Device simulations of (1) the laterally-contacted-unipolar-nuclear detector (LUND), (2) the SpectrumPlus, (3) and the coplanar grid made of Cd{sub 0.9}Zn{sub 0.1}Te (CZT) were performed for {sup 137}Cs irradiation by 662.15 keV gamma-rays. Realistic and controlled simulations of the gamma-ray interactions with the CZT material were done using the MCNP4B2 Monte Carlo program, and the detector responses were simulated using the Sandia three-dimensional multielectrode simulation program (SandTMSP). The simulations were done for the best and the worst expected carrier nobilities and lifetimes of currently commercially available CZT materials for radiation detector applications. For the simulated unipolar devices, the active device volumes were relatively large and the energy resolutions were fairly good, but these performance characteristics were found to be very sensitive to the materials properties. The internal electric fields, the weighting potentials, and the charge induced efficiency maps were calculated to give insights into the operation of these devices.

This report presents an analysis of the relative impact of the base-case scenario used in Annual Energy Outlook 1999 on different population groups. Projections of energy consumption and expenditures, as well as energy expenditure as a share of income, from 1996 to 2020 are given. The projected consumption of electricty, natural gas, distillate fuel, and liquefied petroleum gas during this period is also reported for each population group. In addition, this report compares the findings of the Annual Energy Outlook 1999 report with the 1998 report. Changes in certain indicators and information affect energy use forecasts, and these effects are analyzed and discussed.

This report provides the seismic record at Hanford for FY 1998. Hanford Seismic Monitoring provides an uninterrupted collection of high-quality raw and processed seismic data from the Hanford Seismic Network (HSN) for the U.S. Department of Energy and its contractors. Hanford Seismic Monitoring also locates and identifies sources of seismic activity and monitors changes in the historical pattern of seismic activity at the Hanford Site. The data are compiled, archived, and published for use by the Hanford Site for waste management, Natural Phenomena Hazards assessments, and engineering design and construction. In addition, the seismic monitoring organization works with the Hanford Site Emergency Services Organization to provide assistance in the event of a significant earthquake on the Hanford Site. The HSN and the Eastern Washington Regional Network (EWRN) consist of 40 individual sensor sites and 15 radio relay sites maintained by the Hanford Seismic Monitoring staff. A major reconfiguration of the HSN was initiated at the end of this quarter and the results will be reported in the first quarter report for next fiscal year (FY 2000). For the HSN, there were 390 triggers during the fourth quarter of fiscal year (FY) 1999 on the primary recording system. With the implementation …

This volume of the LLE Review, covering the period July-September 1999, features a theoretical analysis of a process that generates mass perturbations of an imploding target driven by modulated laser illumination. The process, referred to as laser imprint, impacts the integrity of the shell during direct-drive implosions, potentially quenching target performance. In this article V. N. Goncharov, J. A. Delettrez, S. Skupsky, and R. P. J. Town present a model of the generation of mass perturbations and analyze the mass perturbation growth due to nonuniform ablation pressure. Stabilizing mechanisms of thermal conduction smoothing and mass ablation are shown to suppress the acceleration perturbation, and mass ablation is also shown to impact velocity perturbations. The model predicts that a direct-drive cryogenic NIF target will remain intact during the implosion when l-Thz SSD beam smoothing is used.

The purpose of this analysis is to evaluate the factors affecting the longevity of emplacement drift ground support materials and to develop a basis for selection of materials for ground support that will function throughout the preclosure period. The Development Plan (DP) for this analysis is given in CRWMS M&O (Civilian Radioactive Waste Management System Management and Operating Contractor) (1999a). The candidate materials for ground support are steel (carbon steel, ductile cast iron, galvanized steel, and stainless steel, etc.) and cement. Steel will mainly be used for steel sets, lagging, channels, rock bolts, and wire mesh. Cement usage is only considered in the case of grouted rock bolts. The candidate materials for the invert structure are steel and crushed rock ballast. The materials shall be evaluated for the repository emplacement drift environment under a specific thermal loading condition based on the proposed License Application Design Selection (LADS) design. The analysis consists of the following tasks: (1) Identify factors affecting the longevity of ground control materials for use in emplacement drifts. (2) Review existing documents concerning behavior of candidate ground control materials during the preclosure period. The major criteria to be considered for steel are mechanical and thermal properties, and durability, …

Optical properties of Cd{sub 0.9}Zn{sub 0.1}Te (CZT) were studied by variable angle spectroscopic ellipsometry (VASE). Measurements made by VASE were performed on CZT and CdTe samples in air at room temperature at multiple angles of incidence. A parametric function model was employed in the VASE analysis to determine the dielectric functions {var_epsilon}={var_epsilon}{sub 1} + i{var_epsilon}{sub 2} in the range of 0.75 to 6.24 eV. A two-oscillator analytical model was used to describe the dielectric response of native oxides on CZT. Surface oxide optical properties and thickness on CZT were also determined in conjunction with the VASE measurement and analysis of a CdTe sample. Two samples of CZT of different oxide thicknesses were measured and their optical constants were coupled together in a multiple-sample, multiple-model VASE analysis to resolve correlations between fitting parameters. Effective medium approximation (EMA) was used to describe the optical properties of the CZT oxide with roughness. A Kramers-Kronig self-consistency check of the real and imaginary parts of the Cd{sub 0.9}Zn{sub 0.1} dielectric functions was performed over the energy range 0.75 to 6.24 eV. A five-Lorentz-oscillator model was employed to describe the dielectric response of CZT in the range of 1.6 to 6.24 eV. Intensity transmission measurements were …

In this paper, we compare the effectiveness of three preconditioning strategies in simulations of variably saturated flow. Using Richards' equation as our model, we solve the nonlinear system using a Newton-Krylov method. Since Krylov solvers can stagnate, resulting in slow convergence, we investigate different strategies of preconditioning the Jacobian system. Our work uses a multigrid method to solve the preconditioning systems, with three different approximations to the Jacobian matrix. One approximation lags the nonlinearities, the second results from discarding selected off-diagonal contributions, and the third matrix considered is the full Jacobian. Results indicate that although the Jacobian is more accurate, its usage as a preconditioning matrix should be limited, as it requires much more storage than the simpler approximations. Also, simply lagging the nonlinearities gives a preconditioning matrix that is almost as effective as the full Jacobian but much easier to compute.

A program has been initiated for the purpose of developing the chemical separations technologies necessary to support a large Accelerator Transmutation of Waste (ATW) system capable of dealing with the projected inventory of spent fuel from the commercial nuclear power stations in the United States. The first several years of the program will be directed toward an elucidation of related technical issues and to the establishment, by means of comprehensive trade studies, of an optimum configuration of the elements of the chemical processing infrastructure required for support of the total ATW system. By adopting this sort of disciplined systems engineering approach, it is expected that development and demonstration costs can be minimized and that it will be possible to deploy an ATW system that is an environmentally sound and economically viable venture.

Three of the U.S. Department of Energy's solar technology programs are now under one umbrella: the Office of Solar Energy Technologies or the Solar Office. The solar programs of photovoltaics, concentrating solar power, and solar buildings are now integrated into this office where DOE can combine administrative efforts, build on the strengths of each program, and encourage cooperation that bolsters the impact of each technology.

The primary purpose of this document is to develop a preliminary high-level functional and physical control system architecture for the potential repository at Yucca Mountain. This document outlines an overall control system concept that encompasses and integrates the many diverse process and communication systems being developed for the subsurface repository design. This document presents integrated design concepts for monitoring and controlling the diverse set of subsurface operations. The Subsurface Repository Integrated Control System design will be composed of a series of diverse process systems and communication networks. The subsurface repository design contains many systems related to instrumentation and control (I&C) for both repository development and waste emplacement operations. These systems include waste emplacement, waste retrieval, ventilation, radiological and air monitoring, rail transportation, construction development, utility systems (electrical, lighting, water, compressed air, etc.), fire protection, backfill emplacement, and performance confirmation. Each of these systems involves some level of I&C and will typically be integrated over a data communications network throughout the subsurface facility. The subsurface I&C systems will also interface with multiple surface-based systems such as site operations, rail transportation, security and safeguards, and electrical/piped utilities. In addition to the I&C systems, the subsurface repository design also contains systems related to …

A weekly publication, the Texas Register serves as the journal of state agency rulemaking for Texas. Information published in the Texas Register includes proposed, adopted, withdrawn and emergency rule actions, notices of state agency review of agency rules, governor's appointments, attorney general opinions, and miscellaneous documents such as requests for proposals. After adoption, these rulemaking actions are codified into the Texas Administrative Code.