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The epsilon Phase in the UO2 of the Oklo Natural Reactors

Description: In spent nuclear fuel (SNF), the metal epsilon phase consists of an alloy of Mo-Ru-Pd-Tc-Rh, occurring at a micron to sub-micron scale. {sup 99}Tc has a long half life (2.13 x 10{sup 5} years) and can be an important contributor to dose in safety assessments of nuclear waste repositories. Under oxidizing conditions, TcO{sub 4}{sup -} is the predominant species of Tc. In this form, Tc is highly soluble and weakly adsorbed onto mineral surfaces. Because the Oklo reactors are 2.0 billion years old, a majority of the {sup 99}Tc formed by natural fission reactions has decayed to {sup 99}Ru. Thus, this study is focused on Ru and the other constituents of the epsilon phase in order to investigate the occurrence and the fate of epsilon phase elements during the corrosion of this natural SNF. Samples from reactor zone (RZ)-10 (836, 819, 687); from RZ-13 (864, 910); from Okklobondo (943) were studied. High resolution transmission electron microscopy (HRTEM) and high-angle annular dark-field scanning TEM (HAADF-STEM) with energy dispersive X-ray analysis (EDX) were completed on thin foil specimens of uraninite from each reactor zone. Among these samples, no Ru-bearing phase is observed in 910 and 943. A Bi-Pd particle (40-60 nm), froodite, PdBi{sub 2}, occurs with trace amounts of As, Fe, and Te surrounded by an amorphous Pb-rich area (No.864). A Ru-As particle ({approx}300nm) occurs surrounded by Pb-rich inclusion (400-500 nm) in uraninite (No.819). Based on EDX analysis the composition is: As, 59.9 Co, 2.5: Ni, 5.2; Ru, 18.6; Th, 8.4; Pd, 3.1; Sb, 2.4 in atomic%. The Ru-As phase is not a single particle, but an aggregate of 100-200 nm-sized ruthenarsenite, (Ru,Ni)As, particles. Another Ru-particle (600-700 nm) shows that Pb occurs at the core of the particle, and the rim portion consists of Ni, Co, and As without Ru (No.819). Ru-particles, ...
Date: April 15, 2005
Creator: Utsunomiya, S.
Partner: UNT Libraries Government Documents Department

[News Clip: Pools]

Description: Video footage from the KXAS-TV/NBC station in Fort Worth, Texas, to accompany a news story.
Date: June 15, 1982, 5:00 p.m.
Creator: KXAS-TV (Television station : Fort Worth, Tex.)
Partner: UNT Libraries Special Collections

Analysis of Radiation From Hnpf Cold Traps and Primary Sodium Pumps During Removal and Shipping

Description: The expected maximum contamination of the HNPF cold traps and primary sodium pumps was determined along with the maximum dose rates from these components during removal and shipping. Suitable shielding for casks to be used in the removal operation and for shipping these components away from the reactor site is specified. Access to an unshielded cold trap is limited by high dose rates, i.e., 100 mr/hr at 120 ft, after 180 days decay time. A handling cask providing a radial shield of 3 in. of lead will provide adequate personnel protection for the removal operation, if 180 days decay time is allowed before the trap is removed. An additional 2.4 in. of lead is required for offsite shipment of the cask. This additional shielding can be added after the trap is removed from the reactor building. Dose rates from the cold trap after the shield plug is removed from the access hole are shown. If direct line-ofsight exposure is avoided, dose rates to personnel will be below 100 mr/hr at any position, and below 10 mr/hr at distances greater than 20 ft from the access hole. Dose rates from the cask during its travel away from the hole, will be below 100 mr/hr at distances from the cask greater than 10 ft and below 10 mr/hr at 35 ft, if the cask is raised no more than 3 in. from the floor during its travel. Remote, unshielded handling of a primary sodium pump is feasible, since dose rates would be 100 mr/hr at 28 ft and 10 mr/hr at 90 ft, after ten years of operation, and providing that 14 days decay time is allowed to eliminate activity from the Na/sup 24/ film clinging to the pump. Dose rates after only one year of operation would be lower by a ...
Date: December 15, 1959
Creator: Rhoades, W. A.
Partner: UNT Libraries Government Documents Department

Additional Measurements on the Army Package Power Reactor Zero Power Experiments: ZPE-1 and ZPE-2

Description: During the course of the ZPE-2 experimental program additional measurements were performed under the Alco Products Research and Development program. Included in this program were the evaluation of various absorber section compositions and reactivity studies designed to facilitate analytical techniques. The results of these measurements are presented. (auth)
Date: November 15, 1957
Creator: Giesler, H. W.
Partner: UNT Libraries Government Documents Department

X-ray diffraction time-study of uranium tritide materials. [To determine effects of /sup 3/He buildup on lattice parameters]

Description: X-ray powder diffraction analyses of bulk uranium tritides, as a function of time, have been accomplished. The analyses were run during an overall time span of two years. This study was undertaken to determine whether any observable effects of the /sup 3/He buildup could be detected by means of lattice parameter measurements. Four tritiated uranium samples were investigated. The data obtained from three of these samples show expansion of their lattices to be as anticipated. The fourth sample yielded an unexpected growth rate for 10 months, after which the scatter of data points becomes anomalous. Review of the tabulated and plotted data shows that line broadening occurs in each sample at about 10 months. The line broadening, as detected by x-ray diffraction, is indicative of the sample's crystallites becoming smaller in size, viz., less than one micron. The measurement of this line broadening might prove beneficial by revealing the actual crystallite size of the material during storage. The x-ray study of the samples has shown that diffraction analyses, including lattice parameter measurements, do not directly reveal the mechanisms of /sup 3/He release. (auth)
Date: March 15, 1976
Creator: Eckstein, R. R.
Partner: UNT Libraries Government Documents Department


Description: Studies were made on the feasibility of effecting diffusion bonding in U, using pure Au as a catalyst, and by solid state diffusion without the use of a catalyst. It was found that the Au appeared to have promising characteristics for catalyzing the diffusion bonding reaction in joining uranium to itself. Phase diagrams are given U-Au, U--Cr, U--Co, U--Cu, U--Fe, U--Mn, and U--Ni alloys. (P.C.H.)
Date: October 15, 1962
Creator: Bertossa, R.C.
Partner: UNT Libraries Government Documents Department

Filament power regulator for thermal ionization mass spectrometry

Description: A device has been developed that will control the filament temperature in a thermal ionization mass spectrometer. The arrangement is superior to past methods to control this critical parameter. The operating principle lies in the feature of filament power control as contrasted with the formerly used voltage or current controls. Reproducibility and stability of ion beams showed great improvement. The mass spectrometer was developed to analyze for parts-per-billion concentrations of uranium in water samples.
Date: September 15, 1977
Creator: Rogers, E. R. & Ferguson, J. R.
Partner: UNT Libraries Government Documents Department

Geothermal commercial power plant study. Monthly progress report, January 29, 1977-February 25, 1977

Description: Conceptual designs and capital cost estimates were completed for the six different Heber power plants in this study. The six plants involve two types of operating modes, constant geothermal fluid flow rate and constant power output, each for net capacities of 50, 100, and 200 MWe. Conceptual designs were completed for the six plants by modifying and scaling-up the base case design. The capital costs for all six plants were estimated in fourth-quarter 1976 dollars.
Date: April 15, 1977
Partner: UNT Libraries Government Documents Department

Fly ash-enhanced aluminum composites for automotive parts. [Reports for April to June, 1998, and July to September, 1998]

Description: The objectives of this report are to produce and evaluate the use of aluminum ''ashalloys''--metal matrix composites that incorporate coal fly ash--in the commercial manufacture of cast automotive parts. Some highlights are: (1) Ashalloy ingot with ''C'' type fly ash was synthesized using stir casting techniques similar to the successful castings of ''F'' type fly ash. Agglomeration was noted. Stirring periods were increased up to 45 minutes compared to the normal 5 minutes to determine whether the shear force of stirring would disagglomerate the clusters noted with this type of fly ash. The resulting sample showed clustering. (2) The ashalloy ingots of ''C'' type fly ash were remelted and poured into permanent molds using a cloth filter to screen out clusters. There was no major reduction in clusters of fly ash particles in the composite since the filter with the mesh size larger than 1 x 1 mm was used. The composite melt would not flow through when filters with smaller openings were used. (3) The fly ash sample from Wisconsin Electric Power Company was sent for classification. (4) A 1 lb. sample of JTM-processed fly ash was sent to Wisconsin Electric Power Company for classification and 10 lb. of same fly ash was sent to The Jet Pulverizer Company for jet milling. (5) Experiments on fly ash pretreatment as well as synthesis of ash alloy are continuing. (6) Attempts are being made to apply high speed shear mixing with selected liquids to disperse the clusters noted in ashalloy with the ''C'' type fly ash base. Stir casting processes have been developed to incorporate type ''F'' fly ash of different sizes and measuring tensile data on cast bars. This data enables selection of the optimum size of fly ash to meet specific property requirements. Attempts are underway to develop stir ...
Date: October 15, 1998
Creator: Golden, Dean & Rohatgi, Pradeep
Partner: UNT Libraries Government Documents Department


Description: AC complex impedance spectroscopy studies were conducted on symmetrical cells of the type [gas, electrode/LSGM electrolyte/electrode, gas]. The electrode materials were slurry-coated on both sides of the LSGM electrolyte support. The electrodes selected for this investigation are candidate materials for SOFC electrodes. Cathode materials include La{sub 1-x}Sr{sub x}MnO{sub 3} (LSM), LSCF (La{sub 1-x}Sr{sub x}Co{sub y}Fe{sub 1-y}O{sub 3}), a two-phase particulate composite consisting of LSM + doped-lanthanum gallate (LSGM), and LSCF + LSGM. Pt metal electrodes were also used for the purpose of comparison. Anode material investigated was the Ni + GDC composite. The study revealed important details pertaining to the charge-transfer reactions that occur in such electrodes. The information obtained can be used to design electrodes for intermediate temperature SOFCs based on LSGM electrolyte.
Date: February 15, 2004
Creator: Pal, Uday B. & Gopalan, Srikanth
Partner: UNT Libraries Government Documents Department

Fly ash-enhanced aluminum composites for automotive parts. [Reports for October to December, 1997, and January to March, 1998]

Description: The objectives of this report are to produce and evaluate the use of aluminum ''ashalloys''--metal matrix composites that incorporate coal fly ash--in the commercial manufacture of cast automotive parts. Some highlights of this report are: Results of the team coordination meeting in October included--(1) Determination of casting techniques from the candidates of squeeze, high pressure, low pressure, sand casting, and gravity pour; (2) Selection of the low stress/high stress automotive parts from the candidates of brake rotors, intake manifolds, and engine mounts; (3) Integration of the tasks essential for evaluating the fly ash characteristics and appropriate percentages of cenospheres or precipitator in the parts. Fly ash from two plants of Wisconsin Electric Power Company (WEPCo) was dispatched to the laboratories of JTM and UW-M for screening, characterization, and beneficiation. The fly ash was classified into different size fractions and is being analyzed for chemical composition and microstructure. Currently, fly ash beneficiation is removing the carbon, magnetic fractions, and sulfur. After classification and screening, JTM will deliver the processed fly ash to UW-M. Foundries are providing UW-M with information on the specific alloys needed for parts. Thompson Aluminum sent the base alloy 356 to UW-M where, in turn, small size ingots were prepared with fly ash from WEPCo. UW-M will continue process development and preparation of specific MMC ingots for foundries' parts production. Many of the program tasks are iterative over quarters, but findings considered milestones were: Collection and processing of fly ash; and Predictions on microstructure and alloy composites including type, size, and amount of fly ash for component property requirements.
Date: April 15, 1998
Creator: Golden, Dean & Rohatgi, Pradeep
Partner: UNT Libraries Government Documents Department

[News Script: UTA]

Description: Script from the WBAP-TV/NBC station in Fort Worth, Texas, relating a news story.
Date: May 15, 1972, 10:00 p.m.
Creator: WBAP-TV (Television station : Fort Worth, Tex.)
Partner: UNT Libraries Special Collections

MAG-GATE System for Molten metal Flow Control

Description: The need for improved active flow control has been recognized as part of the Steel Industry Technology Roadmap. Under TRP 9808 for the American Iron and Steel Institute and the Department of Energy, Concept Engineering Group Inc. has developed MAG-GATE{trademark}, an electromagnetic system for active molten metal flow control. Two hot steel tests were successfully conducted in 2003 at the Whemco Foundry Division, Midland, PA. Approximately 110,000 pounds of 0.2% carbon steel were poured through the device subject to electromagnetic flow control. Excellent agreement between predicted and actual flow control was found. A survey of the molten metal flow control practices at 100 continuous casters in North America was also conducted in 2003. This report summarizes the results of the development program to date. Preliminary designs are described for the next step of a beta test at an operating billet/bloom or slab caster.
Date: May 15, 2004
Creator: Nathenson, Richard D.
Partner: UNT Libraries Government Documents Department


Description: This report describes work performed during the first year of the project ''Modified Reverse Osmosis System for Treatment of Produced Waters.'' This research project has two objectives. The first objective is to test the use of clay membranes in the treatment of produced waters by reverse osmosis. The second objective is to test the ability of a system patented by the New Mexico Tech Research Foundation to remove salts from reverse osmosis waste streams as a solid. We performed 12 experiments using clay membranes in cross-flow experimental cells. We found that, due to dispersion in the porous frit used adjacent to the membrane, the concentration polarization layer seems to be completely (or nearly completely) destroyed at low flow rates. This observation suggests that clay membranes used with porous frit material many reach optimum rejection rates at lower pumping rates than required for use with synthetic membranes. The solute rejection efficiency decreases with increasing solution concentration. For the membranes and experiments reported here, the rejection efficiency ranged from 71% with 0.01 M NaCl solution down to 12% with 2.3 M NaCl solution. More compacted clay membranes will have higher rejection capabilities. The clay membranes used in our experiments were relatively thick (approximately 0.5 mm). The active layer of most synthetic membranes is only 0.04 {micro}m (0.00004 mm), approximately 1250 times thinner than the clay membranes used in these experiments. Yet clay membranes as thin as 12 {micro}m have been constructed (Fritz and Eady, 1985). Since Darcy's law states that the flow through a material of constant permeability is inversely proportional to it's the material's thickness, then, based on these experimental observations, a very thin clay membrane would be expected to have much higher flow rates than the ones used in these experiments. Future experiments will focus on testing very thin clay ...
Date: September 15, 2002
Creator: Whitworth, T.M. & Li, Liangxiong
Partner: UNT Libraries Government Documents Department


Description: This report describes work performed during the second year of the project ''Modified reverse osmosis system for treatment of produced waters.'' We performed two series of reverse osmosis experiments using very thin bentonite clay membranes compacted to differing degrees. The first series of 10 experiments used NaCl solutions with membranes that ranged between 0.041 and 0.064mm in thickness. Our results showed compaction of such ultra-thin clay membranes to be problematic. The thickness of the membranes was exceeded by the dimensional variation in the machined experimental cell and this is believed to have resulted in local bypassing of the membrane with a resultant decrease in solute rejection efficiency. In two of the experiments, permeate flow was varied as a percentage of the total flow to investigate results of changing permeate flow on solute rejection. In one experiment, the permeate flow was varied between 2.4 and 10.3% of the total flow with no change in solute rejection. In another experiment, the permeate flow was varied between 24.6 and 52.5% of the total flow. In this experiment, the solute rejection rate decreased as the permeate occupied greater fractions of the total flow. This suggests a maximum solute rejection efficiency for these clay membranes for a permeate flow of between 10.3 and 24.6% of the total; flow. Solute rejection was found to decrease with increasing salt concentration and ranged between 62.9% and 19.7% for chloride and between 61.5 and 16.8% for sodium. Due to problems with the compaction procedure and potential membrane bypassing, these rejection rates are probably not the upper limit for NaCl rejection by bentonite membranes. The second series of four reverse osmosis experiments was conducted with a 0.057mm-thick bentonite membrane and dilutions of a produced water sample with an original TDS of 196,250 mg/l obtained from a facility near Loco Hill, ...
Date: September 15, 2002
Creator: Whitworth, T.M. & Li, Liangxiong
Partner: UNT Libraries Government Documents Department

An integrative approach to energy, carbon, and redox metabolism in the cyanobacterium Synechocystis sp. PCC 6803

Description: The team of the Fellowship for Interpretation of Genomes (FIG) under the leadership of Ross Overbeek, began working on this Project in November 2003. During the previous year, the Project was performed at Integrated Genomics Inc. A transition from the industrial environment to the public domain prompted us to adjust some aspects of the Project. Notwithstanding the challenges, we believe that these adjustments had a strong positive impact on our deliverables. Most importantly, the work of the research team led by R. Overbeek resulted in the deployment of a new open source genomic platform, the SEED (Specific Aim 1). This platform provided a foundation for the development of CyanoSEED a specialized portal to comparative analysis and metabolic reconstruction of all available cyanobacterial genomes (Specific Aim 3). The SEED represents a new generation of software for genome analysis. Briefly, it is a portable and extendable system, containing one of the largest and permanently growing collections of complete and partial genomes. The complete system with annotations and tools is freely available via browsing or via installation on a user's Mac or Linux computer. One of the important unique features of the SEED is the support of metabolic reconstruction and comparative genome analysis via encoding and projection of functional subsystems. During the project period, the FIG research team has validated the new software by developing a significant number of core subsystems, covering many aspects of central metabolism (Specific Aim 2), as well as metabolic areas specific for cyanobacteria and other photoautotrophic organisms (Specific Aim 3). In addition to providing a proof of technology and a starting point for further community-based efforts, these subsystems represent a valuable asset. An extensive coverage of central metabolism provides the bulk of information required for metabolic modeling in Synechocystis sp.PCC 6803. Detailed analysis of several subsystems covering energy, ...
Date: February 15, 2005
Creator: Ross Overbeek, Veronika Fonstein, Andrei Osterman, Svetlana Gerdes, Olga Vassieva, Olga Zagnitko, Dmitry Rodionov
Partner: UNT Libraries Government Documents Department