Download or read book Supercritical Fluid Carbon Dioxide Cleaning of Plutonium Parts written by and published by . This book was released on 1991 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt: Supercritical fluid carbon dioxide is under investigation in this work for use as a cleaning solvent for the final cleaning of plutonium parts. These parts must be free of organic residue to avoid corrosion in the stockpile. Initial studies on stainless steel and full-scale mock-up parts indicate that the oils of interest are easily and adequately cleaned from the metal surfaces with supercritical fluid carbon dioxide. Results from compatibility studies show that undesirable oxidation or other surface reactions are not occurring during exposure of plutonium to the supercritical fluid. Cleaning studies indicate that the oils of interest are removed from the plutonium surface under relatively mild conditions. These studies indicate that supercritical fluid carbon dioxide is a very promising cleaning medium for this application.

Download or read book Supercritical fluid Carbon Dioxide SCCO2 Cleaning of Nuclear Weapon Components written by and published by . This book was released on 1998 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: Supercritical fluid carbon dioxide (SCCO2) has been evaluated as a cleaning solvent for the cleaning of plutonium (Pu) metal parts. The results of the evaluation show that SCCO2 is an effective alternative to halogenated solvents that are conventionally used for removing organic and inorganic contaminants from the surface of these parts. The cleaning process was demonstrated at the laboratory scale for steel and uranium substrates and has been found to be compatible with Pu. The efficacy of this cleaning method is found to be dependent on process conditions of pressure, temperature, fluid-flow rate, as well as cleaning time. Process parameters of P> 2,500 psi, T> 40 C, and moderate fluid flow rates, produced good cleaning results in less than 10 minutes using a simple flow-through process configuration. Within the parameter range studied, cleaning efficiency generally improved with increasing process pressure and flow rate. SCCO2 cleaning is suitable for a variety of component cleaning tasks and is adaptable to precision cleaning requirements. The SCCO2 cleaning process is currently being developed for deployment for weapons production at LANL.

Download or read book Liquid supercritical Fluid Carbon Dioxide Cleaning of Stainless Steel Components written by L. M. Bagaasen and published by . This book was released on 1991 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Energy Research Abstracts written by and published by . This book was released on 1995 with total page 782 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Elimination of Solvents and Waste by Supercritical Carbon Dioxide in Precision Cleaning written by and published by . This book was released on 1994 with total page 23 pages. Available in PDF, EPUB and Kindle. Book excerpt: Physiochemical properties of supercritical carbon dioxide make it ideally suited for removing commonly encountered contaminants found in the precision cleaning of optical components, computer parts, and electronic assemblies. Data will be presented on a survey demonstrating the successful removal of cutting and machine oils, silicon oils, body oils and hydraulic fluids from a variety of surfaces with supercritical carbon dioxide to, at, or below precision cleaning standards (less than 10 micrograms of contaminant per square centimeter of surface). Replicate studies were performed in both a small bench-scale unit (10 milliliter cleaning vessel) and in a large-scale unit (60 liter, 14 inch diameter cleaning vessel) showing the ability to scale small experiments to commercial sizes. Applicability of this supercritical fluid cleaning technique to commercial operations was evaluated in the areas of contaminant removal efficiencies, surface interactions, operational costs, and environmental waste reduction/elimination.

Download or read book Re engineering Manufacturing for Sustainability written by Andrew Y. C. Nee and published by Springer Science & Business Media. This book was released on 2013-04-08 with total page 719 pages. Available in PDF, EPUB and Kindle. Book excerpt: This edited volume presents the proceedings of the 20th CIRP LCE Conference, which cover various areas in life cycle engineering such as life cycle design, end-of-life management, manufacturing processes, manufacturing systems, methods and tools for sustainability, social sustainability, supply chain management, remanufacturing, etc.

Download or read book Plutonium Decontamination of Uranium Using CO2 Cleaning written by and published by . This book was released on 2002 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A concern of the Department of Energy (DOE) Environmental Management (EM) and Defense Programs (DP), and of the Los Alamos National Laboratory (LANL) and the Lawrence Livermore National Laboratory (LLNL), is the disposition of thousands of legacy and recently generated plutonium (Pu)-contaminated, highly enriched uranium (HEU) parts. These parts take up needed vault space. This presents a serious problem for LLNL, as site limit could result in the stoppage of future weapons work. The Office of Fissile Materials Disposition (NN-60) will also face a similar problem as thousands of HEU parts will be created with the disassembly of site-return pits for plutonium recovery when the Pit Disassembly and Conversion Facility (PDCF) at the Savannah River Site (SRS) becomes operational. To send HEU to the Oak Ridge National Laboratory and the Y-12 Plant for disposition, the contamination for metal must be less than 20 disintegrations per minute (dpm) of swipable transuranic per 100 cm2 of surface area or the Pu bulk contamination for oxide must be less than 210 parts per billion (ppb). LANL has used the electrolytic process on Pu-contaminated HEU weapon parts with some success. However, this process requires that a different fixture be used for every configuration; each fixture cost approximately $10K. Moreover, electrolytic decontamination leaches the uranium metal substrate (no uranium or plutonium oxide) from the HEU part. The leaching rate at the uranium metal grain boundaries is higher than that of the grains and depends on the thickness of the uranium oxide layer. As the leaching liquid flows past the HEU part, it carries away plutonium oxide contamination and uranium oxide. The uneven uranium metal surface created by the leaching becomes a trap for plutonium oxide contamination. In addition, other DOE sites have used CO2 cleaning for Pu decontamination successfully. In the 1990's, the Idaho National Engineering Laboratory investigated this technology and showed that CO2 pellet blasting (or CO2 cleaning) reduced both fixed and smearable contamination on tools. In 1997, LLNL proved that even tritium contamination could be removed from a variety of different matrices using CO2cleaning. CO2 cleaning is a non-toxic, nonconductive, nonabrasive decontamination process whose primary cleaning mechanisms are: (1) Impact of the CO2 pellets loosens the bond between the contaminant and the substrate. (2) CO2 pellets shatter and sublimate into a gaseous state with large expansion ((almost equal to)800 times). The expanding CO2 gas forms a layer between the contaminant and the substrate that acts as a spatula and peels off the contaminant. (3) Cooling of the contaminant assists in breaking its bond with the substrate. Thus, LLNL conducted feasibility testing to determine if CO2 pellet blasting could remove Pu contamination (e.g., uranium oxide) from uranium metal without abrading the metal matrix. This report contains a summary of events and the results of this test.

Download or read book Hydrogen future Fuel written by Neil A. Olien and published by . This book was released on 1975 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book NBS Technical Note written by and published by . This book was released on 1975-02 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Precision Cleaning with Supercritical Carbon Dioxide for the Elimination of Organic Solvents and the Reduction of Hazardous Wastes written by and published by . This book was released on 1994 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: Private and governmental industrial facilities use chlorofluorocarbons and chlorocarbons for the cleaning of a variety of items. The Montreal Protocol (1987) and amendments to this act will phase out the use of chlorofluorocarbons, or CFCs, by the year 2000 because they are toxic, carcinogenic, and implicated in the depletion of the Earth's ozone layer. The United States has pledged to eliminate these substances by 1995. To stay competitive in the global market, US industries require an economical replacement. Supercritical fluids, which have been used in food, fragrance, and petroleum processes for years, are attractive replacement solvents because of their low environmental impact, high diffusivities, low viscosities, and temperature-pressure dependence of solvent strengths. In the case of nontoxic and nonflammable carbon dioxide (CO2), its critical temperature and pressure are readily accessible with well-established process technology and equipment. In addition, applications using a supercritical fluid such as CO2 are generally safer and environmentally benign. Extractions using supercritical CO2 use less energy than distillation and incineration processes and are less expensive than liquid extraction processes using toxic and costly organic solvents. Finally, CO2 has a very high volatility compared to virtually any organic extractant which facilitates its separation from extract solutions for extract recovery and CO2 recycle. Data will be presented on the successful removal of cutting and machine oils, silicone oils, body oils, and hydraulic fluids from a variety of industrial substrates with supercritical CO2 to, at, or below precision cleaning levels (less than 10 micrograms of contaminant per square centimeter of surface). The applicability of this technique to commercial operations was evaluated in this area of contaminant removal, surface interactions, operational costs, and waste reduction and elimination.

Download or read book Supercritical Fluid Extraction of Plutonium and Americium from Soil written by and published by . This book was released on 2002 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Supercritical fluid extraction (SFE) of plutonium and americium from soil was successfully demonstrated using supercritical fluid carbon dioxide solvent augmented with organophosphorus and beta-diketone complexants. Spiked Idaho soils were chemically and radiologically characterized, then extracted with supercritical fluid carbon dioxide at 2,900 psi and 65°C containing varying concentrations of tributyl phosphate (TBP) and thenoyltrifluoroacetone (TTA). A single 45 minute SFE with 2.7 mol% TBP and 3.2 mol% TTA provided as much as 88% " 6.0 extraction of americium and 69% " 5.0 extraction of plutonium. Use of 5.3 mol% TBP with 6.8 mol% of the more acidic beta-diketone hexafluoroacetylacetone (HFA) provided 95% " 3.0 extraction of americium and 83% " 5.0 extraction of plutonium in a single 45 minute SFE at 3,750 psi and 95°C. Sequential chemical extraction techniques were used to chemically characterize soil partitioning of plutonium and americium in pre-SFE soil samples. Sequential chemical extraction techniques demonstrated that spiked plutonium resides primarily (76.6%) in the sesquioxide fraction with minor amounts being absorbed by the oxidizable fraction (10.6%) and residual fractions (12.8%). Post-SFE soils subjected to sequential chemical extraction characterization demonstrated that 97% of the oxidizable, 78% of the sesquioxide and 80% of the residual plutonium could be removed using SFE. These preliminary results show that SFE may be an effective solvent extraction technique for removal of actinide contaminants from soil.

Download or read book Fluid Dynamic Effects on Precision Cleaning with Supercritical Fluids written by and published by . This book was released on 1994 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: Pacific Northwest Laboratory staff have assembled a small supercritical fluids parts cleaning test stand to characterize how system dynamics affect the efficacy of precision cleaning with supercritical carbon dioxide. A soiled stainless steel coupon, loaded into a ''Berty'' autoclave, was used to investigate how changes in system turbulence and solvent temperature influenced the removal of test dopants. A pulsed laser beam through a fiber optic was used to investigate real-time contaminant removal. Test data show that cleaning efficiency is a function of system agitation, solvent density, and temperature. These data also show that high levels of cleaning efficiency can generally be achieved with high levels of system agitation at relatively low solvent densities and temperatures. Agitation levels, temperatures, and densities needed for optimal cleaning are largely contaminant dependent. Using proper system conditions, the levels of cleanliness achieved with supercritical carbon dioxide compare favorably with conventional precision cleaning methods. Additional research is currently being conducted to generalize the relationship between cleaning performance and parameters such as contaminant solubilities, mass transfer rates, and solvent agitation. These correlations can be used to optimize cleaning performance, system design, and time and energy consumption for particular parts cleaning applications.

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 704 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Government Reports Annual Index written by and published by . This book was released on 1994 with total page 1372 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Hydrometallurgy written by Suresh Bhargava and published by MDPI. This book was released on 2018-07-02 with total page 335 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a printed edition of the Special Issue "Hydrometallurgy" that was published in Metals

Download or read book Demonstration of a Liquid Carbon Dioxide Process for Cleaning Metal Parts written by and published by . This book was released on 1996 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Handbook for Critical Cleaning written by Barbara Kanegsberg and published by CRC Press. This book was released on 2000-12-26 with total page 687 pages. Available in PDF, EPUB and Kindle. Book excerpt: With all the cleaning approaches available, how do you choose which one is best for your needs? Components manufacturers wonder which will provide a competitive edge. Chemists and engineers worry about the effect of any process modification on a critical component or on the stability of an irreplaceable antique. There is no silver bullet, n