Surveys of Organizational Culture and Safety Culture in Nuclear Power (open access)

Surveys of Organizational Culture and Safety Culture in Nuclear Power

The results of a survey of organizational culture at a nuclear power plant are summarized and compared with those of a similar survey which has been described in the literature on high-reliability organizations. A general-purpose cultural inventory showed a profile of organizational style similar to that reported in the literature; the factor structure for the styles was also similar to that of the plant previously described. A specialized scale designed to measure safety culture did not distinguish among groups within the organization that would be expected to differ.
Date: July 30, 2000
Creator: Brown, B. S.
System: The UNT Digital Library
A Two-Stage Model of Radiological Inspection: Spending Time (open access)

A Two-Stage Model of Radiological Inspection: Spending Time

The paper describes a model that visually portrays radiological survey performance as basic parameters (surveyor efficiency and criteria, duration of pause, and probe speed) are varied; field and laboratory tests provided typical parameter values. The model is used to illustrate how practical constraints on the time allotted to the task can affect radiological inspection performance. Similar analyses are applicable to a variety of other tasks (airport baggage inspection, and certain types of non-destructive testing) with similar characteristics and constraints.
Date: July 30, 2000
Creator: Brown, W. S.
System: The UNT Digital Library
Modeling of on-line catalyst addition effects in a short contact time reactor (open access)

Modeling of on-line catalyst addition effects in a short contact time reactor

Recently developed short-contact-time reactors (SCTR), consisting of porous alumina monoliths coated with platinum, have been shown to produce ethylene from rich ethane/oxygen(hydrogen) mixtures with yields and selectivities comparable to conventional steam cracking, using a reactor of much smaller size. Although the overall mechanism is clearly autothermal and catalytic, the details, in particular the relative contributions of heterogeneous and homogeneous chemistry, are a matter of considerable debate. Recent experiments show that reactor performance can be further enhanced by dripping a dilute platinum solution onto the SCTR front face during reaction, resulting in catalyst deposition within only a short (several millimeter) zone of the reactor. The authors have undertaken a computational study of this system, using two-dimensional computational fluid dynamics simulations with full heat and mass transport and detailed heterogeneous and homogeneous kinetic mechanisms. The results indicate that front-face catalyst loading enhances reactor performance by limiting the opportunity for heterogeneous ethane reactions that produce methane. As a result, ethylene selectivity increases and CH{sub 4} selectivity decreases. The results strongly support a mechanism recently proposed by the authors, in which rapid, heterogeneous oxidation of adsorbed hydrogen consumes most of the oxygen. The resulting heat is then released to the gas phase, causing homogeneous …
Date: July 30, 2000
Creator: Zerkle, D. K.; Allendorf, M. d.; Wolf, M. & Deutschmann, O.
System: The UNT Digital Library
Computerization of Nuclear Power Plant Emergency Operating Proce Dures. (open access)

Computerization of Nuclear Power Plant Emergency Operating Proce Dures.

None
Date: July 30, 2000
Creator: Ohara, J. M.
System: The UNT Digital Library
MUON STORAGE RINGS - NEUTRINO FACTORIES (open access)

MUON STORAGE RINGS - NEUTRINO FACTORIES

The concept of a muon storage ring based Neutrino Source (Neutrino Factory) has sparked considerable interest in the High Energy Physics community. Besides providing a first phase of a muon collider facility, it would generate more intense and well collimated neutrino beams than currently available. The BNL-AGS or some other proton driver would provide an intense proton beam that hits a target, produces pions that decay into muons. The muons must be cooled, accelerated and injected into a storage ring with a long straight section where they decay. The decays occurring in the straight sections of the ring would generate neutrino beams that could be directed to detectors located thousands of kilometers away, allowing studies of neutrino oscillations with precisions not currently accessible. For example, with the neutrino source at BNL, detectors at Soudan, Minnesota (1,715 km), and Gran Sasso, Italy (6,527 km) become very interesting possibilities. The feasibility of constructing and operating such a muon-storage-ring based Neutrino-Factory, including geotechnical questions related to building non-planar storage rings (e.g. at 8{degree} angle for BNL-Soudan, and 3{degree} angle for BNL-Gran Sasso) along with the design of the muon capture, cooling, acceleration, and storage ring for such a facility is being explored by …
Date: May 30, 2000
Creator: PARSA,Z.
System: The UNT Digital Library
Combined pdf-sdf approach to partially premixed turbulent combustion (open access)

Combined pdf-sdf approach to partially premixed turbulent combustion

Partially premixed turbulent flames can develop flow regimes where triple flames emerge consisting of essentially premixed and non-premixed zones. The description of such phenomena requires a criterion for the detection of such zones. Such a criterion can be based on a wide range of variables including reaction rates, mass fractions of radicals, etc. These variables are not necessarily suitable for the limit of infinitely fast reactions, for instance, reaction rates are obviously not bounded in this limit. Hence a new single scalar variable based on geometric properties of mixture fraction and non-conserved variables is constructed, that allows the detection of finite rate and, in particular, triple flame domains and is bounded in the limit of infinitely fast reactions. This is first done for systems with simplified chemistry described by two variables and then generalized to combustion with complex chemistry. A pdf-sdf formalism is then outlined for the local thermodynamic state conditioned upon the degree of finite rate effects.
Date: July 30, 2000
Creator: Chen, Jacqueline H. & Im, Hong G.
System: The UNT Digital Library
H-Morph: An indirect approach to advancing front hex meshing (open access)

H-Morph: An indirect approach to advancing front hex meshing

H-Morph is a new automatic algorithm for the generation of a hexahedral-dominant finite element mesh for arbitrary volumes. The H-Morph method starts with an initial tetrahedral mesh and systematically transforms and combines tetrahedral into hexahedra. It uses an advancing front technique where the initial front consists of a set of prescribed quadrilateral surface facets. Fronts are individually processed by recovering each of the six quadrilateral faces of a hexahedron from the tetrahedral mesh. Recovery techniques similar to those used in boundary constrained Delaunay mesh generation are used. Tetrahedral internal to the six hexahedral faces are then removed and a hexahedron is formed. At any time during the H-Morph procedure a valid mixed hexahedral-tetrahedral mesh is in existence within the volume. The procedure continues until no tetrahedral remain within the volume, or tetrahedral remain which cannot be transformed or combined into valid hexahedral elements. Any remaining tetrahedral are typically towards the interior of the volume, generally a less critical region for analysis. Transition from tetrahedral to hexahedra in the final mesh is accomplished through pyramid shaped elements. Advantages of the proposed method include its ability to conform to an existing quadrilateral surface mesh, its ability to mesh without the need to …
Date: May 30, 2000
Creator: OWEN,STEVEN J. & SAIGAL,SUNIL
System: The UNT Digital Library
Unsupervised hyperspectral image analysis using independent component analysis (ICA) (open access)

Unsupervised hyperspectral image analysis using independent component analysis (ICA)

In this paper, an ICA-based approach is proposed for hyperspectral image analysis. It can be viewed as a random version of the commonly used linear spectral mixture analysis, in which the abundance fractions in a linear mixture model are considered to be unknown independent signal sources. It does not require the full rank of the separating matrix or orthogonality as most ICA methods do. More importantly, the learning algorithm is designed based on the independency of the material abundance vector rather than the independency of the separating matrix generally used to constrain the standard ICA. As a result, the designed learning algorithm is able to converge to non-orthogonal independent components. This is particularly useful in hyperspectral image analysis since many materials extracted from a hyperspectral image may have similar spectral signatures and may not be orthogonal. The AVIRIS experiments have demonstrated that the proposed ICA provides an effective unsupervised technique for hyperspectral image classification.
Date: June 30, 2000
Creator: Chiang, S. S. & Ginsberg, I. W.
System: The UNT Digital Library
What is coherent in neutrino oscillations - the analog with a two-slit experiment. (open access)

What is coherent in neutrino oscillations - the analog with a two-slit experiment.

None
Date: May 30, 2000
Creator: Lipkin, H. J.
System: The UNT Digital Library
A case study in working with cell-centered data (open access)

A case study in working with cell-centered data

This case study provides examples of how some simple decisions the authors made in structuring their algorithms for handling cell-centered data can dramatically influence the results. Although they all know that these decisions produce variations in results, they think that they underestimate the potential magnitude of the differences. More importantly, the users of the codes may not be aware that these choices have been made or what they mean to the resulting visualizations of their data. This raises the question of whether or not these decisions are inadvertently distorting user interpretations of data sets.
Date: March 30, 2000
Creator: CROSSNO,PATRICIA J.
System: The UNT Digital Library
Future Lepton Colliders and Laser Acceleration (open access)

Future Lepton Colliders and Laser Acceleration

Future high energy colliders along with their physics potential, and relationship to new laser technology are discussed. Experimental approaches and requirements for New Physics exploration are also described.
Date: May 30, 2000
Creator: Parsa, Z.
System: The UNT Digital Library
Interprocessor communication with memory constraints (open access)

Interprocessor communication with memory constraints

Many parallel applications require periodic redistribution of workloads and associated data. In a distributed memory computer, this redistribution can be difficult if limited memory is available for receiving messages. The authors propose a model for optimizing the exchange of messages under such circumstances which they call the minimum phase remapping problem. They first show that the problem is NP-Complete, and then analyze several methodologies for addressing it. First, they show how the problem can be phrased as an instance of multi-commodity flow. Next, they study a continuous approximation to the problem. They show that this continuous approximation has a solution which requires at most two more phases than the optimal discrete solution, but the question of how to consistently obtain a good discrete solution from the continuous problem remains open. Finally, they devise a simple and practical approximation algorithm for the problem with a bound of 1.5 times the optimal number of phases.
Date: May 30, 2000
Creator: PINAR,ALI & HENDRICKSON,BRUCE A.
System: The UNT Digital Library
A linear mixture analysis-based compression for hyperspectral image analysis (open access)

A linear mixture analysis-based compression for hyperspectral image analysis

In this paper, the authors present a fully constrained least squares linear spectral mixture analysis-based compression technique for hyperspectral image analysis, particularly, target detection and classification. Unlike most compression techniques that directly deal with image gray levels, the proposed compression approach generates the abundance fractional images of potential targets present in an image scene and then encodes these fractional images so as to achieve data compression. Since the vital information used for image analysis is generally preserved and retained in the abundance fractional images, the loss of information may have very little impact on image analysis. In some occasions, it even improves analysis performance. Airborne visible infrared imaging spectrometer (AVIRIS) data experiments demonstrate that it can effectively detect and classify targets while achieving very high compression ratios.
Date: June 30, 2000
Creator: Chang, C. I. & Ginsberg, I. W.
System: The UNT Digital Library
Semiconductor product analysis challenges based on the 1999 ITRS (open access)

Semiconductor product analysis challenges based on the 1999 ITRS

One of the most significant challenges for technology characterization and future analysis is to keep instrumentation and techniques in step with the development of technology itself. Not only are dimensions shrinking and new materials being employed, but the rate of change is increasing. According to the 1999 International Technology Roadmap for Semiconductors (ITRS) the number and difficulty of the technical challenges continue to increase as technology moves forward. It could be argued that technology cannot be developed without appropriate analytical technique, nevertheless while much effort is being directed at materials and processes, only a small proportion is being directed at analysis. Whereas previous versions of the Semiconductor Industry Association roadmap contained a small number of implicit references to characterization and analysis, the 1999 ITRS contains many explicit references. It is clear that characterization is now woven through the roadmap, and technology developers in all areas appreciate the fact that new instrumentation and techniques will be required to sustain the rate of development the semiconductor industry has seen in recent years. Late in 1999, a subcommittee of the Sematech Product Analysis Forum reviewed the ITRS and identified a top-ten list of challenges which the failure analysis community will face as present …
Date: May 30, 2000
Creator: Joseph, Thomas W.; Anderson, Richard E.; Gilfeather, Glen; Leclaire, Carole & Yim, Daniel
System: The UNT Digital Library
Hand-held radio-isotope detection and identification instrument (open access)

Hand-held radio-isotope detection and identification instrument

An instrument combining an array of Cadmium-Zinc-Telluride (CZT) detectors, a NaI scintillator, and two {sup 3}He neutron detectors has been constructed. The instrument uses the CZT array to identify radioactive materials. As an example of this application, the 3 {sigma} Minimum Detectable Activity for the 375 keV peak of {sup 238}Pu is less than 1 gram at a distance of 20 cm for a 100-second counting time. The 2 x 2 NaI scintillator has a dual purpose. First, it is used to supplement the CZT array for identification of high-energy gammas, such as those from {sup 60}Co. Second, the principle use of the NaI scintillator is to help search for radioactive material and to find a suitable measurement location on a suspect package for the CZT-based isotope-identification measurement. This detector also produces energy-corrected exposure-rate data. The {sup 3}He neutron detectors provide an additional confirmation of the presence of some plutonium isotopes. The neutron sensitivity is 90 counts per second at 20 cm from a moderated {sup 252}Cf neutron source.
Date: April 30, 2000
Creator: Quam, W. M.
System: The UNT Digital Library
Direct energy conversion in fission reactors: A U.S. NERI project (open access)

Direct energy conversion in fission reactors: A U.S. NERI project

In principle, the energy released by a fission can be converted directly into electricity by using the charged fission fragments. The first theoretical treatment of direct energy conversion (DEC) appeared in the literature in 1957. Experiments were conducted over the next ten years, which identified a number of problem areas. Research declined by the late 1960's due to technical challenges that limited performance. Under the Nuclear Energy Research Initiative the authors are determining if these technical challenges can be overcome with todays technology. The authors present the basic principles of DEC reactors, review previous research, discuss problem areas in detail, and identify technological developments of the last 30 years that can overcome these obstacles. As an example, the fission electric cell must be insulated to avoid electrons crossing the cell. This insulation could be provided by a magnetic field as attempted in the early experiments. However, from work on magnetically insulated ion diodes they know how to significantly improve the field geometry. Finally, a prognosis for future development of DEC reactors will be presented .
Date: May 30, 2000
Creator: Slutz, Stephen A.; Seidel, David B.; Polansky, Gary F.; Rochau, Gary E.; Lipinski, Ronald J.; Besenbruch, G. et al.
System: The UNT Digital Library
Evaluating intensified camera systems (open access)

Evaluating intensified camera systems

This paper describes image evaluation techniques used to standardize camera system characterizations. The authors group is involved with building and fielding several types of camera systems. Camera types include gated intensified cameras, multi-frame cameras, and streak cameras. Applications range from X-ray radiography to visible and infrared imaging. Key areas of performance include sensitivity, noise, and resolution. This team has developed an analysis tool, in the form of image processing software, to aid an experimenter in measuring a set of performance metrics for their camera system. These performance parameters are used to identify a camera system's capabilities and limitations while establishing a means for camera system comparisons. The analysis tool is used to evaluate digital images normally recorded with CCD cameras. Electro-optical components provide fast shuttering and/or optical gain to camera systems. Camera systems incorporate a variety of electro-optical components such as microchannel plate (MCP) or proximity focused diode (PFD) image intensifiers; electro-static image tubes; or electron-bombarded (EB) CCDs. It is often valuable to evaluate the performance of an intensified camera in order to determine if a particular system meets experimental requirements.
Date: June 30, 2000
Creator: Baker, S. A.
System: The UNT Digital Library
Fault current limiter-predominantly resistive behavior of a BSCCO shielded-core reactor (open access)

Fault current limiter-predominantly resistive behavior of a BSCCO shielded-core reactor

Tests were conducted to determine the electrical and magnetic characteristics of a superconductor shielded core reactor (SSCR). The results show that a closed-core SSCR is predominantly a resistive device and an open-core SSCR is a hybrid resistive/inductive device. The open-core SSCR appears to dissipate less than the closed-core SSCR. However, the impedance of the open-core SSCR is less than that of the closed-core SSCR. Magnetic and thermal diffusion are believed to be the mechanism that facilitates the penetration of the superconductor tube under fault conditions.
Date: June 30, 2000
Creator: Ennis, M. G.; Tobin, T. J.; Cha, Y. S. & Hull, J. R.
System: The UNT Digital Library
Effects of flow transients on the burning velocity of hydrogen-air premixed flames (open access)

Effects of flow transients on the burning velocity of hydrogen-air premixed flames

The effects of unsteady strain rate on the burning velocity of hydrogen-air premixed flames are studied in an opposed nozzle configuration. The numerical method employs adaptive time integration of a system of differential-algebraic equations. Detailed hydrogen-air kinetic mechanism and transport properties are considered. The equivalence ratio is varied from lean to rich premixtures in order to change the effective Lewis number. Steady Markstein numbers for small strain rate are computed and compared with experiment. Different definitions of flame burning velocity are examined under steady and unsteady flow conditions. It is found that, as the unsteady frequency increases, large deviations between different flame speeds are noted depending on the location of the flame speed evaluation. Unsteady flame response is investigated in terms of the Markstein transfer function which depends on the frequency of oscillation. In most cases, the flame speed variation attenuates at higher frequencies, as the unsteady frequency becomes comparable to the inverse of the characteristic flame time. Furthermore, unique resonance-like behavior is observed for a range of rich mixture conditions, consistent with previous studies with linearized theory.
Date: July 30, 2000
Creator: Im, H. G. & Chen, J. H.
System: The UNT Digital Library
FACET: an object-oriented software framework for modeling complex social behavior patterns (open access)

FACET: an object-oriented software framework for modeling complex social behavior patterns

The Framework for Addressing Cooperative Extended Transactions (FACET) is a flexible, object-oriented architecture for implementing models of dynamic behavior of multiple individuals, or agents, in a simulation. These agents can be human (individuals or organizations) or animal and may exhibit any type of organized social behavior that can be logically articulated. FACET was developed by Argonne National Laboratory's (ANL) Decision and Information Sciences Division (DIS) out of the need to integrate societal processes into natural system simulations. The FACET architecture includes generic software components that provide the agents with various mechanisms for interaction, such as step sequencing and logic, resource management, conflict resolution, and preemptive event handling. FACET components provide a rich environment within which patterns of behavior can be captured in a highly expressive manner. Interactions among agents in FACET are represented by Course of Action (COA) object-based models. Each COA contains a directed graph of individual actions, which represents any known pattern of social behavior. The agents' behavior in a FACET COA, in turn, influences the natural landscape objects in a simulation (i.e., vegetation, soil, and habitat) by updating their states. The modular design of the FACET architecture provides the flexibility to create multiple and varied simulation scenarios …
Date: June 30, 2000
Creator: Dolph, J. E.; Christiansen, J. H. & Sydelko, P. J.
System: The UNT Digital Library
Design and first tests of the CDF Run 2 farms (open access)

Design and first tests of the CDF Run 2 farms

The high energy physics experiment CDF, located in the anti-proton-proton collider at Fermilab, will write data in Run 2 at a rate of 20 MByte/s, twenty times the rate of Run 1. The offline production system must be able to handle this rate. Components of that system include a large PC farm, I/O systems to read/write data to and from mass storage, and a system to split the reconstructed data into physics streams which are required for analysis. All of the components must work together seamlessly to ensure the necessary throughput. A description will be given of the overall hardware and software design for the system. A small prototype farm has been used for about one year to study performance, to test software designs and for the first Mock Data Challenge. Results from the tests and experience from the first Mock Data Challenge will be discussed. The hardware for the first production farm is in place and will be used for the second Mock Data Challenge. Finally, the possible scaling of the system to handle larger rates foreseen later in Run 2 will be described.
Date: May 30, 2000
Creator: al., Jaroslav Antos et
System: The UNT Digital Library
Hex-dominant mesh generation using 3D constrained triangulation (open access)

Hex-dominant mesh generation using 3D constrained triangulation

A method for decomposing a volume with a prescribed quadrilateral surface mesh, into a hexahedral-dominated mesh is proposed. With this method, known as Hex-Morphing (H-Morph), an initial tetrahedral mesh is provided. Tetrahedral are transformed and combined starting from the boundary and working towards the interior of the volume. The quadrilateral faces of the hexahedra are treated as internal surfaces, which can be recovered using constrained triangulation techniques. Implementation details of the edge and face recovery process are included. Examples and performance of the H-Morph algorithm are also presented.
Date: May 30, 2000
Creator: Owen, Steven J.
System: The UNT Digital Library
Studies of tritiated co-deposited layers in TFTR (open access)

Studies of tritiated co-deposited layers in TFTR

Plasma facing components in TFTR contain an important record of plasma wall interactions in reactor grade DT plasmas. Tiles, flakes, wall coupons and dust samples have been retrieved from the TFTR vessel for analysis. Selected samples have been baked to release tritium and assay the tritium content. The in-vessel tritium inventory is estimated to be 0.5 g and is consistent with the in-vessel tritium inventory derived from the difference between tritium fueling and tritium exhaust. Relatively high concentrations of tritium were found at the top and bottom of the bumper limiter, as predicted by earlier BBQ modeling. The distribution of tritium on the limiter and vessel wall showed complex patterns of co-deposition.
Date: May 30, 2000
Creator: Skinner, C. H.; Gentile, C. A.; Ascione, G.; Causey, R. A.; Hayaski, T.; Hogan, J. et al.
System: The UNT Digital Library
U1h shaft project (open access)

U1h shaft project

The U1h shaft project is a design/build subcontract to construct one 20 foot (ft) finished diameter shaft to a depth of 1,045 ft at the Nevada Test Site. Atkinson Construction was subcontracted by Bechtel Nevada to construct the U1h Shaft for the Department of Energy. The project consists of furnishing and installing the sinking plant, construction of the 1,045 ft of concrete lined shaft, development of a shaft station at a depth of 976 ft, and construction of a loading pocket at the station. The outfitting of the shaft and installation of a new hoist may be incorporated into the project at a later date. This paper should be of interest to those involved with the construction of relatively deep shafts and underground excavations.
Date: June 30, 2000
Creator: Briggs, Brian & Musick, R. G.
System: The UNT Digital Library