The goal of the 6th International Meshing Roundtable is to bring together researchers and developers from industry, academia, and government labs in a stimulating, open environment for the exchange of technical information related to the meshing process. In the pas~ the Roundtable has enjoyed significant participation born each of these groups from a wide variety of countries. The Roundtable will consist of technical presentations from contributed papers and abstracts, two invited speakers, and two invited panels of experts discussing topics related to the development and use of automatic mesh generation tools. In addition, this year we will feature a "Bring Your Best Mesh" competition and poster session to encourage discussion and participation from a wide variety of mesh generation tool users. The schedule and evening social events are designed to provide numerous opportunities for informal dialog. A proceedings will be published by Sandia National Laboratories and distributed at the Roundtable. In addition, papers of exceptionally high quaIity will be submitted to a special issue of the International Journal of Computational Geometry and Applications. Papers and one page abstracts were sought that present original results on the meshing process. Potential topics include but are got limited to: Unstructured triangular and tetrahedral …

This report covers the progress made on the title project for the project period. The study of coal chemical structure is a vital component of research efforts to develop better chemical utilization of coals, and for furthering our basic understanding of coal geochemistry. In this grant we are addressing several structural questions pertaining to coals with advances in state of the art solids NMR methods. The main activity during this granting period was a completion of a detailed comparative analysis of the suite of spectral editing techniques developed in our laboratory for this purpose. The appended report is a manuscript being submitted to the Journal of Magnetic Resonance on this subject.

'The purpose of this task is to undertake the design, synthesis, and characterization of the next generation of crown ethers for metal-ion separations applicable to the US Department of Energy''s (DOE''s) environmental needs. The general target problem is the removal of alkali and alkaline-earth metal contaminants from certain environmental and waste streams. Although not a radioactivity hazard, Li{sup +} ions leaching from burial sites containing more than 12 metric tons of lithium compounds contaminate the groundwater at the Oak Ridge Y-12 Plant and have raised noncompliance concerns because of the resultant toxicity to aquatic biota. A more highly visible problem has been treatment of high-level wastes stored in underground tanks at Oak Ridge National Laboratory (ORNL), Idaho National Engineering and Environmental Laboratory, and especially the Hanford Site. The fission products {sup 90}Sr and {sup 137}Cs have been explicitly targeted for removal by the following DOE programs: the Office of Environmental Management, the Office of Science and Technology, the Tank Waste Remediation System, the Tanks Focus Area, and the Efficient Separations and Processing Cross-Cutting Program. These seemingly ubiquitous fission products also appear in soil and groundwater at numerous DOE sites. In addition, radium has recently been named as a target contaminant …

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'Biofiltration systems can be used to treat volatile organic compounds (VOCs); however, the systems are poorly understood and are currently operated as black boxes. Common operational problems associated with biofilters include fouling, deactivation, and overgrowth, all of which make biofilters ineffective for continuous, long-term use. The objective of this investigation is to develop generic methods for long-term stable operation, in particular by using selective limitation of supplemental nutrients while maintaining high activity and the ability to regenerate biofilter activity. As part of this effort, the authors will provide a deeper fundamental understanding of the important biological and transport mechanisms in biodestruction of sparingly soluble VOCs and will extend this engineering approach and developed mathematical models to two additional systems of high-priority environmental management (EM) relevance-direct degradation and cometabolic degradation of priority pollutants such as BTEX (benzene, toluene, ethylbenzene, and xylene) and TCE (trichioroethylene), respectively. Preliminary results indicate that the author can control overgrowth of the biofilm while sustaining high degradation rates and develop basic predictive models that elucidate mass transfer and kinetic limitations in this system for alkanes. The alkanes are degraded into CO, and waterwith minimal biomass (due to the methodology proposed). This system will be used to test …

'The objective of this research program is to develop methods for concentrating tritium in water based on large primary isotope effects in catalytic redox processes. Basic research is being conducted to develop the chemistry of a complete cyclic process. Because tritium [generally present as tritiated water (HTO)] is in a rapidly established equilibrium with water, it moves with groundwater and separation from water cannot be achieved by the usual pump-and-treat methods using sorbents. The general methodology developed in this work will be applicable to a number of US Department of Energy waste streams, and as a consequence of the process, tritium could be incorporated in an organic polymer, a form that will prevent its ready transport in groundwater.'

'The goal of this project is to identify the chemical and physical factors that control the transport of groundwater colloids in fractured porous media and develop a generalized capability to predict colloid attachment and detachment based on hydraulic factors (head, flow rate), physical structure (fracture aperture), and chemical properties (surface properties of colloids and fracture surfaces). Understanding the processes that control colloid behavior will increase the confidence with which colloid-facilitated contaminant transport can be predicted and assessed at various contaminated US Department of Energy (DOE) sites. An added benefit is the expectation that this work will yield novel techniques to either immobilize colloid-bound contaminants in situ or mobilize colloids for enhancing remedial techniques such as pump-and-treat and bioremediation. Research Statement A series of field-scale and laboratory-scale experiments, using both natural undisturbed samples and simple one-dimension ``artificial fractures,'''' are in progress to investigate the influence of physical and chemical factors on the transport of colloids in fractured materials. The experimental results will be assessed using a computer model (COLFRAC) developed to simulate colloid transport in fractured materials. The overall goal is to assess the relative influence of chemical and physical factors expected to influence colloid transport in fractured materials and investigate …

The microsegregation behavior of electron beam (EB) and gas tungsten arc (GTA) welds of Al-Cu alloys covering a range from 0.19 to 7.74 wt% Cu were characterized for dendrite core concentrations and fraction eutectic solidification. Although a single weld speed of 12.7 mm/sec was used, some differences were observed in the segregation behavior of the two weld types. The microsegregation behavior was also modeled using a finite differences technique considering dendrite tip and eutectic undercooling and solid state diffusion. Fairly good agreement was observed between measured and calculated segregation behavior although differences between the two weld types could not be completely accounted for. The concept of dendrite tip undercooling was used to explain the formation of a single through thickness centerline grain in the higher alloy content GTA welds.

At the Savannah River Site, the in-tank precipitation (ITP) process uses sodium tetraphenylborate (NaTPB) to precipitate radioactive cesium from alkaline wastes. During this process, potassium is also precipitated to form a 4-wt% KTPB/CsTPB slurry. Residual NaTPB decomposes to form benzene, which is retained by the waste slurry. The retained benzene is also readily released from the waste during subsequent waste processing. While the release of benzene certainly poses both flammability and toxicological safety concerns, the magnitude of the hazard depends on the rate of release. Currently, the mechanisms controlling the benzene release rates are not well understood, and predictive models for estimating benzene release rates are not available. The overall purpose of this study is to obtain quantitative measurements of benzene release rates from a series of ITP slurry stimulants. This information will become a basis for developing a quantitative mechanistic model of benzene release rates. The transient benzene release rate was measured from the surface of various ITP slurry (solution) samples mixed with benzene. The benzene release rate was determined by continuously purging the headspace of a sealed sample vessel with an inert gas (nitrogen) and analyzing that purged headspace vapor for benzene every 3 minutes. The following 75-mL …

A group of Canadian, US and Mexican natural resource specialists, organized by the Pacific Northwest National Laboratory (PNNL) under its North American Energy, Environment and Economy (NA3E) Program, has applied a simulation modeling approach to estimating the impact of ENSO-driven climatic variations on the productivity of major crops grown in the three countries. Methodological development is described and results of the simulations presented in this report. EPIC (the Erosion Productivity Impact Calculator) was the agro-ecosystem model selected-for this study. EPIC uses a daily time step to simulate crop growth and yield, water use, runoff and soil erosion among other variables. The model was applied to a set of so-called representative farms parameterized through a specially-assembled Geographic Information System (GIS) to reflect the soils, topography, crop management and weather typical of the regions represented. Fifty one representative farms were developed for Canada, 66 for the US and 23 for Mexico. El Nino-Southern Oscillation (ENSO) scenarios for the EPIC simulations were created using the historic record of sea-surface temperature (SST) prevailing in the eastern tropical Pacific for the period October 1--September 30. Each year between 1960 and 1989 was thus assigned to an ENSO category or state. The ENSO states were defined …

The Mushroom test is designed to characterize the corner turning performance of a new generation of less insensitive booster explosives. The test is described in detail, and three corner turning figures-of-merit are examined using pure TATB (both Livermore`s Ultrafine and a Los Alamos research blend) and PBX9504 as examples.

Magnetically driven imploding liner systems can be used as a source of shock energy for materials equation of state studies, implosion driven magnetized plasma fusion experiments, and other similar applications. The imploding liner is a cylinder of conducting material through which a current is passed in the longitudinal direction. Interaction of the current with its own magnetic field causes the liner to implode. Sources of electrical energy for imploding liner systems are capacitor banks or explosive pulse power systems seeded by capacitor banks. In August, 1996, a high energy liner experiment (HEL-1) was conducted at the All-Russia Scientific Research Institute (VNIIEF) in Sarov, Russia. A 5 tier 1 meter diameter explosive disk generator provided electrical energy to drive a 48 cm outside diameter, 4 mm thick, aluminum alloy liner having a mass of about 11kg onto an 11 cm diameter diagnostic package. The purpose of the experiment was to measure performance of the explosive pulse power generator and the heavy imploding liner. Electrical performance diagnostics included inductive (B-dot) probes, Faraday Rotation current measurement, Rogowski total current measurement, and voltage probes. Flux loss and conductor motion diagnostics included current-joint voltage measurements and motion sensing contact pins. Optical and electrical impact pins, …

Attention in this project has been focused on the following: the effect of selected metal adatoms on the carbon deposition characteristics of iron and cobalt during interaction with hydrocarbons; the influence of selected non-metallic adatoms on the carbon formation activity of both these metals when treated in hydrocarbons; and the relationship between the structural and morphological characteristics of the carbon deposits and that of the modified metal particles.

Summaries are presented for the following tasks: Development and demonstration of a practical electric downhole steam generator for thermal recovery of heavy oil and tar; Wetting behavior of selected crude oil/brine/rock systems; Coal gasification, power generation and product market study; Impact of leachate from Clean Coal Technology waste on the stability of clay liners; Investigation of coprocessing heavy oil, automobile shredder residue, and coal; Injection into coal seams for simultaneous CO{sub 2} mitigation and enhanced recovery of coalbed methane; Optimization of carbonizer operations in the FMC coke process; Chemical sensor and field screening technology development; Demonstration of the Koppelman Series C process using a batch test unit with Powder River Basin coal as feed; Remote chemical sensor development; Market assessment and technical feasibility study of PFBC ash use; Solid state NMR analysis of naturally and artificially matured kerogens; Contained recovery of oily wastes field demonstration with Bell Lumber and Pole; B Series pilot plant tests; In-situ treatment of manufactured gas plant contaminated soils; Development and demonstration of a wood-fired gas turbine system; Solid state NMR analysis of Mowry Formation shale from different sedimentary basins; Acid mine drainage prevention, control, and treatment development for the Stockett/Sand Coulee Area; PERF dispersion modeling …

This document defines the waste certification program (WCP) developed for implementation at Oak Ridge National Laboratory (ORNL). The document describes the program structure, logic, and methodology for certification of ORNL wastes. The purpose of the WCP is to provide assurance that wastes are properly characterized and that the Waste Acceptance Criteria (WAC) for receiving facilities are met. The program meets the waste certification requirements for mixed (both radioactive and hazardous) and hazardous [including polychlorinated biphenyls (PCB)] waste. Program activities will be conducted according to ORNL Level 1 document requirements.

An Alternative Evaluation Study is a type of systematic approach to problem identification and solution. An Alternative Evaluation Study was convened August 12-15, 1997, for the purpose of making recommendations concerning closure of Disposal Cell U-3ax/bl and other disposal cells and mitigation/accommodation of waste subsidence at the Radioactive Waste Management Sites at the Nevada Test Site. This report includes results of the Alternative Evaluation Study and specific recommendations.

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Further review of the technical literature has provided additional information which will support the development of a superior calcium-based sorbent for hot gas cleanup in IGCC systems. Two general methods of sorbent preparation are being investigated. One method involves impregnating a porous refractory substrate with calcium while another method involves pelletizing lime or other calcium containing materials with a suitable binder. Several potential substrates, which are made of alumina and are commercially available, have been characterized by various methods. The surface area and apparent density of the materials have been measured, and it has been shown that some of the high surface area materials (i.e., 200-400 m{sub 2}/g) undergo a large decrease in surface area when heated to higher temperatures. Some of the lower surface area materials (i.e., 1-30 m{sub 2}/g) have been successfully impregnated with calcium by soaking them in a calcium nitrate solution and then heat treating them to decompose the nitrate. Potentially useful sorbents have also been prepared by pelletizing type I Portland cement and mixtures of cement and lime.

This report examines the most current literature and information available on characterization and remediation technologies that could be used on the Nevada Test Site (NTS) historical hydronuclear test areas. Historical hydronuclear tests use high explosives and a small amount of plutonium. The explosion scatters plutonium within a contained subsurface environment. There is currently a need to characterize these test areas to determine the spatial extent of plutonium in the subsurface and whether geohydrologic processes are transporting the plutonium away from the event site. Three technologies were identified to assist in the characterization of the sites. These technologies are the Pipe Explorer{trademark}, cone penetrometer, and drilling. If the characterization results indicate that remediation is needed, three remediation technologies were identified that should be appropriate, namely: capping or sealing the surface, in situ grouting, and in situ vitrification. Capping the surface would prevent vertical infiltration of water into the soil column, but would not restrict lateral movement of vadose zone water. Both the in situ grouting and vitrification techniques would attempt to immobilize the radioactive contaminants to restrict or prevent leaching of the radioactive contaminants into the groundwater. In situ grouting uses penetrometers or boreholes to inject the soil below the contaminant …

Austenitic 316LN alloy was ion-irradiated using the unique Triple Ion Beam Facility (TIF) at ORNL to investigate radiation damage effects relevant to spallation neutron sources. The TIF was used to simulate significant features of GeV proton irradiation effects in spallation neutron source target materials by producing displacement damage while simultaneously injecting helium and hydrogen at appropriately high gas/dpa ratios. Irradiations were carried out at 80, 200, and 350 C using 3.5 MeV Fe{sup ++}, 360 keV He{sup +}, and 180 keV H{sup +} to accumulate 50 dpa by Fe, 10,000 appm of He, and 50,000 appm of H. Irradiations were also carried out at 200 C in single and dual ion beam modes. The specific ion energies were chosen to maximize the damage and the gas accumulation at a depth of {approximately} 1 {micro}m. Variations in microstructure and hardness of irradiated specimens were studied using transmission electron microscopy (TEM) and a nanoindentation technique, respectively. TEM investigation yielded varying damage defect microstructures, comprising black dots, faulted and unfaulted loops, and a high number density of fine bubbles (typically less than 1 nm in diameter). With increasing temperature, faulted loops had a tendency to unfault, and bubble microstructure changed from a bimodal …

Contents include articles entitled: House votes 309 to 107 to approve Texas compact; Nebraska governor hosts LLRW meeting; Southeast Compact considers funding proposal; Chem-Nuclear explores options re SC revenue requirements; Legislation sets revenue requirements for Barnwell; TCC meets: Supports CA request for technical assistance; DOE approves part of California`s technical assistance request; State legislators discuss LLRW management for OH, IL, NC; Washington governor re Potential New Hanford Role; Federal court enjoins DOE from excluding WCS on new disposal; Appellate court in favor of DOE in surcharge rebates dispute; Hearing set for October in Ward Valley case; court rejects federal motion to dismiss Ward Valley suit; NE sues commission re veto over export authorizations; US Supreme Court dismisses line-item veto challenge; Department of Interior Inspector General investigation requested; USEC privatization plan approved; DOD finalizes LLRW disposal charter; Clinton nominates six DOE appointees; Congress moves FUSRAP to Army Corps of Engineers; Schaefer named interim director of USGS: Nichols leaves EPA: NRC Commissioner Rogers` term expires; NRC: CA ``Well-Quantified`` to license Ward Valley facility; EPA objects to state permit for Louisiana facility; Petitions submitted to EPA oppose Shintech permits; ECOS draft recommendations re Enviro programs; Legislation introduced to prohibit spent fuel shipments to …

The Retrieval Process Development and Enhancements (RPD and E) activities are part of the US Department of Energy (DOE) EM-50 Tanks Focus Area, Retrieval and Closure program. The purpose of RPD and E is to understand retrieval processes, including emerging and existing technologies, and to gather data on these processes, so that end users have requisite technical bases to make retrieval decisions. Technologies addressed during FY97 include enhancements to sluicing, the use of pulsed air to assist mixing, mixer pumps, innovative mixing techniques, confined sluicing retrieval end effectors, borehole mining, light weight scarification, and testing of Russian-developed retrieval equipment. Furthermore, the Retrieval Analysis Tool was initiated to link retrieval processes with tank waste farms and tank geometric to assist end users by providing a consolidation of data and technical information that can be easily assessed. The main technical accomplishments are summarized under the following headings: Oak Ridge site-gunite and associated tanks treatability study; pulsed air mixing; Oak Ridge site-Old Hydrofracture Facility; hydraulic testbed relocation; cooling coil cleaning end effector; light weight scarifier; innovative tank mixing; advanced design mixer pump; enhanced sluicing; Russian retrieval equipment testing; retrieval data analysis and correlation; simulant development; and retrieval analysis tool (RAT).

High current photocathodes operating in vacuum environments as high as 8xE-5 torr are being developed at Los Alamos for use in a new generation of linear induction accelerators. We report quantum efficiencies in wide bandgap semiconductors, pure metals, and compound metal surfaces photocathode materials illuminated by ultraviolet laser radiation.