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The impact of repository heat on hydrological behavior at Yucca Mountain

Description: This report describes the role of radioactive heat-of-decay in the the performance of the Yucca Mountain Facility. Waste package and waste form degradation due to water contact is described.
Date: January 1, 1994
Creator: Buscheck, T.A. & Nitao, J.J.
Partner: UNT Libraries Government Documents Department

Tools for NEPA compliance: Baseline reports and compliance guides

Description: Environmental baseline documents and NEPA compliance guides should be carried in every NEPA implementation ``tool kit``. These two indispensable tools can play a major role in avoiding repeated violations of NEPA requirements that have occurred over the past 26 years. This paper describes these tools, discusses their contents, and explains how they are used to prepare better NEPA documents more cost-effectively. Focus is on experience at Sandia Laboratories (NM).
Date: December 31, 1994
Creator: Wolff, T.A. & Hansen, R.P.
Partner: UNT Libraries Government Documents Department

Edge detection by nonlinear dynamics

Description: We demonstrate how the formulation of a nonlinear scale-space filter can be used for edge detection and junction analysis. By casting edge-preserving filtering in terms of maximizing information content subject to an average cost function, the computed cost at each pixel location becomes a local measure of edgeness. This computation depends on a single scale parameter and the given image data. Unlike previous approaches which require careful tuning of the filter kernels for various types of edges, our scheme is general enough to be able to handle different edges, such as lines, step-edges, corners and junctions. Anisotropy in the data is handled automatically by the nonlinear dynamics.
Date: July 1994
Creator: Wong, Yiu-fai
Partner: UNT Libraries Government Documents Department

Correlation of XANES features with the scintillation efficiencies of Ce doped alkaline earth lithium silicate glasses

Description: Cerium-activated, lithium-silicate glasses are widely used as thermal neutron detectors because of their versatility, robustness and low cost. The glasses convert the energy of the neutrons to visible light pulses that may be counted. This process, scintillation, is generally thought to be composed of three steps: ionization, energy transfer, and luminescence. If defects are present, they can trap the excitations, altering the scintillation output. These features have been discussed previously. The presence of magnesium in these glasses increases scintillation efficiency, but as previously observed the effect drops by a factor greater than 2.5 with substitution through the series of alkaline earths. Here, cerium activated glasses of composition 20Li{sub 2}O{center_dot}15MO{center_dot}64.4SiO{sub 2}{center_dot}0.6Ce{sub 3}O{sub 3} (where m is Mg, Ca, Sr, or Ba) exhibit scintillation efficiencies that vary by more than a factor of 2.5 with the alkaline earth. Previous work has suggested a correlation between the microstructure of these glasses and scintillation efficiency. Measurements of the Ce L{sub III} x-ray absorption edge in the Mg, Ca and Sr glasses display a feature near the absorption edge that is suggestive of the presence of Ce{sup 4+}. The area of this peak is, in fact, correlated with the scintillation efficiency of the glass. The amount of Ce{sup 4+} indicated by the intensity of this feature is, however, too high to be a permanent population. The authors suspect that the feature is a transient phenomenon related to creation of Ce{sup 4+} and trapped electrons due to photoionization by the x-ray beam.
Date: November 1, 1994
Creator: Blanchard, D.L.; Sunberg, D.S.; Craig, R.A.; Bliss, M. & Weber, M.J.
Partner: UNT Libraries Government Documents Department

Over the energy edge: Results from a seven year new commercial buildings research and demonstration project

Description: Edge was a research oriented demonstration project that began in 1985. Twenty-eight commercial buildings were designed and constructed to use 30% less electricity than a hypothetical simulated baseline building. Average savings from the 18 buildings evaluated with post-occupancy, ``tuned`` simulation models were less, at 17%. The cost-effectiveness of the energy-efficiency measures at six of the 18 projects met the target cost-of-conserved (CCE) energy of 5.6cent/kWh for the total package of measures. The most important reason energy savings were not as great as predicted is that the actual, installed energy-efficiency measures and building characteristics changed from the design assumptions. The cost effectiveness of the measures would have been greater if the baseline was common practice rather than assumptions based on the regional building code. For example, the Energy Edge small offices use about 30% to 50% less energy than comparable new buildings. Savings also would have been greater if commissioning had been included within the program. Future projects should consider lower-cost ``hands-on`` evaluation techniques that provide direct feedback on measure performance based on functional and diagnostic testing, with annual check-ups to ensure persistence of savings.
Date: August 1994
Creator: Piette, M. A.; Nordman, B.; deBuen, O.; Diamond, R. & Codey, B.
Partner: UNT Libraries Government Documents Department

Ductile grinding of Ba(Sr)TiO{sub 3} detector substrates

Description: Several precision machining techniques have been applied to barium strontium titanate wafers as deterministic replacements for lapping, polishing and reticulation. Surface finishes approaching polish quality have been achieved in less time than normally required, leading to potentially lower manufacturing costs for uncooled FPA`s.
Date: August 1, 1994
Creator: Kahl, W.K.
Partner: UNT Libraries Government Documents Department

Evaluation of microporous carbon filters as catalysts for ozone decomposition

Description: Ozone is produced in small quantities in photocopiers and laser printers in the workplace and large quantities in industrial waste water treatment facilities. Carbon filters are commonly used to decompose this unwanted ozone. The three most important factors in producing a filter for this purpose are flow properties, efficiency, and cost. Most ozone decomposition applications require very low back-pressure at modest flow rates. The tradeoff between the number of pores and the size of the pores will be discussed. Typical unfiltered emissions in the workplace are approximately 1 ppm. The maximum permissible exposure limit, PEL, for worker exposure to ozone is 0.1 ppm over 8 hours. Several methods have been examined to increase the efficiency of ozone decomposition. Carbon surfaces were modified with catalysts, the surface activated, and the surface area was increased, in attempts to decompose ozone more effectively. Methods to reduce both the processing and raw material costs were investigated. Several sources of microporous carbon were investigated as ozone decomposition catalysts. Cheaper processing routes including macropore templating, faster drying and extracting methods were also studied.
Date: December 31, 1994
Creator: Whinnery, L.; Coutts, D.; Shen, C.; Adams, R.; Quintana, C. & Showalter, S.
Partner: UNT Libraries Government Documents Department

Development of an expert system for transportation of hazardous and radioactive materials

Description: Under the sponsorship of the US Department of Energy`s (DOE`s) Transportation Management Division (EM-261), the Transportation Technologies Group at Oak Ridge National Laboratory (ORNL) has designed and developed an expert system prototype application of the hazardous materials transportation regulations. The objective of this task was to provide a proof-of-concept for developing a computerized expert system that will ensure straightforward, consistent, and error-free application of the hazardous materials transportation regulations. The expert system prototype entailed the analysis of what an expert in hazardous materials shipping information could/should do. From the analysis of the different features required for the expert system prototype, it was concluded that the developmental efforts should be directed to a Windows{trademark} 3.1 hypermedia environment. Hypermedia technology usually works as an interactive software system that gives personal computer users the ability to organize, manage, and present information in a number of formats--text, graphics, sound, and full-motion video.
Date: May 20, 1994
Creator: Ferrada, J.J.; Michelhaugh, R.D. & Rawl, R.R.
Partner: UNT Libraries Government Documents Department

Design, fabrication, and testing of a helium-cooled module for the ITER divertor

Description: The International Thermonuclear Reactor (ITER) will have a single-null divertor with total power flow of 200 MW and a peak heat flux of about 5 MW/m{sup 2}. The reference coolant for the divertor is water. However, helium is a viable alternative and offers advantages from safety considerations, such as excellent radiation stability and chemical inertness. In order to prove the feasibility of helium cooling at ITER relevant heat flux conditions, General Atomics designed, fabricated, and tested a helium-cooled divertor module. The module was made from dispersion strengthened copper, with a heat flux surface 25 mm wide and 80 mm long, designed for twice the ITER divertor heat flux. Different techniques were examined to enhance the heat transfer, which in turn reduced the flow and pumping power required to cool the module. It was concluded that an extended surface was the most practical solution. An optimization study was performed to find the best extended surface parameters. The optimum extended surface geometry consisted of fins: 10 mm high, 0.4 mm thick with a 1 mm pitch. It was estimated to require a pumping power of 150 W to remove 20 kW of power. This is more than an order of magnitude reduction in pumping power requirement, compared to smooth surface. The module was fabricated by electric discharge machining (EDM) process. The testing was carried out at SNLA during August 1993. The testing confirmed the design calculations. The peak heat flux during the test was 10 MW/m{sup 2} applied over a surface area of 20 cm{sup 2}. The pumping power calculated from flow rate and pressure drop measurement was about 160 W, which was less than 1% of the power removed. It is planned to test the module to higher temperature limits and higher heat fluxes during coming months. As a result of ...
Date: August 1, 1994
Creator: Baxi, C.B.; Smith, J.P. & Youchison, D.
Partner: UNT Libraries Government Documents Department

Bit-string physics: A novel theory of everything

Description: We encode the quantum numbers of the standard model of quarks and leptons using constructed bitstrings of length 256. These label a grouting universe of bit-strings of growing length that eventually construct a finite and discrete space-time with reasonable cosmological properties. Coupling constants and mass ratios, computed from closure under XOR and a statistical hypothesis, using only {h_bar}, c and m{sub p} to fix our units of mass, length and time in terms of standard (meterkilogram-second) metrology, agree with the first four to seven significant figures of accepted experimental results. Finite and discrete conservation laws and commutation relations insure the essential characteristics of relativistic quantum mechanics, including particle-antiparticle pair creation. The correspondence limit in (free space) Maxwell electromagnetism and Einstein gravitation is consistent with the Feynman-Dyson-Tanimura ``proof.``
Date: August 1, 1994
Creator: Noyes, H.P.
Partner: UNT Libraries Government Documents Department

FENIX experimental results of large-scale CICC made of bronze-processed Nb{sub 3}Sn strands

Description: The Fusion ENgineering International eXperiments (FENIX) Test Facility recently has successfully complete the testing of a pair of Nb{sub 3}rSn cable-in-conduit conductors developed by the Japan Atomic Energy Research Institute. These conductors, made of bronze-processed strands, were designed to operate stably with 40-kA transport current at a magnetic field of 13 T. In addition to the measurements of major design parameters such as current-sharing temperature, FENIX provided several experiments specifically designed to provide results urgently needed by magnet designers. Performed experiments include measurements of ramp-rate limit, current-distribution, stability, and joint performance. This paper presents the design and results of these special experiments.
Date: October 13, 1994
Creator: Shen, S.S.; Felker, B.; Moller, J.M.; Parker, J.M.; Isono, T.; Yasukawa, Y. et al.
Partner: UNT Libraries Government Documents Department

Permeability of fractured tuff as functions of temperature and confining pressure

Description: Understanding the transport properties of water through fractured rock is critical to predicting and modeling the hydrothermal performance of a geologic nuclear waste repository. Previous studies indicate that intact Topopah Spring tuff from Yucca Mountain, Nevada has a low permeability, {approximately} 1 {times} 10 {sup {minus}18} m{sup 2} ({approximately}1 microDarcy). A single fracture in the tuff increases the permeability to {approximately}100 {times}10{sup {minus}15} m{sup 2} (hundreds of milliDarcies). However, fracture healing may occur when high temperature water flows through the fracture lowering the permeability by one or more orders of magnitude. We report progress on laboratory experiments on permeability of fractured Topopah Spring tuff as functions of confining pressure, temperature, and water/rock ratio.
Date: October 1, 1994
Creator: Roberts, J.J. & Lin, Wunan
Partner: UNT Libraries Government Documents Department

Neutron scattering from amorphous, disordered and nanocrystalline materials

Description: The author has described the power of neutron diffraction and inelastic scattering techniques for determining the structure and dynamics of disordered systems, using the archetypal glass SiO{sub 2} as a detailed example. Of course the field of amorphous and disordered systems contains a much greater variety of types of materials exhibiting a wide range of possible types of disorder. The author gives a brief review of the varieties of order and disorder exhibited by condensed matter.
Date: October 1, 1994
Creator: Price, D.L.
Partner: UNT Libraries Government Documents Department

Innovative directional and position specific sampling technique

Description: The main objective of UTD`s completed contract was to demonstrate the accuracy UTD POsition LOcator (POLO) system d for penetrometer applications. The contract work was accomplished in three phases. Phase I involved sub-scale refinement of the POLO sub-systems which included the design and testing of individual components of POLO. The objectives of Phase II were to integrate a prototype POLO unit and demonstrate its accuracy through laboratory tracking experiments. Phase III objectives included manufacturing and assembly of a full-scale POLO unit and demonstration of its accuracy under field conditions. The success criterion for the entire contract was to calculate the penetrometer tip position with 0.5% accuracy or better with respect to distance traveled both in laboratory and field tests. This criterion was satisfied in Phase II laboratory tests and in Phase III field tests at two different sites. With successful completion of the contract in September, 1994, UTD has embarked on a commercialization plan in order to make commercial POLO units available to DOE contractors and penetrometer users in a timely fashion.
Date: December 31, 1994
Creator: Foster, E.L.
Partner: UNT Libraries Government Documents Department

Process/economic strategy for upgrading shale oil

Description: A prime difficulty with the production of transportation fuels from Western US shale oil is the high heteroatom content, especially nitrogen. Nitrogen containing molecules are known to have high market value for non-fuel uses. Selective extraction of nitrogen-containing molecules from shale oil recovers these potentially valuable components while upgrading the remaining shale oil for refining to transportation fuels. A thermodynamically logical separation process sequence consisting of primarily distillation and liquid-liquid extraction has been shown effective in selective isolation of polar heteroatom-containing molecules. The polar fraction may be processed for the production of chemical intermediates and specialty chemicals of high value. Projected material balances show an overall product split of 80% refinery feed and 20% polar products. Based on product values and composition, a preliminary economic analysis yields 30% internal rate of return. A summary of the economic strategy, process results and promising products will be presented.
Date: December 31, 1994
Creator: Bunger, J.W.; Russell, C.P.; Devineni, P.A.V.; Cogswell, D.E. & Wiser, J.W.
Partner: UNT Libraries Government Documents Department

Workshop on transport for a common ion driver

Description: This report contains research in the following areas related to beam transport for a common ion driver: multi-gap acceleration; neutralization with electrons; gas neutralization; self-pinched transport; HIF and LIF transport, and relevance to common ion driver; LIF and HIF reactor concepts and relevance to common ion driver; atomic physics for common ion driver; code capabilities and needed improvement.
Date: December 31, 1994
Creator: Olson, C.C.; Lee, E. & Langdon, B.
Partner: UNT Libraries Government Documents Department

The minimum pore size obtainable in a silica gel during drying

Description: The pore size r{sub p} in a gel is determined by the extent of shrinkage of the gel network during drying. Shrinkage is driven by the collapse of the gel network in response to the capillary pressure P{sub c} exerted by the pore fluid. The extent of shrinkage depends on the balance between the capillary pressure P{sub c} in the pore fluid and the bulk modulus K{sub p} of the gel. The hydraulic pore radius, r{sub H} = 2V{sub p}/S{sub a}, where V{sub p} is the pore volume and S{sub a} is the apparent N{sub 2} BET surface area, is often used to characterize the pore size of a gel. A series of acid catalyzed silica gels dried in pore fluids with different {gamma}{sub lv}, showed that there is a limit to the minimum apparent r{sub H} obtainable in a gel, and when the volume fraction of porosity {phi} {le} 0.37, r{sub H} becomes constant and {approximately}0.8 nm. In contrast, experimental data show that the true pore size r{sub p} of gels continues to decrease when {phi} {le} 0.37. Analysis of their adsorption isotherms show that while r{sub H} apparently stays constant: (a) the BET C constant continues to increase, (b) the width and average of their pore size distributions continue to decrease, and (c) as shrinkage continues the gels eventually become non-porous to N{sub 2} at 77K but are still porous to CO{sub 2} at 273K. This paper reviews these results and addresses micropore formation in silica gels with the goal of determining how P{sub c} influences the final r{sub p}, and why r{sub p} and r{sub H} diverge when {phi} {le} 0.37.
Date: December 1994
Creator: Wallace, S.; Brinker, C. J. & Smith, D. M.
Partner: UNT Libraries Government Documents Department

Periodically specified problems: An exponential complexity gap between exact and approximate solutions

Description: We study both the complexity and approximability of various graph and combinatorial problems specified using two dimensional narrow periodic specifications (see [CM93, HW92, KMW67, KO91, Or84b, Wa93]). The following two general kinds of results are presented. (1) We prove that a number of natural graph and combinatorial problems are NEXPTIME- or EXPSPACE-complete when instances are so specified; (2) In contrast, we prove that the optimization versions of several of these NEXPTIME-, EXPSPACE-complete problems have polynomial time approximation algorithms with constant performance guarantees. Moreover, some of these problems even have polynomial time approximation schemes. We also sketch how our NEXPTIME-hardness results can be used to prove analogous NEXPTIME-hardness results for problems specified using other kinds of succinct specification languages. Our results provide the first natural problems for which there is a proven exponential (and possibly doubly exponential) gap between the complexities of finding exact and approximate solutions.
Date: November 28, 1994
Creator: Hunt, H.B. III; Rosenkrantz, D.J.; Stearns, R.E.; Marathe, M.V. & Radhakrishnan, V.
Partner: UNT Libraries Government Documents Department

Potential for use of all-MOX fuel in existing and evolutionary/advanced LWRs in the United States

Description: This paper reviews the application of US LWRs that are loaded with all-MOX fuel to dispose of excess weapon plutonium. The information presented is based on the DOE study results summarized in the 1993 DOE report, and the detailed reports submitted by reactor designers to DOE for that report. The reactor designs are the Westinghouse (Plutonium Disposition Reactor) PDR600, the GE Advanced BWR (ABWR), and ABB-Combustion Engineering System 80+. Analysis of published information in the nuclear community is the basis for an estimate of the capabilities of existing LWRs to switch from low-enriched uranium to all-MOX fuel. It is concluded to be feasible, if the conversion to PuO{sub 2} can be begun immediately, and lead test assemblies containing prototypical MOX fuel be made and irradiated. Russian VVERs should also be evaluated for Pu disposition.
Date: December 31, 1994
Creator: Walter, C.E.
Partner: UNT Libraries Government Documents Department

Drought tolerance and osmotic adjustment of four deciduous tree species under altered precipitation: Preliminary results

Description: The degree and biochemical basis of drought tolerance and osmotic adjustment of dogwood (Cornus florida L.), white oak (Quercus alba L.), chestnut oak (Quercus prinus L.), and red maple (Acer rubrum L.) is being assessed in a mature hardwood forest using three hydrologic regimes: ambient, wet (+33% throughfall), and dry ({minus}33% throughfall). Currently, leaf water potential, osmotic potential at saturation, and metabolite concentrations are determined monthly for trees under the three treatments. First year results show that within the dry treatment, dogwood demonstrated the highest osmotic potential at saturation ({minus}1.2 MPa), indicating the greatest sensitivity to water stress. Increasing tolerance was evident in red maple ({minus}1.4 MPa), white oak ({minus}1.6 MPa), and chestnut oak ({minus}1.9 MPa). In June, dogwood displayed a 0.12 MPa adjustment to drought, relative to the ambient control. In July, chestnut oak displayed a 0.18 MPa adjustment. This osmotic adjustment resulted primarily from fructose and glucose accumulation in dogwood, and shikimic acid and sucrose accumulation in chestnut oak.
Date: December 31, 1994
Creator: Shirshac, T.L.; Gebre, G.M.; Hanson, P.J. & Tschaplinski, T.J.
Partner: UNT Libraries Government Documents Department