Double pulse experiment with a velvet cathode on the ATA injector (open access)

Double pulse experiment with a velvet cathode on the ATA injector

Double pulse transport experiments were conducted on the front end of the ATA accelerator to obtain data on the capability of a velvet cloth cathode to produce two successive pulses. Pulses of approximately 3 kA were extracted from the cathode with interpulse spacings varying from 150 ns to 2.8 {micro}s using an anode-cathode voltage of about 1 MV. Analysis of the current and voltage waveform data from the injector indicate that the effects of cathode plasma on the second pulse of a two-pulse burst is minimal.
Date: April 24, 1995
Creator: Westenskow, G.; Caporaso, G.; Chen, Y.; Houck, T. & Sampayan, S.
Object Type: Report
System: The UNT Digital Library
The DOE2000 materials microcharacterization collaboratory. (open access)

The DOE2000 materials microcharacterization collaboratory.

The Materials Microcharacterization Collaborator (MMC) was created last year as a pilot project within the US Department of Energy's DOE2000 program [1]. The DOE2000 program has, as its main goals, to develop improved capabilities for solving DOE's complex scientific problems, to increase DOE's R and D productivity and efficiency, and to enhance the access of R and D partners to DOE resources. One of the strategies to meet these goals is the establishment of national collaboratories to provide access via the Internet to unique or expensive DOE research facilities and to expertise for remote collaboration, experimentation, production, software development, modeling, and measurement. In addition, collaboratories will benefit researchers by providing tools for video conferencing, shared data-viewing, and collaborative analysis. Cooperative pilots projects, jointly funded by DOE2000 and a scientific program area, are expected to lead to significant scientific achievements by developing new capabilities and increasing the efficiency of doing the work (e.g., by reducing travel, increasing communication, and promoting the sharing of data among formerly disparate research groups). The MMC project unites four DOE BES electron microscopy user centers located at ANL, LBNL, ORNL and the University of Illinois with the DOE EE center located at ORNL. Also included in …
Date: April 24, 1998
Creator: Voelkl, E.
Object Type: Article
System: The UNT Digital Library
Dynamics of gas-filled hohlraums (open access)

Dynamics of gas-filled hohlraums

In order to prevent high-Z plasma from filling in the hohlraum in indirect drive experiments, a low-Z material, or tamper is introduced into the hohlraum. This material, when fully ionized is typically less than one-tenth of the critical density for the laser light used to illuminate the hohlraum. This tamper absorbs little of the laser light, thus allowing most of the laser energy to be absorbed in the high-Z material. However, the pressure associated with this tamper is sufficient to keep the hohlraum wall material from moving a significant distance into the interior of the hohlraum. In this paper the authors discuss measurements of the motion of the interface between the tamper and the high-Z hohlraum material. They also present measurements of the effect the tamper has on the hohlraum temperature.
Date: April 24, 1995
Creator: Orzechowski, T.J.; Kauffman, R.L. & Kirkwood, R.K.
Object Type: Article
System: The UNT Digital Library
Fluor Daniel Hanford contract standards/requirements identification document (open access)

Fluor Daniel Hanford contract standards/requirements identification document

This document, the Standards/Requirements Identification Document (S/RID) for the Fluor Daniel Hanford Contract, represents the necessary and sufficient requirements to provide an adequate level of protection of the worker, public health and safety, and the environment.
Date: April 24, 1997
Creator: Bennett, G.L.
Object Type: Report
System: The UNT Digital Library
Integrated safety management approach for the approval and conduct of subcritical experiments (SCE) for the science-based Nuclear Stockpile Stewardship Program (open access)

Integrated safety management approach for the approval and conduct of subcritical experiments (SCE) for the science-based Nuclear Stockpile Stewardship Program

None
Date: April 24, 1997
Creator: Nelson, C. A., LLNL
Object Type: Article
System: The UNT Digital Library
Evaluation of photoneutron production at high energy LINACS (open access)

Evaluation of photoneutron production at high energy LINACS

This report describes an estimate of neutron production at a 9 MeV LINAC, and the potential for photoactivation of materials present at the LINAC facility. It was found that only isotopes of U, W, Ta, and Pb had daughters whose activities might be measurable. The LINAC was found to be capable of producing in the neighborhood of 10{sup 10} neutrons/second from these heavy metals, and that subsequent neutron activation might be more of a concern. Monte Carlo simulation of neutron transport and capture in the concrete and steel found in the LINAC vault indicates that {sup 55}Fe may be produced in measurable quantities.
Date: April 24, 1995
Creator: Bell, Z.W.
Object Type: Report
System: The UNT Digital Library
PUREX facility preclosure work plan (open access)

PUREX facility preclosure work plan

This preclosure work plan presents a description of the PUREX Facility, the history of the waste managed, and addresses transition phase activities that position the PUREX Facility into a safe and environmentally secure configuration. For purposes of this documentation, the PUREX Facility does not include the PUREX Storage Tunnels (DOE/RL-90/24). Information concerning solid waste management units is discussed in the Hanford Facility Dangerous Waste Permit Application, General Information Portion (DOE/RL-91-28, Appendix 2D).
Date: April 24, 1997
Creator: Engelmann, R.H.
Object Type: Report
System: The UNT Digital Library
Recriticality energetics of a hypothetical water reflood accident in a damaged light water reactor (open access)

Recriticality energetics of a hypothetical water reflood accident in a damaged light water reactor

The Three Mile Island (TMI-2) accident in 1979 resulted in approximately 45% of the fuel collapsing into an irregularly-shaped debris bed near the center of the core, while some of the molten material flowed into the lower dome of the reactor vessel where it solidified. The immediate cause of this severely degraded geometry was loss of coolant and subsequent heatup of the fuel from decay heat. The neutron chain reaction had shut down prior to fuel relocation (below 5 wt% {sup 235}U enrichment, fast-spectrum criticality is impossible). After the system had cooled sufficiently to allow for reintroduction of water, the core was reflooded to remove remaining decay heat; to ensure stable shutdown, the reflood water was heavily berated (in excess of 3000 ppm). One scenario considered was the potential for increased nuclear reactivity of the debris bed with the reintroduction of water. This was guarded against by the operators using heavily berated reflood water. If the reflood water is insufficiently berated, and the system goes recritical during reflood, it is important to estimate the energy release. Is the event minor (reactor containment survives), or is the event major (such as the Chernobyl accident)?
Date: April 24, 1997
Creator: Schwinkendorf, K. N.
Object Type: Report
System: The UNT Digital Library
Residual stress effects in containment analysis. (open access)

Residual stress effects in containment analysis.

The manufacturing of steel containment vessels starts with the forming of flat plates into curved plates. A steel containment structure is made by welding individual plates together to form the sections that make up the complex shaped vessels. The metal forming and welding process leaves residual stresses in the vessel walls. Generally, the effect of metal forming residual stresses can be reduced or virtually eliminated by thermally stress relieving the vessel. In large containment vessels this may not be practical and thus, the residual stresses due to manufacturing may become important. The residual stresses could possibly affect the response of the vessel to internal pressurization. When the level of residual stresses is significant it will affect the vessel's response, for instance the yielding pressure and possibly the failure pressure. This paper will address the effect of metal forming residual stresses on the response of a generic pressure vessel to internal pressurization. A scoping analysis investigated the effect of residual forming stresses on the response of an internally pressurized vessel. A simple model was developed to gain understanding of the mechanics of the problem. Residual stresses due to the welding process were not considered in this investigation.
Date: April 24, 1998
Creator: Pfeiffer, P. A.
Object Type: Article
System: The UNT Digital Library
Development of a video-based slurry sensor for on-line ash analysis. Second quarterly technical progress report, January 1, 1995--March 31, 1995 (open access)

Development of a video-based slurry sensor for on-line ash analysis. Second quarterly technical progress report, January 1, 1995--March 31, 1995

Automatic control of fine coal cleaning circuits has traditionally been limited by the lack of sensors for on-line ash analysis. Although several nuclear-based analyzers are available, none have seen widespread acceptance. This is largely due to the fact that nuclear sensors are expensive and tend to be influenced by changes in seam type and pyrite content. Recently, researchers at VPI&SU have developed an optical sensor for phosphate analysis. The sensor uses image processing technology to analyze video images of phosphate ore. It is currently being used by Texasgulf for off-line analysis of dry flotation concentrates. The primary advantages of optical sensors over nuclear sensors are that they are significantly cheaper, are not subject to measurement variations due to changes in high atomic number minerals, are inherently safer and require no special radiation permitting. Purpose of this work is to apply the knowledge gained in the development of an optical phosphate analyzer to the development of an on-line ash analyzer for fine coal slurries. During the past quarter, tests were performed on two prototype sample presentation systems for the optical analyzer. Preliminary results indicate that the flow of slurry past the camera lens is too consistent to provide reliable results. A …
Date: April 24, 1995
Creator: Adel, G. T. & Luttrell, G. H.
Object Type: Report
System: The UNT Digital Library
Three dimensional simulations of a small induction recirculator accelerator (open access)

Three dimensional simulations of a small induction recirculator accelerator

A recirculating induction accelerator has potential cost advantages for a heavy-ion fusion driver. In order to explore the physics and technological issues, a small prototype recirculator is being built. The three dimensional particle-in-cell code, WARP3d, is being used in the design and analysis of the experiments. WARP3d is used to examine the behavior of the beam in the electric dipoles and in the non-linear fields associated with the accelerator lattice elements. The dipoles have focusing and fringe fields which can adversely affect the beam quality. Both single particle and full beam dynamics are examined in the dipoles using realistic geometries. Dipole plate designs which minimize the adverse effects are described. The non-linear fields associated with the permanent magnetic quadrupoles have been included in the simulations. They were found to have little effect on the quality of the beam.
Date: April 24, 1995
Creator: Grote, D. P.; Friedman, A. & Haber, I.
Object Type: Article
System: The UNT Digital Library
Modeling coherent cherenkov radio emissions from high energy electromagnetic showers. (open access)

Modeling coherent cherenkov radio emissions from high energy electromagnetic showers.

A technique currently under study for the detection of ultrahigh energy cosmic ray neutrinos involves the measurement of radio emissions from the electromagnetic shower generated by the neutrino in a large volume of naturally occurring dielectric such as the Antarctic ice cap or salt domes. The formation of an electron excess in the shower leads to the emission of coherent Cherenkov radiation, an effect similar to the generation of wakefields in dielectric loaded structures. We have used the finite difference time domain (FDTD) wakefield code ARRAKIS to model coherent Cherenkov radiation fields from high energy showers; we present as an example calculations of expected signals in a proof of principle experiment proposed for the Fermilab Main Injector.
Date: April 24, 1998
Creator: Schoessow, P.
Object Type: Article
System: The UNT Digital Library
Zero-tension lysimeters: An improved design to monitor colloid-facilitated contaminant transport in the vadose zone (open access)

Zero-tension lysimeters: An improved design to monitor colloid-facilitated contaminant transport in the vadose zone

There is increasing evidence that mobile colloids facilitate the long-distance transport of contaminants. The mobility of fine particles and macromolecules has been linked to the movement of actinides, organic contaminants, and heavy metals through soil. Direct evidence for colloid mobility includes the presence of humic materials in deep aquifers as well as coatings of accumulated clay, organic matter, or sesquioxides on particle or aggregate surfaces in subsoil horizons of many soils. The potential for colloid-facilitated transport of contaminants from hazardous-waste sites requires adequate monitoring before, during, and after in-situ remediation treatments. Zero-tension lysimeters (ZTLs) are especially appropriate for sampling water as it moves through saturated soil, although some unsaturated flow events may be sampled as well. Because no ceramic barrier or fiberglass wick is involved to maintain tension on the water (as is the case with other lysimeters), particles suspended in the water as well as dissolved species may be sampled with ZTLs. In this report, a ZTL design is proposed that is more suitable for monitoring colloid-facilitated contaminant migration. The improved design consists of a cylinder made of polycarbonate or polytetrafluoroethylene (PTFE) that is placed below undisturbed soil material. In many soils, a hydraulically powered tube may be used …
Date: April 24, 1995
Creator: Thompson, M. L.; Scharf, R. L. & Shang, C.
Object Type: Report
System: The UNT Digital Library
Joint UK/US Radar Program. Progress reports, March 1, 1995--March 31, 1995 (open access)

Joint UK/US Radar Program. Progress reports, March 1, 1995--March 31, 1995

This report details the research programs on radar, between the United States and the United Kingdom.
Date: April 24, 1995
Creator: Kiefer, R.; Brase, J. & Mantrom, D.
Object Type: Report
System: The UNT Digital Library
The use of representative cases in hazard analysis of the tank waste remediation system at Hanford. The information in this document is a combination of HNF-SA-3168-A {ampersand} HNF-SA-3169-A - The control identification process (open access)

The use of representative cases in hazard analysis of the tank waste remediation system at Hanford. The information in this document is a combination of HNF-SA-3168-A {ampersand} HNF-SA-3169-A - The control identification process

During calendar year 1996, Duke Engineering and Services Hanford, Inc. conducted a safety analysis in accordance with DOE-STD-3009-94 as part of the development of a Final Safety Analysis Report (TSAR) for the Tank Waste Remediation System (TWRS) at the DOE Hanford site. The scope of the safety analysis of TWRS primarily addressed 177 large underground liquid waste storage tanks and associated equipment for transferring waste to and from tanks. The waste in the tanks was generated by the nuclear production and processing facilities at Hanford. The challenge facing the safety analysis team was to efficiently analyze the system within the time and budget allotted to provide the necessary and sufficient information for accident selection, control identification, and justification on the acceptability of the level of safety of TWRS. It was clear from the start that a hazard and accident analysis for each of the 177 similar tanks and supporting equipment was not practical nor necessary. For example, many of the tanks were similar enough that the results of the analysis of one tank would apply to many tanks. This required the development and use of a tool called the ''Hazard Topography''. The use of the Hazard Topography assured that all …
Date: April 24, 1997
Creator: Niemi, B.J.
Object Type: Report
System: The UNT Digital Library
Crystalline plutonium hosts derived from high-level waste formulations. (open access)

Crystalline plutonium hosts derived from high-level waste formulations.

The Department of Energy has selected immobilization for disposal in a repository as one approach for disposing of excess plutonium (1). Materials for immobilizing weapons-grade plutonium for repository disposal must meet the ''spent fuel standard'' by providing a radiation field similar to spent fuel (2). Such a radiation field can be provided by incorporating fission products from high-level waste into the waste form. Experiments were performed to evaluate the feasibility of incorporating high-level waste (HLW) stored at the Idaho Chemical Processing Plant (ICPP) into plutonium dispositioning materials to meet the spent fuel standard. A variety of materials and preparation techniques were evaluated based on prior experience developing waste forms for immobilizing HLW. These included crystalline ceramic compositions prepared by conventional sintering and hot isostatic pressing (HIP), and glass formulations prepared by conventional melting. Because plutonium solubility in silicate melts is limited, glass formulations were intentionally devitrified to partition plutonium into crystalline host phases, thereby allowing increased overall plutonium loading. Samarium, added as a representative rare earth neutron absorber, also tended to partition into the plutonium host phases. Because the crystalline plutonium host phases are chemically more inert, the plutonium is more effectively isolated from the environment, and its attractiveness for …
Date: April 24, 1998
Creator: O'Holleran, T. P.
Object Type: Article
System: The UNT Digital Library
Irradiation data for the MFA-1 and MFA-2 tests in the FFTF (open access)

Irradiation data for the MFA-1 and MFA-2 tests in the FFTF

This report provides key information on the irradiation environment of the MONJU fuel tests MFA-1 and MFA-2 in the Fast Flux Test Facility (FFTF). This information includes the fission powers, neutron fluxes, sodium temperatures and sodium flow rates in MFA-I, MFA-2 and adjacent assemblies. It also includes MFA-1 and MFA-2 compositions as a function of exposure. The work was performed at the request of Power Reactor and Nuclear Fuels Corporation (PNC) of Japan.
Date: April 24, 1997
Creator: Nelson, J.V.
Object Type: Report
System: The UNT Digital Library
Characterization and testing of a {sup 238}Pu loaded ceramic waste form. (open access)

Characterization and testing of a {sup 238}Pu loaded ceramic waste form.

This paper will describe the preparation and progress of the effort at Argonne National Laboratory-West to produce ceramic waste forms loaded with {sup 238}Pu. The purpose of this study is to determine the extent of damage, if any, that alpha decay events will play over time to the ceramic waste form under development at Argonne. The ceramic waste form is glass-bonded sodalite. The sodalite is utilized to encapsulate the fission products and transuranics which are present in a chloride salt matrix which results from a spent fuel conditioning process. {sup 238}Pu possesses approximately 250 times the specific activity of {sup 239}Pu and thus allows for a much shorter time frame to address the issue. In preparation for production of {sup 238}Pu loaded waste forms {sup 239}Pu loaded samples were produced. Data is presented for samples produced with typical reactor grade plutonium. X-ray diffraction, scanning electron micrographs and durability test results will be presented. The ramifications for the production of the {sup 238}Pu loaded samples will be discussed.
Date: April 24, 1998
Creator: Johnson, S. G.
Object Type: Article
System: The UNT Digital Library
Pilot-scale equipment development for lithium-based reduction of spent oxide fuel. (open access)

Pilot-scale equipment development for lithium-based reduction of spent oxide fuel.

An integral function of the electrometallurgical conditioning of DOE spent nuclear fuel is the standardization of waste forms. Argonne National Laboratory (ANL) has developed and is presently demonstrating the electrometallurgical conditioning of sodium-bonded metal fuel from Experimental Breeder Reactor II, resulting in uranium, ceramic waste, and metal waste forms. Engineering studies are underway at ANL in support of pilot-scale equipment development, which would precondition irradiated oxide fuel and likewise demonstrate the application of electrometallurgical conditioning to such non-metallic fuels. This paper highlights the integration of proposed spent oxide fuel conditioning with existing electrometallurgical processes. Additionally, technical bases for engineering activities to support a scale up of an oxide reduction process are described.
Date: April 24, 1998
Creator: Herrmann, S. D.
Object Type: Article
System: The UNT Digital Library
Rheology of planetary ices (open access)

Rheology of planetary ices

The brittle and ductile rheology of ices of water, ammonia, methane, and other volatiles, in combination with rock particles and each other, have a primary influence of the evolution and ongoing tectonics of icy moons of the outer solar system. Laboratory experiments help constrain the rheology of solar system ices. Standard experimental techniques can be used because the physical conditions under which most solar system ices exist are within reach of conventional rock mechanics testing machines, adapted to the low subsolidus temperatures of the materials in question. The purpose of this review is to summarize the results of a decade-long experimental deformation program and to provide some background in deformation physics in order to lend some appreciation to the application of these measurements to the planetary setting.
Date: April 24, 1996
Creator: Durham, W.B.; Kirby, S.H. & Stern, L.A.
Object Type: Report
System: The UNT Digital Library
1994 Annual wildlife survey report. Natural Resource Protection and Compliance Program (open access)

1994 Annual wildlife survey report. Natural Resource Protection and Compliance Program

This report summarizes the results of wildlife surveys and other wildlife monitoring performed from January through December 1994. These surveys are part of a long-term ecological monitoring program conducted under the Natural Resource Protection and Compliance Program (NRPCP). This program is essential in identifying and quantifying fluctuations of wildlife populations, wildlife habitat use, and changes in the species using the Rocky Flats Environmental Technology Site (Site) as year-round or seasonal habitat. Wildlife population densities vary constantly due to natural pressures, and only well-integrated, long-term monitoring can identify which factors influencing wildlife populations are a consequence of natural causes, and which are due to human activities. An integrated monitoring program that gathers data on ecologically interactive species is essential in evaluating population fluctuations. Such data can be an invaluable tool in predicting and avoiding impacts on the ecology of an area due to projected human activities. With 167 species of birds, three big game species, nine species of carnivores, nine species of mid-sized mammals, and 15 small mammal species, the Site provides habitat to a surprising variety of wildlife. Many of these species are sensitive species or indicator organisms that by their presence or, more significantly, by their absence can indicate …
Date: April 24, 1995
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Interim sanitary landfill groundwater monitoring report. 1995 annual report (open access)

Interim sanitary landfill groundwater monitoring report. 1995 annual report

Eight wells of the LFW series monitor groundwater quality in the Steed Pond Aquifer (Water Table) beneath the Interim Sanitary Landfill at the Savannah River Site (SRS). These wells are sampled biannually to comply with the South Carolina Department of Health and Environmental Control Modified Municipal Solid Waste Permit 025500- 1120 (formerly DWP-087A) and as part of the SRS Groundwater Monitoring Program. Trichlorofluoromethane was elevated in one downgradient and one sidegradient well during 1995. Barium, 1, 1- dichloroethylene, specific conductance, and zinc exceeded standards in one well each. The elevated level of 1, 1-dichloroethylene occurred in a downgradient well. The groundwater flow direction in the Steed Pond Aquifer (Water Table) beneath the Sanitary Landfill was to the southeast (universal transverse Mercator coordinates). The flow rate in this unit was approximately 190 ft/year during first quarter 1995 and 150 ft/yr during third quarter 1995.
Date: April 24, 1996
Creator: Bagwell, L.
Object Type: Report
System: The UNT Digital Library
Revitalizing a mature oil play: Strategies for finding and producing unrecovered oil in Frio fluvial-deltaic reservoirs of South Texas. Technical progress report, January 1--March 31, 1996 (open access)

Revitalizing a mature oil play: Strategies for finding and producing unrecovered oil in Frio fluvial-deltaic reservoirs of South Texas. Technical progress report, January 1--March 31, 1996

Advanced reservoir characterization techniques are being applied to selected reservoirs in the Frio Fluvial-Deltaic Sandstone (Vicksburg Fault Zone) trend of South Texas in order to maximize the economic producibility of resources in this mature oil play. This project is developing interwell-scale geological facies models and assessing engineering attributes of Frio fluvial-deltaic reservoirs in selected fields in order to characterize reservoir architecture, flow-unit boundaries, and the controls that these factors exert on the location and volume of unrecovered mobile and residual oil. The goals of the Industrial Associates program that is the source of industry cofunding to this project are to (1) develop an understanding of sandstone architecture and permeability structure in a spectrum of fluvial-deltaic reservoirs deposited in high- to low-accommodation settings and (2) translate this understanding into more realistic, geologically constrained reservoir models to maximize recovery of hydrocarbons. Project work during the first quarter of 1996 consisted of Phase 3 tasks related to the transfer of technologies to industry. The two primary vehicles for transferring technologies evaluated in the Frio Fluvial-Deltaic Sandstone play (Vicksburg Fault Zone) are a series of two short courses and a microcomputer-based geologic advisor software program. In Rincon field, a three-dimensional (3-D) reservoir model is …
Date: April 24, 1996
Creator: Tyler, N. & Levey, R.A.
Object Type: Report
System: The UNT Digital Library
Can the multianvil apparatus really be used for high-pressure deformation experiments? (open access)

Can the multianvil apparatus really be used for high-pressure deformation experiments?

Past claims of the suitability of the MA-8 multianvil press as a deformation apparatus may have been overstated. On the basis of measurements of final octahedron size and of guide block displacement as a function of time, using the 10/5, 14/8, and 18/11 assemblies (octahedron edge length in mm/truncation edge length in mm) with MgO octahedra and pyrophyllite gasketing, it appears that at run conditions of interest to most researchers there is no appreciable time-dependent creep of gaskets and octahedra. All inelastic deformation occurs at rather low pressures: below about 10 GPa for the 10/5, 7 GPa for the 14/8, and 6 GPa for the 18/11 assemblies, with substantial uncertainties in these pressures. Above these limits all deformation of the pressure medium is elastic. Pressure stepping as a means of increasing the inelastic deformation rate of a sample is probably ineffective. Displacement measured at the guide blocks, previously believed to indicate deformation of the gaskets and octahedron, appears now to be unrelated to creep of these components. The calibrations have not been exhaustive and there is considerable scatter in some of the size measurements, so the above conclusions are not unequivocal. The calibrations do not exclude the possibility of deformation …
Date: April 24, 1996
Creator: Durham, W.B. & Rubie, D.C.
Object Type: Article
System: The UNT Digital Library