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Sample records for molten salt media

  1. Molten salt electrolyte separator

    DOEpatents

    Kaun, Thomas D.

    1996-01-01

    A molten salt electrolyte/separator for battery and related electrochemical systems including a molten electrolyte composition and an electrically insulating solid salt dispersed therein, to provide improved performance at higher current densities and alternate designs through ease of fabrication.

  2. Molten salt technology

    SciTech Connect

    Lovering, D.G.

    1982-01-01

    In this volume, the historical background, scope, problems, economics, and future applications of molten salt technologies are discussed. Topics presented include molten salts in primary production of aluminum, general principles and handling and safety of the alkali metals, first-row transition metals, group VIII metals and B-group elements, solution electrochemistry, transport phenomena, corrosion in different molten salts, cells with molten salt electrolytes and reactants, fuel cell design, hydrocracking and liquefaction, heat storage in phase change materials, and nuclear technologies.

  3. Molecular modelling: An analytical tool with a predictive character for investigating reactivity in molten salt media.

    NASA Astrophysics Data System (ADS)

    Picard, Gérard S.; Bouyer, Frédéric C.

    1995-04-01

    Possibilities offered by Molecular Modelling for studying homogeneous and interfacial processes and reactions in melts are discussed. A few typical illustrative examples covering some of the main research fields of molten salt chemistry and electrochemistry are given. Quantum chemistry calculations, Molecular Dynamics and Monte Carlo methods appear to be fantastic tools for analyzing and predicting reactivity in molten salts.

  4. Molten salt electrolyte separator

    DOEpatents

    Kaun, T.D.

    1996-07-09

    The patent describes a molten salt electrolyte/separator for battery and related electrochemical systems including a molten electrolyte composition and an electrically insulating solid salt dispersed therein, to provide improved performance at higher current densities and alternate designs through ease of fabrication. 5 figs.

  5. Detection and removal of molten salts from molten aluminum alloys

    SciTech Connect

    K. Butcher; D. Smith; C. L. Lin; L. Aubrey

    1999-08-02

    Molten salts are one source of inclusions and defects in aluminum ingots and cast shapes. A selective adsorption media was used to remove these inclusions and a device for detection of molten salts was tested. This set of experiments is described and the results are presented and analyzed.

  6. Electrocrystallization of uranium oxides from molten salt media with adjustable oxygen coefficient value

    SciTech Connect

    Smolenski, V.V.; Bovet, A.L.; Komarov, V.E.

    1993-12-31

    In order to determine the conditions necessary to produce uranium oxides with the preset oxygen coefficient value by electrolyzing salt electrolytes, we have investigated the chemical and electrochemical behavior of the oxychloride uranium compounds with various valancies in molten alkali chlorides. The electrochemical production conditions for uranium dioxide of the pre-stoichiometric composition were determined.

  7. Molten salt electrochemistry

    SciTech Connect

    Gallegos, U.F.; Williamson, M.A.

    1997-12-31

    The objective of this work is to develop preparation and clean-up processes for the fuel and carrier salt used in the Los Alamos Accelerator-Driven Transmutation Technology molten salt nuclear system. The front-end or fuel preparation process focuses on the removal of fission products, uranium, and zirconium from spent nuclear fuel by utilizing electrochemical methods. The same method provide the separation of the transition metal fission products at the back end of the fuel cycle. Molten salts provide a natural medium for the separation of actinides and fission products from one another because they are robust, radiation resistant solvents that can be recycled. The presentation will describe the design of the electrochemistry system, the method used for salt purification, and results of preliminary experiments.

  8. Molten salt techniques. Volume 3

    SciTech Connect

    Lovering, D.G.; Gale, R.J.

    1987-01-01

    This collection of five papers on molten salts deals with the following specific topics: the actinides and their salts, including their availability along with techniques and equipment for their handling, preparation, purification, and physical property measurement; cryolite systems and methods for their handling, preparation, and thermodynamic and physicochemical property assessment, as well as the use of electrodes in molten cryolite; the theory, construction, and application of reference electrodes for molten salt electrolytes; neutron diffraction in molten salt systems including isotope exchange methods for sample preparation; and dry boxes and inert atmosphere techniques for molten salt handling and analysis.

  9. Molten salt lithium cells

    DOEpatents

    Raistrick, I.D.; Poris, J.; Huggins, R.A.

    1980-07-18

    Lithium-based cells are promising for applications such as electric vehicles and load-leveling for power plants since lithium is very electropositive and light weight. One type of lithium-based cell utilizes a molten salt electrolyte and is operated in the temperature range of about 400 to 500/sup 0/C. Such high temperature operation accelerates corrosion problems and a substantial amount of energy is lost through heat transfer. The present invention provides an electrochemical cell which may be operated at temperatures between about 100 to 170/sup 0/C. The cell is comprised of an electrolyte, which preferably includes lithium nitrate, and a lithium or lithium alloy electrode.

  10. Molten salt lithium cells

    DOEpatents

    Raistrick, Ian D.; Poris, Jaime; Huggins, Robert A.

    1983-01-01

    Lithium-based cells are promising for applications such as electric vehicles and load-leveling for power plants since lithium is very electropositive and light weight. One type of lithium-based cell utilizes a molten salt electrolyte and is operated in the temperature range of about 400.degree.-500.degree. C. Such high temperature operation accelerates corrosion problems and a substantial amount of energy is lost through heat transfer. The present invention provides an electrochemical cell (10) which may be operated at temperatures between about 100.degree.-170.degree. C. Cell (10) comprises an electrolyte (16), which preferably includes lithium nitrate, and a lithium or lithium alloy electrode (12).

  11. Molten salt lithium cells

    DOEpatents

    Raistrick, Ian D.; Poris, Jaime; Huggins, Robert A.

    1982-02-09

    Lithium-based cells are promising for applications such as electric vehicles and load-leveling for power plants since lithium is very electropositive and light weight. One type of lithium-based cell utilizes a molten salt electrolyte and is operated in the temperature range of about 400.degree.-500.degree. C. Such high temperature operation accelerates corrosion problems and a substantial amount of energy is lost through heat transfer. The present invention provides an electrochemical cell (10) which may be operated at temperatures between about 100.degree.-170.degree. C. Cell (10) comprises an electrolyte (16), which preferably includes lithium nitrate, and a lithium or lithium alloy electrode (12).

  12. Molten fluoride fuel salt chemistry

    NASA Astrophysics Data System (ADS)

    Toth, L. M.; Del Cul, G. D.; Dai, S.; Metcalf, D. H.

    1995-01-01

    The chemistry of molten fluorides is traced from their development as fuels in the Molten Salt Reactor Experiment with important factors in their selection being discussed. Key chemical characteristics such as solubility, redox behavior, and chemical activity are explained as they relate to the behavior of molten fluoride fuel systems. Development requirements for fitting the current state of the chemistry to modern nuclear fuel system are described. It is concluded that while much is known about molten fluoride behavior which can be used effectively to reduce the amount of development required for future systems, some significant molten salt chemical questions must still be addressed.

  13. Molten fluoride fuel salt chemistry

    NASA Astrophysics Data System (ADS)

    Toth, L. M.; Delcul, G. D.; Dai, S.; Metcalf, D. H.

    The chemistry of molten fluorides is traced from their development as fuels in the Molten Salt Reactor Experiment with important factors in their selection being discussed. Key chemical characteristics such as solubility, redox behavior, and chemical activity are explained as they relate to the behavior of molten fluoride fuel systems. Development requirements for fitting the current state of the chemistry to modern nuclear fuel system are described. It is concluded that while much is known about molten fluoride behavior which can be used effectively to reduce the amount of development required for future systems, some significant molten salt chemical questions must still be addressed.

  14. Molten salt spectroelectrochemistry: recent developments

    SciTech Connect

    Mamantov, G.; Chapman, D.M.; Harward, B.L.; Klatt, L.N.; Smith, G.P.

    1985-01-01

    Molten salt spectroelectrochemistry will be reviewed in this paper. UV-visible transmission, infrared reflectance, resonance and normal Raman, and electron spin resonance spectroelectrochemistry have been used for molten salt studies. Two recent applications of uv-visible transmission spectroelectrochemistry to studies of organic and inorganic solutes in molten SbCl/sub 3/-AlCl/sub 3/-N-(1-butyl)pyridinium chloride and AlCl/sub 3/-NaCl will be described.

  15. Chemistry and technology of Molten Salt Reactors - history and perspectives

    NASA Astrophysics Data System (ADS)

    Uhlíř, Jan

    2007-01-01

    Molten Salt Reactors represent one of promising future nuclear reactor concept included also in the Generation IV reactors family. This reactor type is distinguished by an extraordinarily close connection between the reactor physics and chemical technology, which is given by the specific features of the chemical form of fuel, representing by molten fluoride salt and circulating through the reactor core and also by the requirements of continuous 'on-line' reprocessing of the spent fuel. The history of Molten Salt Reactors reaches the period of fifties and sixties, when the first experimental Molten Salt Reactors were constructed and tested in ORNL (US). Several molten salt techniques dedicated to fresh molten salt fuel processing and spent fuel reprocessing were studied and developed in those days. Today, after nearly thirty years of discontinuance, a renewed interest in the Molten Salt Reactor technology is observed. Current experimental R&D activities in the area of Molten Salt Reactor technology are realized by a relatively small number of research institutions mainly in the EU, Russia and USA. The main effort is directed primarily to the development of separation processes suitable for the molten salt fuel processing and reprocessing technology. The techniques under development are molten salt/liquid metal extraction processes, electrochemical separation processes from the molten salt media, fused salt volatilization techniques and gas extraction from the molten salt medium.

  16. Molten salt techniques. Volume 2

    SciTech Connect

    Gale, R.J.; Lovering, D.G.

    1984-01-01

    This is the second volume in a series addressing the practical aspects of molten salt research. The book covers experiments with alkali metal carbonates, oxides, silicates, phosphates and borates. Additional sections cover molten salt spectroscopy, electrochemistry, and automated admittance spectroscopy of the semiconductor/molten salt electrolyte interface. Particular emphasis is given to safety considerations for working with these high temperature, often corrosive materials. Planning of experiments is of interest, and several experiments are described. Attention is given to the selection of materials to be used in this research, including the purification of the salts themselves, and the requirements for laboratory apparatus.

  17. Beryllium Interactions in Molten Salts

    SciTech Connect

    G. S. Smolik; M. F. Simpson; P. J. Pinhero; M. Hara; Y. Hatano; R. A. Anderl; J. P. Sharpe; T. Terai; S. Tanaka; D. A. Petti; D.-K. Sze

    2006-01-01

    Molten flibe (2LiF·BeF2) is a candidate as a cooling and tritium breeding media for future fusion power plants. Neutron interactions with the salt will produce tritium and release excess free fluorine ions. Beryllium metal has been demonstrated as an effective redox control agent to prevent free fluorine, or HF species, from reacting with structural metal components. The extent and rate of beryllium solubility in a pot design experiments to suppress continuously supplied hydrogen fluoride gas has been measured and modeled[ ]. This paper presents evidence of beryllium loss from specimens, a dependence of the loss upon bi-metal coupling, i.e., galvanic effect, and the partitioning of the beryllium to the salt and container materials. Various posttest investigative methods, viz., scanning electron microscopy (SEM), Auger electron spectroscopy (AES) and x-ray photoelectron spectroscopy (XPS) were used to explore this behavior.

  18. Batteries using molten salt electrolyte

    DOEpatents

    Guidotti, Ronald A.

    2003-04-08

    An electrolyte system suitable for a molten salt electrolyte battery is described where the electrolyte system is a molten nitrate compound, an organic compound containing dissolved lithium salts, or a 1-ethyl-3-methlyimidazolium salt with a melting temperature between approximately room temperature and approximately 250.degree. C. With a compatible anode and cathode, the electrolyte system is utilized in a battery as a power source suitable for oil/gas borehole applications and in heat sensors.

  19. Cathode for molten salt batteries

    DOEpatents

    Mamantov, Gleb; Marassi, Roberto

    1977-01-01

    A molten salt electrochemical system for battery applications comprises tetravalent sulfur as the active cathode material with a molten chloroaluminate solvent comprising a mixture of AlCl.sub.3 and MCl having a molar ratio of AlCl.sub.3 /MCl from greater than 50.0/50.0 to 80/20.

  20. Molten fluoride fuel salt chemistry

    NASA Astrophysics Data System (ADS)

    Toth, L. M.; Del Cul, G. D.; Dai, S.; Metcalf, D. H.

    1995-09-01

    The chemistry of molten fluorides is traced from their development as fuels in the Molten Salt Reactor Experiment with important factors in their selection being discussed. Key chemical characteristics such as solubility, redox behavior, and chemical activity are explained as they relate to the behavior of molten fluoride fuel systems. Fission product behavior is described along with processing experience. Development requirements for fitting the current state of the chemistry to modern nuclear fuel system are described. It is concluded that while much is known about molten fluoride behavior, processing and recycle of the fuel components is a necessary factor if future systems are to be established.

  1. Molten fluoride fuel salt chemistry

    SciTech Connect

    Toth, L.M.; Del Cul, G.D.; Dai, S.; Metcalf, D.H.

    1994-09-01

    The chemistry of molten fluorides is traced from their development as fuels in the Molten Salt Reactor Experiment with important factors in their selection being discussed. Key chemical characteristics such as solubility, redox behavior, and chemical activity are explained as they relate to the behavior of molten fluoride fuel systems. Fission product behavior is described along with processing experience. Development requirements for fitting the current state of the chemistry to modern nuclear fuel system are described. It is concluded that while much is known about molten fluoride behavior, processing and recycle of the fuel components is a necessary factor if future systems are to be established.

  2. The molten salt reactor adventure

    SciTech Connect

    MacPherson, H.G.

    1985-08-01

    A personal history of the development of molten salt reactors in the United States is presented. The initial goal was an aircraft propulsion reactor, and a molten fluoride-fueled Aircraft Reactor Experiment was operated at Oak Ridge National Laboratory in 1954. In 1956, the objective shifted to civilian nuclear power, and reactor concepts were developed using a circulating UF4-ThF4 fuel, graphite moderator, and Hastelloy N pressure boundary. The program culminated in the successful operation of the Molten Salt Reactor Experiment in 1965 to 1969. By then the Atomic Energy Commission's goals had shifted to breeder development; the molten salt program supported on-site reprocessing development and study of various reactor arrangements that had potential to breed. Some commercial and foreign interest contributed to the program which, however, was terminated by the government in 1976. The current status of the technology and prospects for revived interest are summarized.

  3. Multipass apparatus for molten salt spectroelectrochemical experiments

    SciTech Connect

    Harward, B.L.; Klatt, L.N.; Mamantov, G.

    1985-07-01

    Although various spectroelectrochemical methods have been applied to studies in molten salt media, the development of techniques and apparatus to improve the optical sensitivity of such measurements is nonexistent. The corrosive nature, moisture sensitivity, and elevated temperatures associated with molten salts often preclude the use of sophisticated optical systems and fragile cell components. A simple apparatus is described for enhancement of the optical signal in molten salt spectroelectrochemical experiments. In this method, the optical beam is redirected through an OTE (optically transparent electrode) several times by a mirror assembly positioned outside the thin-layer cell. The gain in optical sensitivity is defined as the ratio of the response for n passes to that for a single pass. 29 references, 4 figures.

  4. Molten salt reactors - safety options galore

    SciTech Connect

    Gat, U.; Dodds, H.L.

    1997-03-01

    Safety features and attributes of molten salt reactors (MSR) are described. The unique features of fluid fuel reactors of on-line continuous processing and the ability for so-called external cooling result in simple and safe designs with low excess reactivity, low fission product inventory, and small source term. These, in turn, make a criticality accident unlikely and reduce the severity of a loss of coolant to where they are no longer severe accidents. A melt down is not an accident for a reactor that uses molten fuel. The molten salts are stable, non-reactive and efficient heat transfer media that operate at high temperatures at low pressures and are highly compatible with selected structural materials. All these features reduce the accident plethora. Freeze valves can be used for added safety. An ultimate safe reactor (U.S.R) is described with safety features that are passive, inherent and non-tamperable (PINT).

  5. 13. VIEW OF THE MOLTEN SALT EXTRACTION LINE. THE MOLTEN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    13. VIEW OF THE MOLTEN SALT EXTRACTION LINE. THE MOLTEN SALT EXTRACTION PROCESS WAS USED TO PURIFY PLUTONIUM BY REMOVING AMERICIUM, A DECAY BY-PRODUCT OF PLUTONIUM. (1/98) - Rocky Flats Plant, Plutonium Fabrication, Central section of Plant, Golden, Jefferson County, CO

  6. Metals Electroprocessing in Molten Salts

    NASA Technical Reports Server (NTRS)

    Sadoway, D. R.

    1985-01-01

    The present study seeks to explain the poor quality of solid electrodeposits in molten salts through a consideration of the effects of fluid flow of the electrolyte. Transparent cells allow observation of electrolyte circulation by a laser schlieren optical technique during the electrodeposition of solid zinc from the molten salt electrolyte, ZnCl2 - LiCl-KCl. Experimental variables are current, density, electrolyte composition, and cell geometry. Based on the results of earlier electrodeposition studies as well as reports in the literature, these parameters are identified as having the primary influence on cell performance and deposit quality. Experiments are conducted to measure the fluid flow patterns and the electrochemical cell characteristics, and to correlate this information with the morphology of the solid electrodeposit produced. Specifically, cell voltage, cell current, characteristic time for dendrite evolution, and dendrite growth directions are noted. Their relationship to electrolyte flow patterns and the morphology of the resulting electrodeposit are derived. Results to date indicate that laser schlieren imaging is capable of revealing fluid flow patterns in a molten salt electrolyte.

  7. Cathodic polarization of sulfur in molten salts

    SciTech Connect

    Demidov, A.I.; Dukhanin, G.P.; Morachevskii, A.G.; Simikov, I.A.

    1985-12-01

    As a continuation of studies on the electrochemical behavior of sulfur in molten salts, this paper reports work on the determination of lithium and potassium ion discharge potentials at a sulfur electrode during cathodic polarization in molten LiNO/sub 3/-LiNO/sub 2/-LiOH and LiNO/sub 3/-KNO/sub 3/ at 423/sup 0/K as well as in molten LiF-LiCl-LiI and LiC1-KC1 ay 650/sup 0/K. The studies were carried out by taking polarization curves in a pulsed galvanostatic mode using a three-electrode electrochemical cell. The sulfur electrode floating on the molten salt electrolyte contacted a 5-mm-diameter graphite rod that also touched the molten salt. The same patterns were observed for the cathodic polarization of sulfur in both halide and nitrate melts.

  8. Molten salt destruction of energetic waste materials

    DOEpatents

    Brummond, W.A.; Upadhye, R.S.; Pruneda, C.O.

    1995-07-18

    A molten salt destruction process is used to treat and destroy energetic waste materials such as high explosives, propellants, and rocket fuels. The energetic material is pre-blended with a solid or fluid diluent in safe proportions to form a fluid fuel mixture. The fuel mixture is rapidly introduced into a high temperature molten salt bath. A stream of molten salt is removed from the vessel and may be recycled as diluent. Additionally, the molten salt stream may be pumped from the reactor, circulated outside the reactor for further processing, and delivered back into the reactor or cooled and circulated to the feed delivery system to further dilute the fuel mixture entering the reactor. 4 figs.

  9. Molten salt destruction of energetic waste materials

    DOEpatents

    Brummond, William A.; Upadhye, Ravindra S.; Pruneda, Cesar O.

    1995-01-01

    A molten salt destruction process is used to treat and destroy energetic waste materials such as high explosives, propellants, and rocket fuels. The energetic material is pre-blended with a solid or fluid diluent in safe proportions to form a fluid fuel mixture. The fuel mixture is rapidly introduced into a high temperature molten salt bath. A stream of molten salt is removed from the vessel and may be recycled as diluent. Additionally, the molten salt stream may be pumped from the reactor, circulated outside the reactor for further processing, and delivered back into the reactor or cooled and circulated to the feed delivery system to further dilute the fuel mixture entering the reactor.

  10. The behavior of water in molten salts

    SciTech Connect

    White, S.H.; Twardoch, U.M.

    1983-05-01

    The differing behavior of water equilibrated with three separate molten salt solvents is discussed with respect to the chemistry of the solutions and the electroreductive mechanisms at gold electrodes.

  11. Corrosion of Mullite by Molten Salts

    NASA Technical Reports Server (NTRS)

    Jacobson, Nathan S.; Lee, Kang N.; Yoshio, Tetsuo

    1996-01-01

    The interaction of molten salts of different Na2O activities and mullite is examined with furnace and burner tests. The more-acidic molten salts form small amounts of Al2O3; the more-basic molten salts form various Na2O-Al2O3-SiO2 compounds. The results are interpreted using the Na2O-Al203-SiO2 ternary phase diagram, and some possible diffusion paths are discussed. The generally higher melting points of Na2O-Al2O3-SiO2 compounds lead to better behavior of mullite in molten salts, as compared to SiO2-protected ceramics such as SiC. Mullite-coated SiC is discussed, and the corrosion behavior is evaluated.

  12. Chemical Safety: Molten Salt Baths Cited as Lab Hazards.

    ERIC Educational Resources Information Center

    Baum, Rudy

    1982-01-01

    Discusses danger of explosions with molten salts baths, commonly used as heat-transfer media. One such explosion involved use of a bath containing 3-lb sodium nitrite and 1-lb potassium thiocyanate. Although most commercially available mixtures for heat transfer contain oxidizers, a reducer (thiocyanate) was included which possibly triggered the…

  13. Modelisation of the SECMin molten salts environment

    NASA Astrophysics Data System (ADS)

    Lucas, M.; Slim, C.; Delpech, S.; di Caprio, D.; Stafiej, J.

    2014-06-01

    We develop a cellular automata modelisation of SECM experiments to study corrosion in molten salt media for generation IV nuclear reactors. The electrodes used in these experiments are cylindrical glass tips with a coaxial metal wire inside. As the result of simulations we obtain the current approach curves of the electrodes with geometries characterized by several values of the ratios of glass to metal area at the tip. We compare these results with predictions of the known analytic expressions, solutions of partial differential equations for flat uniform geometry of the substrate. We present the results for other, more complicated substrate surface geometries e. g. regular saw modulated surface, surface obtained by Eden model process, ...

  14. Extracting information from the molten salt database

    NASA Astrophysics Data System (ADS)

    Gadzuric, Slobodan; Suh, Changwon; Gaune-Escard, Marcelle; Rajan, Krishna

    2006-12-01

    Molten salt technology is a catchall phrase that includes some very diverse technologies; electrochemistry, heat transfer, chemical oxidation/reduction baths, and nuclear reactors. All of these technologies are linked by the general characteristics of molten salts that can function as solvents, have good heat-transfer characteristics, function like a fluid, can attain very high temperatures, can conduct electricity, and also may have chemical catalytic properties. The Janz molten salt database is the most comprehensive compilation of property data about molten salts available today and is widely used for both fundamental and applied purposes. Databases are traditionally viewed as “static” documents that are used in a “search and retrieval” mode. These static data can be transformed by informatics and data mining tools into a dynamic dataset for analysis of the properties of the, materials and for making predictions. While this approch has been successful in the chemical and biochemical sciences in searching for and establishing structure-property relationships, it is not widely used in the materials science community. Because the design of the original molten salt database was not oriented toward this informatics goal, it was essential to evaluate this dataset in terms of data mining standards. Two techniques were used—a projection (principal components analysis (PCA)) and a predictive method (partial least squares (PLS))—in conjunction with fundamental knowledge acquired from the long-term practice of molten salt chemistry.

  15. Molten salt chemistry: An introduction and selected applications

    SciTech Connect

    Mamantov, G.; Marassi, R.

    1987-01-01

    The major fundamental topics covered are the structure of melts, thermodynamics of molten salt mixtures, theoretical and experimental studies of transport processes, metal-metal salt solutions, solvent properties of melt systems, acid-base effects in molten salt chemistry, electronic absorption, vibrational and nuclear magnetic resonance spectroscopy of melt systems, electrochemistry and electroanalytical chemistry in molten salts, and organic chemistry in molten salts. The applied aspects include the chemistry of aluminium production, electrodeposition using molten salts, and molten salt batteries and fuel cells.

  16. Molten salts and nuclear energy production

    NASA Astrophysics Data System (ADS)

    Le Brun, Christian

    2007-01-01

    Molten salts (fluorides or chlorides) were considered near the beginning of research into nuclear energy production. This was initially due to their advantageous physical and chemical properties: good heat transfer capacity, radiation insensitivity, high boiling point, wide range solubility for actinides. In addition it was realised that molten salts could be used in numerous situations: high temperature heat transfer, core coolants with solid fuels, liquid fuel in a molten salt reactor, solvents for spent nuclear solid fuel in the case of pyro-reprocessing and coolant and tritium production in the case of fusion. Molten salt reactors, one of the six innovative concepts chosen by the Generation IV international forum, are particularly interesting for use as either waste incinerators or thorium cycle systems. As the neutron balance in the thorium cycle is very tight, the possibility to perform online extraction of some fission product poisons from the salt is very attractive. In this article the most important questions that must be addressed to demonstrate the feasibility of molten salt reactor will be reviewed.

  17. Molten salts and energy related materials.

    PubMed

    Fray, Derek

    2016-08-15

    Molten salts have been known for centuries and have been used for the extraction of aluminium for over one hundred years and as high temperature fluxes in metal processing. This and other molten salt routes have gradually become more energy efficient and less polluting, but there have been few major breakthroughs. This paper will explore some recent innovations that could lead to substantial reductions in the energy consumed in metal production and in carbon dioxide production. Another way that molten salts can contribute to an energy efficient world is by creating better high temperature fuel cells and novel high temperature batteries, or by acting as the medium that can create novel materials that can find applications in high energy batteries and other energy saving devices, such as capacitors. Carbonate melts can be used to absorb carbon dioxide, which can be converted into C, CO and carbon nanoparticles. Molten salts can also be used to create black silicon that can absorb more sunlight over a wider range of wavelengths. Overall, there are many opportunities to explore for molten salts to play in an efficient, low carbon world. PMID:27276650

  18. Molten salts and energy related materials.

    PubMed

    Fray, Derek

    2016-08-15

    Molten salts have been known for centuries and have been used for the extraction of aluminium for over one hundred years and as high temperature fluxes in metal processing. This and other molten salt routes have gradually become more energy efficient and less polluting, but there have been few major breakthroughs. This paper will explore some recent innovations that could lead to substantial reductions in the energy consumed in metal production and in carbon dioxide production. Another way that molten salts can contribute to an energy efficient world is by creating better high temperature fuel cells and novel high temperature batteries, or by acting as the medium that can create novel materials that can find applications in high energy batteries and other energy saving devices, such as capacitors. Carbonate melts can be used to absorb carbon dioxide, which can be converted into C, CO and carbon nanoparticles. Molten salts can also be used to create black silicon that can absorb more sunlight over a wider range of wavelengths. Overall, there are many opportunities to explore for molten salts to play in an efficient, low carbon world.

  19. Studies of metals electroprocessing in molten salts

    NASA Technical Reports Server (NTRS)

    Sadoway, D. R.

    1982-01-01

    Fluid flow patterns in molten salt electrolytes were observed in order to determine how mass transport affects the morphology of the metal deposit. Studies conducted on the same metal, both in aqueous electrolytes in which coherent solid electrodeposits are produced, as well as in transparent molten salt electrolytes are described. Process variables such as current density and composition of the electrolyte are adjusted to change the morphology of the electrodeposit and, thus, to permit the study of the nature of electrolyte flow in relation to the quality of the electrodeposit.

  20. Cathodes for molten-salt batteries

    NASA Technical Reports Server (NTRS)

    Argade, Shyam D.

    1993-01-01

    Viewgraphs of the discussion on cathodes for molten-salt batteries are presented. For the cathode reactions in molten-salt cells, chlorine-based and sulfur-based cathodes reactants have relatively high exchange current densities. Sulfur-based cathodes, metal sulfides, and disulfides have been extensively investigated. Primary thermal batteries of the Li-alloy/FeS2 variety have been available for a number of years. Chlorine based rechargable cathodes were investigated for the pulse power application. A brief introduction is followed by the experimental aspects of research, and the results obtained. Performance projections to the battery system level are discussed and the presentation is summarized with conclusions.

  1. Cathodes for molten-salt batteries

    NASA Astrophysics Data System (ADS)

    Argade, Shyam D.

    1993-02-01

    Viewgraphs of the discussion on cathodes for molten-salt batteries are presented. For the cathode reactions in molten-salt cells, chlorine-based and sulfur-based cathodes reactants have relatively high exchange current densities. Sulfur-based cathodes, metal sulfides, and disulfides have been extensively investigated. Primary thermal batteries of the Li-alloy/FeS2 variety have been available for a number of years. Chlorine based rechargable cathodes were investigated for the pulse power application. A brief introduction is followed by the experimental aspects of research, and the results obtained. Performance projections to the battery system level are discussed and the presentation is summarized with conclusions.

  2. Advances in molten salt chemistry: Vol. 4

    SciTech Connect

    Mamautov, G.; Braunstein, J.

    1981-01-01

    This book presents information on the following topics: electronic properties of solutions of liquid metals and ionic melts; metal-metal halide, metal-chalcogen, and metal-metal solutions; metallic models; the use of high pressure in the study of molten salts; the purpose of high pressure experimentation; melting point curves and phase diagrams; compressibilities and equations of state; electrical conductivity measurements; physical chemistry and electrochemistry of alkali carbonate melts; equilibrium properties of molten carbonates; electrochemical characteristics and corrosion; stability of ceramics; some new molten salt electrolytic processes; sodium metal production by the use of a beta-alumina diaphragm; recovery of metallic sodium or caustic soda and sulfur from flue gas; high temperature electrolysis of water; and LiCl electrolysis by the use of a bipolar liquid metal electrode.

  3. Hybrid Molten Salt Reactor (HMSR) System Study

    SciTech Connect

    Woolley, Robert D; Miller, Laurence F

    2014-04-01

    Can the hybrid system combination of (1) a critical fission Molten Salt Reactor (MSR) having a thermal spectrum and a high Conversion Ratio (CR) with (2) an external source of high energy neutrons provide an attractive solution to the world's expanding demand for energy? The present study indicates the answer is an emphatic yes.

  4. Accelerators for Subcritical Molten-Salt Reactors

    SciTech Connect

    Johnson, Roland

    2011-08-03

    Accelerator parameters for subcritical reactors have usually been based on using solid nuclear fuel much like that used in all operating critical reactors as well as the thorium burning accelerator-driven energy amplifier proposed by Rubbia et al. An attractive alternative reactor design that used molten salt fuel was experimentally studied at ORNL in the 1960s, where a critical molten salt reactor was successfully operated using enriched U235 or U233 tetrafluoride fuels. These experiments give confidence that an accelerator-driven subcritical molten salt reactor will work better than conventional reactors, having better efficiency due to their higher operating temperature, having the inherent safety of subcritical operation, and having constant purging of volatile radioactive elements to eliminate their accumulation and potential accidental release in dangerous amounts. Moreover, the requirements to drive a molten salt reactor can be considerably relaxed compared to a solid fuel reactor, especially regarding accelerator reliability and spallation neutron targetry, to the point that much of the required technology exists today. It is proposed that Project-X be developed into a prototype commercial machine to produce energy for the world by, for example, burning thorium in India and nuclear waste from conventional reactors in the USA.

  5. Al/Cl2 molten salt battery

    NASA Technical Reports Server (NTRS)

    Giner, J.

    1972-01-01

    Molten salt battery has been developed with theoretical energy density of 5.2 j/kg (650 W-h/lb). Battery, which operates at 150 C, can be used in primary mode or as rechargeable battery. Battery has aluminum anode and chlorine cathode. Electrolyte is mixture of AlCl3, NaCl, and some alkali metal halide such as KCl.

  6. Thermal Characterization of Molten Salt Systems

    SciTech Connect

    Toni Y. Gutknecht; Guy L. Fredrickson

    2011-09-01

    The phase stability of molten salts in an electrorefiner (ER) may be adversely affected by the buildup of sodium, fission products, and transuranics in the electrolyte. Potential situations that need to be avoided are the following: (1) salt freezing due to an unexpected change in the liquidus temperature, (2) phase separation or non-homogeneity of the molten salt due to the precipitation of solids or formation of immiscible liquids, and (3) any mechanism that can result in the separation and concentration of fissile elements from the molten salt. Any of these situations would result in an off-normal condition outside the established safety basis for electrorefiner (ER) operations. The stability (and homogeneity) of the phases can potentially be monitored through the thermal characterization of the salts, which can be a function of impurity concentration. This report describes the experimental results of typical salts compositions, which consist of chlorides of potassium, lithium, strontium, samarium, praseodymium, lanthanum, barium, cerium, cesium, neodymium, sodium and gadolinium chlorides as a surrogate for both uranium and plutonium, used for the processing of used nuclear fuels.

  7. Heat transfer behavior of molten nitrate salt

    NASA Astrophysics Data System (ADS)

    Das, Apurba K.; Clark, Michael M.; Teigen, Bard C.; Fiveland, Woodrow A.; Anderson, Mark H.

    2016-05-01

    The usage of molten nitrate salt as heat transfer fluid and thermal storage medium decouples the generation of electricity from the variable nature of the solar resource, allowing CSP plants to avoid curtailment and match production with demand. This however brings some unique challenges for the design of the molten salt central receiver (MSCR). An aspect critical to the use of molten nitrate (60wt%/40wt% - NaNO3/KNO3) salt as heat transfer fluid in the MSCR is to understand its heat transfer behavior. Alstom collaborated with the University of Wisconsin to conduct a series of experiments and experimentally determined the heat transfer coefficients of molten nitrate salt up to high Reynolds number (Re > 2.0E5) and heat flux (q″ > 1000 kW/m2), conditions heretofore not reported in the literature. A cartridge heater instrumented with thermocouples was installed inside a stainless steel pipe to form an annular test section. The test section was installed in the molten salt flow loop at the University of Wisconsin facility, and operated over a range of test conditions to determine heat transfer data that covered the expected operating regime of a practical molten salt receiver. Heat transfer data were compared to widely accepted correlations found in heat transfer literature, including that of Gnielinski. At lower Reynolds number conditions, the results from this work concurred with the molten salt heat transfer data reported in literature and followed the aforementioned correlations. However, in the region of interest for practical receiver design, the correlations did not accurately model the experimentally determined heat transfer data. Two major effects were observed: (i) all other factors remaining constant, the Nusselt numbers gradually plateaued at higher Reynolds number; and (ii) at higher Reynolds number a positive interaction of heat flux on Nusselt number was noted. These effects are definitely not modeled by the existing correlations. In this paper a new

  8. Low temperature oxidation using support molten salt catalysts

    DOEpatents

    Weimer, Alan W.; Czerpak, Peter J.; Hilbert, Patrick M.

    2003-05-20

    Molten salt reactions are performed by supporting the molten salt on a particulate support and forming a fluidized bed of the supported salt particles. The method is particularly suitable for combusting hydrocarbon fuels at reduced temperatures, so that the formation NO.sub.x species is reduced. When certain preferred salts are used, such as alkali metal carbonates, sulfur and halide species can be captured by the molten salt, thereby reducing SO.sub.x and HCl emissions.

  9. Experimental studies of actinides in molten salts

    SciTech Connect

    Reavis, J.G.

    1985-06-01

    This review stresses techniques used in studies of molten salts containing multigram amounts of actinides exhibiting intense alpha activity but little or no penetrating gamma radiation. The preponderance of studies have used halides because oxygen-containing actinide compounds (other than oxides) are generally unstable at high temperatures. Topics discussed here include special enclosures, materials problems, preparation and purification of actinide elements and compounds, and measurements of various properties of the molten volts. Property measurements discussed are phase relationships, vapor pressure, density, viscosity, absorption spectra, electromotive force, and conductance. 188 refs., 17 figs., 6 tabs.

  10. Molten salt processing of mixed wastes with offgas condensation

    SciTech Connect

    Cooper, J.F.; Brummond, W.; Celeste, J.; Farmer, J.; Hoenig, C.; Krikorian, O.H.; Upadhye, R. ); Gay, R.L.; Stewart, A.; Yosim, S. . Energy Systems Group)

    1991-05-13

    We are developing an advanced process for treatment of mixed wastes in molten salt media at temperatures of 700--1000{degrees}C. Waste destruction has been demonstrated in a single stage oxidation process, with destruction efficiencies above 99.9999% for many waste categories. The molten salt provides a heat transfer medium, prevents thermal surges, and functions as an in situ scrubber to transform the acid-gas forming components of the waste into neutral salts and immobilizes potentially fugitive materials by a combination of particle wetting, encapsulation and chemical dissolution and solvation. Because the offgas is collected and assayed before release, and wastes containing toxic and radioactive materials are treated while immobilized in a condensed phase, the process avoids the problems sometimes associated with incineration processes. We are studying a potentially improved modification of this process, which treats oxidizable wastes in two stages: pyrolysis followed by catalyzed molten salt oxidation of the pyrolysis gases at ca. 700{degrees}C. 15 refs., 5 figs., 1 tab.

  11. Advanced heat exchanger development for molten salts

    DOE PAGESBeta

    Sabharwall, Piyush; Clark, Denis; Glazoff, Michael; Zheng, Guiqiu; Sridharan, Kumar; Anderson, Mark

    2014-12-01

    This study addresses present work concerned with advanced heat exchanger development for molten salt in nuclear and non nuclear thermal systems. The molten salt systems discussed herein use alloys, such as Hastelloy N and 242, which show corrosion resistance to molten salt at nominal operating temperatures up to 700°C. These alloys were diffusion welded, and the corresponding information is presented. Test specimens were prepared for exposing diffusion welds to molten salt environments. Hastelloy N and 242 were found to be weldable by diffusion welding, with ultimate tensile strengths about 90% of base metal values. Both diffusion welds and sheet materialmore » in Hastelloy N were corrosion tested in?58 mol% KF and 42 mol% ZrF4 at 650, 700, and 850°C for 200, 500, and 1,000 hours. Corrosion rates found were similar between welded and nonwelded materials, typically <10 mils per year. For materials of construction, nickel and alloys with dense nickel coatings are effectively inert to corrosion in fluorides, but not so in chlorides. Hence, additional testing of selected alloys for resistance to intergranular corrosion is needed, as is a determination of corrosion rate as a function of contaminant type and alloy composition with respect to chromium and carbon to better define the optimal chromium and carbon composition, independent of galvanic or differential solubility effects. Also presented is the division of the nuclear reactor and high temperature components per ASME standards, along with design requirements for a subcritical Rankine power cycle heat exchanger that has to overcome pressure difference of about 17 MPa.« less

  12. Advanced heat exchanger development for molten salts

    SciTech Connect

    Sabharwall, Piyush; Clark, Denis; Glazoff, Michael; Zheng, Guiqiu; Sridharan, Kumar; Anderson, Mark

    2014-12-01

    This study addresses present work concerned with advanced heat exchanger development for molten salt in nuclear and non nuclear thermal systems. The molten salt systems discussed herein use alloys, such as Hastelloy N and 242, which show corrosion resistance to molten salt at nominal operating temperatures up to 700°C. These alloys were diffusion welded, and the corresponding information is presented. Test specimens were prepared for exposing diffusion welds to molten salt environments. Hastelloy N and 242 were found to be weldable by diffusion welding, with ultimate tensile strengths about 90% of base metal values. Both diffusion welds and sheet material in Hastelloy N were corrosion tested in?58 mol% KF and 42 mol% ZrF4 at 650, 700, and 850°C for 200, 500, and 1,000 hours. Corrosion rates found were similar between welded and nonwelded materials, typically <10 mils per year. For materials of construction, nickel and alloys with dense nickel coatings are effectively inert to corrosion in fluorides, but not so in chlorides. Hence, additional testing of selected alloys for resistance to intergranular corrosion is needed, as is a determination of corrosion rate as a function of contaminant type and alloy composition with respect to chromium and carbon to better define the optimal chromium and carbon composition, independent of galvanic or differential solubility effects. Also presented is the division of the nuclear reactor and high temperature components per ASME standards, along with design requirements for a subcritical Rankine power cycle heat exchanger that has to overcome pressure difference of about 17 MPa.

  13. Molten salt battery having inorganic paper separator

    DOEpatents

    Walker, Jr., Robert D.

    1977-01-01

    A high temperature secondary battery comprises an anode containing lithium, a cathode containing a chalcogen or chalcogenide, a molten salt electrolyte containing lithium ions, and a separator comprising a porous sheet comprising a homogenous mixture of 2-20 wt.% chrysotile asbestos fibers and the remainder inorganic material non-reactive with the battery components. The non-reactive material is present as fibers, powder, or a fiber-powder mixture.

  14. Molten salt destruction of base hydrolysate

    SciTech Connect

    Watkins, B.E.; Kanna, R.L.; Chambers, R.D.; Upadhye, R.S.; Promeda, C.O.

    1996-10-01

    There is a great need for alternatives to open burn/open detonation of explosives and propellants from dismantled munitions. LANL has investigated the use of base hydrolysis for the demilitarization of explosives. Hydrolysates of Comp B, Octol, Tritonal, and PBXN-109 were processed in the pilot molten salt unit (in building 191). NOx and CO emissions were found to be low, except for CO from PBXN-109 processing. This report describes experimental results of the destruction of the base hydrolysates.

  15. Molten nitrate salt technology development status report

    SciTech Connect

    Carling, R.W.; Kramer, C.M.; Bradshaw, R.W.; Nissen, D.A.; Goods, S.H.; Mar, R.W.; Munford, J.W.; Karnowsky, M.M.; Biefeld, R.N.; Norem, N.J.

    1981-03-01

    Recognizing thermal energy storage as potentially critical to the successful commercialization of solar thermal power systems, the Department of Energy (DOE) has established a comprehensive and aggressive thermal energy storage technology development program. Of the fluids proposed for heat transfer and energy storage molten nitrate salts offer significant economic advantages. The nitrate salt of most interest is a binary mixture of NaNO/sub 3/ and KNO/sub 3/. Although nitrate/nitrite mixtures have been used for decades as heat transfer and heat treatment fluids the use has been at temperatures of about 450/sup 0/C and lower. In solar thermal power systems the salts will experience a temperature range of 350 to 600/sup 0/C. Because central receiver applications place more rigorous demands and higher temperatures on nitrate salts a comprehensive experimental program has been developed to examine what effects, if any, the new demands and temperatures have on the salts. The experiments include corrosion testing, environmental cracking of containment materials, and determinations of physical properties and decomposition mechanisms. This report details the work done at Sandia National Laboratories in each area listed. In addition, summaries of the experimental programs at Oak Ridge National Laboratory, the University of New York, EIC Laboratories, Inc., and the Norwegian Institute of Technology on molten nitrate salts are given. Also discussed is how the experimental programs will influence the near-term central receiver programs such as utility repowering/industrial retrofit and cogeneration. The report is designed to provide easy access to the latest information and data on molten NaNO/sub 3//KNO/sub 3/ for the designers and engineers of future central receiver projects.

  16. Organic waste processing using molten salt oxidation

    SciTech Connect

    Adamson, M. G., LLNL

    1998-03-01

    Molten Salt Oxidation (MSO) is a thermal means of oxidizing (destroying) the organic constituents of mixed wastes, hazardous wastes, and energetic materials while retaining inorganic and radioactive constituents in the salt. For this reason, MSO is considered a promising alternative to incineration for the treatment of a variety of organic wastes. The U. S. Department of Energy`s Office of Environmental Management (DOE/EM) is currently funding research that will identify alternatives to incineration for the treatment of organic-based mixed wastes. (Mixed wastes are defined as waste streams which have both hazardous and radioactive properties.) One such project is Lawrence Livermore National Laboratory`s Expedited Technology Demonstration of Molten Salt Oxidation (MSO). The goal of this project is to conduct an integrated demonstration of MSO, including off-gas and spent salt treatment, and the preparation of robust solid final forms. Livermore National Laboratory (LLNL) has constructed an integrated pilot-scale MSO treatment system in which tests and demonstrations are presently being performed under carefully controlled (experimental) conditions. The system consists of a MSO process vessel with dedicated off-gas treatment, a salt recycle system, feed preparation equipment, and equipment for preparing ceramic final waste forms. In this paper we describe the integrated system and discuss its capabilities as well as preliminary process demonstration data. A primary purpose of these demonstrations is to identify the most suitable waste streams and waste types for MSO treatment.

  17. Domestic Material Content in Molten-Salt Concentrating Solar Power Plants

    SciTech Connect

    Turchi, Craig; Kurup, Parthiv; Akar, Sertac; Flores, Francisco

    2015-08-26

    This study lists material composition data for two concentrating solar power (CSP) plant designs: a molten-salt power tower and a hypothetical parabolic trough plant, both of which employ a molten salt for the heat transfer fluid (HTF) and thermal storage media. The two designs have equivalent generating and thermal energy storage capacities. The material content of the saltHTF trough plant was approximately 25% lower than a comparably sized conventional oil-HTF parabolic trough plant. The significant reduction in oil, salt, metal, and insulation mass by switching to a salt-HTF design is expected to reduce the capital cost and LCOE for the parabolic trough system.

  18. A Molten Salt Lithium-Oxygen Battery.

    PubMed

    Giordani, Vincent; Tozier, Dylan; Tan, Hongjin; Burke, Colin M; Gallant, Betar M; Uddin, Jasim; Greer, Julia R; McCloskey, Bryan D; Chase, Gregory V; Addison, Dan

    2016-03-01

    Despite the promise of extremely high theoretical capacity (2Li + O2 ↔ Li2O2, 1675 mAh per gram of oxygen), many challenges currently impede development of Li/O2 battery technology. Finding suitable electrode and electrolyte materials remains the most elusive challenge to date. A radical new approach is to replace volatile, unstable and air-intolerant organic electrolytes common to prior research in the field with alkali metal nitrate molten salt electrolytes and operate the battery above the liquidus temperature (>80 °C). Here we demonstrate an intermediate temperature Li/O2 battery using a lithium anode, a molten nitrate-based electrolyte (e.g., LiNO3-KNO3 eutectic) and a porous carbon O2 cathode with high energy efficiency (∼95%) and improved rate capability because the discharge product, lithium peroxide, is stable and moderately soluble in the molten salt electrolyte. The results, supported by essential state-of-the-art electrochemical and analytical techniques such as in situ pressure and gas analyses, scanning electron microscopy, rotating disk electrode voltammetry, demonstrate that Li2O2 electrochemically forms and decomposes upon cycling with discharge/charge overpotentials as low as 50 mV. We show that the cycle life of such batteries is limited only by carbon reactivity and by the uncontrolled precipitation of Li2O2, which eventually becomes electrically disconnected from the O2 electrode. PMID:26871485

  19. A Molten Salt Lithium-Oxygen Battery.

    PubMed

    Giordani, Vincent; Tozier, Dylan; Tan, Hongjin; Burke, Colin M; Gallant, Betar M; Uddin, Jasim; Greer, Julia R; McCloskey, Bryan D; Chase, Gregory V; Addison, Dan

    2016-03-01

    Despite the promise of extremely high theoretical capacity (2Li + O2 ↔ Li2O2, 1675 mAh per gram of oxygen), many challenges currently impede development of Li/O2 battery technology. Finding suitable electrode and electrolyte materials remains the most elusive challenge to date. A radical new approach is to replace volatile, unstable and air-intolerant organic electrolytes common to prior research in the field with alkali metal nitrate molten salt electrolytes and operate the battery above the liquidus temperature (>80 °C). Here we demonstrate an intermediate temperature Li/O2 battery using a lithium anode, a molten nitrate-based electrolyte (e.g., LiNO3-KNO3 eutectic) and a porous carbon O2 cathode with high energy efficiency (∼95%) and improved rate capability because the discharge product, lithium peroxide, is stable and moderately soluble in the molten salt electrolyte. The results, supported by essential state-of-the-art electrochemical and analytical techniques such as in situ pressure and gas analyses, scanning electron microscopy, rotating disk electrode voltammetry, demonstrate that Li2O2 electrochemically forms and decomposes upon cycling with discharge/charge overpotentials as low as 50 mV. We show that the cycle life of such batteries is limited only by carbon reactivity and by the uncontrolled precipitation of Li2O2, which eventually becomes electrically disconnected from the O2 electrode.

  20. Design of a helium-cooled molten salt fusion breeder

    SciTech Connect

    Moir, R.W.; Lee, J.D.; Fulton, F.J.; Huegel, F.; Neef, W.S. Jr.; Sherwood, A.E.; Berwald, D.H.; Whitley, R.H.; Wong, C.P.C.; DeVan, J.H.

    1985-02-01

    A new conceptual blanket design for a fusion reactor produces fissile material for fission power plants. Fission is suppressed by using beryllium, rather than uranium, to multiply neutrons and also by minimizing the fissile inventory. The molten-salt breeding media (LiF + BeF/sub 2/ + TghF/sub 4/) is circulated through the blanket and on to the online processing system where /sup 233/U and tritium are continuously removed. Helium cools the blanket including the steel pipes containing the molten salt. Austenitic steel was chosen because of its ease of fabrication, adequate radiation-damage lifetime, and low corrosion rate by molten salt. We estimate the breeder, having 3000 MW of fusion power, produces 6400 kg of /sup 233/U per year, which is enough to provide make up for 20 GWe of LWR per year (or 14 LWR plants of 4440 MWt) or twice that many HTGRs or CANDUs. Safety is enhanced because the afterheat is low and the blanket materials do not react with air or water. The fusion breeder based on a pre-MARS tandem mirror is estimated to cost $4.9B or 2.35 times an LWR of the same power. The estimated present value cost of the /sup 2/anumber/sup 3/U produced is $40/g if utility financed or $16/g if government financed.

  1. Design of a helium-cooled molten salt fusion breeder

    NASA Astrophysics Data System (ADS)

    Moir, R. W.; Lee, J. D.; Fulton, F. J.; Huegel, F.; Neef, W. S., Jr.; Sherwood, A. E.; Berwald, D. H.; Whitley, R. H.; Wong, C. P. C.; Devan, J. H.

    1985-02-01

    A new conceptual blanket design for a fusion reactor is discussed which produces fissile material for fission power plants. Fission is suppressed by using beryllium, rather than uranium, to multiply neutrons and also by minimizing the fissile inventory. The molten-salt breeding media (LiF + BeF2 + TghF4) is circulated through the blanket and on to the online processing system where (233)U and tritium are continuously removed. Helium cools the blanket including the steel pipes containing the molten salt. Austenitic steel was chosen because of its ease of fabrication, adequate radiation-damage lifetime, and low corrosion rate by molten salt. Safety is enhanced because the afterheat is low and the blanket materials do not react with air or water. The fusion breeder based on a pre-MARS mirror is estimated to cost $4.9B or 2.35 time an LWR of the same power. The estimated present value cost of the (233)U produced is $40/g if utility financed or $16/g if government financed.

  2. Development of fluoride reprocessing technologies devoted to molten-salt reactor systems

    SciTech Connect

    Uhlir, Jan; Marecek, Martin; Tulackova, Radka; Chuchvalcova Bimova, Karolina

    2007-07-01

    Main fuel processing and reprocessing technologies proposed for Molten Salt Reactor fuel cycle are pyrochemical or pyrometallurgical, majority of them are fluoride technologies. It is based on the fact that Molten Salt Reactor fuel is in the chemical form of molten fluorides and the reprocessing technology is needed to be an 'on-line' process. The corresponding pyrochemical separation processes proposed for MSR fuel processing and reprocessing are mainly fluoride volatilization processes, molten salt / liquid metal extraction processes, electrochemical separation processes from the molten salt media and gas extraction from the molten salt medium. Techniques based on fluoride volatilization and on electrochemical separation from fluoride molten salt media are under development in the Czech Republic. Whereas the Fluoride Volatility Method is proposed to be the main 'Front-end' technology of the MSR used as the actinide burner (transmuter), the electro-separation methods should be dedicated to the 'on-line' reprocessing of the circulating MSR fuel and should be used as for MSR incinerating transuranium fuel as for MSR working within the {sup 232}Th - {sup 233}U fuel cycle. (authors)

  3. Delivery system for molten salt oxidation of solid waste

    DOEpatents

    Brummond, William A.; Squire, Dwight V.; Robinson, Jeffrey A.; House, Palmer A.

    2002-01-01

    The present invention is a delivery system for safety injecting solid waste particles, including mixed wastes, into a molten salt bath for destruction by the process of molten salt oxidation. The delivery system includes a feeder system and an injector that allow the solid waste stream to be accurately metered, evenly dispersed in the oxidant gas, and maintained at a temperature below incineration temperature while entering the molten salt reactor.

  4. Fast Spectrum Molten Salt Reactor Options

    SciTech Connect

    Gehin, Jess C; Holcomb, David Eugene; Flanagan, George F; Patton, Bruce W; Howard, Rob L; Harrison, Thomas J

    2011-07-01

    During 2010, fast-spectrum molten-salt reactors (FS-MSRs) were selected as a transformational reactor concept for light-water reactor (LWR)-derived heavy actinide disposition by the Department of Energy-Nuclear Energy Advanced Reactor Concepts (ARC) program and were the subject of a preliminary scoping investigation. Much of the reactor description information presented in this report derives from the preliminary studies performed for the ARC project. This report, however, has a somewhat broader scope-providing a conceptual overview of the characteristics and design options for FS-MSRs. It does not present in-depth evaluation of any FS-MSR particular characteristic, but instead provides an overview of all of the major reactor system technologies and characteristics, including the technology developments since the end of major molten salt reactor (MSR) development efforts in the 1970s. This report first presents a historical overview of the FS-MSR technology and describes the innovative characteristics of an FS-MSR. Next, it provides an overview of possible reactor configurations. The following design features/options and performance considerations are described including: (1) reactor salt options-both chloride and fluoride salts; (2) the impact of changing the carrier salt and actinide concentration on conversion ratio; (3) the conversion ratio; (4) an overview of the fuel salt chemical processing; (5) potential power cycles and hydrogen production options; and (6) overview of the performance characteristics of FS-MSRs, including general comparative metrics with LWRs. The conceptual-level evaluation includes resource sustainability, proliferation resistance, economics, and safety. The report concludes with a description of the work necessary to begin more detailed evaluation of FS-MSRs as a realistic reactor and fuel cycle option.

  5. Molten salt bath circulation design for an electrolytic cell

    DOEpatents

    Dawless, R.K.; LaCamera, A.F.; Troup, R.L.; Ray, S.P.; Hosler, R.B.

    1999-08-17

    An electrolytic cell for reduction of a metal oxide to a metal and oxygen has an inert anode and an upwardly angled roof covering the inert mode. The angled roof diverts oxygen bubbles into an upcomer channel, thereby agitating a molten salt bath in the upcomer channel and improving dissolution of a metal oxide in the molten salt bath. The molten salt bath has a lower velocity adjacent the inert anode in order to minimize corrosion by substances in the bath. A particularly preferred cell produces aluminum by electrolysis of alumina in a molten salt bath containing aluminum fluoride and sodium fluoride. 4 figs.

  6. Molten salt bath circulation design for an electrolytic cell

    DOEpatents

    Dawless, Robert K.; LaCamera, Alfred F.; Troup, R. Lee; Ray, Siba P.; Hosler, Robert B.

    1999-01-01

    An electrolytic cell for reduction of a metal oxide to a metal and oxygen has an inert anode and an upwardly angled roof covering the inert mode. The angled roof diverts oxygen bubbles into an upcomer channel, thereby agitating a molten salt bath in the upcomer channel and improving dissolution of a metal oxide in the molten salt bath. The molten salt bath has a lower velocity adjacent the inert anode in order to minimize corrosion by substances in the bath. A particularly preferred cell produces aluminum by electrolysis of alumina in a molten salt bath containing aluminum fluoride and sodium fluoride.

  7. Molten salt applications in materials processing

    NASA Astrophysics Data System (ADS)

    Mishra, Brajendra; Olson, David L.

    2005-02-01

    The science of molten salt electrochemistry for electrowinning of reactive metals, such as calcium, and its in situ application in pyro-reduction has been described. Calcium electrowinning has been performed in a 5 10 wt% calcium oxide calcium chloride molten salt by the electrolytic dissociation of calcium oxide. This electrolysis requires the use of a porous ceramic sheath around the anode to keep the cathodically deposited calcium and the anodic gases separate. Stainless steel cathode and graphite anode have been used in the temperature range of 850 950 °C. This salt mixture is produced as a result of the direct oxide reduction (DOR) of reactive metal oxides by calcium in a calcium chloride bath. The primary purpose of this process is to recover the expensive calcium reductant and to recycle calcium chloride. Experimental data have been included to justify the suitability as well as limitations of the electrowinning process. Transport of oxygen ions through the sheath is found to be the rate controlling step. Under the constraints of the reactor design, a calcium recovery rate of approx. 150 g/h was achieved. Feasibility of a process to produce metals by pyrometallurgical reduction, using the calcium reductant produced electrolytically within the same reactor, has been shown in a hybrid process. Several processes are currently under investigation to use this electrowon calcium for in situ reduction of metal oxides.

  8. Safe actinide disposition in molten salt reactors

    SciTech Connect

    Gat, U.

    1997-03-01

    Safe molten salt reactors (MSR) can readily accommodate the burning of all fissile actinides. Only minor compromises associated with plutonium are required. The MSRs can dispose safely of actinides and long lived isotopes to result in safer and simpler waste. Disposing of actinides in MSRs does increase the source term of a safety optimized MSR. It is concluded that the burning and transmutation of actinides in MSRs can be done in a safe manner. Development is needed for the processing to handle and separate the actinides. Calculations are needed to establish the neutron economy and the fuel management. 9 refs.

  9. A facile molten-salt route to graphene synthesis.

    PubMed

    Liu, Xiaofeng; Giordano, Cristina; Antonietti, Markus

    2014-01-15

    Efficient synthetic routes are continuously pursued for graphene in order to implement its applications in different areas. However, direct conversion of simple monomers to graphene through polymerization in a scalable manner remains a major challenge for chemists. Herein, a molten-salt (MS) route for the synthesis of carbon nanostructures and graphene by controlled carbonization of glucose in molten metal chloride is reported. In this process, carbohydrate undergoes polymerization in the presence of strongly interacting ionic species, which leads to nanoporous carbon with amorphous nature and adjustable pore size. At a low precursor concentration, the process converts the sugar molecules (glucose) to rather pure few-layer graphenes. The MS-derived graphenes are strongly hydrophobic and exhibit remarkable selectivity and capacity for absorption of organics. The methodology described may open up a new avenue towards the synthesis and manipulation of carbon materials in liquid media.

  10. Thermal-hydraulics of internally heated molten salts and application to the Molten Salt Fast Reactor

    NASA Astrophysics Data System (ADS)

    Fiorina, Carlo; Cammi, Antonio; Luzzi, Lelio; Mikityuk, Konstantin; Ninokata, Hisashi; Ricotti, Marco E.

    2014-04-01

    The Molten Salt Reactors (MSR) are an innovative kind of nuclear reactors and are presently considered in the framework of the Generation IV International Forum (GIF-IV) for their promising performances in terms of low resource utilization, waste minimization and enhanced safety. A unique feature of MSRs is that molten fluoride salts play the distinctive role of both fuel (heat source) and coolant. The presence of an internal heat generation perturbs the temperature field and consequences are to be expected on the heat transfer characteristics of the molten salts. In this paper, the problem of heat transfer for internally heated fluids in a straight circular channel is first faced on a theoretical ground. The effect of internal heat generation is demonstrated to be described by a corrective factor applied to traditional correlations for the Nusselt number. It is shown that the corrective factor can be fully characterized by making explicit the dependency on Reynolds and Prandtl numbers. On this basis, a preliminary correlation is proposed for the case of molten fluoride salts by interpolating the results provided by an analytic approach previously developed at the Politecnico di Milano. The experimental facility and the related measuring procedure for testing the proposed correlation are then presented. Finally, the developed correlation is used to carry out a parametric investigation on the effect of internal heat generation on the main out-of-core components of the Molten Salt Fast Reactor (MSFR), the reference circulating-fuel MSR design in the GIF-IV. The volumetric power determines higher temperatures at the channel wall, but the effect is significant only in case of large diameters and/or low velocities.

  11. Transient simulation of molten salt central receiver

    NASA Astrophysics Data System (ADS)

    Doupis, Dimitri; Wang, Chuan; Carcorze-Soto, Jorge; Chen, Yen-Ming; Maggi, Andrea; Losito, Matteo; Clark, Michael

    2016-05-01

    Alstom is developing concentrated solar power (CSP) utilizing 60/40wt% NaNO3-KNO3 molten salt as the working fluid in a tower receiver for the global renewable energy market. In the CSP power generation cycle, receivers undergo a daily cyclic operation due to the transient nature of solar energy. Development of robust and efficient start-up and shut-down procedures is critical to avoiding component failures due to mechanical fatigue resulting from thermal transients, thus maintaining the performance and availability of the CSP plant. The Molten Salt Central Receiver (MSCR) is subject to thermal transients during normal daily operation, a cycle that includes warmup, filling, operation, draining, and shutdown. This paper describes a study to leverage dynamic simulation and finite element analysis (FEA) in development of start-up, shutdown, and transient operation concepts for the MSCR. The results of the FEA also verify the robustness of the MSCR design to the thermal transients anticipated during the operation of the plant.

  12. Molten Salt Promoting Effect in Double Salt CO2 Absorbents

    SciTech Connect

    Zhang, Keling; Li, Xiaohong S.; Chen, Haobo; Singh, Prabhakar; King, David L.

    2016-01-01

    The purpose of this paper is to elaborate on the concept of molten salts as catalysts for CO2 absorption by MgO, and extend these observations to the MgO-containing double salt oxides. We will show that the phenomena involved with CO2 absorption by MgO and MgO-based double salts are similar and general, but with some important differences. This paper focuses on the following key concepts: i) identification of conditions that favor or disfavor participation of isolated MgO during double salt absorption, and investigation of methods to increase the absorption capacity of double salt systems by including MgO participation; ii) examination of the relationship between CO2 uptake and melting point of the promoter salt, leading to the recognition of the role of pre-melting (surface melting) in these systems; and iii) extension of the reaction pathway model developed for the MgO-NaNO3 system to the double salt systems. This information advances our understanding of MgO-based CO2 absorption systems for application with pre-combustion gas streams.

  13. Parametric study of natural circulation flow in molten salt fuel in molten salt reactor

    NASA Astrophysics Data System (ADS)

    Pauzi, Anas Muhamad; Cioncolini, Andrea; Iacovides, Hector

    2015-04-01

    The Molten Salt Reactor (MSR) is one of the most promising system proposed by Generation IV Forum (GIF) for future nuclear reactor systems. Advantages of the MSR are significantly larger compared to other reactor system, and is mainly achieved from its liquid nature of fuel and coolant. Further improvement to this system, which is a natural circulating molten fuel salt inside its tube in the reactor core is proposed, to achieve advantages of reducing and simplifying the MSR design proposed by GIF. Thermal hydraulic analysis on the proposed system was completed using a commercial computation fluid dynamics (CFD) software called FLUENT by ANSYS Inc. An understanding on theory behind this unique natural circulation flow inside the tube caused by fission heat generated in molten fuel salt and tube cooling was briefly introduced. Currently, no commercial CFD software could perfectly simulate natural circulation flow, hence, modeling this flow problem in FLUENT is introduced and analyzed to obtain best simulation results. Results obtained demonstrate the existence of periodical transient nature of flow problem, hence improvements in tube design is proposed based on the analysis on temperature and velocity profile. Results show that the proposed system could operate at up to 750MW core power, given that turbulence are enhanced throughout flow region, and precise molten fuel salt physical properties could be defined. At the request of the authors and the Proceedings Editor the name of the co-author Andrea Cioncolini was corrected from Andrea Coincolini. The same name correction was made in the Acknowledgement section on page 030004-10 and in reference number 4. The updated article was published on 11 May 2015.

  14. Parametric study of natural circulation flow in molten salt fuel in molten salt reactor

    SciTech Connect

    Pauzi, Anas Muhamad; Cioncolini, Andrea; Iacovides, Hector

    2015-04-29

    The Molten Salt Reactor (MSR) is one of the most promising system proposed by Generation IV Forum (GIF) for future nuclear reactor systems. Advantages of the MSR are significantly larger compared to other reactor system, and is mainly achieved from its liquid nature of fuel and coolant. Further improvement to this system, which is a natural circulating molten fuel salt inside its tube in the reactor core is proposed, to achieve advantages of reducing and simplifying the MSR design proposed by GIF. Thermal hydraulic analysis on the proposed system was completed using a commercial computation fluid dynamics (CFD) software called FLUENT by ANSYS Inc. An understanding on theory behind this unique natural circulation flow inside the tube caused by fission heat generated in molten fuel salt and tube cooling was briefly introduced. Currently, no commercial CFD software could perfectly simulate natural circulation flow, hence, modeling this flow problem in FLUENT is introduced and analyzed to obtain best simulation results. Results obtained demonstrate the existence of periodical transient nature of flow problem, hence improvements in tube design is proposed based on the analysis on temperature and velocity profile. Results show that the proposed system could operate at up to 750MW core power, given that turbulence are enhanced throughout flow region, and precise molten fuel salt physical properties could be defined. At the request of the authors and the Proceedings Editor the name of the co-author Andrea Cioncolini was corrected from Andrea Coincolini. The same name correction was made in the Acknowledgement section on page 030004-10 and in reference number 4. The updated article was published on 11 May 2015.

  15. Energetic materials destruction using molten salt

    SciTech Connect

    Upadhye, R.S.; Watkins, B.E.; Pruneda, C.O.; Brummond, W.A.

    1994-04-29

    The Lawrence Livermore National Laboratory in conjunction with the Energetic Materials Center is developing methods for the safe and environmentally sound destruction of explosives and propellants as a part of the Laboratory`s ancillary demilitarization mission. LLNL has built a small-scale unit to test the destruction of HE using the Molten Salt Destruction (MSD) Process. In addition to the high explosive HMX, destruction has been carried out on RDX, PETN, ammonium picrate, TNT, nitroguanadine, and TATB. Also destroyed was a liquid gun propellant comprising hydroxyammonium nitrate, triethanolammonium nitrate and water. In addition to these pure components, destruction has been carried out on a number of commonly used formulations, such as LX-10, LX-16, LX-17, and PBX-9404.

  16. Molten salt eutectics from atomistic simulations.

    PubMed

    Jayaraman, Saivenkataraman; Thompson, Aidan P; von Lilienfeld, O Anatole

    2011-09-01

    Despite their importance for solar thermal power applications, phase-diagrams of molten salt mixture heat transfer fluids (HTFs) are not readily accessible from first principles. We present a molecular dynamics scheme general enough to identify eutectics of any HTF candidate mixture. The eutectic mixture and temperature are located using the liquid mixture free energy and the pure component solid-liquid free energy differences. The liquid mixture free energy is obtained using thermodynamic integration over particle identity transmutations sampled with molecular dynamics at a single temperature. Drawbacks of conventional phase diagram mapping methodologies are avoided by not considering solid mixtures, thereby evading expensive computations of solid phase free energies. Numerical results for binary and ternary mixtures of alkali nitrates agree well with experimental measurements.

  17. [Fission Working Group -- Molten salt reactors

    SciTech Connect

    Gat, U.; Engel, J.R.

    1992-01-01

    This report provides an assessment of molten salt reactors (MSRs) which are fluid fuel reactors and, as such, have several unique features, some which are important to the burning of fissile material from dismantled weapons. This material can be added on-line during operation in either continuous or batch form. The added fuel need only be in an acceptable chemical form, but no fuel manufacturing or minimum discrete amounts for a fuel element are required. Fluid fuel reactors can have partial or full on-line fuel processing. When online fuel processing is utilized, a particular fuel component, for example the plutonium, can be burned completely, or in some sense can be converted to other kinds of fuel, for example into [sup 233]U. There is no equivalent of fuel burnup in continuous processing reactors, and no need for reprocessing in external plants and manufacturing of fuel elements, transportation, and reinsertion in the reactor.

  18. [Fission Working Group -- Molten salt reactors

    SciTech Connect

    Gat, U.; Engel, J.R.

    1992-12-31

    This report provides an assessment of molten salt reactors (MSRs) which are fluid fuel reactors and, as such, have several unique features, some which are important to the burning of fissile material from dismantled weapons. This material can be added on-line during operation in either continuous or batch form. The added fuel need only be in an acceptable chemical form, but no fuel manufacturing or minimum discrete amounts for a fuel element are required. Fluid fuel reactors can have partial or full on-line fuel processing. When online fuel processing is utilized, a particular fuel component, for example the plutonium, can be burned completely, or in some sense can be converted to other kinds of fuel, for example into {sup 233}U. There is no equivalent of fuel burnup in continuous processing reactors, and no need for reprocessing in external plants and manufacturing of fuel elements, transportation, and reinsertion in the reactor.

  19. Compatibility of molten salts with advanced solar dynamic receiver materials

    NASA Technical Reports Server (NTRS)

    Jaworske, D. A.; Perry, W. D.

    1989-01-01

    Metal-coated graphite fibers are being considered as a thermal conductivity enhancement filler material for molten salts in solar dynamic thermal energy storage systems. The successful metal coating chosen for this application must exhibit acceptable wettability and must be compatible with the molten salt environment. Contact angle values between molten lithium fluoride and several metal, metal fluoride, and metal oxide substrates have been determined at 892 C using a modification of the Wilhelmy plate technique. Reproducible contact angles with repeated exposure to the molten LiF indicated compatibility.

  20. Fast Thorium Molten Salt Reactors Started with Plutonium

    SciTech Connect

    Merle-Lucotte, E.; Heuer, D.; Le Brun, C.; Brissot, R.; Liatard, E.; Meplan, O.; Nuttin, A.

    2006-07-01

    One of the pending questions concerning Molten Salt Reactors based on the {sup 232}Th/{sup 233}U fuel cycle is the supply of the fissile matter, and as a consequence the deployment possibilities of a fleet of Molten Salt Reactors, since {sup 233}U does not exist on earth and is not yet produced in the current operating reactors. A solution may consist in producing {sup 233}U in special devices containing Thorium, in Pressurized Water or Fast Neutrons Reactors. Two alternatives to produce {sup 233}U are examined here: directly in standard Molten Salt Reactors started with Plutonium as fissile matter and then operated in the Th/{sup 233}U cycle; or in dedicated Molten Salt Reactors started and fed with Plutonium as fissile matter and Thorium as fertile matter. The idea is to design a critical reactor able to burn the Plutonium and the minor actinides presently produced in PWRs, and consequently to convert this Plutonium into {sup 233}U. A particular reactor configuration is used, called 'unique channel' configuration in which there is no moderator in the core, leading to a quasi fast neutron spectrum, allowing Plutonium to be used as fissile matter. The conversion capacities of such Molten Salt Reactors are excellent. For Molten Salt Reactors only started with Plutonium, the assets of the Thorium fuel cycle turn out to be quickly recovered and the reactor's characteristics turn out to be equivalent to Molten Salt Reactors operated with {sup 233}U only. Using a combination of Molten Salt Reactors started or operated with Plutonium and of Molten Salt Reactors started with {sup 233}U, the deployment capabilities of these reactors fully satisfy the condition of sustainability. (authors)

  1. Boric ester-type molten salt via dehydrocoupling reaction.

    PubMed

    Matsumi, Noriyoshi; Toyota, Yoshiyuki; Joshi, Prerna; Puneet, Puhup; Vedarajan, Raman; Takekawa, Toshihiro

    2014-11-14

    Novel boric ester-type molten salt was prepared using 1-(2-hydroxyethyl)-3-methylimidazolium chloride as a key starting material. After an ion exchange reaction of 1-(2-hydroxyethyl)-3-methylimidazolium chloride with lithium (bis-(trifluoromethanesulfonyl) imide) (LiNTf2), the resulting 1-(2-hydroxyethyl)-3-methylimidazolium NTf2 was reacted with 9-borabicyclo[3.3.1]nonane (9-BBN) to give the desired boric ester-type molten salt in a moderate yield. The structure of the boric ester-type molten salt was supported by 1H-, 13C-, 11B- and 19F-NMR spectra. In the presence of two different kinds of lithium salts, the matrices showed an ionic conductivity in the range of 1.1 × 10⁻⁴-1.6 × 10⁻⁵ S cm⁻¹ at 51 °C. This was higher than other organoboron molten salts ever reported.

  2. A Possible Regenerative, Molten-Salt, Thermoelectric Fuel Cell

    NASA Technical Reports Server (NTRS)

    Greenberg, Jacob; Thaller, Lawrence H.; Weber, Donald E.

    1964-01-01

    Molten or fused salts have been evaluated as possible thermoelectric materials because of the relatively good values of their figures of merit, their chemical stability, their long liquid range, and their ability to operate in conjunction with a nuclear reactor to produce heat. In general, molten salts are electrolytic conductors; therefore, there will be a transport of materials and subsequent decomposition with the passage of an electric current. It is possible nonetheless to overcome this disadvantage by using the decomposition products of the molten-salt electrolyte in a fuel cell. The combination of a thermoelectric converter and a fuel cell would lead to a regenerative system that may be useful.

  3. Control strategies in a thermal oil - Molten salt heat exchanger

    NASA Astrophysics Data System (ADS)

    Roca, Lidia; Bonilla, Javier; Rodríguez-García, Margarita M.; Palenzuela, Patricia; de la Calle, Alberto; Valenzuela, Loreto

    2016-05-01

    This paper presents a preliminary control scheme for a molten salt - thermal oil heat exchanger. This controller regulates the molten salt mass flow rate to reach and maintain the desired thermal oil temperature at the outlet of the heat exchanger. The controller architecture has been tested using an object-oriented heat exchanger model that has been validated with data from a molten salt testing facility located at CIEMAT-PSA. Different simulations are presented with three different goals: i) to analyze the controller response in the presence of disturbances, ii) to demonstrate the benefits of designing a setpoint generator and iii) to show the controller potential against electricity price variations.

  4. Applications of molten salts in reactive metals processing

    SciTech Connect

    Mishra, B.; Olson, D.L.; Averill, W.A.

    1993-12-31

    Pyrochemical processes using molten salts provide a unique opportunity for the extraction and refining of many reactive and valuable metals either directly from the beneficiated ore or from other process effluent that contain reactive metal compounds. This research program is aimed at developing a process for the production and recovery of reactive and valuable metals, such as zinc, tin, lead, bismuth and silver, in a hybrid reactor combining electrolytic production of the calcium reductant and in-situ utilization of this reductant for pyrochemical reduction of the metal compounds, such as halide or oxides. The process is equally suitable for producing other low melting metals, such as cadmium and antimony. The cell is typically operated below 1000C temperature. Attempts have been made to produce silver, lead, bismuth, tin and cerium by calciothermic reduction in a molten salt media. In a separate effort, calcium has been produced by an electrolytic dissociation of lime in a calcium chloride medium. The most important characteristic of the hybrid technology is its ability to produce metals under ``zero-waste`` conditions.

  5. Novel waste printed circuit board recycling process with molten salt.

    PubMed

    Riedewald, Frank; Sousa-Gallagher, Maria

    2015-01-01

    The objective of the method was to prove the concept of a novel waste PCBs recycling process which uses inert, stable molten salts as the direct heat transfer fluid and, simultaneously, uses this molten salt to separate the metal products in either liquid (solder, zinc, tin, lead, etc.) or solid (copper, gold, steel, palladium, etc.) form at the operating temperatures of 450-470 °C. The PCB recovery reactor is essentially a U-shaped reactor with the molten salt providing a continuous fluid, allowing molten salt access from different depths for metal recovery. A laboratory scale batch reactor was constructed using 316L as suitable construction material. For safety reasons, the inert, stable LiCl-KCl molten salts were used as direct heat transfer fluid. Recovered materials were washed with hot water to remove residual salt before metal recovery assessment. The impact of this work was to show metal separation using molten salts in one single unit, by using this novel reactor methodology. •The reactor is a U-shaped reactor filled with a continuous liquid with a sloped bottom representing a novel reactor concept.•This method uses large PCB pieces instead of shredded PCBs as the reactor volume is 2.2 L.•The treated PCBs can be removed via leg B while the process is on-going.

  6. Novel waste printed circuit board recycling process with molten salt

    PubMed Central

    Riedewald, Frank; Sousa-Gallagher, Maria

    2015-01-01

    The objective of the method was to prove the concept of a novel waste PCBs recycling process which uses inert, stable molten salts as the direct heat transfer fluid and, simultaneously, uses this molten salt to separate the metal products in either liquid (solder, zinc, tin, lead, etc.) or solid (copper, gold, steel, palladium, etc.) form at the operating temperatures of 450–470 °C. The PCB recovery reactor is essentially a U-shaped reactor with the molten salt providing a continuous fluid, allowing molten salt access from different depths for metal recovery. A laboratory scale batch reactor was constructed using 316L as suitable construction material. For safety reasons, the inert, stable LiCl–KCl molten salts were used as direct heat transfer fluid. Recovered materials were washed with hot water to remove residual salt before metal recovery assessment. The impact of this work was to show metal separation using molten salts in one single unit, by using this novel reactor methodology. • The reactor is a U-shaped reactor filled with a continuous liquid with a sloped bottom representing a novel reactor concept. • This method uses large PCB pieces instead of shredded PCBs as the reactor volume is 2.2 L. • The treated PCBs can be removed via leg B while the process is on-going. PMID:26150977

  7. Novel waste printed circuit board recycling process with molten salt.

    PubMed

    Riedewald, Frank; Sousa-Gallagher, Maria

    2015-01-01

    The objective of the method was to prove the concept of a novel waste PCBs recycling process which uses inert, stable molten salts as the direct heat transfer fluid and, simultaneously, uses this molten salt to separate the metal products in either liquid (solder, zinc, tin, lead, etc.) or solid (copper, gold, steel, palladium, etc.) form at the operating temperatures of 450-470 °C. The PCB recovery reactor is essentially a U-shaped reactor with the molten salt providing a continuous fluid, allowing molten salt access from different depths for metal recovery. A laboratory scale batch reactor was constructed using 316L as suitable construction material. For safety reasons, the inert, stable LiCl-KCl molten salts were used as direct heat transfer fluid. Recovered materials were washed with hot water to remove residual salt before metal recovery assessment. The impact of this work was to show metal separation using molten salts in one single unit, by using this novel reactor methodology. •The reactor is a U-shaped reactor filled with a continuous liquid with a sloped bottom representing a novel reactor concept.•This method uses large PCB pieces instead of shredded PCBs as the reactor volume is 2.2 L.•The treated PCBs can be removed via leg B while the process is on-going. PMID:26150977

  8. System Requirements Document for the Molten Salt Reactor Experiment

    SciTech Connect

    Aigner, R.D.

    2000-04-01

    The purpose of the conversion process is to convert the {sup 233}U fluoride compounds that are being extracted from the Molten Salt Reactor Experiment (MSRE) equipment to a stable oxide for long-term storage at Bldg. 3019.

  9. Molten salt electrolyte battery cell with overcharge tolerance

    DOEpatents

    Kaun, Thomas D.; Nelson, Paul A.

    1989-01-01

    A molten salt electrolyte battery having an increased overcharge tolerance employs a negative electrode with two lithium alloy phases of different electrochemical potential, one of which allows self-discharge rates which permits battery cell equalization.

  10. Novel Molten Salts Thermal Energy Storage for Concentrating Solar Power Generation

    SciTech Connect

    Reddy, Ramana G.

    2013-10-23

    The explicit UA program objective is to develop low melting point (LMP) molten salt thermal energy storage media with high thermal energy storage density for sensible heat storage systems. The novel Low Melting Point (LMP) molten salts are targeted to have the following characteristics: 1. Lower melting point (MP) compared to current salts (<222ºC) 2. Higher energy density compared to current salts (>300 MJ/m3) 3. Lower power generation cost compared to current salt In terms of lower power costs, the program target the DOE's Solar Energy Technologies Program year 2020 goal to create systems that have the potential to reduce the cost of Thermal Energy Storage (TES) to less than $15/kWh-th and achieve round trip efficiencies greater than 93%. The project has completed the experimental investigations to determine the thermo-physical, long term thermal stability properties of the LMP molten salts and also corrosion studies of stainless steel in the candidate LMP molten salts. Heat transfer and fluid dynamics modeling have been conducted to identify heat transfer geometry and relative costs for TES systems that would utilize the primary LMP molten salt candidates. The project also proposes heat transfer geometry with relevant modifications to suit the usage of our molten salts as thermal energy storage and heat transfer fluids. The essential properties of the down-selected novel LMP molten salts to be considered for thermal storage in solar energy applications were experimentally determined, including melting point, heat capacity, thermal stability, density, viscosity, thermal conductivity, vapor pressure, and corrosion resistance of SS 316. The thermodynamic modeling was conducted to determine potential high temperature stable molten salt mixtures that have thermal stability up to 1000 °C. The thermo-physical properties of select potential high temperature stable (HMP) molten salt mixtures were also experimentally determined. All the salt mixtures align with the go

  11. Establishment of a room temperature molten salt capability to measure fundamental thermodynamic properties of actinide elements

    SciTech Connect

    Smith, W.H.; Costa, D.A.

    1998-12-31

    This is the final report of a six-month, Laboratory Directed Research and Development (LDRD) project at Los Alamos National Laboratory (LANL). The goal of this work was to establish a capability for the measurement of fundamental thermodynamic properties of actinide elements in room temperature molten salts. This capability will be used to study in detail the actinide chloro- and oxo-coordination chemistries that dominate in the chloride-based molten salt media. Uranium will be the first actinide element under investigation.

  12. Application of lithium in molten-salt reduction processes.

    SciTech Connect

    Gourishankar, K. V.

    1998-11-11

    Metallothermic reductions have been extensively studied in the field of extractive metallurgy. At Argonne National Laboratory (ANL), we have developed a molten-salt based reduction process using lithium. This process was originally developed to reduce actinide oxides present in spent nuclear fuel. Preliminary thermodynamic considerations indicate that this process has the potential to be adapted for the extraction of other metals. The reduction is carried out at 650 C in a molten-salt (LiCl) medium. Lithium oxide (Li{sub 2}O), produced during the reduction of the actinide oxides, dissolves in the molten salt. At the end of the reduction step, the lithium is regenerated from the salt by an electrowinning process. The lithium and the salt from the electrowinning are then reused for reduction of the next batch of oxide fuel. The process cycle has been successfully demonstrated on an engineering scale in a specially designed pyroprocessing facility. This paper discusses the applicability of lithium in molten-salt reduction processes with specific reference to our process. Results are presented from our work on actinide oxides to highlight the role of lithium and its effect on process variables in these molten-salt based reduction processes.

  13. [Bio-oil production from biomass pyrolysis in molten salt].

    PubMed

    Ji, Dengxiang; Cai, Tengyue; Ai, Ning; Yu, Fengwen; Jiang, Hongtao; Ji, Jianbing

    2011-03-01

    In order to investigate the effects of pyrolysis conditions on bio-oil production from biomass in molten salt, experiments of biomass pyrolysis were carried out in a self-designed reactor in which the molten salt ZnCl2-KCl (with mole ratio 7/6) was selected as heat carrier, catalyst and dispersion agent. The effects of metal salt added into ZnCl2-KCl and biomass material on biomass pyrolysis were discussed, and the main compositions of bio-oil were determined by GC-MS. Metal salt added into molten salt could affect pyrolysis production yields remarkably. Lanthanon salt could enhance bio-oil yield and decrease water content in bio-oil, when mole fraction of 5.0% LaCl3 was added, bio-oil yield could reach up to 32.0%, and water content of bio-oil could reduce to 61.5%. The bio-oil and char yields were higher when rice straw was pyrolysed, while gas yield was higher when rice husk was used. Metal salts showed great selectivity on compositions of bio-oil. LiCl and FeCl2 promoted biomass to pyrolyse into smaller molecular weight compounds. CrCl3, CaCl2 and LaCl3 could restrain second pyrolysis of bio-oil. The research provided a scientific reference for production of bio-oil from biomass pyrolysis in molten salt.

  14. Treatment of plutonium process residues by molten salt oxidation

    SciTech Connect

    Stimmel, J.; Wishau, R.; Ramsey, K.B.; Montoya, A.; Brock, J.; Heslop, M.; Wernly, K.

    1999-04-01

    Molten Salt Oxidation (MSO) is a thermal process that can remove more than 99.999% of the organic matrix from combustible {sup 238}Pu material. Plutonium processing residues are injected into a molten salt bed with an excess of air. The salt (sodium carbonate) functions as a catalyst for the conversion of the organic material to carbon dioxide and water. Reactive species such as fluorine, chlorine, bromine, iodine, sulfur, phosphorous and arsenic in the organic waste react with the molten salt to form the corresponding neutralized salts, NaF, NaCl, NaBr, NaI, Na{sub 2}SO{sub 4}, Na{sub 3}PO{sub 4} and NaAsO{sub 2} or Na{sub 3}AsO4. Plutonium and other metals react with the molten salt and air to form metal salts or oxides. Saturated salt will be recycled and aqueous chemical separation will be used to recover the {sup 238}Pu. The Los Alamos National Laboratory system, which is currently in the conceptual design stage, will be scaled down from current systems for use inside a glovebox.

  15. Experience with Alloys Compatibility with Fuel and Coolant Salts and their Application to Molten Salt Actinide Recycler and Transmuter

    SciTech Connect

    Ignatiev, Victor; Surenkov, Aleksandr; Gnidoi, Ivan; Fedulov, Vladimir; Afonichkin, Valery; Bovet, Andrei; Subbotin, Vladimir; Panov, Aleksandr; Toropov, Andrei

    2006-07-01

    This paper summarizes results of recent work and the present state of knowledge about materials for molten salt reactors. The central focus is placed on the compatibility of container alloys with molten salt for Molten Salt Actinide Recycler and Transmuter. Preliminary results from recent thermal convection loop studies are presented. Methods for purification of molten salt composition and improvement of Ni- base container alloys compatibility by maintaining the salt at low redox potential are discussed. (authors)

  16. LIFE Materails: Molten-Salt Fuels Volume 8

    SciTech Connect

    Moir, R; Brown, N; Caro, A; Farmer, J; Halsey, W; Kaufman, L; Kramer, K; Latkowski, J; Powers, J; Shaw, H; Turchi, P

    2008-12-11

    The goals of the Laser Inertial Fusion Fission Energy (LIFE) is to use fusion neutrons to fission materials with no enrichment and minimum processing and have greatly reduced wastes that are not of interest to making weapons. Fusion yields expected to be achieved in NIF a few times per day are called for with a high reliable shot rate of about 15 per second. We have found that the version of LIFE using TRISO fuel discussed in other volumes of this series can be modified by replacing the molten-flibe-cooled TRISO fuel zone with a molten salt in which the same actinides present in the TRISO particles are dissolved in the molten salt. Molten salts have the advantage that they are not subject to radiation damage, and hence overcome the radiation damage effects that may limit the lifetime of solid fuels such as TRISO-containing pebbles. This molten salt is pumped through the LIFE blanket, out to a heat exchanger and back into the blanket. To mitigate corrosion, steel structures in contact with the molten salt would be plated with tungsten or nickel. The salt will be processed during operation to remove certain fission products (volatile and noble and semi-noble fission products), impurities and corrosion products. In this way neutron absorbers (fission products) are removed and neutronics performance of the molten salt is somewhat better than that of the TRISO fuel case owing to the reduced parasitic absorption. In addition, the production of Pu and rare-earth elements (REE) causes these elements to build up in the salt, and leads to a requirement for a process to remove the REE during operation to insure that the solubility of a mixed (Pu,REE)F3 solid solution is not exceeded anywhere in the molten salt system. Removal of the REE will further enhance the neutronics performance. With molten salt fuels, the plant would need to be safeguarded because materials of interest for weapons are produced and could potentially be removed.

  17. Separation of actinides from lanthanides utilizing molten salt electrorefining

    SciTech Connect

    Grimmett, D.L.; Fusselman, S.P.; Roy, J.J.; Gay, R.L.; Krueger, C.L.; Storvick, T.S.; Inoue, T.; Hijikata, T.; Takahashi, N.

    1996-10-01

    TRUMP-S (TRansUranic Management through Pyropartitioning Separation) is a pyrochemical process being developed to separate actinides form fission products in nuclear waste. A key process step involving molten salt electrorefining to separate actinides from lanthanides has been studied on a laboratory scale. Electrorefining of U, Np, Pu, Am, and lanthanide mixtures from molten cadmium at 450 C to a solid cathode utilizing a molten chloride electrolyte resulted in > 99% removal of actinides from the molten cadmium and salt phases. Removal of the last few percent of actinides is accompanied by lowered cathodic current efficiency and some lanthanide codeposition. Actinide/lanthanide separation ratios on the cathode are ordered U > Np > Pu > Am and are consistent with predictions based on equilibrium potentials.

  18. Selective Adsorption of Sodium Aluminum Fluoride Salts from Molten Aluminum

    SciTech Connect

    Leonard S. Aubrey; Christine A. Boyle; Eddie M. Williams; David H. DeYoung; Dawid D. Smith; Feng Chi

    2007-08-16

    Aluminum is produced in electrolytic reduction cells where alumina feedstock is dissolved in molten cryolite (sodium aluminum fluoride) along with aluminum and calcium fluorides. The dissolved alumina is then reduced by electrolysis and the molten aluminum separates to the bottom of the cell. The reduction cell is periodically tapped to remove the molten aluminum. During the tapping process, some of the molten electrolyte (commonly referred as “bath” in the aluminum industry) is carried over with the molten aluminum and into the transfer crucible. The carryover of molten bath into the holding furnace can create significant operational problems in aluminum cast houses. Bath carryover can result in several problems. The most troublesome problem is sodium and calcium pickup in magnesium-bearing alloys. Magnesium alloying additions can result in Mg-Na and Mg-Ca exchange reactions with the molten bath, which results in the undesirable pickup of elemental sodium and calcium. This final report presents the findings of a project to evaluate removal of molten bath using a new and novel micro-porous filter media. The theory of selective adsorption or removal is based on interfacial surface energy differences of molten aluminum and bath on the micro-porous filter structure. This report describes the theory of the selective adsorption-filtration process, the development of suitable micro-porous filter media, and the operational results obtained with a micro-porous bed filtration system. The micro-porous filter media was found to very effectively remove molten sodium aluminum fluoride bath by the selective adsorption-filtration mechanism.

  19. Gasification characteristics of organic waste by molten salt

    NASA Astrophysics Data System (ADS)

    Sugiura, Kimihiko; Minami, Keishi; Yamauchi, Makoto; Morimitsu, Shinsuke; Tanimoto, Kazumi

    Recently, along with the growth in economic development, there has been a dramatic accompanying increase in the amount of sludge and organic waste. The disposal of such is a significant problem. Moreover, there is also an increased in the consumption of electricity along with economic growth. Although new energy development, such as fuel cells, has been promoted to solve the problem of power consumption, there has been little corresponding promotion relating to the disposal of sludge and organic waste. Generally, methane fermentation comprises the primary organic waste fuel used in gasification systems. However, the methane fermentation method takes a long time to obtain the fuel gas, and the quality of the obtained gas is unstable. On the other hand, gasification by molten salt is undesirable because the molten salt in the gasification gas corrodes the piping and turbine blades. Therefore, a gasification system is proposed by which the sludge and organic waste are gasified by molten salt. Moreover, molten carbonate fuel cells (MCFC) are needed to refill the MCFC electrolyte volatilized in the operation. Since the gasification gas is used as an MCFC fuel, MCFC electrolyte can be provided with the fuel gas. This paper elucidates the fundamental characteristics of sludge and organic waste gasification. A crucible filled with the molten salt comprising 62 Li 2CO 3/38 K 2CO 3, is installed in the reaction vessel, and can be set to an arbitrary temperature in a gas atmosphere. In this instance, the gasifying agent gas is CO 2. Sludge or the rice is supplied as organic waste into the molten salt, and is gasified. The chemical composition of the gasification gas is analyzed by a CO/CO 2 meter, a HC meter, and a SO x meter gas chromatography. As a result, although sludge can generate CO and H 2 near the chemical equilibrium value, all of the sulfur in the sludge is not fixed in the molten salt, because the sludge floats on the surface of the carbonate by the specific

  20. Application of molten salts in pyrochemical processing of reactive metals

    SciTech Connect

    Mishra, B.; Olson, D.L. . Kroll Inst. for Extractive Metallurgy); Averill, W.A. . Rocky Flats Plant)

    1992-01-01

    Various mixes of chloride and fluoride salts are used as the media for conducting pyrochemical processes in the production and purification of reactive metals. These processes generate a significant amount of contaminated waste that has to be treated for recycling or disposal. Molten calcium chloride based salt systems have been used in this work to electrolytically regenerate calcium metal from calcium oxide for the in situ reduction of reactive metal oxides. The recovery of calcium is characterized by the process efficiency to overcome back reactions in the electrowinning cell. A thermodynamic analysis, based on fundamental rate theory, has been performed to understand the process parameters controlling the metal deposition, rate, behavior of the ceramic anode-sheath and influence of the back-reactions. It has been observed that the deposition of calcium is dependent on the ionic diffusion through the sheath. It has also been evidenced that the recovered calcium is completely lost through the back-reactions in the absence of a sheath. A practical scenario has also been presented where the electrowon metal can be used in situ as a reductant to reduce another reactive metal oxide.

  1. Injector nozzle for molten salt destruction of energetic waste materials

    DOEpatents

    Brummond, William A.; Upadhye, Ravindra S.

    1996-01-01

    An injector nozzle has been designed for safely injecting energetic waste materials, such as high explosives, propellants, and rocket fuels, into a molten salt reactor in a molten salt destruction process without premature detonation or back burn in the injection system. The energetic waste material is typically diluted to form a fluid fuel mixture that is injected rapidly into the reactor. A carrier gas used in the nozzle serves as a carrier for the fuel mixture, and further dilutes the energetic material and increases its injection velocity into the reactor. The injector nozzle is cooled to keep the fuel mixture below the decomposition temperature to prevent spontaneous detonation of the explosive materials before contact with the high-temperature molten salt bath.

  2. Injector nozzle for molten salt destruction of energetic waste materials

    DOEpatents

    Brummond, W.A.; Upadhye, R.S.

    1996-02-13

    An injector nozzle has been designed for safely injecting energetic waste materials, such as high explosives, propellants, and rocket fuels, into a molten salt reactor in a molten salt destruction process without premature detonation or back burn in the injection system. The energetic waste material is typically diluted to form a fluid fuel mixture that is injected rapidly into the reactor. A carrier gas used in the nozzle serves as a carrier for the fuel mixture, and further dilutes the energetic material and increases its injection velocity into the reactor. The injector nozzle is cooled to keep the fuel mixture below the decomposition temperature to prevent spontaneous detonation of the explosive materials before contact with the high-temperature molten salt bath. 2 figs.

  3. Effects of Stress on Corrosion in a Molten Salt Environment

    NASA Astrophysics Data System (ADS)

    Girdzis, Samuel; Manos, Dennis; Cooke, William

    Molten salt is often used as a heat transfer and energy storage fluid in concentrating solar power plants. Despite its suitable thermal properties, molten salt can present challenges in terms of corrosion. Previous studies have focused extensively on mass loss due to molten salt-induced corrosion. In contrast, we have investigated how corrosion begins and how it changes the surface of stainless steel. Samples of alloys including 304 and 316 stainless steel were exposed to the industry-standard NaNO3-KNO3 (60%-40% by weight) mixture at temperatures over 500°C and then analyzed using Hirox, SEM, and TOF-SIMS. We compare the corrosion at grain boundaries to that within single grain surfaces, showing the effect of the increased internal stresses and the weakened passivation layer. Also, we have examined the enhanced corrosion of samples under mechanical stress, simulating the effects of thermal stresses in a power plant.

  4. Electrochemical-metallothermic reduction of zirconium in molten salt solutions

    SciTech Connect

    McLaughlin, D.F.; Talko, F.

    1990-05-08

    This patent describes a method for separating hafnium from zirconium of the type wherein a feed containing zirconium and hafnium chlorides is prepared from zirconium-hafnium chloride and the feed is introduced into a distillation column, which distillation column has a reboiler connected at the bottom and a reflux condenser connected at the top and wherein a hafnium chloride enriched stream is taken from the top of the column and a zirconium enriched chloride stream is taken from the bottom of the column. It comprises: reducing the zirconium enriched chloride stream taken from the distillation column to metal by electrochemically reducing an alkaline earth metal in a molten salt bath with the molten salt in the molten salt bath consisting essentially of a mixture of at least one alkali metal chloride and at least one alkaline earth metal chloride and zirconium chloride, with the reduced alkaline earth metal reacting with the zirconium chloride to produce zirconium metal and alkaline earth metal chloride.

  5. The chemistry and status of rechargeable molten-salt batteries

    SciTech Connect

    Cairns, E.J.; Mamantov, G.; Tischer, R.P.; Vissers, D.R.

    1983-05-01

    The chemistry and the state of development of rechargeable molten salt cells and batteries of current interest are reviewed in this work. Molten-salt cells offer the most attractive combination of high specific energy (100-200 Wh/kg), high specific power (50-200 W/kg), and long cycle life (300-1500 cycles) of any rechargeable cells under investigation at this time. It is these important features that justify the development and application of cells that have the disadvantages of operation at elevated temperatures, and difficult materials problems. There are two major categories of molten-salt cells: those in which the molten salt is the sole electrolyte, and those in which the molten salt serves as a reactant and as an auxiliary electrolyte (the main electrolyte is a solid). In the first category are such cells as LiAl/LiCl-KCl/FeS, LiAl/LiCl-KCl/FeS/sub 2/, and Li/sub 4/Si/LiCl-KCl/FeS/sub 2/; in the second category are Na/Na/sub 2/O . xAl/sub 2/O/sub 3//Na/sub 2/S /SUB n/ -S, Na/Na/sup +/ glass/Na/sub 2/S /SUB n/ -S, Na/Na/sub 2/O . xAl/sub 2/O/sub 3//SCl/sub 3/AlCl/sub 4/ in NaCl-AlCl/sub 3/, and Li/Li/sub 2/O/LiNO/sub 3/-KNO/sub 3//V/sub 2/O/sub 5/. These cells have operating temperatures ranging from 150 to 475/sup 0/C, and all must be sealed from the atmosphere because of the alkali metal reactants and hydrolytic degradation of molten salt electrolytes.

  6. Corrosion of SiC by Molten Salt

    NASA Technical Reports Server (NTRS)

    Jacobson, Nathan S.; Smialek, James L.

    1987-01-01

    Advanced ceramic materials considered for wide range of applications as in gas turbine engines and heat exchangers. In such applications, materials may be in corrosive environments that include molten salts. Very corrosive to alloys. In order to determine extent of problem for ceramic materials, corrosion of SiC by molten salts studied in both jet fuel burners and laboratory furnaces. Surface of silicon carbide corroded by exposure to flame seeded with 4 parts per million of sodium. Strength of silicon carbide decreased by corrosion in flame and tube-furnace tests.

  7. Spectroscopic characterization of nanohydroxyapatite synthesized by molten salt method.

    PubMed

    Gopi, D; Indira, J; Kavitha, L; Kannan, S; Ferreira, J M F

    2010-10-01

    Hydroxyapatite (HAP) nanopowders were synthesized by molten salt method at 260 degrees C. The as-prepared powders were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscope (SEM) and thermo gravimetric analysis (TGA). With the aid of the obtained results the effect of calcining time on the crystallinity, size and morphology of HAP nanopowders is presented. The HAP nanopowders synthesized by molten salt method consist of pure phase of HAP without any impurities and showed the rod-like morphology without detectable decomposition up to 1100 degrees C.

  8. High-temperature molten-salt thermal electrochemical cell

    SciTech Connect

    Plichta, E.J.; Behl, W.K.

    1990-02-12

    This invention relates in general to a high temperature molten salt thermal electrochemical cell and in particular to such a cell including cobalt oxide (Co{sub 3}O{sub 4}) as the cathode material. High temperature molten salt thermal electrochemical cells are widely used as power sources for projectiles, rockets, bombs, mines, missiles, decoys, jammers and torpedoes. These are also used as fuses. Thermal electrochemical cells are reserve-type cells that can be activated by heating with a pyrotechnic heat source such as zirconium and barium chromate powders or mixtures of iron powder and potassium perchlorate.

  9. Alloys compatibility in molten salt fluorides: Kurchatov Institute related experience

    NASA Astrophysics Data System (ADS)

    Ignatiev, Victor; Surenkov, Alexandr

    2013-10-01

    In the last several years, there has been an increased interest in the use of high-temperature molten salt fluorides in nuclear power systems. For all molten salt reactor designs, materials selection is a very important issue. This paper summarizes results, which led to selection of materials for molten salt reactors in Russia. Operating experience with corrosion thermal convection loops has demonstrated good capability of the “nickel-molybdenum alloys + fluoride salt fueled by UF4 and PuF3 + cover gas” system up to 750 °C. A brief description is given of the container material work in progress. Tellurium corrosion of Ni-based alloys in stressed and unloaded conditions studies was also tested in different molten salt mixtures at temperatures up to 700-750 °C, also with measurement of the redox potential. HN80MTY alloy with 1% added Al is the most resistant to tellurium intergranular cracking of Ni-base alloys under study.

  10. Fission product ion exchange between zeolite and a molten salt

    NASA Astrophysics Data System (ADS)

    Gougar, Mary Lou D.

    The electrometallurgical treatment of spent nuclear fuel (SNF) has been developed at Argonne National Laboratory (ANL) and has been demonstrated through processing the sodium-bonded SNF from the Experimental Breeder Reactor-II in Idaho. In this process, components of the SNF, including U and species more chemically active than U, are oxidized into a bath of lithium-potassium chloride (LiCl-KCl) eutectic molten salt. Uranium is removed from the salt solution by electrochemical reduction. The noble metals and inactive fission products from the SNF remain as solids and are melted into a metal waste form after removal from the molten salt bath. The remaining salt solution contains most of the fission products and transuranic elements from the SNF. One technique that has been identified for removing these fission products and extending the usable life of the molten salt is ion exchange with zeolite A. A model has been developed and tested for its ability to describe the ion exchange of fission product species between zeolite A and a molten salt bath used for pyroprocessing of spent nuclear fuel. The model assumes (1) a system at equilibrium, (2) immobilization of species from the process salt solution via both ion exchange and occlusion in the zeolite cage structure, and (3) chemical independence of the process salt species. The first assumption simplifies the description of this physical system by eliminating the complications of including time-dependent variables. An equilibrium state between species concentrations in the two exchange phases is a common basis for ion exchange models found in the literature. Assumption two is non-simplifying with respect to the mathematical expression of the model. Two Langmuir-like fractional terms (one for each mode of immobilization) compose each equation describing each salt species. The third assumption offers great simplification over more traditional ion exchange modeling, in which interaction of solvent species with each other

  11. Corresponding-states data correlations and molten salts viscosities

    SciTech Connect

    Janz, G.J.; Yamamura, T.; Hansen, M.D.

    1989-01-01

    Transport properties of molten salts are encountered in a broad range of R D tasks, particularly in areas of high-temperature thermal energy storage and in advanced battery concepts. This communication examines a semiempirical corresponding-states correlation as a predictive method using molten salts viscosities. Predictive calculations with molten NaCl and KNO/sub 3/ as model systems, and with calibration quality data sets as the reference base, are used to evaluate this method. While the proper slope for the temperature dependence is forecast, the quality of the predicted data depend directly on the accuracy level of the one experimental value that is the seed for the calculations. Some results are described to show how such calculations have proved useful in guiding value judgments in studies of the viscosity data in the open scientific literature.

  12. Molten Salt Thermal Energy Storage Systems

    NASA Technical Reports Server (NTRS)

    Maru, H. C.; Dullea, J. F.; Kardas, A.; Paul, L.; Marianowski, L. G.; Ong, E.; Sampath, V.; Huang, V. M.; Wolak, J. C.

    1978-01-01

    The feasibility of storing thermal energy at temperatures of 450 C to 535 C in the form of latent heat of fusion was examined for over 30 inorganic salts and salt mixtures. Alkali carbonate mixtures were chosen as phase-change storage materials in this temperature range because of their relatively high storage capacity and thermal conductivity, moderate cost, low volumetric expansion upon melting, low corrosivity, and good chemical stability. Means of improving heat conduction through the solid salt were explored.

  13. R and D of On-line Reprocessing Technology for Molten-Salt Reactor Systems

    SciTech Connect

    Uhlir, Jan; Tulackova, Radka; Chuchvalcova Bimova, Karolina

    2006-07-01

    The Molten Salt Reactor (MSR) represents one of promising future nuclear reactor concept included in the Generation IV reactors family. The reactor can be operated as the thorium breeder or as the actinide transmuter. However, the future deployment of Molten-Salt Reactors will be significantly dependent on the successful mastering of advanced reprocessing technologies dedicated to their fuel cycle. Here the on-line reprocessing technology connected with the fuel circuit of MSR is of special importance because the reactor cannot be operated for a long run without the fuel salt clean-up. Generally, main MSR reprocessing technologies are pyrochemical, majority of them are fluoride technologies. The proposed flow-sheets of MSR on-line reprocessing are based on a combination of molten-salt / liquid metal extraction and electro-separation processes, which can be added to the gas extraction process already verified during the MSRE project in ORNL. The crucial separation method proposed for partitioning of actinides from fission products is based on successive Anodic dissolution and Cathodic deposition processes in molten fluoride media. (authors)

  14. Production of oxygen from lunar soil by molten salt electrolysis

    NASA Technical Reports Server (NTRS)

    Keller, Rudolf

    1989-01-01

    A simple approach to utilizing lunar resources proposes to dissolve lunar soil, without or with little beneficiation, in a suitable molten salt and to electrolyze the oxides to oxygen and a metal byproduct. The envisioned process and the required technological advances are discussed. Promising electrolysis conditions have been identified in a recent experimental program to manufacture silicon and aluminum from anorthite.

  15. Hydrated multivalent cations are new class of molten salt mixtures

    NASA Technical Reports Server (NTRS)

    Angell, C. A.

    1967-01-01

    Electrical conductance and activation energy measurements on mixtures of calcium and potassium nitrate show the hydrated form to be a new class of molten salt. The theoretical glass transition temperature of the hydrate varied in a manner opposite to that of the anhydrous system.

  16. Nuclear performance optimization of the molten-salt fusion breeder

    SciTech Connect

    Lee, J.D.; Bandini, B.R.

    1986-06-05

    Improved nuclear analysis, including the treatment of resonance and spatial self-shielding, coupled with an optimization procedure, has resulted in an improved performance estimate for the molten salt blanket. Net U-233 breeding ratio ranges between 0.58 and 0.63, and blanket energy multiplication ranges between 1.8 and 1.9.

  17. 9. VIEW OF MOLTEN SALT BATH EQUIPMENT AND ROLLER PRESSES ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    9. VIEW OF MOLTEN SALT BATH EQUIPMENT AND ROLLER PRESSES BEING INSTALLED ON THE WEST SIDE (SIDE B) OF BUILDING 883. SIDE B OF BUILDING 883 WAS USED TO PROCESS ENRICHED URANIUM FROM 1957-66. (1/23/57) - Rocky Flats Plant, Uranium Rolling & Forming Operations, Southeast section of plant, southeast quadrant of intersection of Central Avenue & Eighth Street, Golden, Jefferson County, CO

  18. 13. VIEW OF THE MOLTEN SALT BATHS USED TO UNIFORMLY ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    13. VIEW OF THE MOLTEN SALT BATHS USED TO UNIFORMLY AND QUICKLY HEAT METALS PRIOR TO WORKING (ROLLING). (9/16/85) - Rocky Flats Plant, Uranium Rolling & Forming Operations, Southeast section of plant, southeast quadrant of intersection of Central Avenue & Eighth Street, Golden, Jefferson County, CO

  19. Molten-Salt-Based Growth of Group III Nitrides

    DOEpatents

    Waldrip, Karen E.; Tsao, Jeffrey Y.; Kerley, Thomas M.

    2008-10-14

    A method for growing Group III nitride materials using a molten halide salt as a solvent to solubilize the Group-III ions and nitride ions that react to form the Group III nitride material. The concentration of at least one of the nitride ion or Group III cation is determined by electrochemical generation of the ions.

  20. Molten Salts for High Temperature Reactors: University of Wisconsin Molten Salt Corrosion and Flow Loop Experiments -- Issues Identified and Path Forward

    SciTech Connect

    Piyush Sabharwall; Matt Ebner; Manohar Sohal; Phil Sharpe; Thermal Hydraulics Group

    2010-03-01

    Considerable amount of work is going on regarding the development of high temperature liquid salts technology to meet future process needs of Next Generation Nuclear Plant. This report identifies the important characteristics and concerns of high temperature molten salts (with lesson learned at University of Wisconsin-Madison, Molten Salt Program) and provides some possible recommendation for future work

  1. An experimental test plan for the characterization of molten salt thermochemical properties in heat transport systems

    SciTech Connect

    Pattrick Calderoni

    2010-09-01

    Molten salts are considered within the Very High Temperature Reactor program as heat transfer media because of their intrinsically favorable thermo-physical properties at temperatures starting from 300 C and extending up to 1200 C. In this context two main applications of molten salt are considered, both involving fluoride-based materials: as primary coolants for a heterogeneous fuel reactor core and as secondary heat transport medium to a helium power cycle for electricity generation or other processing plants, such as hydrogen production. The reference design concept here considered is the Advanced High Temperature Reactor (AHTR), which is a large passively safe reactor that uses solid graphite-matrix coated-particle fuel (similar to that used in gas-cooled reactors) and a molten salt primary and secondary coolant with peak temperatures between 700 and 1000 C, depending upon the application. However, the considerations included in this report apply to any high temperature system employing fluoride salts as heat transfer fluid, including intermediate heat exchangers for gas-cooled reactor concepts and homogenous molten salt concepts, and extending also to fast reactors, accelerator-driven systems and fusion energy systems. The purpose of this report is to identify the technical issues related to the thermo-physical and thermo-chemical properties of the molten salts that would require experimental characterization in order to proceed with a credible design of heat transfer systems and their subsequent safety evaluation and licensing. In particular, the report outlines an experimental R&D test plan that would have to be incorporated as part of the design and operation of an engineering scaled facility aimed at validating molten salt heat transfer components, such as Intermediate Heat Exchangers. This report builds on a previous review of thermo-physical properties and thermo-chemical characteristics of candidate molten salt coolants that was generated as part of the

  2. Molten salt treatment to minimize and optimize waste

    SciTech Connect

    Gat, U.; Crosley, S.M.; Gay, R.L.

    1993-07-01

    A combination molten salt oxidizer (MSO) and molten salt reactor (MSR) is described for treatment of waste. The MSO is proposed for contained oxidization of organic hazardous waste, for reduction of mass and volume of dilute waste by evaporation of the water. The NTSO residue is to be treated to optimize the waste in terms of its composition, chemical form, mixture, concentration, encapsulation, shape, size, and configuration. Accumulations and storage are minimized, shipments are sized for low risk. Actinides, fissile material, and long-lived isotopes are separated and completely burned or transmuted in an MSR. The MSR requires no fuel element fabrication, accepts the materials as salts in arbitrarily small quantities enhancing safety, security, and overall acceptability.

  3. Technical developments in molten salt solar central receiver systems

    SciTech Connect

    Grant, G.; Johnson, S.D.; Smith, D.C.

    1984-08-01

    Solar system components have undergone considerable analysis and evaluation through various efforts such as the Saguaro and Solar 100 design programs and the experimental work conducted by Sandia National Laboratories. While the foregoing work has established the feasibility of molten salt solar plant design, further prototypical testing is necessary prior to the construction of large scale plants. Work is underway on a program to demonstrate the viability of the receiver design, the operation of full size hot and cold salt pumps, and the operability of major salt valves for a commercial solar plant. This work will be undertaken at the Central Receiver Test Facility (CRTF) in Albuquerque.

  4. Accelerator-driven molten-salt blankets: Physics issues

    SciTech Connect

    Houts, M.G.; Beard, C.A.; Buksa, J.J.; Davidson, J.W.; Durkee, J.W.; Perry, R.T.; Poston, D.I.

    1994-10-01

    A number of nuclear physics issues concerning the Los Alamos molten-salt accelerator-driven plutonium converter are discussed. General descriptions of several concepts using internal and external moderation are presented. Burnup and salt processing requirement calculations are presented for four concepts, indicating that both the high power density externally moderated concept and an internally moderated concept achieve total plutonium burnups approaching 90% at salt processing rates of less than 2 m{sup 3} per year. Beginning-of-life reactivity temperature coefficients and system kinetic response are also discussed. Future research should investigate the effect of changing blanket composition on operational and safety characteristics.

  5. Corrosion Behavior of Alloys in Molten Fluoride Salts

    NASA Astrophysics Data System (ADS)

    Zheng, Guiqiu

    The molten fluoride salt-cooled high-temperature nuclear reactor (FHR) has been proposed as a candidate Generation IV nuclear reactor. This reactor combines the latest nuclear technology with the use of molten fluoride salt as coolant to significantly enhance safety and efficiency. However, an important challenge in FHR development is the corrosion of structural materials in high-temperature molten fluoride salt. The structural alloys' degradation, particularly in terms of chromium depletion, and the molten salt chemistry are key factors that impact the lifetime of nuclear reactors and the development of future FHR designs. In support of materials development for the FHR, the nickel base alloy of Hastelloy N and iron-chromium base alloy 316 stainless steel are being actively considered as critical structural alloys. Enriched 27LiF-BeF2 (named as FLiBe) is a promising coolant for the FHR because of its neutronic properties and heat transfer characteristics while operating at atmospheric pressure. In this study, the corrosion behavior of Ni-5Cr and Ni-20Cr binary model alloys, and Hastelloy N and 316 stainless steel in molten FLiBe with and without graphite were investigated through various microstructural analyses. Based on the understanding of the corrosion behavior and data of above four alloys in molten FLiBe, a long-term corrosion prediction model has been developed that is applicable specifically for these four materials in FLiBe at 700ºC. The model uses Cr concentration profile C(x, t) as a function of corrosion distance in the materials and duration fundamentally derived from the Fick's diffusion laws. This model was validated with reasonable accuracy for the four alloys by fitting the calculated profiles with experimental data and can be applied to evaluate corrosion attack depth over the long-term. The critical constant of the overall diffusion coefficient (Deff) in this model can be quickly calculated from the experimental measurement of alloys' weight

  6. Corrosion of aluminides by molten nitrate salt

    SciTech Connect

    Tortorelli, P.F.; Bishop, P.S.

    1990-01-01

    The corrosion of titanium-, iron-, and nickel-based aluminides by a highly aggressive, oxidizing NaNO{sub 3}(-KNO{sub 3})-Na{sub 2}O{sub 2} has been studied at 650{degree}C. It was shown that weight changes could be used to effectively evaluate corrosion behavior in the subject nitrate salt environments provided these data were combined with salt analyses and microstructural examinations. The studies indicated that the corrosion of relatively resistant aluminides by these nitrate salts proceeded by oxidation and a slow release from an aluminum-rich product layer into the salt at rates lower than that associated with many other types of metallic materials. The overall corrosion process and resulting rate depended on the particular aluminide being exposed. In order to minimize corrosion of nickel or iron aluminides, it was necessary to have aluminum concentrations in excess of 30 at. %. However, even at a concentration of 50 at. % Al, the corrosion resistance of TiAl was inferior to that of Ni{sub 3}Al and Fe{sub 3}Al. At higher aluminum concentrations, iron, nickel, and iron-nickel aluminides exhibited quite similar weight changes, indicative of the principal role of aluminum in controlling the corrosion process in NaNO{sub 3}(-KNO{sub 3})-Na{sub 2}O{sub 2} salts. 20 refs., 5 figs., 3 tabs.

  7. ac impedance measurements of molten salt thermal batteries

    NASA Astrophysics Data System (ADS)

    Singh, Pritpal; Guidotti, Ronald A.; Reisner c, David

    Non-destructive testing of thermal batteries without activating them is a challenging proposition. Molten salt thermal batteries are activated by raising their temperature to above the melting point of the salt constituting the electrolyte. One approach that we have considered is to raise the temperature of the molten salt electrolyte to a temperature below the melting point so that the battery does not get activated yet may provide sufficient mobility of the ionic species to be able to obtain some useful ac impedance measurements. This hypothesis was put to the test for two Li(Si)/FeS 2 molten salt batteries with two electrolytes of different melting points—a standard LiCl-KCl eutectic that melts at 352 °C and a LiBr-KBr-LiCl eutectic with a melting point of 319 °C. ac impedance measurements as a function of frequency and temperature below the melting point are presented for single cells and batteries.

  8. Characteristics of solidified products containing radioactive molten salt waste.

    PubMed

    Park, Hwan-Seo; Kim, In-Tae; Cho, Yong-Zun; Eun, Hee-Chul; Kim, Joon-Hyung

    2007-11-01

    The molten salt waste from a pyroprocess to recover uranium and transuranic elements is one of the problematic radioactive wastes to be solidified into a durable wasteform for its final disposal. By using a novel method, named as the GRSS (gel-route stabilization/solidification) method, a molten salt waste was treated to produce a unique wasteform. A borosilicate glass as a chemical binder dissolves the silicate compounds in the gel products to produce one amorphous phase while most of the phosphates are encapsulated by the vitrified phase. Also, Cs in the gel product is preferentially situated in the silicate phase, and it is vitrified into a glassy phase after a heat treatment. The Sr-containing phase is mainly phosphate compounds and encapsulated by the glassy phase. These phenomena could be identified by the static and dynamic leaching test that revealed a high leach resistance of radionuclides. The leach rates were about 10(-3) - 10(-2) g/m2 x day for Cs and 10(-4) - 10(-3) g/m2 x day for Sr, and the leached fractions of them were predicted to be 0.89% and 0.39% at 900 days, respectively. This paper describes the characteristics of a unique wasteform containing a molten salt waste and provides important information on a newly developed immobilization technology for salt wastes, the GRSS method.

  9. CO2 decomposition using electrochemical process in molten salts

    NASA Astrophysics Data System (ADS)

    Otake, Koya; Kinoshita, Hiroshi; Kikuchi, Tatsuya; Suzuki, Ryosuke O.

    2012-08-01

    The electrochemical decomposition of CO2 gas to carbon and oxygen gas in LiCl-Li2O and CaCl2-CaO molten salts was studied. This process consists of electrochemical reduction of Li2O and CaO, as well as the thermal reduction of CO2 gas by the respective metallic Li and Ca. Two kinds of ZrO2 solid electrolytes were tested as an oxygen ion conductor, and the electrolytes removed oxygen ions from the molten salts to the outside of the reactor. After electrolysis in both salts, the aggregations of nanometer-scale amorphous carbon and rod-like graphite crystals were observed by transmission electron microscopy. When 9.7 %CO2-Ar mixed gas was blown into LiCl-Li2O and CaCl2-CaO molten salts, the current efficiency was evaluated to be 89.7 % and 78.5 %, respectively, by the exhaust gas analysis and the supplied charge. When a solid electrolyte with higher ionic conductivity was used, the current and carbon production became larger. It was found that the rate determining step is the diffusion of oxygen ions into the ZrO2 solid electrolyte.

  10. Continuous extraction of molten chloride salts with liquid cadmium alloys

    SciTech Connect

    Chow, L.S.; Basco, J.K.; Ackerman, J.P.; Johnson, T.R.

    1993-09-01

    A pyrochemical method is being developed at Argonne National Laboratory (ANL) to provide contnuous multistage extractions between molten chloride salts and liquid cadmium alloys at 500{degrees}C. The extraction method will be used to recover transuranic (TRU) elements from the process salt in the electroretiner used in the pyrochemical reprocessing of spent fuel from the Integral Fast Reactor (IFR). The IFR is one of the Department of Energy`s advanced power reactor concepts. The recovered TRU elements are returned to the electrorefiner. The extracted salt undergoes further processing to remove rare earths and other fission products so that most of the purified salt can also be returned to the electrorefiner, thereby extending the useful life of the process salt many times.

  11. Design considerations for concentrating solar power tower systems employing molten salt.

    SciTech Connect

    Moore, Robert Charles; Siegel, Nathan Phillip; Kolb, Gregory J.; Vernon, Milton E.; Ho, Clifford Kuofei

    2010-09-01

    The Solar Two Project was a United States Department of Energy sponsored project operated from 1996 to 1999 to demonstrate the coupling of a solar power tower with a molten nitrate salt as a heat transfer media and for thermal storage. Over all, the Solar Two Project was very successful; however many operational challenges were encountered. In this work, the major problems encountered in operation of the Solar Two facility were evaluated and alternative technologies identified for use in a future solar power tower operating with a steam Rankine power cycle. Many of the major problems encountered can be addressed with new technologies that were not available a decade ago. These new technologies include better thermal insulation, analytical equipment, pumps and values specifically designed for molten nitrate salts, and gaskets resistant to thermal cycling and advanced equipment designs.

  12. Electrochemical Synthesis of Magnesium Hexaboride by Molten Salt Technique.

    PubMed

    Angappan, S; Kalaiselvi, N; Sudha, R; Visuvasam, A

    2014-01-01

    The present work reports electrochemical synthesis of MgB6 from molten salts using the precursor consists of LiF-B2O3-MgCl2. An attempt has been made to synthesize metastable phase MgB6 crystal by electrolysis method. DTA/TGA studies were made to determine the eutectic point of the melt and it was found to be around 900°C. The electrolysis was performed at 900°C under argon atmosphere, at current density of 1.5 A/cm(2). The electrodeposited crystals were examined using XRD, SEM, and XPS. From the above studies, the electrochemical synthesis method for hypothetical MgB6 from chloro-oxy-fluoride molten salt system is provided. Mechanism for the formation of magnesium hexaboride is discussed.

  13. Electrochemical Synthesis of Magnesium Hexaboride by Molten Salt Technique

    PubMed Central

    Angappan, S.; Kalaiselvi, N.; Sudha, R.; Visuvasam, A.

    2014-01-01

    The present work reports electrochemical synthesis of MgB6 from molten salts using the precursor consists of LiF–B2O3–MgCl2. An attempt has been made to synthesize metastable phase MgB6 crystal by electrolysis method. DTA/TGA studies were made to determine the eutectic point of the melt and it was found to be around 900°C. The electrolysis was performed at 900°C under argon atmosphere, at current density of 1.5 A/cm2. The electrodeposited crystals were examined using XRD, SEM, and XPS. From the above studies, the electrochemical synthesis method for hypothetical MgB6 from chloro-oxy-fluoride molten salt system is provided. Mechanism for the formation of magnesium hexaboride is discussed. PMID:27350961

  14. Molten salt reactors for burning dismantled weapons fuel

    SciTech Connect

    Gat, U.; Engel, J.R. ); Dodds, H.L. . Dept. of Nuclear Engineering)

    1992-12-01

    In this paper, the molten salt reactor (MSR) option for burning fissile fuel form dismantled weapons is examined. It is concluded that MSRs are potentially suitable for beneficial utilization of the dismantled fuel. the MSRs have the flexibility to utilize any fissile fuel in continuous operation with no special modifications, as demonstrated in the Molten Salt Reactor Experiment, while maintaining their economy. The MSRs further require a minimum of special fuel preparation and can tolerate denaturing and dilution of the fuel. Fuel shipments can be arbitrarily small, which may reduce the risk of diversion. The MSRs have inherent safety features that make them acceptable and attractive. They can burn a fuel type completely and convert it to other fuels. The MSRs also have the potential for burning the actinides and delivering the waste in an optimal form, thus contributing to the solution of one of the major remaining problems for deployment o nuclear power.

  15. Hydrocracking of coal using molten salts as catalysts

    NASA Astrophysics Data System (ADS)

    Kikkawa, S.; Nomura, M.; Sakashita, H.; Nishimura, M.; Miyake, M.

    1981-10-01

    Characteristics of the reactions during coal liquefaction and the hydrocracking of coal and coal-related materials using ZnCl2-transition metal chloride or ZnCl2-alkaline metal chloride are discussed. The studies involve development of a molten salt catalyst for hydrocracking heavy residual oils or coals, including hydrocarbons containing many heteroatoms. It was found that ZnCl2 shows higher activity for hydrocracking of anthracene and phenanthrene, and experiments with Yubari coal using the binary metal catalysts ZnCl2-MoCl5 and ZnCl2-CrCl3 are described. The use of molten salts in the desulphurization of heavy residual oils is also explored, specifically for the hydrocracking of benziophene, and the possibility that a coal-like polymer structure containing an oxygen surplus might depolymerize above ternary melts is suggested.

  16. Nuclear Hybrid Energy Systems: Molten Salt Energy Storage

    SciTech Connect

    P. Sabharwall; M. Green; S.J. Yoon; S.M. Bragg-Sitton; C. Stoots

    2014-07-01

    With growing concerns in the production of reliable energy sources, the next generation in reliable power generation, hybrid energy systems, are being developed to stabilize these growing energy needs. The hybrid energy system incorporates multiple inputs and multiple outputs. The vitality and efficiency of these systems resides in the energy storage application. Energy storage is necessary for grid stabilizing and storing the overproduction of energy to meet peak demands of energy at the time of need. With high thermal energy production of the primary nuclear heat generation source, molten salt energy storage is an intriguing option because of its distinct properties. This paper will discuss the different energy storage options with the criteria for efficient energy storage set forth, and will primarily focus on different molten salt energy storage system options through a thermodynamic analysis

  17. The viscosity and electrical conductivity of single molten salts

    NASA Astrophysics Data System (ADS)

    Marcus, Yizhak

    2016-08-01

    In addition to the well-established Arrhenius-type temperature-dependence of the specific and molar conductivities of molten salts, it turns out that they also depend linearly on the molar volumes, in analogy with the behavior of their fluidities. Similar values of the molar volumes representing the immobilization of the ions result from both kinds of flow phenomena. However, the activation energy for the fluidity is some five times larger than for the conductivity.

  18. Interaction of Pipeline Materials with Molten Fluoride Salts

    NASA Astrophysics Data System (ADS)

    Šimo, Tomáš; Matal, Oldřich; Nesvadba, Lukáś; Dvořák, Vladimír; Kanický, Viktor; Sulovský, Petr; Machát, Jiří

    2007-12-01

    Molten fluoride salts are very promising carriers for the transport of large amounts of heat for example from a high temperature nuclear reactor to a plant which generates hydrogen by chemical processes or from a nuclear reactor to a heat exchanger being a part of the equipment needed to realize the Brayton cycle with a very high power efficiency. Therefore, in the framework of our project, experimental and theoretical investigations of the interactions of fluoride salts as heat carriers needed as high potential and structural materials for pipelines in order to transport heat at temperatures above 600◦C were started. Experimental investigations of Fe-based and Ni-based materials in molten fluoride salts at high temperatures and with different exposure times were performed. Two components salts (LiF-NaF and NaF-NaBF4) and three components salts (LiF-NaF-ZrF4 and LiF-NaF-RbF) were chosen in the experiments. The salt analysis was focussed on the content of metallic elements before and after the exposure of the samples to the salt melts. It was done by inductively coupled plasma-optical emission spectrometry (ICP-OES) and by titrimetric techniques. The thickness of the material zone affected by the salt melts, characterized by an enriched / reduced content of elements in comparison to the mean original content, and the material attacked zone, characterized by very tiny channels or chains of pores or pits formed preferably at grain boundaries, were the subject of the analysis performed by electron microscopy / microprobe techniques. Theoretical models for the transport of elements in the material samples exposed to salt melts using experimental data were also developed.

  19. Advances in electroanalysis, sensing and monitoring in molten salts.

    PubMed

    Corrigan, Damion K; Elliott, Justin P; Blair, Ewen O; Reeves, Simon J; Schmüser, Ilka; Walton, Anthony J; Mount, Andrew R

    2016-08-15

    Microelectrodes have a number of advantages over macroelectrodes for quantitative electroanalysis and monitoring, including reduced iR drop, a high signal-to-noise ratio and reduced sensitivity to convection. Their use in molten salts has been generally precluded by the combined materials challenges of stresses associated with thermal cycling and physical and corrosive chemical degradation at the relatively high temperatures involved. We have shown that microfabrication, employing high precision photolithographic patterning in combination with the controlled deposition of materials, can be used to successfully address these challenges. The resulting molten salt compatible microelectrodes (MSMs) enable prolonged quantitative microelectrode measurements in molten salts (MSs). This paper reports the fabrication of novel MSM disc electrodes, chosen because they have an established ambient analytical response. It includes a detailed set of electrochemical characterisation studies which demonstrate both their enhanced capability over macroelectrodes and over commercial glass pulled microelectrodes, and their ability to extract quantitative electroanalytical information from MS systems. MSM measurements are then used to demonstrate their potential for shedding new light on the fundamental properties of, and processes in, MSs, such as mass transport, charge transfer reaction rates and the selective plating/stripping and alloying reactions of liquid Bi and other metals; this will underpin the development of enhanced MS industrial processes, including pyrochemical spent nuclear fuel reprocessing.

  20. Advances in electroanalysis, sensing and monitoring in molten salts.

    PubMed

    Corrigan, Damion K; Elliott, Justin P; Blair, Ewen O; Reeves, Simon J; Schmüser, Ilka; Walton, Anthony J; Mount, Andrew R

    2016-08-15

    Microelectrodes have a number of advantages over macroelectrodes for quantitative electroanalysis and monitoring, including reduced iR drop, a high signal-to-noise ratio and reduced sensitivity to convection. Their use in molten salts has been generally precluded by the combined materials challenges of stresses associated with thermal cycling and physical and corrosive chemical degradation at the relatively high temperatures involved. We have shown that microfabrication, employing high precision photolithographic patterning in combination with the controlled deposition of materials, can be used to successfully address these challenges. The resulting molten salt compatible microelectrodes (MSMs) enable prolonged quantitative microelectrode measurements in molten salts (MSs). This paper reports the fabrication of novel MSM disc electrodes, chosen because they have an established ambient analytical response. It includes a detailed set of electrochemical characterisation studies which demonstrate both their enhanced capability over macroelectrodes and over commercial glass pulled microelectrodes, and their ability to extract quantitative electroanalytical information from MS systems. MSM measurements are then used to demonstrate their potential for shedding new light on the fundamental properties of, and processes in, MSs, such as mass transport, charge transfer reaction rates and the selective plating/stripping and alloying reactions of liquid Bi and other metals; this will underpin the development of enhanced MS industrial processes, including pyrochemical spent nuclear fuel reprocessing. PMID:27252128

  1. A theoretical investigation of gadolinium (III) solvation in molten salts

    NASA Astrophysics Data System (ADS)

    Hazebroucq, Sandrine; Picard, Gérard S.; Adamo, Carlo

    2005-06-01

    The solvation of lanthanides [here Gd(III)] in molten LiCl and KCl has been studied using a classical solvation approach, based on clusters of increasing size. In particular, density-functional calculations have been carried out on charged and neutral clusters, containing up to 35 chlorine halide molecules. A number of properties have been then evaluated and analyzed, including structural, vibrational, and thermochemical data. Special attention has also been devoted to the analysis of the local structure of the solvent surrounding the Gd3+ cation, a problem deeply investigated by experimentalists. Our results show that the charged clusters are not suitable to model the first solvation shell in such species, since their structures are strongly affected by the large electrostatic contribution. In contrast, more reliable simulations are obtained using the neutral clusters. In the latter, the coordination of Gd(III) in molten salts is computed to be 8 or 6, according to the salt LiCl or KCl. Furthermore, a good agreement is found with the experimental structural data and Raman spectra. Finally, preliminary results of potential interest for the estimation of solvation thermodynamics, a key parameter for exploiting molten salt chemistry, are reported for neutral clusters.

  2. Enhanced molten salt purification by electrochemical methods: feasibility experiments with flibe

    SciTech Connect

    Alan K Wertsching; Brandon S Grover; Pattrick Calderoni

    2010-09-01

    Molten salts are considered within the Very High Temperature Reactor program as heat transfer media because of their intrinsically favorable thermo-physical properties at temperatures starting from 300 C and extending up to 1200 C. In this context two main applications of molten salt are considered, both involving fluoride-based materials: as primary coolants for a heterogeneous fuel reactor core and as secondary heat transport medium to a helium power cycle for electricity generation or other processing plants, such as hydrogen production. The reference design concept here considered is the Advanced High Temperature Reactor (AHTR), which is a large passively safe reactor that uses solid graphite-matrix coated-particle fuel (similar to that used in gas-cooled reactors) and a molten salt primary and secondary coolant with peak temperatures between 700 and 1000 C, depending upon the application. However, the considerations included in this report apply to any high temperature system employing fluoride salts as heat transfer fluid, including intermediate heat exchangers for gas-cooled reactor concepts and homogenous molten salt concepts, and extending also to fast reactors, accelerator-driven systems and fusion energy systems. The most important initial requirement for heat transfer test of molten salt systems is the establishment of reference coolant materials to use in the experiments. An earlier report produced within the same project (INL/EXT-10-18297) highlighted how thermo-physical properties of the materials that directly impact the heat transfer behavior are strongly correlated to the of composition and impurities concentration of the melt. It is therefore essential to establish laboratory techniques that can measure the melt composition, and to develop purification methods that would allow the production of large quantities of coolant with the desired purity. A companion report titled ‘An experimental test plan for the characterization of molten salt thermo

  3. Liquid fuel molten salt reactors for thorium utilization

    DOE PAGESBeta

    Gehin, Jess C.; Powers, Jeffrey J.

    2016-04-08

    Molten salt reactors (MSRs) represent a class of reactors that use liquid salt, usually fluoride- or chloride-based, as either a coolant with a solid fuel (such as fluoride salt-cooled high temperature reactors) or as a combined coolant and fuel with fuel dissolved in a carrier salt. For liquid-fuelled MSRs, the salt can be processed online or in a batch mode to allow for removal of fission products as well as introduction of fissile fuel and fertile materials during reactor operation. The MSR is most commonly associated with the 233U/thorium fuel cycle, as the nuclear properties of 233U combined with themore » online removal of parasitic absorbers allow for the ability to design a thermal-spectrum breeder reactor; however, MSR concepts have been developed using all neutron energy spectra (thermal, intermediate, fast, and mixed-spectrum zoned concepts) and with a variety of fuels including uranium, thorium, plutonium, and minor actinides. Early MSR work was supported by a significant research and development (R&D) program that resulted in two experimental systems operating at ORNL in the 1960s, the Aircraft Reactor Experiment and the Molten Salt Reactor Experiment. Subsequent design studies in the 1970s focusing on thermal-spectrum thorium-fueled systems established reference concepts for two major design variants: (1) a molten salt breeder reactor (MSBR), with multiple configurations that could breed additional fissile material or maintain self-sustaining operation; and (2) a denatured molten salt reactor (DMSR) with enhanced proliferation-resistance. T MSRs has been selected as one of six most promising Generation IV systems and development activities have been seen in fast-spectrum MSRs, waste-burning MSRs, MSRs fueled with low-enriched uranium (LEU), as well as more traditional thorium fuel cycle-based MSRs. This study provides an historical background of MSR R&D efforts, surveys and summarizes many of the recent development, and provides analysis comparing

  4. Industrial use of molten nitrate/nitrite salts

    SciTech Connect

    Carling, R.W.; Mar, R.W.

    1981-12-01

    Nitrate salts have been used for years as a high-temperature heat transfer medium in the chemical and metal industries. This experience is often cited as an argument for the use of these salts in large-scale solar energy systems. However, this industrial experience has not been well documented and a study was carried out to provide such information to the solar community and to determine the applicability of this data base. Seven different industrial plants were visited and the plant operators were interviewed with regard to operating history and experience. In all cases the molten salt systems operate without problems. However, it is not possible to apply the base of industrial experience directly to solar thermal energy applications because of differences in operating temperature, salt composition, alloys used, and thermal/mechanical conditions.

  5. Technical review of Molten Salt Oxidation

    SciTech Connect

    Not Available

    1993-12-01

    The process was reviewed for destruction of mixed low-level radioactive waste. Results: extensive development work and scaleup has been documented on coal gasification and hazardous waste which forms a strong experience base for this MSO process; it is clearly applicable to DOE wastes such as organic liquids and low-ash wastes. It also has potential for processing difficult-to-treat wastes such as nuclear grade graphite and TBP, and it may be suitable for other problem waste streams such as sodium metal. MSO operating systems may be constructed in relatively small units for small quantity generators. Public perceptions could be favorable if acceptable performance data are presented fairly; MSO will likely require compliance with regulations for incineration. Use of MSO for offgas treatment may be complicated by salt carryover. Figs, tabs, refs.

  6. Role of molten salt flux in melting of used beverage container (UBC) scrap

    SciTech Connect

    Ye, J.; Sahai, Y.

    1995-12-31

    Recycling of aluminum scrap, such as Used Beverage Container (UBC) scrap is steadily increasing. In secondary remelting of such scrap, it is a common practice to use protective molten salt cover. An appropriate salt protects metal from oxidation, promotes coalescence of the suspended metal droplets, and separates clean metal from the oxide contamination. The molten salt also reacts with metal. This causes metal loss and change of resulting metal composition. In this paper, role of molten salt fluxes in melting of UBC scrap is discussed, and selection criteria for molten salt are provided.

  7. Application of molten salt oxidation for the minimization and recovery of plutonium-238 contaminated wastes

    SciTech Connect

    Wishau, R.

    1998-05-01

    Molten salt oxidation (MSO) is proposed as a {sup 238}Pu waste treatment technology that should be developed for volume reduction and recovery of {sup 238}Pu and as an alternative to the transport and permanent disposal of {sup 238}Pu waste to the WIPP repository. In MSO technology, molten sodium carbonate salt at 800--900 C in a reaction vessel acts as a reaction media for wastes. The waste material is destroyed when injected into the molten salt, creating harmless carbon dioxide and steam and a small amount of ash in the spent salt. The spent salt can be treated using aqueous separation methods to reuse the salt and to recover 99.9% of the precious {sup 238}Pu that was in the waste. Tests of MSO technology have shown that the volume of combustible TRU waste can be reduced by a factor of at least twenty. Using this factor the present inventory of 574 TRU drums of {sup 238}Pu contaminated wastes is reduced to 30 drums. Further {sup 238}Pu waste costs of $22 million are avoided from not having to repackage 312 of the 574 drums to a drum total of more than 4,600 drums. MSO combined with aqueous processing of salts will recover approximately 1.7 kilograms of precious {sup 238}Pu valued at 4 million dollars (at $2,500/gram). Thus, installation and use of MSO technology at LANL will result in significant cost savings compared to present plans to transport and dispose {sup 238}Pu TRU waste to the WIPP site. Using a total net present value cost for the MSO project as $4.09 million over a five-year lifetime, the project can pay for itself after either recovery of 1.6 kg of Pu or through volume reduction of 818 drums or a combination of the two. These savings show a positive return on investment.

  8. From molten salts to ionic liquids: a "nano" journey.

    PubMed

    Dupont, Jairton

    2011-11-15

    Ionic liquids (ILs), a special group of classical molten salts, are widely used in various fields of science. Historically, researchers have tested ILs out of curiosity or to improve a specific property in a particular system in many areas of chemistry or materials science. However, today, ILs are far from being simple chemical curiosities and sit at the center of various green industrial innovation processes, where they play important roles in materials extraction, reactive catalytic supports, spatial devices, and biotransformations. In this Account, we describe a journey into a nanostructured universe to better understand the unique properties of ionic liquids and their modern applications. Because molten salts have been known for centuries and have found limited uses, we try to explain why modern nonaqueous ILs deserve increased interest and curiosity. We discuss the characteristics that distinguish modern nonaqueous ILs and compare them with classical molten salts. One of the main differences between room temperature ILs, especially those based on imidazolium cations, and simple molten salts, is the molecular asymmetry built into at least one of the ions. This asymmetry in modern, nonaqueous ILs opposes the strong charge ordering due to ionic interactions that normally would cause the system to crystallize. In addition, the presence of a cooperative network of hydrogen bonds between the cations and anions induces structural directionality (the entropic effect). Therefore, modern ILs form preorganized structures, mainly through hydrogen bonding, that induce structural directionality. In contrast, classical salts form aggregates only through ionic bonds. In other words, weak interactions order the structures in modern ILs while charges order the structure within classical salts. ILs cannot be regarded as merely homogeneous solvents. In fact, ILs form extended hydrogen-bond networks with polar and nonpolar nano domains and therefore are by definition

  9. Molten Chloride Salts for Heat Transfer in Nuclear Systems

    NASA Astrophysics Data System (ADS)

    Ambrosek, James Wallace

    2011-12-01

    A forced convection loop was designed and constructed to examine the thermal-hydraulic performance of molten KCl-MgCl2 (68-32 at %) salt for use in nuclear co-generation facilities. As part of this research, methods for prediction of the thermo-physical properties of salt mixtures for selection of the coolant salt were studied. In addition, corrosion studies of 10 different alloys were exposed to the KCl-MgCl2 to determine a suitable construction material for the loop. Using experimental data found in literature for unary and binary salt systems, models were found, or developed to extrapolate the available experimental data to unstudied salt systems. These property models were then used to investigate the thermo-physical properties of the LINO3-NaNO3-KNO 3-Ca(NO3), system used in solar energy applications. Using these models, the density, viscosity, adiabatic compressibility, thermal conductivity, heat capacity, and melting temperatures of higher order systems can be approximated. These models may be applied to other molten salt systems. Coupons of 10 different alloys were exposed to the chloride salt for 100 hours at 850°C was undertaken to help determine with which alloy to construct the loop. Of the alloys exposed, Haynes 230 had the least amount of weight loss per area. Nickel and Hastelloy N performed best based on maximum depth of attack. Inconel 625 and 718 had a nearly uniform depletion of Cr from the surface of the sample. All other alloys tested had depletion of Cr along the grain boundaries. The Nb in Inconel 625 and 718 changed the way the Cr is depleted in these alloys. Grain-boundary engineering (GBE) of Incoloy 800H improved the corrosion resistance (weight loss and maximum depth of attack) by nearly 50% as compared to the as-received Incoloy 800H sample. A high temperature pump, thermal flow meter, and pressure differential device was designed, constructed and tested for use in the loop, The heat transfer of the molten chloride salt was found to

  10. Molten Salt Fuel Cycle Requirements for ADTT Applications

    SciTech Connect

    Williams, D. F.; Del Cul, G. D.; Toth, L. M.

    1999-06-07

    The operation of an ADT system with the associated nuclear reactions has a profound effect upon the chemistry of the fuel - especially with regards to container compatibility and the chemical separations that may be required. The container can be protected by maintaining the redox chemistry within a relatively narrow, non-corrosive window. Neutron economy as well as other factors require a sophisticated regime of fission product separations. Neither of these control requirements has been demonstrated on the scale or degree of sophistication necessary to support an ADT device. We review the present situation with respect to fluoride salts, and focus on the critical issues in these areas which must be addressed. One requirement for advancement in this area - a supply of suitable materials - will soon be fulfilled by the remediation of ORNL's Molten Salt Reactor Experiment, and the removal of a total of 11,000 kg of enriched (Li-7 > 99.9%) coolant, flush, and fuel salts.

  11. Steam methane reforming in molten carbonate salt. Final report

    SciTech Connect

    Erickson, D.C.

    1996-05-01

    This report documents the work accomplished on the project {open_quotes}Steam Methane Reforming in Molten Carbonate Salt.{close_quotes}. This effort has established the conceptual basis for molten carbonate-based steam reforming of methane. It has not proceeded to prototype verification, because corrosion concerns have led to reluctance on the part of large hydrogen producers to adopt the technology. Therefore the focus was shifted to a less corrosive embodiment of the same technology. After considerable development effort it was discovered that a European company (Catalysts and Chemicals Europe) was developing a similar process ({open_quotes}Regate{close_quotes}). Accordingly the focus was shifted a second time, to develop an improvement which is generic to both types of reforming. That work is still in progress, and shows substantial promise.

  12. Chronopotentiometry of refractory metals, actinides and oxyanions in molten salts: A review

    NASA Technical Reports Server (NTRS)

    Bansal, Narottam P.

    1992-01-01

    The applications of chronopotentiometry to the study of electrochemical behavior of three technologically important areas of refractory metals, actinides, and oxyanions in molten salts are critically reviewed. Chronopotentiometry is a very versatile diagnostic tool to understand the reaction mechanism of the electrode processes for the electrochemical reduction/oxidation of these electroactive species in molten salt solutions. Well adherent, compact, and uniformly thick coatings of refractory metals may be electrodeposited from their solutions in molten salts.

  13. Chronopotentiometry of refractory metals, actinides and oxyanions in molten salts: A review

    SciTech Connect

    Bansal, N.P.

    1992-09-01

    The applications of chronopotentiometry to the study of electrochemical behavior of three technologically important areas of refractory metals, actinides, and oxyanions in molten salts are critically reviewed. Chronopotentiometry is a very versatile diagnostic tool to understand the reaction mechanism of the electrode processes for the electrochemical reduction/oxidation of these electroactive species in molten salt solutions. Well adherent, compact, and uniformly thick coatings of refractory metals may be electrodeposited from their solutions in molten salts.

  14. Oxidation of hydrogen halides to elemental halogens with catalytic molten salt mixtures

    DOEpatents

    Rohrmann, Charles A.

    1978-01-01

    A process for oxidizing hydrogen halides by means of a catalytically active molten salt is disclosed. The subject hydrogen halide is contacted with a molten salt containing an oxygen compound of vanadium and alkali metal sulfates and pyrosulfates to produce an effluent gas stream rich in the elemental halogen. The reduced vanadium which remains after this contacting is regenerated to the active higher valence state by contacting the spent molten salt with a stream of oxygen-bearing gas.

  15. Maintaining molten salt electrolyte concentration in aluminum-producing electrolytic cell

    DOEpatents

    Barnett, Robert J.; Mezner, Michael B.; Bradford, Donald R

    2005-01-04

    A method of maintaining molten salt concentration in a low temperature electrolytic cell used for production of aluminum from alumina dissolved in a molten salt electrolyte contained in a cell free of frozen crust wherein volatile material is vented from the cell and contacted and captured on alumina being added to the cell. The captured volatile material is returned with alumina to cell to maintain the concentration of the molten salt.

  16. Diffusion Welding of Alloys for Molten Salt Service - Status Report

    SciTech Connect

    Denis Clark; Ronald Mizia; Piyush Sabharwall

    2012-09-01

    The present work is concerned with heat exchanger development for molten salt service, including the proposed molten salt reactor (MSR), a homogeneous reactor in which the fuel is dissolved in a circulating fluid of molten salt. It is an outgrowth of recent work done under the Next Generation Nuclear Plant (NGNP) program; what the two reactor systems have in common is an inherently safe nuclear plant with a high outlet temperature that is useful for process heat as well as more conventional generation The NGNP program was tasked with investigating the application of a new generation of nuclear power plants to a variety of energy needs. One baseline reactor design for this program is a high temperature, gas-cooled reactor (HTGR), which provides many options for energy use. These might include the conventional Rankine cycle (steam turbine) generation of electricity, but also other methods: for example, Brayton cycle (gas turbine) electrical generation, and the direct use of the high temperatures characteristic of HTGR output for process heat in the chemical industry. Such process heat is currently generated by burning fossil fuels, and is a major contributor to the carbon footprint of the chemical and petrochemical industries. The HTGR, based on graphite fuel elements, can produce very high output temperatures; ideally, temperatures of 900 °C or even greater, which has significant energy advantages. Such temperatures are, of course, at the frontiers of materials limitations, at the upper end of the performance envelope of the metallic materials for which robust construction codes exist, and within the realm of ceramic materials, the fabrication and joining of which, on the scale of large energy systems, are at an earlier stage of development. A considerable amount of work was done in the diffusion welding of materials of interest for HTGR service with alloys such as 617 and 800H. The MSR output temperature is also materials limited, and is projected at about 700

  17. Diffusion Welding of Alloys for Molten Salt Service - Status Report

    SciTech Connect

    Denis Clark; Ronald Mizia

    2012-05-01

    The present work is concerned with heat exchanger development for molten salt service, including the proposed molten salt reactor (MSR), a homogeneous reactor in which the fuel is dissolved in a circulating fluid of molten salt. It is an outgrowth of recent work done under the Next Generation Nuclear Plant (NGNP) program; what the two reactor systems have in common is an inherently safe nuclear plant with a high outlet temperature that is useful for process heat as well as more conventional generation The NGNP program was tasked with investigating the application of a new generation of nuclear power plants to a variety of energy needs. One baseline reactor design for this program is a high temperature, gas-cooled reactor (HTGR), which provides many options for energy use. These might include the conventional Rankine cycle (steam turbine) generation of electricity, but also other methods: for example, Brayton cycle (gas turbine) electrical generation, and the direct use of the high temperatures characteristic of HTGR output for process heat in the chemical industry. Such process heat is currently generated by burning fossil fuels, and is a major contributor to the carbon footprint of the chemical and petrochemical industries. The HTGR, based on graphite fuel elements, can produce very high output temperatures; ideally, temperatures of 900 C or even greater, which has significant energy advantages. Such temperatures are, of course, at the frontiers of materials limitations, at the upper end of the performance envelope of the metallic materials for which robust construction codes exist, and within the realm of ceramic materials, the fabrication and joining of which, on the scale of large energy systems, are at an earlier stage of development. A considerable amount of work was done in the diffusion welding of materials of interest for HTGR service with alloys such as 617 and 800H. The MSR output temperature is also materials limited, and is projected at about 700 C

  18. Sensitivity and Uncertainty Study for Thermal Molten Salt Reactors

    NASA Astrophysics Data System (ADS)

    Bidaud, Adrien; Ivanona, Tatiana; Mastrangelo, Victor; Kodeli, Ivo

    2006-04-01

    The Thermal Molten Salt Reactor (TMSR) using the thorium cycle can achieve the GEN IV objectives of economy, safety, non-proliferation and durability. Its low production of higher actinides, coupled with its breeding capabilities - even with a thermal spectrum - are very valuable characteristics for an innovative reactor. Furthermore, the thorium cycle is more flexible than the uranium cycle since only a small fissile inventory (<2 tons by GWe) is required to start one reactor. The potential of these reactors is currently being extensively studied at the CNRS and EdF /1,2/. A simplified chemical reprocessing is envisaged compared to that used for the former Molten Salt Breeder Reactor (MSBR). The MSBR concept was developed at Oak Ridge National Laboratory (ORNL) in the 1970's based on the Molten Salt Reactor Experiment (MSRE). The main goals of our current studies are to achieve a reactor concept that enables breeding, improved safety and having chemical reprocessing needs reduced and simplified as much as reasonably possible. The neutronic properties of the new TMSR concept are presented in this paper. As the temperature coefficient is close to zero, we will see that the moderation ratio cannot be chosen to simultaneously achieve a high breeding ratio, long graphite lifetime and low uranium inventory. It is clear that any safety margin taken due to uncertainty in the nuclear data will significantly reduce the capability of this concept, thus a sensitivity analysis is vital to propose measurements which would allow to reduce at present high uncertainties in the design parameters of this reactor. Two methodologies, one based on OECD/NEA deterministic codes and one on IPPE (Obninsk) stochastic code, are compared for keff sensitivity analysis. The uncertainty analysis of keff using covariance matrices available in evaluated files has been performed. Furthermore, a comparison of temperature coefficient sensitivity profiles is presented for the most important reactions

  19. Helium-cooled molten-salt fusion breeder

    SciTech Connect

    Moir, R.W.; Lee, J.D.; Fulton, F.J.; Huegel, F.; Neef, W.S. Jr.; Sherwood, A.E.; Berwald, D.H.; Whitley, R.H.; Wong, C.P.C.; Devan, J.H.

    1984-12-01

    We present a new conceptual design for a fusion reactor blanket that is intended to produce fissile material for fission power plants. Fast fission is suppressed by using beryllium instead of uranium to multiply neutrons. Thermal fission is suppressed by minimizing the fissile inventory. The molten-salt breeding medium (LiF + BeF/sub 2/ + ThF/sub 4/) is circulated through the blanket and to the on-line processing system where /sup 233/U and tritium are continuously removed. Helium cools the blanket and the austenitic steel tubes that contain the molten salt. Austenitic steel was chosen because of its ease of fabrication, adequate radiation-damage lifetime, and low corrosion by molten salt. We estimate that a breeder having 3000 MW of fusion power will produce 6500 kg of /sup 233/U per year. This amount is enough to provide makeup for 20 GWe of light-water reactors per year or twice that many high-temperature gas-cooled reactors or Canadian heavy-water reactors. Safety is enhanced because the afterheat is low and blanket materials do not react with air or water. The fusion breeder based on a pre-MARS tandem mirror is estimated to cost $4.9B or 2.35 times a light-water reactor of the same power. The estimated cost of the /sup 233/U produced is $40/g for fusion plants costing 2.35 times that of a light-water reactor if utility owned or $16/g if government owned.

  20. Specific heat capacity of molten salt-based alumina nanofluid.

    PubMed

    Lu, Ming-Chang; Huang, Chien-Hsun

    2013-06-21

    There is no consensus on the effect of nanoparticle (NP) addition on the specific heat capacity (SHC) of fluids. In addition, the predictions from the existing model have a large discrepancy from the measured SHCs in nanofluids. We show that the SHC of the molten salt-based alumina nanofluid decreases with reducing particle size and increasing particle concentration. The NP size-dependent SHC is resulted from an augmentation of the nanolayer effect as particle size reduces. A model considering the nanolayer effect which supports the experimental results was proposed.

  1. Advances toward industrialization of novel molten salt electrochemical processes.

    PubMed

    Ito, Yasuhiko; Nishikiori, Tokujiro; Tsujimura, Hiroyuki

    2016-08-15

    We have invented various novel molten salt electrochemical processes, that can be put to practical use in the fields of energy and materials. These processes are promising from both technological and commercial viewpoints, and they are currently under development for industrial application. To showcase current developments in work toward industrialization, we focus here on three of these processes: (1) electrolytic synthesis of ammonia from water and nitrogen under atmospheric pressure, (2) electrochemical formation of carbon film, and (3) plasma-induced discharge electrolysis to produce nanoparticles.

  2. Advances toward industrialization of novel molten salt electrochemical processes.

    PubMed

    Ito, Yasuhiko; Nishikiori, Tokujiro; Tsujimura, Hiroyuki

    2016-08-15

    We have invented various novel molten salt electrochemical processes, that can be put to practical use in the fields of energy and materials. These processes are promising from both technological and commercial viewpoints, and they are currently under development for industrial application. To showcase current developments in work toward industrialization, we focus here on three of these processes: (1) electrolytic synthesis of ammonia from water and nitrogen under atmospheric pressure, (2) electrochemical formation of carbon film, and (3) plasma-induced discharge electrolysis to produce nanoparticles. PMID:27265244

  3. Effects of Cations on Corrosion of Inconel 625 in Molten Chloride Salts

    NASA Astrophysics Data System (ADS)

    Zhu, Ming; Ma, Hongfang; Wang, Mingjing; Wang, Zhihua; Sharif, Adel

    2016-04-01

    Hot corrosion of Inconel 625 in sodium chloride, potassium chloride, magnesium chloride, calcium chloride and their mixtures with different compositions is conducted at 900°C to investigate the effects of cations in chloride salts on corrosion behavior of the alloy. XRD, SEM/EDS were used to analyze the compositions, phases, and morphologies of the corrosion products. The results showed that Inconel 625 suffers more severe corrosion in alkaline earth metal chloride molten salts than alkaline metal chloride molten salts. For corrosion in mixture salts, the corrosion rate increased with increasing alkaline earth metal chloride salt content in the mixture. Cations in the chloride molten salts mainly affect the thermal and chemical properties of the salts such as vapor pressure and hydroscopicities, which can affect the basicity of the molten salt. Corrosion of Inconel 625 in alkaline earth metal chloride salts is accelerated with increasing basicity.

  4. Molten Salt Test Loop (MSTL) system customer interface document.

    SciTech Connect

    Gill, David Dennis; Kolb, William J.; Briggs, Ronald D.

    2013-09-01

    The National Solar Thermal Test Facility at Sandia National Laboratories has a unique test capability called the Molten Salt Test Loop (MSTL) system. MSTL is a test capability that allows customers and researchers to test components in flowing, molten nitrate salt. The components tested can range from materials samples, to individual components such as flex hoses, ball joints, and valves, up to full solar collecting systems such as central receiver panels, parabolic troughs, or linear Fresnel systems. MSTL provides realistic conditions similar to a portion of a concentrating solar power facility. The facility currently uses 60/40 nitrate %E2%80%9Csolar salt%E2%80%9D and can circulate the salt at pressure up to 40 bar (600psi), temperature to 585%C2%B0C, and flow rate of 44-50kg/s(400-600GPM) depending on temperature. The purpose of this document is to provide a basis for customers to evaluate the applicability to their testing needs, and to provide an outline of expectations for conducting testing on MSTL. The document can serve as the basis for testing agreements including Work for Others (WFO) and Cooperative Research and Development Agreements (CRADA). While this document provides the basis for these agreements and describes some of the requirements for testing using MSTL and on the site at Sandia, the document is not sufficient by itself as a test agreement. The document, however, does provide customers with a uniform set of information to begin the test planning process.

  5. Summary of the Workshop on Molten Salt Reactor Technologies Commemorating the 50th Anniversary of the Startup of the Molten Salt Reactor Experiment

    SciTech Connect

    Betzler, Benjamin R; Mays, Gary T

    2016-01-01

    A workshop on Molten Salt Reactor (MSR) technologies commemorating the 50th anniversary of the Molten Salt Reactor Experiment (MSRE) was held at Oak Ridge National Laboratory on October 15 16, 2015. The MSRE represented a pioneering experiment that demonstrated an advanced reactor technology: the molten salt eutectic-fueled reactor. A multinational group of more than 130 individuals representing a diverse set of stakeholders gathered to discuss the historical, current, and future technical challenges and paths to deployment of MSR technology. This paper provides a summary of the key messages from this workshop.

  6. Steady State Analysis of Small Molten Salt Reactor

    NASA Astrophysics Data System (ADS)

    Yamamoto, Takahisa; Mitachi, Koshi; Suzuki, Takashi

    The Molten Salt Reactor (MSR) is a thermal neutron reactor with graphite moderation and operates on the thorium-uranium fuel cycle. The feature of the MSR is that fuel salt flows inside the reactor during the nuclear fission reaction. In the previous study, the authors developed numerical model with which to simulate the effects of fuel salt flow on the reactor characteristics. In this study, we apply the model to the steady-state analysis of a small MSR system and estimate the effects of fuel flow. The model consists of two-group neutron diffusion equations for fast and thermal neutron fluxes, transport equations for six-group delayed neutron precursors and energy conservation equations for fuel salt and the graphite moderator. The following results are obtained: (1) in the rated operation condition, the peaks of the neutron fluxes slightly move toward the bottom from the center of the reactor and the delayed neutron precursors are significantly carried by the fuel salt flow, and (2) the extension of residence time in the external-loop system and the rise of the fuel inflow temperature show weak negative reactivity effects, which decrease the neutron multiplication factor of the small MSR system.

  7. Unsteady Characteristics of Three-Core Molten Salt Reactor

    NASA Astrophysics Data System (ADS)

    Yamamoto, Takahisa; Mitachi, Koshi; Nishio, Masatoshi

    Numerical analysis has been performed for load-following capability of a 465 MWth Three-Core Molten Salt Reactor (MSR). “Reactor-slaved-to-turbine control technique” is adopted for reactor control. As for this control technique, a turbine is controlled by a speed regulator of a generator, and subsequently the reactor is controlled so as to follow the turbine output. In this study, the turbine power is rapidly changed in a range of 50-150% of the rated power. Then transient characteristics of fuel salt and graphite temperatures, neutron fluxes, delayed neutron precursors, and reactor output are calculated. The analysis result shows that the reactor output is capable of following the turbine power in the range of the turbine output of 50-150%.

  8. Cooling molten salt reactors using "gas-lift"

    NASA Astrophysics Data System (ADS)

    Zitek, Pavel; Valenta, Vaclav; Klimko, Marek

    2014-08-01

    This study briefly describes the selection of a type of two-phase flow, suitable for intensifying the natural flow of nuclear reactors with liquid fuel - cooling mixture molten salts and the description of a "Two-phase flow demonstrator" (TFD) used for experimental study of the "gas-lift" system and its influence on the support of natural convection. The measuring device and the application of the TDF device is described. The work serves as a model system for "gas-lift" (replacing the classic pump in the primary circuit) for high temperature MSR planned for hydrogen production. An experimental facility was proposed on the basis of which is currently being built an experimental loop containing the generator, separator bubbles and necessary accessories. This loop will model the removal of gaseous fission products and tritium. The cleaning of the fuel mixture of fluoride salts eliminates problems from Xenon poisoning in classical reactors.

  9. Cooling molten salt reactors using “gas-lift”

    SciTech Connect

    Zitek, Pavel E-mail: klimko@kke.zcu.cz; Valenta, Vaclav E-mail: klimko@kke.zcu.cz; Klimko, Marek E-mail: klimko@kke.zcu.cz

    2014-08-06

    This study briefly describes the selection of a type of two-phase flow, suitable for intensifying the natural flow of nuclear reactors with liquid fuel - cooling mixture molten salts and the description of a “Two-phase flow demonstrator” (TFD) used for experimental study of the “gas-lift” system and its influence on the support of natural convection. The measuring device and the application of the TDF device is described. The work serves as a model system for “gas-lift” (replacing the classic pump in the primary circuit) for high temperature MSR planned for hydrogen production. An experimental facility was proposed on the basis of which is currently being built an experimental loop containing the generator, separator bubbles and necessary accessories. This loop will model the removal of gaseous fission products and tritium. The cleaning of the fuel mixture of fluoride salts eliminates problems from Xenon poisoning in classical reactors.

  10. Molten salt thermal energy storage for utility peaking loads

    NASA Technical Reports Server (NTRS)

    Ferrara, A.; Haslett, R.; Joyce, J.

    1977-01-01

    This paper considers the use of thermal energy storage (TES) in molten salts to increase the capacity of power plants. Five existing fossil and nuclear electric utility plants were selected as representative of current technology. A review of system load diagrams indicated that TES to meet loads over 95% of peak was a reasonable goal. Alternate TES heat exchanger locations were evaluated, showing that the stored energy should be used either for feedwater heating or to generate steam for an auxiliary power cycle. Specific salts for each concept are recommended. Design layouts were prepared for one plant, and it was shown that a TES tube/shell heat exchanger system could provide about 7% peaking capability at lower cost than adding steam generation capacity. Promising alternate heat exchanger concepts were also identified.

  11. Wetting behavior of dialkylimidazolium chloroaluminate, a room temperature molten salt

    SciTech Connect

    Eberhart, J.

    1985-08-01

    Eberhart (1979) has found that the wetting behavior of a battery electrolyte can have a dramatic effect on the internal resistance of the battery as well as its cycle life. Good wetting of battery separators by electrolyte is essential for the easy passage of ions through the separator pores, while porous, gas diffusion electrodes require a lesser degree of wetting. For several years, a room temperature molten salt system has been under study. This system is composed of 1-methyl-3-ethylimidazolium chloride (C6N2H11Cl or MeEtImCl) plus aluminum chloride. The application of this novel liquid solution as a battery electrolyte appears to be promising. Available data suggest that likely candidates include cells with a chlorine positive electrode reactant and a magnesium, aluminum, or zinc negative electrode material. The present investigation is concerned with an assessment of the wetting behavior in the considered system, taking into account a study of the contact angles of various room temperature molten salts on candidate battery separator and porous electrode materials. 10 references.

  12. The influence of the anionic species of a molten salt on lipid organization

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Room-temperature molten salts have become the solvent of choice to replace organic solvents in processing commodity plant lipids. Replacing the typical organic solvent with molten salts reduces common hazards, such as volatility and flammability, associated with organic solvent use. In addition, m...

  13. On the exploration of molten salt (FLiNaK) interaction with plasma

    NASA Astrophysics Data System (ADS)

    Choi, Yong-Sup; Park, Hyonjae; Lho, Taihyeop

    2011-10-01

    We investigated possibility of application of molten salt as a liquid wall in plasma confinement device. Plasma interactions of molten salt - FLiNaK (LiF 46.5 mol% + NaF 11.5% + KF 42 mol%) were investigated by OES(Optical Emission Spectroscopy) and RGA(Residual Gas Analyzer). The plasma was generated with ECR source and the molten salt was maintained as liquid with SUS 316 mold-heater. Optical and mass spectrums were measured during hydrogen plasma interaction with the molten salt and qualitative analysis of resultant species was done. Chemical/physical erosion of FLiNaK after interaction of hydrogen plasma was studied with ICP-MS and IC (Ion Chromatography). Viscosity change of FLiNaK after plasma interaction was measured. Based on the preliminary measurement result, a plasma interaction system with flowing molten salt was designed.

  14. Recent advances in the molten salt destruction of energetic materials

    SciTech Connect

    Pruneda, C. O., LLNL

    1996-09-01

    We have demonstrated the use of the Molten Salt Destruction (MSD) Process for destroying explosives, liquid gun propellant, and explosives-contaminated materials on a 1.5 kg of explosive/hr bench- scale unit (1, 2, 3, 4, 5). In our recently constructed 5 kg/hr pilot- scale unit we have also demonstrated the destruction of a liquid gun propellant and simulated wastes containing HMX (octogen). MSD converts the organic constituents of the waste into non-hazardous substances such as carbon dioxide, nitrogen, and water. Any inorganic constituents of the waste, such as metallic particles, are retained in the molten salt. The destruction of energetic materials waste is accomplished by introducing it, together with air, into a vessel containing molten salt (a eutectic mixture of sodium, potassium, and lithium carbonates). The following pure explosives have been destroyed in our bench-scale experimental unit located at Lawrence Livermore National Laboratory`s (LLNL) High Explosives Applications Facility (HEAF): ammonium picrate, HMX, K- 6 (keto-RDX), NQ, NTO, PETN, RDX, TATB, and TNT. In addition, the following compositions were also destroyed: Comp B, LX- IO, LX- 1 6, LX- 17, PBX-9404, and XM46 (liquid gun propellant). In this 1.5 kg/hr bench-scale unit, the fractions of carbon converted to CO and of chemically bound nitrogen converted to NO{sub x} were found to be well below 1%. In addition to destroying explosive powders and compositions we have also destroyed materials that are typical of residues which result from explosives operations. These include shavings from machined pressed parts of plastic-bonded explosives and sump waste containing both explosives and non-explosive debris. Based on the process data obtained on the bench-scale unit we designed and constructed a next-generation 5 kg/hr pilot-scale unit, incorporating LLNL`s advanced chimney design. The pilot unit has completed process implementation operations and explosives safety reviews. To date, in this

  15. Method of removal of heavy metal from molten salt in IFR fuel pyroprocessing

    SciTech Connect

    Gay, E.C.

    1993-12-23

    An electrochemical method of separating heavy metal values from a radioactive molten salt including Li halide at temperatures of about 500{degree}C. The method comprises positioning a solid Li-Cd alloy anode in the molten salt containing the heavy metal values, positioning a Cd-containing cathode or a solid cathode positioned above a catch crucible in the molten salt to recover the heavy metal values, establishing a voltage drop between the anode and the cathode to deposit material at the cathode to reduce the concentration of heavy metals in the salt, and controlling the deposition rate at the cathode by controlling the current between the anode and cathode.

  16. Method of removal of heavy metal from molten salt in IFR fuel pyroprocessing

    DOEpatents

    Gay, Eddie C.

    1995-01-01

    An electrochemical method of separating heavy metal values from a radioactive molten salt including Li halide at temperatures of about 500.degree. C. The method comprises positioning a solid Li--Cd alloy anode in the molten salt containing the heavy metal values, positioning a Cd-containing cathode or a solid cathode positioned above a catch crucible in the molten salt to recover the heavy metal values, establishing a voltage drop between the anode and the cathode to deposit material at the cathode to reduce the concentration of heavy metals in the salt, and controlling the deposition rate at the cathode by controlling the current between the anode and cathode.

  17. Materials corrosion in molten LiF-NaF-KF eutectic salt under different reduction-oxidation conditions

    SciTech Connect

    Sellers, R. S.; Cheng, W. J.; Anderson, M. H.; Sridharan, K.; Wang, C. J.; Allen, T. R.

    2012-07-01

    Molten fluoride salts such as FLiNaK (LiF-NaF-KF: 46.5-11.5-42 mol %) have been proposed for use as secondary reactor coolants, media for transfer of high temperature process heat from nuclear reactors to chemical plants, and for concentrated solar power thermal energy storage. In molten fluoride salts, passive oxide films are chemically unstable, and corrosion is driven largely by the thermodynamically driven dissolution of alloying elements into the molten salt environment. Two alloys, Hastelloy{sup R} N and 316L stainless steel were exposed to molten FLiNaK salt in a 316L stainless steel crucible under argon cover gas for 1000 hours at 850 deg. C. Graphite was present in some of the crucibles with the goal of studying corrosion behavior of relevant reactor material combinations. In addition, a technique to reduce alloy corrosion through modification of the reduction-oxidation state was tested by the inclusion of zirconium to the system. Corrosion of 316L stainless steel was noted to occur primarily through surface depletion of chromium, an effect that was enhanced by the presence of graphite. Hastelloy{sup R} N experienced weight gain through electrochemical plating of corrosion products derived from the 316L stainless steel crucible. In the presence of zirconium, both alloys gained weight through plating of zirconium and as a result formed intermetallic layers. (authors)

  18. High-temperature molten salt thermal energy storage systems

    NASA Technical Reports Server (NTRS)

    Petri, R. J.; Claar, T. D.; Tison, R. R.; Marianowski, L. G.

    1980-01-01

    The results of comparative screening studies of candidate molten carbonate salts as phase change materials (PCM) for advanced solar thermal energy storage applications at 540 to 870 C (1004 to 1600 F) and steam Rankine electric generation at 400 to 540 C (752 to 1004 F) are presented. Alkali carbonates are attractive as latent heat storage materials because of their relatively high storage capacity and thermal conductivity, low corrosivity, moderate cost, and safe and simple handling requirements. Salts were tested in 0.1 kWhr lab scale modules and evaluated on the basis of discharge heat flux, solidification temperature range, thermal cycling stability, and compatibility with containment materials. The feasibility of using a distributed network of high conductivity material to increase the heat flux through the layer of solidified salt was evaluated. The thermal performance of an 8 kWhr thermal energy storage (TES) module containing LiKCO3 remained very stable throughout 5650 hours and 130 charge/discharge cycles at 480 to 535 C (896 to 995 F). A TES utilization concept of an electrical generation peaking subsystem composed of a multistage condensing steam turbine and a TES subsystem with a separate power conversion loop was defined. Conceptual designs for a 100 MW sub e TES peaking system providing steam at 316 C, 427 C, and 454 C (600 F, 800 F, and 850 F) at 3.79 million Pa (550 psia) were developed and evaluated. Areas requiring further investigation have also been identified.

  19. Dismantled weapons fuel burning in molten salt reactors

    SciTech Connect

    Gat, U.; Engel, J.R.

    1993-10-01

    The advantages of burning fissile material from dismantled weapons in molten salt reactors (MSRs) are described. The fluid fuel MSRs with some, or full, processing are nondedicated reactors that generate energy and completely burn the fissile material on a continuous basis. No fuel fabrication is needed, and the entire dismantling can be done in a secure facility. Shipments are made in small, safe, and secure quantities. Denaturing, spiking, or mixing can be done at the source for added safety. MSRs are very safe reactors that help close the fuel cycle and simplify waste treatment, thereby contributing to acceptability. Additionally, MSRs are expected to be economically competitive as electric power stations. The safety, security, simplicity, economy, and proliferation resistant properties support the deployment in countries that have the need.

  20. The case for the thorium molten salt reactor

    NASA Astrophysics Data System (ADS)

    Greaves, E. D.; Furukawa, K.; Sajo-Bohus, L.; Barros, H.

    2012-02-01

    Shortcomings of current PWR and BWR, solid uranium-fuel, nuclear power reactors are summarized. It is shown how the Molten Salt Reactor (MSR) created and operated at Oak Ridge National Laboratory (ORNL), USA (1960s-1970s) and developed as FUJI reactor by Furukawa and collaborators (1980s-1990s), addresses all of these shortcomings. Relevant properties of the MSR regarding to simplicity, its impact on capital and operating costs, safety, waste product production, waste reprocessing, power efficiency and non proliferation properties are reviewed. The Thorium MSR within the THORIMS-NES fuel cycle system is described concluding that the superior properties of the MSR make this the technology of choice to provide the required future energy in the South American region.

  1. Conceptual design of a thorium for molten salt transmutation systems

    SciTech Connect

    Buksa, J.J.; Beard, C.A.; Veneri, F.; Elson, J.S.; Park, J.J.; Prael, R.E.; Waters, L.S.; Davidson, J.W.

    1994-09-01

    A spallation target constructed of thorium metal has been designed for applications using molten-salt as the target coolant. The design consists of an array of wire-wrapped, hastelloy-clad, thorium rods in which a parabolic void region is introduced in the upper regions. Each target rod is approximately 1 m in length, 3.1 an in diameter, and has a clad thickness of 0.05 cm; 140 rods are arranged in a triangular lattice with a pitch of 3.2 cm, which results in a cylindrical target configuration with a radius of 20 cm and an estimated yield of 17 neutrons/proton 800 MeV protons.

  2. Aluminum anodization in a basic ambient temperature molten salt

    SciTech Connect

    Carlin, R.T.; Osteryoung, R.A. . Dept. of Chemistry)

    1989-05-01

    The authors describe aluminum anodization studied in the basic AlCl/sub 3/:1-methyl-3-ethylimidazolium chloride (ImCl) ambient temperature molten salt (AlCl/sub 3/:ImCl molar ratio ..e..1.0). The anodization process was studied as a function of chloride anion concentration. Two different anodization processes are observed with onset potentials of approximately -1.1 and 0V. The more cathodic anodization involves formation of the tetrachloroaluminate anion and exhibits a limiting current controlled by diffusion of chloride to the electrode surface. The number of chlorides required for each Al anodized was determined to be 4.6 +- 0.4. The more anodic anodization shows no diffusion control. A value for the diffusion coefficient of chloride was obtained which is lower than previously reported; the difference involves using an n value of 1, rather than 2/3. No reduction of the tetrachloroaluminate anion was observed even at elevated temperatures.

  3. Nuclear Hybrid Energy System: Molten Salt Energy Storage (Summer Report 2013)

    SciTech Connect

    Piyush Sabharwall; Michael George mckellar; Su-Jong Yoon

    2013-11-01

    Effective energy use is a main focus and concern in the world today because of the growing demand for energy. The nuclear hybrid energy system (NHES) is a valuable technical concept that can potentially diversify and leverage existing energy technologies. This report considers a particular NHES design that combines multiple energy systems including a nuclear reactor, energy storage system (ESS), variable renewable generator (VRG), and additional process heat applications. Energy storage is an essential component of this particular NHES because its design allows the system to produce peak power while the nuclear reactor operates at constant power output. Many energy storage options are available, but this study mainly focuses on a molten salt ESS. The primary purpose of the molten salt ESS is to enable the nuclear reactor to be a purely constant heat source by acting as a heat storage component for the reactor during times of low demand, and providing additional capacity for thermo-electric power generation during times of peak electricity demand. This report will describe the rationale behind using a molten salt ESS and identify an efficient molten salt ESS configuration that may be used in load following power applications. Several criteria are considered for effective energy storage and are used to identify the most effective ESS within the NHES. Different types of energy storage are briefly described with their advantages and disadvantages. The general analysis to determine the most efficient molten salt ESS involves two parts: thermodynamic, in which energetic and exergetic efficiencies are considered; and economic. Within the molten salt ESS, the two-part analysis covers three major system elements: molten salt ESS designs (two tank direct and thermocline), the molten salt choice, and the different power cycles coupled with the molten salt ESS. Analysis models are formulated and analyzed to determine the most effective ESS. The results show that the most

  4. Advanced Thermal Storage System with Novel Molten Salt: December 8, 2011 - April 30, 2013

    SciTech Connect

    Jonemann, M.

    2013-05-01

    Final technical progress report of Halotechnics Subcontract No. NEU-2-11979-01. Halotechnics has demonstrated an advanced thermal energy storage system with a novel molten salt operating at 700 degrees C. The molten salt and storage system will enable the use of advanced power cycles such as supercritical steam and supercritical carbon dioxide in next generation CSP plants. The salt consists of low cost, earth abundant materials.

  5. Protection of nuclear graphite toward fluoride molten salt by glassy carbon deposit

    NASA Astrophysics Data System (ADS)

    Bernardet, V.; Gomes, S.; Delpeux, S.; Dubois, M.; Guérin, K.; Avignant, D.; Renaudin, G.; Duclaux, L.

    2009-02-01

    Molten salt reactor represents one of the promising future Generation IV nuclear reactors families where the fuel, a liquid molten fluoride salt, is circulating through the graphite reactor core. The interactions between nuclear graphite and fluoride molten salt and also the graphite surface protection were investigated in this paper by powder X-ray diffraction, micro-Raman spectroscopy and scanning electron microscopy coupled with X-ray microanalysis. Nuclear graphite discs were covered by two kinds of protection deposit: a glassy carbon coating and a double coating of pyrolitic carbon/glassy carbon. Different behaviours have been highlighted according to the presence and the nature of the coated protection film. Intercalation of molten salt between the graphite layers did not occur. Nevertheless the molten salt adhered more or less to the surface of the graphite disc, filled more or less the graphite surface porosity and perturbed more or less the graphite stacking order at the disc surface. The behaviour of unprotected graphite was far to be satisfactory after two days of immersion of graphite in molten salt at 500 °C. The best protection of the graphite disc surface, with the maximum of inertness towards molten salt, has been obtained with the double coating of pyrolitic carbon/glassy carbon.

  6. Preliminary decommissioning study reports. Volume 5, Molten Salt Reactor Experiment

    SciTech Connect

    Peretz, F.J.

    1984-09-01

    The Molten Salt Reactor Experiment (MSRE) is one of approximately 76 facilities currently managed by the ORNL Surplus Facilities Management Program (SFMP). This program, as part of the DOE national SFMP, is responsible for the maintenance and surveillance and the final decommissioning of radioactively-contaminated surplus ORNL facilities. A long range planning effort is being conducted that will outline the scope and objectives of the ORNL program and establish decommissioning priorities based on health and safety concerns, budget constraints, and other programmatic constraints. In support of this SFMP planning activity, preliminary engineering assessments are being conducted for each of the ORNL surplus facilities currently managed under the program. These efforts, in general, are designed to: (1) provide an initial assessment of the potential decommissioning alternatives; (2) choose a preferred alternative and provide a justification for that choice, and (3) provide a preliminary description of the decommissioning plan, including cost and schedule estimates. Because of several issues which cannot be evaluated quantitatively at this time, this report on the MSRE does not select a ``most probable decommissioning mode`` but rather discusses the issues and representative alternatives for disposal of the MSRE fuel salts and decommissioning of the facility. A budget and schedule representative of the types of activities likely to be required is also suggested for preliminary use in the SFMP Long Range Plan.

  7. Development of High-Temperature Transport Technologies of Molten Salt Slurry in Pyrometallurgical Reprocessing

    NASA Astrophysics Data System (ADS)

    Hijikata, Takatoshi; Koyama, Tadafumi

    Pyrometallurgical-reprocessing is one of the most promising technologies for advanced fuel cycle with favorable economic potential and intrinsic proliferation resistance. The development of transport technology for molten salt is a key issue in the industrialization of pyro-reprocessing. As for pure molten LiCl-KCl eutectic salt at approximately 773 K, we have already reported the successful results of transport using gravity and a centrifugal pump. However, molten salt in an electrorefiner mixes with insoluble fines when spent fuel is dissolved in porous anode basket. The insoluble consists of noble metal fission products, such as Pd, Ru, Mo, and Zr. There have been very few transport studies of a molten salt slurry (metal fines-molten salt mixture). Hence, transport experiments on a molten salt slurry were carried out to investigate the behavior of the slurry in a tube. The apparatus used in the transport experiments on the molten salt slurry consisted of a supply tank, a 10° inclined transport tube (10 mm inner diameter), a valve, a filter, and a recovery tank. Stainless steel (SS) fines with diameters from 53 to 415 μm were used. To disperse these fines homogenously, the molten salt and fines were stirred in the supply tank by an impeller at speeds from 1200 to 2100 rpm. The molten salt slurry containing 0.04 to 0.4 vol.% SS fines was transported from the supply tank to the recovery tank through the transportation tube. In the recovery tank, the fines were separated from the molten salt by the filter to measure the transport behavior of molten salt and SS fines. When the velocity of the slurry was 0.02 m/s, only 1% of the fines were transported to the recovery tank. On the other hand, most of the fines were transported when the velocity of the slurry was more than 0.8 m/s. Consequently, the molten salt slurry can be transported when the velocity is more than 0.8 m/s.

  8. Magneto-hydrodynamic detection of vortex shedding for molten salt flow sensing.

    SciTech Connect

    Kruizenga, Alan Michael; Crocker, Robert W.

    2012-09-01

    High temperature flow sensors must be developed for use with molten salts systems at temperatures in excess of 600ÀC. A novel magneto-hydrodynamic sensing approach was investigated. A prototype sensor was developed and tested in an aqueous sodium chloride solution as a surrogate for molten salt. Despite that the electrical conductivity was a factor of three less than molten salts, it was found that the electrical conductivity of an electrolyte was too low to adequately resolve the signal amidst surrounding noise. This sensor concept is expected to work well with any liquid metal application, as the generated magnetic field scales proportionately with electrical conductivity.

  9. High-temperature molten salt thermal energy storage systems

    SciTech Connect

    Petri, R.J.; Claar, T.D.; Tison, R.R.

    1980-02-01

    Experimental results of comparative screening studies of candidate molten carbonate salts as phase-change materials (PCM) for advanced solar-thermal energy storage applications at 540/sup 0/ to 870/sup 0/C and steam-Rankine electric generation at 400/sup 0/ to 540/sup 0/C are presented. Alkali carbonates are attractive as latent-heat storage materials because of their relatively high storage capacity and thermal conductivity, low corrosivity, moderate cost, and safe and simple handling requirements. Salts were tested in 0.1 kWhr lab-scale modules and evaluated on the basis of discharge heat flux, solidification temperature range, thermal cycling stability, and compatibility with containment materials. The feasibility of using a distributed network of high-conductivity material to increase the heat flux through the layer of solidified salt was experimentally evaluated. The thermal performance of an 8 kWhr thermal energy storage (TES) module containing LiKCO/sub 3/ remained very stable throughout 5650 h and 130 charge/discharge cycles at 480/sup 0/ to 535/sup 0/C. A TES utilization concept of an electrical generation peaking subsytem composed of a multistage condensing steam turbine and a TES subsystem with a separate power conversion loop was defined. Conceptual designs for a 100 MW/sub e/ TES peaking system providing steam at 316/sup 0/, 427/sup 0/, and 454/sup 0/ at 3.79 x 10/sup 6/ Pa were developed and evaluated. Areas requiring further investigation have also been identiied.

  10. Molten salt synthesis and localized surface plasmon resonance study of vanadium dioxide nanopowders

    SciTech Connect

    Wang Fu; Liu Yun; Liu Chunyan

    2009-12-15

    Rutile-type vanadium dioxide nanopowders with four different sizes were successfully synthesized by carbothermal reducing V{sub 2}O{sub 5} in KCl-LiCl molten salt. XRD and TEM characterizations suggested that vanadium dioxide particles formed by a broken and reunited process of vanadium oxide. Molten salt and organic carbon sources are crucial to the size of final particles. In the presence of the molten salt, the organic carbon with a shorter chain length would induce smaller particles. The UV-VIS-IR spectral measurements for as-prepared vanadium dioxide announced an obvious localized surface plasmon resonance band in the near infrared region at 90 deg. C. - Graphical abstract: Schematic illustration of the formation mechanism of VO{sub 2}(M) nanoparticles in molten salt, particles size can be controlled by choosing organic carbon sources with different chain length.

  11. Transient Analyses for a Molten Salt Transmutation Reactor Using the Extended SIMMER-III Code

    SciTech Connect

    Wang, Shisheng; Rineiski, Andrei; Maschek, Werner; Ignatiev, Victor

    2006-07-01

    Recent developments extending the capabilities of the SIMMER-III code for the dealing with transient and accidents in Molten Salt Reactors (MSRs) are presented. These extensions refer to the movable precursor modeling within the space-time dependent neutronics framework of SIMMER-III, to the molten salt flow modeling, and to new equations of state for various salts. An important new SIMMER-III feature is that the space-time distribution of the various precursor families with different decay constants can be computed and took into account in neutron/reactivity balance calculations and, if necessary, visualized. The system is coded and tested for a molten salt transmuter. This new feature is also of interest in core disruptive accidents of fast reactors when the core melts and the molten fuel is redistributed. (authors)

  12. Electrical double layers and differential capacitance in molten salts from density functional theory

    DOE PAGESBeta

    Frischknecht, Amalie L.; Halligan, Deaglan O.; Parks, Michael L.

    2014-08-05

    Classical density functional theory (DFT) is used to calculate the structure of the electrical double layer and the differential capacitance of model molten salts. The DFT is shown to give good qualitative agreement with Monte Carlo simulations in the molten salt regime. The DFT is then applied to three common molten salts, KCl, LiCl, and LiKCl, modeled as charged hard spheres near a planar charged surface. The DFT predicts strong layering of the ions near the surface, with the oscillatory density profiles extending to larger distances for larger electrostatic interactions resulting from either lower temperature or lower dielectric constant. Inmore » conclusion, overall the differential capacitance is found to be bell-shaped, in agreement with recent theories and simulations for ionic liquids and molten salts, but contrary to the results of the classical Gouy-Chapman theory.« less

  13. Review of the Molten Salt Electric Experiment: A solar central receiver project

    SciTech Connect

    Delameter, W.R.; Bergan, N.E.

    1986-12-01

    The Molten Salt Electric Experiment was the first full solar-to-electric central receiver system to use molten nitrate salt as a primary working fluid. The experiment was built and tested at the Central Receiver Test Facility in Albuquerque, New Mexico, between 1982 and 1985. The purpose of the project was to demonstrate the technical feasibility of a molten salt central receiver system. The Molten Salt Electric Experiment was operated through a year of successful testing; system performance was measured, operating procedures and an effective receiver control algorithm were developed, and personnel from participating electrical utilities and solar industries were trained to operate the system. The testing culminated in a one-month power production campaign to measure daily performance, component reliability, and system availability. This paper discusses the major accomplishments and some of the more significant problems of the project.

  14. Method for converting UF5 to UF4 in a molten fluoride salt

    DOEpatents

    Bennett, Melvin R.; Bamberger, Carlos E.; Kelmers, A. Donald

    1977-01-01

    The reduction of UF.sub.5 to UF.sub.4 in a molten fluoride salt by sparging with hydrogen is catalyzed by metallic platinum. The reaction is also catalyzed by platinum alloyed with gold reaction equipment.

  15. Electrical double layers and differential capacitance in molten salts from density functional theory

    SciTech Connect

    Frischknecht, Amalie L.; Halligan, Deaglan O.; Parks, Michael L.

    2014-08-05

    Classical density functional theory (DFT) is used to calculate the structure of the electrical double layer and the differential capacitance of model molten salts. The DFT is shown to give good qualitative agreement with Monte Carlo simulations in the molten salt regime. The DFT is then applied to three common molten salts, KCl, LiCl, and LiKCl, modeled as charged hard spheres near a planar charged surface. The DFT predicts strong layering of the ions near the surface, with the oscillatory density profiles extending to larger distances for larger electrostatic interactions resulting from either lower temperature or lower dielectric constant. In conclusion, overall the differential capacitance is found to be bell-shaped, in agreement with recent theories and simulations for ionic liquids and molten salts, but contrary to the results of the classical Gouy-Chapman theory.

  16. Electrical double layers and differential capacitance in molten salts from density functional theory.

    PubMed

    Frischknecht, Amalie L; Halligan, Deaglan O; Parks, Michael L

    2014-08-01

    Classical density functional theory (DFT) is used to calculate the structure of the electrical double layer and the differential capacitance of model molten salts. The DFT is shown to give good qualitative agreement with Monte Carlo simulations in the molten salt regime. The DFT is then applied to three common molten salts, KCl, LiCl, and LiKCl, modeled as charged hard spheres near a planar charged surface. The DFT predicts strong layering of the ions near the surface, with the oscillatory density profiles extending to larger distances for larger electrostatic interactions resulting from either lower temperature or lower dielectric constant. Overall the differential capacitance is found to be bell-shaped, in agreement with recent theories and simulations for ionic liquids and molten salts, but contrary to the results of the classical Gouy-Chapman theory.

  17. Viscosity of multi-component molten nitrate salts : liquidus to 200 degrees C.

    SciTech Connect

    Bradshaw, Robert W.

    2010-03-01

    The viscosity of molten salts comprising ternary and quaternary mixtures of the nitrates of sodium, potassium, lithium and calcium was determined experimentally. Viscosity was measured over the temperature range from near the relatively low liquidus temperatures of he individual mixtures to 200C. Molten salt mixtures that do not contain calcium nitrate exhibited relatively low viscosity and an Arrhenius temperature dependence. Molten salt mixtures that contained calcium nitrate were relatively more viscous and viscosity increased as the roportion of calcium nitrate increased. The temperature dependence of viscosity of molten salts containing calcium nitrate displayed curvature, rather than linearity, when plotted in Arrhenius format. Viscosity data for these mixtures were correlated by the Vogel-Fulcher- ammann-Hesse equation.

  18. Optimized molten salt receivers for ultimate trough solar fields

    NASA Astrophysics Data System (ADS)

    Riffelmann, Klaus-J.; Richert, Timo; Kuckelkorn, Thomas

    2016-05-01

    Today parabolic trough collectors are the most successful concentrating solar power (CSP) technology. For the next development step new systems with increased operation temperature and new heat transfer fluids (HTF) are currently developed. Although the first power tower projects have successfully been realized, up to now there is no evidence of an all-dominant economic or technical advantage of power tower or parabolic trough. The development of parabolic trough technology towards higher performance and significant cost reduction have led to significant improvements in competitiveness. The use of molten salt instead of synthetic oil as heat transfer fluid will bring down the levelized costs of electricity (LCOE) even further while providing dispatchable energy with high capacity factors. FLABEG has developed the Ultimate TroughTM (UT) collector, jointly with sbp Sonne GmbH and supported by public funds. Due to its validated high optical accuracy, the collector is very suitable to operate efficiently at elevated temperatures up to 550 °C. SCHOTT will drive the key-innovations by introducing the 4th generation solar receiver that addresses the most significant performance and cost improvement measures. The new receivers have been completely redesigned to provide a product platform that is ready for high temperature operation up to 550 °C. Moreover distinct product features have been introduced to reduce costs and risks in solar field assembly and installation. The increased material and design challenges incurred with the high temperature operation have been reflected in sophisticated qualification and validation procedures.

  19. Treatment of Difficult Wastes with Molten Salt Oxidation

    SciTech Connect

    Hsu, P C; Kwak, S

    2003-02-21

    Molten salt oxidation (MSO) is a good alternative to incineration for the treatment of a variety of organic wastes such as explosives, low-level mixed waste streams, PCB contaminated oils, spent resins and carbon. Since mid-1990s, the U.S. Army Defense Ammunition Center (DAC) and the Department of Energy (DOE) have jointly invested in MSO development at the Lawrence Livermore National Laboratory (LLNL). LLNL first demonstrated the MSO process for the effective destruction of explosives, explosives-contaminated materials, and other wastes on a 1.5-kg/hr bench-scale unit, and then in an integrated MSO facility capable of treating 8 kg/hr of low-level radioactive mixed wastes. Several MSO systems have been built with sizes up to 10 ft in height and 16 inches in diameter. LLNL in 2001 completed a MSO plant for DAC for the destruction of explosives-contaminated sludge and explosives-contaminated carbon. We will present in this paper our latest demonstration data and our operational experience with MSO.

  20. Room temperature molten salt as medium for lithium battery

    NASA Astrophysics Data System (ADS)

    Fung, Y. S.; Zhou, R. Q.

    Due to the wide electrochemical window and high ionic conductivity, the 1-methyl-3-ethylimidazolium chloride (MeEtImCl) room temperature molten salt (RTMS) was investigated as the medium for lithium battery in the present work. The addition of C 6H 5SO 2Cl to the RTMS was shown to improve its chemical stability and the reversibility of the lithium electrode because of the removal of Al 2Cl 7- from the melt. Electrochemical reaction which occurred at the LiCoO 2 was studied and the carbon current collector was found to interact with the melt. Out of the various carbon materials studied, graphite was found to be the best material. A LiAl/LiCoO 2 battery using RTMS as the electrolyte was assembled for battery test. Satisfactory results were obtained in preliminary cycling, showing a cell voltage of 3.45 V with better than 90% coulombic efficiency and a discharging capacity of 112 mA h/g LiCoO 2 at current density of 1 mA/cm 2.

  1. Resistance of Nanostructured Environmental Barrier Coatings to the Movement of Molten Salts

    NASA Astrophysics Data System (ADS)

    Rao, S.; Frederick, L.; McDonald, A.

    2012-09-01

    Corrosion of components in a recovery boiler is a major problem faced by the pulp and paper industry. The superheater tubes become severely corroded due to the presence of sulfidic gases in the boiler and molten salts which are deposited on the surface of the tubes. As a result, the boiler must be decommissioned for expensive maintenance and repairs. Yttria-stabilized zirconia (YSZ) coatings have been shown to provide corrosion resistance when applied on gas turbines operating at high temperatures. Air plasma-sprayed YSZ environmental barrier coatings on Type 309 stainless steel were exposed to three different corrosive environments: Test A—600 °C, salt vapors, flue gases, 168 h; Test B—600 °C, molten salt, air, 168 h; and Test C—600 °C, molten salt, flue gases, 168 h. Two different types of YSZ coatings—conventional YSZ and nanostructured YSZ—were tested to study their resistance to corrosion and molten salt penetration. The performances of both types of coatings were evaluated, and a comparative study was conducted. It was found that the nanostructured YSZ samples protected the stainless steel substrate better than their conventional counterparts. This superior performance was attributed to the presence of semi-molten nano-agglomerates present in the coating microstructure, which acted as collection points for the penetrating molten salts.

  2. Molten Metal Treatment by Salt Fluxing with Low Environmental Emissions

    SciTech Connect

    Yogeshwar Sahai

    2007-07-31

    Abstract: Chlorine gas is traditionally used for fluxing of aluminum melt for removal of alkali and alkaline earth elements. However this results in undesirable emissions of particulate matter and gases such as HCl and chlorine, which are often at unacceptable levels. Additionally, chlorine gas is highly toxic and its handling, storage, and use pose risks to employees and the local community. Holding of even minimal amounts of chlorine necessitates extensive training for all plant employees. Fugitive emissions from chlorine usage within the plant cause accelerated corrosion of plant equipment. The Secondary Aluminum Maximum Achievable Control Technology (MACT) under the Clean Air Act, finalized in March 2000 has set very tough new limits on particulate matter (PM) and total hydrogen chloride emissions from aluminum melting and holding furnaces. These limits are 0.4 and 0.1 lbs per ton of aluminum for hydrogen chloride and particulate emissions, respectively. Assuming new technologies for meeting these limits can be found, additional requirements under the Clean Air Act (Prevention of Significant Deterioration and New Source Review) trigger Best Available Control Technology (BACT) for new sources with annual emissions (net emissions not expressed per ton of production) over specified amounts. BACT currently is lime coated bag-houses for control of particulate and HCl emissions. These controls are expensive, difficult to operate and maintain, and result in reduced American competitiveness in the global economy. Solid salt fluxing is emerging as a viable option for the replacement of chlorine gas fluxing, provided emissions can be consistently maintained below the required levels. This project was a cooperative effort between the Ohio State University and Alcoa to investigate and optimize the effects of solid chloride flux addition in molten metal for alkali impurity and non-metallic inclusion removal minimizing dust and toxic emissions and maximizing energy

  3. Materials considerations for molten salt accelerator-based plutonium conversion systems

    NASA Astrophysics Data System (ADS)

    DeVan, J. H.; DiStefano, J. R.; Eatherly, W. P.; Keiser, J. R.; Klueh, R. L.

    1995-09-01

    A Molten-Salt Reactor Program for civilian power applications was initiated at the Oak Ridge National Laboratory in 1956. In 1965 the Molten Salt Reactor Experiment (MSRE) went critical and was successfully operated for several years. Operation of the MSRE revealed two deficiencies in the Hastelloy N alloy that had been developed specifically for molten-salt systems. The alloy embrittled at elevated temperatures as a result of exposure to thermal neutrons (radiation damage) and grain boundary embrittlement occurred in materials exposed to fuel salt. Intergranular cracking was found to be associated with fission products, viz. tellurium. An improved Hastelloy N composition was subsequently developed that had better resistance to both of these problems. However, the discovery that fission product cracking could be significantly decreased by making the salt sufficiently reducing offers the prospect of improved compatibility with molten salts containing fission products and resistance to radiation damage in ABC applications. Recommendations are made regarding the types of corrosion tests and mechanistic studies needed to qualify materials for operation with PuF3-containing molten salts.

  4. Materials considerations for molten salt accelerator-based plutonium conversion systems

    SciTech Connect

    DeVan, J.H.; DiStefano, J.R.; Eatherly, W.P.; Keiser, J.R.; Klueh, R.L.

    1994-12-31

    A Molten-Salt Reactor Program for power applications was initiated at the Oak Ridge National Laboratory in 1956. In 1965 the Molten Salt Reactor Experiment (MSRE) went critical and was successfully operated for several years. Operation of the MSRE revealed two deficiencies in the Hastelloy N alloy that had been developed specifically for molten-salt systems. The alloy embrittled at elevated temperatures as a result of exposure to thermal neutrons (radiation damage) and grain boundary embrittlement occurred in materials to fuel salt. Intergranular cracking was found to be associated with fission products, viz. tellurium. An improved Hastelloy N composition was subsequently developed that had better resistance to both of these problems. However, the discovery that fission product cracking could be significantly decreased by making the salt sufficiently reducing offers the prospect of improved compatibility with molten salts containing fission products and resistance to radiation damage in ABC applications. Recommendations are made regarding the types of corrosion tests and mechanistic studies needed to qualify materials for operation with PuF{sub 3}-containing molten salts.

  5. Solar gasification of biomass: design and characterization of a molten salt gasification reactor

    NASA Astrophysics Data System (ADS)

    Hathaway, Brandon Jay

    The design and implementation of a prototype molten salt solar reactor for gasification of biomass is a significant milestone in the development of a solar gasification process. The reactor developed in this work allows for 3 kWth operation with an average aperture flux of 1530 suns at salt temperatures of 1200 K with pneumatic injection of ground or powdered dry biomass feedstocks directly into the salt melt. Laboratory scale experiments in an electrically heated reactor demonstrate the benefits of molten salt and the data was evaluated to determine the kinetics of pyrolysis and gasification of biomass or carbon in molten salt. In the presence of molten salt overall gas yields are increased by up to 22%; pyrolysis rates double due to improved heat transfer, while carbon gasification rates increase by an order of magnitude. Existing kinetic models for cellulose pyrolysis fit the data well, while carbon gasification in molten salt follows kinetics modeled with a 2/3 order shrinking-grain model with a pre-exponential factor of 1.5*106 min-1 and activation energy of 158 kJ/mol. A reactor concept is developed based around a concentric cylinder geometry with a cavity-style solar receiver immersed within a volume of molten carbonate salt. Concentrated radiation delivered to the cavity is absorbed in the cavity walls and transferred via convection to the salt volume. Feedstock is delivered into the molten salt volume where biomass gasification reactions will be carried out producing the desired product gas. The features of the cavity receiver/reactor concept are optimized based on modeling of the key physical processes. The cavity absorber geometry is optimized according to a parametric survey of radiative exchange using a Monte Carlo ray tracing model, resulting in a cavity design that achieves absorption efficiencies of 80%-90%. A parametric survey coupling the radiative exchange simulations to a CFD model of molten salt natural convection is used to size the annulus

  6. Waste Stream Generated and Waste Disposal Plans for Molten Salt Reactor Experiment at Oak Ridge National Laboratory

    SciTech Connect

    Haghighi, M. H.; Szozda, R. M.; Jugan, M. R.

    2002-02-26

    The Molten Salt Reactor Experiment (MSRE) site is located in Tennessee, on the U.S. Department of Energy (DOE) Oak Ridge Reservation (ORR), south of the Oak Ridge National Laboratory (ORNL) main plant across Haw Ridge in Melton Valley. The MSRE was run by ORNL to demonstrate the desirable features of the molten-salt concept in a practical reactor that could be operated safely and reliably. It introduced the idea of a homogeneous reactor using fuel salt media and graphite moderation for power and breeder reactors. The MSRE reactor and associated components are located in cells beneath the floor in the high-bay area of Building 7503 (Figure 1). The reactor was operated from June 1965 to December 1969. When the reactor was shut down, fuel salt was drained from the reactor circuit to two drain tanks. A ''clean'' salt was then circulated through the reactor as a decontamination measure and drained to a third drain tank. When operations ceased, the fuel and flush salts were allowed t o cool and solidify in the drain tanks. At shutdown, the MSRE facility complex was placed in a surveillance and maintenance program. As a result of the S&M program, it was discovered in 1994 that gaseous uranium (233U/232U) hexafluoride (UF6) had moved throughout the MSRE process systems. The UF6 was generated when radiolysis of the fluorine salts caused the individual constituents to dissociate to their component atoms, including free fluorine.Some of the free fluorine combined with uranium fluorides (UF4) in the salt to form UF6. UF6 is gaseous at slightly above ambient temperatures; thus, periodic heating of the fuel salts (which was intended to remedy the radiolysis problems) and simple diffusion had allowed the UF6 to move out of the salt and into the process systems of MSRE.

  7. Heat Transfer and Latent Heat Storage in Inorganic Molten Salts for Concentrating Solar Power Plants

    SciTech Connect

    Mathur, Anoop

    2013-08-14

    A key technological issue facing the success of future Concentrating Solar Thermal Power (CSP) plants is creating an economical Thermal Energy Storage (TES) system. Current TES systems use either sensible heat in fluids such as oil, or molten salts, or use thermal stratification in a dual-media consisting of a solid and a heat-transfer fluid. However, utilizing the heat of fusion in inorganic molten salt mixtures in addition to sensible heat , as in a Phase change material (PCM)-based TES, can significantly increase the energy density of storage requiring less salt and smaller containers. A major issue that is preventing the commercial use of PCM-based TES is that it is difficult to discharge the latent heat stored in the PCM melt. This is because when heat is extracted, the melt solidifies onto the heat exchanger surface decreasing the heat transfer. Even a few millimeters of thickness of solid material on heat transfer surface results in a large drop in heat transfer due to the low thermal conductivity of solid PCM. Thus, to maintain the desired heat rate, the heat exchange area must be large which increases cost. This project demonstrated that the heat transfer coefficient can be increase ten-fold by using forced convection by pumping a hyper-eutectic salt mixture over specially coated heat exchanger tubes. However,only 15% of the latent heat is used against a goal of 40% resulting in a projected cost savings of only 17% against a goal of 30%. Based on the failure mode effect analysis and experience with pumping salt at near freezing point significant care must be used during operation which can increase the operating costs. Therefore, we conclude the savings are marginal to justify using this concept for PCM-TES over a two-tank TES. The report documents the specialty coatings, the composition and morphology of hypereutectic salt mixtures and the results from the experiment conducted with the active heat exchanger along with the lessons learnt during

  8. Convective heat transfer in the laminar-turbulent transition region with molten salt in a circular tube

    SciTech Connect

    Yu-ting, Wu; Bin, Liu; Chong-fang, Ma; Hang, Guo

    2009-10-15

    In order to understand the heat transfer characteristics of molten salt and testify the validity of the well-known empirical convective heat transfer correlations, experimental study on transition convective heat transfer with molten salt in a circular tube was conducted. Molten salt circulations were realized and operated in a specially designed system over 1000 h. The average forced convective heat transfer coefficients of molten salt were determined by least-squares method based on the measured data of flow rates and temperatures. Finally, a heat transfer correlation of transition flow with molten salt in a circular tube was obtained and good agreement was observed between the experimental data of molten salt and the well-known correlations presented by Hausen and Gnielinski, respectively. (author)

  9. Application of molten salt oxidation for the minimization and recovery of plutonium-238 contaminated wastes

    SciTech Connect

    Wishau, R.; Ramsey, K.B.; Montoya, A.

    1998-12-31

    This paper presents the technical and economic feasibility of molten salt oxidation technology as a volume reduction and recovery process for {sup 238}Pu contaminated waste. Combustible low-level waste material contaminated with {sup 238}Pu residue is destroyed by oxidation in a 900 C molten salt reaction vessel. The combustible waste is destroyed creating carbon dioxide and steam and a small amount of ash and insoluble {sup 2328}Pu in the spent salt. The valuable {sup 238}Pu is recycled using aqueous recovery techniques. Experimental test results for this technology indicate a plutonium recovery efficiency of 99%. Molten salt oxidation stabilizes the waste converting it to a non-combustible waste. Thus installation and use of molten salt oxidation technology will substantially reduce the volume of {sup 238}Pu contaminated waste. Cost-effectiveness evaluations of molten salt oxidation indicate a significant cost savings when compared to the present plans to package, or re-package, certify and transport these wastes to the Waste Isolation Pilot Plant for permanent disposal. Clear and distinct cost advantages exist for MSO when the monetary value of the recovered {sup 238}Pu is considered.

  10. Integrated demonstration of molten salt oxidation with salt recycle for mixed waste treatment

    SciTech Connect

    Hsu, P.C.

    1997-11-01

    Molten Salt Oxidation (MSO) is a thermal, nonflame process that has the inherent capability of completely destroying organic constituents of mixed wastes, hazardous wastes, and energetic materials while retaining inorganic and radioactive constituents in the salt. For this reason, MSO is considered a promising alternative to incineration for the treatment of a variety of organic wastes. Lawrence Livermore National Laboratory (LLNL) has prepared a facility and constructed an integrated pilot-scale MSO treatment system in which tests and demonstrations are performed under carefully controlled (experimental) conditions. The system consists of a MSO processor with dedicated off-gas treatment, a salt recycle system, feed preparation equipment, and equipment for preparing ceramic final waste forms. This integrated system was designed and engineered based on laboratory experience with a smaller engineering-scale reactor unit and extensive laboratory development on salt recycle and final forms preparation. In this paper we present design and engineering details of the system and discuss its capabilities as well as preliminary process demonstration data. A primary purpose of these demonstrations is identification of the most suitable waste streams and waste types for MSO treatment.

  11. Molten salt extraction of transuranic and reactive fission products from used uranium oxide fuel

    DOEpatents

    Herrmann, Steven Douglas

    2014-05-27

    Used uranium oxide fuel is detoxified by extracting transuranic and reactive fission products into molten salt. By contacting declad and crushed used uranium oxide fuel with a molten halide salt containing a minor fraction of the respective uranium trihalide, transuranic and reactive fission products partition from the fuel to the molten salt phase, while uranium oxide and non-reactive, or noble metal, fission products remain in an insoluble solid phase. The salt is then separated from the fuel via draining and distillation. By this method, the bulk of the decay heat, fission poisoning capacity, and radiotoxicity are removed from the used fuel. The remaining radioactivity from the noble metal fission products in the detoxified fuel is primarily limited to soft beta emitters. The extracted transuranic and reactive fission products are amenable to existing technologies for group uranium/transuranic product recovery and fission product immobilization in engineered waste forms.

  12. Molten Salt Heat Transport Loop: Materials Corrosion and Heat Transfer Phenomena

    SciTech Connect

    Dr. Kumar Sridharan; Dr. Mark Anderson; Dr. Michael Corradini; Dr. Todd Allen; Luke Olson; James Ambrosek; Daniel Ludwig

    2008-07-09

    An experimental system for corrosion testing of candidate materials in molten FLiNaK salt at 850 degree C has been designed and constructed. While molten FLiNaK salt was the focus of this study, the system can be utilized for evaluation of materials in other molten salts that may be of interest in the future. Using this system, the corrosion performance of a number of code-certified alloys of interest to NGNP as well as the efficacy of Ni-electroplating have been investigated. The mechanisums underlying corrosion processes have been elucidated using scanning electron microscopy, x-ray diffraction, and x-ray photoelectron spectroscopy of the materials after the corrosion tests, as well as by the post-corrosion analysis of the salts using inductively coupled plasma (ICP) and neutron activation analysis (NAA) techniques.

  13. Method of removal of heavy metal from molten salt in IFR fuel pyroprocessing

    DOEpatents

    Gay, E.C.

    1995-10-03

    An electrochemical method is described for separating heavy metal values from a radioactive molten salt including Li halide at temperatures of about 500 C. The method comprises positioning a solid Li--Cd alloy anode in the molten salt containing the heavy metal values, positioning a Cd-containing cathode or a solid cathode positioned above a catch crucible in the molten salt to recover the heavy metal values, establishing a voltage drop between the anode and the cathode to deposit material at the cathode to reduce the concentration of heavy metals in the salt, and controlling the deposition rate at the cathode by controlling the current between the anode and cathode. 3 figs.

  14. Space Molten Salt Reactor Concept for Nuclear Electric Propulsion and Surface Power

    NASA Astrophysics Data System (ADS)

    Eades, M.; Flanders, J.; McMurray, N.; Denning, R.; Sun, X.; Windl, W.; Blue, T.

    Students at The Ohio State University working under the NASA Steckler Grant sought to investigate how molten salt reactors with fissile material dissolved in a liquid fuel medium can be applied to space applications. Molten salt reactors of this kind, built for non-space applications, have demonstrated high power densities, high temperature operation without pressurization, high fuel burn up and other characteristics that are ideal for space fission systems. However, little research has been published on the application of molten salt reactor technology to space fission systems. This paper presents a conceptual design of the Space Molten Salt Reactor (SMSR), which utilizes molten salt reactor technology for Nuclear Electric Propulsion (NEP) and surface power at the 100 kWe to 15 MWe level. Central to the SMSR design is a liquid mixture of LiF, BeF2 and highly enriched U235F4 that acts as both fuel and core coolant. In brief, some of the positive characteristics of the SMSR are compact size, simplified core design, high fuel burn up percentages, proliferation resistant features, passive safety mechanisms, a considerable body of previous research, and the possibility for flexible mission architecture.

  15. Measurement of thermophysical properties of molten salts: Mixtures of alkaline carbonate salts

    SciTech Connect

    Araki, N.; Matsuura, M.; Makino, A.; Hirata, T.; Kato, Y.

    1988-11-01

    The purpose of this study is to develop measuring methods for the thermal diffusivity, the specific heat capacity, and the density of molten salts, as well as to measure these properties of mixtures of alkaline carbonate salts. The thermal diffusivity is measured by the stepwise heating method. The sample salt is poured into a thin container, and as a result, a three-layered cell is formed. The thermal diffusivity is obtained from the ratio of temperature rises at different times measured at the rear surface of the cell when the front surface is heated by the stepwise energy from an iodine lamp. The specific heat capacity is measured using an adiabatic scanning calorimeter. The density is measured by Archimedes' principle. Thermal conductivity is determined from the above properties. Measured samples are Li/sub 2/CO/sub 3/-K/sub 2/CO/sub 3/ (42.7-57.3, 50.0-50.0, and 62.0-38.0 mol%).

  16. Molten-Salt Batteries for Medium and Large-Scale Energy Storage

    SciTech Connect

    Lu, Xiaochuan; Yang, Zhenguo

    2014-12-01

    This chapter discusses two types of molten salt batteries. Both of them are based on a beta-alumina solid electrolyte and molten sodium anode, i.e., sodium-sulfur (Na-S) battery and sodium-metal halide (ZEBRA) batteries. The chapter first reviews the basic electrochemistries and materials for various battery components. It then describes the performance of state-of-the-art batteries and future direction in material development for these batteries.

  17. Potentiometric Sensor for Real-Time Monitoring of Multivalent Ion Concentrations in Molten Salt

    SciTech Connect

    Peter A. Zink; Jan-Fong Jue; Brenda E. Serrano; Guy L. Fredrickson; Ben F. Cowan; Steven D. Herrmann; Shelly X. Li

    2010-07-01

    Electrorefining of spent metallic nuclear fuel in high temperature molten salt systems is a core technology in pyroprocessing, which in turn plays a critical role in the development of advanced fuel cycle technologies. In electrorefining, spent nuclear fuel is treated electrochemically in order to effect separations between uranium, noble metals, and active metals, which include the transuranics. The accumulation of active metals in a lithium chloride-potassium chloride (LiCl-KCl) eutectic molten salt electrolyte occurs at the expense of the UCl3-oxidant concentration in the electrolyte, which must be periodically replenished. Our interests lie with the accumulation of active metals in the molten salt electrolyte. The real-time monitoring of actinide concentrations in the molten salt electrolyte is highly desirable for controlling electrochemical operations and assuring materials control and accountancy. However, real-time monitoring is not possible with current methods for sampling and chemical analysis. A new solid-state electrochemical sensor is being developed for real-time monitoring of actinide ion concentrations in a molten salt electrorefiner. The ultimate function of the sensor is to monitor plutonium concentrations during electrorefining operations, but in this work gadolinium was employed as a surrogate material for plutonium. In a parametric study, polycrystalline sodium beta double-prime alumina (Na-ß?-alumina) discs and tubes were subject to vapor-phase exchange with gadolinium ions (Gd3+) using a gadolinium chloride salt (GdCl3) as a precursor to produce gadolinium beta double-prime alumina (Gd-ß?-alumina) samples. Electrochemical impedance spectroscopy and microstructural analysis were performed on the ion-exchanged discs to determine the relationship between ion exchange and Gd3+ ion conductivity. The ion-exchanged tubes were configured as potentiometric sensors in order to monitor real-time Gd3+ ion concentrations in mixtures of gadolinium

  18. Preparation of Ferrotitanium Alloy from Ilmenite by Electrochemical Reduction in Chloride Molten Salts

    NASA Astrophysics Data System (ADS)

    Qi, Can-can; Hua, Yi-xin; Chen, Kong-hao; Jie, Ya-fei; Zhou, Zhong-ren; Ru, Juan-jian; Xiong, Li; Gong, Kai

    2016-02-01

    Ferrotitanium alloy is prepared by electrochemical reduction from ilmenite in LiCl-KCl and LiCl-KCl-CaCl2 molten salts, respectively. The products prepared are observed by x-ray diffraction (XRD). It is shown that Fe2Ti can be prepared from ilmenite in LiCl-KCl molten salt at 1073 K with a cell voltage of 3.2 V. Ilmenite can be electrochemically reduced to FeTi in LiCl-KCl-CaCl2 molten salt under the same condition. It is indicated that CaCl2 can promote the reaction and is favors the deoxidization of the FeTiO3.

  19. A silane-based electroactive film prepared in an imidazolium chloroaluminate molten salt

    SciTech Connect

    Carlin, R.T. . Frank J. Seiler Research Lab.); Osteryoung, R.A. . Dept. of Chemistry)

    1994-07-01

    Electrochemical oxidation of Ph[sub 3]SiCl (Ph = phenyl) in the room-temperature molten salt AlCl[sub 3]:EMICl (EMICl = 1-ethyl-3-methylimidazolium chloride) results in the formation of an adherent electroactive film on the surface of solid electrodes. The film is reversibly oxidized and reduced in the molten salt and is conducting when in the oxidized state. Based on x-ray photoelectron spectroscopy analysis, the film consists of both a silane and an imidazole component, and the charge storage properties of the film are localized on the heterocyclic rings. This electroactive film compares favorably to other conducting polymers currently being investigated as positive electrodes in room-temperature molten salt batteries.

  20. Measurements of the partial electronic conductivity in lithium chloride - potassium chloride molten salts

    SciTech Connect

    Reynolds, G.J.; Huggins, R.A.; Lee, M.C.Y.

    1983-05-01

    The partial electronic conductivity of the lithium chloride-potassium chloride eutectic molten salt electrolyte has been studied as a function of lithium activity, temperature and melt composition using the Wagner asymmetric d-c polarization technique. Measurements were made over the temperature range 383-465/sup 0/C and at lithium activities extending from 1.95 X 10/sup -7/ to unity. The results confirmed the applicability of this technique to molten salt systems. The partial electronic conductivity was shown to be much greater than the partial hole conductivity over the range of lithium activities investigated, and was found to increase monotonically with temperature and lithium activity, but decreased on addition of excess LiCl to the eutectic composition. Approximate values of self-discharge currents for cells utilizing an ''Al/LiAl'' negative electrode and a LiCl-KCl molten salt electrolyte have been calculated.

  1. Substituent effects on ferrocenes in aluminum chloride-butylpyridinium chloride molten-salt mixtures

    SciTech Connect

    Edgecombe, A.L.; Fowler, J.S.; Gibbard, H.F. ); Slocum, D.W. ); Phillips, J. )

    1990-02-01

    The visible absorption spectra and reduction potentials of 11 ferrocenes containing electron-withdrawing substituents were determined in an N-n-butylpyridinium chloride-aluminum chloride molten salt. When the substituent(s) on the cyclopentadienyl ring(s) of ferrocene were varied, the reduction potential was caused to range over 1.25 V, and the wavelength for maximum absorption of visible light was varied by nearly 200 nm. These changes are greater than have been observed for similar ferrocenes in other nonaqueous solvents. Evidence is presented for specific interactions of particular ferrocenes with the molten salt.

  2. Reversibility of electrochemical reactions of sulfur supported on inverse opal carbon in glyme-Li salt molten complex electrolytes.

    PubMed

    Tachikawa, Naoki; Yamauchi, Kento; Takashima, Eriko; Park, Jun-Woo; Dokko, Kaoru; Watanabe, Masayoshi

    2011-07-28

    Electrochemical reactions of sulfur supported on three-dimensionally ordered macroporous carbon in glyme-Li salt molten complex electrolytes exhibit good reversibility and large capacity based on the mass of sulfur, which suggests that glyme-Li salt molten complexes are suitable electrolytes for Li-S batteries.

  3. An evaluation of pressure and flow measurement in the Molten Salt Test Loop (MSTL) system.

    SciTech Connect

    Gill, David Dennis; Kolb, William J.; Briggs, Ronald J.

    2013-07-01

    The National Solar Thermal Test Facility at Sandia National Laboratories has a unique test capability called the Molten Salt Test Loop (MSTL) system. MSTL allows customers and researchers to test components in flowing, molten nitrate salt at plant-like conditions for pressure, flow, and temperature. An important need in thermal storage systems that utilize molten salts is for accurate flow and pressure measurement at temperatures above 535ÀC. Currently available flow and pressure instrumentation for molten salt is limited to 535ÀC and even at this temperature the pressure measurement appears to have significant variability. It is the design practice in current Concentrating Solar Power plants to measure flow and pressure on the cold side of the process or in dead-legs where the salt can cool, but this practice wont be possible for high temperature salt systems. For this effort, a set of tests was conducted to evaluate the use of the pressure sensors for flow measurement across a device of known flow coefficient Cv. To perform this task, the pressure sensors performance was evaluated and was found to be lacking. The pressure indicators are severely affected by ambient conditions and were indicating pressure changes of nearly 200psi when there was no flow or pressure in the system. Several iterations of performance improvement were undertaken and the pressure changes were reduced to less than 15psi. The results of these pressure improvements were then tested for use as flow measurement. It was found that even with improved pressure sensors, this is not a reliable method of flow measurement. The need for improved flow and pressure measurement at high temperatures remains and will need to be solved before it will be possible to move to high temperature thermal storage systems with molten salts.

  4. Thermal Properties of LiCl-KCl Molten Salt for Nuclear Waste Separation

    SciTech Connect

    Sridharan, Kumar; Allen, Todd; Anderson, Mark; Simpson, Mike

    2012-11-30

    This project addresses both practical and fundamental scientific issues of direct relevance to operational challenges of the molten LiCl-KCl salt pyrochemical process, while providing avenues for improvements in the process. In order to understand the effects of the continually changing composition of the molten salt bath during the process, the project team will systematically vary the concentrations of rare earth surrogate elements, lanthanum, cerium, praseodymium, and neodymium, which will be added to the molten LiCl-KCl salt. They will also perform a limited number of focused experiments by the dissolution of depleted uranium. All experiments will be performed at 500 deg C. The project consists of the following tasks. Researchers will measure density of the molten salts using an instrument specifically designed for this purpose, and will determine the melting points with a differential scanning calorimeter. Knowledge of these properties is essential for salt mass accounting and taking the necessary steps to prevent melt freezing. The team will use cyclic voltammetry studies to determine redox potentials of the rare earth cations, as well as their diffusion coefficients and activities in the molten LiCl-KCl salt. In addition, the team will perform anodic stripping voltammetry to determine the concentration of the rare earth elements and their solubilities, and to develop the scientific basis for an on-line diagnostic system for in situ monitoring of the cation species concentration (rare earths in this case). Solubility and activity of the cation species are critically important for the prediction of the salt's useful lifetime and disposal.

  5. Grain orientation in high Tc superconductors by molten salt powder synthesis

    NASA Technical Reports Server (NTRS)

    Gopalakrishnan, Sudhakar; Schulze, Walter A.

    1991-01-01

    The molten salt or the flux method is used to fabricate a grain oriented YBa2Cu3O(7-x) (123) superconductor. Here we suggest a two-stage approach in using the 'green phase', Y2BaCuO5 (211), as seed crystals in the formation of YBa2Cu3O(7-x). The process uses Y2BaCuO5 formed by molten salt synthesis. The Y2BaCuO5 phase was observed to be stable in water and in most of the salt systems. Salt processing can form a small quantity of anisotropic particles of Y2BaCuO5. This material can form the 123 phase when tape cast and sintered in the presence of the required levels of Ba and Cu.

  6. Effect of composition on the density of multi-component molten nitrate salts.

    SciTech Connect

    Bradshaw, Robert W.

    2009-12-01

    The density of molten nitrate salts was measured to determine the effects of the constituents on the density of multi-component mixtures. The molten salts consisted of various proportions of the nitrates of potassium, sodium, lithium and calcium. Density measurements ere performed using an Archimedean method and the results were compared to data reported in the literature for the individual constituent salts or simple combinations, such as the binary Solar Salt mixture of NaNO3 and KNO3. The addition of calcium nitrate generally ncreased density, relative to potassium nitrate or sodium nitrate, while lithium nitrate decreased density. The temperature dependence of density is described by a linear equation regardless of composition. The molar volume, and thereby, density of multi-component mixtures an be calculated as a function of temperature using a linear additivity rule based on the properties of the individual constituents.

  7. Prediction of the thermophysical properties of molten salt fast reactor fuel from first-principles

    NASA Astrophysics Data System (ADS)

    Gheribi, A. E.; Corradini, D.; Dewan, L.; Chartrand, P.; Simon, C.; Madden, P. A.; Salanne, M.

    2014-05-01

    Molten fluorides are known to show favourable thermophysical properties which make them good candidate coolants for nuclear fission reactors. Here we investigate the special case of mixtures of lithium fluoride and thorium fluoride, which act both as coolant and as fuel in the molten salt fast reactor concept. By using ab initio parameterised polarisable force fields, we show that it is possible to calculate the whole set of properties (density, thermal expansion, heat capacity, viscosity and thermal conductivity) which are necessary for assessing the heat transfer performance of the melt over the whole range of compositions and temperatures. We then deduce from our calculations several figures of merit which are important in helping the optimisation of the design of molten salt fast reactors.

  8. Cadmium transport through molten salts in the reprocessing of spent fuel for the integral fast reactor

    SciTech Connect

    Goff, K.M.; Schneider, A. ); Battles, J.E. )

    1993-06-01

    The reprocessing of spent fuel from the Integral Fast Reactor is to be accomplished with a pyrochemical process employing molten LiCl-KCl salt covering a pool of cadmium. An examination of this system demonstrates that cadmium metal is soluble to a small extent in this salt and that it diffuses through the salt covering and vaporizes at the surface. The cadmium is soluble in the salt because of either chemical or physical solubility, both of which are dependent on the salt's surface tension. Mixing increases the vaporization rate of the cadmium by increasing its transport to the salt surface. The cadmium vapors can therefore be reduced by decreasing the mixing conditions, by choosing a salt with a higher surface tension so that the cadmium is less soluble, or by decreasing the temperature of the system, thereby lowering the vapor pressure of the cadmium.

  9. Oxygen production by molten alkali metal salts using multiple absorption-desorption cycles

    DOEpatents

    Cassano, A.A.

    1985-07-02

    A continuous chemical air separation is performed wherein oxygen is recovered with a molten alkali metal salt oxygen acceptor in a series of absorption zones which are connected to a plurality of desorption zones operated in separate parallel cycles with the absorption zones. A greater recovery of high pressure oxygen is achieved at reduced power requirements and capital costs. 3 figs.

  10. Oxygen production by molten alkali metal salts using multiple absorption-desorption cycles

    DOEpatents

    Cassano, Anthony A.

    1985-01-01

    A continuous chemical air separation is performed wherein oxygen is recovered with a molten alkali metal salt oxygen acceptor in a series of absorption zones which are connected to a plurality of desorption zones operated in separate parallel cycles with the absorption zones. A greater recovery of high pressure oxygen is achieved at reduced power requirements and capital costs.

  11. Application of Molten Salt Reactor Technology to MMW In-Space NEP and Surface Power Missions

    NASA Technical Reports Server (NTRS)

    Patton, Bruce; Sorensen, Kirk; Rodgers, Stephen (Technical Monitor)

    2002-01-01

    Anticipated manned nuclear electric propulsion (NEP) and planetary surface power missions will require multimegawatt nuclear reactors that are lightweight, operationally robust, and scalable in power for widely varying scientific mission objectives. Molten salt reactor technology meets all of these requirements and offers an interesting alternative to traditional multimegawatt gas-cooled and liquid metal concepts.

  12. Materials considerations for molten salt accelerator-based plutonium conversion systems

    NASA Astrophysics Data System (ADS)

    Distefano, J. R.; Devan, J. H.; Keiser, J. R.; Klueh, R. L.; Eatherly, W. P.

    1995-03-01

    Accelerator-driven transmutation technology (ADTT) refers to a concept for a system that uses a blanket assembly driven by a source of neutrons produced when high-energy protons from an accelerator strike a heavy metal target. One application for such a system is called Accelerator-Based Plutonium Conversion, or ABC. Currently, the version of this concept being proposed by the Los Alamos National Laboratory features a liquid lead target material and a blanket fuel of molten fluorides that contain plutonium. Thus, the materials to be used in such a system must have, in addition to adequate mechanical strength, corrosion resistance to molten lead, corrosion resistance to molten fluoride salts, and resistance to radiation damage. In this report the corrosion properties of liquid lead and the LiF-BeF2 molten salt system are reviewed in the context of candidate materials for the above application. Background information has been drawn from extensive past studies. The system operating temperature, type of protective environment, and oxidation potential of the salt are shown to be critical design considerations. Factors such as the generation of fission products and transmutation of salt components also significantly affect corrosion behavior, and procedures for inhibiting their effects are discussed. In view of the potential for extreme conditions relative to neutron fluxes and energies that can occur in an ADTT, a knowledge of radiation effects is a most important factor. Present information for potential materials selections is summarized.

  13. Application of Molten Salt Reactor Technology to Nuclear Electric Propulsion Mission

    NASA Technical Reports Server (NTRS)

    Patton, Bruce; Sorensen, Kirk; Rodgers, Stephen L. (Technical Monitor)

    2002-01-01

    Nuclear electric propulsion (NEP) and planetary surface power missions require reactors that are lightweight, operationally robust, and scalable in power for widely varying scientific mission objectives. Molten salt reactor technology meets all of these requirements and offers an interesting alternative to traditional gas cooled, liquid metal, and heat pipe space reactors.

  14. Absorption and desorption of SO2 in aqueous solutions of diamine-based molten salts.

    PubMed

    Lim, Seung Rok; Hwang, Junhyeok; Kim, Chang Soo; Park, Ho Seok; Cheong, Minserk; Kim, Hoon Sik; Lee, Hyunjoo

    2015-05-30

    SO2 absorption and desorption behaviors were investigated in aqueous solutions of diamine-derived molten salts with a tertiary amine group on the cation and a chloride anion, including butyl-(2-dimethylaminoethyl)-dimethylammonium chloride ([BTMEDA]Cl, pKb=8.2), 1-butyl-1,4-dimethylpiperazinium chloride ([BDMP]Cl, pKb=9.8), and 1-butyl-4-aza-1-azoniabicyclo[2,2,2]octane chloride ([BDABCO]Cl, pKb=11.1). The SO2 absorption and desorption performance of the molten salt were greatly affected by the basicity of the molten salt. Spectroscopic, X-ray crystallographic, and computational results for the interactions of SO2 with molten salts suggest that two types of SO2-containg species could be generated depending on the basicity of the unquaternized amino group: a dicationic species comprising two different anions, HSO3(-) and Cl(-), and a monocationic species bearing Cl(-) interacting with neutral H2SO3.

  15. Materials considerations for molten salt accelerator-based plutonium conversion systems

    SciTech Connect

    DiStefano, J.R.; DeVan, J.H.; Keiser, J.R.; Klueh, R.L.; Eatherly, W.P.

    1995-02-01

    Accelerator-driven transmutation technology (ADTT) refers to a concept for a system that uses a blanket assembly driven by a source of neutrons produced when high-energy protons from an accelerator strike a heavy metal target. One application for such a system is called Accelerator-Based Plutonium Conversion, or ABC. Currently, the version of this concept being proposed by the Los Alamos National Laboratory features a liquid lead target material and a blanket fuel of molten fluorides that contain plutonium. Thus, the materials to be used in such a system must have, in addition to adequate mechanical strength, corrosion resistance to molten lead, corrosion resistance to molten fluoride salts, and resistance to radiation damage. In this report the corrosion properties of liquid lead and the LiF-BeF{sub 2} molten salt system are reviewed in the context of candidate materials for the above application. Background information has been drawn from extensive past studies. The system operating temperature, type of protective environment, and oxidation potential of the salt are shown to be critical design considerations. Factors such as the generation of fission products and transmutation of salt components also significantly affect corrosion behavior, and procedures for inhibiting their effects are discussed. In view of the potential for extreme conditions relative to neutron fluxes and energies that can occur in an ADTT, a knowledge of radiation effects is a most important factor. Present information for potential materials selections is summarized.

  16. Materials considerations for molten salt accelerator-based plutonium conversion systems

    SciTech Connect

    DiStefano, J.R.; DeVan, J.H.; Keiser, J.R.; Klueh, R.L.; Eatherly, W.P.

    1995-03-01

    Accelerator-driven transmutation technology (ADTT) refers to a concept for a system that uses a blanket assembly driven by a source of neutrons produced when high-energy protons from an accelerator strike a heavy metal target. One application for such a system is called Accelerator-Based Plutonium Conversion, or ABC. Currently, the version of this concept being proposed by the Los Alamos National Laboratory features a liquid lead target material and a blanket fuel of molten fluorides that contain plutonium. Thus, the materials to be used in such a system must have, in addition to adequate mechanical strength, corrosion resistance to molten lead, corrosion resistance to molten fluoride salts, and resistance to radiation damage. In this report the corrosion properties of liquid lead and the LiF-BeF{sub 2} molten salt system are reviewed in the context of candidate materials for the above application. Background information has been drawn from extensive past studies. The system operating temperature, type of protective environment, and oxidation potential of the salt are shown to be critical design considerations. Factors such as the generation of fission products and transmutation of salt components also significantly affect corrosion behavior, and procedures for inhibiting their effects are discussed. In view of the potential for extreme conditions relative to neutron fluxes and energies that can occur in an ADTT, a knowledge of radiation effects is a most important factor. Present information for potential materials selections is summarized.

  17. Molecular Dynamics Simulation of the Transport Properties of Molten Transuranic Salt Mixtures

    NASA Astrophysics Data System (ADS)

    Baty, Austin; McIntyre, Peter; Sattarov, Akhdiyor; Sooby, Elizabeth

    2012-10-01

    The Accelerator Research Laboratory at Texas A&M is proposing a revolutionary design for accelerator-driven subcritical fission in molten salt (ADSMS), a system that destroys the transuranic elements in spent nuclear fuel. The transuranics are the most enduring hazard of nuclear power, since they contain high radiotoxicity and have half-lives of a thousand to a million years. The ADSMS core is fueled by a homogeneous chloride-based molten salt mixture containing the chlorides of the transuranics and NaCl. Knowledge of the density, heat capacity, thermal conductivity, etc. of the salt mixtures is needed to accurately model the complex ADSMS system. There is a lack of experimental data on the density and transport properties of such mixtures. Molecular dynamics simulations using polarizable ion potentials are used to determine the density and heat capacity of these melts as a function of temperature. Green-Kubo methods are employed to calculate the electrical conductivity, thermal conductivity, and viscosity of the salt using the outputs of the model. Results for pure molten salt systems are compared to experimental data when possible to validate the potentials used. Here we discuss potential salt systems, their neutronic behavior, and the calculated transport properties.

  18. Molten Salt Fuel Version of Laser Inertial Fusion Fission Energy (LIFE)

    SciTech Connect

    Moir, R W; Shaw, H F; Caro, A; Kaufman, L; Latkowski, J F; Powers, J; Turchi, P A

    2008-10-24

    Molten salt with dissolved uranium is being considered for the Laser Inertial Confinement Fusion Fission Energy (LIFE) fission blanket as a backup in case a solid-fuel version cannot meet the performance objectives, for example because of radiation damage of the solid materials. Molten salt is not damaged by radiation and therefore could likely achieve the desired high burnup (>99%) of heavy atoms of {sup 238}U. A perceived disadvantage is the possibility that the circulating molten salt could lend itself to misuse (proliferation) by making separation of fissile material easier than for the solid-fuel case. The molten salt composition being considered is the eutectic mixture of 73 mol% LiF and 27 mol% UF{sub 4}, whose melting point is 490 C. The use of {sup 232}Th as a fuel is also being studied. ({sup 232}Th does not produce Pu under neutron irradiation.) The temperature of the molten salt would be {approx}550 C at the inlet (60 C above the solidus temperature) and {approx}650 C at the outlet. Mixtures of U and Th are being considered. To minimize corrosion of structural materials, the molten salt would also contain a small amount ({approx}1 mol%) of UF{sub 3}. The same beryllium neutron multiplier could be used as in the solid fuel case; alternatively, a liquid lithium or liquid lead multiplier could be used. Insuring that the solubility of Pu{sup 3+} in the melt is not exceeded is a design criterion. To mitigate corrosion of the steel, a refractory coating such as tungsten similar to the first wall facing the fusion source is suggested in the high-neutron-flux regions; and in low-neutron-flux regions, including the piping and heat exchangers, a nickel alloy, Hastelloy, would be used. These material choices parallel those made for the Molten Salt Reactor Experiment (MSRE) at ORNL. The nuclear performance is better than the solid fuel case. At the beginning of life, the tritium breeding ratio is unity and the plutonium plus {sup 233}U production rate is {approx}0

  19. Materials Testing for an Accelerator-Driven Subcritical Molten Salt Fission System: A look at the Materials Science of Molten Salt Corrosion

    NASA Astrophysics Data System (ADS)

    Sooby, Elizabeth; Balachandran, Shreyas; Foley, David; Hartwig, Karl; McIntyre, Peter; Phongikaroon, Supathorn; Pogue, Nathaniel; Simpson, Michael; Tripathy, Prabhat

    2011-10-01

    For an accelerator-driven subcritical molten salt fission core to survive its 50+ year fuel life, the primary vessel, heat exchanger, and various internal components must be made of materials that resist corrosion and radiation damage in a high-temperature environment, (500-800 C). An experimental study of the corrosion behavior of candidate metals in contact with molten salt is being conducted at the Center for Advanced Energy Studies. Initial experiments have been run on Nb, Ta, Ni, two zirconium alloys, Hastelloy-N, and a series of steel alloys to form a base line for corrosion in both chloride and bromide salt. Metal coupons were immersed in LiCl-KCl or LiBr-KBr at 700 C in an inert-atmosphere. Salt samples were extracted on a time schedule over a 24-hr period. The samples were analyzed using inductively coupled plasma-mass spectrometry to determine concentrations of metals from corrosion. Preliminary results will be presented.

  20. Disposition of the fluoride fuel and flush salts from the Molten Salt Reactor experiment at Oak Ridge National Laboratory

    SciTech Connect

    Peretz, F.J.

    1996-03-01

    The Molten Salt Reactor Experiment (MSRE) is an 8 MW reactor that was operated at Oak Ridge National Laboratory (ORNL) from 1965 through 1969. The reactor used a unique liquid salt fuel, composed of a mixture of LIF, BeF{sub 2}, ZrF{sub 4}, and UF{sub 4}, and operated at temperatures above 600{degrees}C. The primary fuel salt circulation system consisted of the reactor vessel, a single fuel salt pump, and a single primary heat exchanger. Heat was transferred from the fuel salt to a coolant salt circuit in the primary heat exchanger. The coolant salt was similar to the fuel salt, except that it contains only LiF (66%) and BeF, (34%). The coolant salt passed from the primary heat exchanger to an air-cooled radiator and a coolant salt pump, and then returned to the primary heat exchanger. Each of the salt loops was provided with drain tanks, located such that the salt could be drained out of either circuit by gravity. A single drain tank was provided for the non-radioactive coolant salt. Two drain tanks were provided for the fuel salt. Since the fuel salt contained radioactive fuel, fission products, and activation products, and since the reactor was designed such that the fuel salt could be drained immediately into the drain tanks in the event of a problem in the fuel salt loop, the fuel salt drain tanks were provided with a system to remove the heat generated by radioactive decay. A third drain tank connected to the fuel salt loop was provided for a batch of flush salt. This batch of salt, similar in composition to the coolant salt, was used to condition the fuel salt loop after it had been exposed to air and to flush the fuel salt loop of residual fuel salt prior to accessing the reactor circuit for maintenance or experimental activities. This report discusses the disposition of the fluoride fuel and flush salt.

  1. Transient analysis of a molten salt central receiver (MSCR) in a solar power plant

    NASA Astrophysics Data System (ADS)

    Joshi, A.; Wang, C.; Akinjiola, O.; Lou, X.; Neuschaefer, C.; Quinn, J.

    2016-05-01

    Alstom is developing solar power tower plants utilizing molten salt as the working fluid. In solar power tower, the molten salt central receiver (MSCR) atop of the tower is constructed of banks of tubes arranged in panels creating a heat transfer surface exposed to the solar irradiation from the heliostat field. The molten salt heat transfer fluid (HTF), in this case 60/40%wt NaNO3-KNO3, flows in serpentine flow through the surface collecting sensible heat thus raising the HTF temperature from 290°C to 565°C. The hot molten salt is stored and dispatched to produce superheated steam in a steam generator, which in turn produces electricity in the steam turbine generator. The MSCR based power plant with a thermal energy storage system (TESS) is a fully dispatchable renewable power plant with a number of opportunities for operational and economic optimization. This paper presents operation and controls challenges to the MSCR and the overall power plant, and the use of dynamic model computer simulation based transient analyses applied to molten salt based solar thermal power plant. This study presents the evaluation of the current MSCR design, using a dynamic model, with emphasis on severe events affecting critical process response, such as MS temperature deviations, and recommend MSCR control design improvements based on the results. Cloud events are the scope of the transient analysis presented in this paper. The paper presents results from a comparative study to examine impacts or effects on key process variables related to controls and operation of the MSCR plant.

  2. Thermal conductivity of molten salt mixtures: Theoretical model supported by equilibrium molecular dynamics simulations.

    PubMed

    Gheribi, Aïmen E; Chartrand, Patrice

    2016-02-28

    A theoretical model for the description of thermal conductivity of molten salt mixtures as a function of composition and temperature is presented. The model is derived by considering the classical kinetic theory and requires, for its parametrization, only information on thermal conductivity of pure compounds. In this sense, the model is predictive. For most molten salt mixtures, no experimental data on thermal conductivity are available in the literature. This is a hindrance for many industrial applications (in particular for thermal energy storage technologies) as well as an obvious barrier for the validation of the theoretical model. To alleviate this lack of data, a series of equilibrium molecular dynamics (EMD) simulations has been performed on several molten chloride systems in order to determine their thermal conductivity in the entire range of composition at two different temperatures: 1200 K and 1300 K. The EMD simulations are first principles type, as the potentials used to describe the interactions have been parametrized on the basis of first principle electronic structure calculations. In addition to the molten chlorides system, the model predictions are also compared to a recent similar EMD study on molten fluorides and with the few reliable experimental data available in the literature. The accuracy of the proposed model is within the reported numerical and/or experimental errors.

  3. Thermal conductivity of molten salt mixtures: Theoretical model supported by equilibrium molecular dynamics simulations

    NASA Astrophysics Data System (ADS)

    Gheribi, Aïmen E.; Chartrand, Patrice

    2016-02-01

    A theoretical model for the description of thermal conductivity of molten salt mixtures as a function of composition and temperature is presented. The model is derived by considering the classical kinetic theory and requires, for its parametrization, only information on thermal conductivity of pure compounds. In this sense, the model is predictive. For most molten salt mixtures, no experimental data on thermal conductivity are available in the literature. This is a hindrance for many industrial applications (in particular for thermal energy storage technologies) as well as an obvious barrier for the validation of the theoretical model. To alleviate this lack of data, a series of equilibrium molecular dynamics (EMD) simulations has been performed on several molten chloride systems in order to determine their thermal conductivity in the entire range of composition at two different temperatures: 1200 K and 1300 K. The EMD simulations are first principles type, as the potentials used to describe the interactions have been parametrized on the basis of first principle electronic structure calculations. In addition to the molten chlorides system, the model predictions are also compared to a recent similar EMD study on molten fluorides and with the few reliable experimental data available in the literature. The accuracy of the proposed model is within the reported numerical and/or experimental errors.

  4. Thermal conductivity of molten salt mixtures: Theoretical model supported by equilibrium molecular dynamics simulations.

    PubMed

    Gheribi, Aïmen E; Chartrand, Patrice

    2016-02-28

    A theoretical model for the description of thermal conductivity of molten salt mixtures as a function of composition and temperature is presented. The model is derived by considering the classical kinetic theory and requires, for its parametrization, only information on thermal conductivity of pure compounds. In this sense, the model is predictive. For most molten salt mixtures, no experimental data on thermal conductivity are available in the literature. This is a hindrance for many industrial applications (in particular for thermal energy storage technologies) as well as an obvious barrier for the validation of the theoretical model. To alleviate this lack of data, a series of equilibrium molecular dynamics (EMD) simulations has been performed on several molten chloride systems in order to determine their thermal conductivity in the entire range of composition at two different temperatures: 1200 K and 1300 K. The EMD simulations are first principles type, as the potentials used to describe the interactions have been parametrized on the basis of first principle electronic structure calculations. In addition to the molten chlorides system, the model predictions are also compared to a recent similar EMD study on molten fluorides and with the few reliable experimental data available in the literature. The accuracy of the proposed model is within the reported numerical and/or experimental errors. PMID:26931711

  5. Thermal Analysis of Surrogate Simulated Molten Salts with Metal Chloride Impurities for Electrorefining Used Nuclear Fuel

    SciTech Connect

    Toni Y. Gutknecht; Guy L. Fredrickson; Vivek Utgikar

    2012-04-01

    This project is a fundamental study to measure thermal properties (liquidus, solidus, phase transformation, and enthalpy) of molten salt systems of interest to electrorefining operations, which are used in both the fuel cycle research & development mission and the spent fuel treatment mission of the Department of Energy. During electrorefining operations the electrolyte accumulates elements more active than uranium (transuranics, fission products and bond sodium). The accumulation needs to be closely monitored because the thermal properties of the electrolyte will change as the concentration of the impurities increases. During electrorefining (processing techniques used at the Idaho National Laboratory to separate uranium from spent nuclear fuel) it is important for the electrolyte to remain in a homogeneous liquid phase for operational safeguard and criticality reasons. The phase stability of molten salts in an electrorefiner may be adversely affected by the buildup of fission products in the electrolyte. Potential situations that need to be avoided are: (i) build up of fissile elements in the salt approaching the criticality limits specified for the vessel (ii) freezing of the salts due to change in the liquidus temperature and (iii) phase separation (non-homogenous solution) of elements. The stability (and homogeneity) of the phases can potentially be monitored through the thermal characterization of the salts, which can be a function of impurity concentration. This work describes the experimental results of typical salts compositions, consisting of chlorides of strontium, samarium, praseodymium, lanthanum, barium, cerium, cesium, neodymium, sodium and gadolinium (as a surrogate for both uranium and plutonium), used in the processing of used nuclear fuels. Differential scanning calorimetry was used to analyze numerous salt samples providing results on the thermal properties. The property of most interest to pyroprocessing is the liquidus temperature. It was

  6. First-principles molecular dynamics modeling of the molten fluoride salt with Cr solute

    NASA Astrophysics Data System (ADS)

    Nam, H. O.; Bengtson, A.; Vörtler, K.; Saha, S.; Sakidja, R.; Morgan, D.

    2014-06-01

    Fluoride salts and their interactions with metals are of wide interest for the nuclear community. In this work, first-principles molecular dynamics (FPMD) was employed to study both pure molten fluoride salt and fluoride salt with dissolved solute Cr ions (a common corrosion product) at high temperature (823-1423 K). Two types of molten fluoride salts, namely flibe (LiF-BeF2) and flinak (LiF-NaF-KF), with the Cr0, Cr2+ and Cr3+ ions were chosen as a target system for the FPMD modeling. The prediction of thermo-kinetic properties of pure fluoride salt, such as the equilibrium volume, density, bulk modulus, coefficient of thermal expansion, and self-diffusion coefficient, provide useful extensions of existing data and verify the accuracy of the FPMD simulation in modeling of fluoride salts. The FPMD modeling of solute Cr in fluoride salt shows the effect of Cr valence on diffusivity and local structure in the salt.

  7. Fabrication of aluminum nitride crucibles for molten salt and plutonium compatibility studies

    SciTech Connect

    Phillips, J.A.

    1991-07-24

    The overall objective of this research was to fabricate a calcium oxide sinter-aided aluminum nitride crucible and determine the compatibility of this crucible with molten chloride salts and plutonium metal in the DOR process. Calcium oxide sinter-aided aluminum nitride was preferred over yttrium oxide sinter-aided aluminum nitride because of (1) the presence of calcium chloride, calcium oxide, and calcium metal in the molten salts utilized in the DOR process, and (2) the higher volatility of the secondary phases formed compared with phases resulting from the addition of yttrium oxide during the aluminum nitride sintering process. The calcium oxide system may yield a higher purity crystal structure with fewer secondary phases present than in the yttrium oxide system. The secondary phases that are present in the grain boundaries may be unreactive with the calcium chloride salt due to the presence of calcium in the secondary phases.

  8. Assessment of molten-salt solar central-receiver freeze-up and recovery events

    SciTech Connect

    Pacheco, J.E.; Dunkin, S.R.

    1996-02-01

    Molten salt used as a heat transfer fluid in central-receiver so ar power plants has a high freezing point (430{degrees}F (221{degrees}C)). It is very likely during the life of the plant that the receiver will accidentally freeze up due to equipment malfunction or operator error. Experiments were conducted to measure the effects of a molten salt receiver freeze-up and recovery event and methods to thaw the receiver. In addition, simulated freeze/thaw experiments were conducted to determine what happens when salt freezes and is thawed in receiver tubes and to quantify the damage caused to candidate receiver tube materials. Fourteen tube samples of various materials, diameters and wall thicknesses were tested to destruction. Results of these tests are presented in this paper.

  9. Exploratory corrosion tests on alloys in molten salts at 900/sup 0/C

    SciTech Connect

    Coyle, R.T.; Thomas, T.M.; Lai, G.Y.

    1984-10-01

    Exploratory corrosion tests were conducted on 16 commercial alloys in carbonate, chloride, and hydroxide molten salts at 900/sup 0/C for up to three weeks. Corrosion information, including weight change, observations of the coupons, metallographic examination, and evaluation of the corrosion product by SEM, was obtained on the coupons exposed to these salts. These tests indicated that a number of the alloys showed significant resistance to metal loss in the carbonate molten salt with corrosion rates on the order of several millimeters per year. The corrosion product is an interpenetrating structure of metal from the more noble alloy ingredients and of an oxide made up of the reaction between melt components and oxidizable metals from the alloy.

  10. Porous membrane electrochemical cell for uranium and transuranic recovery from molten salt electrolyte

    DOEpatents

    Willit, James L.

    2010-09-21

    An improved process and device for the recovery of the minor actinides and the transuranic elements (TRU's) from a molten salt electrolyte. The process involves placing the device, an electrically non-conducting barrier between an anode salt and a cathode salt. The porous barrier allows uranium to diffuse between the anode and cathode, yet slows the diffusion of uranium ions so as to cause depletion of uranium ions in the catholyte. This allows for the eventual preferential deposition of transuranics present in spent nuclear fuel such as Np, Pu, Am, Cm. The device also comprises an uranium oxidation anode. The oxidation anode is solid uranium metal in the form of spent nuclear fuel. The spent fuel is placed in a ferric metal anode basket which serves as the electrical lead or contact between the molten electrolyte and the anodic uranium metal.

  11. Porous membrane electrochemical cell for uranium and transuranic recovery from molten salt electrolyte

    DOEpatents

    Willit, James L.

    2007-09-11

    An improved process and device for the recovery of the minor actinides and the transuranic elements (TRU's) from a molten salt electrolyte. The process involves placing the device, an electrically non-conducting barrier between an anode salt and a cathode salt. The porous barrier allows uranium to diffuse between the anode and cathode, yet slows the diffusion of uranium ions so as to cause depletion of uranium ions in the catholyte. This allows for the eventual preferential deposition of transuranics present in spent nuclear fuel such as Np, Pu, Am, Cm. The device also comprises an uranium oxidation anode. The oxidation anode is solid uranium metal in the form of spent nuclear fuel. The spent fuel is placed in a ferric metal anode basket which serves as the electrical lead or contact between the molten electrolyte and the anodic uranium metal.

  12. Spin-injection optical pumping of molten cesium salt and its NMR diagnosis

    SciTech Connect

    Ishikawa, Kiyoshi

    2015-07-15

    Nuclear spin polarization of cesium ions in the salt was enhanced during optical pumping of cesium vapor at high magnetic field. Significant motional narrowing and frequency shift of NMR signals were observed by intense laser heating of the salt. When the hyperpolarized salt was cooled by blocking the heating laser, the signal width and frequency changed during cooling and presented the phase transition from liquid to solid. Hence, we find that the signal enhancement is mostly due to the molten salt and nuclear spin polarization is injected into the salt efficiently in the liquid phase. We also show that optical pumping similarly induces line narrowing in the solid phase. The use of powdered salt provided an increase in effective surface area and signal amplitude without glass wool in the glass cells.

  13. Behavior of toxic metals and radionuclides during molten salt oxidation of chlorinated plastics.

    PubMed

    Yang, Hee-Chul; Cho, Yong-Jun; Eun, Hee-Chul; Yoo, Jae-Hyung; Kim, Joon-Hyung

    2004-01-01

    Molten salt oxidation is one of the promising alternatives to incineration for chlorinated organics without the emission of chlorinated organic pollutants. This study investigated the behavior of three hazardous metals (Cd, Pb, and Cr) and four radioactive metal surrogates (Cs, Ce, Gd, and Sm) in the molten Na2CO3 oxidation reactor during the destruction of PVC plastics. In the tested temperature ranges (1143 1223K) and NaCl content (0-10%), the impact of temperature on the retention of cadmium and lead in the molten salt reactor was very small, but that of the NaCl content for their retention was relatively higher. The influence of NaCl accumulation was, however, proven to be practically negligible due to the low-temperature operating characteristics of the molten salt oxidation system. Neither temperature increase nor chlorine accumulation in the MSO reactor reduced the retention of Cr, Ce, Gd, and Sm. Over 99.98% of these metals remained in the reactor. The influence of the temperature on the cesium behavior is relatively large for a chlorine addition, however, over 99.7% of cesium remained in the reactor throughout the entire test. The experimental metal entrainment rate and the entrained metal particle size distribution agree well with the theoretical equilibrium metal distributions.

  14. Temperature effect on laser-induced breakdown spectroscopy spectra of molten and solid salts

    SciTech Connect

    Cynthia Hanson; Supathorn Phongikaroon; Jill R. Scott

    2014-07-01

    Laser-induced breakdown spectroscopy (LIBS) has been investigated as a potential analytical tool to improve operations and safeguards for electrorefiners, such as those used in processing spent nuclear fuel. This study set out to better understand the effect of sample temperature and physical state on LIBS spectra of molten and solid salts by building calibration curves of cerium and assessing self-absorption, plasma temperature, electron density, and local thermal equilibrium (LTE). Samples were composed of a LiCl–KCl eutectic salt, an internal standard of MnCl2, and varying concentrations of CeCl3 (0.1, 0.3, 0.5, 0.8, and 1.0 wt.% Ce) under different temperatures (773, 723, 673, 623, and 573 K). Analysis of salts in their molten form is preferred as plasma plumes from molten samples experienced less self-absorption, less variability in plasma temperature, and higher clearance of the minimum electron density required for local thermal equilibrium. These differences are attributed to plasma dynamics as a result of phase changes. Spectral reproducibility was also better in the molten state due to sample homogeneity.

  15. Stress corrosion cracking of Ti-8Al-1 Mo-1V in molten salts

    NASA Technical Reports Server (NTRS)

    Smyrl, W. H.; Blackburn, M. J.

    1975-01-01

    The stress corrosion cracking (SCC) behavior of Ti-8Al-1 Mo-1V has been studied in several molten salt environments. Extensive data are reported for the alloy in highly pure LiCl-KCl. The influence of the metallurgical heat treatment and texture, and the mechanical microstructure show similarities with aqueous solutions at lower temperature. The fracture path and cracking modes are also similar to that found in other environments. The influence of H2O and H(-) in molten LiCl-KCl lead to the conclusion that hydrogen does not play a major role in crack extension in this environment.

  16. Preliminary Neutronics Design Studies for a Molten Salt Blanket LIFE Engine

    SciTech Connect

    Powers, J

    2008-10-23

    The Laser Inertial Confinement Fusion Fission Energy (LIFE) Program being developed at Lawrence Livermore National Laboratory (LLNL) aims to design a hybrid fission-fusion subcritical nuclear engine that uses a laser-driven Inertial Confinement Fusion (ICF) system to drive a subcritical fission blanket. This combined fusion-fission hybrid system could be used for generating electricity, material transmutation or incineration, or other applications. LIFE does not require enriched fuel since it is a sub-critical system and LIFE can sustain power operation beyond the burnup levels at which typical fission reactors need to be refueled. In light of these factors, numerous options have been suggested and are being investigated. Options being investigated include fueling LIFE engines with spent nuclear fuel to aid in disposal/incineration of commercial spent nuclear fuel or using depleted uranium or thorium fueled options to enhance proliferation resistance and utilize non-fissile materials [1]. LIFE engine blanket designs using a molten salt fuel system represent one area of investigation. Possible applications of a LIFE engine with a molten salt blanket include uses as a spent nuclear fuel burner, fissile fuel breeding platform, and providing a backup alternative to other LIFE engine blanket designs using TRISO fuel particles in case the TRISO particles are found to be unable to withstand the irradiation they will be subjected to. These molten salts consist of a mixture of LiF with UF{sub 4} or ThF{sub 4} or some combination thereof. Future systems could look at using PuF{sub 3} or PuF{sub 4} as well, though no work on such system with initial plutonium loadings has been performed for studies documented in this report. The purpose of this report is to document preliminary neutronics design studies performed to support the development of a molten salt blanket LIFE engine option, as part of the LIFE Program being performed at Lawrence Livermore National laboratory

  17. Engineering Evaluation of Proposed Alternative Salt Transfer Method for the Molten Salt Reactor Experiement for the Oak Ridge National Laboratory

    SciTech Connect

    Carlberg, Jon A.; Roberts, Kenneth T.; Kollie, Thomas G.; Little, Leslie E.; Brady, Sherman D.

    2009-09-30

    This evaluation was performed by Pro2Serve in accordance with the Technical Specification for an Engineering Evaluation of the Proposed Alternative Salt Transfer Method for the Molten Salt Reactor Experiment at the Oak Ridge National Laboratory (BJC 2009b). The evaluators reviewed the Engineering Evaluation Work Plan for Molten Salt Reactor Experiment Residual Salt Removal, Oak Ridge National Laboratory, Oak Ridge, Tennessee (DOE 2008). The Work Plan (DOE 2008) involves installing a salt transfer probe and new drain line into the Fuel Drain Tanks and Fuel Flush Tank and connecting them to the new salt transfer line at the drain tank cell shield. The probe is to be inserted through the tank ball valve and the molten salt to the bottom of the tank. The tank would then be pressurized through the Reactive Gas Removal System to force the salt into the salt canisters. The Evaluation Team reviewed the work plan, interviewed site personnel, reviewed numerous documents on the Molten Salt Reactor (Sects. 7 and 8), and inspected the probes planned to be used for the transfer. Based on several concerns identified during this review, the team recommends not proceeding with the salt transfer via the proposed alternate salt transfer method. The major concerns identified during this evaluation are: (1) Structural integrity of the tanks - The main concern is with the corrosion that occurred during the fluorination phase of the uranium removal process. This may also apply to the salt transfer line for the Fuel Flush Tank. Corrosion Associated with Fluorination in the Oak Ridge National Laboratory Fluoride Volatility Process (Litman 1961) shows that this problem is significant. (2) Continued generation of Fluorine - Although the generation of Fluorine will be at a lower rate than experienced before the uranium removal, it will continue to be generated. This needs to be taken into consideration regardless of what actions are taken with the salt. (3) More than one phase of material

  18. Producing titanium by reducing TiCl2-MgCl2 mixed salt with magnesium in the molten state

    NASA Astrophysics Data System (ADS)

    Fuwa, Akio; Takaya, Satoru

    2005-10-01

    In the Kroll process for titanium sponge metal production, TiCl4 gas is introduced and reacted with molten magnesium metal via a gas-liquid reduction reaction. The magnesium reduction reaction of the mixed salt of TiCl2-MgCl2 via a liquid-liquid reaction has been investigated and the results are reported in this article. First, the molten mixed salt was synthesized through chlorination reaction of solid titanium sponge placed in molten MgCl2 salt, while TiCl4 gas was bubbled at around 1,173K. Then, the TiCl2-MgCl2 was reacted with molten magnesium at similar temperatures. This proposed magnesium reduction reaction of the TiCl2-MgCl2 in the molten state may be more efficient, easier to control, and suitable for realizing continuous titanium production.

  19. Investigation on the Oxidation and Reduction of Titanium in Molten Salt with the Soluble TiC Anode

    NASA Astrophysics Data System (ADS)

    Wang, Shulan; Wan, Chaopin; Liu, Xuan; Li, Li

    2015-12-01

    To reveal the oxidation process of titanium from TiC anode and the reduction mechanism of titanium ions in molten NaCl-KCl, the polarization curve of TiC anode in molten NaCl-KCl and cyclic voltammograms of the molten salt after polarization were studied. Investigation on the polarization curve shows that titanium can be oxidized and dissociated from the TiC anode at very low potential. The cyclic voltammograms demonstrated that the reduction reaction of titanium ions in the molten salt is a one-step process. By potentiostatic electrolysis, dendritic titanium is obtained on the steel plate. The work promotes the understanding on the process of electrochemical oxidization/dissociation of titanium from TiC anode and the reduction mechanism of titanium ions in molten salt.

  20. Effect of Using Thorium Molten Salts on the Neutronic Performance of PACER

    NASA Astrophysics Data System (ADS)

    Acır, Adem; Übeyli, Mustafa

    2010-04-01

    Utilization of nuclear explosives can produce a significant amount of energy which can be converted into electricity via a nuclear fusion power plant. An important fusion reactor concept using peaceful nuclear explosives is called as PACER which has an underground containment vessel to handle the nuclear explosives safely. In this reactor, Flibe has been considered as a working coolant for both tritium breeding and heat transferring. However, the rich neutron source supplied from the peaceful nuclear explosives can be used also for fissile fuel production. In this study, the effect of using thorium molten salts on the neutronic performance of the PACER was investigated. The computations were performed for various coolants bearing thorium and/or uranium-233 with respect to the molten salt zone thickness in the blanket. Results pointed out that an increase in the fissile content of the salt increased the neutronic performance of the reactor remarkably. In addition, higher energy production was obtained with thorium molten salts compared to the pure mode of the reactor. Moreover, a large quantity of 233U was produced in the blanket in all cases.

  1. Effect of chloride content of molten nitrate salt on corrosion of A516 carbon steel.

    SciTech Connect

    Bradshaw, Robert W.; Clift, W. Miles

    2010-11-01

    The corrosion behavior of A516 carbon steel was evaluated to determine the effect of the dissolved chloride content in molten binary Solar Salt. Corrosion tests were conducted in a molten salt consisting of a 60-40 weight ratio of NaNO{sub 3} and KNO{sub 3} at 400{sup o}C and 450{sup o}C for up to 800 hours. Chloride concentrations of 0, 0.5 and 1.0 wt.% were investigated to determine the effect on corrosion of this impurity, which can be present in comparable amounts in commercial grades of the constituent salts. Corrosion rates were determined by descaled weight losses, corrosion morphology was examined by metallographic sectioning, and the types of corrosion products were determined by x-ray diffraction. Corrosion proceeded by uniform surface scaling and no pitting or intergranular corrosion was observed. Corrosion rates increased significantly as the concentration of dissolved chloride in the molten salt increased. The adherence of surface scales, and thus their protective properties, was degraded by dissolved chloride, fostering more rapid corrosion. Magnetite was the only corrosion product formed on the carbon steel specimens, regardless of chloride content or temperature.

  2. Molten salt destruction of energetic material wastes as an alternative to open burning. Revision 1

    SciTech Connect

    Upadhye, R.S.; Brummond, W.A.; Pruneda, C.O.; Watkins, B.E.

    1994-11-02

    As a result of the end of the Cold War and the shift in emphasis to a smaller stockpile, many munitions, both conventional and nuclear, are scheduled for retirement and rapid dismantlement and demilitarization. Major components of these munitions are the explosives and propellants, or energetic materials. The Molten Salt Destruction (MSD) Process has been demonstrated for the destruction of HE and HE-containing wastes. MSD converts the organic constituents of the waste into non-hazardous substances such as carbon dioxide, nitrogen and water. Any inorganic constituents of the waste, such as binders and metallic particles, are retained in the molten salt. LLNL has built a small-scale (about 1 kg/hr throughput) unit to test the destruction of HE using the MSD process. The authors have demonstrated that HE`s and liquid propellants can be safely and fully destroyed using the molten salt destruction process. The authors are currently working on a number of improvements to the process. They are modifying the design of unit to obtain more throughput without any increase in salt entrainment. They are implementing an advanced nozzle design for injection of larger particles. They are defining operating envelopes for a number of high explosives and formulations. They are developing models to study the temperature profile of a top-feed nozzle for feeding larger particles into the unit.

  3. An evaluation of possible next-generation high temperature molten-salt power towers.

    SciTech Connect

    Kolb, Gregory J.

    2011-12-01

    Since completion of the Solar Two molten-salt power tower demonstration in 1999, the solar industry has been developing initial commercial-scale projects that are 3 to 14 times larger. Like Solar Two, these initial plants will power subcritical steam-Rankine cycles using molten salt with a temperature of 565 C. The main question explored in this study is whether there is significant economic benefit to develop future molten-salt plants that operate at a higher receiver outlet temperature. Higher temperatures would allow the use of supercritical steam cycles that achieve an improved efficiency relative to today's subcritical cycle ({approx}50% versus {approx}42%). The levelized cost of electricity (LCOE) of a 565 C subcritical baseline plant was compared with possible future-generation plants that operate at 600 or 650 C. The analysis suggests that {approx}8% reduction in LCOE can be expected by raising salt temperature to 650 C. However, most of that benefit can be achieved by raising the temperature to only 600 C. Several other important insights regarding possible next-generation power towers were also drawn: (1) the evaluation of receiver-tube materials that are capable of higher fluxes and temperatures, (2) suggested plant reliability improvements based on a detailed evaluation of the Solar Two experience, and (3) a thorough evaluation of analysis uncertainties.

  4. SEPARATION OF PROTACTINIUM FROM MOLTEN SALT REACTOR FUEL COMPOSITIONS

    DOEpatents

    Shaffer, J.H.; Strain, J.E.; Cuneo, D.R.; Kelly, M.J.

    1963-11-12

    A method for selectively precipitating protactinium from a neutron- irradiated fused fluoride salt composition comprising at least one metal fluoride selected from the group consisting of an alkali metal fluoride and an alkaline earth metal fluoride containing dissolved thorium-232 values is presented. An inorganic metal oxide corresponding to any of the metal fluorides of the composition is also added. (AEC)

  5. Expedited demonstration of molten salt mixed waste treatment technology. Final report

    SciTech Connect

    1995-02-02

    This final report discusses the molten salt mixed waste project in terms of the various subtasks established. Subtask 1: Carbon monoxide emissions; Establish a salt recycle schedule and/or a strategy for off-gas control for MWMF that keeps carbon monoxide emission below 100 ppm on an hourly averaged basis. Subtask 2: Salt melt viscosity; Experiments are conducted to determine salt viscosity as a function of ash composition, ash concentration, temperature, and time. Subtask 3: Determine that the amount of sodium carbonate entrained in the off-gas is minimal, and that any deposited salt can easily be removed form the piping using a soot blower or other means. Subtask 4: The provision of at least one final waste form that meets the waste acceptance criteria of a landfill that will take the waste. This report discusses the progress made in each of these areas.

  6. Diagnosis of sources of current inefficiency in industrial molten salt electrolysis cells by Raman spectroscopy: A topical report on chlorides: Topical report, June 1982-June 1987

    SciTech Connect

    Sadoway, D. R.

    1987-06-01

    Molten salt electrolysis, a very energy-intensive process, is used in the extraction of light metals. Aluminum production by the Hall process and magnesium production in the Dow and I.G. Farbenindustrie cells constitute the major commercial applications of metal electrowinning from molten-salt media at present. The energy input into the electrolysis cell is in the form of direct current, and the energy efficiencies in the magnesium or aluminum processes are only in the 30 to 40% range. Major energy reductions are achieved by reducing the cell voltage or by increasing the current efficiency. Goal of the research is to identify the sources of the current losses occurring in molten salt electrolysis. This research worked on the systems of I.G. Farben magnesium chloride and Alcoa smelting aluminum chloride processes. Raman spectra were measured and analyzed for each component or their mixtures of the electrolyte for magnesium and aluminum reduction in chloride melts. Raman measurements were also conducted on the melts of industrial composition for aluminum and magnesium electrolysis. In laboratory-scale cells which imitated industrial practice, Raman spectra were measured in situ during electrolysis in attempts to identify the streamers, coloration of electrolyte, and any subvalent species. They were known to occur only during electrolysis, and they have been reported to be possible current losses. Cyclic voltammetry was conducted to obtain information about the generation of subvalent species which were not detected by Raman measurement. These were thought to be kinetic entities present only during electrolysis. Results of Raman spectroscopy and electrochemistry of magnesium and aluminum reduction from molten chloride bath are presented. The results would be useful to establish the basis for the study of electrolysis of aluminum from molten fluoride media. 119 refs., 66 figs.

  7. Preliminary molten salt extraction experiments with dicesium hexachloroplutonate (Cs/sub 2/PuCl/sub 6/)

    SciTech Connect

    Thomas, R.L.; Long, J.L.; Humiston, T.J.; Murray, A.M.

    1989-01-30

    Dicesium hexachloroplutonate was prepared on a 200-gram scale and used as an oxidant in the molten salt extraction process to remove americium from plutonium metal. Single-pass extraction efficiencies exceeding 90% were achieved in molten calcium chloride. 7 refs., 2 figs., 3 tabs.

  8. Electrochemical studies of calcium chloride-based molten salt systems

    SciTech Connect

    Blanchard, T.P. Jr.

    1992-12-01

    Conductance and EMF studies of CaCl{sub 2}-based melts were performed in the temperature range 790--990 C. Conductivity data collected using magnesia tubes and capillaries showed deviations from the data recommended by the National Bureau of Standards. These deviations are attributed to the slow dissolution of magnesia by the CaCl{sub 2}-CaO melt. Conductivity data for molten CaCl{sub 2} using a pyrolytic boron nitride capillary were in reasonable agreement with the recommended data; however, undissolved CaO in CaCl{sub 2} may have caused blockage of the pyrolytic boron nitride capillary, resulting in fluctuations in the measured resistance. The utility of the AgCl/Ag reference electrode in CaCl{sub 2}-AgCl and CaCl{sub 2}-CaO-AgCl melts, using asbestos diaphragms and Vycor glass as reference half-cell membranes, was also investigated. Nernstian behavior was observed using both types of reference half-cell membranes in CaCl{sub 2}-AgCl melts. The AgCl/Ag reference electrode also exhibited Nernstian behavior in CaCl{sub 2}-CaO-AgCl melts using a Vycor reference half-cell membrane and a magnesia crucible. The use of CaCl{sub 2} as a solvent is of interest since it is used in plutonium metal purification, as well as various other commercial applications. 97 refs., 33 figs., 13 tabs.

  9. Monte Carlo study of molten salt with charge asymmetry near the electrode surface

    NASA Astrophysics Data System (ADS)

    Kłos, Jacek; Lamperski, Stanisław

    2014-02-01

    Results of the Monte Carlo simulation of the electrode | molten salt or ionic liquid interface are reported. The system investigated is approximated by the primitive model of electrolyte being in contact with a charged hard wall. Ions differ in charges, namely anions are divalent and cations are monovalent but they are of the same diameter d = 400 pm. The temperature analysis of heat capacity at a constant volume Cv and the anion radial distribution function, g2-/2-, allowed the choice of temperature of the study, which is T = 2800 K and corresponds to T* = 0.34 (definition of reduced temperature T* in text). The differential capacitance curve of the interface with the molten salt or ionic liquid at c = 5.79 M has a distorted bell shape. It is shown that with increasing electrolyte concentration from c = 0.4 to 5 M the differential capacitance curves undergo transition from U shape to bell shape.

  10. Monte Carlo study of molten salt with charge asymmetry near the electrode surface.

    PubMed

    Kłos, Jacek; Lamperski, Stanisław

    2014-02-01

    Results of the Monte Carlo simulation of the electrode | molten salt or ionic liquid interface are reported. The system investigated is approximated by the primitive model of electrolyte being in contact with a charged hard wall. Ions differ in charges, namely anions are divalent and cations are monovalent but they are of the same diameter d = 400 pm. The temperature analysis of heat capacity at a constant volume Cv and the anion radial distribution function, g2-/2-, allowed the choice of temperature of the study, which is T = 2800 K and corresponds to T(*) = 0.34 (definition of reduced temperature T(*) in text). The differential capacitance curve of the interface with the molten salt or ionic liquid at c = 5.79 M has a distorted bell shape. It is shown that with increasing electrolyte concentration from c = 0.4 to 5 M the differential capacitance curves undergo transition from U shape to bell shape.

  11. Modeling and analysis of a molten salt electrowinning system with liquid cadmium cathode

    SciTech Connect

    Kim, K.R.; Ahn, D.H.; Paek, S.; Kwon, S.W.; Kim, S.H.; Shim, J.B.; Chung, H.; Kim, E.H.

    2007-07-01

    In the present work, an electrowinning process in the LiCl-KCl/Cd system is considered to model and analyze the equilibrium behavior and electro-transport of the actinide and rare-earth elements. Equilibrium distributions of the actinide and rare-earth elements in a molten salt and liquid cadmium system have been estimated for an infinite potentiostatic electrolysis from the thermodynamic data and material balance. A simple dynamic modeling of this process was performed by taking into account the material balances and diffusion-controlled electrochemical reactions in a diffusion layer at an electrode interface between the molten salt and liquid cadmium cathode. This model demonstrated a prediction of the concentration behaviors, a faradic current of each element and an electrochemical potential as function of the time up to the corresponding electro-transport satisfying a given applied current based on a galvano-static electrolysis. (authors)

  12. On-line Monitoring of Actinide Concentrations in Molten Salt Electrolyte

    SciTech Connect

    Curtis W. Johnson; Mary Lou Dunzik-Gougar; Shelly X. Li

    2006-11-01

    Pyroprocessing, a treatment method for spent nuclear fuel (SNF), is currently being studied at the Idaho National Laboratory. The key operation of pyroprocessing which takes place in an electrorefiner is the electrochemical separation of actinides from other constituents in spent fuel. Efficient operation of the electrorefiner requires online monitoring of actinide concentrations in the molten salt electrolyte. Square-wave voltammetry (SWV) and normal pulse voltammetry (NPV) are being investigated to assess their applicability to the measurement of actinide concentrations in the electrorefiner.

  13. Ceramic waste form for residues from molten salt oxidation of mixed wastes

    SciTech Connect

    Van Konynenburg, R.A.; Hopper, R.W.; Rard, J.A.

    1995-11-01

    A ceramic waste form based on Synroc-D is under development for the incorporation of the mineral residues from molten salt oxidation treatment of mixed low-level wastes. Samples containing as many as 32 chemical elements have been fabricated, characterized, and leach-tested. Universal Treatment Standards have been satisfied for all regulated elements except and two (lead and vanadium). Efforts are underway to further improve chemical durability.

  14. Discharge characteristics of lithium/molten nitrate thermal battery cells using silver salts as solid cathode materials

    NASA Astrophysics Data System (ADS)

    McManis, G. E.; Miles, M. H.; Fletcher, A. N.

    1985-12-01

    Thermal battery cells using molten nitrate electrolytes and liquid lithium anodes have been evaluated using several silver salts with low solubility in molten nitrates as solid cathode materials. These cathode materials do not readily diffuse into the anolyte and, thus, do not have parasitic reactions with the lithium anode. Furthermore, the solid cathode materials have voltammetric characteristics as favorable as many soluble silver salt cathodes. This paper presents the effects of temperature, current density, and cathode material on cell discharge characteristics.

  15. Molten Salt Electrodeposition of Silicon in Cu-Si

    NASA Astrophysics Data System (ADS)

    Sokhanvaran, Samira

    Widespread use of solar energy has not been realized to date because its cost is not competitive with conventional energy sources. The high price of solar grade silicon has been one of the barriers against photovoltaic industry achieving its much anticipated growth. Therefore, developing a method, which is energy efficient and will deliver inexpensive silicon feedstock material is essential. The electrodeposition of Si from a cryolite-based melt was investigated in the present work as a possible solution. This study proposed electrowinning of Si in molten Cu-Si alloy, to decrease the working temperature and increase the efficiency. Solvent refining can be used to recover Si from Cu-Si and also as a second purification method. The physicochemical properties of the potential electrolyte, cryolite-SiO 2 melts, were studied in the first step of this work. The deposition potential of Si on a graphite cathode was measured to determine the working potential and the effect of SiO2 concentration on it. In the next step, the deposition potential of Si from cryolite--SiO2 melt on Cu and Cu-Si cathodes was determined using cyclic voltammetry. Next, the cathodic and the anodic current inefficiencies of the process were measured. Continuous analysis of the evolved gas enabled the instantaneous measurement of the current efficiency and the kinetics of the deposition. Finally, the effectiveness of the process in delivering high purity Si was investigated. Si dendrites were precipitated out of the Cu-Si cathode and recovered to determine the purity of the final product as the final step of this study. The produced Si was separated from the alloy matrix by crushing and acid leaching and the purity was reported. The findings of this research show that the proposed method has the potential to produce high purity silicon with low B content. Further development is required to remove some metallic impurities that are remained in Si.

  16. JUPITER-II Molten Salt Flibe Research: An Update On Tritium, Mobilization and Redox Chemistry Experiments

    SciTech Connect

    D.A. Petti; D. A. Petti; G. R. Smolik; Michael F. Simpson; John P. Sharpe; R. A. Anderl; S. Fukada; Y. Hatano; Masanori Hara; Y. Oya; T. Terai; D.-K. Sze; S. Tanaka

    2005-05-01

    The second Japan/US Program on Irradiation Tests for Fusion Research (JUPITER-II) began on April 1, 2001. Part of the collaborative research centers on studies of the molten salt 2LiF2–BeF2 (also known as Flibe) for fusion applications. Flibe has been proposed as a self-cooled breeder in both magnetic and inertial fusion power plant designs over the last 25 years. The key feasibility issues associated with the use of Flibe are the corrosion of structural material by the molten salt, tritium behavior and control in the molten salt blanket system, and safe handling practices and releases from Flibe during an accidental spill. These issues are all being addressed under the JUPITER-II program at the Idaho National Laboratory in the Safety and Tritium Applied Research (STAR) facility. In this paper, we review the program to date in the area of tritium/deuterium behavior, Flibe mobilization under accident conditions and testing of Be as a redox agent to control corrosion. Future activities planned through the end of the collaboration are also presented.

  17. Diagnosis of sources of current inefficiency in industrial molten salt electrolysis cells by Raman spectroscopy

    SciTech Connect

    Sadoway, D.R.

    1988-07-29

    The purpose of this project was to employ Raman spectroscopy in the study of industrial molten salt electrolysis cells. The objective was to improve the understanding of the chemistry and electrochemistry of the relevant melt systems and, in turn, of energy loss mechanisms in the industrial processes. On this basis new ways to improve the energy efficiency of these industrial reactors might be identified. The research plan has several principal elements. First, there was the design and construction of laboratory scale representations of industrial molten salt electrolysis cells that would at the same time serve a spectrocells. Secondly, there was the mastery of the preparation of the molten salt electrolytes, what in industry is called the ''front end.'' Thirdly, there was the adaptation of commercially available Raman instrumentation in order to facilitate the proposed studies. It is the nature of the specimens that so dramatically distinguished this work from conventional Raman studies for which commercial instrumentation is designed: first, the laboratory scale electrolysis cells are large compared to typical spectrocells; and secondly, the cells operate at, what for Raman studies are, extremely high temperatures. 4 refs., 2 figs.

  18. Synthesis of ZrO{sub 2} in molten salt mixtures: Control of the evolved gas and the oxide texture

    SciTech Connect

    Afanasiev, P.; Geantet, C.; Lacroix, M.; Breysse, M.

    1996-08-01

    The authors investigated a mixture of KNO{sub 3}-NaNO{sub 3}-Na{sub 2}CO{sub 3} as a reaction medium for the preparation of ZrO{sub 2}. The formation of ZrO{sub 2} in molten nitrate can be considered as an acid-base reaction in which the zirconium salt plays the role of an acid and the melt anions that of a base. The higher reactivity of the carbonate ion in comparison to that of nitrate could modify the reaction mechanism, and different physico-chemical properties of the resulting solid could be expected. Carbonate may also act as a textural modifier similarly to preparations performed in aqueous media. 20 refs.

  19. Molten salt oxidation for treating low-level mixed wastes

    SciTech Connect

    Adamson, M G; Ford, T D; Foster, K G; Hipple, D L; Hopper, R W; Hsu, P C

    1998-12-10

    MS0 is a promising alternative to incineration for the treatment of a variety of organic wastes. Lawrence Livermore National Laboratory (LLNL) has prepared a facility (please see the photo attached) in which an integrated pilot-scale MS0 treatment system is being tested and demonstrated. The system consists of a MS0 vessel with a dedicated off-gas treatment system, a salt recycle system, feed preparation equipment, and a ceramic final waste forms immobilization system. The MSO/off-gas system has been operational since December 1997. The salt recycle system and the ceramic final forms immobilization became operational in May and August 1998, respectively. We have tested the MS0 facility with various organic feeds, including chlorinated solvents; tributyl phosphate/kerosene, PCB-contaminated waste oils & solvents, booties, plastic pellets, ion exchange resins, activated carbon, radioactive-spiked organics, and well-characterized low- level liquid mixed wastes. MS0 is a versatile technology for hazardous waste treatment and may be a solution to many waste disposal problems. In this paper we will present our operational experience with MS0 and also discuss its process capabilities as well as performance data with different feeds.

  20. Destruction of decabromodiphenyl ether (BDE-209) in a ternary carbonate molten salt reactor.

    PubMed

    Yao, Zhi-tong; Li, Jin-hui; Zhao, Xiang-yang

    2013-09-30

    Soil contamination by PBDEs has become a significant environmental concern and requires appropriate remediation technologies. In this study, the destruction of decabromodiphenyl ether (BDE-209) in a ternary molten salt (Li, Na, K)2 CO3 reactor was evaluated. The effects of reaction temperature, additive amount of BDE-209 and salt mixture, on off-gas species, were investigated. The salt mixture after reaction was characterized by XRD analysis and a reaction pathway proposed. The results showed that the amounts of C2H6, C2H4, C4H8 and CH4 in the off-gas decreased with increases in temperature, while the CO2 level increased. When the reaction temperature reached 750 °C, incomplete combustion products (PICs) were no longer detected. Increasing BDE-209 loading was not helpful for the reaction, as more PICs were produced. Larger amounts of salt mixture were helpful for the reaction and PICs were not observed with the mole ratio 1: 2000 of BDE-209 to carbonate melt. XRD analysis confirmed the capture of bromine in BDE-209 by the molten salt.

  1. Separation of Actinides from LWR Spent Fuel Using Molten-Salt-Based Electrochemical Processes

    SciTech Connect

    Karell, Eric J.; Gourishankar, Karthick V.; Smith, James L.; Chow, Lorac S.; Redey, Laszlo

    2001-12-15

    Results are presented of work done at Argonne National Laboratory to develop a molten-salt-based electrochemical technology for extracting uranium and transuranic elements from spent light water reactor fuel. In this process, the actinide oxides in the spent fuel are reduced using lithium at 650 deg. C in the presence of molten LiCl, yielding the corresponding actinides and Li{sub 2}O. The actinides are then extracted from the reduction product by means of electrorefining. Associated with the reduction step is an ancillary salt-recovery step designed to electrochemically reduce the Li{sub 2}O concentration of the salt and recover the lithium metal.Experiments were performed at the laboratory scale (50 to 150 g of fuel and 0.5 to 3.5 l of salt) and engineering scale (3.7 to 5.2 kg of fuel and 50 l of salt). Laboratory-scale experiments were designed to obtain information on the fundamental factors affecting process rates. Engineering-scale experiments were conducted to verify that the parameters controlling process scaleup are sufficiently understood, and to test equipment and operating concepts at or near full scale. All indications are that the electrochemical-based process should be workable at practical plant sizes.

  2. Thermal Storage Properties of Molten Nitrate Salt-Based Nanofluids with Graphene Nanoplatelets.

    PubMed

    Xie, Qiangzhi; Zhu, Qunzhi; Li, Yan

    2016-12-01

    In this study, the effect of concentration of nanoparticles on the thermal storage properties of molten nitrate salt-based nanofluids with graphene nanoplatelets (GNPs) was investigated. Solar salt consisting of sodium nitrate and potassium nitrate was utilized as the base material for the nanofluids. Homogeneous dispersion of GNPs within the solar salt was observed through scanning electron microscopy analysis. For both solar salt and resultant nanofluids, differential scanning calorimetry was employed to measure the thermal storage properties, including characteristic temperatures of phase change, startup heat, and specific heat capacity (SHC). A maximum increase of 16.7 % in SHC at the liquid phase was found at an optimal concentration of 1 wt% of GNPs. At the same concentration, the onset temperature decreased by 10.4 °C, the endset temperature decreased by 4.7 °C, and the startup heat decreased by 9 %.

  3. Thermal Storage Properties of Molten Nitrate Salt-Based Nanofluids with Graphene Nanoplatelets

    NASA Astrophysics Data System (ADS)

    Xie, Qiangzhi; Zhu, Qunzhi; Li, Yan

    2016-06-01

    In this study, the effect of concentration of nanoparticles on the thermal storage properties of molten nitrate salt-based nanofluids with graphene nanoplatelets (GNPs) was investigated. Solar salt consisting of sodium nitrate and potassium nitrate was utilized as the base material for the nanofluids. Homogeneous dispersion of GNPs within the solar salt was observed through scanning electron microscopy analysis. For both solar salt and resultant nanofluids, differential scanning calorimetry was employed to measure the thermal storage properties, including characteristic temperatures of phase change, startup heat, and specific heat capacity (SHC). A maximum increase of 16.7 % in SHC at the liquid phase was found at an optimal concentration of 1 wt% of GNPs. At the same concentration, the onset temperature decreased by 10.4 °C, the endset temperature decreased by 4.7 °C, and the startup heat decreased by 9 %.

  4. Thermal Storage Properties of Molten Nitrate Salt-Based Nanofluids with Graphene Nanoplatelets.

    PubMed

    Xie, Qiangzhi; Zhu, Qunzhi; Li, Yan

    2016-12-01

    In this study, the effect of concentration of nanoparticles on the thermal storage properties of molten nitrate salt-based nanofluids with graphene nanoplatelets (GNPs) was investigated. Solar salt consisting of sodium nitrate and potassium nitrate was utilized as the base material for the nanofluids. Homogeneous dispersion of GNPs within the solar salt was observed through scanning electron microscopy analysis. For both solar salt and resultant nanofluids, differential scanning calorimetry was employed to measure the thermal storage properties, including characteristic temperatures of phase change, startup heat, and specific heat capacity (SHC). A maximum increase of 16.7 % in SHC at the liquid phase was found at an optimal concentration of 1 wt% of GNPs. At the same concentration, the onset temperature decreased by 10.4 °C, the endset temperature decreased by 4.7 °C, and the startup heat decreased by 9 %. PMID:27325522

  5. Incorporating supercritical steam turbines into molten-salt power tower plants :

    SciTech Connect

    Pacheco, James Edward; Wolf, Thorsten; Muley, Nishant

    2013-03-01

    Sandia National Laboratories and Siemens Energy, Inc., examined 14 different subcritical and supercritical steam cycles to determine if it is feasible to configure a molten-salt supercritical steam plant that has a capacity in the range of 150 to 200 MWe. The effects of main steam pressure and temperature, final feedwater temperature, and hot salt and cold salt return temperatures were determined on gross and half-net efficiencies. The main steam pressures ranged from 120 bar-a (subcritical) to 260 bar-a (supercritical). Hot salt temperatures of 566 and 600ÀC were evaluated, which resulted in main steam temperatures of 553 and 580ÀC, respectively. Also, the effects of final feedwater temperature (between 260 and 320ÀC) were evaluated, which impacted the cold salt return temperature. The annual energy production and levelized cost of energy (LCOE) were calculated using the System Advisory Model on 165 MWe subcritical plants (baseline and advanced) and the most promising supercritical plants. It was concluded that the supercritical steam plants produced more annual energy than the baseline subcritical steam plant for the same-size heliostat field, receiver, and thermal storage system. Two supercritical steam plants had the highest annual performance and had nearly the same LCOE. Both operated at 230 bar-a main steam pressure. One was designed for a hot salt temperature of 600ÀC and the other 565ÀC. The LCOEs for these plants were about 10% lower than the baseline subcritical plant operating at 120 bar-a main steam pressure and a hot salt temperature of 565ÀC. Based on the results of this study, it appears economically and technically feasible to incorporate supercritical steam turbines in molten-salt power tower plants.

  6. Concentrating Solar Power - Molten Salt Pump Development, Final Technical Report (Phase 1)

    SciTech Connect

    Michael McDowell; Alan Schwartz

    2010-03-31

    The purpose of this project is to develop a long shafted pump to operate at high temperatures for the purpose of producing energy with renewable resources. In Phase I of this three phase project we developed molten salt pump requirements, evaluated existing hardware designs for necessary modifications, developed a preliminary design of the pump concept, and developed refined cost estimates for Phase II and Phase III of the project. The decision has been made not to continue the project into Phases II and III. There is an ever increasing world-wide demand for sources of energy. With only a limited supply of fossil fuels, and with the costs to obtain and produce those fuels increasing, sources of renewable energy must be found. Currently, capturing the sun's energy is expensive compared to heritage fossil fuel energy production. However, there are government requirements on Industry to increase the amount of energy generated from renewable resources. The objective of this project is to design, build and test a long-shafted, molten salt pump. This is the type of pump necessary for a molten salt thermal storage system in a commercial-scale solar trough plant. This project is under the Department of Energy (DOE) Solar Energy Technologies Program, managed by the Office of Energy Efficiency and Renewable Energy. To reduce the levelized cost of energy (LCOE), and to meet the requirements of 'tomorrows' demand, technical innovations are needed. The DOE is committed to reducing the LCOE to 7-10 cents/kWh by 2015, and to 5-7 cents/kWh by 2020. To accomplish these goals, the performance envelope for commercial use of long-shafted molten salt pumps must be expanded. The intent of this project is to verify acceptable operation of pump components in the type of molten salt (thermal storage medium) used in commercial power plants today. Field testing will be necessary to verify the integrity of the pump design, and thus reduce the risk to industry. While the primary goal is to

  7. Method for removal of heavy metal from molten salt in IFR fuel pyroprocessing

    SciTech Connect

    Gay, E.C.; Miller, W.E.; Laidler, J.J.

    1994-02-01

    This report details the pyrometallurgical process for recycling spent metal fuels from the Integral Fast Reactor (IFR) which involves electrorefining spent fuel in a molten salt electrolyte (LiCl-KCI-U/PuCl{sub 3}) at 500{degree}C. The total heavy metal chloride concentration in the salt will be about 2 mol %. At some point, the concentrations of alkali, alkaline earth, and rare earth fission products in the salt must be reduced to lower the amount of heat generated in the electrorefiner. The heavy metal concentration in the salt must be reduced before removing the fission products from the salt. The operation uses a lithium-cadmium alloy anode that is solid at 500{degree}C, a solid mandrel cathode with a ceramic catch crucible below to collect heavy metal that falls off it, and a liquid cadmium cathode. The design criteria that had to be met by this equipment included the following: (1) control of the reduction rate by lithium, (2) good separation between heavy metal and rare earths, and (3) the capability to collect heavy metal and rare earths over a wide range of salt compositions. In tests conducted in an engineering-scale electrorefiner (10 kg uranium per cathode), good separation was achieved while removing uranium and rare earths from the salt. Only 13% of the rare earths was removed, while 99.9% of the uranium in the salt was removed; subsequently, the rare earths were also reduced to low concentrations. The uranium concentration in the salt was reduced to 0.05 ppm after uranium and rare earths were transferred from the salt to a solid mandrel cathode with a catch crucible. Rare earth concentrations in the salt were reduced to less than 0.01 wt % in these operations. Similar tests are planned to remove plutonium from the salt in a laboratory-scale (100--300 g heavy metal) electrorefiner.

  8. Development of Molten-Salt Heat Transfer Fluid Technology for Parabolic Trough Solar Power Plants - Public Final Technical Report

    SciTech Connect

    Grogan, Dylan C. P.

    2013-08-15

    Executive Summary This Final Report for the "Development of Molten-Salt Heat Transfer Fluid (HTF) Technology for Parabolic Trough Solar Power Plants” describes the overall project accomplishments, results and conclusions. Phase 1 analyzed the feasibility, cost and performance of a parabolic trough solar power plant with a molten salt heat transfer fluid (HTF); researched and/or developed feasible component options, detailed cost estimates and workable operating procedures; and developed hourly performance models. As a result, a molten salt plant with 6 hours of storage was shown to reduce Thermal Energy Storage (TES) cost by 43.2%, solar field cost by 14.8%, and levelized cost of energy (LCOE) by 9.8% - 14.5% relative to a similar state-of-the-art baseline plant. The LCOE savings range met the project’s Go/No Go criteria of 10% LCOE reduction. Another primary focus of Phase 1 and 2 was risk mitigation. The large risk areas associated with a molten salt parabolic trough plant were addressed in both Phases, such as; HTF freeze prevention and recovery, collector components and piping connections, and complex component interactions. Phase 2 analyzed in more detail the technical and economic feasibility of a 140 MWe,gross molten-salt CSP plant with 6 hours of TES. Phase 2 accomplishments included developing technical solutions to the above mentioned risk areas, such as freeze protection/recovery, corrosion effects of applicable molten salts, collector design improvements for molten salt, and developing plant operating strategies for maximized plant performance and freeze risk mitigation. Phase 2 accomplishments also included developing and thoroughly analyzing a molten salt, Parabolic Trough power plant performance model, in order to achieve the project cost and performance targets. The plant performance model and an extensive basic Engineering, Procurement, and Construction (EPC) quote were used to calculate a real levelized cost of energy (LCOE) of 11.50

  9. Preliminary safety calculations to improve the design of Molten Salt Fast Reactor

    SciTech Connect

    Brovchenko, M.; Heuer, D.; Merle-Lucotte, E.; Allibert, M.; Capellan, N.; Ghetta, V.; Laureau, A.

    2012-07-01

    Molten salt reactors are liquid fuel reactors so that they are flexible in operation but very different in the safety approach from solid fuel reactors. This study bears on the specific concept named Molten Salt Fast Reactor (MSFR). Since this new nuclear technology is in development, safety is an essential point to be considered all along the R and D studies. This paper presents the first step of the safety approach: the systematic description of the MSFR, limited here to the main systems surrounding the core. This systematic description is the basis on which we will be able to devise accidental scenarios. Thanks to the negative reactivity feedback coefficient, most accidental scenarios lead to reactor shut down. Because of the decay heat generated in the fuel salt, it must be cooled. After the description of the tools developed to calculate the residual heat, the different contributions are discussed in this study. The decay heat of fission products in the MSFR is evaluated to be low (3% of nominal power), mainly due to the reprocessing that transfers the fission products to the gas reprocessing unit. As a result, the contribution of the actinides is significant (0.5% of nominal power). The unprotected loss of heat sink transients are studied in this paper. It appears that slow transients are favorable (> 1 min) to minimize the temperature increase of the fuel salt. This work will be the basis of further safety studies as well as an essential parameter for the design of the draining system. (authors)

  10. Microstructure and kinetics of hot corrosion for a nickel alloy in molten salt

    SciTech Connect

    Stevens, D.W.; Brummond, W.A.; Grimmett, D.L.; Newcomb, J.C.; Chiang, K.T.; Gay, R.L.

    1996-12-01

    Metallography, analytical SEM, and XRD were used to measure kinetics and characterize the microstructure of hot corrosion of the Ni-Cr-Fe alloy INCONEL 600 after 500 h immersion in molten Na{sub 2}CO{sub 3}- NaCl salt at 900-950 C in an oxidizing atmosphere. This was done to assess the alloy as a reaction vessel material for a waste treatment process known as Molten Salt Oxidation. The alloy was found to hot corrode by surface oxidation and intergranular attack. Combined rate for loss of load-bearing cross-section metal was comparable to corrosion rates for analogous salts. About 5% of the oxide scale was a continuous, dense, protective layer of Cr{sub 2}O{sub 3} at the metal/oxide interface. A middle portion comprised about 55% of the scale and was a porous, mixed oxide of NiO>Cr{sub 2}O{sub 3}>Fe{sub 2}O{sub 3}. The outer 40% was nearly all NiO with dense grains and cavitated grain boundaries. Overall, the NiO was dominant and the lesser amounts of Cr{sub 2}O{sub 3} and Fe{sub 2}O{sub 3} were roughly equivalent. No direct invasion of salt through the oxide to the metal was observed.

  11. Customer interface document for the Molten Salt Test Loop (MSTL) system.

    SciTech Connect

    Pettit, Kathleen; Kolb, William J.; Gill, David Dennis; Briggs, Ronald D.

    2012-03-01

    The National Solar Thermal Test Facility at Sandia National Laboratories has a unique test capability called the Molten Salt Test Loop (MSTL) system. MSTL is a test capability that allows customers and researchers to test components in flowing, molten nitrate salt. The components tested can range from materials samples, to individual components such as flex hoses, ball joints, and valves, up to full solar collecting systems such as central receiver panels, parabolic troughs, or linear Fresnel systems. MSTL provides realistic conditions similar to a portion of a concentrating solar power facility. The facility currently uses 60/40 nitrate 'solar salt' and can circulate the salt at pressure up to 600psi, temperature to 585 C, and flow rate of 400-600GPM depending on temperature. The purpose of this document is to provide a basis for customers to evaluate the applicability to their testing needs, and to provide an outline of expectations for conducting testing on MSTL. The document can serve as the basis for testing agreements including Work for Others (WFO) and Cooperative Research and Development Agreements (CRADA). While this document provides the basis for these agreements and describes some of the requirements for testing using MSTL and on the site at Sandia, the document is not sufficient by itself as a test agreement. The document, however, does provide customers with a uniform set of information to begin the test planning process.

  12. Metals recovering from waste printed circuit boards (WPCBs) using molten salts.

    PubMed

    Flandinet, L; Tedjar, F; Ghetta, V; Fouletier, J

    2012-04-30

    Recycling of waste electrical and electronic equipments (WEEE) has been taken into consideration in the literature due to the large quantity of concerned wastes and their hazardous contents. The situation is so critical that EU published European Directives imposing collection and recycling with a minimum of material recovery [1]. Moreover, WEEEs contain precious metals, making the recycling of these wastes economically interesting, but also some critical metals and their recycling leads to resource conservation. This paper reports on a new approach for recycling waste printed circuit boards (WPCBs). Molten salts and specifically molten KOH-NaOH eutectic is used to dissolve glasses, oxides and to destruct plastics present in wastes without oxidizing the most valuable metals. This method is efficient for recovering a copper-rich metallic fraction, which is, moreover, cleared of plastics and glasses. In addition, analyses of gaseous emission show that this method is environmentally friendly since most of the process gases, such as carbon monoxide and dioxide and halogens, are trapped in the highly basic molten salt. In other respects, under operation without oxygen, a large quantity of hydrogen is produced and might be used as fuel gas or as synthesis gas, leading to a favourable energy balance for this new process.

  13. Molten salt-based growth of bulk GaN and InN for substrates.

    SciTech Connect

    Waldrip, Karen Elizabeth

    2007-08-01

    An atmospheric pressure approach to growth of bulk group III-nitrides is outlined. Native III-nitride substrates for optoelectronic and high power, high frequency electronics are desirable to enhance performance and reliability of these devices; currently, these materials are available in research quantities only for GaN, and are unavailable in the case of InN. The thermodynamics and kinetics of the reactions associated with traditional crystal growth techniques place these activities on the extreme edges of experimental physics. The novel techniques described herein rely on the production of the nitride precursor (N{sup 3-}) by chemical and/or electrochemical methods in a molten halide salt. This nitride ion is then reacted with group III metals in such a manner as to form the bulk nitride material. The work performed during the period of funding (February 2006-September 2006) focused on establishing that mass transport of GaN occurs in molten LiCl, the construction of a larger diameter electrochemical cell, the design, modification, and installation of a made-to-order glove box (required for handling very hygroscopic LiCl), and the feasibility of using room temperature molten salts to perform nitride chemistry experiments.

  14. Molten salt synthesis (MSS) of Cu{sub 2}Mo{sub 6}S{sub 8}-New way for large-scale production of Chevrel phases

    SciTech Connect

    Lancry, E. . E-mail: eli.lancry@intel.com; Levi, E.; Mitelman, A.; Malovany, S.; Aurbach, D.

    2006-06-15

    The Chevrel phase (CP), Mo{sub 6}S{sub 8}, was found to be an excellent cathode material for rechargeable magnesium batteries. Mo{sub 6}S{sub 8} is obtained by a leaching process of Cu{sub 2}Mo{sub 6}S{sub 8}, which removes the copper. A new method of Cu{sub 2}Mo{sub 6}S{sub 8} production was developed. In contrast to the well-known solid-state synthesis of CP, the method is based on the reaction in a molten salt media (KCl). A fast kinetics of this reaction allows using less active, but more convenient precursors (sulfides instead of sulfur), decreasing temperature and synthesis duration, as well as operation in the inert atmosphere instead of dynamic evacuated systems. It was shown that the composition and the electrochemical behavior of the products obtained by MSS and by the solid-state synthesis are identical. Thus, the molten salt method is extremely attractive for the large-scale production of the active materials for Mg batteries. - Graphical abstract: The layout of the molten salt synthesis system.

  15. Destruction of XM-46 (aka LGP-1846) using the Molten Salt Destruction Process

    SciTech Connect

    Upadhye, R.S.; Watkins, B.E.

    1994-03-01

    The experimental work done on the destruction of the liquid gun propellant XM-46 (or LGP-1846) using the Molten Salt Destruction (MSD) Process at the Lawrence Livermore National Laboratory (LLNL) for the US Army is described in this report. The current methods of disposal of large quantities of high explosives (HE), propellants and wastes containing energetic materials by open burning or open detonation (OB/OD), or by incineration, are becoming undesirable. LLNL is developing MSD as an alternative to OB/OD and incineration of energetic materials. A series of 18 continuous experimental runs were made wherein a solution of XM-46 and water was injected into a bed of molten salt comprising the carbonates of sodium, potassium and lithium, along with air. The results from these experiments, described in detail in the main body of this report, show that: XM-46 can be safely and completely destroyed in a bed of molten salt at temperatures well below those needed for incineration. Under optimum operating conditions, less than 1% of the chemically bound nitrogen in the XM-46 is converted to NO{sub x}, and less than 1% carbon is converted to CO. There exist, however, a number of technical uncertainties: We need to understand better why nitrates build up in the salt bath, and what we can do to reduce this amount. We need to understand the mechanism of XM-46 oxidation and ways to minimize the formation of CO and NO{sub x}. In addition, we would like to find out ways by which a more concentrated solution of XM-46 can be introduced into the reactor, so as to increase the throughputs.

  16. Purification and Chemical Control of Molten Li2BeF 4 for a Fluoride Salt Cooled Reactor

    NASA Astrophysics Data System (ADS)

    Kelleher, Brian Christopher

    Out of the many proposed generation IV, high-temperature reactors, the molten salt reactor (MSR) is one of the most promising. The first large scale MSR, the molten salt reactor experiment (MSRE), operated from 1965 to 1969 using Li2BeF4, or flibe, as a coolant and solvent for uranium fluoride fuel, at maximum temperatures of 654°C, for over 15000 hours. The MSRE experienced no concept breaking surprises and was considered a success. Newly proposed designs of molten salt reactors use solid fuels, making them less exotic compared to the MSRE. However, any molten salt reactor will require a great deal of research pertaining to the chemical and mechanical mastery of molten salts in order to prepare it for commercialization. To supplement the development of new molten salt reactors, approximately 100 kg of flibe was purified using the standard hydrofluorination process. Roughly half of the purified salt was lithium-7 enriched salt from the secondary loop of the MSRE. Purification rids the salt of impurities and reduces its capacity for corrosion, also known as the redox potential. The redox potential of flibe was measured at various stages of purification for the first time using a dynamic beryllium reference electrode. These redox measurements have been superimposed with metal impurities measurements found by neutron activation analysis. Lastly, reductions of flibe with beryllium metal have been investigated. Over reductions have been performed, which have shown to decrease redox potential while seemingly creating a beryllium-beryllium halide system. Recommendations of the lowest advisable redox potential for corrosion tests are included along with suggestions for future work.

  17. Molten salt considerations for accelerator-driven subcritical fission to close the nuclear fuel cycle

    NASA Astrophysics Data System (ADS)

    Sooby, Elizabeth; Adams, Marvin; Baty, Austin; Gerity, James; McIntyre, Peter; Melconian, Karie; Phongikaroon, Supathorn; Pogue, Nathaniel; Sattarov, Akhdiyor; Simpson, Michael; Tripathy, Prabhat; Tsevkov, Pavel

    2013-04-01

    The host salt selection, molecular modeling, physical chemistry, and processing chemistry are presented here for an accelerator-driven subcritical fission in a molten salt core (ADSMS). The core is fueled solely with the transuranics (TRU) and long-lived fission products (LFP) from used nuclear fuel. The neutronics and salt composition are optimized to destroy the transuranics by fission and the long-lived fission products by transmutation. The cores are driven by proton beams from a strong-focusing cyclotron stack. One such ADSMS system can destroy the transuranics in the used nuclear fuel produced by a 1GWe conventional reactor. It uniquely provides a method to close the nuclear fuel cycle for green nuclear energy.

  18. Molten salt considerations for accelerator-driven subcritical fission to close the nuclear fuel cycle

    SciTech Connect

    Sooby, Elizabeth; Baty, Austin; Gerity, James; McIntyre, Peter; Melconian, Karie; Pogue, Nathaniel; Sattarov, Akhdiyor; Adams, Marvin; Tsevkov, Pavel; Phongikaroon, Supathorn; Simpson, Michael; Tripathy, Prabhat

    2013-04-19

    The host salt selection, molecular modeling, physical chemistry, and processing chemistry are presented here for an accelerator-driven subcritical fission in a molten salt core (ADSMS). The core is fueled solely with the transuranics (TRU) and long-lived fission products (LFP) from used nuclear fuel. The neutronics and salt composition are optimized to destroy the transuranics by fission and the long-lived fission products by transmutation. The cores are driven by proton beams from a strong-focusing cyclotron stack. One such ADSMS system can destroy the transuranics in the used nuclear fuel produced by a 1GWe conventional reactor. It uniquely provides a method to close the nuclear fuel cycle for green nuclear energy.

  19. Electrochemical preparation of single-crystalline Cr 2O 3 from molten salts

    NASA Astrophysics Data System (ADS)

    Abe, Hideki; Nishida, Kenji; Imai, Motoharu; Kitazawa, Hideaki

    2004-06-01

    Single crystals of Cr 2O 3 have been grown by means of electrolysis on a 1:100 stoichiometric mixture of CrO 3 and cesium molybdate, Cs 2MoO 4, fused at 1000°C in an ambient atmosphere. Potentiometric measurements on the molten salts have shown the existence of a critical voltage of -320 mV below which hexagonal platelets-shaped single-crystalline Cr 2O 3 is grown on the surface of the working electrode. Coulometry measurements have revealed that the Cr ions are at their highest oxidation state of Cr +6 in the molten electrolyte, which suggests that the electric reduction of Cr +6 to Cr +3 drives the single-crystal growth of Cr 2O 3.

  20. Conceptual Design of Forced Convection Molten Salt Heat Transfer Testing Loop

    SciTech Connect

    Manohar S. Sohal; Piyush Sabharwall; Pattrick Calderoni; Alan K. Wertsching; S. Brandon Grover

    2010-09-01

    This report develops a proposal to design and construct a forced convection test loop. A detailed test plan will then be conducted to obtain data on heat transfer, thermodynamic, and corrosion characteristics of the molten salts and fluid-solid interaction. In particular, this report outlines an experimental research and development test plan. The most important initial requirement for heat transfer test of molten salt systems is the establishment of reference coolant materials to use in the experiments. An earlier report produced within the same project highlighted how thermophysical properties of the materials that directly impact the heat transfer behavior are strongly correlated to the composition and impurities concentration of the melt. It is therefore essential to establish laboratory techniques that can measure the melt composition, and to develop purification methods that would allow the production of large quantities of coolant with the desired purity. A companion report describes the options available to reach such objectives. In particular, that report outlines an experimental research and development test plan that would include following steps: •Molten Salts: The candidate molten salts for investigation will be selected. •Materials of Construction: Materials of construction for the test loop, heat exchangers, and fluid-solid corrosion tests in the test loop will also be selected. •Scaling Analysis: Scaling analysis to design the test loop will be performed. •Test Plan: A comprehensive test plan to include all the tests that are being planned in the short and long term time frame will be developed. •Design the Test Loop: The forced convection test loop will be designed including extensive mechanical design, instrument selection, data acquisition system, safety requirements, and related precautionary measures. •Fabricate the Test Loop. •Perform the Tests. •Uncertainty Analysis: As a part of the data collection, uncertainty analysis will

  1. Implementation of Molten Salt Properties into RELAP5-3D/ATHENA

    SciTech Connect

    Cliff Davis

    2005-01-01

    Molten salts are being considered as coolants for the Next Generation Nuclear Plant (NGNP) in both the reactor and the heat transport loop between the reactor and the hydrogen production plant because of their superior thermophysical properties compared to helium. Because specific molten salts have not been selected for either application, four separate molten salts were implemented into the RELAP5-3D/ATHENA computer program as working fluids. The implemented salts were LiF-BeF2 in a molar mixture that is 66% LiF and 34% BeF2, respectively, NaBF4-NaF (92% and 8%), LiF-NaF-KF (11.5%, 46.5%, and 42%), and NaF-ZrF4 (50% and 50%). LiF-BeF2 is currently the first choice for the primary coolant for the Advanced High- Temperature Reactor, while NaF-ZrF4 is being considered as an alternate. NaBF4-NaF and LiFNaF- KF are being considered as possible coolants for the heat transport loop. The molten salts were implemented into ATHENA using a simplified equation of state based on data and correlations obtained from Oak Ridge National Laboratory. The simplified equation of state assumes that the liquid density is a function of temperature and pressure and that the liquid heat capacity is constant. The vapor is assumed to have the same composition as the liquid and is assumed to be a perfect gas. The implementation of the thermodynamic properties into ATHENA for LiF-BeF2 was verified by comparisons with results from a detailed equation of state that utilized a soft-sphere model. The comparisons between the simplified and soft-sphere models were in reasonable agreement for liquid. The agreement for vapor properties was not nearly as good as that obtained for liquid. Large uncertainties are possible in the vapor properties because of a lack of experimental data. The simplified model used here is not expected to be accurate for boiling or single-phase vapor conditions. Because neither condition is expected during NGNP applications, the simplified equation of state is considered

  2. Direct oxygen removal technique for recycling titanium using molten MgCl2 salt.

    PubMed

    Okabe, Toru H; Hamanaka, Yuki; Taninouchi, Yu-Ki

    2016-08-15

    Deoxidation of Ti, or direct removal of O dissolved in metallic Ti, is known to be extremely difficult when Mg is used as the deoxidizing agent. This difficulty arises because the chemical potential of O2, pO2, under Mg/MgO equilibrium is high (approximately 10(-41) atm at 1200 K) and is equivalent to that of Ti containing ∼2 mass% O at 1200 K. Therefore, when deoxidizing Ti to the commercial level of high-grade pure Ti (below 0.05 mass% O) using an Mg reductant at 1200 K, the activity of the reaction product MgO (aMgO) must be decreased to below ∼0.025, which is difficult in practice. In this study, the removal of O in Ti in molten MgCl2 salt using an electrochemical technique was examined at ∼1173 K with the objective of obtaining Ti containing less than 0.05 mass% O. Ti samples and graphite electrodes immersed in molten MgCl2 served as the cathode and anode, respectively. A constant voltage was applied between the electrodes using an external DC source. Molten MgCl2 was employed to produce the deoxidizing agent Mg and to facilitate deoxidation of Ti by decreasing the activity of the reaction product MgO. By applying a voltage of approximately 3.1 V between the electrodes, the chemical potential of Mg in the molten MgCl2 was increased at the surface of the Ti cathode, and the Ti samples were deoxidized. The resulting O species, mainly formed O(2-) dissolved in the molten MgCl2, was removed from the molten salt by reacting with the C anode to form CO (or CO2) gas. Ti wires containing 0.12 mass% O were deoxidized to less than 0.02 mass% O. In some cases, the O concentration in the Ti samples was reduced to the level of 0.01 mass%, which cannot be accomplished using the conventional Kroll process. The possible application of this deoxidation technique to practical industrial recycling processes is discussed.

  3. Steady state investigation on neutronics of a molten salt reactor considering the flow effect of fuel salt

    NASA Astrophysics Data System (ADS)

    Zhang, Da-Lin; Qiu, Sui-Zheng; Liu, Chang-Liang; Su, Guang-Hui

    2008-08-01

    The Molten Salt Reactor (MSR), one of the `Generation IV' concepts, is a liquid-fuel reactor, which is different from the conventional reactors using solid fissile materials due to the flow effect of fuel salt. The study on its neutronics considering the fuel salt flow, which is the base of the thermal-hydraulic calculation and safety analysis, must be done. In this paper, the theoretical model on neutronics under steady condition for a single-liquid-fueled MSR is conducted and calculated by numerical method. The neutronics model consists of two group neutron diffusion equations for fast and thermal neutron fluxes, and balance equations for six-group delayed neutron precursors considering the flow effect of fuel salt. The spatial discretization of the above models is based on the finite volume method, and the discretization equations are computed by the source iteration method. The distributions of neutron fluxes and the distributions of the delayed neutron precursors in the core are obtained. The numerical calculated results show that, the fuel salt flow has little effect on the distribution of fast and thermal neutron fluxes and the effective multiplication factor; however, it affects the distribution of the delayed neutron precursors significantly, especially the long-lived one. In addition, it could be found that the delayed neutron precursors influence the neutronics slightly under the steady condition. Supported by National Nature Science Foundation of China (10575079)

  4. Modeling Solute Thermokinetics in LiCI-KCI Molten Salt for Nuclear Waste Separation

    SciTech Connect

    Morgan, Dane; Eapen, Jacob

    2013-10-01

    Recovery of actinides is an integral part of a closed nuclear fuel cycle. Pyrometallurgical nuclear fuel recycling processes have been developed in the past for recovering actinides from spent metallic and nitride fuels. The process is essentially to dissolve the spent fuel in a molten salt and then extract just the actinides for reuse in a reactor. Extraction is typically done through electrorefining, which involves electrochemical reduction of the dissolved actinides and plating onto a cathode. Knowledge of a number of basic thermokinetic properties of salts and salt-fuel mixtures is necessary for optimizing present and developing new approaches for pyrometallurgical waste processing. The properties of salt-fuel mixtures are presently being studied, but there are so many solutes and varying concentrations that direct experimental investigation is prohibitively time consuming and expensive (particularly for radioactive elements like Pu). Therefore, there is a need to reduce the number of required experiments through modeling of salt and salt-fuel mixture properties. This project will develop first-principles-based molecular modeling and simulation approaches to predict fundamental thermokinetic properties of dissolved actinides and fission products in molten salts. The focus of the proposed work is on property changes with higher concentrations (up to 5 mol%) of dissolved fuel components, where there is still very limited experimental data. The properties predicted with the modeling will be density, which is used to assess the amount of dissolved material in the salt; diffusion coefficients, which can control rates of material transport during separation; and solute activity, which determines total solubility and reduction potentials used during electrorefining. The work will focus on La, Sr, and U, which are chosen to include the important distinct categories of lanthanides, alkali earths, and actinides, respectively. Studies will be performed using LiCl-KCl salt

  5. Analysis of fluid fuel flow to the neutron kinetics on molten salt reactor FUJI-12

    NASA Astrophysics Data System (ADS)

    Aji, Indarta Kuncoro; Waris, Abdul; Permana, Sidik

    2015-09-01

    Molten Salt Reactor is a reactor are operating with molten salt fuel flowing. This condition interpret that the neutron kinetics of this reactor is affected by the flow rate of the fuel. This research analyze effect by the alteration velocity of the fuel by MSR type Fuji-12, with fuel composition LiF-BeF2-ThF4-233UF4 respectively 71.78%-16%-11.86%-0.36%. Calculation process in this study is performed numerically by SOR and finite difference method use C programming language. Data of reactivity, neutron flux, and the macroscopic fission cross section for calculation process obtain from SRAC-CITATION (Standard thermal Reactor Analysis Code) and JENDL-4.0 data library. SRAC system designed and developed by JAEA (Japan Atomic Energy Agency). This study aims to observe the effect of the velocity of fuel salt to the power generated from neutron precursors at fourth year of reactor operate (last critical condition) with number of multiplication effective; 1.0155.

  6. Tritium permeation and recovery for the helium-cooled molten salt fusion breeder

    SciTech Connect

    Sherwood, A.E.

    1984-09-01

    Design concepts are presented to control tritium permeation from a molten salt/helium fusion breeder reactor. This study assumes tritium to be a gas dissolved in molten salt, with TF formation suppressed. Tritium permeates readily through the hot steel tubes of the reactor and steam generator and will leak into the steam system at the rate of about one gram per day in the absence of special permeation barriers, assuming that 1% of the helium coolant flow rate is processed for tritium recovery at 90% efficiency per pass. The proposed permeation barrier for the reactor tubes is a 10 ..mu..m layer of tungsten which, in principle, will reduce tritium blanket permeation by a factor of about 300 below the bare-steel rate. A research and development effort is needed to prove feasibility or to develop alternative barriers. A 1 mm aluminum sleeve is proposed to suppress permeation through the steam generator tubes. This gives a calculated reduction factor of more than 500 relative to bare steel, including a factor of 30 due to an assumed oxide layer. The permeation equations are developed in detail for a multi-layer tube wall including a frozen salt layer and with two fluid boundary-layer resistances. Conditions are discussed for which Sievert's or Henry's Law materials become flux limiters. An analytical model is developed to establish the tritium split between wall permeation and reactor-tube flow.

  7. Molten Salt Power Tower Cost Model for the System Advisor Model (SAM)

    SciTech Connect

    Turchi, C. S.; Heath, G. A.

    2013-02-01

    This report describes a component-based cost model developed for molten-salt power tower solar power plants. The cost model was developed by the National Renewable Energy Laboratory (NREL), using data from several prior studies, including a contracted analysis from WorleyParsons Group, which is included herein as an Appendix. The WorleyParsons' analysis also estimated material composition and mass for the plant to facilitate a life cycle analysis of the molten salt power tower technology. Details of the life cycle assessment have been published elsewhere. The cost model provides a reference plant that interfaces with NREL's System Advisor Model or SAM. The reference plant assumes a nominal 100-MWe (net) power tower running with a nitrate salt heat transfer fluid (HTF). Thermal energy storage is provided by direct storage of the HTF in a two-tank system. The design assumes dry-cooling. The model includes a spreadsheet that interfaces with SAM via the Excel Exchange option in SAM. The spreadsheet allows users to estimate the costs of different-size plants and to take into account changes in commodity prices. This report and the accompanying Excel spreadsheet can be downloaded at https://sam.nrel.gov/cost.

  8. Thermal energy storage heat exchanger: Molten salt heat exchanger design for utility power plants

    NASA Technical Reports Server (NTRS)

    Ferarra, A.; Yenetchi, G.; Haslett, R.; Kosson, R.

    1977-01-01

    The use of thermal energy storage (TES) in the latent heat of molten salts as a means of conserving fossil fuels and lowering the cost of electric power was evaluated. Public utility systems provided electric power on demand. This demand is generally maximum during late weekday afternoons, with considerably lower overnight and weekend loads. Typically, the average demand is only 60% to 80% of peak load. As peak load increases, the present practice is to purchase power from other grid facilities or to bring older less efficient fossil-fuel plants on line which increase the cost of electric power. The widespread use of oil-fired boilers, gas turbine and diesel equipment to meet peaking loads depletes our oil-based energy resources. Heat exchangers utilizing molten salts can be used to level the energy consumption curve. The study begins with a demand analysis and the consideration of several existing modern fossil-fuel and nuclear power plants for use as models. Salts are evaluated for thermodynamic, economic, corrosive, and safety characteristics. Heat exchanger concepts are explored and heat exchanger designs are conceived. Finally, the economics of TES conversions in existing plants and new construction is analyzed. The study concluded that TES is feasible in electric power generation. Substantial data are presented for TES design, and reference material for further investigation of techniques is included.

  9. Sintering and Microstructure of BaTiO3 Nano Particles Synthesized by Molten Salt Method.

    PubMed

    Lee, Chang-Hyun; Shin, Hyo-Soon; Yeo, Dong-Hun; Ha, Gook-Hyun; Nahm, Sahn

    2016-05-01

    In order to establish thinner dielectric layers in thick film electronic components such as MLCC (Multilayer ceramic capacitor), BaTiO3 nanoparticles have been utilized. However, studies on the synthesis of nanoparticles smaller than 20 nm, the characteristics of the BaTiO3 powder, and the powder's sintering are lacking. Therefore, this paper aims to synthesize BaTiO3 particles smaller than 20 nm by using the molten salt method and evaluate the microstructure and dielectric properties by varying the sintering temperature from 750 degrees C to 1200 degrees C. Through the molten salt method and by using KOH-KCl mixed salt, 20 nm BaTiO3 powder was synthesized at a low temperature of 150 degrees C. Sintering the pellets formed from the synthesized 20 nm BaTiO3 nano powder led to the observation of an unusual phenomenon where the particles grew to approximate sizes below 850 degrees C where densification progressed. At sintering temperatures above 950 degrees C, particles that expanded into rod shapes were observed and these particles were identified to be unreacted TiO2 based on the results of the EDX (Energy Dispersive X-ray Spectroscopy) analysis and phase analysis results.

  10. Determination and evaluation of the thermophysical properties of an alkali carbonate eutectic molten salt.

    PubMed

    An, Xuehui; Cheng, Jinhui; Zhang, Peng; Tang, Zhongfeng; Wang, Jianqiang

    2016-08-15

    The thermal physical properties of Li2CO3-Na2CO3-K2CO3 eutectic molten salt were comprehensively investigated. It was found that the liquid salt can remain stable up to 658 °C (the onset temperature of decomposition) by thermal analysis, and so the investigations on its thermal physical parameters were undertaken from room temperature to 658 °C. The density was determined using a self-developed device, with an uncertainty of ±0.00712 g cm(-3). A cooling curve was obtained from the instrument, giving the liquidus temperature. For the first time, we report the obtainment of the thermal diffusivity using a laser flash method based on a special crucible design and establishment of a specific sample preparation method. Furthermore, the specific heat capacity was also obtained by use of DSC, and combined with thermal diffusivity and density, was used to calculate the thermal conductivity. We additionally built a rotating viscometer with high precision in order to determine the molten salt viscosity. All of these parameters play an important part in the energy storage and transfer calculation and safety evaluation for a system.

  11. Conceptual Design of a 100 MWe Modular Molten Salt Power Tower Plant

    SciTech Connect

    James E. Pacheco; Carter Moursund, Dale Rogers, David Wasyluk

    2011-09-20

    A conceptual design of a 100 MWe modular molten salt solar power tower plant has been developed which can provide capacity factors in the range of 35 to 75%. Compared to single tower plants, the modular design provides a higher degree of flexibility in achieving the desired customer's capacity factor and is obtained simply by adjusting the number of standard modules. Each module consists of a standard size heliostat field and receiver system, hence reengineering and associated unacceptable performance uncertainties due to scaling are eliminated. The modular approach with multiple towers also improves plant availability. Heliostat field components, receivers and towers are shop assembled allowing for high quality and minimal field assembly. A centralized thermal-storage system stores hot salt from the receivers, allowing nearly continuous power production, independent of solar energy collection, and improved parity with the grid. A molten salt steam generator converts the stored thermal energy into steam, which powers a steam turbine generator to produce electricity. This paper describes the conceptual design of the plant, the advantages of modularity, expected performance, pathways to cost reductions, and environmental impact.

  12. Novel ternary molten salt electrolytes for intermediate-temperature sodium/nickel chloride batteries

    NASA Astrophysics Data System (ADS)

    Li, Guosheng; Lu, Xiaochuan; Coyle, Christopher A.; Kim, Jin Y.; Lemmon, John P.; Sprenkle, Vincent L.; Yang, Zhenguo

    2012-12-01

    The sodium-nickel chloride (ZEBRA) battery is operated at relatively high temperature (250-350 °C) to achieve adequate electrochemical performance. Reducing the operating temperature in the range of 150200 °C can not only lead to enhanced cycle life by suppressing temperature-related degradations, but also allow the use of lower cost materials for construction. To achieve adequate electrochemical performance at lower operating temperatures, reduction in ohmic losses is required, including the reduced ohmic resistance of β″-alumina solid electrolyte (BASE) and the incorporation of low melting point secondary electrolytes. In present work, planar-type Na/NiCl2 cells with a thin BASE (600 μm) and low melting point secondary electrolyte were evaluated at reduced temperatures. Molten salts used as secondary electrolytes were fabricated by the partial replacement of NaCl in the standard secondary electrolyte (NaAlCl4) with other lower melting point alkali metal salts such as NaBr, LiCl, and LiBr. Electrochemical characterization of these ternary molten salts demonstrated improved ionic conductivity and sufficient electrochemical window at reduced temperatures. Furthermore, Na/NiCl2 cells with 50 mol% NaBr-containing secondary electrolyte exhibited reduced polarizations at 175 °C compared to the cell with the standard NaAlCl4 catholyte. The cells also exhibited stable cycling performance even at 150 °C.

  13. Novel ternary molten salt electrolytes for intermediate-temperature sodium/nickel chloride batteries

    SciTech Connect

    Li, Guosheng; Lu, Xiaochuan; Coyle, Christopher A.; Kim, Jin Y.; Lemmon, John P.; Sprenkle, Vincent L.; Yang, Zhenguo

    2012-12-15

    The sodium–nickel chloride (ZEBRA) battery is operated at relatively high temperature (250–350 °C) to achieve adequate electrochemical performance. Reducing the operating temperature in the range of 150200 °C can not only lead to enhanced cycle life by suppressing temperature-related degradations, but also allow the use of lower cost materials for construction. To achieve adequate electrochemical performance at lower operating temperatures, reduction in ohmic losses is required, including the reduced ohmic resistance of β"-alumina solid electrolyte (BASE) and the incorporation of low melting point secondary electrolytes. In present work, planar-type Na/NiCl2 cells with a thin BASE (600 μm) and low melting point secondary electrolyte were evaluated at reduced temperatures. Molten salts used as secondary electrolytes were fabricated by the partial replacement of NaCl in the standard secondary electrolyte (NaAlCl4) with other lower melting point alkali metal salts such as NaBr, LiCl, and LiBr. Electrochemical characterization of these ternary molten salts demonstrated improved ionic conductivity and sufficient electrochemical window at reduced temperatures. Furthermore, Na/NiCl2 cells with 50 mol% NaBr-containing secondary electrolyte exhibited reduced polarizations at 175 °C compared to the cell with the standard NaAlCl4 catholyte. Finally, the cells also exhibited stable cycling performance even at 150 °C.

  14. Analysis of fluid fuel flow to the neutron kinetics on molten salt reactor FUJI-12

    SciTech Connect

    Aji, Indarta Kuncoro; Waris, Abdul Permana, Sidik

    2015-09-30

    Molten Salt Reactor is a reactor are operating with molten salt fuel flowing. This condition interpret that the neutron kinetics of this reactor is affected by the flow rate of the fuel. This research analyze effect by the alteration velocity of the fuel by MSR type Fuji-12, with fuel composition LiF-BeF{sub 2}-ThF{sub 4}-{sup 233}UF{sub 4} respectively 71.78%-16%-11.86%-0.36%. Calculation process in this study is performed numerically by SOR and finite difference method use C programming language. Data of reactivity, neutron flux, and the macroscopic fission cross section for calculation process obtain from SRAC-CITATION (Standard thermal Reactor Analysis Code) and JENDL-4.0 data library. SRAC system designed and developed by JAEA (Japan Atomic Energy Agency). This study aims to observe the effect of the velocity of fuel salt to the power generated from neutron precursors at fourth year of reactor operate (last critical condition) with number of multiplication effective; 1.0155.

  15. Equilibrium Model for Ion Exchange Between Multivalent Cations and Zeolite-A in a Molten Salt

    SciTech Connect

    Supathorn Phongikaroon; Michael Simpson

    2005-10-01

    A two-site equilibrium model that previously only accommodated monovalent cations has been extended to include divalent and trivalent cations for ion exchange between zeolite-A and molten chloride salts, a process being considered for concentrating nuclear fission products into high level waste forms. Equilibrium constants were determined by fitting the model to equilibrium data sets for ion exchange between zeolite-A and Cs ternary salt (CsCl-LiCl-KCl), Rb ternary salt (RbCl-LiCl-KCl), Na ternary salt (NaCl-LiCl-KCl), Sr ternary salt (SrCl2-LiCl-KCl), and U ternary salt (UCl3-LiCl-KCl). The results reveal a good fit between the experimental data sets and the model. The two ion exchange sites, framework sites and occluded sites, demonstrate different relative selectivities for the cations. It was found that Sr2_ is the preferred cation in the ion exchange site, and Cs_ is the preferred cation in the occlusion site. Meanwhile, Li_ has the highest combined selectivity when both ion exchange and occlusion sites are considered. Interestingly, divalent and trivalent species are more preferred in the ion exchange site than the monovalent species with the exception of Li_.

  16. Investigation of residual anode material after electrorefining uranium in molten chloride salt

    NASA Astrophysics Data System (ADS)

    Rose, M. A.; Williamson, M. A.; Willit, J.

    2015-12-01

    A buildup of material at uranium anodes during uranium electrorefining in molten chloride salts has been observed. Potentiodynamic testing has been conducted using a three electrode cell, with a uranium working electrode in both LiCl/KCl eutectic and LiCl each containing ∼5 mol% UCl3. The anodic current response was observed at 50° intervals between 450 °C and 650 °C in the eutectic salt. These tests revealed a buildup of material at the anode in LiCl/KCl salt, which was sampled at room temperature, and analyzed using ICP-MS, XRD and SEM techniques. Examination of the analytical data, current response curves and published phase diagrams has established that as the uranium anode dissolves, the U3+ ion concentration in the diffusion layer surrounding the electrode rises precipitously to levels, which may at low temperatures exceed the solubility limit for UCl3 or in the case of the eutectic salt for K2UCl5. The reduction in current response observed at low temperature in eutectic salt is eliminated at 650 °C, where K2UCl5 is absent due to its congruent melting and only simple concentration polarization effects are seen. In LiCl similar concentration effects are seen though significantly longer time at applied potential is required to effect a reduction in the current response as compared to the eutectic salt.

  17. Thermo-mechanical and optical optimization of the molten salt receiver for a given heliostat field

    NASA Astrophysics Data System (ADS)

    Augsburger, Germain; Das, Apurba K.; Boschek, Erik; Clark, Michael M.

    2016-05-01

    The tower type molten salt solar thermal power plant has proven to be advantageous over other utility scale solar power plant configurations due to its scalability and provision of storage, thereby improving the dispatchability. The configuration consists of a molten salt central receiver (MSCR) located atop an optimally located tower within a heliostat field with thousands of mirrors. The MSCR receives the concentrated energy from the heliostat field which heats a molten salt heat transfer fluid for thermal storage and utilization in producing steam as and when required for power generation. The MSCR heat transfer surface consists of banks of tangent tubes arranged in panels. The combined cost of the heliostat field and the receiver is 40%-50% of the total plant cost, which calls for optimization to maximize their utilization. Several previous studies have looked into the optimum solar power plant size based on various site conditions. However, the combined optimization of the receiver and the heliostat field has not been reported before. This study looks into the optimum configuration of the receiver for a given heliostat field. An in-house tool has been developed to select and rank a few receiver surface configurations (typically <50) from a list of hundreds of thousands of possible options. The operating limits which the heliostat field needs to obey are defined for the ranked surface configurations based on several different design considerations (e.g. mechanical integrity, corrosion limits). The thermal output of the receiver configurations for a given heliostat field is maximized. A combined rank indicating the optimum configurations in descending order of preference is presented based on the performance and various other practical considerations (e.g. total surface area, cost of material, ability of aiming strategies to distribute the flux). The methodology thus provided can be used as a guideline to arrive at an optimum receiver configuration for a given

  18. Molten salt steam generator subsystem research experiment. Volume I. Phase 1 - Final report

    SciTech Connect

    1984-10-01

    A study was conducted for Phase 1 of a two-phase project whose objectives were to develop a reliable, cost-effective molten salt steam generating subsystem for solar thermal plants, minimize uncertainty in capital, operating, and maintenance costs, and demonstrate the ability of molten salt to generate high-pressure, high-temperature steam. The Phase 1 study involved the conceptual design of molten salt steam generating subsystems for a nominal 100-MWe net stand-alone solar central receiver electric generating plant, and a nominal 100-MWe net hybrid fossil-fueled electric power generating plant that is 50% repowered by a solar central receiver system. As part of Phase 1, a proposal was prepared for Phase 2, which involves the design, construction, testing and evaluation of a Subsystem Research Experiment of sufficient size to ensure successful operation of the full-size subsystem designed in Phase 1. Evaluation of several concepts resulted in the selection of a four-component (preheater, evaporator, superheater, reheater), natural circulation, vertically oriented, shell and tube (straight) heat exchanger arrangement. Thermal hydraulic analysis of the system included full and part load performance, circulation requirements, stability, and critical heat flux analysis. Flow-induced tube vibration, tube buckling, fatigue evaluation of tubesheet junctions, steady-state tubesheet analysis, and a simplified transient analysis were included in the structural analysis of the system. Operating modes and system dynamic response to load changes were identified. Auxiliary equipment, fabrication, erection, and maintenance requirements were also defined. Installed capital costs and a project schedule were prepared for each design.

  19. Investigation on corrosion behavior of Ni-based alloys in molten fluoride salt using synchrotron radiation techniques

    NASA Astrophysics Data System (ADS)

    Liu, Min; Zheng, Junyi; Lu, Yanling; Li, Zhijun; Zou, Yang; Yu, Xiaohan; Zhou, Xingtai

    2013-09-01

    Ni-based alloys have been selected as the structural materials in molten-salt reactors due to their high corrosion resistance and excellent mechanical properties. In this paper, the corrosion behavior of some Ni-based superalloys including Inconel 600, Hastelloy X and Hastelloy C-276 were investigated in molten fluoride salts at 750 °C. Morphology and microstructure of corroded samples were analyzed using scanning electron microscope (SEM), synchrotron radiation X-ray microbeam fluorescence (μ-XRF) and synchrotron radiation X-ray diffraction (SR-XRD) techniques. Results from μ-XRF and SR-XRD show that the main depleted alloying element of Ni-based alloys in molten fluoride salt is Cr. In addition, the results indicate that Mo can enhance the corrosion resistance in molten FLiNaK salts. Among the above three Ni-based alloys, Hastelloy C-276 exhibits the best corrosion resistance in molten fluoride salts 750 °C. Higher-content Mo and lower-content Cr in Hastelloy C-276 alloy were responsible for the better anti-corrosive performance, compared to the other two alloys.

  20. Glovebox design requirements for molten salt oxidation processing of transuranic waste

    SciTech Connect

    Ramsey, K.B.; Acosta, S.V.; Wernly, K.D.

    1998-12-31

    This paper presents an overview of potential technologies for stabilization of {sup 238}Pu-contaminated combustible waste. Molten salt oxidation (MSO) provides a method for removing greater than 99.999% of the organic matrix from combustible waste. Implementation of MSO processing at the Los Alamos National Laboratory (LANL) Plutonium Facility will eliminate the combustible matrix from {sup 238}Pu-contaminated waste and consequently reduce the cost of TRU waste disposal operations at LANL. The glovebox design requirements for unit operations including size reduction and MSO processing will be presented.

  1. Conception of electron beam-driven subcritical molten salt ultimate safety reactor

    NASA Astrophysics Data System (ADS)

    Abalin, S. S.; Alekseev, P. N.; Ignat'ev, V. V.; Kolyaskin, O. E.; Men'shikov, L. I.; Mostovoi, V. I.; Prusakov, V. N.; Subbotin, S. A.; Krasnykh, A. K.; Popov, Yu. P.; Rudenko, V. T.; Somov, L. N.; Dikansky, N. S.; Novokhatsky, A. V.; Dovbnia, A. N.

    1995-09-01

    This paper is a preliminary sketch of a conception to develop the ``ultimate safety reactor'' using modern reactor and accelerator technologies. This approach would not require a long-range R&D program. The ultimate safety reactor could produce heat and electric energy, expand the production of fuel, or be used for the transmutation of long-lived wastes. The use of the combined double molten salt reactor system allows adequate neutron multiplication to permit using an electron accelerator for the initial neutron flux. The general parameters of such a system are discussed in this paper.

  2. Coupled neutronics and thermal-hydraulics numerical simulations of a Molten Fast Salt Reactor (MFSR)

    NASA Astrophysics Data System (ADS)

    Laureau, A.; Rubiolo, P. R.; Heuer, D.; Merle-Lucotte, E.; Brovchenko, M.

    2014-06-01

    Coupled neutronics and thermalhydraulic numerical analyses of a molten salt fast reactor are presented. These preliminary numerical simulations are carried-out using the Monte Carlo code MCNP and the Computation Fluid Dynamic code OpenFOAM. The main objectives of this analysis performed at steady-reactor conditions are to confirm the acceptability of the current neutronic and thermalhydraulic designs of the reactor, to study the effects of the reactor operating conditions on some of the key MSFR design parameters such as the temperature peaking factor. The effects of the precursor's motion on the reactor safety parameters such as the effective fraction of delayed neutrons have been evaluated.

  3. Molten salt oxidation: a versatile and promising technology for the destruction of organic-containing wastes.

    PubMed

    Yao, Zhitong; Li, Jinhui; Zhao, Xiangyang

    2011-08-01

    Molten salt oxidation (MSO), a robust thermal but non-flame process, has the inherent capability of destroying organic constituents in wastes, while retaining inorganic and radioactive materials in situ. It has been considered as an alternative to incineration and may be a solution to many waste disposal problems. The present review first describes the history and development of MSO, as well as design and engineering details, and then focuses on reaction mechanisms and its potential applications in various wastes, including hazardous wastes, medical wastes, mixed wastes, and energetic materials. Finally, the current status of and prospects for the MSO process and directions for future research are considered.

  4. Electrochemical synthesis of superconductive MgB 2 from molten salts

    NASA Astrophysics Data System (ADS)

    Yoshii, Kenji; Abe, Hideki

    2003-05-01

    We have found that superconductive MgB2 can be electrochemically synthesized from molten salts. The electrolysis was performed in an Ar flow at 600 °C on fused mixtures composed of MgCl2, MgB2O4, Na2B2O4 and alkali halides such as KCl, NaCl, and LiCl. Superconductivity was observed for a wide variety of electrolytes. It was also found that the magnetic and electrical transport properties are the most improved for samples prepared from MgCl2-NaCl-KCl-MgB2O4 electrolytes.

  5. The source term and waste optimization of molten salt reactors with processing

    SciTech Connect

    Gat, U.; Dodds, H.L.

    1993-07-01

    The source term of a molten salt reactor (MSR) with fuel processing is reduced by the ratio of processing time to refueling time as compared to solid fuel reactors. The reduction, which can be one to two orders of magnitude, is due to removal of the long-lived fission products. The waste from MSRs can be optimized with respect to its chemical composition, concentration, mixture, shape, and size. The actinides and long-lived isotopes can be separated out and returned to the reactor for transmutation. These features make MSRs more acceptable and simpler in operation and handling.

  6. Reactions of coal and model coal compounds in room temperature molten salt mixtures

    SciTech Connect

    Newman, D.S.; Winans, R.E.; McBeth, R.L.

    1984-05-01

    A 2:1 AlCl/sub 3/-pyridinium chloride molten salt solution was used as the reaction medium for the alkylation of diphenylethane and a bituminous coal by 2-propanol. Probably accompanying the room temperature Friedel-Crafts alkylation is a reduction of C=O to -C-OH. Completely deuterated 2-propanol did not react at all with the pyridinium ring. The pyridinium chloride serves to lower the temperature at which the AlCl/sub 3/ is able to catalyze the reactions. The pyridinium chloride also catalyzes the Friedel-Crafts alkylation.

  7. The use of molten salts as physical models for the study of solidification in metals and semiconductors

    NASA Technical Reports Server (NTRS)

    Koziol, Jurek K.; Sadoway, Donald R.

    1987-01-01

    It is presently noted that molten salts possess attributes rendering them attractive as physical models of cast metals in solidification studies. Molten alkali halides have an approximately correct Prandtl number for this modeling of metallic melts, and are transparent to visible light. Attention is given to solidification in the LiCl-KCl system, in order to determine whether such phenomena as solute rejection can be observed and characterized through the application of laser schlieren imaging.

  8. Neutronic Analysis of the Laser Inertial Confinement Fusion-Fission Energy (LIFE) Engine Using Various Thorium Molten Salts

    NASA Astrophysics Data System (ADS)

    Acır, Adem

    2013-08-01

    In this study, a neutronic performance of the Laser Inertial Confinement Fusion Fission Energy (LIFE) molten salt blanket is investigated. Neutronic calculations are performed by using XSDRNPM/SCALE5 codes in S8-P3 approximation. The thorium molten salt composition considered in this calculation is 75 % LiF—25 % ThF4, 75 % LiF—24 % ThF4—1 % 233UF4, 75 % LiF—23 % ThF4—2 % 233UF4. Also, effects of the 6Li enrichment in molten salt are performed for all heavy metal salt. The radiation damage behaviors of SS-304 structural material with respect to higher fissionable fuel content and 6Li enrichment are computed. By higher fissionable fuel content in molten salt and with 6Li enrichment (20 and 50 %) in the coolant in form of 75 % LiF—23 % ThF4—2 % 233UF4, an initial TBR >1.05 can be realized. On the other hand, the 75 % LiF—25 % ThF4 or 75 % LiF—24 % ThF4—1 % 233UF4 molten salt fuel as regards maintained tritium self-sufficiency is not suitable as regards improving neutronic performance of LIFE engine. A high quality fissile fuel with a rate of ~2,850 kg/year of 233U can be produced with 75 % LiF—23 % ThF4—2 % 233UF4. The energy multiplication factor is increased with high rate fission reactions of 233U occurring in the molten salt zone. Major damage mechanisms in SS-304 first wall stell have been computed as DPA = 48 and He = 132 appm per year with 75 % LiF—23 % ThF4—2 % 233UF4. This implies a replacement of the SS-304 first wall stell of every between 3 and 4 years.

  9. Convective heat transfer from molten salt droplets in a direct contact heat exchanger

    NASA Astrophysics Data System (ADS)

    Jaber, O.; Naterer, G. F.; Dincer, I.

    2010-10-01

    This paper presents a new predictive model of droplet flow and heat transfer from molten salt droplets in a direct contact heat exchanger. The process is designed to recover heat from molten CuCl in a thermochemical copper-chlorine (Cu-Cl) cycle of hydrogen production. This heat recovery occurs through the physical interaction between high temperature CuCl droplets and air. Convective heat transfer between droplets and air is analyzed in a counter-current spray flow heat exchanger. Numerical results for the variations of temperature, velocity and heat transfer rate are presented for two cases of CuCl flow. The optimal dimensions of the heat exchanger are found to be a diameter of 0.13 m, with a height of 0.6 and 0.8 m, for 1 and 0.5 mm droplet diameters, respectively. Additional results are presented and discussed for the heat transfer effectiveness and droplet solidification during heat recovery from the molten CuCl droplets.

  10. Treatment of waste by the Molten Salt Oxidation process at the Oak Ridge National Laboratory

    SciTech Connect

    Crosley, S.M.; Lorenzo, D.K.; Van Cleve, J.E.; Gay, R.L.; Barclay, K.M.; Newcomb, J.C.; Yosim, S.J.

    1993-03-01

    The Molten Salt Oxidation (MSO) process has been under development by the Energy Technology Engineering Center (ETEC) to treat hazardous, radioactive, and mixed waste. Testing of the system was done on a number of wastes to demonstrate the technical feasibility of the process. This testing included simulated intermediate level waste (ILW) from the Oak Ridge National Laboratory. The intermediate level waste stream consisted of a slurry of concentrated aqueous solutions of sodium hydroxide and sodium nitrate, with a small amount of miscellaneous combustible components (PVC, TBP, kerosene, and ion exchange resins). The purpose of these tests was to evaluate the destruction of the organics, evaporation of the water, and conversion of the hazardous salts (hydroxide and nitrate) to non-hazardous sodium carbonate. Results of the tests are discussed and analyzed, and the possibilities of applying the MSO process to different waste streams at ORNL in the future are explored.

  11. Air/molten salt direct-contact heat-transfer experiment and economic analysis

    NASA Astrophysics Data System (ADS)

    Bohn, M. S.

    1983-11-01

    Direct-contact heat-transfer coefficients have been measured in a pilot-scale packed column heat exchanger for molten salt/air duty. Two types of commercial tower packings were tested: metal Raschig rings and initial Pall rings. Volumetric heat-transfer coefficients were measured and appeared to depend upon air flow but not on salt flow rate. An economic analysis was used to compare the cost-effectiveness of direct-contact heat exchange with finned-tube heat exchanger in this application. Incorporating the measured volumetric heat-transfer coefficients, a direct-contact system appeared to be from two to five times as cost-effective as a finned-tube heat exchanger, depending upon operating temperature. The large cost advantage occurs for higher operating temperatures (2700(0)C), where high rates of heat transfer and flexibility in materials choice give the cost advantage to the direct-contact heat exchanger.

  12. Characterization of the effects of continuous salt processing on the performance of molten salt fusion breeder blankets

    NASA Astrophysics Data System (ADS)

    Patterson-Hine, F. A.; Davidson, J. W.; Klein, D. E.; Lee, J. D.

    1985-12-01

    Several continuous salt processing options are available for use in molten salt fusion breeder blanket designs: fluorination only, fluorination plus reductive extraction, and fluorination, plus reductive extraction, plus metal transfer. The effects of processing on blanket performance have been assessed for these three levels of processing and various equilibrium uranium concentrations in the salt. A one-dimensional model of the blanket was used in the neutronics analysis, which incorporated transport calculations with time-dependent isotope generation and depletion calculations. The method of salt processing was found to have little affect on the level of radioactivity, toxicity, or the thermal behavior of the salt during operation of the reactor. The processing rates necessary to maintain the desired uranium concentrations in the suppressed-fission environment were quite low, which permitted only long-lived species to be removed from the salt. The effects of the processing therefore became apparent only after the radioactivity due to the short-lived species diminished. The effects of the additional processing (reductive extraction and metal transfer) could be seen after approximately 1 year of decay, but were not significant at times closer to shutdown. The reduced radioactivity and corresponding heat deposition were thus of no consequence in accident or maintenance situations. Net fissile production in the Be/MS blanket concept at a fusion power level of 3000 MW at 70% capacity ranged from 5100 kg/year to 5170 kg/year for uranium concentrations of 0.11% and 1.0%233U in thorium, respectively, with fluorination-only processing. The addition of processing by reductive extraction resulted in 5125 kg/year for the 0.11%233U case and 5225 kg/year for the 1.0%233U case.

  13. Corrosion resistance of ceramic materials in pyrochemical reprocessing condition by using molten salt for spent nuclear oxide fuel

    NASA Astrophysics Data System (ADS)

    Takeuchi, M.; Kato, T.; Hanada, K.; Koizumi, T.; Aose, S.

    2005-02-01

    The corrosion resistance of ceramic materials in pyrochemical reprocessing using molten salts was discussed through the thermodynamic calculation and corrosion test. The corrosion test was basically carried out in alkali molten salt under chlorine gas. In addition, the effects of oxygen, carbon and main fission product's chlorides on ceramics corrosion were evaluated in that condition. Most of ceramic oxides showed good chemical stability on chlorine, oxygen and uranyl chloride from thermodynamic calculation results. On the other hand, from corrosion test result, silicon nitride, mullite (Al6Si2O13) and cordierite (Mg2Al3(AlSi5O18)) have a good corrosion resistance which is corresponding to 0.1 mm/y or less. No cracks on the materials were observed and flexural strength did not drop remarkably after 480 h corrosion testing in molten salt under Cl2 O2 atmosphere.

  14. Calculation of activities of ions in molten salts with potential application to the pyroprocessing of nuclear waste.

    PubMed

    Salanne, Mathieu; Simon, Christian; Turq, Pierre; Madden, Paul A

    2008-01-31

    The ability to separate fission products by electrodeposition from molten salts depends, in part, on differences between the interactions of the different fission product cations with the ions present in the molten salt "solvent". These differences may be expressed as ratios of activity coefficients, which depend on the identity of the solvent and other factors. Here, we demonstrate the ability to calculate these activity coefficient ratios using molecular dynamics simulations with sufficient precision to guide the choice of suitable solvent systems in practical applications. We use polarizable ion interaction potentials which have previously been shown to give excellent agreement with structural, transport, and spectroscopic information of the molten salts, and the activity coefficients calculated in this work agree well with experimental data. The activity coefficients are shown to vary systematically with cation size for a set of trivalent cations.

  15. Solid oxide membrane-assisted controllable electrolytic fabrication of metal carbides in molten salt.

    PubMed

    Zou, Xingli; Zheng, Kai; Lu, Xionggang; Xu, Qian; Zhou, Zhongfu

    2016-08-15

    Silicon carbide (SiC), titanium carbide (TiC), zirconium carbide (ZrC), and tantalum carbide (TaC) have been electrochemically produced directly from their corresponding stoichiometric metal oxides/carbon (MOx/C) precursors by electrodeoxidation in molten calcium chloride (CaCl2). An assembled yttria stabilized zirconia solid oxide membrane (SOM)-based anode was employed to control the electrodeoxidation process. The SOM-assisted controllable electrochemical process was carried out in molten CaCl2 at 1000 °C with a potential of 3.5 to 4.0 V. The reaction mechanism of the electrochemical production process and the characteristics of these produced metal carbides (MCs) were systematically investigated. X-ray diffraction, scanning electron microscopy, and transmission electron microscopy analyses clearly identify that SiC, TiC, ZrC, and TaC carbides can be facilely fabricated. SiC carbide can be controlled to form a homogeneous nanowire structure, while the morphologies of TiC, ZrC, and TaC carbides exhibit porous nodular structures with micro/nanoscale particles. The complex chemical/electrochemical reaction processes including the compounding, electrodeoxidation, dissolution-electrodeposition, and in situ carbonization processes in molten CaCl2 are also discussed. The present results preliminarily demonstrate that the molten salt-based SOM-assisted electrodeoxidation process has the potential to be used for the facile and controllable electrodeoxidation of MOx/C precursors to micro/nanostructured MCs, which can potentially be used for various applications. PMID:27195950

  16. Solid oxide membrane-assisted controllable electrolytic fabrication of metal carbides in molten salt.

    PubMed

    Zou, Xingli; Zheng, Kai; Lu, Xionggang; Xu, Qian; Zhou, Zhongfu

    2016-08-15

    Silicon carbide (SiC), titanium carbide (TiC), zirconium carbide (ZrC), and tantalum carbide (TaC) have been electrochemically produced directly from their corresponding stoichiometric metal oxides/carbon (MOx/C) precursors by electrodeoxidation in molten calcium chloride (CaCl2). An assembled yttria stabilized zirconia solid oxide membrane (SOM)-based anode was employed to control the electrodeoxidation process. The SOM-assisted controllable electrochemical process was carried out in molten CaCl2 at 1000 °C with a potential of 3.5 to 4.0 V. The reaction mechanism of the electrochemical production process and the characteristics of these produced metal carbides (MCs) were systematically investigated. X-ray diffraction, scanning electron microscopy, and transmission electron microscopy analyses clearly identify that SiC, TiC, ZrC, and TaC carbides can be facilely fabricated. SiC carbide can be controlled to form a homogeneous nanowire structure, while the morphologies of TiC, ZrC, and TaC carbides exhibit porous nodular structures with micro/nanoscale particles. The complex chemical/electrochemical reaction processes including the compounding, electrodeoxidation, dissolution-electrodeposition, and in situ carbonization processes in molten CaCl2 are also discussed. The present results preliminarily demonstrate that the molten salt-based SOM-assisted electrodeoxidation process has the potential to be used for the facile and controllable electrodeoxidation of MOx/C precursors to micro/nanostructured MCs, which can potentially be used for various applications.

  17. Electrochemical corrosion of iron-magnesium-alumina spinel (FMAS) in molten potassium salts and coal slag

    SciTech Connect

    Marchant, D.D.; Griffin, C.W.; Bates, J.L.

    1981-01-01

    Iron, magnesium-alumina spinel (FMAS) (0.25 Fe/sub 3/O/sub 4/ . 0.75 MgAl/sub 2/O/sub 4/) has been considered for use as an electrode in magnetohydrodynamic (MHD) generator channels. Predominantly an electronic conductor, FMAS has adequate electrical conductivity (>1 S/m) above 520/sup 0/K. In addition, FMAS can be easily fabricated into a form and sintered in air to >90% theoretical density and has a melting point of 2124 +- 20/sup 0/K. Laboratory tests to measure both the electrochemical and chemical corrosion of FMAS in molten K/sub 2/CO/sub 3/, K/sub 2/SO/sub 4/ and coal slags were developed at the Pacific Northwest Laboratory to evaluate the relative corrosion of FMAS. Under isothermal conditions, a direct electric current was passed between an anode and a cathode through a molten electrolyte. The molten coal slags were synthetic high-calcium, low-iron Montana Rosebud and low-calcium, high-iron Illinois No. 6. Evaluations of electrochemical corrosion were made as functions of current density, temperature, and slag composition. These results were compared to those of FMAS tested without electric current. The corrosion rates and reaction products were investigated by optical microscopy and scanning electron microscopy. Overall, FMAS has too-high an electrochemical corrosion rate to be considered as MHD electrodes in Montana Rosebud coal slag or in systems where only molten potassium salts are present. However, FMAS may be considered for use in high-iron coal slags although the corrosion rates are still quite high even in these slags.

  18. Corrosion of Ferritic Steels in High Temperature Molten Salt Coolants for Nuclear Applications

    SciTech Connect

    Farmer, J; El-Dasher, B; de Caro, M S; Ferreira, J

    2008-11-25

    Corrosion of ferritic steels in high temperature molten fluoride salts may limit the life of advanced reactors, including some hybrid systems that are now under consideration. In some cases, the steel may be protected through galvanic coupling with other less noble materials with special neutronic properties such a beryllium. This paper reports the development of a model for predicting corrosion rates for various ferritic steels, with and without oxide dispersion strengthening, in FLiBe (Li{sub 2}BeF{sub 4}) and FLiNaK (Li-Na-K-F) coolants at temperatures up to 800 C. Mixed potential theory is used to account for the protection of steel by beryllium, Tafel kinetics are used to predict rates of dissolution as a function of temperature and potential, and the thinning of the mass-transfer boundary layer with increasing Reynolds number is accounted for with dimensionless correlations. The model also accounts for the deceleration of corrosion as the coolants become saturated with dissolved chromium and iron. This paper also reports electrochemical impedance spectroscopy of steels at their corrosion potentials in high-temperature molten salt environments, with the complex impedance spectra interpreted in terms of the interfacial charge transfer resistance and capacitance, as well as the electrolyte conductivity. Such in situ measurement techniques provide valuable insight into the degradation of materials under realistic conditions.

  19. Destruction of chlorobenzene and carbon tetrachloride in a two-stage molten salt oxidation reactor system.

    PubMed

    Yang, Hee-Chul; Cho, Yong-Jun; Eun, Hee-Chul; Kim, Eung-Ho

    2008-08-01

    Molten salt oxidation (MSO) is one of the promising alternative destruction technologies for chlorinated organics, because it is capable of trapping chlorine during organic destruction. This study investigated the characteristics of a two-stage MSO reactor system for the destruction of CCl(4) and C(6)H(5)Cl. Investigated parameters were the MSO reactor temperature (from 1023 K to 1223 K) and the excess oxidizing air feed rate (50% and 100%). The destruction of chlorinated solvents is substantial in the Li(2)CO(3)-Na(2)CO(3) eutectic molten salt, irrespective of the tested condition. However, further oxidation of CO, which is found to be the major destruction product, is not substantial due to the limited temperature and gas residence time in the MSO reactor. Increases in the reactor temperature as well as those in the oxidizing air feed rate consistently lead to decreased emissions of carbon monoxide. No significant influence of the MSO reactor operating condition on the chlorine capturing efficiency was found. Over 99.95% and 99.997% of the chlorine was captured in the hot MSO reactors during the C(6)H(5)Cl and CCl(4) destructions, respectively. This result suggests a relatively low potential of the MSO system in the recombination of chlorinated organics, when compared to a conventional incineration system. PMID:18501405

  20. A final report on the Phase 1 testing of a molten-salt cavity receiver

    SciTech Connect

    Chavez, J M; Smith, D C

    1992-05-01

    This report describes the design, construction, and testing of a solar central receiver using molten nitrate salt as a heat exchange fluid. Design studies for large commercial plants (30--100 MWe) have shown molten salt to be an excellent fluid for solar thermal plants as it allows for efficient thermal storage. Plant design studies concluded that an advanced receiver test was required to address uncertainties not covered in prior receiver tests. This recommendation led to the current test program managed by Sandia National Laboratories for the US Department of Energy. The 4.5 MWt receiver is installed at Sandia National Laboratories' Central Receiver Test Facility in Albuquerque, New Mexico. The receiver incorporates features of large commercial receiver designs. This report describes the receiver's configuration, heat absorption surface (design and sizing), the structure and supporting systems, and the methods for control. The receiver was solar tested during a six-month period at the Central Receiver Test Facility in Albuquerque, NM. The purpose of the testing was to characterize the operational capabilities of the receiver under a number of solar operating and stand-by conditions. This testing consisted of initial check-out of the systems, followed by steady-state performance, transient receiver operation, receiver operation in clouds, receiver thermal loss testing, receiver start-up operation, and overnight thermal conditioning tests. This report describes the design, fabrication, and results of testing of the receiver.

  1. Parametric analyses of single-zone thorium-fueled molten salt reactor fuel cycle options

    SciTech Connect

    Powers, J.J.; Worrall, A.; Gehin, J.C.; Harrison, T.J.; Sunny, E.E.

    2013-07-01

    Analyses of fuel cycle options based on thorium-fueled Molten Salt Reactors (MSRs) have been performed in support of fuel cycle screening and evaluation activities for the United States Department of Energy. The MSR options considered are based on thermal spectrum MSRs with 3 different separations levels: full recycling, limited recycling, and 'once-through' operation without active separations. A single-fluid, single-zone 2250 MWth (1000 MWe) MSR concept consisting of a fuel-bearing molten salt with graphite moderator and reflectors was used as the basis for this study. Radiation transport and isotopic depletion calculations were performed using SCALE 6.1 with ENDF/B-VII nuclear data. New methodology developed at Oak Ridge National Laboratory (ORNL) enables MSR analysis using SCALE, modeling material feed and removal by taking user-specified parameters and performing multiple SCALE/TRITON simulations to determine the resulting equilibrium operating conditions. Parametric analyses examined the sensitivity of the performance of a thorium MSR to variations in the separations efficiency for protactinium and fission products. Results indicate that self-sustained operation is possible with full or limited recycling but once-through operation would require an external neutron source. (authors)

  2. Electrochemistry of LiCl-Li2O-H2O Molten Salt Systems

    SciTech Connect

    Natalie J. Gese; Batric Pesic

    2013-03-01

    Uranium can be recovered from uranium oxide (UO2) spent fuel through the combination of the oxide reduction and electrorefining processes. During oxide reduction, the spent fuel is introduced to molten LiCl-Li2O salt at 650 degrees C and the UO2 is reduced to uranium metal via two routes: (1) electrochemically, and (2) chemically by lithium metal (Li0) that is produced electrochemically. However, the hygroscopic nature of both LiCl and Li2O leads to the formation of LiOH, contributing hydroxyl anions (OH-), the reduction of which interferes with the Li0 generation required for the chemical reduction of UO2. In order for the oxide reduction process to be an effective method for the treatment of uranium oxide fuel, the role of moisture in the LiCl-Li2O system must be understood. The behavior of moisture in the LiCl-Li2O molten salt system was studied using cyclic voltammetry, chronopotentiometry and chronoamperometry, while reduction to hydrogen was confirmed with gas chromatography.

  3. Large-scale synthesis of mullite nanowires by molten salt method.

    PubMed

    Huo, Kaifu; Zhu, Boquan; Fu, Jijiang; Li, Xuedong; Chu, Paul K

    2010-07-01

    Single-crystalline mullite (3Al2O3 2SiO2) nanowires have been produced in large quantities by a low cost and environmentally benign molten salt synthesis (MSS) method. The raw materials, Al2(SO4)3 and SiO2 powders, react in molten Na2SO4 at 1000 degrees C to produce mullite nanowires without the use of surfactants or templates. After the synthesis, the remaining salts can be easily separated from the products by washing with water. The final products are characterized by X-ray powder diffraction, field emission scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy, selected-area electron diffraction, and inductively coupled plasma-atomic emission spectrometry. The thermal and chemical behavior of the raw materials is investigated by heating at a rate of 10 degrees C/min up to 1200 degrees C in air followed by thermogravimetric and differential scanning calorimetry analyses. The single-crystalline mullite nanowires have diameters of 30-80 nm and lengths from several hundreds of nanometers to micrometers and the growth mechanism is discussed.

  4. Destruction of chlorobenzene and carbon tetrachloride in a two-stage molten salt oxidation reactor system.

    PubMed

    Yang, Hee-Chul; Cho, Yong-Jun; Eun, Hee-Chul; Kim, Eung-Ho

    2008-08-01

    Molten salt oxidation (MSO) is one of the promising alternative destruction technologies for chlorinated organics, because it is capable of trapping chlorine during organic destruction. This study investigated the characteristics of a two-stage MSO reactor system for the destruction of CCl(4) and C(6)H(5)Cl. Investigated parameters were the MSO reactor temperature (from 1023 K to 1223 K) and the excess oxidizing air feed rate (50% and 100%). The destruction of chlorinated solvents is substantial in the Li(2)CO(3)-Na(2)CO(3) eutectic molten salt, irrespective of the tested condition. However, further oxidation of CO, which is found to be the major destruction product, is not substantial due to the limited temperature and gas residence time in the MSO reactor. Increases in the reactor temperature as well as those in the oxidizing air feed rate consistently lead to decreased emissions of carbon monoxide. No significant influence of the MSO reactor operating condition on the chlorine capturing efficiency was found. Over 99.95% and 99.997% of the chlorine was captured in the hot MSO reactors during the C(6)H(5)Cl and CCl(4) destructions, respectively. This result suggests a relatively low potential of the MSO system in the recombination of chlorinated organics, when compared to a conventional incineration system.

  5. Influence of volatile chlorides on the molten salt synthesis of ternary oxide nanorods and nanoparticles.

    PubMed

    Rørvik, Per Martin; Lyngdal, Tone; Saeterli, Ragnhild; van Helvoort, Antonius T J; Holmestad, Randi; Grande, Tor; Einarsrud, Mari-Ann

    2008-04-21

    A molten salt synthesis route, previously reported to yield BaTiO3, PbTiO3, and Na2Ti6O13 nanorods, has been re-examined to elucidate the role of volatile chlorides. A precursor mixture containing barium (or lead) and titanium was annealed in the presence of NaCl at 760 or 820 degrees C. The main products were respectively isometric nanocrystalline BaTiO3 and PbTiO3. Nanorods were also detected, but electron diffraction revealed that the composition of the nanorods was respectively BaTi2O5/BaTi5O11 and Na2Ti6O13 for the two different systems, in contradiction to the previous studies. It was shown that NaCl reacted with BaO (PbO) resulting in loss of volatile BaCl2 (PbCl2) and formation and preferential growth of titanium oxide-rich nanorods instead of the target phase BaTiO3 (or PbTiO3). The molten salt synthesis route may therefore not necessarily yield nanorods of the target ternary oxide as reported previously. In addition, the importance of NaCl(g) for the growth of nanorods below the melting point of NaCl was demonstrated in a special experimental setup, where NaCl and the precursors were physically separated.

  6. Measuring lanthanide concentrations in molten salt using laser-induced breakdown spectroscopy (LIBS).

    PubMed

    Weisberg, Arel; Lakis, Rollin E; Simpson, Michael F; Horowitz, Leo; Craparo, Joseph

    2014-01-01

    The versatility of laser-induced breakdown spectroscopy (LIBS) as an analytical method for high-temperature applications was demonstrated through measurement of the concentrations of the lanthanide elements europium (Eu) and praseodymium (Pr) in molten eutectic lithium chloride-potassium chloride (LiCl-KCl) salts at a temperature of 500 °C. Laser pulses (1064 nm, 7 ns, 120 mJ/pulse) were focused on the top surface of the molten salt samples in a laboratory furnace under an argon atmosphere, and the resulting LIBS signals were collected using a broadband Echelle-type spectrometer. Partial least squares (PLS) regression using leave-one-sample-out cross-validation was used to quantify the concentrations of Eu and Pr in the samples. The root mean square error of prediction (RMSEP) for Eu was 0.13% (absolute) over a concentration range of 0-3.01%, and for Pr was 0.13% (absolute) over a concentration range of 0-1.04%.

  7. Archimede solar energy molten salt parabolic trough demo plant: Improvements and second year of operation

    NASA Astrophysics Data System (ADS)

    Maccari, Augusto; Donnola, Sandro; Matino, Francesca; Tamano, Shiro

    2016-05-01

    Since July 2013, the first stand-alone Molten Salt Parabolic Trough (MSPT) demo plant, which was built in collaboration with Archimede Solar Energy and Chiyoda Corporation, is in operation, located adjacent to the Archimede Solar Energy (ASE) manufacturing plant in Massa Martana (Italy). During the two year's operating time frame, the management of the demo plant has shown that MSPT technology is a suitable and reliable option. Several O&M procedures and tests have been performed, as Heat Loss and Minimum Flow Test, with remarkable results confirming that this technology is ready to be extended to standard size CSP plant, if the plant design takes into account molten salt peculiarities. Additionally, the plant has been equipped on fall 2014 with a Steam Generator system by Chiyoda Corporation, in order to test even this important MSPT plant subsystem and to extend the solar field active time, overcoming the previous lack of an adequate thermal load. Here, a description of the plant improvements and the overall plant operation figures will be presented.

  8. Corrosion resistance of stainless steels during thermal cycling in alkali nitrate molten salts.

    SciTech Connect

    Bradshaw, Robert W.; Goods, Steven Howard

    2001-09-01

    The corrosion behavior of three austenitic stainless steels was evaluated during thermal cycling in molten salt mixtures consisting of NaNO{sub 3} and KNO{sub 3}. Corrosion tests were conducted with Types 316, 316L and 304 stainless steels for more than 4000 hours and 500 thermal cycles at a maximum temperature of 565 C. Corrosion rates were determined by chemically descaling coupons. Metal losses ranged from 5 to 16 microns and thermal cycling resulted in moderately higher corrosion rates compared to isothermal conditions. Type 316 SS was somewhat more corrosion resistant than Type 304 SS in these tests. The effect of carbon content on corrosion resistance was small, as 316L SS corroded only slightly slower than 316 SS. The corrosion rates increased as the dissolved chloride content of the molten salt mixtures increased. Chloride concentrations approximating 1 wt.%, coupled with thermal cycling, resulted in linear weight loss kinetics, rather than parabolic kinetics, which described corrosion rates for all other conditions. Optical microscopy and electron microprobe analysis revealed that the corrosion products consisted of iron-chromium spinel, magnetite, and sodium ferrite, organized as separate layers. Microanalysis of the elemental composition of the corrosion products further demonstrated that the chromium content of the iron-chromium spinel layer was relatively high for conditions in which parabolic kinetics were observed. However, linear kinetics were observed when the spinel layer contained relatively little chromium.

  9. Effect of the graphite electrode material on the characteristics of molten salt electrolytically produced carbon nanomaterials

    SciTech Connect

    Kamali, Ali Reza Schwandt, Carsten; Fray, Derek J.

    2011-10-15

    The electrochemical erosion of a graphite cathode during the electrolysis of molten lithium chloride salt may be used for the preparation of nano-structured carbon materials. It has been found that the structures and morphologies of these carbon nanomaterials are dependent on those of the graphite cathodes employed. A combination of tubular and spherical carbon nanostructures has been produced from a graphite with a microstructure of predominantly planar micro-sized grains and a minor fraction of more irregular nano-sized grains, whilst only spherical carbon nanostructures have been produced from a graphite with a microstructure of primarily nano-sized grains. Based on the experimental results, a best-fit regression equation is proposed that relates the crystalline domain size of the graphite reactants and the carbon products. The carbon nanomaterials prepared possess a fairly uniform mesoporosity with a sharp peak in pore size distribution at around 4 nm. The results are of crucial importance to the production of carbon nanomaterials by way of the molten salt electrolytic method. - Highlights: {yields} Carbon nanomaterials are synthesised by LiCl electrolysis with graphite electrodes. {yields} The degree of crystallinity of graphite reactant and carbon product are related. {yields} A graphite reactant is identified that enables the preparation of carbon nanotubes. {yields} The carbon products possess uniform mesoporosity with narrow pore size distribution.

  10. Molten salt coal gasification process development unit. Phase 1. Volume 2. Commercial plant study. Final report

    SciTech Connect

    Kohl, Arthur L.

    1980-05-01

    This report summarizes the results of a test program conducted on the Molten Salt Coal Gasification Process, which included the design, construction, and operation of a Process Development Unit (PDU). This process, coal is gasified by contacting it with air in a turbulent pool of molten sodium carbonate. Sulfur and ash are retained in the melt, and a small stream is continuously removed from the gasifier for regeneration of the salt. The process can handle a wide variety of feed materials, including highly caking coals, and produces a gas relatively free from tars and other impurities. The gasification step is carried out at approximately 1800/sup 0/F. The PDU was designed to process 1 ton per hour of coal at pressures up to 20 atm. It is a completely integrated facility including systems for feeding solids to the gasifier, regenerating sodium carbonate for reuse, and removing sulfur and ash in forms suitable for disposal. Five extended test runs were made. The observed product gas composition was quite close to that predicted on the basis of earlier small-scale tests and thermodynamic considerations. All plant systems were operated in an integrated manner. Test data and discussions regarding plant equipment and process performance are presented. The program also included a commercial plant study which showed the process to be attractive for use in a combined cycle, electric power plant. The report is presented in two volumes, Volume 1, PDU Operations, and Volume 2, Commercial Plant Study.

  11. Measuring lanthanide concentrations in molten salt using laser-induced breakdown spectroscopy (LIBS).

    PubMed

    Weisberg, Arel; Lakis, Rollin E; Simpson, Michael F; Horowitz, Leo; Craparo, Joseph

    2014-01-01

    The versatility of laser-induced breakdown spectroscopy (LIBS) as an analytical method for high-temperature applications was demonstrated through measurement of the concentrations of the lanthanide elements europium (Eu) and praseodymium (Pr) in molten eutectic lithium chloride-potassium chloride (LiCl-KCl) salts at a temperature of 500 °C. Laser pulses (1064 nm, 7 ns, 120 mJ/pulse) were focused on the top surface of the molten salt samples in a laboratory furnace under an argon atmosphere, and the resulting LIBS signals were collected using a broadband Echelle-type spectrometer. Partial least squares (PLS) regression using leave-one-sample-out cross-validation was used to quantify the concentrations of Eu and Pr in the samples. The root mean square error of prediction (RMSEP) for Eu was 0.13% (absolute) over a concentration range of 0-3.01%, and for Pr was 0.13% (absolute) over a concentration range of 0-1.04%. PMID:25226247

  12. Hot gas cleanup using solid supported molten salt for integrated coal gasification/molten carbonate fuel cell power plants. Topical report, October 1982-December 1983

    SciTech Connect

    Lyke, S.E.; Sealock, L.J. Jr.; Roberts, G.L.

    1983-12-01

    Battelle, Pacific Northwest Laboratories is developing a solid supported molten salt (SSMS) hot gas cleanup process for integrated coal gasification/molten carbonate fuel cell (MCFC) power plants. Exploratory and demonstration experiments have been completed to select a salt composition and evaluate its potential for simultaneous hydrogen sulfide (H/sub 2/S) and hydrogen chloride (HCl) removal under the conditions projected for the MCFC plants. Results to date indicate that equilibrium capacity and removal efficiencies may be adequate for one step H/sub 2/S and HCl removal. Regeneration produced a lower H/sub 2/S concentration than expected, but one from which sulfur could be recovered. Bench scale experiments will be designed to confirm laboratory results, check carbonyl sulfide removal, refine dual cycle (sulfide-chloride) regeneration techniques and obtain data for engineering/economic evaluation and scale-up. 8 references, 24 figures, 7 tables.

  13. The effect of salt composition on reductive extraction of some typical elements from molten LiF-BeF/sub 2/ salt into liquid bismuth

    SciTech Connect

    Hirotake, M.; Jun, O.; Kimikazu, M.; Kunimitsu, Y.; Yasunobu, T.

    1983-08-01

    The distribution coefficients of thorium and radium between molten LiF-BeF/sub 2/ and liquid bismuth solutions were measured at 600/sup 0/C in support of the processing of the molten-salt breeder reactor (MSBR) fuel. The increasing mole fraction of LiF in the salt phase from 40 to 70 mol% resulted in the rapid decrease of the distribution coefficient of thorium and in the slow decrease of that of radium. A comprehensive correlation of distribution behavior with salt composition is given by taking into account the formation of complex ions. The equilibrium distribution data affirm that thorium and radium exist mainly as Li/sub 2/ThF/sub 6/ and RaF/sub 2/, respectively, in the salt phase. It is suggested that the lower mole fraction of LiF in the fuel salt is effective in the MSBR fuel processing.

  14. Accelerator-driven subcritical fission in molten salt core: Closing the nuclear fuel cycle for green nuclear energy

    NASA Astrophysics Data System (ADS)

    McIntyre, Peter; Assadi, Saeed; Badgley, Karie; Baker, William; Comeaux, Justin; Gerity, James; Kellams, Joshua; McInturff, Al; Pogue, Nathaniel; Phongikaroon, Supathorn; Sattarov, Akhdiyor; Simpson, Michael; Sooby, Elizabeth; Tsvetkov, Pavel

    2013-04-01

    A technology for accelerator-driven subcritical fission in a molten salt core (ADSMS) is being developed as a basis for the destruction of the transuranics in used nuclear fuel. The molten salt fuel is a eutectic mixture of NaCl and the chlorides of the transuranics and fission products. The core is driven by proton beams from a strong-focusing cyclotron stack. This approach uniquely provides an intrinsically safe means to drive a core fueled only with transuranics, thereby eliminating competing breeding terms.

  15. Use of Molten Salt Fluxes and Cathodic Protection for Preventing the Oxidation of Titanium at Elevated Temperatures

    NASA Astrophysics Data System (ADS)

    Schwandt, Carsten; Fray, Derek J.

    2014-12-01

    The current study demonstrates that it is possible to protect both solid and liquid titanium and titanium alloys from attack from air by cathodically polarizing the titanium component using an electro-active high-temperature molten salt flux and a moderate polarization potential. The electrolytic cell used comprises a cathode of either solid titanium or liquid titanium alloy, an electrolyte based on molten calcium chloride or fluoride salt, and an anode consisting of an inert oxygen-evolving material such as iridium metal. The new approach renders possible the processing of titanium at elevated temperatures in the presence of oxygen-containing atmospheres.

  16. Accelerator-driven subcritical fission in molten salt core: Closing the nuclear fuel cycle for green nuclear energy

    SciTech Connect

    McIntyre, Peter; Assadi, Saeed; Badgley, Karie; Baker, William; Comeaux, Justin; Gerity, James; Kellams, Joshua; McInturff, Al; Pogue, Nathaniel; Sattarov, Akhdiyor; Sooby, Elizabeth; Tsvetkov, Pavel; Phongikaroon, Supathorn; Simpson, Michael

    2013-04-19

    A technology for accelerator-driven subcritical fission in a molten salt core (ADSMS) is being developed as a basis for the destruction of the transuranics in used nuclear fuel. The molten salt fuel is a eutectic mixture of NaCl and the chlorides of the transuranics and fission products. The core is driven by proton beams from a strong-focusing cyclotron stack. This approach uniquely provides an intrinsically safe means to drive a core fueled only with transuranics, thereby eliminating competing breeding terms.

  17. Molten Salt-Carbon Nanotube Thermal Energy Storage for Concentrating Solar Power Systems Final Report

    SciTech Connect

    Michael Schuller; Frank Little; Darren Malik; Matt Betts; Qian Shao; Jun Luo; Wan Zhong; Sandhya Shankar; Ashwin Padmanaban

    2012-03-30

    We demonstrated that adding nanoparticles to a molten salt would increase its utility as a thermal energy storage medium for a concentrating solar power system. Specifically, we demonstrated that we could increase the specific heat of nitrate and carbonate salts containing 1% or less of alumina nanoparticles. We fabricated the composite materials using both evaporative and air drying methods. We tested several thermophysical properties of the composite materials, including the specific heat, thermal conductivity, latent heat, and melting point. We also assessed the stability of the composite material with repeated thermal cycling and the effects of adding the nanoparticles on the corrosion of stainless steel by the composite salt. Our results indicate that stable, repeatable 25-50% improvements in specific heat are possible for these materials. We found that using these composite salts as the thermal energy storage material for a concentrating solar thermal power system can reduce the levelized cost of electricity by 10-20%. We conclude that these materials are worth further development and inclusion in future concentrating solar power systems.

  18. RETRACTED ARTICLE: The Evaluation of Reactor Performance by using Flibe and Flinabe Molten Salts in the APEX Hybrid Reactor

    NASA Astrophysics Data System (ADS)

    Korkut, Turgay; Hançerlioğulları, Aybaba

    2012-04-01

    The modeling of APEX hybrid reactor, produced by using ARIES-RS hybrid reactor technology, has been performed by using the MCNP-4B computer code and ENDF/B-V-VI nuclear data. Around the fusion chamber, molten salts Flibe (Li2BeF4) and Flinabe (LiNaBeF4) were used as cooling materials. APEX reactor was modeled in the torus form by adding nuclear materials of low significance in the specified percentages between percent 0-12 to the molten salts. The result of the study indicated that fissile material production, UF4 and ThF4 heavy metal salt increased nearly at the same percentage and it was observed that the percentage of it was practically the same in both materials. In order for the hybrid reactor to work itself in terms of tritium, TBR (tritium breeding ratio) should be lower than 1.05. When flibe molten salt was utilized in the APEX hybrid reactor, TBR was calculated as >1, 22 and when flinabe molten salt was used, TBR was calculated as >1.06.

  19. High-temperature molten salt thermal energy storage systems for solar applications

    NASA Technical Reports Server (NTRS)

    Petri, R. J.; Claar, T. D.; Ong, E.

    1983-01-01

    Experimental results of compatibility screening studies of 100 salt/containment/thermal conductivity enhancement (TCE) combinations for the high temperature solar thermal application range of 704 deg to 871 C (1300 to 1600 F) are presented. Nine candidate containment/HX alloy materials and two TCE materials were tested with six candidate solar thermal alkali and alkaline earth carbonate storage salts (both reagent and technical grade of each). Compatibility tests were conducted with salt encapsulated in approx. 6.0 inch x 1 inch welded containers of test material from 300 to 3000 hours. Compatibility evaluations were end application oriented, considering the potential 30 year lifetime requirement of solar thermal power plant components. Analyses were based on depth and nature of salt side corrosion of materials, containment alloy thermal aging effects, weld integrity in salt environment, air side containment oxidation, and chemical and physical analyses of the salt. A need for more reliable, and in some cases first time determined thermophysical and transport property data was also identified for molten carbonates in the 704 to 871 C temperature range. In particular, accurate melting point (mp) measurements were performed for Li2CO3 and Na2CO3 while melting point, heat of fusion, and specific heat determinations were conducted on 81.3 weight percent Na2CO3-18.7 weight percent K2CO3 and 52.2 weight percent BaCO3-47.8 weight percent Na2CO3 to support future TES system design and ultimate scale up of solar thermal energy storage (TES) subsystems.

  20. The filtration of molten 1XXX series aluminum alloys with rigid media tube filter

    SciTech Connect

    Hoshino, K.; Nishizaka, T.; Kakimoto, K.; Yoshida, T.

    1996-10-01

    Recently it has been increasing that molten 1XXX series aluminum alloys are filtered by Rigid Media Tube Filters (RMF). In that case, it occasionally happens that the pressure drop across the RMF rapidly increases in its relatively early stage of use. The authors have investigated inclusions captured in the RMF and conducted some model tests to define the cause. Consequently the mechanism of the rapid increase of pressure drop is given.

  1. The mechanics of pressed-pellet separators in molten salt batteries.

    SciTech Connect

    Long, Kevin Nicholas; Roberts, Christine Cardinal; Roberts, Scott Alan; Grillet, Anne

    2014-06-01

    We present a phenomenological constitutive model that describes the macroscopic behavior of pressed-pellet materials used in molten salt batteries. Such materials include separators, cathodes, and anodes. The purpose of this model is to describe the inelastic deformation associated with the melting of a key constituent, the electrolyte. At room temperature, all constituents of these materials are solid and do not transport cations so that the battery is inert. As the battery is heated, the electrolyte, a constituent typically present in the separator and cathode, melts and conducts charge by flowing through the solid skeletons of the anode, cathode, and separator. The electrochemical circuit is closed in this hot state of the battery. The focus of this report is on the thermal-mechanical behavior of the separator, which typically exhibits the most deformation of the three pellets during the process of activating a molten salt battery. Separator materials are composed of a compressed mixture of a powdered electrolyte, an inert binder phase, and void space. When the electrolyte melts, macroscopically one observes both a change in volume and shape of the separator that depends on the applied boundary conditions during the melt transition. Although porous flow plays a critical role in the battery mechanics and electrochemistry, the focus of this report is on separator behavior under flow-free conditions in which the total mass of electrolyte is static within the pellet. Specific poromechanics effects such as capillary pressure, pressure-saturation, and electrolyte transport between layers are not considered. Instead, a phenomenological model is presented to describe all such behaviors including the melting transition of the electrolyte, loss of void space, and isochoric plasticity associated with the binder phase rearrangement. The model is appropriate for use finite element analysis under finite deformation and finite temperature change conditions. The model

  2. Chloroaluminate molten salt electrolytes and vanadium pentoxide xerogel cathodes for high energy density batteries

    NASA Astrophysics Data System (ADS)

    Xie, Jian

    The work presented here is part of an effort to develop a new type of battery which uses an alkali metal such as lithium or sodium or the alkaline earth magnesium, as the anode, a V2O5 xerogel as cathode, and a 1-ethyl-3-methylimidazolium chloride/aluminum chloride room temperature molten salt as electrolyte. First, the stability of the electrolyte was studied. The electrochemistry of 1-ethyl-3-methylimidazolium chloride (EMIC), the organic component of the 1-ethyl-3-methylimidazolium chloride/aluminum chloride molten salt, was examined in acetonitrile. Cyclic voltammetry and differential pulse voltammetry were used to study the reduction of EMI+, the cation of EMIC. Controlled potential coulometry was used to determine the number of electrons involved in the EMI+ reduction process. EMI+ reduction was found to be a one-electron, diffusion controlled process occurring at -2.35V (vs. a reference electrode consisting of a Ag wire in 0.1 M tetra-n-butylammonium perchlorate (TBAP)/acetonitrile solution) in 0.1M TBAP/acetonitrile solution. Two products were generated from the reduction, which are oxidized at about -0.45 and -0.65V. Mass spectroscopy data for these two products suggest that they are degradation products of EMI+. The major products of EMI+ reduction are not electrochemically active within the available potential window. Thus, small amounts of these species should not have a serious effect on the operation of a cell using an EMIC/AlCl3 electrolyte. The second project was to develop a method for buffering a melt which contains free Mg2+ ion for insertion into a V2O 5 xerogel cathode. The buffering of melts with MgCl2 and Mg metal was investigated starting with both acidic and basic melts. The following reaction is proposed for the Mg ribbon in acidic melt: 8Al2Cl - 7+3Mg→2Al+3Mg2++14AlCl -4 This was verified by electrochemical and atomic emission spectroscopy inductively coupled plasma (AES/ICP) data. Finally, the intercalation of Li+, Na+, and Mg2+ ions

  3. Potentiometric Sensor for Real-Time Remote Surveillance of Actinides in Molten Salts

    SciTech Connect

    Natalie J. Gese; Jan-Fong Jue; Brenda E. Serrano; Guy L. Fredrickson

    2012-07-01

    A potentiometric sensor is being developed at the Idaho National Laboratory for real-time remote surveillance of actinides during electrorefining of spent nuclear fuel. During electrorefining, fuel in metallic form is oxidized at the anode while refined uranium metal is reduced at the cathode in a high temperature electrochemical cell containing LiCl-KCl-UCl3 electrolyte. Actinides present in the fuel chemically react with UCl3 and form stable metal chlorides that accumulate in the electrolyte. This sensor will be used for process control and safeguarding of activities in the electrorefiner by monitoring the concentrations of actinides in the electrolyte. The work presented focuses on developing a solid-state cation conducting ceramic sensor for detecting varying concentrations of trivalent actinide metal cations in eutectic LiCl-KCl molten salt. To understand the basic mechanisms for actinide sensor applications in molten salts, gadolinium was used as a surrogate for actinides. The ß?-Al2O3 was selected as the solid-state electrolyte for sensor fabrication based on cationic conductivity and other factors. In the present work Gd3+-ß?-Al2O3 was prepared by ion exchange reactions between trivalent Gd3+ from GdCl3 and K+-, Na+-, and Sr2+-ß?-Al2O3 precursors. Scanning electron microscopy (SEM) was used for characterization of Gd3+-ß?-Al2O3 samples. Microfocus X-ray Diffraction (µ-XRD) was used in conjunction with SEM energy dispersive X-ray spectroscopy (EDS) to identify phase content and elemental composition. The Gd3+-ß?-Al2O3 materials were tested for mechanical and chemical stability by exposing them to molten LiCl-KCl based salts. The effect of annealing on the exchanged material was studied to determine improvements in material integrity post ion exchange. The stability of the ß?-Al2O3 phase after annealing was verified by µ-XRD. Preliminary sensor tests with different assembly designs will also be presented.

  4. High-temperature corrosion of UNS N10003 in molten Li2BeF4 (FLiBe) salt

    DOE PAGESBeta

    Zheng, Guiqiu; Kelleher, Brian; He, Lingfeng; Cao, Guoping; Anderson, Mark; Allen, Todd; Sridharan, Kumar

    2015-07-30

    Here, corrosion testing of Hastelloy N in molten fluoride salt was performed in purified molten 27LiF-BeF2 (66-34mol%) (FLiBe) salt at 700°C for 1000 hours, in pure nickel and graphite capsules. In the nickel capsule tests, the near-surface region of the alloy exhibited an about 200 nm porous structure, an approximately 3.5 μm chromium depleted region, and MoSi2 precipitates. In tests performed in graphite capsules, the alloy samples gained weight due to the formation of a variety of Cr3C2, Cr7C3, Mo2C and Cr23C6, carbide phases on the surface and in the subsurface regions of the alloy. A Cr depleted region wasmore » observed in the near-surface region where Mo thermally diffused toward either surface or grain boundary, which induced approximately 1.4 μm Ni3Fe alloy layer in this region. The carbide containing layer extended to about 7 μm underneath the Ni3Fe layer. The presence of graphite dramatically changes the mechanisms of corrosion attack in Hastelloy N in molten FLiBe salt. Evaluated by in terms of the depth of attack, graphite clearly accelerates corrosion, but the results appear to indicate that the formation of Cr23C6 phase might stabilize the Cr and mitigate its dissolution in molten FLiBe salt.« less

  5. Electrochemical studies of kinetic properties of titanium- and vanadium-hydrogen systems at intermediate temperatures using molten salt techniques

    SciTech Connect

    Liaw, B.Y.; Deublein, G.; Huggins, R.A.

    1995-07-01

    A novel molten salt technique for studying hydrogen transport in Ti an V metals is described. The molten-salt electrolytes were eutectic mixtures of alkali halides dissolved with excess LiH, operating in temperature ranges typically above 300 C, to which electrochemical techniques were difficult to apply conventionally. The authors used the molten salt technique to investigate the thermodynamic properties of the Ti-H system previously. In this work, they determined composition-dependent diffusion and permeation data of hydrogen in Ti and in binary hydride phases using a galvanostatic intermittent titration technique (GITT). The results are in accordance with the best values reported by others using different techniques. They also reported some preliminary results regarding the kinetic properties of hydrogen in V and its hydride measured by more conventional time-lag and steady-state permeation techniques. The successful application of this molten salt technique in the metal hydrogen systems opened a new arena for potential application in energy conversion and storage.

  6. Utilization of Heavy Metal Molten Salts in the ARIES-RS Fusion Reactor

    NASA Astrophysics Data System (ADS)

    Übeyli, Mustafa; Yapıcı, Hüseyin

    2008-09-01

    ARIES-RS is one of the major magnetic fusion energy reactor designs that uses a blanket having vanadium alloy structure cooled by lithium [1, 2]. It is a deuterium-tritium (DT) fusion driven reactor, having a fusion power of 2170 MW [1, 2]. This study presents the neutronic analysis of the ARIES-RS fusion reactor using heavy metal molten salts in which Li2BeF4 as the main constituent was mixed with increased mole fractions of heavy metal salt (ThF4 or UF4) starting by 2 mol.% up to 12 mol.%. Neutron transport calculations were carried out with the help of the SCALE 4.3 system by solving the Boltzmann transport equation with the XSDRNPM code in 238 neutron groups and a S 8- P 3 approximation. According to the numerical results, tritium self-sufficiency was attained for the coolants, Flibe with 2% UF4 or ThF4 and 4% UF4. In addition, higher energy multiplication values were found for the salt with UF4 compared to that with ThF4. Furthermore, significant amount of high quality nuclear fuel was produced to be used in external reactors.

  7. Glyme-lithium salt equimolar molten mixtures: concentrated solutions or solvate ionic liquids?

    PubMed

    Ueno, Kazuhide; Yoshida, Kazuki; Tsuchiya, Mizuho; Tachikawa, Naoki; Dokko, Kaoru; Watanabe, Masayoshi

    2012-09-13

    To demonstrate a new family of ionic liquids (ILs), i.e., "solvate" ionic liquids, the properties (thermal, transport, and electrochemical properties, Lewis basicity, and ionicity) of equimolar molten mixtures of glymes (triglyme (G3) and tetraglyme (G4)) and nine different lithium salts (LiX) were investigated. By exploring the anion-dependent properties and comparing them with the reported data on common aprotic ILs, two different classes of liquid regimes, i.e., ordinary concentrated solutions and "solvate" ILs, were found in the glyme-Li salt equimolar mixtures ([Li(glyme)]X) depending on the anionic structures. The class a given [Li(glyme)]X belonged to was governed by competitive interactions between the glymes and Li cations and between the counteranions (X) and Li cations. [Li(glyme)]X with weakly Lewis basic anions can form long-lived [Li(glyme)](+) complex cations. Thus, they behaved as typical ionic liquids. The lithium "solvate" ILs based on [Li(glyme)]X have many desirable properties for lithium-conducting electrolytes, including high ionicity, a high lithium transference number, high Li cation concentration, and high oxidative stability, in addition to the common properties of ionic liquids. The concept of "solvate" ionic liquids can be utilized in an unlimited number of combinations of other metal salts and ligands, and will thus open a new field of research on ionic liquids.

  8. Electrochemical separation of actinides and fission products in molten salt electrolyte

    SciTech Connect

    Gay, R. L.; Grantham, L. F.; Fusselman, S. P.; Grimmett, D. L.; Roy, J. J.

    1995-09-15

    Molten salt electrochemical separation may be applied to accelerator-based conversion (ABC) and transmutation systems by dissolving the fluoride transport salt in LiCl-KCl eutectic solvent. The resulting fluoride-chloride mixture will contain small concentrations of fission product rare earths (La, Nd, Gd, Pr, Ce, Eu, Sm, and Y) and actinides (U, Np, Pu, Am, and Cm). The Gibbs free energies of formation of the metal chlorides are grouped advantageously such that the actinides can be deposited on a solid cathode with the majority of the rare earths remaining in the electrolyte. Thus, the actinides are recycled for further transmutation. Rockwell and its partners have measured the thermodynamic properties of the metal chlorides of interest (rare earths and actinides) and demonstrated separation of actinides from rare earths in laboratory studies. A model is being developed to predict the performance of a commercial electrochemical cell for separations starting with PUREX compositions. This model predicts excellent separation of plutonium and other actinides from the rare earths in metal-salt systems.

  9. Stabilization/Solidification of radioactive molten salt waste via gel-route pretreatment.

    PubMed

    Park, Hwan-Seo; Kim, In-Tae; Kim, Hwan-Young; Ryu, Seung-Kon; Kim, Joon-Hyung

    2007-02-15

    The volatilization of radionuclides during the stabilization/solidification of radioactive wastes at high temperatures is one of the major problems to be considered in choosing suitable wasteforms, process, material systems, etc. This paper reports a novel method to convert volatile wastes into nonvolatile compounds via a sol-gel process, which is different from the conventional method using metal-alkoxides and organic solvents. The material system was designed with sodium silicate (Si) as a gelling agent, phosphoric acid (P) as a catalyst/stabilizer, aluminum nitrate (Al) as a property promoter, and H20 as a solvent. A novel structural model for the chemical conversion of molten salt waste, named RPRM (Reaction Product in Reaction Module), was established, and the waste could be solidified with glass matrix via a simple procedure. The leached fraction of Cs and Sr by a PCT leaching method was 0.72% and 0.014%, respectively. In conclusion, the RPRM model isto converttargetwastes into stable and manageable products, not to obtain a specific crystalline product for each radionuclide. This paper suggested a new stabilization/solidification method for salt wastes by establishing the gel-forming material system and showing a practical example, not a new synthesis method of stable crystalline phase. This process, named "gel-route stabilization/solidification (GRSS)", will be a prospective alternative with stable chemical process on the immobilization of salt wastes and various mixed radioactive waste for final disposal.

  10. Molten Salt-Based Growth of Bulk GaN and InN for Substrates

    SciTech Connect

    Waldrip, Karen Elizabeth; Tsao, Jeffrey Yeenien; Kerley, Thomas M.

    2006-09-01

    An atmospheric pressure approach to growth of bulk group III-nitrides is outlined. Native III-nitride substrates for optoelectronic and high power, high frequency electronics are desirable to enhance performance and reliability of these devices; currently, these materials are available in research quantities only for GaN, and are unavailable in the case of InN. The thermodynamics and kinetics of the reactions associated with traditional crystal growth techniques place these activities on the extreme edges of experimental physics. The technique described herein relies on the production of the nitride precursor (N3-) by chemical and/or electrochemical methods in a molten halide salt. This nitride ion is then reacted with group III metals in such a manner as to form the bulk nitride material. The work performed during the period of funding (July 2004-September 2005) focused on the initial measurement of the solubility of GaN in molten LiCl as a function of temperature, the construction of electrochemical cells, the modification of a commercial glove box (required for handling very hygroscopic LiCl), and on securing intellectual property for the technique.

  11. Ultraviolet and infrared spectroscopy for effluent analysis in a molten salt electrochemical cell

    NASA Astrophysics Data System (ADS)

    Moore, J. F.; Pellin, M. J.; Calaway, W. F.; Hryn, J. N.

    2003-08-01

    An apparatus that combines gas phase spectroscopy over two wavelength ranges for analysis of effluent from a molten salt electrochemical cell is described. The cell is placed in a quartz tube that is sealed at the top with a cap containing feedthrus for power, thermometry, and gas flow. A resistance furnace brings the cell assembly to the desired temperature while the cap remains cooled by water. Inert gas continually purges the cell headspace carrying effluent from the electrolysis sequentially through two gas cells, one in a Fourier transform infrared (FTIR) spectrometer and one in a fiber-optic coupled ultraviolet visible spectrometer. Strong vibrational absorptions in the IR can easily identify common effluent components such as HCl, CO, CO2, and H2O. Electronic bands can identify IR-inactive molecules of importance including Cl2 and O2. Since the absorptivity of all of these species is known, determinations of the gas concentration can be made without using standards. Spectra from the electrolysis of molten MgCl2 are shown and discussed, as well as the limit of detection and inherent time resolution of the apparatus as implemented.

  12. Molten salt rolling bubble column, reactors utilizing same and related methods

    DOEpatents

    Turner, Terry D.; Benefiel, Bradley C.; Bingham, Dennis N.; Klinger, Kerry M.; Wilding, Bruce M.

    2015-11-17

    Reactors for carrying out a chemical reaction, as well as related components, systems and methods are provided. In accordance with one embodiment, a reactor is provided that includes a furnace and a crucible positioned for heating by the furnace. The crucible may contain a molten salt bath. A downtube is disposed at least partially within the interior crucible along an axis. The downtube includes a conduit having a first end in communication with a carbon source and an outlet at a second end of the conduit for introducing the carbon material into the crucible. At least one opening is formed in the conduit between the first end and the second end to enable circulation of reaction components contained within the crucible through the conduit. An oxidizing material may be introduced through a bottom portion of the crucible in the form of gas bubbles to react with the other materials.

  13. -Coated Superni 600 Under Molten Salt at 900 °C

    NASA Astrophysics Data System (ADS)

    Mudgal, Deepa; Kumar, Sanjeet; Singh, Surendra; Prakash, Satya

    2014-11-01

    Cr3C2-25(NiCr) and Cr3C2-25(NiCr)+0.4%CeO2 coatings were deposited on nickel-based superalloy Superni 600 by Detonation-gun technique. Studies were conducted on bare and coated alloys in molten salt environment (Na2SO4-25%NaCl) at 900 °C under cyclic condition. Characterization of the corrosion product was done using field emission scanning electron microscopy/energy dispersive spectroscopy and x-ray diffraction techniques. The bare Superni 600 shows penetration of corrosion beneath the metal layer thereby indicating internal oxidation. The coating of Cr3C2-25(NiCr) with 0.4%CeO2 leads to the formation of adherent scale.

  14. Preliminary study on weapon grade uranium utilization in molten salt reactor miniFUJI

    NASA Astrophysics Data System (ADS)

    Aji, Indarta Kuncoro; Waris, A.

    2014-09-01

    Preliminary study on weapon grade uranium utilization in 25MWth and 50MWth of miniFUJI MSR (molten salt reactor) has been carried out. In this study, a very high enriched uranium that we called weapon grade uranium has been employed in UF4 composition. The 235U enrichment is 90 - 95 %. The results show that the 25MWth miniFUJI MSR can get its criticality condition for 1.56 %, 1.76%, and 1.96% of UF4 with 235U enrichment of at least 93%, 90%, and 90%, respectively. In contrast, the 50 MWth miniFUJI reactor can be critical for 1.96% of UF4 with 235U enrichment of at smallest amount 95%. The neutron spectra are almost similar for each power output.

  15. Passive compact molten salt reactor (PCMSR), modular thermal breeder reactor with totally passive safety system

    NASA Astrophysics Data System (ADS)

    Harto, Andang Widi

    2012-06-01

    Design Study Passive Compact Molten Salt Reactor (PCMSR) with totally passive safety system has been performed. The term of Compact in the PCMSR name means that the reactor system is designed to have relatively small volume per unit power output by using modular and integral concept. In term of modular, the reactor system consists of three modules, i.e. reactor module, turbine module and fuel management module. The reactor module is an integral design that consists of reactor, primary and intermediate heat exchangers and passive post shutdown cooling system. The turbine module is an integral design of a multi heating, multi cooling, regenerative gas turbine. The fuel management module consists of all equipments related to fuel preparation, fuel reprocessing and radioactive handling. The preliminary calculations show that the PCMSR has negative temperature and void reactivity coefficient, passive shutdown characteristic related to fuel pump failure and possibility of using natural circulation for post shutdown cooling system.

  16. Nuclear-grade zirconium prepared by combining combustion synthesis with molten-salt electrorefining technique

    NASA Astrophysics Data System (ADS)

    Li, Hui; Nersisyan, Hayk H.; Park, Kyung-Tae; Park, Sung-Bin; Kim, Jeong-Guk; Lee, Jeong-Min; Lee, Jong-Hyeon

    2011-06-01

    Zirconium has a low absorption cross-section for neutrons, which makes it an ideal material for use in nuclear reactor applications. However, hafnium typically contained in zirconium causes it to be far less useful for nuclear reactor materials because of its high neutron-absorbing properties. In the present study, a novel effective method has been developed for the production of hafnium-free zirconium. The process includes two main stages: magnesio-thermic reduction of ZrSiO 4 under a combustion mode, to produce zirconium silicide (ZrSi), and recovery of hafnium-free zirconium by molten-salt electrorefining. It was found that, depending on the electrorefining procedure, it is possible to produce zirconium powder with a low hafnium content: 70 ppm, determined by ICP-AES analysis.

  17. A rechargeable cadmium-bromine battery using room temperature chloroaluminate molten salts

    SciTech Connect

    Dymek, C.J. Jr.; Reynolds, G.F.; Wilkes, J.S.

    1987-07-01

    Galvanic cells were tested using as electrolytes room temperature molten salts formed by mixing AlCl/sub 3/ with 1-methyl-3-ethylimidazolium chloride (MEICl). Zn and Cd, each with basic melt (containing Cl/sup -/ and AlCl/sub 4//sup -/) were the anodes. Br/sub 2/ dissolved in basic melt with a reticulated vitreous carbon current collector was the cathode in each case. MEI/sup +/-selective Nafion was used as a separator. The Zn electrode was found to be irreversible, while the Cd/Br/sub 2/ cell is rechargeable with an open-circuit voltage of 2.0V, an extended temperature range of operation, and potential for high specific energy.

  18. Passive compact molten salt reactor (PCMSR), modular thermal breeder reactor with totally passive safety system

    SciTech Connect

    Harto, Andang Widi

    2012-06-06

    Design Study Passive Compact Molten Salt Reactor (PCMSR) with totally passive safety system has been performed. The term of Compact in the PCMSR name means that the reactor system is designed to have relatively small volume per unit power output by using modular and integral concept. In term of modular, the reactor system consists of three modules, i.e. reactor module, turbine module and fuel management module. The reactor module is an integral design that consists of reactor, primary and intermediate heat exchangers and passive post shutdown cooling system. The turbine module is an integral design of a multi heating, multi cooling, regenerative gas turbine. The fuel management module consists of all equipments related to fuel preparation, fuel reprocessing and radioactive handling. The preliminary calculations show that the PCMSR has negative temperature and void reactivity coefficient, passive shutdown characteristic related to fuel pump failure and possibility of using natural circulation for post shutdown cooling system.

  19. Molten salt synthesis of single-crystalline K2Ti6O13 annular nanostructures.

    PubMed

    Zhang, Xianke; Tang, Shaolong; Yu, Jiangying; Zhai, Lin; Shi, Yangguang; Deng, Yu; Du, Youwei

    2010-08-01

    Single-crystalline K2Ti6O13 ring-like structures have been synthesized via a simple molten salt method without any templates and surfactants. The annular structures have several different types, such as nanoring, wheel-like and diskette-like ring. Each type of rings was characterized individually by scanning electron microscopy (SEM), transmission electron microscopy (TEM), selected area electron diffraction (SAED) and high-resolution transmission electron microscopy (HRTEM). These annular structures are formed by the loop-by-loop self-coiling of K2Ti6O13 nanobelts in the ring plane. The driving force of self-coiling is suggested to minimize the local electrostatic energy introduced by spontaneous polarization.

  20. Electrochemical behavior of simulated debris from a severe accident using a molten salt system

    SciTech Connect

    Takahashi, Yuya; Nakamura, Hitoshi; Yamada, Akira; Mizuguchi, Koji; Fujita, Reiko

    2013-07-01

    In a severe nuclear accident, the fuel in the reactor may melt, forming debris, which contains a UO{sub 2}-ZrO{sub 2} stable oxide mixture and parts of the reactor, such as Zircaloy and iron components. Proper handling of the debris is a critically important issue. The debris does not have the same composition as spent fuel, and so it is impossible to apply conventional reprocessing technology directly. In this study, we successfully separated Zr and Fe from simulated debris using NaCl-KCl molten salt electrolysis, and we selectively recovered the Zr and Fe. The simulated debris was made from Zr, Fe, and CeO{sub 2}. The CeO{sub 2} was used for simulating stable UO{sub 2}-ZrO{sub 2}. With this approach, it should be possible to reduce the volume of the debris by recovering metals, which can then be treated as low level radioactive wastes.

  1. Low-temperature nitridation of manganese and iron oxides using NaNH2 molten salt.

    PubMed

    Miura, Akira; Takei, Takahiro; Kumada, Nobuhiro

    2013-10-21

    Manganese and iron nitrides are important functional materials, but their synthesis processes from oxides often require high temperatures. Herein, we show a novel meta-synthesis method for manganese and iron nitrides by low-temperature nitridation of their oxides using NaNH2 molten salt as the nitrogen source in an autoclave at 240 °C. With this method, nitridation of micrometer-sized oxide particles kept their initial morphologies, but the size of the primary particles decreased. The thermodynamic driving force is considered to be the conversion of oxides to sodium hydroxide, and the kinetic of nitridation is improved by the decrease of particle size and the low melting point of NaNH2. This technique as developed here has the advantages of low reaction temperature, reduced consumption of ammonia, employing nonspecialized equipment, and providing facile control of the reactions for producing nitrides from oxides.

  2. Large-scale synthesis of monodisperse magnesium ferrite via an environmentally friendly molten salt route.

    PubMed

    Lou, Zhengsong; He, Minglong; Wang, Ruikun; Qin, Weiwei; Zhao, Dejian; Chen, Changle

    2014-02-17

    Sub-micrometer-sized magnesium ferrite spheres consisting of uniform small particles have been prepared using a facile, large-scale solid-state reaction employing a molten salt technique. Extensive structural characterization of the as-prepared samples has been performed using scanning electron microscope, transmission electron microscopy, high-resolution transmission electron microscopy, selected area electron diffraction, and X-ray diffraction. The yield of the magnesium ferrite sub-micrometer spheres is up to 90%, and these sub-micrometer spheres are made up of square and rectangular nanosheets. The magnetic properties of magnesium ferrite sub-micrometer spheres are investigated, and the magnetization saturation value is about 24.96 emu/g. Moreover, the possible growth mechanism is proposed based on the experimental results.

  3. Electrochemistry of actinides and fission products in molten salts-Data review

    NASA Astrophysics Data System (ADS)

    Zhang, Jinsuo

    2014-04-01

    The thermodynamic and electrochemical properties of actinides and fission products in the molten salt determine the pyroprocessing separation performance. Extensive measurements have been carried out to provide fundamental data for evaluating the separation efficiency and technology feasibility of pyroprocessing although the technology has been very well developed in laboratory. The state of the art of fundamental data for substance or materials involved in pyropocessing will be reviewed in the present article. The available data will be summarized and reanalyzed. New correlations, which extend the available data to a broad range of applications, will be developed based on available data from different measurements. Further research topics on providing fundamental data that is needed for scaling the current laboratory technology to industrial applications are identified.

  4. First-principles calculations of the thermodynamic properties of transuranium elements in a molten salt medium

    NASA Astrophysics Data System (ADS)

    Noh, Seunghyo; Kwak, Dohyun; Lee, Juseung; Kang, Joonhee; Han, Byungchan

    2014-03-01

    We utilized first-principles density-functional-theory (DFT) calculations to evaluate the thermodynamic feasibility of a pyroprocessing methodology for reducing the volume of high-level radioactive materials and recycling spent nuclear fuels. The thermodynamic properties of transuranium elements (Pu, Np and Cm) were obtained in electrochemical equilibrium with a LiCl-KCl molten salt as ionic phases and as adsorbates on a W(110) surface. To accomplish the goal, we rigorously calculated the double layer interface structures on an atomic resolution, on the thermodynamically most stable configurations on W(110) surfaces and the chemical activities of the transuranium elements for various coverages of those elements. Our results indicated that the electrodeposition process was very sensitive to the atomic level structures of Cl ions at the double-layer interface. Our studies are easily expandable to general electrochemical applications involving strong redox reactions of transition metals in non-aqueous solutions.

  5. An aluminum/chlorine rechargeable cell employing a room temperature molten salt electrolyte

    NASA Astrophysics Data System (ADS)

    Gifford, P. R.; Palmisano, J. B.

    1988-03-01

    A novel Al/Cl2 rechargeable electrochemical cell is decribed which employs an Al negative and graphtie positive electrode in a room temperature molten salt electrolyte of 1.5:1 AlCl3:1,2-dimethyl-3-propylimidazolium chloride. The graphite positive electrode functions as a reversible intercalation electrode for chlorine, eliminating the need for separate anolyte and catholyte compartments. The cell possesses an average discharge voltage of 1.7V for currents of 1-10 mA/g graphite, and over 150 cycles at 100 percent depth-of-discharge for positive electrode limited cells have been demonstrated. Improvements in the chlorine storage capacity of the positive electrode are needed to obtain satisfactory energy densities.

  6. Preliminary study on weapon grade uranium utilization in molten salt reactor miniFUJI

    SciTech Connect

    Aji, Indarta Kuncoro; Waris, A.

    2014-09-30

    Preliminary study on weapon grade uranium utilization in 25MWth and 50MWth of miniFUJI MSR (molten salt reactor) has been carried out. In this study, a very high enriched uranium that we called weapon grade uranium has been employed in UF{sub 4} composition. The {sup 235}U enrichment is 90 - 95 %. The results show that the 25MWth miniFUJI MSR can get its criticality condition for 1.56 %, 1.76%, and 1.96% of UF{sub 4} with {sup 235}U enrichment of at least 93%, 90%, and 90%, respectively. In contrast, the 50 MWth miniFUJI reactor can be critical for 1.96% of UF{sub 4} with {sup 235}U enrichment of at smallest amount 95%. The neutron spectra are almost similar for each power output.

  7. Development of pyro-processing technology for thorium-fuelled molten salt reactor

    SciTech Connect

    Uhlir, J.; Straka, M.; Szatmary, L.

    2012-07-01

    The Molten Salt Reactor (MSR) is classified as the non-classical nuclear reactor type based on the specific features coming out from the use of liquid fuel circulating in the MSR primary circuit. Other uniqueness of the reactor type is based on the fact that the primary circuit of the reactor is directly connected with the on-line reprocessing technology, necessary for keeping the reactor in operation for a long run. MSR is the only reactor system, which can be effectively operated within the {sup 232}Th- {sup 233}U fuel cycle as thorium breeder with the breeding factor significantly higher than one. The fuel cycle technologies proposed as ford the fresh thorium fuel processing as for the primary circuit fuel reprocessing are pyrochemical and mainly fluoride. Although these pyrochemical processes were never previously fully verified, the present-day development anticipates an assumption for the successful future deployment of the thorium-fuelled MSR technology. (authors)

  8. Preparation of pyrolytic carbon coating on graphite for inhibiting liquid fluoride salt and Xe135 penetration for molten salt breeder reactor

    NASA Astrophysics Data System (ADS)

    Song, Jinliang; Zhao, Yanling; He, Xiujie; Zhang, Baoliang; Xu, Li; He, Zhoutong; Zhang, DongSheng; Gao, Lina; Xia, Huihao; Zhou, Xingtai; Huai, Ping; Bai, Shuo

    2015-01-01

    A fixed-bed deposition method was used to prepare rough laminar pyrolytic carbon coating (RLPyC) on graphite for inhibiting liquid fluoride salt and Xe135 penetration during use in molten salt breeder reactor. The RLPyC coating possessed a graphitization degree of 44% and had good contact with graphite substrate. A high-pressure reactor was constructed to evaluate the molten salt infiltration in the isostatic graphite (IG-110, TOYO TANSO CO., LTD.) and RLPyC coated graphite under 1.01, 1.52, 3.04, 5.07 and 10.13 × 105 Pa for 12 h. Mercury injection and molten-salt infiltration experiments indicated the porosity and the salt-infiltration amount of 18.4% and 13.5 wt% under 1.52 × 105 Pa of IG-110, which was much less than 1.2% and 0.06 wt% under 10.13 × 105 Pa of the RLPyC, respectively. A vacuum device was constructed to evaluate the Xe135 penetration in the graphite. The helium diffusion coefficient of RLPyC coated graphite was 2.16 × 10-12 m2/s, much less than 1.21 × 10-6 m2/s of the graphite. Thermal cycle experiment indicated the coatings possessed excellent thermal stability. The coated graphite could effectively inhibit the liquid fluoride salt and Xe135 penetration.

  9. Preparation of Al-Si Master Alloy by Electrochemical Reduction of Fly Ash in Molten Salt

    NASA Astrophysics Data System (ADS)

    Liu, Aimin; Li, Liangxing; Xu, Junli; Shi, Zhongning; Hu, Xianwei; Gao, Bingliang; Wang, Zhaowen; Yu, Jiangyu; Chen, Gong

    2014-05-01

    An electrochemical method on preparation of Al-Si master alloy was investigated in fluoride-based molten salts of 47.7wt.%NaF-43.3wt.%AlF3-4wt.%CaF2 containing 5 wt.% fly ash at 1233 K. The cathodic products obtained by galvanostatic electrolysis were analyzed by means of x-ray diffraction, x-ray fluorescence, scanning electron microscopy, and energy-dispersive spectrometry. The result showed that the compositions of the products are Al, Si, and Al3.21Si0.47. Meanwhile, the cathodic electrochemical process was studied by cyclic voltammetry, and the results showed the reduction peak of aluminum deposition is at -1.3 V versus the platinum quasi-reference electrode in 50.3wt.%NaF-45.7wt.%AlF3-4wt.%CaF2 molten salts, while the reduction peak at -1.3 V was the co-deposition of aluminum and silicon when the fly ash was added. The silicon and iron were formed via both co-deposition and aluminothermic reduction. In the electrolysis experiments, current efficiency first increased to a maximum value of 40.7% at a current density of 0.29 A/cm2, and then it decreased with the increase of current density. With the electrolysis time lasting, the content of aluminum in the alloys decreased from 76.05 wt.% to 48.29 wt.% during 5 h, while the content of silicon increased from 15.94 wt.% to 37.89 wt.%.

  10. Gaseous fission product management for molten salt reactors and vented fuel systems

    SciTech Connect

    Messenger, S. J.; Forsberg, C.; Massie, M.

    2012-07-01

    Fission gas disposal is one of the unresolved difficulties for Molten Salt Reactors (MSRs) and advanced reactors with vented fuel systems. As these systems operate, they produce many radioactive isotopes of xenon and krypton (e.g. {sup 135}Xe t{sub 1/2} = 9.14 hours and {sup 85}Kr t{sub 1/2}= 10.73 years). Removing these gases proves vital to the success of such reactor designs for two reasons. First, the gases act as large neutron sinks which decrease reactivity and must be counterbalanced by increasing fuel loading. Second, for MSRs, inert fission product gases naturally separate quickly from high temperature salts, thus creating high vapor pressure which poses safety concerns. For advanced reactors with solid vented fuel, the gases are allowed to escape into an off-gas system and thus must be managed. Because of time delays in transport of fission product gases in vented fuel systems, some of the shorter-lived radionuclides will decay away thereby reducing the fission gas source term relative to an MSR. To calculate the fission gas source term of a typical molten salt reactor, we modeled a 1000 MWe graphite moderated thorium MSR similar to that detailed in Mathieu et al. [1]. The fuel salt used in these calculations was LiF (78 mole percent) - (HN)F 4 (22 mole percent) with a heavy nuclide composition of 3.86% {sup 233}U and 96.14% {sup 232}Th by mass. Before we can remove the fission product gases produced by this reactor configuration, we must first develop an appropriate storage mechanism. The gases could be stored in pressurized containers but then one must be concerned about bottle failure. Methods to trap noble gases in matrices are expensive and complex. Alternatively, there are direct storage/disposal options: direct injection into the Earth or injecting a grout-based product into the Earth. Advances in drilling technologies, hydro fracture technologies, and methods for the sequestration of carbon dioxide from fossil fuel plants are creating new options

  11. Room temperature inorganic ``quasi-molten salts`` as alkali-metal electrolytes

    SciTech Connect

    Xu, K.; Zhang, S.; Angell, C.A.

    1996-11-01

    Room temperature inorganic liquids of high ionic conductivity have been prepared by reacting Lewis acid AlCl with sulfonyl chlorides. The mechanism is not clear at this time since a crystal structure study of the 1:1 complex with CH{sub 3}SO{sub 2}Cl (T{sub m} = 30 C) is not consistent with a simple chloride transfer to create AlClO{sub 4}{sup {minus}} anions. The liquid is in a state somewhere between ionic and molecular. A new term quasi-molten salt is adopted to describe this state. A comparably conducting liquid can be made using BCL{sub 3} in place of AlCl{sub 3}. Unlike their organic counterparts based on ammonium cations (e.g., pyridinium or imidazolium) which reduce in the presence of alkali metals, this inorganic class of cation shows great stability against electrochemical reduction (ca. {minus}1.0 V vs. Li{sup +}/Li), with the useful consequence that reversible lithium and sodium metal deposition/stripping can be supported. The electrochemical window for these quasi-salts with AlCl{sub 3} ranges up to 5.0 V, and their room temperature conductivities exceed 10{sup {minus}4} S/cm. They dissolve lithium and sodium tetrachloroaluminates up to mole fraction {approximately} 0.6 at 100 C and intermediate compositions are permanently stable at ambient. The resultant lithium or sodium salt solutions exhibit electrochemical windows of 4.5--5.0 V vs. Li{sup +}/Li or Na{sup +}/Na and show room temperature conductivities of 10{sup {minus}3.0}--10{sup {minus}2.5} S/cm. In preliminary charge/discharge tests, the cell Li/``quasi-ionic liquid electrolyte``/Li{sub 1+x}Mn{sub 2}O{sub 4} showed a discharge capacity of ca. 110 mAh/(g of cathode) and sustained 80% of the initial capacity after 60 cycles, indicating that these quasi-molten salt-based electrolytes are promising candidates for alkali-metal batteries.

  12. Preliminary study of the electrolysis of aluminum sulfide in molten salts

    SciTech Connect

    Minh, N.Q.; Loutfy, R.O.; Yao, N.P.

    1983-02-01

    A preliminary laboratory-scale study of the electrolysis of aluminum sulfide in molten salts investigated the (1) solubility of Al/sub 2/S/sub 3/ in molten salts, (2) electrochemical behavior of Al/sub 2/S/sub 3/, and (3) electrolysis of Al/sub 2/S/sub 3/ with the determination of current efficiency as a function of current density. The solubility measurements show that MgCl/sub 2/-NaCl-KCl eutectic electrolyte at 1023 K can dissolve up to 3.3 mol % sulfide. The molar ratio of sulfur to aluminum in the eutectic is about one, which suggests that some sulfur remains undissolved, probably in the form of MgS. The experimental data and thermodynamic calculations suggest that Al/sub 2/S/sub 3/ dissolves in the eutectic to form AlS/sup +/ species in solution. Addition of AlCl/sub 3/ to the eutectic enhances the solubility of Al/sub 2/S/sub 3/; the solubility increases with increasing AlCl/sub 3/ concentration. The electrode reaction mechanism for the electrolysis of Al/sub 2/S/sub 3/ was elucidated by using linear sweep voltammetry. The cathodic reduction of aluminum-ion-containing species to aluminum proceeds by a reversible, diffusion-controlled, three-electron reaction. The anodic reaction involves the two-electron discharge of sulfide-ion-containing species, followed by the fast dimerization of sulfur atoms to S/sub 2/. Electrolysis experiments show that Al/sub 2/S/sub 3/ dissolved in molten MgCl/sub 2/-NaCl-KCl eutectic or in eutectic containing AlCl/sub 3/ can be electrolyzed to produce aluminum and sulfur. In the eutectic at 1023 K, the electrolysis can be conducted up to about 300 mA/cm/sup 2/ for the saturation solubility of Al/sub 2/S/sub 3/. Although these preliminary results are promising, additional studies are needed to elucidate many critical operating parameters before the technical potential of the electrolysis can be accurately assessed. 20 figures, 18 tables.

  13. Investigation of cold filling receiver panels and piping in molten-nitrate-salt central-receiver solar power plants

    SciTech Connect

    Pacheco, J.E.; Ralph, M.E.; Chavez, J.M.

    1994-12-31

    Cold filling refers to flowing a fluid through piping or tubes that are at temperatures below the fluid`s freezing point. Since the piping and areas of the receiver in a molten-nitrate salt central-receiver solar power plant must be electrically heated to maintain their temperatures above the nitrate salt freezing point (430{degrees}F, 221{degrees}C), considerable energy could be used to maintain such temperatures during nightly shut down and bad weather. Experiments and analyses have been conducted to investigate cold filling receiver panels and piping as a way of reducing parasitic electrical power consumption and increasing the availability of the plant. The two major concerns with cold filling are: (1) how far can the molten salt penetrate cold piping before freezing closed and (2) what thermal stresses develop during the associated thermal shock. Cold fill experiments were conducted by flowing molten salt at 550{degrees}F (288{degrees}C) through cold panels, manifolds, and piping to determine the feasibility of cold filling the receiver and piping. The transient thermal responses were measured and heat transfer coefficients were calculated from the data. Nondimensional analysis is presented which quantifies the thermal stresses in a pipe or tube undergoing thermal shock. In addition, penetration distances were calculated to determine the distance salt could flow in cold pipes prior to freezing closed.

  14. A nightly conditioning method to reduce parasitic power consumption in molten-salt central-receiver solar-power plants

    SciTech Connect

    Pacheco, J.E.

    1995-06-01

    A method to reduce nightly parasitic power consumption in a molten salt central receiver is discussed where salt is drained from the piping and heat tracing is turned off to allow the piping to cool to ambient overnight, then in the morning the pipes are filled while they are cold. Since the piping and areas of the receiver in a molten-nitrate salt central-receiver solar power plant must be electrically heated to maintain their temperatures above the nitrate salt freezing point (430{degrees}F, 221{degrees}C), considerable energy could be used to maintain such temperatures during nightly shut down and bad weather. Experiments and analyses have been conducted to investigate cold filling receiver panels and piping as a way of reducing parasitic electrical power consumption and increasing the availability of the plant. The two major concerns with cold filling are: (1) how far can the molten salt penetrate cold piping before freezing closed and (2) what thermal stresses develop during the associated thermal shock. Experiments and analysis are discussed.

  15. Molten salt-supported polycondensation of optically active diacid monomers with an aromatic thiazole-bearing diamine using microwave irradiation.

    PubMed

    Mallakpour, Shadpour; Zadehnazari, Amin

    2014-05-01

    Microwave heating was used to prepare optically active thiazole-bearing poly(amide-imide)s. Polymerization reactions were carried out in the molten tetrabutylammonium bromide as a green molten salt medium and triphenyl phosphite as the homogenizer. Structural elucidation of the compounds was performed by Fourier transform infrared and NMR spectroscopic data and elemental analysis results. The polymeric samples were readily soluble in various organic solvents, forming low-colored and flexible thin films via solution casting. They showed high thermal stability with decomposition temperature being above 360 °C. They were assembled randomly in a nanoscale size.

  16. Molten salt-supported polycondensation of optically active diacid monomers with an aromatic thiazole-bearing diamine using microwave irradiation

    PubMed Central

    Mallakpour, Shadpour; Zadehnazari, Amin

    2013-01-01

    Microwave heating was used to prepare optically active thiazole-bearing poly(amide-imide)s. Polymerization reactions were carried out in the molten tetrabutylammonium bromide as a green molten salt medium and triphenyl phosphite as the homogenizer. Structural elucidation of the compounds was performed by Fourier transform infrared and NMR spectroscopic data and elemental analysis results. The polymeric samples were readily soluble in various organic solvents, forming low-colored and flexible thin films via solution casting. They showed high thermal stability with decomposition temperature being above 360 °C. They were assembled randomly in a nanoscale size. PMID:25685498

  17. Control of molten salt corrosion of fusion structural materials by metallic beryllium

    SciTech Connect

    P. Calderoni; P. Sharpe; H. Nishimura; T. Terai

    2009-04-01

    A series of tests have been performed between 2001 and 2006 at the Safety and Tritium Applied Research facility of the Idaho National Laboratory to demonstrate chemical compatibility between the molten salt flibe (2LiF+BeF2 in moles) and fusion structural materials once suitable fluoride potential control methods are established. The tests adopted metallic beryllium contact as main fluoride potential control, and the results have been published in recent years. A further step was to expose two specimens of low activation ferritic/martensitic steel 9Cr-2W to static corrosion tests that include an active corrosion agent (hydrofluoric gas) in controlled conditions at 530 C, and the results of the tests are presented in this paper. The results confirmed the expected correlation of the HF recovery with the concentration of metallic impurities dissolved in the salt because of specimen corrosion. The metals concentration dropped to level close to the detectable limit when the beryllium rod was inserted and increased once the content of excess beryllium in the system had been consumed by HF reduction and specimens corrosion progressed. Metallographic analysis of the samples after 500 hours exposure in reactive conditions showed evidence of the formation of unstable chromium oxide layers on the specimens surface.

  18. Synthesis of Nano Sized Cr2AlC Powders by Molten Salt Method.

    PubMed

    Xiao, Dan; Zhu, Jianfeng; Wang, Fen; Tang, Yi

    2015-09-01

    Cr2AlC powders were successfully synthesized by molten salt method using Cr, Al and C as starting materials. The effects of the process parameters and amount of Al addition on the purity of the Cr2AlC powders were also investigated in details. The formation mechanism of Cr2AlC powders was investigated by XRD and DSC. The results indicated that intermediates of Cr7C3 and Cr- Al intermetallics, such as CrAl17, Cr2Al, Cr2Al8, were formed by the reactions among the initial elements, then the intermediates gradually transformed to Cr2AlC. From the fixed composition of Cr:Al:C = 2:1.2:1, high purity Cr2AlC powders could be obtained with an inorganic salt KCl as a solvent at 1250 degrees C for 60 min under argon atmosphere which was lower than that (generally 1450 degrees C) of conventional solid state reaction.

  19. Mixed-convective, conjugate heat transfer during molten salt quenching of small parts

    SciTech Connect

    Chenoweth, D.R.

    1997-02-01

    It is common in free quenching immersion heat treatment calculations to locally apply constant or surface-averaged heat-transfer coefficients obtained from either free or forced steady convection over simple shapes with small temperature differences from the ambient fluid. This procedure avoids the solution of highly transient, non-Boussinesq conjugate heat transfer problems which often involve mixed convection, but it leaves great uncertainty about the general adequacy of the results. In this paper we demonstrate for small parts (dimensions of the order of inches rather than feet) quenched in molten salt, that it is feasible to calculate such nonuniform surface heat transfer from first principles without adjustable empirical parameters. We use literature physical property salt data from the separate publications of Kirst et al., Nissen, Carling, and Teja, et al. for T<1000 F, and then extrapolate it to the initial part temperature. The reported thermal/chemical breakdown of NaNO{sub 2} for T>800 F is not considered to be important due to the short time the surface temperature exceeds that value for small parts. Similarly, for small parts, the local Reynolds and Rayleigh numbers are below the corresponding critical values for most if not all of the quench, so that we see no evidence of the existence of significant turbulence effects, only some large scale unsteadiness for brief periods. The experimental data comparisons from the open literature include some probe cooling-rate results of Foreman, as well as some cylinder thermal histories of Howes.

  20. A molten Salt Am242M Production Reactor for Space Applications

    NASA Technical Reports Server (NTRS)

    Emrich, William

    2005-01-01

    The use of Am242m holds great promise for increasing the efficiency nuclear thermal rocket engines. Because Am242m has the highest fission cross section of any known isotope (1000's of barns), its extremely high reactivity may be used to directly heat a propellant gas with fission fragments. Since this isotope does not occur naturally, it must be bred in special production reactors designed for that purpose. The primary advantage to using molten salt reactors for breeding Am242m is that the reactors can be reprocessed continually yielding a constant rate of production of the isotope. Once built and initially fueled, the reactor will continually breed the additional fuel it needs to remain critical. The only feedstock required is a salt of U238. No enriched fuel is required during normal operation and all fissile material, except the Am242m, is maintained in a closed loop. For a reactor operating at 200 MW several kilograms of Am242m may be bred each year.

  1. Molten salt coal gasification process development unit. Phase 1. Volume 1. PDU operations. Final report

    SciTech Connect

    Kohl, A.L.

    1980-05-01

    This report summarizes the results of a test program conducted on the Molten Salt Coal Gasification Process, which included the design, construction, and operation of a Process Development Unit. In this process, coal is gasified by contacting it with air in a turbulent pool of molten sodium carbonate. Sulfur and ash are retained in the melt, and a small stream is continuously removed from the gasifier for regeneration of sodium carbonate, removal of sulfur, and disposal of the ash. The process can handle a wide variety of feed materials, including highly caking coals, and produces a gas relatively free from tars and other impurities. The gasification step is carried out at approximately 1800/sup 0/F. The PDU was designed to process 1 ton per hour of coal at pressures up to 20 atm. It is a completely integrated facility including systems for feeding solids to the gasifier, regenerating sodium carbonate for reuse, and removing sulfur and ash in forms suitable for disposal. Five extended test runs were made. The observed product gas composition was quite close to that predicted on the basis of earlier small-scale tests and thermodynamic considerations. All plant systems were operated in an integrated manner during one of the runs. The principal problem encountered during the five test runs was maintaining a continuous flow of melt from the gasifier to the quench tank. Test data and discussions regarding plant equipment and process performance are presented. The program also included a commercial plant study which showed the process to be attractive for use in a combined-cycle, electric power plant. The report is presented in two volumes, Volume 1, PDU Operations, and Volume 2, Commercial Plant Study.

  2. Impact of thorium based molten salt reactor on the closure of the nuclear fuel cycle

    NASA Astrophysics Data System (ADS)

    Jaradat, Safwan Qasim Mohammad

    Molten salt reactor (MSR) is one of six reactors selected by the Generation IV International Forum (GIF). The liquid fluoride thorium reactor (LFTR) is a MSR concept based on thorium fuel cycle. LFTR uses liquid fluoride salts as a nuclear fuel. It uses 232Th and 233U as the fertile and fissile materials, respectively. Fluoride salt of these nuclides is dissolved in a mixed carrier salt of lithium and beryllium (FLiBe). The objective of this research was to complete feasibility studies of a small commercial thermal LFTR. The focus was on neutronic calculations in order to prescribe core design parameter such as core size, fuel block pitch (p), fuel channel radius, fuel path, reflector thickness, fuel salt composition, and power. In order to achieve this objective, the applicability of Monte Carlo N-Particle Transport Code (MCNP) to MSR modeling was verified. Then, a prescription for conceptual small thermal reactor LFTR and relevant calculations were performed using MCNP to determine the main neutronic parameters of the core reactor. The MCNP code was used to study the reactor physics characteristics for the FUJI-U3 reactor. The results were then compared with the results obtained from the original FUJI-U3 using the reactor physics code SRAC95 and the burnup analysis code ORIPHY2. The results were comparable with each other. Based on the results, MCNP was found to be a reliable code to model a small thermal LFTR and study all the related reactor physics characteristics. The results of this study were promising and successful in demonstrating a prefatory small commercial LFTR design. The outcome of using a small core reactor with a diameter/height of 280/260 cm that would operate for more than five years at a power level of 150 MWth was studied. The fuel system 7LiF - BeF2 - ThF4 - UF4 with a (233U/ 232Th) = 2.01 % was the candidate fuel for this reactor core.

  3. Salt-Zeolite Ion Exchange Equilibrium Studies for Complete Set of Fission Products in Molten LiCl-KCl

    SciTech Connect

    Tae-Sic Yoo; Steven M. Frank; Michael F. Simpson; Paula A. Hahn; Terry J. Battisti; Supathorn Phongikaroon

    2010-09-01

    This paper presents results on LiCl-KCl based molten salts/zeolite-A contact experiments and the associated equilibrium ion exchange model. Experiments examine the contact behaviors of various ternary salts (LiCl-KCl-YCl3, LiCl-KCl-LaCl3, and LiCl-KCl-PrCl3) and quaternary salts (LiCl-KCl-CsCl-NdCl3 and LiCl-KCl-CsCl-SrCl2) with the zeolite-A. The developed equilibrium model assumes that there are ion exchange and occlusion sites, both of which are in equilibrium with the molten salt phase. A systematic approach in estimating total occlusion capacity of the zeolite-A is developed. The parameters of the model, including the total occlusion capacity of the zeolite-A, were determined from fitting experimental data collected via multiple independent studies including the ones reported in this paper. Experiments involving ternary salts were used for estimating the parameters of the model, while those involving quaternary salts were used to validate the model.

  4. Preparation of Binary and Ternary Oxides by Molten Salt Method and its Electrochemical Properties

    NASA Astrophysics Data System (ADS)

    Reddy, M. V.; Theng, L. Pei; Soh, Hulbert; Beichen, Z.; Jiahuan, F.; Yu, C.; Ling, A. Yen; Andreea, L. Y.; Ng, C. H. Justin; Liang, T. J. L. Galen; Ian, M. F.; An, H. V. T.; Ramanathan, K.; Kevin, C. W. J.; Daryl, T. Y. W.; Hao, T. Yi; Loh, K. P.; Chowdari, B. V. R.

    2013-07-01

    We report simple binary oxides namely SnO2, TiO2, CuO, MnO2, Fe2O3, Co3O4 and ternary oxides like MnCo2O4 by molten salt method at a temperature range of 280°C to 950°C in air and discuss the effect of morphology, crystal structure and electrochemical properties of binary and ternary oxides. Materials were characterized by X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Brunauer-Emmett-Teller (BET) surface area methods. XRD patterns showed all MSM prepared materials exhibited characteristic lattice parameter values. BET surface area varies depending on the nature of the material, molten salt and preparation temperature and the obtained values are in the range, 1 to 160 m2/g. Electrochemical properties were studied using cyclic voltammetry (CV) and electrochemical performance studies were carried in the voltage range, 0.005-1.0V for SnO2, 1.0-2.8V for TiO2 and Fe2O3, MCo2O4 (M = Co, Mn), MnO2 and CuO were cycled in the range, 0.005-3.0V. At a current rates of 30-100 mA/g and a scan rate of 0.058 mV/sec was used for galvanostatic cycling and cyclic voltammetry. SnO2 showed that an alloying-de-alloying reaction occurs at ˜0.2 and ˜0.5 V vs. Li. TiO2 main intercalation and de-interaction reactions at ˜1.7 and ˜1.8 V vs. Li. Co3O4, MnCo2O4, and MnO2 main discharge potentials at ˜1.2, 0.9V and 0.4V, resp. and charge potentials peak ˜2.0V and 1.5V vs. Li. CuO prepared at 750°C exhibited main anodic peak at ˜2.45V and cathodic peaks at ˜0.85V and ˜1.25V. We discussed the possible reaction mechanisms and Li-storage performance values in detail.

  5. Simplified Reference Electrode for Electrorefining of Spent Nuclear Fuel in High Temperature Molten Salt

    SciTech Connect

    Kim Davies; Shelly X Li

    2007-09-01

    Pyrochemical processing plays an important role in development of proliferation- resistant nuclear fuel cycles. At the Idaho National Laboratory (INL), a pyrochemical process has been implemented for the treatment of spent fuel from the Experimental Breeder Reactor II (EBR-II) in the last decade. Electrorefining in a high temperature molten salt is considered a signature or central technology in pyroprocessing fuel cycles. Separation of actinides from fission products is being demonstrated by electrorefining the spent fuel in a molten UCl3-LiCl-KCl electrolyte in two engineering scale electrorefiners (ERs). The electrorefining process is current controlled. The reference electrode provides process information through monitoring of the voltage difference between the reference and the anode and cathode electrodes. This information is essential for monitoring the reactions occurring at the electrodes, investigating separation efficiency, controlling the process rate, and determining the process end-point. The original reference electrode has provided good life expectancy and signal stability, but is not easily replaceable. The reference electrode used a vycor-glass ion-permeable membrane containing a high purity silver wire with one end positioned in ~2 grams of LiCl/KCl salt electrolyte with a low concentration (~1%) AgCl. It was, however, a complex assembly requiring specialized skill and talent to fabricate. The construction involved multiple small pieces, glass joints, ceramic to glass joints, and ceramic to metal joints all assembled in a high purity inert gas environment. As original electrodes reached end-of-life it was uncertain if the skills and knowledge were readily available to successfully fabricate replacements. Experimental work has been conducted to identify a simpler electrode design while retaining the needed long life and signal stability. This improved design, based on an ion-permeable membrane of mullite has been completed. Use of the silver wire

  6. Combined Evaporation and Salt Precipitation in Porous Media

    NASA Astrophysics Data System (ADS)

    Weisbrod, N.; Dragila, M. I.; Nachshon, U.; Or, D.; Shaharani, E.; Grader, A.

    2012-12-01

    The vadose zone pore water contains dissolved salts and minerals; therefore, evaporation results in high rates of salt accumulation that may change the physical and chemical properties of the porous media. Here, a series of experiments, together with a mathematical model, are presented to shed new light on these processes. Experiments included: (1) long-term column evaporation experiments to quantify changes in evaporation rates due to salt precipitation; (2) CT scans of evaporated porous media samples saturated with salt solutions, to observe salt precipitation from micro to macro scales; and (3) Infrared thermography analysis to quantify evaporation rates from porous media surfaces for homogeneous and heterogeneous conditions and constant water table, in the presence of salt precipitation. As expected, the majority of salt crystallization occurs in the upper parts of the matrix, near the evaporation front. For heterogeneous porous matrices, salt precipitation will occur mainly in the fine pore regions as preferential evaporation takes place in these locations. In addition, it was found that the precipitated NaCl salt crust diffusion coefficient for water vapor is one to two orders of magnitude lower than the vapor diffusion coefficient in free air, depending on environmental conditions and salt crystallization rates. Three new stages of evaporation were defined for saline solutions: SS1, SS2 and SS3. SS1 exhibits a low and gradual decrease in the evaporation rate due to osmotic pressure. During SS2, the evaporation rate falls progressively due to salt precipitation; SS3 is characterized by a constant low evaporation rate and determined by the diffusion rate of water vapor through the precipitated salt layer. Even though phenomenologically similar to the classical evaporation stages of pure water, these stages correspond to different mechanisms and the transition between stages can occur regardless the hydraulic conditions. As well, it was shown that matrix

  7. New operating strategies for molten salt in line focusing solar fields - Daily drainage and solar receiver preheating

    NASA Astrophysics Data System (ADS)

    Eickhoff, Martin; Meyer-Grünefeldt, Mirko; Keller, Lothar

    2016-05-01

    Nowadays molten salt is efficiently used in point concentrating solar thermal power plants. Line focusing systems still have the disadvantage of elevated heat losses at night because of active freeze protection of the solar field piping system. In order to achieve an efficient operation of line focusing solar power plants using molten salt, a new plant design and a novel operating strategy is developed for Linear Fresnel- and Parabolic Trough power plants. Daily vespertine drainage of the solar field piping and daily matutinal refilling of the solar preheated absorber tubes eliminate the need of nocturnal heating of the solar field and reduce nocturnal heat losses to a minimum. The feasibility of this new operating strategy with all its sub-steps has been demonstrated experimentally.

  8. Wetting behavior of imidazolium-containing, room-temperature molten salt. Technical report, 11 June 28-August 1984

    SciTech Connect

    Eberhart, J.G.

    1984-08-28

    A room-temperature, molten-salt system composed of 1-methyl-3-ethylimidazolium chloride plus aluminum chloride has been developed and extensively studied over the last few years. The most promising application of this liquid mixture is as a battery electrolyte, and for this reason a study was undertaken of the wettability of various candidate battery component materials by the molten salt. Advancing and receding contact angles were determined for the binary melt as a function of such variables as mixture composition, chlorination of the imidazolium ion, replacement of AlCl3 by LiCl, solid porosity, and solid surface cleaning procedure. Measurements were also made of the surface tension of the melt at one basic composition. Surface tension data was helpful in understanding the composition dependence of melt wetting behavior.

  9. Preparation of SiC/SiO2 core-shell nanowires via molten salt mediated carbothermal reduction route

    NASA Astrophysics Data System (ADS)

    Zhang, Ju; Yan, Shuai; Jia, Quanli; Huang, Juntong; Lin, Liangxu; Zhang, Shaowei

    2016-06-01

    The growth of silicon carbide (SiC) crystal generally requires a high temperature, especially when low quality industrial wastes are used as the starting raw materials. In this work, SiC/SiO2 core-shell nanowires (NWs) were synthesized from low cost silica fume and sucrose via a molten salt mediated carbothermal reduction (CR) route. The molten salt was found to be effective in promoting the SiC growth and lowering the synthesis temperature. The resultant NWs exhibited a heterostructure composed of a 3C-SiC core of 100 nm in diameter and a 5-10 nm thick amorphous SiO2 shell layer. The photoluminescence spectrum of the achieved SiC NWs displayed a significant blue shift (a dominant luminescence at round 422 nm), which suggested that they were high quality and could be a promising candidate material for future optoelectronic applications.

  10. The procedure and results of calculations of the equilibrium isotopic composition of a demonstration subcritical molten salt reactor

    NASA Astrophysics Data System (ADS)

    Nevinitsa, V. A.; Dudnikov, A. A.; Blandinskiy, V. Yu.; Balanin, A. L.; Alekseev, P. N.; Titarenko, Yu. E.; Batyaev, V. F.; Pavlov, K. V.; Titarenko, A. Yu.

    2015-12-01

    A subcritical molten salt reactor with an external neutron source is studied computationally as a facility for incineration and transmutation of minor actinides from spent nuclear fuel of reactors of VVER-1000 type and for producing 233U from 232Th. The reactor configuration is chosen, the requirements to be imposed on the external neutron source are formulated, and the equilibrium isotopic composition of heavy nuclides and the key parameters of the fuel cycle are calculated.

  11. Aerosol-assisted molten salt synthesis of NaInS(2) nanoplates for use as a new photoanode material.

    PubMed

    Mann, Amanda K P; Wicker, Susanne; Skrabalak, Sara E

    2012-12-01

    NaInS(2) , a H(2) -evolving photocatalyst, is synthesized as single-crystalline hexagonal plates by coupling a molten salt synthesis with ultrasonic spray pyrolysis (USP) for the first time. USP NaInS(2) films are used as a new photoanode material and have an initial photocurrent of ≈37 μA/cm(2) upon illumination and activities 25 times greater than films made from a standard non-aerosol NaInS(2) sample.

  12. Effects assessment of 10 functioning years on the main components of the molten salt PCS experimental facility of ENEA

    NASA Astrophysics Data System (ADS)

    Gaggioli, Walter; Di Ascenzi, Primo; Rinaldi, Luca; Tarquini, Pietro; Fabrizi, Fabrizio

    2016-05-01

    In the frame of the Solar Thermodynamic Laboratory, ENEA has improved CSP Parabolic Trough technologies by adopting new advanced solutions for linear tube receivers and by implementing a binary mixture of molten salt (60% NaNO3 and 40% KNO3) [1] as both heat transfer fluid and heat storage medium in solar field and in storage tanks, thus allowing the solar plants to operate at high temperatures up to 550°C. Further improvements have regarded parabolic mirror collectors, piping and process instrumentation. All the innovative components developed by ENEA, together with other standard parts of the plant, have been tested and qualified under actual solar operating conditions on the PCS experimental facility at the ENEA Casaccia Research Center in Rome (Italy). The PCS (Prova Collettori Solari, i.e. Test of Solar Collectors) facility is the main testing loop built by ENEA and it is unique in the world for what concerns the high operating temperature and the fluid used (mixture of molten salt). It consists in one line of parabolic trough collectors (test section of 100 m long life-size solar collectors) using, as heat transfer fluid, the aforesaid binary mixture of molten salt up to 10 bar, at high temperature in the range 270° and 550°C and a flow rate up to 6.5 kg/s. It has been working since early 2004 [2] till now; it consists in a unique closed loop, and it is totally instrumented. In this paper the effects of over ten years qualification tests on the pressurized tank will be presented, together with the characterization of the thermal losses of the piping of the molten salt circuit, and some observations performed on the PCS facility during its first ten years of operation.

  13. The procedure and results of calculations of the equilibrium isotopic composition of a demonstration subcritical molten salt reactor

    SciTech Connect

    Nevinitsa, V. A. Dudnikov, A. A.; Blandinskiy, V. Yu.; Balanin, A. L.; Alekseev, P. N.; Titarenko, Yu. E.; Batyaev, V. F.; Pavlov, K. V.; Titarenko, A. Yu.

    2015-12-15

    A subcritical molten salt reactor with an external neutron source is studied computationally as a facility for incineration and transmutation of minor actinides from spent nuclear fuel of reactors of VVER-1000 type and for producing {sup 233}U from {sup 232}Th. The reactor configuration is chosen, the requirements to be imposed on the external neutron source are formulated, and the equilibrium isotopic composition of heavy nuclides and the key parameters of the fuel cycle are calculated.

  14. Reactor Controllability of 3-Region-Core Molten Salt Reactor System - A Study on Load Following Capability

    SciTech Connect

    Takahisa Yamamoto; Koshi Mitachi; Masatoshi Nishio

    2006-07-01

    The Molten Salt Reactor (MSR) systems are liquid-fueled reactors that can be used for actinide burning, production of electricity, production of hydrogen, and production of fissile fuels (breeding). Thorium (Th) and uranium-233 ({sup 233}U) are fertile and fissile of the MSR systems, and dissolved in a high-temperature molten fluoride salt (fuel salt) with a very high boiling temperature (up to 1650 K), that is both the reactor nuclear fuel and the coolant. The MSR system is one of the six advanced reactor concepts identified by the Generation IV International Forum (GIF) as a candidate for cooperative development. In the MSR system, fuel salt flows through a fuel duct constructed around a reactor core and fuel channel of a graphite moderator accompanied by fission reaction and heat generation, and flows out to an external-loop system consisted of a heat exchanger and a circulation pump. Due to the motion of fuel salt, delayed neutron precursors that are one of the source of neutron production make to change their position between the fission reaction and neutron emission events and decay even occur in the external loop system. Hence the reactivity and effective delayed neutron precursor fraction of the MSR system are lower than those of solid fuel reactor systems such as Boiling Water Reactors (BWRs) and Pressurised Water Reactor (PWRs). Since all of the presently operating nuclear power reactors utilize solid fuel, little attention had been paid to the MSR analysis of the reactivity loss and reactor characteristics change caused by the fuel salt circulation. Sides et al. and Shimazu et al. developed MSR analytical models based on the point reactor kinetics model to consider the effect of fuel salt flow. Their models represented a reactor as having six zones for fuel salt and three zones for the graphite moderator. Since their models employed the point reactor kinetics model and the rough temperature approximation, their results were not sufficiently accurate to

  15. Dechlorination and stabilization of radioactive chloride salt waste in a molten state

    SciTech Connect

    In-Tae Kim; Hwan-Seo Park; Yong-Jun Cho; Hwan-Young Kim; Seong-Won Park; Eung-Ho Kim

    2007-07-01

    This study suggests a new method to stabilize the molten salt wastes generated from he pyro-processing of a LWR spent fuel. Using a conventional sol-gel process, an inorganic material (SiO{sub 2}-Al{sub 2}O{sub 3}-P{sub 2}O{sub 5}, SAP) reactive to metal chlorides was prepared. In this paper, the reactivity of the SAP on the metal chlorides at 650-850 deg. C, the thermal stability of the reaction products and their leach-resistance under the PCT-A leach test were investigated. In the SAP, three different kinds of chains are available; Si-O-Si (main chain), Si-O-Al (side chain) and Al-O-P/P-O-P (reactive chain). Alkali metal chlorides were converted into metal aluminosilicate (Li{sub x}Al{sub x}Si{sub 1-x}O{sub 2-x}) and metal phosphate(Li{sub 3}PO{sub 4} and Cs{sub 2}AlP{sub 3}O{sub 10}) while the alkaline earth and rare earth chlorides were changed into only metal phosphates (Sr{sub 5}(PO{sub 4}){sub 3}Cl and CePO{sub 4}). The conversion rate was about 96% at a salt waste/SAP weight ratio of 0.5 and a weight loss up to 1100 deg. C measured by the thermo-gravimetric analysis was below 1 Wt%. The leach rates of Cs and Sr under the PCT-A leaching condition were about 10{sup -2} and 10{sup -4} g/m{sup 3}.day, respectively. From these results, it could be concluded that the SAP developed in this study can be considered as an effective stabilizer for metal chlorides and the method of using the SAP could provide a chance to minimize the final waste volume to be disposed off. (authors)

  16. Application of ceramic membrane in molten salt electrolysis of CaO-CaCl{sub 2}

    SciTech Connect

    Ferro, P.D.; Mishra, B.; Olson, D.L.; Averill, W.A.

    1998-09-01

    Calciothermic reduction of radioactive metal oxides and halides produces calcium compounds as the by-product which require subsequent processing to mitigate and control a potential source of waste generation. Attempts to recover elemental calcium by direct molten salt electrolysis of calcium compounds using carbon anodes have met with very limited success due to severe process limitations and stringent cell design requirements. A feasible process to win calcium in a modified cell is discussed where a porous anodic diaphragm has been used around the carbon anode. The effective diffusion coefficient for steady state cell operation has been estimated and is found to depend on the porosity and morphology of the anode sheath. An expression for the maximum electrowinning rate, incorporating an effective diffusion coefficient, has been developed and can be used to determine the limiting current density under steady-state conditions. The possibility of enhancing the current efficiency to an acceptable level by in situ application of calcium as a reductant is suggested.

  17. Optimal spacing within a tubed, volumetric, cavity receiver suitable for modular molten salt solar towers

    NASA Astrophysics Data System (ADS)

    Turner, Peter

    2016-05-01

    A 2-dimensional radiation analysis has been developed to analyse the radiative efficiency of an arrangement of heat transfer tubes distributed in layers but spaced apart to form a tubed, volumetric receiver. Such an arrangement could be suitable for incorporation into a cavity receiver. Much of the benefit of this volumetric approach is gained after using 5 layers although improvements do continue with further layers. The radiation analysis splits each tube into multiple segments in which each segment surface can absorb, reflect and radiate rays depending on its surface temperature. An iterative technique is used to calculate appropriate temperatures depending on the distribution of the net energy absorbed and assuming that the cool heat transfer fluid (molten salt) starts at the front layer and flows back through successive layers to the rear of the cavity. Modelling the finite diameter of each layer of tubes increases the ability of a layer to block radiation scattered at acute angles and this effect is shown to reduce radiation losses by nearly 25% compared to the earlier 1-d analysis. Optimum efficient designs tend to occur when the blockage factor is 0.2 plus the inverse of the number of tube layers. It is beneficial if the distance between successive layers is ≥ 2 times the diameter of individual tubes and in this situation, if the incoming radiation is spread over a range of angles, the performance is insensitive to the degree of any tube positional offset or stagger between layers.

  18. Corrosion Resistance of Sintered and Pyrolytic Boron Nitride in Molten Salts

    SciTech Connect

    Kuznestsov, S.A.; Polyakov, E.G.; Stangrit, P.T.

    1986-02-01

    This paper compares the behavior of sintered and pyrolytic boron nitride in the following molten salts: KC1-NaC1-K/sub 3/A1F/sub 6/ (15 wt. %), LiF-BaF/sub 2/-LaF/sub 3/ (40 wt. %)-La/sub 2/O/sub 3/ (2 wt. %), KC1-NaC1-K/sub 2/HFF/sub 6/ (15 wt. %), KC1-NaC1-K/sub 2/ZrF/sub 6/ (15 wt. %), KC1-NaC1-K/sub 2/NbF/sub 7/ (10 wt. %), and KC1-NaC1-K/sub 2/TaF/sub 7/ (10 wt. %). The gas phase composition was determined on a Perkin-Elmer F-30 chromatograph and the boron in the electrolyte by reaction with carminic acid. The lack of adhesion of pyrolytic boron nitride to glassy carbon and pyrographite makes it possible to use it for producing various articles, particularly capillaries, and to fabricate highly stable cells for measuring the electrical conductivity of extremely aggressive melts. Pyrolytic boron nitride is inapplicable as an electrical insulator in melts contining K/sub 2/NbF/sub 7/ and K/sub 2/TaF/sub 7/ due to surface formation of conductive metal nitrides.

  19. Direct Conversion of Greenhouse Gas CO2 into Graphene via Molten Salts Electrolysis.

    PubMed

    Hu, Liwen; Song, Yang; Jiao, Shuqiang; Liu, Yingjun; Ge, Jianbang; Jiao, Handong; Zhu, Jun; Wang, Junxiang; Zhu, Hongmin; Fray, Derek J

    2016-03-21

    Producing graphene through the electrochemical reduction of CO2 remains a great challenge, which requires precise control of the reaction kinetics, such as diffusivities of multiple ions, solubility of various gases, and the nucleation/growth of carbon on a surface. Here, graphene was successfully created from the greenhouse gas CO2 using molten salts. The results showed that CO2 could be effectively fixed by oxygen ions in CaCl2-NaCl-CaO melts to form carbonate ions, and subsequently electrochemically split into graphene on a stainless steel cathode; O2 gas was produced at the RuO2-TiO2 inert anode. The formation of graphene in this manner can be ascribed to the catalysis of active Fe, Ni, and Cu atoms at the surface of the cathode and the microexplosion effect through evolution of CO in between graphite layers. This finding may lead to a new generation of proceedures for the synthesis of high value-added products from CO2, which may also contribute to the establishment of a low-carbon and sustainable world.

  20. Thermal analysis to support decommissioning of the molten salt reactor experiment

    SciTech Connect

    Sulfredge, C.D.; Morris, D.G.; Park, J.E.; Williams, P.T.

    1996-06-01

    As part of the decommissioning process for the Molten Salt Reactor Experiment (MSRE) at Oak Ridge National Laboratory, several thermal-sciences issues were addressed. Apparently a mixture of UF{sub 6} and F{sub 2} had diffused into the upper portion of one charcoal column in the MSRE auxiliary charcoal bed (ACB), leading to radiative decay heating and possible chemical reaction sources. A proposed interim corrective action was planned to remove the water from the ACB cell to reduce criticality and reactivity concerns and then fill the ACB cell with an inert material. This report describes design of a thermocouple probe to obtain temperature measurements for mapping the uranium deposit, as well as development of steady-state and transient numerical models for the heat transfer inside the charcoal column. Additional numerical modeling was done to support filling of the ACB cell. Results from this work were used to develop procedures for meeting the goals of the MSRE Remediation Project without exceeding appropriate thermal limits.

  1. Direct Conversion of Greenhouse Gas CO2 into Graphene via Molten Salts Electrolysis.

    PubMed

    Hu, Liwen; Song, Yang; Jiao, Shuqiang; Liu, Yingjun; Ge, Jianbang; Jiao, Handong; Zhu, Jun; Wang, Junxiang; Zhu, Hongmin; Fray, Derek J

    2016-03-21

    Producing graphene through the electrochemical reduction of CO2 remains a great challenge, which requires precise control of the reaction kinetics, such as diffusivities of multiple ions, solubility of various gases, and the nucleation/growth of carbon on a surface. Here, graphene was successfully created from the greenhouse gas CO2 using molten salts. The results showed that CO2 could be effectively fixed by oxygen ions in CaCl2-NaCl-CaO melts to form carbonate ions, and subsequently electrochemically split into graphene on a stainless steel cathode; O2 gas was produced at the RuO2-TiO2 inert anode. The formation of graphene in this manner can be ascribed to the catalysis of active Fe, Ni, and Cu atoms at the surface of the cathode and the microexplosion effect through evolution of CO in between graphite layers. This finding may lead to a new generation of proceedures for the synthesis of high value-added products from CO2, which may also contribute to the establishment of a low-carbon and sustainable world. PMID:26871684

  2. Uncertainty studies of real anode surface area in computational analysis for molten salt electrorefining

    NASA Astrophysics Data System (ADS)

    Choi, Sungyeol; Park, Jaeyeong; Hoover, Robert O.; Phongikaroon, Supathorn; Simpson, Michael F.; Kim, Kwang-Rag; Hwang, Il Soon

    2011-09-01

    This study examines how much cell potential changes with five differently assumed real anode surface area cases. Determining real anode surface area is a significant issue to be resolved for precisely modeling molten salt electrorefining. Based on a three-dimensional electrorefining model, calculated cell potentials compare with an experimental cell potential variation over 80 h of operation of the Mark-IV electrorefiner with driver fuel from the Experimental Breeder Reactor II. We succeeded to achieve a good agreement with an overall trend of the experimental data with appropriate selection of a mode for real anode surface area, but there are still local inconsistencies between theoretical calculation and experimental observation. In addition, the results were validated and compared with two-dimensional results to identify possible uncertainty factors that had to be further considered in a computational electrorefining analysis. These uncertainty factors include material properties, heterogeneous material distribution, surface roughness, and current efficiency. Zirconium's abundance and complex behavior have more impact on uncertainty towards the latter period of electrorefining at given batch of fuel. The benchmark results found that anode materials would be dissolved from both axial and radial directions at least for low burn-up metallic fuels after active liquid sodium bonding was dissolved.

  3. Thorium-Fueled Underground Power Plant Based on Molten Salt Technology

    SciTech Connect

    Moir, Ralph W.; Teller, Edward

    2005-09-15

    This paper addresses the problems posed by running out of oil and gas supplies and the environmental problems that are due to greenhouse gases by suggesting the use of the energy available in the resource thorium, which is much more plentiful than the conventional nuclear fuel uranium. We propose the burning of this thorium dissolved as a fluoride in molten salt in the minimum viscosity mixture of LiF and BeF{sub 2} together with a small amount of {sup 235}U or plutonium fluoride to initiate the process to be located at least 10 m underground. The fission products could be stored at the same underground location. With graphite replacement or new cores and with the liquid fuel transferred to the new cores periodically, the power plant could operate for up to 200 yr with no transport of fissile material to the reactor or of wastes from the reactor during this period. Advantages that include utilization of an abundant fuel, inaccessibility of that fuel to terrorists or for diversion to weapons use, together with good economics and safety features such as an underground location will diminish public concerns. We call for the construction of a small prototype thorium-burning reactor.

  4. Molten salt synthesis and luminescent properties of YVO4:Ln (Ln = Eu3+, Dy3+) nanophosphors.

    PubMed

    Liu, Chenglu; Wang, Fang; Jia, Peiyun; Lin, Jun; Zhou, Zhiqiang

    2012-01-01

    Eu3+ and Dy(3+)-doped YVO4 nanocrystallites were successfully prepared at 400 degrees C in equal moles of NaNO3 and KNO3 molten salts. X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, transmission electronic microscopy (TEM), photoluminescence (PL) spectrum and lifetime were used to characterize the nanocrystallites. XRD results demonstrate that NaOH concentration and annealing temperature play important roles in phase purity and crystallinity of the nanocrystallites, the optimum NaOH concentration and annealing temperature being 6:40 and 400 degrees C respectively. TEM micrographs show the nanocrystallites are well crystallized with a cubic morphology in an average grain size of about 18 nm. Upon excitation of the vanadate group at 314 nm, YVO4:Eu3+ and YVO4:Dy3+ nanocrystallites exhibit the characteristic emission of Eu3+ and Dy3+, which indicates that there is an energy transfer from the vanadate group to the rare earth ions. Moreover, the structure and luminescent properties of the nanocrystallites were compared with their bulk counterparts with same composition in detail.

  5. A new approach for modeling and analysis of molten salt reactors using SCALE

    SciTech Connect

    Powers, J. J.; Harrison, T. J.; Gehin, J. C.

    2013-07-01

    The Office of Fuel Cycle Technologies (FCT) of the DOE Office of Nuclear Energy is performing an evaluation and screening of potential fuel cycle options to provide information that can support future research and development decisions based on the more promising fuel cycle options. [1] A comprehensive set of fuel cycle options are put into evaluation groups based on physics and fuel cycle characteristics. Representative options for each group are then evaluated to provide the quantitative information needed to support the valuation of criteria and metrics used for the study. Included in this set of representative options are Molten Salt Reactors (MSRs), the analysis of which requires several capabilities that are not adequately supported by the current version of SCALE or other neutronics depletion software packages (e.g., continuous online feed and removal of materials). A new analysis approach was developed for MSR analysis using SCALE by taking user-specified MSR parameters and performing a series of SCALE/TRITON calculations to determine the resulting equilibrium operating conditions. This paper provides a detailed description of the new analysis approach, including the modeling equations and radiation transport models used. Results for an MSR fuel cycle option of interest are also provided to demonstrate the application to a relevant problem. The current implementation is through a utility code that uses the two-dimensional (2D) TRITON depletion sequence in SCALE 6.1 but could be readily adapted to three-dimensional (3D) TRITON depletion sequences or other versions of SCALE. (authors)

  6. Molten salt synthesis and luminescent properties of YVO4:Ln (Ln = Eu3+, Dy3+) nanophosphors.

    PubMed

    Liu, Chenglu; Wang, Fang; Jia, Peiyun; Lin, Jun; Zhou, Zhiqiang

    2012-03-01

    Eu3+ and Dy(3+)-doped YVO4 nanocrystallites were successfully prepared at 400 degrees C in equal moles of NaNO3 and KNO3 molten salts. X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, transmission electronic microscopy (TEM), photoluminescence (PL) spectrum and lifetime were used to characterize the nanocrystallites. XRD results demonstrate that NaOH concentration and annealing temperature play important roles in phase purity and crystallinity of the nanocrystallites, the optimum NaOH concentration and annealing temperature being 6:40 and 400 degrees C respectively. TEM micrographs show the nanocrystallites are well crystallized with a cubic morphology in an average grain size of about 18 nm. Upon excitation of the vanadate group at 314 nm, YVO4:Eu3+ and YVO4:Dy3+ nanocrystallites exhibit the characteristic emission of Eu3+ and Dy3+, which indicates that there is an energy transfer from the vanadate group to the rare earth ions. Moreover, the structure and luminescent properties of the nanocrystallites were compared with their bulk counterparts with same composition in detail.

  7. Electrochemical study of the properties of indium in room temperature chloroaluminate molten salts

    SciTech Connect

    Liu, J.S.Y.; Sun, I.W.

    1997-01-01

    The electrochemistry of indium was studied with voltammetry and chronoamperometry at glassy carbon, tungsten, and nickel electrodes in the basic and acidic aluminum chloride-1,2-dimethyl-3-propylimidazolium chloride molten salt at 27 C. In the basic melt, In(III) is complexed as [InCl{sub 5}]{sup 2{minus}}, which could be reduced to indium metal through a three-electron reduction process. The electrodeposition of indium on glassy carbon and tungsten electrodes involves progressive three-dimensional nucleation on a finite number of active sites with diffusion-controlled growth of the nuclei. The electrodeposition of indium metal on a nickel electrode entails progressive three-dimensional nucleation on a large number of active sites. The formal potentials of the In(III)/In couple in the 44.4 to 55.6 and 49.0 to 51.0 mole percent (m/o) melts are {minus}1.096 and {minus}1.009 V, respectively, vs. Al(III)Al in the 66.7 to 33.3 m/o.

  8. Uncertainty Studies of Real Anode Surface Area in Computational Analysis for Molten Salt Electrorefining

    SciTech Connect

    Sungyeol Choi; Jaeyeong Park; Robert O. Hoover; Supathorn Phongikaroon; Michael F. Simpson; Kwang-Rag Kim; Il Soon Hwang

    2011-09-01

    This study examines how much cell potential changes with five differently assumed real anode surface area cases. Determining real anode surface area is a significant issue to be resolved for precisely modeling molten salt electrorefining. Based on a three-dimensional electrorefining model, calculated cell potentials compare with an experimental cell potential variation over 80 hours of operation of the Mark-IV electrorefiner with driver fuel from the Experimental Breeder Reactor II. We succeeded to achieve a good agreement with an overall trend of the experimental data with appropriate selection of a mode for real anode surface area, but there are still local inconsistencies between theoretical calculation and experimental observation. In addition, the results were validated and compared with two-dimensional results to identify possible uncertainty factors that had to be further considered in a computational electrorefining analysis. These uncertainty factors include material properties, heterogeneous material distribution, surface roughness, and current efficiency. Zirconium's abundance and complex behavior have more impact on uncertainty towards the latter period of electrorefining at given batch of fuel. The benchmark results found that anode materials would be dissolved from both axial and radial directions at least for low burn-up metallic fuels after active liquid sodium bonding was dissolved.

  9. Primary and secondary room temperature molten salt electrochemical cells. Rept. for Jun 84-Mar 85

    SciTech Connect

    Reynolds, G.F.; Dymek, C.J.

    1985-01-01

    Three primary cells (a, b, and c) and two secondary cell candidates (d and e) were examined using room-temperature molten salts as electrolytes in each case: (a) A1 anode / A1Cl3-MEIC1 (N=0.37) // FeCl3-MEIC1 (N=0.33) / W cathode (b) A1 anode / A1Cl3-MEIC1 (N=0.37) // WCL6-MEIC1 (N=0.33) / W cathode (c) A1 anode / A1Br3-MEIBr (N=0.33) / BR2 / RVC, Pt cathode (d) Zn anode / A1Cl3-MEIC1 (N=0.33) // A1Cl3-MEIC1 (N=0.60) / A1 cathode (e) Cd anode / A1Cl3-MEIC1 (N=0.33) // A1Cl3-MEIC1 (N=0.60) / A1 cathode. All cells except (c) used electrolytes containing 1-methyl-3-ethylimidazolium chloride (MEIC1), where N is the mole fraction of aluminum halide in the melt. Cell (c) used electrolytes containing 1-methyl-3-ethylimidazolium bromide (MEIBr). An IONAC anion exchange membrane separated the anolyte and catholyte solutions in cells (a) and (b), while in cells (d) and (e) a NAFION cation exchange membrane separated the anolyte and catholyte solutions. In cell (c) a phase boundary separated the anolyte and catholyte solutions, with reticulated vitreous carbon (RVC) acting as the anode current carrier.

  10. Economic evaluation of solar-only and hybrid power towers using molten salt technology

    SciTech Connect

    Kolb, G.J.

    1996-12-01

    Several hybrid and solar-only configurations for molten-salt power towers were evaluated with a simple economic model, appropriate for screening analysis. The solar specific aspects of these plants were highlighted. In general, hybrid power towers were shown to be economically superior to solar-only plants with the same field size. Furthermore, the power-booster hybrid approach was generally preferred over the fuel-saver hybrid approach. Using today`s power tower technology, economic viability for the solar power-boost occurs at fuel costs in the neighborhood of $2.60/MBtu to $4.40/ MBtu (low heating value) depending on whether coal-based or gas-turbine-based technology is being offset. The cost Of CO[sub 2] avoidance was also calculated for solar cases in which the fossil fuel cost was too low for solar to be economically viable. The avoidance costs are competitive with other proposed methods of removing CO[sub 2] from fossil-fired power plants.

  11. Radon Measurements at the Molten Salt Reactor Experiment (MSRE) Facility from August 1997 through April 1998

    SciTech Connect

    Coleman, R.L.

    1999-04-01

    From August 1997 through April 1998, radon and radon progeny measurements were collected at the Molten Salt Reactor Experiment (MSRE) facility at Oak Ridge National Laboratory. The purpose of the measurements was to determine the baseline concentrations of 222Rn (radon), 220Rn (thoron), and their progeny in the air at selected points with emphasis on the characterization of 220Rn and its daughter products in the high bay area. The daughter product concentrations ranged from the equivalent of approximately 0.001 times the derived air concentration (DAC) of the isotope mixture up to 0.09 DAC, with the highest measurements occurring inside the pit above the equipment drain tank cell. Direct radon measurements in this area indicated a relatively constant 222Rn concentration with an average value of 1.4 pCi/L and a 220Rn concentration that fluctuated from <1 pCi/L up to about 30 pCi/L. Measurements were also collected inside the vent house adjacent to building 7503. The progeny concentrations inside the room ranged from an equivalent of about 0.002 DAC up to 0.01 DAC. The direct radon measurements in the vent house indicated a relatively constant 222Rn concentration with an average value of 0.7 pCi/L while the 220Rn concentration varied appreciably and ranged from <0.5 pCi/L up to almost 200 pCi/L with an average concentration of 18 pCi/L.

  12. Molten salt synthesis and luminescent properties of YVO4:Ln (Ln = Eu3+, Dy3+) nanophosphors.

    PubMed

    Liu, Chenglu; Wang, Fang; Jia, Peiyun; Lin, Jun; Zhou, Zhiqiang

    2012-01-01

    Eu3+ and Dy(3+)-doped YVO4 nanocrystallites were successfully prepared at 400 degrees C in equal moles of NaNO3 and KNO3 molten salts. X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, transmission electronic microscopy (TEM), photoluminescence (PL) spectrum and lifetime were used to characterize the nanocrystallites. XRD results demonstrate that NaOH concentration and annealing temperature play important roles in phase purity and crystallinity of the nanocrystallites, the optimum NaOH concentration and annealing temperature being 6:40 and 400 degrees C respectively. TEM micrographs show the nanocrystallites are well crystallized with a cubic morphology in an average grain size of about 18 nm. Upon excitation of the vanadate group at 314 nm, YVO4:Eu3+ and YVO4:Dy3+ nanocrystallites exhibit the characteristic emission of Eu3+ and Dy3+, which indicates that there is an energy transfer from the vanadate group to the rare earth ions. Moreover, the structure and luminescent properties of the nanocrystallites were compared with their bulk counterparts with same composition in detail. PMID:22523959

  13. Molten salt extraction process for the recovery of valued transition metals from land-based and deep-sea minerals

    DOEpatents

    Maroni, Victor A.; von Winbush, Samuel

    1988-01-01

    A process for extracting transition metals and particularly cobalt and manganese together with iron, copper and nickel from low grade ores (including ocean-floor nodules) by converting the metal oxides or other compositions to chlorides in a molten salt, and subsequently using a combination of selective distillation at temperatures below about 500.degree. C., electrolysis at a voltage not more negative than about -1.5 volt versus Ag/AgCl, and precipitation to separate the desired manganese and cobalt salts from other metals and provide cobalt and manganese in metallic forms or compositions from which these metals may be more easily recovered.

  14. Molten salt extraction process for the recovery of valued transition metals from land-based and deep-sea minerals

    DOEpatents

    Maroni, V.A.; von Winbush, S.

    1987-05-01

    A process for extracting transition metals and particularly cobalt and manganese together with iron, copper and nickel from low grade ores (including ocean-floor nodules) by converting the metal oxides or other compositions to chlorides in a molten salt, and subsequently using a combination of selective distillation at temperatures below about 500/degree/C, electrolysis at a voltage not more negative that about /minus/1.5 volt versus Ag/AgCl, and precipitation to separate the desired manganese and cobalt salts from other metals and provide cobalt and manganese in metallic forms or compositions from which these metals may be more easily recovered.

  15. A molecular dynamics study of the influence of ionic charge distribution on the dynamics of a molten salt.

    PubMed

    Li, Hualin; Kobrak, Mark N

    2009-11-21

    The distribution of charge in an ion of a fused salt is known to be an important determinant of liquid dynamics. However, the details of this relationship remain poorly understood. We present the results of molecular dynamics simulations on a model molten salt system and show that changes in the distribution of ionic charge can have a profound effect on liquid dynamics. In particular, we observe complex relationships between the distribution of charge, the rate of ionic rotation, and the translational diffusion of ions in the liquid.

  16. Front-end and back-end electrochemistry of molten salt in accelerator-driven transmutation systems

    SciTech Connect

    Williamson, M.A.; Venneri, F.

    1995-07-01

    The objective of this work is to develop preparation and clean-up processes for the fuel and carrier salt in the Los Alamos Accelerator-Driven Transmutation Technology molten salt nuclear system. The front-end or fuel preparation process focuses on the removal of fission products, uranium, and zirconium from spent nuclear fuel by utilizing electrochemical methods (i.e., electrowinning). The same method provides the separation of the so-called noble metal fission products at the back-end of the fuel cycle. Both implementations would have important diversion safeguards. The proposed separation processes and a thermodynamic analysis of the electrochemical separation method are presented.

  17. Molten Salt Mixture Properties (KF-ZrF4 and KCl-MgCl2) for Use in RELAP5-3D for High Temperature Reactor Application

    SciTech Connect

    N. A. Anderson; P. Sabharwall

    2012-06-01

    Molten salt coolants are being investigated as primary coolants for a fluoride high-temperature reactor and as secondary coolants for high temperature reactors such as the next generation nuclear plant. This work provides a review of the thermophysical properties of candidate molten salt coolants for use as a secondary heat transfer medium from a high temperature reactor to a processing plant. The molten salts LiF-NaF-KF, KF-ZrF4 and KCl-MgCl2 were considered for use in the secondary coolant loop. The thermophysical properties necessary to add the molten salts KF-ZrF4 and KCl-MgCl2 to RELAP5-3D were gathered for potential modeling purposes. The properties of the molten salt LiF-NaF-KF were already available in RELAP5-3D. The effect that the uncertainty in individual properties had on the Nusselt number was evaluated. This uncertainty in the Nusselt number was shown to be nearly independent of the molten salt temperature.

  18. Identification and evaluation of alternatives for the disposition of fluoride fuel and flush salts from the molten salt reactor experiment at Oak Ridge National Laboratory, Oak Ridge, Tennessee

    SciTech Connect

    1996-08-15

    This document presents an initial identification and evaluation of the alternatives for disposition of the fluoride fuel and flush salts stored in the drain tanks at the Molten Salt Reactor Experiment (MSRE) at Oak Ridge National Laboratory (ORNL). It will serve as a resource for the U.S. Department of Energy contractor preparing the feasibility study for this activity under the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA). This document will also facilitate further discussion on the range of credible alternatives, and the relative merits of alternatives, throughout the time that a final alternative is selected under the CERCLA process.

  19. Evaluation of the Molten Salt Reactor Experiment drain tanks for reuse in salt disposal, Oak Ridge National Laboratory, Oak Ridge, Tennessee

    SciTech Connect

    1998-05-01

    This report was prepared to identify the source documentation used to evaluate the drain tanks in the Molten Salt Reactor Experiment (MSRE) at Oak Ridge National Laboratory (ORNL). The evaluation considered the original quality of the tanks, their service history, and their intended use during the removal of fluoride salts. It also includes recommendations for a quality verification plan. The estimates of corrosion damage to the salt containing system at the MSRE are low enough to lend optimism that the system will be fit for its intended use, which is disposal of the salt by transferring it to transport containers. The expected corrosion to date is estimated between 10 and 50 mil, or 2 to 10% of the shell wall. The expected corrosion rate when the tanks are used to remove the salt at 110 F is estimated to be .025 to 0.1 mil per hour of exposure to HF and molten salt. To provide additional assurance that the estimates of corrosion damage are accurate, cost effective nondestructive examination (NDE) has been recommended. The NDE procedures are compared with industry standards and give a perspective for the extent of additional measures taken in the recommendation. A methodology for establishing the remaining life has been recommended, and work is progressing towards providing an engineering evaluation based upon thickness and design conditions for the future use of the tanks. These extra measures and the code based analysis will serve to define the risk of salt or radioactive gases leaking during processing and transfer of the salt as acceptable.

  20. Reductive smelting of spent lead-acid battery colloid sludge in a molten Na2CO3 salt

    NASA Astrophysics Data System (ADS)

    Hu, Yu-jie; Tang, Chao-bo; Tang, Mo-tang; Chen, Yong-ming

    2015-08-01

    Lead extraction from spent lead-acid battery paste in a molten Na2CO3 salt containing ZnO as a sulfur-fixing agent was studied. Some influencing factors, including smelting temperature, reaction time, ZnO and salt dosages, were investigated in detail using single-factor experiments. The optimum conditions were determined as follows: T = 880°C; t = 60 min; Na2CO3/paste mass ratio = 2.8:1; and the ZnO dosage is equal to the stoichiometric requirement. Under the optimum conditions, the direct recovery rate of lead reached 98.14%. The results suggested that increases in temperature and salt dosage improved the direct recovery rate of lead. XRD results and thermodynamic calculations indicated that the reaction approaches of lead and sulfur were PbSO4→Pb and PbSO4→ZnS, respectively. Sulfur was fixed in the form of ZnS, whereas the molten salt did not react with other components, serving only as a reaction medium.

  1. Physical chemistry of molten salt batteries. Final report for period October 1, 1979-September 30, 1980. Current-induced composition gradients in molten LiCl-KCl

    SciTech Connect

    Braunstein, J.; Cantor, S.; Vallet, C.E.

    1981-03-01

    Current induced composition gradients were demonstrated in the molten LiCl-KCl eutectic mixture, the electrolyte of an LiAl/LiCl-KCl/FeS/sub x/ battery. The gradients were produced by electrolysis of the salt between LiAl electrodes at currents of 50 to 100 mA cm/sup -2/, and quenching. Analysis of composition profiles in quenched samples was by atomic absorption spectroscopy, which gave good precision, and by x-ray fluorescence spectroscopy in a scanning electron microscope (SEM/EDX), which gave good distance resolution. Work is in progress to improve the precision of the SEM/EDX measurements to that demonstrated in model systems.

  2. Effects of arginine on rabbit muscle creatine kinase and salt-induced molten globule-like state.

    PubMed

    Ou, Wen-bin; Wang, Ri-Sheng; Lu, Jie; Zhou, Hai-Meng

    2003-11-01

    The arginine (Arg)-induced unfolding and the salt-induced folding of creatine kinase (CK) have been studied by measuring enzyme activity, fluorescence emission spectra, native polyacrylamide gel electrophoresis and size exclusion chromatography (SEC). The results showed that Arg caused inactivation and unfolding of CK, but there was no aggregation during CK denaturation. The kinetics of CK unfolding followed a one-phase process. At higher concentrations of Arg (>160 mM), the CK dimers were fully dissociated, the alkali characteristic of Arg mainly led to the dissociation of dimers, but not denaturation effect of Arg's guanidine groups on CK. The inactivation of CK occurred before noticeable conformational changes of the whole molecules. KCl induced monomeric and dimeric molten globule-like states of CK denatured by Arg. These results suggest that as a protein denaturant, the effect of Arg on CK differed from that of guanidine and alkali, its denaturation for protein contains the double effects, which acts not only as guanidine hydrochloride but also as alkali. The active sites of CK have more flexibility than the whole enzyme conformation. Monomeric and dimeric molten globule-like states of CK were formed by the salt inducing in 160 and 500 mM Arg H(2)O solutions, respectively. The molten globule-like states indicate that monomeric and dimeric intermediates exist during CK folding. Furthermore, these results also proved the orderly folding model of CK.

  3. Laminar iridium coating produced by pulse current electrodeposition from chloride molten salt

    NASA Astrophysics Data System (ADS)

    Zhu, Li'an; Bai, Shuxin; Zhang, Hong; Ye, Yicong

    2013-10-01

    Due to the unique physical and chemical properties, Iridium (Ir) is one of the most promising oxidation-resistant coatings for refractory materials above 1800 °C in aerospace field. However, the Ir coatings prepared by traditional methods are composed of columnar grains throughout the coating thickness. The columnar structure of the coating is considered to do harm to its oxidation resistance. The laminar Ir coating is expected to have a better high-temperature oxidation resistance than the columnar Ir coating does. The pulse current electrodeposition, with three independent parameters: average current density (Jm), duty cycle (R) and pulse frequency (f), is considered to be a promising method to fabricate layered Ir coating. In this study, laminar Ir coatings were prepared by pulse current electrodeposition in chloride molten salt. The morphology, roughness and texture of the coatings were determined by scanning electron microscope (SEM), profilometer and X-ray diffraction (XRD), respectively. The results showed that the laminar Ir coatings were composed of a nucleation layer with columnar structure and a growth layer with laminar structure. The top surfaces of the laminar Ir coatings consisted of cauliflower-like aggregates containing many fine grains, which were separated by deep grooves. The laminar Ir coating produced at the deposition condition of 20 mA/cm2 (Jm), 10% (R) and 6 Hz (f) was quite smooth (Ra 1.01 ± 0.09 μm) with extremely high degree of preferred orientation of <1 1 1>, and its laminar structure was well developed with clear boundaries and uniform thickness of sub-layers.

  4. Measurements and Analysis of Oxygen Bubble Distributions in LiCl-KCl Molten Salt

    SciTech Connect

    Ryan W. Bezzant; Supathorn Phongikaroon; Michael F. Simpson

    2013-03-01

    Transparent system experimental studies have been performed to provide measurement and analysis of oxygen bubble distributions and mass transfer coefficients at different sparging rates ranging from 0.05 to 0.20 L/min in LiCl-KCl molten salt at 500 degrees C using a high-speed digital camera and an oxygen sensor. The results reveal that bubble sizes and rise velocities increased with an increase in oxygen sparging rate. The bubbles observed were ellipsoidal in shape, and an equivalent diameter based on the ellipsoid volume was calculated. The average equivalent bubble diameters at 500 degrees C and these oxygen sparging rates range from 2.63 to 4.07 mm. Results show that the bubble equivalent diameters at each respective sparging rate are normally distributed. A Fanning friction factor correlation was produced to predict a bubble’s rise velocity based on its equivalent diameter. The oxygen mass transfer coefficients for four sparging rates were calculated using the oxygenation model. These calculated values were within the order of magnitude of 10-2 cm/sec and followed a decreasing trend corresponding to an increasing bubble size and sparging rate. The diffusivities were calculated based on two different types of mechanisms, one based on physics of the bubbles and the other on systematic properties. The results reveal that diffusivity values calculated from bubble physics are 1.65 to 8.40 x 10-5 cm2/sec, which are within the range suggested by literature for gases in liquids of a similar viscosity.

  5. Tungsten coatings electro-deposited on CFC substrates from oxide molten salt

    NASA Astrophysics Data System (ADS)

    Sun, Ningbo; Zhang, Yingchun; Lang, Shaoting; Jiang, Fan; Wang, Lili

    2014-12-01

    Tungsten is considered as plasma facing material in fusion devices because of its high melting point, its good thermal conductivity, its low erosion rate and its benign neutron activation properties. On the other hand, carbon based materials like C/C fiber composites (CFC) have been used for plasma facing materials (PFMs) due to their high thermal shock resistance, light weight and high strength. Tungsten coatings on CFC substrates are used in the JET divertor in the frame of the JET ITER-like wall project, and have been prepared by plasma spray (PS) and other techniques. In this study, tungsten coatings were electro-deposited on CFC from Na2WO4-WO3 molten salt under various deposition parameters at 900 °C in air. In order to obtain tungsten coatings with excellent performance, the effects of pulse duration ratio and pulse current density on microstructures and crystal structures of tungsten coatings were investigated by X-ray diffraction (XRD, Rigaku Industrial Co., Ltd., D/MAX-RB) and a scanning electron microscope (SEM, JSM 6480LV). It is found that the pulsed duration ratio and pulse current density had a significant influence on tungsten nucleation and electro-crystallization phenomena. SEM observation revealed that intact, uniform and dense tungsten coatings formed on the CFC substrates. Both the average grain size and thickness of the coating increased with the pulsed current density. The XRD results showed that the coatings consisted of a single phase of tungsten with the body centered cubic (BCC) structure. The oxygen content of electro-deposited tungsten coatings was lower than 0.05%, and the micro-hardness was about 400 HV.

  6. The electrochemistry of metals in room-temperature chloroaluminate molten salts

    SciTech Connect

    Xu, Xiao-Hong.

    1992-01-01

    The room-temperature chloroaluminate molten salt, aluminum chloride-1-methyl-3-ethylimidazolium chloride has proven to be useful electrolyte for the electrodeposition and electrodissolution of metals. The electrodeposition of lead, tin, silver, gold, and mercury was studied in this melt. Evidence for the underpotential deposition of lead and silver in acidic (66.7-33.3 mol%) melt and tin in acidic and basic (44.4-55.6 mol%) melt was found at polycrystalline gold. Nucleation overpotentials were observed for the deposition of mercury on gold in basic melt. The deposition of lead and silver from acidic melt and the deposition of gold from basic melt on glassy carbon involves progressive 3-D nucleation on a large number of active sites with hemispherical diffusion-controlled growth of the nuclei. The deposition of tin and and mercury from acidic melt exhibits progressive 3-D nucleation on a finite number of active sites. The deposition of tin and mercury from basic melt on glassy carbon involves instantaneous 3-D nucleation. The electrode-position of lead and silver from acidic melt on tungsten involves instantaneous 3-D nucleation, whereas the electrodeposition of gold and mercury from basic melt exhibits 3-D progressive nucleation. The deposition of lead and silver from acidic melt and the deposition of tin from both acidic and basic melt on platinum does not exhibit obvious evidence for either UPD or nucleation. The electrodeposition of gold and mercury on platinum from basic melt involves progressive 3-D nucleation. The voltammetric oxidation of Sn(II) to Sn(IV) is hindered by the weak adsorption of Sn(II). Sn(IV) is complexed as [SnCl[sub 6

  7. Facile molten salt synthesis of Li2NiTiO4 cathode material for Li-ion batteries.

    PubMed

    Wang, Yanming; Wang, Yajing; Wang, Fei

    2014-01-01

    Well-crystallized Li2NiTiO4 nanoparticles are rapidly synthesized by a molten salt method using a mixture of NaCl and KCl salts. X-ray diffraction pattern and scanning electron microscopic image show that Li2NiTiO4 has a cubic rock salt structure with an average particle size of ca. 50 nm. Conductive carbon-coated Li2NiTiO4 is obtained by a facile ball milling method. As a novel 4 V positive cathode material for Li-ion batteries, the Li2NiTiO4/C delivers high discharge capacities of 115 mAh g(-1) at room temperature and 138 mAh g(-1) and 50°C, along with a superior cyclability. PMID:24855459

  8. Program management plan for the Molten Salt Reactor Experiment Remediation Project at Oak Ridge National Laboratory, Oak Ridge, Tennessee

    SciTech Connect

    1996-09-01

    The primary mission of the Molten Salt Reactor Experiment (MSRE) Remediation Project is to effectively implement the risk-reduction strategies and technical plans to stabilize and prevent further migration of uranium within the MSRE facility, remove the uranium and fuel salts from the system, and dispose of the fuel and flush salts by storage in appropriate depositories to bring the facility to a surveillance and maintenance condition before decontamination and decommissioning. This Project Management Plan (PMP) for the MSRE Remediation Project details project purpose; technical objectives, milestones, and cost objectives; work plan; work breakdown structure (WBS); schedule; management organization and responsibilities; project management performance measurement planning, and control; conduct of operations; configuration management; environmental, safety, and health compliance; quality assurance; operational readiness reviews; and training.

  9. Facile molten salt synthesis of Li2NiTiO4 cathode material for Li-ion batteries.

    PubMed

    Wang, Yanming; Wang, Yajing; Wang, Fei

    2014-01-01

    Well-crystallized Li2NiTiO4 nanoparticles are rapidly synthesized by a molten salt method using a mixture of NaCl and KCl salts. X-ray diffraction pattern and scanning electron microscopic image show that Li2NiTiO4 has a cubic rock salt structure with an average particle size of ca. 50 nm. Conductive carbon-coated Li2NiTiO4 is obtained by a facile ball milling method. As a novel 4 V positive cathode material for Li-ion batteries, the Li2NiTiO4/C delivers high discharge capacities of 115 mAh g(-1) at room temperature and 138 mAh g(-1) and 50°C, along with a superior cyclability.

  10. Radiation Damage and Tritium Breeding Study in a Fusion Reactor Using a Liquid Wall of Various Thorium Molten Salts

    NASA Astrophysics Data System (ADS)

    Übeyli, Mustafa

    2007-12-01

    A new magnetic fusion reactor design, called APEX uses a liquid wall between fusion plasma and solid first wall to reach high neutron wall loads and eliminate the replacement of the first wall structure during the reactor's operation due to the radiation damage. In this paper, radiation damage behavior of the inboard and outboard first walls made of a ferritic steel, 9Cr-2WVTa, in the APEX blanket using various thorium molten salts, 75% LiF-25% ThF4, 75% LiF-24% ThF4-1% 233UF4 and 75% LiF-23% ThF4-2% 233UF4 was investigated. Furthermore, tritium breeding potential of these salts in such a blanket was also examined. Computations were carried out using the code Scale 4.3 by solving Boltzmann neutron transport equation. Numerical results brought out that only the liquid wall containing the molten salt, 75% LiF-23% ThF4-2% 233UF4 and having a thickness of ≥38 cm would be suitable to be used in the APEX reactor with respect to radiation damage criteria for the first wall structures and tritium self-sufficiency for the (DT) fusion driver.

  11. Comparison of corrosion performance of grade 316 and grade 347H stainless steels in molten nitrate salt

    NASA Astrophysics Data System (ADS)

    Trent, M. C.; Goods, S. H.; Bradshaw, R. W.

    2016-05-01

    Stainless steel samples machined from SA-312 TP316 and SA-213 TP347H pipe were exposed to a molten nitrate salt environment at 600°C (1112°F) for up to 3000 hours in order to generate corrosion rates for use in concentrated solar power (CSP) facilities. Descaled weight loss measurements were made at 1000, 2000, and 3000 hours, with optical and scanning electron microscopy being performed on samples at the longest exposure time. The 316 and 347H alloys exhibited metal losses of 4.4 and 4.8 um respectively at 3000 hours. A linear fit to the data sets yielded annualized metal loss rates of 8.4 and 8.8 um/yr. The oxides were relatively uniform in thickness and multilayered. The inner layer consisted of a (Fe, Cr)-spinel with appreciable amounts of Mn while the outer layer was an oxide composed of only Fe. No pitting, intergranular attack, or other localized attack was found, despite the presence of a sensitized microstructure in both alloys and chloride impurity in the salt mixture. The observations presented here indicate that the two alloys perform quite comparably with respect to molten salt-induced corrosion and in that regard; either would be expected to perform satisfactorily in the intended application.

  12. Molten salt synthesis of nanocrystalline phase of high dielectric constant material CaCu3Ti4O12.

    PubMed

    Prakash, B Shri; Varma, K B R

    2008-11-01

    Nanocrystalline powders of giant dielectric constant material, CaCu3Ti4O12 (CCTO), have been prepared successfully by the molten salt synthesis (MSS) using KCl at 750 degrees C/10 h, which is significantly lower than the calcination temperature (approximately 1000 degrees C) that is employed to obtain phase pure CCTO in the conventional solid-state reaction route. The water washed molten salt synthesized powder, characterized by X-ray powder diffraction (XRD), Scanning electron microscopy (SEM), and Transmission electron microscopy (TEM) confirmed to be a phase pure CCTO associated with approximately 150 nm sized crystallites of nearly spherical shape. The decrease in the formation temperature/duration of CCTO in MSS method was attributed to an increase in the diffusion rate or a decrease in the diffusion length of reacting ions in the molten salt medium. As a consequence of liquid phase sintering, pellets of as-synthesized KCl containing CCTO powder exhibited higher sinterability and grain size than that of KCl free CCTO samples prepared by both MSS method and conventional solid-state reaction route. The grain size and the dielectric constant of KCl containing CCTO ceramics increased with increasing sintering temperature (900 degrees C-1050 degrees C). Indeed the dielectric constants of these ceramics were higher than that of KCl free CCTO samples prepared by both MSS method and those obtained via the solid-state reaction route and sintered at the same temperature. Internal barrier layer capacitance (IBLC) model was invoked to correlate the observed dielectric constant with the grain size in these samples.

  13. The preliminary analysis on the steady-state and kinetic features of the molten salt pebble-bed reactor

    SciTech Connect

    Xia, B.; Lu, Y.

    2012-07-01

    A novel design concept of molten salt pebble-bed reactor with an ultra-simplified integral primary circuit called 'Nuclear Hot Spring' has been proposed, featured by horizontal coolant flow in a deep pool pebble-bed reactor, providing 'natural safety' features with natural circulation under full power operation and less expensive primary circuit arrangement. In this work, the steady-state physical properties of the equilibrium state of the molten salt pebble-bed reactor are calculated by using the VSOP code, and the steady-state thermo-hydraulic analysis is carried out based on the approximation of absolutely horizontal flow of the coolant through the core. A new concept of 2-dimensional, both axial and radial, multi-pass on-line fuelling scheme is presented. The result reveals that the radial multi-pass scheme provides more flattened power distribution and safer temperature distribution than the one-pass scheme. A parametric analysis is made corresponding to different pebble diameters, the key parameter of the core resistance and the temperature at the pebble center. It is verified that within a wide range of pebble diameters, the maximum pebble center temperatures are far below the safety limit of the fuel, and the core resistance is considerably less than the buoyant force, indicating that the natural circulation under full power operation is achievable and the ultra-simplified integral primary circuit without any pump is possible. For the kinetic properties, it is verified that the negative temperature coefficient is achieved in sufficient under-moderated condition through the preliminary analysis on the temperature coefficients of fuel, coolant and moderator. The requirement of reactivity compensation at the shutdown stages of the operation period is calculated for the further studies on the reactivity control. The molten salt pebble-bed reactor with horizontal coolant flow can provide enhanced safety and economical features. (authors)

  14. High-value use of weapons-plutonium by burning in molten salt accelerator-driven subcritical systems or reactors

    SciTech Connect

    Bowman, C.D.; Venneri, F.

    1993-11-01

    The application of thermal-spectrum molten-salt reactors and accelerator-driven subcritical systems to the destruction of weapons-return plutonium is considered from the perspective of deriving the maximum societal benefit. The enhancement of electric power production from burning the fertile fuel {sup 232}Th with the plutonium is evaluated. Also the enhancement of destruction of the accumulated waste from commercial nuclear reactors is considered using the neutron-rich weapons plutonium. Most cases examined include the concurrent transmutation of the long-lived actinide and fission product waste ({sup 99}Tc, {sup 129}I, {sup 135}Cs, {sup 126}Sn and {sup 79}Se).

  15. Thermal Stability of FeS2 Cathode Material in "Thermal" Batteries: Effect of Dissolved Oxides in Molten Salt Electrolytes

    NASA Astrophysics Data System (ADS)

    Masset, Patrick J.

    2008-09-01

    The thermal stability of FeS2 cathode material for thermal batteries is investigated in the LiCl-KCl eutectic containing up to 10 wt% Li2O (used as anti-peak). The results show that the decomposition of pyrite shifts to higher temperatures in the presence of molten salts as the S2 gas is repressed by the liquid phase. For high lithium oxide contents the decomposition temperature of pyrite decreases by 100 °C. In addition Li2FeS2 as reaction product is evidenced whereas Li3Fe2S4 is expected from literature data.

  16. Synthesis of functional carbon nanospheres by a composite-molten-salt method and amperometric sensing of hydrogen peroxide.

    PubMed

    Wang, Xue; Hu, Chenguo; Xiong, Yufeng; Zhang, Cuiling

    2013-02-01

    Functional carbon nanospheres have been synthesized from analytically pure glucose by a composite-molten-salt (CMS) method. Field emission scanning electron microscopy, transmission electron microscopy, Raman and Fourier transformation infra-red spectroscopy indicate the carbon nanospheres are solid, bond hybridisation (sp2/sp3) and with many functional groups on their surfaces. Amperometric sensor based on the synthesized carbon nanospheres have been fabricated without pretreatment or modification. The detection of hydrogen peroxide exhibits high sensitivity and good selectivity. The electrochemical measurement of these nanospheres demonstrates much superior performance to those of the carbon nanospheres synthesized by hydrothermal method.

  17. Corrosion of 316 stainless steel in high temperature molten Li2BeF4 (FLiBe) salt

    NASA Astrophysics Data System (ADS)

    Zheng, Guiqiu; Kelleher, Brian; Cao, Guoping; Anderson, Mark; Allen, Todd; Sridharan, Kumar

    2015-06-01

    In support of structural material development for the fluoride-salt-cooled high-temperature reactor (FHR), corrosion tests of 316 stainless steel were performed in the potential primary coolant, molten Li2BeF4 (FLiBe) at 700 °C for an exposure duration up to 3000 h. Tests were performed in both 316 stainless steel and graphite capsules. Corrosion in both capsule materials occurred by the dissolution of chromium from the stainless steel into the salt which led to the depletion of chromium predominantly along the grain boundaries of the test samples. The samples tested in graphite capsules showed a factor of two greater depth of corrosion attack as measured in terms of chromium depletion, compared to those tested in 316 stainless steel capsules. The samples tested in graphite capsules showed the formation of Cr7C3 particulate phases throughout the depth of the corrosion layer. Samples tested in both types of capsule materials showed the formation of MoSi2 phase due to increased activity of Mo and Si as a result of Cr depletion, and furthermore corrosion promoted the formation of a α-ferrite phase in the near-surface regions of the 316 stainless steel. Based on the corrosion tests, the corrosion attack depth in FLiBe salt was predicted as 17.1 μm/year and 31.2 μm/year for 316 stainless steel tested in 316 stainless steel and in graphite capsules respectively. It is in an acceptable range compared to the Hastelloy-N corrosion in the Molten Salt Reactor Experiment (MSRE) fuel salt.

  18. Thermodynamic Assessment of Hot Corrosion Mechanisms of Superalloys Hastelloy N and Haynes 242 in Eutectic Mixture of Molten Salts KF and ZrF4

    SciTech Connect

    Michael V. Glazoff

    2012-02-01

    The KF - ZrF4 system was considered for the application as a heat exchange agent in molten salt nuclear reactors (MSRs) beginning with the work carried out at ORNL in early fifties. Based on a combination of excellent properties such as thermal conductivity, viscosity in the molten state, and other thermo-physical and rheological properties, it was selected as one of possible candidates for the nuclear reactor secondary heat exchanger loop.

  19. Materials compatibility during the chlorination of molten CaCl/sub 2/. CaO salts. [CaCl/sub 2/. CaO salt

    SciTech Connect

    Rense, C.E.C.; Fife, K.W.; Bowersox, D.F.; Ferran, M.D.

    1987-01-01

    As part of our effort to develop a semicontinuous PuO/sub 2/ reduction process, we are investigating promising materials for containing a 900/sup 0/C molten CaCl/sub 2/ . CaO chlorination reaction. We want the material to contain this reaction and to be reusable. We tested candidate materials in a simulated salt (no plutonium) using anhydrous HCl as the chlorinating agent. Data are presented on the performance of 36 metals and alloys, 9 ceramics, and 3 coatings.

  20. Heat transfer and pressure drop measurements in an air/molten salt direct-contact heat exchanger

    SciTech Connect

    Bohn, M.S.

    1988-11-01

    This paper presents a comparison of experimental data with a recently published model of heat exchange in irrigated packed beds. Heat transfer and pressure drop were measured in a 150 mm (ID) column with a 610-mm bed of metal Pall rings. Molten nitrate salt and preheated air were the working fluids with a salt inlet temperature of approximately 440{degree}C and air inlet temperatures of approximately 230{degree}C. A comparison between the experimental data and the heat transfer model is made on the basis of heat transfer from the salt. For the range of air and salt flow rates tested, 0.3 to 1.2 kg/m{sup 2} s air flow and 6 to 18 kg/m{sup 2} s salt flow, the data agree with the model within 22% standard deviation. In addition, a model for the column pressure drop was validated, agreeing with the experimental data within 18% standard deviation over the range of column pressure drop from 40 to 1250 Pa/m. 25 refs., 7 figs., 2 tabs.

  1. Method to Reduce Molten Salt Penetration into Bulk Vitrification Refractory Materials

    SciTech Connect

    Bagaasen, Larry M.; Hrma, Pavel R.; Kim, Dong-Sang; Schweiger, Michael J.; Matyas, Josef; Rodriguez, Carmen P.; Witwer, Keith S.

    2008-01-18

    Bulk vitrification (BV) is a process that heats a feed material that consists of glass-forming solids and dried low-activity waste (LAW) in a disposable refractory-lined metal box using electrical power supplied through carbon electrodes. The feed is heated to the point that the LAW decomposes and combines with the solids to generate a vitreous waste form. However, the castable refractory block (CRB) portion of the refractory lining has sufficient porosity to allow the low-viscosity molten ionic salt (MIS), which contains technetium (Tc) in a soluble form, to penetrate the CRB. This limits the effectiveness of the final waste form. This paper describes tests conducted to develop a method aimed at reducing the quantities of soluble Tc in the CRB. Tests showed that MIS formed in significant quantities at temperatures above 300°C, remained stable until roughly 550°C where it began to thermally decompose, and was completely decomposed by 800°C. The estimated volume fraction of MIS in the feed was greater than 40%, and the CRB material contained 11 to 15% open porosity, a combination allowing a large quantity of MIS to migrate through the feed and penetrate the open porosity of the CRB. If the MIS is decomposed at temperatures below 300°C or can be contained in the feed until it fully decomposes by 800°C, MIS migration into the CRB can be avoided. Laboratory and crucible-scale experiments showed that a variety of methods, individually or in combination, can decrease MIS penetration into the CRB. Modifying the CRB to block MIS penetration was not deemed practical as a method to prevent the large quantities of MIS penetration seen in the full-scale tests, but it may be useful to reduce the impacts of lower levels of MIS penetration. Modifying the BV feed materials to better contain the MIS proved to be more successful. A series of qualitative and quantitative crucible tests were developed that allowed screening of feed modifications that might be used to reduce MIS

  2. Novel band gap-tunable K-Na co-doped graphitic carbon nitride prepared by molten salt method

    NASA Astrophysics Data System (ADS)

    Zhao, Jiannan; Ma, Lin; Wang, Haoying; Zhao, Yanfeng; Zhang, Jian; Hu, Shaozheng

    2015-03-01

    Novel band gap-tunable K-Na co-doped graphitic carbon nitride was prepared by molten salt method using melamine, KCl, and NaCl as precursor. X-ray diffraction (XRD), N2 adsorption, Scanning electron microscope (SEM), UV-vis spectroscopy, Photoluminescence (PL), and X-ray photoelectron spectroscopy (XPS) were used to characterize the prepared catalysts. The CB and VB potentials of graphitic carbon nitride could be tuned from -1.09 and +1.55 eV to -0.29 and +2.25 eV by controlling the weight ratio of eutectic salts to melamine. Besides, ions doping inhibited the crystal growth of graphitic carbon nitride, enhanced the surface area, and increased the separation rate of photogenerated electrons and holes. The visible-light-driven Rhodamine B (RhB) photodegradation and mineralization performances were significantly improved after K-Na co-doping.

  3. Zr electrorefining process for the treatment of cladding hull waste in LiCl-KCl molten salts

    SciTech Connect

    Lee, Chang Hwa; Lee, You Lee; Jeon, Min Ku; Kang, Kweon Ho; Choi, Yong Taek; Park, Geun Il

    2013-07-01

    Zr electrorefining for the treatment of Zircaloy-4 cladding hull waste is demonstrated in LiCl-KCl-ZrCl{sub 4} molten salts. Although a Zr oxide layer thicker than 5 μm strongly inhibits the Zr dissolution process, pre-treatment processes increases the dissolution kinetics. For 10 g-scale experiments, the purities of the recovered Zr were 99.54 wt.% and 99.74 wt.% for fresh and oxidized cladding tubes, respectively, with no electrical contact issue. The optimal condition for Zr electrorefining has been found to improve the morphological feature of the recovered Zr, which reduces the salt incorporation by examining the effect of the process parameters such as the ZrCl{sub 4} concentration and the applied potential.

  4. Absorption characteristics of anions (I-, Br-, and Te2-) into zeolite in molten LiCl-KCl eutectic salt

    NASA Astrophysics Data System (ADS)

    Uozumi, Koichi; Sugihara, Kei; Kinoshita, Kensuke; Koyama, Tadafumi; Tsukada, Takeshi; Terai, Takayuki; Suzuki, Akihiro

    2014-04-01

    The behaviors of anion fission product (FP) elements to be absorbed into zeolite in molten LiCl-KCl eutectic salt were studied using iodine, bromine, and tellurium. First, the type-A zeolite was selected as the most suitable type of zeolite among type-A, type-X, and type-Y zeolites through experiments in which zeolites were heated together with LiCl-KCl-KI salt. As the next step, experiments in which the type-A zeolite was immersed in molten LiCl-KCl salt containing various concentrations of iodine, bromine, or tellurium were performed. The degree of absorption of the anion FP elements was evaluated using the separation factor (SF) value versus chlorine. Although the SF values for iodine and tellurium were higher than 1.0, which meant that these elements were absorbed into the type-A zeolite more intensively than chlorine in the salt, the corresponding value for bromine was approximately 1.0. The effects of coexisting cation FPs were also examined using cesium, strontium, and neodymium, and it was revealed that the SF values for iodine were less than those in the case without cation addition. On the other hand, the SF values for tellurium were not affected by the coexistence of cesium and strontium. Finally, the feasibility of the present pyroprocess flowsheet was evaluated by calculating the inventory of each anion FP in an electrorefiner based on the obtained SF values instead of temporary values for the anion FPs absorption, which were set due to lack of experimental data.

  5. Accelerator-Driven Subcritical Fission in a Molten Salt Core: Green Nuclear Power for the New Millennium

    NASA Astrophysics Data System (ADS)

    McIntyre, Peter

    2011-10-01

    Scientists at Texas A&M University, Brookhaven National Lab, and Idaho National Lab are developing a design for accelerator-drive subcritical fission in a molten salt core (ADSMS). Three high-power proton beams are delivered to spallation targets in a molten salt core, where they provide ˜3% of the fast neutrons required to sustain 600 MW of fission. The proton beams are produced by a flux-coupled stack of superconducting strong-focusing cyclotrons. The fuel consists of a eutectic of sodium chloride with either spent nuclear fuel from a conventional U power reactor (ADSMS-U) or thorium (ADSMS-Th). The subcritical core cannot go critical under any failure mode. The core cannot melt down even if all power is suddenly lost to the facility for a prolonged period. The ultra-fast neutronics of the core makes it possible to operate in an isobreeding mode, in which neutron capture breeds the fertile nuclide into a fissile nuclide at the same rate that fission burns the fissile nuclide, and consumes 90% of the fertile inventory instead of the 5% consumed in the original use in a conventional power plant. The ultra-fast neutronics produces a very low equilibrium inventory of the long-lived minor actinides, ˜10^4 less than what is produced in conventional power plants. ADSMS offers a method to safely produce the energy needs for all mankind for the next 3000 years.

  6. High Temperature Corrosion studies on Pulsed Current Gas Tungsten Arc Welded Alloy C-276 in Molten Salt Environment

    NASA Astrophysics Data System (ADS)

    Manikandan, M.; Arivarasu, M.; Arivazhagan, N.; Puneeth, T.; Sivakumar, N.; Murugan, B. Arul; Sathishkumar, M.; Sivalingam, S.

    2016-09-01

    Alloy C-276 is widely used in the power plant environment due to high strength and corrosion in highly aggressive environment. The investigation on high- temperature corrosion resistance of the alloy C-276 PCGTA weldment is necessary for prolonged service lifetime of the components used in corrosive environments. Investigation has been carried out on Pulsed Current Gas Tungsten Arc Welding by autogenous and different filler wires (ERNiCrMo-3 and ERNiCrMo-4) under molten state of K2SO4-60% NaCl environment at 675oC under cyclic condition. Thermogravimetric technique was used to establish the kinetics of corrosion. Weight gained in the molten salt reveals a steady-state parabolic rate law while the kinetics with salt deposits displays multi-stage growth rates. PCGTA ERNiCrMo-3 shows the higher parabolic constant compared to others. The scale formed on the weldment samples upon hot corrosion was characterized by using X-ray diffraction, SEM and EDAX analysis to understand the degradation mechanisms. From the results of the experiment the major phases are identified as Cr2O3, Fe2O3, and NiCr2O4. The result showed that weld fabricated by ERNiCrMo-3 found to be more prone to degradation than base metal and ERNiCrMo-4 filler wire due to higher segregation of alloying element of Mo and W in the weldment

  7. Dynamic modelling and simulation of linear Fresnel solar field model based on molten salt heat transfer fluid

    NASA Astrophysics Data System (ADS)

    Hakkarainen, Elina; Tähtinen, Matti

    2016-05-01

    Demonstrations of direct steam generation (DSG) in linear Fresnel collectors (LFC) have given promising results related to higher steam parameters compared to the current state-of-the-art parabolic trough collector (PTC) technology using oil as heat transfer fluid (HTF). However, DSG technology lacks feasible solution for long-term thermal energy storage (TES) system. This option is important for CSP technology in order to offer dispatchable power. Recently, molten salts have been proposed to be used as HTF and directly as storage medium in both line-focusing solar fields, offering storage capacity of several hours. This direct molten salt (DMS) storage concept has already gained operational experience in solar tower power plant, and it is under demonstration phase both in the case of LFC and PTC systems. Dynamic simulation programs offer a valuable effort for design and optimization of solar power plants. In this work, APROS dynamic simulation program is used to model a DMS linear Fresnel solar field with two-tank TES system, and example simulation results are presented in order to verify the functionality of the model and capability of APROS for CSP modelling and simulation.

  8. The Electrochemistry of Li-LiCl-Li2O Molten Salt Systems and the Role of Moisture

    NASA Astrophysics Data System (ADS)

    Gese, Natalie J.

    Uranium can be recovered from uranium-oxide (UO2) spent fuel through the combination of oxide reduction and electrorefining processes. During oxide reduction, the spent fuel is introduced to molten LiCl-Li 2O salt at 650°C, and the UO2 is reduced to uranium metal via two routes: (1) electrochemically, and (2) chemically by lithium metal (Li°) that is produced electrochemically. However, the hygroscopic nature of both LiCl and Li2O leads to the formation of LiOH, contributing hydroxyl anions (OH-), the reduction of which interferes with the Li° generation required for the chemical reduction of UO 2. In order for the oxide reduction process to be an effective method for the treatment of uranium-oxide fuel, the role of moisture in the LiCl-Li 2O system must be understood. The behavior of moisture in the LiCl-Li 2O molten-salt system was studied using cyclic voltammetry, chronopotentiometry, and chronoamperometry while reduction to hydrogen was confirmed with gas chromatography.

  9. Preparation and luminescence characteristics of monazite Eu3+:LaPO4 nanocrystals in NH4NO3 molten salt

    NASA Astrophysics Data System (ADS)

    Huang, Xinyang

    2015-12-01

    Molten-salt method and NH4NO3 flux were developed to fabricate monoclinic monazite Eu3+:LaPO4 nanocrystals for the first time. The products were characterized by X-ray powder diffraction, transmission electron microscopy, high-resolution transmission electron microscopy, excitation spectra, emission spectra and luminescence decay curves. The as-obtained products were quasihexagonal Eu3+:LaPO4 nanocrystals with the mean size of 30 nm. The room temperature charge transfer bands (CTB) exhibited red-shift and spectral broadening in comparison with 10 K CTB. The optimal Eu3+ concentration was determined to be 8 mol% by a comparative study of the relative emission intensities for different Eu3+ doping concentrations. The higher concentration quenching could be caused by the possible nonradiative energy transfer (electric multipole-multipole interaction). The relationship between the FL lifetime of 5D0 energy level and Eu3+ concentration was investigated based on Auzel's model. This work is important not only to understand the unique physical properties of Eu3+:LaPO4 nanocrystals but also to bring an opportunity for the development of the other nanocrystals via the molten salt synthesis in NH4NO3 flux.

  10. Reshaping the folding energy landscape by chloride salt: impact on molten-globule formation and aggregation behavior of carbonic anhydrase.

    PubMed

    Borén, Kristina; Grankvist, Hannah; Hammarström, Per; Carlsson, Uno

    2004-05-21

    During chemical denaturation different intermediate states are populated or suppressed due to the nature of the denaturant used. Chemical denaturation by guanidine-HCl (GuHCl) of human carbonic anhydrase II (HCA II) leads to a three-state unfolding process (Cm,NI=1.0 and Cm,IU=1.9 M GuHCl) with formation of an equilibrium molten-globule intermediate that is stable at moderate concentrations of the denaturant (1-2 M) with a maximum at 1.5 M GuHCl. On the contrary, urea denaturation gives rise to an apparent two-state unfolding transition (Cm=4.4 M urea). However, 8-anilino-1-naphthalene sulfonate (ANS) binding and decreased refolding capacity revealed the presence of the molten globule in the middle of the unfolding transition zone, although to a lesser extent than in GuHCl. Cross-linking studies showed the formation of moderate oligomer sized (300 kDa) and large soluble aggregates (>1000 kDa). Inclusion of 1.5 M NaCl to the urea denaturant to mimic the ionic character of GuHCl leads to a three-state unfolding behavior (Cm,NI=3.0 and Cm,IU=6.4 M urea) with a significantly stabilized molten-globule intermediate by the chloride salt. Comparisons between NaCl and LiCl of the impact on the stability of the various states of HCA II in urea showed that the effects followed what could be expected from the Hofmeister series, where Li+ is a chaotropic ion leading to decreased stability of the native state. Salt addition to the completely urea unfolded HCA II also led to an aggregation prone unfolded state, that has not been observed before for carbonic anhydrase. Refolding from this state only provided low recoveries of native enzyme.

  11. Ab initio study of collective excitations in a disparate mass molten salt.

    PubMed

    Bryk, Taras; Klevets, Ivan

    2012-12-14

    Ab initio molecular dynamics simulations and the approach of generalized collective modes are applied for calculations of spectra of longitudinal and transverse collective excitations in molten LiBr. Dispersion and damping of low- and high-frequency branches of collective excitations as well as wave-number dependent relaxing modes were calculated. The main mode contributions to partial, total, and concentration dynamic structure factors were estimated in a wide region of wave numbers. A role of polarization effects is discussed from comparison of mode contributions to concentration dynamic structure factors calculated for molten LiBr from ab initio and classical rigid ion simulations.

  12. The results of the investigations of Russian Research Center—``Kurchatov Institute'' on molten salt applications to problems of nuclear energy systems

    NASA Astrophysics Data System (ADS)

    Novikov, Vladimir M.

    1995-09-01

    The results of investigations on molten salt (MS) applications to problems of nuclear energy systems that have been conducted in Russian Research ``Kurchatov Institute'' are presented and discussed. The spectrum of these investigations is rather broad and covers the following items: physical characteristics of molten salt nuclear energy systems (MSNES); nuclear and radiation safety of MSNES; construction materials compatible with MS of different compositions; technological aspects of MS loops; in-reactor loop testing. It is shown that main findings of completed program support the conclusion that there are no physical nor technological obstacles on a way of MS application to different nuclear energy systems.

  13. Fundamental electrochemical investigation of bromoaluminate and mixed chloro-bromoaluminate room-temperature molten-salt systems. Technical report, January 1987-August 1988

    SciTech Connect

    Boon, J.A.; Wilkes, J.S.; Lanning, J.A.

    1989-03-01

    In this project, the chemical and electrochemical properties of the bromoaluminate molten-salt system were determined. With knowledge of the bromide system, the chemical and electrochemical properties of the mixed chloro-bromoaluminate molten salt system were determined, allowing further work on the applicability of these systems as electrolytes in high-density electrical storage devices. The qualitative electrochemical behavior of the bromide and chloride systems were compared. The systems were found to behave similarly, but the basic bromide system had two oxidative processes, compared to the single process of the chloride system. The bromide system was also shown to have a smaller electrochemical voltage window.

  14. Inverse temperature dependence of electrical conductivity of solutions of lithium salts in aprotic media

    SciTech Connect

    Plakhotnik, V.N.; Tovmash, N.F.; Kovtum, Yu.V.

    1987-08-01

    Solutions of lithium salts in aprotic dipolar solvents are studied in this paper for their use as electrolytes in lithium batteries. The temperature dependence and isotherms of the electric conductivity of molten salts of lithium fluorides with arsenic and boron are assessed against a range of solvents including tetrahydrofuran, propylene carbonate, 1,3-dioxolane, gamma-butyrolactone, water, hydrogen, and dimethoxyethane. Ionization potentials are given and molar ratios for the salts and solvents are tabulated.

  15. Evaluation of Static Thermophysical Properties of the Ternary Molten Salt System Li, Na and Be/F Based on the Modified Peng-Robinson Equation

    NASA Astrophysics Data System (ADS)

    Zhang, Dalin; Qiu, Suizheng; Su, Guanghui; Jia, Dounan

    The static thermophysical properties of the molten salt system like LiF-NaF-BeF2 influence the design and construction of the fuel salt and coolant in the Molten Salt Reactor for the new generation. In this paper, the equation of state of the ternary system 0.15LiF-0.58NaF-0.27BeF2, over the temperature range from 873.15K to 1073.15K at one atmosphere pressure, is described by using modified Peng-Robinson equation. The density of the ternary system is evaluated by this equation directly, and compared with the experimental data. Base on the equation of state, the other static thermophysical properties such as the enthalpy, entropy and heat capacity at constant pressure are evaluated by the fugacity coefficient and residual function methods respectively. The density calculated by Peng-Robinson equation is in highly agreement with the experimental data, and the enthalpy, entropy and heat capacity evaluated by such two different methods are consistent with each other. It could be concluded that the modified Peng-Robinson equation could be applicable to estimate the density of the molten salt system, and the Peng-Robinson equation is recommended to be as the fundamental to evaluate the enthalpy, entropy and heat capacity of the molten salt system.

  16. Preliminary Study on LiF4-ThF4-PuF4 Utilization as Fuel Salt of miniFUJI Molten Salt Reactor

    NASA Astrophysics Data System (ADS)

    Waris, Abdul; Aji, Indarta K.; Pramuditya, Syeilendra; Widayani; Irwanto, Dwi

    2016-08-01

    miniFUJI reactor is molten salt reactor (MSR) which is one type of the Generation IV nuclear energy systems. The original miniFUJI reactor design uses LiF-BeF2-ThF4-233UF4 as a fuel salt. In the present study, the use of LiF4-ThF4-PuF4 as fuel salt instead of LiF-BeF2-ThF4-UF4 will be discussed. The neutronics cell calculation has been performed by using PIJ (collision probability method code) routine of SRAC 2006 code, with the nuclear data library is JENDL-4.0. The results reveal that the reactor can attain the criticality condition with the plutonium concentration in the fuel salt is equal to 9.16% or more. The conversion ratio diminishes with the enlarging of plutonium concentration in the fuel. The neutron spectrum of miniFUJI MSR with plutonium fuel becomes harder compared to that of the 233U fuel.

  17. Improving Activity of Salt-Lyophilized Enzymes in Organic Media

    NASA Astrophysics Data System (ADS)

    Borole, Abhijeet P.; Davison, Brian H.

    Lyophilization with salts has been identified as an important method of activating enzymes in organic media. Using salt-activated enzymes to transform molecules tethered to solid surfaces in organic phase requires solubilization of enzymes in the solvents. Methods of improving performance of salt-lyophilized enzymes, further, via chemical modification, and use of surfactants and surfactants to create fine emulsions prior to lyophilization are investigated. The reaction system used is transesterification of N-acetyl phenylalanine ethyl ester with methanol or propanol. Initial rate of formation of amino acid esters by subtilisin Carlsberg (SC) was studied and found to increase two to sevenfold by either chemical modification or addition of surfactants in certain solvents, relative to the salt (only)-lyophilized enzyme. The method to prepare highly dispersed enzymes in a salt-surfactant milieu also improved activity by two to threefold. To test the effect of chemical modification on derivatization of drug molecules, acylation of bergenin was investigated using chemically modified SC.

  18. Improving activity of salt-lyophilized enzymes in organic media

    SciTech Connect

    Borole, Abhijeet P; Davison, Brian H

    2008-01-01

    Lyophilization with salts has been identified as an important method of activating enzymes in organic media. Using salt-activated enzymes to transform molecules tethered to solid surfaces in organic phase requires solubilization of enzymes in the solvents. Methods of improving performance of salt-lyophilized enzymes, further, via chemical modification, and use of surfactants and surfactants to create fine emulsions prior to lyophilization are investigated. The reaction system used is transesterification of N-acetyl phenylalanine ethyl ester with methanol or propanol. Initial rate of formation of amino acid esters by subtilisin Carlsberg (SC) was studied and found to increase two to sevenfold by either chemical modification or addition of surfactants in certain solvents, relative to the salt (only)-lyophilized enzyme. The method to prepare highly dispersed enzymes in a salt-surfactant milieu also improved activity by two to threefold. To test the effect of chemical modification on derivatization of drug molecules, acylation of bergenin was investigated using chemically modified SC.

  19. Molten salt oxidation of chloro-organic compounds: Experimental results for product gas compositions and final forms studies

    SciTech Connect

    Rudolph, J.C.; Haas, P.A.; Bell, J.T.; Crosley, S.M.; Calhoun, C.L. Jr.; Gorin, A.H.; Nulf, L.E.

    1995-04-01

    Molten salt oxidation (MSO) has been selected as a promising technology for treatment of some US Department of Energy (DOE) mixed wastes. Mixed wastes are defined as those wastes that contain both radioactive components, which are regulated by the Atomic Energy Act of 1954, and hazardous waste components, which are regulated under the Resource Conservation and Recovery Act (RCRA). Oak Ridge National Laboratory (ORNL) has installed and operated a bench-scale MSO apparatus to obtain experimental information needed before the design and construction of an MSO pilot plant. The primary objective of the experiments performed was to show that dioxin and furan emissions from a molten salt oxidation (MSO) unit were below the proposed regulatory limit of 0.1 ng/m{sup 3} as 2,3,7,8-tetrachlorodibenzo-para-dioxin equivalents or toxic equivalence quotient. The feed stream was to contain 2,4-dichlorophenol, a suspected precursor to the formation of dioxin and furans. The tests were to be done over a range of salt compositions and flow rates expected in a pilot- or full-scale MSO unit. Two other objectives were to demonstrate destruction and removal efficiencies (DREs) greater than US Environmental Protection Agency requirements and to show that levels of products of incomplete combustion (PICs) are the same as, or lower than, those observed in incinerators for two common waste constituents [carbon tetrachloride (CCl{sub 4}) and CH{sub 3}CCl{sub 3}]. A final objective was to perform some initial studies of final waste forms using sulfur polymer cement (SPC). This report presents the results from the operation of the bench-scale MSO system.

  20. Effect of nanoparticles on heat capacity of nanofluids based on molten salts as PCM for thermal energy storage

    PubMed Central

    2013-01-01

    In this study, different nanofluids with phase change behavior were developed by mixing a molten salt base fluid (selected as phase change material) with nanoparticles using the direct-synthesis method. The thermal properties of the nanofluids obtained were investigated. These nanofluids can be used in concentrating solar plants with a reduction of storage material if an improvement in the specific heat is achieved. The base salt mixture was a NaNO3-KNO3 (60:40 ratio) binary salt. The nanoparticles used were silica (SiO2), alumina (Al2O3), titania (TiO2), and a mix of silica-alumina (SiO2-Al2O3). Three weight fractions were evaluated: 0.5, 1.0, and 1.5 wt.%. Each nanofluid was prepared in water solution, sonicated, and evaporated. Measurements on thermophysical properties were performed by differential scanning calorimetry analysis and the dispersion of the nanoparticles was analyzed by scanning electron microscopy (SEM). The results obtained show that the addition of 1.0 wt.% of nanoparticles to the base salt increases the specific heat of 15% to 57% in the solid phase and of 1% to 22% in the liquid phase. In particular, this research shows that the addition of silica-alumina nanoparticles has a significant potential for enhancing the thermal storage characteristics of the NaNO3-KNO3 binary salt. These results deviated from the predictions of the theoretical model used. SEM suggests a greater interaction between these nanoparticles and the salt. PMID:24168168

  1. Effect of nanoparticles on heat capacity of nanofluids based on molten salts as PCM for thermal energy storage

    NASA Astrophysics Data System (ADS)

    Chieruzzi, Manila; Cerritelli, Gian F.; Miliozzi, Adio; Kenny, José M.

    2013-10-01

    In this study, different nanofluids with phase change behavior were developed by mixing a molten salt base fluid (selected as phase change material) with nanoparticles using the direct-synthesis method. The thermal properties of the nanofluids obtained were investigated. These nanofluids can be used in concentrating solar plants with a reduction of storage material if an improvement in the specific heat is achieved. The base salt mixture was a NaNO3-KNO3 (60:40 ratio) binary salt. The nanoparticles used were silica (SiO2), alumina (Al2O3), titania (TiO2), and a mix of silica-alumina (SiO2-Al2O3). Three weight fractions were evaluated: 0.5, 1.0, and 1.5 wt.%. Each nanofluid was prepared in water solution, sonicated, and evaporated. Measurements on thermophysical properties were performed by differential scanning calorimetry analysis and the dispersion of the nanoparticles was analyzed by scanning electron microscopy (SEM). The results obtained show that the addition of 1.0 wt.% of nanoparticles to the base salt increases the specific heat of 15% to 57% in the solid phase and of 1% to 22% in the liquid phase. In particular, this research shows that the addition of silica-alumina nanoparticles has a significant potential for enhancing the thermal storage characteristics of the NaNO3-KNO3 binary salt. These results deviated from the predictions of the theoretical model used. SEM suggests a greater interaction between these nanoparticles and the salt.

  2. Effect of nanoparticles on heat capacity of nanofluids based on molten salts as PCM for thermal energy storage.

    PubMed

    Chieruzzi, Manila; Cerritelli, Gian F; Miliozzi, Adio; Kenny, José M

    2013-10-29

    In this study, different nanofluids with phase change behavior were developed by mixing a molten salt base fluid (selected as phase change material) with nanoparticles using the direct-synthesis method. The thermal properties of the nanofluids obtained were investigated. These nanofluids can be used in concentrating solar plants with a reduction of storage material if an improvement in the specific heat is achieved. The base salt mixture was a NaNO3-KNO3 (60:40 ratio) binary salt. The nanoparticles used were silica (SiO2), alumina (Al2O3), titania (TiO2), and a mix of silica-alumina (SiO2-Al2O3). Three weight fractions were evaluated: 0.5, 1.0, and 1.5 wt.%. Each nanofluid was prepared in water solution, sonicated, and evaporated. Measurements on thermophysical properties were performed by differential scanning calorimetry analysis and the dispersion of the nanoparticles was analyzed by scanning electron microscopy (SEM). The results obtained show that the addition of 1.0 wt.% of nanoparticles to the base salt increases the specific heat of 15% to 57% in the solid phase and of 1% to 22% in the liquid phase. In particular, this research shows that the addition of silica-alumina nanoparticles has a significant potential for enhancing the thermal storage characteristics of the NaNO3-KNO3 binary salt. These results deviated from the predictions of the theoretical model used. SEM suggests a greater interaction between these nanoparticles and the salt.

  3. The origin of the conductivity maximum in molten salts. II. SnCl2 and HgBr2

    NASA Astrophysics Data System (ADS)

    Aravindakshan, Nikhil P.; Kuntz, Colin M.; Gemmell, Kyle E.; Johnson, Keith E.; East, Allan L. L.

    2016-09-01

    The phenomenon of electrical conductivity maxima of molten salts versus temperature during orthobaric (closed-vessel) conditions is further examined via ab initio simulations. Previously, in a study of molten BiCl3, a new theory was offered in which the conductivity falloff at high temperatures is due not to traditional ion association, but to a rise in the activation energy for atomic ions hopping from counterion to counterion. Here this theory is further tested on two more inorganic melts which exhibit conductivity maxima: another high-conducting melt (SnCl2, σmax = 2.81 Ω-1 cm-1) and a low-conducting one (HgBr2, σmax = 4.06 × 10-4 Ω-1 cm-1). First, ab initio molecular dynamics simulations were performed and again appear successful in reproducing the maxima for both these liquids. Second, analysis of the simulated liquid structure (radial distributions, species concentrations) was performed. In the HgBr2 case, a very molecular liquid like water, a clear Grotthuss chain of bromide transfers was observed in simulation when seeding the system with a HgBr+ cation and HgBr3- anion. The first conclusion is that the hopping mechanism offered for molten BiCl3 is simply the Grotthuss mechanism for conduction, applicable not just to H+ ions, but also to halide ions in post-transition-metal halide melts. Second, it is conjectured that the conductivity maximum is due to rising activation energy in network-covalent (halide-bridging) melts (BiCl3, SnCl2, PbCl2), but possibly a falling Arrhenius prefactor (collision frequency) for molecular melts (HgBr2).

  4. The origin of the conductivity maximum in molten salts. II. SnCl2 and HgBr2.

    PubMed

    Aravindakshan, Nikhil P; Kuntz, Colin M; Gemmell, Kyle E; Johnson, Keith E; East, Allan L L

    2016-09-01

    The phenomenon of electrical conductivity maxima of molten salts versus temperature during orthobaric (closed-vessel) conditions is further examined via ab initio simulations. Previously, in a study of molten BiCl3, a new theory was offered in which the conductivity falloff at high temperatures is due not to traditional ion association, but to a rise in the activation energy for atomic ions hopping from counterion to counterion. Here this theory is further tested on two more inorganic melts which exhibit conductivity maxima: another high-conducting melt (SnCl2, σmax = 2.81 Ω(-1) cm(-1)) and a low-conducting one (HgBr2, σmax = 4.06 × 10(-4) Ω(-1) cm(-1)). First, ab initio molecular dynamics simulations were performed and again appear successful in reproducing the maxima for both these liquids. Second, analysis of the simulated liquid structure (radial distributions, species concentrations) was performed. In the HgBr2 case, a very molecular liquid like water, a clear Grotthuss chain of bromide transfers was observed in simulation when seeding the system with a HgBr(+) cation and HgBr3 (-) anion. The first conclusion is that the hopping mechanism offered for molten BiCl3 is simply the Grotthuss mechanism for conduction, applicable not just to H(+) ions, but also to halide ions in post-transition-metal halide melts. Second, it is conjectured that the conductivity maximum is due to rising activation energy in network-covalent (halide-bridging) melts (BiCl3, SnCl2, PbCl2), but possibly a falling Arrhenius prefactor (collision frequency) for molecular melts (HgBr2). PMID:27609001

  5. Orientation control of (K,Na)NbO3 ceramics using platelike NaNbO3 templates prepared by single-step molten salt synthesis with mixed salt

    NASA Astrophysics Data System (ADS)

    Ishii, Keisuke; Tashiro, Shinjiro

    2016-10-01

    In order to shorten the firing time for sintering textured (K,Na)NbO3 system ceramics, the fabrication method of the single-step molten salt synthesis for preparing platelike NaNbO3 single-crystal particles was improved. An uneven shape was formed on the surfaces of platelike NaNbO3 single-crystal particles obtained by single-step molten salt synthesis in the mixed salts of KCl and NaCl. Using these single-crystal particles as the templates, textured (K,Na)NbO3 ceramics were fabricated. The sinterability of the textured ceramics and their piezoelectricity were compared between two kinds of templates synthesized in the mixed salt and in the conventional NaCl salt. The diffusivity of K atoms into these templates from the matrix powder of (K,Na)NbO3 during firing was also compared.

  6. Testing thermocline filler materials and molten-salt heat transfer fluids for thermal energy storage systems used in parabolic trough solar power plants.

    SciTech Connect

    Kelly, Michael James; Hlava, Paul Frank; Brosseau, Douglas A.

    2004-07-01

    Parabolic trough power systems that utilize concentrated solar energy to generate electricity are a proven technology. Industry and laboratory research efforts are now focusing on integration of thermal energy storage as a viable means to enhance dispatchability of concentrated solar energy. One option to significantly reduce costs is to use thermocline storage systems, low-cost filler materials as the primary thermal storage medium, and molten nitrate salts as the direct heat transfer fluid. Prior thermocline evaluations and thermal cycling tests at the Sandia National Laboratories' National Solar Thermal Test Facility identified quartzite rock and silica sand as potential filler materials. An expanded series of isothermal and thermal cycling experiments were planned and implemented to extend those studies in order to demonstrate the durability of these filler materials in molten nitrate salts over a range of operating temperatures for extended timeframes. Upon test completion, careful analyses of filler material samples, as well as the molten salt, were conducted to assess long-term durability and degradation mechanisms in these test conditions. Analysis results demonstrate that the quartzite rock and silica sand appear able to withstand the molten salt environment quite well. No significant deterioration that would impact the performance or operability of a thermocline thermal energy storage system was evident. Therefore, additional studies of the thermocline concept can continue armed with confidence that appropriate filler materials have been identified for the intended application.

  7. Effect of titanium substitution in layered LiNiO 2 cathode material prepared by molten-salt synthesis

    NASA Astrophysics Data System (ADS)

    Ha, Hyung-Wook; Jeong, Kyung Hee; Kim, Keon

    LiNi 1- xTi xO 2 (0 ≤ x ≤ 0.1) compounds have been synthesized by a direct molten-salt method that uses a eutectic mixture of LiNO 3 and LiOH salts. According to X-ray diffraction analysis, these materials have a well-developed layered structure (R3-m) and are an isostructure of LiNiO 2. The LiNi 1- xTi xO 2 (0 ≤ x ≤ 0.1) compounds have average particle sizes of 1-5 μm depending on the amount of Ti salt. Charge-discharge tests show that a LiNi 1- xTi xO 2 (0 ≤ x ≤ 0.1) cathode prepared at 700 °C has an initial discharge capacity as high as 171 mA h g -1 and excellent capacity retention in the range 4.3-2.8 V at a current density of 0.2 mA cm -2.

  8. Towards large scale preparation of graphene in molten salts and its use in the fabrication of highly toughened alumina ceramics.

    PubMed

    Kamali, Ali Reza; Feighan, John; Fray, Derek J

    2016-08-15

    Highly crystalline graphene nanosheets were reproducibly generated by the electrochemical exfoliation of graphite electrodes in molten LiCl containing protons. The graphene product has been successfully applied in several applications. This paper discusses the effect of molten salt produced graphene on the microstructures and mechanical properties of alumina articles produced by slip casting and pressureless sintering, which is one of the most convenient methods for the commercial production of alumina ceramics. In addition to graphene, graphite powder and multi-walled carbon nanotubes (CNTs) were also used to prepare alumina articles for comparative purposes. A graphene strengthening effect was realized through microstructural refinement and by influencing the formation of alumina nanorods during the sintering of α-Al2O3 articles. The fracture toughness of the sintered alumina articles increased to an impressive value of 6.98 MPa m(1/2) by adding 0.5 wt% graphene nanosheets. This was attributed to the unique microstructure obtained, comprised of micrometer sized alumina grains separated by alumina nanorods. PMID:27231211

  9. Towards large scale preparation of graphene in molten salts and its use in the fabrication of highly toughened alumina ceramics.

    PubMed

    Kamali, Ali Reza; Feighan, John; Fray, Derek J

    2016-08-15

    Highly crystalline graphene nanosheets were reproducibly generated by the electrochemical exfoliation of graphite electrodes in molten LiCl containing protons. The graphene product has been successfully applied in several applications. This paper discusses the effect of molten salt produced graphene on the microstructures and mechanical properties of alumina articles produced by slip casting and pressureless sintering, which is one of the most convenient methods for the commercial production of alumina ceramics. In addition to graphene, graphite powder and multi-walled carbon nanotubes (CNTs) were also used to prepare alumina articles for comparative purposes. A graphene strengthening effect was realized through microstructural refinement and by influencing the formation of alumina nanorods during the sintering of α-Al2O3 articles. The fracture toughness of the sintered alumina articles increased to an impressive value of 6.98 MPa m(1/2) by adding 0.5 wt% graphene nanosheets. This was attributed to the unique microstructure obtained, comprised of micrometer sized alumina grains separated by alumina nanorods.

  10. Theoretical studies of structure and dynamics of molten salts: the LiF-ThF4 system.

    PubMed

    Liu, Jian-Biao; Chen, Xin; Qiu, Yi-Heng; Xu, Chao-Fei; Schwarz, W H Eugen; Li, Jun

    2014-12-01

    LiF-ThF4 molten salt (MS) is the fuel for advanced MS reactors. Knowledge of the microscopic MS structure and dynamics is required for an understanding of the macroscopic physical and chemical properties of the MS phases. We have performed molecular dynamics simulations on LiF-ThF4 MS at different molar percentages (LiF/ThF4 = 20.0 to 0.5) and temperatures (1100 to 1400 K). Experimental deductions and recent theoretical results on the coordination structures and transport properties of the MS are well reproduced. The density of states of the [ThF8](4-) species and the character of the Th-F bonding are investigated. The interplay between the microscopic structures and the dynamical properties is elucidated. Corresponding to the smaller effective radius of Zr, the activation barrier of the M(4+)-F(-) dissociation and the lifetime of the first coordination shell of M(4+) are both smaller for M = Th than for M = Zr in the respective LiF-MF4 systems. The shorter Zr-F bond is stronger than the longer Th-F bond, while the coordination number of the predominant [ZrF7](3-) species is smaller than that of the dominant [ThF8](4-) species. An approximate formula is proposed for the lifetime of F(-) ions in the first solvation shell of molten MFn (M = Y, Zr, Th) in terms of the radial distribution function. PMID:25361071

  11. Assessment of Candidate Molten Salt Coolants for the Advanced High Temperature Reactor (AHTR)

    SciTech Connect

    Williams, D.F.

    2006-03-24

    The Advanced High-Temperature Reactor (AHTR) is a novel reactor design that utilizes the graphite-matrix high-temperature fuel of helium-cooled reactors, but provides cooling with a high-temperature fluoride salt. For applications at temperatures greater than 900 C the AHTR is also referred to as a Liquid-Salt-Cooled Very High-Temperature Reactor (LS-VHTR). This report provides an assessment of candidate salts proposed as the primary coolant for the AHTR based upon a review of physical properties, nuclear properties, and chemical factors. The physical properties most relevant for coolant service were reviewed. Key chemical factors that influence material compatibility were also analyzed for the purpose of screening salt candidates. Some simple screening factors related to the nuclear properties of salts were also developed. The moderating ratio and neutron-absorption cross-section were compiled for each salt. The short-lived activation products, long-lived transmutation activity, and reactivity coefficients associated with various salt candidates were estimated using a computational model. Table A presents a summary of the properties of the candidate coolant salts. Certain factors in this table, such as melting point, vapor pressure, and nuclear properties, can be viewed as stand-alone parameters for screening candidates. Heat-transfer properties are considered as a group in Sect. 3 in order to evaluate the combined effects of various factors. In the course of this review, it became apparent that the state of the properties database was strong in some areas and weak in others. A qualitative map of the state of the database and predictive capabilities is given in Table B. It is apparent that the property of thermal conductivity has the greatest uncertainty and is the most difficult to measure. The database, with respect to heat capacity, can be improved with modern instruments and modest effort. In general, ''lighter'' (low-Z) salts tend to exhibit better heat

  12. Influence of aluminum salt addition on in situ sintering of electrolyte matrices for molten carbonate fuel cells

    NASA Astrophysics Data System (ADS)

    Lee, Insung; Kim, Wonsun; Moon, Youngjoon; Lim, Heechun; Lee, Dokyol

    Three aluminum salts are investigated as a sintering aid for the in situ sintering of electrolyte matrices for molten carbonate fuel cells (MCFCs). Only aluminum acetylacetonate shows a potential. At or above 420°C, aluminum acetylacetonate changes to Al 2O 3 and reacts with Li 2CO 3 in the electrolyte to produce γ-LiAlO 2. This reaction product forms necks between matrix particles. Necks grow with increasing sintering time and correspondingly, the mechanical strength of the electrolyte matrix shows an abrupt increase, starting at a sintering time of about 100 h until it levels off at about 250 h. The porosity of the matrices fabricated with aluminum acetylacetonate is in the range acceptable for use in MCFCs.

  13. Development of a high-resolution Thomson scattering system for plasma interactions with molten salt (FLiNaK)

    NASA Astrophysics Data System (ADS)

    Lee, K. Y.

    2014-10-01

    A high-resolution Thomson scattering system is presently being developed to measure the electron temperature and density profile during plasma interaction with molten salt. The system uses a 20-Hz Nd:YAG laser operating at the second harmonic (532 nm). The collection lens, having a 1:10 magnification ratio, measures 63 points along the 10-cm profile. The scattered light is transmitted by using an optical-fiber bundle, and is analyzed with a triple-grating spectrometer to further reduce stray light. Its spectral resolution is expected to be 0.03 nm. An intensified charge-coupled device (ICCD) camera consisting of a gated image intensifier coupled to the CCD camera is used to record the spectral distribution of the scattered light. An additional feature of operating the ICCD camera at 40-Hz to record the background signal is incorporated.

  14. A view of treatment process of melted nuclear fuel on a severe accident plant using a molten salt system

    SciTech Connect

    Fujita, R.; Takahashi, Y.; Nakamura, H.; Mizuguchi, K.; Oomori, T.

    2013-07-01

    At severe accident such as Fukushima Daiichi Nuclear Power Plant Accident, the nuclear fuels in the reactor would melt and form debris which contains stable UO2-ZrO2 mixture corium and parts of vessel such as zircaloy and iron component. The requirements for solution of issues are below; -) the reasonable treatment process of the debris should be simple and in-situ in Fukushima Daiichi power plant, -) the desirable treatment process is to take out UO{sub 2} and PuO{sub 2} or metallic U and TRU metal, and dispose other fission products as high level radioactive waste; and -) the candidate of treatment process should generate the smallest secondary waste. Pyro-process has advantages to treat the debris because of the high solubility of the debris and its total process feasibility. Toshiba proposes a new pyro-process in molten salts using electrolysing Zr before debris fuel being treated.

  15. Structural characteristics of 1-ethyl-3-methylimidazolium bifluoride: HF-deficient form of a highly conductive room temperature molten salt

    NASA Astrophysics Data System (ADS)

    Matsumoto, Kazuhiko; Tsuda, Tetsuya; Hagiwara, Rika; Ito, Yasuhiko; Tamada, Osamu

    2002-01-01

    EMIF·HF, 1-ethyl-3-methylimidazolium bifluoride, has been obtained by eliminating HF from a room temperature molten salt EMIF·2.3HF at around 400 K. EMIF·HF crystallizes in space group P2 1/m with a=7.281(1) Å, b=6.762(1) Å, c=8.403(1) Å, β=107.26(1)°, V=395.09(18) Å 3, Z=2 at room temperature. The cations are stacked in pillars via the hydrogen bonding between the C4 proton and the ring π-electrons of the adjacent cation. The cations and the anions coupled by strong hydrogen bondings are co-planar.

  16. Analysis of a helical coil once-through molten salt steam generator: Experimental results and heat transfer evaluation

    NASA Astrophysics Data System (ADS)

    Seubert, B.; Rojas, E.; Rivas, E.; Gaggioli, W.; Rinaldi, L.; Fluri, T.

    2016-05-01

    A molten salt helical coil steam generator is an alternative to kettle- or drum-type evaporators which are currently used in commercial-scale solar thermal power plants. A 300 kW prototype was tested during the OPTS project at ENEA. The experimental results presented in this paper have been used to validate a detailed heat transfer analysis of the whole system. The heat transfer analysis deals with the study of both the overall heat transfer coefficient and the shell-side heat transfer coefficient. Due to the specific features of this type of system, no correlations were available in the literature. A new numerical model to predict the performance of large-scale systems is also presented.

  17. Synthesis and optical properties of high-purity CoO nanowires prepared by an environmentally friendly molten salt route

    NASA Astrophysics Data System (ADS)

    Wang, Wenzhong; Zhang, Guling

    2009-08-01

    CoO nanowires with diameters of 50 _80 nm, and lengths of up to more than 5 μm have been successfully synthesized by a simple environmentally friendly molten salt route, in which the precursor CoCO 3 nanoparticles are decomposed to form high-purity CoO nanowires in NaCl flux. The structure features and morphology of the as-prepared CoO nanowires were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), high-resolution TEM (HRTEM), and selected area electron diffraction (SAED). The chemical composition and oxidation state of the prepared nanowires were systemically studied by X-ray photoelectron spectra (XPS) and laser Raman spectroscopy. The results indicated that the as-prepared CoO nanowires were composed of pure cubic CoO phase. The growth mechanism of the synthesized nanowires was also discussed in detail based on the experimental results.

  18. Hydrogen-transparent metal surfaces produced by use of molten salts with very low oxygen and water activities

    SciTech Connect

    Deublein, G.; Huggins, R.A. . Dept. of Materials Science and Engineering)

    1989-08-01

    One can employ simple thermodynamic principles to predict conditions under which metals will not form hydrogen-blocking surface oxide layers in electrolyte environments. These principles are used to show that very low oxygen and water activities can be produced in some halide-based molten salt systems by the incorporation of alkali hydrides. Under these conditions, some normally very reactive metals will not form oxide surface layers. As a result, rapid interfacial and surface/bulk equilibria with hydrogen can be attained. Experiments are presented that verify these principles in the titanium-hydrogen and vanadium-hydrogen systems by using electro chemical methods to measure the thermodynamic and kinetic aspects of the solution of hydrogen and the formation of metal hydrides. In addition, it is shown that interfacial equilibrium is obtained very rapidly upon iron and aluminum in such metals.

  19. MOLTEN SALT SYNTHESIS OF YF3:Yb3+/Ln3+(Ln = Er3+, Tm3+) MICROSHEETS WITH MULTICOLOR UPCONVERSION LUMINESCENCE

    NASA Astrophysics Data System (ADS)

    Ding, Mingye; Lu, Chunhua; Cao, Linhai; Ni, Yaru; Xu, Zhongzi

    2013-12-01

    In this paper, highly crystalline YF3:Yb3+/Ln3+(Ln = Er3+, Tm3+) microsheets were successfully synthesized by a surfactant-free molten salt method for the first time. The results indicated that the as-obtained samples belonged to orthorhombic system and exhibited microsheets morphology with side lengths of 30 to 80 μm and wall thickness from 1 to 1.5 μm. By changing the dopant's species (Ln3+), multicolor (yellow and blue) upconversion emission can be observed in YF3:Yb3+/Ln3+ microsheets under 980 nm laser diode (LD) excitation. The upconversion mechanisms in co-doping YF3 samples were analyzed in detail based on the emission spectra. Importantly, this approach not only proposes a new alternative in synthesizing such materials, but also opens the possibility to meet the increasing commercial demand.

  20. An electrochemical study of the ruthenium (III) and (IV) hexachlorometallates in a basic room temperature chloroaluminate molten salt

    SciTech Connect

    Hussey, C.L.; Barnard, P.A.; Sun, I.W. ); Appleby, D.; Hitchcock, P.B.; Seddon, K.R.; Welton, T.; Zora, J.A. )

    1991-09-01

    This paper reports that the ruthenium (IV) complex, RuCl{sub 6}{sup 2{minus}}, exhibits two successive voltammetric reduction waves with peak potentials of 0.34 and {minus} 1.09 V, respectively, in the 49.0/51.0 m/o aluminum chloride-1-methyl-3-ethylimidazolium chloride room temperature molten salt vs. the Al{sup 3+}/Al couple in the 66.7/33.3 m/o melt at 40{degrees}C. The first wave corresponds to the reversible uncomplicated reduction of RuCl{sub 6}{sup 2{minus}} to RuCl{sub 6}{sup 3 {minus}}, and the second appears to arise from the multielectron reduction of the latter complex to produce more than one species. The formal potential of the RuCl{sub 6}{sup 2{minus}/3{minus}} redox system is 0.389 V, and the average Stokes-Einstein products of RuCl{sub 6}{sup 2{minus}} and RuCl{sub 6}{sup 3{minus}} are 1.8 {times} 10{sup {minus}10} and 1.3 {times} 10{sup {minus}10} g cm s{sup {minus}2} K{sup {minus}1}, respectively, in this melt. The reversible half-wave potentials for a variety of 4d- and 5d-hexachlorometallate redox couples that were measured in this molten salt exhibit the same orderly trends with increasing atomic number found in CH{sub 2}Cl{sub 2}. This result was used in conjunction with the half-wave potential of the RuCl{sub 6}{sup 2{minus}/3 {minus}} couple to predict the potential of the (Tc)Cl{sub 6}{sup 2{minus}/3{minus}} redox system in the melt.