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Sample records for molten v2o5-k2s2o7-khso4 systems

  1. Molten metal injector system and method

    DOEpatents

    Meyer, Thomas N.; Kinosz, Michael J.; Bigler, Nicolas; Arnaud, Guy

    2003-04-01

    Disclosed is a molten metal injector system including a holder furnace, a casting mold supported above the holder furnace, and a molten metal injector supported from a bottom side of the mold. The holder furnace contains a supply of molten metal having a metal oxide film surface. The bottom side of the mold faces the holder furnace. The mold defines a mold cavity for receiving the molten metal from the holder furnace. The injector projects into the holder furnace and is in fluid communication with the mold cavity. The injector includes a piston positioned within a piston cavity defined by a cylinder for pumping the molten metal upward from the holder furnace and injecting the molten metal into the mold cavity under pressure. The piston and cylinder are at least partially submerged in the molten metal when the holder furnace contains the molten metal. The cylinder further includes a molten metal intake for receiving the molten metal into the piston cavity. The molten metal intake is located below the metal oxide film surface of the molten metal when the holder furnace contains the molten metal. A method of injecting molten metal into a mold cavity of a casting mold is also disclosed.

  2. 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.

  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. Recirculating Molten Metal Supply System And Method

    DOEpatents

    Kinosz, Michael J.; Meyer, Thomas N.

    2003-07-01

    The melter furnace includes a heating chamber (16), a pump chamber (18), a degassing chamber (20), and a filter chamber (22). The pump chamber (18) is located adjacent the heating chamber (16) and houses a molten metal pump (30). The degassing chamber (20) is located adjacent and in fluid communication with the pump chamber (18), and houses a degassing mechanism (36). The filter chamber (22) is located adjacent and in fluid communication with the degassing chamber (20). The filter chamber (22) includes a molten metal filter (38). The melter furnace (12) is used to supply molten metal to an externally located holder furnace (14), which then recirculates molten metal back to the melter furnace (12).

  5. CONTAINMENT SYSTEM, SPRAY CHAMBER, LOOKING NORTH WITH MIST COOLING MOLTEN ...

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

    CONTAINMENT SYSTEM, SPRAY CHAMBER, LOOKING NORTH WITH MIST COOLING MOLTEN STEEL SLABS AS THEY PROGRESS THROUGH THIS CHAMBER. - U.S. Steel, Fairfield Works, Continuous Caster, Fairfield, Jefferson County, AL

  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. Molten metal feed system controlled with a traveling magnetic field

    DOEpatents

    Praeg, Walter F.

    1991-01-01

    A continuous metal casting system in which the feed of molten metal is controlled by means of a linear induction motor capable of producing a magnetic traveling wave in a duct that connects a reservoir of molten metal to a caster. The linear induction motor produces a traveling magnetic wave in the duct in opposition to the pressure exerted by the head of molten metal in the reservoir so that p.sub.c =p.sub.g -p.sub.m where p.sub.c is the desired pressure in the caster, p.sub.g is the gravitational pressure in the duct exerted by the force of the head of molten metal in the reservoir, and p.sub.m is the electromagnetic pressure exerted by the force of the magnetic field traveling wave produced by the linear induction motor. The invention also includes feedback loops to the linear induction motor to control the casting pressure in response to measured characteristics of the metal being cast.

  8. 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

  9. Systems to Control Molten Metal Transfer in Arc Welding

    NASA Astrophysics Data System (ADS)

    Filonov, A. V.; Kryukov, A. V.; Gusarov, D. E.

    2015-09-01

    The paper analyzes the systems used for controlling molten wire metal droplets during the arc welding process in shielding gases. The variations for implementing the relevant systems are given, with the positive and negative aspects of such implementation taken into account. Electrical systems are currently investigated to the fullest extent possible and implemented in different power sources for pulsed welding arc. Mechanical systems are represented by different types of feeders that provide the pulsed wire feeding process. The feed mechanisms driven by electric motors and electromagnets are analyzed. In addition to the mechanical and electrical systems, the examples of combined control systems are given.

  10. MAG-GATE System for Molten metal Flow Control

    SciTech Connect

    Richard D. Nathenson, P.E.

    2004-05-15

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

  11. Fundamental study of molten pool depth measurement method using an ultrasonic phased array system

    NASA Astrophysics Data System (ADS)

    Mizota, Hirohisa; Nagashima, Yoshiaki; Obana, Takeshi

    2015-07-01

    The molten pool depth measurement method using an ultrasonic phased array system has been developed. The molten pool depth distribution is evaluated by comparing the times taken by the ultrasonic wave to propagate through a molten pool and a solid-phase and through only the solid-phase near the molten pool. Maximum molten pool depths on a flat type-304 stainless-steel plate, formed with a gas tungsten arc welding machine for different welding currents from 70 to 150 A, were derived within an error of ±0.5 mm.

  12. Molten metal holder furnace and casting system incorporating the molten metal holder furnace

    DOEpatents

    Kinosz, Michael J.; Meyer, Thomas N.

    2003-02-11

    A bottom heated holder furnace (12) for containing a supply of molten metal includes a storage vessel (30) having sidewalls (32) and a bottom wall (34) defining a molten metal receiving chamber (36). A furnace insulating layer (42) lines the molten metal receiving chamber (36). A thermally conductive heat exchanger block (54) is located at the bottom of the molten metal receiving chamber (36) for heating the supply of molten metal. The heat exchanger block (54) includes a bottom face (65), side faces (66), and a top face (67). The heat exchanger block (54) includes a plurality of electrical heaters (70) extending therein and projecting outward from at least one of the faces of the heat exchanger block (54), and further extending through the furnace insulating layer (42) and one of the sidewalls (32) of the storage vessel (30) for connection to a source of electrical power. A sealing layer (50) covers the bottom face (65) and side faces (66) of the heat exchanger block (54) such that the heat exchanger block (54) is substantially separated from contact with the furnace insulating layer (42).

  13. 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.

  14. Tunable molten oxide pool assisted plasma-melter vitrification systems

    DOEpatents

    Titus, Charles H.; Cohn, Daniel R.; Surma, Jeffrey E.

    1998-01-01

    The present invention provides tunable waste conversion systems and apparatus which have the advantage of highly robust operation and which provide complete or substantially complete conversion of a wide range of waste streams into useful gas and a stable, nonleachable solid product at a single location with greatly reduced air pollution to meet air quality standards. The systems provide the capability for highly efficient conversion of waste into high quality combustible gas and for high efficiency conversion of the gas into electricity by utilizing a high efficiency gas turbine or an internal combustion engine. The solid product can be suitable for various commercial applications. Alternatively, the solid product stream, which is a safe, stable material, may be disposed of without special considerations as hazardous material. In the preferred embodiment, the arc plasma furnace and joule heated melter are formed as a fully integrated unit with a common melt pool having circuit arrangements for the simultaneous independently controllable operation of both the arc plasma and the joule heated portions of the unit without interference with one another. The preferred configuration of this embodiment of the invention utilizes two arc plasma electrodes with an elongated chamber for the molten pool such that the molten pool is capable of providing conducting paths between electrodes. The apparatus may additionally be employed with reduced use or without further use of the gases generated by the conversion process. The apparatus may be employed as a net energy or net electricity producing unit where use of an auxiliary fuel provides the required level of electricity production. Methods and apparatus for converting metals, non-glass forming waste streams and low-ash producing inorganics into a useful gas are also provided. The methods and apparatus for such conversion include the use of a molten oxide pool having predetermined electrical, thermal and physical

  15. 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

  16. 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.

  17. Magnetic Gate System for Molten Metal Flow Control

    SciTech Connect

    2001-02-01

    Electromagnetics Offer Many Advantages For Better Control Of The Molten Steel. Over 80 percent of all of the world's yearly steel production or approximately 650 million tons, is produced by the continuous casting process.

  18. 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.

  19. 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

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. Automatic Welding System of Aluminum Pipe by Monitoring Backside Image of Molten Pool Using Vision Sensor

    NASA Astrophysics Data System (ADS)

    Baskoro, Ario Sunar; Kabutomori, Masashi; Suga, Yasuo

    An automatic welding system using Tungsten Inert Gas (TIG) welding with vision sensor for welding of aluminum pipe was constructed. This research studies the intelligent welding process of aluminum alloy pipe 6063S-T5 in fixed position and moving welding torch with the AC welding machine. The monitoring system consists of a vision sensor using a charge-coupled device (CCD) camera to monitor backside image of molten pool. The captured image was processed to recognize the edge of molten pool by image processing algorithm. Neural network model for welding speed control were constructed to perform the process automatically. From the experimental results it shows the effectiveness of the control system confirmed by good detection of molten pool and sound weld of experimental result.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. Conjugate heat transfer analysis of an ultrasonic molten metal treatment system

    NASA Astrophysics Data System (ADS)

    Zhu, Youli; Bian, Feilong; Wang, Yanli; Zhao, Qian

    2014-09-01

    In piezoceramic ultrasonic devices, the piezoceramic stacks may fail permanently or function improperly if their working temperatures overstep the Curie temperature of the piezoceramic material. While the end of the horn usually serves near the melting point of the molten metal and is enclosed in an airtight chamber, so that it is difficult to experimentally measure the temperature of the transducer and its variation with time, which bring heavy difficulty to the design of the ultrasonic molten metal treatment system. To find a way out, conjugate heat transfer analysis of an ultrasonic molten metal treatment system is performed with coupled fluid and heat transfer finite element method. In modeling of the system, the RNG model and the SIMPLE algorithm are adopted for turbulence and nonlinear coupling between the momentum equation and the energy equation. Forced air cooling as well as natural air cooling is analyzed to compare the difference of temperature evolution. Numerical results show that, after about 350 s of working time, temperatures in the surface of the ceramic stacks in forced air cooling drop about 7 K compared with that in natural cooling. At 240 s, The molten metal surface emits heat radiation with a maximum rate of about 19 036 W/m2, while the heat insulation disc absorbs heat radiation at a maximum rate of about 7922 W/m2, which indicates the effectiveness of heat insulation of the asbestos pad. Transient heat transfer film coefficient and its distribution, which are difficult to be measured experimentally are also obtained through numerical simulation. At 240 s, the heat transfer film coefficient in the surface of the transducer ranges from -17.86 to 20.17 W/(m2 · K). Compared with the trial and error method based on the test, the proposed research provides a more effective way in the design and analysis of the temperature control of the molten metal treatment system.

  14. 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

  15. 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)

  16. Multi-functional sensor system for molten salt technologies

    SciTech Connect

    Redey, Laszlo; Gourishankar, Karthick; Williamson, Mark A.

    2009-12-15

    The present invention relates to a multi-functional sensor system that simultaneously measures cathode and anode electrode potentials, dissolved ion (i.e. oxide) concentration, and temperatures in an electrochemical cell. One embodiment of the invented system generally comprises: a reference(saturated) electrode, a reference(sensing) electrode, and a data acquisition system. Thermocouples are built into the two reference electrodes to provide important temperature information.

  17. The study of integrated coal-gasifier molten carbonate fuel cell systems

    NASA Technical Reports Server (NTRS)

    1983-01-01

    A novel integration concept for a coal-fueled coal gasifier-molten carbonate fuel cell power plant was studied. Effort focused on determining the efficiency potential of the concept, design, and development requirements of the processes in order to achieve the efficiency. The concept incorporates a methane producing catalytic gasifier of the type previously under development by Exxon Research and Development Corp., a reforming molten carbonate fuel cell power section of the type currently under development by United Technologies Corp., and a gasifier-fuel cell recycle loop. The concept utilizes the fuel cell waste heat, in the form of hydrogen and carbon monoxide, to generate additional fuel in the coal gasifier, thereby eliminating the use of both an O2 plant and a stream bottoming cycle from the power plant. The concept has the potential for achieving coal-pile-to-busbar efficiencies of 50-59%, depending on the process configuration and degree of process configuration and degree of process development requirements. This is significantly higher than any previously reported gasifier-molten carbonate fuel cell system.

  18. 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.

  19. Molten-Caustic-Leaching (Gravimelt) system integration project

    SciTech Connect

    Not Available

    1990-03-01

    The objectives of the tasks covered in this document are to design, construct, and shakedown a 20 pounds of coal per hour integrated MCL test circuit to demonstrate the feasibility of the technology for producing a demineralized and desulfurized coal that meets New Source Performance Standards (NSPS). These objectives were met with the construction and shakedown of the integrated test circuit. Although mild kiln conditions (340{degree}C and 2 hours residence time) and a low caustic to coal ratio (1 to 1) were used, the combination of continuous operation and rigorous exclusion of air from the system allowed the production of MCL coal, from high sulfur, high ash coal, which has virtually no carbonate and volatiles loss, which does not form excessively wet cakes in during washing, and which has low alkali retention by the product MCL coal. Equipment performance was generally consistent with design requirements.

  20. 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.

  1. 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.

  2. 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.

  3. 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

  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. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. Electrochemical separation of uranium in the molten system LiF-NaF-KF-UF4

    NASA Astrophysics Data System (ADS)

    Korenko, M.; Straka, M.; Szatmáry, L.; Ambrová, M.; Uhlíř, J.

    2013-09-01

    This article is focused on the electrochemical investigation (cyclic voltammetry and related studies) of possible reduction of U4+ ions to metal uranium in the molten system LiF-NaF-KF(eut.)-UF4 that can provide basis for the electrochemical extraction of uranium from molten salts. Two-step reduction mechanism for U4+ ions involving one electron exchange in soluble/soluble U4+/U3+ system and three electrons exchange in the second step were found on the nickel working electrode. Both steps were found to be reversible and diffusion controlled. Based on cyclic voltammetry, the diffusion coefficients of uranium ions at 530 °C were found to be D(U4+) = 1.64 × 10-5 cm2 s-1 and D(U3+) 1.76 × 10-5 cm2 s-1. Usage of the nickel spiral electrode for electrorefining of uranium showed fairly good feasibility of its extraction. However some oxidant present during the process of electrorefining caused that the solid deposits contained different uranium species such as UF3, UO2 and K3UO2F5.

  11. Experimental observations on electrorefining spent nuclear fuel in molten LiCl-KCl/liquid cadmium system.

    SciTech Connect

    Johnson, T. A.; Laug, D. V.; Li, S. X.; Sofu, T.

    1999-07-14

    Argonne National Laboratory (ANL) is currently performing a demonstration program for the Department of Energy (DOE) which processes spent nuclear fuel from the Experimental Breeder Reactor (EBR-II). One of the key steps in this demonstration program is electrorefining of the spent fuel in a molten LiCl-KCl/liquid cadmium system using a pilot scale electrorefiner (Mk-IV ER). This article summarizes experimental observations and engineering aspects for electrorefining spent fuel in the molten LiCl-KCl/liquid cadmium system. It was found that the liquid cadmium pool acted as an intermediate electrode during the electrorefining process in the ER. The cadmium level was gradually decreased due to its high vapor pressure and vaporization rate at the ER operational temperature. The low cadmium level caused the anode assembly momentarily to touch the ER vessel hardware, which generated a periodic current change at the salt/cathode interface and improved uranium recovery efficiency for the process. The primary current distributions calculated by numerical simulations were used in interpreting the experimental results.

  12. Video imaging system and thermal mapping of the molten hearth in an electron beam melting furnace

    SciTech Connect

    Miszkiel, M.E.; Davis, R.A.; Van Den Avyle, J.A.

    1995-12-31

    This project was initiated to develop an enhanced video imaging system for the Liquid Metal Processing Laboratory Electron Beam Melting (EB) Furnace at Sandia and to use color video images to map the temperature distribution of the surface of the molten hearth. In a series of test melts, the color output of the video image was calibrated against temperatures measured by an optical pyrometer and CCD camera viewing port above the molten pool. To prevent potential metal vapor deposition onto line-of-sight optical surfaces above the pool, argon backfill was used along with a pinhole aperture to obtain the vide image. The geometry of the optical port to the hearth set the limits for the focus lens and CCD camera`s field of view. Initial melts were completed with the pyrometer and pinhole aperture port in a fixed position. Using commercially available vacuum components, a second flange assembly was constructed to provide flexibility in choosing pyrometer target sights on the hearth and to adjust the field of view for the focus lens/CCD combination. RGB video images processed from the melts verified that red wavelength light captured with the video camera could be calibrated with the optical pyrometer target temperatures and used to generate temperature maps of the hearth surface. Two color ratio thermal mapping using red and green video images, which has theoretical advantages, was less successful due to probable camera non-linearities in the red and green image intensities.

  13. 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.

  14. 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.

  15. 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.

  16. 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)

  17. Experimental study on the dynamic characteristics of kW-scale molten carbonate fuel cell systems

    NASA Astrophysics Data System (ADS)

    Kang, Byoung Sam; Koh, Joon-Ho; Lim, Hee Chun

    The aim of this work is to develop dynamic models for two types of kW-scale molten carbonate fuel cell (MCFC) systems on the basis of experimental data. The dynamic models are represented as a 3×3 transfer function matrix for a multi-input and multi-output (MIMO) system with three inputs and three outputs. The three controlled variables which severely affect the stack performance and lifetime are the temperature difference in the stack and the pressure drop at the anode and the cathode. Three manipulated variables, namely, current load, fuel and oxidant utilization, are selected to keep the three controlled variables within their safety limits for the reliable operation and protection of the system in case of emergency. Each element in the transfer function matrix is in the form of a first-order model using a simple, unit step, response test during operation. The non-zero off-diagonal elements in the transfer function matrix show that some interactions exist among the operating variables, and two zeros show no interaction between fuel and oxidant flow without gas cross-over. The stability of both dynamic models is analyzed using the relative gain array (RGA) method. Large diagonal elements in the RGA matrix show that the pairing between the manipulated and controlled variables is appropriate. Proper pairing is also proven by the singular value analysis (SVA) method with a smaller singular value in each system.

  18. 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

  19. Research of online weighing system of molten-iron based on image processing

    NASA Astrophysics Data System (ADS)

    Zhang, Lei; Hu, Jia-long; Qian, Ya-ping

    2008-03-01

    A non-contact online detection method of molten-iron weighing based on image processing being researched in the paper. The digital image of the cross on torpedo cans can be obtained via video camera. The moved distance of the spring on flatbed can be measured through image processing. Meanwhile, the surface resolution can be flagged by the use of parallel-lines detection method. Finally, the weight and velocity of molten iron can be calculated with the elastic law.

  20. Cycle Analysis of Micro Gas Turbine-Molten Carbonate Fuel Cell Hybrid System

    NASA Astrophysics Data System (ADS)

    Kimijima, Shinji; Kasagi, Nobuhide

    A hybrid system based on a micro gas turbine (µGT) and a high-temperature fuel cell, i.e., molten carbonate fuel cell (MCFC) or solid oxide fuel cell (SOFC), is expected to achieve a much higher efficiency than conventional distributed power generation systems. In this study, a cycle analysis method and the performance evaluation of a µGT-MCFC hybrid system, of which the power output is 30kW, are investigated to clarify its feasibility. We developed a general design strategy in which a low fuel input to a combustor and higher MCFC operating temperature result in a high power generation efficiency. A high recuperator temperature effectiveness and a moderate steam-carbon ratio are the requirements for obtaining a high material strength in a turbine. In addition, by employing a combustor for complete oxidation of MCFC effluents without additional fuel input, i.e., a catalytic combustor, the power generation efficiency of a µGT-MCFC is achieved at over 60%(LHV).

  1. 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.

  2. Laser-produced plasma sensor-probe system for in situ molten metal analysis. Final technical report

    SciTech Connect

    Kim, Y.W.

    1997-01-28

    The radically new methodology of in-situ laser-produced plasma (LPP) analysis of molten metals, as developed at Lehigh University, has been implemented into an LPP sensor-probe system, ready for deployment at steelmaking facilities. The system consists of an LPP sensor-probe head, which is immersed into the molten metal bath for the short duration of measurement, a control console, an umbilical cord connecting the above two units, and a support console providing coolants and pneumatic supports to the control console. The Department of Energy funding has supported Phase III-A and -B of the project in a joint sponsorship with AISI, CTU 5-2 Consortium, and Lehigh University. The objectives have been to: (1) implement the molten metal calibration protocol for the LPP analysis methodology; (2) implement the methodology in the form of a second-generation LPP sensor-probe system, which facilitates real-time process control by in-situ determination of elemental composition of molten steel alloys; (3) deploy such developmental systems in steelmaking facilities; (4) upgrade the systems to a third-generation design; and (5) effect technology transfer by selecting a manufacturer of commercial LPP sensor-probe systems. Four of the five objectives have been fully met. The deployment objective has been partially realized at present. The full LPP sensor-probe system has been put through trial immersion runs at a foundry, but its deployment at steelmaking facilities has progressed to a stage where various issues of financial and legal nature are being codified into a formal agreement between a host site and Lehigh University.

  3. 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.

  4. Behaviour of materials for accelerator driven systems in stagnant molten lead

    NASA Astrophysics Data System (ADS)

    Benamati, Gianluca; Buttol, Patrizia; Imbeni, Valentina; Martini, Carla; Palombarini, Giuseppe

    2000-06-01

    The behaviour of a modified F82H martensitic steel (both uncoated and aluminised) and tungsten was evaluated by immersion tests in stagnant, oxygen-saturated liquid lead at 793 K under an argon atmosphere, for exposure times up to 3700 h. The F82H steel is a candidate structural material for Accelerator Driven Systems (ADS), while tungsten is potentially suitable for a beam window working immersed in liquid lead. Layers of Me 3O 4 consisting of an inner sublayer with Me=Fe and Cr and an outer chromium-free sublayer of Fe 3O 4, formed on the surface of the uncoated steel while the aluminised steel showed no significant alteration. On tungsten, a compact and adherent layer of WO 3 formed and reacted with liquid lead leading to the formation of friable Pb-W-O ternary compounds. A two-step mechanism is proposed for interactions of metals and alloys exposed to oxygen-saturated molten lead: the first step is the solid phase oxidation of the base metal; the second is the interaction between liquid lead and the oxide layer formed on the metal surface.

  5. 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.

  6. 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)

  7. 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.

  8. 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.

  9. 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.

  10. 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).

  11. 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.

  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. 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.

  14. 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.

  15. 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.

  16. 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

  17. 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

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. Theoretical Studies of Structure and Dynamics of Molten Salts: The LiF–ThF4 System

    SciTech Connect

    Liu, Jian-Biao; Chen, Xin; Qiu, YiHeng; Xu, Chao-Fei; Schwarz, W H E.; Li, Jun

    2014-12-04

    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 M4+–F– dissociation and the lifetime of the first coordination shell of M4+ 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.

  4. 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.

  5. Molten carbonate fuel cell

    DOEpatents

    Kaun, T.D.; Smith, J.L.

    1986-07-08

    A molten electrolyte fuel cell is disclosed with an array of stacked cells and cell enclosures isolating each cell except for access to gas manifolds for the supply of fuel or oxidant gas or the removal of waste gas. The cell enclosures collectively provide an enclosure for the array and effectively avoid the problems of electrolyte migration and the previous need for compression of stack components. The fuel cell further includes an inner housing about and in cooperation with the array enclosure to provide a manifold system with isolated chambers for the supply and removal of gases. An external insulated housing about the inner housing provides thermal isolation to the cell components.

  6. Molten carbonate fuel cell

    DOEpatents

    Kaun, Thomas D.; Smith, James L.

    1987-01-01

    A molten electrolyte fuel cell with an array of stacked cells and cell enclosures isolating each cell except for access to gas manifolds for the supply of fuel or oxidant gas or the removal of waste gas, the cell enclosures collectively providing an enclosure for the array and effectively avoiding the problems of electrolyte migration and the previous need for compression of stack components, the fuel cell further including an inner housing about and in cooperation with the array enclosure to provide a manifold system with isolated chambers for the supply and removal of gases. An external insulated housing about the inner housing provides thermal isolation to the cell components.

  7. Reactive transport in a partially molten system with binary solid solution

    NASA Astrophysics Data System (ADS)

    Jordan, Jacob S.; Hesse, Marc A.

    2015-12-01

    Melt extraction from the Earth's mantle through high-porosity channels is required to explain the composition of the oceanic crust. Feedbacks from reactive melt transport are thought to localize melt into a network of high-porosity channels. Recent studies invoke lithological heterogeneities in the Earth's mantle to seed the localization of partial melts. Therefore, it is necessary to understand the reaction fronts that form as melt flows across the lithological interface between the heterogeneity and the ambient mantle. Here we present a chromatographic analysis of reactive melt transport across lithological boundaries, using the theory of hyperbolic conservation laws. This is an extension of linear trace element chromatography to the coupling of major elements and energy transport. Our analysis allows the prediction of the nonlinear feedbacks that arise in reactive melt transport due to changes in porosity. This study considers the special case of a partially molten porous medium with binary solid solution. As melt traverses a lithological contact, binary solid solution leads to the formation of a reacted zone between an advancing reaction front and the initial contact. The analysis also shows that the behavior of a fertile heterogeneity depends on its absolute concentration, in addition to compositional differences between itself and the refractory background. We present a regime diagram that predicts if melt emanating from a fertile heterogeneity localizes into high-porosity channels or develops a zero porosity shell. The theoretical framework presented here provides a useful tool for understanding nonlinear feedbacks in reactive melt transport, because it can be extended to more complex and realistic phase behaviors.

  8. Remediation of 1,2,3-trichlorobenzene contaminated soil using a combined thermal desorption-molten salt oxidation reactor system.

    PubMed

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

    2014-02-01

    A combined thermal desorption (TD)-molten salt oxidation (MSO) reactor system was applied to remediate the 1,2,3-trichlorobenzene (1,2,3-TCB) contaminated soil. The TD reactor was used to enrich the contaminant from soil, and its dechlorination of the contaminant was achieved in the MSO reactor. The optimum operating conditions of TD, and the effects of MSO reactor temperatures, additive amounts of the TCB on destruction and removal efficiency (DRE) of TCB and chlorine retention efficiency (CRE) were investigated. The reaction mechanism and pathway were proposed as well. The combined system could remediate the contaminated soil at a large scale of concentration from 5 to 25gkg(-1), and the DRE and CRE reached more than 99% and 95%, respectively, at temperatures above 850°C. The reaction emissions included C6H6, CH4, CO and CO2, and chlorinated species were not detected. It was found that a little increase in the temperature can considerably reduce the emission of C6H6, CH4, and CO, while the CO2 level increased.

  9. Composite superconducting wires obtained by high-rate tinning in molten Bi-Pb-Sr-Ca-Cu-O system

    NASA Technical Reports Server (NTRS)

    Grosav, A. D.; Konopko, L. A.; Leporda, N. I.

    1991-01-01

    Long lengths of metal superconductor composites were prepared by passing a copper wire through the bismuth based molten oxide system at a constant speed. The key to successful composite preparation is the high pulling speed involved, which permits minimization of the severe interaction between the unbuffered metal surface and the oxide melt. Depending on the temperature of the melt and the pulling speed, a coating with different thickness and microstructure appeared. The nonannealed thick coatings contained a Bi2(Sr,Ca)2Cu1O6 phase as a major component. After relatively short time annealing at 800 C, both resistivity and initial magnetization versus temperature measurements show superconducting transitions beginning in the 110 to 115 K region. The effects of annealing and composition on obtained results are discussed. This method of manufacture led to the fabrication of wire with a copper core in a dense covering with uniform thickness of about h approximately equal to 5 to 50 microns. Composite wires with h approximately equal to 10 microns (h/d approximately equal to 0.1) sustained bending on a 15 mm radius frame without cracking during flexing.

  10. Casting Apparatus Including A Gas Driven Molten Metal Injector And Method

    DOEpatents

    Trudel, David R.; Meyer, Thomas N.; Kinosz, Michael J.; Arnaud, Guy; Bigler, Nicolas

    2003-06-17

    The filtering molten metal injector system includes a holder furnace, a casting mold supported above the holder furnace, and at least one molten metal injector supported from a bottom side of the casting mold. The holder furnace contains a supply of molten metal. The mold defines a mold cavity for receiving the molten metal from the holder furnace. The molten metal injector projects into the holder furnace. The molten metal injector includes a cylinder defining a piston cavity housing a reciprocating piston for pumping the molten metal upward from the holder furnace to the mold cavity. The cylinder and piston are at least partially submerged in the molten metal when the holder furnace contains the molten metal. The cylinder or the piston includes a molten metal intake for receiving the molten metal into the piston cavity when the holder furnace contains molten metal. A conduit connects the piston cavity to the mold cavity. A molten metal filter is located in the conduit for filtering the molten metal passing through the conduit during the reciprocating movement of the piston. The molten metal intake may be a valve connected to the cylinder, a gap formed between the piston and an open end of the cylinder, an aperture defined in the sidewall of the cylinder, or a ball check valve incorporated into the piston. A second molten metal filter preferably covers the molten metal intake to the injector.

  11. Electrodeposition of molten silicon

    DOEpatents

    De Mattei, Robert C.; Elwell, Dennis; Feigelson, Robert S.

    1981-01-01

    Silicon dioxide is dissolved in a molten electrolytic bath, preferably comprising barium oxide and barium fluoride. A direct current is passed between an anode and a cathode in the bath to reduce the dissolved silicon dioxide to non-alloyed silicon in molten form, which is removed from the bath.

  12. Electrodeposition of molten silicon

    SciTech Connect

    De Mattei, R.C.; Elwell, D.; Feigelson, R.S.

    1981-09-29

    Silicon dioxide is dissolved in a molten electrolytic bath, preferably comprising barium oxide and barium fluoride. A direct current is passed between an anode and a cathode in the bath to reduce the dissolved silicon dioxide to non-alloyed silicon in molten form, which is then removed from the bath.

  13. Solidification of high temperature molten salts for thermal energy storage systems

    NASA Technical Reports Server (NTRS)

    Sheffield, J. W.

    1981-01-01

    The solidification of phase change materials for the high temperature thermal energy storage system of an advanced solar thermal power system has been examined theoretically. In light of the particular thermophysical properties of candidate phase change high temperature salts, such as the eutectic mixture of NaF - MgF2, the heat transfer characteristics of one-dimensional inward solidification for a cylindrical geometry have been studied. The Biot number for the solidified salt is shown to be the critical design parameter for constant extraction heat flux. A fin-on-fin design concept of heat transfer surface augmentation is proposed in an effort to minimize the effects of the salt's low thermal conductivity and large volume change upon fusing.

  14. Application of the Evacuated Canister System for Removing Residual Molten Glass From the West Valley Demonstration Project High-Level Waste Melter

    SciTech Connect

    May, Joseph J.; Dombrowski, David J.; Valenti, Paul J.; Houston, Helene M.

    2003-02-27

    The principal mission of the West Valley Demonstration Project (WVDP) is to meet a series of objectives defined in the West Valley Demonstration Project Act (Public Law 96-368). Chief among these is the objective to solidify liquid high-level waste (HLW) at the WVDP site into a form suitable for disposal in a federal geologic repository. In 1982, the Secretary of Energy formally selected vitrification as the technology to be used to solidify HLW at the WVDP. One of the first steps in meeting the HLW solidification objective involved designing, constructing and operating the Vitrification (Vit) Facility, the WVDP facility that houses the systems and subsystems used to process HLW into stainless steel canisters of borosilicate waste-glass that satisfy waste acceptance criteria (WAC) for disposal in a federal geologic repository. HLW processing and canister production began in 1996. The final step in meeting the HLW solidification objective involved ending Vit system operations and shut ting down the Vit Facility. This was accomplished by conducting a discrete series of activities to remove as much residual material as practical from the primary process vessels, components, and associated piping used in HLW canister production before declaring a formal end to Vit system operations. Flushing was the primary method used to remove residual radioactive material from the vitrification system. The inventory of radioactivity contained within the entire primary processing system diminished by conducting the flushing activities. At the completion of flushing activities, the composition of residual molten material remaining in the melter (the primary system component used in glass production) consisted of a small quantity of radioactive material and large quantities of glass former materials needed to produce borosilicate waste-glass. A special system developed during the pre-operational and testing phase of Vit Facility operation, the Evacuated Canister System (ECS), was

  15. Molten salt fuels for treatment of plutonium and radwastes in ADS critical systems

    NASA Astrophysics Data System (ADS)

    Ignatiev, Victor V.

    2000-07-01

    Introduction of the innovative reactor concept of the incinerator type in the future nuclear power system should provide the following: • Low Plutonium and Minor Actinides Total Inventory in the Nuclear Fuel Cycle (M) • Reduced Actinides Total Losses to Waste (W) • Minimal Uranium-235 SupportMinimal Neutron Captures Outside Actinides (Coolant & Structural Material Activation Products). Estimations have shown strong dependence of the first two parameters (M and W), which are responsible for incinerator efficiency, from the burnup (c) reached in the core of an incinerator and the actinides mass flow rate in the fuel cycle (A(t)=G(t)/Q(t), where G(t)=amount of TRU fed to the process during t, and Q(t)=electricity produced during (t).

  16. Update on Small Modular Reactors Dynamics System Modeling Tool -- Molten Salt Cooled Architecture

    SciTech Connect

    Hale, Richard Edward; Cetiner, Sacit M.; Fugate, David L.; Qualls, A L.; Borum, Robert C.; Chaleff, Ethan S.; Rogerson, Doug W.; Batteh, John J.; Tiller, Michael M.

    2014-08-01

    The Small Modular Reactor (SMR) Dynamic System Modeling Tool project is in the third year of development. The project is designed to support collaborative modeling and study of various advanced SMR (non-light water cooled) concepts, including the use of multiple coupled reactors at a single site. The objective of the project is to provide a common simulation environment and baseline modeling resources to facilitate rapid development of dynamic advanced reactor SMR models, ensure consistency among research products within the Instrumentation, Controls, and Human-Machine Interface (ICHMI) technical area, and leverage cross-cutting capabilities while minimizing duplication of effort. The combined simulation environment and suite of models are identified as the Modular Dynamic SIMulation (MoDSIM) tool. The critical elements of this effort include (1) defining a standardized, common simulation environment that can be applied throughout the program, (2) developing a library of baseline component modules that can be assembled into full plant models using existing geometry and thermal-hydraulic data, (3) defining modeling conventions for interconnecting component models, and (4) establishing user interfaces and support tools to facilitate simulation development (i.e., configuration and parameterization), execution, and results display and capture.

  17. 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.

  18. 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.

  19. Design of a californium source-driven measurement system for accountability of material recovered from the Molten Salt Reactor Experiment charcoal bed

    SciTech Connect

    Bentzinger, D.L.; Perez, R.B.; Mattingly, J.K.; Valentine, T.E.; Mihalczo, J.T.

    1998-05-01

    The Molten Salt Reactor Experiment Facility (MSRE) operated from 1965 to 1969. The fuel was a molten salt that flowed through the reactor core which consisted of uranium tetrafluoride with molten lithium and beryllium salt used as the coolant. In 1968 the fuel was switched from {sup 235}U to {sup 233}U. The Molten Salt Reactor Experiment was canceled in 1969 at which time approximately 4800 kg of salt was transferred to the fuel drain tanks. There was about 36.3 kg of uranium, 675 grams of plutonium and various fission products present in the fuel salt. The salt was allowed to solidify in the fuel drain tanks. The salt was heated on a yearly basis to recombine the fluorine gas with the uranium salt mixture. In March 1994, a gas sample was taken from the off gas system that indicated {sup 233}U had migrated from the fuel drain tank system to the off gas system. It was found that approximately 2.6 kg of uranium had migrated to the Auxiliary Charcoal Bed (ACB). The ACB is located in the concrete-lined charcoal bed cell which is below ground level located outside the MSRE building. Therefore, there was a concern for the potential of a nuclear criticality accident, although water would have to leak into the chamber for a criticality accident to occur. Unstable carbon/fluorine compounds were also formed when the fluorine reacted with the charcoal in the charcoal bed. The purpose of the proposed measurement system was to perform an accountability measurement to determine the fissile mass of {sup 233}U in the primary vessel. The contents of the primary containment assembly will then be transferred to three smaller containers for long term storage. Calculations were performed using MCNP-DSP to determine the configuration of the measurement system. The information obtained from the time signatures can then be compared to the measurement data to determine the amount of {sup 233}U present in the primary containment assembly.

  20. Molten metal reactors

    DOEpatents

    Bingham, Dennis N; Klingler, Kerry M; Turner, Terry D; Wilding, Bruce M

    2013-11-05

    A molten metal reactor for converting a carbon material and steam into a gas comprising hydrogen, carbon monoxide, and carbon dioxide is disclosed. The reactor includes an interior crucible having a portion contained within an exterior crucible. The interior crucible includes an inlet and an outlet; the outlet leads to the exterior crucible and may comprise a diffuser. The exterior crucible may contain a molten alkaline metal compound. Contained between the exterior crucible and the interior crucible is at least one baffle.

  1. Neutronics Study on Accelerator Driven Subcritical Systems with Thorium-Based Fuel for Comparison Between Solid and Molten-Salt Fuels

    SciTech Connect

    Ishimoto, Shunsuke; Ishibashi, Kenji; Tenzou, Hideki; Sasa, Toshinobu

    2002-06-15

    Since thorium is an abundant fertile material, there is hope for the thorium-cycle fuels for an accelerator driven subcritical system (ADS). The ADS utilizes neutrons, which are generated by high-energy protons of giga-electron-volt-grade, but cross sections for the interaction of high-energy particles are not available for use in current ADS engineering design. In this paper the neutron behavior in the ADS target based on the related experimental data is clarified, and the feasibility of the ADS regarding both the molten salts (Flibe: {sup 7}LiF-BeF{sub 2}-ThF{sub 4}-{sup 233}UF{sub 4}, chloride: NaCl-ThCl{sub 4}-{sup 233}UCl{sub 4}) and oxide ([Th, {sup 233}U]O{sub 2}) fuels is examined. The difference between the experiment and the calculated result at the ADS high-energy region is discussed. In a comparison of the fuels, the time evolution of k{sub eff} and the beam current in the burning period are calculated. The calculated results suggest that the ADS with solid fuel has better future prospects than that with molten-salt fuels. The ADS with Flibe molten-salt fuel tends to require a high beam current and consequently needs the installation of a metallic spallation target and the continuous removal for fission products and protactinium. In comparison with the Flibe fuel, the ADS with chloride fuel has a flux distribution that is similar to a solid fuel reactor.

  2. Composite superconducting wires obtained by high-rate tinning in molten Bi-Pb-Sr-Ca-Cu-O system

    NASA Technical Reports Server (NTRS)

    Grozav, A. D.; Konopko, L. A.; Leporda, N. I.

    1990-01-01

    The preparation of high-T(sub c) superconducting long composite wires by short-time tinning of the metal wires in a molten Bi-Pb-Sr-Ca-Cu-O compound is discussed. The application of this method to the high-T(sub c) materials is tested, possibly for the first time. The initial materials used for this experiment were ceramic samples with nominal composition Bi(1.5)Pb(0.5)Sr2Ca2Cu3O(x) and T(sub c) = 80 K prepared by the ordinary solid-state reaction, and industrial copper wires from 100 to 400 microns in diameter and from 0.5 to 1 m long. The continuously moving wires were let through a small molten zone (approximately 100 cubic mm). The Bi-based high-T(sub c) ceramics in a molten state is a viscous liquid and it has a strongly pronounced ability to spread on metal wire surfaces. The maximum draw rate of the Cu-wire, at which a dense covering is still possible, corresponds to the time of direct contact of wire surfaces and liquid ceramics for less than 0.1 s. A high-rate draw of the wire permits a decrease in the reaction of the oxide melt and Cu-wire. This method of manufacture led to the fabrication of wire with a copper core in a dense covering with uniform thickness of about h approximately equal to 5 to 50 microns. Composite wires with h approximately equal to 10 microns (h/d approximately equal to 0.1) sustained bending on a 15 mm radius frame without cracking during flexing.

  3. 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.

  4. Thermodynamic assessment of the LiF-CeF3-ThF4 system: Prediction of PuF3 concentration in a molten salt reactor fuel

    NASA Astrophysics Data System (ADS)

    Beneš, O.; Konings, R. J. M.

    2013-04-01

    A thermodynamic description of the LiF-CeF3-ThF4 system is made in this study using a two-sublattice model for the description of the solid solution and a quasi-chemical model based on quadruplet approximation for the liquid phase. New calorimetric experimental data of the binary LiF-CeF3, CeF3-ThF4 and ternary LiF-CeF3-ThF4 systems have been obtained in this work justifying the calculated phase diagrams. Using the obtained thermodynamic assessment the concentration of PuF3 in the LiF-ThF4 melt was estimated based on the similarities with CeF3 and the melting behaviour of the initial molten salt fast reactor fuel was discussed.

  5. 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.

  6. 46 CFR 151.50-55 - Sulfur (molten).

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false Sulfur (molten). 151.50-55 Section 151.50-55 Shipping... BULK LIQUID HAZARDOUS MATERIAL CARGOES Special Requirements § 151.50-55 Sulfur (molten). (a... depositing of sulfur within the system. (b) Void spaces: (1) Openings to void spaces adjacent to cargo...

  7. 46 CFR 151.50-55 - Sulfur (molten).

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 5 2012-10-01 2012-10-01 false Sulfur (molten). 151.50-55 Section 151.50-55 Shipping... BULK LIQUID HAZARDOUS MATERIAL CARGOES Special Requirements § 151.50-55 Sulfur (molten). (a... depositing of sulfur within the system. (b) Void spaces: (1) Openings to void spaces adjacent to cargo...

  8. 46 CFR 151.50-55 - Sulfur (molten).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 5 2014-10-01 2014-10-01 false Sulfur (molten). 151.50-55 Section 151.50-55 Shipping... BULK LIQUID HAZARDOUS MATERIAL CARGOES Special Requirements § 151.50-55 Sulfur (molten). (a... depositing of sulfur within the system. (b) Void spaces: (1) Openings to void spaces adjacent to cargo...

  9. 46 CFR 151.50-55 - Sulfur (molten).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 5 2013-10-01 2013-10-01 false Sulfur (molten). 151.50-55 Section 151.50-55 Shipping... BULK LIQUID HAZARDOUS MATERIAL CARGOES Special Requirements § 151.50-55 Sulfur (molten). (a... depositing of sulfur within the system. (b) Void spaces: (1) Openings to void spaces adjacent to cargo...

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. Imaging molten steel flow profiles

    NASA Astrophysics Data System (ADS)

    Binns, R.; Lyons, A. R. A.; Peyton, A. J.; Pritchard, W. D. N.

    2001-08-01

    Control of delivery of molten steel in continuous casting is critical in order to ensure stability of the meniscus and satisfactory mould flow patterns, which in turn are determinants of cleanness and surface quality of steel. Considerable effort has been expended over the last ten years on optimizing the design of the metal delivery system, particularly the pouring nozzle, in order to allow the consistent production of high quality steel at a high throughput. This paper looks forward to possible systems that are capable of tomographically imaging the distribution of molten steel flows in these applications. The paper will concentrate on the feasibility of using electromagnetic methods. The paper will present some initial results; an overview of the applied image reconstruction process will also be included. The paper will conclude with a discussion of possible future developments, such as the use of a tomographic or multi-frequency approach, future research on the reconstruction image procedures and the potential for visualization and flow measurement. There is a need for further research in this area and some priority areas for future work will be suggested.

  15. Molten Glass for Thermal Storage: Advanced Molten Glass for Heat Transfer and Thermal Energy Storage

    SciTech Connect

    2012-01-01

    HEATS Project: Halotechnics is developing a high-temperature thermal energy storage system using a new thermal-storage and heat-transfer material: earth-abundant and low-melting-point molten glass. Heat storage materials are critical to the energy storage process. In solar thermal storage systems, heat can be stored in these materials during the day and released at night—when the sun is not out—to drive a turbine and produce electricity. In nuclear storage systems, heat can be stored in these materials at night and released to produce electricity during daytime peak-demand hours. Halotechnics new thermal storage material targets a price that is potentially cheaper than the molten salt used in most commercial solar thermal storage systems today. It is also extremely stable at temperatures up to 1200°C—hundreds of degrees hotter than the highest temperature molten salt can handle. Being able to function at high temperatures will significantly increase the efficiency of turning heat into electricity. Halotechnics is developing a scalable system to pump, heat, store, and discharge the molten glass. The company is leveraging technology used in the modern glass industry, which has decades of experience handling molten glass.

  16. Analysis of the design and economics of molten carbonate fuel cell tri-generation systems providing heat and power for commercial buildings and H2 for FC vehicles

    NASA Astrophysics Data System (ADS)

    Li, Xuping; Ogden, Joan; Yang, Christopher

    2013-11-01

    This study models the operation of molten carbonate fuel cell (MCFC) tri-generation systems for “big box” store businesses that combine grocery and retail business, and sometimes gasoline retail. Efficiency accounting methods and parameters for MCFC tri-generation systems have been developed. Interdisciplinary analysis and an engineering/economic model were applied for evaluating the technical, economic, and environmental performance of distributed MCFC tri-generation systems, and for exploring the optimal system design. Model results show that tri-generation is economically competitive with the conventional system, in which the stores purchase grid electricity and NG for heat, and sell gasoline fuel. The results are robust based on sensitivity analysis considering the uncertainty in energy prices and capital cost. Varying system sizes with base case engineering inputs, energy prices, and cost assumptions, it is found that there is a clear tradeoff between the portion of electricity demand covered and the capital cost increase of bigger system size. MCFC Tri-generation technology provides lower emission electricity, heat, and H2 fuel. With NG as feedstock the CO2 emission can be reduced by 10%-43.6%, depending on how the grid electricity is generated. With renewable methane as feedstock CO2 emission can be further reduced to near zero.

  17. Molten core retention assembly

    DOEpatents

    Lampe, Robert F.

    1976-06-22

    Molten fuel produced in a core overheating accident is caught by a molten core retention assembly consisting of a horizontal baffle plate having a plurality of openings therein, heat exchange tubes having flow holes near the top thereof mounted in the openings, and a cylindrical, imperforate baffle attached to the plate and surrounding the tubes. The baffle assembly is supported from the core support plate of the reactor by a plurality of hanger rods which are welded to radial beams passing under the baffle plate and intermittently welded thereto. Preferably the upper end of the cylindrical baffle terminates in an outwardly facing lip to which are welded a plurality of bearings having slots therein adapted to accept the hanger rods.

  18. Occlusion and ion exchange in the molten (lithium chloride + potassium chloride + alkaline earth chloride) salt + zeolite 4A system with alkaline earth chlorides of calcium and strontium, and in the molten (lithium chloride + potassium chloride + actinide chloride) salt + zeolite 4A system with the actinide chloride of uranium.

    SciTech Connect

    Lexa, D.; Chemical Engineering

    2003-04-01

    The interaction between molten salts of the type LiCl-KCl-MeCl n (Me=Ca, Sr, U; x{sub MeCLn} $$ = to 0.45; and x {sub KCl}/x LiCl=0.69) and zeolite 4A have been studied at 823 K. The main interactions between these salts and zeolite are molten salt occlusion to form salt-loaded zeolite and ion exchange between the molten salt and salt-loaded zeolite. An irreversible chemical reaction has been observed in the LiCl-KCl-UCl{sup 3+}zeolite system. The extent of occlusion is a function of the concentration of MeCl n in the zeolite and is equal to 10{+-}1 Cl- per zeolite unit cell, (AlSiO{sub 4}){sub 12}, at infinite MeCl n dilution. The ion-exchange mole-fraction equilibrium constants (separation factors) with respect to Li are decreasing functions of the concentration of SrCl{sub 2} and UCl{sub 3}, but an increasing function of the concentration of CaCl{sub 2} in the zeolite. At infinite MeCl n dilution, they are equal to 0.9, 11.9, and 13 for CaCl{sub 2}, SrCl{sub 2}, and UCl{sub 3}, respectively. The standard ion-exchange chemical potentials are equal to -50.0, -84, and -101.1 kJ x mol-1 for Ca{sup 2+}, Sr{sup 2+}, and U{sup 3+}, respectively.

  19. A comparison between molten carbonate fuel cells based hybrid systems using air and supercritical carbon dioxide Brayton cycles with state of the art technology

    NASA Astrophysics Data System (ADS)

    Sánchez, D.; Muñoz de Escalona, J. M.; Chacartegui, R.; Muñoz, A.; Sánchez, T.

    A proposal for high efficiency hybrid systems based on molten carbonate fuel cells is presented in this paper. This proposal is based on adopting a closed cycle bottoming gas turbine using supercritical carbon dioxide as working fluid as opposed to open cycle hot air turbines typically used in this type of power generators. First, both bottoming cycles are compared for the same operating conditions, showing that their performances do not differ as much as initially expected, even if the initial objective of reducing compression work is accomplished satisfactorily. In view of these results, a profound review of research and industrial literature is carried out in order to determine realistic specifications for the principal components of the bottoming systems. From this analysis, it is concluded that an appropriate set of specifications must be developed for each bottoming cycle as the performances of compressor, turbine and recuperator differ significantly from one working fluid to another. Thus, when the operating conditions are updated, the performances of the resulting systems show a remarkable advantage of carbon dioxide based systems over conventional air units. Actually, the proposed hybrid system shows its capability to achieve 60% net efficiency, what represents a 10% increase with respect to the reference system.

  20. 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.

  1. 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.

  2. 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.

  3. 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

  4. 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.

  5. 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).

  6. 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).

  7. Thermal modeling of a secondary concentrator integrated with an open direct-absorption molten-salt volumetric receiver in a beam-down tower system

    NASA Astrophysics Data System (ADS)

    Lahlou, Radia; Armstrong, Peter; Grange, Benjamin; Almheiri, Saif; Calvet, Nicolas; Slocum, Alexander; Shamim, Tariq

    2016-05-01

    An upward-facing three-dimensional secondary concentrator, herein termed Final Optical Element (FOE), is designed to be used in a beam-down tower in combination with an open volumetric direct-absorption molten-salt receiver tank acting simultaneously as a thermal energy storage system. It allows reducing thermal losses from the open receiver by decreasing its aperture area while keeping minimal spillage losses. The FOE is exposed to high solar fluxes, a part of which is absorbed by its reflector material, leading to material degradation by overheating. Consequently, the FOE may require active cooling. A thermal model of the FOE under passive cooling mechanism is proposed as a first step to evaluate its sensitivity to some design parameters. Then, it will be used to evaluate the requirements for the active cooling system. The model provides insights on the FOE thermal behavior and highlights the effectiveness of a design modification on passive cooling enhancement. First prototype tests under reduced flux and with no active cooling will be used for model adjustment.

  8. Dual intercalating molten electrolyte batteries

    SciTech Connect

    Carlin, R.T.; De Long, H.C.; Fuller, J.; Trulove, P.C. . Frank J. Seiler Research Lab.)

    1994-07-01

    The reductive and oxidative intercalation of ions into graphite from room-temperature and low temperature molten salts is demonstrated. For this investigation, the molten salts use 1-ethyl-3-methylimidazolium (EMI[sup +]) or 1,2-dimethyl-3-propylimidazolium (DMPI[sup +]) as the cation and AlCl[sup [minus

  9. Removing Dross From Molten Solder

    NASA Technical Reports Server (NTRS)

    Webb, Winston S.

    1990-01-01

    Automatic device helps to assure good solder connections. Machine wipes dross away from area on surface of molten solder in pot. Sweeps across surface of molten solder somewhat in manner of windshield wiper. Each cycle of operation triggered by pulse from external robot. Equipment used wherever precise, automated soldering must be done to military specifications.

  10. 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.

  11. Heat capacity of molten halides.

    PubMed

    Redkin, Alexander A; Zaikov, Yurii P; Korzun, Iraida V; Reznitskikh, Olga G; Yaroslavtseva, Tatiana V; Kumkov, Sergey I

    2015-01-15

    The heat capacities of molten salts are very important for their practical use. Experimental investigation of this property is challenging because of the high temperatures involved and the corrosive nature of these materials. It is preferable to combine experimental investigations with empirical relationships, which allows for the evaluation of the heat capacity of molten salt mixtures. The isobaric molar heat capacities of all molten alkali and alkaline-earth halides were found to be constant for each group of salts. The value depends on the number of atoms in the salt, and the molar heat capacity per atom is constant for all molten halide salts with the exception of the lithium halides. The molar heat capacities of molten halides do not change when the anions are changed.

  12. Heat capacity of molten halides.

    PubMed

    Redkin, Alexander A; Zaikov, Yurii P; Korzun, Iraida V; Reznitskikh, Olga G; Yaroslavtseva, Tatiana V; Kumkov, Sergey I

    2015-01-15

    The heat capacities of molten salts are very important for their practical use. Experimental investigation of this property is challenging because of the high temperatures involved and the corrosive nature of these materials. It is preferable to combine experimental investigations with empirical relationships, which allows for the evaluation of the heat capacity of molten salt mixtures. The isobaric molar heat capacities of all molten alkali and alkaline-earth halides were found to be constant for each group of salts. The value depends on the number of atoms in the salt, and the molar heat capacity per atom is constant for all molten halide salts with the exception of the lithium halides. The molar heat capacities of molten halides do not change when the anions are changed. PMID:25530462

  13. 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.

  14. 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.

  15. Electrolysis of a molten semiconductor.

    PubMed

    Yin, Huayi; Chung, Brice; Sadoway, Donald R

    2016-08-24

    Metals cannot be extracted by electrolysis of transition-metal sulfides because as liquids they are semiconductors, which exhibit high levels of electronic conduction and metal dissolution. Herein by introduction of a distinct secondary electrolyte, we reveal a high-throughput electro-desulfurization process that directly converts semiconducting molten stibnite (Sb2S3) into pure (99.9%) liquid antimony and sulfur vapour. At the bottom of the cell liquid antimony pools beneath cathodically polarized molten stibnite. At the top of the cell sulfur issues from a carbon anode immersed in an immiscible secondary molten salt electrolyte disposed above molten stibnite, thereby blocking electronic shorting across the cell. As opposed to conventional extraction practices, direct sulfide electrolysis completely avoids generation of problematic fugitive emissions (CO2, CO and SO2), significantly reduces energy consumption, increases productivity in a single-step process (lower capital and operating costs) and is broadly applicable to a host of electronically conductive transition-metal chalcogenides.

  16. Electrolysis of a molten semiconductor

    NASA Astrophysics Data System (ADS)

    Yin, Huayi; Chung, Brice; Sadoway, Donald R.

    2016-08-01

    Metals cannot be extracted by electrolysis of transition-metal sulfides because as liquids they are semiconductors, which exhibit high levels of electronic conduction and metal dissolution. Herein by introduction of a distinct secondary electrolyte, we reveal a high-throughput electro-desulfurization process that directly converts semiconducting molten stibnite (Sb2S3) into pure (99.9%) liquid antimony and sulfur vapour. At the bottom of the cell liquid antimony pools beneath cathodically polarized molten stibnite. At the top of the cell sulfur issues from a carbon anode immersed in an immiscible secondary molten salt electrolyte disposed above molten stibnite, thereby blocking electronic shorting across the cell. As opposed to conventional extraction practices, direct sulfide electrolysis completely avoids generation of problematic fugitive emissions (CO2, CO and SO2), significantly reduces energy consumption, increases productivity in a single-step process (lower capital and operating costs) and is broadly applicable to a host of electronically conductive transition-metal chalcogenides.

  17. 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

  18. 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.

  19. Dynamics of the Molten Contact Line

    NASA Technical Reports Server (NTRS)

    Sonin, Ain A.; Duthaler, Gregg; Liu, Michael; Torresola, Javier; Qiu, Taiqing

    1999-01-01

    The purpose of this program is to develop a basic understanding of how a molten material front spreads over a solid that is below its melting point, arrests, and freezes. Our hope is that the work will contribute toward a scientific knowledge base for certain new applications involving molten droplet deposition, including the "printing" of arbitrary three-dimensional objects by precise deposition of individual molten microdrops that solidify after impact. Little information is available at this time on the capillarity-driven motion and arrest of molten contact line regions. Schiaffino and Sonin investigated the arrest of the contact line of a molten microcrystalline wax spreading over a subcooled solid "target" of the same material. They found that contact line arrest takes place at an apparent liquid contact angle that depends primarily on the Stefan number S=c(T(sub f) -T(sub t)/L based on the temperature difference between the fusion point and the target temperature, and proposed that contact line arrest occurs when the liquid's dynamic contact angle approaches the angle of attack of the solidification front just behind the contact line. They also showed, however, that the conventional continuum equations and boundary conditions have no meaningful solution for this angle. The solidification front angle is determined by the heat flux just behind the contact line, and the heat flux is singular at that point. By comparing experiments with numerical computations, Schiaffino and Sonin estimated that the conventional solidification model must break down within a distance of order 0.1 - 1 microns of the contact line. The physical mechanism for this breakdown is as yet undetermined, and no first-principles theory exists for the contact angle at arrest. Schiaffino and Sonin also presented a framework for understanding how to moderate Weber number molten droplet deposition in terms of similarity laws and experimentation. The study is based on experiments with three molten

  20. Structure of molten titanium dioxide

    NASA Astrophysics Data System (ADS)

    Alderman, O. L. G.; Skinner, L. B.; Benmore, C. J.; Tamalonis, A.; Weber, J. K. R.

    2014-09-01

    The x-ray structure factor of molten TiO2 has been measured, enabled by the use of aerodynamic levitation and laser beam heating, to a temperature of T=2250(30)K. The Ti-O coordination number in the melt is close to nTiO=5.0(2), with modal Ti-O bond length rTiO=1.881(5)Å, both values being significantly smaller than for the high temperature stable rutile crystal structure (nTiO=6.0,rTiO=1.959Å). The structural differences between melt and crystal are qualitatively similar to those for alumina, which is rationalized in terms of the similar field strengths of Ti4+ and Al3+. The diffraction data are used to generate physically and chemically reasonable structural models, which are then compared to the predictions based on various classical molecular dynamics (MD) potentials. Interatomic potentials, suitable for modeling molten TiO2, are introduced, given the inability of existing MD models to reproduce the diffraction data. These potentials have the additional advantage of being able to predict the density and thermal expansion of the melt, as well as solid amorphous TiO2, in agreement with published results. This is of critical importance given the strong correlation between density and structural parameters such as nTiO. The large thermal expansion of the melt is associated with weakly temperature dependent structural changes, whereby simulations show that nTiO=5.85(2)-[3.0(1)×10-4]T(K ,2.75Åcutoff). The TiO2 liquid is structurally analogous to the geophysically relevant high pressure liquid silica system at around 27 GPa. We argue that the predominance of fivefold polyhedra in the melt implies the existence of as-yet-undiscovered TiO2 polymorphs, based on lower-than-octahedral coordination numbers, which are likely to be metastable under ambient conditions. Given the industrial importance of titanium oxides, experimental and computational searches for such polymorphs are well warranted.

  1. Structure of molten titanium dioxide

    SciTech Connect

    Alderman, O. L. G.; Skinner, L. B.; Benmore, C. J.; Tamalonis, A.; Weber, J. K. R.

    2014-09-18

    The x-ray structure factor of molten TiO2 has been measured for the first time, enabled by the use of aerodynamic levitation and laser beam heating, to a temperature of T = 2250(30) K. Ti-O coordination number in the melt is close to nTiO = 5.0(2), with modal Ti-O bond length rTiO = 1.881(5) Å, both values being significantly smaller than for the high temperature stable Rutile crystal structure (nTiO = 6.0, rTiO = 1.959 Å). The structural differences between melt and crystal are qualitatively similar to those for alumina, which is rationalized in terms of the similar field strengths of Ti4+ and Al3+. The diffraction data are used to generate physically and chemically reasonable structural models, which are then compared to the predictions based on various classical molecular dynamics (MD) potentials. New interatomic potentials, suitable for modelling molten TiO2, are introduced, given the inability of existing MD models to reproduce the diffraction data. These new potentials have the additional great advantage of being able to predict the density and thermal expansion of the melt, as well as solid amorphous TiO2, in agreement with published results. This is of critical importance given the strong correlation between density and structural parameters such as nTiO. The large thermal expansion of the melt is associated with weakly temperature dependent structural changes, whereby simulations show that nTiO = 5.85(2) – (3.0(1) x 10-4 )T (K, 2.75 Å cut-off). The TiO2 liquid is structurally analogous to the geophysically relevant high pressure liquid silica system at around 27 GPa. We argue that the predominance of 5-fold polyhedra in the melt implies the existence of as yet undiscovered TiO2 polymorphs, based on lowerthan-octahedral coordination numbers, which are likely to be metastable under ambient conditions. Given the industrial importance of titanium oxides, experimental and computational searches for such polymorphs are well warranted.

  2. Effect of sand and moisture on molten salt properties for open direct absorption solar receiver/storage system

    NASA Astrophysics Data System (ADS)

    AlQaydi, M. S.; Delclos, T.; AlMheiri, S.; McKrell, T.; Calvet, N.

    2016-05-01

    Solar Salt (60 wt. % sodium nitrate, 40 wt. % potassium nitrate) is one candidate salt mixture for the CSPonD Demo project (Concentrated Solar Power On Demand Demonstration), ongoing collaboration between Masdar Institute and MIT. One prototype is under preparation at the Masdar Institute Solar Platform in Abu Dhabi. In this new concept, the salt will be used as an open direct absorption solar receiver integrated with a storage system so that the effects of dust/sand and moisture on the thermophysical properties have to be investigated. Thermal Gravimetric Analysis (TGA) was used to study the thermal stability and mass loss, while a Differential Scanning Calorimeter (DSC) was used to study the thermal properties and heat capacity of the salt mixture with and without sand. Considering the worst case scenario, the maximum mass loss rate at 550 °C, and in a fully open configuration, was measured to be 0.29 % per hour, around 2.34 per day of use (8 h of operation). The effect of sand was the same under nitrogen gas environment and air with moisture, which resulted in decreasing the melting temperature of the salts mixture and increasing its freezing temperature. The thermal properties remained stable even after 3 temperature cycles with impurities. Finally, the salt heat capacity increased due to the addition of 2 wt. % of sand.

  3. 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.

  4. 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.

  5. Apparatus for controlling molten core debris

    DOEpatents

    Golden, Martin P. [Trafford, PA; Tilbrook, Roger W. [Monroeville, PA; Heylmun, Neal F. [Pittsburgh, PA

    1977-07-19

    Apparatus for containing, cooling, diluting, dispersing and maintaining subcritical the molten core debris assumed to melt through the bottom of a nuclear reactor pressure vessel in the unlikely event of a core meltdown. The apparatus is basically a sacrificial bed system which includes an inverted conical funnel, a core debris receptacle including a spherical dome, a spherically layered bed of primarily magnesia bricks, a cooling system of zig-zag piping in graphite blocks about and below the bed and a cylindrical liner surrounding the graphite blocks including a steel shell surrounded by firebrick. Tantalum absorber rods are used in the receptacle and bed.

  6. Apparatus for controlling molten core debris. [LMFBR

    DOEpatents

    Golden, M.P.; Tilbrook, R.W.; Heylmun, N.F.

    1977-07-19

    Disclosed is an apparatus for containing, cooling, diluting, dispersing and maintaining subcritical the molten core debris assumed to melt through the bottom of a nuclear reactor pressure vessel in the unlikely event of a core meltdown. The apparatus is basically a sacrificial bed system which includes an inverted conical funnel, a core debris receptacle including a spherical dome, a spherically layered bed of primarily magnesia bricks, a cooling system of zig-zag piping in graphite blocks about and below the bed and a cylindrical liner surrounding the graphite blocks including a steel shell surrounded by firebrick. Tantalum absorber rods are used in the receptacle and bed. 9 claims, 22 figures.

  7. Ceramics for Molten Materials Transfer

    NASA Technical Reports Server (NTRS)

    Standish, Evan; Stefanescu, Doru M.; Curreri, Peter A.

    2009-01-01

    The paper reviews the main issues associated with molten materials transfer and handling on the lunar surface during the operation of a hig h temperature electrowinning cell used to produce oxygen, with molten iron and silicon as byproducts. A combination of existing technolog ies and purposely designed technologies show promise for lunar exploi tation. An important limitation that requires extensive investigation is the performance of refractory currently used for the purpose of m olten metal containment and transfer in the lunar environment associa ted with electrolytic cells. The principles of a laboratory scale uni t at a scale equivalent to the production of 1 metric ton of oxygen p er year are introduced. This implies a mass of molten materials to be transferred consistent with the equivalent of 1kg regolithlhr proces sed.

  8. Supported molten-metal catalysts

    DOEpatents

    Datta, Ravindra; Singh, Ajeet; Halasz, Istvan; Serban, Manuela

    2001-01-01

    An entirely new class of catalysts called supported molten-metal catalysts, SMMC, which can replace some of the existing precious metal catalysts used in the production of fuels, commodity chemicals, and fine chemicals, as well as in combating pollution. SMMC are based on supporting ultra-thin films or micro-droplets of the relatively low-melting (<600.degree. C.), inexpensive, and abundant metals and semimetals from groups 1, 12, 13, 14, 15 and 16, of the periodic table, or their alloys and intermetallic compounds, on porous refractory supports, much like supported microcrystallites of the traditional solid metal catalysts. It thus provides orders of magnitude higher surface area than is obtainable in conventional reactors containing molten metals in pool form and also avoids corrosion. These have so far been the chief stumbling blocks in the application of molten metal catalysts.

  9. Rheological behavior and constitutive equations of heterogeneous titanium-bearing molten slag

    NASA Astrophysics Data System (ADS)

    Jiang, Tao; Liao, De-ming; Zhou, Mi; Zhang, Qiao-yi; Yue, Hong-rui; Yang, Song-tao; Duan, Pei-ning; Xue, Xiang-xin

    2015-08-01

    Experimental studies on the rheological properties of a CaO-SiO2-Al2O3-MgO-TiO2-(TiC) blast furnace (BF) slag system were conducted using a high-temperature rheometer to reveal the non-Newtonian behavior of heterogeneous titanium-bearing molten slag. By measuring the relationships among the viscosity, the shear stress and the shear rate of molten slags with different TiC contents at different temperatures, the rheological constitutive equations were established along with the rheological parameters; in addition, the non-Newtonian fluid types of the molten slags were determined. The results indicated that, with increasing TiC content, the viscosity of the molten slag tended to increase. If the TiC content was less than 2wt%, the molten slag exhibited the Newtonian fluid behavior when the temperature was higher than the critical viscosity temperature of the molten slag. In contrast, the molten slag exhibited the non-Newtonian pseudoplastic fluid characteristic and the shear thinning behavior when the temperature was less than the critical viscosity temperature. However, if the TiC content exceeded 4wt%, the molten slag produced the yield stress and exhibited the Bingham and plastic pseudoplastic fluid behaviors when the temperature was higher and lower than the critical viscosity temperature, respectively. When the TiC content increased further, the yield stress of the molten slag increased and the shear thinning phenomenon became more obvious.

  10. Molten fatty acid based microemulsions.

    PubMed

    Noirjean, Cecile; Testard, Fabienne; Dejugnat, Christophe; Jestin, Jacques; Carriere, David

    2016-06-21

    We show that ternary mixtures of water (polar phase), myristic acid (MA, apolar phase) and cetyltrimethylammonium bromide (CTAB, cationic surfactant) studied above the melting point of myristic acid allow the preparation of microemulsions without adding a salt or a co-surfactant. The combination of SANS, SAXS/WAXS, DSC, and phase diagram determination allows a complete characterization of the structures and interactions between components in the molten fatty acid based microemulsions. For the different structures characterized (microemulsion, lamellar or hexagonal phases), a similar thermal behaviour is observed for all ternary MA/CTAB/water monophasic samples and for binary MA/CTAB mixtures without water: crystalline myristic acid melts at 52 °C, and a thermal transition at 70 °C is assigned to the breaking of hydrogen bounds inside the mixed myristic acid/CTAB complex (being the surfactant film in the ternary system). Water determines the film curvature, hence the structures observed at high temperature, but does not influence the thermal behaviour of the ternary system. Myristic acid is partitioned in two "species" that behave independently: pure myristic acid and myristic acid associated with CTAB to form an equimolar complex that plays the role of the surfactant film. We therefore show that myristic acid plays the role of a solvent (oil) and a co-surfactant allowing the fine tuning of the structure of oil and water mixtures. This solvosurfactant behaviour of long chain fatty acid opens the way for new formulations with a complex structure without the addition of any extra compound. PMID:27241163

  11. Electrolysis of a molten semiconductor.

    PubMed

    Yin, Huayi; Chung, Brice; Sadoway, Donald R

    2016-01-01

    Metals cannot be extracted by electrolysis of transition-metal sulfides because as liquids they are semiconductors, which exhibit high levels of electronic conduction and metal dissolution. Herein by introduction of a distinct secondary electrolyte, we reveal a high-throughput electro-desulfurization process that directly converts semiconducting molten stibnite (Sb2S3) into pure (99.9%) liquid antimony and sulfur vapour. At the bottom of the cell liquid antimony pools beneath cathodically polarized molten stibnite. At the top of the cell sulfur issues from a carbon anode immersed in an immiscible secondary molten salt electrolyte disposed above molten stibnite, thereby blocking electronic shorting across the cell. As opposed to conventional extraction practices, direct sulfide electrolysis completely avoids generation of problematic fugitive emissions (CO2, CO and SO2), significantly reduces energy consumption, increases productivity in a single-step process (lower capital and operating costs) and is broadly applicable to a host of electronically conductive transition-metal chalcogenides. PMID:27553525

  12. Stability of Molten Core Materials

    SciTech Connect

    Layne Pincock; Wendell Hintze

    2013-01-01

    The purpose of this report is to document a literature and data search for data and information pertaining to the stability of nuclear reactor molten core materials. This includes data and analysis from TMI-2 fuel and INL’s LOFT (Loss of Fluid Test) reactor project and other sources.

  13. Electrolysis of a molten semiconductor

    PubMed Central

    Yin, Huayi; Chung, Brice; Sadoway, Donald R.

    2016-01-01

    Metals cannot be extracted by electrolysis of transition-metal sulfides because as liquids they are semiconductors, which exhibit high levels of electronic conduction and metal dissolution. Herein by introduction of a distinct secondary electrolyte, we reveal a high-throughput electro-desulfurization process that directly converts semiconducting molten stibnite (Sb2S3) into pure (99.9%) liquid antimony and sulfur vapour. At the bottom of the cell liquid antimony pools beneath cathodically polarized molten stibnite. At the top of the cell sulfur issues from a carbon anode immersed in an immiscible secondary molten salt electrolyte disposed above molten stibnite, thereby blocking electronic shorting across the cell. As opposed to conventional extraction practices, direct sulfide electrolysis completely avoids generation of problematic fugitive emissions (CO2, CO and SO2), significantly reduces energy consumption, increases productivity in a single-step process (lower capital and operating costs) and is broadly applicable to a host of electronically conductive transition-metal chalcogenides. PMID:27553525

  14. 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

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. Removal of H2S using molten carbonate at high temperature.

    PubMed

    Kawase, Makoto; Otaka, Maromu

    2013-12-01

    Gasification is considered to be an effective process for energy conversion from various sources such as coal, biomass, and waste. Cleanup of the hot syngas produced by such a process may improve the thermal efficiency of the overall gasification system. Therefore, the cleanup of hot syngas from biomass gasification using molten carbonate is investigated in bench-scale tests. Molten carbonate acts as an absorbent during desulfurization and dechlorination and as a thermal catalyst for tar cracking. In this study, the performance of molten carbonate for removing H2S was evaluated. The temperature of the molten carbonate was set within the range from 800 to 1000 °C. It is found that the removal of H2S is significantly affected by the concentration of CO2 in the syngas. When only a small percentage of CO2 is present, desulfurization using molten carbonate is inadequate. However, when carbon elements, such as char and tar, are continuously supplied, H2S removal can be maintained at a high level. To confirm the performance of the molten carbonate gas-cleaning system, purified biogas was used as a fuel in power generation tests with a molten carbonate fuel cell (MCFC). The fuel cell is a high-performance sensor for detecting gaseous impurities. When purified gas from a gas-cleaning reactor was continuously supplied to the fuel cell, the cell voltage remained stable. Thus, the molten carbonate gas-cleaning reactor was found to afford good gas-cleaning performance.

  2. MOLTEN FLUORIDE NUCLEAR REACTOR FUEL

    DOEpatents

    Barton, C.J.; Grimes, W.R.

    1960-01-01

    Molten-salt reactor fuel compositions consisting of mixtures of fluoride salts are reported. In its broadest form, the composition contains an alkali fluoride such as sodium fluoride, zirconium tetrafluoride, and a uranium fluoride, the latter being the tetrafluoride or trifluoride or a mixture of the two. An outstanding property of these fuel compositions is a high coeffieient of thermal expansion which provides a negative temperature coefficient of reactivity in reactors in which they are used.

  3. Molten carbonate fuel cell matrices

    DOEpatents

    Vogel, Wolfgang M.; Smith, Stanley W.

    1985-04-16

    A molten carbonate fuel cell including a cathode electrode of electrically conducting or semiconducting lanthanum containing material and an electrolyte containing matrix of an electrically insulating lanthanum perovskite. In addition, in an embodiment where the cathode electrode is LaMnO.sub.3, the matrix may include LaAlO.sub.3 or a lithium containing material such as LiAlO.sub.2 or Li.sub.2 TiO.sub.3.

  4. 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.

  5. 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.

  6. Partially molten magma ocean model

    SciTech Connect

    Shirley, D.N.

    1983-02-15

    The properties of the lunar crust and upper mantle can be explained if the outer 300-400 km of the moon was initially only partially molten rather than fully molten. The top of the partially molten region contained about 20% melt and decreased to 0% at 300-400 km depth. Nuclei of anorthositic crust formed over localized bodies of magma segregated from the partial melt, then grew peripherally until they coverd the moon. Throughout most of its growth period the anorthosite crust floated on a layer of magma a few km thick. The thickness of this layer is regulated by the opposing forces of loss of material by fractional crystallization and addition of magma from the partial melt below. Concentrations of Sr, Eu, and Sm in pristine ferroan anorthosites are found to be consistent with this model, as are trends for the ferroan anorthosites and Mg-rich suites on a diagram of An in plagioclase vs. mg in mafics. Clustering of Eu, Sr, and mg values found among pristine ferroan anorthosites are predicted by this model.

  7. 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.

  8. 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.

  9. 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.

  10. 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)

  11. 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.

  12. Oxygen electrode reaction in molten carbonate fuel cells

    SciTech Connect

    Appleby, A.J.; White, R.E.

    1992-07-07

    Molten carbonate fuel cell system is a leading candidate for the utility power generation because of its high efficiency for fuel to AC power conversion, capability for an internal reforming, and a very low environmental impact. However, the performance of the molten carbonate fuel cell is limited by the oxygen reduction reaction and the cell life time is limited by the stability of the cathode material. An elucidation of oxygen reduction reaction in molten alkali carbonate is essential because overpotential losses in the molten carbonate fuel cell are considerably greater at the oxygen cathode than at the fuel anode. Oxygen reduction on a fully-immersed gold electrode in a lithium carbonate melt was investigated by electrochemical impedance spectroscopy and cyclic voltammetry to determine electrode kinetic and mass transfer parameters. The dependences of electrode kinetic and mass transfer parameters on gas composition and temperature were examined to determine the reaction orders and the activation energies. The results showed that oxygen reduction in a pure lithium carbonate melt occurs via the peroxide mechanism. A mass transfer parameter, D{sub O}{sup 1/2}C{sub O}, estimated by the cyclic voltammetry concurred with that calculated by the EIS technique. The temperature dependence of the exchange current density and the product D{sub O}{sup 1/2}C{sub O} were examined and the apparent activation energies were determined to be about 122 and 175 kJ/ mol, respectively.

  13. Molten Composition B Viscosity at Elevated Temperature

    NASA Astrophysics Data System (ADS)

    Zerkle, David K.; Núñez, Marcel P.; Zucker, Jonathan M.

    2016-10-01

    A shear-thinning viscosity model is developed for molten Composition B at elevated temperature from analysis of falling ball viscometer data. Results are reported with the system held at 85, 110, and 135°C. Balls of densities of 2.7, 8.0, and 15.6 g/cm3 are dropped to generate a range of strain rates in the material. Analysis of video recordings gives the speed at which the balls fall. Computer simulation of the viscometer is used to determine parameters for a non-Newtonian model calibrated to measured speeds. For the first time, viscosity is shown to be a function of temperature and strain rate-dependent maximum RDX (cyclotrimethylenetrinitramine) particle volume fraction.

  14. The removal of iron from molten aluminium

    SciTech Connect

    Donk, H.M. van der; Nijhof, G.H.; Castelijns, C.A.M.

    1995-12-31

    In this work an overview is given about the techniques available for the removal of metallic impurities from molten aluminium. The overview is focused on the removal of iron. Also, some experimental results are given about the creation of iron-rich intermetallic compounds in an aluminium system, which are subsequently removed by gravity segregation and filtration techniques. This work is part of an ongoing research project of three major European aluminium companies who are co-operating on the subject of recycling of aluminium packaging materials recovered from household waste by means of Eddy-Current techniques. Using this technique the pick-up of some contaminating metals, particularly iron, is almost unavoidable.

  15. 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.

  16. Design report on SCDAP/RELAP5 model improvements - debris bed and molten pool behavior

    SciTech Connect

    Allison, C.M.; Rempe, J.L.; Chavez, S.A.

    1994-11-01

    the SCDAP/RELAP5/MOD3 computer code is designed to describe the overall reactor coolant system thermal-hydraulic response, core damage progression, and in combination with VICTORIA, fission product release and transport during severe accidents. Improvements for existing debris bed and molten pool models in the SCDAP/RELAP5/MOD3.1 code are described in this report. Model improvements to address (a) debris bed formation, heating, and melting; (b) molten pool formation and growth; and (c) molten pool crust failure are discussed. Relevant data, existing models, proposed modeling changes, and the anticipated impact of the changes are discussed. Recommendations for the assessment of improved models are provided.

  17. Molten carbonate fuel cell separator

    DOEpatents

    Nickols, R.C.

    1984-10-17

    In a stacked array of molten carbonate fuel cells, a fuel cell separator is positioned between adjacent fuel cells to provide isolation as well as a conductive path therebetween. The center portion of the fuel cell separator includes a generally rectangular, flat, electrical conductor. Around the periphery of the flat portion of the separator are positioned a plurality of elongated resilient flanges which form a gas-tight seal around the edges of the fuel cell. With one elongated flange resiliently engaging a respective edge of the center portion of the separator, the sealing flanges, which are preferably comprised of a noncorrosive material such as an alloy of yttrium, iron, aluminum or chromium, form a tight-fitting wet seal for confining the corrosive elements of the fuel cell therein. This arrangement permits a good conductive material which may be highly subject to corrosion and dissolution to be used in combination with a corrosion-resistant material in the fuel cell separator of a molten carbonate fuel cell for improved fuel cell conductivity and a gas-tight wet seal.

  18. Molten carbonate fuel cell separator

    DOEpatents

    Nickols, Richard C.

    1986-09-02

    In a stacked array of molten carbonate fuel cells, a fuel cell separator is positioned between adjacent fuel cells to provide isolation as well as a conductive path therebetween. The center portion of the fuel cell separator includes a generally rectangular, flat, electrical conductor. Around the periphery of the flat portion of the separator are positioned a plurality of elongated resilient flanges which form a gas-tight seal around the edges of the fuel cell. With one elongated flange resiliently engaging a respective edge of the center portion of the separator, the sealing flanges, which are preferably comprised of a noncorrosive material such as an alloy of yttrium, iron, aluminum or chromium, form a tight-fitting wet seal for confining the corrosive elements of the fuel cell therein. This arrangement permits a good conductive material which may be highly subject to corrosion and dissolution to be used in combination with a corrosion-resistant material in the fuel cell separator of a molten carbonate fuel cell for improved fuel cell conductivity and a gas-tight wet seal.

  19. Grain boundary wetness of partially molten dunite

    NASA Astrophysics Data System (ADS)

    Mu, S.; Faul, U.

    2013-12-01

    The grain scale melt distribution plays a key role for physical properties of partially molten regions in Earth's upper mantle, but our current understanding of the distribution of basaltic melt at the grain scale is still incomplete. A recent experimental study shows that wetted two-grain boundaries are a common feature of partially molten dunite at small melt fractions (Garapic et al., G3, 2013). In early ideal models which assume isotropic surface energy, the grain scale melt distribution is uniquely determined by knowing the melt fraction and the dihedral angle between two crystalline grains and the melt (von Bargen and Waff, JGR, 1986). Olivine is anisotropic in surface energy, hence the grain scale melt distribution at given melt fraction cannot be characterized by the dihedral angle alone. The grain boundary wetness, which is defined as the ratio of solid-liquid boundary area over the total interfacial area (Takei, JGR, 1998), is a more objective measure of the grain scale melt distribution. The aim of this study is to quantify the relationship between grain size, melt fraction, temperature and grain boundary wetness of partially molten dunite under dry conditions. We annealed olivine-basalt aggregates with melt fractions from 0.03% to 6% at a range of temperatures and 1 GPa in a piston cylinder for 1 to 336 hours, with resulting mean grain sizes of 10 to 60 μm. The samples were sectioned, polished and imaged at high resolution by using a field emission SEM. Each image had a size of 2048 x 1536 pixels with a resolution of 0.014 to 0.029 μm/pixel, depending on magnification. For each sample, depending on grain sizes, we made mosaics of 3 x 3 or 6 x 6 overlapping images. Measurements of melt fraction, grain boundary wetness and grain size were carried out on these high resolution mosaics by using ImageJ software. Analyses of mosaics show that grain boundary wetness increases with increasing melt fraction at constant grain size to values well above those

  20. 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.

  1. Thermal and physical properties of molten fluorides for nuclear applications

    NASA Astrophysics Data System (ADS)

    van der Meer, J. P. M.; Konings, R. J. M.

    2007-01-01

    LiF-BeF 2-ThF 4 is a key system in molten salt reactor fuel studies. In this paper we give an overview of some important features of this ternary system. We discuss the phase behavior, vapor pressure, density and viscosity, based on what is known in the literature and on our own data from previous work on the thermodynamic assessment of LiF-BeF 2-ThF 4.

  2. 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.

  3. 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.

  4. Probes and monitors for the study of solidification of molten semiconductors

    NASA Technical Reports Server (NTRS)

    Sadoway, D. R.

    1986-01-01

    The purpose is to examine solidification in the LiCl-KCl system to determine if phenomena such as solute rejection can be obseved by laser schlieren imaging. Molten salts have attributes that make them attractive as physical models in solidification studies. With optical techniques of investigation such as schlieren imaging, it is possible to study fluid flow phenomena in molten salts and to watch the trajectory of the solid-liquid interface.

  5. Development of molten carbonate fuel cell power plant, volume 1

    NASA Astrophysics Data System (ADS)

    1985-03-01

    The technical results of a molten carbonate fuel cell power plant evelopment program are presented which establish the necessary technology base and demonstrate readiness to proceed with the fabrication and test of full size prototype stacks for coal fueled molten carbonate fuel cell power plants. The effort covered power plant systems studies, fuel cell component technology development, fuel cell stack design and analysis, manufacturing process definition, and an extensive experimental program. The reported results include: the definition and projected costs for a reference coal fueled power plant system based on user requirements, state-of-the-art advances in anode and electrolyte matrix technology, the detailed description of an internally manifolded stack design concept offering a number of attractive advantages, and the specification of the fabrication processes and methods necessary to produce and assemble this design. Results from the experimental program are documented.

  6. Cathode for molten carbonate fuel cell

    DOEpatents

    Kaun, Thomas D.; Mrazek, Franklin C.

    1990-01-01

    A porous sintered cathode for a molten carbonate fuel cell and method of making same, the cathode including a skeletal structure of a first electronically conductive material slightly soluble in the electrolyte present in the molten carbonate fuel cell covered by fine particles of a second material of possibly lesser electronic conductivity insoluble in the electrolyte present in the molten carbonate fuel cell, the cathode having a porosity in the range of from about 60% to about 70% at steady-state cell operating conditions consisting of both macro-pores and micro-pores.

  7. Thermophysical properties data on molten semiconductors

    SciTech Connect

    Nakamura, S.; Hibiya, T. )

    1992-01-01

    Thermophysical properties of molten semiconductors are reviewed. Published data for viscosity, thermal conductivity, surface tension, and other properties are presented. Several measurement methods often used for molten semiconductors are described. Recommended values of thermophysical properties are tabulated for Si, Ge, GaAs, InP, InSb, GaSh, and other compounds. This review shows that further measurements of thermophysical properties of GaAs and InP in the molten state are required. It is also indicated that a very limited amount of data on emissivity is available. Space experiments relating to thermophysical property measurements are described briefly. 77 refs., 9 figs., 3 tabs.

  8. Development of large scale internal reforming molten carbonate fuel cell

    SciTech Connect

    Sasaki, A.; Shinoki, T.; Matsumura, M.

    1996-12-31

    Internal Reforming (IR) is a prominent scheme for Molten Carbonate Fuel Cell (MCFC) power generating systems in order to get high efficiency i.e. 55-60% as based on the Higher Heating Value (HHV) and compact configuration. The Advanced Internal Reforming (AIR) technology has been developed based on two types of the IR-MCFC technology i.e. Direct Internal Reforming (DIR) and Indirect Internal Reforming (DIR).

  9. An on-line ultrasonic cleanliness analyzer for molten light metals

    NASA Astrophysics Data System (ADS)

    Ono, Yuu; Moisan, Jean-François; Jen, Cheng-Kuei; Zhang, Yuanbei; Su, Chun-Yi

    2004-02-01

    Ultrasonic techniques to evaluate the cleanliness of molten aluminum and magnesium using clad steel buffer rods are presented in this article. Backscattered ultrasonic signals from silicon carbide particles, added to molten aluminum, were detected with ultrasonic pulse-echo and pitch-catch modes at an ultrasonic frequency of 10 MHz. The scattered signals from inclusions, which might be oxide films and/or particles, in molten magnesium, were also detected. To establish the procedure and to investigate the optimum system configurations for evaluating melt cleanliness, a particle flow simulator was constructed that uses water and polyvinyl chloride particles. Also developed was a prototype of an on-line ultrasonic cleanliness analyzer for molten magnesium.

  10. 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)

  11. 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.

  12. Molten Hydroxide Trapping Process for Radioiodine

    SciTech Connect

    Trowbridge, L.D.

    2003-01-28

    A molten hydroxide trapping process has been considered for removing radioiodine species from off-gas streams whereby iodine is reacted directly with molten hydroxides such as NaOH or KOH. The resulting product is the corresponding iodide, which can be separated by simple cooling of the molten mixture to grow the iodide primary phase once the mixture reaches 70-80 mol% in the iodide component. Thermodynamic analysis indicates that such a chemical process is highly favorable. Experimental testing of the trapping process using molecular iodine showed trapping of up to 96% of the volatile iodine. The trapping efficiency was dependent on operational parameters such as temperature and gas-melt contact efficiency, and higher efficiencies are expected as the process is further developed. While an iodide phase could be effectively isolated by slow cooling of a molten iodide-hydroxide mixture, the persistent appearance of hydroxide indicated that an appreciable solubility of hydroxide occurred in the iodide phase.

  13. 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.

  14. Electrode for molten carbonate fuel cell

    DOEpatents

    Iacovangelo, Charles D.; Zarnoch, Kenneth P.

    1983-01-01

    A sintered porous electrode useful for a molten carbonate fuel cell is produced which is composed of a plurality of 5 wt. % to 95 wt. % nickel balance copper alloy encapsulated ceramic particles sintered together by the alloy.

  15. Hot filament technique for measuring the thermal conductivity of molten lithium fluoride

    NASA Technical Reports Server (NTRS)

    Jaworske, Donald A.; Perry, William D.

    1990-01-01

    Molten salts, such as lithium fluoride, are attractive candidates for thermal energy storage in solar dynamic space power systems because of their high latent heat of fusion. However, these same salts have poor thermal conductivities which inhibit the transfer of heat into the solid phase and out of the liquid phase. One concept for improving the thermal conductivity of the thermal energy storage system is to add a conductive filler material to the molten salt. High thermal conductivity pitch-based graphite fibers are being considered for this application. Although there is some information available on the thermal conductivity of lithium fluoride solid, there is very little information on lithium fluoride liquid, and no information on molten salt graphite fiber composites. This paper describes a hot filament technique for determining the thermal conductivity of molten salts. The hot filament technique was used to find the thermal conductivity of molten lithium fluoride at 930 C, and the thermal conductivity values ranged from 1.2 to 1.6 W/mK. These values are comparable to the slightly larger value of 5.0 W/mK for lithium fluoride solid. In addition, two molten salt graphite fiber composites were characterized with the hot filament technique and these results are also presented.

  16. Solids concentration measurements in molten wax by an ultrasonic technique

    SciTech Connect

    Soong, Y.; Gamwo, I.K.; Blackwell, A.G.; Schehl, R.R.; Zarochak, M.F.

    1994-12-31

    The application of the three-phase slurry reactor system to coal liquefaction processing and chemical industries has recently received considerable attention. To design and efficiently operate a three-phase slurry reactor, the degree of dispersion of the solid (catalyst) in the reactor should be understood. The solids distribution within the reactor greatly affects its performance. An ultrasonic technique is under development for measuring solids concentration in a three-phase slurry reactor. Preliminary measurements have been made on slurries consisting of molten paraffin wax, glass beads, and nitrogen bubbles at 189 C. The data show that the velocity and attenuation of the sound are well-defined functions of the solid and gas concentrations in the molten wax.

  17. 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.

  18. 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

  19. Removal of H{sub 2}S using molten carbonate at high temperature

    SciTech Connect

    Kawase, Makoto Otaka, Maromu

    2013-12-15

    Highlights: • The performance of molten carbonate for the removal of H{sub 2}S improves at higher temperatures. • The degree of H{sub 2}S removal is significantly affected by the CO{sub 2} concentration in syngas. • Addition of carbon elements, such as char and tar, decrease the negative effects of CO{sub 2}. • Continuous addition of carbon elements into molten carbonate enables continuous desulfurization. • Desulfurization using molten carbonate is suitable for gasification gas. - Abstract: Gasification is considered to be an effective process for energy conversion from various sources such as coal, biomass, and waste. Cleanup of the hot syngas produced by such a process may improve the thermal efficiency of the overall gasification system. Therefore, the cleanup of hot syngas from biomass gasification using molten carbonate is investigated in bench-scale tests. Molten carbonate acts as an absorbent during desulfurization and dechlorination and as a thermal catalyst for tar cracking. In this study, the performance of molten carbonate for removing H{sub 2}S was evaluated. The temperature of the molten carbonate was set within the range from 800 to 1000 °C. It is found that the removal of H{sub 2}S is significantly affected by the concentration of CO{sub 2} in the syngas. When only a small percentage of CO{sub 2} is present, desulfurization using molten carbonate is inadequate. However, when carbon elements, such as char and tar, are continuously supplied, H{sub 2}S removal can be maintained at a high level. To confirm the performance of the molten carbonate gas-cleaning system, purified biogas was used as a fuel in power generation tests with a molten carbonate fuel cell (MCFC). The fuel cell is a high-performance sensor for detecting gaseous impurities. When purified gas from a gas-cleaning reactor was continuously supplied to the fuel cell, the cell voltage remained stable. Thus, the molten carbonate gas-cleaning reactor was found to afford good gas

  20. 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.

  1. 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

  2. Vacuum Refining of Molten Silicon

    NASA Astrophysics Data System (ADS)

    Safarian, Jafar; Tangstad, Merete

    2012-12-01

    Metallurgical fundamentals for vacuum refining of molten silicon and the behavior of different impurities in this process are studied. A novel mass transfer model for the removal of volatile impurities from silicon in vacuum induction refining is developed. The boundary conditions for vacuum refining system—the equilibrium partial pressures of the dissolved elements and their actual partial pressures under vacuum—are determined through thermodynamic and kinetic approaches. It is indicated that the vacuum removal kinetics of the impurities is different, and it is controlled by one, two, or all the three subsequent reaction mechanisms—mass transfer in a melt boundary layer, chemical evaporation on the melt surface, and mass transfer in the gas phase. Vacuum refining experimental results of this study and literature data are used to study the model validation. The model provides reliable results and shows correlation with the experimental data for many volatile elements. Kinetics of phosphorus removal, which is an important impurity in the production of solar grade silicon, is properly predicted by the model, and it is observed that phosphorus elimination from silicon is significantly increased with increasing process temperature.

  3. 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.

  4. Pipe Poiseuille flow of viscously anisotropic, partially molten rock

    NASA Astrophysics Data System (ADS)

    Allwright, Jane; Katz, Richard F.

    2014-12-01

    Laboratory experiments in which synthetic, partially molten rock is subjected to forced deformation provide a context for testing hypotheses about the dynamics and rheology of the mantle. Here our hypothesis is that the aggregate viscosity of partially molten mantle is anisotropic, and that this anisotropy arises from deviatoric stresses in the rock matrix. We formulate a model of pipe Poiseuille flow based on theory by Takei & Holtzman and Takei & Katz. Pipe Poiseuille is a configuration that is accessible to laboratory experimentation but for which there are no published results. We analyse the model system through linearized analysis and numerical simulations. This analysis predicts two modes of melt segregation: migration of melt from the centre of the pipe towards the wall and localization of melt into high-porosity bands that emerge near the wall, at a low angle to the shear plane. We compare our results to those of Takei & Katz for plane Poiseuille flow; we also describe a new approximation of radially varying anisotropy that improves the self-consistency of models over those of Takei & Katz. This study provides a set of baseline, quantitative predictions to compare with future laboratory experiments on forced pipe Poiseuille flow of partially molten mantle.

  5. 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.

  6. 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.

  7. 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

  8. Crystallization Behavior of Copper Smelter Slag During Molten Oxidation

    NASA Astrophysics Data System (ADS)

    Fan, Yong; Shibata, Etsuro; Iizuka, Atsushi; Nakamura, Takashi

    2015-10-01

    Copper slag is composed of iron silicate obtained by smelting copper concentrate and silica flux. One of the most important criteria for the utilization of this secondary resource is the recovery of iron from the slag matrix to decrease the volume of dumped slag. The molten oxidation process with crushing magnetic separation appears to be a more sustainable approach and is based on directly blowing oxidizing gas onto molten slag after the copper smelting process. In the current study, using an infrared furnace, the crystallization behavior of the slag during molten oxidation was studied to better understand the trade-off between magnetite and hematite precipitations, as assessed by X-ray diffraction (using an internal standard). Furthermore, the crystal morphology was examined using a laser microscope and Raman imaging system to understand the iron oxide transformation, and the distribution of impurities such as Cu, Zn, As, Cr, and Pb were complemented with scanning electron microscopy and energy dispersive spectroscopy. In addition, the reaction mechanism was investigated with a focus on the oxidation processes.

  9. Method and apparatus for atomization and spraying of molten metals

    DOEpatents

    Hobson, D.O.; Alexeff, I.; Sikka, V.K.

    1988-07-19

    A method and device for dispersing molten metal into fine particulate spray, the method comprises applying an electric current through the molten metal and simultaneously applying a magnetic field to the molten metal in a plane perpendicular to the electric current, whereby the molten metal is caused to form into droplets at an angle perpendicular to both the electric current and the magnetic field. The device comprises a structure for providing a molten metal, appropriately arranged electrodes for applying an electric current through the molten metal, and a magnet for providing a magnetic field in a plane perpendicular to the electric current. 11 figs.

  10. Method and apparatus for atomization and spraying of molten metals

    DOEpatents

    Hobson, David O.; Alexeff, Igor; Sikka, Vinod K.

    1990-01-01

    A method and device for dispersing molten metal into fine particulate spray, the method comprises applying an electric current through the molten metal and simultaneously applying a magnetic field to the molten metal in a plane perpendicular to the electric current, whereby the molten metal is caused to form into droplets at an angle perpendicular to both the electric current and the magnetic field. The device comprises a structure for providing a molten metal, appropriately arranged electrodes for applying an electric current through the molten metal, and a magnet for providing a magnetic field in a plane perpendicular to the electric current.

  11. A method of measuring a molten metal liquid pool volume

    DOEpatents

    Garcia, G.V.; Carlson, N.M., Donaldson, A.D.

    1990-12-12

    A method of measuring a molten metal liquid pool volume and in particular molten titanium liquid pools, including the steps of (a) generating an ultrasonic wave at the surface of the molten metal liquid pool, (b) shining a light on the surface of a molten metal liquid pool, (c) detecting a change in the frequency of light, (d) detecting an ultrasonic wave echo at the surface of the molten metal liquid pool, and (e) computing the volume of the molten metal liquid. 3 figs.

  12. Performance Testing of Molten Regolith Electrolysis with Transfer of Molten Material for the Production of Oxygen and Metals on the Moon

    NASA Technical Reports Server (NTRS)

    Sibille, Laurent; Sadoway, Donald; Tripathy, Prabhat; Standish, Evan; Sirk, Aislinn; Melendez, Orlando; Stefanescu, Doru

    2010-01-01

    Previously, we have demonstrated the production of oxygen by electrolysis of molten regolith simulants at temperatures near 1600 C. Using an inert anode and suitable cathode, direct electrolysis (no supporting electrolyte) of the molten silicate is carried out, resulting in the production of molten metallic products at the cathode and oxygen gas at the anode. Initial direct measurements of current efficiency have confirmed that the process offer potential advantages of high oxygen production rates in a smaller footprint facility landed on the moon, with a minimum of consumables brought from Earth. We now report the results of a scale-up effort toward the goal of achieving production rates equivalent to 1 metric ton O2/year, a benchmark established for the support of a lunar base. We previously reported on the electrochemical behavior of the molten electrolyte as dependent on anode material, sweep rate and electrolyte composition in batches of 20-200g and at currents of less than 0.5 A. In this paper, we present the results of experiments performed at currents up to 10 Amperes) and in larger volumes of regolith simulant (500 g - 1 kg) for longer durations of electrolysis. The technical development of critical design components is described, including: inert anodes capable of passing continuous currents of several Amperes, container materials selection, direct gas analysis capability to determine the gas components co-evolving with oxygen. To allow a continuous process, a system has been designed and tested to enable the withdrawal of cathodically-reduced molten metals and spent molten oxide electrolyte. The performance of the withdrawal system is presented and critiqued. The design of the electrolytic cell and the configuration of the furnace were supported by modeling the thermal environment of the system in an effort to realize a balance between external heating and internal joule heating. We will discuss the impact these simulations and experimental findings have

  13. 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

  14. 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.

  15. Dynamics of the Molten Contact Line

    NASA Technical Reports Server (NTRS)

    Sonin, Ain A.; Schiaffino, Stefano

    1996-01-01

    In contrast to the ordinary contact line problem, virtually no information is available on the similar problem associated with a molten material spreading on a solid which is below the melt's fusion point. The latter is a more complex problem which heat transfer and solidification take place simultaneously with spreading, and requires answers not only for the hot melt's advance speed over the cold solid as a function of contact angle, but also for how one is to predict the point of the molten contact line's arrest by freezing. This issues are of importance in evolving methods of materials processing. The purpose of our work is to develop, based on both experiments and theory, an understanding of the dynamic processes that occur when a molten droplet touches a subcooled solid, spreads partly over it by capillary action, and freezes. We seek answers to the following basic questions. First, what is the relationship between the melt's contact line speed and the apparent (dynamic) contact angle? Secondly, at what point will the contact line modon be arrested by freezing? The talk will describe three components of our work: (1) deposition experiments with small molten droplets; (2) investigation of the dynamics of the molten contact line by means of a novel forced spreading method; and (3) an attempt to provide a theoretical framework for answering the basic questions posed above.

  16. Physical properties of molten carbonate electrolyte

    SciTech Connect

    Kojima, T.; Yanagida, M.; Tanimoto, K.

    1996-12-31

    Recently many kinds of compositions of molten carbonate electrolyte have been applied to molten carbonate fuel cell in order to avoid the several problems such as corrosion of separator plate and NiO cathode dissolution. Many researchers recognize that the addition of alkaline earth (Ca, Sr, and Ba) carbonate to Li{sub 2}CO{sub 3}-Na{sub 2}CO{sub 3} and Li{sub 2}CO{sub 3}-K{sub 2}CO{sub 3} eutectic electrolytes is effective to avoid these problems. On the other hand, one of the corrosion products, CrO{sub 4}{sup 2-} ion is found to dissolve into electrolyte and accumulated during the long-term MCFC operations. This would affect the performance of MCFC. There, however, are little known data of physical properties of molten carbonate containing alkaline earth carbonates and CrO{sub 4}{sup 2-}. We report the measured and accumulated data for these molten carbonate of electrical conductivity and surface tension to select favorable composition of molten carbonate electrolytes.

  17. Molten carbonate fuel cell networks: Principles, analysis, and performance

    NASA Astrophysics Data System (ADS)

    Wimer, J. G.; Williams, M. C.

    1993-01-01

    The chemical reactions in an internally reforming molten carbonate fuel cell (IRMCFC) are described and combined into the overall IRMCFC reaction. Thermodynamic and electrochemical principles are discussed, and structure and operation of fuel cell stacks are explained. In networking, multiple fuel cell stacks are arranged so that reactant streams are fed and recycled through stacks in series for higher reactant utilization and increased system efficiency. Advantages and performance of networked and conventional systems are compared, using ASPEN simulations. The concept of networking can be applied to any electrochemical membrane, such as that developed for hot gas cleanup in future power plants.

  18. 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).

  19. 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.

  20. Dissolution of Si in Molten Al with Gas Injection

    NASA Astrophysics Data System (ADS)

    Seyed Ahmadi, Mehran

    Silicon is an essential component of many aluminum alloys, as it imparts a range of desirable characteristics. However, there are considerable practical difficulties in dissolving solid Si in molten Al, because the dissolution process is slow, resulting in material and energy losses. It is thus essential to examine Si dissolution in molten Al, to identify means of accelerating the process. This thesis presents an experimental study of the effect of Si purity, bath temperature, fluid flow conditions, and gas stirring on the dissolution of Si in molten Al, plus the results of physical and numerical modeling of the flow to corroborate the experimental results. The dissolution experiments were conducted in a revolving liquid metal tank to generate a bulk velocity, and gas was introduced into the melt using top lance injection. Cylindrical Si specimens were immersed into molten Al for fixed durations, and upon removal the dissolved Si was measured. The shape and trajectory of injected bubbles were examined by means of auxiliary water experiments and video recordings of the molten Al free surface. The gas-agitated liquid was simulated using the commercial software FLOW-3D. The simulation results provide insights into bubble dynamics and offer estimates of the fluctuating velocities within the Al bath. The experimental results indicate that the dissolution rate of Si increases in tandem with the melt temperature and bulk velocity. A higher bath temperature increases the solubility of Si at the solid/liquid interface, resulting in a greater driving force for mass transfer, and a higher liquid velocity decreases the resistance to mass transfer via a thinner mass boundary layer. Impurities (with lower diffusion coefficients) in the form of inclusions obstruct the dissolution of the Si main matrix. Finally, dissolution rate enhancement was observed by gas agitation. It is postulated that the bubble-induced fluctuating velocities disturb the mass boundary layer, which

  1. 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.

  2. 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.

  3. Sodium-tetravalent sulfur molten chloroaluminate cell

    DOEpatents

    Mamantov, Gleb

    1985-04-02

    A sodium-tetravalent sulfur molten chloroaluminate cell with a .beta."-alumina sodium ion conductor having a S-Al mole ratio of above about 0.15 in an acidic molten chloroaluminate cathode composition is disclosed. The cathode composition has an AlCl.sub.3 -NaCl mole percent ratio of above about 70-30 at theoretical full charge. The cell provides high energy densities at low temperatures and provides high energy densities and high power densities at moderate temperatures.

  4. Advanced Ceramic Composites for Improved Thermal Management in Molten Aluminum Applications

    SciTech Connect

    Peters, Klaus-Markus; Cravens, Robert; Hemrick, James Gordon

    2009-01-01

    Degradation of refractories in molten aluminum applications leads to energy inefficiencies, both in terms of increased energy consumption during use as well as due to frequent and premature production shutdowns. Therefore, the ability to enhance and extend the performance of refractory systems will improve the energy efficiency through out the service life. TCON ceramic composite materials are being produced via a collaboration between Fireline TCON, Inc. and Rex Materials Group. These materials were found to be extremely resistant to erosion and corrosion by molten aluminum alloys during an evaluation funded by the U.S. Department of Energy and it was concluded that they positively impact the performance of refractory systems. These findings were subsequently verified by field tests. Data will be presented on how TCON shapes are used to significantly improve the thermal management of molten aluminum contact applications and extend the performance of such refractory systems.

  5. 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.

  6. Process for recovering tritium from molten lithium metal

    DOEpatents

    Maroni, Victor A.

    1976-01-01

    Lithium tritide (LiT) is extracted from molten lithium metal that has been exposed to neutron irradiation for breeding tritium within a thermonuclear or fission reactor. The extraction is performed by intimately contacting the molten lithium metal with a molten lithium salt, for instance, lithium chloride - potassium chloride eutectic to distribute LiT between the salt and metal phases. The extracted tritium is recovered in gaseous form from the molten salt phase by a subsequent electrolytic or oxidation step.

  7. Method for recovering hydrocarbons from molten metal halides

    DOEpatents

    Pell, Melvyn B.

    1979-01-01

    In a process for hydrocracking heavy carbonaceous materials by contacting such carbonaceous materials with hydrogen in the presence of a molten metal halide catalyst to produce hydrocarbons having lower molecular weights and thereafter recovering the hydrocarbons so produced from the molten metal halide, an improvement comprising injecting into the spent molten metal halide, a liquid low-boiling hydrocarbon stream is disclosed.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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

  13. 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.

  14. Anodic oxidation of sulfide ions in molten lithium fluoride

    SciTech Connect

    Lloyd, C.L.; Gilbert, J.B. II . Applied Research Lab.)

    1994-10-01

    The study of sulfur and sulfide oxidation in molten salt systems is of current interest in high energy battery, and metallurgical applications. Cyclic voltammetry experiments have been performed on lithium sulfide in a lithium fluoride electrolyte at 1,161 K using a graphite working electrode and a platinum quasi-reference electrode. Two distinct oxidation mechanisms are observed for the sulfide ions. The first oxidation produces sulfur and at a higher potential a disulfide species is proposed to have formed. Both oxidations appear to be reversible and diffusion controlled.

  15. Synthesis and characterization of phosphates in molten systems Cs 2O-P 2O 5-CaO- MIII2O 3 ( MIII—Al, Fe, Cr)

    NASA Astrophysics Data System (ADS)

    Zatovsky, Igor V.; Strutynska, Nataliya Yu.; Baumer, Vyacheslav N.; Slobodyanik, Nikolay S.; Ogorodnyk, Ivan V.; Shishkin, Oleg V.

    2011-03-01

    The crystallization of complex phosphates from the melts of Cs 2O-P 2O 5-CaO- MIII2O 3 ( MIII—Al, Fe, Cr) systems have been investigated at fixed value Cs/P molar ratios equal to 0.7, 1.0 and 1.3 and Са/Р=0.2 and Ca/ МIII=1. The fields of crystallization of CsCaP 3O 9, β-Ca 2P 2O 7, Cs 2CaP 2O 7, Cs 3CaFe(P 2O 7) 2, Ca 9MIII(PO 4) 7 ( MIII—Fe, Cr), Cs 0.63Ca 9.63Fe 0.37(PO 4) 7 and CsCa 10(PO 4) 7 were determined. Obtained phosphates were investigated using powder X-ray diffraction and FTIR spectroscopy. Novel whitlockite-related phases CsCa 10(PO 4) 7 and Cs 0.63Ca 9.63Fe 0.37(PO 4) 7 have been characterized by single crystal X-ray diffraction: space group R3c, a=10.5536(5) and 10.5221(4) Å, с=37.2283(19) and 37.2405(17) Å, respectively.

  16. Oxygen electrode in molten carbonate fuel cells

    NASA Astrophysics Data System (ADS)

    Dave, B. B.; White, R. E.; Srinivasan, S.; Appleby, A. J.

    1990-12-01

    During this quarter, impedance data were analyzed for an oxygen reduction process in molten carbonate electrolyte and a manuscript, Impedance Analysis for Oxygen Reduction in a Lithium Carbonate Melt: Effects of Partial Pressure of Carbon Dioxide and Temperature, was prepared to be submitted to Journal of the Electrochemical Society for publication.

  17. 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.

  18. 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.

  19. MOLTEN PLUTONIUM FUELED FAST BREEDER REACTOR

    DOEpatents

    Kiehn, R.M.; King, L.D.P.; Peterson, R.E.; Swickard, E.O. Jr.

    1962-06-26

    A description is given of a nuclear fast reactor fueled with molten plutonium containing about 20 kg of plutonium in a tantalum container, cooled by circulating liquid sodium at about 600 to 650 deg C, having a large negative temperature coefficient of reactivity, and control rods and movable reflector for criticality control. (AEC)

  20. Molten metal processes reap profit from waste

    SciTech Connect

    Mather, R.; Steckler, D.; Kimmel, S.; Tanner, A.

    1996-05-01

    Over the past few years, a new tool has been added to the waste-processing arsenal. The use of a reactor filled with molten metal has been proven for dissociating a wide range of organic, organometallic, metallic and inorganic wastes into their constituent elements. Such reactors allow users to manipulate the solution chemistry and operating conditions inside, to reconfigure the dissociated elements into useful products, such as synthesis gas (hydrogen and carbon monoxide), HCl, metal alloys and ceramics, while ensuring high levels of environmental performance. A commercial-scale, molten metal processing unit is being constructed at Hoechst Celanese Corp.`s Bay City, Tex., chemical manufacturing plant. The unit with an estimated capital cost of $25 million, will be constructed, owned and operated by Molten Metal Technology, Inc., and will use MMT`s Catalytic Extraction processing. Once online, the facility will process wastes from Hoechst Celanese`s Gulf Coast plants and from other nearby chemical manufacturers. In addition to processing wastes, the facility will generate a syngas product that will be used onsite as a raw material during chemical manufacturing. Presented are the results of commercial-scale demonstrations using a prototype molten metal reactor for a wide range of industrial waste streams.

  1. 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

  2. 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

  3. 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

  4. 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

  5. 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.

  6. Feet sunk in molten aluminium: The burn and its prevention.

    PubMed

    Alonso-Peña, David; Arnáiz-García, María Elena; Valero-Gasalla, Javier Luis; Arnáiz-García, Ana María; Campillo-Campaña, Ramón; Alonso-Peña, Javier; González-Santos, Jose María; Fernández-Díaz, Alaska Leonor; Arnáiz, Javier

    2015-08-01

    Nowadays, despite improvements in safety rules and inspections in the metal industry, foundry workers are not free from burn accidents. Injuries caused by molten metals include burns secondary to molten iron, aluminium, zinc, copper, brass, bronze, manganese, lead and steel. Molten aluminium is one of the most common causative agents of burns (60%); however, only a few publications exist concerning injuries from molten aluminium. The main mechanisms of lesion from molten aluminium include direct contact of the molten metal with the skin or through safety apparel, or when the metal splash burns through the pants and rolls downward along the leg. Herein, we report three cases of deep dermal burns after 'soaking' the foot in liquid aluminium and its evolutive features. This paper aims to show our experience in the management of burns due to molten aluminium. We describe the current management principles and the key features of injury prevention.

  7. Occlusion and ion exchange in the molten (lithium chloride-potassium chloride-alkali metal chloride) salt + zeolite 4A system with alkali metal chlorides of sodium, rubidium, and cesium

    NASA Astrophysics Data System (ADS)

    Lexa, Dusan; Johnson, Irving

    2001-06-01

    Interaction between molten salts of the type LiCl-KCl-MeCl (Me = Na, Rb, Cs, x MeCl = 0 to 0.5, x KCl/ x LiCl = 0.69) and zeolite 4A have been studied at 823 K. The main interactions between these salts and zeolite are molten salt occlusion to form salt-loaded zeolite and ion exchange between the molten salt and salt-loaded zeolite. No chemical reaction has been observed. The extent of occlusion is a function of the concentration of MeCl in the zeolite and is equal to 11±1 Cl- per zeolite unit cell, (AlSiO4)12, at infinite MeCl dilution. The ion-exchange mole fraction equilibrium constants (separation factors) with respect to Li are decreasing functions of concentration of MeCl in the zeolite. At infinite MeCl dilution, they are equal to 0.84, 0.87, and 2.31 for NaCl, RbCl, and CsCl, respectively, and increase in the order Na

  8. 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.

  9. 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

  10. 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.

  11. Assessment of deposition for power-plant molten-carbonate fuel cells

    NASA Astrophysics Data System (ADS)

    Wenglarz, R. A.

    1982-03-01

    Particulate deposition in molten carbonate fuel cell anodes is addressed for operation with future coal gasification power plants. Power plant systems factors affecting deposition are explored such as gas cleanup requirements for particulate removal and gasifier product gas composition differences for various gasifier types and operational modes (air blown versus oxygen blown). Effects of fuel cell characteristics (including average cell current density and fuel utilization) on anode deposition are also quantified. Particulate effects on molten carbonate fuel cell anode performance may not be as detrimental as perhaps perceived in the past. Gas cleanup to remove virtually all particles larger than one micron in diameter is expected to prevent or at least greatly reduce anode deposition. However, cathode deposition in molten carbonate fuel cells should be evaluated in the future since cathodes are likely more prone to deposition than anodes even though cathode channel particle concentrations are much lower.

  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. 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.

  14. 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.

  15. Molten uranium dioxide structure and dynamics

    SciTech Connect

    Skinner, L. B.; Parise, J. B.; Benmore, C. J.; Weber, J. K.R.; Williamson, M. A.; Tamalonis, A.; Hebden, A.; Wiencek, T.; Alderman, O. L.G.; Guthrie, M.; Leibowitz, L.

    2014-11-21

    Uranium dioxide (UO2) is the major nuclear fuel component of fission power reactors. A key concern during severe accidents is the melting and leakage of radioactive UO2 as it corrodes through its zirconium cladding and steel containment. Yet, the very high temperatures (>3140 kelvin) and chemical reactivity of molten UO2 have prevented structural studies. In this work, we combine laser heating, sample levitation, and synchrotron x-rays to obtain pair distribution function measurements of hot solid and molten UO2. The hot solid shows a substantial increase in oxygen disorder around the lambda transition (2670 K) but negligible U-O coordination change. On melting, the average U-O coordination drops from 8 to 6.7 ± 0.5. Molecular dynamics models refined to this structure predict higher U-U mobility than 8-coordinated melts.

  16. Molten uranium dioxide structure and dynamics

    DOE PAGESBeta

    Skinner, L. B.; Parise, J. B.; Benmore, C. J.; Weber, J. K.R.; Williamson, M. A.; Tamalonis, A.; Hebden, A.; Wiencek, T.; Alderman, O. L.G.; Guthrie, M.; et al

    2014-11-21

    Uranium dioxide (UO2) is the major nuclear fuel component of fission power reactors. A key concern during severe accidents is the melting and leakage of radioactive UO2 as it corrodes through its zirconium cladding and steel containment. Yet, the very high temperatures (>3140 kelvin) and chemical reactivity of molten UO2 have prevented structural studies. In this work, we combine laser heating, sample levitation, and synchrotron x-rays to obtain pair distribution function measurements of hot solid and molten UO2. The hot solid shows a substantial increase in oxygen disorder around the lambda transition (2670 K) but negligible U-O coordination change. Onmore » melting, the average U-O coordination drops from 8 to 6.7 ± 0.5. Molecular dynamics models refined to this structure predict higher U-U mobility than 8-coordinated melts.« less

  17. Molten uranium dioxide structure and dynamics.

    PubMed

    Skinner, L B; Benmore, C J; Weber, J K R; Williamson, M A; Tamalonis, A; Hebden, A; Wiencek, T; Alderman, O L G; Guthrie, M; Leibowitz, L; Parise, J B

    2014-11-21

    Uranium dioxide (UO2) is the major nuclear fuel component of fission power reactors. A key concern during severe accidents is the melting and leakage of radioactive UO2 as it corrodes through its zirconium cladding and steel containment. Yet, the very high temperatures (>3140 kelvin) and chemical reactivity of molten UO2 have prevented structural studies. In this work, we combine laser heating, sample levitation, and synchrotron x-rays to obtain pair distribution function measurements of hot solid and molten UO2. The hot solid shows a substantial increase in oxygen disorder around the lambda transition (2670 K) but negligible U-O coordination change. On melting, the average U-O coordination drops from 8 to 6.7 ± 0.5. Molecular dynamics models refined to this structure predict higher U-U mobility than 8-coordinated melts. PMID:25414311

  18. Method and apparatus for spraying molten materials

    DOEpatents

    Glovan, Ronald J.; Tierney, John C.; McLean, Leroy L.; Johnson, Lawrence L.; Nelson, Gordon L.; Lee, Ying-Ming

    1996-01-01

    A metal spray apparatus is provided with a supersonic nozzle. Molten metal is injected into a gas stream flowing through the nozzle under pressure. By varying the pressure of the injected metal, the droplet can be made in various selected sizes with each selected size having a high degree of size uniformity. A unique one piece graphite heater provides easily controlled uniformity of temperature in the nozzle and an attached tundish which holds the pressurized molten metal. A unique U-shaped gas heater provides extremely hot inlet gas temperatures to the nozzle. A particularly useful application of the spray apparatus is coating of threads of a fastener with a shape memory alloy. This permits a fastener to be easily inserted and removed but provides for a secure locking of the fastener in high temperature environments.

  19. Method and apparatus for spraying molten materials

    DOEpatents

    Glovan, R.J.; Tierney, J.C.; McLean, L.L.; Johnson, L.L.; Nelson, G.L.; Lee, Y.M.

    1996-06-25

    A metal spray apparatus is provided with a supersonic nozzle. Molten metal is injected into a gas stream flowing through the nozzle under pressure. By varying the pressure of the injected metal, the droplet can be made in various selected sizes with each selected size having a high degree of size uniformity. A unique one piece graphite heater provides easily controlled uniformity of temperature in the nozzle and an attached tundish which holds the pressurized molten metal. A unique U-shaped gas heater provides extremely hot inlet gas temperatures to the nozzle. A particularly useful application of the spray apparatus is coating of threads of a fastener with a shape memory alloy. This permits a fastener to be easily inserted and removed but provides for a secure locking of the fastener in high temperature environments. 12 figs.

  20. Molten uranium dioxide structure and dynamics.

    PubMed

    Skinner, L B; Benmore, C J; Weber, J K R; Williamson, M A; Tamalonis, A; Hebden, A; Wiencek, T; Alderman, O L G; Guthrie, M; Leibowitz, L; Parise, J B

    2014-11-21

    Uranium dioxide (UO2) is the major nuclear fuel component of fission power reactors. A key concern during severe accidents is the melting and leakage of radioactive UO2 as it corrodes through its zirconium cladding and steel containment. Yet, the very high temperatures (>3140 kelvin) and chemical reactivity of molten UO2 have prevented structural studies. In this work, we combine laser heating, sample levitation, and synchrotron x-rays to obtain pair distribution function measurements of hot solid and molten UO2. The hot solid shows a substantial increase in oxygen disorder around the lambda transition (2670 K) but negligible U-O coordination change. On melting, the average U-O coordination drops from 8 to 6.7 ± 0.5. Molecular dynamics models refined to this structure predict higher U-U mobility than 8-coordinated melts.

  1. 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.

  2. Molten Wax As A Dust Control Agent

    SciTech Connect

    Carter, E.E.

    2008-07-01

    Molten wax shows considerable promise as a fixative and dust control agent in demolition of radioactively contaminated facilities. Sticky molten wax, modified with special surfactants and wetting agents, is capable of not only coating materials but also penetrating into friable or dusty materials and making them incapable of becoming airborne during demolition. Wax also shows significant promise for stabilization of waste residuals that may be contained in buildings undergoing demolition. Some of the building materials that have been tested to date include concrete, wood, sheet-rock, fiber insulation, lime, rock, and paper. Protective clothing, clay, sand, sulfur, and bentonite clay have been tested as surrogates for certain waste materials that may be encountered during building demolition. The paper describes several potential applications of molten wax for dust control in demolition of radioactive contaminated facilities. As a case-study, this paper describes a research test performed for a pipeline closure project being completed by the Idaho Cleanup Project at the Idaho National Laboratory. The project plans to excavate and remove a section of buried Duriron drain piping containing highly radioactive and friable and 'flighty' waste residuals. A full-scale pipeline mockup containing simulated waste was buried in sand to simulate the direct-buried subsurface condition of the subject piping. The pipeline was pre-heated by drawing hot air through the line with a HEPA vacuum blower unit. Molten wax was pumped into the line and allowed to cool. The line was then broken apart in various places to evaluate the permeation performance of the wax. The wax fully permeated all the surrogate materials rendering them non-friable with a consistency similar to modeling clay. Based on the performance during the mockup, it is anticipated that the wax will be highly effective in controlling the spread of radiological contamination during pipe demolition activities. A larger test

  3. 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.

  4. Crucible cast from beryllium oxide and refractory cement is impervious to flux and molten metal

    NASA Technical Reports Server (NTRS)

    Jastrzebski, Z. D.

    1966-01-01

    Crucible from a mixture of a beryllium oxide aggregate and hydraulic refractory cement, and coated with an impervious refractory oxide will not deteriorate in the presence of fused salt- molten metal mixtures such as uranium- magnesium-zinc-halide salt systems. Vessels cast by this process are used in the flux reduction of oxides of thorium and uranium.

  5. 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

  6. 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

  7. 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.

  8. Electrolytic production of neodymium metal from a molten chloride electrolyte

    SciTech Connect

    Chambers, M.F.; Murphy, J.E.

    1991-01-01

    This paper reports that the U.S. Bureau of Mines conducted experiments on electrowinning of neodymium metal by using a molten-metal cathode at 650{degrees} C and an electrolyte of 50 mol pet NdCl, (neodymium chloride) and 50 mol pet KCl (potassium chloride). The molten-metal cathodes were alloys of magnesium and zinc or magnesium and cadmium. Current efficiencies were 90 pct with a Mg-Zn cathode and 80 pct with a Mg-Cd cathode. The Mg-Cd cathode was easily separated from the electrolyte. In contrast, the Mg-Zn cathode tended to mix with the electrolyte, making separation difficult. The cathode metals were separated from the neodymium by distillation at 1,100{degrees} C under a vacuum of 10{sup {minus}4} torr. Neodymium metal of 99.9 + purity was recovered from the Mg-Cd alloy cathode after 30 min distillation time. The neodymium recovered from the Mg-Zn system contained almost 2 pct Zn after vacuum distillation. Continuous operation using the Mg-Cd alloy cathode was demonstrated.

  9. Compaction around a rigid, circular inclusion in partially molten rock

    NASA Astrophysics Data System (ADS)

    Alisic, Laura; Rudge, John F.; Katz, Richard F.; Wells, Garth N.; Rhebergen, Sander

    2014-07-01

    Conservation laws that describe the behavior of partially molten mantle rock have been established for several decades, but the associated rheology remains poorly understood. Constraints on the rheology may be obtained from recently published experiments involving deformation of partially molten rock around a rigid, spherical inclusion. These experiments give rise to patterns of melt segregation that exhibit the competing effects of pressure shadows and melt-rich bands. Such patterns provide an opportunity to infer rheological parameters through comparison with models based on the conservation laws and constitutive relations that hypothetically govern the system. To this end, we have developed software tools to simulate finite strain, two-phase flow around a circular inclusion in a configuration that mirrors the experiments. Simulations indicate that the evolution of porosity is predominantly controlled by the porosity-weakening exponent of the shear viscosity and the poorly known bulk viscosity. In two-dimensional simulations presented here, we find that the balance of pressure shadows and melt-rich bands observed in experiments only occurs for bulk-to-shear viscosity ratio of less than about five. However, the evolution of porosity in simulations with such low bulk viscosity exceeds physical bounds at unrealistically small strain due to the unchecked, exponential growth of the porosity variations. Processes that limit or balance porosity localization should be incorporated in the formulation of the model to produce results that are consistent with the porosity evolution in experiments.

  10. Electrochemical evidence on the molten globule conformation of cytochrome c.

    PubMed

    Pineda, T; Sevilla, J M; Román, A J; Blázquez, M

    1997-12-01

    To explore a new approach for characterizing the molten globule conformation, cyclic voltammetric studies of salt induced transitions at acidic pH of cyt c have been carried out. The use of modified electrodes has made the observation of direct electrochemistry in native cyt c possible. However, most of these electrodes do not show reversible responses at acidic pH, due to the fact that, for this system, a deprotonated electrode surface is needed. In these studies, we have used a 6-mercaptopurine and cysteine-modified gold electrodes which are effective for direct rapid electron transfer to cyt c, even in acid solutions. The change in the absorption bands of cyt c are used to monitor the conformational states and, hence, to compare the voltammetric results. Under the experimental conditions where the A state of cyt c is obtained, a reversible voltammetric signal is observed. The midpoint peak potentials are found to be very close to the formal potential of native cyt c. Results are discussed in terms of a cooperative two-state transition between the acid unfolded and the globular acidic states of cyt c. This finding establishes, for the first time, the similarity of both the native and the molten globule-like conformations in terms of its redox properties. PMID:9434113

  11. Electrochemical evidence on the molten globule conformation of cytochrome c.

    PubMed

    Pineda, T; Sevilla, J M; Román, A J; Blázquez, M

    1997-12-01

    To explore a new approach for characterizing the molten globule conformation, cyclic voltammetric studies of salt induced transitions at acidic pH of cyt c have been carried out. The use of modified electrodes has made the observation of direct electrochemistry in native cyt c possible. However, most of these electrodes do not show reversible responses at acidic pH, due to the fact that, for this system, a deprotonated electrode surface is needed. In these studies, we have used a 6-mercaptopurine and cysteine-modified gold electrodes which are effective for direct rapid electron transfer to cyt c, even in acid solutions. The change in the absorption bands of cyt c are used to monitor the conformational states and, hence, to compare the voltammetric results. Under the experimental conditions where the A state of cyt c is obtained, a reversible voltammetric signal is observed. The midpoint peak potentials are found to be very close to the formal potential of native cyt c. Results are discussed in terms of a cooperative two-state transition between the acid unfolded and the globular acidic states of cyt c. This finding establishes, for the first time, the similarity of both the native and the molten globule-like conformations in terms of its redox properties.

  12. Development of Molten Corium Using An Exothermic Chemical Reaction for the Molten- Fuel Moderator-Interaction Studies at Chalk River Laboratories

    SciTech Connect

    Nitheanandan, T.; Sanderson, D.B.; Kyle, G.; Farmer, M.

    2004-07-01

    Atomic Energy of Canada Limited (AECL) has partnered with Argonne National Laboratory to develop a corium thermite prototypical of Candu material and test the concept of ejecting {approx}25 kg of the molten material from a pressure tube with a driving pressure of 10 MPa. This development program has been completed and the technology transferred to AECL. Preparation for the molten-fuel moderator-interaction tests at AECL's Chalk River Laboratories is well underway. A mixture of 0.582 U/0.077 U{sub 3}O{sub 8}/0.151 Zr/0.19 CrO{sub 3} (wt%) as reactant chemicals has been demonstrated to produce a corium consisting of 0.73 UO{sub 2}/0.11 Zr/0.06 ZrO{sub 2}/0.10 Cr (wt%) at {approx}2400 deg. C. This is comparable to the target Candu specific corium of 0.9 UO{sub 2}/0.1 Zr (wt%), with limited oxidation. The peak melt temperature was confirmed from small-scale thermitic reaction tests. Several small-scale tests were completed to qualify the thermite to ensure operational safety and a quantifiable experimental outcome. The proposed molten-fuel moderator-interaction experiments at Chalk River Laboratories will consist of heating the thermite mixture inside a 1.14-m long insulated pressure tube. Once the molten material has reached the desired temperature of {approx}2400 deg. C, the pressure inside the tube will be raised to about 10 MPa, and the pressure tube will fail at a pre-machined flaw, ejecting the molten material into the surrounding tank of water. The test apparatus, instrumentation, data acquisition and control systems have been assembled, and a series of successful commissioning tests have been completed. (authors)

  13. 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

  14. Supported Molten Metal Membranes for Hydrogen Separation

    SciTech Connect

    Datta, Ravindra; Ma, Yi Hua; Yen, Pei-Shan; Deveau, Nicholas; Fishtik, Ilie; Mardilovich, Ivan

    2013-09-30

    We describe here our results on the feasibility of a novel dense metal membrane for hydrogen separation: Supported Molten Metal Membrane, or SMMM.1 The goal in this work was to develop these new membranes based on supporting thin films of low-melting, non- precious group metals, e.g., tin (Sn), indium (In), gallium (Ga), or their alloys, to provide a flux and selectivity of hydrogen that rivals the conventional but substantially more expensive palladium (Pd) or Pd alloy membranes, which are susceptible to poisoning by the many species in the coal-derived syngas, and further possess inadequate stability and limited operating temperature range. The novelty of the technology presented numerous challenges during the course of this project, however, mainly in the selection of appropriate supports, and in the fabrication of a stable membrane. While the wetting instability of the SMMM remains an issue, we did develop an adequate understanding of the interaction between molten metal films with porous supports that we were able to find appropriate supports. Thus, our preliminary results indicate that the Ga/SiC SMMM at 550 ºC has a permeance that is an order of magnitude higher than that of Pd, and exceeds the 2015 DOE target. To make practical SMM membranes, however, further improving the stability of the molten metal membrane is the next goal. For this, it is important to better understand the change in molten metal surface tension and contact angle as a function of temperature and gas-phase composition. A thermodynamic theory was, thus, developed, that is not only able to explain this change in the liquid-gas surface tension, but also the change in the solid-liquid surface tension as well as the contact angle. This fundamental understanding has allowed us to determine design characteristics to maintain stability in the face of changing gas composition. These designs are being developed. For further progress, it is also important to understand the nature of solution and

  15. 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.

  16. Electrochemical cell utilizing molten alkali metal electrode-reactant

    DOEpatents

    Virkar, Anil V.; Miller, Gerald R.

    1983-11-04

    An improved electrochemical cell comprising an additive-modified molten alkali metal electrode-reactant and/or electrolyte is disclosed. Various electrochemical cells employing a molten alkali metal, e.g., sodium, electrode in contact with a cationically conductive ceramic membrane experience a lower resistance and a lower temperature coefficient of resistance whenever small amounts of selenium are present at the interface of the electrolyte and the molten alkali metal. Further, cells having small amounts of selenium present at the electrolyte-molten metal interface exhibit less degradation of the electrolyte under long term cycling conditions.

  17. Fluoride coatings make effective lubricants in molten sodium environment

    NASA Technical Reports Server (NTRS)

    1966-01-01

    Coating bearing surfaces with calcium fluoride-barium fluoride film provides effective lubrication against sliding friction in molten sodium and other severe environments at high and low temperatures.

  18. 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.

  19. 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.

  20. Crust formation and its effect on the molten pool coolability

    SciTech Connect

    Park, R.J.; Lee, S.J.; Sim, S.K.

    1995-09-01

    Experimental and analytical studies of the crust formation and its effect on the molten pool coolability have been performed to examine the crust formation process as a function of boundary temperatures as well as to investigate heat transfer characteristics between molten pool and overlying water in order to evaluate coolability of the molten pool. The experimental test results have shown that the surface temperature of the bottom plate is a dominant parameter in the crust formation process of the molten pool. It is also found that the crust thickness of the case with direct coolant injection into the molten pool is greater than that of the case with a heat exchanger. Increasing mass flow rate of direct coolant injection to the molten pool does not affect the temperature of molten pool after the crust has been formed in the molten pool because the crust behaves as a thermal barrier. The Nusselt number between the molten pool and the coolant of the case with no crust formation is greater than that of the case with crust formation. The results of FLOW-3D analyses have shown that the temperature distribution contributes to the crust formation process due to Rayleigh-Benard natural convection flow.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. Electrically conductive containment vessel for molten aluminum

    DOEpatents

    Holcombe, C.E.; Scott, D.G.

    1984-06-25

    The present invention is directed to a containment vessel which is particularly useful in melting aluminum. The vessel of the present invention is a multilayered vessel characterized by being electrically conductive, essentially nonwettable by and nonreactive with molten aluminum. The vessel is formed by coating a tantalum substrate of a suitable configuration with a mixture of yttria and particulate metal 10 borides. The yttria in the coating inhibits the wetting of the coating while the boride particulate material provides the electrical conductivity through the vessel. The vessel of the present invention is particularly suitable for use in melting aluminum by ion bombardment.

  6. Electrically conductive containment vessel for molten aluminum

    DOEpatents

    Holcombe, Cressie E.; Scott, Donald G.

    1985-01-01

    The present invention is directed to a containment vessel which is particularly useful in melting aluminum. The vessel of the present invention is a multilayered vessel characterized by being electrically conductive, essentially nonwettable by and nonreactive with molten aluminum. The vessel is formed by coating a tantalum substrate of a suitable configuration with a mixture of yttria and particulate metal borides. The yttria in the coating inhibits the wetting of the coating while the boride particulate material provides the electrical conductivity through the vessel. The vessel of the present invention is particularly suitable for use in melting aluminum by ion bombardment.

  7. Anode composite for molten carbonate fuel cell

    DOEpatents

    Iacovangelo, Charles D.; Zarnoch, Kenneth P.

    1983-01-01

    An anode composite useful for a molten carbonate fuel cell comprised of a porous sintered metallic anode component having a porous bubble pressure barrier integrally sintered to one face thereof, said barrier being comprised of metal coated ceramic particles sintered together and to said anode by means of said metal coating, said metal coating enveloping said ceramic particle and being selected from the group consisting of nickel, copper and alloys thereof, the median pore size of the barrier being significantly smaller than that of the anode.

  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. Oxygen electrode reaction in molten carbonate fuel cells. Final report, September 15, 1987--September 14, 1990

    SciTech Connect

    Appleby, A.J.; White, R.E.

    1992-07-07

    Molten carbonate fuel cell system is a leading candidate for the utility power generation because of its high efficiency for fuel to AC power conversion, capability for an internal reforming, and a very low environmental impact. However, the performance of the molten carbonate fuel cell is limited by the oxygen reduction reaction and the cell life time is limited by the stability of the cathode material. An elucidation of oxygen reduction reaction in molten alkali carbonate is essential because overpotential losses in the molten carbonate fuel cell are considerably greater at the oxygen cathode than at the fuel anode. Oxygen reduction on a fully-immersed gold electrode in a lithium carbonate melt was investigated by electrochemical impedance spectroscopy and cyclic voltammetry to determine electrode kinetic and mass transfer parameters. The dependences of electrode kinetic and mass transfer parameters on gas composition and temperature were examined to determine the reaction orders and the activation energies. The results showed that oxygen reduction in a pure lithium carbonate melt occurs via the peroxide mechanism. A mass transfer parameter, D{sub O}{sup 1/2}C{sub O}, estimated by the cyclic voltammetry concurred with that calculated by the EIS technique. The temperature dependence of the exchange current density and the product D{sub O}{sup 1/2}C{sub O} were examined and the apparent activation energies were determined to be about 122 and 175 kJ/ mol, respectively.

  10. 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.

  11. Apparatus and Method for Increasing the Diameter of Metal Alloy Wires Within a Molten Metal Pool

    DOEpatents

    Hartman, Alan D.; Argetsinger, Edward R.; Hansen, Jeffrey S.; Paige, Jack I.; King, Paul E.; Turner, Paul C.

    2002-01-29

    In a dip forming process the core material to be coated is introduced directly into a source block of coating material eliminating the need for a bushing entrance component. The process containment vessel or crucible is heated so that only a portion of the coating material becomes molten, leaving a solid portion of material as the entrance port of, and seal around, the core material. The crucible can contain molten and solid metals and is especially useful when coating core material with reactive metals. The source block of coating material has been machined to include a close tolerance hole of a size and shape to closely fit the core material. The core material moves first through the solid portion of the source block of coating material where the close tolerance hole has been machined, then through a solid/molten interface, and finally through the molten phase where the diameter of the core material is increased. The crucible may or may not require water-cooling depending upon the type of material used in crucible construction. The system may operate under vacuum, partial vacuum, atmospheric pressure, or positive pressure depending upon the type of source material being used.

  12. Apparatus and method for increasing the diameter of metal alloy wires within a molten metal pool

    DOEpatents

    Hartman, Alan D.; Argetsinger, Edward R.; Hansen, Jeffrey S.; Paige, Jack I.; King, Paul E.; Turner, Paul C.

    2002-01-29

    In a dip forming process the core material to be coated is introduced directly into a source block of coating material eliminating the need for a bushing entrance component. The process containment vessel or crucible is heated so that only a portion of the coating material becomes molten, leaving a solid portion of material as the entrance port of, and seal around, the core material. The crucible can contain molten and solid metals and is especially useful when coating core material with reactive metals. The source block of coating material has been machined to include a close tolerance hole of a size and shape to closely fit the core material. The core material moves first through the solid portion of the source block of coating material where the close tolerance hole has been machined, then through a solid/molten interface, and finally through the molten phase where the diameter of the core material is increased. The crucible may or may not require water-cooling depending upon the type of material used in crucible construction. The system may operate under vacuum, partial vacuum, atmospheric pressure, or positive pressure depending upon the type of source material being used.

  13. Investigation of molten metal droplet deposition and solidification for 3D printing techniques

    NASA Astrophysics Data System (ADS)

    Wang, Chien-Hsun; Tsai, Ho-Lin; Wu, Yu-Che; Hwang, Weng-Sing

    2016-09-01

    This study investigated the transient transport phenomenon during the pile up of molten lead-free solder via the inkjet printing method. With regard to the droplet impact velocity, the distance from nozzle to substrate can be controlled by using the pulse voltage and distance control apparatus. A high-speed digital camera was used to record the solder impact and examine the accuracy of the pile up. These impact conditions correspond to We  =  2.1-15.1 and Oh  =  5.4  ×  10-3-3.8  ×  10-3. The effects of impact velocity and relative distance between two types of molten droplets on the shape of the impact mode are examined. The results show that the optimal parameters of the distance from nozzle to substrate and the spreading factor in this experiment are 0.5 mm and 1.33. The diameter, volume and velocity of the inkjet solder droplet are around 37-65 μm, 25-144 picoliters, and 2.0-3.7 m s-1, respectively. The vertical and inclined column structures of molten lead-free solder can be fabricated using piezoelectric ink-jet printing systems. The end-shapes of the 3D micro structure have been found to be dependent upon the distance from nozzle to substrate and the impact velocity of the molten lead-free solder droplet.

  14. 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.

  15. 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.

  16. 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.

  17. Production of Oxygen from Lunar Regolith using Molten Oxide Electrolysis

    NASA Technical Reports Server (NTRS)

    Sibille, Laurent; Sadoway, Donald R.; Sirk, Aislinn; Tripathy, Prabhat; Melendez, Orlando; Standish, Evan; Dominquez, Jesus A.; Stefanescu, Doru M.; Curreri, Peter A.; Poizeau, Sophie

    2009-01-01

    This slide presentation reviews the possible use of molten oxide electrolysis to extract oxygen from the Lunar Regolith. The presentation asserts that molten regolith electrolysis has advanced to be a useful method for production of oxygen and metals in situ on the Moon. The work has demonstrated an 8 hour batch of electrolysis at 5 amps using Iridium inert anodes.

  18. Method of making molten carbonate fuel cell ceramic matrix tape

    DOEpatents

    Maricle, Donald L.; Putnam, Gary C.; Stewart, Jr., Robert C.

    1984-10-23

    A method of making a thin, flexible, pliable matrix material for a molten carbonate fuel cell is described. The method comprises admixing particles inert in the molten carbonate environment with an organic polymer binder and ceramic particle. The composition is applied to a mold surface and dried, and the formed compliant matrix material removed.

  19. Pitting corrosion of aluminized seals in molten carbonate fuel cells

    SciTech Connect

    Krumpelt, M.; Roche, M.F.; Bloom, I.

    1994-08-01

    The objective of this research is to gain a better understanding of the corrosion of the aluminized type 316 stainless steel employed in the seal areas of the molten carbonate fuel cell. The seals are formed between the aluminized Type 316 SS surface and the electrolyte (generally a mixture of molten alkali carbonates and lithium aluminate).

  20. Pendant-Drop Surface-Tension Measurement On Molten Metal

    NASA Technical Reports Server (NTRS)

    Man, Kin Fung; Thiessen, David

    1996-01-01

    Method of measuring surface tension of molten metal based on pendant-drop method implemented in quasi-containerless manner and augmented with digital processing of image data. Electrons bombard lower end of sample rod in vacuum, generating hanging drop of molten metal. Surface tension of drop computed from its shape. Technique minimizes effects of contamination.

  1. 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.

  2. 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.

  3. Modeling of molten-fuel-moderator interactions

    NASA Astrophysics Data System (ADS)

    Diab, Aya K.

    CANDU reactors are pressurized heavy-water moderated and cooled reactor designs. During commissioning of nuclear power plants a range of possible accidents must be considered to assure the plants' robust design. Consider a complete channel blockage in the CANDU reactor. Such an extreme flow blockage event would result in fuel overheating, pressure tube failure, partial melting of fuel rods and possible molten fuel-moderator interactions (MFMI). The MFMI phenomenon would occur immediately after tube rupture, and would involve a mixture of steam, hydrogen and molten fuel being ejected into the surrounding moderator water in the form of a high-pressure vapor bubble mixture. This bubble mixture would accelerate the surrounding denser water, causing interfacial mixing due to hydrodynamic instabilities at the interface. As a result of these interfacial instabilities, water is entrained into the growing two-phase bubble mixture with the attendant mass and heat transfer; e.g., water vaporization, fuel oxidation. A comprehensive model is developed to investigate these complex phenomena resulting from a postulated complete flow blockage and complete pressure tube failure. This dynamic model serves as a baseline to characterize the pressure response due to a pressure tube rupture and the associated MFMI phenomena. Theoretical modeling of these interrelated complex phenomena is not known a priori and therefore a semi-empirical approach is adopted. Consequently, experimental work is being proposed as part of the thesis work to verify key hypotheses regarding these interfacial fluid instabilities, such as the entrainment fraction into the rapidly expanding bubble.

  4. Modeling Molten-Fuel-Moderator Interactions

    NASA Astrophysics Data System (ADS)

    Diab, Aya

    2005-11-01

    CANDU reactors are pressurized heavy-water moderated and cooled nuclear reactor designs. During commissioning of nuclear power plants a range of possible accidents must be considered to assure the plants' robust design. One must consider a complete channel blockage in the CANDU reactor. Such an extreme flow blockage event would result in fuel overheating, pressure tube failure, partial melting of fuel rods and possible molten fuel-moderator interactions (MFMI). The MFMI phenomenon would occur immediately following tube rupture, and involves a mixture of steam, hydrogen and molten fuel being ejected into the surrounding moderator water in the form of a high-pressure vapor bubble mixture. This bubble mixture would accelerate the surrounding denser water, causing interfacial mixing due to hydrodynamic instabilities at the interface. As a result of these interfacial instabilities, water is entrained into the growing two-phase bubble mixture with the attendant mass and heat transfer; e.g., water vaporization, fuel oxidation. A comprehensive model has been developed to investigate the complex phenomena resulting from a postulated complete flow blockage and pressure tube failure. This dynamic model will serve as a baseline to characterize the pressure response due to a pressure tube rupture and the associated MFMI phenomena.

  5. Pump for molten metal or other fluid

    DOEpatents

    Horton, James A.; Brown, Donald L.

    1994-01-01

    A pump having no moving parts which can be used to pump high temperature molten metal or other fluids in a vacuum or low pressure environment, and a method for pumping such fluids. The pump combines elements of a bubble pump with a trap which isolates the vacuum or low pressure region from the gas used to create the bubbles. When used in a vacuum the trap prevents the pumping gas from escaping into the isolated region and thereby reducing the quality of the vacuum. The pump includes a channel in which a pumping gas is forced under pressure into a cavity where bubbles are formed. The cavity is in contact with a reservoir which contains the molten metal or other fluid which is to be pumped. The bubbles rise up into a column (or pump tube) carrying the fluid with them. At the top of the column is located a deflector which causes the bubbles to burst and the drops of pumped fluid to fall into a trap. The fluid accumulates in the trap, eventually forcing its way to an outlet. A roughing pump can be used to withdraw the pumping gas from the top of the column and assist with maintaining the vacuum or low pressure environment.

  6. Alternative cathodes for molten carbonate fuel cells

    SciTech Connect

    Bloom, I.; Lanagan, M.; Roche, M.F.; Krumpelt, M.

    1996-02-01

    Argonne National Laboratory (ANL) is developing advanced cathodes for pressurized operation of the molten carbonate fuel cell (MCFC). The present cathode, lithiated nickel oxide, tends to transport to the anode of the MCFC, where it is deposited as metallic nickel. The rate of transport increases with increasing CO{sub 2} pressure. This increase is due to an increased solubility of nickel oxide (NiO) in the molten carbonate electrolyte. An alternative cathode is lithium cobaltate (LiCoO{sub 2})-Solid solutions of LiCoO{sub 2} in LiFeO{sub 2} show promise for long-lived cathode materials. We have found that small additions of LiCoO{sub 2} to LiFeO{sub 2} markedly decrease the resistivity of the cathode material. Cells containing the LiCoO{sub 2}-LiFeO{sub 2} cathodes have stable performance for more than 2100 h of operation and display lower cobalt migration.

  7. 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

  8. 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

  9. 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.

  10. 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.

  11. Impact, thermal, and shock sensitivity of molten TNT and of asphalt-contaminated molten TNT

    SciTech Connect

    Mainiero, R.J.; Miron, Y.; Kwak, S.S.W.; Kopera, L.H.; Wheeler, J.Q.

    1996-12-01

    The research reported here was part of an effort to evaluate the safety of a process to recover TNT from MK-9 depth bombs by the autoclave meltout process. In this process the depth bombs are heated to 121 C so that the TNT will melt and run into a vat. Unfortunately, asphalt lining the inside surface of the bomb also melts and flows out with the TNT. Testing was conducted on molten TNT and molten TNT contaminated with 2 pct asphalt at 90, 100, 110, 120, 125, and 130 C. In the liquid drop test apparatus with a 2-kg weight, the molten TNT yielded a 50 pct probability of initiation at a drop height of 6.5 cm at 110 C, decreasing to 4.5 cm at 130 C. Asphalt-contaminated TNT was somewhat less impact-sensitive than pure TNT at temperatures of 110 to 125 C, but became more sensitive at 130 C. There is a 50 pct probability of initiation at a drop height of 7.8 cm at 110 C, decreasing to 3.3 cm at 130 C. In the card gap test, the molten TNT detonated at high velocity for a gap of 0.25 inches at 90 to 125 C and detonated at high velocity for a gap of 0.5 inches at 130 C. For gaps of 0.5 to 3 inches at 90 to 125 C and 0.75 inches to 3 inches at 130 C, the TNT did not detonate at high velocity but produced a violent explosion that caused significant damage to the test fixture. The thermal analysis test results showed that when asphalt is present in TNT, it greatly accelerates the exothermic decomposition of TNT, starting at temperatures near 200 C. It appears that at relatively low shock stimulus levels, the molten TNT may be undergoing a low velocity detonation, wherein the shock wave traveling through the gap test pipe cavitates the molten TNT, greatly increasing its sensitivity. These results are crucial for assuring continued safety in recovering TNT from munitions through the autoclave meltout process.

  12. Major design issues of molten carbonate fuel cell power generation unit

    SciTech Connect

    Chen, T.P.

    1996-04-01

    In addition to the stack, a fuel cell power generation unit requires fuel desulfurization and reforming, fuel and oxidant preheating, process heat removal, waste heat recovery, steam generation, oxidant supply, power conditioning, water supply and treatment, purge gas supply, instrument air supply, and system control. These support facilities add considerable cost and system complexity. Bechtel, as a system integrator of M-C Power`s molten carbonate fuel cell development team, has spent substantial effort to simplify and minimize these supporting facilities to meet cost and reliability goals for commercialization. Similiar to other fuels cells, MCFC faces design challenge of how to comply with codes and standards, achieve high efficiency and part load performance, and meanwhile minimize utility requirements, weight, plot area, and cost. However, MCFC has several unique design issues due to its high operating temperature, use of molten electrolyte, and the requirement of CO2 recycle.

  13. Compaction Around a Spherical Inclusion in Partially Molten Rock

    NASA Astrophysics Data System (ADS)

    Alisic, Laura; Rhebergen, Sander; Rudge, John F.; Katz, Richard F.; Wells, Garth N.

    2015-04-01

    Conservation laws that describe the behavior of partially molten mantle rock have been established for several decades, but the associated rheology remains poorly understood. Constraints on the rheology may be obtained from recently published torsion experiments involving deformation of partially molten rock around a rigid, spherical inclusion. These experiments give rise to patterns of melt segregation that exhibit the competing effects of pressure shadows around the inclusion and melt-rich bands through the medium. Such patterns provide an opportunity to infer rheological parameters through comparison with models based on the conservation laws and constitutive relations that hypothetically govern the system. To this end, we have developed software tools using the automated code generation package FEniCS to simulate finite strain, two-phase flow around a rigid, spherical inclusion in a three-dimensional configuration that mirrors the laboratory experiments. The equations for compaction and advection-diffusion of a porous medium are solved utilising newly developed matrix preconditioning techniques. Simulations indicate that the evolution of porosity and therefore of melt distribution is predominantly controlled by the non-linear porosity-weakening exponent of the shear viscosity and the poorly known bulk viscosity. In the simulations presented here, we find that the balance of pressure shadows and melt-rich bands observed in experiments only occurs for bulk-to-shear viscosity ratio of less than about five. However, the evolution of porosity in simulations with such low bulk viscosity exceeds physical bounds at unrealistically small strain due to the unchecked, exponential growth of the porosity variations. Processes that limit or balance porosity localization will have to be incorporated in the formulation of the model to produce results that are consistent with the porosity evolution in experiments.

  14. Reaction Infiltration Instabilities in Partially Molten Rocks

    NASA Astrophysics Data System (ADS)

    Pec, M.; Holtzman, B. K.; Zimmerman, M. E.; Kohlstedt, D. L.

    2015-12-01

    Tabular dunites in ophiolites are thought to form high-permeability, melt channels due to a positive feedback between melt flow and melt-solid reaction in the upper mantle. Reaction-infiltration instability (RII) theory predicts whether or not channels emerge from background flow. To test the applicability of RII theory to mantle rocks, we sandwiched a partially molten rock between a melt reservoir and a porous sink. Hot-pressed 50:50 mixtures of olivine (Ol) and clinopyroxene (Cpx) with either 4, 10 or 20 vol% alkali basalt formed ~4 mm long cylinders of partially molten rock. Source and sink are disks of alkali basalt and porous alumina. We annealed the melt-rock-sink triplets for up to 5 h at a confining pressure of Pc=300 MPa with effective pressure Pe=0 to 299.9 MPa at T=1200° or 1250°C. The melt fraction in the partially molten rock influences the permeability, which, together with the applied pressure gradient, controls the melt migration velocity. The temperature influences the reaction rate. Melt velocity and reaction rate are fundamental parameters in RII theory. In experiments, two distinct features form due to melt migration, 1) a planar reaction layer (RL) and 2) finger-shaped channels. Both the RL and the channels contain Ol+melt with no Cpx, indicating that the reaction melt1+Cpx→melt2+Ol occurs. The channels develop only if the melt velocity is >5µm/s. Once a channel reaches the porous sink, a large increase in the effective permeability is detected. The morphology and spacing of the channels depends on the initial melt fraction. With 20 vol% melt, multiple, voluminous channels with a spacing of 1.8±0.5 mm develop. At lower melt contents, fewer, thinner channels with a spacing of ~3 mm develop. The channel spacing predicted by theory is about a factor 2-4 smaller than observed. Our results indicate that RII theory provides a solid framework for investigating melt migration in experiments and potentially a basis for extrapolation to mantle

  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. 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, ...

  18. [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.

  19. [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.

  20. Single ion dynamics in molten sodium bromide

    SciTech Connect

    Alcaraz, O.; Trullas, J.; Demmel, F.

    2014-12-28

    We present a study on the single ion dynamics in the molten alkali halide NaBr. Quasielastic neutron scattering was employed to extract the self-diffusion coefficient of the sodium ions at three temperatures. Molecular dynamics simulations using rigid and polarizable ion models have been performed in parallel to extract the sodium and bromide single dynamics and ionic conductivities. Two methods have been employed to derive the ion diffusion, calculating the mean squared displacements and the velocity autocorrelation functions, as well as analysing the increase of the line widths of the self-dynamic structure factors. The sodium diffusion coefficients show a remarkable good agreement between experiment and simulation utilising the polarisable potential.

  1. Dynamics of vitreous and molten zinc chloride

    SciTech Connect

    Price, D.L.; Saboungi, M.L.; Susman, S.; Volin, K.J. ); Wright, A.C. . J.J. Thomson Physical Lab.)

    1991-09-01

    The dynamics of vitreous and molten zinc chloride have been studied with inelastic neutron scattering at the Intense Pulsed Neutron Source. The results are analyzed in terms of the scattering function S(Q,E) and the effective vibrational density of states G(E). The vibrational spectra of both glass and liquid are dominated by broad features centered at 15 and 35 MeV which are identified with F{sub 2} modes of ZnCl{sub 4}{sup 2{minus}} tetrahedra. The other two normal modes are not observed because of inadequate resolution and broadening and overlap resulting from coupling between tetrahedra. The behavior of ZnCl{sub 2} is contrasted with other tetrahedrally coordinated glasses that have been studied with the same technique. 15 refs,. 5 figs., 1 tab.

  2. Milliwave melter monitoring system

    DOEpatents

    Daniel, William E.; Woskov, Paul P.; Sundaram, Shanmugavelayutham K.

    2011-08-16

    A milliwave melter monitoring system is presented that has a waveguide with a portion capable of contacting a molten material in a melter for use in measuring one or more properties of the molten material in a furnace under extreme environments. A receiver is configured for use in obtaining signals from the melt/material transmitted to appropriate electronics through the waveguide. The receiver is configured for receiving signals from the waveguide when contacting the molten material for use in determining the viscosity of the molten material. Other embodiments exist in which the temperature, emissivity, viscosity and other properties of the molten material are measured.

  3. Grain boundary wetness of partially molten dunite

    NASA Astrophysics Data System (ADS)

    Mu, Shangshang; Faul, Ulrich H.

    2016-05-01

    Samples of Fo90 olivine and basaltic melt were annealed at a range of temperatures and a pressure of 1 GPa in a piston cylinder apparatus from 1 to 336 h. Post-run samples have melt contents from 0.3 to 6.8 % and mean grain sizes from 4.3 to 84.5 μm. Grain boundary wetness, a measure of the intergranular melt distribution, was determined by analyzing scanning electron microscope images with sufficiently high resolution to detect thin layers wetting grain boundaries, as well as small triple junctions. The measurements show that grain boundary wetness increases with increasing melt content to values well above those predicted by the idealized isotropic equilibrium model for a finite dihedral angle. Additionally, the melt geometry changes with grain size, with grain boundary wetness increasing with increasing grain size at fixed melt content. Grain boundary wetness and dihedral angle of samples annealed at a range of temperatures, but constant melt content does not depend on temperature. These observations emphasize that the dihedral angle alone is not adequate to characterize the melt distribution in partially molten rocks, as the idealized isotropic model does not account for the influence of grain growth. Diffusion creep viscosities calculated from the measured wetness reflect the grain size and melt content dependence. Accordingly, experimentally measured viscosities at small grain sizes underestimate the effect of melt to weaken partially molten rocks for coarser grain sizes. The presence of melt in the mantle may therefore enhance diffusion creep relative to dislocation creep.

  4. Production of Lunar Concrete Using Molten Sulfur

    NASA Technical Reports Server (NTRS)

    Omar, Husam A.

    1993-01-01

    The United States has made a commitment to go back to the moon to stay in the early part of the next century. In order to achieve this objective it became evident to NASA that a Lunar Outpost will be needed to house scientists and astronauts who will be living on the moon for extended periods of time. A study has been undertaken by the authors and supported by NASA to study the feasibility of using lunar regolith with different binders such as molten sulfur, epoxy or hydraulic cement as a construction material for different lunar structures. The basic premise of this study is that it will be more logical and cost effective to manufacture lunar construction materials utilizing indigenous resources rather than transporting needed materials from earth. Lunar concrete (made from Hydraulic Cement and lunar soil) has been studied and suggested as the construction material of choice for some of the lunar projects. Unfortunately, its hydration requires water which is going to be a precious commodity on the moon. Therefore this study explores the feasibility of using binders other than hydraulic cement such as sulfur or epoxy with lunar regolith as a construction material. This report describes findings of this study which deals specifically with using molten sulfur as a binder for Lunar concrete. It describes laboratory experiments in which the sulfur to lunar soil simulant ratios by weight were varied to study the minimum amount of sulfur required to produce a particular strength. The compressive and tensile strengths of these mixes were evaluated. Metal and fiber glass fibers were added to some of the mixes to study their effects on the compressive and tensile strengths. This report also describes experiments where the sulfur is melted and mixed with the lunar regolith in a specially designed vacuum chamber. The properties of the produced concrete were compared to those of concrete produced under normal pressure.

  5. 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.

  6. Temperature Dependence of Behavior of Interface Between Molten Sn and LiCl-KCl Eutectic Melt Due to Rising Gas Bubble

    NASA Astrophysics Data System (ADS)

    Natsui, Shungo; Nashimoto, Ryota; Takai, Hifumi; Kumagai, Takehiko; Kikuchi, Tatsuya; Suzuki, Ryosuke O.

    2016-06-01

    The behavior of the interface between molten Sn and the LiCl-KCl eutectic melt system was observed directly. We found that the transient behavior of the interface exhibits considerable temperature dependence through a change in its physical properties. The "metal film" generated in the upper molten salt phase significantly influences the shape of the interface. Although the lifetime of the metal film depends on the gas flow rate, it is not affected by the buoyancy if the interfacial tension is dominant.

  7. 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)

  8. 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.

  9. Performance of an internal reforming molten carbonate fuel cell supplied with ethanol/water mixture

    SciTech Connect

    Freni, S.; Maggio, G.; Barone, F.

    1996-12-31

    The state of an on the field of molten carbonate fuel cell (MCFC) systems covers many technological aspects related to the use of these systems for the production of electricity. In this respect, extensive research efforts have been made to develop a technology using the methane based on the steam reforming process, and different configurations have been analyzed and their performance determined for several operative cell conditions. However, the operative temperature (T-923 K) of the MCFC. that allows the direct conversion of hydrocarbons or alcohols into H{sub 2} and CO, promotes researches in the field of alternative fuels, more easily transported and reformed compared to methane. In this paper are described the most indicative results obtained by a study that considers the use of water/ethanol mixture as an attractive alternative to the methane for a molten carbonate fuel cell.

  10. 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.

  11. Method for the regeneration of spent molten zinc chloride

    DOEpatents

    Zielke, Clyde W.; Rosenhoover, William A.

    1981-01-01

    In a process for regenerating spent molten zinc chloride which has been used in the hydrocracking of coal or ash-containing polynuclear aromatic hydrocarbonaceous materials derived therefrom and which contains zinc chloride, zinc oxide, zinc oxide complexes and ash-containing carbonaceous residue, by incinerating the spent molten zinc chloride to vaporize the zinc chloride for subsequent condensation to produce a purified molten zinc chloride: an improvement comprising the use of clay in the incineration zone to suppress the vaporization of metals other than zinc. Optionally water is used in conjunction with the clay to further suppress the vaporization of metals other than zinc.

  12. 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.

  13. 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.

  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. 19. Inside the cast house at Furnace A. Molten iron ...

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

    19. Inside the cast house at Furnace A. Molten iron flowed into eight ladles. The furnace was cast (or tapped) six times each day. - Central Furnaces, 2650 Broadway, east bank of Cuyahoga River, Cleveland, Cuyahoga County, OH

  16. Polymers' surface interactions with molten iron: A theoretical study

    NASA Astrophysics Data System (ADS)

    Assadi, M. Hussein N.; Sahajwalla, Veena

    2014-10-01

    Environmental concerns are the chief drive for more innovative recycling techniques for end-of-life polymeric products. One attractive option is taking advantage of C and H content of polymeric waste in steelmaking industry. In this work, we examined the interaction of two high production polymers i.e. polyurethane and polysulfide with molten iron using ab initio molecular dynamics simulation. We demonstrate that both polymers can be used as carburizers for molten iron. Additionally, we found that light weight H2 and CHx molecules were released as by-products of the polymer-molten iron interaction. The outcomes of this study will have applications in the carburization of molten iron during ladle metallurgy and waste plastic injection in electric arc furnace.

  17. Degassing of molten alloys with the assistance of ultrasonic vibration

    DOEpatents

    Han, Qingyou; Xu, Hanbing; Meek, Thomas T.

    2010-03-23

    An apparatus and method are disclosed in which ultrasonic vibration is used to assist the degassing of molten metals or metal alloys thereby reducing gas content in the molten metals or alloys. High-intensity ultrasonic vibration is applied to a radiator that creates cavitation bubbles, induces acoustic streaming in the melt, and breaks up purge gas (e.g., argon or nitrogen) which is intentionally introduced in a small amount into the melt in order to collect the cavitation bubbles and to make the cavitation bubbles survive in the melt. The molten metal or alloy in one version of the invention is an aluminum alloy. The ultrasonic vibrations create cavitation bubbles and break up the large purge gas bubbles into small bubbles and disperse the bubbles in the molten metal or alloy more uniformly, resulting in a fast and clean degassing.

  18. 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.

  19. 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.

  20. 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.

  1. Molten globules, entropy-driven conformational change and protein folding.

    PubMed

    Baldwin, Robert L; Rose, George D

    2013-02-01

    The exquisite side chain close-packing in the protein core and at binding interfaces has prompted a conviction that packing selectivity is the primary mechanism for molecular recognition in folding and/or binding reactions. Contrary to this view, molten globule proteins can adopt native topology and bind targets tightly and specifically in the absence of side chain close-packing. The molten globule is a highly dynamic form with native-like secondary structure and a loose protein core that admits solvent. The related (but still controversial) dry molten globule is an expanded form of the native protein with largely intact topology but a tighter protein core that excludes solvent. Neither form retains side chain close-packing, and therefore both structure and function must result from other factors, assuming that the reality of the dry molten globule is accepted. This simplifying realization calls for a re-evaluation of established models. PMID:23237704

  2. WORKER REMOVING SLAG FROM THE MOLTEN METAL BATH IN THE ...

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

    WORKER REMOVING SLAG FROM THE MOLTEN METAL BATH IN THE ELECTRIC FURNACE AFTER ADDING A CHEMICAL COAGULANT TO FORCE IT TO THE SURFACE. - Southern Ductile Casting Company, Melting, 2217 Carolina Avenue, Bessemer, Jefferson County, AL

  3. 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.

  4. 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.

  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. Pressurized tundish for controlling a continuous flow of molten metal

    DOEpatents

    Lewis, Thomas W.; Hamill, Jr., Paul E.; Ozgu, Mustafa R.; Padfield, Ralph C.; Rego, Donovan N.; Brita, Guido P.

    1990-01-01

    A pressurized tundish for controlling a continous flow of molten metal characterized by having a pair of principal compartments, one being essentially unpressurized and receiving molten metal introduced thereto, and the other being adapted for maintaining a controlled gaseous pressure over the surface of the fluid metal therein, whereby, by controlling the pressure within the pressurized chamber, metal exiting from the tundish is made to flow continually and at a controlled rate.

  7. Pressurized tundish for controlling a continuous flow of molten metal

    DOEpatents

    Lewis, T.W.; Hamill, P.E. Jr.; Ozgu, M.R.; Padfield, R.C.; Rego, D.N.; Brita, G.P.

    1990-07-24

    A pressurized tundish for controlling a continuous flow of molten metal is characterized by having a pair of principal compartments, one being essentially unpressurized and receiving molten metal introduced thereto, and the other being adapted for maintaining a controlled gaseous pressure over the surface of the fluid metal therein, whereby, by controlling the pressure within the pressurized chamber, metal exiting from the tundish is made to flow continually and at a controlled rate. 1 fig.

  8. 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.

  9. 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.

  10. 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

  11. 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

  12. Density and surface tension of the fluorides of sodium, beryllium, thorium, and uranium in the molten state

    SciTech Connect

    Klimenkov, A.A.; Kurbatov, N.N.; Raspopin, S.P.; Chervinskii, Yu.F.

    1987-08-01

    The authors present data on the density and surface tension of a molten salt four-component fuel system comprised of sodium monofluoride, beryllium difluoride, thorium hexafluoride, and uranium hexafluoride in different proportions over a temperature range of 950 to 1180 degrees K. The measurements were processed by the method of least squares. The results for the two properties and their isotherms are tabulated.

  13. Molten carbonate fuel cell product design & improvement - 2nd quarter, 1996. Quarterly report, April 1--June 30, 1996

    SciTech Connect

    1997-05-01

    The main objective of this project is to establish the commercial readiness of a molten carbonate fuel cell power plant for distributed power generation, cogeneration, and compressor station applications. This effort includes marketing, systems design and analysis, packaging and assembly, test facility development, and technology development, improvement, and verification.

  14. 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.

  15. Molten metal reactor and method of forming hydrogen, carbon monoxide and carbon dioxide using the molten alkaline metal reactor

    DOEpatents

    Bingham, Dennis N.; Klingler, Kerry M.; Turner, Terry D.; Wilding, Bruce M.

    2012-11-13

    A molten metal reactor for converting a carbon material and steam into a gas comprising hydrogen, carbon monoxide, and carbon dioxide is disclosed. The reactor includes an interior crucible having a portion contained within an exterior crucible. The interior crucible includes an inlet and an outlet; the outlet leads to the exterior crucible and may comprise a diffuser. The exterior crucible may contain a molten alkaline metal compound. Contained between the exterior crucible and the interior crucible is at least one baffle.

  16. Rechargable molten-electrolyte lithium batteries

    NASA Astrophysics Data System (ADS)

    Kaun, T. D.

    1989-10-01

    Lithium-alloy/metal sulfide cells with on molten-halide electrolytes, which are operated in a temperature range of 375 to 474 C, have undergone many improvements in recent years. Cycle life now exceeds 1000 cycles. The Li-alloy/LiCl-LiBr-KBr eutectic (25:37:38 mol percent)/upper-plateau (U.P.) FeS2 cell operated at 400 C has shown excellence performance prospects: 200 Wh/kg specific energy and 200-W/kg specific power. Electrolyte composition has played a dominant role in attaining long-term stable electrochemical performance. A modified LiCl-LiBr-KBr composition (34:32.5:33.5 mol percent) was found to exhibit 25 percent increased ionic conductivity over that of the eutectic. This higher-conductivity electrolyte approximately compensates for the reduced electrolyte content of the electrolyte-starved FeS2 cell. Such a cell has attained of 95 percent utilization of U.P. FeS2 electrode capacity at a comparable cell impedance (0.8 to 1.0 ohm sq cm) to that of an electrolyte-flooded cell. Advancements in cell design and materials application have reduced materials costs and increased battery durability. Both FeS and FeS2 cell tests have demonstrated overcharge tolerance (3 to 5 mA/sq cm) for electrolyte-starved operation with MgO powder separators.

  17. Molten aluminum alloy fuel fragmentation experiments

    SciTech Connect

    Gabor, J.D.; Purviance, R.T.; Cassulo, J.C.; Spencer, B.W.

    1992-09-01

    Experiments were conducted in which molten aluminum alloys were injected into a 1.2 m deep pool of water. The parameters varied were (i) injectant material (8001 aluminum alloy and 12.3 wt% U-87.7 wt% Al), (ii) melt superheat (O to 50 K), (iii) water temperature (313, 343 and 373 K) and (iv) size and geometry of the pour stream (5, 10 and 20 mm diameter circular and 57 mm annular). The pour stream fragmentation was dominated by surface tension with large particles ({approximately}30 mm) being formed from varicose wave breakup of the 10-mm circular pours and from the annular flow off a 57 mm diameter tube. The fragments produced by the 5 mm circular et were smaller ({approximately} mm), and the 20 mm jet which underwent sinuous wave breakup produced {approximately}100 mm fragments. The fragments froze to form solid particles in 313 K water, and when the water was {ge}343 K, the melt fragments did not freeze during their transit through 1.2 m of water.

  18. Molten aluminum alloy fuel fragmentation experiments

    SciTech Connect

    Gabor, J.D.; Purviance, R.T.; Cassulo, J.C.; Spencer, B.W.

    1992-01-01

    Experiments were conducted in which molten aluminum alloys were injected into a 1.2 m deep pool of water. The parameters varied were (i) injectant material (8001 aluminum alloy and 12.3 wt% U-87.7 wt% Al), (ii) melt superheat (O to 50 K), (iii) water temperature (313, 343 and 373 K) and (iv) size and geometry of the pour stream (5, 10 and 20 mm diameter circular and 57 mm annular). The pour stream fragmentation was dominated by surface tension with large particles ({approximately}30 mm) being formed from varicose wave breakup of the 10-mm circular pours and from the annular flow off a 57 mm diameter tube. The fragments produced by the 5 mm circular et were smaller ({approximately} mm), and the 20 mm jet which underwent sinuous wave breakup produced {approximately}100 mm fragments. The fragments froze to form solid particles in 313 K water, and when the water was {ge}343 K, the melt fragments did not freeze during their transit through 1.2 m of water.

  19. Critical issues and future prospects for molten carbonate fuel cells

    NASA Astrophysics Data System (ADS)

    Joon, K.

    The molten carbonate fuel cell (MCFC) has several potential advantages over low-temperature fuel cells by virtue of its operating temperature of 650°C. This temperature allows the reforming of, for examples, methane from natural gas in the fuel cell stack itself, resulting in reduced systems cost and increased efficiency. In addition, high temperature waste heat is available for industrial processes or bottoming cycles. Furthermore, CO, which is produced in almost all fossil fuel conversion processes, can be used as fuel instead of acting as a poison as in other types of fuel cell. Drawbacks of MCFCs are the high corrosivity of the electrolyte at the operating temperature and the need for a continuous supply of CO 2 to the cathode. Research into and development of MCFCs actually started in 1950 by Ketelaar and Broers when they investigated an earlier idea of Davtyan. Since then, a lot of progress has been made with respect to understanding the cell mechanisms, improving the materials, the performance, the manufacturing techniques and up-scaling. This resulted a few years ago in proof-of-principle tests at the 100 kWe level. At present, the MCFC is the first demonstration phase with full-scale systems at the 250 kWe to 2 MWe level, marking the transition from fundamental and applied R&D to product development or from a technology push to a market pull situation. This paper reviews the most important remaining as well as expected new issues to be resolved.

  20. Investigation of molten metal droplet deposition and solidification for 3D printing techniques

    NASA Astrophysics Data System (ADS)

    Wang, Chien-Hsun; Tsai, Ho-Lin; Wu, Yu-Che; Hwang, Weng-Sing

    2016-09-01

    This study investigated the transient transport phenomenon during the pile up of molten lead-free solder via the inkjet printing method. With regard to the droplet impact velocity, the distance from nozzle to substrate can be controlled by using the pulse voltage and distance control apparatus. A high-speed digital camera was used to record the solder impact and examine the accuracy of the pile up. These impact conditions correspond to We  =  2.1–15.1 and Oh  =  5.4  ×  10‑3–3.8  ×  10‑3. The effects of impact velocity and relative distance between two types of molten droplets on the shape of the impact mode are examined. The results show that the optimal parameters of the distance from nozzle to substrate and the spreading factor in this experiment are 0.5 mm and 1.33. The diameter, volume and velocity of the inkjet solder droplet are around 37–65 μm, 25–144 picoliters, and 2.0–3.7 m s‑1, respectively. The vertical and inclined column structures of molten lead-free solder can be fabricated using piezoelectric ink-jet printing systems. The end-shapes of the 3D micro structure have been found to be dependent upon the distance from nozzle to substrate and the impact velocity of the molten lead-free solder droplet.

  1. 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.

  2. 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.

  3. 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.

  4. Continuous replenishment of molten semiconductor in a Czochralski-process, single-crystal-growing furnace

    NASA Technical Reports Server (NTRS)

    Fiegl, George (Inventor); Torbet, Walter (Inventor)

    1981-01-01

    A replenishment crucible is mounted adjacent the usual drawing crucible, from which a monocrystalline boule is drawn according to the Czochralski method. A siphon tube for molten semiconductor transfer extends from the replenishment crucible to the drawing crucible. Each crucible is enclosed within its own hermetic shell and is provided with its own heater. The siphon tube is initially filled with molten semiconductor by raising the inert atmospheric pressure in the shell surrounding the replenishment crucible above that surrounding the drawing crucible. Thereafter, adjustment of the level of molten semiconductor in the drawing crucible may be achieved by adjusting the level in either crucible, since the siphon tube will establish the same level in both crucibles. For continuous processing, solid semiconductor may be added to and melted in the replenishment crucible during the process of drawing crystals from the drawing crucible. A constant liquid level of melted semiconductor is maintained in the system by an optical monitoring device and any of several electromechanical controls of the rate of replenishment or crucible height.

  5. Molten sodium-induced graphitization towards highly crystalline and hierarchical porous graphene frameworks

    NASA Astrophysics Data System (ADS)

    Wang, Huanwen; Zhang, Yu; Wu, Xing-Long; Fan, Haosen; Luo, Zhong-Zhen; Madhavi, Srinivasan; Yan, Qingyu

    2015-09-01

    Mass production of high quality graphene platelets has attracted considerable interest for potential applications in various fields. Nevertheless, in literature, the graphite oxide (GO)-derived graphene is always lacking high crystallinity and hierarchical porosity. Herein, we report a new molten sodium-induced graphitization for mass-fabricating highly crystalline and porous graphene sheets. The 3D graphene hydrogels (GHs) obtained from GO by the hydrothermal self-assembly are directly annealed in molten sodium at 800 °C. As a result, the D band intensity in Raman spectroscopy is reduced significantly, while 2D band intensity is increased prominently, which is a typical characteristic of highly crystalline graphene. More importantly, the resulting Na-GFs-800 sample exhibits increased surface area and narrow mesopore size distribution (∼3.6 nm). The excellent supercapacitive performance of Na-GFs-800 has been demonstrated in an organic symmetric system. Meanwhile, the possible interaction mechanism between molten sodium and GHs has been proposed in the text.

  6. Dissipative particle dynamics simulations of the viscosities of molten TNT and molten TNT suspensions containing nanoparticles.

    PubMed

    Zhou, Yang; Li, Yixue; Qian, Wen; He, Bi

    2016-09-01

    Based on dissipative particle dynamics (DPD) methods and experimental data, we used an empirical relationship between the DPD temperature and the real temperature to build a model that describes the viscosity of molten TNT fluids. The errors in the predicted viscosity based on this model were no more than 2.3 %. We also studied the steady-state shear rheological behavior of molten TNT fluids containing nanoparticles ("nanofluids"). The dependence of the nanofluid viscosity on the temperature was found to satisfy an Arrhenius-type equation, η = Ae (B/T) , where B, the flow activation energy, depends on particle content, size, and shape. We modified the Einstein-type viscosity model to account for the effects of nanoparticle solvation in TNT nanofluids. The resulting model was able to correctly predict the viscosities of suspensions containing nano- to microsized particles, and did not require any changes to the physical background of Einstein's viscosity theory. Graphical Abstract The revised Einstein viscosity model that correctly predict the viscosity of TNT suspensions containing nanoparticles. PMID:27553301

  7. Development of Channeled Flow in Partially Molten Medium

    NASA Astrophysics Data System (ADS)

    Takashima, S.; Kumagai, I.; Kurita, K.

    2002-12-01

    There exist two contrasting models as to the style of melt migration in the partially molten medium; homogeneous permeable flow on grain scale and heterogeneous localized one (channeled flow on larger scale than the grain scale). It is considered that the style evolves from the homogeneous flow to the heterogeneous one as the degree of melting increases, but the physics responsible for this flow organization is not yet clarified. Several models as to this process and the melt segregation are proposed based on numerical simulation, though the experimental verification is not given yet. Here we present simple experimental results on the flow organization. We utilized highly deformable transparent gel as the solid phase. Due to this high deformability the matrix composed of the gel is easy to vary its internal structure. We have conducted the following experiments; the gel (about 5mm in diameter) is mingled with methyl-cellulose solution (MS) with almost same density as the gel, 1.01g/cm3, packed in a rectangular parallelepiped case (2.4cm*18cm*14.4cm), and a compaction state is realized by covering with wire netting at the upper boundary. Gel fraction of this mixture system is controlled by changing the ratio of the gel to MS (about 100% to 60%). Glycerol solution (GS) with density of 1.2g/cm3 is poured at the upper boundary. This is a kind of Rayleigh-Taylor Instability and the dense GS flows downward through the mixture. The flow pattern of the GS is analyzed. A series of these procedures is carried out at various gel fractions (from about 100% to 60%), and how the flow style varies with the gel fraction is investigated. At median fraction of the gel about 80% to 70% the evolution from homogeneous permeable flow to heterogeneous localized flow was observed. At higher gel fraction, liquid phase flows as homogeneous permeable flow. Fragility of the solid frame is a most important factor for flow organization. The structure of the partially molten medium can be easily

  8. Supported Molten Metal Catalysis. A New Class of Catalysts

    SciTech Connect

    Ravindra Datta; Ajeet Singh; Manuela Serban; Istvan Halasz

    2006-06-02

    We describe a new class of heterogeneous catalysts called supported molten metal catalysis (SMMC), in which molten metal catalysts are dispersed as nanodroplets on the surface of porous supports, allowing much larger active surface area than is possible in conventional contacting techniques for catalytic metals that are molten under reaction conditions, thus greatly enhancing their activity and potential utility. Specific examples of different types of reactions are provided to demonstrate the broad applicability of the technique in designing active, selective, and stable new catalysts. It is shown that dispersing the molten metal on a support in the suggested manner can enhance the rate of a reaction by three to four orders of magnitude as a result of the concomitant increase in the active surface area. New reaction examples include {gamma}-Al{sub 2}O{sub 3} supported molten Te (melting point 450 C) and Ga (MP 30 C) catalysts for bifunctional methylcyclohexane dehydrogenation. These catalysts provide activity similar to conventional Pt-based catalysts for this with better resistance to coking. In addition, results are described for a controlled pore glass supported molten In (MP 157 C) catalyst for the selective catalytic reduction of NO with ethanol in the presence of water, demonstrating activities superior to conventional catalysts for this reaction. A discussion is also provided on the characterization of the active surface area and dispersion of these novel supported catalysts. It is clear based on the results described that the development of new active and selective supported molten metal catalysts for practical applications is entirely plausible.

  9. Oxygen reduction on Ni, Ag, and Cu meniscus electrodes in molten carbonate

    SciTech Connect

    Ogura, Hiroyuki; Shirogami, Tamotsu

    1994-12-31

    The oxygen reduction pathways in molten carbonates have been investigated by analyzing the charge transfer resistances of the i-V curves on the meniscus electrodes of Ni, Cu, and Ag screens at 550 C. The electrochemical reduction pathways of oxygen at the meniscus electrode were found to be different depending on the electrode materials. For the Ni meniscus electrode system, the reactive material of charge transfer is the lithium doped nickel oxide, for the Ag system that is the silver oxide ion, and for the Cu system that is peroxide ion, respectively.

  10. Shear rheology of molten crumb chocolate.

    PubMed

    Taylor, J E; Van Damme, I; Johns, M L; Routh, A F; Wilson, D I

    2009-03-01

    The shear rheology of fresh molten chocolate produced from crumb was studied over 5 decades of shear rate using controlled stress devices. The Carreau model was found to be a more accurate description than the traditional Casson model, especially at shear rates between 0.1 and 1 s(-1). At shear rates around 0.1 s(-1) (shear stress approximately 7 Pa) the material exhibited a transition to a solid regime, similar to the behavior reported by Coussot (2005) for other granular suspensions. The nature of the suspension was explored by investigating the effect of solids concentration (0.20 < phi < 0.75) and the nature of the particles. The rheology of the chocolate was then compared with the rheology of (1) a synthetic chocolate, which contained sunflower oil in place of cocoa butter, and (2) a suspension of sugar of a similar size distribution (volume mean 15 mum) in cocoa butter and emulsifier. The chocolate and synthetic chocolate showed very similar rheological profiles under both steady shear and oscillatory shear. The chocolate and the sugar suspension showed similar Krieger-Dougherty dependency on volume fraction, and a noticeable transition to a stiff state at solids volume fractions above approximately 0.5. Similar behavior has been reported by Citerne and others (2001) for a smooth peanut butter, which had a similar particle size distribution and solids loading to chocolate. The results indicate that the melt rheology of the chocolate is dominated by hydrodynamic interactions, although at high solids volume fractions the emulsifier may contribute to the departure of the apparent viscosity from the predicted trend.

  11. 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.

  12. 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.

  13. Assessment of commercial prospects of molten carbonate fuel cells

    NASA Astrophysics Data System (ADS)

    Dicks, Andrew; Siddle, Angie

    The commercial prospects of molten carbonate fuel cells have been evaluated. Market applications, and the commercial criteria that the MCFC will need to satisfy for these applications, were identified through interviews with leading MCFC developers. Strengths, weaknesses, opportunities and threats (SWOT) analyses were carried out to critically evaluate the prospects for commercialisation. There are many competing technologies, but it is anticipated that MCFCs can make significant penetration into markets where their attributes, such as quality of power, low emissions and availability, give them a leading position in comparison with, for example, engine and turbine-based power generation systems. Analysis suggests that choosing the size for MCFC plant is more important than the target market sector/niche. Opportunities will exist in many market sectors, though the commercial market would be easier to penetrate initially. Developers are optimistic about the commercial prospects for the MCFC. Most believe that early commercial MCFC plants may start to appear in the first decade of the next century, the earliest date suggested for initial market entry being 2002.

  14. 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.

  15. 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

  16. 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.

  17. Viscosity of molten lithium, thorium and beryllium fluorides mixtures

    NASA Astrophysics Data System (ADS)

    Merzlyakov, Alexander V.; Ignatiev, Victor V.; Abalin, Sergei S.

    2011-12-01

    Considering development of Molten Salt Fast Reactor (MSFR) concept, following Molten Salt fluorides mixtures have been chosen as an object for viscosity studies in this work (in mol%): 78LiF-22ThF 4; 71LiF-27ThF 4-2BeF 2 and 75LiF-20ThF 4-5BeF 2. Additionally, the effect of the 3 mol% CeF 3 additives on viscosity of the molten 75LiF-20ThF 4-5BeF 2 (mol%) salt mixture has been investigated experimentally. The method of torsional oscillations of cylindrical crucible filled by molten fluorides mixture has been chosen for kinematic viscosity measurement at temperatures up to 800-850 °C. In temperature ranges, where melts behave as normal liquids, dependences on viscosity vs. temperature are received: ν = А exp [B/T(K)], where ν - kinematic viscosity, m 2/s; T - temperature, K. The kinematic viscosity Rout mean squares (RMS) estimated in the assumption about dispersion homoscedasticity is (0.04-0.12) × 10 -6 (m 2/s). Discrepancies left in the data of viscosity for molten mixtures of LiF, BeF 2 and ThF 4 received by different researchers need further investigations in this area to be continued.

  18. 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)

  19. 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.

  20. Molten carbonate fuel cell networks: Principles, analysis, and performance. Technical note

    SciTech Connect

    Wimer, J.G.; Williams, M.C.

    1993-01-01

    The chemical reactions in an internally reforming molten carbonate fuel cell (IRMCFC) are described and combined into the overall IRMCFC reaction. Thermodynamic and electrochemical principles are discussed, and structure and operation of fuel cell stacks are explained. In networking, multiple fuel cell stacks are arranged so that reactant streams are fed and recycled through stacks in series, for higher reactant utilization and increased system efficiency. Advantages and performance of networked and conventional systems are compared, using ASPEN simulations. The concept of networking can be applied to any electrochemical membrane, such as that developed for hot gas cleanup in future power plants. 2 tabs, 16 figs, 9 refs.

  1. Modelling of molten fuel/concrete interactions. [PWR; BWR

    SciTech Connect

    Muir, J. F.; Benjamin, A. S.

    1980-01-01

    A computer program modelling the interaction between molten core materials and structural concrete (CORCON) is being developed to provide quantitative estimates of fuel-melt accident consequences suitable for risk assessment of light water reactors. The principal features of CORCON are reviewed. Models developed for the principal interaction phenomena, inter-component heat transfer, concrete erosion, and melt/gas chemical reactions, are described. Alternative models for the controlling phenomenon, heat transfer from the molten pool to the surrounding concrete, are presented. These models, formulated in conjunction with the development of CORCON, are characterized by the presence or absence of either a gas film or viscous layer of molten concrete at the melt/concrete interface. Predictions of heat transfer based on these models compare favorably with available experimental data.

  2. 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.

  3. Presence of Li clusters in molten LiCl-Li

    DOE PAGESBeta

    Merwin, Augustus; Phillips, William C.; Williamson, Mark A.; Willit, James L.; Motsegood, Perry N.; Chidambaram, Dev

    2016-05-05

    Molten mixtures of lithium chloride and metallic lithium are of significant interest in various metal oxide reduction processes. These solutions have been reported to exhibit seemingly anomalous physical characteristics that lack a comprehensive explanation. ln the current work, the physical chemistry of molten solutions of lithium chloride and metallic lithium, with and without lithium oxide, was investigated using in situ Raman spectroscopy. The Raman spectra obtained from these solutions were in agreement with the previously reported spectrum of the lithium cluster, Li8. Furthermore, this observation is indicative of a nanofluid type colloidal suspension of Li8, in a molten salt matrix.more » It is suggested that the formation and suspension of lithium clusters in lithium chloride is the cause of various phenomena exhibited by these solutions that were previously unexplainable.« less

  4. Presence of Li Clusters in Molten LiCl-Li

    NASA Astrophysics Data System (ADS)

    Merwin, Augustus; Phillips, William C.; Williamson, Mark A.; Willit, James L.; Motsegood, Perry N.; Chidambaram, Dev

    2016-05-01

    Molten mixtures of lithium chloride and metallic lithium are of significant interest in various metal oxide reduction processes. These solutions have been reported to exhibit seemingly anomalous physical characteristics that lack a comprehensive explanation. In the current work, the physical chemistry of molten solutions of lithium chloride and metallic lithium, with and without lithium oxide, was investigated using in situ Raman spectroscopy. The Raman spectra obtained from these solutions were in agreement with the previously reported spectrum of the lithium cluster, Li8. This observation is indicative of a nanofluid type colloidal suspension of Li8 in a molten salt matrix. It is suggested that the formation and suspension of lithium clusters in lithium chloride is the cause of various phenomena exhibited by these solutions that were previously unexplainable.

  5. Presence of Li Clusters in Molten LiCl-Li

    PubMed Central

    Merwin, Augustus; Phillips, William C.; Williamson, Mark A.; Willit, James L.; Motsegood, Perry N.; Chidambaram, Dev

    2016-01-01

    Molten mixtures of lithium chloride and metallic lithium are of significant interest in various metal oxide reduction processes. These solutions have been reported to exhibit seemingly anomalous physical characteristics that lack a comprehensive explanation. In the current work, the physical chemistry of molten solutions of lithium chloride and metallic lithium, with and without lithium oxide, was investigated using in situ Raman spectroscopy. The Raman spectra obtained from these solutions were in agreement with the previously reported spectrum of the lithium cluster, Li8. This observation is indicative of a nanofluid type colloidal suspension of Li8 in a molten salt matrix. It is suggested that the formation and suspension of lithium clusters in lithium chloride is the cause of various phenomena exhibited by these solutions that were previously unexplainable. PMID:27145895

  6. 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.

  7. Presence of Li Clusters in Molten LiCl-Li.

    PubMed

    Merwin, Augustus; Phillips, William C; Williamson, Mark A; Willit, James L; Motsegood, Perry N; Chidambaram, Dev

    2016-01-01

    Molten mixtures of lithium chloride and metallic lithium are of significant interest in various metal oxide reduction processes. These solutions have been reported to exhibit seemingly anomalous physical characteristics that lack a comprehensive explanation. In the current work, the physical chemistry of molten solutions of lithium chloride and metallic lithium, with and without lithium oxide, was investigated using in situ Raman spectroscopy. The Raman spectra obtained from these solutions were in agreement with the previously reported spectrum of the lithium cluster, Li8. This observation is indicative of a nanofluid type colloidal suspension of Li8 in a molten salt matrix. It is suggested that the formation and suspension of lithium clusters in lithium chloride is the cause of various phenomena exhibited by these solutions that were previously unexplainable. PMID:27145895

  8. 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

  9. Grain growth and inclusion formation in partially molten carbonate rocks

    NASA Astrophysics Data System (ADS)

    Renner, Jörg; Evans, Brian; Hirth, Greg

    To learn more about the kinetics and mechanisms of coarsening and melt inclusion formation, we investigated the effects of melt content, viscosity, and topology on the microstructural evolution of partially molten and melt-free calcite aggregates. Synthetic marbles with eutectic melts were produced by annealing mixtures of calcite and either calcium hydroxide or lithium carbonate for up to 80 h at a confining pressure of 300 MPa and temperatures of 973-1,023 K. The melts produced in the two systems are expected to differ significantly in viscosity. Generally, coarsening rates decrease with increasing melt fraction, probably because the diffusion length across melt pockets increases. Analysis of grain shapes in the samples with about 40% melt indicated that coarsening was accommodated by agglomeration in the samples of the calcium/lithium carbonate system. In the calcium carbonate/hydroxide system, classical Ostwald ripening occurred. For melt contents about 10% and below, melt-filled pores are either dropped from or dragged along with migrating grain boundaries, depending on the pore size and the grain boundary curvature. These data can be used to constrain the conditions where fluid or melt inclusions form under natural conditions. Combining our results and previous studies illustrates a systematic relation between the grain boundary mobility in calcite aggregates and the diffusion kinetics associated with second phases residing on the grain boundaries. In particular, boundaries with no porosity are most mobile, those boundaries dragging melt-filled pores are slower, those with gas-filled pores are slower yet, and those containing solid phases are slowest or may even be motionless.

  10. Grain growth and inclusion formation in partially molten carbonate rocks

    NASA Astrophysics Data System (ADS)

    Renner, Jörg; Evans, Brian; Hirth, Greg

    2001-11-01

    To learn more about the kinetics and mechanisms of coarsening and melt inclusion formation, we investigated the effects of melt content, viscosity, and topology on the microstructural evolution of partially molten and melt-free calcite aggregates. Synthetic marbles with eutectic melts were produced by annealing mixtures of calcite and either calcium hydroxide or lithium carbonate for up to 80 h at a confining pressure of 300 MPa and temperatures of 973-1,023 K. The melts produced in the two systems are expected to differ significantly in viscosity. Generally, coarsening rates decrease with increasing melt fraction, probably because the diffusion length across melt pockets increases. Analysis of grain shapes in the samples with about 40% melt indicated that coarsening was accommodated by agglomeration in the samples of the calcium/lithium carbonate system. In the calcium carbonate/hydroxide system, classical Ostwald ripening occurred. For melt contents about 10% and below, melt-filled pores are either dropped from or dragged along with migrating grain boundaries, depending on the pore size and the grain boundary curvature. These data can be used to constrain the conditions where fluid or melt inclusions form under natural conditions. Combining our results and previous studies illustrates a systematic relation between the grain boundary mobility in calcite aggregates and the diffusion kinetics associated with second phases residing on the grain boundaries. In particular, boundaries with no porosity are most mobile, those boundaries dragging melt-filled pores are slower, those with gas-filled pores are slower yet, and those containing solid phases are slowest or may even be motionless.

  11. The redox combustion of carbon monoxide for recovering pure carbon dioxide by using molten (Na+,K+)2(CO32-,SO42-) mixtures.

    PubMed

    Shimano, Satoshi; Asakura, Shukuji

    2006-06-01

    Large-scale combustion systems, such as thermal power plants, emit large amounts of carbon dioxide, which can increase global warming. A molten salt redox combustion system was proposed to recover pure carbon dioxide exhausted from the combustion of fossil fuels. This system is composed of two successive processes by using reactions occurring in a molten salt. The molten salt is the mixture of the molten alkali metal sulfates and carbonates. The sulfate ions oxidize the fuels in first processes, being changed to reductive species such as sulfide ions. In this process, carbon dioxide and water are exclusively exhausted. The reductive species of sulfur compounds are oxidized to regenerate the sulfate ions by air in the second process. In this study, these above two processes were tried by using molten [(Na(+))(0.5),(K(+))(0.5)](2)[(CO(3)(2-))(0.9),(SO(4)(2-))(0.1)] alternatively. The oxidation of carbon monoxide as fuel by sulfate ions and the regeneration of sulfate ions by air were investigated in the temperature range of 700-950 degrees C, respectively. These reactions were exothermic. The rate of the regeneration of the sulfate ions was extremely high. During the oxidation of carbon monoxide, the reaction was first order in carbon monoxide with an activation energy of 101 kJ mol(-1). The optimum condition to recover pure carbon dioxide on practical operation was discussed.

  12. Crystallization of a designed peptide from a molten globule ensemble.

    PubMed

    Betz; Raleigh; DeGrado; Lovejoy; Anderson; Ogihara; Eisenberg

    1995-01-01

    Backgound. The design of amino acid sequences that adopt a desired three-dimensional fold has been of keen interest over the past decade. However, the design of proteins that adopt unique conformations is still a considerable problem. Until very recently, all of the designed proteins that have been extensively characterized possess the hallmarks of the molten globular state. Molten globular intermediates have been observed in both equilibrium and kinetic protein folding/stability studies, and understanding the forces that determine compact non-native states is critical for a comprehensive understanding of proteins. This paper describes the solution and early solid state characterization of peptides that form molten globular ensembles. Results. Crystals diffracting to 3.5Å resolution have been grown of a 16-residue peptide (alpha1A) designed to form a tetramer of alpha-helices. In addition, a closely related peptide, alpha1, has previously been shown to yield crystals that diffract to 1.2Å resolution. The solution properties of these two peptides were examined to determine whether their well defined crystalline conformations were retained in solution. On the basis of an examination of their NMR spectra, sedimentation equilibria, thermal unfolding, and ANS binding, it is concluded that the peptides form alpha-helical aggregates with properties similar to those of the molten globule state. Thus, for these peptides, the process of crystallization bears many similarities to models of protein folding. Upon dissolution, the peptides rapidly assume compact molten globular states similar to the molten globule like intermediates that are formed at short times after refolding is initiated. Following a rate-determining nucleation step, the peptides crystallize into a single or a small number of conformations in a process that mimics the formation of native structure in proteins. PMID:9162140

  13. 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.

  14. Metals processing control by counting molten metal droplets

    DOEpatents

    Schlienger, Eric; Robertson, Joanna M.; Melgaard, David; Shelmidine, Gregory J.; Van Den Avyle, James A.

    2000-01-01

    Apparatus and method for controlling metals processing (e.g., ESR) by melting a metal ingot and counting molten metal droplets during melting. An approximate amount of metal in each droplet is determined, and a melt rate is computed therefrom. Impedance of the melting circuit is monitored, such as by calculating by root mean square a voltage and current of the circuit and dividing the calculated current into the calculated voltage. Analysis of the impedance signal is performed to look for a trace characteristic of formation of a molten metal droplet, such as by examining skew rate, curvature, or a higher moment.

  15. ADVANCED CERAMIC COMPOSITES FOR MOLTEN ALUMINUM CONTACT APPLICATIONS

    SciTech Connect

    Hemrick, James Gordon; Peters, Klaus-Markus

    2009-01-01

    A new refractory material which was developed for use in molten aluminum contact applications was shown to exhibit improved corrosion and wear resistance leading to improved thermal management through reduced heat losses caused by refractory thinning and wastage. This material was developed based on an understanding of the corrosion and wear mechanisms associated with currently used aluminum contact refractories under a U.S. Department of Energy funded project to investigate multifunctional refractory materials for energy efficient handling of molten metals. This new material has been validated through an industrial trial at a commercial aluminum rod and cable mill. Material development and results of this industrial validation trial are discussed.

  16. Fabrication of catalytic electrodes for molten carbonate fuel cells

    DOEpatents

    Smith, James L.

    1988-01-01

    A porous layer of catalyst material suitable for use as an electrode in a molten carbonate fuel cell includes elongated pores substantially extending across the layer thickness. The catalyst layer is prepared by depositing particulate catalyst material into polymeric flocking on a substrate surface by a procedure such as tape casting. The loaded substrate is heated in a series of steps with rising temperatures to set the tape, thermally decompose the substrate with flocking and sinter bond the catalyst particles into a porous catalytic layer with elongated pores across its thickness. Employed as an electrode, the elongated pores provide distribution of reactant gas into contact with catalyst particles wetted by molten electrolyte.

  17. Porous electrolyte retainer for molten carbonate fuel cell. [lithium aluminate

    DOEpatents

    Singh, R.N.; Dusek, J.T.

    1979-12-27

    A porous tile for retaining molten electrolyte within a fuel cell is prepared by sintering particles of lithium aluminate into a stable structure. The tile is assembled between two porous metal plates which serve as electrodes with fuels gases such as H/sub 2/ and CO opposite to oxidant gases such as O/sub 2/ and CO/sub 2/. The tile is prepared with a porosity of 55 to 65% and a pore size distribution selected to permit release of sufficient molten electrolyte to wet but not to flood the adjacent electrodes.

  18. Porous electrolyte retainer for molten carbonate fuel cell

    DOEpatents

    Singh, Raj N.; Dusek, Joseph T.

    1983-06-21

    A porous tile for retaining molten electrolyte within a fuel cell is prepared by sintering particles of lithium aluminate into a stable structure. The tile is assembled between two porous metal plates which serve as electrodes with fuels gases such as H.sub.2 and CO opposite to oxidant gases such as O.sub.2 and CO.sub.2. The tile is prepared with a porosity of 55-65% and a pore size distribution selected to permit release of sufficient molten electrolyte to wet but not to flood the adjacent electrodes.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. Molten metal containment vessel with rare earth oxysulfide protective coating thereon and method of making same

    DOEpatents

    Krikorian, Oscar H.; Curtis, Paul G.

    1992-01-01

    An improved molten metal containment vessel is disclosed in which wetting of the vessel's inner wall surfaces by molten metal is inhibited by coating at least the inner surfaces of the containment vessel with one or more rare earth oxysulfide or rare earth sulfide compounds to inhibit wetting and or adherence by the molten metal to the surfaces of the containment vessel.

  4. Chemical Interactions of Alumina-Carbon Refractories with Molten Steel at 1823 K (1550 °C): Implications for Refractory Degradation and Steel Quality

    NASA Astrophysics Data System (ADS)

    Khanna, R.; Ikram-Ul Haq, M.; Wang, Y.; Seetharaman, S.; Sahajwalla, V.

    2011-08-01

    A sessile-drop study was carried out on Al2O3-10 pct C refractory substrates in contact with molten iron to investigate possible chemical reactions in the system and to determine the influence of carbon and the role, if any, played by the presence of molten iron that can act both as a reducing agent and as a metallic solvent. These investigations were carried out at 1823 K (1550 °C) in argon atmosphere for times ranging between 15 minutes and 3 hours. We report the occurrence of chemical reactions in the Al2O3-10 pct C/Fe system, associated generation of CO gas, and carbon pickup by molten iron. Video images of the iron droplet started to show minor deviations after 30 minutes of contact followed by intense activity in the form of fine aluminum oxide whiskers emanating from the droplet and on the refractory substrate. The interfacial region also changed significantly over time, and the formation of small quantities of iron aluminide intermetallics was recorded after 30 minutes as a reaction product in the interfacial region. These chemical reactions also caused extensive penetration of molten iron into the refractory substrate. This study has shown that alumina cannot be treated as chemically inert at steelmaking temperatures when both carbon and molten iron are present simultaneously. These findings point to an additional reaction pathway during steelmaking that could have significant implications for refractory degradation and contamination of steel with reaction products.

  5. Energy Saving Strategies for the Use of Refractory Materials in Molten Material Contact

    SciTech Connect

    Hemrick, James Gordon; Peters, Klaus-Markus; Damiano, John

    2009-01-01

    Work was performed by Oak Ridge National Laboratory (ORNL), in collaboration with industrial refractory manufacturers, refractory users, and academic institutions, to employ novel refractory systems and techniques to reduce energy consumption of molten material processing vessels found in industries such as aluminum, glass and pulp and paper. The energy savings strategies discussed are achieved through reduction of chemical reactions, elimination of mechanical degradation caused by the service environment, reduction of temperature limitations of materials, and elimination of costly installation and repair needs. Key results of several case studies resulting from US Department of Energy (DOE) funded research programs are discussed with emphasis on applicability of these results to high temperature processing industries.

  6. Conductivity of molten sodium chloride in an arbitrarily weak dc electric field.

    PubMed

    Delhommelle, Jerome; Cummings, Peter T; Petravic, Janka

    2005-09-15

    We use nonequilibrium molecular-dynamics (NEMD) simulations to characterize the response of a fluid subjected to an electric field. We focus on the response for very weak fields. Fields accessible by conventional NEMD methods are typically of the order of 10(9) V m(-1), i.e., several orders of magnitude larger than those typically used in experiments. Using the transient time-correlation function, we show how NEMD simulations can be extended to study systems subjected to a realistic dc electric field. We then apply this approach to study the response of molten sodium chloride for a wide range of dc electric fields.

  7. MOLTEN METAL FROM ELECTRIC MELTING FURNACE IS TRANSFERRED THROUGH RUNNER ...

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

    MOLTEN METAL FROM ELECTRIC MELTING FURNACE IS TRANSFERRED THROUGH RUNNER BOX TO HOLDING FURNACE PRIOR TO POURING. VIEW FROM BEHIND "NORTH STATION" IN CAST SHOP. THE RUNNER BOX MUST BE HEATED PRIOR TO THE TRANSFER. - American Brass Foundry, 70 Sayre Street, Buffalo, Erie County, NY

  8. 19. MOLTEN IRON FLOWS INTO A 'BOTTLE' AT FURNACE NO. ...

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

    19. MOLTEN IRON FLOWS INTO A 'BOTTLE' AT FURNACE NO. 1. THE IRON WILL BE TRANSPORTED BY RAIL TO THE OPEN HEARTH OR BASIC OXYGEN FURNACES, WHERE IT IS A MAJOR COMPONENT IN THE PRODUCTION OF STEEL. - Corrigan, McKinney Steel Company, 3100 East Forty-fifth Street, Cleveland, Cuyahoga County, OH

  9. Structural change in molten basalt at deep mantle conditions.

    PubMed

    Sanloup, Chrystèle; Drewitt, James W E; Konôpková, Zuzana; Dalladay-Simpson, Philip; Morton, Donna M; Rai, Nachiketa; van Westrenen, Wim; Morgenroth, Wolfgang

    2013-11-01

    Silicate liquids play a key part at all stages of deep Earth evolution, ranging from core and crust formation billions of years ago to present-day volcanic activity. Quantitative models of these processes require knowledge of the structural changes and compression mechanisms that take place in liquid silicates at the high pressures and temperatures in the Earth's interior. However, obtaining such knowledge has long been impeded by the challenging nature of the experiments. In recent years, structural and density information for silica glass was obtained at record pressures of up to 100 GPa (ref. 1), a major step towards obtaining data on the molten state. Here we report the structure of molten basalt up to 60 GPa by means of in situ X-ray diffraction. The coordination of silicon increases from four under ambient conditions to six at 35 GPa, similar to what has been reported in silica glass. The compressibility of the melt after the completion of the coordination change is lower than at lower pressure, implying that only a high-order equation of state can accurately describe the density evolution of silicate melts over the pressure range of the whole mantle. The transition pressure coincides with a marked change in the pressure-evolution of nickel partitioning between molten iron and molten silicates, indicating that melt compressibility controls siderophile-element partitioning.

  10. Impact of corrosion test container material in molten fluorides

    SciTech Connect

    Olson, Luke C.; Fuentes, Roderick E.; Martinez-Rodriguez, Michael J.; Ambrosek, James W.; Sridharan, Kumar; Anderson, Mark H.; Garcia-Diaz, Brenda L.; Gray, Joshua; Allen, Todd R.

    2015-10-15

    The effects of crucible material choice on alloy corrosion rates in immersion tests in molten LiF–NaF–KF (46.5–11.5-42 mol. %) salt held at 850 °C for 500 hrs are described. Four crucible materials were studied. Molten salt exposures of Incoloy-800H in graphite, Ni, Incoloy-800H, and pyrolytic boron nitride (PyBN) crucibles all led to weight-loss in the Incoloy-800H coupons. Alloy weight loss was ~30 times higher in the graphite and Ni crucibles in comparison to the Incoloy-800H and PyBN crucibles. It is hypothesized galvanic coupling between the alloy coupons and crucible materials contributed to the higher corrosion rates. Alloy salt immersion in graphite and Ni crucibles had similar weight-loss hypothesized to occur due to the rate limiting out diffusion of Cr in the alloys to the surface where it reacts with and dissolves into the molten salt, followed by the reduction of Cr from solution at the molten salt and graphite/Ni interfaces. As a result, both the graphite and the Ni crucibles provided sinks for the Cr, in the formation of a Ni–Cr alloy in the case of the Ni crucible, and Cr carbide in the case of the graphite crucible.

  11. Study of an F center in molten KCl

    SciTech Connect

    Parrinello, M.; Rahman, A.

    1983-05-01

    It is shown that a discretized version of Feynman's path integral provides a convenient tool for the numerical investigation of the properties of an electron solvated in molten KCl. The binding energy and the pair correlation functions are calculated. The local structure around the solute electron appears to be different from that of an F center in the solid.

  12. Research and development issues for molten carbonate fuel cells

    SciTech Connect

    Krumpelt, M.

    1996-04-01

    This paper describes issues pertaining to the development of molten carbonate fuel cells. In particular, the corrosion resistance and service life of nickel oxide cathodes is described. The resistivity of lithium oxide/iron oxides and improvement with doping is addressed.

  13. Impact of corrosion test container material in molten fluorides

    DOE PAGESBeta

    Olson, Luke C.; Fuentes, Roderick E.; Martinez-Rodriguez, Michael J.; Ambrosek, James W.; Sridharan, Kumar; Anderson, Mark H.; Garcia-Diaz, Brenda L.; Gray, Joshua; Allen, Todd R.

    2015-10-15

    The effects of crucible material choice on alloy corrosion rates in immersion tests in molten LiF–NaF–KF (46.5–11.5-42 mol. %) salt held at 850 °C for 500 hrs are described. Four crucible materials were studied. Molten salt exposures of Incoloy-800H in graphite, Ni, Incoloy-800H, and pyrolytic boron nitride (PyBN) crucibles all led to weight-loss in the Incoloy-800H coupons. Alloy weight loss was ~30 times higher in the graphite and Ni crucibles in comparison to the Incoloy-800H and PyBN crucibles. It is hypothesized galvanic coupling between the alloy coupons and crucible materials contributed to the higher corrosion rates. Alloy salt immersion inmore » graphite and Ni crucibles had similar weight-loss hypothesized to occur due to the rate limiting out diffusion of Cr in the alloys to the surface where it reacts with and dissolves into the molten salt, followed by the reduction of Cr from solution at the molten salt and graphite/Ni interfaces. As a result, both the graphite and the Ni crucibles provided sinks for the Cr, in the formation of a Ni–Cr alloy in the case of the Ni crucible, and Cr carbide in the case of the graphite crucible.« less

  14. 30 CFR 57.16013 - Working with molten metal.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Working with molten metal. 57.16013 Section 57.16013 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES...

  15. 30 CFR 57.16013 - Working with molten metal.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Working with molten metal. 57.16013 Section 57.16013 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES...

  16. 30 CFR 56.16013 - Working with molten metal.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Working with molten metal. 56.16013 Section 56.16013 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Materials...

  17. 30 CFR 56.16013 - Working with molten metal.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Working with molten metal. 56.16013 Section 56.16013 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Materials...

  18. 30 CFR 57.16013 - Working with molten metal.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Working with molten metal. 57.16013 Section 57.16013 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES...

  19. 30 CFR 56.16013 - Working with molten metal.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Working with molten metal. 56.16013 Section 56.16013 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Materials...

  20. 30 CFR 56.16013 - Working with molten metal.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Working with molten metal. 56.16013 Section 56.16013 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Materials...

  1. 30 CFR 57.16013 - Working with molten metal.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Working with molten metal. 57.16013 Section 57.16013 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES...

  2. 30 CFR 56.16013 - Working with molten metal.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Working with molten metal. 56.16013 Section 56.16013 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Materials...

  3. 30 CFR 57.16013 - Working with molten metal.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Working with molten metal. 57.16013 Section 57.16013 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES...

  4. [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.

  5. 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.

  6. Two techniques enable sampling of filtered and unfiltered molten metals

    NASA Technical Reports Server (NTRS)

    Burris, L., Jr.; Pierce, R. D.; Tobias, K. R.; Winsch, I. O.

    1967-01-01

    Filtered samples of molten metals are obtained by filtering through a plug of porous material fitted in the end of a sample tube, and unfiltered samples are obtained by using a capillary-tube extension rod with a perforated bucket. With these methods there are no sampling errors or loss of liquid.

  7. 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…

  8. Oxygen from the lunar soil by molten silicate electrolysis

    NASA Technical Reports Server (NTRS)

    Colson, Russell O.; Haskin, Larry A.

    1992-01-01

    Accepting that oxygen, rather than gigantic gems or gold, is likely to make the Moon's Klondike, the extraction of oxygen from the lunar soil by molten silicate electrolysis has chosen to be investigated. Process theory and proposed lunar factory are addressed.

  9. Sulfur tolerant molten carbonate fuel cell anode and process

    DOEpatents

    Remick, Robert J.

    1990-01-01

    Molten carbonate fuel cell anodes incorporating a sulfur tolerant carbon monoxide to hydrogen water-gas-shift catalyst provide in situ conversion of carbon monoxide to hydrogen for improved fuel cell operation using fuel gas mixtures of over about 10 volume percent carbon monoxide and up to about 10 ppm hydrogen sulfide.

  10. Henry's Law Activity of Oxygen in Molten Iron

    NASA Astrophysics Data System (ADS)

    Matousek, J. W.

    2015-09-01

    A model is proposed for the solubility of oxygen in molten iron in dilute solutions in which the oxygen exists in two states, free and associated. Only the free oxygen has thermodynamic activity in the sense of interaction with an electrochemical cell to produce the voltage described by the Nernst equation.

  11. INTERIOR VIEW OF IRON TREATMENT (DESULPHURIZATION) AREA. MOLTEN IRON PROCEEDS ...

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

    INTERIOR VIEW OF IRON TREATMENT (DESULPHURIZATION) AREA. MOLTEN IRON PROCEEDS FROM CUPOLA TO IRON TREATMENT AREAS BEFORE BEING TRANSFERRED TO PIPE CASTING MACHINES. - United States Pipe & Foundry Company Plant, Melting & Treatment Areas, 2023 St. Louis Avenue at I-20/59, Bessemer, Jefferson County, AL

  12. Liquid surface skimmer apparatus for molten lithium and method

    DOEpatents

    Robinson, Samuel C.; Pollard, Roy E.; Thompson, William F.; Stark, Marshall W.; Currin, Jr., Robert T.

    1995-01-01

    This invention relates to an apparatus for separating two fluids having different specific gravities. The invention also relates to a method for using the separating apparatus of the present invention. This invention particularly relates to the skimming of molten lithium metal from the surface of a fused salt electrolyte in the electrolytic production of lithium metal from a mixed fused salt.

  13. 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.

  14. 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

  15. 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

  16. 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.

  17. Conduit for high temperature transfer of molten semiconductor crystalline material

    NASA Technical Reports Server (NTRS)

    Fiegl, George (Inventor); Torbet, Walter (Inventor)

    1983-01-01

    A conduit for high temperature transfer of molten semiconductor crystalline material consists of a composite structure incorporating a quartz transfer tube as the innermost member, with an outer thermally insulating layer designed to serve the dual purposes of minimizing heat losses from the quartz tube and maintaining mechanical strength and rigidity of the conduit at the elevated temperatures encountered. The composite structure ensures that the molten semiconductor material only comes in contact with a material (quartz) with which it is compatible, while the outer layer structure reinforces the quartz tube, which becomes somewhat soft at molten semiconductor temperatures. To further aid in preventing cooling of the molten semiconductor, a distributed, electric resistance heater is in contact with the surface of the quartz tube over most of its length. The quartz tube has short end portions which extend through the surface of the semiconductor melt and which are lef bare of the thermal insulation. The heater is designed to provide an increased heat input per unit area in the region adjacent these end portions.

  18. 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

  19. Validation studies of a computational model for molten material freezing

    SciTech Connect

    Sawada, Tetsuo; Ninokata, Hisashi; Shimizu, Akinao

    1996-02-01

    Validation studies are described of a computational model for the freezing of molten core materials under core disruptive accident conditions of fast breeder reactors. A series of out-of-pile experiments named SIMBATH, performed at Forschungszentrum Karlsruhe in Germany, has already been analyzed with the SIMMER-II code. In the current study, TRAN simulation tests in the SIMBATH facility are analyzed by SIMMER-II for its modeling validation of molten material freezing. The original TRAN experiments were performed at Sandia National laboratories to examine the freezing behavior of molten UO{sub 2} injected into an annular channels. In the TAN simulation experiments of the SIMBATH series, similar freezing phenomena are investigated for molten thermite, a mixture of Al{sub 2}O{sub 3} and iron, instead of UO{sub 2}. Two typical TRAN simulation tests are analyzed that aim at clarification of the applicability of the code to the freezing process during the experiments. The distribution of molten materials that are deposited in the test section according to the experimental measurements and in calculations by SIMMER-II is compared. These studies confirm that the conduction-limited freezing model combined with the rudimentary bulk freezing (particle-jamming) model of SIMMER-II is compared. These studies confirm that the conduction-limited freezing model combined with the rudimentary bulk freezing (particle-jamming) model of SIMMER-II could be used to reproduce the TRAN simulation experiments satisfactorily. This finding encourages the extrapolation of the results of previous validation research for SIMMER-II based on other SIMBATH tests to reactor case analyses. The calculation by SIMMER-II suggest that further improvements of the model, such as freezing on a convex surface of pin cladding and the scraping of crusts, make possible more accurate simulation of freezing phenomena.

  20. Casting Apparatus Including A Gas Driven Molten Metal Injector And Method

    DOEpatents

    Meyer, Thomas N.

    2004-06-01

    The casting apparatus (50) includes a holding vessel (10) for containing a supply of molten metal (12) and a casting mold (52) located above the holding vessel (10) and having a casting cavity (54). A molten metal injector (14) extends into the holding vessel (10) and is at least partially immersed in the molten metal (12) in the holding vessel (10). The molten metal injector (14) is in fluid communication with the casting cavity (54). The molten metal injector (14) has an injector body (16) defining an inlet opening (24) for receiving molten metal into the injector body (16). A gas pressurization source (38) is in fluid communication with the injector body (16) for cyclically pressurizing the injector body (16) and inducing molten metal to flow from the injector body (16) to the casting cavity (54). An inlet valve (42) is located in the inlet opening (24) in the injector body (16) for filling molten metal into the injector body (16). The inlet valve (42) is configured to prevent outflow of molten metal from the injector body (16) during pressurization and permit inflow of molten metal into the injector body (16) after pressurization. The inlet valve (42) has an inlet valve actuator (44) located above the surface of the supply of molten metal (12) and is operatively connected to the inlet valve (42) for operating the inlet valve (42) between open and closed positions.

  1. 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.

  2. 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

  3. 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.

  4. 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)

  5. 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.

  6. 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.

  7. Evidence for melt partitioning between olivine and orthopyroxene in partially molten harzburgite

    NASA Astrophysics Data System (ADS)

    Miller, K.; Zhu, W.; Montesi, L. G.; Le Roux, V.; Gaetani, G. A.

    2013-12-01

    During melting at mid-ocean ridges, melt is driven into an equilibrium, minimum-energy configuration by surface energy gradients between solid-solid and solid-liquid phase boundaries. Such a configuration, where melt is mostly restricted to three and four-grain junctions, acts as a porous medium through which melt can percolate to the surface. For a monomineralic system, melt is distributed evenly among all grains. However, in mineralogical heterogeneous systems, melt partitions unevenly between the various solid phases to minimize the total energy of the system. In a ocean ridge melting environment, where olivine is often juxtaposed against orthopyroxene (opx), lithologic partitioning is expected to turn olivine-rich regions into high-permeability conduits, through which melt can be quickly extracted, drastically increasing the permeability of the mantle [Zhu and Hirth, 2003]. Lithologic partitioning has been demonstrated in experiments using analogue systems [Watson, 1999]; however, to date, no experiment has confirmed its existence in partially molten mantle systems. We present experimental results that determine the degree of melt partitioning between olivine and opx in partially molten harzburgites. Samples were prepared from a powdered mixture of oxides and carbonates and then hot-pressed in a solid-media piston-cylinder apparatus at 1350°C and 1.5GPa [Zhu et al., 2011] to achieve an 82/18 vol. % ratio of olivine to opx. Prior to hot-pressing, basalt was added to the powdered mixtures in various proportions to test for lithologic partitioning across a range of melt fractions. Three-dimensional, 700nm-resolution images of our samples were obtained using synchrotron X-ray microtomography on the 2BM station of the Advanced Photon Source at Argonne National Labs. Image data were filtered using an anisotropic diffusion filter to enhance phase contrast and then segmented to produce binary representations of each phase. In order to quantitatively demonstrate

  8. Micromechanical modelling of partially molten and sand reinforced polycrystalline ice

    NASA Astrophysics Data System (ADS)

    Castelnau, O.; Duval, P.

    2009-12-01

    The viscoplastic behaviour of polycrystalline ice is strongly affected by the very strong anisotropy of ice crystals. Indeed, in the dislocations creep regime relevant for ice sheet flow, dislocation glide on the basal plane of ice single crystals leads to strain-rates ~6 order of magnitude larger than strain-rates that might be obtain if only non-basal glide is activated. At the polycrystal scale, this behaviour is responsible for a strong mechanical interaction between grains in the secondary (stationary) creep regime, and strain-rate is essentially partitioned between soft grains well-oriented for basal glide and hard grains exhibiting an unfavourable orientation for basal slip. As a consequence, the macroscopic flow stress at the polycrystal scale essentially depends on the resistance of the hardest slip systems or on the associated accommodation processes such as climb of basal dislocation on non-basal planes. Creep experiments performed on polycrystalline ices containing a small amount (less than 10% volume fraction) of liquid water show a dramatic increase of strain-rate, by more than one order of magnitude, compared to solid ice when deformed under similar thermo-mechanical conditions. Similarly, a strong hardening is observed when polycrystalline ice is reinforced by sand (which can be considered as a rigid phase here). This behaviour can be explained by micromechanical models, which aims at estimating the mechanical interactions between grains. For example, the presence of water releases stress concentrations at grain boundaries and therefore favours the inactivation of non-basal systems. To estimate such effect and to reach quantitative comparison with experimental data, we make use of the recent Second-Order homogenization mean-field approach of Ponte-Castaneda, based on self-consistent scheme. The advantage of this approach, which has been shown to provide excellent results when applied to many different non-linear composite materials, comes from the

  9. 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.

  10. 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.

  11. 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

  12. 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.

  13. Electromagnetic valve for controlling the flow of molten, magnetic material

    DOEpatents

    Richter, T.

    1998-06-16

    An electromagnetic valve for controlling the flow of molten, magnetic material is provided, which comprises an induction coil for generating a magnetic field in response to an applied alternating electrical current, a housing, and a refractory composite nozzle. The nozzle is comprised of an inner sleeve composed of an erosion resistant refractory material (e.g., a zirconia ceramic) through which molten, magnetic metal flows, a refractory outer shell, and an intermediate compressible refractory material, e.g., unset, high alumina, thermosetting mortar. The compressible refractory material is sandwiched between the inner sleeve and outer shell, and absorbs differential expansion stresses that develop within the nozzle due to extreme thermal gradients. The sandwiched layer of compressible refractory material prevents destructive cracks from developing in the refractory outer shell. 5 figs.

  14. Electromagnetic valve for controlling the flow of molten, magnetic material

    DOEpatents

    Richter, Tomas

    1998-01-01

    An electromagnetic valve for controlling the flow of molten, magnetic material is provided, which comprises an induction coil for generating a magnetic field in response to an applied alternating electrical current, a housing, and a refractory composite nozzle. The nozzle is comprised of an inner sleeve composed of an erosion resistant refractory material (e.g., a zirconia ceramic) through which molten, magnetic metal flows, a refractory outer shell, and an intermediate compressible refractory material, e.g., unset, high alumina, thermosetting mortar. The compressible refractory material is sandwiched between the inner sleeve and outer shell, and absorbs differential expansion stresses that develop within the nozzle due to extreme thermal gradients. The sandwiched layer of compressible refractory material prevents destructive cracks from developing in the refractory outer shell.

  15. Laser Acoustic Molten Metal Depth Sensing in Titanium

    SciTech Connect

    J. B. Walter; K. L. Telschow; R. E. Haun

    1999-09-22

    A noncontacting ultrasonic method has been investigated for probing the solidification front in molten titanium for the purposes of profiling the channel depth in a plasma hearth re-melter. The method, known as Laser Ultrasonics, utilized a pulsed laser for generation of ultrasonic waves at the surface of a molten metal pool. The ultrasonic waves propagated into the liquid titanium reflected from the solidification front and the boundaries of the solid plug. A Fabry-Perot interferometer, driven by a second laser, demodulated the small displacements caused by the ultrasonic wave motion at the liquid surface. The method and results of measurements taken within a small research plasma melting furnace will be described. Successful results were obtained even directly beneath the plasma arc using this all-optical approach.

  16. Burning molten metallic spheres: One class of ball lightning?

    NASA Astrophysics Data System (ADS)

    Stephan, Karl D.; Massey, Nathan

    2008-08-01

    Abrahamson and Dinniss [2000. Ball lightning caused by oxidation of nanoparticle networks from normal lightning strikes on soil. Nature 403, 519-521] proposed a theory of ball lighting in which silicon nanoparticles undergo slow oxidation and emit light. Paiva et al. [2007. Production of ball-lightning-like luminous balls by electrical discharges in silicon. Physical Review Letters 98, 048501] reported that an electric arc to silicon produced long-lasting luminous white spheres showing many characteristics of ball lightning. We show experimentally that these consist of burning molten silicon spheres with diameters in the 0.1-1 mm range. The evidence of our experiments leads us to propose that a subset of ball lightning events may consist of macro-scale molten spheres of burning metallic materials likely to be ejected from a conventional lightning strike to earth.

  17. Review of literature surface tension data for molten silicon

    NASA Technical Reports Server (NTRS)

    Hardy, S.

    1981-01-01

    Measurements of the surface tension of molten silicon are reported. For marangoni flow, the important parameter is the variation of surface tension with temperature, not the absolute value of the surface tension. It is not possible to calculate temperature coefficients using surface tension measurements from different experiments because the systematic errors are usually larger than the changes in surface tension because of temperature variations. The lack of good surface tension data for liquid silicon is probably due to its extreme chemical reactivity. A material which resists attack by molten silicon is not found. It is suggested that all of the sessile drip surface tension measurements are probably for silicon which is contaminated by the substrate materials.

  18. Plasma-sprayed ceramic coatings for protection against molten metal.

    SciTech Connect

    Hollis, K. J.; Peters, M. I.; Bartram, B. D.

    2002-01-01

    Molten metal environments pose a special demand on materials due to the high temperature corrosion effects and thermal expansion mismatch induced stress effects. A solution that has been successfully employed is the use of a base material for the mechanical strength and a coating material for the chemical compatibility with the molten metal. The work described here used such an approach coating tungsten rods with aluminum oxide, yttria-stabilized zirconia, yttrium oxide, and erbium oxide deposited by atmospheric plasma spraying. The ceramic materials were deposited under varying conditions to produce different structures. Measurement of particle characteristics was performed to correlate to material properties. The coatings were tested in a thermal cycling environment to simulate the metal melting cycle expected in service. Results of the testing indicate the effect of material composition and spray conditions on the thermal cycle crack resistance of the coatings.

  19. 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.

  20. Uranium (III) precipitation in molten chloride by wet argon sparging

    NASA Astrophysics Data System (ADS)

    Vigier, Jean-François; Laplace, Annabelle; Renard, Catherine; Miguirditchian, Manuel; Abraham, Francis

    2016-06-01

    In the context of pyrochemical processes for nuclear fuel treatment, the precipitation of uranium (III) in molten salt LiCl-CaCl2 (30-70 mol%) at 705 °C is studied. First, this molten chloride is characterized with the determination of the water dissociation constant. With a value of 10-4.0, the salt has oxoacid properties. Then, the uranium (III) precipitation using wet argon sparging is studied. The salt is prepared using UCl3 precursor. At the end of the precipitation, the salt is totally free of solubilized uranium. The main part is converted into UO2 powder but some uranium is lost during the process due to the volatility of uranium chloride. The main impurity of the resulting powder is calcium. The consequences of oxidative and reductive conditions on precipitation are studied. Finally, coprecipitation of uranium (III) and neodymium (III) is studied, showing a higher sensitivity of uranium (III) than neodymium (III) to precipitation.

  1. Lithium-ferrate-based cathodes for molten carbonate fuel cells

    SciTech Connect

    Lanagan, M.T.; Wolfenstine, J.; Bloom, I.; Kaun, T.D.; Krumpelt, M.

    1996-12-31

    Argonne National Laboratory is developing advanced cathodes for pressurized operation of the molten carbonate fuel cell (MCFC) at approximately 650 degrees Centigrade. These cathodes are based on lithium ferrate (LiFeO[sub 2]) which is attractive because of its very low solubility in the molten (Li,K)[sub 2]CO[sub 3] electrolyte. Because of its high resistivity, LiFeO[sub 2] cannot be used as a direct substitute for NiO. Cation substitution is, therefore, necessary to decrease resistivity. The effect of cation substitution on the resistivity and deformation of LiFeO[sub 2] was determined. The substitutes were chosen because their respective oxides as well as LiFeO[sub 2] crystallize with the rock-salt structure.

  2. Micro encapsulation in situ with super permeating molten wax

    SciTech Connect

    Carter, E.

    2007-07-01

    A new class of grout material based on molten wax offers a dramatic improvement in permeation grouting performance. This new material makes a perfect in situ containment of buried radioactive waste both feasible and cost effective. This paper describes various ways the material can be used to isolate buried waste in situ. Potential applications described in the paper include buried radioactive waste in deep trenches, deep shafts, Infiltration trenches, and large buried objects. Use of molten wax for retrieval of waste is also discussed. Wax can also be used for retrieval of air sensitive materials or drummed waste. This paper provides an analysis of the methods of application and the expected performance and cost of several potential projects. (authors)

  3. Laser Acoustic Molten Metal Depth Sensing in Titanium

    SciTech Connect

    Walter, John Bradley; Telschow, Kenneth Louis; Haun, R.E.

    1999-08-01

    A noncontacting ultrasonic method has been investigated for probing the solidification front in molten titanium for the purposes of profiling the channel depth in plasma hearth re-melter. The method, known as Laser Ultrasonics, utilized a pulsed laser for generation of ultrasonic waves at the surface of a molten metal pool. The ultrasonic waves propagated into the liquid titanium reflected from the solidification front and the boundaries of the solid plug. A Fabry-Perot interferometer, driven by a second laser, demodulated the small displacements caused by the ultrasonic wave motion at the liquid surface. The method and results of measurements taken within a small research plasma melting furnace will be described. Successful results were obtained even directly beneath the plasma arc using this all optical approach.

  4. 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.

  5. 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.

  6. 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.

  7. Report on large scale molten core/magnesia interaction test

    SciTech Connect

    Chu, T.Y.; Bentz, J.H.; Arellano, F.E.; Brockmann, J.E.; Field, M.E.; Fish, J.D.

    1984-08-01

    A molten core/material interaction experiment was performed at the Large-Scale Melt Facility at Sandia National Laboratories. The experiment involved the release of 230 kg of core melt, heated to 2923/sup 0/K, into a magnesia brick crucible. Descriptions of the facility, the melting technology, as well as results of the experiment, are presented. Preliminary evaluations of the results indicate that magnesia brick can be a suitable material for core ladle construction.

  8. METHOD OF PROTECTING TANTALUM CRUCIBLES AGAINST REACTION WITH MOLTEN URANIUM

    DOEpatents

    Feder, H.M.; Chellew, N.R.

    1960-08-16

    Tantalum crucibles against reaction with molten uranium by contacting the surfaces to be protected with metallic boron (as powder, vapor, or suspension in a liquid-volatilenonreacting medium, such as acetone and petroleum oil) at about 1800 deg C in vacuum, discontinuing contact with the boron, and heating the crucibles to a temperature of between 1800 aad 2000 deg C, whereby the tantalum boride formed in the first heating step is converted to tantalum monoboride.

  9. Molten carbonate fuel cell cathode with mixed oxide coating

    DOEpatents

    Hilmi, Abdelkader; Yuh, Chao-Yi

    2013-05-07

    A molten carbonate fuel cell cathode having a cathode body and a coating of a mixed oxygen ion conductor materials. The mixed oxygen ion conductor materials are formed from ceria or doped ceria, such as gadolinium doped ceria or yttrium doped ceria. The coating is deposited on the cathode body using a sol-gel process, which utilizes as precursors organometallic compounds, organic and inorganic salts, hydroxides or alkoxides and which uses as the solvent water, organic solvent or a mixture of same.

  10. DFT Study of Oxygen Dissociation in Molten Carbonate.

    PubMed

    Lei, Xueling; Haines, Kahla; Huang, Kevin; Qin, Changyong

    2015-08-20

    Using density functional theory method, we have studied the oxygen dissociation in alkali molten carbonate at the B3LYP/6-31G(d) level. The calculated energies were then verified by MP4 and CCSD(T). A four-formula cluster (M2CO3)4, M = Li, Na, and K was used to describe the molten carbonate. It was found that the adsorption of oxygen to molten carbonate is of a chemical type and leads to the formation of CO5(2-) in MC, which was confirmed for the first time by DFT calculations. The energy barrier for its dissociation is calculated to be 197.9, 116.7, and 170.3 kJ/mol in the (M2CO3)4 cluster, M = Li, Na, and K, respectively. If the reaction of O2 + 2CO3(2-) → 2CO4(2-) is approximated as a one-step reaction, the activation energy is estimated to be 96.2, 15.1, and 68.6 kJ/mol, respectively. The reaction rate is first order to the pressure of oxygen. Surprisingly, the reaction of oxygen dissociation has the lowest energy barrier in sodium carbonate, which is consistent with the recent experimental findings. It is very clear that the molten carbonate salt has directly participated in the ORR process and plays an important role as a catalyst in the cathode of SOFCs. The oxygen reduction has been facilitated by MC and enhanced cell performance has been observed.

  11. 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.

  12. Molten carbonate fuel cell reduction of nickel deposits

    DOEpatents

    Smith, James L.; Zwick, Stanley A.

    1987-01-01

    A molten carbonate fuel cell with anode and cathode electrodes and an eleolyte formed with two tile sections, one of the tile sections being adjacent the anode and limiting leakage of fuel gas into the electrolyte with the second tile section being adjacent the cathode and having pores sized to permit the presence of oxygen gas in the electrolyte thereby limiting the formation of metal deposits caused by the reduction of metal compositions migrating into the electrolyte from the cathode.

  13. Non-segregating electrolytes for molten carbonate fuel cells

    SciTech Connect

    Krumpelt, M.; Kaun, T.; Lanagan, M.

    1996-08-01

    Current MCFCs use a Li/K carbonate mixture; the segregation increases the K concentration near the cathode, leading to increase cathode solubility and performance decline. ANL is developing molten carbonates that have minimal segregation; the approach is using Li-Na carbonates. In screening tests, fully developed potential distributions were obtained for 4 Li/Na compositions, and performance data were used to compare these.

  14. High current density cathode for electrorefining in molten electrolyte

    DOEpatents

    Li, Shelly X.

    2010-06-29

    A high current density cathode for electrorefining in a molten electrolyte for the continuous production and collection of loose dendritic or powdery deposits. The high current density cathode eliminates the requirement for mechanical scraping and electrochemical stripping of the deposits from the cathode in an anode/cathode module. The high current density cathode comprises a perforated electrical insulated material coating such that the current density is up to 3 A/cm.sup.2.

  15. Is the Molten Globule a Third Phase of Proteins?

    NASA Astrophysics Data System (ADS)

    Pande, Vijay S.; Rokhsar, Daniel S.

    1998-02-01

    The equilibrium properties of proteins are studied by Monte Carlo simulation of two simplified models of protein-like heteropolymers. These models emphasize the polymeric entropy of the fluctuating polypeptide chain. Our calculations suggest a generic phase diagram that contains a thermodynamically distinct ``molten globule'' state in addition to a rigid native state and a nontrivial unfolded state. The roles of side-chain packing and loop entropy are discussed.

  16. Electromagnetic confinement for vertical casting or containing molten metal

    DOEpatents

    Lari, Robert J.; Praeg, Walter F.; Turner, Larry R.

    1991-01-01

    An apparatus and method adapted to confine a molten metal to a region by means of an alternating electromagnetic field. As adapted for use in the present invention, the alternating electromagnetic field given by B.sub.y =(2.mu..sub.o .rho.gy).sup.1/2 (where B.sub.y is the vertical component of the magnetic field generated by the magnet at the boundary of the region; y is the distance measured downward form the top of the region, .rho. is the metal density, g is the acceleration of gravity and .mu..sub.o is the permeability of free space) induces eddy currents in the molten metal which interact with the magnetic field to retain the molten metal with a vertical boudnary. As applied to an apparatus for the continuous casting of metal sheets or rods, metal in liquid form can be continuously introduced into the region defined by the magnetic field, solidified and conveyed away from the magnetic field in solid form in a continuous process.

  17. Experimental investigation of molten metal freezing on to a structure

    SciTech Connect

    Mizanur Rahman, M.; Hino, Tomohiko; Morita, Koji; Matsumoto, Tatsuya; Nakagawa, Kiyoshi; Fukuda, Kenji; Maschek, Werner

    2007-10-15

    During core disruptive accidents (CDAs) of Liquid Metal Reactors (LMRs), it is important to understand the freezing phenomena of molten metal, which may prevent fuel dispersal and subsequent shutdown. The present paper describes the freezing behavior of molten metal during interaction with a structure with a view to the safety of LMRs. In this study, Wood's metal (melting point 78.8 C) was used as a simulant melt, while stainless steel and copper were used as freezing structures. A series of simulation experiments was conducted to study the freezing behavior of Wood's metal during pouring on to the freezing structures immersed in a coolant. In the experiments, simulant melt was poured into a stainless steel tube and finally ejected into a coolant through a nozzle so as to observe the freezing behavior of the molten metal. The penetration length and width were measured in the air cooled experiments, whereas penetration length and the proportion of adhering frozen metal were measured in water coolant experiment. The melt flow and distribution were observed in both types of experiment using a high-speed video camera. Distinct freezing modes were observed in the water coolant experiments, whereas only one freezing mode with a longer melt penetration was found in air coolant experiments. The present result will be utilized to create a relevant database for the verification of reactor safety analysis codes. (author)

  18. 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.

  19. Density functional theory study of oxygen migration in molten carbonate

    NASA Astrophysics Data System (ADS)

    Lei, Xueling; Haines, Kahla; Huang, Kevin; Qin, Changyong

    2016-02-01

    The process of oxygen migration in alkali molten carbonate salts has been examined using density functional theory method. All geometries were optimized at the B3LYP/6-31G(d) level, while single point energy corrections were performed using MP4 and CCSD(T). At TS, a O-O-O linkage is formed and O-O bond forming and breaking is concerted. A cooperative "cogwheel" mechanism as described in the equation of CO42- + CO32- → CO32- ⋯O ⋯ CO32- → CO32- + CO42- is involved. The energy barrier is calculated to be 103.0, 136.3 and 127.9 kJ/mol through an intra-carbonate pathway in lithium, sodium and potassium carbonate, respectively. The reliability and accuracy of B3LYP/6-31G(d) were confirmed by CCSD(T). The calculated low values of activation energy indicate that the oxygen transfer in molten carbonate salts is fairly easy. In addition, it is found that lithium carbonate is not only a favorable molten carbonate salt for better cathode kinetics, but also it is widely used for reducing the melting point of Li/Na and Li/K eutectic MC mixtures. The current results imply that the process of oxygen reduction in MC modified cathodes is facilitated by the presence of MC, resulting in an enhancement of cell performance at low operating temperatures.

  20. 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.

  1. Corrosion studies in molten calcium chloride with chlorine

    SciTech Connect

    McLaughlin, D.F. . Science and Technology Center); Sessions, C.E.; Marra, J.E. )

    1990-01-01

    This study is aimed at testing new materials for use in molten salt processing of plutonium. Because of the high corrosiveness of chlorine, present materials have a high rate of failure. Materials less subject to corrosion are needed to minimize costs resulting from rapid failure of sparge tubes, stirring apparatus, and crucibles; to reduce the quantity of plutonium-contaminated scrap; and to improve the purity of the plutonium product. The processing environment of molten CaCl{sub 2}--CaO salts, molten plutonium, and chlorine-oxygen gas at temperatures from 750{degree} to 900{degree} is extremely severe. Materials with resistance to both corrosion and mechanical failure are desired. Also, the incorporation of corrosion products into the final plutonium product cannot exceed the allowable impurity limits. We require materials for crucibles, sparge tubes, stirrers, and containment and pull cans. Four metallic and two ceramics materials were tested. The metallic materials were Inconel-601, Inconel-617, tantalum, and tungsten. Silicon nitride and magnesium oxide were the ceramics tested.

  2. 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.

  3. Thermodynamic and transport properties of aqueous and molten electrolytes

    SciTech Connect

    Conway, B.E.; Bockris, J.O.M.; Yeager, E.

    1983-01-01

    This book examines the physical chemistry of electrolytes in solution and in the molten state. Topics considered include ionic solvation (solvents, thermodynamic and transport properties, spectroscopic and diffraction methods, theoretical aspects of solvation), ionic interactions and activity behavior of electrolyte solutions (the Debye-Hueckel evaluation of the activity coefficient of an electrolyte in solution, statistical-mechanical treatments of ionic interactions in solution, ion-solvent interactions in the activity behavior of electrolytes, short-range ionic interactions), the conductance of electrolyte solutions (the basis of the Onsager approach, the boundary conditions, differential equations for two-particle distribution functions, recent developments in conductance, transference numbers, ionic limiting mobilities, the conductance of mixtures of electrolytes, optimization in measurements and data processing), proton solvation and proton transfer in chemical and electrochemical processes (proton solvation and characterization of the H/sub 3/O/sup +/ ion, proton transfer in chemical ionization processes in solution, continuous proton transfer in conductance processes, proton transfer in electrode processes), and the structure and thermodynamics of molten salts (molten salts as liquids, single salts, salt mixtures). Nonaqueous solutions are not covered in this volume.

  4. 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.

  5. Removal of Inclusions from Molten Aluminum by Supergravity Filtration

    NASA Astrophysics Data System (ADS)

    Song, Gaoyang; Song, Bo; Yang, Zhanbing; Yang, Yuhou; Zhang, Jing

    2016-09-01

    A new approach to removing inclusions from aluminum melt by supergravity filtration was investigated. The molten aluminum containing MgAl2O4 spinel and coarse Al3Ti particles was isothermally filtered with different gravity coefficients, different filtering times, and various filtering temperatures under supergravity field. When the gravity coefficient G ≥ 50, the alloy samples were divided automatically into two parts: the upper residue and the lower filtered aluminum. All inclusions (MgAl2O4 and Al3Ti particles) were nearly intercepted in the upper residue by filter felt with average pore size of 44.78 μm. The removal efficiencies of oxide inclusions and Al3Ti particles exceeded 98 and 90 pct, respectively, at G ≥ 50, t = 2 minutes, T = 973 K (700 °C). Besides, the yield of purified aluminum was up to 92.1 pct at G = 600, t = 2 minutes, and T = 973 K (700 °C). The calculations of centrifugal pressure indicated that supergravity filtration could effectively overcome the pressure drop without meeting the rigorous requirement of height of molten metal, especially for using the fine-pore filter medium. Moreover, cake-mode filtration was the major mechanism of supergravity filtration of molten metal in this work.

  6. Prebiotic formation of polyamino acids in molten urea

    NASA Astrophysics Data System (ADS)

    Mita, H.; Nomoto, S.; Terasaki, M.; Shimoyama, A.; Yamamoto, Y.

    2005-04-01

    It is important for research into the origins of life to elucidate polyamino acid formation under prebiotic conditions. Only a limited set of amino acids has been reported to polymerize thermally. In this paper we demonstrate a novel thermal polymerization mechanism in a molten urea of alkylamino acids (i.e. glycine, alanine, β-alanine, α-aminobutyric acid, valine, norvaline, leucine and norleucine), which had been thought to be incapable of undergoing thermal polymerization. Also, aspartic acid was found to polymerize in molten urea at a lower temperature than that at which aspartic acid alone had previously been thermally polymerized. Individual oligomers produced in heating experiments on urea-amino acid mixtures were analysed using a liquid chromatograph mass spectrometer. Major products in the reaction mixture were three different types of polyamino acid derivatives: N-carbamoylpolyamino acids, polyamino acids containing a hydantoin ring at the N-terminal position and unidentified derivatives with molecular weights that were greater by 78 than those of the corresponding peptide forms. The polymerization reaction occurred by taking advantage of the high polarity of molten urea as well as its dehydrating ability. Under the presumed prebiotic conditions employed here, many types of amino acids were thus revealed to undergo thermal polymerization.

  7. 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.

  8. Electrolytic production of neodymium metal from a molten chloride electrolyte. Rept. of Investigations/1991

    SciTech Connect

    Chambers, M.F.; Murphy, J.E.

    1991-01-01

    Electrowinning of neodymium metal was accomplished by using a molten-metal cathode at 650 C and an electrolyte of 50 mol pct neodymium chloride-50 mol pct potassium chloride. The molten-metal cathodes were alloys of magnesium and zinc or magnesium and cadmium. Current efficiencies were 90 pct with a Mg/Zn cathode and 80 pct with a Mg-Cd cathode. The Mg-Cd cathode was easily separated from the electrolyte. In contrast, the Mg-Zn cathode tended to mix with the electrolyte, making separation difficult. The cathode metals were separated from the neodymium by distillation at 1,100 C under a vacuum of 10 to the -3rd power torr. Neodymium metal of 99.9+ purity was recovered from the Mg-Cd alloy cathode after 30 min distillation time. The neodymium recovered from the Mg-Zn system contained almost 2 pct Zn after vacuum distillation. Continuous operation using the Mg-Cd alloy cathode was demonstrated.

  9. 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.

  10. Thermodynamic Model and Database for Sulfides Dissolved in Molten Oxide Slags

    NASA Astrophysics Data System (ADS)

    Kang, Youn-Bae; Pelton, Arthur D.

    2009-12-01

    A thermodynamic model has been developed in the framework of the modified quasichemical model in the quadruplet approximation to permit the calculation of solubilities of various gaseous species (sulfide, sulfate, nitride, carbide, water, etc.) in molten slags. The model calculates the solubilities solely from knowledge of the thermodynamic activities of the component oxides and the Gibbs energies of the pure liquid components (oxides, sulfides, sulfates, etc.). In the current article, it is shown that solubilities of sulfur as sulfide in Al2O3-CaO-FeO-Fe2O3-MgO-MnO-SiO2-TiO2-Ti2O3 multicomponent slags, which are predicted from the current model with no adjustable model parameters, are in good agreement with all available experimental data. The article also provides a thorough review of experimental sulfide capacity data for this system. The model applies at all compositions from pure oxides to pure sulfides and from basic to acidic slags. By coupling this database with other evaluated databases, such as those for molten metal and gaseous phases, and with general software for Gibbs energy minimization, practically important slag/metal/gas/solid equilibria can be computed such as S-distribution ratios.

  11. 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.

  12. Br diffusion in molten NaBr explored by coherent quasielastic neutron scattering.

    PubMed

    Demmel, F; Alcaraz, O; Trullas, J

    2016-04-01

    Molten sodium bromide has been investigated by quasielastic neutron scattering focusing on the wave vector range around the first structure factor peak. The linewidth of the scattering function shows a narrowing around the wave number of the structure factor peak, known as deGennes narrowing. In a monatomic system, this narrowing or in the time domain slowing down, has been related to a self-diffusion process of the caged particle. Here we show that this methodology can be applied to the molten alkali halide NaBr. The incoherent scattering from the sodium ions at small wave vectors provides the self-diffusion coefficient of sodium and the dynamics of bromine ions can be studied at wave numbers around the structure factor peak. With input from molecular dynamics simulations on the partial structure factors, diffusion coefficients of the bromine ions can be obtained. These experimentally derived diffusion coefficients are in good agreement with molecular dynamics simulation results. This methodology to extract self-diffusion coefficients from coherent quasielastic neutron scattering is applicable to binary fluids in general when one particle dominates the scattering response at the structure factor maximum. PMID:27176349

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. Electrochemistry of carbides and carbon cathodes in molten halides. Final report

    SciTech Connect

    Selman, J.R.

    1983-06-01

    During the six-year period 1977 to 1983 the electrochemistry of lithium and calcium carbides and of carbon cathodes was investigated with emphasis on: (1) the characteristics of carbon electrode potentials in carbide-containing melts; (2) the behavior of carbon as an intercalating cathode in lithium-based melts. A direct connection between the carbon/carbide electrochemistry and the intercalation kinetics of graphite was demonstrated in the case of lithium, with likely extension to calcium. Five intercalation stages of lithium were identified by coulometry and their lithium activity measured for the first time, by the emf method. The diffusivity of lithium in graphite was also determined for the first time, as a function of the intercalation stage. The above results were, or are being, reported in eight publications. Molten-salt experiments and modeling analyses, carried out in preparation for the intercalation experiments, are reported in five additional publications. Support is also acknowledged for seven major review papers dealing with molten-salt systems and transport-property related techniques.

  19. 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.

  20. 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.