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Flammable gas tank safety program: Technical basis for gas analysis and monitoring (open access)

Flammable gas tank safety program: Technical basis for gas analysis and monitoring

Several Hanford waste tanks have been observed to exhibit periodic releases of significant quantities of flammable gases. Because potential safety issues have been identified with this type of waste behavior, applicable tanks were equipped with instrumentation offering the capability to continuously monitor gases released from them. This document was written to cover three primary areas: (1) describe the current technical basis for requiring flammable gas monitoring, (2) update the technical basis to include knowledge gained from monitoring the tanks over the last three years, (3) provide the criteria for removal of Standard Hydrogen Monitoring System(s) (SHMS) from a waste tank or termination of other flammable gas monitoring activities in the Hanford Tank farms.
Date: April 22, 1998
Creator: Estey, S.D.
Object Type: Report
System: The UNT Digital Library
Mixing materials within zone boundaries using shape overlays (open access)

Mixing materials within zone boundaries using shape overlays

Shape overlays provide a means of statically imposing a physical region containing specified material properties onto a zoned mesh. In the most general case, material interface boundaries are unrelated to mesh zone boundaries, causing zones to contain a mixture of materials, and the mesh itself is not uniform in physical space. We develop and apply an algorithm for shape overlays on nonorthogonal, nonuniform meshes in two dimensions. Examples of shape generation in a multiblock uid dynamics code are shown.
Date: April 22, 1997
Creator: Grandy, J.
Object Type: Report
System: The UNT Digital Library
Energy Efficiency and Renewable Energy Network (EREN): Customer satisfaction survey (open access)

Energy Efficiency and Renewable Energy Network (EREN): Customer satisfaction survey

The Energy Efficiency and Renewable Energy Network (EREN) Customer Satisfaction Survey was developed and executed in support of EREN`s continuous quality improvement (CQI) plan. The study was designed to provide information about the demographic make up of EREN users, the value or benefits they derive from EREN, the kinds and quality of services they want, their levels of satisfaction with existing services, their preferences in both the sources of service and the means of delivery, and to provide benchmark data for the establishment of continuous quality improvement measures. The survey was performed by soliciting voluntary participation from members of the EREN Users Group. It was executed in two phases; the first being conducted by phone using a randomly selected group; and the second being conducted electronically and which was open to all of the remaining members of the Users Group. The survey results are described.
Date: April 22, 1996
Creator: Anderson, A. V. & Henderson, D. P.
Object Type: Report
System: The UNT Digital Library
Research needs of c-Si technology required to meet roadmap milestones (open access)

Research needs of c-Si technology required to meet roadmap milestones

In this paper, the authors examined the areas in c-Si growth, materials, and processing that require improvement through research to overcome barriers to the implementation of the photovoltaic road maps's Si goals. To obtain PV module throughput to the roadmap target of 200 MW/factory/year, the typical Si PV factory must produce >4,000 m{sup 2}/day of silicon.
Date: April 22, 2000
Creator: Ruby, Douglas S.; Ciszek, T. F. & Sopori, B. L.
Object Type: Article
System: The UNT Digital Library
Thermodynamic Factors Affecting UC<sub>1-x</sub>N<sub>x</sub>Irradiation and Synthesis (open access)

Thermodynamic Factors Affecting UC<sub>1-x</sub>N<sub>x</sub>Irradiation and Synthesis

There is interest in attempting to synthesize nearly pure uranium nitride (UN) kernels for high-temperature gas-cooled reactor (HTGR) fuel. Because the proposed process involves carbothermic conversion of a urania-carbon mixture in nitrogen and because there is a complete ideal solution of uranium carbide (UC) and UN, which is written as UC{sub 1-x}N{sub x}, the practical value of x for fuel irradiation needs to be determined. Insight is to be gained by relevant thermodynamic calculations of carbide-nitride equilibria for the fuel and fission product systems. The equilibria are readily compared on the nitrogen-based Ellingham diagram, which, in turn, provides guidance in interpreting past irradiations and in synthesis of the UC{sub 1-x}N{sub x} kernels.
Date: April 22, 2005
Creator: Lindemer, T. B.
Object Type: Report
System: The UNT Digital Library
Development of a Commercial Process for the Production of Silicon Carbide Fibrils (open access)

Development of a Commercial Process for the Production of Silicon Carbide Fibrils

The current work continues a project completed in 1999 by ReMaxCo Technologies in which a novel, microwave based, VLS Silicon Carbide Fibrils concept was verified. This project continues the process development of a pilot scale commercial reactor. Success will lead to sufficient quantities of fibrils to expand work by ORNL and others on heat exchanger tube development. A semicontinuous, microwave heated, vacuum reactor was designed, fabricated and tested in these experiments. Cylindrical aluminum oxide reaction boats are coated, on the inner surface, with a catalyst and placed into the reactor under a light vacuum. A series of reaction boats are then moved, one at a time, through the reactor. Each boat is first preheated with resistance heaters to 850 C to 900 C. Each reaction boat is then moved, in turn, to the microwave heated section. The catalyst is heated to the required temperature of 1200 C to 1300 C while a mixture of MTS (methyl trichlorosilane) and hydrogen are introduced into the annulus of the boat. The MTS is dissociated to allow the carbon and silicon components to be dissolved into the catalyst. The catalyst saturates and precipitates silicon carbide onto the surface of the reaction boat to grow …
Date: April 22, 2003
Creator: Nixdorf, Richard D.
Object Type: Article
System: The UNT Digital Library