For the FAIR-project at GSI a model dipole was built at BNL with the nominal field of 4 T and a nominal ramp rate of 1 T/S. The magnet design was similar to the RHIC dipole, with some changes for loss reduction and better cooling. The magnet was already successfully tested in a vertical cryostat, with good training behavior. Cryogenic losses were measured and first results of field harmonics were published. However, for a better understanding of the cooling process, quench currents at several ramp rates were investigated. Detailed measurements of the field harmonics at 2 T/S between 0 and 4 T were performed.

New disposal limits have been computed for Vault 4 of the Saltstone Disposal Facility based on several revisions to the models in the existing Performance Assessment and the Special Analysis issued in 2002. The most important changes are the use of a more rigorous groundwater flow and transport model, and consideration of radon emanation. Other revisions include refinement of the aquifer mesh to more accurately model the footprint of the vault, a new plutonium chemistry model accounting for the different transport properties of oxidation states III/IV and V/VI, use of variable infiltration rates to simulate degradation of the closure system, explicit calculation of gaseous releases and consideration of the effects of settlement and seismic activity on the vault structure. The disposal limits have been compared with the projected total inventory expected to be disposed in Vault 4. The resulting sum-of-fractions of the 1000-year disposal limits is 0.2, which indicates that the performance objectives and requirements of DOE 435.1 will not be exceeded. This SA has not altered the conceptual model (i.e., migration of radionuclides from the Saltstone waste form and Vault 4 to the environment via the processes of diffusion and advection) of the Saltstone PA (MMES 1992) nor has …

This study examined waste feed and solvent limits for the Modular Caustic-Side Solvent Extraction Unit (MCU) currently being designed and built at the Savannah River Site (SRS) to remove cesium from highly alkaline radioactive waste. The study involved proposing ranges for 12 waste feed components (i.e., Na{sup +}, K{sup +}, Cs{sup +}, OH{sup -}, NO{sub 3}{sup -}, NO{sub 2}{sup -}, Cl{sup -}, F{sup -}, SO{sub 4}{sup 2-}, PO{sub 4}{sup 3-}, and CO{sub 3}{sup 2-}, and AlO{sub 2}{sup -}) through a compilation of SRS waste data. Statistical design methods were used to generate numerous wastes with varying compositions from the proposed ranges. An Oak Ridge National Laboratory (ORNL) model called SXFIT was used to predict the cesium extraction distribution coefficients (D-values) between the organic (solvent) phase and the aqueous waste phase using the waste component concentrations as inputs. The D-values from the SXFIT model were used as input along with MCU base case process parameters to a SASSE (Spreadsheet Algorithm for Stagewise Solvent Extraction) model to calculate final cesium concentrations for the MCU. The SASSE model was developed at Argonne National Laboratory (ANL). The SXFIT D-value and the waste component concentration data were used to develop a handier alternative model (neural …

Previous X-ray Diffraction (XRD) and Nuclear Magnetic Resonance (NMR) studies on Ti-doped NaAlH{sub 4} revealed the reaction products of two heavily doped (33.3 at.%) samples that were solvent-mixed and mechanically-milled. This investigation revealed that nano-crystalline or amorphous Al{sub 2}O{sub 3} forms from the possible coordination of aluminum with oxygen atom of the furan ring system from added tetrahydrofuran (THF) in the solvent-mixed sample, and that TiAl{sub 3} forms in mechanically-milled samples. The present paper provides a more sophisticated NMR investigation of the these materials. On heavily doped (33.3 at.%) solvent-mixed samples, {sup 27}Al Magic Angle Spinning (MAS) NMR {sup 27}Al multiple quantum MAS (MQMAS) indicates the presence of an oxide layer of Al{sub 2}O{sub 3} on the surfaces of potentially bulk nanocrystalline Ti, nanocrystalline TiAl{sub 3}, and/or metallic aluminum. The {sup 1}H MAS NMR data also indicate the possible coordination of aluminum with the oxygen atom in the THF. On heavily doped samples that were mechanically milled, {sup 27}Al MAS NMR and static NMR confirms the presence of TiAl{sub 3}. In addition, the {sup 1}H MAS NMR and {sup 1}H spin-lattice relaxation (T{sub 1}) measurements are consistent with the presence of TiH{sub 2}. These results are in agreement with recent …

We have developed a novel insulator concept that involves the use of alternating layers of conductors and insulators with periods less than 1 mm. We have demonstrated that these structures perform 2 to 5 times better than conventional insulators in long pulse, short pulse, and alternating polarity applications. We present new testing results showing exceptional behavior at DC, with gradients in excess of 110kV/cm in vacuum.

Location, timing, and volumes of post-Miocene volcanic activity, along with expert judgment, provide the basis for assessing the probability of future volcanism intersecting a proposed repository for nuclear waste at Yucca Mountain, Nevada. Analog studies of eruptive centers in the region that may represent the style and extent of possible future igneous activity at Yucca Mountain have aided in defining the consequence scenarios for intrusion into and eruption through a proposed repository. Modeling of magmatic processes related to magma/proposed repository interactions has been used to assess the potential consequences of a future igneous event through a proposed repository at Yucca Mountain. Results of work to date indicate future igneous activity in the Yucca Mountain region has a very low probability of intersecting the proposed repository. Probability of a future event intersecting a proposed repository at Yucca Mountain is approximately 1.7 x 10{sup -8} per year. Since completion of the Probabilistic Volcanic Hazard Assessment (PVHA) in 1996, anomalies representing potential buried volcanic centers have been identified from aeromagnetic surveys. A re-assessment of the hazard is currently underway to evaluate the probability of intersection in light of new information and to estimate the probability of one or more volcanic conduits located in …

As part of the Department of Energy's (DOE) initiation on developing new technologies for storage of carbon dioxide in geologic reservoir, Battelle has been awarded a project to investigate the feasibility of CO{sub 2} sequestration in the deep saline reservoirs in the Ohio River Valley region. This project is the Phase III of Battelle's work under the Novel Concepts in Greenhouse Gas Management grant. The main objective of the project is to demonstrate that CO{sub 2} sequestration in deep formations is feasible from engineering and economic perspectives, as well as being an inherently safe practice and one that will be acceptable to the public. In addition, the project is designed to evaluate the geology of deep formations in the Ohio River Valley region in general and in the vicinity of AEP's Mountaineer Power Plant in particular, in order to determine their potential use for conducting a long-term test of CO{sub 2} disposal in deep saline formations and potentially in nearby deep coal seams. The current technical progress report summarizes activities completed for the January through March 2005 period of the project. As discussed in the report, the technical activities focused on development of injection well design, preparing a Class V …

Most single-crystal shock experiments have been performed in high-symmetry directions while the nature of shock propagation in low-symmetry directions remains relatively unstudied. It is well known that small-amplitude, linear acoustic waves propagating in low-symmetry directions can focus and/or form caustics (Wolfe, 1995). In this report we provide evidence for similar focusing behavior in nonlinear (shock) waves propagating in single crystals of silicon and diamond. Using intense lasers, we have driven non-planar (divergent geometry) shock waves through single-crystals of silicon or diamond and into an isotropic backing plate. On recovery of the backing plates we observe a depression showing evidence of anisotropic plastic strain with well-defined crystallographic registration. We observe 4-, 2-, and 3-fold symmetric impressions for [100], [110], and [111] oriented crystals respectively.

The Multi-Group Analysis (MGA) code is widely used to determine nondestructively the relative isotopic abundances of plutonium by gamma-ray spectrometry. MGA users have expressed concern about the lack of flexibility and transparency in the code. Users often have to ask the code developers for modifications to the code to accommodate new measurement situations, such as additional peaks being present in the plutonium spectrum or expected peaks being absent. We are testing several new improvements to a prototype, general gamma-ray isotopic analysis tool with the intent of either revising or replacing the MGA code. These improvements will give the user the ability to modify, add, or delete the gamma- and x-ray energies and branching intensities used by the code in determining a more precise gain and in the determination of the relative detection efficiency. We have also fully integrated the determination of the relative isotopic abundances with the determination of the relative detection efficiency to provide a more accurate determination of the errors in the relative isotopic abundances. We provide details in this paper on these improvements and a comparison of results obtained with current versions of the MGA code.

We have conducted a series of deliquescence, boiling point, chemical transformation, and evaporation experiments to determine the composition of waters likely to contact waste package surfaces over the thermal history of the repository as it heats up and cools back down to ambient conditions. In the above-boiling period, brines will be characterized by high nitrate to chloride ratios that are stable to higher temperatures than previously predicted. This is clearly shown for the NaCl-KNO{sub 3} salt system in the deliquescence and boiling point experiments in this report. Our results show that additional thermodynamic data are needed in nitrate systems to accurately predict brine stability and composition due to salt deliquescence in dust deposited on waste package surfaces. Current YMP models capture dry-out conditions but not composition for NaCl-KNO{sub 3} brines, and they fail to predict dry-out conditions for NaCl-KNO{sub 3}-NaNO{sub 3} brines. Boiling point and deliquescence experiments are needed in NaCl-KNO{sub 3}-NaNO{sub 3} and NaCl-KNO{sub 3}-NaNO{sub 3}-Ca(NO{sub 3}){sub 2} systems to directly determine dry-out conditions and composition, because these salt mixtures are also predicted to control brine composition in the above-boiling period. Corrosion experiments are needed in high temperature and high NO{sub 3}:Cl brines to determine if nitrate inhibits corrosion …

Results are presented from a study investigating the effect of explosive and impact loading on geological media using the Livermore Distinct Element Code (LDEC). LDEC was initially developed to simulate tunnels and other structures in jointed rock masses with large numbers of intact polyhedral blocks. However, underground structures in jointed rock subjected to explosive loading can fail due to both rock motion along preexisting interfaces and fracture of the intact rock mass itself. Many geophysical applications, such as projectile penetration into rock, concrete targets, and boulder fields, require a combination of continuum and discrete methods in order to predict the formation and interaction of the fragments produced. In an effort to model these types of problems, we have implemented Cosserat point theory and cohesive element formulations into the current version of LDEC, thereby allowing for dynamic fracture and combined finite element/discrete element simulations. Results of a large-scale LLNL simulation of an explosive shock wave impacting an elaborate underground facility are also discussed. It is confirmed that persistent joints lead to an underestimation of the impact energy needed to fill the tunnel systems with rubble. Non-persistent joint patterns, which are typical of real geologies, inhibit shear within the surrounding rock mass …

We introduce a new technique using resonant soft x-ray scattering for characterizing heterogeneous chemical structure at nanometer length scales in polymers, biological material, and other soft matter. Resonant enhancements bring new contrast mechanisms and increased sensitivity to bridge a gap between bond-specific contrast in chemical sensitive imaging and the higher spatial resolution of traditional small-angle scattering techniques. We illustrate sensitivity to chemical bonding with the resonant scattering near the carbon K edge from latex spheres of differing chemistry and sizes. By tuning to x-ray absorption resonances associated with particular carbon-carbon or carbon-oxygen bonds we can isolate the scattering from different phases in a 2-phase mixture. We then illustrate this increased scattering contrast with a study of the templating process to form nanometer scale pores in 100 nm thick polymer films.

Microbial degradation of chlorinated ethenes (CE) in rhizosphere soils was investigated at seepline areas impacted by CE plumes. Successful bioremediation of CE in rhizosphere soils is dependent on microbial activity, soil types, plant species, and groundwater CE concentrations. Seepline soils were exposed to trichloroethylene (TCE) and perchloroethylene (PCE) in the 10-50 ppb range. Greenhouse soils were exposed to 2-10 ppm TCE. Plants at the seepline were poplar and pine while the greenhouse contained sweet gum, willow, pine, and poplar. Phospholipid fatty acid (PLFA) analyses were performed to assess the microbial activity in rhizosphere soils. Biomass content was lowest in the nonvegetated control soil and highest in the Sweet Gum soil. Bacterial rhizhosphere densities, as measured by PLFA, were similar in different vegetated soils while fungi biomass was highly variable. The PLFA soil profiles showed diverse microbial communities primarily composed of Gram-negative bacteria. Adaptation of the microbial community to CE was determined by the ratio of {omega}7t/{omega}7c fatty acids. Ratios (16:1{omega}7v16:1{omega}7c and 18:l{omega}7t/18:1{omega}7c) greater than 0.1 were demonstrated in soils exposed to higher CE concentrations (10-50 ppm), indicating an adaptation to CE resulting in decreased membrane permeability. Ratios of cyclopropyl fatty acids showed that the vegetated control soil sample contained the …

This paper discusses switch requirements from basic circuit analysis and the experimental setup, parameters, and results of an experiment to investigate the feasibility of UV laser triggering of up to 40 Blumlein lines in a very compact Stacked Blumlein Line System. In addition, the method of fabricating a very compact SBL transmission lines is presented. Then the behavior of the switch parameters in the stack when closure is initiated with a UV laser pulse is presented. Specifically, the time varying inductance and resistance of the laser initiated gas discharge channel is presented and compared with a circuit model to elucidate the switch performance.

The DARHT II accelerator at LANL is preparing a series of preliminary tests at the reduced voltage of 7.8 MeV. The transport hardware between the end of the accelerator and the final target magnet was shipped to LLNL and installed on ETA II. Using the ETA II beam at 5.2 MeV we completed a set of experiments designed reduce start up time on the DARHT II experiments and run the equipment in a configuration adapted to the reduced energy. Results of the beam transport using a reduced energy beam, including the kicker and kicker pulser system will be presented.

Lawrence Livermore National Laboratory (LLNL) is a USDOE research and development institution for science and technology applied to national security. The specific area that is the subject of this document, Area 514, was the location of active LLNL waste treatment facilities until November 2003, and the operations there were authorized under interim status. The site is being closed pursuant to the requirements of the Resource Conservation Recovery Act. The DTSC-approved ''Closure Plan for Area 514 Treatment and Storage Facility, LLNL 2004'', states clean closure concentrations for certain organic compounds, metals and metalloids. if all soil samples contained measured concentrations less than these levels, it was agreed that the site would meet the requirements for clean closure. However, if the samples had measured concentrations greater than the clean closure levels, a more detailed risk assessment could be prepared to evaluate the potential effects of the actual measured levels. Soil samples collected from 33 locations in Area 514 were analyzed for 37 constituents of potential concern, as identified by the Closure Plan. Many of these compounds and elements were not detected. However, 10 metals or metalloids were present at levels above the clean closure requirements, and 19 organic compounds were identified as …

This paper discusses the methods and materials being developed to package semi-insulating Silicon Carbide (SiC) in a high electric field, high current package while providing entrance for photo-conductive optical energy necessary for closure. The switch requirements and design goals are presented. The switch material package combination must enable a relatively large current and control the current density at the contacts and through the material while supporting a very high electric blocking field. The material parameters and methods of controlling the current density and the peak electric field in the region where the electrode separated from the SiC material are discussed. The mask design and Ohmic contact formation processes at the SiC--metal electrode interface as well as the methods used to bond the semiconductor contact to the electrode are discussed. In addition, images of package failures are presented and the direction being pursued for improving package performance is presented.

None