Office of Scientific and Technical Information
SciTec Connect (Office of Scientific and Technical Information - OSTI, U.S. Department of Energy)Not a member yet
500 research outputs found
Sort by
Phase III: Implementation and Operation of the Repository
No full textAll of the hardware is installed and all available databases are loaded into the metadata repository. The final stages of beta testing of GeoTrek and necessary revisions are underway, with a targeted public release of the NGDRS system in April or May 1998. The Eastern Gulf Region PTTC, Oklahoma Geological Survey, and A2D databases have been converted and loaded into the metadata repository. These are in addition to the four previously installed databases, including the BEG, MMS, PGS, and Fairfield. Data quality improvements, particularly with the MMS and BEG data is continuing, including making the data more intuitive for the typical user. The beta-testing process has resulted in a number of action items that have been reviewed and addressed. Most of these issues have been resolved, and the remaining issues will be resolved early in the second quarter of 1998, leading to the public launch of the NGDRS metadata repository. Installation of GeoTrek at the BEG, in an effort to bring their core holdings into the NDGRS, was completed in December. A review was held concerning the experiences of the BEG with GeoTrek during January. The feedback was largely positive, with only a couple technical details to address. A number of companies have also expressed interest and/or are evaluating PetroTrek, the commercial version of GeoTrek. Thus far, most of those companies, including PGS and Fairfield, which have licensed PetroTrek have simultaneously joined the NGDRS as well. Several data transfer efforts are underway. Vastar has committed to the transfer of 2D Appalachian seismic lines to the NDGRS clearinghouse. Receiving repositories have been identified and the final preparations are being made for transfer to these public repositories. Additionally, discussions continue with the Stapleton Development Corporation concerning the transfer of facilities in Denver for use as a central core repository
Investigation of Combined S02/N0x Removal by Ceria Sorbents
No full textSimultaneous removal of S02 and NOX using a regenerable solid sorbent will constitute an important improvement over the use of separate processes for the removal of these two pollutants from stack gases and possibly eliminate several shortcomings of the individual S02 and NOX removal operations. Recent studies at PETC considered cerium oxide as an alternate sorbent to CUO. The present study aims to determine the effects of ammonia on ihe sulfation of the sorbent and to obtain a rate expression for the regeneration of alumina-supported CeOa sorbents. In the past quarter the effect of cerium content of the sorbent on its performance through four sulfation-regeneration cycles were investigated and the analysis of the economics of a commercial scale ceria process wcs sub-contracted to TECOGEN. It was found that all ceria sorbents did not show any capacity loss after the first cycle and, in fact, their performance improved slightly after the third cycle. Increasing cerium loading appears to reduce the S/Cc ratio to about 2 as monolayer coverage is approached. It was found that the sulfation rate for the sorbents containing 9.28% and 7.64% cerium were first order with respect to cerium oxide up to 90% conversion. The sorbents containing 4.39% and 1.59 showed first order kinetics up to only about 40% conversion. The effects of product layer diffusion and gas phase diffusion are currently being considered for these sorbents
Glass Development for Treatment of LANL Evaporator Bottoms Waste
No full textVitrification is an attractive treatment option for meeting the stabilization and final disposal requirements of many plutonium (Pu) bearing materials and wastes at the Los Alamos National Laboratory (LANL) TA-55 facility, Rocky Flats Environmental Technology Site (RFETS), Hanford, and other Department of Energy (DOE) sites. The Environmental Protection Agency (EPA) has declared that vitrification is the "best demonstrated available technology" for high- level radioactive wastes (HLW) (Federal Register 1990) and has produced a handbook of vitriilcation technologies for treatment of hazardous and radioactive waste (US EPA, 1992). This technology has been demonstrated to convert Pu-containing materials (Kormanos, 1997) into durable (Lutze, 1988) and accountable (Forsberg, 1995) waste. forms with reduced need for safeguarding (McCulhun, 1996). The composition of the Evaporator Bottoms Waste (EVB) at LANL, like that of many other I%-bearing materials, varies widely and is generally unpredictable. The goal of this study is to optimize the composition of glass for EVB waste at LANL, and present the basic techniques and tools for developing optimized glass compositions for other Pu-bearing materials in the complex. This report outlines an approach for glass formulation with fixed property restrictions, using glass property-composition databases. This approach is applicable to waste glass formulation for many variable waste streams and vitrification technologies.. Also reported are the preliminary property data for simulated evaporator bottom glasses, including glass viscosity and glass leach resistance using the Toxicity Characteristic Leaching Procedure (TCLP)
Optimum Condition for Accurate Heat Capacity Measurements in Temperature-Modulated Differential Scanning Calorimetry
No full textWe explored the optimum conditions in modulation of the program temperature and sample preparation to obtain absolute values of heat capac- ity from quasi-isothermal measurements of temperature-modulated differen- tial scanning calorimetry. A Mettler-Toledo 820 calorimeter and Perkin-Elmer DSC 7 were used for this work, using saw-tooth modulation as well as sinu- soidal modulation. We adopted a simple model to analyze the temperature response of the calorimeters and calibrated the results more precisely
Control of Trace Metal Emissions During Coal Combustion
No full textEmissions of toxic trace metals in the form of metal fumes or submicron particulate from a coal-fired combustion source have received greater environmental and regulatory concern over the past years. Current practice of controlling these emissions is to collect them at the cold-end of the process by air-pollution control devices (APCDS) such as electrostatic precipitators and baghouses. However, trace metal fumes may not always be effectively collected by these devices because the formed fumes are extremely small. The proposed research is to explore the opportunities for improved control of toxic trace metal emissions, alternatively, at the hot-end of the coal combustion process, i.e., in the combustion chamber. The technology proposed is to prevent the metal fumes from forming during the process, which would effectively eliminate the metal emission problems. Specifically, the technology is to employ suitable sorbents to (1) reduce the amount of metal volatilization during combustion and (2) capture volatilized metal vapors. The objectives of the project are to demonstrate the technology and to characterize the metal capture process during coal combustion in a fluidized bed combustor
Quarterly Technical Progress Report
No full textThe temperature dependence of the oxygen flux across the BaCe0G03 dense membrane (BCG membrane) tube was investigated. In the temperature range of 688C to 955C, the increase in the oxygen flux with temperature obeyed the Arrhenius law. An increase in the helium sweep flow membrane tube. rate in the tube side resulted in an increase in the oxygen flux through the The oxygen fluxes through the BCG dense membrane tube were measured at different oxygen partial pressures in the shell side. The oxygen flux increased with the oxygen partial pressure in the shell side. The BCG dense membrane was tested in a membrane reactor for the catalytic oxidative coupling of methane. The BCG membrane is not a complete combustion catalyst, and the catalytic activity of the BCG membrane was found to be much higher than the Argonne dense membrane. As the oxygen partial pressure in the shell side increased, the C2 decreased while the C2 yield remained unchanged, indicating that non-selective, reactions still played a significant role in the membrane reactor
Shielding Design of the Spallation Neutron Source (SNS)
No full textThe shielding design is important for the construction of an intense high-energy accelerator facility like the proposed Spallation Neutron Source (SNS) due to its impact on conventional facility design, maintenance operations, and since the cost for the radiation shielding shares a considerable part of the total facility costs. A calculational strategy utilizing coupled high energy Monte Carlo calculations and multi-dimensional discrete ordinates calculations, along with semi-empirical calculations, was implemented to perform the conceptual design shielding assessment of the proposed SNS. Biological shields have been designed and assessed for the proton beam transport system and associated beam dumps, the target station, and the target service cell and general remote maintenance cell. Shielding requirements have been assessed with respect to weight, space, and dose-rate constraints for operating, shutdown, and accident conditions. A discussion of the proposed facility design, conceptual design shielding requirements, calculational strategy, source terms, preliminary results and conclusions, and recommendations for additional analyses are presented
Effects of High-pH and High-Ionic-Strength Groundwater on Iodide, Pertechnetate, and Selenate Sorption to Hanford Sediments: Final Report for Subtask 3a
No full textAs part of the Immobilized Low-Activity Waste-Performance Assessment three experiments were conducted to evaluate the effect of the expected near-field chemistry on the sorption of iodide, selenate, and pertechnetate onto a sediment obtained from the Hanford Site. These experiments were performed in fiscal year 1998 at the Pacific Northwest National Laboratory.' During these experiments, attention was directed at the identification of the chemical mechanisms controlling the sorption processes to provide technical defensibility for the selection of the distribution coefficients (IQ to be used in the remainder of the performance assessment. It was found, during the conduct of the experiments, that selenium and technetium I&s increased as ionic strength increased. The cause for this is most likely to be that the higher ionic strength caused the double layer around the particles to decrease, thereby permitting greater interaction with the mineral surfaces. Further, the pH level had an effect on the sorption of these anions. These are the first-ever experiments conducted with Hanford Site sediment in which the IQ were measured as a function of ionic strength and pH. Overall, the observed trends were consistent with more generalized geochemical principles. One of the most important contributions of these experiments was that they quantified the & changes induced by variations in ionic strength and pH that are expected to exist in the near field
Investigation of combined S02/N0x Removal by Ceria Sorbents
No full textThis final report describes the work done under the sponsorship of the U.S. DOE for the support of advanced fossil resource utilization research at historically black colleges and universities, Grant No. DE-Ps22-92MT920 on "Investigation of Combined S02/NOx Removal by Ceria Sorbents". The work was conducted at the Department of Chemical Engineering of Hampton University. The industrial partner was Malcolm Pirnie,Inc. Environmental Engineers, Scientists and Planners, who handled the metal analysis and XRD measurements on the solid sorbents; they have also supplied the flyash used in the experimental program. The development of a commercial process concept, economic analysis, and evaluation of process alternatives were undertaken by TECOGEN of Waltham, MA
Annual Technical Progress Report - West Hackberry Tertiary Project
No full textThe West Hackberry Tertiary Project is a field test of the concept that air injection can be combined with the Double Displacement Process to produce a tertiary recovery process that is both low cost and economic at current oil prices. The Double Displacement Process is the gas displacement of a water invaded oil column for the purpose of recovering tertiary oil by gravity drainage. In reservoirs with pronounced bed dip such as those found in West Hackberry and other Gulf Coast salt dome fields, reservoir performance has shown that gravity drainage recoveries average 80% to 90% of the original oil in place while waterdrive recoveries average 50% to 60% of the original oil in place. The target for tertiary oil recovery in the Double Displacement Process is the incremental oil between the 50% to 60% waterdrive recoveries and the 80% to 90% gravity drainage recoveries. Air injection on the west flank began in November of 1994. Although west flank air injection has increased reservoir pressure by 500 pounds per square inch (psi), production response has not yet occurred. The gas cap on the west flank has not expanded sufficiently to push the oil rim down to the nearest downstructure well