A fundamental part of geophysics is to make inferences about the interior of the earth on the basis of data collected at or near the surface of the earth. In almost all cases these measured data are only indirectly related to the properties of the earth that are of interest, so an inverse problem must be solved in order to obtain estimates of the physical properties within the earth. In February of 1999 the U.S. Department of Energy sponsored a workshop that was intended to examine the methods currently being used to solve geophysical inverse problems and to consider what new approaches should be explored in the future. The interdisciplinary area between inverse problems in geophysics and optimization methods in mathematics was specifically targeted as one where an interchange of ideas was likely to be fruitful. Thus about half of the participants were actively involved in solving geophysical inverse problems and about half were actively involved in research on general optimization methods. This report presents some of the topics that were explored at the workshop and the conclusions that were reached. In general, the objective of a geophysical inverse problem is to find an earth model, described by a set …

A comprehensive investigation of natural and manmade silicate glasses, and nuclear melt glass was undertaken in order to derive an estimate of glass reactive surface area. Reactive surface area is needed to model release rates of radionuclides from nuclear melt glass in the subsurface. Because of the limited availability of nuclear melt glasses, natural volcanic glass samples were collected which had similar textures and compositions as those of melt glass. A flow-through reactor was used to measure the reactive surface area of the analog glasses in the presence of simplified NTS site ground waters. A measure of the physical surface area of these glasses was obtained using the BET gas-adsorption method. The studies on analog glasses were supplemented by measurement of the surface areas of pieces of actual melt glass using the BET method. The variability of the results reflect the sample preparation and measurement techniques used, as well as textural heterogeneity inherent to these samples. Based on measurements of analog and actual samples, it is recommended that the hydraulic source term calculations employ a range of 0.001 to 0.01 m{sup 2}/g for the reactive surface area of nuclear melt glass.

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Fluidized-bed calcination at the Idaho Nuclear Technologies and Engineering Center (INTEC, formally called the Idaho Chemical Processing Plant) has been used to solidify acidic metal nitrate fuel reprocessing and incidental wastes wastes since 1961. A summary of waste calcination in full-scale and pilot plant calciners has been compiled for future reference. It contains feed compositions and operating conditions for all the processing campaigns for the original Waste Calcining Facility (WCF), the New Waste Calcining Facility (NWCF) started up in 1982, and numerous small scale pilot plant tests for various feed types. This summary provides a historical record of calcination at INTEC, and will be useful for evaluating calcinability of future wastes.

The TMAP Code was written in the late 1980s as a tool for safety analysis of systems involving tritium. Since then it was upgraded to TMAP4 and used in numerous applications including experiments supporting fusion safety predictions for advanced systems such as the International Thermonuclear Experimental Reactor (ITER), and estimates involving tritium production technologies. Its further upgrade to TMAP2000 was accomplished in response to several needs. TMAP and TMAP4 had the capacity to deal with only a single trap for diffusing gaseous species in solid structures. TMAP2000 has been revised to include up to three separate traps and to keep track separately of each of up to 10 diffusing species in each of the traps. A difficulty in the original code dealing with heteronuclear molecule formation such as HD and DT has been removed. Under equilibrium boundary conditions such as Sieverts' law, TMAP2000 generates heteronuclear molecular partial pressures when solubilities and partial pressures of the homonuclear molecular species and the equilibrium stoichiometry are provided. A further sophistication is the addition of non-diffusing surface species and surface binding energy dynamics options. Atoms such as oxygen or nitrogen on metal surfaces are sometimes important in molecule formation with diffusing hydrogen isotopes but …

The quarterly activities of the Advanced Gas Turbine Systems Research (AGTSR) program are described in this quarterly report. As this program administers research, we have included all program activity herein within the past quarter as dated. More specific research progress reports are provided weekly at the request of the AGTSR COR and are being sent to NETL As for the administration of this program, items worthy of note are presented in extended bullet format following the appropriate heading.

The U.S. Department of Energy's nuclear complex, a nation-wide system of facilities for research and production of nuclear materials and weapons, contains large amounts of radioactively contaminated concrete[1]. This material must be disposed of prior to the decommissioning of the various sites. Often the radioactive contaminants in concrete occupy only the surface and near-surface ({approx}3-6 mm deep) regions of the material. Since many of the structures such as walls and floors are 30 cm or more thick, it makes environmental and economic sense to try to remove and store only the thin contaminated layer rather than to treat the entire structure as waste. Current mechanical removal methods, known as scabbling, are slow and labor intensive, suffer from dust control problems, and expose workers to radiation fields. Improved removal methods are thus in demand[2-5]. Prior to decontamination, the surface must be characterized to determine the types and amounts of contaminants present i n order to decide on an appropriate cleaning strategy. Contamination occurs via exposure to air and water-borne radionuclides and by neutron activation. The radionuclides of greatest concern are (in order of abundance) [1]: 137Cs & 134Cs, 238U, 60Co, and 90Sr, followed by 3H, radioactive iodine, and a variety of …

The objective of the research described in this report was to provide data and insights that will enable the natural gas industry to (1) significantly improve the assessment of subsurface glycol-related contamination at sites where it is known or suspected to have occurred and (2) make scientifically valid decisions concerning the management and/or remediation of that contamination. The described research was focused on subsurface transport and fate issues related to triethylene glycol (TEG), diethylene glycol (DEG), and ethylene glycol (EG). TEG and DEG were selected for examination because they are used in a vast majority of gas dehydration units, and EG was chosen because it is currently under regulatory scrutiny as a drinking water pollutant. Because benzene, toluene, ethylbenzene, and xylenes (collectively referred to as BTEX) compounds are often very closely associated with glycols used in dehydration processes, the research necessarily included assessing cocontaminant effects on waste mobility and biodegradation. BTEX hydrocarbons are relatively water-soluble and, because of their toxicity, are of regulatory concern. Although numerous studies have investigated the fate of BTEX, and significant evidence exists to indicate the potential biodegradability of BTEX in both aerobic and anaerobic environments (Kazumi and others, 1997; Krumholz and others, 1996; Lovely and …

This work presents modeling studies investigating the effects of capillary barriers on fluid-flow and tracer-transport processes in the unsaturated zone of Yucca Mountain, Nevada, a potential site for storing high-level radioactive waste. These studies are designed to identify factors controlling the formation of capillary barriers and to estimate their effects on the extent of possible large-scale lateral flow in unsaturated fracture rocks. The modeling approach is based on a continuum formulation of coupled multiphase fluid and tracer transport through fractured porous rock. Flow processes in fractured porous rock are described using a dual-continuum concept. In addition, approximate analytical solutions are developed and used for assessing capillary-barrier effects in fractured rocks. This study indicates that under the current hydrogeologic conceptualization of Yucca Mountain, strong capillary-barrier effects exist for significantly diverting moisture flow.

Authenticating and upgrading system software plays a critical role in information security, yet practical tools for assessing and installing software are lacking in today's marketplace. The SafePatch tool provides the mechanism of performing automated analysis, notification, distribution, and installation of security patches and related software to network-based computer systems in a vendor-independent fashion. SafePatch assists in the authentication of software by comparing the system's objects with the patch's objects. SafePatch will monitor vendor's sites to determine when new patches are released and will upgrade system software on target systems automatically. This paper describes the design of SafePatch, motivations behind the project and the advantages of SafePatch over existing tools.

This research was undertaken to meet the need for a robust portfolio of carbon management options to ensure continued use of coal in electrical power generation. In response to this need, the Ohio Coal Research Center at Ohio University developed a novel technique to control the emissions of CO{sub 2} from fossil-fired power plants by growing organisms capable of converting CO{sub 2} to complex sugars through the process of photosynthesis. Once harvested, the organisms could be used in the production of fertilizer, as a biomass fuel, or fermented to produce alcohols. In this work, a mesophilic organism, Nostoc 86-3, was examined with respect to the use of thermophilic algae to recycle CO{sub 2} from scrubbed stack gases. The organisms were grown on stationary surfaces to facilitate algal stability and promote light distribution. The testing done throughout the year examined properties of CO{sub 2} concentration, temperature, light intensity, and light duration on process viability and the growth of the Nostoc. The results indicate that the Nostoc species is suitable only in a temperature range below 125 F, which may be practical given flue gas cooling. Further, results indicate that high lighting levels are not suitable for this organism, as bleaching occurs …

A molecular genetic characterization of the maize R-r complex of maize was completed during the period of support. The complex was shown to consist of two main regions: the P region, containing the r-p gene which controlled pigmentation of plant parts, and the S subcomplex, containing two rl-s genes in head-to-head orientation and a nonfunctional component termed rl-q. By examining the DNA sequences at the junction of the rl genes, the complex was shown to be derived by a series of abortive transposition events. The transposable element involved in the gene duplication and rearrangements was characterized and called doppia. Meiotic instability of the R-r complex was also characterized. Loss of P or S function was associated with several structural changes including intrachromosomal recombination and excision of a novel transposable element that appears to show instability only during meiosis.

Solid oxide fuel cells (SOFCs) are the future of energy production in America. They offer great promise as a clean and efficient process for directly converting chemical energy to electricity while providing significant environmental benefits (they produce negligible CO, HC, or NOx and, as a result of their high efficiency, produce about one-third less CO{sub 2} per kilowatt hour than internal combustion engines). Unfortunately, the current SOFC technology, based on a stabilized zirconia electrolyte, must operate in the region of 1000 C to avoid unacceptably high ohmic losses. These high temperatures demand (a) specialized (expensive) materials for the fuel cell interconnects and insulation, (b) time to heat up to the operating temperature and (c) energy input to arrive at the operating temperature. Therefore, if fuel cells could be designed to give a reasonable power output at lower temperatures tremendous benefits may be accrued, not the least of which is reduced cost. The problem is, at lower temperatures the conductivity of the conventional stabilized zirconia electrolyte decreases to the point where it cannot supply electrical current efficiently to an external load. The primary objectives of the proposed research is to develop a stable high conductivity (>0.05 S cm{sup -1} at 550 …

The diversity and abundance of native grasses and herbaceous species characteristic of the longleaf savanna were compared between remnant stands that were not previously under agriculture and recent old-fields.The objective of the study was to establish a baseline for future restoration objectives and to compare the degree of degradation associated with agriculture. In most cases even the natural stands have suffered degradation as a result of fire exclusion and as such are not representative of pristine conditions. Community classification and ordination procedures were implemented to array the communities. Three distinct sub-units were identified and associated with xeric, sub-xeric, and medic types associated with texture and soil moisture. Between plantations and natural stands, the xeric group demonstrated the most similarity. The presence of a B horizon was the most important discriminate variable in both groups.

A monolithic block of densely welded tuff was excavated from a site on Fran Ridge near Yucca Mountain, Nevada so that coupled thermohydrological processes could be studied in a controlled, in situ experiment. A series of heaters were placed in a horizontal plane about 3 m from the top of the 3 m by 3 m by 4.5 m high block. Temperatures were measured at many points within and on the block surface and a suite of other measurements were taken to define the thermal and hydrologic response. Electrical resistance tomography (ERT) was used to map 2 dimensional images of moisture content changes along four planes in the block. The ERT images clearly delineate the drying and wetting of the rockmass during the 13 months of heating and subsequent six months of cool down. The main feature is a prominent dry zone that forms around the heaters then gradually disappears as the rock cools down. Other features include linear anomalies of decreasing moisture content which are fractures dehydrating as the block heats up. There are also examples of compact anomalies of wetting. Some of these appear to be water accumulation in fractures which are draining condensate from the block. Others …

This issue contains the following articles: (1) ''Visualization Tools Take on Supercomputing Challenges''. (2) ''A New World of Seeing'' See and understand is the mantra of the scientists and engineers who are building new visualization tools to better interpret supercomputer data. (3) ''The Many Faces of Carbon Dioxide''. (4) ''Award-Winning System Assays Radioactive Waste with Radiation''. (5) ''Nanoscale Chemistry Yields Better Explosives''.

The information contained in, and/or referenced in, this Annual Hanford Site Environmental Permitting Status Report addresses Permit Condition II.W (Other Permits and/or Approvals) of the Dangerous Waste Portion of the Resource Conservation and Recovery Act Permit for the Treatment, Storage, and Disposal of Dangerous Waste, issued by the Washington State Department of Ecology (WA7890008967). Condition II.W specifies that the Permittees are responsible for obtaining all other applicable federal, state, and local permits authorizing the development and operation of the Hanford Facility. This status report also addresses Permit Condition I.E.22, as interpreted in Section 12.1.25 of the Hanford Facility Dangerous Waste Permit Application, General Information Portion (DOE/RL-91-28, Rev. 4), that states this report will be prepared annually and a copy of this report will be placed in the Facility Operating Record, General Information file by October 1 of each year.

We are concerned with the numerical solution linear systems that arise from a hybridization of the Finite Element Method (FEM) and the Boundary Element Method (BEM). Our present focus is hybrid FEM-BEM discretization of the frequency-domain vector Helmholtz equation of electromagnetics, but similar hybrid techniques are used in electrostatics, acoustics, elasticity, etc. The hybrid FEM-BEM technique is used to solve ''open'' or ''infinite'' problems, where the FEM is used to discretize the interior of the problem and the BEM is used to simulate the effect of the infinite domain. This is illustrated generically in two dimensions in Figure 1 below. The FEM is applied to the interior V, the BEM is applied to the fictitious surface S, and the two methods are appropriately coupled to form a well-posed problem.

A gas chromatographic method has been developed for the quantitation of sulfur removed from coal as tributyl phosphine sulfide (SPBu{sub 3}). This method also works very well for speciating and quantitating the products of sulfur removal from organosulfur removal from organosulfur compounds such as dibenzothiophene. Remarkably mild conditions have been discovered for quantitative sulfur removal from dibenzothiophene and other organosulfur systems using relatively cheap elemental sodium.

This section provides an executive level summary of the performance information covered in this report and is intended to bring to Management's attention that information considered to be most noteworthy. All cost, schedule, milestone commitments, performance measures. and safety data is current as of August 31. Accomplishments, Issues and Integration items are current as of September 18 unless otherwise noted. The section begins with a description of notable accomplishments that have occurred since the last report and are considered to have made the greatest contribution toward safe, timely, and cost-effective clean up. Following the accomplishment section is an overall fiscal year-to-date summary analysis addressing cost, schedule, and milestone performance. Overviews of safety ensue. The next segment of the Executive Summary, entitled Critical Issues, is designed to identify the high-level challenges to achieving cleanup progress. The next section includes FY 2000 EM Management Commitment High Visibility Project Milestones and Critical Few Performance Measures. The Key Integration Activities section follows next, highlighting PHMC activities that cross contractor boundaries and demonstrate the shared value of partnering with other Site entities to accomplish the work. Concluding the Executive Summary, a forward-looking synopsis of Upcoming Planned Key Events is provided.

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