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Performance characteristics of cryofocusing GC/MS system at BWXT Pantex Plant

Brown, Jason R.; Thornberg, Steve M.; Banet, Judith F.

Ensuring the reliability of all components within a weapon system becomes increasingly important as the stockpile ages. One of the most noteworthy surveillance techniques designed to circumvent (or take place alongside) traditional D&I operations is to collect a sample of gas from within the internal atmosphere of a particular region in a weapon. While a wealth of information about the weapon may be encoded within the composition of its gas sample, our access to that information is only as good as the method used to analyze the sample. It has been shown that cryofocusing-GC/MS offers advantages in terms of sensitivity, ease of sample collection, and robustness of the equipment/hardware used. Attention is therefore focused on qualifying a cryo-GC/MS system for routine stockpile surveillance operations at Pantex. A series of tests were performed on this instrument to characterize the linearity and repeatability of its response using two different standard gas mixes (ozone precursor and TO-14) at various concentrations. This paper outlines the methods used and the results of these tests in order to establish a baseline by which to compare future cryo-GC/MS analyses. A summary of the results is shown.

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Analysis of cavern shapes for the strategic petroleum reserve

Sobolik, Steven

This report presents computational analyses to determine the structural integrity of different salt cavern shapes. Three characteristic shapes for increasing cavern volumes are evaluated and compared to the baseline shape of a cylindrical cavern. Caverns with enlarged tops, bottoms, and mid-sections are modeled. The results address pillar to diameter ratios of some existing caverns in the system and will represent the final shape of other caverns if they are repeatedly drawn down. This deliverable is performed in support of the U.S. Strategic Petroleum Reserve. Several three-dimensional models using a close-packed arrangement of 19 caverns have been built and analyzed using a simplified symmetry involving a 30-degree wedge portion of the model. This approach has been used previously for West Hackberry (Ehgartner and Sobolik, 2002) and Big Hill (Park et al., 2005) analyses. A stratigraphy based on the Big Hill site has been incorporated into the model. The caverns are modeled without wells and casing to simplify the calculations. These calculations have been made using the power law creep model. The four cavern shapes were evaluated at several different cavern radii against four design factors. These factors included the dilatant damage safety factor in salt, the cavern volume closure, axial well strain in the caprock, and surface subsidence. The relative performance of each of the cavern shapes varies for the different design factors, although it is apparent that the enlarged bottom design provides the worst overall performance. The results of the calculations are put in the context of the history of cavern analyses assuming cylindrical caverns, and how these results affect previous understanding of cavern behavior in a salt dome.

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Quantum gate decomposition algorithms

Slepoy, Alexander S.

Quantum computing algorithms can be conveniently expressed in a format of a quantum logical circuits. Such circuits consist of sequential coupled operations, termed ''quantum gates'', or quantum analogs of bits called qubits. We review a recently proposed method [1] for constructing general ''quantum gates'' operating on an qubits, as composed of a sequence of generic elementary ''gates''.

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MPC&A training needs of the NIS/Baltics States

Beck, David F.; Stoy-Mcleod, Carol L.

This report serves to document contract deliverables considered to be of continuing interest associated with two workshops conducted as part of an initial assessment of Material Protection, Control, and Accounting (MPC&A) training needs of the Newly Independent and Baltic States (NIS/Baltics). These workshops were held in Kiev, Ukraine, ca. 2003-2004, with the assistance of personnel from the George Kuzmycz Training Center (GKTC) of the Kiev Institute of Nuclear Research (KINR). Because of the dominant role Ukraine plays in the region in terms of the nuclear industry, one workshop focused exclusively on Ukrainian training needs, with participants attending from twelve Ukrainian organizations (plus U.S. DOE/NNSA representatives). The second workshop included participation by a further ten countries from the NIS/Baltics region. In addition, the training needs data developed during the workshop were supplemented by the outcomes of surveys and studies conducted by the GKTC.

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Screening protocol for iodine-specific getters in YMP-related invert applications

Krumhansl, James L.; Chwirka, J.B.

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Modeling the 10-gigabit ethernet ASC WAN

Tolendino, Lawrence F.; Wertz, Jason W.

In recent years, modeling and simulation has played an increasingly important role in the maintenance of the nuclear stockpile. The Advanced Simulation and Computing (ASC) program continues to support and encourage the development of a modeling and simulation infrastructure to make these goals a reality. The Distance Computing Network has been making make the ASC resources available to users throughout the tri-lab environment for over five years. This network relies on the Transmission Control Protocol/Internet Protocol (TCP/IP) protocol suite to provide high performance and reliable communications. Understanding TCP/IP operation in this unique environment is critical. Software modeling has been used to analyze current network performance and predict the effect of proposed changes. Recently the network architecture was radically changed and the software model had to be changed as well. Whereas the original network was based on 2.5 gigabit per second ATM links, the redesigned network is comprised of 10-gigabit Ethernet links arranged as a 3-node ring. Therefore, a new software model was needed to continue to predict the performance of proposed changes and allow engineers to experiment with new network applications without the risk of interfering with critical operations.

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A knowledge continuity management program for the energy, infrastructure and knowledge systems center, Sandia National Laboratories

Menicucci, David F.

A growing recognition exists in companies worldwide that, when employees leave, they take with them valuable knowledge that is difficult and expensive to recreate. The concern is now particularly acute as the large ''baby boomer'' generation is reaching retirement age. A new field of science, Knowledge Continuity Management (KCM), is designed to capture and catalog the acquired knowledge and wisdom from experience of these employees before they leave. The KCM concept is in the final stages of being adopted by the Energy, Infrastructure, and Knowledge Systems Center and a program is being applied that should produce significant annual cost savings. This report discusses how the Center can use KCM to mitigate knowledge loss from employee departures, including a concise description of a proposed plan tailored to the Center's specific needs and resources.

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National SCADA Test Bed: FY05 Progress on Virtual Control System Environment (VCSE)

Van Leeuwen, Brian P.; Michalski, John T.; Lee, Erik

This document provides the status of the Virtual Control System Environment (VCSE) under development at Sandia National Laboratories. This development effort is funded by the Department of Energy's (DOE) National SCADA Test Bed (NSTB) Program. Specifically the document presents a Modeling and Simulation (M&S) and software interface capability that supports the analysis of Process Control Systems (PCS) used in critical infrastructures. This document describes the development activities performed through June 2006 and the current status of the VCSE development task. Initial activities performed by the development team included researching the needs of critical infrastructure systems that depend on PCS. A primary source describing the security needs of a critical infrastructure is the Roadmap to Secure Control Systems in the Energy Sector. A literature search of PCS analysis tools was performed and we identified a void in system-wide PCS M&S capability. No existing tools provide a capability to simulate control system devices and the underlying supporting communication network. The design team identified the requirements for an analysis tool to fill this void. Since PCS are comprised of multiple subsystems, an analysis framework that is modular was selected for the VCSE. The need for a framework to support the interoperability of multiple simulators with a PCS device model library was identified. The framework supports emulation of a system that is represented by models in a simulation interacting with actual hardware via a System-in-the-Loop (SITL) interface. To identify specific features for the VCSE analysis tool the design team created a questionnaire that briefly described the range of potential capabilities the analysis tool could include and requested feedback from potential industry users. This initial industry outreach was also intended to identify several industry users that are willing to participate in a dialog through the development process so that we maximize usefulness of the VCSE to industry. Industry involvement will continue throughout the VCSE development process. The teams activities have focused on creating a modeling and simulation capability that will support the analysis of PCS. An M&S methodology that is modular in structure was selected. The framework is able to support a range of model fidelities depending on the analysis being performed. In some cases high-fidelity network communication protocol and device models are necessary which can be accomplished by including a high-fidelity communication network simulator such as OPNET Modeler. In other cases lower fidelity models could be used in which case the high-fidelity communication network simulator is not needed. In addition, the framework supports a range of control system device behavior models. The models could range from simple function models to very detailed vendor-specific models. Included in the FY05 funding milestones was a demonstration of the framework. The development team created two scenarios that demonstrated the VCSE modular framework. The first demonstration provided a co-simulation using a high-fidelity communication network simulator interoperating with a custom developed control system simulator and device library. The second scenario provided a system-in-the-loop demonstration that emulated a system with a virtual network segment interoperating with a real-device network segment.

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Physical security and vulnerability modeling for infrasturcture facilities

Jones, Dean A.; Davis, Chad E.

A model of malicious intrusions in infrastructure facilities is developed, using a network representation of the system structure together with Markov models of intruder progress and strategy. This structure provides an explicit mechanism to estimate the probability of successful breaches of physical security, and to evaluate potential improvements. Simulation is used to analyze varying levels of imperfect information on the part of the intruders in planning their attacks. An example of an intruder attempting to place an explosive device on an airplane at an airport gate illustrates the structure and potential application of the model.

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Phase transformation of "chem-prep" PZT 95/5-2Nb HF1035 ceramic under quasi-static loading conditions

Montgomery, Stephen; Hofer, John

Specimens of poled and unpoled ''chem-prep'' PNZT ceramic from batch HF1035 were tested under hydrostatic, uniaxial, and constant stress difference loading conditions at -55, 25, and 75 C. The objective of this experimental study was to characterize the mechanical properties and conditions for the ferroelectric (FE) to antiferroelectric (AFE) phase transformations of this ''chem-prep'' PNZT ceramic to aid grain-scale modeling efforts in developing and testing realistic response models for use in simulation codes. As seen from a previously characterized material (batch HF803), poled ceramic from HF1035 was seen to undergo anisotropic deformation during the transition from a FE to an AFE phase. Also, the phase transformation was found to be permanent for the two low temperature conditions, whereas the transformation can be completely reversed at the highest temperature. The rates of increase in the phase transformation pressures with temperature were practically identical for both unpoled and poled PNZT HF1035 specimens. We observed that temperature spread the phase transformation over mean stress analogous to the observed spread over mean stress due to shear stress. Additionally, for poled ceramic samples, the FE to AFE phase transformation was seen to occur when the normal compressive stress, acting perpendicular to a crystallographic plane about the polar axis, equals the hydrostatic pressure at which the transformation otherwise takes place.

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Results 84001–84100 of 99,299
Results 84001–84100 of 99,299