A novel system has been deployed to obtain geochemical samples of water and gas, at in situ pressure, during a geologic CO2 sequestration experiment conducted in the Frio brine aquifer in Liberty County, Texas. Project goals required high-frequency recovery of representative and uncontaminated aliquots of a rapidly changing two-phase (supercritical CO2-brine) fluid from 1.5 km depth. The datasets collected, using both the liquid and gas portions of the downhole samples, provide insights into the coupled hydro-geochemical issues affecting CO2 sequestration in brine-filled formations. While the basic premise underlying the U-Tube sampler is not new, the system is unique because careful consideration was given to the processing of the recovered two-phase fluids. In particular, strain gauges mounted beneath the high-pressure surface sample cylinders measured the ratio of recovered brine to supercritical CO2. A quadrupole mass spectrometer provided real-time gas analysis for perfluorocarbon and noble gas tracers that were injected along with the CO2. The U-Tube successfully acquired frequent samples, facilitating accurate delineation of the arrival of the CO2 plume, and on-site analysis revealed rapid changes in geochemical conditions.

This paper presents an evaluation of robotics and remote handling technologies that have the potential to increase the efficiency of handling waste packages at the proposed Yucca Mountain High-Level Nuclear Waste Repository. It is expected that increased efficiency will reduce the cost of operations. The goal of this work was to identify technologies for consideration as potential projects that the U.S. Department of Energy Office of Civilian Radioactive Waste Management, Office of Science and Technology International Programs, could support in the near future, and to assess their ''payback'' value. The evaluation took into account the robotics and remote handling capabilities planned for incorporation into the current baseline design for the repository, for both surface and subsurface operations. The evaluation, completed at the end of fiscal year 2004, identified where significant advantages in operating efficiencies could accrue by implementing any given robotics technology or approach, and included a road map for a multiyear R&D program for improvements to remote handling technology that support operating enhancements.

Nucleation-growth kinetic expressions are derived for thermal decomposition of HMX from a variety of types of data, including mass loss for isothermal and constant rate heating in an open pan, and heat flow for isothermal and constant rate heating in open and closed pans. Conditions are identified in which thermal runaway is small to nonexistent, which typically means temperatures less than 255 C and heating rates less than 1 C/min. Activation energies are typically in the 140 to 165 kJ/mol regime for open pan experiments and about 150-165 kJ/mol for sealed-pan experiments. The reaction clearly displays more than one process, and most likely three processes, which are most clearly evident in open pan experiments. The reaction is accelerated for closed pan experiments, and one global reaction fits the data fairly well. Our A-E values lie in the middle of the values given in a compensation-law plot by Brill et al. (1994). Comparison with additional open and closed low temperature pyrolysis experiments support an activation energy of 165 kJ/mol at 10% conversion.

We describe a multiple monochromatic x-ray imager designed for implosion experiments. This instrument uses an array of pinholes in front of a flat multilayered Bragg mirror to provide many individual quasi-monochromatic x-ray pinhole images spread over a wide spectral range. We discuss design constraints and optimizations, and we discuss the specific details of the instrument we have used to obtain temperature and density maps of implosion plasmas.