Accelerating the Reduction of Excess Russian Highly Enriched Uranium (open access)

Accelerating the Reduction of Excess Russian Highly Enriched Uranium

This paper presents the latest information on one of the Accelerated Highly Enriched Uranium (HEU) Disposition initiatives that resulted from the May 2002 Summit meeting between Presidents George W. Bush and Vladimir V. Putin. These initiatives are meant to strengthen nuclear nonproliferation objectives by accelerating the disposition of nuclear weapons-useable materials. The HEU Transparency Implementation Program (TIP), within the National Nuclear Security Administration (NNSA) is working to implement one of the selected initiatives that would purchase excess Russian HEU (93% 235U) for use as fuel in U.S. research reactors over the next ten years. This will parallel efforts to convert the reactors' fuel core from HEU to low enriched uranium (LEU) material, where feasible. The paper will examine important aspects associated with the U.S. research reactor HEU purchase. In particular: (1) the establishment of specifications for the Russian HEU, and (2) transportation safeguard considerations for moving the HEU from the Mayak Production Facility in Ozersk, Russia, to the Y-12 National Security Complex in Oak Ridge, TN.
Date: February 18, 2004
Creator: Benton, J; Wall, D; Parker, E & Rutkowski, E
System: The UNT Digital Library
Adaptations of the Purge Water Management System for Long-Term Groundwater Monitoring at Savannah River Site, South Carolina (final) (open access)

Adaptations of the Purge Water Management System for Long-Term Groundwater Monitoring at Savannah River Site, South Carolina (final)

To monitor the groundwater contamination and the effectiveness of remedial actions, over a thousand monitoring wells are in active operation (i.e., require quarterly or semi-annual sampling) at SRS. Most wells are expected to continue in operation for another 20 to 40 more years. Required sample volumes can range from a less than a liter to 10 liters. To support the long-term groundwater monitoring requirements of these wells, SRS actively seeks technologies that can maximize data acquisition and minimize costs. To meet this end, SRS has implemented the Purge Water Management System (PWMS). The key attributes of this system lie in its ability to reduce or eliminate the generation of purged groundwater, which is costly in terms of the time and management.
Date: February 10, 2004
Creator: Schiefer, E
System: The UNT Digital Library
Adapting high-resolution speckle imaging to moving targets and platforms (open access)

Adapting high-resolution speckle imaging to moving targets and platforms

High-resolution surveillance imaging with apertures greater than a few inches over horizontal or slant paths at optical or infrared wavelengths will typically be limited by atmospheric aberrations. With static targets and static platforms, we have previously demonstrated near-diffraction limited imaging of various targets including personnel and vehicles over horizontal and slant paths ranging from less than a kilometer to many tens of kilometers using adaptations to bispectral speckle imaging techniques. Nominally, these image processing methods require the target to be static with respect to its background during the data acquisition since multiple frames are required. To obtain a sufficient number of frames and also to allow the atmosphere to decorrelate between frames, data acquisition times on the order of one second are needed. Modifications to the original imaging algorithm will be needed to deal with situations where there is relative target to background motion. In this paper, we present an extension of these imaging techniques to accommodate mobile platforms and moving targets.
Date: February 5, 2004
Creator: Carrano, C J & Brase, J M
System: The UNT Digital Library
Analysis and Simulation of the Structure of Nanoparticles That Undergo a Surface-Driven Structural Transformation (open access)

Analysis and Simulation of the Structure of Nanoparticles That Undergo a Surface-Driven Structural Transformation

This report addresses the analysis and simulation of the structure of nanoparticles that undergo a surface-driven structural transformation.
Date: February 1, 2004
Creator: Gilbert, Benjamin; Zhang, Hengzhong; Huang, Feng; Ren, Yang; Haskel, Daniel; Lang, J.C. et al.
System: The UNT Digital Library
Analysis of Boron Dilution Transients in PWRS. (open access)

Analysis of Boron Dilution Transients in PWRS.

A study has been carried out with PARCS/RELAP5 to understand the consequences of hypothetical boron dilution events in pressurized water reactors. The scenarios of concern start with a small-break loss-of-coolant accident. If the event leads to boiling in the core and then the loss of natural circulation, a boron-free condensate can accumulate in the cold leg. The dilution event happens when natural circulation is re-established or a reactor coolant pump (RCP) is restarted in violation of operating procedures. This event is of particular concern in B&W reactors with a lowered-loop design and is a Generic Safety Issue for the U.S. Nuclear Regulatory Commission. The results of calculations with the reestablishment of natural circulation show that there is no unacceptable fuel damage. This is determined by calculating the maximum fuel pellet enthalpy, based on the three-dimensional model, and comparing it with the criterion for damage. The calculation is based on a model of a B&W reactor at beginning of the fuel cycle. If an RCP is restarted, unacceptable fuel damage may be possible in plants with sufficiently large volumes of boron-free condensate in the cold leg.
Date: February 4, 2004
Creator: Diamond, David J.; Bromley, Blair P. & Aronson, Arnold L.
System: The UNT Digital Library
Analysis of High-n Dielectronic Rydberg Satellites in the Spectra of Na-like ZnXX and Mg-like ZnXIX (open access)

Analysis of High-n Dielectronic Rydberg Satellites in the Spectra of Na-like ZnXX and Mg-like ZnXIX

We have observed spectra from highly charged zinc ions in a variety of laser-produced plasmas. Spectral features that are Na- and Mg-like satellites to high-n Rydberg transitions in the Ne-like ZnXXI spectrum are analyzed and modeled. Identifications and analysis are made by comparison with highly accurate atomic structure calculations and steady state collisional-radiative models. Each observed ZnXX and ZnXIX feature comprises up to {approx} 2 dozen individual transitions, these transitions are excited principally by dielectronic recombination through autoionizing levels in Na- and Mg-like Zn{sup 19+} Zn{sup 18+}. We find these satellites to be ubiquitous in laser-produced plasmas formed by lasers with pulse lengths that span four orders of magnitude, from 1 ps to {approx} 10 ns. The diagnostic potential of these Rydberg satellite lines is demonstrated.
Date: February 19, 2004
Creator: Petrocelli, G; Vinogradov, V I; Magunov, A I; Flora, F; Martellucci, S; Matafonov, A P et al.
System: The UNT Digital Library
An analytical solution for transient radial flow through unsaturated fractured porous media (open access)

An analytical solution for transient radial flow through unsaturated fractured porous media

This paper presents analytical solutions for one-dimensional radial transient flow through horizontal, unsaturated fractured rock formation. In these solutions, unsaturated flow through fractured media is described by a linearized Richards' equation, while fracture-matrix interaction is handled using the dual-continuum concept. Although linearizing Richards' equation requires a specially correlated relationship between relative permeability and capillary pressure functions for both fractures and matrix, these specially formed relative permeability and capillary pressure functions are still physically meaningful. These analytical solutions can thus be used to describe the transient behavior of unsaturated flow in fractured media under the described model conditions. They can also be useful in verifying numerical simulation results, which, as demonstrated in this paper, are otherwise difficult to validate.
Date: February 13, 2004
Creator: Wu, Yu-Shu & Pan, Lehua
System: The UNT Digital Library
Annual Growth Bands in Hymenaea courbaril (open access)

Annual Growth Bands in Hymenaea courbaril

One significant source of annual temperature and precipitation data arises from the regular annual secondary growth rings of trees. Several tropical tree species are observed to form regular growth bands that may or may not form annually. Such growth was observed in one stem disk of the tropical legume Hymenaea courbaril near the area of David, Panama. In comparison to annual reference {Delta}{sup 14}C values from wood and air, the {Delta}{sup 14}C values from the secondary growth rings formed by H. courbaril were determined to be annual in nature in this one stem disk specimen. During this study, H. courbaril was also observed to translocate recently produced photosynthate into older growth rings as sapwood is converted to heartwood. This process alters the overall {Delta}{sup 14}C values of these transitional growth rings as cellulose with a higher {Delta}{sup 14}C content is translocated into growth rings with a relatively lower {Delta}{sup 14}C content. Once the annual nature of these growth rings is established, further stable isotope analyses on H. courbaril material in other studies may help to complete gaps in the understanding of short and of long term global climate patterns.
Date: February 9, 2004
Creator: Westbrook, J. A.; Guilderson, T. P. & Colinvaux, P. A.
System: The UNT Digital Library
Anthocyanidin reductases from Medicago truncatula and Arabidopsis thaliana (open access)

Anthocyanidin reductases from Medicago truncatula and Arabidopsis thaliana

Article on anthocyanidin reductases from Medicago truncatula and Arabidopsis thaliana.
Date: February 1, 2004
Creator: Xie, De-Yu; Sharma, Shashi B. & Dixon, R. A.
System: The UNT Digital Library
An Application of the Coda Methodology for Moment-Rate Spectra Using Broadband Stations in Turkey (open access)

An Application of the Coda Methodology for Moment-Rate Spectra Using Broadband Stations in Turkey

A recently developed coda magnitude methodology was applied to selected broadband stations in Turkey for the purpose of testing the coda method in a large, laterally complex region. As found in other, albeit smaller regions, coda envelope amplitude measurements are significantly less variable than distance-corrected direct wave measurements (i.e., L{sub g} and surface waves) by roughly a factor 3-to-4. Despite strong lateral crustal heterogeneity in Turkey, we found that the region could be adequately modeled assuming a simple 1-D, radially symmetric path correction for 10 narrow frequency bands ranging between 0.02 to 2.0 Hz. For higher frequencies however, 2-D path corrections will be necessary and will be the subject of a future study. After calibrating the stations ISP, ISKB, and MALT for local and regional distances, single-station moment-magnitude estimates (M{sub w}) derived from the coda spectra were in excellent agreement with those determined from multi-station waveform modeling inversions of long-period data, exhibiting a data standard deviation of 0.17. Though the calibration was validated using large events, the results of the calibration will extend M{sub w} estimates to significantly smaller events which could not otherwise be waveform modeled due to poor signal-to-noise ratio at long periods and sparse station coverage. The …
Date: February 3, 2004
Creator: Eken, T; Mayeda, K; Hofstetter, A; Gok, R; Orgulu, G & Turkelli, N
System: The UNT Digital Library
Applications of contaminant fate and bioaccumulation models in assessing ecological risks of chemicals: A case study for gasoline hydrocarbons (open access)

Applications of contaminant fate and bioaccumulation models in assessing ecological risks of chemicals: A case study for gasoline hydrocarbons

Mass balance models of chemical fate and transport can be applied in ecological risk assessments for quantitative estimation of concentrations in air, water, soil and sediment. These concentrations can, in turn, be used to estimate organism exposures and ultimately internal tissue concentrations that can be compared to mode-of-action-based critical body residues that correspond to toxic effects. From this comparison, risks to the exposed organism can be evaluated. To illustrate the practical utility of fate models in ecological risk assessments of commercial products, the EQC model and a simple screening level biouptake model including three organisms, (a bird, a mammal and a fish) is applied to gasoline. In this analysis, gasoline is divided into 24 components or ''blocks'' with similar environmental fate properties that are assumed to elicit ecotoxicity via a narcotic mode of action. Results demonstrate that differences in chemical properties and mode of entry into the environment lead to profound differences in the efficiency of transport from emission to target biota. We discuss the implications of these results and insights gained into the regional fate and ecological risks associated with gasoline. This approach is particularly suitable for assessing mixtures of components that have similar modes of action. We conclude …
Date: February 1, 2004
Creator: MacLeod, Matthew; McKone, Thomas E.; Foster, Karen L.; Maddalena, Randy L.; Parkerton, Thomas F. & Mackay, Don
System: The UNT Digital Library
Applying INEEL Research and Technologies to Improve LLW Disposal (open access)

Applying INEEL Research and Technologies to Improve LLW Disposal

The low-level radioactive waste (LLW) disposal facility at the Idaho National Engineering and Environmental Laboratory (INEEL) is operated in compliance with United States Department of Energy (DOE) Order 435.1, “Radioactive Waste Management.” DOE Order 435.1 includes requirements to conduct a performance assessment and composite analysis (PA/CA) to project the potential doses that may be received by a member of the public as a result of releases that may occur from the facility and other surrounding sources. Although the PA/CA were deemed sufficient to justify issuing the Disposal Authorization for the disposal facility, the DOE Low-Level Waste Disposal Facilities Federal Review Group (LFRG) identified some assumptions that required additional confirmation. Thus, the Disposal Authorization was granted with some conditions that required resolution in order to maintain the capability to operate the LLW disposal facility. This paper summarizes INEEL research and technologies that contributed to successful resolution of all of the conditions imposed on the Disposal Authorization.
Date: February 1, 2004
Creator: Seitz, Roger R.
System: The UNT Digital Library
Applying New Methods to Research Reactor Analysis. (open access)

Applying New Methods to Research Reactor Analysis.

Detailed reactor physics and safety analyses are being performed for the 20 MW D{sub 2}O-moderated research reactor at the National Institute of Standards and Technology (NIST). The analyses employ state-of-the-art calculational methods and will contribute to an update to the Final Safety Analysis Report (FSAR). Three-dimensional MCNP Monte Carlo neutron and photon transport calculations are performed to determine power and reactivity parameters, including feedback coefficients and control element worths. The core depletion and determination of the fuel compositions are performed with MONTEBURNS to model the reactor at the beginning, middle, and end-of-cycle. The time-dependent analysis of the primary loop is determined with a RELAP5 transient analysis model that includes the pump, heat exchanger, fuel element geometry, and flow channels. A statistical analysis used to assure protection from critical heat flux (CHF) is performed using a Monte Carlo simulation of the uncertainties contributing to the CHF calculation. The power distributions used to determine the local fuel conditions and margin to CHF are determined with MCNP. Evaluations have been performed for the following accidents: (1) the control rod withdrawal startup accident, (2) the maximum reactivity insertion accident, (3) loss-of-flow resulting from loss of electrical power, (4) loss-of-flow resulting from a primary pump …
Date: February 5, 2004
Creator: Diamond, David J.; Cheng, L.; Hanson, A.; Xu, J. & Carew, J. F.
System: The UNT Digital Library
Arsenic Mobilization from Contaminated Sediments: A Full-scale Experiment in Progress (open access)

Arsenic Mobilization from Contaminated Sediments: A Full-scale Experiment in Progress

The mobilization of arsenic was examined in a system where the deposition of iron and arsenic have been substantially modified by large-scale manipulations. This engineering practice was designed to decrease arsenic concentrations in water supplied to the City of Los Angeles. Accomplishing this objective, however, has resulted in significant accumulation of arsenic and iron in the sediments of a reservoir on the Los Angeles Aqueduct. Arsenic and iron are released into the porewater at depth in the sediment, consistent with reductive dissolution of iron(III) oxyhydroxides. Factors influencing the possible re-sorption of arsenic onto residual iron(III) oxyhydroxides solids have been examined. Reduction of As(V) to As(III) alone cannot account for arsenic mobilization since arsenic occurs in the solid phase as As(III) well above the depth at which it is released into the porewater. Competition from other porewater constituents could suppress re-sorption of arsenic released by reductive dissolution.
Date: February 3, 2004
Creator: O'Day, P A; Campbell, K; Dixit, S & Hering, J G
System: The UNT Digital Library
Asymmetric injection of cathodic arc plasma into a macroparticlefilter (open access)

Asymmetric injection of cathodic arc plasma into a macroparticlefilter

The cathodic arc plasmas produced by cathode spots usuallyinclude macroparticles, which is undesirable for many applications. Acommon way of removing macroparticles is to use curved solenoid filterswhich guide the plasma from the source to the substrate. In this work, anarc source with relatively small cathode is used, limiting the possiblelocations of plasma production. The relative position of cathodic arcsource and macroparticle filtered was systematically varied and thefiltered plasma current was recorded. It was found that axis-symmetricplasma injection leads to maximum throughput only if an anode aperturewas used, which limited the plasma to near-axis flow by scraping offplasma at larger angles to the axis. When the anode aperture was removed,more plasma could enter the filter. In this case, maximum filtered ioncurrent was achieved when the plasma was injected off-axis, namely offsetin the direction where the filter is curved. Such behavior wasanticipated because the plasma column in the filter is known to beshifted by ExB and centrifugal drift as well as by non-axis-symmetriccomponents of the magnetic field in the filter entrance and exit plane.The data have implications for plasma transport variations caused bydifferent spot locations on cathodes that are not small compared to thefilter cross section.
Date: February 11, 2004
Creator: Anders, Andre & MacGill, Robert A.
System: The UNT Digital Library
Atmospheric Dispersion Analysis using MACCS2 (open access)

Atmospheric Dispersion Analysis using MACCS2

The Nuclear Regulatory Commission (NRC) Regulatory Guide 1.145 requires an evaluation of the offsite atmospheric dispersion coefficient, {Chi}/Q, as a part of the acceptance criteria in the accident analysis. In it, it requires in sequence computations of (1) the overall site 95th percentile {Chi}/Q, (2) the maximum of the sixteen sector 99.5th percentile {Chi}/Q, and (3) comparison and selection of the worst of the two values for reporting in the safety analysis report (SAR). In all cases, the site-specific meteorology and sector-specific site boundary distances are employed in the evaluation. There are sixteen 22.5-sectors, the nearest site boundary of which is determined within the 45-arc centered on each of the sixteen compass directions.
Date: February 2, 2004
Creator: Glaser, R. & Yang, J. M.
System: The UNT Digital Library
Atomic scale structure of the 5-fold surface of an AlPdMn quasicrystal: A quantitative X-Ray photoelectron diffraction analysis (open access)

Atomic scale structure of the 5-fold surface of an AlPdMn quasicrystal: A quantitative X-Ray photoelectron diffraction analysis

The atomic scale structure of the 5-fold symmetric surface of an AlPdMn quasicrystal is investigated quantitatively by comparing x-ray photoelectron diffraction (XPD) simulations to experiment. The observed 5-fold symmetry of the diffraction patterns indicates that the surface is quasicrystalline with no hint of a reconstruction from the bulk structure. In analyzing the experimental data, many possible bulk terminations have been tested. Those few that fit best to the data have in common that they contain an Al-rich surface layer followed by a dense mixed Al/Pd/Mn layer. These best terminations, while not identical to each other, are suggested to form terraces coexisting on a real surface. Structural relaxations of the quasicrystal surface are also analyzed: mixing several best-fit terminations gives average best-fit interlayer spacing changes of Dd12 = -0.057 Angstrom, Dd24 = +0.159 Angstrom. These results are in good agreement with a prior structure determination by LEED on a sample that was prepared in a different manner.
Date: February 11, 2004
Creator: Zheng, Jin-Cheng; Huan, C. H. A.; Wee, A. T. S.; Van Hove, M. A.; Fadley, C. S.; Shi, F. J. et al.
System: The UNT Digital Library
Automatic segmentation of histological structures in mammary gland tissue sections (open access)

Automatic segmentation of histological structures in mammary gland tissue sections

Real-time three-dimensional (3D) reconstruction of epithelial structures in human mammary gland tissue blocks mapped with selected markers would be an extremely helpful tool for breast cancer diagnosis and treatment planning. Besides its clear clinical application, this tool could also shed a great deal of light on the molecular basis of breast cancer initiation and progression. In this paper we present a framework for real-time segmentation of epithelial structures in two-dimensional (2D) images of sections of normal and neoplastic mammary gland tissue blocks. Complete 3D rendering of the tissue can then be done by surface rendering of the structures detected in consecutive sections of the blocks. Paraffin embedded or frozen tissue blocks are first sliced, and sections are stained with Hematoxylin and Eosin. The sections are then imaged using conventional bright field microscopy and their background is corrected using a phantom image. We then use the Fast-Marching algorithm to roughly extract the contours of the different morphological structures in the images. The result is then refined with the Level-Set method which converges to an accurate (sub-pixel) solution for the segmentation problem. Finally, our system stacks together the 2D results obtained in order to reconstruct a 3D representation of the entire tissue …
Date: February 17, 2004
Creator: Fernandez-Gonzalez, Rodrigo; Deschamps, Thomas; Idica, Adam K.; Malladi, Ravikanth & Ortiz de Solorzano, Carlos
System: The UNT Digital Library
Autonomous Pathogen Detection System (open access)

Autonomous Pathogen Detection System

None
Date: February 18, 2004
Creator: Hindson, Benjamin; McBride, Mary; Makarewicz, Anthony; Henderer, Bruce; Sathyam, Ujwal; Nasarabadi, Shanavaz et al.
System: The UNT Digital Library
B Physics at the Tevatron (open access)

B Physics at the Tevatron

After a five year upgrade period, the Fermilab experiments CDF and D0 are taking high quality data in Run II of the Tevatron Collider. We report on the start-up of both detectors and present a selection of first B physics results from the Tevatron. We also compare different B hadron producers such as the {Upsilon}(4S) with the hadron collider environment and discuss general features of B physics at a hadron collider.
Date: February 10, 2004
Creator: Paulini, Manfred
System: The UNT Digital Library
Bovine Enterovirus Type 2. Complete Genomic Sequence and Molecular Modeling of a Reference Strain and a Wild Type Isolate from Endemically Infected US Cattle. (open access)

Bovine Enterovirus Type 2. Complete Genomic Sequence and Molecular Modeling of a Reference Strain and a Wild Type Isolate from Endemically Infected US Cattle.

None
Date: February 11, 2004
Creator: Zhou, C E; Zemla, A; Goens, S D; Botero, S & Perdue, M L
System: The UNT Digital Library
The BTeV Software Tutorial Suite (open access)

The BTeV Software Tutorial Suite

The BTeV Collaboration is starting to develop its C++ based offline software suite, an integral part of which is a series of tutorials. These tutorials are targeted at a diverse audience, including new graduate students, experienced physicists with little or no C++ experience, those with just enough C++ to be dangerous, and experts who need only an overview of the available tools. The tutorials must both teach C++ in general and the BTeV specific tools in particular. Finally, they must teach physicists how to find and use the detailed documentation. This report will review the status of the BTeV experiment, give an overview of the plans for and the state of the software and will then describe the plans for the tutorial suite.
Date: February 20, 2004
Creator: Kutschke, Robert K.
System: The UNT Digital Library
Building Biochips: A Protein Production Pipeline (open access)

Building Biochips: A Protein Production Pipeline

Protein arrays are emerging as a practical format in which to study proteins in high-throughput using many of the same techniques as that of the DNA microarray. The key advantage to array-based methods for protein study is the potential for parallel analysis of thousands of samples in an automated, high-throughput fashion. Building protein arrays capable of this analysis capacity requires a robust expression and purification system capable of generating hundreds to thousands of purified recombinant proteins. We have developed a method to utilize LLNL-I.M.A.G.E. cDNAs to generate recombinant protein libraries using a baculovirus-insect cell expression system. We have used this strategy to produce proteins for analysis of protein/DNA and protein/protein interactions using protein microarrays in order to understand the complex interactions of proteins involved in homologous recombination and DNA repair. Using protein array techniques, a novel interaction between the DNA repair protein, Rad51B, and histones has been identified.
Date: February 9, 2004
Creator: de Carvalho-Kavanagh, M & Albala, J S
System: The UNT Digital Library
CDF Run 2 muon system (open access)

CDF Run 2 muon system

The CDF muon detection system for Run 2 of the Fermilab Tevatron is described. Muon stubs are detected for |{eta}| < 1.5, and are matched to tracks in the central drift chamber at trigger level 1 for |{eta}| < 1.25. Detectors in the |{eta}| < 1 central region, built for previous runs, have been enhanced to survive the higher rate environment and closer bunch spacing (3.5 {micro}sec to 396 nsec) of Run 2. Azimuthal gaps in the central region have been filled in. New detectors have been added to extend the coverage from |{eta}| < 1 to |{eta}| < 1.5, consisting of four layers of drift chambers covered with matching scintillators for triggering. The Level 1 Extremely Fast Tracker supplies matching tracks with measured p{sub T} for the muon trigger. The system has been in operation for over 18 months. Operating experience and reconstructed data are presented.
Date: February 5, 2004
Creator: Ginsburg, C. M.
System: The UNT Digital Library