Fracture/matrix (F/M) interaction is a key factor affecting flow and transport in unsaturated fractured rocks. In classic continuum approaches (Warren and Root, 1963), it is assumed that flow occurs through all the connected fractures and is uniformly distributed over the entire fracture area, which generally gives a relatively large F/M interaction. However, fractures seem to have limited interaction with the surrounding matrix at Yucca Mountain, Nevada, as suggested by geochemical nonequilibrium between the perched water (resulting mainly from fracture flow) and pore water in the rock matrix. Because of the importance of the F/M interaction and related issues, there is a critical need to develop new approaches to accurately consider the interaction reduction inferred from field data at the Yucca Mountain site. Motivated by this consideration, they have developed an active fracture model based on the hypothesis that not all connected fractures actively conduct water in unsaturated fractured rocks.

The Advanced Limiter-divertor Plasma-facing Systems (ALPS) program was initiated in order to evaluate the potential for improved performance and lifetime for plasma-facing systems. The main goal of the program is to demonstrate the advantages of advanced limiter/divertor systems over conventional systems in terms of power density capability, component lifetime, and power conversion efficiency, while providing for safe operation and minimizing impurity concerns for the plasma. Most of the work to date has been applied to free surface liquids. A multi-disciplinary team from several institutions has been organized to address the key issues associated with these systems. The main performance goals for advanced limiters and diverters are a peak heat flux of >50 MW/m{sup 2},elimination of a lifetime limit for erosion, and the ability to extract useful heat at high power conversion efficiency ({approximately}40%). The evaluation of various options is being conducted through a combination of laboratory experiments, modeling of key processes, and conceptual design studies. The current emphasis for the work is on the effects of free surface liquids on plasma edge performance.

This report provides a brief overview of California's proposition 187, a 1994 ballot initiative to deny illegal aliens state benefits and to require reporting of illegal alien applicants for benefits to federal immigration officials.

The authors have analyzed the splitting of shear waves from microearthquakes recorded by a 16-station three-component seismic network at the Northwest Geysers geothermal field, Geysers, California, to determine the preferred orientation of subsurface fractures and cracks. Average polarization crack directions with standard deviation were computed for each station. Also, graphical fracture characterizations in the form of equal-area projections and rose diagrams were created to depict the results. The main crack orientations within the steam field are predominantly in the N10{degree}E to N50{degree}E direction, consistent with expected fracture directions in a pull-apart basin created by sub-parallel right-lateral strike-slip faults related to the San Andreas fault system. Time delays range from 15--60 ms, similar to the time delays from previous studies at geothermal reservoirs. They have detected a significant increase in time delays between 1988 and 1994, which they attribute to widening of the cracks or filling of the cracks with fluid. Increase in production activities during this time also could have influenced this widening.

The bioavailability of soil contaminants can be measured using in vitro or in vivo techniques. Since there was no standard method for intercomparison among laboratories, we compared two techniques for bioavailability estimation: in vitro dissolution and in vivo rat feeding model for a NIST-traceable soil material. Bioaccessibility was measured using a sequential soil extraction in synthetic analogues of human saliva, gastric and intestinal fluids. Bioavailability was measured in Sprague Dawley rats by determining metal levels in the major organs and urine, feces, and blood. Bioaccessibility was found to be a good indicator of relative metal bioavailability. Results are presented from bioaccessible experiments with Cesium in contaminated DOE soils, and total alpha and beta bioaccessibility. The results indicate that the modified methodology for bioaccessibility can be used for specific radionuclide analysis.

The Yucca Mountain Site Characterization Project is concerned with the corrosion resistance of candidate engineered waste package materials. A variety of waste package designs have been proposed for US and Canadian High Level Nuclear Waste Repositories. A common feature of each design is the possibility of utilizing a corrosion resistant material such as a nickel-based super alloy or titanium-based alloy. A suitable corrosion resistant material may provide (a) kinetic immunity if the combination of repository environmental conditions and alloy resistance assure both: (i) a passive condition with negligible chance of localized corrosion stabilization, as well as (ii) low enough passive dissolution rates to insure conventional corrosion allowance over geological times, (b) a second form of ''corrosion allowance,'' if it can be scientifically demonstrated that a mechanism for stifling (i.e., death) of localized corrosion propagation occurs well before waste canisters are penetrated, or (c) such a low probability of initiation and continued propagation that a tolerably low degree of penetration occurs. Unfortunately, a large database on the crevice corrosion properties of alloy 22 does not exist in comparison to alloy 625. Alloy screening tests in oxidizing acids containing FeCl3 indicate that alloy 22 is more resistant to crevice corrosion than 625 …

Other written product issued by the General Accounting Office with an abstract that begins "GAO provided comments on whether the District of Columbia would violate the Antideficiency Act by: (1) approving vouchers for attorney's Criminal Justice Act (CJA) claims after the available fiscal year 1999 appropriations funds were exhausted; and (2) paying out CJA obligations exceeding the limitation contained in the 1999 District of Columbia Appropriations Act, GAO held that: (1) the Courts could not, upon submission of a CJA claim, delay the recognition of an obligation by withholding the voucher's approval; and (2) because attorney representation in CJA cases is a mandatory expense, obligations for this purpose may be incurred and may exceed the capped amount without violating the Antideficiency Act."

A letter report issued by the General Accounting Office with an abstract that begins "Pursuant to a legislative requirement, GAO: (1) followed-up on the status of the Federal Reserve Banks' (FRB) corrective actions to address vulnerabilities identified in GAO's fiscal year (FY) 1997 financial statement audit; and (2) reviewed the general and application controls that support key Financial Management Service (FMS) and Bureau of the Public Debt (BPD) automated financial systems maintained and operated by the FRBs."

The purpose of this calculation is to evaluate the structural response of the standard high-level waste (HLW) canister and the HLW canister containing the cans of immobilized plutonium (''can-in-canister'' throughout this document) to the drop event during the handling operation. The objective of the calculation is to provide the structure parameter information to support the canister design and the waste handling facility design. Finite element solution is performed using the commercially available ANSYS Version (V) 5.4 finite element code. Two-dimensional (2-D) axisymmetric and three-dimensional (3-D) finite element representations for the standard HLW canister and the can-in-canister are developed and analyzed using the dynamic solver.

None

Report explaining the fundamentals of immigration in the United States including key terms, statistics, limits, and more.

None

Changes in physical and chemical characteristics of aquatic habitats made to reduce or eliminate ecological risks can sometimes have unforeseen consequences. Environmental management activities on the U.S. Dept. of Energy reservation in Oak Ridge, Tennessee,have succeeded in improving water quality in streams impacted by discharges fi-om industrial facilities and waste disposal sites. The diversity and abundance of pollution-sensitive components of the benthic macroinvertebrate communities of three streams improved after new waste treatment systems or remedial actions reduced inputs of various toxic chemicals. Two of the streams were known to be mercury-contaminated from historical spills and waste disposal practices. Waterborne mercury concentrations in the third were typical of uncontaminated systems. In each case, concentrations of mercury in fish, or the apparent biological availability of mercury increased over the period during which ecological metrics indicated improved water quality. In the system where waterborne mercury concentrations were at background levels, increased mercury bioaccumulation was probably a result of reduced aqueous selenium concentrations; however, the mechanisms for increased mercury accumulation in the other two streams remain under investigation. In each of the three systems, reduced inputs of metals and inorganic anions was followed by improvements in the health of aquatic invertebrate communities. However, this …

Testimony issued by the General Accounting Office with an abstract that begins "Pursuant to a congressional request, GAO discussed issues surrounding Indian contract support costs, focusing on: (1) the different categories of contract support costs; (2) the extent of, and reasons for, increases in contract support costs over the last several years; and (3) four alternatives for funding these costs."

Copyright law protects works of authorship that exhibit original, creative expression, including creativity in the selection, arrangement, or coordination both of traditional printed and electronic databases. Noncreative databases are not subject to copyright protection, although some protection is available through a combination of contract law, trade secrecy law, and misappropriation doctrines of state law.

High expansion aqueous foam is an aggregation of bubbles that has the appearance of soap suds and is used to isolate individuals both visually and acoustically. It was developed in the 1920's in England to fight coal mine fires and has been widely used since for fire fighting and dust suppression. It was developed at Sandia National Laboratories (SNL) in the 1970's for nuclear safeguards and security applications. In the mid-1990s, the National Institute of Justice (NIJ), the research arm of the Department of Justice, began a project with SNL to determine the applicability of high expansion aqueous foam for correctional applications. NIJ funded the project as part of its search for new and better less-than-lethal weapons for responding to violent and dangerous individuals, where other means of force could lead to serious injuries. The phase one objectives of the project were to select a low-to-no toxicity foam concentrate (foaming agent) with physical characteristics suited for use in a single cell or large prison disturbances, and to determine if the selected foam concentrate could serve as a carrier for Oleoresin Capsicum (OC) irritant. The phase two objectives were to conduct an extensive toxicology review of the selected foam concentrate and …

Testimony issued by the General Accounting Office with an abstract that begins "Pursuant to a congressional request, GAO discussed the effects of the Balanced Budget Act of 1997 (BBA) on the Medicare fee-for-service program."

This granted funded research into the application of nanoscience to Li-ion batteries. Different synthesis strategies were employed to create a nanofiber electrode (based on tin-oxide) and a honeycomb electrode (carbon). In both cases, we showed that the nanostructured material was capable of delivering dramatically increased specific capacity (mAh/g) upon discharge when compared to conventional film electrodes. This ability is due to the decreased solid-state diffusion distance of the Li-ion in the nanostructured electrodes. The nanofiber-SnO{sub 2} electrode was created by the template synthesis method. Briefly, a precursor solution impregnates the monodisperse nanoscopic pores of a sacrificial template membrane. The pores run the membrane's entire length. The precursor solution is then processed to the desired material, here using sol-gel chemistry, and the template is removed. This leaves nanostructures of the desired product intact and extending from a substrate like the bristles of a brush. This research topic combines this nanofabrication technique with the Sn-based anode. Tin-oxide based composites have shown great promise as an alternative material for Li-ion battery anodes. This material is electrochemically converted to composite Sn/LiO{sub 2} electrodes. In this form, they are theoretically capable of storing twice the amount of Li as carbon, the current commercial anode. We …

This study was conducted to evaluate the performance of a small scale ion exchange unit (Krudico, Inc of Auborn, IA) for removal of nitrate and perchlorate from groundwater at Lawrence Livermore National Laboratory's Site 300. The unit was able to treat 3,600 gallons of Site 300 groundwater, at an average influent concentration of 100 mg/L NO{sub 3}{sup -} before breakthrough occurred. The unit contained 2.5 ft{sup 3} of Sybron SR-7 resin. Seventy gallons of regeneration waste were generated (water treated to waste ratio of 51:1). The effluent concentration was about 20 mg/L NO{sub 3}{sup -}, which is equivalent to a treatment efficiency of at least 80%. There are several options for implementing this technology at Site 300. A target well, in the 817 area, has been selected. It has a 3 to 4 gpm flow rate, and concentrations of 90 mg/L NO{sub 3}{sup -} and 40 {micro}g/L perchlorate. The different treatment options include ion exchange treatment of nitrate only, nitrate and perchlorate, or perchlorate only. Option 1: For the treatment of nitrate only, this unit will be able to treat 3,700 gallons of water before regeneration is required. If both columns of the ion exchange unit are used, 7,400 gallons …

Research to address aging of the containment pressure boundary in light-water reactor plants is summarized. This research is aimed at understanding the significant factors relating occurrence of corrosion, efficacy of inspection, and structural capacity reduction of steel containment and liners of concrete containment. This understanding will lead to improvements in risk-informed regulatory decision making. Containment pressure boundary components are described and potential aging factors identified. Quantitative tools for condition assessments of aging structures to maintain an acceptable level of reliability over the service life of the plant are discussed. Finally, the impact of aging (i.e., loss of shell thickness due to corrosion) on steel containment fragility for a pressurized water reactor ice-condenser plant is presented.

Correspondence issued by the General Accounting Office with an abstract that begins "GAO identified weaknesses in the Navy's personnel practices."

This report summarizes the validation of the WRAP NDA systems against the various QAOs. A brief description of each test and any significant conclusions is included. Variables which may have affected test outcomes are examined. This report will be reviewed semi-annually and updated as necessary.

None

This is the first of several, informal technical memos in which I will attempt both a ''memory dump'' and an update on past and present research on shock wave-turbulence interaction. Despite decades of attention, questions remain about wily, how, and to what degree shock interaction with V-existing turbulence amplifies the turbulence, extends its active range and, consequently, has the potential to significantly increase the average level of turbulent component mixing. (As used here, pre-existing turbulence is defined as an initial state of fluid. dynamic turbulence which has been produced independently and prior to encountering the shock wave). However, much as in the underlying, unresolved problem of fluid dynamic turbulence, a general solution is not sought (even if such an unlikely goal could be considered attainable in a professional lifetime). Instead, our more limited (but achievable) goal is to elevate our understanding of the phenomena by combining scaleable experiments, appropriately sensitive diagnostic techniques, approximating model developments, and analysis. We also hope to attain a reasonable level of confidence in our ability to estimate the influence of the phenomena when subjected to a range of thermo-physical states and flow conditions of programmatic interest. Additionally, this review should help establish a carefully evaluated …