3,533 Matching Results

Willis Library will be without power on Tuesday, August 20, 2019 from 5:00-7:00 AM CDT. All websites and web services will be down during this period.

Search Results

Basaltic volcanic episodes of the Yucca Mountain region

Description: The purpose of this paper is to summarize briefly the distribution and geologic characteristics of basaltic volcanism in the Yucca Mountain region during the last 10--12 Ma. This interval largely postdates the major period of silicic volcanism and coincides with and postdates the timing of major extensional faulting in the region. Field and geochronologic data for the basaltic rocks define two distinct episodes. The patterns in the volume and spatial distribution of these basaltic volcanic episodes in the central and southern part of the SNVF are used as a basis for forecasting potential future volcanic activity in vicinity of Yucca Mountain. 33 refs., 2 figs.
Date: March 1, 1990
Creator: Crowe, B.M.
Partner: UNT Libraries Government Documents Department

Preliminary drift design analyses for nuclear waste repository in tuff

Description: The Yucca Mountain Project (YMP) is examining the feasibility of siting a repository for high-level nuclear waste at Yucca Mountain, on and adjacent to the Nevada Test Site (NTS). The proposed repository will be excavated in the Topopah Spring Member, which is a moderately fractured, unsaturated, welded tuff. Excavation stability will be required during construction, waste emplacement, retrieval (if required), and closure to ensure worker safety. The subsurface excavations will be subject to stress changes resulting from thermal expansion of the rock mass and seismic events associated with regional tectonic activity and underground nuclear explosions (UNEs). Analyses of drift stability are required to assess the acceptable waste emplacement density, to design the drift shapes and ground support systems, and to establish schedules and cost of construction. This paper outlines the proposed methodology to assess drift stability and then focuses on an example of its application to the YMP repository drifts based on preliminary site data. Because site characterization activities have not begun, the database currently lacks the extensive site-specific field and laboratory data needed to form conclusions as to the final ground support requirements. This drift design methodology will be applied and refined as more site-specific data are generated and as analytical techniques and methodologies are verified during the site characterization process.
Date: January 30, 1990
Creator: Hardy, M.P.; Brechtel, C.E.; Goodrich, R.R. & Bauer, S.J.
Partner: UNT Libraries Government Documents Department

The interpretation of HRTEM images of partially amorphized pyrochlore structure types

Description: Results of image simulations on partially amorphous microlite (Ca{sub 2}Ta{sub 2}O{sub 7}, pyrochlore structure) are presented. Results indicate that HRTEM images are not sensitive to position of amorphous layers within a crystalline matrix. It is also observed that the limit of detection of amorphous material within a crystalline matrix is dependent on total thickness. In thin crystals (<150{Angstrom}), up to 75 vol% crystalline material can give rise to aperiodic images, yet addition of a small amount of crystalline material (80 vol% crystalline) produces a periodic image. Images calculated for isolated spheres of amorphous material distributed within crystalline microlite suggest that isolated domains of amorphization are observable at sample thicknesses less than 3x the diameter of the feature. Image contrast of amorphized domains is enhanced by imaging at defocus settings significantly different than Scherzer focus. This indicate that interpretation of HRTEM images of partially amorphized crystalline materials should be undertaken with caution, and estimates of the volume of damage considered only qualitative.
Date: December 31, 1990
Creator: Miller, M.L. & Ewing, R.C.
Partner: UNT Libraries Government Documents Department

Implementation of NUREG-1318 guidance within the Yucca Mountain Project

Description: The US Department of Energy`s Yucca Mountain Project is implementing a quality assurance program that fulfills the requirements of the US Nuclear Regulatory Commission (NRC). Additional guidance for this program was provided in NUREG 1318, ``Technical Position on Items and Activities in the High-Level Waste Geologic Repository Program Subject to Quality Assurance Requirements`` for identification of items and activities important to public radiological safety and waste isolation. The process and organization for implementing this guidance is discussed. 3 refs., 2 figs.
Date: April 1, 1990
Creator: La Monica, L.B.; Waddell, J.D. & Hardin, E.L.
Partner: UNT Libraries Government Documents Department

Preparing a Safety Analysis Report using the building block approach

Description: The credibility of the applicant in a licensing proceeding is severely impacted by the quality of the license application, particularly the Safety Analysis Report. To ensure the highest possible credibility, the building block approach was devised to support the development of a quality Safety Analysis Report. The approach incorporates a comprehensive planning scheme that logically ties together all levels of the investigation and provides the direction necessary to prepare a superior Safety Analysis Report.
Date: March 1, 1990
Creator: Herrington, C.C.
Partner: UNT Libraries Government Documents Department

The single-chip FASTBUS Slave Interface

Description: A single-chip implementation of the general-purpose FASTBUS Slave Interface (FSI) has been developed in ECL gate-array technology. The FSI will occupy only 1.6% of the available circuit board space while providing a complete 32-bit interface to the FASTBUS. All mandatory slave-interface requirements of IEEE 960 are supported, in addition to several non-mandatory requirements and the optional, extended MS code features. Geographic, logical, and broadcast addressing are implemented using on-chip registers. An optional multiple-module addressing technique is included that allows participating modules residing on a common crate or cable segment to respond as if individually addressed in sequence. The user interface provided by the FSI allows control of slave status-response and connection timing for both address and data cycles. The BIT1 ECL array technology used for the FSI allows direct connections to the FASTBUS, eliminating the need for external driver/receiver buffers.
Date: December 31, 1990
Creator: Nelson, R.O.; Machen, D.R. & Downing, R.W.
Partner: UNT Libraries Government Documents Department

Ocean margins workshop

Description: The Department of Energy (DOE) is announcing the refocusing of its marine research program to emphasize the study of ocean margins and their role in modulating, controlling, and driving Global Change phenomena. This is a proposal to conduct a workshop that will establish priorities and an implementation plan for a new research initiative by the Department of Energy on the ocean margins. The workshop will be attended by about 70 scientists who specialize in ocean margin research. The workshop will be held in the Norfolk, Virginia area in late June 1990.
Date: December 31, 1990
Partner: UNT Libraries Government Documents Department

Low-Level Waste Forum meeting report. Quarterly meeting, April 25--27, 1990

Description: The Low-Level Radioactive Waste Forum is an association of representatives of states and compacts established to facilitate state and compact commission implementation of the Low-Level Radioactive Waste Policy Act of 1980 and the Low-Level Radioactive Waste Policy Amendments Act of 1985 and to promote the objectives of low-level radioactive waste regional compacts. The Forum provides an opportunity for states and compacts to share information with one another and to exchange views with officials of federal agencies. The Forum participants include representatives from regional compacts, designated host states, unaffiliated states, and states with currently-operating low-level radioactive waste facilities. This report contains information synthesizing the accomplishments of the Forum, as well as any new advances that have been made in the management of low-level radioactive wastes.
Date: December 31, 1990
Partner: UNT Libraries Government Documents Department

Low-Level Waste Forum meeting report. Quarterly meeting, July 23--24, 1990

Description: The Low-Level Radioactive Waste Forum is an association of representatives of states and compacts established to facilitate state and compact commission implementation of the Low-Level Radioactive Waste Policy Act of 1980 and the Low-Level Radioactive Waste Policy Amendments Act of 1985 and to promote the objectives of low-level radioactive waste regional compacts. The Forum provides an opportunity for states and compacts to share information with one another and to exchange views with officials of federal agencies. The Forum participants include representatives from regional compacts, designated host states, unaffiliated states, and states with currently-operating low-level radioactive waste facilities. This report contains information synthesizing the accomplishments of the Forum, as well as any new advances that have been made in the management of low-level radioactive wastes.
Date: December 31, 1990
Partner: UNT Libraries Government Documents Department

In situ TEM study of ion-beam-induced amorphization of complex silicate structures

Description: In-situ TEM with ion irradiation was used to study the radiation- induced amorphization (metamictization) of naturally occurring silicates: neptunite [Na2KLi(Fe,Mn)2Ti2(SiO3)8], titanite (CaTiSiO5), gadolinite (REE2FeBe2Si2O10), zircon (ZrSiO4), and olivine [(Mg, Fe)2SiO4]. They were irradiated with 1.5 MeV Kr{sup +} ions the Argonne HVEM-Tandem Facility at room temperature with electron diffraction pattern monitored in situ. Critical doses required for amorphization of the electron transparent thickness of neptunite, titanite, gadolinite, zircon, and olivine are 1.7, 2.0, 2.3, 4.8, and 6.0x10{sup 14} ions/cm{sup 2}, respectively. Results show a correlation between amorphization dose and the chemical/structural complexity of these 5 minerals. The most complex, neptunite, becomes amorphous at the lowest critical dose. The critical amorphization dose also increases with the melting point.
Date: December 31, 1990
Creator: Wang, L.M.; Eby, R.K.; Janeczek, J. & Ewing, R.C.
Partner: UNT Libraries Government Documents Department

Eleventh annual U.S. DOE low-level radioactive waste management conference: Executive summary, opening plenary, technical session summaries, and attendees

Description: The conference consisted of ten technical sessions, with three sessions running simultaneously each day. Session topics included: regulatory updates; performance assessment;understanding remedial action efforts; low-level waste strategy and planning (Nuclear Energy); low-level waste strategy and planning (Defense); compliance monitoring; decontamination and decommissioning; waste characterization; waste reduction and minimization; and prototype licensing application workshop. Summaries are presented for each of these sessions.
Date: January 1990
Partner: UNT Libraries Government Documents Department

The method of boundary perturbation, and its application to wakefield calculations

Description: The boundary perturbation method, suggested by Zhang and (independently) by Chatard-Moulin, Cooper, and their colleagues, is employed to the wakefield calculations for geometrical discontinuities in accelerators. Results are compared with that obtained from the mesh calculations using TBCI. When the perturbation is small and the geometry is suitable for TBCI, agreement is good. Discrepancies observed in other cases are also discussed.
Date: December 31, 1990
Creator: Chou, W.
Partner: UNT Libraries Government Documents Department

Acceleration of compact toruses and fusion applications

Description: The Compact Torus (Spheromak-type) is a near ideal plasma confinement configuration for acceleration. The fields are mostly generated by internal plasma currents, plasma confinement is toroidal, and the compact torus exhibits resiliency and stability in virtue of the ``rugged`` helicity invariant. Based on these considerations we are developing a coaxial rail-gun type Compact Torus Accelerator (CTA). In the CTA, the CT ring is formed between coaxial electrodes using a magnetized Marshall gun, it is quasistatically ``precompressed`` in a conical electrode section for inductive energy storage, it is accelerated in a straight-coaxial electrode section as in a conventional rail-gun, and it is focused to small size and high energy and power density in a final ``focus`` cone section. The dynamics of slow precompression and acceleration have been demonstrated experimentally in the RACE device with results in good agreement with 2-D MHD code calculations. CT plasma rings with 100 {micro}gms mass have been accelerated to 40 Kj kinetic energy at 20% efficiency with final velocity = 1 X 10{sup 8} cm/s (= 5 KeV/H{sup +}). Preliminary focus tests exhibi dynamics of radius compression, deceleration, and bouncing. Compression ratios of 2-3 have been achieved. A scaled-up 10-100 MJ CTA is predicted to achieve a focus radius of several cm to deliver = 30 MJ ring kinetic energy in 5-10 nsec. This is sufficient energy, power, and power density to enable the CTA to act as a high efficiency, low cost ICF driver. Alternatively, the focused CT can form the basis for an magnetically insulated, inertial confinement fusion (MICF) system. Preliminary calculations of these fusion systems will be discussed.
Date: October 11, 1990
Creator: Hartman, C.W.; Eddleman, J.L.; Hammer, J.H.; Logan, B.G.; McLean, H.S. & Molvik, A.W.
Partner: UNT Libraries Government Documents Department

High-temperature annealing of natural UO{sub 2+x}

Description: Four powdered samples of natural UO{sub 2+x} (uraninite) were annealed in a reducing atmosphere up to 1200 C. Initial unit cell parameters ranged from a{sub o}=0.5463 to 0.5385 nm. Small amounts of UO{sub 2.25} occur in all samples after annealing. Annealing curves show effects of recovery of point defects in the oxygen sublattice, ordering of U{sup 4+} and U{sup 6+}, vacancy migration in the cation sublattice, and second order phase transformations. Difference in annealing behavior of UO{sub 2+x} with x<0.15 as compared to x=0.25 between 400 and 700 C is due to ordering of U{sup 4+} and U{sup 6+}. Density increased after annealing except for one sample in which a large number of cavities (1-2{mu}m) formed. Oxidation and chemical composition have a more dramatic effect on the structural state of natural UO{sub 2+x} than self-irradiation caused by {alpha}-decay damage.
Date: December 31, 1990
Creator: Janeczek, J. & Ewing, R.C.
Partner: UNT Libraries Government Documents Department

The status of detectors at the SSC

Description: The announcement of the location of the SSC at the site near Waxahachie, Texas was made in January, 1989. Since then a great many important steps have been taken toward the start of the new Laboratory. Some 900 people have been brought to the site as the starting nucleus of the staff that will ultimate number about 2200. A design baseline has been completed that includes a conceptual design for the accelerator, and the detectors. Also, the process has begun to determine the configuration of detectors that will be built for the SSC. This process has several steps, and now the first of these has been taken: The detector collaborations have submitted the Expression of Interest to the Laboratory. These were reviewed by Laboratory management and the Physics Advisory Committee in July, 1990 and recommendations were made to the collaborations. Decisions were deferred for all of the detectors. But perhaps the most significant recommendation was the request to reduce the size and cost of the general purpose detectors. The detector collaborations are now reviewing their initial designs to prepare for the Letters of Intent, the next step in the detector planning process. This is clearly a difficult and crucial step in that the redesign of the detectors must be done with minimal reduction in detector quality. It is an interesting time in the development of the new laboratory, and a crucial time for the ultimate physics that will be done at the SSC.
Date: September 1, 1990
Creator: Stefanski, R.
Partner: UNT Libraries Government Documents Department

Red-Cockaded Woodpecker Habitat and Timber Management Production Possibilities

Description: In order to mitigate the impact of longer rotations for the red-cockaded woodpecker on timber production, a multi-objective linear programming model was used. Various streams of habitat in relation to timber management were examined. Large areas immediately set aside for habitat may, in fact, lead to long term declines as a result of poor initial stand conditions. Timber production, harvesting and various silvicultural activities will have a short term impact but lead to long-term sustainable habitat condition for this species.
Date: February 1990
Creator: Roise, Joseph; Chung, Joosang; Lancia, Richard & Lennartz, Mike
Partner: UNT Libraries Government Documents Department

Bulk Modulus Capacitor Load Cells

Description: Measurement of forces present at various locations within the SSC Model Dipole collared coil assembly is of great practical interest to development engineers. Of particular interest are the forces between coils at the parting plane and forces that exist between coils and pole pieces. It is also desired to observe these forces under the various conditions that a magnet will experience such as: during the collaring process, post-collaring, under the influence of cryogens, and during field excitation. A twenty eight thousandths of an inch thick capacitor load cell which utilizes the hydrostatic condition of a stressed plastic dielectric has been designed. These cells are currently being installed on SSC Model Dipoles. The theory, development, and application of these cells will be discussed.
Date: April 1, 1990
Creator: Dickey, C.E.
Partner: UNT Libraries Government Documents Department

Hatchery Effectiveness Technical Work Group Retreat Proceedings, January 9-11, 1990.

Description: This report summarizes a retreat held for the Hatchery Effectiveness Technical Work Group (HETWG). The objectives were to improve the effectiveness of the Technical Work Group (TWG) through developing procedures for its operation, and to develop an action plan for revision of their current research plan.
Date: April 1990
Creator: Fickeisen, Duane H.; Neitzel, D. A. & Dauble, Dennis D.
Partner: UNT Libraries Government Documents Department

Prototype testing for the Yucca Mountain Project

Description: The US Department of Energy, through its Yucca Mountain Project Office, has been conducting prototype activities in welded and non-welded tuff. These activities are in preparation for characterization of the Yucca Mountain area, which is under consideration as a site for a geologic repository in which high-level nuclear waste could be safely stored. Investigators from organizations that will conduct the site investigation have been afforded opportunity, through the prototype program, to test, evaluate, and develop instruments, equipment, and methods. The Exploratory Shaft Facility will be used to collect significant amounts of underground site characterization data. The prototype tests are conducted under similar conditions. 3 refs., 4 figs.
Date: February 1990
Creator: Kalia, H. N.; Oliver, R. D. & Girdley, W. A.
Partner: UNT Libraries Government Documents Department

US DOE-AECL cooperative program for development of high-level radioactive waste container fabrication, closure, and inspection techniques

Description: The US Department of Energy (DOE) and Atomic Energy of Canada Limited (AECL) plan to initiate a cooperative research program on development of manufacturing processes for high-level radioactive waste containers. This joint program will benefit both countries in the development of processes for the fabrication, final closure in a hot-cell, and certification of the containers. Program activity objectives can be summarized as follows: to support the selection of suitable container fabrication, final closure, and inspection techniques for the candidate materials and container designs that are under development or are being considered in the US and Canadian repository programs; and to investigate these techniques for alternate materials and/or container designs, to be determined in future optimization studies relating to long-term performance of the waste packages. The program participants will carry out this work in a conditional phased approach, and the scope of work for subsequent years will evolve subject to developments in earlier years. The overall term of this cooperative program is planned to run roughly three years. 5 refs., 2 tabs.
Date: June 1, 1990
Creator: Russell, E.W.
Partner: UNT Libraries Government Documents Department

{sup 14}C release from failed spent fuel containers

Description: Partially failed containers may provide a meaningful barrier to the release of gaseous radionuclides. A modeling approach is outlined and sample calculations are provided that show the effects on release due to a limited perforation area, to decreasing temperature, and to the partial occlusion of the perforated area by corrosion products. 8 refs., 2 tabs.
Date: February 1, 1990
Creator: Pescatore, C.
Partner: UNT Libraries Government Documents Department