LLW Notes, Volume 10, Number 5, July 1995 (open access)

LLW Notes, Volume 10, Number 5, July 1995

Newsletter distributed to the Low-Level Radioactive Waste Forum members describing current news, policies, and legislation, as well as other information relevant to the management of low-level radioactive waste.
Date: July 31, 1995
Creator: Afton Associates, Inc.
Object Type: Journal/Magazine/Newsletter
System: The UNT Digital Library
A 2D electrostatic PIC code for the Mark III Hypercube (open access)

A 2D electrostatic PIC code for the Mark III Hypercube

We have implemented a 2D electrostastic plasma particle in cell (PIC) simulation code on the Caltech/JPL Mark IIIfp Hypercube. The code simulates plasma effects by evolving in time the trajectories of thousands to millions of charged particles subject to their self-consistent fields. Each particle`s position and velocity is advanced in time using a leap frog method for integrating Newton`s equations of motion in electric and magnetic fields. The electric field due to these moving charged particles is calculated on a spatial grid at each time by solving Poisson`s equation in Fourier space. These two tasks represent the largest part of the computation. To obtain efficient operation on a distributed memory parallel computer, we are using the General Concurrent PIC (GCPIC) algorithm previously developed for a 1D parallel PIC code.
Date: December 31, 1990
Creator: Ferraro, R. D.; Liewer, P. C. & Decyk, V. K.
Object Type: Article
System: The UNT Digital Library
Waste minimization opportunities at the U.S. Uranium Mill Tailings Remedial Action (UMTRA) Project, Rifle, Colorado, site (open access)

Waste minimization opportunities at the U.S. Uranium Mill Tailings Remedial Action (UMTRA) Project, Rifle, Colorado, site

At two uranium mill sites in Rifle, Colorado, the US Department of Energy (DOE) Uranium Mill Tailings Remedial Action (UMTRA) Project is removing uranium mill tailings and contaminated subgrade soils. This remediation activity will result in the production of groundwater contaminated with uranium, heavy metals, ammonia, sulfates, and total dissolved solids (TDS). The initial remediation plan called for a wastewater treatment plant for removal of the uranium, heavy metals, and ammonia, with disposal of the treated water, which still includes the sulfates and TDSS, to the Colorado River. The National Pollutant Discharge Elimination (NPDES) permit issued by the Colorado Department of Health for the two Rifle sites contained more restrictive discharge limits than originally anticipated. During the detailed review of alternate treatment systems to meet these more restrictive limits, the proposed construction procedures were reviewed emphasizing the methods to minimize groundwater production to reduce the size of the water treatment facility, or to eliminate it entirely. It was determined that with changes to the excavation procedures and use of the contaminated groundwater for use in dust suppression at the disposal site, discharge to the river could be eliminated completely.
Date: December 31, 1993
Creator: Hartmann, George L.; Arp, Sharon & Hempill, Hugh
Object Type: Report
System: The UNT Digital Library
Surfactant studies for bench-scale operation. Final technical progress report, July 1, 1992--March 31, 1994 (open access)

Surfactant studies for bench-scale operation. Final technical progress report, July 1, 1992--March 31, 1994

The present work effort relates to an investigation of surfactant-assisted coal liquefaction with the objective of quantifying the enhancement in overall coal conversions and the product quality. Based on the results of a Phase 1 preliminary study on the effect of several surfactants on coal liquefaction, sodium lignosulfonate was chosen as the surfactant for a detailed parametric study to be conducted at JPL using a batch autoclave reactor. These tests primarily related to thermal liquefaction of coal. The results of JPL autoclave test runs showed an increase in overall conversions from 5 to 15% due to surfactant addition over the base case of coal alone. A continuous-flow bench scale coal liquefaction process run was conducted over a 5-day period at Hydrocarbon Research Incorporated (HRI). This test showed that the surfactant is suitable for an industrial continuous recycle process, and does not interfere with the supported catalyst. After the bench scale test, a series of autoclave runs were conducted with coprocessing the surfactant and the Ni-Mo catalyst. These experiments showed that high conversions and product quality can be maintained at milder processing conditions. Based on results of the autoclave test runs, the overall product values were obtained for two stage reactors …
Date: March 31, 1994
Creator: Hickey, G. S. & Sharma, P. K.
Object Type: Report
System: The UNT Digital Library
Dynamic load balancing in a concurrent plasma PIC code on the JPL/Caltech Mark III hypercube (open access)

Dynamic load balancing in a concurrent plasma PIC code on the JPL/Caltech Mark III hypercube

Dynamic load balancing has been implemented in a concurrent one-dimensional electromagnetic plasma particle-in-cell (PIC) simulation code using a method which adds very little overhead to the parallel code. In PIC codes, the orbits of many interacting plasma electrons and ions are followed as an initial value problem as the particles move in electromagnetic fields calculated self-consistently from the particle motions. The code was implemented using the GCPIC algorithm in which the particles are divided among processors by partitioning the spatial domain of the simulation. The problem is load-balanced by partitioning the spatial domain so that each partition has approximately the same number of particles. During the simulation, the partitions are dynamically recreated as the spatial distribution of the particles changes in order to maintain processor load balance.
Date: December 31, 1990
Creator: Liewer, P. C.; Leaver, E. W.; Decyk, V. K. & Dawson, J. M.
Object Type: Article
System: The UNT Digital Library
Direct Conversion of Methane to Methanol in a Non-Isothermal Catalytic Membrane Reactor (open access)

Direct Conversion of Methane to Methanol in a Non-Isothermal Catalytic Membrane Reactor

The direct partial oxidation of CH{sub 4} to CH{sub 3}OH has been studied in a non-permselective, non-isothermal catalytic membrane reactor system. A cooling tube introduced coaxially inside a tubular membrane reactor quenches the product stream rapidly so that further oxidation of CH{sub 3}OH is inhibited. Selectivity for CH{sub 3}OH formation is significantly higher with quenching than in experiments without quenching. For CH{sub 4} conversion of 4% to 7% CH{sub 3}OH selectivity is 40% to 50% with quenching and 25% to 35% without quenching.
Date: December 31, 1993
Creator: Noble, R. D. & Falconer, J. L.
Object Type: Article
System: The UNT Digital Library
Catalytic applications of mono- and dinuclear complexes containing metal-carbon sigma bonds. Final report, November 1, 1993--October 31, 1996 (open access)

Catalytic applications of mono- and dinuclear complexes containing metal-carbon sigma bonds. Final report, November 1, 1993--October 31, 1996

This report discusses results from several studies involved in the project. Investigations include: vibrational models for surface olefins and alkylidenes; mechanism of the formation and fragmentation of diosmacyclobutanes; reaction of dienes and allenes with diosmacyclobutanes; determination by nematic phase NMR of the structure of mononuclear and dinuclear ethylene complexes of osmium; and generation of ``coordinatively unsaturated`` complexes by protonation of methyl osmium complexes.
Date: December 31, 1996
Creator: Norton, J.R.
Object Type: Report
System: The UNT Digital Library
Chemically Assisted in Situ Recovery of Oil Shale (open access)

Chemically Assisted in Situ Recovery of Oil Shale

The purpose of the research project was to investigate the feasibility of the chemically assisted in situ retort method for recovering shale oil from Colorado oil shale. The chemically assisted in situ procedure uses hydrogen chloride (HCl), steam (H{sub 2}O), and carbon dioxide (CO{sub 2}) at moderate pressure to recovery shale oil from Colorado oil shale at temperatures substantially lower than those required for the thermal decomposition of kerogen. The process had been previously examined under static, reaction-equilibrium conditions, and had been shown to achieve significant shale oil recoveries from powdered oil shale. The purpose of this research project was to determine if these results were applicable to a dynamic experiment, and achieve penetration into and recovery of shale oil from solid oil shale. Much was learned about how to perform these experiments. Corrosion, chemical stability, and temperature stability problems were discovered and overcome. Engineering and design problems were discovered and overcome. High recovery (90% of estimated Fischer Assay) was observed in one experiment. Significant recovery (30% of estimated Fischer Assay) was also observed in another experiment. Minor amounts of freed organics were observed in two more experiments. Penetration and breakthrough of solid cores was observed in six experiments.
Date: December 31, 1993
Creator: Ramierz, W. F.
Object Type: Report
System: The UNT Digital Library
Chemically Assisted in Situ Recovery of Oil Shale. [Quarterly Report], April 1, 1990--June 30, 1990 (open access)

Chemically Assisted in Situ Recovery of Oil Shale. [Quarterly Report], April 1, 1990--June 30, 1990

The objective of this work is to investigate, in the laboratory, the parameters associated with a chemically assisted in situ recovery procedure, using hydrogen chloride (HCI), carbon dioxide (CO{sub 2}), and steam (H{sub 2}O), to obtain-data useful to develop a process more economic than existing processes and to report all findings. The technical progress of the project is reported. The progress of the project is that experiment preparations are underway. Reactor design, process design, and experiment design have been completed. The laboratory to be used has required extensive clean-up, and is nearly ready. Safety considerations are underway. Finally, an initial literature search has revealed some important aspects that need to be considered.
Date: December 31, 1990
Creator: Ramirez, W. F.
Object Type: Report
System: The UNT Digital Library
Chemically Assisted in Situ Recovery of Oil Shale. [Quarterly Report], October 1, 1991--December 31, 1991 (open access)

Chemically Assisted in Situ Recovery of Oil Shale. [Quarterly Report], October 1, 1991--December 31, 1991

The objective of this work is to investigate, in the laboratory, the parameters associated with a chemically assisted in situ recovery procedure, using hydrogen chloride (HCI), carbon dioxide (CO{sub 2}), and steam (H{sub 2}O), to obtain data useful to develop a process more economic than existing processes and to report all findings. The technical progress of the project is reported. The project status is that the solutions to the problems discussed in the third quarter status, were found to function satisfactorily. Future needs have been considered, and appropriate equipment and instrumentation changes have been designed. Only one experiment was performed this quarter, with some improvement over the previous experiments. The increase in shale oil recovery followed directly from the changes discussed last quarter, but the improvement could have been larger with wider-spread implementation of the changes. Equipment was purchased to rectify the need, and will be installed shortly. Further, a minor change in the design was necessary to account for the brittleness of high temperature electrical resistance heating tapes. The focus of the work this quarter has been on the development of computer software to enable the use of on-line parameter identification, the design of the instrumentation necessary to adequately …
Date: December 31, 1991
Creator: Ramirez, W. F.
Object Type: Report
System: The UNT Digital Library
Role of polycrystallinity in CdTe and CuInSe{sub 2} photovoltaic cells. Annual subcontract report, 1 April 1990--31 March 1991 (open access)

Role of polycrystallinity in CdTe and CuInSe{sub 2} photovoltaic cells. Annual subcontract report, 1 April 1990--31 March 1991

The polycrystalline nature of thin-film CdTe and CuInSe{sub 2} solar cells continues to be a major factor in several individual losses that limit overall cell efficiency. This report describes progress in the quantitative separation of these losses, including both measurement and analysis procedures. It also applies these techniques to several individual cells to help document the overall progress with CdTe and CuInSe{sub 2} cells. Notably, CdTe cells from Photon Energy have reduced window photocurrent losses to 1 mA/Cm{sup 2}; those from the University of South Florida have achieved a maximum power voltage of 693 mV; and CuInSe{sub 2} cells from International Solar Electric Technology have shown a hole density as high as 7 {times} 10{sup 16} cm{sup {minus}3}, implying a significant reduction in compensation. 9 refs.
Date: December 31, 1991
Creator: Sites, J. R.
Object Type: Report
System: The UNT Digital Library
Underground facility for geoenvironmental and geotechnical research at the SSC Site in Texas (open access)

Underground facility for geoenvironmental and geotechnical research at the SSC Site in Texas

The subsurface environment is an important national resource that is utilized for construction, waste disposal and groundwater supply. Conflicting and unwise use has led to problems of groundwater contamination. Cleanup is often difficult and expensive, and perhaps not even possible in many cases. Construction projects often encounter unanticipated difficulties that increase expenses. Many of the difficulties of predicting mechanical behavior and fluid flow and transport behavior stem from problems in characterizing what cannot be seen. An underground research laboratory, such as can be developed in the nearly 14 miles of tunnel at the Superconducting Super Collider (SSC) site, will provide a unique opportunity to advance scientific investigations of fluid flow, chemical transport, and mechanical behavior in situ in weak and fractured, porous rock on a scale relevant to civil and environmental engineering applications involving the subsurface down to a depth of 100 m. The unique element provided by underground studies at the SSC site is three-dimensional access to a range of fracture conditions in two rock types, chalk and shale. Detailed experimentation can be carried out in small sections of the SSC tunnel where different types of fractures and faults occur and where different rock types or contacts are exposed. …
Date: October 31, 1994
Creator: Wang, Herbert F. & Myer, Larry R.
Object Type: Report
System: The UNT Digital Library
Advances in high temperature components for AMTEC (alkali metal thermal-to-electric converter) (open access)

Advances in high temperature components for AMTEC (alkali metal thermal-to-electric converter)

Long lifetimes are required for AMTEC (or sodium heat engine) components for aerospace and terrestrial applications, and the high heat input temperature as well as the alkali metal liquid and vapor environment places unusual demands on the materials used to construct AMTEC devices. In addition, it is important to maximize device efficiency and power density, while maintaining a long life capability. In addition to the electrode, which must provide both efficient electrode kinetics, transport of the alkali metal, and low electrical resistance, other high temperature components of the cell face equally demanding requirements. The beta{double_prime} alumina solid electrolyte (BASE), the seal between the BASE ceramic and its metallic transition to the hot alkali metal (liquid or vapor) source, and metallic components of the device are exposed to hot liquid alkali metal. Modification of AMTEC components may also be useful in optimizing the device for particular operating conditions. In particular, a potassium AMTEC may be expected to operate more efficiently at lower temperatures.
Date: December 31, 1991
Creator: Williams, R. M.; Jeffries-Nakamura, B.; Underwood, M. L.; Ryan, M. A.; O`Connor, D. & Kikkert, S.
Object Type: Article
System: The UNT Digital Library
Finding of No Significant Impact, Proposed Remediation of the Maybell Uranium Mill Processing Site, Maybell, Colorado (open access)

Finding of No Significant Impact, Proposed Remediation of the Maybell Uranium Mill Processing Site, Maybell, Colorado

The U.S. Department of Energy (DOE) has prepared an environmental assessment (EA) (DOE/EA-0347) on the proposed surface remediation of the Maybell uranium mill processing site in Moffat County, Colorado. The mill site contains radioactively contaminated materials from processing uranium ore that would be stabilized in place at the existing tailings pile location. Based on the analysis in the EA, DOE has determined that the proposed action does not constitute a major federal action significantly affecting the quality of the human environment within the meaning of the National Environmental Policy Act (NEPA) of 1969, Public Law 91-190 (42 U.S.C. {section}4321 et seq.), as amended. Therefore, preparation of an environmental impact statement is not required and DOE is issuing this Finding of No Significant Impact (FONSI).
Date: December 31, 1995
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Spectroscopic diagnostics of high temperature plasmas, January 1, 1991--December 31, 1991 (open access)

Spectroscopic diagnostics of high temperature plasmas, January 1, 1991--December 31, 1991

During 1991, the activities of the John Hopkins University Plasma Spectroscopy Group have covered several areas of research, in the domain of XUV spectroscopy of magnetically confined fusion plasmas. While the main effort concentrated on the development of novel diagnostics which utilize Layered Synthetic Microstructures (LSMs) as the dispersive/filtering elements, work has been done in the area of detector development and the physics of the tokamak edge plasma. An XUV monochromator for the 20--200{Angstrom} range, which uses flat LSMs, has been built and is currently operated on the D3-D tokamak at General Atomics in San Diego. A design for a follow-up experiment at D3-D is now in progress. As a preliminary step toward tokamak plasma imaging in the XUV wavelength range using curved LSM coated substrates, a prototype XUV camera was built and operated in our laboratory in image the A1 3 emission at {lambda}-175{Angstrom} from a Penning Ionization Discharge plasma. Based on these laboratory results, the design of the XUV camera, which will image plasma in the Phaedrus T tokamak O VI emission (150{Angstrom}), has been completed. This instrument is presently under construction. Also a detailed design of a system composed of four LSM based imaging devices for N{sub …
Date: December 31, 1991
Creator: unknown
Object Type: Report
System: The UNT Digital Library
The study of redox-active inorganic substituents of cellulase enzymes. Quarterly report, 25 August--25 November 1993 (open access)

The study of redox-active inorganic substituents of cellulase enzymes. Quarterly report, 25 August--25 November 1993

Cellulase (CBHI) was modified by bis (2,2- bipyridine) ruthenium (II) and the modified enzyme was assayed for cellulase activity using p- nitrophenyl beta-D-cellobioside as substrate. Absorption spectroscopy of native and modified CBHI was also conducted.
Date: December 31, 1993
Creator: unknown
Object Type: Report
System: The UNT Digital Library