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PERSPECTIVES ON A DOE CONSEQUENCE INPUTS FOR ACCIDENT ANALYSIS APPLICATIONS

Description: Department of Energy (DOE) accident analysis for establishing the required control sets for nuclear facility safety applies a series of simplifying, reasonably conservative assumptions regarding inputs and methodologies for quantifying dose consequences. Most of the analytical practices are conservative, have a technical basis, and are based on regulatory precedent. However, others are judgmental and based on older understanding of phenomenology. The latter type of practices can be found in modeling hypothetical releases into the atmosphere and the subsequent exposure. Often the judgments applied are not based on current technical understanding but on work that has been superseded. The objective of this paper is to review the technical basis for the major inputs and assumptions in the quantification of consequence estimates supporting DOE accident analysis, and to identify those that could be reassessed in light of current understanding of atmospheric dispersion and radiological exposure. Inputs and assumptions of interest include: Meteorological data basis; Breathing rate; and Inhalation dose conversion factor. A simple dose calculation is provided to show the relative difference achieved by improving the technical bases.
Date: July 30, 2008
Creator: (NOEMAIL), K; Jonathan Lowrie, J; David Thoman (NOEMAIL), D & Austin Keller (NOEMAIL), A
Item Type: Article

SRS BEDROCK PROBABILISTIC SEISMIC HAZARD ANALYSIS (PSHA) DESIGN BASIS JUSTIFICATION (U)

Description: This represents an assessment of the available Savannah River Site (SRS) hard-rock probabilistic seismic hazard assessments (PSHAs), including PSHAs recently completed, for incorporation in the SRS seismic hazard update. The prior assessment of the SRS seismic design basis (WSRC, 1997) incorporated the results from two PSHAs that were published in 1988 and 1993. Because of the vintage of these studies, an assessment is necessary to establish the value of these PSHAs considering more recently collected data affecting seismic hazards and the availability of more recent PSHAs. This task is consistent with the Department of Energy (DOE) order, DOE O 420.1B and DOE guidance document DOE G 420.1-2. Following DOE guidance, the National Map Hazard was reviewed and incorporated in this assessment. In addition to the National Map hazard, alternative ground motion attenuation models (GMAMs) are used with the National Map source model to produce alternate hazard assessments for the SRS. These hazard assessments are the basis for the updated hard-rock hazard recommendation made in this report. The development and comparison of hazard based on the National Map models and PSHAs completed using alternate GMAMs provides increased confidence in this hazard recommendation. The alternate GMAMs are the EPRI (2004), USGS (2002) and a regional specific model (Silva et al., 2004). Weights of 0.6, 0.3 and 0.1 are recommended for EPRI (2004), USGS (2002) and Silva et al. (2004) respectively. This weighting gives cluster weights of .39, .29, .15, .17 for the 1-corner, 2-corner, hybrid, and Greens-function models, respectively. This assessment is judged to be conservative as compared to WSRC (1997) and incorporates the range of prevailing expert opinion pertinent to the development of seismic hazard at the SRS. The corresponding SRS hard-rock uniform hazard spectra are greater than the design spectra developed in WSRC (1997) that were based on the LLNL ...
Date: December 14, 2005
Creator: (NOEMAIL), R
Item Type: Report

Time-Resolved Hard X-Ray Spectrometer

Description: Wired array studies are being conducted at the SNL Z accelerator to maximize the x-ray generation for inertial confinement fusion targets and high energy density physics experiments. An integral component of these studies is the characterization of the time-resolved spectral content of the x-rays. Due to potential spatial anisotropy in the emitted radiation, it is also critical to diagnose the time-evolved spectral content in a space-resolved manner. To accomplish these two measurement goals, we developed an x-ray spectrometer using a set of high-speed detectors (silicon PIN diodes) with a collimated field-of-view that converged on a 1-cm-diameter spot at the pinch axis. Spectral discrimination is achieved by placing high Z absorbers in front of these detectors. We built two spectrometers to permit simultaneous different angular views of the emitted radiation. Spectral data have been acquired from recent Z shots for the radial and polar views. UNSPEC1 has been adapted to analyze and unfold the measured data to reconstruct the x-ray spectrum. The unfold operator code, UFO2, is being adapted for a more comprehensive spectral unfolding treatment.
Date: March 1, 2007
Creator: (NSTec), Kenneth Moya; (NSTec), Ian McKennaa; (NSTec), Thomas Keenana & (Sandia), Michael Cuneob
Item Type: Article

Large-Format X-Ray Pinhole Camera

Description: National Security Technologies, LLC, has successfully implemented many scientific and engineering innovations in the new Large-Format Pinhole Camera (LFPHC), which have dramatically increased the detection sensitivity and reliability of the camera in exotic locations, such as the Sandia National Laboratories Z-facility. Quality improvements of the LFPHC have been demonstrated in its fielding at Z, where high-quality images were recorded. A major improvement was the development of a new, user-friendly LFPHC camera back that would tolerate high radiation, electromagnetic interference, and mechanical shock. Key modifications resulted in improved detection sensitivity, spatial resolution, uniformity along the microchannel plate strip, and stability of the interframe timing and delay. Design considerations and improvements will be discussed.
Date: June 22, 2007
Creator: (NSTec), Nathan Joseph; (NSTec), Aric Tibbits; (NSTec), Ming Wu & (Sandia), Gordon Chandler
Item Type: Article

Understanding the dynamic performance of microchannel plates in pulsed mode

Description: The dynamic performance of a microchannel plate (MCP) is highly dependent on the high-voltage waveforms that are applied to it. Impedance mismatches in MCP detectors can significantly vary the waveforms on the MCP compared to the input pulses. High-voltage pulse waveforms launched onto surface coatings on the MCPs have historically been difficult and expensive to measure. Over the past few years, we have developed and tested techniques utilizing probes to measure the voltage propagation on the surface of MCPs. Square and Gaussian pulses with widths ranging from 200 ps to 2 ns have been applied. We have investigated the effects of coating thickness, microstrip width, and openended versus terminated strips. These data provide a wealth of knowledge that is enabling a better understanding of images recorded with these devices. This presentation discusses a method for measuring voltage profiles on the surface of the MCP and presents Monte Carlo simulations of the optical gate profiles based on the measured waveforms. Excellent agreement in the optical gate profiles have been achieved between the simulations and the experimental measurements using a short-pulse ultraviolet laser.
Date: June 22, 2007
Creator: (NSTec), Ray Thomas; (NSTec), Ming Wu; (NSTec), Nathan Joseph; (NSTec), Craig Kruschwitz & Laboratories), Gregroy A. Rochau (Sandia National
Item Type: Article

Megagauss Magnetic Field Sensors Based on Ag2Te

Description: Pulsed power machines capable of producing tremendous energy face various diagnostic and characterizing challenges. Such devices, which may produce 10 - 100MAs, have traditionally relied on Faraday rotation and Rogowski coil technology for time-varying current measurements. Faraday rotation requires a host of costly optical components, including fibers, polarizers, retarders, lasers, and detectors, as well as setup, alignment, and time-consuming post-processing to unwrap the time-dependent current signal. Rogowski coils face potential problems such as physical distortion to the sensor itself due to the tremendous strain caused by magnetically induced pressures, which is proportional to the magnetic field squared (B2). Electrical breakdown in the intense field region is also a major concern. Other related challenges include, but are not limited to, bandwidth and inductance limitations and susceptibility issues related to electrical magnetic interference (EMI).
Date: November 30, 2006
Creator: (NSTec), Stephen Mitchen; (UNLV), Allen L. Johnson & (UNLV), John W. Farley
Item Type: Article

Comprehensive Epidemiologic Data Resource (CEDR) (Poster)

Description: This poster introduces the Comprehensive Epidemiologic Data Resource (CEDR), an electronic database with demographic, health outcome, and exposure information for over a million DOE nuclear plant and laboratory workers.
Date: December 12, 2012
Creator: (ORISE), Oak Ridge Institute for Science and Education
Item Type: Article

U.S. Department of Energy Human Subjects Research Database (HSRD) A model for internal oversight and external transparency

Description: This poster introduces the Department of Energy (DOE) Human Subjects Research Database (HSRD), which contains information on all Department of Energy research projects involving human subjects that: are funded by DOE; are conducted in DOE facilities; are performed by DOE personnel; include current or former DOE or contract personnel.
Date: December 12, 2012
Creator: (ORISE), Oak Ridge Institute for Science and Education
Item Type: Article

Reliability Results of NERSC Systems

Description: In order to address the needs of future scientific applications for storing and accessing large amounts of data in an efficient way, one needs to understand the limitations of current technologies and how they may cause systeminstability or unavailability. A number of factors can impact system availability ranging from facility-wide power outage to a single point of failure such as network switches or global file systems. In addition, individual component failure in a system can degrade the performance of that system. This paper focuses on analyzing both of these factors and their impacts on the computational and storage systems at NERSC. Component failure data presented in this report primarily focuses on disk drive in on of the computational system and tape drive failure in HPSS. NERSC collected available component failure data and system-wide outages for its computational and storage systems over a six-year period and made them available to the HPC community through the Petascale Data Storage Institute.
Date: May 27, 2008
Creator: (PDSI), Petascale Data Storage Institute; Mokhtarani, Akbar; Mokhtarani, Akbar; Kramer, William & Hick, Jason
Item Type: Report

SUPPORTED LIQUID CATALYSTS FOR REMOVAL OF HIGH TEMPERATURE FUEL CELL CONTAMINANTS

Description: A novel catalytic synthesis gas oxidation process using molten carbonate salts supported on compatible fluidized iron oxide particles (supported-liquid-phase-catalyst (SLPC) fluidized bed process) was investigated. This process combines the advantages of large scale fluidized bed processing with molten salt bath oxidation. Molten salt catalysts can be supported within porous fluidized particles in order to improve mass transfer rates between the liquid catalysts and the reactant gases. Synthesis gas can be oxidized at reduced temperatures resulting in low NO{sub x} formation while trace sulfides and halides are captured in-situ. Hence, catalytic oxidation of synthesis gas can be carried out simultaneously with hot gas cleanup. Such SLPC fluidized bed processes are affected by inter-particle liquid capillary forces that may lead to agglomeration and de-fluidization of the bed. An understanding of the origin and strength of these forces is needed so that they can be overcome in practice. Process design is based on thermodynamic free energy minimization calculations that indicate the suitability of eutectic Na{sub 2}CO{sub 3}/K{sub 2}CO{sub 3} mixtures for capturing trace impurities in-situ (< 1 ppm SO{sub x} released) while minimizing the formation of NO{sub x}(< 10 ppm). Iron oxide has been identified as a preferred support material since it is non-reactive with sodium, is inexpensive, has high density (i.e. inertia), and can be obtained in various particle sizes and porosities. Force balance modeling has been used to design a surrogate ambient temperature system that is hydrodynamically similar to the real system, thus allowing complementary investigation of the governing fluidization hydrodynamics. The primary objective of this research was to understand the origin of and to quantify the liquid capillary interparticle forces affecting the molten carbonate SLPC fluidized bed process. Substantial theoretical and experimental exploratory results indicate process feasibility. The potential environmental gain from success is enormous, impacting all areas of the ...
Date: January 1, 2000
Creator: (PI), Alan W. Weimer; Czerpak, Peter & Hilbert, Patrick
Item Type: Report

RTE1, A Novel Regulator of Ethylene Receptor Function

Description: RTE1 is a novel conserved gene found in both plants and animals. The main aims of this project were to: 1) examine Arabidopsis RTE1 function using genetic and cell biological analyses, and 2) determine whether the Arabidopsis RTH gene plays a role similar to that of RTE1 in ethylene signaling.
Date: February 5, 2013
Creator: (PI), Caren Chang
Item Type: Report

Multiphase Flow in Complex Fracture Apertures under a Wide Range of Flow Conditions

Description: A better understanding of multiphase flow through fractures requires knowledge of the detailed physics of interfacial flows at the microscopic pore scale. The objective of our project was to develop tools for the simulation of such phenomena. Complementary work was performed by a group led by Dr.~Paul Meakin of the Idaho National Engineering and Environmental Laboratory. Our focus was on the lattice-Boltzmann (LB) method. In particular, we studied both the statics and dynamics of contact lines where two fluids (wetting and non-wetting) meet solid boundaries. Previous work had noted deficiencies in the way LB methods simulate such interfaces. Our work resulted in significant algorithmic improvements that alleviated these deficiencies. As a result, we were able to study in detail the behavior of the dynamic contact angle in flow through capillary tubes. Our simulations revealed that our LB method reproduces the correct scaling of the dynamic contact angle with respect to velocity, viscosity, and surface tension, without specification of an artificial slip length. Further study allowed us to identify the microscopic origin of the dynamic contact angle in LB methods. These results serve to delineate the range of applicability of multiphase LB methods to flows through complex geometries.
Date: December 12, 2006
Creator: (PI), Daniel H. Rothman
Item Type: Report

Particle and Blood Cell Dynamics in Oscillatory Flows Final Report

Description: Our aim has been to uncover fundamental aspects of the suspension and dislodgement of particles in wall-bounded oscillatory flows, in flows characterized by Reynolds numbers en- compassing the situation found in rivers and near shores (and perhaps in some industrial processes). Our research tools are computational and our coverage of parameter space fairly broad. Computational means circumvent many complications that make the measurement of the dynamics of particles in a laboratory setting an impractical task, especially on the broad range of parameter space we plan to report upon. The impact of this work on the geophysical problem of sedimentation is boosted considerably by the fact that the proposed calculations can be considered ab-initio, in the sense that little to no modeling is done in generating dynamics of the particles and of the moving fluid: we use a three-dimensional Navier Stokes solver along with straightforward boundry conditions. Hence, to the extent that Navier Stokes is a model for an ideal incompressible isotropic Newtonian fluid, the calculations yield benchmark values for such things as the drag, buoyancy, and lift of particles, in a highly controlled environment. Our approach will be to make measurements of the lift, drag, and buoyancy of particles, by considering progressively more complex physical configurations and physics.
Date: September 1, 2008
Creator: (PI), Juan M. Restrepo
Item Type: Report

Continuous Severe Plastic Deformation Processing of Aluminum Alloys

Description: Metals with grain sizes smaller than 1-micrometer have received much attention in the past decade. These materials have been classified as ultra fine grain (UFG) materials (grain sizes in the range of 100 to 1000-nm) and nano-materials (grain size <100-nm) depending on the grain size. This report addresses the production of bulk UFG metals through the use of severe plastic deformation processing, and their subsequent use as stock material for further thermomechanical processing, such as forging. A number of severe plastic deformation (SPD) methods for producing bulk UFG metals have been developed since the early 1990s. The most promising of these processes for producing large size stock that is suitable for forging is the equal channel angular extrusion or pressing (ECAE/P) process. This process involves introducing large shear strain in the work-piece by pushing it through a die that consists of two channels with the same cross-sectional shape that meet at an angle to each other. Since the cross-sections of the two channels are the same, the extruded product can be re-inserted into the entrance channel and pushed again through the die. Repeated extrusion through the ECAE/P die accumulates sufficient strain to breakdown the microstructure and produce ultra fine grain size. It is well known that metals with very fine grain sizes (< 10-micrometer) have higher strain rate sensitivity and greater elongation to failure at elevated temperature, exhibiting superplastic behavior. However, this superplastic behavior is usually manifest at high temperature (> half the melting temperature on the absolute scale) and very low strain rates (< 0.0001/s). UFG metals have been shown to exhibit superplastic characteristics at lower temperature and higher strain rates, making this phenomenon more practical for manufacturing. This enables part unitization and forging more complex and net shape parts. Laboratory studies have shown that this is particularly true ...
Date: June 30, 2006
Creator: (PI), Raghavan Srinivasan; Chaudhury, Prabir K.; Cherukuri, Balakrishna; Han, Qingyou; Swenson, David & Gros, Percy
Item Type: Report

Collaborative Research: Metabolic Engineering of E. coli Sugar-Utilization Regulatory Systems for the Consumption of Plant Biomass Sugars.

Description: The overall objective of this project is to metabolically engineer the E. coli sugar-utilization regulatory systems (SURS) to utilize sugar mixtures obtained from plant biomass. Of particular relevance is the implementation of a metabolic engineering cycle aided by functional genomics and systems biology tools. Our findings will help in the establishment of a platform for the efficient production of fuels and chemicals from lignocellulosic sugars. Our research has improved the understanding of the role of SURS in regulating sugar utilization and several other cellular functions. For example, we discovered that Mlc, a global regulatory protein, regulates the utilization of xylose and demonstrated the existence of an important link between catabolite repression and respiratory/fermentative metabolism. The study of SURS mutants also revealed a connection between flagellar biosynthesis and catabolite repression. Several tools were also developed as part of this project. A novel tool (Elementary Network Decomposition, END) to help elucidate the network topology of regulatory systems was developed and its utility as a discovery tool was demonstrated by applying it to the SURS in E. coli. A novel method (and software) to estimate metabolic fluxes that uses labeling experiments and eliminates reliance on extracellular fluxes was also developed. Although not initially considered in the scope of this project, we have developed a novel and superior method for optimization of HPLC separation and applied it to the simultaneous quantification of different functionalities (sugars, organic acids, ethanol, etc.) present in our fermentation samples. Currently under development is a genetic network driven metabolic flux analysis framework to integrate transcriptional and flux data.
Date: March 31, 2006
Creator: (PI), Ramon Gonzalez; (Co-PI), J. V. Shanks & (Co-PI)., K-Y. San
Item Type: Report

DOE-ER-46139-Phase II-Final-Report-Tritt-2011

Description: This proposal emphasizes investigations of the thermal and electrical transport properties of new and novel solid-state materials, with the specific goal of achieving higher efficiency solid-state thermoelectric materials. This program will continue to build a very strong collaborative research effort between researchers at Oak Ridge National Laboratory (ONRL) and Clemson University. We propose three new faculty hires and major equipment purchases in order to further enhance our level of national recognition. We will be positioned for competition for major non-EPSCoR DOE and DOD funding (i.e. NSF-Materials Research Center) and able to address many other areas of DOE and national importance. Graduate and undergraduate students will be extensively involved in this project, spending significant time at ORNL, thus gaining important training and educational opportunities. We will also include an outreach program to bring in outside students and faculty. An External Advisory Board of distinguished scientists will provide oversight to the program.
Date: October 21, 2011
Creator: (PI), Terry M. Tritt
Item Type: Report

Magnetic Adsorption Method for the Treatment of Metal Contaminated Aqueous Waste

Description: There have been many recent developments in separation methods used for treating radioactive and non-radioactive metal bearing liquid wastes. These methods have included adsorption, ion exchange, solvent extraction and other chemical and physical techniques. To date very few, if any, of these processes can provide a low cost and environmentally benign solution. Recent research into the use of magnetite for wastewater treatment indicates the potential for magnetite both cost and environment drivers. A brief review of recent work in using magnetite as a sorbent is presented as well as recent work performed in our laboratory using supported magnetite in the presence of an external magnetic field. The application to groundwater and other aqueous waste streams is discussed. Recent research has focused on supporting magnetite in an economical (as compared to the magnetic polymine-epichlorohydrine resin) and inert (non-reactive, chemically or otherwise) environment that promotes both adsorption and satisfactory flow characteristics.
Date: March 1, 1999
Creator: (Parsons), G. B. Cotten; (INEEL), J. D. Navratil & Idaho), H. B. Eldredge (U of
Item Type: Article

Evaluation of Natural Attenuation as One Component of Chloroethene-Contaminated Groundwater Remediation

Description: Test Area North (TAN) at the Idaho National Engineering and Environmental Laboratory (INEEL) is the site of a large trichloroethene (TCE) plume resulting from the historical injection of wastewater into the Snake River Plain Aquifer. The TAN Record of Decision (ROD) selected pump and treat as the final remedy and included a contingency for post-ROD treatability studies of alternative technologies. The technologies still under consideration are in-situ bioremediation, in-situ chemical oxidation, and natural attenuation. Both anaerobic and aerobic laboratory microcosm studies indicate the presence of microorganisms capable of chloroethene degradation. Field data indicate that TCE concentrations decrease relative to tritium and tetrachloroethene indicating an as yet unknown process is contributing to natural attenuation of TCE. Several methods for analyzing the field data have been evaluated and important limitations identified. Early results from the continued evaluation of the three alternative technologies suggest the combined approach of active remediation of the source area (in situ bioremediation and/or chemical oxidation replacing or augmenting pump and treat) and natural attenuation within the dissolved phase plume may be more cost and schedule effective than the base case pump and treat.
Date: October 1, 1998
Creator: (Parsons), K.S. Sorenson; Peterson, L.N. & (LMITCO), T.S. Green
Item Type: Article

Development of Cost-Effective Low-Permeability Ceramic and Refractory Components for Aluminum Melting and Casting

Description: The primary goal of this project was to develop and validate new classes of cost-effective low-permeability ceramic and refractory components for handling molten aluminum in both melting and casting environments. Three approaches were employed with partial to full success to achieve this goal: (1) Develop materials and methods for sealing surface porosity in thermal-shock-resistant ceramic refractories; (2) Develop new ceramic coatings for extreme service in molten aluminum operations, with particular emphasis on coatings based on highly stable oxide phases; and (3) Develop new monolithic refractories designed for lower-permeability applications using controlled porosity gradients and particle size distributions. The results of the research work and the field tests performed utilizing these three approaches are listed below: (1) It was demonstrated that high-density IR heating could be a tool for altering and sealing the surface porosity of fused silica. However, the process was not very cost-effective. (2) A low-cost glaze composition having a coefficient of thermal expansion (CTE) similar to that of a DFS tube was identified and was successfully tested for its integrity and adherence to DFS. Although the glaze acted as a barrier between the molten aluminum and the DFS, persistent porosity and crazing within the glaze affected its performance during the reactivity tests, thus acting as an obstacle in scaling up production of this glaze. (3) Pyrotek's XL glaze showed great success in improving the life of the DFS tubes. Pyrotek has reported an increasing market demand for the XL-coated DFS tubes, which exhibit useful lifetimes three times better than those of uncoated tubes. (4) A computer model to optimize particle size distribution for reduced permeability was developed and successfully applied to casting formulations. Silica riser tubes produced using these new formulations have been tested in a commercial aluminum casting facility and have been reported to increase the life ...
Date: December 15, 2005
Creator: (Pyrotek), Dale E. Brown & (ORNL), Puja B. Kadolkar
Item Type: Report

A Transient Numerical Simulation of Perched Ground-Water Flow at the Test Reactor Area, Idaho National Engineering and Environmental Laboratory, Idaho, 1952-94

Description: Studies of flow through the unsaturated zone and perched ground-water zones above the Snake River Plain aquifer are part of the overall assessment of ground-water flow and determination of the fate and transport of contaminants in the subsurface at the Idaho National Engineering and Environmental Laboratory (INEEL). These studies include definition of the hydrologic controls on the formation of perched ground-water zones and description of the transport and fate of wastewater constituents as they moved through the unsaturated zone. The definition of hydrologic controls requires stratigraphic correlation of basalt flows and sedimentary interbeds within the saturated zone, analysis of hydraulic properties of unsaturated-zone rocks, numerical modeling of the formation of perched ground-water zones, and batch and column experiments to determine rock-water geochemical processes. This report describes the development of a transient numerical simulation that was used to evaluate a conceptual model of flow through perched ground-water zones beneath wastewater infiltration ponds at the Test Reactor Area (TRA).
Date: November 1, 1999
Creator: (USGS), B. R. Orr
Item Type: Report