Resource Type

Chemical and isotopic data for groundwater in southern Nevada (open access)

Chemical and isotopic data for groundwater in southern Nevada

This document presents a compilation of chemical and isotopic data for groundwater samples analyzed by Lawrence Livermore National Laboratory (LLNL) in support of the Hydrology and Radionuclide Migration Program (HRMP) and the Underground Test Area Program (UGTA) for the U.S. Department of Energy, Nevada Operations Office. Included are data for 107 samples collected from wells and springs located on and around the Nevada Test Site (NTS), within an area approximately bounded by latitudes 36{sup o} to 38{sup o}15'N and longitudes 115{sup o} to 117{sup o}15'W. The samples were collected during the time period 1992 to early 1997. The data represents one of the largest internally consistent geochemical data sets to be gathered for groundwater in southern Nevada. This database is available in electronic or hardcopy formats to interested parties upon request. In addition to the LLNL data we have included a table of selected isotopic data summarized from a larger database compiled by GeoTrans, Inc. (1994). This data is included for comparative purposes as a means of placing the LLNL data in the context of other data for the same geographic region.
Date: July 1, 1997
Creator: Rose, T. P., LLNL
System: The UNT Digital Library
Field Studies at the Apache Leap Research Site in Support of Alternative Conceptual Models (open access)

Field Studies at the Apache Leap Research Site in Support of Alternative Conceptual Models

This is a final technical report for a project of the U.S Nuclear Regulatory Commission (sponsored contract NRC-04-090-51) with the University of Arizona. The contract was an optional extension that was initiated on July 21, 1994 and that expired on May 31, 1995. The project manager was Thomas J. Nicholson, Office of Nuclear Regulatory Research. The objectives of this contract were to examine hypotheses and conceptual models concerning unsaturated flow and transport through fractured rock, and to design and execute confirmatory field and laboratory experiments to test these hypotheses and conceptual models at the Apache Leap Research Site near Superior, Arizona. The results discussed here are products of specific tasks that address a broad spectrum of issues related to flow and transport through fractures. Each chapter in this final report summarizes research related to a specific set of objectives and can be read and interpreted as a separate entity. The tasks include detection and characterization of historical rapid fluid flow through fractured rock and the relationship to perched water systems using environmental isotopic tracers of {sup 3}H and {sup 14}C, fluid- and rock-derived {sup 2343}U/{sup 238}U measurements, and geophysical data. The water balance in a small watershed at the ALRS …
Date: August 1, 1997
Creator: Woodhouse, E. G.; Davidson, G. R. & Theis, C.
System: The UNT Digital Library
Growth of epitaxial (Sr,Ba){sub n+1}Ru{sub n}O{sub 3n+1} films (open access)

Growth of epitaxial (Sr,Ba){sub n+1}Ru{sub n}O{sub 3n+1} films

We have grown epitaxial (Sr,Ba) (n+1)Ru(n)O(3n+1) films, n = 1, 2, and infinity, by pulsed laser deposition (PLD) and controlled their orientation by choosing appropriate substrates. The growth conditions yielding phase pure films have been mapped out. Resistivity versus temperature measurements show that both a and c axis films of Sr2RuO4 are metallic, but not superconducting. The latter is probably due to the presence of low-level impurities that are difficult to avoid given the target preparation process involved in growing these films by PLD.
Date: December 1, 1997
Creator: Schlom, D.G.; Knapp, S.B. & Wozniak, S.
System: The UNT Digital Library
Baseline geochemistry of soil and bedrock Tshirege Member of the Bandelier Tuff at MDA-P (open access)

Baseline geochemistry of soil and bedrock Tshirege Member of the Bandelier Tuff at MDA-P

This report provides baseline geochemistry for soils (including fill), and for bedrock within three specific areas that are planned for use in the remediation of Material Disposal Area P (MDA-P) at Technical Area 16 (TA-16). The baseline chemistry includes leachable element concentrations for both soils and bedrock and total element concentrations for all soil samples and for two selected bedrock samples. MDA-P operated from the early 1950s to 1984 as a landfill for rubble and debris generated by the burning of high explosives (HE) at the TA-16 Burning Ground, HE-contaminated equipment and material, barium nitrate sand, building materials, and trash. The aim of this report is to establish causes for recognizable chemical differences between the background and baseline data sets. In many cases, the authors conclude that recognizable differences represent natural enrichments. In other cases, differences are best attributed to analytical problems. But most importantly, the comparison of background and baseline geochemistry demonstrates significant contamination for several elements not only at the two remedial sites near the TA-16 Burning Ground, but also within the entire region of the background study. This contamination is highly localized very near to the surface in soil and fill, and probably also in bedrock; consequently, …
Date: August 1, 1997
Creator: Warren, R.G.; McDonald, E.V. & Ryti, R.T.
System: The UNT Digital Library
Environmental surveillance and compliance at Los Alamos during 1996 (open access)

Environmental surveillance and compliance at Los Alamos during 1996

This report presents environmental data that characterize environmental performance and addresses compliance with environmental standards and requirements at Los Alamos National Laboratory (LANL or the Laboratory) during 1996. The Laboratory routinely monitors for radiation and for radioactive nonradioactive materials at Laboratory sites as well as in the surrounding region. LANL uses the monitoring results to determine compliance with appropriate standards and to identify potentially undesirable trends. Data were collected in 1996 to assess external penetrating radiation; quantities of airborne emissions; and concentrations of chemicals and radionuclides in ambient air, surface waters and groundwaters, the municipal water supply, soils and sediments, and foodstuffs. Using comparisons with standards and regulations, this report concludes that environmental effects from Laboratory operations are small and do not pose a demonstrable threat to the public, Laboratory employees, or the environment. Laboratory operations were in compliance with all major environmental regulations.
Date: September 1, 1997
Creator: unknown
System: The UNT Digital Library
Final closure plan for the high-explosives open burn treatment facility at Lawrence Livermore National Laboratory Experimental Test Site 300 (open access)

Final closure plan for the high-explosives open burn treatment facility at Lawrence Livermore National Laboratory Experimental Test Site 300

This document addresses the interim status closure of the HE Open Bum Treatment Facility, as detailed by Title 22, Division 4.5, Chapter 15, Article 7 of the Califonia Code of Regulations (CCR) and by Title 40, Code of Federal Regulations (CFR) Part 265, Subpart G, ``Closure and Post Closure.`` The Closure Plan (Chapter 1) and the Post- Closure Plan (Chapter 2) address the concept of long-term hazard elimination. The Closure Plan provides for capping and grading the HE Open Bum Treatment Facility and revegetating the immediate area in accordance with applicable requirements. The Closure Plan also reflects careful consideration of site location and topography, geologic and hydrologic factors, climate, cover characteristics, type and amount of wastes, and the potential for contaminant migration. The Post-Closure Plan is designed to allow LLNL to monitor the movement, if any, of pollutants from the treatment area. In addition, quarterly inspections will ensure that all surfaces of the closed facility, including the cover and diversion ditches, remain in good repair, thus precluding the potential for contaminant migration.
Date: April 1, 1997
Creator: Mathews, S.
System: The UNT Digital Library
Final report of the radiological release survey of Building 30B at the Grand Junction Office Facility (open access)

Final report of the radiological release survey of Building 30B at the Grand Junction Office Facility

The U.S. Department of Energy (DOE) Grand Junction Office (GJO) occupies a 61.7-acre facility along the Gunnison River near Grand Junction, Colorado. This site was contaminated with uranium ore concentrates and mill tailings during vanadium refining activities of the Manhattan Engineer District, and during sampling, assaying, pilot milling, storage, and brokerage activities conducted for the U.S. Atomic Energy Commission`s domestic uranium procurement program. The DOE Defense Decontamination and Decommissioning Program established the GJO Remedial Action Project (GJORAP) to clean up and restore the facility lands, improvements, and underlying aquifer. WASTREN-Grand Junction is the site contractor for the facility and the remedial action contractor for GJORAP. Building 30B and the underlying soil were found not to be radiologically contaminated; therefore, the building can be released for unrestricted use. Placards have been placed at the building entrances indicating the completion of the radiological release survey and prohibiting the introduction of any radioactive materials within the building without written approvals from the GJO Facilities Operations Manager. This document was prepared in response to a DOE-GJO request for an individual final release report for each GJO building.
Date: September 1, 1997
Creator: Krauland, P.A. & Corle, S.G.
System: The UNT Digital Library
Final report of the radiological release survey of Building 19 at the Grand Junction Office Facility (open access)

Final report of the radiological release survey of Building 19 at the Grand Junction Office Facility

The U.S. Department of Energy (DOE) Grand Junction Office (GJO) occupies a 61.7-acre facility along the Gunnison River near Grand Junction, Colorado. This site was contaminated with uranium ore concentrates and mill tailings during vanadium refining activities of the Manhattan Engineer District, and during sampling, assaying, pilot milling, storage, and brokerage activities conducted for the U.S. Atomic Energy Commission`s domestic uranium procurement program. The DOE Defense Decontamination and Decommissioning Program established the GJO Remedial Action Project (GJORAP) to clean up and restore the facility lands, improvements, and underlying aquifer. WASTREN-Grand Junction is the site contractor for the facility and the remedial action contractor for GJORAP. Building 19 and the underlying soil were found not to be radiologically contaminated; therefore, the building can be released for unrestricted use. Placards have been placed at the building entrances indicating the completion of the radiological release survey and prohibiting the introduction of any radioactive materials within the building without written approvals from the GJO Facilities Operations Manager. This document was prepared in response to a DOE-GJO request for an individual final release report for each GJO building.
Date: September 1, 1997
Creator: Johnson, R.K. & Corle, S.G.
System: The UNT Digital Library
Streamlined approach for environmental restoration plan for corrective action unit 416, Mud Pit, Project Shoal Area (open access)

Streamlined approach for environmental restoration plan for corrective action unit 416, Mud Pit, Project Shoal Area

This plan addresses the actions necessary for the restoration and closure of the Project Shoal Area (PSA), Surface Corrective Action Unit (CAU) 416, Mud Pit (Corrective Action Site No. 57-09-01), a pit that was used to store effluent produced during drilling of the Post-Shot Borehole PS-1 in 1963. This plan describes the activities that will occur at the site and the steps that will be taken to gather enough data to obtain a notice of completion from the Nevada Division of Environmental Protection (NDEP). This plan was prepared under the Streamlined Approach for Environmental Restoration (SAFER) concept, and it will be implemented with the Federal Facility Agreement and Consent Order (FFACO) (FFACO, 1996) and the Industrial Sites Quality Assurance Project Plan (DOE/NV, 1994). The SAFER process is being employed at this CAU where enough information exists about the nature and extent of contamination to propose an appropriate corrective action without completing a Corrective Action Decision Document and Corrective Action Plan. This process combines elements of the Data Quality Objective (DQO) process and the observational approach to help plan and conduct corrective actions. DQOs are used to identify the problem and define the type and quality of data needed to complete …
Date: July 1, 1997
Creator: unknown
System: The UNT Digital Library
Fiber optic sensor: Feedback control design and implementation (open access)

Fiber optic sensor: Feedback control design and implementation

Digital feedback control of Gas Tungsten Arc Welding (GTAW) has been demonstrated on a tube sample of stainless steel and titanium alloy. A fiber optic sensor returns a signal proportional to backside radiance from the workpiece; that signal is used by the controller to compute a compensation weld current. The controller executes 10 times a second on an Intel 486 chip. For travel speeds of 3 to 6 inches per minute and thicknesses between 0.025 and 0.10 inches, constant backside bead width was maintained within 0.02 inches, from startup to tie-in.
Date: July 1, 1997
Creator: Tung, D.; Bertram, L.; Hillaire, R.; Anderson, S.; Leonard, S. & Marburger, S.
System: The UNT Digital Library
Short- and long-lived radionuclide particle size measurements in a uranium mine (open access)

Short- and long-lived radionuclide particle size measurements in a uranium mine

The radon-222 progeny and long-lived radionuclide measurements were done in a wet underground uranium mine in Saskatchewan, Canada, on Nov. 8-12, 1995. Radon-222 in the mine varied from 2 kBq/m{sup 3} at 90 m below surface to 12 kBq/m{sup 3} in the mining areas, 240 m below surface. Radon-222 progeny activity and potential alpha energy concentration appear affected by the airborne particle number concentration and size distribution. Particle number was up to 200x10{sup 3}/cm{sup 3}. Only an accumulation mode (30-1000 nm) and some bimodal size distributions in this accumulation size range were significant. Diesel particles and combustion particles from burning propane caused a major modal diameter shift to a smaller size range (50-85 nm) compared with previous values (100-200 nm). The high particle number reduced the unattached progeny (0.5-2 nm) to >5%. The nuclei mode (2-30 nm) in this test was nonexistent, and the coarse mode (>1000 nm), except from the drilling areas and on the stopes, was mostly not measurable. Airborne particle total mass and long- lived radionuclide alpha activity concentrations were very low (80- 100 {mu}g/m{sup 3} and 4-5 mBq/m{sup 3}) owing to high ventilation rates. Mass-weighted size distributions were trimodal, with the major mode at the accumulation …
Date: April 1, 1997
Creator: Tu, Keng-Wu; Fisenne, I.M. & Hutter, A.R.
System: The UNT Digital Library
Contracts for field projects and supporting research on enhanced oil recovery. Progress review number 87 (open access)

Contracts for field projects and supporting research on enhanced oil recovery. Progress review number 87

Approximately 30 research projects are summarized in this report. Title of the project, contract number, company or university, award amount, principal investigators, objectives, and summary of technical progress are given for each project. Enhanced oil recovery projects include chemical flooding, gas displacement, and thermal recovery. Most of the research projects though are related to geoscience technology and reservoir characterization.
Date: October 1, 1997
Creator: unknown
System: The UNT Digital Library
Bibliography of reports on studies of the geology, hydrogeology and hydrology at the Nevada Test Site, Nye County, Nevada, from 1951--1996 (open access)

Bibliography of reports on studies of the geology, hydrogeology and hydrology at the Nevada Test Site, Nye County, Nevada, from 1951--1996

The Nevada Test Site (NTS) was established in 1951 as a proving ground for nuclear weapons. The site had formerly been part of an Air Force bombing and gunnery range during World War II. Sponsor-directed studies of the geology, hydrogeology, and hydrology of the NTS began about 1956 and were broad based in nature, but were related mainly to the effects of the detonation of nuclear weapons. These effects included recommending acceptable media and areas for underground tests, the possibility of off-site contamination of groundwater, air blast and surface contamination in the event of venting, ground-shock damage that could result from underground blasts, and studies in support of drilling and emplacement. The studies were both of a pure scientific nature and of a practical applied nature. The NTS was the site of 828 underground nuclear tests and 100 above-ground tests conducted between 1951 and 1992 (U.S. Department of Energy, 1994a). After July 1962, all nuclear tests conducted in the United States were underground, most of them at the NTS. The first contained underground nuclear explosion was detonated on September 19, 1957, following extensive study of the underground effect of chemical explosives. The tests were performed by U.S. Department of Energy …
Date: April 1, 1997
Creator: Seaber, P. R.; Stowers, E. D. & Pearl, R. H.
System: The UNT Digital Library
Electrokinetic removal of uranium from contaminated, unsaturated soils (open access)

Electrokinetic removal of uranium from contaminated, unsaturated soils

Electrokinetic remediation of uranium-contaminated soil was studied in a series of laboratory-scale experiments in test cells with identical geometry using quartz sand at approximately 10 percent moisture content. Uranium, when present in the soil system as an anionic complex, could be migrated through unsaturated soil using electrokinetics. The distance that the uranium migrated in the test cell was dependent upon the initial molar ratio of citrate to uranium used. Over 50 percent of the uranium was recovered from the test cells using the citrate and carbonate complexing agents over of period of 15 days. Soil analyses showed that the uranium remaining in the test cells had been mobilized and ultimately would have been extracted. Uranium extraction exceeded 90 percent in an experiment that was operated for 37 days. Over 70 percent of the uranium was removed from a Hanford waste sample over a 55 day operating period. Citrate and carbonate ligand utilization ratios required for removing 50 percent of the uranium from the uranium-contaminated sand systems were approximately 230 moles ligand per mole uranium and 1320 moles ligand per mole uranium for the waste. Modifying the operating conditions to increasing the residence time of the complexants is expected to improved …
Date: January 1, 1997
Creator: Booher, Wyatt F.; Lindgren, Eric R. & Brady, Patrick V.
System: The UNT Digital Library
Development and testing of a high-pressure downhole pump for jet-assist drilling. Topical report, Phase II (open access)

Development and testing of a high-pressure downhole pump for jet-assist drilling. Topical report, Phase II

The goal of jet-assisted drilling is to increase the rate of penetration (ROP) in deeper gas and oil wells, where the rocks become harder and more difficult to drill. Increasing the ROP can result in fewer drilling days, and therefore, lower drilling cost. In late 1993, FlowDril and the Gas Research Institute (GRI) began a three-year development of a down hole pump (DHP{reg_sign}) capable of producing 30,000 psi out pressure to provide the high-pressure flow for high-pressure jet-assist of the drill bit. The U.S. Department of Energy (DOE) through its Morgantown, WV (DOE-Morgantown) field office, joined with GRI and FlowDril to develop and test a second prototype designed for drilling in 7-7/8 inch holes. This project, {open_quotes}Development and Testing of a High-Pressure Down Hole Pump for Jet-Assist Drilling,{close_quotes} is for the development and testing of the second prototype. It was planned in two phases. Phase I included an update of a market analysis, a design, fabrication, and an initial laboratory test of the second prototype. Phase II is continued iterative laboratory and field developmental testing. This report summarizes the results of Phase II. In the downhole pump approach shown in the following figure, conventional drill pipe and drill collars are …
Date: October 1, 1997
Creator: unknown
System: The UNT Digital Library
The potential for criticality following disposal of uranium at low-level waste facilities: Uranium blended with soil (open access)

The potential for criticality following disposal of uranium at low-level waste facilities: Uranium blended with soil

The purpose of this study was to evaluate whether or not fissile uranium in low-level-waste (LLW) facilities can be concentrated by hydrogeochemical processes to permit nuclear criticality. A team of experts in hydrology, geology, geochemistry, soil chemistry, and criticality safety was formed to develop achievable scenarios for hydrogeochemical increases in concentration of special nuclear material (SNM), and to use these scenarios to aid in evaluating the potential for nuclear criticality. The team`s approach was to perform simultaneous hydrogeochemical and nuclear criticality studies to (1) identify some achievable scenarios for uranium migration and concentration increase at LLW disposal facilities, (2) model groundwater transport and subsequent concentration increase via sorption or precipitation of uranium, and (3) evaluate the potential for nuclear criticality resulting from potential increases in uranium concentration over disposal limits. The analysis of SNM was restricted to {sup 235}U in the present scope of work. The outcome of the work indicates that criticality is possible given established regulatory limits on SNM disposal. However, a review based on actual disposal records of an existing site operation indicates that the potential for criticality is not a concern under current burial practices.
Date: June 1, 1997
Creator: Toran, L. E.; Hopper, C. M. & Naney, M. T.
System: The UNT Digital Library
Double-helix stellarator (open access)

Double-helix stellarator

A new stellarator configuration, the Double-Helix Stellarator (DHS), is introduced. This novel configuration features a double-helix center post as the only helical element of the stellarator coil system. The DHS configuration has many unique characteristics. One of them is the extreme low plasma aspect ratio, A {approx} 1--1.2. Other advantages include a high enclosed volume, appreciable rotational transform, and a possibility of extreme-high-{beta} MHD equilibria. Moreover, the DHS features improved transport characteristics caused by the absence of the magnetic field ripple on the outboard of the torus. Compactness, simplicity and modularity of the coil system add to the DHS advantages for fusion applications.
Date: September 1, 1997
Creator: Moroz, P. E.
System: The UNT Digital Library
Geological and Petrophysical Characterization of the Ferron Sandstone for 3-D Simulation of a Fluvial-Deltaic Reservoir, Annual Report: 1996 (open access)

Geological and Petrophysical Characterization of the Ferron Sandstone for 3-D Simulation of a Fluvial-Deltaic Reservoir, Annual Report: 1996

The objective of the Ferron Sandstone project is to develop a comprehensive, interdisciplinary, quantitative characterization of a fluvial-deltaic reservoir to allow realistic inter-well and reservoir-scale models to be developed for improved oil-field development in similar reservoirs world-wide. Quantitative geological and petrophysical information on the Cretaceous Ferron Sandstone in east-central Utah was collected. Both new and existing data is being integrated into a three-dimensional model of spatial variations in porosity, storativity, and tensorial rock permeability at a scale appropriate for inter-well to regional-scale reservoir simulation. Simulation results could improve reservoir management through proper infill and extension drilling strategies, reduction of economic risks, increased recovery from existing oil fields, and more reliable reserve calculations. Transfer of the project results to the petroleum industry is an integral component of the project. This report covers research activities for fiscal year 1995-96, the third year of the project. Most work consisted of interpreting the large quantity of data collected over two field seasons. The project is divided into four tasks: (1) regional stratigraphic analysis, (2) case studies, (3) reservoirs models, and (4) field-scale evaluation of exploration strategies. The primary objective of the regional stratigraphic analysis is to provide a more detailed interpretation of the stratigraphy …
Date: May 1, 1997
Creator: Chidsey, Thomas C., Jr.
System: The UNT Digital Library
Reservoir class field demonstration. Publication and presentation bibliography (open access)

Reservoir class field demonstration. Publication and presentation bibliography

The Reservoir Class Field Demonstration Program was initiated in FY92 in response to rapidly declining domestic production and the realization that huge volumes of oil are being abandoned in reservoirs because of uneconomic production techniques. This program is just one of the critical elements of the National Oil Program necessary to move Improved Oil Recovery (IOR) technology from the conceptual stage through research, pilot scale field experiments, and full-scale field demonstrations to industry acceptance and commercialization. Both the successful results and failures of the field demonstrations will provide focus to concurrent research programs. Elements of the field demonstrations that are suitable for broad industry application are being communicated to the industry through the oil program`s technology transfer effort. As part of the technology transfer effort, this listing of publications and presentations by the project operators has been compiled by the US Department of energy`s (DOE) National Petroleum Technology Office (NPTO). The bibliography contains 240 citations for publications and a similar number of citations for presentations.
Date: December 1997
Creator: unknown
System: The UNT Digital Library
Catalog of databases and reports (open access)

Catalog of databases and reports

This catalog provides information about the many reports and materials made available by the US Department of Energy`s (DOE`s) Global Change Research Program (GCRP) and the Carbon Dioxide Information Analysis Center (CDIAC). The catalog is divided into nine sections plus the author and title indexes: Section A--US Department of Energy Global Change Research Program Research Plans and Summaries; Section B--US Department of Energy Global Change Research Program Technical Reports; Section C--US Department of Energy Atmospheric Radiation Measurement (ARM) Program Reports; Section D--Other US Department of Energy Reports; Section E--CDIAC Reports; Section F--CDIAC Numeric Data and Computer Model Distribution; Section G--Other Databases Distributed by CDIAC; Section H--US Department of Agriculture Reports on Response of Vegetation to Carbon Dioxide; and Section I--Other Publications.
Date: April 1, 1997
Creator: Burtis, M. D.
System: The UNT Digital Library
Recovery of bypassed oil in the Dundee Formation using horizontal drains, Quarterly technical report, 1/1/97--3/31/97 (open access)

Recovery of bypassed oil in the Dundee Formation using horizontal drains, Quarterly technical report, 1/1/97--3/31/97

This Class 11 field project has demonstrated that economic quantities of hydrocarbons can be produced from abandoned or nearly abandoned fields in the Dundee Formation of Central Michigan using horizontal drilling technology. The site selected for the demonstration horizontal well was Crystal Field, a nearly abandoned Dundee oil field in Montcalm County, Michigan. This field had produced over 8 million barrels of oil, mostly in the 1930`s and 1940`s. At the height of development, Crystal Field produced from 193 wells, but by 1995, only seven producing wells remained, each producing less than 10 bbls/day. A horizontal well, the TOW 1-3, drilled as a field demonstration pilot was successful, producing at rate of 100 bbls of oil per day with a zero water cut. Although the well is capable of producing at a rate of 500+ bbls/day, the production rate is being kept low deliberately to try to prevent premature water coning. Cumulative production exceeded 50,000 bbls of oil by the end of April, 1997 and lead to the permitting and licensing of several dozen Dundee wells by project end. Twelve of these permits were for continued development of Crystal Field. Two subsequent wells, the Frost 5-3 and the Happy Holidays …
Date: March 30, 1997
Creator: unknown
System: The UNT Digital Library
Colloid suspension stability and transport through unsaturated porous media (open access)

Colloid suspension stability and transport through unsaturated porous media

Contaminant transport is traditionally modeled in a two-phase system: a mobile aqueous phase and an immobile solid phase. Over the last 15 years, there has been an increasing awareness of a third, mobile solid phase. This mobile solid phase, or mobile colloids, are organic or inorganic submicron-sized particles that move with groundwater flow. When colloids are present, the net effect on radionuclide transport is that radionuclides can move faster through the system. It is not known whether mobile colloids exist in the subsurface environment of the Hanford Site. Furthermore, it is not known if mobile colloids would likely exist in a plume emanating from a Low Level Waste (LLW) disposal site. No attempt was made in this study to ascertain whether colloids would form. Instead, experiments and calculations were conducted to evaluate the likelihood that colloids, if formed, would remain in suspension and move through saturated and unsaturated sediments. The objectives of this study were to evaluate three aspects of colloid-facilitated transport of radionuclides as they specifically relate to the LLW Performance Assessment. These objectives were: (1) determine if the chemical conditions likely to exist in the near and far field of the proposed disposal site are prone to induce …
Date: April 1, 1997
Creator: McGraw, M. A. & Kaplan, D. I.
System: The UNT Digital Library
Refractive aiming corrections for satellite observation of stars (open access)

Refractive aiming corrections for satellite observation of stars

Standard references describe how apparent zenith angles differ from true zenith angles for observers on the Earth. In fact, correction formulae are available for aiming Earth-based sensors at stars; some corrections give variations as a function of observer altitude. Such corrections have not been available for observers in space. This report develops formulae appropriate for proper aiming from space-based sensors toward the relatively few stars that are near the Earth`s limb at any given time. These formulae correct for refractive effects and may be critical for steerable space-borne sensors with fields of view less than one degree, tasked to observe starlight passing near the Earth`s surface. Ray tracing in the U.S. Standard Atmosphere, 1976 including H{sub 2}O effects, is used to determine relations between the refracted tangent height, the apparent tangent height resulting from observation at the sensor, and the angle through which the detected rays have deviated. Analytic fits of the ray deviation as a function of apparent tangent height allows quick determination of corrections needed for a space-borne sensor. Using those results that apply in the plane of incidence and using the necessary coordinate rotations, alterations in the star`s apparent right ascension and declination are evaluated to improve …
Date: March 1, 1997
Creator: Vittitoe, C. N. & Schmidt, R. L.
System: The UNT Digital Library
Spectrum of the ballooning Schroedinger equation (open access)

Spectrum of the ballooning Schroedinger equation

The ballooning Schroedinger equation (BSE) is a model equation for investigating global modes that can, when approximated by a Wentzel-Kramers-Brillouin (WKB) ansatz, be described by a ballooning formalism locally to a field line. This second order differential equation with coefficients periodic in the independent variable {theta}{sub k} is assumed to apply even in cases where simple WKB quantization conditions break down, thus providing an alternative to semiclassical quantization. Also, it provides a test bed for developing more advanced WKB methods: e.g. the apparent discontinuity between quantization formulae for {open_quotes}trapped{close_quotes} and {open_quotes}passing{close_quotes} modes, whose ray paths have different topologies, is removed by extending the WKB method to include the phenomena of tunnelling and reflection. The BSE is applied to instabilities with shear in the real part of the local frequency, so that the dispersion relation is inherently complex. As the frequency shear is increased, it is found that trapped modes go over to passing modes, reducing the maximum growth rate by averaging over {theta}{sub k}.
Date: January 1, 1997
Creator: Dewar, R. L.
System: The UNT Digital Library