, Angelina L.; Meirelles, Osorio; Roy, Sushmita; Davidson, George S.; Tapia, Phillip H.; Allen, Chris; Joe, Ray; Benn, Don; Werner-Washburne, Margaret

Cells in glucose-limited Saccharomyces cerevisiae cultures differentiate into quiescent (Q) and nonquiescent (NQ) fractions before entering stationary phase. To understand this differentiation, Q and NQ cells from 101 deletion-mutant strains were tested for viability and reproductive capacity. Eleven mutants that affected one or both phenotypes in Q or NQ fractions were identified. NQ fractions exhibit a high level of petite colonies, and nine mutants affecting this phenotype were identified. Microarray analysis revealed >1300 mRNAs distinguished Q from NQ fractions. Q cell-specific mRNAs encode proteins involved in membrane maintenance, oxidative stress response, and signal transduction. NQ-cell mRNAs, consistent with apoptosis in these cells, encode proteins involved in Ty-element transposition and DNA recombination. More than 2000 protease-released mRNAs were identified only in Q cells, consistent with these cells being physiologically poised to respond to environmental changes. Our results indicate that Q and NQ cells differentiate significantly, with Q cells providing genomic stability and NQ cells providing nutrients to Q cells and a regular source of genetic diversity through mutation and transposition. These studies are relevant to chronological aging, cell cycle, and genome evolution, and they provide insight into complex responses that even simple organisms have to starvation. © 2008 by The American Society for Cell Biology.

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TYPE Journal Article YEAR 2008
ScopusOSTI

Simulations of nanotribology with realistic probe tip models

Langmuir

Chandross, Michael; Lorenz, Christian D.; Stevens, Mark J.; Grest, Gary S.

We present the results of massively parallel molecular dynamics simulations aimed at understanding the nanotribological properties of alkylsilane self-assembled monolayers (SAMs) on amorphous silica. In contrast to studies with opposing flat plates, as found in the bulk of the simulation literature, we use a model system with a realistic AFM tip (radius of curvature ranging from 3 to 30 nm) in contact with a SAM-coated silica substrate. We compare the differences in response between systems in which chains are fully physisorbed, fully chemisorbed, and systems with a mixture of the two. Our results demonstrate that the ubiquitous JKR and DMT models do not accurately describe the contact mechanics of these systems. In shear simulations, we find that the chain length has minimal effects on both the friction force and coefficient. The tip radius affects the friction force only (i.e., the coefficient is unchanged) by a constant shift in magnitude due to the increase in pull-off force with increasing radius. We also find that at extremely low loads, on the order of 10 nN, shearing from the tip causes damage to the physisorbed monolayers by removal of molecules. © 2008 American Chemical Society.

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TYPE Journal Article YEAR 2008
ScopusOSTI

High resolution electrochemical STM: New structural results for underpotentially deposited Cu on Au(1 1 1) in acid sulfate solution

Journal of Electroanalytical Chemistry

Vasiljevic, Natasa V.; Viyannalage, Lasantha T.; Dimitrov, Nikolay; Sieradzki, Karl

Adsorption of sulfate assists Cu monolayer underpotential deposition (upd) on Au(1 1 1) in a unique way, rendering two distinct structural stages: (i) formation of a low-density Cu phase at coverage of 2/3 ML known as the fenced(sqrt(3) × sqrt(3)) R 30 ° or honeycomb phase; (ii) formation of a complete monolayer, i.e., Cu-(1 × 1) phase pseudomorphic with respect to underlying Au(1 1 1) substrate. In this paper we present new structural in situ scanning tunneling microscopy (STM) results for this system. We show and discuss the STM imaging of the copper honeycomb superstructure probed underneath the co-adsorbed fenced(sqrt(3) × sqrt(3)) R 30 ° sulfate adlayer in the low-density phase. High resolution imaging during the phase transition from the low to high density copper phase unambiguously shows the existence of an ordered sulfate structure p(2 × 2) on the pseudomorphic Cu-(1 × 1) layer. The new structure is seen during the co-existence of two copper phases as well as upon completion of the Cu-(1 × 1) monolayer. While supported by earlier chronocoulometric measurements in the same system, the new structural results raise questions that need to be addressed in a future work. © 2007 Elsevier B.V. All rights reserved.

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TYPE Journal Article YEAR 2008
ScopusOSTI

Modeling and simulation of blast-induced, early-time intracranial wave physics leading to traumatic brain injury

Taylor, Paul A.

The objective of this modeling and simulation study was to establish the role of stress wave interactions in the genesis of traumatic brain injury (TBI) from exposure to explosive blast. A high resolution (1 mm{sup 3} voxels), 5 material model of the human head was created by segmentation of color cryosections from the Visible Human Female dataset. Tissue material properties were assigned from literature values. The model was inserted into the shock physics wave code, CTH, and subjected to a simulated blast wave of 1.3 MPa (13 bars) peak pressure from anterior, posterior and lateral directions. Three dimensional plots of maximum pressure, volumetric tension, and deviatoric (shear) stress demonstrated significant differences related to the incident blast geometry. In particular, the calculations revealed focal brain regions of elevated pressure and deviatoric (shear) stress within the first 2 milliseconds of blast exposure. Calculated maximum levels of 15 KPa deviatoric, 3.3 MPa pressure, and 0.8 MPa volumetric tension were observed before the onset of significant head accelerations. Over a 2 msec time course, the head model moved only 1 mm in response to the blast loading. Doubling the blast strength changed the resulting intracranial stress magnitudes but not their distribution. We conclude that stress localization, due to early time wave interactions, may contribute to the development of multifocal axonal injury underlying TBI. We propose that a contribution to traumatic brain injury from blast exposure, and most likely blunt impact, can occur on a time scale shorter than previous model predictions and before the onset of linear or rotational accelerations traditionally associated with the development of TBI.

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TYPE SAND Report YEAR 2008
DOIOSTI

Sandia National Laboratories Advanced Simulation and Computing (ASC) : appraisal method for the implementation of the ASC software quality engineering practices: Version 1.0

Turgeon, Jennifer T.; Minana, Molly A.

This document provides a guide to the process of conducting software appraisals under the Sandia National Laboratories (SNL) ASC Program. The goal of this document is to describe a common methodology for planning, conducting, and reporting results of software appraisals thereby enabling: development of an objective baseline on implementation of the software quality engineering (SQE) practices identified in the ASC Software Quality Plan across the ASC Program; feedback from project teams on SQE opportunities for improvement; identification of strengths and opportunities for improvement for individual project teams; guidance to the ASC Program on the focus of future SQE activities Document contents include process descriptions, templates to promote consistent conduct of appraisals, and an explanation of the relationship of this procedure to the SNL ASC software program.

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TYPE SAND Report YEAR 2008
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Tape casting of magnesium oxide

Corral, Erica L.; Loehman, Ronald E.; Bencoe, Denise N.

A tape casting procedure for fabricating ceramic magnesium oxide tapes has been developed as a method to produce flat sheets of sintered MgO that are thin and porous. Thickness of single layer tapes is in the range of 200-400 {micro}m with corresponding surface roughness values in the range of 10-20 {micro}m as measured by laser profilometry. Development of the tape casting technique required optimization of pretreatment for the starting magnesium oxide (MgO) powder as well as a detailed study of the casting slurry preparation and subsequent heat treatments for sintering and final tape flattening. Milling time of the ceramic powder, plasticizer, and binder mixture was identified as a primary factor affecting surface morphology of the tapes. In general, longer milling times resulted in green tapes with a noticeably smoother surface. This work demonstrates that meticulous control of the entire tape casting operation is necessary to obtain high-quality MgO tapes.

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TYPE SAND Report YEAR 2008
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The application of high-speed digital image correlation

Proposed for publication in Journal of Strain Analysis.

Digital image correlation (DIC) is a method of using digital images to calculate two-dimensional displacement and deformation or for stereo systems three-dimensional shape, displacement, and deformation. While almost any imaging system can be used with DIC, there are some important challenges when working with the technique in high- and ultra-high-speed applications. This article discusses three of these challenges: camera sensor technology, camera frame rate, and camera motion mitigation. Potential solutions are treated via three demonstration experiments showing the successful application of high-speed DIC for dynamic events. The application and practice of DIC at high speeds, rather than the experimental results themselves, provide the main thrust of the discussion.

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TYPE Journal Article YEAR 2008
OSTIDOI

Innovative solar thermochemical water splitting

Diver, Richard B.; Siegel, Nathan P.; Moss, Timothy A.; Miller, James E.; Hogan, Roy E.; Allendorf, Mark D.

Sandia National Laboratories (SNL) is evaluating the potential of an innovative approach for splitting water into hydrogen and oxygen using two-step thermochemical cycles. Thermochemical cycles are heat engines that utilize high-temperature heat to produce chemical work. Like their mechanical work-producing counterparts, their efficiency depends on operating temperature and on the irreversibility of their internal processes. With this in mind, we have invented innovative design concepts for two-step solar-driven thermochemical heat engines based on iron oxide and iron oxide mixed with other metal oxides (ferrites). The design concepts utilize two sets of moving beds of ferrite reactant material in close proximity and moving in opposite directions to overcome a major impediment to achieving high efficiency--thermal recuperation between solids in efficient counter-current arrangements. They also provide inherent separation of the product hydrogen and oxygen and are an excellent match with high-concentration solar flux. However, they also impose unique requirements on the ferrite reactants and materials of construction as well as an understanding of the chemical and cycle thermodynamics. In this report the Counter-Rotating-Ring Receiver/Reactor/Recuperator (CR5) solar thermochemical heat engine and its basic operating principals are described. Preliminary thermal efficiency estimates are presented and discussed. Our ferrite reactant material development activities, thermodynamic studies, test results, and prototype hardware development are also presented.

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TYPE SAND Report YEAR 2008
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Towards risk-based management of critical infrastructures : enabling insights and analysis methodologies from a focused study of the bulk power grid

Laviolette, Randall A.; Richardson, Bryan T.; Cook, Benjamin K.

This report summarizes research on a holistic analysis framework to assess and manage risks in complex infrastructures, with a specific focus on the bulk electric power grid (grid). A comprehensive model of the grid is described that can approximate the coupled dynamics of its physical, control, and market components. New realism is achieved in a power simulator extended to include relevant control features such as relays. The simulator was applied to understand failure mechanisms in the grid. Results suggest that the implementation of simple controls might significantly alter the distribution of cascade failures in power systems. The absence of cascade failures in our results raises questions about the underlying failure mechanisms responsible for widespread outages, and specifically whether these outages are due to a system effect or large-scale component degradation. Finally, a new agent-based market model for bilateral trades in the short-term bulk power market is presented and compared against industry observations.

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TYPE SAND Report YEAR 2008
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Elements of a function analytic approach to probability

Red-Horse, John R.

We first provide a detailed motivation for using probability theory as a mathematical context in which to analyze engineering and scientific systems that possess uncertainties. We then present introductory notes on the function analytic approach to probabilistic analysis, emphasizing the connections to various classical deterministic mathematical analysis elements. Lastly, we describe how to use the approach as a means to augment deterministic analysis methods in a particular Hilbert space context, and thus enable a rigorous framework for commingling deterministic and probabilistic analysis tools in an application setting.

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TYPE SAND Report YEAR 2008
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Benefit/cost framework for evaluating modular energy storage : a study for the DOE energy storage systems program

Eyer, James M.; Schoenung, Susan M.

The work documented in this report represents another step in the ongoing investigation of innovative and potentially attractive value propositions for electricity storage by the United States Department of Energy (DOE) and Sandia National Laboratories (SNL) Energy Storage Systems (ESS) Program. This study uses updated cost and performance information for modular energy storage (MES) developed for this study to evaluate four prospective value propositions for MES. The four potentially attractive value propositions are defined by a combination of well-known benefits that are associated with electricity generation, delivery, and use. The value propositions evaluated are: (1) transportable MES for electric utility transmission and distribution (T&D) equipment upgrade deferral and for improving local power quality, each in alternating years, (2) improving local power quality only, in all years, (3) electric utility T&D deferral in year 1, followed by electricity price arbitrage in following years; plus a generation capacity credit in all years, and (4) electric utility end-user cost management during times when peak and critical peak pricing prevail.

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TYPE SAND Report YEAR 2008
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Wind turbine reliability : a database and analysis approach

Hill, Roger; Stinebaugh, Jennifer S.; Briand, Daniel B.

The US wind Industry has experienced remarkable growth since the turn of the century. At the same time, the physical size and electrical generation capabilities of wind turbines has also experienced remarkable growth. As the market continues to expand, and as wind generation continues to gain a significant share of the generation portfolio, the reliability of wind turbine technology becomes increasingly important. This report addresses how operations and maintenance costs are related to unreliability - that is the failures experienced by systems and components. Reliability tools are demonstrated, data needed to understand and catalog failure events is described, and practical wind turbine reliability models are illustrated, including preliminary results. This report also presents a continuing process of how to proceed with controlling industry requirements, needs, and expectations related to Reliability, Availability, Maintainability, and Safety. A simply stated goal of this process is to better understand and to improve the operable reliability of wind turbine installations.

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TYPE SAND Report YEAR 2008
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Ship dynamics for maritime ISAR imaging

Doerry, Armin

Demand is increasing for imaging ships at sea. Conventional SAR fails because the ships are usually in motion, both with a forward velocity, and other linear and angular motions that accompany sea travel. Because the target itself is moving, this becomes an Inverse- SAR, or ISAR problem. Developing useful ISAR techniques and algorithms is considerably aided by first understanding the nature and characteristics of ship motion. Consequently, a brief study of some principles of naval architecture sheds useful light on this problem. We attempt to do so here. Ship motions are analyzed for their impact on range-Doppler imaging using Inverse Synthetic Aperture Radar (ISAR). A framework for analysis is developed, and limitations of simple ISAR systems are discussed.

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TYPE SAND Report YEAR 2008
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Results 77001–77200 of 96,771
Results 77001–77200 of 96,771