Separation and Analysis of Actinides by Extraction Chromotography Coupled with Alpha Liquid Scintillation Spectrometry (open access)

Separation and Analysis of Actinides by Extraction Chromotography Coupled with Alpha Liquid Scintillation Spectrometry

This work describes the development and testing of a new method for the separation and analysis of most actinides of interest in environmental samples. It combines simplified extraction chromatography using highly selective absorption resins to partition the individual actinides with the measurement of their alpha activities by liquid scintillation spectrometry. The liquid scintillation counting technique pioneered by McDowell proved useful in determination of alpha emitting radionuclide in a wide variety of matrices. Alpha emitters are chemically extracted into an organic phase which also contains the scintillation cocktail. Oxygen is purged from the solution to improve the energy resolution of the measurement and the counting sample is sealed in a small glass tube for assay. The Photon-Electron Rejecting Alpha Liquid Scintillation (PERALS{trademark}) Spectrometer provides high counting efficiency, low background, pulse shape discrimination for photon/electron/{beta} particle rejection and moderate energy resolution in a compact package. Chemical extraction/liquid scintillation counting significantly reduces the extensive chemical purification and electroplating required for conventional alpha spectrometry with semiconductor detectors. PERALS{trademark} analyses have been used routinely for quickly surveying suspect samples and determining the source of unknown alpha activities.
Date: September 21, 1995
Creator: Cadieux, J.R. & Reboul, S.H.
Object Type: Article
System: The UNT Digital Library
Flavor tests of quark-lepton unification (open access)

Flavor tests of quark-lepton unification

We could become convinced that a particular theory of very-high-energy physics is correct if (1) it has a tightly constrained structure and is linked strongly enough with observed particle interactions, or (2) it predicts new physics beyond the standard model which is discovered. The author makes the case that experiments of this decade and the next allow the possibility that we might become convinced that grand unification, a candidate theory of the second type, is correct.
Date: March 21, 1995
Creator: Hall, L. J.
Object Type: Article
System: The UNT Digital Library
Residual waste volume measurement for Hanford underground storage tanks (open access)

Residual waste volume measurement for Hanford underground storage tanks

The Acquire Commercial Technology for Retrieval program seeks commercial solutions to measure any waste residual (i.e., heel)left after waste retrieval operations of underground radioactive storage tanks. The technology identified should operate in a range of waste depth thickness of 0 - 6 inches. This report provides a description of the need, requirements, and constraints for the residual waste volume measurement system; describes a logical approach to measuring waste volume; provides a brief review and assessment of available technologies; and outlines a set of integrated tests that will evaluate the performance of candidate technologies.
Date: August 21, 1996
Creator: Berglin, E.J.
Object Type: Report
System: The UNT Digital Library
HIGH PT PHYSICS WITH THE STAR EXPERIMENT AT RHIC. (open access)

HIGH PT PHYSICS WITH THE STAR EXPERIMENT AT RHIC.

The STAR experiment at RHIC is a TPC-based, general purpose detector designed to obtain charged particle spectra, with an emphasis on hadrons over a large phase space. An electromagnetic calorimeter provides measurement of e's, {gamma}'s, {pi}{sup 0}'s and jets. Data-taking with Au + Au collisions at {radical}5 = 200 GeV/c{sup 2} begins in Fall 1999. The STAR experiment's investigation of techniques and signals using hard probes to study the high energy-density matter at RHIC and to search for quark-gluon plasma formation will be described.
Date: March 21, 1999
Creator: TURNER,K. FOR THE STAR COLLABORATION
Object Type: Article
System: The UNT Digital Library
New developments in the application of synchrotron radiation to material science. (open access)

New developments in the application of synchrotron radiation to material science.

Recent developments in the application of synchrotrons radiation to materials science are discussed, using techniques which exploit the high brilliance of the newer synchrotrons sources, such as microbeam techniques and correlation spectroscopy. These include studies of environmental systems, residual stress, slow dynamics of condensed matter systems and studies of liquid surfaces and thin magnetic films.
Date: April 21, 1999
Creator: Sinha, S. K.
Object Type: Article
System: The UNT Digital Library
Diamond Anvils With Integrated Diamond-Encapsulated Microprobes for High-Pressure Electrical Transport Experiments (open access)

Diamond Anvils With Integrated Diamond-Encapsulated Microprobes for High-Pressure Electrical Transport Experiments

We have fabricated diamond anvils specially designed for use in ultra-high pressure electrical transport experiments. These anvils, which we refer to as ''designer anvils'', feature thin-film metal microprobes which are encased in a layer of high-quality, epitaxial, chemically vapor deposited (CVD) diamond. The synthetic diamond film ensures that the microprobes are survivable to Mbar pressures, and also serves to electrically insulate the microprobes from the high-pressure gasket. High-pressure resistivity experiments were performed on KI and FeO to pressures of approximately 1.8 and 1.7 Mbars, respectively. Future possible applications of designer anvils are also discussed. [electrical conductivity, synthetic diamond, band overlap, metallization, designer anvils]
Date: July 21, 1999
Creator: Akella, J.; Catledge, S. A.; Vohra, Y. K. & Weir, S. T.
Object Type: Article
System: The UNT Digital Library
Synchrotron x-ray reflectivity study of oxidation/passivation of copper and silicon. (open access)

Synchrotron x-ray reflectivity study of oxidation/passivation of copper and silicon.

Synchrotron x-ray-scattering technique studies of copper and silicon electrochemical interfaces are reported. These two examples illustrate the application of synchrotron x-ray techniques for oxidation, passivation, and dissolution of metals and semiconductors.
Date: July 21, 1999
Creator: Chu, Y.; Nagy, Z.; Parkhutik, V. & You, H.
Object Type: Article
System: The UNT Digital Library
The effects of neutron irradiation on fracture toughness of austenitic stainless steels. (open access)

The effects of neutron irradiation on fracture toughness of austenitic stainless steels.

Austenitic stainless steels are used extensively as structural alloys in reactor pressure vessel internal components because of their superior fracture toughness properties. However, exposure to high levels of neutron irradiation for extended periods leads to significant reduction in the fracture resistance of these steels. This paper presents results of fracture toughness J-R curve tests on four heats of Type 304 stainless steel that were irradiated to fluence levels of {approx}0.3 and 0.9 x 10{sup 21} n cm{sup {minus}2} (E >1 MeV) at {approx}288 C in a helium environment in the Halden heavy water boiling reactor. The tests were performed on 1/4-T compact tension specimens in air at 288 C; crack extensions were determined by both DC potential and elastic unloading compliance techniques.
Date: May 21, 1999
Creator: Chopra, O. K.; Gruber, E. E. & Shack, W. J.
Object Type: Article
System: The UNT Digital Library
Near-Field Hydrology Data Package for the Immobilized Low-Activity Waste 2001 Performance Assessment (open access)

Near-Field Hydrology Data Package for the Immobilized Low-Activity Waste 2001 Performance Assessment

Lockheed Martin Hanford Company (LMHC) is designing and assessing the performance of disposal facilities to receive radioactive wastes that are currently stored in single- and double-shell tanks at the Hanford Site. The preferred method for disposing of the portion that is classified as immobilized low-activity waste (ILAW) is to vitrify the waste and place the product in new-surface, shallow land burial facilities. The LMHC project to assess the performance of these disposal facilities is the Hanford ILAW Performance Assessment (PA) Activity. The goal of this project is to provide a reasonable expectation that the disposal of the waste is protective of the general public, groundwater resources, air resources, surface water resources, and inadvertent intruders. Achieving this goal will require prediction of contaminant migration from the facilities. This migration is expected to occur primarily via the movement of water through the facilities and the consequent transport of dissolved contaminants in the pore water of the vadose zone. Pacific Northwest National Laboratory (PNNL) assists LMHC in its performance assessment activities. One of PNNL's tasks is to provide estimates of the physical, hydraulic, and transport properties of the materials comprising the disposal facilities and the disturbed region around them. These materials are referred …
Date: December 21, 1999
Creator: Meyer, PD & Serne, RJ
Object Type: Report
System: The UNT Digital Library
A novel thin film solid oxide fuel cell for microscale energy conversion (open access)

A novel thin film solid oxide fuel cell for microscale energy conversion

A novel approach for the fabrication and assembly of a solid oxide fuel cell system is described which enables effective scaling of the fuel delivery, manifold, and fuel cell stack components for applications in miniature and microscale energy conversion. Electrode materials for solid oxide fuel cells are developed using sputter deposition techniques. A thin film anode is formed by co-deposition of nickel and yttria-stabilized zirconia (YSZ). This approach provides a mixed conducting inter-facial layer between the nickel electrode and electrolyte layer. Similarly, a thin film cathode is formed by co-deposition of silver and yttria-stabilized zirconia. Additionally, sputter deposition of yttria-stabilized zirconia thin film electrolyte enables high quality, continuous films to be formed having thicknesses on the order of 1-2 {micro}m. This will effectively lower the temperature of operation for the fuel cell stack significantly below the traditional ranges at which solid oxide electrolyte systems are operated (600-1000 C), thereby rendering this fuel cell system suitable for miniaturization, Scaling towards miniaturization is accomplished by utilizing novel micromachining approaches which allow manifold channels and fuel delivery system to be formed within the substrate which the thin film fuel cell stack is fabricated on, thereby circumventing the need for bulky manifold components which …
Date: July 21, 1999
Creator: Jankowski, Alan F. & Morse, Jeffrey D.
Object Type: Article
System: The UNT Digital Library
Energy Technology Division research summary 1997. (open access)

Energy Technology Division research summary 1997.

The Energy Technology Division provides materials and engineering technology support to a wide range of programs important to the US Department of Energy. As shown on the preceding page, the Division is organized into ten sections, five with concentrations in the materials area and five in engineering technology. Materials expertise includes fabrication, mechanical properties, corrosion, friction and lubrication, and irradiation effects. Our major engineering strengths are in heat and mass flow, sensors and instrumentation, nondestructive testing, transportation, and electromechanics and superconductivity applications. The Division Safety Coordinator, Environmental Compliance Officers, Quality Assurance Representative, Financial Administrator, and Communication Coordinator report directly to the Division Director. The Division Director is personally responsible for cultural diversity and is a member of the Laboratory-wide Cultural Diversity Advisory Committee. The Division's capabilities are generally applied to issues associated with energy production, transportation, utilization or conservation, or with environmental issues linked to energy. As shown in the organization chart on the next page, the Division reports administratively to the Associate Laboratory Director (ALD) for Energy and Environmental Science and Technology (EEST) through the General Manager for Environmental and Industrial Technologies. While most of our programs are under the purview of the EEST ALD, we also have had …
Date: October 21, 1997
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Hybrid electric vehicles TOPTEC (open access)

Hybrid electric vehicles TOPTEC

This one-day TOPTEC session began with an overview of hybrid electric vehicle technology. Updates were given on alternative types of energy storage, APU control for low emissions, simulation programs, and industry and government activities. The keynote speech was about battery technology, a key element to the success of hybrids. The TOPEC concluded with a panel discussion on the mission of hybrid electric vehicles, with a perspective from industry and government experts from United States and Canada on their view of the role of this technology.
Date: June 21, 1994
Creator: unknown
Object Type: Article
System: The UNT Digital Library
Instrumented, Shielded Test Canister System for Evaluation of Spent Nuclear Fuel in Dry Storage (open access)

Instrumented, Shielded Test Canister System for Evaluation of Spent Nuclear Fuel in Dry Storage

This document describes the development of an instrumented, shielded test canister system to store and monitor aluminum-based spent nuclear duel under dry storage conditions.
Date: October 21, 1999
Creator: Sindelar, R.L.
Object Type: Report
System: The UNT Digital Library
Radioactive Release from Aluminum-Based Spent Nuclear Fuel in Basin Storage (open access)

Radioactive Release from Aluminum-Based Spent Nuclear Fuel in Basin Storage

The report provides an evaluation of: (1) the release rate of radionuclides through minor cladding penetrations (breaches) on aluminum-based spent nuclear fuel (AL SNF), and (2) the consequences of direct storage of breached AL SNF relative to the authorization basis for SRS basin operation.
Date: October 21, 1999
Creator: Sindelar, R.L.
Object Type: Report
System: The UNT Digital Library
Development of NDE methods for hot gas filters. (open access)

Development of NDE methods for hot gas filters.

Ceramic hot gas candle filters are currently under development for hot gas particulate cleanup in advanced coal-based power systems. The ceramic materials for these filters include nonoxide monolithic, nonoxide-fiber-reinforced composites, and nonoxide reticulated foam. A concern is the lack of reliable data on which to base decisions for reusing or replacing hot gas filters during plant shutdowns. The work in this project is aimed at developing nondestructive evaluation (FIDE) technology to allow detection, and determination of extent, of life-limiting characteristics such as thermal fatigue, oxidation, damage from ash bridging such as localized cracking, damage from local burning, and elongation at elevated temperature. Although in-situ NDE methods are desirable in order to avoid disassembly of the candle filter vessels, the current vessel designs, the presence of filter cakes and possible ash bridging, and the state of NDE technology prevent this. Candle filter producers use a variety of NDE methods to ensure as-produced quality. While impact acoustic resonance offers initial promise for examining new as-produced filters and for detecting damage in some monolithic filters when removed from service, it presents difficulties in data interpretation, it lacks localization capability, and its applicability to composites has yet to be demonstrated. Additional NDE technologies being …
Date: July 21, 1999
Creator: Deemer, C.; Ellingson, W. A.; Koehl, E. R.; Lee, H.; Spohnholtz, T. & Sun, J. G.
Object Type: Article
System: The UNT Digital Library
Allocating resources and building confidence in public-safety decisions for nuclear waste sites (open access)

Allocating resources and building confidence in public-safety decisions for nuclear waste sites

There are three basic ways to protect the public from the hazards of exposure to radionuclides in nuclear waste: completely contain the waste; limit the rate at which radionuclides are released; and, once radionuclides are released, minimize their impact by reducing concentrations and retarding transport. A geologic repository system that implements all three provides maximum protection for the public: if one element fails, the others serve to protect. This is ''defense-in-depth.'' Demonstrating confidence in the ability of a designed system to provide the requisite safety to the public must rely on a combination of the following aspects relating to engineered and natural system components: 1 Knowledge or understanding of properties and processes 2 Uniformity of (or ability to understand or control) the range of variability associated with each component 3 Experience over time This paper proposes a tool based on defining a ''confidence region'' determined by these three essential aspects of confidence. The defense-in-depth decision-making tool described identifies the portion of the ultimate confidence region that is not well demonstrated and indicates where there is potential for changing a specific component's confidence region, therefore providing in-formation for decisions on emphasis--either for demonstrating performance or for focusing on further studies. The …
Date: May 21, 1999
Creator: Lew, K L & Wilder, D G
Object Type: Article
System: The UNT Digital Library
Cavitational hydrothermal oxidation: A new remediation process. Annual progress report, September 1996--August 1997 (open access)

Cavitational hydrothermal oxidation: A new remediation process. Annual progress report, September 1996--August 1997

'During the past year, the authors have continued to make substantial scientific progress on the understanding of cavitation phenomena in aqueous media and applications of cavitation to remediation processes. The efforts have focused on three separate areas: sonoluminescence as a probe of conditions created during cavitational collapse in aqueous media, the use of cavitation for remediation of contaminated water, and an addition of the use of ultrasound in the synthesis of novel heterogeneous catalysts for hydrodehalogenation of halocarbons under mild conditions. In order to gain further understanding of the conditions present during cavitation, the author has continued his studies of sonoluminescence. He has made recent breakthroughs in the use of emission spectroscopy for temperature and pressure measurement of cavitation events, which he expects to publish shortly. He has been able to measure for the first time the temperature of cavitation in water during multi-bubble cavitation in the presence of aromatic hydrocarbons. The emission from excited states of C{sub 2} in water gives temperatures that are consistent with adiabatic compressional heating, with maximum temperatures of 4,300 K. Prior measurements of cavitation temperatures in low vapor pressure nonaqueous media gave somewhat higher temperatures of 5,000 K. This work lays permanently to rest …
Date: November 21, 1997
Creator: Suslick, K. S.
Object Type: Report
System: The UNT Digital Library
Thermal recovery measurements on multi-segment amplifiers (open access)

Thermal recovery measurements on multi-segment amplifiers

We present the results of a series of experiments to measure the thermal recovery times of a flashlamp-pumped, Nd:Glass multi-segment laser amplifier. In particular, we investigated the thermal recovery times under the following cooling options: (1) passive cooling; (2) active cooling of the flashlamp cassettes, and (3) active cooling of the flashlamp cassettes and gas flow in the pump cavity.
Date: September 21, 1995
Creator: Rotter, M.D.; McCracken, R.W.; Erlandson, A.C. & Brown, D.
Object Type: Article
System: The UNT Digital Library
Historical Background on the Performance Assessment for the Waste Isolation Pilot Plant (open access)

Historical Background on the Performance Assessment for the Waste Isolation Pilot Plant

In 1979, six years after selecting the Delaware Basin as a potential disposal area, Congress authorized the U.S. Department of Energy to build the Waste Isolation Pilot Plant (WIPP) near Carlsbad, New Mexico, as a Research and development facility for the safe management storage, and disposal of waste contaminated with transuranic radioisotopes. In 1998, 19 years after authorization and after site selection, the U.S. Environmental Protection Agency (EPA) certified that the WIPP disposal system complied with its regulations. The EPA's decision was primarily based on the results from a performance. assessment conducted in 1996, which is summarized in this special issue of Reliability Engineering and System Safety. This performance assessment was the culmination of four preliminary performance assessments conducted between 1989 and 1992. This paper provides a historical setting and context for how the performance of the deep geologic repository at the WIPP was analyzed. Also included is background on political forces acting on the project.
Date: October 21, 1999
Creator: RECHARD,ROBERT P.
Object Type: Article
System: The UNT Digital Library
Low frequency electromagnetic signals from underground explosions: On-site inspections research progress report (open access)

Low frequency electromagnetic signals from underground explosions: On-site inspections research progress report

We are investigating the characteristics of extremely low frequency (ELF) electromagnetic pulse (EMW) phenomena from underground nuclear and chemical explosions and from surface chemical explosions as they may be applied in an On-Site Inspection (OSI) context under a Comprehensive Test-Ban Treaty (CTBT). The principal application of these phenomena is for discrimination among underground chemical explosions, underground nuclear explosions, and earthquakes. Underground chemical and nuclear explosions both generate low-frequency EMP signals (about 1 Hz) that are observable within several kilometers of ground zero. During this fiscal year we have been gathering data from explosions of opportunity to see if ELF EMP signals are observable from large ripple-fired blasts and from smaller dedicated explosions such as those occurring at the NTS. In addition, we are continuing to review data from the Henderson Mine deployment that took place during FY94 and data from previous underground nuclear tests including Hunter`s Trophy and past underground nuclear tests have been analyzed and we here make estimates of the properties of the EMP ftom underground nuclear ard chemical explosions, including detectability, dependence on yield, and dependence on distance from the source. Data from the Henderson Mine provide information about detection of EMP from typical moderate size underground …
Date: July 21, 1995
Creator: Sweeney, J. J.
Object Type: Report
System: The UNT Digital Library
High-Resolution Transmission Electron Microscopy Calibration of Critical Dimension (CD) Reference Materials (open access)

High-Resolution Transmission Electron Microscopy Calibration of Critical Dimension (CD) Reference Materials

NIST and Sandia have developed a procedure for producing and calibrating critical dimension (CD), or linewidth, reference materials. These reference materials will be used to calibrate metrology instruments used in semiconductor manufacturing. The artifacts, with widths down to 100 nm, are produced in monocrystalline silicon with all feature edges aligned to specific crystal planes. A two-part calibration of these linewidths is used: the primary calibration, with accuracy to within a few lattice plane thicknesses, is accomplished by counting the lattice planes across the sample as-imaged through use of high-resolution transmission electron microscopy (HRTEM). The secondary calibration is the high-precision electrical CD technique. NIST and Sandia are developing critical dimension (CD), or linewidth, reference materials for use by the semiconductor industry. To meet the current requirements of this rapidly changing industry, the widths of the reference features must be at or below the widths of the finest features in production and/or development. Further, these features must produce consistent results no matter which metrology tool (e.g., scanning electron microscope, scanned probe microscope, electrical metrology) is used to make the measurement. This leads to a requirement for the samples to have planar surfaces, known sidewall angles, and uniform material composition. None of the …
Date: September 21, 1999
Creator: Allen, Richard A.; Cresswell, Michael W.; Everist, Sarah C.; Ghoshtagore, Rathindra N.; Headley, Thomas J. & Linholm, Loren W.
Object Type: Article
System: The UNT Digital Library
A practical microgripper by fine alignment, eutectic bonding and SMA actuation (open access)

A practical microgripper by fine alignment, eutectic bonding and SMA actuation

A silicon microgripper with a large gripping force, a relatively rigid structural body, and flexibility in functional design is presented. The actuation is generated by Ni-Ti-Cu shape memory alloy (SMA) films and the stress induced can deflect each side of the microgripper up to 55 {mu}m for a total gripping motion of 110 {mu}m. When fully open, the force exerted by the film corresponds to a 40 mN gripping force on the tip of the gripper.
Date: April 21, 1995
Creator: Lee, A. P.; Ciarlo, D. R. & Krulevitch, P. A.
Object Type: Article
System: The UNT Digital Library
Structural and magnetic studies of fcc Fe films with self-organized lateral modulation on striped Cu(110)-O(2x1) substrates. (open access)

Structural and magnetic studies of fcc Fe films with self-organized lateral modulation on striped Cu(110)-O(2x1) substrates.

Fcc Fe wedges of 0-12 monolayer (ML) were grown by means of molecular beam epitaxy onto a novel substrate: flat Cu(110) with an oxygen-induced, long-range ordered striped phase, and studied in-situ with medium energy electron diffraction (MEED) and the surface magneto-optical Kerr effect (SMOKE). In contrast to Fe growth on either clean or oxygen-saturated Cu(110), the films on the striped substrates retain a layer-by-layer growth mode up to 6-7 ML and are fcc at least up to 12 ML. In addition, satellite peaks were observed on both sides of the MEED (0,0) streak, indicating a long-range-ordered lateral modulation of the Fe surface. We postulate that the Fe films grow conformally onto the original striped substrate. SMOKE studies show that these fcc Fe wedges are ferromagnetic with an easy axis along the original stripes for Fe thickness > 4ML and a remnant magnetization that increases linearly with thickness beyond 4 ML.
Date: September 21, 1998
Creator: Li, D.
Object Type: Article
System: The UNT Digital Library
Roles and Delegation of Authority (R/DA) System (open access)

Roles and Delegation of Authority (R/DA) System

The processes of defining managerial roles and providing for delegation of authority are essential to any enterprise. At most large organizations, these processes are defined in policy manuals and through sets of standard operating procedures for many, if not all, business and administrative functions. Many of these staff-initiated, administrative functions require the routing of documents for approval to one or more levels of management. These employee-oriented, back office types of workflows tend to require more flexibility in determining to whom these documents should go to, while, at the same time, providing the responsible parties with the flexibility to delegate their approval authority or allow others to review their work. Although this practice is commonplace in manual, paper-based processes that exist in many organizations, it is difficult to provide the same flexibility in the more structured, electronic-based, workflow systems.
Date: October 21, 1999
Creator: Abbott, John P.; Hutchins, James C. & Schoch, David G.
Object Type: Article
System: The UNT Digital Library