2-Page Summary for Neptunium solubility in the Near-field Environment of A Proposed Yucca Mountain Repository (open access)

2-Page Summary for Neptunium solubility in the Near-field Environment of A Proposed Yucca Mountain Repository

The total system performance assessment (TSPA) for the proposed repository at Yucca Mountain, NV, includes a wide variety of processes to evaluate the potential release of radionuclides from the Engineered Barrier System into the unsaturated zone of the geosphere. The principal processes controlling radionuclide release and mobilization from the waste forms are captured in the model to assess the dissolved concentrations of radionuclides in the source-term. The TSPA model of the source-term incorporates the far-from-equilibrium dissolution of, for example, spent nuclear fuel (SNF) to capture bounding rates of radionuclide availability as the SNF degrades. In addition, for individual radionuclides, the source-term model evaluates solubility constraints that are more indicative of longer-term, equilibrium processes that can limit the potential mass transport from the source term in those cases. These solubility limits represent phase saturation and precipitation processes that can occur either at the waste form as it alters, or at other locations in the near-field environment (e.g., within the invert) if chemical conditions are different. Identification and selection of applicable constraints for solubility-limited radionuclide concentrations is a primary focus in formulating the source-term model for the TSPA. Neptunium is a long-lived radionuclide that becomes a larger fraction of the potential dose …
Date: March 29, 2005
Creator: Sassani, D.; van Luik, A. & Summerson, J.
Object Type: Report
System: The UNT Digital Library
661L Pre Shot Report (open access)

661L Pre Shot Report

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Date: March 29, 2004
Creator: Bosson, S. T.
Object Type: Report
System: The UNT Digital Library
Acceptance Test Plan for the Sludge Pickup Adaptor (open access)

Acceptance Test Plan for the Sludge Pickup Adaptor

This test plan documents the acceptance testing of the sludge pickup adapter for potential use during PSI Phases 3 and 4 fuel cleanliness inspection activities. The adaptex is attached to the strainer tip of the vacuum wand and used to suction up residual sludge captured in a sludge collection tray. The material is vacuumed into a chamber of known volume in the sludge pickup adapter. The device serves as an aid in helping to determine whether the observed quantity of sludge is within allowable limits (1.4 cm{sup 3} per fuel assembly). This functionality test involves underwater testing in the 305 Building Cold Test Facility to verify that sludge can be successfully vacuumed from a collection tray. Ancillary activities in this acceptance test include demonstration that the sludge pickup adapter CM be successfully attached to and detached from the vacuum wand underwater.
Date: March 29, 2000
Creator: Pitner, A. L.
Object Type: Report
System: The UNT Digital Library
ADMP Mixing of Tank 18F: History, Modeling, Testing, and Results (open access)

ADMP Mixing of Tank 18F: History, Modeling, Testing, and Results

Residual radioactive waste was removed from Tank 18F in the F-Area Tank Farm at Savannah River Site (SRS), using the advanced design mixer pump (ADMP). Known as a slurry pump, the ADMP is a 55 foot long pump with an upper motor mounted to a steel super structure, which spans the top of the waste tank. The motor is connected by a long vertical drive shaft to a centrifugal pump, which is submerged in waste near the tank bottom. The pump mixes, or slurries, the waste within the tank so that it may be transferred out of the tank. Tank 18F is a 1.3 million gallon, 85 foot diameter underground waste storage tank, which has no internal components such as cooling coils or structural supports. The tank contained a residual 47,000 gallons of nuclear waste, consisting of a gelatinous radioactive waste known as sludge and particulate zeolite. The prediction of the ADMP success was based on nearly twenty five years of research and the application of that research to slurry pump technology. Many personnel at SRS and Pacific Northwest National Laboratories (PNNL) have significantly contributed to these efforts. This report summarizes that research which is pertinent to the ADMP performance …
Date: March 29, 2004
Creator: LEISHEAR, ROBERTA
Object Type: Article
System: The UNT Digital Library
Advances in Electromagnetic Modelling through High Performance Computing (open access)

Advances in Electromagnetic Modelling through High Performance Computing

Under the DOE SciDAC project on Accelerator Science and Technology, a suite of electromagnetic codes has been under development at SLAC that are based on unstructured grids for higher accuracy, and use parallel processing to enable large-scale simulation. The new modeling capability is supported by SciDAC collaborations on meshing, solvers, refinement, optimization and visualization. These advances in computational science are described and the application of the parallel eigensolver Omega3P to the cavity design for the International Linear Collider is discussed.
Date: March 29, 2006
Creator: Ko, K.; Folwell, N.; Ge, L.; Guetz, A.; Lee, L.; Li, Z. et al.
Object Type: Report
System: The UNT Digital Library
An agent-based microsimulation of critical infrastructure systems (open access)

An agent-based microsimulation of critical infrastructure systems

US infrastructures provide essential services that support the economic prosperity and quality of life. Today, the latest threat to these infrastructures is the increasing complexity and interconnectedness of the system. On balance, added connectivity will improve economic efficiency; however, increased coupling could also result in situations where a disturbance in an isolated infrastructure unexpectedly cascades across diverse infrastructures. An understanding of the behavior of complex systems can be critical to understanding and predicting infrastructure responses to unexpected perturbation. Sandia National Laboratories has developed an agent-based model of critical US infrastructures using time-dependent Monte Carlo methods and a genetic algorithm learning classifier system to control decision making. The model is currently under development and contains agents that represent the several areas within the interconnected infrastructures, including electric power and fuel supply. Previous work shows that agent-based simulations models have the potential to improve the accuracy of complex system forecasting and to provide new insights into the factors that are the primary drivers of emergent behaviors in interdependent systems. Simulation results can be examined both computationally and analytically, offering new ways of theorizing about the impact of perturbations to an infrastructure network.
Date: March 29, 2000
Creator: BARTON,DIANNE C. & STAMBER,KEVIN L.
Object Type: Article
System: The UNT Digital Library
Appendix D-16A Building 515 Waste Accumulation Area (open access)

Appendix D-16A Building 515 Waste Accumulation Area

The B-515 WAA is located in the southeast quadrant of the LLNL Main Site (see Figure D-1) along the west side of Building 515 (B-515). Hazardous wastes may be stored at the B-515 WAA for 90 days or less, until transferred to the appropriate Radioactive and Hazardous Waste Management (RHWM) facility or other permitted treatment, storage or disposal facility (TSDF). The design storage capacity of this WAA is 4,840 gallons. This appendix is designed to provide information specific to the Building 515 Waste Accumulation Area (B-515 WAA), a waste storage area. This appendix is not designed to be used as a sole source of information. All general information that is not specific to the B-515 WAA is included in the Contingency Plan for Waste Accumulation Areas, dated July 2004, and should be referenced.
Date: March 29, 2005
Creator: Tidwell, L
Object Type: Report
System: The UNT Digital Library
Argonne National Laboratory Summary Site Environmental Report for Calendar Year 2004. (open access)

Argonne National Laboratory Summary Site Environmental Report for Calendar Year 2004.

This report talks about Argonne National Laboratory summary site environmental report for calendar year 2004
Date: March 29, 2006
Creator: Golchert, N. W.
Object Type: Report
System: The UNT Digital Library
Aromatics Oxidation and Soot Formation in Flames (open access)

Aromatics Oxidation and Soot Formation in Flames

This project is concerned with the kinetics and mechanisms of aromatics oxidation and the growth process to polycyclic aromatic hydrocarbons (PAH) of increasing size, soot and fullerenes formation in flames. The overall objective of the experimental aromatics oxidation work is to extend the set of available data by measuring concentration profiles for decomposition intermediates such as phenyl, cyclopentadienyl, phenoxy or indenyl radicals which could not be measured with molecular-beam mass spectrometry to permit further refinement and testing of benzene oxidation mechanisms. The focus includes PAH radicals which are thought to play a major role in the soot formation process while their concentrations are in many cases too low to permit measurement with conventional mass spectrometry. The radical species measurements are used in critical testing and improvement of a kinetic model describing benzene oxidation and PAH growth. Thermodynamic property data of selected species are determined computationally, for instance using density functional theory (DFT). Potential energy surfaces are explored in order to identify additional reaction pathways. The ultimate goal is to understand the conversion of high molecular weight compounds to nascent soot particles, to assess the roles of planar and curved PAH and relationships between soot and fullerenes formation. The specific aims …
Date: March 29, 2005
Creator: Howard, J. B. & Richter, H.
Object Type: Report
System: The UNT Digital Library
Attenuation of P-Waves by Wave-Induced Fluid Flow (open access)

Attenuation of P-Waves by Wave-Induced Fluid Flow

Analytical expressions for three P-wave attenuation mechanisms in rocks are given and numerically-compared. The mechanisms are: (1) Biot loss, in which flow occurs at the scale of the wavelength between the peaks and troughs of a P wave; (2) squirt loss, in which flow occurs at the grain scale between microcracks the grains and the adjacent pores; and (3) mesoscopic loss, in which flow occurs at intermediate scales between the various lithological bodies that are present in an averaging volume of earth material. Each mechanism is of importance over different frequency bands. Typically, Biot loss is only important at the highest of ultrasonic frequencies (> 1 MHz), squirt-loss (when it occurs) is important in the range of 10 kHz to 1 MHz, while mesoscale loss dominates at the lower frequencies (<10 kHz) employed in seismology.
Date: March 29, 2002
Creator: Pride, S R & Berryman, J G
Object Type: Article
System: The UNT Digital Library
Automated {sup 99}Tc analysis in AW-101 and AN-107 ``diluted feed'' matrixes (open access)

Automated {sup 99}Tc analysis in AW-101 and AN-107 ``diluted feed'' matrixes

A process monitor is needed by British Nuclear Fuels Limited, Inc. (BNFL Inc.) to measure total {sup 99}Tc levels in column effluents during technetium removal from the aqueous fraction of the Hanford high-level tank wastes. The monitor must achieve detection limits of 1 x 10{sup {minus}8}Ci/mL (0.6 {micro}g/mL). Measurements must be done in near real time, with an analysis frequency of {approximately}15 min. The monitoring technology must be sufficiently simple and robust for unattended continuous operation in the plant settings.
Date: March 29, 2000
Creator: Egorov, O. B. & Kurath, D. E.
Object Type: Report
System: The UNT Digital Library
Beam Losses in the Extraction Line of a TeV E+ E- Linear Collider With a 20-Mrad Crossing Angle (open access)

Beam Losses in the Extraction Line of a TeV E+ E- Linear Collider With a 20-Mrad Crossing Angle

In this paper, we perform a detailed study of the power losses along the postcollision extraction line of a TeV e+e- collider with a crossing angle of 20 mrad between the beams at the interaction point. Five cases are considered here: four luminosity configurations for ILC and one for CLIC. For all of them, the strong beam-beam effects at the interaction point lead to an emittance growth for the outgoing beams, as well as to the production of beamstrahlung photons and e+e- pairs. The power losses along the 20 mrad extraction line, which are due to energy deposition by a fraction of the disrupted beam, of the beamstrahlung photons and of the e+e- coherent pairs, were estimated in the case of ideal collisions, as well as with a vertical position or angular o set at the interaction point.
Date: March 29, 2006
Creator: Ferrari, A.; U., /Uppsala & Nosochkov, Y.
Object Type: Report
System: The UNT Digital Library
Borehole Data Package for Calendar Year 2001 RCRA Wells at Single-Shell Tank Waste Management Area U (open access)

Borehole Data Package for Calendar Year 2001 RCRA Wells at Single-Shell Tank Waste Management Area U

This document provides information on the construction of three new RCRA wells at Waste Management Area U in September 2001.
Date: March 29, 2002
Creator: Horton, Duane G.
Object Type: Report
System: The UNT Digital Library
Borehole Data Package for One CY 2005 CERCLA Well 699-S20-E10, 300-FF-5 Operable Unit, Hanford Site, Washington (open access)

Borehole Data Package for One CY 2005 CERCLA Well 699-S20-E10, 300-FF-5 Operable Unit, Hanford Site, Washington

This report supplies the information obtained during drilling, characterization, and installation of the new groundwater monitoring well. This document also provides a compilation of hydrogeologic and well construction information obtained during drilling, well development, and sample collection/analysis activities.
Date: March 29, 2006
Creator: Williams, Bruce A.; Bjornstad, Bruce N.; Lanigan, David C.; Keller, Jason M. & Rockhold, Mark L.
Object Type: Report
System: The UNT Digital Library
BuildingPI: A future tool for building life cycle analysis (open access)

BuildingPI: A future tool for building life cycle analysis

Traditionally building simulation models are used at the design phase of a building project. These models are used to optimize various design alternatives, reduce energy consumption and cost. Building performance assessment for the operational phase of a buildings life cycle is sporadic, typically working from historical metered data and focusing on bulk energy assessment. Building Management Systems (BMS) do not explicitly incorporate feedback to the design phase or account for any changes, which have been made to building layout or fabric during construction. This paper discusses a proposal to develop an Industry Foundation Classes (IFC) compliant data visualization tool Building Performance Indicator (BuildingPI) for performance metric and performance effectiveness ratio evaluation.
Date: March 29, 2004
Creator: O'Donnell, James; Morrissey, Elmer; Keane, Marcus & Bazjanac,Vladimir
Object Type: Article
System: The UNT Digital Library
Changing Perspectives on Nonproliferation and Nuclear Fuel Cycles (open access)

Changing Perspectives on Nonproliferation and Nuclear Fuel Cycles

The concepts of international control over technologies and materials in the proliferation sensitive parts of the nuclear fuel cycle, specifically those related to enrichment and reprocessing, have been the subject of many studies and initiatives over the years. For examples: the International Fissionable Material Storage proposal in President Eisenhower's Speech on Atoms for Peace, and in the Charter of the International Atomic Energy Agency (IAEA) when the organization was formed in 1957; the regional nuclear fuel cycle center centers proposed by INFCE in the 80's; and most recently and notably, proposals by Dr. ElBaradei, the Director General of IAEA to limit production and processing of nuclear weapons usable materials to facilities under multinational control; and by U.S. President George W. Bush, to limit enrichment and reprocessing to States that have already full scale, functioning plants. There are other recent proposals on this subject as well. In this paper, the similarities and differences, as well as the effectiveness and challenges in proliferation prevention of these proposals and concepts will be discussed. The intent is to articulate a ''new nuclear regime'' and to develop concrete steps to implement such regime for future nuclear energy and deployment.
Date: March 29, 2005
Creator: Choi, J & Isaacs, T H
Object Type: Article
System: The UNT Digital Library
Chemical Analysis of Impurity Boron Atoms in Diamond Using Soft X-ray Emission Spectroscopy (open access)

Chemical Analysis of Impurity Boron Atoms in Diamond Using Soft X-ray Emission Spectroscopy

To analyze the local structure and/or chemical states of boron atoms in boron-doped diamond, which can be synthesized by the microwave plasma-assisted chemical vapor deposition method (CVD-B-diamond) and the temperature gradient method at high pressure and high temperature (HPT-B-diamond), we measured the soft X-ray emission spectra in the CK and BK regions of B-diamonds using synchrotron radiation at the Advanced Light Source (ALS). X-ray spectral analyses using the fingerprint method and molecular orbital calculations confirm that boron atoms in CVD-B-diamond substitute for carbon atoms in the diamond lattice to form covalent B-C bonds, while boron atoms in HPT-B-diamond react with the impurity nitrogen atoms to form hexagonal boron nitride. This suggests that the high purity diamond without nitrogen impurities is necessary to synthesize p-type B-diamond semiconductors.
Date: March 29, 2008
Creator: Muramatsu, Yasuji; Iihara, Junji; Takebe, Toshihiko & Denlinger, Jonathan D.
Object Type: Article
System: The UNT Digital Library
Combining a Multithreaded Scene Graph System with a Tiled Display Environment (open access)

Combining a Multithreaded Scene Graph System with a Tiled Display Environment

This case study highlights the technical challenges of creating an application that uses a multithreaded scene graph toolkit for rendering and uses a software environment for management of tiled display systems. Scene graph toolkits simplify and streamline graphics applications by providing data management and rendering services. Software for tiled display environments typically performs device and event management by opening windows on displays, by gathering and processing input device events, and by orchestrating the execution of application rendering code. These environments serve double-duty as frameworks for creating parallel rendering applications. We explore technical issues related to interfacing scene graph systems with software that manages tiled projection systems in the context of an implementation, and formulate suggestions for the future growth of such systems.
Date: March 29, 2001
Creator: Frank, R & Bethel, W
Object Type: Article
System: The UNT Digital Library
Concepts for Waste Retrieval and Alternate Storage of Radioactive Waste (open access)

Concepts for Waste Retrieval and Alternate Storage of Radioactive Waste

The primary purpose of this technical report is to present concepts for retrieval operations, equipment to be used, scenarios under which waste retrieval operations will take place, methods for responding to potential retrieval problems, and compliance with the preclosure performance objectives of 10 CFR 63.111(a) and (b) [DIRS 156605] during the retrieval of waste packages from the subsurface repository. If a decision for retrieval is made for any or all of the waste, the waste to be retrieved would be dispositioned in accordance with the regulations applicable at the time.
Date: March 29, 2005
Creator: Bierich, F.J.
Object Type: Report
System: The UNT Digital Library
Constructing Material Interfaces from Data Sets with Volume-Fraction Information (open access)

Constructing Material Interfaces from Data Sets with Volume-Fraction Information

We present a new algorithm for material boundary interface reconstruction from data sets containing volume fractions. We transform the reconstruction problem to a problem that analyzes the dual data set, where each vertex in the dual mesh has an associated barycentric coordinate tuple that represents the fraction of each material present. After constructing the dual tetrahedral mesh from the original mesh, we construct material boundaries by mapping a tetrahedron into barycentric space and calculating the intersections with Voronoi cells in barycentric space. These intersections are mapped back to the original physical space and triangulated to form the boundary surface approximation. This algorithm can be applied to any grid structure and can treat any number of materials per element/vertex.
Date: March 29, 2000
Creator: Bonnell, K.; Duchaineau, M. A.; Schikore, D. R.; Hamann, B. & Joy, K. I.
Object Type: Article
System: The UNT Digital Library
Coupled Vadose Zone and Atmospheric Surface-Layer Transport of CO2 from Geologic Carbon Sequestration Sites (open access)

Coupled Vadose Zone and Atmospheric Surface-Layer Transport of CO2 from Geologic Carbon Sequestration Sites

Geologic carbon dioxide (CO{sub 2}) sequestration is being considered as a way to offset fossil-fuel-related CO{sub 2} emissions to reduce the rate of increase of atmospheric CO{sub 2} concentrations. The accumulation of vast quantities of injected carbon dioxide (CO{sub 2}) in geologic sequestration sites may entail health and environmental risks from potential leakage and seepage of CO{sub 2} into the near-surface environment. We are developing and applying a coupled subsurface and atmospheric surface-layer modeling capability built within the framework of the integral finite difference reservoir simulator TOUGH2. The overall purpose of modeling studies is to predict CO{sub 2} concentration distributions under a variety of seepage scenarios and geologic, hydrologic, and atmospheric conditions. These concentration distributions will provide the basis for determining above-ground and near-surface instrumentation needs for carbon sequestration monitoring and verification, as well as for assessing health, safety, and environmental risks. A key feature of CO{sub 2} is its large density ({rho} = 1.8 kg m{sup -3}) relative to air ({rho} = 1.2 kg m{sup -3}), a property that may allow small leaks to cause concentrations in air above the occupational exposure limit of 4 percent in low-lying and enclosed areas such as valleys and basements where dilution rates …
Date: March 29, 2004
Creator: Oldenburg, Curtis M. & Unger, Andre J. A.
Object Type: Article
System: The UNT Digital Library
Criticality Safety Support to a Project Addressing SNM Legacy Items at LLNL (open access)

Criticality Safety Support to a Project Addressing SNM Legacy Items at LLNL

The programmatic, facility and criticality safety support staffs at the LLNL Plutonium Facility worked together to successfully develop and implement a project to process legacy (DNFSB Recommendation 94-1 and non-Environmental, Safety, and Health (ES&H) labeled) materials in storage. Over many years, material had accumulated in storage that lacked information to adequately characterize the material for current criticality safety controls used in the facility. Generally, the fissionable material mass information was well known, but other information such as form, impurities, internal packaging, and presence of internal moderating or reflecting materials were not well documented. In many cases, the material was excess to programmatic need, but such a determination was difficult with the little information given on MC&A labels and in the MC&A database. The material was not packaged as efficiently as possible, so it also occupied much more valuable storage space than was necessary. Although safe as stored, the inadequately characterized material posed a risk for criticality safety noncompliances if moved within the facility under current criticality safety controls. A Legacy Item Implementation Plan was developed and implemented to deal with this problem. Reasonable bounding conditions were determined for the material involved, and criticality safety evaluations were completed. Two appropriately designated …
Date: March 29, 2005
Creator: Pearson, J S; Burch, J G; Dodson, K E & Huang, S T
Object Type: Article
System: The UNT Digital Library
Design and Implementation of the Control System for a 2 kHz Rotary Fast Tool Servo (open access)

Design and Implementation of the Control System for a 2 kHz Rotary Fast Tool Servo

This paper presents a summary of the performance of our 2 kHz rotary fast tool servo and an overview of its control systems. We also discuss the loop shaping techniques used to design the power amplifier current control loop and the implementation of that controller in an op-amp circuit. The design and development of the control system involved a long list of items including: current compensation; tool position compensation; notch filter design and phase stabilizing with an additional pole for a plant with an undamped resonance; adding viscous damping to the fast tool servo; voltage budget for driving real and reactive loads; dealing with unwanted oscillators; ground loops; digital-to-analog converter glitches; electrical noise from the spindle motor switching power supply; and filtering the spindle encoder signal to generate smooth tool tip trajectories. Eventually, all of these topics will be discussed in detail in a Ph.D. thesis that will include this work. For the purposes of this paper, rather than present a diluted discussion that attempts to touch on all of these topics, we will focus on the first item with sufficient detail for providing insight into the design process.
Date: March 29, 2004
Creator: Montesanti, R C & Trumper, D L
Object Type: Article
System: The UNT Digital Library
DEVELOPMENT OF A CANDLE FILTER FAILURE SAFEGUARD DEVICE (open access)

DEVELOPMENT OF A CANDLE FILTER FAILURE SAFEGUARD DEVICE

The full-flow mechanical safeguard device (FFMSGD) has been developed under contract to the National Energy Technology Laboratory (NETL) to address problems with the reliability of ceramic candle filter elements installed on high-temperature, high-pressure (HTHP) Hot Gas Cleanup (HGCU) filters. Although systems candle filters are expected to perform satisfactorily when in good operating condition, the failure of even a single filter element can increase the filter system outlet dust loading enough to potentially damage gas turbine blades, contaminate other downstream processes, and limit the availability of the power system. Filter failure safeguard devices that are installed on each individual candle filter element are envisioned as a guarantee of a candle filter system's ability to withstand some number of element failures and continue operation without these negative consequences. The intention of the FFMSGD is to provide this guarantee without incurring any significant pressure drop penalty or constraining the filter system's reverse-pulse cleaning procedures. The FFMSGD provides a clear flow path for filtered and reverse-flow cleaning gases when its filter element is intact, and activates to provide a positive mechanical seal against gas flow in either direction when its filter element breaks or fails. This activation is induced by the increase in the …
Date: March 29, 2002
Creator: Snyder, Todd R.
Object Type: Report
System: The UNT Digital Library