The Economic Future of Nuclear Power

This presentation discusses the economic future of nuclear power.
Date: October 5, 2004
Creator: Tolley, G.S. & Jones, D.W.
Object Type: Presentation
System: The UNT Digital Library
Targetry at the LANL 100 MeV Isotope Production Facility: Les-Sons Learned From Facility Commissioning (open access)

Targetry at the LANL 100 MeV Isotope Production Facility: Les-Sons Learned From Facility Commissioning

The new Isotope Production Facility (IPF) at Los Alamos National Laboratory has been commissioned during the spring of 2004. Commissioning activities focused on the establishment of a radionuclide database, the review and approval of two specific target stack designs, and four trial irradiation runs with subsequent chemical processing and data analyses. This paper highlights some aspects of the facility and the targetry of the two approved target stacks used during the commissioning process.
Date: October 5, 2004
Creator: Nortier, F. M.; Fassbender, M. E.; DeJohn, M.; Hamilton, V. T.; Heaton, R. C.; Jamriska, D. J. et al.
Object Type: Article
System: The UNT Digital Library
IRRADIATION EFFECTS ON THE PHYSICAL CHARACTERISTICS OF SEWAGE SLUDGE (open access)

IRRADIATION EFFECTS ON THE PHYSICAL CHARACTERISTICS OF SEWAGE SLUDGE

The radiation effects on the physical characteristic of the sewage sludge were studied in order to obtain information which will be used for study on the enhancement of the sludge's dewaterability. Water contents, capillary suction time, zeta potential, irradiation dose, sludge acidity, total solid concentration, sludge particle size and microbiology before and after irradiation were investigated. Irradiation gave an effect on physical characteristics sludge. Water content in sludge cake could be reduced by irradiation at the dose of 10kGy.
Date: October 5, 2004
Creator: Lee, M. J.; Lee, J. K.; Yoo, D. H. & Ho, K.
Object Type: Article
System: The UNT Digital Library

Isotope Production in Light of Increasing Demand

This presentation is a part of the panel discussion on isotope production in light of increasing demand.
Date: October 5, 2004
Creator: Patton, B.
Object Type: Presentation
System: The UNT Digital Library
Iridium-192 Production for Cancer Treatment (open access)

Iridium-192 Production for Cancer Treatment

The purpose of this work is to settle a laboratory for Iridium -192 sources production, that is, to determine a wire activation method and to build a hot cell for the wires manipulation, quality control and packaging. The paper relates, mainly, the wire activation method and its quality control. The wire activation is carried out in our nuclear reactor, IEA- R1m.
Date: October 5, 2004
Creator: Rostelato, M.E.C.M.; Silva, C.P.G.; Rela, P.R.; Zeituni, C.A.; Lepki, V. & Feher, A.
Object Type: Article
System: The UNT Digital Library

PANEL DISCUSSION: ISOTOPE PRODUCTION IN LIGHT OF INCREASING DEMAND

This presentation is a part of the panel discussion on isotope production in light of increasing demand.
Date: October 5, 2004
Creator: Srivastava, S. & del Mastro, N.
Object Type: Presentation
System: The UNT Digital Library
Acceleressence: Dark energy from a phase transition at the seesawscale (open access)

Acceleressence: Dark energy from a phase transition at the seesawscale

Simple models are constructed for ''acceleressence'' dark energy: the latent heat of a phase transition occurring in a hidden sector governed by the seesaw mass scale v{sup 2}/M{sub Pl}, where v is the electroweak scale and M{sub Pl} the gravitational mass scale. In our models, the seesaw scale is stabilized by supersymmetry, implying that the LHC must discover superpartners with a spectrum that reflects a low scale of fundamental supersymmetry breaking. Newtonian gravity may be modified by effects arising from the exchange of fields in the acceleressence sector whose Compton wavelengths are typically of order the millimeter scale. There are two classes of models. In the first class the universe is presently in a metastable vacuum and will continue to inflate until tunneling processes eventually induce a first order transition. In the simplest such model, the range of the new force is bounded to be larger than 25 {micro}m in the absence of fine-tuning of parameters, and for couplings of order unity it is expected to be {approx} 100 {micro}m. In the second class of models thermal effects maintain the present vacuum energy of the universe, but on further cooling, the universe will ''soon'' smoothly relax to a matter dominated …
Date: October 5, 2004
Creator: Chacko, Z.; Hall, Lawrence J. & Nomura, Yasunori
Object Type: Article
System: The UNT Digital Library
The effect of thin film thickness on the incorporation of Mn interstitials in Ga{sub 1-x}Mn{sub x}As (open access)

The effect of thin film thickness on the incorporation of Mn interstitials in Ga{sub 1-x}Mn{sub x}As

We have investigated the effect of film thickness on the distribution of Mn atoms at various lattice sites in Ga{sub 1-x}Mn{sub x}As thin films. We find that the growth surface acts as a sink facilitating the out-diffusion of Mn interstitials (Mn{sub I}), and thus reducing its concentration in the film. The out-diffused Mn{sub I} accumulate on the surface in a surface oxide layer and do not participate in the ferromagnetism of the film. For thin films less than 15 nm thick, no Mn{sub I} can be detected. Because of the absence of compensating Mn{sub I} defects, higher T{sub C} can be achieved for such extremely thin Ga{sub 1-x}Mn{sub x}As layers. These results agree with our previously suggested Fermi-level-governed upper limit of the T{sub C} of III-Mn-V ferromagnetic semiconductors.
Date: October 5, 2004
Creator: Yu, K. M.; Walukiewicz, W.; Wojtowicz, T.; Denlinger, J.; Scarpulla, M. A.; Liu, X. et al.
Object Type: Article
System: The UNT Digital Library
Method for Making a Uranium Chloride Salt Product (open access)

Method for Making a Uranium Chloride Salt Product

The subject apparatus provides a means to produce UCl3, in large quantities without incurring corrosion of the containment vessel or associated apparatus. Gaseous Cl is injected into a lower layer of Cd where CdCl2 is formed. Due to is lower density, the CdCl2 rises through the Cd layer into a layer of molten LiCl-KCL salt where a rotatable basket containing uranium ingots is suspended. The CdCl2 reacts with the uranium to form UCl, and Cd. Due to density differences, the Cd sinks down to the liquid Cd layer and is reused. The UCl3 combines with the molten salt. During production the temperature is maintained at about 600 degrees C. while after the uranium has been depleted the salt temperature is lowered, the molten salt is pressure siphoned from the vessel, and the salt product LiCl-KCl-30 mol% UCl3 is solidified.
Date: October 5, 2004
Creator: Miller, William F. & Tomczuk, Zygmunt
Object Type: Patent
System: The UNT Digital Library

Overview of the U.S. Department of Energy's Isotope Programs

This presentation provides an overview of the U.S. Department of Energy's Isotopes Program. The charter of the Isotope Programs covers the production and sale of radioactive and stable isotopes, associated byproducts, surplus materials, and related isotope services.
Date: October 5, 2004
Creator: Carty, J.
Object Type: Presentation
System: The UNT Digital Library

Bone-Localizing Electron-Emitting Therapeutic Radiopharmaceuticals

This presentation discusses bone-localizing electron-emitting therapeutic radiopharmaceuticals.
Date: October 5, 2004
Creator: Srivastava, S.C.
Object Type: Presentation
System: The UNT Digital Library
Stress Corrosion Cracking Model for High Level Radioactive-Waste Packages (open access)

Stress Corrosion Cracking Model for High Level Radioactive-Waste Packages

A stress corrosion cracking (SCC) model has been adapted for performance prediction of high level radioactive-waste packages to be emplaced in the proposed Yucca Mountain repository. For waste packages of the proposed Yucca Mountain repository, the outer barrier material is the highly corrosion-resistant Alloy UNS-N06022 (Alloy 22), the environment is represented by aqueous brine films present on the surface of the waste package from dripping or deliquescence of soluble salts present in any surface deposits, and the tensile stress is principally from weld induced residual stress. SCC has historically been separated into ''initiation'' and ''propagation'' phases. Initiation of SCC will not occur on a smooth surface if the surface stress is below a threshold value defined as the threshold stress. Cracks can also initiate at and propagate from flaws (or defects) resulting from manufacturing processes (such as welding); or that develop from corrosion processes such as pitting or dissolution of inclusions. To account for crack propagation, the slip dissolution/film rupture (SDFR) model is adopted to provide mathematical formulae for prediction of the crack growth rate. Once the crack growth rate at an initiated SCC is determined, it can be used by the performance assessment to determine the time to through-wall …
Date: October 5, 2004
Creator: Andresen, P.; Gordon, G. & Lu, S.
Object Type: Report
System: The UNT Digital Library
Improved Energy Coupling into the Gain Region of the Ni-Like Pd Transient Collisional X-Ray Laser (open access)

Improved Energy Coupling into the Gain Region of the Ni-Like Pd Transient Collisional X-Ray Laser

We present within this paper a series of experiments, which yield new observations to further our understanding of the transient collisional x-ray laser medium. We use the recently developed technique of picosecond x-ray laser interferometry to probe the plasma conditions in which the x-ray laser is generated and propagates. This yields two dimensional electron density maps of the plasma taken at different times relative to the peak of the 600ps plasma-forming beam. In another experimental campaign, the output of the x-ray laser plasma column is imaged with a spherical multilayer mirror onto a CCD camera to give a two-dimensional intensity map of the x-ray laser output. Near-field imaging gives insights into refraction, output intensity and spatial mode structure. Combining these images with the density maps gives an indication of the electron density at which the x-ray laser is being emitted at (yielding insights into the effect of density gradients on beam propagation). Experimental observations coupled with simulations predict that most effective coupling of laser pump energy occurs when the duration of the main heating pulse is comparable to the gain lifetime ({approx}10ps for Ni-like schemes). This can increase the output intensity by more than an order of magnitude relative to …
Date: October 5, 2004
Creator: Smith, R.; Dunn, J.; Filevich, J.; Moon, S.; Nilsen, J.; Keenan, R. et al.
Object Type: Article
System: The UNT Digital Library
Dangerous Waste Characteristics of Contact-Handled Transuranic Mixed Wastes from Hanford Tanks (open access)

Dangerous Waste Characteristics of Contact-Handled Transuranic Mixed Wastes from Hanford Tanks

This report summarizes existing analytical data gleaned from samples taken from the Hanford tanks designated as potentially containing transuranic mixed process wastes. Process knowledge of the wastes transferred to these tanks has been reviewed to determine whether the dangerous waste characteristics now assigned to all Hanford underground storage tanks are applicable to these particular wastes. Supplemental technologies are being examined to accelerate the Hanford tank waste cleanup mission and accomplish waste treatment safely and efficiently. To date, 11 Hanford waste tanks have been designated as potentially containing contact-handled (CH) transuranic mixed (TRUM) wastes. The CH-TRUM wastes are found in single-shell tanks B-201 through B-204, T-201 through T-204, T-104, T-110, and T-111. Methods and equipment to solidify and package the CH-TRUM wastes are part of the supplemental technologies being evaluated. The resulting packages and wastes must be acceptable for disposal at the Waste Isolation Pilot Plant (WIPP). The dangerous waste characteristics being considered include ignitability, corrosivity, reactivity, and toxicity arising from the presence of 2,4,5-trichlorophenol at levels above the dangerous waste threshold. The analytical data reviewed include concentrations of sulfur, sulfate, cyanide, 2,4,5-trichlorophenol, total organic carbon, and oxalate; the composition of the tank headspace, pH, and mercury. Differential scanning calorimetry results …
Date: October 5, 2004
Creator: Tingey, Joel M.; Bryan, Garry H. & Deschane, Jaquetta R.
Object Type: Report
System: The UNT Digital Library
Possible Laminographic and Tomosynthesis Applications for Wolter Microscope Scan Geometries (open access)

Possible Laminographic and Tomosynthesis Applications for Wolter Microscope Scan Geometries

The Wolter microscope includes a number of attractive features for x-ray imaging, and possible connections to laminographic and tomosynthesis 3D object recovery algorithms. This type of instrument employs x-ray optics to sift out single energy x-rays from a broader spectral energy source, and direct those x-rays to a ''focus plane'' similar to the operation of a optical microscope (see Figure 1 for schematic of a Wolter instrument). Unlike optical microscopes the 3D object can be thick in the direction of the x-rays and in this case more of the intensity of the image is affected by the out-of-focus planes, since the ray-paths span the entire depth of the object. It is clear that the ''in-focus'' plane of a Wolter contain more 3D information than a simple ''point-projection'' radiograph. However, it is not clear just how the impact of the out-of-focus planes obscures or distorts features of interest for the in-focus planes. Further, it is not clear just how object positioning can be combined with multiple acquisitions to enable recovery of other planes within the object function or the entire object function. Of particular interest here are Wolter microscopes configured for mesoscale objects (mm extent with um features). Laminographic and tomosynthesis …
Date: October 5, 2004
Creator: Schneberk, D; Jackson, J & Martz, H
Object Type: Report
System: The UNT Digital Library
Pressure Gradient Effects On Two-Dimensional Plasma Expansion (open access)

Pressure Gradient Effects On Two-Dimensional Plasma Expansion

Recent advances in interferometry has allowed for the characterization of the electron density expansion within a laser produced plasma to within 10 {micro}m of the target surface and over picosecond timescales. This technique employs the high brightness output of the transient gain Ni-like Pd collisional x-ray laser at 14.7 nm to construct an effective moving picture of the two-dimensional (2-D) expansion of the plasma. We present experimentally measured density profiles of an expanding Al plasma generated through laser irradiation in a 14mm line focus geometry. Significant lateral expansion was observed at all times as well as a pronounced on-axis electron density dip. Detailed modeling with a 2-D plasma physics code gives good agreement to experimental observations. Large pressure gradients associated with the tight focal spot conditions are calculated to dominate in shaping the plasma density profile.
Date: October 5, 2004
Creator: Moon, S.; Smith, R. F.; Dunn, J.; Keenan, R.; Nilsen, J.; Hunter, J. R. et al.
Object Type: Article
System: The UNT Digital Library
Dimensional Measurements of Three Tubes by Computed Tomography (open access)

Dimensional Measurements of Three Tubes by Computed Tomography

Low density polyethylene (LDPE), copper (Cu), and gold (Au) tubes were scanned on KCAT to identify and evaluate the impact of phase effects on quantitative object recovery. These tubes are phantoms for high energy density capsules.[Logan, et al. 2004] Digital radiographs for each tube are shown in Figure 1. The LDPE tube was scanned at 60 kV, while the Cu and the Au tubes were scanned at 140 kV. All tubes were scanned at a magnification of 3, with approximately 100-mm distance between the exit plane of the tube and the scintillator. Notice the prominence of the outer bright and inner dark edges for the LDPE tube DR, and their absence from the Cu and Au tube DRs. The bright and dark edges are a result of change in phase of the x-rays. The x-ray fluence is partly attenuated and partly refracted. The location near the outer edge of the tube appears to be more attenuating since those x-rays have refracted to locations just outside the tube. Alternatively, the added counts from the refraction result in intensities that are greater than the incident intensity effectively representing a ''negative attenuation''. This results in more counts in that location than in the …
Date: October 5, 2004
Creator: Schneberk, D. J.; Martz, H. E., Jr. & Brown, W. D.
Object Type: Report
System: The UNT Digital Library