WorldWideScience

Sample records for molten pyrosulfate-based membranes

  1. Electrochemical flue gas desulfurization: Reactions in a pyrosulfate-based electrolyte

    Scott, K.; Fannon, T.; Winnick, J.

    1988-01-01

    A new electrolyte has been found suitable for use in an electrochemical membrane cell for flue gas desulfurization (FGD). The electrolyte is primarily K/sub 2/S/sub 2/O/sub 7/ and K/sub 2/SO/sub 4/ with V/sub 2/O/sub 5/ as oxidation enhancer. This electrolyte has a melting point near 300/sup 0/C which is compatible with flue gas exiting the economizer of coal-burning power plants. Standard electrochemical tests have revealed high exchange current densities around 30 mA/cm/sup 2/, in the free electrolyte. Sulfur dioxide is found to be removed from simulated flue gas in a multiple-step process, the first of which is electrochemical reduction of pyrosulfate

  2. Methane-steam reforming by molten salt - membrane reactor using concentrated solar thermal energy

    Watanuki, K.; Nakajima, H.; Hasegawa, N.; Kaneko, H.; Tamaura, Y.

    2006-01-01

    By utilization of concentrated solar thermal energy for steam reforming of natural gas, which is an endothermic reaction, the chemical energy of natural gas can be up-graded. The chemical system for steam reforming of natural gas with concentrated solar thermal energy was studied to produce hydrogen by using the thermal storage with molten salt and the membrane reactor. The original steam reforming module with hydrogen permeable palladium membrane was developed and fabricated. Steam reforming of methane proceeded with the original module with palladium membrane below the decomposition temperature of molten salt (around 870 K). (authors)

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

    Willit, James L [Batavia, IL

    2010-09-21

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

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

    Willit, James L.

    2007-09-11

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

  5. Molten salt breeder reactor

    1977-01-01

    MSBR Study Group formed in October 1974 has studied molten salt breeder reactor and its various aspects. Usage of a molten salt fuel, extremely interesting as reactor chemistry, is a great feature to MSBR; there is no need for separate fuel making, reprocessing, waste storage facilities. The group studied the following, and these results are presented: molten salt technology, molten salt fuel chemistry and reprocessing, reactor characteristics, economy, reactor structural materials, etc. (Mori, K.)

  6. Molten salt electrorefining method

    Tanaka, Hiroshi; Nakamura, Hitoshi; Shoji, Yuichi; Matsumaru, Ken-ichi.

    1994-01-01

    A molten cadmium phase (lower side) and a molten salt phase (upper side) are filled in an electrolytic bath. A basket incorporating spent nuclear fuels is inserted/disposed in the molten cadmium phase. A rotatable solid cathode is inserted/disposed in the molten salt phase. The spent fuels, for example, natural uranium, incorporated in the basket is dissolved in the molten cadmium phase. In this case, the uranium concentration in the molten salt phase is determined as from 0.5 to 20wt%. Then, electrolysis is conducted while setting a stirring power for stirring at least the molten salt phase of from 2.5 x 10 2 to 1 x 10 4 based on a reynolds number. Crystalline nuclei of uranium are precipitated uniformly on the surface of the solid cathode, and they grow into fine dendrites. With such procedures, since short-circuit between the cathode precipitates and the molten cadmium phase (anode) is scarcely caused, to improve the recovering rate of uranium. (I.N.)

  7. Gases in molten salts

    Tomkins, RPT

    1991-01-01

    This volume contains tabulated collections and critical evaluations of original data for the solubility of gases in molten salts, gathered from chemical literature through to the end of 1989. Within the volume, material is arranged according to the individual gas. The gases include hydrogen halides, inert gases, oxygen, nitrogen, hydrogen, carbon dioxide, water vapor and halogens. The molten salts consist of single salts, binary mixtures and multicomponent systems. Included also, is a special section on the solubility of gases in molten silicate systems, focussing on slags and fluxes.

  8. Metalcasting: Filtering Molten Metal

    Lauren Poole; Lee Recca

    1999-01-01

    A more efficient method has been created to filter cast molten metal for impurities. Read about the resulting energy and money savings that can accrue to many different industries from the use of this exciting new technology

  9. Hydrogen production using the waste heat of Benchmark pressurized Molten carbonate fuel cell system via combination of organic Rankine cycle and proton exchange membrane (PEM) electrolysis

    Nami, Hossein; Akrami, Ehsan; Ranjbar, Faramarz

    2017-01-01

    Highlights: • Waste heat of the Benchmark system recovered using an ORC. • An integrated system is proposed to produce power and hydrogen. • The effects of some decision parameters on the produced hydrogen have investigated. - Abstract: Energy and exergy analyses are carried out for hydrogen production via combination of Benchmark system and organic Rankine cycle (ORC) coupled with a proton exchange membrane electrolyzer. A parametric study is reported and effects of such organic Rankine cycle significant variables as evaporator temperature, pinch point temperature difference in the evaporator and degree of superheat at the ORC turbine inlet on the rate of produced hydrogen, sustainability index, overall exergy efficiency and organic Rankine cycle net produced power are investigated. It is observed that the rate of produced hydrogen and overall exergy efficiency of the proposed combined system take the maximum value to change in the evaporator temperature. Also, it is revealed that increasing the pinch point temperature difference in the evaporator decreases the rate of produced hydrogen and the overall exergy efficiency of the system. Furthermore, the effects on the rate of produced hydrogen and the overall exergy efficiency of the degree of superheat at the ORC turbine inlet are the same as the effect of pinch point temperature difference.

  10. Molten salt reactors

    Bouchter, J.C.; Dufour, P.; Guidez, J.; Simon, N.; Renault, C.

    2014-01-01

    Molten salt reactors are one of the 6 concepts retained for the 4. generation of nuclear reactors. The principle of this reactor is very innovative: the nuclear fuel is dissolved in the coolant which allows the online reprocessing of the fuel and the online recovery of the fission products. A small prototype: the Molten Salt Reactor Experiment (MSRE - 8 MWt) was operating a few years in the sixties in the USA. The passage towards a fast reactor by the suppression of the graphite moderator leads to the concept of Molten Salt Fast Reactor (MSFR) which is presently studied through different European projects such as MOST, ALISIA and EVOL. Worldwide the main topics of research are: the adequate materials resisting to the high level of corrosiveness of the molten salts, fuel salt reprocessing, the 3-side coupling between neutron transport, thermohydraulics and thermo-chemistry, the management of the changing chemical composition of the salt, the enrichment of lithium with Li 7 in the case of the use of lithium fluoride salt and the use of MSFR using U 233 fuel (thorium cycle). The last part of the article presents a preliminary safety analysis of the MSFR. (A.C.)

  11. Molten salt reactors: chemistry

    1983-01-01

    This work is a critical analysis of the 1000 MW MSBR project. Behavior of rare gases in the primary coolant circuit, their extraction from helium. Coating of graphite by molybdenum, chemistry of protactinium and niobium produced in the molten salt, continuous reprocessing of the fuel salt and use of stainless steel instead of hastelloy are reviewed [fr

  12. Molten fluoride fuel salt chemistry

    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. copyright American Institute of Physics 1995

  13. Molten salt breeder reactor

    Furukawa, Kazuo; Tsukada, Kineo; Nakahara, Yasuaki; Oomichi, Toshihiko; Oono, Hideo.

    1982-01-01

    Purpose: To simplify the structure, as well as improve the technical reliability and safety by the elimination of a proton beam entering window. Constitution: The nuclear reactor container main body is made of Hastelloy N and provided at the inner surface with two layers of graphite shields except for openings. An aperture was formed in the upper surface of the container, through which protons accelerated by a linear accelerator are directly entered to the liquid surface of molten salts such as 7LiF-BeF 2 -ThF 4 , 7LiF-NaF-ThF 4 , 7LiF-Rb-UF 4 , NaF-KF-UF 4 and the like. The heated molten salts are introduced by way of a pipeway into a heat exchanger where the heat is transferred to coolant salts and electric generation is conducted by way of heated steams. (Furukawa, Y.)

  14. Molten core retention assembly

    Lampe, R.F.

    1976-01-01

    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

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

    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.

  16. Molten carbonate fuel cell

    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.

  17. Molten fuel studies at Winfrith

    Edwards, A.J.; Knowles, J.B.; Tattersall, R.B.

    1988-01-01

    This report describes the experimental facilities available for molten fuel studies at Winfrith. These include a large facility capable of testing components at full LMFBR subassembly scale and also a high pressure facility for experiments at pressures up to 25 MPa, covering the whole range of temperatures and pressures of interest for the PWR. If the hypothetical accident conditions initiating the release of molten fuel do not produce an explosive transfer of thermal energy on contact of molten fuel with the reactor coolant, then an intermediate rate of heat transfer over several hundred milliseconds may occur. Theoretical work is described which is being carried out to predict the resulting pressurisation and the degree of mechanical loading on the reactor structure. Finally the current programme of molten fuel studies and recent progress are reviewed, and future plans, which are chiefly focussed on the study of thermal interactions between molten fuel and sodium coolant for the LMFBR are outlined. (author)

  18. Molten salt reactor concept

    Sood, D.D.

    1980-01-01

    Molten salt reactor is an advanced breeder concept which is suited for the utilization of thorium for nuclear power production. This reactor is based on the use of solutions of uranium or plutonium fluorides in LiF-BeF 2 -ThF 4 as fuel. Unlike the conventional reactors, no external coolant is used in the reactor core and the fuel salt itself is circulated through heat exchangers to transfer the fission produced heat to a secondary salt (NaF-NaBF 4 ) for steam generation. A part of the fuel stream is continuously processed to isolate 233 Pa, so that it can decay to fissile 233 U without getting converted to 234 Pa, and for the removal of neutron absorbing fission products. This on-line processing scheme makes this reactor concept to achieve a breeding ratio of 1.07 which is the highest for any thermal breeder reactor. Experimental studies at the Bhabha Atomic Research Centre, Bombay, have established the use of plutonium as fuel for this reactor. This molten salt reactor concept is described and the work conducted at the Bhabha Atomic Research Centre is summarised. (auth.)

  19. Molten salt reactor type

    1977-01-01

    This document is one of the three parts of a first volume devoted to the compilations of American data on the molten salt reactor concept. This part describes the MSBR core (data presented are from ORNL 4541). The principal characteristics of the core are presented in tables together with plane and elevation drawings, stress being put upon the reflector, and loading and unloading. Neutronic, and thermal and hydraulic characteristics (core and reflectors) are more detailed. The reasons why a graphite with a tight graphite layer has been chosen are briefly exposed. The physical properties of the standard graphite (irradiation behavior) have been determined for an isotropic graphite with fine granulometry; its dimensional variations largely ressemble that of Gilsonite. The mechanical stresses computed (Wigner effect) do not implicate in any way the graphite stack [fr

  20. Molten salt reactor type

    1977-01-01

    This document is one of the three parts of a first volume devoted to the compilations of American data on the molten salt reactor concept. This part 'CIRCUITS' regroups under a condensed form - in French and using international units - the essential information contained in both basic documents of the American project for a molten-salt breeder power plant. This part is only dealing with things relating to the CEA-EDF workshop 'CIRCUITS'. It is not concerned with information on: the reactor and the moderator replacement, the primary and secondary salts, and the fuel salt reprocessing, that are dealt with in parts 'CORE' and 'CHEMISTRY' respectively. The possible evolutions in the data - and solutions - taken by the American designers for their successive projects (1970 to 1972) are shown. The MSBR power plant comprises three successive heat transfer circuits. The primary circuit (Hastelloy N), radioactive and polluted, containing the fuel salt, includes the reactor, pumps and exchangers. The secondary circuit (pipings made of modified Hastelloy N) contaminated in the exchanger, ensures the separation between the fuel and the fluid operating the turbo-alternator. The water-steam circuit feeds the turbine with steam. This steam is produced in the steam generator flowed by the secondary fluid. Some subsidiary circuits (discharge and storage of the primary and secondary salts, ventilation of the primary circuit ...) complete the three principal circuits which are briefly described. All circuits are enclosed inside the controlled-atmosphere building of the nuclear boiler. This building also ensures the biological protection and the mechanical protection against outer aggressions [fr

  1. The molten salt reactor adventure

    MacPherson, H.G.

    1985-01-01

    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 UF 4 -ThF 4 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

  2. Molten V2O5/Cs0.9K0.9Na0.2S2O7 and V2O5/K2S2O7 catalysts as electrolytes in an electrocatalytic membrane separation device for SO2 removal

    Rasmussen, Søren Birk; Eriksen, Kim Michael; Fehrmann, Rasmus

    2002-01-01

    Bench scale fuel cell tests have been carried out on the SO2 oxidation catalyst systems V2O5/M2S2O7 (M = alkali) used as electrolytes in a standard molten carbonate fuel cell (MCFC) fuel cell setup for removal of SO2 from power plant flue gases. Porous LixNi(1-x)O electrodes were used both as anode...... and cathode. The cleaning cell removes SO2 when a potential is applied across the membrane, potentially providing cheap and ecological viable means for regeneration of SO2 from off-gases into high quality H2SO4. Results show that successful removal of up to 80% SO2 at 450 degreesC can be achieved...

  3. Molten material-containing vessel

    Akagawa, Katsuhiko

    1998-01-01

    The molten material-containing vessel of the present invention comprises a vessel main body having an entrance opened at the upper end, a lid for closing the entrance, an outer tube having an upper end disposed at the lower surface of the lid, extended downwardly and having an closed lower end and an inner tube disposed coaxially with the outer tube. When a molten material is charged from the entrance to the inside of the vessel main body of the molten material-containing vessel and the entrance is closed by the lid, the outer tube and the inner tube are buried in the molten material in the vessel main body, accordingly, a fluid having its temperature elevated by absorption of the heat of the molten material rises along the inner circumferential surface of the outer tube, abuts against the lower surface of the lid and cooled by exchanging heat with the lid and forms a circulating flow. Since the heat in the molten material is continuously absorbed by the fluid, transferred to the lid and released from the lid to the atmospheric air, heat releasing efficiency can be improved compared with conventional cases. (N.H.)

  4. Molten salt reactor type

    1977-01-01

    This document is one of the three parts of a first volume devoted to the compilations of American data on the molten salt reactor concept. Emphasize is put essentially on the fuel salt of the primary circuit inside which fission reactions occur. The reasons why the (LiF-BeF 2 -ThF 4 -UF 4 ) salt was chosen for the M.S.B.R. concept are examined; the physical, physicochemical and chemical properties of this salt are discussed with its interactions with the structural materials and its evolution in time. An important part of this volume is devoted to the continuous reprocessing of the active salt, the project designers having deemed advisable to take advantage at best from the availability of a continuous purification, in a thermal breeding. The problem of tritium formation and distribution inside the reactor is also envisaged and the fundamentals of the chemistry of the secondary coolant salt are given. The solutions proposed are: the hydrogen scavenging of the primary circuit, a reduction in metal permeability by an oxyde layer deposition on the side in contact with the vapor, and tritium absorption through an isotope exchange with the hydroxifluoroborate [fr

  5. Actuation method of molten carbonate fuel cell

    Ito, Yasuhiko; Kimoto, Mamoru; Murakami, Shuzo; Furukawa, Nobuhiro

    1987-10-17

    A molten carbonate fuel cell uses reformed gas of crude fuel as fuel gas, but in this gas, CO/sub 2/ is contained in addition to H/sub 2/ and CO which participate the reaction in its fuel electrode. In order to make the reaction of the cell by these gases smoothly, CO/sub 2/ in the exhaust gas from the fuel electrode must be introduced efficiently to its oxygen electrode, however since unreacted H/sub 2/ and CO are contained in the above exhaust gas, they are oxidated and burned once in a boiler and transformed into H/sub 2/O (steam) and CO/sub 2/, then CO/sub 2/ generated in the fuel electrode is added thereto, and afterwards these gases with the air are introduced into the oxygen electrode. However, since this method hinders the high power generation efficiency, in this invention, the exhaust gas from the fuel electrode which burns the reformed gas is introduced into separation chambers separated with CO/sub 2/ permselective membranes, and the mixture of CO/sub 2/ in the above exhaust gas separated with the aforementioned permeable membranes and the air is supplied to the oxygen electrode. At the same time, H/sub 2/ and CO in the above exhaust gas which were not separated with the above permeable membranes are recirculated to the above fuel electrode. (3 figs)

  6. Molten fuel-moderator interaction

    Lee, J.H.S.; Kynstautas, R.

    1987-02-01

    A critical review of the current understanding of vapor explosions was carried out. It was concluded that, on the basis of actual industrial accidents and large scale experiments, energetic high yield steam explosion cannot be regarded as an improbable event if large quantities of molten fuel and coolant are mixed together. This study also reviewed a hydrodynamic transient model proposed by Henry and Fauske Associates to assess a molten fuel-moderator interaction event. It was found that the proposed model negates a priori the possibility of a violent event, by introducing two assumptions: 1) fine fragmentation of the molten fuel, and ii) rapid heat transfer from the fine fragments to form steam. Using the Hicks and Menzies thermodynamic model, maximum work potential and pressure rise in the calandria were estimated. However, it is recommended that a more representative upper bound model based on an underwater explosion of a pressurized volume of steam be developed

  7. Ceramics for Molten Materials Transfer

    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. Aluminum titanate crucible for molten uranium

    Asbury, J.J.

    1975-01-01

    An improved crucible for molten uranium is described. The crucible or crucible liner is formed of aluminum titanate which essentially eliminates contamination of uranium and uranium alloys during molten states thereof. (U.S.)

  9. Molten-salt converter reactors

    Perry, A.M.

    1975-01-01

    Molten-salt reactors appear to have substantial promise as advanced converters. Conversion ratios of 0.85 to 0.9 should be attainable with favourable fuel cycle costs, with 235 U valued at $12/g. An increase in 235 U value by a factor of two or three ($10 to $30/lb. U 3 O 8 , $75/SWU) would be expected to increase the optimum conversion ratio, but this has not been analyzed in detail. The processing necessary to recover uranium from the fuel salt has been partially demonstrated in the MSRE. The equipment for doing this would be located at the reactor, and there would be no reliance on an established recycle industry. Processing costs are expected to be quite low, and fuel cycle optimization depends primarily on inventory and burnup or replacement costs for the fuel and for the carrier salt. Significant development problems remain to be resolved for molten-salt reactors, notably the control of tritium and the elimination of intergranular cracking of Hastelloy-N in contact with tellurium. However, these problems appear to be amenable to solution. It is appropriate to consider separating the development schedule for molten-salt reactors from that for the processing technology required for breeding. The Molten-Salt Converter Reactor should be a useful reactor in its own right and would be an advance towards the achievement of true breeding in thermal reactors. (author)

  10. Catalysis in Molten Ionic Media

    Boghosian, Soghomon; Fehrmann, Rasmus

    2013-01-01

    This chapter deals with catalysis in molten salts and ionic liquids, which are introduced and reviewed briefly, while an in-depth review of the oxidation catalyst used for the manufacturing of sulfuric acid and cleaning of flue gas from electrical power plants is the main topic of the chapter...

  11. thermic oil and molten salt

    Boukelia T.E, Mecibah M.S and Laouafi A

    1 mai 2016 ... [27] Zavoico, AB. Solar Power Tower Design Basis Document. Tech. rep, Sandia National. Laboratories, SAND2001-2100, 2001. How to cite this article: Boukelia T.E, Mecibah M.S and Laouafi A. Performance simulation of parabolic trough solar collector using two fluids (thermic oil and molten salt).

  12. Accelerator molten-salt breeder reactor

    Furukawa, Kazuo; Kuroi, Hideo; Kato, Yoshio; Oomichi, Toshihiko.

    1979-01-01

    Purpose: To obtain fission products and to transmute transuranium elements and other radioactive wastes by the use of Accelerator Molten-Salt Breeder Reactor. Constitution: Beams from an accelerator pipe at one end of a target vessel is injected through a window into target molten salts filled inside of the target vessel. The target molten salts are subjected to pump recycling or spontaneous convection while forcively cooled by blanket molten salts in an outer vessel. Then, energy is recovered from the blanket molten salts or the target molten salts at high temperatures through electric power generation or the like. Those salts containing such as thorium 232 and uranium 238 are used as the blanket molten salts so that fission products may be produced by neutrons generated in the target molten salts. PbCl 2 -PbF 2 and LiF-BeF 2 -ThF 4 can be used as the target molten salts and as the blanket molten salts respectively. (Seki, T.)

  13. Partially molten magma ocean model

    Shirley, D.N.

    1983-01-01

    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

  14. Partial structures in molten AgBr

    Ueno, Hiroki [Department of Condensed Matter Chemistry and Physics, Faculty of Sciences, Kyushu University, 4-2-1 Ropponmatsu, Chuo-ku, Fukuoka 810-8560 (Japan)], E-mail: ueno@gemini.rc.kyushu-u.ac.jp; Tahara, Shuta [Faculty of Pharmacy, Niigata University of Pharmacy and Applied Life Science, Higashijima, Akiha-ku, Niigata 956-8603 (Japan); Kawakita, Yukinobu [Department of Physics, Faculty of Sciences, Kyushu University, 4-2-1 Ropponmatsu, Chuo-ku, Fukuoka 810-8560 (Japan); Kohara, Shinji [Research and Utilization Division, Japan Synchrotron Radiation Research Institute (JASRI, SPring-8), 1-1-1 Koto, Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Takeda, Shin' ichi [Department of Physics, Faculty of Sciences, Kyushu University, 4-2-1 Ropponmatsu, Chuo-ku, Fukuoka 810-8560 (Japan)

    2009-02-21

    The structure of molten AgBr has been studied by means of neutron and X-ray diffractions with the aid of structural modeling. It is confirmed that the Ag-Ag correlation has a small but well-defined first peak in the partial pair distribution function whose tail penetrates into the Ag-Br nearest neighbor distribution. This feature on the Ag-Ag correlation is intermediate between that of molten AgCl (non-superionic melt) and that of molten AgI (superionic melt). The analysis of Br-Ag-Br bond angle reveals that molten AgBr preserves a rocksalt type local ordering in the solid phase, suggesting that molten AgBr is clarified as non-superionic melt like molten AgCl.

  15. Thermal performances of molten salt steam generator

    Yuan, Yibo; He, Canming; Lu, Jianfeng; Ding, Jing

    2016-01-01

    Highlights: • Thermal performances of molten salt steam generator were experimentally studied. • Overall heat transfer coefficient reached maximum with optimal molten salt flow rate. • Energy efficiency first rose and then decreased with salt flow rate and temperature. • Optimal molten salt flow rate and temperature existed for good thermal performance. • High inlet water temperature benefited steam generating rate and energy efficiency. - Abstract: Molten salt steam generator is the key technology for thermal energy conversion from high temperature molten salt to steam, and it is used in solar thermal power station and molten salt reactor. A shell and tube type molten salt steam generator was set up, and its thermal performance and heat transfer mechanism were studied. As a coupling heat transfer process, molten salt steam generation is mainly affected by molten salt convective heat transfer and boiling heat transfer, while its energy efficiency is also affected by the heat loss. As molten salt temperature increased, the energy efficiency first rose with the increase of heat flow absorbed by water/steam, and then slightly decreased for large heat loss as the absorbed heat flow still rising. At very high molten salt temperature, the absorbed heat flow decreased as boiling heat transfer coefficient dropping, and then the energy efficiency quickly dropped. As the inlet water temperature increased, the boiling region in the steam generator remarkably expanded, and then the steam generation rate and energy efficiency both rose with the overall heat transfer coefficient increasing. As the molten salt flow rate increased, the wall temperature rose and the boiling heat transfer coefficient first increased and then decreased according to the boiling curve, so the overall heat transfer coefficient first increased and then decreased, and then the steam generation rate and energy efficiency of steam generator both had maxima.

  16. Niobium electrodeposition from molten fluorides

    Sartori, A.F.

    1987-01-01

    Niobium electrodeposition from molten alkali fluorides has been studied aiming the application of this technic to the processes of electrorefining and galvanotechnic of this metal. The effects of current density, temperature, niobium concentration in the bath, electrolysis time, substrate nature, ratio between anodic and cathodic areas, electrodes separation and the purity of anodes were investigated in relation to the cathodic current efficiency, electrorefining, electroplating and properties of the deposit and the electrolytic solution. The work also gives the results of the conctruction and operation of a pilot plant for refractory metals electrodeposition and shows the electrorefining and electroplating compared to those obtained at the laboratory scale. (author) [pt

  17. Compatibility of molten salt and structural materials

    Kawakami, Masahiro

    1994-01-01

    As the important factors for considering the compatibility of fuel salt and coolant salt with structural materials in molten salt reactors, there are the moisture remaining in molten salt and the fluorine potential in molten salt. In this study, as for the metals which are the main components of corrosion resistant alloys, the corrosion by the moisture remaining in molten salt and the dependence of the corrosion on fluorine potential were examined. As the molten salts, an eutectic molten salt LiF-BeF 2 was mainly used, and LiF-KF was used in combination. As the metallic materials, Cr, Ni and Cu which are the main components of corrosion resistant and heat resistant alloys, Hastelloy and Monel, were used. In the experiment, the metal pieces were immersed in the molten salt, and by sampling the molten salt, the change with time lapse of the concentration of the dissolved metals was examined. Besides, the electrochemical measurement was carried out for Cr, of which the corrosion was remarkable, and the change with time lapse of the dissolved ions was examined. The experimental setup, the experimental method, and the results of the immersion test and the electrochemical test are reported. The experiment on the corrosion of metals depending on fluorine potential is also reported. (K.I.)

  18. Compatibility of molten salt and structural materials

    Kawakami, Masahiro [Toyohashi Univ. of Technology, Aichi (Japan)

    1994-12-01

    As the important factors for considering the compatibility of fuel salt and coolant salt with structural materials in molten salt reactors, there are the moisture remaining in molten salt and the fluorine potential in molten salt. In this study, as for the metals which are the main components of corrosion resistant alloys, the corrosion by the moisture remaining in molten salt and the dependence of the corrosion on fluorine potential were examined. As the molten salts, an eutectic molten salt LiF-BeF{sub 2} was mainly used, and LiF-KF was used in combination. As the metallic materials, Cr, Ni and Cu which are the main components of corrosion resistant and heat resistant alloys, Hastelloy and Monel, were used. In the experiment, the metal pieces were immersed in the molten salt, and by sampling the molten salt, the change with time lapse of the concentration of the dissolved metals was examined. Besides, the electrochemical measurement was carried out for Cr, of which the corrosion was remarkable, and the change with time lapse of the dissolved ions was examined. The experimental setup, the experimental method, and the results of the immersion test and the electrochemical test are reported. The experiment on the corrosion of metals depending on fluorine potential is also reported. (K.I.).

  19. Fundamentals of molten-salt thermal technology

    1980-08-01

    This book has been published by the Society of Molten-Salt Thermal Technology to publish a part of the achievement of its members. This book is composed of seven chapters. The chapter 1 is Introduction. The chapter 2 explains the physical properties of molten salts, such as thermal behavior, surface tension, viscosity, electrical conductivity and others. The chapter 3 presents the compatibility with construction materials. Corrosion in molten salts, the electrochemical behavior of fluoride ions on carbon electrodes in fluoride melts, the behaviors of hastelloy N and metals in melts are items of this chapter. The equipments and instruments for molten salts are described in chapter 4. The heat transfer in molten salts is discussed in chapter 5. The chapter 6 explains the application of molten salt technology. The molten salt technology can be applied not only to thermal engineering and energy engineering but also to chemical and nuclear engineerings, and the technical fundamentals, current development status, technical problems and the perspective for the future are outlined. The chapter 7 is the summary of this book. The commercialization of molten salt power reactors is discussed at the end of this book. (Kato, T.)

  20. Metal Production by Molten Salt Electrolysis

    Grjotheim, K.; Kvande, H.; Qingfeng, Li

    Chemistry and electrochemistry of molten salts are reviewed. Technological aspects of electrolytic production of aluminium, magnesium, and other metals are comprehensively surveyed.......Chemistry and electrochemistry of molten salts are reviewed. Technological aspects of electrolytic production of aluminium, magnesium, and other metals are comprehensively surveyed....

  1. Molten salt processes in special materials preparation

    Krishnamurthy, N.; Suri, A.K.

    2013-01-01

    As a class, molten salts are the largest collection of non aqueous inorganic solvents. On account of their stability at high temperature and compatibility to a number of process requirements, molten salts are considered indispensable to realize many of the numerous benefits of high temperature technology. They play a crucial role and form the basis for numerous elegant processes for the preparation of metals and materials. Molten salt are considered versatile heat transfer media and have led to the evolution of many interesting reactor concepts in fission and possibly in fusion. They also have been the basis of thinking for few novel processes for power generation. While focusing principally on the actual utilization of molten salts for a variety of materials preparation efforts in BARC, this lecture also covers a few of the other areas of technological applications together with the scientific basis for considering the molten salts in such situations. (author)

  2. Improvement to molten salt reactors

    Bienvenu, Claude.

    1975-01-01

    The invention proposes a molten salt nuclear reactor whose core includes a mass of at least one fissile element salt to which can be added other salts to lower the melting temperature of the mass. This mass also contains a substance with a low neutron capture section that does not give rise to a chemical reaction or to an azeotropic mixture with these salts and having an atmospheric boiling point under that of the mass in operation. Means are provided for collecting this substance in the vapour state and returning it as a liquid to the mass. The kind of substance chosen will depend on that of the molten salts (fissile element salts and, where required, salts to lower the melting temperature). In actual practice, the substance chosen will have an atmospheric pressure boiling point of between 600 and 1300 0 C and a melting point sufficiently below 600 0 C to prevent solidification and clogging in the return line of the substance from the exchanger. Among the materials which can be considered for use, mention is made of magnesium, rubidium, cesium and potassium but metal cesium is not employed in the case of many fissile salts, such as fluorides, which it would reduced to the planned working temperatures [fr

  3. Sampling device for radioactive molten salt

    Shindo, Masato

    1998-01-01

    The present invention provides a device for accurately sampling molten salts to which various kinds of metals in a molten salt storage tank are mixed for analyzing them during a spent fuel dry type reprocessing. Namely, the device comprises a sampling tube having an opened lower end to be inserted into the radioactive molten salts stored in a tank and keeps reduced pressure from the upper end, and a pressure reducing pipeline having one end connected to the sampling tube and other end connected to an evacuating pump. In this device, the top end of the sampling tube is inserted to a position for sampling the radioactive molten salts (molten salts). The pressure inside the evacuating pipeline connected to the upper portion of the sampling tube is reduced for a while. In this case, the inside of the pressure reducing pipeline is previously evacuated by the evacuating pump so as to keep a predetermined pressure. Since the pressure in the sampling tube is lowered, molten salts are inserted into the sampling tube, the sampling tube is withdrawn, and the molten salts flown in the sampling tube are analyzed. (I.S.)

  4. Thermal conductivity of molten metals

    Peralta-Martinez, Maria Vita

    2000-02-01

    A new instrument for the measurement of the thermal conductivity of molten metals has been designed, built and commissioned. The apparatus is based on the transient hot-wire technique and it is intended for operation over a wide range of temperatures, from ambient up to 1200 K, with an accuracy approaching 2%. In its present form the instrument operates up to 750 K. The construction of the apparatus involved four different stages, first, the design and construction of the sensor and second, the construction of an electronic system for the measurement and storage of data. The third stage was the design and instrumentation of the high temperature furnace for the melting and temperature control of the sample, and finally, an algorithm was developed for the extraction of the thermal conductivity from the raw measurement data. The sensor consists of a cylindrical platinum-wire symmetrically sandwiched between two rectangular plane sheets of alumina. The rectangular sensor is immersed in the molten metal of interest and a voltage step is applied to the ends of the platinum wire to induce heat dissipation and a consequent temperature rise which, is in part, determined by the thermal conductivity of the molten metal. The process is described by a set of partial differential equations and appropriate boundary conditions rather than an approximate analytical solution. An electronic bridge configuration was designed and constructed to perform the measurement of the resistance change of the platinum wire in the time range 20 {mu}s to 1 s. The resistance change is converted to temperature change by a suitable calibration. From these temperature measurements as a function of time the thermal conductivity of the molten metals has been deduced using the Finite Element Method for the solution of the working equations. This work has achieved its objective of improving the accuracy of the measurement of the thermal conductivity of molten metals from {+-}20% to {+-}2%. Measurements

  5. Inertia-confining thermonuclear molten salt reactors

    Furukawa, Kazuo; Yamanaka, Chiyoe; Nakai, Sadao; Imon, Shunji; Nakajima, Hidenori; Nakamura, Norio; Kato, Yoshio.

    1984-01-01

    Purpose: To increase the heat generating efficiency while improving the reactor safety and thereby maintaining the energy balance throughout the reactor. Constitution: In an inertia-confining type D-T thermonuclear reactor, the blanket is made of lithium-containing fluoride molten salts (LiF.BeF 2 , LiF.NaF.KF, LiF.KF, etc) which are cascaded downwardly in a large thickness (50 - 100 cm) along the inner wall of the thermonuclear reaction vessel, and neutrons generated by explosive compression are absorbed to lithium in the molten salts to produce tritium, Heat transportation is carried out by the molten salts. (Ikeda, J.)

  6. NOVEL CERAMIC MEMBRANE FOR HIGH TEMPERATURE CARBON DIOXIDE SEPARATION

    Ida, Jun-ichi; Yang, Zhaohui; Lin, Jerry Y.S.

    2002-01-01

    A new CO 2 semi-permeable dense inorganic membrane consisting of a porous metal phase and molten carbonate was proposed. A simple direct infiltration method was used to synthesize the metal-carbonate dual-phase membrane. Hermetic (gas-tight) dual phase membrane was successfully obtained. Permeation data showed that nitrogen or helium is not permeable through the membrane (only CO 2 , with O 2 can permeate through the membrane based on transport mechanism)

  7. Structure and thermodynamics of molten salts

    Papatheodorou, G.N.

    1983-01-01

    This chapter investigates single-component molten salts and multicomponent salt mixtures. Molten salts provide an important testing ground for theories of liquids, solutions, and plasmas. Topics considered include molten salts as liquids (the pair potential, the radial distribution function, methods of characterization), single salts (structure, thermodynamic correlations), and salt mixtures (the thermodynamics of mixing; spectroscopy and structure). Neutron and X-ray scattering techniques are used to determine the structure of molten metal halide salts. The corresponding-states theory is used to obtain thermodynamic correlations on single salts. Structural information on salt mixtures is obtained by using vibrational (Raman) and electronic absorption spectroscopy. Charge-symmetrical systems and charge-unsymmetrical systems are used to examine the thermodynamics of salt mixtures

  8. Waste treatment using molten salt oxidation

    Navratil, J.D.; Stewart, A.E.

    1996-01-01

    MSO technology can be characterized as a submerged oxidation process; the basic concept is to introduce air and wastes into a bed of molten salt, oxidize the organic wastes in the molten salt, use the heat of oxidation to keep the salt molten and remove the salt for disposal or processing and recycling. The molten salt (usually sodium carbonate at 900-1000 C) provides four waste management functions: providing a heat transfer medium, catalyzing the oxidation reaction, preventing the formation of acid gases by forming stable salts, and efficiently capturing ash particles and radioactive materials by the combined effects of wetting, encapsulation and dissolution. The MSO process requires no wet scrubbing system for off-gas treatment. The process has been developed through bench-scale and pilot-scale testing, with successful destruction demonstration of a wide variety of hazardous and mixed (radioactive and hazardous wastes). (author). 24 refs, 2 tabs, 2 figs

  9. Molten salts processes and generic simulation

    Ogawa, Toru; Minato, Kazuo

    2001-01-01

    Development of dry separation process (pyrochemical process) using molten salts for the application of spent-nuclear fuel reprocessing requires a rather complete fundamental database as well as process simulation technique with wide applicability. The present report concerns recent progress and problems in this field taking behaviors of co-electrodeposition of UO 2 and PuO 2 in molten salts as an example, and using analytical simulation of local equilibrium combined with generic diffusion. (S. Ohno)

  10. Molten salts processes and generic simulation

    Ogawa, Toru; Minato, Kazuo [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2001-12-01

    Development of dry separation process (pyrochemical process) using molten salts for the application of spent-nuclear fuel reprocessing requires a rather complete fundamental database as well as process simulation technique with wide applicability. The present report concerns recent progress and problems in this field taking behaviors of co-electrodeposition of UO{sub 2} and PuO{sub 2} in molten salts as an example, and using analytical simulation of local equilibrium combined with generic diffusion. (S. Ohno)

  11. Controlling the discharge of molten material

    Geel, J. van; Dobbels, F.; Theunissen, W.

    1980-01-01

    A method and device are described for controlling the discharge of molten material from a melter or an intermediate vessel, in which a primary outflow is fed to an overflow system, the working level of which is regulated by means of pneumatic pressure on a communicating chamber pertaining to the overflow system. Molten material may be led into a primary overflow by means of a pneumatic lift. The material melted may be a glass used for disposing of radioactive liquid wastes. (author)

  12. Electrochemical ion separation in molten salts

    Spoerke, Erik David; Ihlefeld, Jon; Waldrip, Karen; Wheeler, Jill S.; Brown-Shaklee, Harlan James; Small, Leo J.; Wheeler, David R.

    2017-12-19

    A purification method that uses ion-selective ceramics to electrochemically filter waste products from a molten salt. The electrochemical method uses ion-conducting ceramics that are selective for the molten salt cations desired in the final purified melt, and selective against any contaminant ions. The method can be integrated into a slightly modified version of the electrochemical framework currently used in pyroprocessing of nuclear wastes.

  13. Apparatus for making molten silicon

    Levin, Harry (Inventor)

    1988-01-01

    A reactor apparatus (10) adapted for continuously producing molten, solar grade purity elemental silicon by thermal reaction of a suitable precursor gas, such as silane (SiH.sub.4), is disclosed. The reactor apparatus (10) includes an elongated reactor body (32) having graphite or carbon walls which are heated to a temperature exceeding the melting temperature of silicon. The precursor gas enters the reactor body (32) through an efficiently cooled inlet tube assembly (22) and a relatively thin carbon or graphite septum (44). The septum (44), being in contact on one side with the cooled inlet (22) and the heated interior of the reactor (32) on the other side, provides a sharp temperature gradient for the precursor gas entering the reactor (32) and renders the operation of the inlet tube assembly (22) substantially free of clogging. The precursor gas flows in the reactor (32) in a substantially smooth, substantially axial manner. Liquid silicon formed in the initial stages of the thermal reaction reacts with the graphite or carbon walls to provide a silicon carbide coating on the walls. The silicon carbide coated reactor is highly adapted for prolonged use for production of highly pure solar grade silicon. Liquid silicon (20) produced in the reactor apparatus (10) may be used directly in a Czochralski or other crystal shaping equipment.

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

    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.

  15. Molten salts and nuclear energy production

    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

  16. Electrochemistry of plutonium in molten halides

    McCurry, L.E.; Moy, G.M.M.; Bowersox, D.F.

    1987-01-01

    The electrochemistry of plutonium in molten halides is of technological importance as a method of purification of plutonium. Previous authors have reported that plutonium can be purified by electrorefining impure plutonium in various molten haldies. Work to eluciate the mechanism of the plutonium reduction in molten halides has been limited to a chronopotentiometric study in LiCl-KCl. Potentiometric studies have been carried out to determine the standard reduction potential for the plutonium (III) couple in various molten alkali metal halides. Initial cyclic voltammetric experiments were performed in molten KCL at 1100 K. A silver/silver chloride (10 mole %) in equimolar NaCl-KCl was used as a reference electrode. Working and counter electrodes were tungsten. The cell components and melt were contained in a quartz crucible. Background cyclic voltammograms of the KCl melt at the tungsten electrode showed no evidence of electroactive impurities in the melt. Plutonium was added to the melt as PuCl/sub 3/, which was prepared by chlorination of the oxide. At low concentrations of PuCl/sub 3/ in the melt (0.01-0.03 molar), no reduction wave due to the reduction of Pu(III) was observed in the voltammograms up to the potassium reduction limit of the melt. However on scan reversal after scanning into the potassium reduction limit a new oxidation wave was observed

  17. Physical properties of molten carbonate electrolyte

    Kojima, T.; Yanagida, M.; Tanimoto, K. [Osaka National Research Institute (Japan)] [and others

    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.

  18. Metallic oxide reduction in molten chlorides: electrochemical solvent regeneration

    Martin, A.

    2005-11-01

    We consider the reaction MeO 2 + 2 Ca → Me + 2 CaO in CaCl 2 at 850 C. We want to re-use the molten media, which is a CaO-CaCl 2 melt at the end of the reaction. For that we want to de-oxidize it. When we electrolyse CaO we obtain Ca and O 2 ; it presents three difficult points that we want to solve: (1) it is difficult to oxidize O 2 - without oxidizing Cl - because their oxidation potential are very closed, (2) the chemical or electrochemical anodic corrosion, (3) the anodically produced gas dissolution in the mell One way of avoiding chlorine gas evolution is to prevent chloride ions from reaching the anode, for example using a selective membrane. Furthermore, the best prevention of the anodically produced gas dissolution in the melt can be done with a compartment, physically separating the anode from the rest of the reactional media. Thus in this work we have used an yttria stabilized zirconia membrane as a selective membrane for the deoxidation of a CaO-CaCl 2 melt at 850 C. (author)

  19. Development of viscometers for molten salts

    Hayashi, Hirokazu; Kato, Yoshio; Ogawa, Toru; Sato, Yuzuru.

    1997-06-01

    Viscometers specially designed for molten salts were made. One is a oscillating cup type and the other is a capillary type. In the case of the oscillating cup viscometer, the viscosity is determined absolutely through the period and the logarithmic decrement of oscillation with other physical parameters. The period and the logarithmic decrement are calculated from the time intervals between two photo-detectors' intercepts of the reflected laser beam. The capillary viscometer used is made of quartz and the sample is sealed under vacuum, which is placed in a transparent furnace. Efflux time is measured by direct visual observation. Cell constants are determined with distilled water as a calibrating liquid. Viscosities of molten KCl are measured with each viscometer. The differences between measured and standard values of molten KCl at several temperatures are within 5% for the oscillating cup viscometer and within 3% for the capillary viscometer. (author)

  20. Molten salt burner fuel behaviour and treatment

    Ignatiev, V.V.; Zakirov, R.Y.; Grebenkine, K.F.

    2001-01-01

    The objective of this paper is to discuss the feasibility of molten salt reactor technology for treatment of Pu, minor actinides and fission products, when the reactor and fission product clean-up unit are planned as an integral system. This contribution summarises the available R and D which led to selection of the fuel compositions for the molten salt reactor of the TRU burner type (MSB). Special characteristics of behaviour of TRUs and fission products during power operation of MSB concepts are presented. The present paper briefly reviews the processing developments underlying the prior molten salt reactor programmes and relates them to the separation requirements of the MSB concept, including the permissible range of processing cycle times and removal times. Status and development needs in the thermodynamic properties of fluorides, fission product clean-up methods and container materials compatibility with the working fluids for the fission product clean-up unit are discussed. (authors)

  1. Molten salt reactors - safety options galore

    Gat, U.; Dodds, H.L.

    1997-01-01

    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)

  2. Thorium Molten-Salt Nuclear Energy Synergetics

    Furukawa, Kazuo; Lecocq, A.; Kato, Yoshio; Mitachi, Kohshi.

    1990-01-01

    In the next century, the 'fission breeder' concept will not be practical to solve the global energy problems, including environmental and North-South problems. As a new measure, a simple rational Th molten salt breeding fuel cycle system, named 'Thorium Molten-Salt Nuclear Energy Synergetics (THORIMS-NES)', which composed of simple power stations and fissile producers, is proposed. This is effective to establish the essential improvement in issues of resources, safety, power-size flexibility, anti-nuclear proliferation and terrorism, radiowaste, economy, etc. securing the simple operation, maintenance, chemical processing, and rational breeding fuel cycle. As examples, 155 MWe fuel self-sustaining power station 'FUJI-II', 7 MWe pilot-plant 'miniFUJI-II', 1 GeV-300 mA proton Accelerator Molten-Salt Breeder 'AMSB', and their combined fuel cycle system are explained. (author)

  3. Modelling of molten fuel/concrete interactions

    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

  4. Process for recovering tritium from molten lithium metal

    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.

  5. Experimental studies of actinides in molten salts

    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

  6. Experimental studies of actinides in molten salts

    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.

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

    Uhlir, 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 and 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

  8. Broadband phase difference method for ultrasonic velocimetry in molten glass

    Kikura, Hiroshige; Ihara, Tomonori

    2016-01-01

    This study aims to develop ultrasonic Doppler velocimetry in molten glass. Realization of such a technique has two difficulties: ultrasonic transmission into molten salt and Doppler signal processing. Buffer rod technique was developed in our research to transmit ultrasound into high temperature molten glass. This article discusses newly developed signal processing technique named broadband phase difference method. (J.P.N.)

  9. Refractory thermowell for continuous high temperature measurement of molten metal

    Thiesen, T.J.

    1992-01-01

    This patent describes a vessel for handling molten metal having an interior refractory lining, apparatus for continuous high temperature measurement of the molten metal. It comprises a thermowell; the thermowell containing a multiplicity of thermocouples; leads being coupled to a means for continuously indicating the temperature of the molten metal in the vessel

  10. Combined system of accelerator molten-salt breeder (AMSB) apd molten-salt converter reactor (MSCR)

    Furukawa, K.; Kato, Y.; Ohmichi, T.; Ohno, H.

    1983-01-01

    A design and research program is discUssed of the development of accelerator molten-salt breeder (AMSB) consisting of a proton accelerator and a molten fluoride target. The target simultaneously serves as a blanket for fissionable material prodUction. An addition of some amoUnt of fissile nuclides to a melt expands the AMSB potentialities as the fissionable material production increases and the energy generation also grows up to the level of self-provision. Besides the blanket salts may be used as nuclear fuel for molten-salt converter reactor (MSCR). The combined AM SB+MSCR system has better parameters as compared to other breeder reactors, molten-salt breeder reactors (MSBR) included

  11. Recent electroanalytical studies in molten fluorides

    Manning, D.L.; Mamantov, G.

    1976-01-01

    This paper summarizes the voltametric and chronopotentiometric studies of Bi, Fe, Te, oxide and U(IV)/U(III) ratio determinations in molten LiF--BeF 2 --ThF 4 (72-16-12 mole percent) and LiF--BeF 2 --ZrF 4 (65.6-29.4-5.0 mole percent). 54 references, 11 figures

  12. Investigation of molten salt fast reactor

    Kubota, Kenichi; Konomura, Mamoru

    2002-01-01

    On survey research for practicability strategy of fast reactor (FR) (phase 1), to extract future practicability image candidates of FR from wide options, in addition to their survey and investigation objects of not only solid fuel reactors of conventional research object but also molten salt reactor as a flowing fuel reactor, investigation on concept of molten salt FR plant was carried out. As a part of the first step of the survey research for practicability strategy, a basic concept on plant centered at nuclear reactor facility using chloride molten salt reactor capable of carrying out U-Pu cycle was examined, to perform a base construction to evaluate economical potential for a practical FBR. As a result, a result could be obtained that because of inferior fuel inventory and heat transmission to those in Na cooling reactor in present knowledge, mass of reactor vessel and intermediate heat exchanger were to widely increased to expect reduction of power generation unit price even on considering cheapness of its fuel cycle cost. Therefore, at present step further investigation on concept design of the chloride molten salt reactor plant system is too early in time, and it is at a condition where basic and elementary researches aiming at upgrading of economical efficiency such as wide reduction of fuel inventory, a measure expectable for remarkable rationalization effect of reprocessing system integrating a reactor to a processing facility, and so on. (G.K.)

  13. Galvanic high energy cells with molten electrolytes

    Borger, W.; Kappus, W.; Kunze, D.; Laig-Hoerstebrock, H.; Panesar, H.; Sterr, G.

    1981-01-01

    To develop a galvanic cell with molten salt electrolyte for electric vehicle propulsion and load leveling as well as to fabricate ten prototype cells with a capacity of at least 150 Ah (5 hour rate) and an energy density of 80 Wh/kg was the objective of this project.

  14. Thorium Molten Salt Nuclear Energy Synergetic System (THORIMS-NES)

    Yoshioka, Ritsuo; Mitachi, Koshi

    2013-01-01

    The authors have been promoting nuclear energy technology based on thorium molten salt as Thorium Molten Salt Nuclear Energy Synergetic System (THORIMS-NES). This system is a combination of fission power reactor of Molten Salt Reactor (MSR), and Accelerator Molten Salt Breeder (AMSB) for production of fissile 233 U with connecting chemical processing facility. In this paper, concept of THORIMS-NES, advantages of thorium and molten salt recent MSR design results such as FUJI-U3 using 233 U fuel, FUJI-Pu, large sized super-FUJI, pilot plant miniFUJI, AMSB, and chemical processing facility are described. (author)

  15. Molten salt: Corrosion problems and electrometallurgy in nuclear applications

    Santarini, G.

    1981-01-01

    A bibliographic survey is given of corrosion problems and electrometallurgical problems of molten salt in nuclear reactor applications. Due to the high potential to be achieved, their high ionic conductivity and the rapidity of reactions in a molten salt atmosphere, molten salts are interesting solvents for various electrometallurgical processes. Another important field of application is in the separation or electrolytical refining of various metals (Be, U, Pu, Th, Hf, Zr). However, these very characteristics of molten salts may also cause serious corrosion problems. Results obtained for the molten-salt reactor and the different causes of corrosion are reviewed an possible countermeasures analyzed. (orig.)

  16. Computer simulation on molten ionic salts

    Kawamura, K.; Okada, I.

    1978-01-01

    The extensive advances in computer technology have since made it possible to apply computer simulation to the evaluation of the macroscopic and microscopic properties of molten salts. The evaluation of the potential energy in molten salts systems is complicated by the presence of long-range energy, i.e. Coulomb energy, in contrast to simple liquids where the potential energy is easily evaluated. It has been shown, however, that no difficulties are encountered when the Ewald method is applied to the evaluation of Coulomb energy. After a number of attempts had been made to approximate the pair potential, the Huggins-Mayer potential based on ionic crystals became the most often employed. Since it is thought that the only appreciable contribution to many-body potential, not included in Huggins-Mayer potential, arises from the internal electrostatic polarization of ions in molten ionic salts, computer simulation with a provision for ion polarization has been tried recently. The computations, which are employed mainly for molten alkali halides, can provide: (1) thermodynamic data such as internal energy, internal pressure and isothermal compressibility; (2) microscopic configurational data such as radial distribution functions; (3) transport data such as the diffusion coefficient and electrical conductivity; and (4) spectroscopic data such as the intensity of inelastic scattering and the stretching frequency of simple molecules. The computed results seem to agree well with the measured results. Computer simulation can also be used to test the effectiveness of a proposed pair potential and the adequacy of postulated models of molten salts, and to obtain experimentally inaccessible data. A further application of MD computation employing the pair potential based on an ionic model to BeF 2 , ZnCl 2 and SiO 2 shows the possibility of quantitative interpretation of structures and glass transformation phenomena

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

    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. Copyright © 2014 Elsevier Ltd and ISBI. All rights reserved.

  18. Symbiotic molten-salt systems coupled with accelerator molten-salt breeder (AMSB) or inertial-confined fusion hybrid molten-salt breeder (IHMSB) and their comparison

    Furukawa, K.

    1984-01-01

    Two types of breeder systems are proposed. One is the combined system of Accelerator Molten-Salt Breeder (AMSB) and Molten-Salt Converter Reactor (MSCR), and the other is the combined system of Inertial-confined Fusion Hybrid Molten-Salt Breeder (IHMSB) and modified MSCR. Both apply the molten-fluorides and have technically deep relations. AMSB would be much simpler and have already high technical feasibility. This will become economical the Th breeder system having a doubling time shorter than ten years and distributing any size of power stations MSCR. (orig.) [de

  19. Advanced heat exchanger development for molten salts

    Sabharwall, Piyush, E-mail: Piyush.Sabharwall@inl.gov [Idaho National Laboratory, Idaho Falls, ID 83415 (United States); Clark, Denis; Glazoff, Michael [Idaho National Laboratory, Idaho Falls, ID 83415 (United States); Zheng, Guiqiu; Sridharan, Kumar; Anderson, Mark [University of Wisconsin, Madison (United States)

    2014-12-15

    Highlights: • Hastelloy N and 242, shows corrosion resistance to molten salt at nominal operating temperatures. • Both diffusion welds and sheet material in Hastelloy N were corrosion tested in at 650, 700, and 850 °C for 200, 500, and 1000 h. • Thermal gradients and galvanic couples in the molten salts enhance corrosion rates. • Corrosion rates found were typically <10 mils per year. - Abstract: 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, that show good corrosion resistance in 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% ZrF{sub 4} at 650, 700, and 850 °C for 200, 500, and 1000 h. Corrosion rates were similar between welded and nonwelded materials, typically <100 μm per year after 1000 h of corrosion tests. No catastrophic corrosion was observed in the diffusion welded regions. For materials of construction, nickel-based alloys 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 the type of salt impurity and alloy composition, with respect to chromium and carbon, to better define the best conditions for corrosion resistance. Also presented is the division of the nuclear reactor and high-temperature components per American Society of Mechanical

  20. Dynamics of the Molten Contact Line

    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

  1. Mixing of zeolite powders and molten salt

    Pereira, C.; Zyryanov, V.N.; Lewis, M.A.; Ackerman, J.P.

    1996-01-01

    Transuranics and fission products in a molten salt can be incorporated into zeolite A by an ion exchange process and by a batch mixing or blending process. The zeolite is then mixed with glass and consolidated into a monolithic waste form for geologic disposal. Both processes require mixing of zeolite powders with molten salt at elevated temperatures (>700 K). Complete occlusion of salt and a uniform distribution of chloride and fission products are desired for incorporation of the powders into the final waste form. The relative effectiveness of the blending process was studied over a series of temperature, time, and composition profiles. The major criteria for determining the effectiveness of the mixing operations were the level and uniformity of residual free salt in the mixtures. High operating temperatures (>775 K) improved salt occlusion. Reducing the chloride levels in the mixture to below 80% of the full salt capacity of the zeolite significantly reduced the free salt level in the final product

  2. Molten-salt reactor information system

    Haubenreich, P.N.; Cardwell, D.W.; Engel, J.R.

    1975-06-01

    The Molten-Salt Reactor Information System (MSRIS) is a computer-based file of abstracts of documents dealing with the technology of molten-salt reactors. The file is stored in the IBM-360 system at ORNL, and may be searched through the use of established interactive computer programs from remote terminals connected to the computer via telephone lines. The system currently contains 373 entries and is subject to updating and expansion as additional information is developed. The nature and general content of the data file, a general approach for obtaining information from it, and the manner in which material is added to the file are described. Appendixes provide the list of keywords currently in use, the subject categories under which information is filed, and simplified procedures for searching the file from remote terminals. (U.S.)

  3. Molten salt reactors. The AMSTER concept

    Vergnes, J.; Garzenne, C.; Lecarpentier, D.; Mouney, H.

    2001-01-01

    This article presents the concept of actinide molten salt transmuter (AMSTER). This reactor is graphite-moderated and is dedicated to the burning of actinides. The main difference with a molten salt reactor is that its liquid fuel undergoes an on-line partial reprocessing in which fission products are extracted and heavy nuclei are reintroduced into the fuel. In order to maintain the reactivity regular injections of 235 U-salt are made. In classical reactors, fuel burn-up is limited by the swelling of the cladding and the radiation fuel pellets resistance, in AMSTER there is no limitation to the irradiation time of the fuel, so all the actinides can be burnt or transmuted. (A.C.)

  4. Molten salt combustion of radioactive wastes

    Grantham, L.F.; McKenzie, D.E.; Richards, W.L.; Oldenkamp, R.D.

    1976-01-01

    The Atomics International Molten Salt Combustion Process reduces the weight and volume of combustible β-γ contaminated transuranic waste by utilizing air in a molten salt medium to combust organic materials, to trap particulates, and to react chemically with any acidic gases produced during combustion. Typically, incomplete combustion products such as hydrocarbons and carbon monoxide are below detection limits (i.e., 3 ) is directly related to the sodium chloride vapor pressure of the melt; >80% of the particulate is sodium chloride. Essentially all metal oxides (combustion ash) are retained in the melt, e.g., >99.9% of the plutonium, >99.6% of the europium, and >99.9% of the ruthenium are retained in the melt. Both bench-scale radioactive and pilot scale (50 kg/hr) nonradioactive combustion tests have been completed with essentially the same results. Design of three combustors for industrial applications are underway

  5. Analysis of a molten salt reactor benchmark

    Ghosh, Biplab; Bajpai, Anil; Degweker, S.B.

    2013-01-01

    This paper discusses results of our studies of an IAEA molten salt reactor (MSR) benchmark. The benchmark, proposed by Japan, involves burnup calculations of a single lattice cell of a MSR for burning plutonium and other minor actinides. We have analyzed this cell with in-house developed burnup codes BURNTRAN and McBURN. This paper also presents a comparison of the results of our codes and those obtained by the proposers of the benchmark. (author)

  6. Molten salt battery having inorganic paper separator

    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.

  7. Electrochemical studies in molten sodium fluoroborate

    Brigaudeau, M.; Wagner, J.F.

    1979-01-01

    Physical properties of sodium fluoroborate are recalled and first results obtained during experimental study of molten NaBF 4 are exposed. The system Cu/CuF is used as an indicator of fluoride ion activity and dissociation constant of the solvent is determined by adding NaF to NaBF 4 saturated with BF 3 at a pressure of 1 atm and found equal to 2.7x10 -3 [fr

  8. Corrosion of technical ceramics by molten aluminium

    Schwabe, U.; Wolff, L.R.; Loo, van F.J.J.; Ziegler, G.

    1992-01-01

    The corrosion of 8 types of ceramics, i.e., 1 grade of hot isostatically pressed reaction-bonded Si3N4 (HIPRBSN), 3 grades of hot pressed Si3N4 (HPSN), and 4 grades of RBSN, and 2 types of SiC (HIPSiC and Si-impregnated SiC (SiSiC)) in molten Al (pure Al and AlZnMgCu1.5) was studied. The HIPRBSN and

  9. Thorium molten-salt nuclear energy synergetics

    Furukawa, Kazuo

    1989-01-01

    One of the most practical and rational approaches for establishing the idealistic Thorium resource utilization program has been presented, which might be effective to solve the principal energy problems, concerning safety, proliferation and terrorism, resource, power size and fuel cycle economy, for the next century. The first step will be the development of Small Molten-Salt Reactors as a flexible power station, which is suitable for early commercialization of Th reactors not necessarily competing with proven Large Solid-Fuel Reactors. Therefore, the more detailed design works and practical R and D planning should be performed under the international cooperations soon, soundly depending on the basic technology established by ORNL already. R and D cost would be surprisingly low. This reactor(MSR) seems to be idealistic not only in power-size, siting, safety, safeguard and economy, but also as an effective partner of Molten-Salt Fissile Breeders(MSB) in order to establish the simplest and economical Thorium molten-salt breeding fuel cycle named THORIMS-NES in all over the world including the developing countries and isolated areas. This would be one of the most practical replies to the Lilienthal's appeal of 'A NEW START' in Nuclear Energy. (author)

  10. Thermal Characterization of Molten Salt Systems

    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.

  11. Thermal interaction of molten copper with water

    Zyszkowski, W.

    1975-01-01

    Experimental work was performed to study the thermal interaction between molten copper particles (in the range of temperature from the copper melting point to about 1800 0 C) and water from about 15-80 0 C. The transient temperatures of the copper particles and water before and during their thermal interaction were measured. The history of the phenomena was filmed by means of a high speed FASTAX camera (to 8000 f/s). Classification of the observed phenomena and description of the heat-transfer modes were derived. One among the phenomena was the thermal explosion. The necessary conditions for the thermal explosion are discussed and their physical interpretation is given. According to the hypothesis proposed, the thermal explosion occurs when the molten metal has the temperature of its solidification and the heat transfer on its surface is sufficiently intensive. The 'sharp-change' of the crystalline structure during the solidification of the molten metal is the cause of the explosion fragmentation. (author)

  12. The Experiences and Challenges in Drilling into Semi molten or Molten Intrusive in Menengai Geothermal Field

    Mortensen, A. K.; Mibei, G. K.

    2017-12-01

    Drilling in Menengai has experienced various challenges related to drilling operations and the resource itself i.e. quality discharge fluids vis a vis gas content. The main reason for these challenges is related to the nature of rocks encountered at depths. Intrusives encountered within Menengai geothermal field have been group into three based on their geological characteristics i.e. S1, S2 and S3.Detailed geology and mineralogical characterization have not been done on these intrusive types. However, based on physical appearances, S1 is considered as a diorite dike, S2 is syenite while S3 is molten rock material. This paper summarizes the experiences in drilling into semi molten or molten intrusive (S3).

  13. Molten salt engineering for thorium cycle. Electrochemical studies as examples

    Ito, Yasuhiko

    1998-01-01

    A Th-U nuclear energy system utilizing accelerator driven subcritical molten salt breeder reactor has several advantages compared to conventional U-Pu nuclear system. In order to obtain fundamental data on molten salt engineering of Th-U system, electrochemical study was conducted. As the most primitive simulated study of beam irradiation of molten salt, discharge electrolysis was investigated in molten LiCl-KCl-AgCl system. Stationary discharge was generated under atmospheric argon gas and fine Ag particles were obtained. Hydride ion (H - ) behavior in molten salts was also studied to predict the behavior of tritide ion (T - ) in molten salt fuel. Finally, hydrogen behavior in metals at high temperature was investigated by electrochemical method, which is considered to be important to confine and control tritium. (author)

  14. Tritium loss in molten flibe systems

    Longhurst, G.R.; Anderl, R.A. [Idaho National Eng. and Environ. Lab., Idaho Falls, ID (United States); Scott Willms, R. [Los Alamos National Lab., NM (United States)

    2000-04-01

    An emerging issue relative to beryllium technology in fusion involves tritium interactions with molten beryllium-bearing salts. Innovative designs for fusion reactors, both magnetic and inertially confined, feature the molten salt mixture 2LiF.BeF{sub 2}, commonly called Flibe, as a tritium breeder and coolant. Tritium is bred in the Flibe as neutrons from the plasma are absorbed by Li atoms, which then transmute to tritium and helium. Transmutation of tritium from Be also occurs. Among the issues to be resolved for such coolant systems is the potential loss of tritium from the Flibe coolant to the walls of the system, particularly through heat exchanger tubes, and from there into secondary coolants or working fluids and the environment. Effectively removing tritium from Flibe in clean-up units is also important. In quiescent or low Reynolds number flow, tritium movement through Flibe is governed by diffusion. For Flibe in turbulent flow, as in heat exchanger tubes, transport is by turbulent mixing, and the same flow conditions and structural design features that maximize heat transfer to the heat exchanger walls will enhance the transport of tritium to those same surfaces. Analyses have been performed to estimate the fractional loss of tritium through heat exchanger tubes and release rates from Flibe droplets in vacuum disengagers in molten Flibe systems. The calculations suggest unacceptably large losses of tritium through heat exchanger tubes. The gravity of the implications of these estimates calls for experimental verification to determine if tritium losses through molten Flibe heat exchangers or other Flibe systems can really be so high and whether vacuum disengagers will really work. There is also a need for better information on evolution of tritium from Flibe droplets in a vacuum. Several experiments are presently being planned to address these issues and are discussed. These include experiments to induce tritium in Flibe using spontaneous fission neutrons

  15. Tritium loss in molten flibe systems

    Longhurst, G.R.; Anderl, R.A.; Scott Willms, R.

    2000-01-01

    An emerging issue relative to beryllium technology in fusion involves tritium interactions with molten beryllium-bearing salts. Innovative designs for fusion reactors, both magnetic and inertially confined, feature the molten salt mixture 2LiF.BeF 2 , commonly called Flibe, as a tritium breeder and coolant. Tritium is bred in the Flibe as neutrons from the plasma are absorbed by Li atoms, which then transmute to tritium and helium. Transmutation of tritium from Be also occurs. Among the issues to be resolved for such coolant systems is the potential loss of tritium from the Flibe coolant to the walls of the system, particularly through heat exchanger tubes, and from there into secondary coolants or working fluids and the environment. Effectively removing tritium from Flibe in clean-up units is also important. In quiescent or low Reynolds number flow, tritium movement through Flibe is governed by diffusion. For Flibe in turbulent flow, as in heat exchanger tubes, transport is by turbulent mixing, and the same flow conditions and structural design features that maximize heat transfer to the heat exchanger walls will enhance the transport of tritium to those same surfaces. Analyses have been performed to estimate the fractional loss of tritium through heat exchanger tubes and release rates from Flibe droplets in vacuum disengagers in molten Flibe systems. The calculations suggest unacceptably large losses of tritium through heat exchanger tubes. The gravity of the implications of these estimates calls for experimental verification to determine if tritium losses through molten Flibe heat exchangers or other Flibe systems can really be so high and whether vacuum disengagers will really work. There is also a need for better information on evolution of tritium from Flibe droplets in a vacuum. Several experiments are presently being planned to address these issues and are discussed. These include experiments to induce tritium in Flibe using spontaneous fission neutrons

  16. Study on electrolytic reduction with controlled oxygen flow for iron from molten oxide slag containing FeO

    Gao Y.M.

    2013-01-01

    Full Text Available A ZrO2-based solid membrane electrolytic cell with controlled oxygen flow was constructed: graphite rod /[O]Fe+C saturated / ZrO2(MgO/(FeO slag/iron crucible. The feasibility of extraction of iron from molten oxide slag containing FeO at an applied voltage was investigated by means of the electrolytic cell. The effects of some important process factors on the FeO electrolytic reduction with the controlled oxygen flow were discussed. The results show that: solid iron can be extracted from molten oxide slag containing FeO at 1450ºC and an applied potential of 4V. These factors, such as precipitation and growth of solid iron dendrites, change of the cathode active area on the inner wall of the iron crucible and ion diffusion flux in the molten slag may affect the electrochemical reaction rate. The reduction for Fe2+ ions mainly appears on new iron dendrites of the iron crucible cathode, and a very small amount of iron are also formed on the MSZ (2.18% MgO partially stabilized zirconia tube/slag interface due to electronic conductance of MSZ tube. Internal electronic current through MSZ tube may change direction at earlier and later electrolytic reduction stage. It has a role of promoting electrolytic reduction for FeO in the molten slag at the earlier stage, but will lower the current efficiency at the later stage. The final reduction ratio of FeO in the molten slag can achieve 99%. A novel electrolytic method with controlled oxygen flow for iron from the molten oxide slag containing FeO was proposed. The theory of electrolytic reduction with the controlled oxygen flow was developed.

  17. Molten metal feed system controlled with a traveling magnetic field

    Praeg, W.F.

    1991-01-01

    This patent describes a continuous metal casting system in which the feed of molten metal 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

  18. Compatibility studies of potential molten-salt breeder reactor materials in molten fluoride salts

    Keiser, J.R.

    1977-05-01

    The molten fluoride salt compatibility studies carried out during the period 1974--76 in support of the Molten-Salt Reactor Program are summarized. Thermal-convection and forced-circulation loops were used to measure the corrosion rate of selected alloys. Results confirmed the relationship of time, initial chromium concentration, and mass loss developed by previous workers. The corrosion rates of Hastelloy N and Hastelloy N modified by the addition of 1--3 wt percent Nb were well within the acceptable range for use in an MSBR. 13 figures, 3 tables

  19. Accelerator molten-salt breeding and thorium fuel cycle

    Furukawa, Kazuo; Nakahara, Yasuaki; Kato, Yoshio; Ohno, Hideo; Mitachi, Kohshi.

    1990-01-01

    The recent efforts at the development of fission energy utilization have not been successful in establishing fully rational technology. A new philosophy should be established on the basis of the following three principles: (1) thorium utilization, (2) molten-salt fuel concept, and (3) separation of fissile-breeding and power-generating functions. Such philosophy is called 'Thorium Molten-Salt Nuclear Energy Synergetics [THORIMS-NES]'. The present report first addresses the establishment of 233 U breeding fuel cycle, focusing on major features of the Breeding and Chemical Processing Centers and a small molten-salt power station (called FUJI-II). The development of fissile producing breeders is discussed in relation to accelerator molten-salt breeder (AMSB), impact fusion molten-salt breeder, and inertial-confined fusion hybrid molten-salt breeder. Features of the accelerator molten-salt breeder are described, focusing on technical problems with accelerator breeders (or spallators), design principle of the accelerator molten-salt breeder, selection of molten salt compositions, and nuclear- and reactor-chemical aspects of AMSB. Discussion is also made of further research and development efforts required in the future for AMSB. (N.K.)

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

    Park, R.J.; Lee, S.J.; Sim, S.K. [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    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. Core-concrete molten pool dynamics and interfacial heat transfer

    Benjamin, A.S.

    1980-01-01

    Theoretical models are derived for the heat transfer from molten oxide pools to an underlying concrete surface and from molten steel pools to a general concrete containment. To accomplish this, two separate effects models are first developed, one emphasizing the vigorous agitation of the molten pool by gases evolving from the concrete and the other considering the insulating effect of a slag layer produced by concrete melting. The resulting algebraic expressions, combined into a general core-concrete heat transfer representation, are shown to provide very good agreement with experiments involving molten steel pours into concrete crucibles

  2. Studies on components for a molten salt reactor

    Nejedly, M.; Matal, O.

    2003-01-01

    The aim is contribute to a design of selected components of molten salt reactors with fuel in the molten fluoride salt matrix. Molten salt reactors (MSRs) permit the utilization of plutonium and minor actinides as new nuclear fuel from a traditional nuclear power station with production of electric energy. Results of preliminary feasibility studies of an intermediate heat exchanger, a small power molten salt pump and a modular conception of a steam generator for a demonstration unit of the MSR (30 MW) are summarized. (author)

  3. Thorium-based Molten Salt Reactor (TMSR) project in China

    Dai, Zhimin; Liu, Wei

    2013-01-01

    Making great efforts in development of nuclear energy is one of the long-term-plan in China's energy strategies. The advantages of Thorium-based nuclear energy are: rich resource in nature, less nuclear waste, low toxicity, nuclear non-proliferation and so on. Furthermore, China is a country with abundant thorium, thus it is necessary to develop the Thorium-based Molten Salt Reactor (TMSR) in China. Shanghai Institute of Applied Physics, Chinese Academy of Sciences (SINAP) had designed and constructed the first China's light-water reactor and developed a zero-power thorium-based molten salt reactor successfully in the early 1970s. The applied research project 'thorium molten salt reactor nuclear power system' by SINAP together with several other institutes had been accepted and granted by China government in 2011. The whole project has been divided into three stages: Firstly, built a 2 MW-zero-power high temperature solid molten salt reactor in 2015 and a 2 MW-zero-power high temperature liquid molten salt reactor in 2017. Secondly, in 2020 built a 10 MW high temperature liquid molten salt reactor. Thirdly, on the base of previous work, a 100 MW high temperature molten salt reactor should be achieving in 2030. After more than one years of efforts, a high quality scientific research team has been formed, which is able to design the molten salt reactor, the molten salt loop and related key equipment, the systems of molten salt preparation, purification and the radioactive gas removal. In the past one year, the initial physical design of high temperature molten salt reactor has been completed; the nuclear chemistry and radiation chemical laboratory has been built, a high temperature salt (HTS) loop and radioactive gas removal experiment device system have been successfully developed and constructed. Further, the preliminary study on reactor used carbon-carbon composite material has been investigated. (author)

  4. Electrochemical studies on plutonium in molten salts

    Bourges, G.; Lambertin, D.; Rochefort, S.; Delpech, S.; Picard, G.

    2007-01-01

    Electrochemical studies on plutonium have been supporting the development of pyrochemical processes involving plutonium at CEA. The electrochemical properties of plutonium have been studied in molten salts - ternary eutectic mixture NaCl-KCl-BaCl 2 , equimolar mixture NaCl-KCl and pure CaCl 2 - and in liquid gallium at 1073 K. The formal, or apparent, standard potential of Pu(III)/Pu redox couple in eutectic mixture of NaCl-KCl-BaCl 2 at 1073 K determined by potentiometry is equal to -2.56 V (versus Cl 2 , 1 atm/Cl - reference electrode). In NaCl-KCl eutectic mixture and in pure CaCl 2 the formal standard potentials deduced from cyclic voltammetry are respectively -2.54 V and -2.51 V. These potentials led to the calculation of the activity coefficients of Pu(III) in the molten salts. Chronoamperometry on plutonium in liquid gallium using molten chlorides - CaCl 2 and equimolar NaCl/KCl - led to the determination of the activity coefficient of Pu in liquid Ga, log γ = -7.3. This new data is a key parameter to assess the thermodynamic feasibility of a process using gallium as solvent metal. By comparing gallium with other solvent metals - cadmium, bismuth, aluminum - gallium appears to be, with aluminum, more favorable for the selectivity of the separation at 1073 K of plutonium from cerium. In fact, compared with a solid tungsten electrode, none of these solvent liquid metals is a real asset for the selectivity of the separation. The role of a solvent liquid metal is mainly to trap the elements

  5. Applications of molten salts in plutonium processing

    Bowersox, D.F.; Christensen, D.C.; Williams, J.D.

    1987-01-01

    Plutonium is efficiently recovered from scrap at Los Alamos by a series of chemical reactions and separations conducted at temperatures ranging from 700 to 900 0 C. These processes usually employ a molten salt or salt eutectic as a heat sink and/or reaction medium. Salts for these operations were selected early in the development cycle. The selection criteria are being reevaluated. In this article we describe the processes now in use at Los Alamos and our studies of alternate salts and eutectics

  6. Apparatus for controlling molten core debris

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

    1972-01-01

    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. Electrorecovery of tantalum in molten fluorides

    Espinola, A.; Dutra, A.J.B.; Silva, F.T. da

    1988-01-01

    Considering the privileged situation of Brazil as a productor of tantaliferous minerals, the authors have in view the development of a technology for production of metallic tantalum via molten salts electrolysis; this has the advantage of improving the aggregate value of exportation products, additionally to tantalum oxide and tantalum concentrates. Having in view the preliminary determintion of better conditions of temperature, electrolyte composition and current density for this process, electrolysis were conducted with a solvent composed of an eutetic mixture of lithium, sodium and potassium fluoride for dipotassium fluotantalate and occasionally for tantalum oxide. Current efficiencies as high as 83% were obtained in favoured conditions. (author) [pt

  8. Safe actinide disposition in molten salt reactors

    Gat, U.

    1997-01-01

    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. Interaction of calcium oxide with molten alkali metal chlorides

    Volkovich, A.V.; Zhuravlev, V.I.; Ermakov, D.S.; Magurina, M.V.

    1999-01-01

    Calcium oxide solubility in molten lithium, sodium, potassium, cesium chlorides and their binary mixtures is determined in a temperature range of 973-1173 K by the method of isothermal saturation. Mechanisms of calcium oxide interaction with molten alkali metal chlorides are proposed

  10. Molten salt fueled reactors with a fast salt draining

    Ventre, Edmond; Blum, J.M.

    1976-01-01

    This invention relates to a molten salt nuclear reactor which comprises a new arrangement for shutting it down in complete safety. This nuclear reactor has a molten salt primary circuit comprising, in particular, the core of this reactor. It includes a leak tight vessel the capacity of which is appreciably greater than that of the molten salt volume of the circuit and placed so that the level of the molten salt, when all the molten salt of the circuit is contained in this vessel, is less than that of the base of the core. There are facilities for establishing and maintaining an inert gas pressure in the vessel above the molten salt, for releasing the compressed gas and for connecting the vessel to the primary circuit entering this vessel at a lower level than that of the molten salt and enabling molten salt to enter or leave the vessel according to the pressure of the inert gas. The particular advantage of this reactor is that it can be shut down safely since the draining of the primary circuit no longer results from a 'positive action' but from the suppression of an arrangement essential for the operation of the reactor consisting of the build-up of the said inert gas pressure in the said vessel [fr

  11. Advancing Molten Salts and Fuels at Sandia National Laboratories

    Rodriguez, Salvador B. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-09-26

    SNL has a combination of experimental facilities, nuclear engineering, nuclear security, severe nuclear accidents, and nuclear safeguards expertise that can enable significant progress towards molten salts and fuels for Molten Salt Reactors (MSRs). The following areas and opportunities are discussed in more detail in this white paper.

  12. On the ionic equilibrium between complexes in molten fluoroaluminates

    Akdeniz, Z.; Tankeshwar, K.; Tosi, M.P.

    1991-02-01

    We discuss theoretically (i) the effect of the alkali cation species on the ionic equilibrium between (AlF 6 ) 3- and (AlF 4 ) - complexes in molten alkali fluoroaluminates, and (ii) the possible presence of (AlF 5 ) 2 - complexes in molten cryolite, in relation to very recent Raman scattering experiments by Gilbert and Materne. (author). 7 refs, 2 tabs

  13. 46 CFR 151.50-55 - Sulfur (molten).

    2010-10-01

    ... BULK LIQUID HAZARDOUS MATERIAL CARGOES Special Requirements § 151.50-55 Sulfur (molten). (a.... Heat transfer media shall be steam, and alternate media will require specific approval of the... 46 Shipping 5 2010-10-01 2010-10-01 false Sulfur (molten). 151.50-55 Section 151.50-55 Shipping...

  14. Proton conducting ceramics for potentiometric hydrogen sensors for molten metals

    Borland, H.; Llivina, L.; Colominas, S.; Abellà, J., E-mail: jordi.abella@iqs.edu

    2013-10-15

    Highlights: • Synthesis and chemical characterization of proton conductor ceramics. • Qualification of ceramics for hydrogen sensors in molten lithium–lead. • Ceramics have well-defined grains with a wide distribution of sizes. • Good agreement with predictions obtained with BaZrY, BaCeZrY and SrFeCo ceramics. -- Abstract: Tritium monitoring in lithium–lead eutectic (Pb–15.7Li) is of great importance for the performance of liquid blankets in fusion reactors. Also, tritium measurements will be required in order to proof tritium self-sufficiency in liquid metal breeding systems. On-line hydrogen (isotopes) sensors must be design and tested in order to accomplish these goals. Potentiometric hydrogen sensors for molten lithium–lead eutectic have been designed at the Electrochemical Methods Lab at Institut Quimic de Sarria (IQS) at Barcelona and are under development and qualification. The probes are based on the use of solid state electrolytes and works as proton exchange membranes (PEM). In this work the following compounds: BaZr{sub 0.9}Y{sub 0.1}O{sub 3}, BaCe{sub 0.6}Zr{sub 0.3}Y{sub 0.1}O{sub 3−α}, Sr(Ce{sub 0.6}-Zr{sub 0.4}){sub 0.9}Y{sub 0.1}O{sub 3−α} and Sr{sub 3}Fe{sub 1.8}Co{sub 2}O{sub 7} have been synthesized in order to be tested as PEM H-probes. Potentiometric measurements of the synthesized ceramic elements at 500 °C have been performed at a fixed hydrogen concentration. The sensors constructed using the proton conductor elements BaZr{sub 0.9}Y{sub 0.1}O{sub 3}, BaCe{sub 0.6}Zr{sub 0.3}Y{sub 0.1}O{sub 3−δ} and Sr{sub 3}Fe{sub 1.8}Co{sub 0.2}O{sub 7−δ} exhibited stable output potential and its value was close to the theoretical value calculated with the Nernst equation (deviation around 60 mV). In contrast, the sensor constructed using the proton conductor element Sr(Ce{sub 0.6}–Zr{sub 0.4}){sub 0.9}Y{sub 0.1}O{sub 3−δ} showed a deviation higher than 100 mV between experimental an theoretical data.

  15. Membrane dynamics

    Bendix, Pól Martin

    2015-01-01

    Current topics include membrane-protein interactions with regard to membrane deformation or curvature sensing by BAR domains. Also, we study the dynamics of membrane tubes of both cells and simple model membrane tubes. Finally, we study membrane phase behavior which has important implications...... for the lateral organization of membranes as wells as for physical properties like bending, permeability and elasticity...

  16. Experimental studies of oxidic molten corium-vessel steel interaction

    Bechta, S.V.; Khabensky, V.B.; Vitol, S.A.; Krushinov, E.V.; Lopukh, D.B.; Petrov, Yu.B.; Petchenkov, A.Yu.; Kulagin, I.V.; Granovsky, V.S.; Kovtunova, S.V.; Martinov, V.V.; Gusarov, V.V.

    2001-01-01

    The experimental results of molten corium-steel specimen interaction with molten corium on the 'Rasplav-2' test facility are presented. In the experiments, cooled vessel steel specimens positioned on the molten pool bottom and uncooled ones lowered into the molten pool were tested. Interaction processes were studied for different corium compositions, melt superheating and in alternative (inert and air) overlying atmosphere. Hypotheses were put forward explaining the observed phenomena and interaction mechanisms. The studies presented in the paper were aimed at the detection of different corium-steel interaction mechanisms. Therefore certain identified phenomena are more typical of the ex-vessel localization conditions than of the in-vessel corium retention. Primarily, this can be referred to the phenomena of low-temperature molten corium-vessel steel interaction in oxidizing atmosphere

  17. Experimental studies of oxidic molten corium-vessel steel interaction

    Bechta, S.V. E-mail: niti-npc@sbor.net; Khabensky, V.B.; Vitol, S.A.; Krushinov, E.V.; Lopukh, D.B.; Petrov, Yu.B.; Petchenkov, A.Yu.; Kulagin, I.V.; Granovsky, V.S.; Kovtunova, S.V.; Martinov, V.V.; Gusarov, V.V

    2001-12-01

    The experimental results of molten corium-steel specimen interaction with molten corium on the 'Rasplav-2' test facility are presented. In the experiments, cooled vessel steel specimens positioned on the molten pool bottom and uncooled ones lowered into the molten pool were tested. Interaction processes were studied for different corium compositions, melt superheating and in alternative (inert and air) overlying atmosphere. Hypotheses were put forward explaining the observed phenomena and interaction mechanisms. The studies presented in the paper were aimed at the detection of different corium-steel interaction mechanisms. Therefore certain identified phenomena are more typical of the ex-vessel localization conditions than of the in-vessel corium retention. Primarily, this can be referred to the phenomena of low-temperature molten corium-vessel steel interaction in oxidizing atmosphere.

  18. Measurement and analyses of molten Ni-Co alloy density

    XIAO Feng; K. MUKAI; FANG Liang; FU Ya; YANG Ren-hui

    2006-01-01

    With the advent of powerful mathematical modeling techniques for material phenomena, there is renewed interest in reliable data for the density of the Ni-based superalloys. Up to now, there has been few report on the density of molten Ni-Co alloy.In order to obtain more accurate density data for molten Ni-Co alloy, the density of molten Ni-Co alloy was measured with a modified sessile drop method, and the accommodation of different atoms in molten Ni-Co alloy was analyzed. The density of alloy is found to decrease with increasing temperature and Co concentration in the alloy. The molar volume of molten Ni-Co alloy increases with increasing Co concentration. The molar volume of Ni-Co alloy determined shows a positive deviation from the linear molar volume, and the deviation of molar volume from ideal mixing increases with increasing Co concentration over the experimental concentration range.

  19. Advances in molten salt electrochemistry towards future energy systems

    Ito, Yasuhiko

    2005-01-01

    This review article describes some selected novel molten salt electrochemical processes which have been created/developed by the author and his coworkers, with emphasis on the applications towards future energy systems. After showing a perspective of the applications of molten salt electrochemistry from the viewpoints of energy and environment, several selected topics are described in detail, which include nitride fuel cycle in a nuclear field, hydrogen energy system coupled with ammonia economy, thermally regenerative fuel cell systems, novel Si production process for solar cell and novel molten salt electrochemical processes for various energy and environment related functional materials including nitrides, rare earth-transition metal alloys, fine particles obtained by plasma-induced electrolysis, and carbon film. And finally, the author stresses again, the importance and potential of molten salt electrochemistry, and encourages young students, scientists and researchers to march in a procession hand in hand towards a bright future of molten salts. (author)

  20. Molten salt extractive distillation process for zirconium-hafnium separation

    McLaughlin, D.F.; Stoltz, R.A.

    1989-01-01

    This patent describes an improvement in a process for zirconium-hafnium separation. It utilizes an extractive distillation column with a mixture of zirconium and hafnium tetrachlorides introduced into a distillation column having a top and bottom with hafnium enriched overheads taken from the top of the column and a molten salt solvent circulated through the column to provide a liquid phase, and with molten salt solvent containing zirconium chloride being taken from the bottom of the distillation column. The improvements comprising: utilizing a molten salt solvent consisting principally of lithium chloride and at least one of sodium, potassium, magnesium and calcium chlorides; stripping of the zirconium chloride taken from the bottom of the distillation column by electrochemically reducing zirconium from the molten salt solvent; and utilizing a pressurized reflux condenser on the top of the column to add the hafnium chloride enriched overheads to the molten salt solvent previously stripped of zirconium chloride

  1. Molten core material holding device in a nuclear reactor

    Nakamura, Hisashi; Tanaka, Nobuo; Takahashi, Katsuro.

    1985-01-01

    Purpose: To improve the function of cooling to hold molten core materials in a molten core material holding device. Constitution: Plenum structures are formed into a pan-like configuration, in which liners made of metal having high melting point and relatively high heat conductivity such as tantalum, tungsten, rhenium or alloys thereof are integrally appended to hold and directly cool the molten reactor core materials. Further, a plurality of heat pipes, passing through the plenum structures, facing the cooling portion thereof to the coolants at the outer side and immersing the heating portion into the molten core materials fallen to deposit in the inner liners are disposed radially. Furthermore, heat pipes embodded in the plenum structure are disposed in the same manner below the liners. Thus, the plenum structures and the molten reactor core materials can be cooled at a high efficiency. (Seki, T.)

  2. Fuel processing for molten-salt reactors

    Hightower, J.R. Jr.

    1976-01-01

    Research devoted to development of processes for the isolation of protactinium and for the removal of fission products from molten-salt breeder reactors is reported. During this report period, engineering development progressed on continuous fluorinators for uranium removal, the metal transfer process for rare-earth removal, the fuel reconstitution step, and molten salt--bismuth contactors to be used in reductive extraction processes. The metal transfer experiment MTE-3B was started. In this experiment all parts of the metal transfer process for rare-earth removal are demonstrated using salt flow rates which are about 1 percent of those required to process the fuel salt in a 1000-MW(e) MSBR. During this report period the salt and bismuth phases were transferred to the experimental vessels, and two runs with agitator speeds of 5 rps were made to measure the rate of transfer of neodymium from the fluoride salt to the Bi--Li stripper solution. The uranium removed from the fuel salt by fluorination must be returned to the processed salt in the fuel reconstitution step before the fuel salt is returned to the reactor. An engineering experiment to demonstrate the fuel reconstitution step is being installed. In this experiment gold-lined equipment will be used to avoid introducing products of corrosion by UF 6 and UF 5 . Alternative methods for providing the gold lining include electroplating and mechanical fabrication

  3. Organic waste processing using molten salt oxidation

    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.

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

    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.

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

    Pauzi, Anas Muhamad, E-mail: Anas@uniten.edu.my [Centre of Nuclear Energy, Universiti Tenaga Nasional (UNITEN), Jalan IKRAM-UNITEN, 43000 Kajang, Selangor (Malaysia); Cioncolini, Andrea; Iacovides, Hector [School of Mechanical, Aerospace, and Civil Engineering (MACE), University of Manchester, Oxford Road, M13 9PL Manchester (United Kingdom)

    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.

  6. Fast Thorium Molten Salt Reactors Started with Plutonium

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

    2006-01-01

    One of the pending questions concerning Molten Salt Reactors based on the 232 Th/ 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 233 U does not exist on earth and is not yet produced in the current operating reactors. A solution may consist in producing 233 U in special devices containing Thorium, in Pressurized Water or Fast Neutrons Reactors. Two alternatives to produce 233 U are examined here: directly in standard Molten Salt Reactors started with Plutonium as fissile matter and then operated in the Th/ 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 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 233 U only. Using a combination of Molten Salt Reactors started or operated with Plutonium and of Molten Salt Reactors started with 233 U, the deployment capabilities of these reactors fully satisfy the condition of sustainability. (authors)

  7. Corrosion study in molten fluoride salt

    Keny, S.J.; Kumbhar, A.G.; Rangarajan, S.; Gupta, V.K.; Maheshwari, N.K.; Vijayan, P.K.

    2013-01-01

    Corrosion behaviors of two alloys viz. Inconel 625 and Inconel 617 were tested in molten fluoride salts of lithium, sodium and potassium (FLiNaK) in the temperature range of 550-750 ℃ in a nickel lined Inconel vessel. Electrochemical polarization (Tafel plot) technique was used for this purpose. For both alloys, the corrosion rate was found to increase sharply beyond 650 ℃ . At 600 ℃ , Inconel 625 showed a decreasing trend in the corrosion rate over a period of 24 hours, probably due to changes in the surface conditions. After fifteen days, re-testing of Inconel 625 in the same melt showed an increase in the corrosion rate. Inconel 625 was found to be more corrosion resistant than Inconel 617. (author)

  8. The Integral Molten Salt Reactor (IMSR)

    Leblanc, D. [Terrestrial Energy, Mississauga, Ontario (Canada)

    2014-12-15

    The Integral Molten Salt Reactor is a simple burner or converter design that seeks to maximize passive and inherent safety features in order to minimize development time and achieve true cost innovation. Its integration of all primary systems into a unit sealed for the design life of the reactor will be reviewed with focus on the unique design aspects that make this a pragmatic approach. The IMSR is being developed by Terrestrial Energy in a range of power outputs with initial focus on an 80 MWth (32.5 MWe) unit primarily for remote energy needs. Similar units of modestly larger dimension and up to 600 MWth (291 MWe) are planned that remain truck transportable and able to compete in base load electricity markets worldwide. (author)

  9. The Integral Molten Salt Reactor (IMSR)

    LeBlanc, D., E-mail: dleblanc@terrestrialenergy.com [Terrestrial Energy, Mississauga, Ontario (Canada)

    2014-07-01

    The Integral Molten Salt Reactor is a simple burner or converter design that seeks to maximize passive and inherent safety features in order to minimize development time and achieve true cost innovation. Its integration of all primary systems into a unit sealed for the design life of the reactor will be reviewed with focus on the unique design aspects that make this a pragmatic approach. The IMSR is being developed by Terrestrial Energy in a range of power outputs with initial focus on an 80 MWth (32.5 MWe) unit primarily for remote energy needs. Similar units of modestly larger dimension and up to 600 MWth (291 MWe) are planned that remain truck transportable and able to compete in base load electricity markets worldwide. (author)

  10. Structure of partly quenched molten copper chloride

    Pastore, G.; Tosi, M.P.

    1995-09-01

    The structural modifications induced in a model of molten CuCl by quenching the chlorine component into a microporous disordered matrix are evaluated using the hypernetted-chain closure in Ornstein-Zernike relations for the pair distribution functions in random systems. Aside from obvious changes in the behaviour of long-wavelength density fluctuations, the main effect of partial quenching is an enhanced delocalization of the Cu + ions. The model suggests that the ionic mobility in a superionic glass is enhanced relative to the melt at the same temperature and density. Only very minor quantitative differences are found in the structural functions when the replica Ornstein-Zernike relations derived by Given and Stell for a partly quenched system are simplified to those given earlier by Madden and Glandt. (author). 19 refs, 6 figs

  11. Terrestrial Energy bets on molten salt reactors

    Anon.

    2015-01-01

    Terrestrial Energy is a Canadian enterprise, founded in 2013, for marketing the integral molten salt reactor (IMSR). A first prototype (called MSRE and with an energy output of 8 MW) was designed and operated between 1965 and 1969 by the Oak Ridge National Laboratory. IMSR is a small, modular reactor with a thermal energy output of 400 MW. According to Terrestrial Energy the technology of conventional power reactors is too complicated and too expensive. On the contrary IMSR's technology appears to be simple, easy to operate and affordable. With a staff of 30 people Terrestrial Energy appears to be a start-up in the nuclear sector. A process of pre-licensing will be launched in 2016 with the Canadian nuclear safety authority. (A.C.)

  12. Fuel processing for molten-salt reactors

    Hightower, J.R. Jr.

    1975-01-01

    Progress is reported on the development of processes for the isolation of protactinium and for the removal of fission products from molten-salt breeder reactors. The metal transfer experiment MTE-3 (for removing rare earths from MSRE fuel salt) was completed and the equipment used in that experiment was examined. The examination showed that no serious corrosion had occurred on the internal surfaces of the vessels, but that serious air oxidation occurred on the external surfaces of the vessels. Analyses of the bismuth phases indicated that the surfaces in contact with the salts were enriched in thorium and iron. Mass transfer coefficients in the mechanically agitated nondispersing contactors were measured in the Salt/Bismuth Flow-through Facility. The measured mass transfer coefficients are about 30 to 40 percent of those predicted by the preferred literature correlation, but were not as low as those seen in some of the runs in MTE-3. Additional studies using water--mercury systems to simulate molten salt-bismuth systems indicated that the model used to interpret results from previous measurements in the water--mercury system has significant deficiencies. Autoresistance heating studies were continued to develop a means of internal heat generation for frozen-wall fluorinators. Equipment was built to test a design of a side arm for the heating electrode. Results of experiments with this equipment indicate that for proper operation the wall temperature must be held much lower than that for which the equipment was designed. Studies with an electrical analog of the equipment indicate that no regions of abnormally high current density exist in the side arm. (JGB)

  13. Fast Spectrum Molten Salt Reactor Options

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

    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.

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

    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, a...

  15. Mechanical structure and problem of thorium molten salt reactor

    Kamei, Takashi

    2011-01-01

    After Fukushima Daiichi accident, there became great interest in Thorium Molten Salt Reactor (MSR) for the safety as station blackout leading to auto drainage of molten salts with freeze valve. This article described mechanical structure of MSR and problems of materials and pipes. Material corrosion problem by molten salts would be solved using modified Hastelloy N with Ti and Nb added, which should be confirmed by operation of an experimental reactor. Trends in international activities of MSR were also referred including China declaring MSR development in January 2011 to solve thorium contamination issues at rare earth production and India rich in thorium resources. (T. Tanaka)

  16. Indian programme on molten salt cooled nuclear reactors

    DuIera, I.V.; Vijayan, P.K.; Sinha, R.K.

    2013-01-01

    Bhabha Atomic Research Centre (BARC) is developing a 600 MWth pebble bed high temperature reactor, cooled by natural circulation of molten fluoride salts and is capable of supplying process heat at 1000 ℃ to facilitate hydrogen production by splitting water. BARC has also initiated studies for a reactor concept in which salts of molten fluoride fuel and coolant in fluid form, flows through the reactor core of graphite moderator, resulting in nuclear fission within the molten salt. For thorium fuel cycle, this concept is very attractive, since the fuel can be re-processed on-line, enabling it to be an efficient neutron breeder. (author)

  17. Fission product removal from molten salt using zeolite

    Pereira, C.; Babcock, B.D.

    1996-01-01

    Spent nuclear fuel (SNF) can be treated in a molten salt electrorefiner for conversion into metal and mineral waste forms for geologic disposal. The fuel is dissolved in molten chloride salt. Non-transuranic fission products in the molten salt are ion-exchanged into zeolite A, which is subsequently mixed with glass and consolidated. Zeolite was found to be effective in removing fission product cations from the molten salt. Breakthrough of cesium and the alkaline earths occurred more rapidly than was observed for the rare earths. The effluent composition as a function of time is presented, as well as results for the distribution of fission products along the length of the column. Effects of temperature and salt flow rate are also discussed

  18. Boric Ester-Type Molten Salt via Dehydrocoupling Reaction

    Noriyoshi Matsumi

    2014-11-01

    Full Text Available 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. Dynamics and control of molten-salt breeder reactor

    Vikram Singh

    2017-08-01

    Full Text Available Preliminary results of the dynamic analysis of a two-fluid molten-salt breeder reactor (MSBR system are presented. Based on an earlier work on the preliminary dynamic model of the concept, the model presented here is nonlinear and has been revised to accurately reflect the design exemplified in ORNL-4528. A brief overview of the model followed by results from simulations performed to validate the model is presented. Simulations illustrate stable behavior of the reactor dynamics and temperature feedback effects to reactivity excursions. Stable and smooth changes at various nodal temperatures are also observed. Control strategies for molten-salt reactor operation are discussed, followed by an illustration of the open-loop load-following capability of the molten-salt breeder reactor system. It is observed that the molten-salt breeder reactor system exhibits “self-regulating” behavior, minimizing the need for external controller action for load-following maneuvers.

  20. Conceptual design of Indian molten salt breeder reactor

    Vijayan, P.K.; Basak, A.; Dulera, I.V.; Vaze, K.K.; Basu, S.; Sinha, R.K.

    2014-01-01

    The fuel in a molten salt breeder reactor is in the form of a continuously circulating molten salt. Fluoride based salts have been almost universally proposed. A crucial part for achieving reasonable breeding in such reactors is the need to reprocess the salt continuously, either online or in batch mode. This constitutes a major technological challenge for this type of reactors. India has recently started carrying out fundamental studies so as to arrive at a conceptual design of Indian Molten Salt Breeder Reactor (IMSBR). Presently various design options and possibilities are being studied from the point of view of reactor physics and thermal hydraulic design. In parallel fundamental studies as regards various molten salts have also been initiated. This paper would discuss conceptual design of these reactors, as well as associated issues and technologies

  1. Dynamics and control of molten-salt breeder reactor

    Sing, Vikram; Lish, Matthew R.; Chvala, Ondrej; Upadhyaya, Belle R. [Dept. of Nuclear Engineering, University of Tennessee, Knoxville (United States)

    2017-08-15

    Preliminary results of the dynamic analysis of a two-fluid molten-salt breeder reactor (MSBR) system are presented. Based on an earlier work on the preliminary dynamic model of the concept, the model presented here is nonlinear and has been revised to accurately reflect the design exemplified in ORNL-4528. A brief overview of the model followed by results from simulations performed to validate the model is presented. Simulations illustrate stable behavior of the reactor dynamics and temperature feedback effects to reactivity excursions. Stable and smooth changes at various nodal temperatures are also observed. Control strategies for molten-salt reactor operation are discussed, followed by an illustration of the open-loop load-following capability of the molten-salt breeder reactor system. It is observed that the molten-salt breeder reactor system exhibits “self-regulating” behavior, minimizing the need for external controller action for load-following maneuvers.

  2. Advanced Additive Manufacturing Feedstock from Molten Regolith Electrolysis

    National Aeronautics and Space Administration — Demonstrate the feasibility of Molten Regolith Electrolysis (MRE) Reactor start by initiating resistive-heating of the regolith past its melting point using...

  3. High Surface Iridium Anodes for Molten Oxide Electrolysis, Phase I

    National Aeronautics and Space Administration — Processing of lunar regolith into oxygen for habitat and propulsion is needed to support future space missions. Direct electrochemical reduction of molten regolith...

  4. System Requirements Document for the Molten Salt Reactor Experiment

    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.

  5. Density and Structure Analysis of Molten Ni-W Alloys

    Feng XIAO; Liang FANG

    2004-01-01

    Density of molten Ni and Ni-W alloys was measured in the temperature range of 1773~1873 K with a sessile drop method.The density of molten Ni and Ni-W alloys trends to decrease with increasing temperature. The density and molar volume of the alloys trend to increase with increasing W concentration in the alloys. The calculation result shows an ideal mixing of Ni-W alloys.

  6. Molten fluoride mixtures as possible fission reactor fuels

    Grimes, W.R.

    1978-01-01

    Molten mixtures of fluorides with UF 4 as a component have been used as combined fuel and primary heat transfer agent in experimental high-temperature reactors and have been proposed for use in breeders or converters of 233 U from thorium. Such use places stringent and diverse demands upon the fluid fuel. A brief review of chemical behavior of molten fluorides is given to show some of their strengths and weaknesses for such service

  7. Internal cation mobilities in molten lithium. Potassium fluoride

    Matsuura, Haruaki; Ohashi, Ryo; Chou, Pao-Hwa; Takagi, Ryuzo

    2006-01-01

    Relative differences between internal cation mobilities in molten (Li, K) F have been measured by countercurrent electromigration (Klemm method) at 1023 K. Internal mobilities of K + are larger than those of Li + in all composition on which we have measured so far. More striking feature is that the isotherms have minimum of mobilities at ca. x K =0.5. The local structural parameters would be highly related to the ionic conduction behavior in molten fluorides. (author)

  8. Measurement of emittance of metal interface in molten salt

    Araki, N.; Makino, A.; Nakamura, Y.

    1995-01-01

    A new technique for measuring the total normal emittance of a metal in a semi-transparent liquid has been proposed and this technique has been applied to measure the emittance of stainless steel (SUS304), nickel, and gold in molten potassium nitrate KNO 3 . These emittance data are indispensable to analyzing the radiative heat transfer between a metal and a semitransparent liquid, such as a molten salt

  9. Hydrogen permeation through Flinabe fluoride molten salts for blanket candidates

    Nishiumi, Ryosuke, E-mail: r.nishiumi@aees.kyushu-u.ac.jp; Fukada, Satoshi; Nakamura, Akira; Katayama, Kazunari

    2016-11-01

    Highlights: • H{sub 2} diffusivity, solubility and permeability in Flinabe as T breeder are determined. • Effects in composition differences among Flibe, Fnabe and Flinabe are compared. • Changes of pressure dependence of Flinabe permeation rate are clarified. - Abstract: Fluoride molten salt Flibe (2LiF + BeF{sub 2}) is a promising candidate for the liquid blanket of a nuclear fusion reactor, because of its large advantages of tritium breeding ratio and heat-transfer fluid. Since its melting point is higher than other liquid candidates, another new fluoride molten salt Flinabe (LiF + NaF + BeF{sub 2}) is recently focused on because of its lower melting point while holding proper breeding properties. In this experiment, hydrogen permeation behavior through the three molten salts of Flibe (2LiF + BeF{sub 2}), Fnabe (NaF + BeF{sub 2}) and Flinabe are investigated in order to clarify the effects of their compositions on hydrogen transfer properties. After making up any of the three molten salts and purifying it using HF, hydrogen permeability, diffusivity and solubility of the molten salts are determined experimentally by using a system composed of tertiary cylindrical tubes. Close agreement is obtained between experimental data and analytical solutions. H{sub 2} permeability, diffusivity and solubility are correlated as a function of temperature and are compared among the three molten salts.

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

    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.

  11. Thermohydraulic behaviour and heat transfer in the molten core

    Reineke, H.H.

    1977-01-01

    Increasing the application of nuclear reactors to produce electrical power extremely unprobable accidents should be investigated too. In the Federal Republic of Germany, a research program is performed for some years engaged in accidents at light water reactors in which the melting of the reactor core is presumed. A part of this program is to investigate the thermohydraulic and the heat transfer behavior in an accumulation of molten core material. The knowledge of these events is necessary to analyse the accident exactly. Further on the results of this work are of great importance to build a catcher for the molten core material. As a result of the decay heat the molten material is heated up and the density differences induce a free convection motion. In this work the thermohydraulic behavior and the distribution of the escaping heat fluxes for several accumulations of molten core material were determined. The numerical methods for solving the system of partial differential equation were used to develop computer codes, able to compute the average and local heat fluxes at the walls enclosing the molten core material and the inside increase of the temperature. The numerical computations were confirmed and verified by experimental investigations. In these investigations the molten core material was always assumed as a homogeneous fluid. In this case, the results could be reproduced by simple power laws

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

    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

  13. Study on mechanical interaction between molten alloy and water

    Nishimura, Satoshi; Ueda, Nobuyuki; Nishi, Yoshihisa; Furuya, Masahiro; Kinoshita, Izumi

    1999-01-01

    Simulant experiments using low melting point molten alloy and water have been conducted to observe both fragmentation behavior of molten jet and boiling phenomena of water, and to measure both particle size and shape of fragmented solidified jet, focusing on post-pin-failure molten fuel-coolant interaction (FCl) which was important to evaluate the sequence of the initiating phase for metallic fueled FBR. In addition, characteristics of coolant boiling phenomena on FCIs have been investigated, focusing on the boiling heat transfer in the direct contact heat transfer mode. As a results, it is concluded that the fragmentation of poured molten alloy jet is affected by a degree of boiling of water and is classified into three modes by thermal conditions of both the instantaneous contact interface temperature of two liquids and subcooling of water. In the case of forced convection boiling in direct contact mode, it is found that the heat transfer performance is enhanced by increase of the heat transfer area, due to oscillation of the surface and fragmentation of molten alloy. As a results of preliminary investigation of FCI behavior for metallic fuel core based on these results, it is expected that the ejected molten fuel is fragmented into almost spherical particles due to the developed boiling of sodium. (author)

  14. Membrane fusion

    Bendix, Pól Martin

    2015-01-01

    At Stanford University, Boxer lab, I worked on membrane fusion of small unilamellar lipid vesicles to flat membranes tethered to glass surfaces. This geometry closely resembles biological systems in which liposomes fuse to plasma membranes. The fusion mechanism was studied using DNA zippering...... between complementary strands linked to the two apposing membranes closely mimicking the zippering mechanism of SNARE fusion complexes....

  15. Molten Salt Breeder Reactor Analysis Methods

    Park, Jinsu; Jeong, Yongjin; Lee, Deokjung [Ulsan National Institute of Science and Technology, Ulsan (Korea, Republic of)

    2015-05-15

    Utilizing the uranium-thorium fuel cycle shows considerable potential for the possibility of MSR. The concept of MSBR should be revised because of molten salt reactor's advantage such as outstanding neutron economy, possibility of continuous online reprocessing and refueling, a high level of inherent safety, and economic benefit by keeping off the fuel fabrication process. For the development of MSR research, this paper provides the MSBR single-cell, two-cell and whole core model for computer code input, and several calculation results including depletion calculation of each models. The calculations are carried out by using MCNP6, a Monte Carlo computer code, which has CINDER90 for depletion calculation using ENDF-VII nuclear data. From the calculation results of various reactor design parameters, the temperature coefficients are all negative at the initial state and MTC becomes positive at the equilibrium state. From the results of core rod worth, the graphite control rod alone cannot makes the core subcritical at initial state. But the equilibrium state, the core can be made subcritical state only by graphite control rods. Through the comparison of the results of each models, the two-cell method can represent the MSBR core model more accurately with a little more computational resources than the single-cell method. Many of the thermal spectrum MSR have adopted a multi-region single-fluid strategy.

  16. Materials testing for molten carbonate fuel cells

    Di Mario, F.; Frangini, S.

    1995-01-01

    Unlike conventional generation systems fuel cells use an electrochemical reaction between a fossil fuel and an oxidant to produce electricity through a flame less combustion process. As a result, fuel cells offer interesting technical and operating advantages in terms of conversion efficiencies and environmental benefits due to very low pollutant emissions. Among the different kinds of fuel cells the molten carbonate fuel cells are currently being developed for building compact power generation plants to serve mainly in congested urban areas in virtue of their higher efficiency capabilities at either partial and full loads, good response to power peak loads, fuel flexibility, modularity and, potentially, cost-effectiveness. Starting from an analysis of the most important degradative aspects of the corrosion of the separator plate, the main purpose of this communication is to present the state of the technology in the field of corrosion control of the separator plate in order to extend the useful lifetime of the construction materials to the project goal of 40,000 hours

  17. Fragmentation of molten core material by sodium

    Chu, T.Y.

    1982-01-01

    A series of scoping experiments was performed to study the fragmentation of prototypic high temperature melts in sodium. The quantity of melt involved was at least one order of magnitude larger than previous experiments. Two modes of contact were used: melt streaming into sodium and sodium into melt. The average bulk fragment size distribution was found to be in the range of previous data and the average size distribution was found to be insensitive to mode of contact. SEM studies showed that the metal component typically fragmented in the molten phase while the oxide component fragmented in the solid phase. For UO 2 -ZrO 2 /stainless steel melts no sigificant spatial separation of the metal and oxide was observed. The fragment size distribution was stratified vertically in the debris bed in all cases. While the bulk fragment size showed generally consistent trends, the individual experiments were sufficiently different to cause different degrees of stratification in the debris bed. For the highly stratified beds the permeability can decrease by as much as a factor of 20 from the bottom to the top of the bed

  18. Molten aluminum alloy fuel fragmentation experiments

    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 (∼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 (∼ mm), and the 20 mm jet which underwent sinuous wave breakup produced ∼100 mm fragments. The fragments froze to form solid particles in 313 K water, and when the water was ≥343 K, the melt fragments did not freeze during their transit through 1.2 m of water

  19. Molten salt destruction process for mixed wastes

    Upadhye, R.S.; Wilder, J.G.; Karlsen, C.E.

    1993-04-01

    We are developing an advanced two-stage process for the treatment of mixed wastes, which contain both hazardous and radioactive components. The wastes, together with an oxidant gas, such as air, are injected into a bed of molten salt comprising a mixture of sodium-, potassium-, and lithium-carbonates, with a melting point of about 580 degree C. The organic constituents of the mixed waste are destroyed through the combined effect of pyrolysis and oxidation. Heteroatoms. such as chlorine, in the mixed waste form stable salts, such as sodium chloride, and are retained in the melt. The radioactive actinides in the mixed waste are also retained in the melt because of the combined action of wetting and partial dissolution. The original process, consists of a one-stage unit, operated at 900--1000 degree C. The advanced two-stage process has two stages, one for pyrolysis and one for oxidation. The pyrolysis stage is designed to operate at 700 degree C. The oxidation stage can be operated at a higher temperature, if necessary

  20. Molten salt reactor related research in Switzerland

    Krepel, Jiri; Hombourger, Boris; Fiorina, Carlo

    2015-01-01

    Switzerland represented by the Paul Scherrer Institute (PSI) is a member of the Generation IV International Forum (GIF). In the past, the research at PSI focused mainly on HTR, SFR, and GFR. Currently, a research program was established also for Molten Salt Reactors (MSR). Safety is the key point and main interest of the MSR research at the Nuclear Energy and Safety (NES) department of PSI. However, it cannot be evaluated without knowing the system design, fuel chemistry, salt thermal-hydraulics features, safety and fuel cycle approach, and the relevant material and chemical limits. Accordingly, sufficient knowledge should be acquired in the other individual fields before the safety can be evaluated. The MSR research at NES may be divided into four working packages (WP): WP1: MSR core design and fuel cycle, WP2: MSR fuel behavior at nominal and accidental conditions, WP3: MSR thermal-hydraulics and decay heat removal system, WP4: MSR safety, fuel stream, and relevant limits. The WPs are proposed so that there are research topics which can be independently studied within each of them. The work plan of the four WPs is based on several ongoing or past national and international projects relevant to MSR, where NES/PSI participates. At the current stage, the program focuses on several specific and design independent studies. The safety is the key point and main long-term interest of the MSR research at NES. (author)

  1. Molten fuel behaviour during slow overpower transients

    Guerin, Y.; Boidron, M.

    1985-01-01

    In large commercial reactors as Super-Phenix, if we take into account all the uncertainties on the pins and on the core, it is no longer possible to guarantee the absence of fuel melting during incidental events such as slow overpower transients. We have then to explain what happens in the pins when fuel melting occurs and to demonstrate that a limited amount of molten fuel generates no risk of clad failure. For that purpose, we may use the results of a great number of experiments (about 40) that have been performed at C.E.A., most of them in thermal reactor, but some experiments have also been performed in Rapsodie, especially during the last run of this reactor. In a great part of these experiments, fuel melting occurred at beginning of life, but we have also some results at different burnups up to 5 at %. It is not the aim of this paper to describe all these experiments and the results of their post irradiation examination, but to summarize the main conclusions that have been set out of them and that have enabled us to determine the main characteristics of fuel element behaviour when fuel melting occurs

  2. Facilitated transport ceramic membranes for high-temperature gas cleanup. Final report, February 1990--April 1994

    Quinn, R.; Minford, E.; Damle, A.S.; Gangwal, S.K.; Hart, B.A.

    1994-04-01

    The objective of this program was to demonstrate the feasibility of developing high temperature, high pressure, facilitated transport ceramic membranes to control gaseous contaminants in Integrated Gasification Combined Cycle (IGCC) power generation systems. Meeting this objective requires that the contaminant gas H{sub 2}S be removed from an IGCC gas mixture without a substantial loss of the other gaseous components, specifically H{sub 2} and CH{sub 4}. As described above this requires consideration of other, nonconventional types of membranes. The solution evaluated in this program involved the use of facilitated transport membranes consisting of molten mixtures of alkali and alkaline earth carbonate salts immobilized in a microporous ceramic support. To accomplish this objective, Air Products and Chemicals, Inc., Golden Technologies Company Inc., and Research Triangle Institute worked together to develop and test high temperature facilitated membranes for the removal of H{sub 2}S from IGCC gas mixtures. Three basic experimental activities were pursued: (1) evaluation of the H{sub 2}S chemistry of a variety of alkali and alkaline earth carbonate salt mixtures; (2) development of microporous ceramic materials which were chemically and physically compatible with molten carbonate salt mixtures under IGCC conditions and which could function as a host to support a molten carbonate mixture and; (3) fabrication of molten carbonate/ceramic immobilized liquid membranes and evaluation of these membranes under conditions approximating those found in the intended application. Results of these activities are presented.

  3. On some regularities of metal oxide solubility in molten CsI at T = 973 K

    Cherginets, V.L., E-mail: v_cherginets@ukr.net [Institute for Scintillation Materials, National Academy of Sciences of Ukraine, Lenin Avenue, 60, Kharkov 61001 (Ukraine); National Technical University ' Kharkiv Polytechnical Institute' , 21 Frunze St., 61002 Kharkov (Ukraine); Rebrova, T.P.; Datsko, Yu.N.; Shtitelman, V.A. [Institute for Scintillation Materials, National Academy of Sciences of Ukraine, Lenin Avenue, 60, Kharkov 61001 (Ukraine); Bryleva, E.Yu. [State Scientific Organization STC ' Institute for Single Crystals' , National Academy of Sciences of Ukraine, Lenin Avenue, 60, Kharkov 61001 (Ukraine)

    2011-08-15

    Highlights: > CdO, ZnO, NiO, and EuO are insoluble in CsI melt at 973 K. > The oxide solubilities are lower than those in chloride melts. > The oxide solubilities reduce with the cation radius. > ZnO, NiO, and EuO are suitable for scavenging CsO from oxide ion traces. - Abstract: Solubility products of CdO (pK{sub s,CdO} = 6.80 {+-} 0.2), ZnO (pK{sub s,ZnO} = 10.0 {+-} 0.5), NiO (pK{sub s,NiO} = 11.2 {+-} 0.2) and EuO (pK{sub s,EuO} = 13.1 {+-} 0.2) in molten CsI at T = 973 K are determined by potentiometric titration of (0.02 to 0.03) mol . kg{sup -1} solutions of the corresponding metal chlorides by strong base (KOH) using a membrane oxygen electrode Pt(O{sub 2})|ZrO{sub 2}(Y{sub 2}O{sub 3}) as an indicator. On the basis of pK{sub s,MeO} values, all the oxides studied are referred to practically insoluble in molten CsI. The values of the oxide solubility in CsI melt are lower than the corresponding values in molten alkali metal chlorides. This can be explained by 'softer' basic properties of I{sup -} as compared with Cl{sup -} in the frames of the Pearson 'hard' and 'soft' acid-base concept. In the oxide samples studied, the values of the solubility fall with the decreasing cation radius. The correlation between pK{sub s,MeO} and the polarizing action by Goldshmidt (Zr{sub Me{sup 2+}}{sup -2}) of the cation is practically linear and may be proposed for estimation of the solubility of s- and d- element oxides in molten CsI on the basis of their cation radii.

  4. Experimental studies on natural circulation in molten salt loops

    Srivastava, A.K.; Borgohain, A.; Maheshwari, N.K.; Vijayan, P.K.

    2015-01-01

    Molten salts are increasingly getting attention as a coolant and storage medium in solar thermal power plants and as a liquid fuel, blanket and coolant in Molten Salt Reactors (MSR’s). Two different test facilities named Molten Salt Natural Circulation Loop (MSNCL) and Molten Active Fluoride salt Loop (MAFL) have been setup for thermal hydraulics, instrument development and material related studies relevant to MSR and solar power plants. The working medium for MSNCL is a molten nitrate salt which is a mixture of NaNO 3 and KNO 3 in 60:40 ratio and proposed as one of the coolant option for molten salt based reactor and coolant as well as storage medium for solar thermal power application. On the other hand, the working medium for MAFL is a eutectic mixture of LiF and ThF 4 and proposed as a blanket salt for Indian Molten Salt Breeder Reactor (MSBR). Steady state natural circulation experiments at different power level have been performed in the MSNCL. Transient studies for startup of natural circulation, loss of heat sink, heater trip and step change in heater power have also been carried out in the same. A 1D code LeBENC, developed in-house to simulate the natural circulation characteristics in closed loops, has been validated with the experimental data obtained from MSNCL. Further, LeBENC has been used for Pretest analysis of MAFL. This paper deals with the description of both the loops and experimental studies carried out in MSNCL. Validation of LeBENC along with the pretest analysis of MAFL using the same are also reported in this paper. (author)

  5. Study of Reaction of Curium Oxy-Compound Formation in Molten Chlorides

    Osipenko, A.G.; Mayorshin, A.A.; Bychkov, A.V. [Dimitrovgrad-10, Ulyanovsk region, 433510 (Russian Federation)

    2008-07-01

    The method of potentiometric titration using oxygen sensors with solid electrolyte membrane was applied for the study of the interaction of curium cations with oxygen anions in the molten alkali metal chlorides in the temperature range of 450-850 C degrees depending on oxy-acidity of the environment. Assumptions were made concerning ion and phase composition of the obtained high-temperature compounds and chemical reactions taking place in the melts. This scheme assumes that as the basicity of the melt increases, initially the formation of soluble curium oxychlorides takes place in the melt (presumably CmO{sup -}) that is followed by formation of solid CmOCl and finally sesquioxide Cm{sub 2}O{sub 3}. Basic thermodynamic values were calculated for the resultant curium oxy-compounds.

  6. LIFE Materails: Molten-Salt Fuels Volume 8

    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.

  7. LIFE Materails: Molten-Salt Fuels Volume 8

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

    2008-01-01

    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.

  8. Fundamental experiment on simulated molten core/concrete interaction

    Toda, S.; Katsumura, Y.

    1994-01-01

    If a complete and prolonged failure of coolant flow were to occur in a LWR or FBR, fission product decay heat would cause the fuel to overheat. If no available action to cool the fuel were taken, it would eventually melt. Ibis could lead to slumping of the molten core material and to the failure of the reactor pressure vessel and deposition of these materials into the concrete reactor cavity. Consequently, the molten core could melt and decompose the concrete. Vigorous agitation of the molten core pool by concrete decomposition gases is expected to enhance the convective heat transfer process. Besides the decomposition gases, melting concrete (slag) generated under the molten core pool will be buoyed up, and will also affect the downward heat transfer. Though, in this way, the heat transfer process across the interface is complicated by the slag and the gases evolved from the decomposed concrete, it is very important to make its process clear for the safety evaluation of nuclear reactors. Therefore, in this study, fundamental experiments were performed using simulated materials to observe the behaviors of the hot pool, slag and gases at the interface. Moreover, from the experimental observation, a correlation without empirical constants was proposed to calculate the interface heat transfer. The heat transfer across the interface would depend on thermo-physical interactions between the pool, slag and concrete which are changed by their thermal properties and interface temperature and so on. For example, the molten concrete is miscible in molten oxidic core debris, but is immiscible in metallic core debris. If a contact temperature between the molten core pool and the concrete falls below the solidus of the pool, solidification of the pool will occur. In this study, the case of immiscible slag in the pool is treated and solidification of the pool does not occur. Thus, water, paraffin and air were selected as the simulated molten core pool, concrete, and decomposition

  9. Simulation of Molten Salt Reactor dynamics

    Krepel, J.; Rohde, U.; Grundmann, U.

    2005-01-01

    Dynamics of the Molten Salt Reactor - one of the 'Generation IV' concepts - was studied in this paper. The graphite-moderated channel type MSR was selected for the numerical simulation of the reactor with liquid fuel. The MSR dynamics is very specific because of two physical peculiarities of the liquid fueled reactor: the delayed neutrons precursors are drifted by the fuel flow and the fission energy is immediately released directly into the coolant. Presently, there are not many accessible numerical codes appropriate for the MSR simulation, therefore the DYN3D-MSR code was developed based on the FZR in-house code DYN3D. It allows calculating of full 3D transient neutronics in combination with parallel channel type thermal-hydraulics. By means of DYN3D-MSR, several transients typical for the liquid fuel system were analyzed. Those transients were initiated by reactivity insertion, by overcooling of fuel at the core inlet, by the fuel pump start-up or coast-down, or by the blockage of selected fuel channels. In these considered transients, the response of the MSR is characterized by the immediate change of the fuel temperature with changing power and fast negative temperature feedback to the power. The response through the graphite temperature is slower. Furthermore, for big MSR cores fueled with U233 the graphite feedback coefficient can be positive. In this case the addition of erbium to the graphite can ensure the inherent safety features. The DYN3D-MSR code has been shown to be an effective tool for MSR dynamics studies. (author)

  10. Development of High Temperature Transport System for Molten Salt

    Lee, S. H.; Lee, H. S.; Kim, J. G.

    2011-01-01

    Pyroprocessing technology is one of the the most promising technologies for the advanced fuel cycle with favorable economic potential and intrinsic proliferation-resistance. The electrorefining process, one of main processes which is composed of pyroprocess to recover the useful elements from spent fuel, is under development at the Korea Atomic Energy Research Institute as a sub process of the pyrochemical treatment of spent PWR fuel. High-temperature molten salt transport technologies are required because a molten salt should be transported from the electrorefiner to electrowiner after the electrorefining process. Therefore, in pyrometallurgical processing, the development of high-temperature molten salt transport technologies is a crucial prerequisite. However, there have been a few transport studies on high-temperature molten salt. In this study, an apparatus for suction transport experiments was designed and constructed for the development of high temperature transport technology for molten salt, and the performance test of the apparatus was performed. And also, predissolution test of the salt was carried out using the reactor with furnace in experimental apparatus

  11. Application of lithium in molten-salt reduction processes

    Gourishankar, K. V.

    1998-01-01

    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 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

  12. Steam gasification of plant biomass using molten carbonate salts

    Hathaway, Brandon J.; Honda, Masanori; Kittelson, David B.; Davidson, Jane H.

    2013-01-01

    This paper explores the use of molten alkali-carbonate salts as a reaction and heat transfer medium for steam gasification of plant biomass with the objectives of enhanced heat transfer, faster kinetics, and increased thermal capacitance compared to gasification in an inert gas. The intended application is a solar process in which concentrated solar radiation is the sole source of heat to drive the endothermic production of synthesis gas. The benefits of gasification in a molten ternary blend of lithium, potassium, and sodium carbonate salts is demonstrated for cellulose, switchgrass, a blend of perennial plants, and corn stover through measurements of reaction rate and product composition in an electrically heated reactor. The feedstocks are gasified with steam at 1200 K in argon and in the molten salt. The use of molten salt increases the total useful syngas production by up to 25%, and increases the reactivity index by as much as 490%. Secondary products, in the form of condensable tar, are reduced by 77%. -- Highlights: ► The presence of molten salt increases the rate of gasification by up to 600%. ► Reaction rates across various feedstocks are more uniform with salt present. ► Useful syngas yield is increased by up to 30% when salt is present. ► Secondary production of liquid tars are reduced by 77% when salt is present.

  13. Natural convection heat transfer in the molten metal pool

    Park, R.J.; Kim, S.B.; Kim, H.D.; Choi, S.M.

    1997-01-01

    Analytical studies using the FLOW-3D computer program have been performed on natural convection heat transfer of a high density molten metal pool, in order to evaluate the coolability of the corium pool. The FLOW-3D results on the temperature distribution and the heat transfer rate in the molten metal pool region have been compared and evaluated with the experimental data. The FLOW-3D results have shown that the developed natural convection flow contributes to the solidified crust formation of the high density molten metal pool. The present FLOW-3D results, on the relationship between the Nusselt number and the Rayleigh number in the molten metal pool region, are more similar to the calculated results of Globe and Dropkin's correlation than any others. The natural convection heat transfer in the low aspect ratio case is more substantial than that in the high aspect ratio case. The FLOW-3D results, on the temperature profile and on the heat transfer rate in the molten metal pool region, are very similar to the experimental data. The heat transfer rate of the internal heat generation case is higher than that of the bottom heating case at the same heat supply condition. (author)

  14. New rational nuclear energy system composed of accelerator molten-salt breeder (AMSB) and molten-salt power stations (MSCR)

    Furukawa, K.

    1985-01-01

    For the next century, it was predicted that some rational fission energy system breeding in significantly short doubling time less than 10 years should be developed replacing the fossil fuels. In practice, this rationality, that is, simplicity and high economy could be realized by the natural combination of: molten salt fuel concept; accelerator (spallation) breeding concept; and Thorium fuel cycle concept, in the symbiont system of Accelerator Molten-Salt breeders and Molten-Salt Power Stations. The economy of this system might significantly become better than the other breeder systems, although the prediction in Chapter 6 was too much conservative. Its more important aspect is the low cost of future R and D, which depend on the rational character of Molten-Fluoride Technology and really is verified by the basic R and D cost (only $0.13 B) in Oak Ridge N.L. It is interesting that molten-salt technology will be able to apply to chemical processing of U-Pu oxide fuels by the developing effort by USSR in near future. This fact and the demand of small power stations such as 150MWe MSCR presented here will be able to bridge between the present and the next century

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

    McLaughlin, D.F.; Talko, F.

    1990-01-01

    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

  16. Critical survey on electrode aging in molten carbonate fuel cells

    Kinoshita, K.

    1979-12-01

    To evaluate potential electrodes for molten carbonate fuel cells, we reviewed the literature pertaining to these cells and interviewed investigators working in fuel cell technology. In this critical survey, the effect of three electrode aging processes - corrosion or oxidation, sintering, and poisoning - on these potential fuel-cell electrodes is presented. It is concluded that anodes of stabilized nickel and cathodes of lithium-doped NiO are the most promising electrode materials for molten carbonate fuel cells, but that further research and development of these electrodes are needed. In particular, the effect of contaminants such as H/sub 2/S and HCl on the nickel anode must be investigated, and methods to improve the physical strength and to increase the conductivity of NiO cathodes must be explored. Recommendations are given on areas of applied electrode research that should accelerate the commercialization of the molten carbonate fuel cell. 153 references.

  17. Propagating particle density fluctuations in molten NaCl

    Demmel, F.; Hosokawa, S.; Pilgrim, W.-C.; Lorenzen, M.

    2004-01-01

    In this paper we present the observation of acoustic modes in the spectra of molten NaCl measured over a large momentum transfer range using synchrotron radiation. A surprisingly large positive dispersion was deduced with a mode velocity exceeding the adiabatic value by nearly 70%. The large effect seems to be describable as a viscoelastic reaction of the liquid. Additionally, the derived dispersion resembles the Q-ω relation of the acoustic modes in liquid sodium. As an explanation for the large positive dispersion we propose that the density fluctuations in molten NaCl can be interpreted as a decoupled motion of the lighter and smaller cations on a nearly resting anionic background. These molten alkali halide measurements are the first experimental evidences for the so-called fast sound in a binary ionic liquid

  18. Workshop on large molten pool heat transfer summary and conclusions

    1994-01-01

    The CSNI Workshop on Large Molten Heat Transfer held at Grenoble (France) in March 1994 was organised by CSNI's Principal Working Group on the Confinement of Accidental Radioactive Releases (PWG4) with the cooperation of the Principal Working Group on Coolant System Behaviour (FWG2) and in collaboration with the Grenoble Nuclear Research Centre of the French Commissariat a l'Energie Atomique (CEA). Conclusions and recommendations are given for each of the five sessions of the workshops: Feasibility of in-vessel core debris cooling through external cooling of the vessel; Experiments on molten pool heat transfer; Calculational efforts on molten pool convection; Heat transfer to the surrounding water - experimental techniques; Future experiments and ex-vessel studies (open forum discussion)

  19. Behaviour of molten reactor fuels under accident conditions

    Xavier Swamikannu, A.; Mathews, C.K.

    1980-01-01

    The behaviour of molten reactor fuels under accident conditions has received considerable importance in recent times. The chemical processes that occur in the molten state among the fuel, the clad components and the concrete of the containment building under the conditions of a core melt down accident in oxide fuelled reactors have been reviewed with the purpose of identifying areas of developmental work required to be performed to assess and minimize the consequences of such an accident. This includes the computation and estimation of vapour pressure of various gaseous species over the fuel, the clad and the coolant, providing of sacrificial materials in the concrete in order to protect the containment building in order to prevent release of radioactive gases into the atmosphere and understanding the distribution and chemical state of fission products in the molten fuel in order to provide for the effective removal of their decay heats. (auth.)

  20. Deuterium retention in molten salt electrodeposition tungsten coatings

    Zhou, Hai-Shan; Xu, Yu-Ping; Sun, Ning-Bo; Zhang, Ying-Chun; Oya, Yasuhisa; Zhao, Ming-Zhong; Mao, Hong-Min; Ding, Fang; Liu, Feng; Luo, Guang-Nan

    2016-01-01

    Highlights: • We investigate D retention in electrodeposition W coatings. • W coatings are exposed to D plasmas in the EAST tokamak. • A cathodic current density dependence on D retention is found. • Electrodeposition W exhibits lower D retention than VPS-W. - Abstract: Molten salt electrodeposition is a promising technology to manufacture the first wall of a fusion reactor. Deuterium (D) retention behavior in molten salt electrodeposition tungsten (W) coatings has been investigated by D-plasma exposure in the EAST tokamak and D-ion implantation in an ion beam facility. Tokamak exposure experiments demonstrate that coatings prepared with lower current density exhibit less D retention and milder surface damage. Deuterium-ion implantation experiments indicate the D retention in the molten salt electrodeposition W is less than that in vacuum plasma spraying W and polycrystalline W.

  1. Basic studies for molten-salt reactor engineering in Japan

    Ishiguro, R.; Sugiyama, K.; Sakashita, H.

    1985-01-01

    A research project of nuclear engineering for the molten-salt reactor is underway which is supported by the Grant-in-Aid for Scientific Research of the Ministry of Education of Japan. At present, the major effort is devoted only to basic engineering problems because of the limited amount of the grant. The reporters introduce these and related studies that have been carrying out in Japanese universities. Discussions on the following four subjects are summerized in this report: a) Vapour explosion when hight temperature molten-salts are brought into direct contact with water. b) Measurements of exact thermophysical properties of molten-salt. c) Free convection heat transfer with uniform internal heat generation and a constant heating rate from the bottem. d) Stability of frozen salt film on the container surface. (author)

  2. Deuterium retention in molten salt electrodeposition tungsten coatings

    Zhou, Hai-Shan [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei (China); Xu, Yu-Ping [Science Island Branch of Graduate School, University of Science and Technology of China, Hefei (China); Sun, Ning-Bo; Zhang, Ying-Chun [School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing (China); Oya, Yasuhisa [Radioscience Research Laboratory, Faculty of Science, Shizuoka University, Shizuoka (Japan); Zhao, Ming-Zhong [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei (China); Mao, Hong-Min [Science Island Branch of Graduate School, University of Science and Technology of China, Hefei (China); Ding, Fang; Liu, Feng [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei (China); Luo, Guang-Nan, E-mail: gnluo@ipp.ac.cn [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei (China); Science Island Branch of Graduate School, University of Science and Technology of China, Hefei (China); Hefei Center for Physical Science and Technology, Hefei (China); Hefei Science Center of Chinese Academy of Science, Hefei (China)

    2016-12-15

    Highlights: • We investigate D retention in electrodeposition W coatings. • W coatings are exposed to D plasmas in the EAST tokamak. • A cathodic current density dependence on D retention is found. • Electrodeposition W exhibits lower D retention than VPS-W. - Abstract: Molten salt electrodeposition is a promising technology to manufacture the first wall of a fusion reactor. Deuterium (D) retention behavior in molten salt electrodeposition tungsten (W) coatings has been investigated by D-plasma exposure in the EAST tokamak and D-ion implantation in an ion beam facility. Tokamak exposure experiments demonstrate that coatings prepared with lower current density exhibit less D retention and milder surface damage. Deuterium-ion implantation experiments indicate the D retention in the molten salt electrodeposition W is less than that in vacuum plasma spraying W and polycrystalline W.

  3. Molten salt reactors. Synthesis of studies realized between 1973 and 1983. Chemistry file

    1983-03-01

    The chemistry of molten salt reactors was first acquired by foreign literature and developed by experimental studies. Salt preparation, analysis, chemical and electrochemical properties, interaction with metals or graphites and use of molten lead for direct cooling are examined. [fr

  4. Compatibility of AlN ceramics with molten lithium

    Yoneoka, Toshiaki; Sakurai, Toshiharu; Sato, Toshihiko; Tanaka, Satoru [Tokyo Univ., Department of Quantum Engineering and Systems Science, Tokyo (Japan)

    2002-04-01

    AlN ceramics were a candidate for electrically insulating materials and facing materials against molten breeder in a nuclear fusion reactor. In the nuclear fusion reactor, interactions of various structural materials with solid and liquid breeder materials as well as coolant materials are important. Therefore, corrosion tests of AlN ceramics with molten lithium were performed. AlN specimens of six kinds, different in sintering additives and manufacturing method, were used. AlN specimens were immersed into molten lithium at 823 K. Duration for the compatibility tests was about 2.8 Ms (32 days). Specimens with sintering additive of Y{sub 2}O{sub 3} by about 5 mass% formed the network structure of oxide in the crystals of AlN. It was considered that the corrosion proceeded by reduction of the oxide network and the penetration of molten lithium through the reduced pass of this network. For specimens without sintering additive, Al{sub 2}O{sub 3} containing by about 1.3% in raw material was converted to fine oxynitride particles on grain boundary or dissolved in AlN crystals. After immersion into lithium, these specimens were found to be sound in shape but reduced in electrical resistivity. These degradation of the two types specimens were considered to be caused by the reduction of oxygen components. On the other hand, a specimen sintered using CaO as sintering additive was finally became appreciably high purity. This specimen showed good compatibility for molten lithium at least up to 823 K. It was concluded that the reduction of oxygen concentration in AlN materials was essential in order to improve the compatibility for molten lithium. (author)

  5. Beryllium research on FFHR molten salt blanket

    Terai, T.; Tanaka, S.; Sze, D.-K.

    2000-01-01

    Force-free helical reactor, FFHR, is a demo-relevant heliotron-type D-T fusion reactor based on the great amount of R and D results obtained in the LHD project. Since 1993, collaboration works have made great progress in design studies of FFHR with standing on the major advantage of current-less steady operation with no dangerous plasma disruptions. There are two types of reference designs, FFHR-1 and FFHR-2, where molten Flibe (LiF-BeF2) is utilized as tritium breeder and coolant. In this paper, we present the outline of FFHR blanket design and some related R and D topics focusing on Be utilization. Beryllium is used as a neutron multiplier in the design and Be pebbles are placed in the front part of the tritium breeding zone. In a Flibe blanket, HF (TF) generated due to nuclear transmutation will be a problem because of its corrosive property. Though nickel-based alloys are thought to be intact in such a corrosive environment, FFHR blanket design does not adopt the alloys because of their induced radioactivity. The present candidate materials for the structure are low-activated ferritic steel (JLF-1), V-4Cr-4Ti, etc. They are capable to be corroded by HF in the operation condition, and Be is expected to work as a reducing agent in the system as well. Whether Be pebbles placed in a Flibe flow can work well or not is a very important matter. From this point, Be solubility in Flibe, reaction rate of the Redox reaction with TF in the liquid and on the surface of Be pebbles under irradiation, flowing behavior of Flibe through a Be pebble bed, etc. should be investigated. In 1997, in order to establish more practical and new data bases for advanced design works, we started a collaboration work of R and D on blanket engineering, where the Be research above mentioned is included. Preliminary dipping-test of Be sheets and in-situ tritium release experiment from Flibe with Be sheets have got started. (orig.)

  6. The introduction of the safety of molten salt reactor

    Zuo Jiaxu; Zhang Chunming

    2011-01-01

    This paper introduces the generation TV Nuclear Energy Systems and molten salt reactor which is the only fluid fuel reactor in the Gen-TV. Safety features and attributes of MSR are described. The supply of fuel and the minimum of waste are described. The clean molten salt in the secondary heat transport system transfers the heat from the primary heat exchanger to a high-temperature Brayton cycle that converts the heat to electricity. With the Brayton cycle, the thermal efficiency of the system will be improved. Base on the MSR, the thorium-uranium fuel cycle is also introduced. (authors)

  7. Calculation of β-effective of a molten salt reactor

    Hirakawa, N.; Sakaba, H.

    1987-01-01

    A method to calculate the β eff of a molten salt reactor was developed taking the effect of the flow of the molten salt into account. The method was applied to the 1000MW MSR design made by ORNL. The change in β eff due to the change in the residence time outside of the core of the fuel salt and to the change in the flow velocity when the total amount of the fuel salt is kept constant were investigated. It was found that β eff was reduced to 47.9% of the value when the fuel salt is at rest for the present design. (author)

  8. Subcritical enhanced safety molten-salt reactor concept

    Alekseev, P.N.; Ignatiev, V.V.; Men'shikov, L.I.; Prusakov, V.N.; Ponomarev-Stepnoy, N.N.; Subbotin, S.A.; Krasnykh, A.K.; Rudenko, V.T.; Somov, L.N.

    1995-01-01

    The nuclear power and its fuel cycle safety requirements can be met in the main by providing nuclear power with subcritical molten salt reactors (SMSR) - 'burner' with an external neutron source. The utilized molten salt fuel is the decisive advantage of the SMSR over other burners. Fissile and fertile nuclides in the burner are solved in a liquid salt in the form of fluorides. This composition acts simultaneously as: a) fuel, b) coolant, c) medium for chemical partitioning and reprocessing. The effective way of reducing the external source power consists in the cascade neutron multiplication in the system of coupled reactors with suppressed feedback between them. (author)

  9. Metallic materials corrosion problems in molten salt reactors

    Chauvin, G.; Dixmier, J.; Jarny, P.

    1977-01-01

    The USA forecastings concerning the molten salt reactors are reviewed (mixtures of fluorides containing the fuel, operating between 560 and 700 0 C). Corrosion problems are important in these reactors. The effects of certain characteristic factors on corrosion are analyzed: humidity and metallic impurities in the salts, temperature gradients, speed of circulation of salts, tellurium from fission products, coupling. In the molten fluorides and experimental conditions, the materials with high Ni content are particularly corrosion resistant alloys (hastelloy N). The corrosion of this material is about 2.6 mg.cm -2 at 700 0 C [fr

  10. Study of an F center in molten KCl

    Parrinello, M.; Rahman, A.

    1984-01-15

    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, the magnetic susceptibility, 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. The Feynman path of the electron dissolved in molten KCl is highly localized thus justifying the F center model. The effect of varying the e/sup -/-K/sup +/ pseudopotential is also reported.

  11. Molten core debris-sodium interactions: M-Series experiments

    Sowa, E.S.; Gabor, J.D.; Pavlik, J.R.; Cassulo, J.C.; Cook, C.J.; Baker, L. Jr.

    1979-01-01

    Five new kilogram-scale experiments have been carried out. Four of the experiments simulated the situation where molten core debris flows from a breached reactor vessel into a dry reactor cavity and is followed by a flow of sodium (Ex-vessel case) and one experiment simulated the flow of core debris into an existing pool of sodium (In-vessel case). The core debris was closely simulated by a thermite reaction which produced a molten mixture of UO 2 , ZrO 2 , and stainless steel. There was efficient fragmentation of the debris in all experiments with no explosive interactions observed

  12. Molten carbonate fuel cell integral matrix tape and bubble barrier

    Reiser, C.A.; Maricle, D.L.

    1983-01-01

    A molten carbonate fuel cell matrix material is described made up of a matrix tape portion and a bubble barrier portion. The matrix tape portion comprises particles inert to molten carbonate electrolyte, ceramic particles and a polymeric binder, the matrix tape being flexible, pliable and having rubber-like compliance at room temperature. The bubble barrier is a solid material having fine porosity preferably being bonded to the matrix tape. In operation in a fuel cell, the polymer binder burns off leaving the matrix and bubble barrier providing superior sealing, stability and performance properties to the fuel cell stack

  13. Thermal conditions and functional requirements for molten fuel containment

    Kang, C.S.; Torri, A.

    1980-05-01

    This paper discusses the configuration and functional requirements for the molten fuel containment system (MFCS) in the GCFR demonstration plant design. Meltdown conditions following a loss of shutdown cooling (LOSC) accident were studied to define the core debris volume for a realistic meltdown case. Materials and thicknesses of the molten fuel container were defined. Stainless steel was chosen as the sacrificial material and magnesium oxide was chosen as the crucible material. Thermal conditions for an expected quasi-steady state were analyzed. Highlights of the functional requirements which directly affect the MFCS design are discussed

  14. High-frequency dynamics in a molten binary alloy

    Alvarez, M.; Bermejo, F.J.; Verkerk, P.; Roessli, B.

    1999-01-01

    The nature of the finite wavelength collective excitations in liquid binary mixtures composed of atoms of very different masses has been of interest for more than a decade. The most prominent fact is the high frequencies at which they appear, well above those expected for a continuation to large wave vector of hydrodynamic sound. To better understand the microscopic dynamics of such systems, an inelastic neutron scattering experiment was performed on the molten alloy Li 4 Pb. We present the high-frequency excitations of molten Li 4 Pb which indeed show features substantially deviating from those expected for the propagation of an acoustic mode. (authors)

  15. Compatibility tests between molten salts and metal materials (2)

    Shiina, Yasuaki

    2003-08-01

    Latent heat storage technology using molten salts can reduce temperature fluctuations of heat transfer fluid by latent heat for middle and high temperature regions. This enables us to operate several heat utilization systems in cascade connected to High Temperature Gas Cooled Reactors (HTGRs) from high to low temperature range by setting the latent heat storage system after a heat utilization system to reduce thermal load after the heat utilization systems. This latent heat technology is expected to be used for effective use of heat such as equalization of electric load between night and daytime. In the application of the latent heat technology, compatibility between molten salts and metal materials is very important because molten salts are corrosive, and heat transfer pipes and vessels will contact with the molten salts. It will be necessary to prevail the latent heat storage technique that normal metal materials can be used for the pipes and vessels. However, a few studies have been reported of compatibility between molten salts and metals in middle and high temperature ranges. In this study, four molten salts, range of the melting temperature from 490degC to 800degC, are selected and five metals, high temperature and corrosion resistance steels of Alloy600, HastelloyB2, HastelloyC276, SUS310S and pure Nickel are selected for the test with the consideration of metal composition. Test was performed in an electric furnace by setting the molten salts and the metals in melting pots in an atmosphere of nitrogen. Results revealed excellent corrosion resistance of pure Nickel and comparatively low corrosion resistance of nickel base alloys such as Alloy600 and Hastelloys against Li 2 CO 3 . Corrosion resistance of SUS310S was about same as nickel based alloys. Therefore, if some amount of corrosion is permitted, SUS310S would be one of the candidate alloys for structure materials. These results will be used as reference data to select metals in latent heat technology

  16. Fabrication of catalytic electrodes for molten carbonate fuel cells

    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. Molten salt reactors. Synthesis of studies realized between 1973 and 1983. General synthesis

    Hery, M.; Lecocq, A.

    1983-03-01

    After a brief recall of the MSBR project, French studies on molten salt reactors are summed up. Theoretical and experimental studies for a graphite moderated 1000 MWe reactor using molten Li, Be, Th and U fluorides cooled by salt-lead direct contact are given. These studies concern the core, molten salt chemistry, graphite, metals (molybdenum, alloy TZM), corrosion, reactor components [fr

  18. Thermochemical investigation of molten fluoride salts for Generation IV nuclear applications - an equilibrium exercise

    van der Meer, J.P.M.

    2006-01-01

    The concept of the Molten Salt Reactor, one of the so-called Generation IV future reactors, is that the fuel, a fissile material, which is dissolved in a molten fluoride salt, circulates through a closed circuit. The heat of fission is transferred to a second molten salt coolant loop, the heat of

  19. Membrane Biophysics

    Ashrafuzzaman, Mohammad

    2013-01-01

    Physics, mathematics and chemistry all play a vital role in understanding the true nature and functioning of biological membranes, key elements of living processes. Besides simple spectroscopic observations and electrical measurements of membranes we address in this book the phenomena of coexistence and independent existence of different membrane components using various theoretical approaches. This treatment will be helpful for readers who want to understand biological processes by applying both simple observations and fundamental scientific analysis. It provides a deep understanding of the causes and effects of processes inside membranes, and will thus eventually open new doors for high-level pharmaceutical approaches towards fighting membrane- and cell-related diseases.

  20. Corrosion Behavior of Superalloys in Hot Lithium Molten Salt

    Cho, Soo-Haeng; Hur, Jin-Mok; Seo, Chung-Seok; Park, Seoung-Won

    2006-01-01

    The Li-reduction process involves the chemical reduction of spent fuel oxides by liquid lithium metal in a molten LiCl salt bath at 650 .deg. C followed by a separate electrochemical reduction of lithium oxide (Li 2 O), which builds up in the salt bath. This process requires a high purity inert gas atmosphere inside remote hot cell nuclear facility to prevent unwanted Li oxidation and fires during the handling of chemically active Li metal. In light of the limitations of the Li-reduction process, a direct electrolytic reduction technology is being developed by KAERI to enhance process safety and economic viability. The electrolytic reduction of spent oxide fuel involves the liberation of oxygen in a molten LiCl electrolyte, which results in a chemically aggressive environment that is too corrosive for typical structural materials. Even so, the electrochemical process vessel must be resilient at ∼ 650 .deg. C in the presence of oxygen to enable high processing rates and an extended service life. But, the mechanism and the rate of the corrosion of metals in LiCl-Li 2 O molten salt under oxidation condition are not clear. In the present work, the corrosion behavior and corrosion mechanism of superalloys have been studied in the molten salt of LiCl-Li 2 O under oxidation condition

  1. Study of an F center in molten KCl

    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

  2. Ion diffusion related to structure in molten salts

    Tosi, M.P.

    1996-08-01

    A model first developed by Zwanzig to derive transport coefficients in cold dense fluids directly from the Green-Kubo time correlation formulae allows one to relate macroscopic diffusion coefficients to the local fluid structure. Applications to various ionic diffusion processes in molten salts are reviewed. Consequences of partial structural quenching are also discussed. (author). 28 refs, 3 tabs

  3. Molten metal feed system controlled with a traveling magnetic field

    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.

  4. Experimental investigation of a molten salt thermocline storage tank

    Yang, Xiaoping; Yang, Xiaoxi; Qin, Frank G. F.; Jiang, Runhua

    2016-07-01

    Thermal energy storage is considered as an important subsystem for solar thermal power stations. Investigations into thermocline storage tanks have mainly focused on numerical simulations because conducting high-temperature experiments is difficult. In this paper, an experimental study of the heat transfer characteristics of a molten salt thermocline storage tank was conducted by using high-temperature molten salt as the heat transfer fluid and ceramic particle as the filler material. This experimental study can verify the effectiveness of numerical simulation results and provide reference for engineering design. Temperature distribution and thermal storage capacity during the charging process were obtained. A temperature gradient was observed during the charging process. The temperature change tendency showed that thermocline thickness increased continuously with charging time. The slope of the thermal storage capacity decreased gradually with the increase in time. The low-cost filler material can replace the expensive molten salt to achieve thermal storage purposes and help to maintain the ideal gravity flow or piston flow of molten salt fluid.

  5. Treatment of plutonium process residues by molten salt oxidation

    Stimmel, J.; Wishau, R.; Ramsey, K.B.; Montoya, A.; Brock, J. [Los Alamos National Lab., NM (United States); Heslop, M. [Naval Surface Warfare Center (United States). Indian Head Div.; Wernly, K. [Molten Salt Oxidation Corp. (United States)

    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.

  6. Thermodynamic characterization of salt components for Molten Salt Reactor fuel

    Capelli, E.

    2016-01-01

    The Molten Salt Reactor (MSR) is a promising future nuclear fission reactor technology with excellent performance in terms of safety and reliability, sustainability, proliferation resistance and economics. For the design and safety assessment of this concept, it is extremely important to have a

  7. Probability safety assessment of LOOP accident to molten salt reactor

    Mei Mudan; Shao Shiwei; Yu Zhizhen; Chen Kun; Zuo Jiaxu

    2013-01-01

    Background: Loss of offsite power (LOOP) is a possible accident to any type of reactor, and this accident can reflect the main idea of reactor safety design. Therefore, it is very important to conduct a study on probabilistic safety assessment (PSA) of the molten salt reactor that is under LOOP circumstance. Purpose: The aim is to calculate the release frequency of molten salt radioactive material to the core caused by LOOP, and find out the biggest contributor to causing the radioactive release frequency. Methods: We carried out the PSA analysis of the LOOP using the PSA process risk spectrum, and assumed that the primary circuit had no valve and equipment reliability data based on the existing mature power plant equipment reliability data. Results: Through the PSA analysis, we got the accident sequences of the release of radioactive material to the core caused by LOOP and its frequency. The results show that the release frequency of molten salt radioactive material to the core caused by LOOP is about 2×10 -11 /(reactor ·year), which is far below that of the AP1000 LOOP. In addition, through the quantitative analysis, we obtained the point estimation and interval estimation of uncertainty analysis, and found that the biggest contributor to cause the release frequency of radioactive material to the core is the reactor cavity cooling function failure. Conclusion: This study provides effective help for the design and improvement of the following molten salt reactor system. (authors)

  8. Nuclear energy synergetics and molten-salt technology

    Furukawa, Kazuo

    1988-01-01

    There are various problems with nuclear energy techniques in terms of resources, safety, environmental effects, nuclear proliferation, reactor size reduction and overall economics. To overcome these problems, future studies should be focused on utilization of thorium resources, separation of multiplication process and power generation process, and application of liquid nuclear fuel. These studies will lead to the development of molten thorium salt nuclear synergetics. The most likely candidate for working medium is Lif-BeF 2 material (flibe). 233 U production facilities are required for the completion of the Th cycle. For this, three ideas have been proposed: accelerator M.S. breeder, impact fusion MSB and inertial conf. fusion hybrid MSB. The first step toward the development of molten Th salt nuclear energy synergetics will be the construction of a pilot plant of an extreme small size. As candidate reactor, the author has selected mini FUJI-II (7.0 MWe), an extremely small molten salt power reactor. Mini FUJI-II facilities are expected to be developed in 7 - 8 years. For the next step (demonstration step), the designing of a small power reactor (FUJI 160 MWe) has already been carried out. A small molten salt reactor will have good safety characteristics in terms of chemistry, material, structure, nuclear safety and design basis accidents. Such reactors will also have favorable economic aspects. (Nogami, K.)

  9. Nonmetal-metal transition in metal–molten-salt solutions

    Silvestrelli, P.-L.; Alavi, A.; Parrinello, M.; Frenkel, D.

    1996-01-01

    The method of ab initio molecular dynamics, based on finite-temperature density-functional theory, is used to study the nonmetal-metal transition in two different metal–molten-salt solutions, Kx(KCl)1-x and Nax(NaBr)1-x. As the excess metal concentration is increased the electronic density becomes

  10. Study of an F center in molten KCl

    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.

  11. Candidate molten salt investigation for an accelerator driven subcritical core

    Sooby, E., E-mail: soobyes@tamu.edu [Texas A and M University, Accelerator Research Laboratory, 3380 University Dr. East, College Station, TX 77845 (United States); Baty, A. [Texas A and M University, Accelerator Research Laboratory, 3380 University Dr. East, College Station, TX 77845 (United States); Beneš, O. [European Commission, DG Joint Research Centre, Institute for Transuranium Elements, P.O. Box 2340, 76125 Karlsruhe (Germany); McIntyre, P.; Pogue, N. [Texas A and M University, Accelerator Research Laboratory, 3380 University Dr. East, College Station, TX 77845 (United States); Salanne, M. [Université Pierre et Marie Curie, CNRS, Laboratoire PECSA, F-75005 Paris (France); Sattarov, A. [Texas A and M University, Accelerator Research Laboratory, 3380 University Dr. East, College Station, TX 77845 (United States)

    2013-09-15

    Highlights: • Developing accelerator driven subcritical fission to destroy transuranics in SNF. • The core is a vessel containing a molten mixture of NaCl and transuranic chlorides. • Molecular dynamics used to calculate the thermophysical properties of the salt. • Density and molecular structure for actinide salts reported here. • The neutronics of ADS fission in molten salt are presented. -- Abstract: We report a design for accelerator-driven subcritical fission in a molten salt core (ADSMS) that utilizes a fuel salt composed of NaCl and transuranic (TRU) chlorides. The ADSMS core is designed for fast neutronics (28% of neutrons >1 MeV) to optimize TRU destruction. The choice of a NaCl-based salt offers benefits for corrosion, operating temperature, and actinide solubility as compared with LiF-based fuel salts. A molecular dynamics (MD) code has been used to estimate properties of the molten salt system which are important for ADSMS design but have never been measured experimentally. Results from the MD studies are reported. Experimental measurements of fuel salt properties and studies of corrosion and radiation damage on candidate metals for the core vessel are anticipated.

  12. Sorbitol dehydration into isosorbide in a molten salt hydrate medium

    Li, J.; Spina, A.; Moulijn, J.A.; Makkee, M.

    2013-01-01

    The sorbitol conversion in a molten salt hydrate medium (ZnCl2; 70 wt% in water) was studied. Dehydration is the main reaction, initially 1,4- and 3,6-anhydrosorbitol are the main products that are subsequently converted into isosorbide; two other anhydrohexitols, (1,5- and 2,5-), formed are in less

  13. Raman spectra of zirconium tetrachloride in molten and evaporational states

    Salyuev, A.B.; Kornyakova, I.D.

    1994-01-01

    For the first time raman spectra of ZrCl 4 are obtained in the temperature range of its existence in molten state as well as in vapors near the critical point. It is shown, that rupture of zigzag chains is taking place when ZrCl 4 is melting

  14. Candidate molten salt investigation for an accelerator driven subcritical core

    Sooby, E.; Baty, A.; Beneš, O.; McIntyre, P.; Pogue, N.; Salanne, M.; Sattarov, A.

    2013-01-01

    Highlights: • Developing accelerator driven subcritical fission to destroy transuranics in SNF. • The core is a vessel containing a molten mixture of NaCl and transuranic chlorides. • Molecular dynamics used to calculate the thermophysical properties of the salt. • Density and molecular structure for actinide salts reported here. • The neutronics of ADS fission in molten salt are presented. -- Abstract: We report a design for accelerator-driven subcritical fission in a molten salt core (ADSMS) that utilizes a fuel salt composed of NaCl and transuranic (TRU) chlorides. The ADSMS core is designed for fast neutronics (28% of neutrons >1 MeV) to optimize TRU destruction. The choice of a NaCl-based salt offers benefits for corrosion, operating temperature, and actinide solubility as compared with LiF-based fuel salts. A molecular dynamics (MD) code has been used to estimate properties of the molten salt system which are important for ADSMS design but have never been measured experimentally. Results from the MD studies are reported. Experimental measurements of fuel salt properties and studies of corrosion and radiation damage on candidate metals for the core vessel are anticipated

  15. Molten salt scrubbing of zirconium or hafnium tetrachloride

    Lee, E.D.; McLaughlin, D.F.

    1990-01-01

    This patent describes a continuous process for removing impurities of iron or aluminum chloride or both from vaporous zirconium or hafnium chloride or both. It comprises: introducing impure zirconium or hafnium chloride vapor or both into a middle portion of an absorbing column containing a molten salt phase, the molten salt phase absorbing the impurities of iron or aluminum chloride or both to produce chloride vapor stripped of zirconium or hafnium chloride; introducing sodium or potassium chloride or both into a top portion of the column; controlling the top portion of the column to between 300--375 degrees C.; heating a bottom portion of the column to 450--550 degrees C. To vaporize zirconium chloride or hafnium chloride or hafnium and zirconium chloride from the molten salt; withdrawing molten salt substantially free of zirconium and hafnium chloride from the bottom portion of the column; and withdrawing zirconium chloride or hafnium chloride or hafnium and zirconium chloride vapor substantially free of impurities of iron and aluminum chloride from the top of the column

  16. Nickel catalysts for internal reforming in molten carbonate fuel cells

    Berger, R.J.; Berger, R.J.; Doesburg, E.B.M.; Doesburg, E.B.M.; van Ommen, J.G.; Ross, J.R.H.; Ross, J.R.H.

    1996-01-01

    Natural gas may be used instead of hydrogen as fuel for the molten carbonate fuel cell (MCFC) by steam reforming the natural gas inside the MCFC, using a nickel catalyst (internal reforming). The severe conditions inside the MCFC, however, require that the catalyst has a very high stability. In

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

    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. Visualization of steam bubbles with evaporation in molten alloy

    Nishi, Yoshihisa; Furuya, Masahiro; Kinoshita, Izumi; Takenaka, Nobuyuki; Matsubayashi, Masahito

    1997-01-01

    An innovative Steam Generator concept of Fast Breeder Reactors by using liquid-liquid direct contact heat transfer has been developed. In this concept, the SG shell is filled with a molten alloy heated by primary sodium. Water is fed into the high temperature molten alloy, and evaporates by direct contact heating. In order to obtain the fundamental information to discuss the heat transfer mechanisms of the direct contact between the water and the molten alloy, this phenomenon was visualized by neutron radiography. JRR-3M radiography in Japan Atomic Energy Research Institute was used. Followings are main results. (1) The bubbles with evaporation are risen with vigorous form changing, coalescence and break-up. Because of these vigorous evaporation, this system have the high heat transfer performance. (2) The rising velocities and volumes of bubbles are calculated from pixcel values of images. The velocities of the bubbles with evaporation are about 60 cm/s, which is larger than that of inert gas bubbles in molten alloy (20-40 cm/s). (3) The required heat transfer length of evaporation is calculated from pixcel values of images. The relation between heat transfer length and superheat temperature, obtained through the heat transfer test, is conformed by this calculation. (author)

  19. Fluid Mechanics Of Molten Metal Droplets In Additive Manufacturing

    Tesař, Václav; Šonský, Jiří

    2016-01-01

    Roč. 4, č. 4 (2016), s. 403-412 ISSN 2046-0546 R&D Projects: GA ČR GA13-23046S Institutional support: RVO:61388998 Keywords : additive manufacturing * droplets * molten metal Subject RIV: BK - Fluid Dynamics http://www.witpress.com/elibrary/cmem-volumes/4/4/1545

  20. Research and development issues for molten carbonate fuel cells

    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.

  1. Structure and thermodynamic properties of molten rubidium chloride

    Ballone, P.; Pastore, G.; Tosi, M.P.; Trieste Univ.

    1984-02-01

    Self-consistent calculations of partial pair distribution functions and thermodynamic properties are presented for molten RbCl in a non-polarizable-ion model and compared with computer simulation data. The theory, which is quantitatively very successful, hinges on an empirical evaluation of bridge diagrams including both excluded-volume effects and long-range Coulomb effects. (author)

  2. Release properties of UC sub x and molten U targets

    Roussière, B; Sauvage, J; Bajeat, O; Barre, N; Clapier, F; Cottereau, E; Donzaud, C; Ducourtieux, M; Essabaa, S; Guillemaud-Müller, D; Lau, C; Lefort, H; Liang, C F; Le Blanc, F; Müller, A C; Obert, J; Pauwels, N; Potier, J C; Pougheon, F; Proust, J; Sorlin, O; Verney, D; Wojtasiewicz, A

    2002-01-01

    The release properties of UC sub x and molten U thick targets associated with a Nier-Bernas ion source have been studied. Two experimental methods are used to extract the release time. Results are presented and discussed for Kr, Cd, I and Xe.

  3. Thorium and Molten Salt Reactors: "Essential Questions for Classroom Discussions"

    DiLisi, Gregory A.; Hirsch, Allison; Murray, Meredith; Rarick, Richard

    2018-01-01

    A little-known type of nuclear reactor called the "molten salt reactor" (MSR), in which nuclear fuel is dissolved in a liquid carrier salt, was proposed in the 1940s and developed at the Oak Ridge National Laboratory in the 1960s. Recently, the MSR has generated renewed interest as a remedy for the drawbacks associated with conventional…

  4. Treatment of plutonium process residues by molten salt oxidation

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

    1999-01-01

    Molten Salt Oxidation (MSO) is a thermal process that can remove more than 99.999% of the organic matrix from combustible 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 2 SO 4 , Na 3 PO 4 and NaAsO 2 or Na 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 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

  5. Time-of-flight pulsed neutron diffraction of molten salts

    Fukushima, Y; Misawa, M; Suzuki, K [Tohoku Univ., Sendai (Japan). Research Inst. for Iron, Steel and Other Metals

    1975-06-01

    In this work, the pulsed neutron diffraction of molten alkali metal nitrate and bismuth trihalide was measured by the time-of-flight method. An electron linear accelerator was used as the pulsed neutron source. All the measurements were carried out with the T-O-F neutron diffractometer installed on the 300 MeV electron lineac. Molten NaNO/sub 3/ and RbNO/sub 3/ were adopted as the samples for alkali metal nitrate. The measurement is in progress for KNO/sub 3/ and LiNO/sub 3/. As the first step of the study on bismuth-bismuth trihalide system, the temperature dependence of structure factors was observed for BiCl/sub 3/, BiBr/sub 3/ and BiI/sub 3/ in the liquid state. The structure factors Sm(Q) for molten NaNO/sub 3/ at 340/sup 0/C and RbNO/sub 3/ at 350/sup 0/C were obtained, and the form factor F/sub 1/(Q) for single NO/sub 3//sup -/ radical with equilateral triangle structure was calculated. In case of molten NaNO/sub 3/, the first peak of Sm(Q) is simply smooth and a small hump can be observed in the neighbourhood of the first minimum Q position. The first peak of Sm(Q) for molten RbNO/sub 3/ is divided into two peaks, whereas a hump at the first minimum becomes big, and shifts to the low Q side of the second peak. The size of the NO/sub 3//sup -/ radical in molten NaNO/sub 3/ is a little smaller than that in molten RbNO/sub 3/. The values of the bond length in the NO/sub 3//sup -/ radical are summarized for crystal state and liquid state. The temperature dependence of the structure factor S(Q) was observed for BiCl/sub 3/, BiBr/sub 3/ and BiI/sub 3/, and shown in a figure.

  6. Molar Volume Analysis of Molten Ni-Al-Co Alloy by Measuring the Density

    XIAO Feng; FANG Liang; FU Yuechao; YANG Lingchuan

    2004-01-01

    The density of molten Ni-Al-Co alloys was measured in the temperature range of 1714~1873K using a modified pycnometric method, and the molar volume of molten alloys was analyzed. The density of molten Ni-Al-Co alloys was found to decrease with increasing temperature and Co concentration in alloys. The molar volume of molten Ni-Al-Co alloys increases with increasing Co concentration in alloys. The molar volume of molten Ni-Al-Co alloys shows a negative deviation from the linear molar volume.

  7. Supplying Fe from molten coal ash to revive kelp community

    Matsumoto, K.; Yamamoto, M.; Sadakata, M. [University of Tokyo, Tokyo (Japan)

    2006-02-15

    The phenomenon of a kelp-dominated community changing to a crust-dominated community, which is called 'barren-ground', is progressing in the world, and causing serious social problems in coastal areas. Among several suggested causes of 'barren-ground', we focused on the lack of Fe in seawater. Kelp needs more than 200 nM of Fe to keep its community. However there are the areas where the concentration of Fe is less than 1 nM, and the lack of Fe leads to the 'barren-ground.' Coal ash is one of the appropriate materials to compensate the lack of Fe for the kelp growth, because the coal ash is a waste from the coal combustion process and contains more than 5 wt% of Fe. The rate of Fe elution from coal fly ash to water can be increased by 20 times after melting in Ar atmosphere, because 39 wt% of the Fe(III) of coal fly ash was reduced to Fe(II). Additionally molten ash from the IGCC (integrated coal gasification combined cycle) furnace in a reducing atmosphere and one from a melting furnace pilot plant in an oxidizing atmosphere were examined. Each molten ash was classified into two groups; cooled rapidly with water and cooled slowly without water. The flux of Fe elution from rapidly cooled IGCC molten ash was the highest; 9.4 x 10{sup -6} g m{sup -2} d{sup -1}. It was noted that the coal ash melted in a reducing atmosphere could elute Fe effectively, and the dissolution of the molten ash itself controlled the rate of Fe elution in the case of rapidly cooled molten ash.

  8. Propagation mechanisms of molten fuel/moderator interactions

    Frost, D.L.; Ciccarelli, G.

    1991-06-01

    It is well known that a vapor explosion can result when molten is suddenly brought into contact with a cold volatile liquid such as water. However, the rapid melt fragmentation and heat transfer processes that occur during a propagating melt-water interaction are poorly understood. Experiments were carried out in the present work to investigate the fragmentation processes for single molten metal drops in water. To determine the time scale for the fragmentation of a drop, liquid metal drops (in thermal equilibrium with the water) as well as hot molten drops surrounded by a vapor film were subjected to underwater shocks with overpressures of up to about 20 MPa. In the hot molten drop tests, the induction time for the initiation of the explosion is typically less than 100 μs; at a corresponding time in the cold drop tests, very little or no direct hydrodynamic fragmentation of the drop has occurred. Therefore, in the hot drop case the fragmentation of the drop is dominated by thermal effects; i.e., the heat transfer from the melt to the water leads to violent boiling, pressurization, and drop fragmentation. The melt-water interaction consists of several cycles involving bubble growth and collapse. The strength of the interaction was not found to be a strong function of initial shock pressure (for molten tin drops with trigger pressures of up to 20 MPa), but depends on the thermal energy in the melt: high-temperature thermite drops generated a larger first bubble than lower temperature melt drops. A model for the fine fragmentation process for a hot drop is proposed that is based on thermal effects. The fragmentation processes governed by thermal effects observed in the present experiments are expected to play an important role in the escalation of a local interaction to a large-scale coherent vapor explosion, and are not accounted for in current transient models for propagating vapor explosions

  9. Molten salt oxidation as an alternative to incineration

    Gray, L.W.; Adamson, M.G.; Cooper, J.F.; Farmer, J.C.; Upadhye, R.S.

    1992-03-01

    Molten Salt Oxidation was originally developed by Rockwell International as part of their coal gasification, and nuclear-and hazardous-waste treatment programs. Single-stage oxidation units employing molten carbonate salt mixtures were found to process up to one ton/day of common solid and liquid wastes (such as paper, rags, plastics, and solvents), and (in larger units) up to one ton/hour of coal. After the oxidation of coal with excess oxygen, coal ash residuals (alumina-silicates) were found adhering to the vessel walls above the liquid level. The phenomenon was not observed with coal gasification-i.e., under oxygen-deficient conditions. Lawrence Livermore National Laboratory (LLNL) is developing a two-stage/two-vessel approach as a possible means of extending the utility of the process to wastes which contain high concentrations of alumina-silicates in the form of soils or clays, or high concentrations of nitrates including low-level and transuranic wastes. The first stage operates under oxygen-deficient (''pyrolysis'') conditions; the second stage completes oxidation of the evolved gases. The process allows complete oxidation of the organic materials without an open flame. In addition, all acidic gases that would be generated in incinerators are directly metathesized via the molten Na 2 CO 3 to form stable salts (NaCl, Na 2 SO 4 etc.). Molten salt oxidation therefore avoids the corrosion problems associated with free HCl in incineration. The process is being developed to use pure O 2 feeds in lieu of air, in order to reduce offgas volume and retain the option of closed system operation. In addition, ash is wetted and retained in the melt of the first vessel which must be replaced (continuously or batch-wise). The LLNL Molten Salt unit is described together with the initial operating data

  10. In-line monitoring of an oxide ion in LiCl molten salt using a YSZ based oxide ion selective electrode

    Cho, Young Hwan; Jeon, Jong Seon; Yeon, Jei Won; Choi, In Kyu; Kim, Won Ho

    2004-01-01

    The electrode potential characteristics of a YSZ based membrane metal oxide electrode have been studied in molten LiCl at 700 .deg. C by the potentiometric method. The electrode exhibited a good potential response to log[O 2 ] and data reproducibility. The calibration plot (potential vs. log[O 2 ] was found to be linear, obeying the nernst equation. The electrode potential showed a good reversibility corresponding to increase/decrease of the oxide ion present in the molten LiCl. The physical and chemical durability appeared to be sound after several repeated uses, resulting in reproducible results. However, 'the proposed electrode' failed when metallic Li was present in the melt

  11. Transfer characteristics of a lithium chloride–potassium chloride molten salt

    Eve Mullen

    2017-12-01

    Full Text Available Pyroprocessing is an alternative method of reprocessing spent fuel, usually involving the dissolving spent fuel in a molten salt media. The National Nuclear Laboratory designed, built, and commissioned a molten salt dynamics rig to investigate the transfer characteristics of molten lithium chloride–potassium chloride eutectic salt. The efficacy and flow characteristics of a high-temperature centrifugal pump and argon gas lift were obtained for pumping the molten salt at temperatures up to 500°C. The rig design proved suitable on an industrial scale and transfer methods appropriate for use in future molten salt systems. Corrosion within the rig was managed, and melting techniques were optimized to reduce stresses on the rig. The results obtained improve the understanding of molten salt transport dynamics, materials, and engineering design issues and support the industrialization of molten salts pyroprocessing.

  12. CFD to modeling molten core behavior simultaneously with chemical phenomena

    Vladimir V Chudanov; Anna E Aksenova; Valerii A Pervichko

    2005-01-01

    Full text of publication follows: This paper deals with the basic features of a computing procedure, which can be used for modeling of destruction and melting of a core with subsequent corium retaining into the reactor vessel. The destruction and melting of core mean the account of the following phenomena: a melting, draining (moving of the melt through a porous layer of core debris), freezing with release of an energy, change of geometry, formation of the molten pool, whose convective intermixing and distribution influence on a mechanism of borders destruction. It is necessary to take into account that during of heating molten pool and development in it of convective fluxes a stratification of a multi-component melt on two layers of metal light and of oxide heavy components is observed. These layers are in interaction, they can exchange by the separate components as result of diffusion or oxidizing reactions. It can have an effect considerably on compositions, on a specific weight, and on properties of molten interacting phases, and on a structure of the molten stratified pool. In turn, the retaining of the formed molten masses in reactor vessel requires the solution of a matched heat exchange problem, namely, of a natural convection in a heat generating fluid in partially or completely molten corium and of heat exchange problem with taking into account of a melting of the reactor vessel. In addition, it is necessary to take into account phase segregation, caused by influence of local and of global natural convective flows and thermal lag of heated up boundaries. The mathematical model for simulation of the specified phenomena is based on the Navier-Stokes equations with variable properties together with the heat transfer equation. For modeling of a corium moving through a porous layer of core debris, the special computing algorithm to take into account density jump on interface between a melt and a porous layer of core debris is designed. The model was

  13. Membrane paradigm

    Price, R.H.; Thorne, K.S.

    1986-01-01

    The membrane paradigm is a modified frozen star approach to modeling black holes, with particles and fields assuming a complex, static, boundary-layer type structure (membrane) near the event horizon. The membrane has no effects on the present or future evolution of particles and fields above itself. The mathematical representation is a combination of a formalism containing terms for the shear and bulk viscosity, surface pressure, momentum, temperature, entropy, etc., of the horizon and the 3+1 formalism. The latter model considers a family of three-dimensional spacelike hypersurfaces in one-dimensional time. The membrane model considers a magnetic field threading the hole and undergoing torque from the hole rotation. The field is cleaned by the horizon and distributed over the horizon so that ohmic dissipation is minimized. The membrane paradigm is invalid inside the horizon, but is useful for theoretically probing the properties of slowly evolving black holes

  14. Membrane processes

    Staszak, Katarzyna

    2017-11-01

    The membrane processes have played important role in the industrial separation process. These technologies can be found in all industrial areas such as food, beverages, metallurgy, pulp and paper, textile, pharmaceutical, automotive, biotechnology and chemical industry, as well as in water treatment for domestic and industrial application. Although these processes are known since twentieth century, there are still many studies that focus on the testing of new membranes' materials and determining of conditions for optimal selectivity, i. e. the optimum transmembrane pressure (TMP) or permeate flux to minimize fouling. Moreover the researchers proposed some calculation methods to predict the membrane processes properties. In this article, the laboratory scale experiments of membrane separation techniques, as well their validation by calculation methods are presented. Because membrane is the "heart" of the process, experimental and computational methods for its characterization are also described.

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

    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

  16. Cracking of crude oil in the molten metals

    Marat A. Glikin

    2014-03-01

    Full Text Available In this paper is investigated the process of crude oil and its individual fractions cracking in the molten metals medium to produce light petroleum products. Thermodynamic calculations demonstrate the possibility of using lead and tin including alloys thereof as the melt. The cracking of West Siberian crude oil is studied at temperatures 400-600 °C. It is detected that as the temperature increases there is increase of aromatic hydrocarbons and olefins content in gasoline while naphthenes, n- and i-paraffins content reduces. Optimal temperature for cracking in molten metals is ~500 °C. The use of a submerged nozzle increases the yield of light petroleum products by ~2%. The research octane number of gasoline produced is 82-87 points. It is determined that the yield of light petroleum products depending on the experimental conditions is increased from 46.9 to 55.1-61.3% wt.   

  17. Molecular dynamics calculation of shear viscosity for molten salt

    Okamoto, Yoshihiro; Yokokawa, Mitsuo; Ogawa, Toru

    1993-12-01

    A computer program of molecular dynamics simulation has been made to calculate shear viscosity of molten salt. Correlation function for an off-diagonal component of stress tensor can be obtained as the results of calculation. Shear viscosity is calculated by integration of the correlation function based on the Kubo-type formula. Shear viscosities for a molten KCl ranging in temperature from 1047K to 1273K were calculated using the program. Calculation of 10 5 steps (1 step corresponds to 5 x 10 -15 s) was performed for each temperature in the 216 ions system. The obtained results were in good agreement with the reported experimental values. The program has been vectorized to achieve a faster computation in supercomputer. It makes possible to calculate the viscosity using a large number of statistics amounting to several million MD steps. (author)

  18. Structure Formation Mechanisms during Solid Ti with Molten Al Interaction

    Gurevich, L; Pronichev, D; Trunov, M

    2016-01-01

    The study discuses advantages and disadvantages of previously proposed mechanisms of the formation of structure between solid Ti and molten Al and presents a new mechanism based on the reviewed and experimental data. The previously proposed mechanisms were classified into three groups: mechanisms of precipitation, mechanisms of destruction and mechanisms of chemical interaction between intermetallics and melt. The reviewed mechanisms did not explain the formation of heterogeneous interlayer with globular aluminide particles and thin layers of pure Al, while the present study reveals variation in the solid Ti/molten Al reaction kinetics during various phases of laminated metal-intermetallic composite formation. The proposed mechanism considers formed during composite fabrication thin oxide interlayers between Ti and Al evolution and its impact on the intermetallic compound formation and explains the initial slow rate of intermetallic interlayer formation and its subsequent acceleration when the oxide foils are ruptured. (paper)

  19. Molten salt treatment to minimize and optimize waste

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

    1993-01-01

    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

  20. Recent developments in the modeling of molten carbonate fuel cells

    Wilemski, G.

    1984-01-01

    Modeling of porous electrodes and overall performance of molten carbonate fuel cells is reviewed. Aspects needing improvement are discussed. Some preliminary results on internal methane reforming cells are presented. Successful modeling of molten carbonate fuel cells has been carried out at two levels. The first concerns the prediction of overall cell performance and performance decay, i.e., the calculation of current-voltage curves and their decay rates for various cell operating conditions. The second involves the determination of individual porous electrode performance, i.e., how the electrode overpotential is affected by pore structure, gas composition, degree of electrolyte fill, etc. Both levels are treated mechanistically, as opposed to empirically, using fundamental mathematical descriptions of the relevant physical and chemical phenomena, in order to provide quantitative predictive capability

  1. Ionic charge transport in strongly structured molten salts

    Tatlipinar, H.; Amoruso, M.; Tosi, M.P.

    1999-08-01

    Data on the d.c. ionic conductivity for strongly structured molten halides of divalent and trivalent metals near freezing are interpreted as mainly reflecting charge transport by the halogen ions. On this assumption the Nernst-Einstein relation allows an estimate of the translational diffusion coefficient D tr of the halogen. In at least one case (molten ZnCl 2 ) D tr is much smaller than the measured diffusion coefficient, pointing to substantial diffusion via neutral units. The values of D tr estimated from the Nernst-Einstein relation are analyzed on the basis of a model involving two parameters, i.e. a bond-stretching frequency ω and an average waiting time τ. With the help of Raman scattering data for ω, the values of τ are evaluated and found to mostly lie in the range 0.02 - 0.3 ps for a vast class of materials. (author)

  2. Steam explosion studies with single drops of molten refractory materials

    Nelson, L.S.

    1980-01-01

    Laser heating, levitation melting, and metal combustion were used to prepare individual drops of molten refractory materials which simulate LWR fuel melt products. Drop temperatures ranged from approx. = 1500 to > 3000K. These drops, several millimeters in diameter, were injected into water and subjected to pressure transients (approx. = 1MPa peak pressures) generated by a submerged exploding bridgewire. Molten oxides of Fe, Al and Zr could be induced to explode with bridgewire initiation. High speed films showed the explosions with exceptional clarity, and pressure transducer records could be correlated with individual frames in the films. Pressure spikes one or two MPa high were generated whenever an explosion occurred. Debris particles were mostly spheroidal, with diameters in the range 10 to 1000 μm

  3. Fuel cycle costs for molten-salt reactors

    Nagashima, Kikusaburo

    1983-01-01

    This report describes FCC (fuel cycle cost) estimates for MSCR (molten-salt converter reactor) and MSBR (molten-salt breeder reactor) compared with those for LWRs (PWR and BWR). The calculation is based on the present worth technique with a given discount rate for each cost item, which enables us to make comparison between FCC's for MSCR, MSBR and LWRs. As far as the computational results obtained here are concerned, shown that the FCC's for MSCR and MSBR are 70 -- 60 % lower than the values for LWRs. And it could be said that the FCC for MSCR (Pu-converter) is about 10 % lower than that for MSBR, because of the smaller amount of fissile inventory of MSCR than the inventory of MSBR. (author)

  4. Molten Triazolium Chloride Systems as New Aluminum Battery Electrolytes

    Vestergaard, B.; Bjerrum, Niels; Petrushina, Irina

    1993-01-01

    -170-degrees-C) depending on melt acidity and anode material. DMTC, being specifically adsorbed and reduced on the tungsten electrode surface, had an inhibiting effect on the aluminum reduction, but this effect was suppressed on the aluminum substrate. An electrochemical process with high current density (tens...... of milliamperes per square centimeter) was observed at 0.344 V on the acidic sodium tetrachloroaluminate background, involving a free triazolium radical mechanism. Molten DMTC-AlCl3 electrolytes are acceptable for battery performance and both the aluminum anode and the triazolium electrolyte can be used as active......The possibility of using molten mixtures of 1,4-dimethyl-1,2,4-triazolium chloride (DMTC) and aluminum chloride (AlCl3) as secondary battery electrolytes was studied, in some cases extended by the copresence of sodium chloride. DMTC-AlCl, mixtures demonstrated high specific conductivity in a wide...

  5. Structure and dynamic properties on molten cuprous halides

    Takeda, Shin' ichi [Department of Physics, Faculty of Sciences, Kyushu University, 4-2-1 Ropponmatsu Chuo-ku, Fukuoka 810 8560 (Japan)]. E-mail: takeda@rc.kyushu-u.ac.jp; Fujii, Hiroyuki [Graduate School of Sciences, Kyushu University, 4-2-1 Ropponmatsu Chuo-ku, Fukuoka 810 8560 (Japan); Japan Synchrotron Radiation Research Institute, 1-1-1 Kouto Mikazuki-cho, Sayo-gun, Hyogo 679 5198 (Japan); Kawakita, Yukinobu [Department of Physics, Faculty of Sciences, Kyushu University, 4-2-1 Ropponmatsu Chuo-ku, Fukuoka 810 8560 (Japan); Kato, Yasuhiko [Graduate School of Sciences, Kyushu University, 4-2-1 Ropponmatsu Chuo-ku, Fukuoka 810 8560 (Japan); Kohara, Sinji [Japan Synchrotron Radiation Research Institute, 1-1-1 Kouto Mikazuki-cho, Sayo-gun, Hyogo 679 5198 (Japan); Maruyama, Kenji [Department of Chemistry, Faculty of Science, 8050 Igarashi 2, Niigata University, Niigata 950 2181 (Japan)

    2006-11-15

    Neutron and X-ray diffraction measurements have been carried out for molten CuI at 650 deg. C. Both structure factors have been obtained in the wavenumber region beyond 20 A{sup -1}. The three partial structure factors and partial correlation functions have been derived from them with the aid of Reverse Monte Carlo analysis. The Cu-Cu correlation function has the first peak at 2.7 A penetrating into the first coordination shell of Cu-I correlation and a structureless tail, while the I-I correlation exibits long-range oscillations behind the first peak located around 4.35 A. The atomic arrangements for molten CuI are visualized in the figures.

  6. The multi region molten-salt reactor concept

    Gyula, Csom; Sandor, Feher; Szieberth, M.; Szabolcs, Czifrus

    2003-01-01

    The molten-salt reactor (MSR) concept is one of the most promising systems for the realisation of transmutation. The objective is the development of a transmutation technique along with a device implementing it, which yield higher transmutation efficiencies than that of the known procedures. The procedure is the multi-step transmutation, in which the transformation is carried out in several consecutive steps of different neutron flux and spectrum. In order to implement this, a multi-region transmutation device, i.e. nuclear reactor or sub-critical system is proposed, in which several separate flow-through irradiation rooms are formed with various neutron spectra and fluxes. The paper presents calculations that were performed for a special 5-region version of the multi-region molten-salt reactor. (author)

  7. On modeling of beryllium molten depths in simulated plasma disruptions

    Tsotridis, G.; Rother, H.

    1996-01-01

    Plasma-facing components in tokamak-type fusion reactors are subjected to intense heat loads during plasma disruptions. The influence of high heat fluxes on the depth of heat-affected zones of pure beryllium metal and beryllium containing very low levels of surface active impurities is studied by using a two-dimensional transient computer model that solves the equations of motion and energy. Results are presented for a range of energy densities and disruption times. Under certain conditions, impurities, through their effect on surface tension, create convective flows and hence influence the flow intensities and the resulting depths of the beryllium molten layers during plasma disruptions. The calculated depths of the molten layers are also compared with other mathematical models that are based on the assumption that heat is transported through the material by conduction only. 32 refs., 6 figs., 1 tab

  8. Using physical properties of molten glass to estimate glass composition

    Choi, Kwan Sik; Yang, Kyoung Hwa; Park, Jong Kil

    1997-01-01

    A vitrification process is under development in KEPRI for the treatment of low-and medium-level radioactive waste. Although the project is for developing and building Vitrification Pilot Plant in Korea, one of KEPRI's concerns is the quality control of the vitrified glass. This paper discusses a methodology for the estimation of glass composition by on-line measurement of molten glass properties, which could be applied to the plant for real-time quality control of the glass product. By remotely measuring viscosity and density of the molten glass, the glass characteristics such as composition can be estimated and eventually controlled. For this purpose, using the database of glass composition vs. physical properties in isothermal three-component system of SiO 2 -Na 2 O-B 2 O 3 , a software TERNARY has been developed which determines the glass composition by using two known physical properties (e.g. density and viscosity)

  9. Wettability of TiAlN films by molten aluminum

    Shen Ping [Joining and Welding Research Institute, Osaka University, 11-1 Mihogaoka Ibaraki, Osaka, 567-0047 (Japan) and Key Laboratory of Automobile Materials, Department of Materials Science and Engineering, Jilin University, No. 5988 Renmin Street, Changchun, 130025 (China)]. E-mail: shenping@jlu.edu.cn; Nose, Masateru [Department of Industrial Art and Craft, Takaoka National College, 180 Futagami-machi, Takaoka City, Toyama 933-8588 (Japan); Fujii, Hidetoshi [Joining and Welding Research Institute, Osaka University, 11-1 Mihogaoka Ibaraki, Osaka, 567-0047 (Japan); Nogi, Kiyoshi [Joining and Welding Research Institute, Osaka University, 11-1 Mihogaoka Ibaraki, Osaka, 567-0047 (Japan)

    2006-12-05

    In this study, we made an attempt to measure the wettability of the TiAlN films by molten Al at temperatures between 1073 K and 1273 K using an improved sessile drop method. The true contact angles cannot be obtained for the films deposited on the stainless steel and tungsten substrates due to considerable interdiffusion or reaction between molten Al and the substrate constituents. For the films deposited on the stable alumina single crystals and in contact with clean Al, the true contact angles are possible in the range of 80-100 deg. at 1173-1273 K and the work of adhesion is 0.77-1.08 J m{sup -2}. In the case of oxidized Al, typically at T < 1173 K, however, the wettability and the adhesion are significantly decreased.

  10. Decommissioning the Los Alamos Molten Plutonium Reactor Experiment (LAMPRE I)

    Harper, J.R.; Garde, R.

    1981-11-01

    The Los Alamos Molten Plutonium Reactor Experiment (LAMPRE I) was decommissioned at the Los Alamos National Laboratory, Los Alamos, New Mexico, in 1980. The LAMPRE I was a sodium-cooled reactor built to develop plutonium fuels for fast breeder applications. It was retired in the mid-1960s. This report describes the decommissioning procedures, the health physics programs, the waste management, and the costs for the operation

  11. Reactor chemical considerations of the accelerator molten-salt breeders

    Furukawa, Kazuo; Kato, Yoshio; Ohno, Hideo; Ohmichi, Toshihiko

    1982-01-01

    A single phase of the molten fluoride mixture is simultaneously functionable as a nuclear reaction medium, a heat medium and a chemical processing medium. Applying this characteristics of molten salts, the single-fluid type accelerator molten-salt breeder (AMSB) concept was proposed, in which 7 LiF-BeF 2 -ThF 4 was served as a target-and-blanket salt (Fig. 1 and Table 1), and the detailed discussion on the chemical aspects of AMSB are presented (Tables 2 -- 4 and Fig.2). Owing to the small total amount of radiowaste and the low concentrations of each element in target salt, AMSB would be chemically managable. The performance of the standard-type AMSB is improved by adding 0.3 -- 0.8 m/o 233 UF 4 as follows(Tables 1 and 4, and Figs. 2 and 3): (a) this ''high-gain'' type AMSB is feasible to design chemically, in which still only small amount of radiowaste is included ; (b) the fissile material production rate will be increased significantly; (c) this target salt is straightly fed as an 233 U additive to the fuel of molten-salt converter reactor (MSCR) ; (d) the dirty fuel salt suctioned from MSCR is batch-reprocessed in the safeguarded regional center, in which many AMSB are facilitated ; (e) the isolated 233 UF 4 is blended in the target salt sent to many MSCRs, and the cleaned residual fertile salt is used as a diluent of AMSB salt ; (f) this simple and rational thorium fuel breeding cycle system is also suitable for the nuclear nonproliferation and for the fabrication of smaller size power-stations. (author)

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

    Sasaki, A.; Shinoki, T.; Matsumura, M. [Mitsubishi Electric Corp., Hyogo (Japan)

    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).

  13. Cation exchange process for molten salt extraction residues

    Proctor, S.G.

    1975-01-01

    A new method, utilizing a cation exchange technique, has been developed for processing molten salt extraction (MSE) chloride salt residues. The developed ion exchange procedure has been used to separate americium and plutonium from gross quantities of magnesium, potassium, and sodium chloride that are present in the residues. The recovered plutonium and americium contained only 20 percent of the original amounts of magnesium, potassium, and sodium and were completely free of any detectable amounts of chloride impurity. (U.S.)

  14. Molten carbonate fuel cell cathode with mixed oxide coating

    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.

  15. Study of trans-uranian incineration in molten salt reactor

    Valade, M.

    2000-01-01

    With the emergence of new options for nuclear power, molten salt reactors are envisaged for waste management. The aim of this thesis is to show how molten salt reactors can help to solve the transuranics issue. Their high versatility regarding to isotopic vector allows to accommodate large fractions of minor actinides as compared to solid fuel system. In this thesis, a neutronics study of molten salt reactors, MSR, has been conducted. For this purpose, two reference systems were considered, TIER1 and AMSTER. In the case of TIER1, an optimisation was made to reach an equilibrium. The analysis of both systems showed the main characteristics of MSR: their link to chemistry and on line reprocessing. In this work, several methods to drive the system to a state of equilibrium have been implemented and compared. During this process the isotopic composition and neutron spectrum, thus the nuclear reaction cross sections, vary tremendously. It is essential to take these evolutions into account in order to accurately estimate the equilibrium state. This has been accomplished inside the multi-recycling procedure we set with ERANOS. A dedicated calculation schema has been realized to simulate superthermal systems with this computation code. These results were checked through a benchmark against other computer codes. Then, with multi-recycling method, several molten salt systems have been compared in order to define the optimal reactor for transuranics incineration. Nevertheless, a final choice can not only be done using only neutronics characteristics since chemistry and thermal-hydraulics constraints are really important for MSR. Moreover, a complete safety study would be required. (author)

  16. Electrodeposition of niobium and titanium in molten salts

    Sartori, A.F.; Chagas, H.C.

    1988-01-01

    The electrodeposition of niobium and titanium in molten fluorides from the additions of fluorine niobates and fluorine titanates of potassium is described in laboratory and pilot scale. The temperature influence, the current density and the time deposition over the current efficiency, the deposits structure and the deposits purity are studied. The conditions for niobium coating over copper and carbon steel and for titanium coating over carbon steel are also presented. (C.G.C.) [pt

  17. Primordial membranes

    Hanczyc, Martin M; Monnard, Pierre-Alain

    2017-01-01

    Cellular membranes, which are self-assembled bilayer structures mainly composed of lipids, proteins and conjugated polysaccharides, are the defining feature of cell physiology. It is likely that the complexity of contemporary cells was preceded by simpler chemical systems or protocells during...... the various evolutionary stages that led from inanimate to living matter. It is also likely that primitive membranes played a similar role in protocell 'physiology'. The composition of such ancestral membranes has been proposed as mixtures of single hydrocarbon chain amphiphiles, which are simpler versions...

  18. PRE design of a molten salt thorium reactor loop

    Caire, Jean-Pierre; Roure, Anthony

    2007-01-01

    This study is a contribution to the 2004 PCR-RSF program of the Centre National de la Recherche Scientifique (CNRS) devoted to research on high temperature thorium molten salt reactors. A major issue of high temperature molten salt reactors is the very large heat duty to be transferred from primary to secondary loop of the reactor with minimal thermal losses. A possible inner loop made of a series of conventional graphite filter plate exchangers, pipes and pumps was investigated. The loop was assumed to use two counter current flows of the same LiF, BeF 2 , ZrF 4 , UF 4 molten salt flowing through the reactor. The 3D model used the coupling of k-ε turbulent Navier-Stokes equations and thermal applications of the Heat Transfer module of COMSOL Multiphysics. For a reactor delivering 2700 MWth, the model required a set of 114 identical exchangers. Each one was optimized to limit the heat losses to 2882 W. The pipes made of a succession of graphite, ceramics, Hastelloy-N alloy and insulating Microtherm layers led to a thermal loss limited to 550 W per linear meter. In such conditions, the global thermal losses represent only 0.013% of the reactor thermal power for elements covered with an insulator only 3 cm thick. (author)

  19. Thermodynamic characterization of the molten salt reactor fuel - 5233

    Capelli, E.; Konings, R.J.M.; Benes, O.

    2015-01-01

    The Molten Salt Reactor (MSR) has been selected as one of the Generation IV nuclear systems. The very unique feature of this reactor concept is the liquid nature of the fuel which offers numerous advantages concerning the reactor safety. Nowadays, the research in Europe is focused on an innovative concept, the MSFR (Molten Salt Fast Reactor), that combines the generic assets of molten salt as liquid fuel with those related to fast neutron reactors and the thorium fuel cycle. For the design and safety assessment of the MSFR concept, it is extremely important to have a thorough knowledge of the physico-chemical properties of fluorides salts, which is the class of materials that is the best suited for nuclear applications. Potential chemical systems have been critically reviewed and an extensive thermodynamic database describing the most relevant systems has been created at the Institute for Transuranium Elements of the Joint Research Centre (JRC). Thermochemical equilibrium calculations are a very important tool that allows the evaluation of the performance of several salt mixtures predicting their properties and thus the optimization of the fuel composition. The work combines the experimental determination of different salt properties with the modelling of the thermodynamic functions, using the Calphad method. An overview of the experimental work and the thermodynamic assessments will be given in this paper and different fuel options for the MSFR will be discussed. (authors)

  20. Electromagnetic confinement for vertical casting or containing molten metal

    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.

  1. Molten salt processing of mixed wastes with offgas condensation

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

    1991-01-01

    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

  2. Structure and thermodynamic properties of molten alkali chlorides

    Ballone, P.; Pastore, G.; Tosi, M.P.; Trieste Univ.

    1984-03-01

    Self-consistent calculations of partial pair distribution functions and thermodynamic properties are presented for molten alkali chlorides in a non-polarizable-ion model. The theory starts from the hypernetted chain approximation and analyzes the role of bridge diagrams both for a two-component ionic plasma on a neutralizing background and for a binary ionic liquid of cations and anions. A simple account of excluded-volume effects suffices for a good description of the pair distribution functions in the two-component plasma, in analogy with earlier work on one-component fluids. The interplay of Coulomb attractions and repulsions in the molten salt requires, on the other hand, the inclusion of (i) excluded-volume effects for the various ion pairs as in a mixture of hard spheres with non-additive radii and (ii) medium-range Coulomb effects reflected mainly in the like-ion correlations. All these effects are included approximately in an empirical evaluation of the bridge functions, with numerical results which compare very well with computer simulation data. A detailed discussion of the results against experimental structural data is then given in the case of molten sodium chloride. (author)

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

    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.

  4. Densities of molten Ni-(Cr, Co, W) superalloys

    XIAO Feng; YANG Ren-hui; FANG Liang; LIU Lan-xiao; ZHAO Hong-kai

    2008-01-01

    In order to obtain more accurate density for molten Ni-(Cr, Co, W) binary alloy, the densities of molten pure Ni and Ni-Cr, Ni-Co, Ni-W alloys were measured with a sessile drop method. It is found that the measured densities of molten pure Ni and Ni-Cr, Ni-Co, Ni-W alloys decrease with increasing temperature in the experimental temperature range. The density of alloys increases with increasing W and Co concentrations while it decreases with increasing Cr concentration in the alloy at 1 773-1 873 K. The molar volume of Ni-based alloys increases with increasing W concentration while it decreases with increasing Co concentration. The effect of Cr concentration on the molar volume of the alloy is little in the studied concentration range. The accommodation among atomic species was analyzed. The deviation of molar volume from ideal mixing shows an ideal mixing of Ni-(Cr, Co, W) binary alloys.

  5. Candidate molten salt investigation for an accelerator driven subcritical core

    Sooby, E.; Baty, A.; Beneš, O.; McIntyre, P.; Pogue, N.; Salanne, M.; Sattarov, A.

    2013-09-01

    We report a design for accelerator-driven subcritical fission in a molten salt core (ADSMS) that utilizes a fuel salt composed of NaCl and transuranic (TRU) chlorides. The ADSMS core is designed for fast neutronics (28% of neutrons >1 MeV) to optimize TRU destruction. The choice of a NaCl-based salt offers benefits for corrosion, operating temperature, and actinide solubility as compared with LiF-based fuel salts. A molecular dynamics (MD) code has been used to estimate properties of the molten salt system which are important for ADSMS design but have never been measured experimentally. Results from the MD studies are reported. Experimental measurements of fuel salt properties and studies of corrosion and radiation damage on candidate metals for the core vessel are anticipated. A special thanks is due to Prof. Paul Madden for introducing the ADSMS group to the concept of using the molten salt as the spallation target, rather than a conventional heavy metal spallation target. This feature helps to optimize this core as a Pu/TRU burner.

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

    Vigier, Jean-François, E-mail: jean-francois.vigier@ec.europa.eu [CEA, Nuclear Energy Division, Radiochemistry & Processes Department, F-30207 Bagnols sur Cèze (France); Unité de Catalyse et de Chimie du Solide, UCCS UMR CNRS 8181, Univ. Lille Nord de France, ENSCL-USTL, B.P. 90108, 59652 Villeneuve d' Ascq Cedex (France); Laplace, Annabelle [CEA, Nuclear Energy Division, Radiochemistry & Processes Department, F-30207 Bagnols sur Cèze (France); Renard, Catherine [Unité de Catalyse et de Chimie du Solide, UCCS UMR CNRS 8181, Univ. Lille Nord de France, ENSCL-USTL, B.P. 90108, 59652 Villeneuve d' Ascq Cedex (France); Miguirditchian, Manuel [CEA, Nuclear Energy Division, Radiochemistry & Processes Department, F-30207 Bagnols sur Cèze (France); Abraham, Francis [Unité de Catalyse et de Chimie du Solide, UCCS UMR CNRS 8181, Univ. Lille Nord de France, ENSCL-USTL, B.P. 90108, 59652 Villeneuve d' Ascq Cedex (France)

    2016-06-15

    In the context of pyrochemical processes for nuclear fuel treatment, the precipitation of uranium (III) in molten salt LiCl-CaCl{sub 2} (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{sup −4.0}, the salt has oxoacid properties. Then, the uranium (III) precipitation using wet argon sparging is studied. The salt is prepared using UCl{sub 3} precursor. At the end of the precipitation, the salt is totally free of solubilized uranium. The main part is converted into UO{sub 2} 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. - Highlights: • Precipitation of Uranium (III) is quantitative in molten salt LiCl-CaCl{sub 2} (30–70 mol%). • The salt is oxoacid with a water dissociation constant of 10{sup −4.0} at 705 °C. • Volatility of uranium chloride is strongly reduced in reductive conditions. • Coprecipitation of U(III) and Nd(III) leads to a consecutive precipitation of the two elements.

  7. Study on corrosion of metal materials in nitrate molten salts

    Zhai, Wei; Yang, Bo; Li, Maodong; Li, Shiping; Xin, Mingliang; Zhang, Shuanghong; Huang, Guojia

    2017-01-01

    High temperature molten salts as a heat transfer heat storage medium has been more widely used in the field of concentrated solar thermal power generation. In the thermal heat storage system, metal material stability and performance at high temperatures are of one major limitation in increasing this operating temperature. In this paper, study on corrosion of 321H, 304, 316L, P91 metal materials in modified solar two molten salts. The corrosion kinetics of 304, 316L, 321H, P91 metal material in the modified solar two molten salts at 450°C, 500°C is also investigated. Under the same condition it was found that 304, 321H corroded at a rate of 40% less than P91. Spallation of corrosion products was observed on P91 steel, while no obvious observed on other kinds of stainless steel. Corrosion rates of 304, 321H, and 316L slowly increased with temperature. Oxidation mechanisms little varied with temperature. Corrosion products of metal materials observed at 450°C, 500°C were primarily Fe oxide and Fe, Cr oxide.

  8. Corrosion resistance of metals and alloys in molten alkalies

    Zarubitskij, O.G.; Dmitruk, B.F.; Minets, L.A.

    1979-01-01

    Literature data on the corrosion of non-ferrous and noble metals, iron and steels in the molten alkalis and mixtures of their base are presented. It is shown that zirconium, niobium and tantalum are characterized by high corrosion stability in the molten NaOH. Additions of NaOH and KOH to the alkali chloride melts result in a 1000 time decrease of zirconium corrosion rate at 850 deg. The data testify to the characteristic passivating properties of OH - ions; Mo and W do not possess an ability to selfpassivation in hydroxide melts. Corrosion resistance of carbon and chromium-nickel steels in hydroxide melts depends considerably on the temperature, electrolyte composition and atmosphere over them. At the temperatures up to 600 deg C chromium-nickel steel is corrosion resistant in the molten alkali only in the inert atmosphere. Corrosion rate of chromium-nickel alloy is the lower the less chromium and the more nickel it contains. For the small installations the 4Kh18N25S2 and Kh23N28M3D3T steels can be recommended

  9. Simplified Reference Electrode for Electrorefining of Spent Nuclear Fuel in High Temperature Molten Salt

    Kim Davies; Shelly X Li

    2007-01-01

    Pyrochemical processing plays an important role in development of proliferation-resistant nuclear fuel cycles. At the Idaho National Laboratory (INL), a pyrochemical process has been implemented for the treatment of spent fuel from the Experimental Breeder Reactor II (EBR-II) in the last decade. Electrorefining in a high temperature molten salt is considered a signature or central technology in pyroprocessing fuel cycles. Separation of actinides from fission products is being demonstrated by electrorefining the spent fuel in a molten UCl3-LiCl-KCl electrolyte in two engineering scale electrorefiners (ERs). The electrorefining process is current controlled. The reference electrode provides process information through monitoring of the voltage difference between the reference and the anode and cathode electrodes. This information is essential for monitoring the reactions occurring at the electrodes, investigating separation efficiency, controlling the process rate, and determining the process end-point. The original reference electrode has provided good life expectancy and signal stability, but is not easily replaceable. The reference electrode used a vycor-glass ion-permeable membrane containing a high purity silver wire with one end positioned in ∼2 grams of LiCl/KCl salt electrolyte with a low concentration (∼1%) AgCl. It was, however, a complex assembly requiring specialized skill and talent to fabricate. The construction involved multiple small pieces, glass joints, ceramic to glass joints, and ceramic to metal joints all assembled in a high purity inert gas environment. As original electrodes reached end-of-life it was uncertain if the skills and knowledge were readily available to successfully fabricate replacements. Experimental work has been conducted to identify a simpler electrode design while retaining the needed long life and signal stability. This improved design, based on an ion-permeable membrane of mullite has been completed. Use of the silver

  10. Simplified Reference Electrode for Electrorefining of Spent Nuclear Fuel in High Temperature Molten Salt

    Kim Davies; Shelly X Li

    2007-09-01

    Pyrochemical processing plays an important role in development of proliferation- resistant nuclear fuel cycles. At the Idaho National Laboratory (INL), a pyrochemical process has been implemented for the treatment of spent fuel from the Experimental Breeder Reactor II (EBR-II) in the last decade. Electrorefining in a high temperature molten salt is considered a signature or central technology in pyroprocessing fuel cycles. Separation of actinides from fission products is being demonstrated by electrorefining the spent fuel in a molten UCl3-LiCl-KCl electrolyte in two engineering scale electrorefiners (ERs). The electrorefining process is current controlled. The reference electrode provides process information through monitoring of the voltage difference between the reference and the anode and cathode electrodes. This information is essential for monitoring the reactions occurring at the electrodes, investigating separation efficiency, controlling the process rate, and determining the process end-point. The original reference electrode has provided good life expectancy and signal stability, but is not easily replaceable. The reference electrode used a vycor-glass ion-permeable membrane containing a high purity silver wire with one end positioned in ~2 grams of LiCl/KCl salt electrolyte with a low concentration (~1%) AgCl. It was, however, a complex assembly requiring specialized skill and talent to fabricate. The construction involved multiple small pieces, glass joints, ceramic to glass joints, and ceramic to metal joints all assembled in a high purity inert gas environment. As original electrodes reached end-of-life it was uncertain if the skills and knowledge were readily available to successfully fabricate replacements. Experimental work has been conducted to identify a simpler electrode design while retaining the needed long life and signal stability. This improved design, based on an ion-permeable membrane of mullite has been completed. Use of the silver wire

  11. Pourbaix diagrams of actinides in molten chlorides using an indicating electrode for oxide ion activity

    Lambertin, D.; Lacquement, J.

    2000-01-01

    Pyrochemical separation methods using high temperature molten salt media could emerge as promising and valuable routes compared with aqueous methods for separation and transmutation strategies for long-lived radionuclides. A good knowledge of the molten salt chemistry is essential for controlling these separations, and elementary data are required for molten halide salts, which can be readily provided by electrochemical methods. Applying the chemical principles of aqueous solutions to the molten salt media, Pourbaix diagrams - called in this case potential-oxo-acidity (pO 2- ) - can be plotted. They offer a rapid and comprehensive view of the thermodynamic properties of selected elements in a solvent of interest. Two methods are available for preparing these diagrams. The first is based on available thermodynamic data on pure element oxide (and oxychloride) compounds and on element chloride activity coefficients in melt (which can be electrochemically determined). In this method, we consider the oxide anion exchange reactions between the pure compounds, water and hydrogen chloride. The second method is a direct and experimental determination of the oxo-acidic properties of the studied element chlorides in melts. Use of an Yttria-Stabilised Zirconia Membrane (YSZM) electrode (oxide anion selective electrode) helps determine the nature of the stable oxide compounds in melts as well as their stabilities. The YSZM is used with a silver/silver chloride reference system, and was developed 25 years ago. Two examples of Potential-acidity diagrams. Employing the first method and the determination of the standard potential of plutonium in LiCl-KCl and NaCl-KCl eutectic mixtures, potential-oxo-acidity diagrams were plotted for these melts at various temperatures. It was found that the stability domain for plutonium chloride depends on the melt composition (influence of oxide anion solvation). We also used the Omega acidity function - based on reaction (1) - which is a

  12. Membranous nephropathy

    ... skin-lightening creams Systemic lupus erythematosus , rheumatoid arthritis, Graves disease, and other autoimmune disorders The disorder occurs at ... diagnosis. The following tests can help determine the cause of membranous nephropathy: Antinuclear antibodies test Anti-double- ...

  13. Thermal behavior of molten corium during TMI-2 core relocation event

    Anderson, J.L.; Sienicki, J.J.

    1988-01-01

    During the TMI-2 accident, a pool of molten corium formed in the central region of the core and was contained by solidified crusts. Failure of the crust surrounding the molten material, at approximately 224 min, resulted in a relocation of an estimated 20-25 tons of molten corium through peripheral fuel assemblies in the east side of the vessel, as well as through the core barrel assembly (CBA) at the periphery of the core. This paper presents the results of an analyses carried out to investigate the thermal interactions of molten corium with the CBA structures during the relocation event. The principal objectives of the analyses are: (a) to assess the potential for relocation to take place through the CBA versus the flow of molten core material directly downward through the core via the fuel assemblies; and (b) to understand the distribution of prior molten corium observed during vessel defueling examinations. 5 refs., 1 fig

  14. Online monitoring of corrosion behavior in molten metal using laser-induced breakdown spectroscopy

    Zeng, Qiang; Pan, Congyuan; Li, Chaoyang; Fei, Teng; Ding, Xiaokang; Du, Xuewei; Wang, Qiuping

    2018-04-01

    The corrosion behavior of structure materials in direct contact with molten metals is widespread in metallurgical industry. The corrosion of casting equipment by molten metals is detrimental to the production process, and the corroded materials can also contaminate the metals being produced. Conventional methods for studying the corrosion behavior by molten metal are offline. This work explored the application of laser-induced breakdown spectroscopy (LIBS) for online monitoring of the corrosion behavior of molten metal. The compositional changes of molten aluminum in crucibles made of 304 stainless steel were obtained online at 1000 °C. Several offline techniques were combined to determine the corrosion mechanism, which was highly consistent with previous studies. Results proved that LIBS was an efficient method to study the corrosion mechanism of solid materials in molten metal.

  15. Electrochemical behavior for a reduction of uranium oxide in a LiCl-Li2O molten salt with an integrated cathode assembly

    Park, Sung Bin; Park, Byung Heung; Seo, Chung Seok; Jung, Ki Jung; Park, Seong Won

    2005-01-01

    Electrolytic reduction of uranium oxide to uranium metal was studied in a LiCl-Li 2 O molten salt system. The reduction mechanism of the uranium oxide to a uranium metal has been studied by means of a cyclic voltammetry. Effects of the layer thickness of the uranium oxide and the thickness of the MgO on the overpotential of the cathode and the anode were investigated by means of a chronopotentiometry. From the cyclic voltamograms, the decomposition potentials of the metal oxides are the determining factors for the mechanism of the reduction of the uranium oxide in a Li Cl-3 wt% Li 2 O molten salt and the two mechanisms of the electrolytic reduction were considered with regards to the applied cathode potential. In the chronopotentiograms, the exchange current and the transfer coefficient based on the Tafel behavior were obtained with regard to the layer thickness of the uranium oxide which is loaded into the porous MgO membrane and the thickness of the porous MgO membrane. The maximum allowable currents for the changes of the layer thickness of the uranium oxide and the thickness of the MgO membrane were also obtained from the limiting potential which is the decomposition potential of LiCl

  16. Dissolution of Si in Molten Al with Gas Injection

    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

  17. State-of-the-Art Report on Molten Corium Concrete Interaction and Ex-Vessel Molten Core Coolability

    Bonnet, Jean-Michel; Cranga, Michel; Vola, Didier; Marchetto, Cathy; Kissane, Martin; ); Robledo, Fernando; Farmer, Mitchel T.; Spengler, Claus; Basu, Sudhamay; Atkhen, Kresna; Fargette, Andre; Fisher, Manfred; Foit, Jerzi; Hotta, Akitoshi; Morita, Akinobu; Journeau, Christophe; Moiseenko, Evgeny; Polidoro, Franco; Zhou, Quan

    2017-01-01

    Activities carried out over the last three decades in relation to core-concrete interactions and melt coolability, as well as related containment failure modes, have significantly increased the level of understanding in this area. In a severe accident with little or no cooling of the reactor core, the residual decay heat in the fuel can cause the core materials to melt. One of the challenges in such cases is to determine the consequences of molten core materials causing a failure of the reactor pressure vessel. Molten corium will interact, for example, with structural concrete below the vessel. The reaction between corium and concrete, commonly referred to as MCCI (molten core concrete interaction), can be extensive and can release combustible gases. The cooling behaviour of ex-vessel melts through sprays or flooding is also complex. This report summarises the current state of the art on MCCI and melt coolability, and thus should be useful to specialists seeking to predict the consequences of severe accidents, to model developers for severe-accident computer codes and to designers of mitigation measures

  18. Thorium cycle and molten salt reactors: field parameters and field constraints investigations toward 'thorium molten salt reactor' definition

    Mathieu, L.

    2005-09-01

    Producing nuclear energy in order to reduce the anthropic CO 2 emission requires major technological advances. Nuclear plants of 4. generation have to respond to several constraints, as safety improvements, fuel breeding and radioactive waste minimization. For this purpose, it seems promising to use Thorium Cycle in Molten Salt Reactors. Studies on this domain have already been carried out. However, the final concept suffered from serious issues and was discontinued. A new reflection on this topic is being led in order to find acceptable solutions, and to design the Thorium Molten Salt Reactor concept. A nuclear reactor is simulated by the coupling of a neutron transport code with a materials evolution code. This allows us to reproduce the reactor behavior and its evolution all along its operation. Thanks to this method, we have studied a large number of reactor configurations. We have evaluated their efficiency through a group of constraints they have to satisfy. This work leads us to a better understanding of many physical phenomena controlling the reactor behavior. As a consequence, several efficient configurations have been discovered, allowing the emergence of new points of view in the research of Molten Salt Reactors. (author)

  19. On the chemical constitution of a molten oxide core of a fast breeder reactor

    Hodkin, D.J.; Potter, P.E.

    1980-01-01

    A knowledge of the chemical constitution of a molten oxide fast reactor core is of great importance in the assessment of heat transfer from a cooling molten pool of debris and in the selection of materials for the construction of sacrificial beds for core containment. In this paper we describe some thermodynamic assessments of the likely chemical constitution of a molten oxide core, and then support our assessments by experimental observations

  20. Molten pool-lower head integrity. Heat transfer models including advanced numerical simulations (DNS)

    Seiler, J.M.; Bonnet, J.M.; Bernaz, L.

    2001-01-01

    Extensive studies have been performed to investigate the heat transfer within a molten corium pool (homogeneous, stratified and with miscibility gap): Synthesis of heat transfer correlations in molten pool (homogeneous and stratified), Focusing effect in stratified metal layer, DNS analysis of Rayleigh Benard instabilities at the top boundary; interpretation of the different convection regimes and exponents affecting the Rayleigh number in the heat transfer correlations, Molten pool model for corium presenting a miscibility gap. Condition for de-stratification. (authors)

  1. Molten salt oxidation of organic hazardous waste with high salt content.

    Lin, Chengqian; Chi, Yong; Jin, Yuqi; Jiang, Xuguang; Buekens, Alfons; Zhang, Qi; Chen, Jian

    2018-02-01

    Organic hazardous waste often contains some salt, owing to the widespread use of alkali salts during industrial manufacturing processes. These salts cause complications during the treatment of this type of waste. Molten salt oxidation is a flameless, robust thermal process, with inherent capability of destroying the organic constituents of wastes, while retaining the inorganic ingredients in the molten salt. In the present study, molten salt oxidation is employed for treating a typical organic hazardous waste with a high content of alkali salts. The hazardous waste derives from the production of thiotriazinone. Molten salt oxidation experiments have been conducted using a lab-scale molten salt oxidation reactor, and the emissions of CO, NO, SO 2 , HCl and dioxins are studied. Impacts are investigated from the composition of the molten salts, the types of feeding tube, the temperature of molten carbonates and the air factor. Results show that the waste can be oxidised effectively in a molten salt bath. Temperature of molten carbonates plays the most important role. With the temperature rising from 600 °C to 750 °C, the oxidation efficiency increases from 91.1% to 98.3%. Compared with the temperature, air factor has but a minor effect, as well as the composition of the molten salts and the type of feeding tube. The molten carbonates retain chlorine with an efficiency higher than 99.9% and the emissions of dioxins are below 8 pg TEQ g -1 sample. The present study shows that molten salt oxidation is a promising alternative for the disposal of organic hazardous wastes containing a high salt content.

  2. Molten pool-lower head integrity. Heat transfer models including advanced numerical simulations (DNS)

    Seiler, J.M.; Bonnet, J.M.; Bernaz, L. [CEA Grenoble (France)

    2001-07-01

    Extensive studies have been performed to investigate the heat transfer within a molten corium pool (homogeneous, stratified and with miscibility gap): Synthesis of heat transfer correlations in molten pool (homogeneous and stratified), Focusing effect in stratified metal layer, DNS analysis of Rayleigh Benard instabilities at the top boundary; interpretation of the different convection regimes and exponents affecting the Rayleigh number in the heat transfer correlations, Molten pool model for corium presenting a miscibility gap. Condition for de-stratification. (authors)

  3. The molten salt reactor: R and D status and perspectives in Europe

    Renault, Claude; Delpech, Sylvie; Merle-Lucotte, Elsa; Konings, Rudy; Hron, Miloslav; Ignatiev, Victor

    2010-01-01

    The paper concentrates on molten salt fast reactor (MSFR) concepts which are receiving most attention in the EU context. It shows the main R and D achievements and some remaining issues to be addressed in such essential areas as (a) reactor conceptual design, (b) molten salt properties, (c) fuel salt clean-up scheme and (d) high temperature materials. The status and perspectives of molten salt reactor R and D efforts in Europe are then discussed

  4. Study of the pyrochemical treatment-recycling process of the Molten Salt Reactor fuel

    Boussier, H.; Heuer, D.

    2010-01-01

    The Separation Processes Studies Laboratory (Commissariat a l'energie Atomique) has made a preliminary assessment of the reprocessing system associated with Molten Salt Fast Reactor (MSFR). The scheme studied in this paper is based on the principle of reductive extraction and metal transfer that constituted the core process designed for the Molten Salt Breeder Reactor (MSBR), although the flow diagram has been adapted to the current needs of the Molten Salt Reactor Fast (MSFR).

  5. Hybrid Molten Bed Gasifier for High Hydrogen Syngas Production

    Rue, David [Gas Technology Institute, Des Plaines, IL (United States)

    2017-05-23

    The techno-economic analyses of the hybrid molten bed gasification technology and laboratory testing of the HMB process were carried out in this project by the Gas Technology Institute and partner Nexant, Inc. under contract with the US Department of Energy’s National Energy Technology Laboratory. This report includes the results of two complete IGCC and Fischer-Tropsch TEA analyses comparing HMB gasification with the Shell slagging gasification process as a base case. Also included are the results of the laboratory simulation tests of the HMB process using Illinois #6 coal fed along with natural gas, two different syngases, and steam. Work in this 18-month project was carried out in three main Tasks. Task 2 was completed first and involved modeling, mass and energy balances, and gasification process design. The results of this work were provided to Nexant as input to the TEA IGCC and FT configurations studied in detail in Task 3. The results of Task 2 were also used to guide the design of the laboratory-scale testing of the HMB concept in the submerged combustion melting test facility in GTI’s industrial combustion laboratory. All project work was completed on time and budget. A project close-out meeting reviewing project results was conducted on April 1, 2015 at GTI in Des Plaines, IL. The hybrid molten bed gasification process techno-economic analyses found that the HMB process is both technically and economically attractive compared with the Shell entrained flow gasification process. In IGCC configuration, HMB gasification provides both efficiency and cost benefits. In Fischer-Tropsch configuration, HMB shows small benefits, primarily because even at current low natural gas prices, natural gas is more expensive than coal on an energy cost basis. HMB gasification was found in the TEA to improve the overall IGCC economics as compared to the coal only Shell gasification process. Operationally, the HMB process proved to be robust and easy to operate. The burner

  6. Study for electrochemical behavior of uranium oxide in a molten LiCl-Li2O system

    Park, Sung Bin; Park, Byung Heung; Seo, Chung Seok; Jung, Ki Jung; Park, Seong Won

    2005-01-01

    Interest in the electrolytic reduction of uranium oxide is increasing in the treatment of spent fuel oxides. With complicated and expensive procedures many reactive metals can be prepared in a pure metal form, the electrochemical reduction of a metal oxide has been recently proposed in metallurgy. The electrochemical reduction process is simple and rapid when compared to the conventional processes. The process can reduce the production costs and be applicable to a wide range of metal oxides. Chen et al. proposed the direct electrochemical reduction of titanium dioxide to titanium in a molten calcium chloride. Argonne National Laboratory (ANL) has reported the experimental results of an electrochemical reduction of the uranium oxide fuel in a bench-scale apparatus with a cyclic voltammetry, and has designed high-capacity reduction (HCR) cells and conducted three kg-scale UO 2 reduction runs. Gourishankar et al. classified the mechanisms of the electrolytic reduction of the metal oxides in a LiCl-Li 2 O molten salt system into two types; the simultaneous reduction and the direct electrochemical reduction. The uranium oxide in LiCl-Li 2 O molten salt was converted to uranium metal according to two mechanisms. Korea Atomic Energy Research Institute (KAERI) has developed the Advanced Spent Fuel Conditioning Process (ACP) to be an innovative technology in handling the PWR spent fuel. As part of ACP, the electrolytic reduction process (ER process) is the electrochemical reduction process of uranium oxide to uranium metal in molten salt. The ER process has advantages in a technical stability, an economic potential and a good proliferation resistance. KAERI has reported on the good experimental results of an electrochemical reduction of the uranium oxide in a 20 kg HM/batch lab-scale. In this work, cyclic voltammograms for a LiCl-3 wt% Li 2 O system and an U 3 O 8 -LiCl-3 wt% Li 2 O system with the integrated cathode assembly have been obtained. From the cyclic

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

    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.

  8. Electrochemical behavior of uranium oxide in a LiCl-Li2O molten salt with the integrated cathode assembly

    Park, Sung Bin; Park, Byung Heung; Kang, Dae Seoung; Kwon, Seon Gil; Seo, Chung Seok; Park, Seong Won

    2005-01-01

    Electrochemical reduction of uranium oxide to uranium metal was studied in a LiCl-Li 2 O molten salt system. By means of a cyclic voltammetry and a chronopotentiometry, the electrolytic reduction of uranium oxide has been studied to establish the reduction mechanisms and the effects of the thickness of the uranium oxide on the overpotential of the cathode and anode were investigated. From the voltamograms, the reduction potentials of the uranium oxide and Li 2 O were obtained and the two mechanisms of the electrolytic reduction were considered with regards to the applied cathode potential. In the chronopotentiograms, the exchange current, the transfer coefficient and the maximum allowable current based on the Tafel behavior were obtained according to the thickness of the uranium oxide which is loaded into the porous MgO membrane. (author)

  9. Axionic membranes

    Aurilia, A.; Spallucci, E.

    1992-01-01

    A metal ring removed from a soap-water solution encloses a film of soap which can be mathematically described as a minimal surface having the ring as its only boundary. This is known to everybody. In this letter we suggest a relativistic extension of the above fluidodynamic system where the soap film is replaced by a Kalb-Ramand gauge potential B μν (x) and the ring by a closed string. The interaction between the B μν field and the string current excites a new configuration of the system consisting of a relativistic membrane bounded by the string. We call such a classical solution of the equation of motion an axionic membrane. As a dynamical system, the axionic membrane admits a Hamilton-Jacobi formulation which is an extension of the HJ theory of electromagnetic strings. (orig.)

  10. Metamaterial membranes

    Restrepo-Flórez, Juan Manuel; Maldovan, Martin

    2017-01-01

    We introduce a new class of metamaterial device to achieve separation of compounds by using coordinate transformations and metamaterial theory. By rationally designing the spatial anisotropy for mass diffusion, we simultaneously concentrate different compounds in different spatial locations, leading to separation of mixtures across a metamaterial membrane. The separation of mixtures into their constituent compounds is critically important in biophysics, biomedical, and chemical applications. We present a practical case where a mixture of oxygen and nitrogen diffusing through a polymeric planar matrix is separated. This work opens doors to new paradigms in membrane separations via coordinate transformations and metamaterials by introducing novel properties and unconventional mass diffusion phenomena. (paper)

  11. Preliminary safety analysis of molten salt breeder reactor

    Cheng Maosong; Dai Zhimin

    2013-01-01

    Background: The molten salt reactor is one of the six advanced reactor concepts identified by the Generation IV International Forum as a candidate for cooperative development, which is characterized by remarkable advantages in inherent safety, fuel cycle, miniaturization, effective utilization of nuclear resources and proliferation resistance. ORNL finished the conceptual design of Molten Salt Breeder Reactor (MSBR) based on the design, building and operation of Molten Salt Reactor Experiment (MSRE). Purpose: We attempt to implement the preliminary safety analysis of MSBR in order to provide a reference for the design and optimization of MSBR in the future. Methods: According to the conceptual design of MSBR, a model of safety analysis using point kinetics coupled with the simplified heat transfer mechanism is presented. The model is applied to simulate the transient phenomena of MSBR initiated by an abnormal step reactivity addition and an abnormal ramp reactivity addition at full-power equilibrium condition. Results: The thermal power in the core increases rapidly at the beginning and is accompanied by a rise of the fuel and graphite temperatures after 100, 300, 500 and 600 pcm reactivity addition. The maximum outlet temperature of the fuel in the core is at 1250℃ in 500 pcm reactivity addition, but up to 1350℃ in 600 pcm reactivity addition. The maximum of the power and the temperature are delayed and lower in the ramp reactivity addition rather than in the step reactivity addition. Conclusions: Based on the results, when the reactivity inserted is less than 500 pcm in maximum at full power equilibrium condition, the structural material in Hastelloy-N is not melted and can keep integrity without external control action. And it is necessary to try to avoid inserting a reactivity at short time. (authors)

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

    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

  13. Molten salt reactors: A new beginning for an old idea

    LeBlanc, David

    2010-01-01

    Molten salt reactors have seen a marked resurgence of interest over the past decade, highlighted by their inclusion as one of six Generation IV reactor types. The most active development period however was between the mid 1950s and early 1970s at Oak Ridge National Laboratories (ORNL) and any new re-examination of this concept must bear in mind the far different priorities then in place. High breeding ratios and short doubling times were paramount and this guided the evolution of the Molten Salt Breeder Reactor (MSBR) program. As the inherent advantages of the molten salt concept have become apparent to an increasing number of researchers worldwide it is important to not simply look to continue where ORNL left off but to return to basics in order to offer the best design using updated goals and abilities. A major potential change to the traditional Single Fluid, MSBR design and a subject of this presentation is a return to the mode of operation that ORNL proposed for the majority of its MSR program. That being the Two Fluid design in which separate salts are used for fissile 233 UF 4 and fertile ThF 4 . Oak Ridge abandoned this promising route due to what was known as the 'plumbing problem'. It will be shown that a simple yet crucial modification to core geometry can solve this problem and enable the many advantages of the Two Fluid design. In addition, another very promising route laid out by ORNL was simplified Single Fluid converter reactors that could obtain far superior lifetime uranium utilization than LWR or CANDU without the need for any fuel processing beyond simple chemistry control. Updates and potential improvements to this very attractive concept will also be explored.

  14. Metal-carbide multilayers for molten Pu containment

    Summers, T.S.E.; Curtis, P.G.; Juntz, R.S.; Krueger, R.L.

    1991-12-01

    Multilayers composed of nine or ten alternating layers of Ta or W and TaC were studied for the feasibility of their use in containing molten plutonium (Pu) at 1200 degrees C. Single layers of W and TaC were also investigated. A two-source electron beam evaporation process was developed to deposit these coatings onto the inside surface of hemispherical Ta cups about 38 mm in diameter. Pu testing was done by melting Pu in the coated hemispherical cups and holding them under vacuum at 1200 degrees C for two hours. Metallographic examination and microprobe analysis of cross sections showed that Pu had penetrated to the Ta substrate in all cases to some extent. Full penetration to the outer surface of the Ta substrate, however, occurred in only a few of the samples. The fact that full penetration occurred in any of the samples suggests that it would have occurred in uncoated Ta under these testing conditions which in turn suggests that the multilayer coatings do afford some protection against Pu attack. The TaC used for these specimens was wet by Pu under these testing conditions, and following testing, Pu was found uniformly distributed throughout the carbide layers which appeared to be rather porous. Pu was seen in the W and Ta layers only when exposed directly to molten Pu during testing or near defects suggesting that Pu penetrated the multilayers at defects in the coating and traveled parallel to the layers along the carbide layers. These results indicate that the use of alternating metal and ceramic layers for Pu containment should be possible through the use of nonporous ceramic that is not wet by molten Pu and defect-free films

  15. Modelling transient energy release from molten fuel coolant interaction debris

    Fletcher, D.F.

    1984-05-01

    A simple model of transient energy release in a Molten Fuel Coolant Interaction is presented. A distributed heat transfer model is used to examine the effect of heat transfer coefficient, time available for rapid energy heat transfer and particle size on transient energy release. The debris is assumed to have an Upper Limit Lognormal distribution. Model predictions are compared with results from the SUW series of experiments which used thermite-generated uranium dioxide molybdenum melts released below the surface of a pool of water. Uncertainties in the physical principles involved in the calculation of energy transfer rates are discussed. (author)

  16. Opportunities in the electrowinning of molten titanium from titanium dioxide

    Van Vuuren, DS

    2005-10-01

    Full Text Available used, the following forms of titanium are produced: titanium sponge, sintered electrode sponge, powder, molten titanium, electroplated titanium, hydride powder, and vapor-phase depos- ited titanium. Comparing the economics of alter- native...-up for producing titanium via the Kroll process is approximately as follows: ilmenite ($0.27/kg titanium sponge); titanium slag ($0.75/kg titanium sponge); TiCl4 ($3.09/kg titanium sponge); titanium sponge raw materials costs ($5.50/kg titanium sponge); total...

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

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

    1994-01-01

    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 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

  18. Fission product behavior in the Molten Salt Reactor Experiment

    Compere, E.L.; Kirslis, S.S.; Bohlmann, E.G.; Blankenship, F.F.; Grimes, W.R.

    1975-10-01

    Essentially all the fission product data for numerous and varied samples taken during operation of the Molten Salt Reactor Experiment or as part of the examination of specimens removed after particular phases of operation are reported, together with the appropriate inventory or other basis of comparison, and relevant reactor parameters and conditions. Fission product behavior fell into distinct chemical groups. Evidence for fission product behavior during operation over a period of 26 months with 235 U fuel (more than 9000 effective full-power hours) was consistent with behavior during operation using 233 U fuel over a period of about 15 months (more than 5100 effective full-power hours)

  19. Coating applications for the molten carbonate fuel cell

    Pigeaud, A.; Skok, A.J.; Patel, P.S.; Maru, H.C.

    1981-09-25

    The molten carbonate fuel cell is a highly efficient low polluting fuel-to-electricity conversion device which is at present being developed for power plant and industrial use. Because the alkali carbonates at the operating temperature of 650/sup 0/C are corrosive and the methods employed for sealing the cell lead to certain electrochemical corrosion couples, different types of protective coatings are needed to minimize attack in a cost-effective manner. Besides protective purposes, other opportunities are also described where coating technology can be gainfully employed in this system.

  20. Kinetics, dynamics and neutron noise in Molten Salt Reactors

    Pazsit, Imre

    2013-01-01

    Reactor kinetic and dynamic properties of Molten Salt Reactors (MSR) are investigated in a simple model, which allows closed compact analytical solutions to be obtained. The goal is to gain insight, rather than to produce high-quality quantitative data. Through an interpretation of the different terms in the basic equations, and by means of analytical solutions, various approximations are introduced and their validity discussed. The dynamical behaviour of MSRs and their response to small stationary perturbations is described and discussed in comparison with traditional systems. (author)

  1. Calculation of the evolution of molten salt breeder reactor

    Esteves, Fernando de Avelar

    1999-01-01

    A forecast for the future electrical consumption in Brazil and forecast of the nuclear electrical generation demand are discussed in this paper, which includes also an analysis on advanced nuclear reactors concept to supply that demand. This paper presents a concise description of the Molten Salt Breeder Reactor, considered the most appropriated to meet that demand. This paper also presents the burnup calculation modeling, including the operation modeling of this type of reactor from an initial load o 233 U up to the equilibrium cycle, the results of these calculations and its analysis. (author)

  2. Corrosion of vessel steel during its interaction with molten corium

    Bechta, S.V.; Khabensky, V.B.; Vitol, S.A.; Krushinov, E.V.; Granovsky, V.S.; Lopukh, D.B.; Gusarov, V.V.; Martinov, A.P.; Martinov, V.V.; Fieg, G.; Tromm, W.; Bottomley, D.; Tuomisto, H.

    2006-01-01

    An experimental examination of the cooled vessel steel corrosion during the interaction with molten corium is presented. The experiments have been conducted on 'Rasplav-2' test facility and followed up with physico-chemical and metallographic analyses of melt samples and corium-specimen ingots. The results discussed in the first part of the paper have revealed specific corrosion mechanisms for air and inert atmosphere above the melt. Models have been proposed based on this information and approximate curves constructed for the estimation of the corrosion rate or corrosion depth of vessel steel in conditions simulated by the experiments

  3. Corrosion of vessel steel during its interaction with molten corium

    Bechta, S.V.; Khabensky, V.B.; Vitol, S.A.; Krushinov, E.V.; Granovsky, V.S.; Lopukh, D.B.; Gusarov, V.V.; Martinov, A.P.; Martinov, V.V.; Fieg, G.; Tromm, W.; Bottomley, D.; Tuomisto, H.

    2006-01-01

    This paper is concerned with corrosion of a cooled vessel steel structure interacting with molten corium in air and neutral (nitrogen) atmospheres during an in-vessel retention scenario. The data on corrosion kinetics at different temperatures on the heated steel surface, heat flux densities and oxygen potential in the system are presented. The post-test physico-chemical and metallographic analyses of melt samples and the corium-specimen ingot have clarified certain mechanisms of steel corrosion taking place during the in-vessel melt interaction

  4. Corrosion of vessel steel during its interaction with molten corium

    Bechta, S.V. [Scientific Research Technological Institute (NITI), Sosnovy Bor of Leningrad Oblast 188540 (Russian Federation)]. E-mail: bechta@sbor.spb.su; Khabensky, V.B. [Scientific Research Technological Institute (NITI), Sosnovy Bor of Leningrad Oblast 188540 (Russian Federation); Vitol, S.A. [Scientific Research Technological Institute (NITI), Sosnovy Bor of Leningrad Oblast 188540 (Russian Federation); Krushinov, E.V. [Scientific Research Technological Institute (NITI), Sosnovy Bor of Leningrad Oblast 188540 (Russian Federation); Granovsky, V.S. [Scientific Research Technological Institute (NITI), Sosnovy Bor of Leningrad Oblast 188540 (Russian Federation); Lopukh, D.B. [SPb Electrotechnical University (SpbGETU), Professor Popov str., b.5/3, 197376 St. Petersburg (Russian Federation); Gusarov, V.V. [Institute of Silicate Chemistry of Russian Academy of Science (ISC of RAS), Odoevsky str., b. 24/2, 199155 St. Petersburg (Russian Federation); Martinov, A.P. [SPb Electrotechnical University (SpbGETU), Professor Popov str., b.5/3, 197376 St. Petersburg (Russian Federation); Martinov, V.V. [Scientific Research Technological Institute (NITI), Sosnovy Bor of Leningrad Oblast 188540 (Russian Federation); Fieg, G. [Forshungszentrum Karlsruhe (FZK), Institut fur Neutronenphysik and Reaktortechnik, Postfach 3640, D-78021 Karlsruhe (Germany); Tromm, W. [Forshungszentrum Karlsruhe (FZK), Institut fur Neutronenphysik and Reaktortechnik, Postfach 3640, D-78021 Karlsruhe (Germany); Bottomley, D. [Europaeische Kommission, General Direktion GFS, Institut fuer Transurane (ITU), Postfach 2340, 76125 Karlsruhe (Germany); Tuomisto, H. [Fortum Engineering Ltd. 00048 FORTUM, Rajatorpantie 8, Vantaa (Finland)

    2006-07-15

    An experimental examination of the cooled vessel steel corrosion during the interaction with molten corium is presented. The experiments have been conducted on 'Rasplav-2' test facility and followed up with physico-chemical and metallographic analyses of melt samples and corium-specimen ingots. The results discussed in the first part of the paper have revealed specific corrosion mechanisms for air and inert atmosphere above the melt. Models have been proposed based on this information and approximate curves constructed for the estimation of the corrosion rate or corrosion depth of vessel steel in conditions simulated by the experiments.

  5. Measurement of plutonium and americium in molten salt residues

    Haas, F.X.; Lawless, J.L.; Herren, W.E.; Hughes, M.E.

    1979-01-01

    The measurement of plutonium and americium in molten salt residues using a segmented gamma-ray scanning device is described. This system was calibrated using artificially fabricated as well as process generated samples. All samples were calorimetered and the americium to plutonium content of the samples determined by gamma-ray spectroscopy. For the nine samples calorimetered thus far, no significant biases are present in the comparison of the segmented gamma-ray assay and the calorimetric assay. Estimated errors are of the order of 10 percent and is dependent on the americium to plutonium ratio determination

  6. ESR hollows molten metal/slag interface detection

    Harris, B.; Klein, H.J.

    1983-01-01

    A system for detecting the location of a molten metal/slag interface during the casting of electroslag remelted hollows includes a gamma ray radiation source and a scintillation counter. The source and counter reside outside the casting mould and are held in fixed spatial relationships with respect to one another and with respect to the mandrel. The radiation from the source is directed chordally through the mould and through the annular casting zone, defined between the sidewalls of the upwardly driven mandrel and the mould without contacting said mandrel. The counter provides an electrical signal responsive to the rate of radiation events detected thereby. (author)

  7. Local coordination of polyvalent metal ions in molten halide mixtures

    Akdeniz, Z.; Tosi, M.P.

    1989-07-01

    Ample experimental evidence is available in the literature on the geometry and the stability of local coordination for polyvalent metal ions in molten mixtures of their halides with alkali halides. Recent schemes for classifying this evidence are discussed. Dissociation of tetrahedral halocomplexes in good ionic systems can be viewed as a classical Mott problem of bound-state stability in a conducting matrix. More generally, structural coordinates can be constructed from properties of the component elements, to separate out systems with long-lived fourfold or sixfold coordination and to distinguish between these. (author). 11 refs, 1 fig

  8. Optical absorption of dilute solutions of metals in molten salts

    Senatore, G.; Parrinello, M.; Tosi, M.P. (Trieste Univ. (Italy). Ist. di Fisica Teorica; Gruppo Nazionale di Struttura dell material del CNR, Trieste (Italy); International Centre for Theoretical Physics, Trieste (Italy))

    1978-12-23

    The theory of liquid structure for fluids of charged hard spheres is applied to an evaluation of the F-centre model for valence electrons in metal-molten salt solutions at high dilution. Minimization of the free energy yields the groundstate radius of the elctron bubble and hence the optical excitation energy in a Franck-Condon transition, the shift and broadening of the transition due to fluctuations in the bubble radius, the volume of mixing, and the activity of the salt in the solution.

  9. Precipitation of lamellar gold nanocrystals in molten polymers

    Palomba, M.; Carotenuto, G.

    2016-01-01

    Non-aggregated lamellar gold crystals with regular shape (triangles, squares, pentagons, etc.) have been produced by thermal decomposition of gold chloride (AuCl) molecules in molten amorphous polymers (polystyrene and poly(methyl methacrylate)). Such covalent inorganic gold salt is high soluble into non-polar polymers and it thermally decomposes at temperatures compatible with the polymer thermal stability, producing gold atoms and chlorine radicals. At the end of the gold precipitation process, the polymer matrix resulted chemically modified because of the partial cross-linking process due to the gold atom formation reaction.

  10. Recovery of protactinium from molten fluoride nuclear fuel compositions

    Baes, C.F. Jr.; Bamberger, C.; Ross, R.G.

    1973-12-25

    A method is provided for separating protactinium from a molten fluonlde salt composition consisting essentially of at least one alkali and alkaline earth metal fluoride and at least one soluble fluoride of uranium or thorium which comprises oxidizing the protactinium in said composition to the + 5 oxidation state and contacting said composition with an oxide selected from the group consisting of an alkali metal oxide, an alkaline earth oxide, thorium oxide, and uranium oxide, and thereafter isolating the resultant insoluble protactinium oxide product from said composition. (Official Gazette)

  11. Thermal-hydraulic studies on molten core-concrete interactions

    Greene, G.A.

    1986-10-01

    This report discusses studies carried out in connection with light water power reactor accidents. Recent assessments have indicated that the consequences of molten-core concrete interactions dominate the considerations of severe accidents. The two areas of interest that have been investigated are interlayer heat and mass transfer and liquid-liquid boiling. Interlayer heat and mass transfer refers to processes that occur within a core melt between the stratified, immiscible phases of core oxides and metals. Liquid-liquid boiling refers to processes that occur at the melt-concrete on melt-coolant interface

  12. The compatibility of various austenitic steels with molten sodium (1963)

    Champeix, L.; Sannier, J.; Darras, R.; Graff, W.; Juste, P.

    1963-01-01

    Various techniques for studying corrosion by molten sodium have been developed and applied to the case of 18/10 austenitic steels. The results obtained are discussed as a function of various parameters: type of steel, temperature, oxygen content of the sodium, surface treatment, welds, mechanical strain. In general, these steels have an excellent resistance to sodium when the oxygen content is limited by a simple purification system of the 'cold trap' type, and when an attempt is made to avoid cavitation phenomena which are particularly dangerous, as is shown by the example given. (authors) [fr

  13. All ceramic structure for molten carbonate fuel cell

    Smith, James L.; Kucera, Eugenia H.

    1992-01-01

    An all-ceramic molten carbonate fuel cell having a composition formed of a multivalent metal oxide or oxygenate such as an alkali metal, transition metal oxygenate. The structure includes an anode and cathode separated by an electronically conductive interconnect. The electrodes and interconnect are compositions ceramic materials. Various combinations of ceramic compositions for the anode, cathode and interconnect are disclosed. The fuel cell exhibits stability in the fuel gas and oxidizing environments. It presents reduced sealing and expansion problems in fabrication and has improved long-term corrosion resistance.

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

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

    1994-01-01

    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 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

  15. Energy Dissipation Rate in an Agitated Crucible Containing Molten Metal

    Li, Tao; Shimasaki, Shin-ichi; Narita, Shunsuke; Taniguchi, Shoji

    2017-10-01

    The energy dissipation rate (EDR) is an important parameter for characterizing the behavior of inclusion coagulation in agitated molten metal. To clarify the inclusion coagulation mechanism, we review previous water model studies by particularly focusing on the relation between the impeller torque and the EDR of the fluid, which indicates the ratio of energy dissipated in the viscous medium to the energy inputted by the rotating impeller. In the present study, simulations coupled with experiments were performed to determine the relation between the torque and the effective EDR for water and liquid Al in crucibles with and without baffles.

  16. Thermal interaction for molten tin dropped into water

    Arakeri, V.H.; Catton, I.; Kastenberg, W.E.; Plesset, M.S.

    1978-03-01

    Multiflash photography with extremely short duration exposure times per flash was used to observe the interaction of molten tin dropped into a water bath. Detailed photographic evidence is presented which demonstrates that transition, or nucleate boiling, is a possible triggering mechanism for vapor explosions. It was also found that the thermal constraints required to produce vapor explosions could be relaxed by introducing a stable thermal stratification within the coolant. In the present work, the threshold value of the initial tin temperature required for vapor explosion was reduced from about 500 to 343/sup 0/C.

  17. Molten material relocation into the lower plenum: a status report

    1998-09-01

    This report, prepared by the task group 'Degraded Core Cooling' (DCC) for the CSNI, summarizes the experimental and theoretical knowledge of molten material relocation from a degraded core to the lower plenum of the reactor vessel under the main severe accident scenarios envisaged for both PWRs and BWRs, and boundary conditions. Consequences of movement of material to the lower head are considered with respect to the potential for reactor pressure vessel failure. The following models are reviewed: SCDAP/RELAP5, ICARE/CATHARE, ATHLET-CD/KESS, MELCOR, MAAP4, ESCADRE, etc.

  18. Molten salt/metal extractions for recovery of transuranic elements

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

    1992-01-01

    The integral fast reactor (EFR) is an advanced reactor concept that incorporates metallic driver and blanket fuels, an inherently safe, liquid-sodium-cooled, pool-type, reactor design, and on-site pyrochemical reprocessing (including electrorefining) of spent fuels and wastes. This paper describes a pyrochemical method that is being developed at Argonne National Laboratory to recover transuranic elements from the EFR electrorefiner process salt. The method uses multistage extractions between molten chloride salts and cadmium metal at high temperatures. The chemical basis of the salt extraction method, the test equipment, and a test plan are discussed

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

    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

  20. Study on dissolution behavior of molten solidified waste

    Mizuno, Tsuyoshi; Maeda, Toshikatsu

    2005-01-01

    Radioactive molten solidified waste (slag) has been generated by melting non-metallic low-level radioactive wastes (LLW). Slag is expected to immobilize radionuclides in the waste repository. The chemical durability of slag is an important factor for the safety assessment of the disposal in that the durability provides the source term in the assessment. Since a chemical characteristic of slag is similar to that of glass, the general information on the chemical durability of slag might be provided from previous studies on nuclear waste glass. We have investigated effects of chemical compositions of slag and alkaline environments of repository on the chemical durability of slag. (author)

  1. Thermal interaction for molten tin dropped into water

    Arakeri, V.H.; Catton, I.; Kastenberg, W.E.; Plesset, M.S.

    1978-01-01

    Multiflash photography with extremely short duration exposure times per flash has been used to observe the interaction of molten tin dropped into a water bath. Detailed photographic evidence is presented which demonstrates that transition, or nucleate boiling, is a possible triggering mechanism for vapour explosions. It was also found that the thermal constraints required to produce vapour explosions could be relaxed by introducing a stable thermal stratification within the coolant. In the present work, the threshold value of the initial tin temperature required for vapour explosion was reduced from about 500 to 343 0 C. (author)

  2. Corrosion-Resistant Container for Molten-Material Processing

    Stern, Theodore G.; McNaul, Eric

    2010-01-01

    In a carbothermal process, gaseous methane is passed over molten regolith, which is heated past its melting point to a temperature in excess of 1,625 C. At this temperature, materials in contact with the molten regolith (or regolith simulant) corrode and lose their structural properties. As a result, fabricating a crucible to hold the molten material and providing a method of contact heating have been problematic. Alternative containment approaches use a large crucible and limit the heat zone of the material being processed, which is inefficient because of volume and mass constraints. Alternative heating approaches use non-contact heating, such as by laser or concentrated solar energy, which can be inefficient in transferring heat and thus require higher power heat sources to accomplish processing. The innovation is a combination of materials, with a substrate material having high structural strength and stiffness and high-temperature capability, and a coating material with a high corrosion resistance and high-temperature capability. The material developed is a molybdenum substrate with an iridium coating. Creating the containment crucible or heater jacket using this material combination requires only that the molybdenum, which is easily processed by conventional methods such as milling, electric discharge machining, or forming and brazing, be fabricated into an appropriate shape, and that the iridium coating be applied to any surfaces that may come in contact with the corrosive molten material. In one engineering application, the molybdenum was fashioned into a container for a heat pipe. Since only the end of the heat pipe is used to heat the regolith, the container has a narrowing end with a nipple in which the heat pipe is snugly fit, and the external area of this nipple, which contacts the regolith to transfer heat into it, is coated with iridium. At the time of this reporting, no single material has been found that can perform the functions of this combination

  3. Recovery and purification of americium from molten salt extraction residues

    Navratil, J.D.; Martella, L.L.; Thompson, G.H.

    1980-01-01

    Americium recovery and purification development at Rocky Flats involves the testing of a combined anion exchange - bidentate organophosphorus liquid - liquid extraction or extraction chromatography process for separating americium from molten salt extraction residues. Laboratory-scale and preliminary pilot-plant results have shown that americium can be effectively recovered and purified from impurity elements such as aluminum, calcium, magnesium, plutonium, potassium, sodium, and zinc. The purified americium oxide product from the liquid - liquid extraction process contained greater than 95% AmO 2 with less than 1% of any individual impurity element

  4. Penetration of molten core materials into basaltic and limestone concrete

    Sutherland, H.J.

    1978-01-01

    In conjunction with the small-scale, melt-concrete interaction tests being conducted at Sandia Laboratories, an acoustic technique has been used to monitor the penetration of molten core materials into basaltic and limestone concrete. Real time plots of the position of the melt/concrete interface have been obtained, and they illustrate that the initial penetration rate of the melt may be of the order of 80 mm/min. Phenomena deduced by the technique include a non-wetted melt/concrete interface

  5. Large longitude libration of Mercury reveals a molten core.

    Margot, J L; Peale, S J; Jurgens, R F; Slade, M A; Holin, I V

    2007-05-04

    Observations of radar speckle patterns tied to the rotation of Mercury establish that the planet occupies a Cassini state with obliquity of 2.11 +/- 0.1 arc minutes. The measurements show that the planet exhibits librations in longitude that are forced at the 88-day orbital period, as predicted by theory. The large amplitude of the oscillations, 35.8 +/- 2 arc seconds, together with the Mariner 10 determination of the gravitational harmonic coefficient C22, indicates that the mantle of Mercury is decoupled from a core that is at least partially molten.

  6. Molten LWR core material interactions with water and with concrete

    Dahlgren, D.A.; Buxton, L.D.; Muir, J.F.; Murfin, W.B.; Nelson, L.S.; Powers, D.A.

    1977-01-01

    Nuclear power reactors are designed and operated to minimize the possibility of fuel melting. Nevertheless, in order to assess the risks associated with reactor operation, a realistic assessment is required for postulated accident sequences in which melting occurs. To investigate the experimental basis of the fuel melt accident analyses, a comprehensive review was performed at Sandia Laboratories. The results of that study indicated several phenomenological areas where additional experimental data should be gathered to verify common assumptions made in risk studies. In particular, vapor explosions and molten core material/concrete interactions were identified for further study. Results of these studies are presented

  7. Transmutation and inventory analysis in an ATW molten salt system

    Sisolak, J.E.; Truebenbach, M.T.; Henderson, D.L. [Univ. of Wisconsin, Madison, WI (United States)

    1995-10-01

    As an extension of earlier work to determine the equilibrium state of an ATW molten salt, power producing, reactor/transmuter, the WAIT code provides a time dependent view of material inventories and reactor parameters. By considering several cases, the authors infer that devices of this type do not reach equilibrium for dozens of years, and that equilibrium design calculations are inapplicable over most of the reactor life. Fissile inventory and k{sub eff} both vary by factors of 1.5 or more between reactor startup and ultimate convergence to equilibrium.

  8. CAPTURING EXHAUST CO2 GAS USING MOLTEN CARBONATE FUEL CELLS

    Prateek Dhawan

    2016-03-01

    Full Text Available Carbon dioxide is considered as one of the major contenders when the question of greenhouse effect arises. So for any industry or power plant it is of utmost importance to follow certain increasingly stringent environment protection rules and laws. So it is significant to keep eye on any possible methods to reduce carbon dioxide emissions in an efficient way. This paper reviews the available literature so as to try to provide an insight of the possibility of using Molten Carbonate Fuel Cells (MCFCs as the carbon capturing and segregating devices and the various factors that affect the performance of MCFCs during the process of CO2 capture.

  9. Chelating polymeric membranes

    Peinemann, Klaus-Viktor; Villalobos Vazquez de la Parra, Luis Francisco; Hilke, Roland

    2015-01-01

    microporous chelating polymeric membrane. Embodiments include, but are not limited to, microporous chelating polymeric membranes, device comprising the membranes, and methods of using and making the same.

  10. Establishment of cooperation basis of joint research on the mixed waste molten salt oxidation technology

    Yang, Hee Chul; Cho, Y. J.; Kim, J. H.; Yoo, J. H.; Yun, H. C.; Lee, D. G.

    2005-08-01

    Molten salt oxidation, MSO for short, is a robust technology that can effectively treat mixed waste (radioactive waste including hazardous metals or organics). It can safely and economically treat the difficult wastes such as not-easily destroyable toxic organic waste, medical waste, chemical warfare and energetic materials such as propellant and explosives, all of which are not easily treated by an incinerator or other currently existing thermal treatment system. Therefore, molten salt oxidation technology should be developed and utilized to treat a lot of niche waste stored in the nuclear and environmental industries. So, if we put the MSO technology to practical use by Korea-Vietnam joint research, we can reduce R and D fund for MSO technology by ourselves and we can expect an export of the outcome of nuclear R and D in Korea. For Establishment of cooperation basis of joint research concerning molten salt oxidation technology between KOREA and VIETNAM, in this research, We invited two Vietnamese researchers and we introduced our experimental scale molten salt oxidation system in order to let them understand molten salt oxidation technology. We also visited Viet man and we consulted about molten salt oxidation process. We held seminar on the mixed waste molten salt oxidation technology, discussed on the joint research on the mixed waste molten salt oxidation technology and finally we wrote MOU for joint research

  11. Establishment of cooperation basis of joint research on the mixed waste molten salt oxidation technology

    Yang, Hee Chul; Cho, Y. J.; Kim, J. H.; Yoo, J. H.; Yun, H. C.; Lee, D. G

    2005-08-01

    Molten salt oxidation, MSO for short, is a robust technology that can effectively treat mixed waste (radioactive waste including hazardous metals or organics). It can safely and economically treat the difficult wastes such as not-easily destroyable toxic organic waste, medical waste, chemical warfare and energetic materials such as propellant and explosives, all of which are not easily treated by an incinerator or other currently existing thermal treatment system. Therefore, molten salt oxidation technology should be developed and utilized to treat a lot of niche waste stored in the nuclear and environmental industries. So, if we put the MSO technology to practical use by Korea-Vietnam joint research, we can reduce R and D fund for MSO technology by ourselves and we can expect an export of the outcome of nuclear R and D in Korea. For Establishment of cooperation basis of joint research concerning molten salt oxidation technology between KOREA and VIETNAM, in this research, We invited two Vietnamese researchers and we introduced our experimental scale molten salt oxidation system in order to let them understand molten salt oxidation technology. We also visited Viet man and we consulted about molten salt oxidation process. We held seminar on the mixed waste molten salt oxidation technology, discussed on the joint research on the mixed waste molten salt oxidation technology and finally we wrote MOU for joint research.

  12. Chemical Reactions of Simulated Producer Gas with Molten Tin-Bismuth Alloy

    Keith J. Bourne

    2012-01-01

    A pyrolysis and gasification system utilizing molten metal as an energy carrier has been proposed and the initial stages of its design have been completed. However, there are several fundamental questions that need to be answered before the design of this system can be completed. These questions include: How will the molten metal interact with the products of biomass...

  13. A study on conductivity, density, and viscosity of molten salt systems

    Cho, Kangjo

    1976-01-01

    A relation between the equivalent conductivity and density for molten salts is deduced with the aid of significant structures theory, and the solid state density at melting point is evaluated approximately for some rare-earth metal chlorides and the other chlorides. Furthermore, the relation among the equivalent conductivity, density, and viscosity for some molten salts is discussed. (auth.)

  14. Experiment on heat transfer in simulated molten core/concrete interaction

    Katsumura, Yukihiro; Hashizume, Hidetoshi; Toda, Saburo; Kawaguchi, Takahiro.

    1993-01-01

    In order to investigate heat transfer between molten core and concrete in LWR severe accidents, experiments were performed using water as the molten core, paraffin as the concrete, and air as gases from the decomposition of concrete. It was found that the heat transfer on the interface between paraffin and water were promoted strongly by the air gas. (author)

  15. Heat transfer on liquid-liquid interface of molten-metal and water

    Tanaka, T.; Saito, Yasushi; Mishima, Kaichiro

    2001-01-01

    Molten-core pool had been formed in the lower-head of TMI-2 pressure vessel at the severe accident. The lower head, however, didn't receive any damage by reactor core cooling. Heat transfer at outside of the lower head and boiling heat transfer at liquid-liquid interface of molten-metal and water, however, are important for initial cooling process of the molten-core pool. The heat transfer experiments for the liquid-liquid interface of molten-metal and water are carried out over the range of natural convection to film boiling region. Phenomenon on the heat transfer experiments are visualized by using of high speed video camera. Wood's metal and U-alloy 78 are used as molten-metal. The test section of the experiments consists of a copper block with heater, wood's metal, and water. Three thermocouple probes are used for temperature measurement of water side and the molten-metal side. Stability of the liquid-liquid interface is depended on the wetness of container wall for molten metal and the temperature distribution of the interface. Entrainment phenomena of molten-metal occurs by a fluctuation of the interface after boiling on the container wall surface. The boiling curves obtained from the liquid-liquid interface experiments are agree with the nucleate boiling and the film boiling correlations of solid-liquid system. (Suetake, M.)

  16. Sythesis of rare earth metal - GIC graphite intercalation compound in molten chloride system

    Ito, Masafumi; Hagiwara, Rika; Ito, Yasuhiko

    1994-01-01

    Graphite intercalation compounds of ytterbium and neodymium have been prepared by interacting graphite and metals in molten chlorides. These rare earth metals can be suspended in molten chlorides in the presence of trichlorides via disproportionation reaction RE(0) + RE(III) = 2RE(II) at lower than 300 degC. Carbides-free compounds are obtained in these systems. (author)

  17. Studies on yttrium oxide coatings for corrosion protection against molten uranium

    Chakravarthy, Y.; Bhandari, Subhankar; Pragatheeswaran; Thiyagarajan, T.K.; Ananthapadmanabhan, P.V.; Das, A.K.; Kumar, Jay; Kutty, T.R.G.

    2012-01-01

    Yttrium oxide is resistant to corrosion by molten uranium and its alloys. Yttrium oxide is recommended as a protective oxide layer on graphite and metal components used for melting and processing uranium and its alloys. This paper presents studies on the efficacy of plasma sprayed yttrium oxide coatings for barrier applications against molten uranium

  18. Thermal diffusivity measurement of molten fluoride salt containing ThF4 (improvement of the simple ceramic cell)

    Kato, Y.; Araki, N.; Kobayashi, K.; Makino, A.

    1985-01-01

    Design conditions of a cylindrical ceramic cell are estimated which can be used to measure the absolute value of thermal diffusivity of molten salts by applying the stepwise heating method. Molten salt is expected to be used in nuclear systems such as the Molten-Salt Reactor, the Accelerator Molten-Salt Breeder, the Fusion Reactor Blanket Coolant, the Fuel Reprocessing System, and so on

  19. Conformational selection in the molten globule state of the nuclear coactivator binding domain of CBP

    Kjærgaard, Magnus; Teilum, Kaare; Poulsen, Flemming M

    2010-01-01

    Native molten globules are the most folded kind of intrinsically disordered proteins. Little is known about the mechanism by which native molten globules bind to their cognate ligands to form fully folded complexes. The nuclear coactivator binding domain (NCBD) of CREB binding protein is particul......Native molten globules are the most folded kind of intrinsically disordered proteins. Little is known about the mechanism by which native molten globules bind to their cognate ligands to form fully folded complexes. The nuclear coactivator binding domain (NCBD) of CREB binding protein....... Biophysical studies show that despite the molten globule nature of the domain, it contains a small cooperatively folded core. By NMR spectroscopy, we have demonstrated that the folded core of NCBD has a well ordered conformer with specific side chain packing. This conformer resembles the structure of the NCBD...

  20. Cold crucible technique for interaction test of molten corium with structure

    Ha, Kwang Soon; An, Sang Mo; Min, Beong Tae; Kim, Hwan Yeol

    2012-01-01

    During a severe accident, the molten corium might interact with several structures in a nuclear power plant such as core peripheral structures, lower plenum, lower head vessel, and external structures of a reactor vessel. The interaction of the molten corium with the structure depends on the molten corium composition, temperature, structural materials, and environmental conditions such as pressure and humidity. For example, the interaction of a metallic molten corium containing metal uranium (U) and zirconium (Zr) with the oxidized steel structure (Fe 2O3 ) is affected by not only thermal ablation but oxidation reduction reaction because the oxidation quotients of the U and Zr are higher than that of Fe. KAERI set up an experimental facility and technique using a cold crucible melting method to verify the interaction mechanism between the metallic molten corium and structural materials. This technique includes the generation of the metallic melt, melt delivery, measurement of the interaction process, and post analyses after the test

  1. Preliminary Study on the High Temperature Transport System for Molten Salt

    Lee, S. H.; Lee, H. S.; Kim, J. G.

    2012-01-01

    Pyroprocessing technology is one of the the most promising technologies for the advanced fuel cycle with favorable economic potential and intrinsic proliferation-resistance. The electrorefining process, one of main processes is compos- ed of pyroprocess to recover the useful elements from spent fuel, is under development at the Korea Atomic Energy Research Institute as a sub process of the pyrochemical treatment of spent PWR fuel. High-temperature molten salt transport technologies are required because a molten salt should be transported from the electrorefiner to electrowiner after the electrorefining process. Therefore, in pyroprocessing technology, the development of high-temperature transport technologies for molten salt is a crucial prerequisite. However, there have been a few transport studies on high-temperature molten salt. In this study, an apparatus for suction transport experiments was designed and constructed for the development of high temperature molten salt transport technology. Suction transport experiments were performed using LiC-KCl eutectic salt

  2. Prospects of subcritical molten salt reactor for minor actinides incineration in closed fuel cycle

    Alekseev, Pavel N.; Balanin, Andrey L.; Dudnikov, Anatoly A.; Fomichenko, Petr A.; Nevinitsa, Vladimir A.; Frolov, Aleksey A.; Lubina, Anna S.; Sedov, Aleksey A.; Subbotin, Aleksey S.; Blandinsky, Viktor Yu. [Nuclear Research Centre ' ' Kurchatov Institute' ' , Moscow (Russian Federation)

    2015-09-15

    A subcritical molten salt reactor is proposed for minor actinides (separated from spent fuel VVER-1000 light water reactor) incineration and for {sup 233}U conversion from {sup 232}Th. Here the subcritical molten salt reactor with fuel composition of heavy nuclide fluorides in molten LiF - NaF - KF salt and with external neutron source, based on 1 GeV proton accelerator and molten salt cooled tungsten target is considered. The paper presents the results of parametrical analysis of equilibrium nuclide composition of molten salt reactor with minor actinides feed in dependence of core dimensions, average neutron flux and external neutron source intensity. Reactor design is defined; requirements to external neutron source are posed; heavy nuclides equilibrium and fuel cycle main parameters are calculated.

  3. A basic study on fluoride-based molten salt electrolysis technology

    Hwang, Il Soon [Seoul National University, Seoul (Korea); Kim, Kwang Bum [Yonsei University, Seoul (Korea); Park, Byung Gi [Seoul National University, Seoul (Korea)

    2001-04-01

    The objective of this project is to study on the physicochemical properties of fluoride molten salt, to develop numerical model for simulation of molten salt electrolysis, and to establish experimental technique of fluoride molten salt. Physicochemical data of fluoride molten salt are investigated and summarized. The numerical model, designated as REFIN is developed with diffusion-layer theory and electrochemical reaction kinetics. REFIN is benchmarked with published experimental data. REFIN has a capability to simulate multicomponent electrochemical system at transient conditions. Experimental device is developed to measure electrochemical properties of structural material for fluoride molten salt. Ni electrode is measured with cyclic voltammogram in the conditions of 600 .deg. C LiF-BeF{sub 2} and 700 .deg. C LiF-BeF{sub 2}. 74 refs., 23 figs., 57 tabs. (Author)

  4. Facile preparation of highly pure KF-ZrF4 molten salt

    Zong, Guoqiang; Cui, Zhen-Hua; Zhang, Zhi-Bing; Zhang, Long; Xiao, Ji-Chang

    2018-03-01

    The preparation of highly pure KF-ZrF4 (FKZr) molten salt, a potential secondary coolant in molten salt reactors, was realized simply by heating a mixture of (NH4)2ZrF6 and KF. X-ray diffraction analysis indicated that the FKZr molten salt was mainly composed of KZrF5 and K2ZrF6. The melting point of the prepared FKZr molten salt was 420-422 °C under these conditions. The contents of all metal impurities were lower than 20 ppm, and the content of oxygen was lower than 400 ppm. This one-step protocol avoids the need for a tedious procedure to prepare ZrF4 and for an additional purification process to remove oxide impurities, and is therefore a convenient, efficient and economic preparation method for high-purity FKZr molten salt.

  5. Zirconium and hafnium tetrachloride separation by extractive distillation with molten zinc chloride lead chloride solvent

    McLaughlin, D.F.; Stoltz, R.A.

    1988-01-01

    In an extractive distillation method for separating hafniuim tetrachloride from zirconium tetrachloride of the type wherein a mixture of zirconium and hafnium tetrachlorides is introduced into an extractive distillation column, which extractive distillation column has a reboiler connected at the bottom and a reflux condenser connected at the top and wherein a molten salt solvent is circulated into the reflux condenser and through the column to provide a liquid phase, and wherein molten salt solvent containing zirconium tetrachloride is taken from the reboiler and run through a stripper to remove zirconium tetrachloride product from the molten salt solvent and the stripped molten salt solvent is returned to the reflux condenser and hafnium tetrachloride enriched vapor is taken as product from the reflux condenser, the improvement is described comprising: the molten salt having a composition of at least 30 mole percent zinc chloride and at least 10 mole percent of lead chloride

  6. Experimental study on thermal interaction between a high-temperature molten jet and plates

    Sato, K.; Saito, M.; Furutani, A.; Isozaki, M.; Imahori, S.; Konishi, K.

    1994-01-01

    This paper summarizes the recent simulant experiments to study molten corium-structure interactions under postulated core disruptive accident (CDA) conditions in liquid-metal fast breeder reactors (LMFMRs). These experiments were conducted in the MELT-II facility generating high-temperature molten simulants by an induction heating technique. From a series of molten jet-structure interaction experiments, the effects of the solidified crust layer and molten layer on the erosion behavior were identified, and analytical models were developed to assess the structure erosion rate with and without crust formation. Especially, we revealed the inherent mitigation mechanism that when the molten oxide jet with high melting point falls down onto the structure plate, solidified crust of the oxide can significantly reduce the erosion rate. (author)

  7. Absorption behavior of iodine from molten salt mixture to zeolite

    Sugihara, Kei; Terai, Takayuki; Suzuki, Akihiro; Uozumi, Koichi; Tsukada, Takeshi; Koyama, Tadafumi

    2011-01-01

    Behavior of zeolite to absorb anion fission product (FP) elements in molten LiCl-KCl eutectic salt was studied using iodine. At first, zeolite-A was selected as the suitable type of zeolite among zeolite-A (powder), zeolite-X (powder and granule), and zeolite-Y (powder) through experiments to heat the zeolite together with LiCl-KCl-KI salt, respectively. As the next step, similar experiments to immerse zeolite-A in molten LiCl-KCl-KI salt containing various concentrations of iodine were performed. The affinity of iodine to zeolite was evaluated using the separation factor (SF) value, which is defined as [I/(I+Cl) mol ratio in zeolite after immersion]/[I/(I+Cl) mol ratio in salt after immersion]. Since the SF values ranged between 4.3 and 9.1, stronger affinity of iodine than chlorine to zeolite-A was revealed. Finally, influence of co-existing cation FPs was studied by similar absorption experiments in LiCl-KCl-KI salt containing CsCl, SrCl 2 , or NdCl 3 . The SF values were less than those obtained in the LiCl-KCl-KI salt and this can be ascribed to the sharing of inner space of zeolite cage among absorbed cations and anions. (author)

  8. Thorium and Molten Salt Reactors: Essential Questions for Classroom Discussions

    DiLisi, Gregory A.; Hirsch, Allison; Murray, Meredith; Rarick, Richard

    2018-04-01

    A little-known type of nuclear reactor called the "molten salt reactor" (MSR), in which nuclear fuel is dissolved in a liquid carrier salt, was proposed in the 1940s and developed at the Oak Ridge National Laboratory in the 1960s. Recently, the MSR has generated renewed interest as a remedy for the drawbacks associated with conventional uranium-fueled light-water reactors (LWRs) in use today. Particular attention has been given to the "thorium molten salt reactor" (TMSR), an MSR engineered specifically to use thorium as its fuel. The purpose of this article is to encourage the TPT community to incorporate discussions of MSRs and the thorium fuel cycle into courses such as "Physics and Society" or "Frontiers of Physics." With this in mind, we piloted a pedagogical approach with 27 teachers in which we described the underlying physics of the TMSR and posed five essential questions for classroom discussions. We assumed teachers had some preexisting knowledge of nuclear reactions, but such prior knowledge was not necessary for inclusion in the classroom discussions. Overall, our material was perceived as a real-world example of physics, fit into a standards-based curriculum, and filled a need in the teaching community for providing unbiased references of alternative energy technologies.

  9. Molten salt synthesis of lead lanthanum zirconate titanate ceramic powders

    Cai Zongying; Xing Xianran; Li Lu; Xu Yeming

    2008-01-01

    Lead lanthanum zirconate titanate (Pb 0.95 La 0.03 )(Zr 0.52 Ti 0.48 )O 3 (PLZT) was synthesized by one step molten salt method with the starting materials of PbC 2 O 4 , La 2 O 3 , ZrO(NO 3 ) 2 .2H 2 O and TiO 2 in the NaCl-KCl eutectic mixtures in the temperature range of 700-1000 deg. C. The single phase of (Pb 0.95 La 0.03 )(Zr 0.52 Ti 0.48 )O 3 powders was prepared at a temperature as low as 850 deg. C for 5 h. The effects of process parameters, such as soaking temperature and time, salt species, and the amount of flux with respect to the starting materials were investigated. The growth process of the PLZT particles in the molten salt undergoes a transition from a diffusion controlled mechanism to an interfacial reaction controlled mechanism at 900 deg. C

  10. Optimization of the LENS process for steady molten pool size

    Wang, L. [Center for Advanced Vehicular Systems, Mississippi State University, Mississippi State, MS 39762 (United States); Felicelli, S. [Mechanical Engineering Department, Mississippi State University, Mississippi State, MS 39762 (United States)], E-mail: felicelli@me.msstate.edu; Gooroochurn, Y. [ESI Group, Bloomfield Hills, MI 48304 (United States); Wang, P.T.; Horstemeyer, M.F. [Center for Advanced Vehicular Systems, Mississippi State University, Mississippi State, MS 39762 (United States)

    2008-02-15

    A three-dimensional finite element model was developed and applied to analyze the temperature and phase evolution in deposited stainless steel 410 (SS410) during the Laser Engineered Net Shaping (LENS) rapid fabrication process. The effect of solid phase transformations is taken into account by using temperature and phase dependent material properties and the continuous cooling transformation (CCT) diagram. The laser beam is modeled as a Gaussian distribution of heat flux from a moving heat source with conical shape. The laser power and translational speed during deposition of a single-wall plate are optimized in order to maintain a steady molten pool size. It is found that, after an initial transient due to the cold substrate, the dependency of laser power with layer number is approximately linear for all travel speeds analyzed. The temperature distribution and cooling rate surrounding the molten pool are predicted and compared with experiments. Based upon the predicted thermal cycles and cooling rate, the phase transformations and their effects on the hardness of the part are discussed.

  11. Molten Salt Breeder Reactor Analysis Based on Unit Cell Model

    Jeong, Yongjin; Choi, Sooyoung; Lee, Deokjung [Ulsan National Institute of Science and Technology, Ulsan (Korea, Republic of)

    2014-05-15

    Contemporary computer codes like the MCNP6 or SCALE are only good for solving a fixed solid fuel reactor. However, due to the molten-salt fuel, MSR analysis needs some functions such as online reprocessing and refueling, and circulating fuel. J. J. Power of Oak Ridge National Laboratory (ORNL) suggested in 2013 a method for simulating the Molten Salt Breeder Reactor (MSBR) with SCALE, which does not support continuous material processing. In order to simulate MSR characteristics, the method proposes dividing a depletion time into short time intervals and batchwise reprocessing and refueling at each step. We are applying this method by using the MCNP6 and PYTHON and NEWT-TRITON-PYTHON and PYTHON code systems to MSBR. This paper contains various parameters to analyze the MSBR unit cell model such as the multiplication factor, breeding ratio, change of amount of fuel, amount of fuel feeding, and neutron flux distribution. The result of MCNP6 and NEWT module in SCALE show some difference in depletion analysis, but it still seems that they can be used to analyze MSBR. Using these two computer code system, it is possible to analyze various parameters for the MSBR unit cells such as the multiplication factor, breeding ratio, amount of material, total feeding, and neutron flux distribution. Furthermore, the two code systems will be able to be used for analyzing other MSR model or whole core models of MSR.

  12. Structure and thermodynamic properties of molten strontium chloride

    Pastore, G.; Ballone, P.; Tosi, M.P.; Trieste Univ.

    1985-05-01

    Self-consistent calculations of pair distribution functions and thermodynamic properties are presented for a pair-potentials model of molten strontium chloride. The calculations extend to a strongly asymmetric ionic liquid an earlier assessment of bridge diagrams in a modified hypernetted chain approach to the liquid structure of alkali halides. Good agreement is found with computer simulation data obtained by de Leeuw with the same set of pair potentials, showing that the present approach incorporates genuine general features of liquid structure theory for multicomponent liquids with strong relative ordering of the component species. It is further shown that the strong correlations between the divalent cations, both in the model and in real molten strontium chloride, can be approximately reproduced on the basis of a simple one-component-plasma model, provided that dielectric screening is allowed for in the real liquid. This allows us to tentatively attribute the significant level of disagreement between a pair potentials model of this liquid and the neutron diffraction data of McGreevy and Mitchell to many-body distortions of the electronic shells of the ions. (author)

  13. Characterization of acoustic cavitation in water and molten aluminum alloy.

    Komarov, Sergey; Oda, Kazuhiro; Ishiwata, Yasuo; Dezhkunov, Nikolay

    2013-03-01

    High-intensive ultrasonic vibrations have been recognized as an attractive tool for refining the grain structure of metals in casting technology. However, the practical application of ultrasonics in this area remains rather limited. One of the reasons is a lack of data needed to optimize the ultrasonic treatment conditions, particularly those concerning characteristics of cavitation zone in molten aluminum. The main aim of the present study was to investigate the intensity and spectral characteristics of cavitation noise generated during radiation of ultrasonic waves into water and molten aluminum alloys, and to establish a measure for evaluating the cavitation intensity. The measurements were performed by using a high temperature cavitometer capable of measuring the level of cavitation noise within five frequency bands from 0.01 to 10MHz. The effect of cavitation treatment was verified by applying high-intense ultrasonic vibrations to a DC caster to refine the primary silicon grains of a model Al-17Si alloy. It was found that the level of high frequency noise components is the most adequate parameter for evaluating the cavitation intensity. Based on this finding, it was concluded that implosions of cavitation bubbles play a decisive role in refinement of the alloy structure. Copyright © 2012 Elsevier B.V. All rights reserved.

  14. Oxidation behavior of molten magnesium in atmospheres containing SO2

    Wang Xianfei; Xiong Shoumei

    2011-01-01

    Graphical abstract: Highlights: → We found the film formed on molten magnesium had a two or three layers structure. → The formation mechanism of film was investigated and a growth model was proposed. → We found the formation of MgSO 4 was critical and promoted the growth of the film. - Abstract: The microchemistry and morphology of the oxide layer formed on molten magnesium in atmospheres containing SO 2 were examined. Based on the results and the thermodynamic and kinetic calculations of oxide-growth process, a schematic oxidation mechanism is presented. The results showed that the oxide scales with network structure were generally composed of MgO, MgS, and MgSO 4 with different layers, depending on the SO 2 content, the time and the temperature. The formation of MgSO 4 was important for the formation of the protective oxide scales. The growth of the oxide scales followed the parabolic law at 973 K and was controlled by diffusion.

  15. Development of a safety analysis code for molten salt reactors

    Zhang Dalin; Qiu Suizheng; Su Guanghui

    2009-01-01

    The molten salt reactor (MSR) well suited to fulfill the criteria defined by the Generation IV International Forum (GIF) is presently revisited all around the world because of different attractive features of current renewed relevance. The MSRs are characterized by using the fluid-fuel, so that their technologies are fundamentally different from those used in the conventional solid-fuel reactors. In this work, in particular, the attention is focused on the safety characteristic analysis of the MSRs, in which a point kinetic model considering the flow effects of the fuel salt is established for the MSRs and calculated by developing a microcomputer code coupling with a simplified heat transfer model in the core. The founded models and developed code are applied to analyze the safety characteristics of the molten salt actinide recycler and transmuter system (MOSART) by simulating three types of basic transient conditions including the unprotected loss of flow, unprotected overcooling accident and unprotected transient overpower. Some reasonable results are obtained for the MOSART, which show that the MOSART conceptual design is an inherently stable reactor design. The present study provides some valuable information for the research and design of the new generation MSRs.

  16. Low-Dimensional Network Formation in Molten Sodium Carbonate.

    Wilding, Martin C; Wilson, Mark; Alderman, Oliver L G; Benmore, Chris; Weber, J K R; Parise, John B; Tamalonis, Anthony; Skinner, Lawrie

    2016-04-15

    Molten carbonates are highly inviscid liquids characterized by low melting points and high solubility of rare earth elements and volatile molecules. An understanding of the structure and related properties of these intriguing liquids has been limited to date. We report the results of a study of molten sodium carbonate (Na2CO3) which combines high energy X-ray diffraction, containerless techniques and computer simulation to provide insight into the liquid structure. Total structure factors (F(x)(Q)) are collected on the laser-heated carbonate spheres suspended in flowing gases of varying composition in an aerodynamic levitation furnace. The respective partial structure factor contributions to F(x)(Q) are obtained by performing molecular dynamics simulations treating the carbonate anions as flexible entities. The carbonate liquid structure is found to be heavily temperature-dependent. At low temperatures a low-dimensional carbonate chain network forms, at T = 1100 K for example ~55% of the C atoms form part of a chain. The mean chain lengths decrease as temperature is increased and as the chains become shorter the rotation of the carbonate anions becomes more rapid enhancing the diffusion of Na(+) ions.

  17. Synthesis of CeS and interactions with molten metals

    Krikorian, O.H.; Curtis, P.G.

    1988-01-01

    Hot-pressed and sintered discs of single-phase CeS were tested for interaction with molten aluminium, uranium, and iron to determine the conditions under which reaction first begins and the nature of the reaction. Aluminium begins to react with CeS at ∼ 1190 K, slowly dissolving cerium and forming a thin layer of Ce 3 S 4 at the reaction interface. At 1363 K, aluminium wets and spreads over the CeS surface and dissolves ∼ 01 at% Ce. Ce 3 Al 11 precipitates out in the aluminium phase on cooldown. Uranium does not react with CeS at 1673 K, but at 1873 K it wets and spreads on CeS and dissolves ∼ 100 atom ppm S, which precipitates out as US on cooldown. Iron wets CeS at 1873 K and 1973 K but does not spread or interact. Because of the desirable containment characteristics of CeS and similar sulfides for molten metals, we recommend their use in a number of applications. (author)

  18. Molten Salt Breeder Reactor Analysis Based on Unit Cell Model

    Jeong, Yongjin; Choi, Sooyoung; Lee, Deokjung

    2014-01-01

    Contemporary computer codes like the MCNP6 or SCALE are only good for solving a fixed solid fuel reactor. However, due to the molten-salt fuel, MSR analysis needs some functions such as online reprocessing and refueling, and circulating fuel. J. J. Power of Oak Ridge National Laboratory (ORNL) suggested in 2013 a method for simulating the Molten Salt Breeder Reactor (MSBR) with SCALE, which does not support continuous material processing. In order to simulate MSR characteristics, the method proposes dividing a depletion time into short time intervals and batchwise reprocessing and refueling at each step. We are applying this method by using the MCNP6 and PYTHON and NEWT-TRITON-PYTHON and PYTHON code systems to MSBR. This paper contains various parameters to analyze the MSBR unit cell model such as the multiplication factor, breeding ratio, change of amount of fuel, amount of fuel feeding, and neutron flux distribution. The result of MCNP6 and NEWT module in SCALE show some difference in depletion analysis, but it still seems that they can be used to analyze MSBR. Using these two computer code system, it is possible to analyze various parameters for the MSBR unit cells such as the multiplication factor, breeding ratio, amount of material, total feeding, and neutron flux distribution. Furthermore, the two code systems will be able to be used for analyzing other MSR model or whole core models of MSR

  19. Physics of coolability of top flooded molten corium

    Kulkarni, P.P.; Singh, R.K.; Nayak, A.K.; Vijayan, P.K.; Saha, D.; Sinha, R.K.

    2011-01-01

    During a postulated severe accident in a nuclear reactor in case of ex-vessel scenario the molten corium can be relocated in the containment cavity forming a melt pool. In order to arrest further progression of severe accident, complete quenching of the molten corium pool is necessary. Most common way to deal with ex-vessel scenario is to flood the melt pool with large quantity of water. However, the mechanism of coolability is much more complex involving multi-component, multiphase heat, mass and momentum transfer. In this paper, a mechanistic model has been presented for the corium coolability under top flooding conditions. The model has been validated with the experimental data of COMECO test facility available in literature. Simulations have been carried out using the model to explore the physics behind the corium coolability with MCCI under top flooding condition. Variations in the thermo-physical properties as a result of MCCI have been considered and its effect on coolability has been studied. (author)

  20. Static fuel molten salt reactors - simpler, cheaper and safer

    Scott, Ian

    2015-01-01

    The many conceptual designs for Molten Salt Reactors (MSR's) today are all evolutions from the prototype MSR that went critical at Oak Ridge 50 years ago. Critically, they are based on pumping the molten fuel salt from a reaction chamber where the fuel achieves critical mass through a heat exchanger where the resulting heat is transferred to another working fluid. This basic concept was not the first idea that the Oak Ridge scientists considered. Their initial preference was to put the molten salt fuel into tubes, just like solid fuel pellets in their cladding, and circulate a coolant past the tubes. They concluded however that the low thermal conductivity of the salt meant that the tubes could be no wider than 2mm which would be entirely impractical. In this analysis they ignored the contribution of convection to heat transfer in fluids, probably because they were designing an aircraft engine where varying g forces would make convection unreliable. Moltex Energy has re-examined this decision using the modern tools of computational fluid dynamics to simulate convective flow in the molten salt and discovered that in fact tubes of similar diameter to those used for solid fuels are entirely practical. Power densities of 250kW/litre of fuel salt are readily attainable providing a higher overall power density than a PWR reactor. This discovery permits MSR's to be built without any of the complex pumping, passively safe drain systems, on line degassing, filtration and chemical processing needed in pumped MSR's. Their design is very simple and they have many intrinsic safety factors including low pressure operation, chemically unreactive fluids and strongly negative fuel thermal and coolant voiding reactivity coefficients. Most importantly, the highly radioactive fission products are retained in non-volatile form within the fuel tubes in the reactor core. Radioactive fuel salt never leaves the reactor vessel except in an immobile frozen form during

  1. Heat transfer investigation of molten salts under laminar and turbulent flow regimes

    Srivastava, A.K.; Vaidya, A.M.; Maheshwari, N.K.; Vijayan, P.K.

    2014-01-01

    High temperature reactor and solar thermal power plants use Molten Salt as a coolant, as it has low melting point and high boiling point, enabling us to operate the system at low pressure. Molten fluoride salt (eutectic mixture of LiF-NaF-KF) and molten nitrate salt (mixture of NaNO 3 and KNO 3 in 60:40 ratios by weight) are proposed as a candidate coolant for High Temperature Reactors (HTR) and solar power plant respectively. BARC is developing a 600 MWth pebble bed high temperature reactor, cooled by natural circulation of fluoride salt and capable of supplying process heat at 1000℃ to facilitate hydrogen production by splitting water. Beside this, BARC is also developing a 2MWe solar power tower system using molten nitrate salt as a primary coolant and storage medium. In order to design this, it is necessary to study the heat transfer characteristics of various molten salts. Most of the previous studies related to molten salts are based on the experimental works. These experiments essentially measured the physical properties of molten salts and their heat transfer characteristics. Ferri et al. introduced the property definitions for molten salts in the RELAP5 code to perform transient simulations at the ProvaCollettoriSolari (PCS) test facility. In this paper, a CFD analysis has been performed to study the heat transfer characteristics of molten fluoride salt and molten nitrate salt flowing in a circular pipe for various regimes of flow. Simulation is performed with the help of in-house developed CFD code, NAFA, acronym for Numerical Analysis of Flows in Axi-symmetric geometries. Uniform velocity and temperature distribution are set as the inlet boundary condition and pressure is employed at the outlet boundary condition. The inlet temperature for all simulation is set as 300℃ for nitrate salt and 500℃ for fluoride salt and the operating pressure is 1 atm in both the cases

  2. Numerical study on heat transfer characteristics of liquid-fueled molten salt using OpenFOAM

    Jeong, Yeong Shin; Bang, In Cheol

    2017-01-01

    To pursue sustainability and safety enhancement of nuclear energy, molten salt reactor is regarded as a promising candidate among various types of gen-IV reactors. Besides, pyroprocessing, which treats molten salt containing fission products, should consider safety related to decay heat from fuel material. For design of molten salt-related nuclear system, it is required to consider both thermal-hydraulic characteristics and neutronic behaviors for demonstration. However, fundamental heat transfer study of molten salt in operation condition is not easy to be experimentally studied due to its large scale, high temperature condition as well as difficulties of treating fuel material. >From that reason, numerical study can have benefit to investigate behaviors of liquid-fueled molten salt in real condition. In this study, open source CFD package OpenFOAM was used to analyze liquid-fueled molten salt loop having internal heat source as a first step of research. Among various molten salts considered as a candidate of liquid fueled molten salt reactors, in this study, FLiBe was chosen as liquid salt. For simulating heat generation from fuel material within fluid flow, volumetric heat source was set for fluid domain and OpenFOAM solver was modified as fvOptions as customized. To investigate thermal-hydraulic behavior of molten salt, CFD model was developed and validated by comparing experimental results in terms of heat transfer and pressure drop. As preliminary stage, 2D cavity simulations were performed to validate the modeling capacity of modified solver of OpenFOAM by comparison with those of ANSYS-CFX. In addition, cases of external heat flux and internal heat source were compared to configure the effect of heat source setting in various operation condition. As a result, modified solver of OpenFOAM considering internal heat source have sufficient modeling capacity to simulate liquid-fueled molten salt systems including heat generation cases. (author)

  3. Structure of molten Bi-Sb-alloys by means of neutron diffraction

    Lamparter, P.; Knoll, W.; Steeb, S.

    1976-01-01

    The structural investigations with melts can be subdivided into two groups: The first group contains molten metals and molten alloys, and one can state that the structure of molten metals and of molten alloys nowadays is rather well understood. Interference functions of molten metals may be described by a hard sphere model. This is valid also for molten alloys with statistical distribution. For the second group, namely molten non-metals and molecular melts, the interference functions as well as the pair correlation functions are very offen rather complicated and not well understood. The present study is concerned with the transition region between these two groups. It is shown that the melts of the Bi-Sb system exhibit a change from metallic to non-metallic structure. Regarding the experimental details: the experiments were done with the two-axes spectrometer D 4 at the high-flux reactor at Grenoble. The containers consisted of cylindrical quartz tubes with a wall thickness of 0.1 cm. The furnace consisted of a direct-heated vanadium tube. The wavelength of the neutrons was 0.695 A. The final result is that the structure in molten Bi-Sb-alloys consists of primitive tetrahedra with coordination number 3. There are less tetrahedra in molten Bi than in molten Sb. Also with rising temperature the number of tetrahedra decreases. It is shown how to compose the coordination numbers of two structures to get the observed coordination number. The observed values are always the mean values of the two structures. (orig./HK) [de

  4. Characteristics of an integrated cathode assembly for the electrolytic reduction of uranium oxide in a LiCl-Li2O molten salt

    Sung Bin Park; Byung Heung Park; Sang Mun Jeong; Jin Mok Hur; Chung Seok Seo; Seong Won Park; Seung-Hoon Choi

    2006-01-01

    Electrochemical behavior of the reduction of uranium oxide was studied in a LiCl-Li 2 O molten salt system with an integrated cathode assembly. The mechanism for the electrolytic reduction of uranium oxide was studied through cyclic voltammetry. By means of a chronopotentiometry, the effects of the thickness of the uranium oxide, the thickness of the MgO membrane and the material of the conductor of an integrated cathode assembly on the overpotential of the cathode were investigated. From the voltamograms, the reduction potential of the uranium oxide and Li 2 O was obtained and the two mechanisms of the electrolytic reduction were considered with regard to the applied cathode potential. From the chronopotentiograms, the exchange current, the transfer coefficient and the maximum allowable current based on the Tafel behavior were obtained with regard to the thickness of the uranium oxide, and of the MgO membrane and the material of the conductor of an integrated cathode assembly. (author)

  5. Molten Chloride Salts for Heat Transfer in Nuclear Systems

    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

  6. ANALISIS TRANSIEN PADA PASSIVE COMPACT MOLTEN SALT REACTOR (PCMSR

    M. Makrus Imron

    2015-04-01

    Full Text Available Penggunaan bahan bakar cair berupa garam LiF-BeF2-ThF4-UF4 pada Passive Compact Molten Salt Reactor (PCMSR meyebabkan pengendalian daya pada PCMSR dapat dilakukan dengan mengendalikan laju aliran bahan bakar dan pendingin. Sedangkan dari sistem keselamatan, penggunaan bahan bakar cair menjadikan PCMSR memiliki karakter keselamatan melekat (inherent safety yang baik. Pada penelitian ini telah dilakukan analisis transien PCMSR pada tiga kondisi, yaitu: ketika terjadi perubahan laju aliran bahan bakar, ketika terjadi perubahan laju aliran pendingin dan ketika terdapat kegagalan pada sistem pelepasan panas (loss of heat sink. Penelitian dilakukan dengan memodelkan reaktor pada kondisi tunak menggunakan paket program. Standart Reactor Analysis Code (SRAC. Selanjutnya dari keluaran paket program SRAC diperoleh data data yang meliputi fluks netron,konstanta grup, kontanta peluran prekusor netron, fraksi netron kasip untuk perhitungan transien. Penelitian ini menunjukkan bahwa penurunan laju aliran bahan bakar sebesar 50 % dari laju bahan bakar sebelumnya, menyebabkan daya pada PCMSR turun menjadi 78 % dari daya sebelumnya. Dan penurunan laju aliran pendingin sebesar 50 % dari laju pendingin sebelumnya, menyebabkan daya pada PCMSR turun menjadi 63 % dari daya sebelumnya. Sedangkan pada saat terjadi loss of heat sink daya PCMSR menunjukkan penurunan. Kata kunci: PCMSR, transien, daya, laju aliran.   The use of liquid fuels in the form of molten salts LiF-BeF2-ThF4-UF4 in Passive Compact Molten Salt Reactor (PCMSR makes power control at PCMSR can be done by controlling the flow rate of fuel and coolant. In addition, from safety systems aspect, the use of liquid fuels makes PCMSR has good inherent safety characteristics. In this study transient analysis has been carried out on three conditions of PCMSR, namely when the fuel flow rate is changing, when the coolant flow rate is changing and when there is loss of heat sink condition. This research is

  7. REAKTOR INNOVATIVE MOLTEN SALT (IMSR DENGAN SISTEM KESELAMATAN PASIF MENYELURUH

    Andang Widiharto

    2015-04-01

    Full Text Available Pengembangan Teknologi Reaktor Nuklir pada masa mendatang mengarah pada peningkatan aspek keselamatan, peningkatan pendayagunaan bahan bakar, reduksi limbah radioaktif, ketahanan terhadap proliferasi bahan-bakar nuklir dan peningkatan aspek ekonomi. reaktor Innovative Molten Salt (IMSR adalah reaktor nuklir yang menggunakan bahan bakar cair berupa garam lebur fluoride (7LiF-ThF4-UF4-MaFx. Reaktor IMSR didesain sebagai reaktor pembiak termal, yaitu membiakkan U-233 dari Th-232. Hal ini untuk menjawab permasalahan sustainabilitas ketersedian sumber daya bahan bakar nuklir dan reduksi limbah radioaktif. Dalam aspek keselamatan, desain reaktor IMSR memiliki sifat inherent safe, yaitu koefisien umpan balik daya yang negatif serta memiliki fitur-fitur keselamatan pasif. Fitur-fitur keselamatan pasif terdiri dari sistem shutdown pasif, sistem pendinginan pasif pasca shutdown serta sistem pendinginan pasif untuk produk fisi. Kecelakaan yang berpotensi terjadi pada IMSR, yaitu kecelakaan kehilangan aliran bahan bakar, kecelakaan kehilangan aliran pendingin, kecelakaan kehilangan kemampuan pengambilan kalor serta kecelakaan kerusakan integritas sistem reaktor, dapat ditangani sepenuhnya secara pasif hingga mencapai kondisi shutdown selamat. Kata kunci: keselamatan pasif, inherent safe, IMSR   The next Nuclear Reactor Technology developments are directed to the increasing of the aspects of safety, fuel utility, radioactive waste reduction, proliferation retention and economy. Innovative Molten Salt Reactor (IMSR is a nuclear reactor design that uses fluoride molten salt (7LiF-ThF4-UF4-MaFx. IMSR is designed as a thermal breeder reactor, i.e. to produce U-233 from Th-232. This is the answer of natural nuclear fuel sustainability and radioactive waste problems. In term of safety aspect, IMSR design has inherent safe characteristics, i.e. negative power feedback coefficient, and passive safety features. The passive safety features are passive shutdown

  8. Evolution and dynamics of Earth from a molten initial stage

    Louro Lourenço, D. J.; Tackley, P.

    2016-12-01

    It is now well established that most of the terrestrial planets underwent a magma ocean stage during their accretion. On Earth, it is probable that at the end of accretion, giant impacts like the hypothesised Moon-forming impact, together with other sources of heat, melted a substantial part of the mantle. The thermal and chemical evolution of the resulting magma ocean most certainly had dramatic consequences on the history of the planet. Considerable research has been done on magma oceans using simple 1-D models (e.g.: Abe, PEPI 1997; Solomatov, Treat. Geophys. 2007; Elkins-Tanton EPSL 2008). However, some aspects of the dynamics may not be adequately addressed in 1-D and require the use of 2-D or 3-D models. Moreover, new developments in mineral physics that indicate that melt can be denser than solid at high pressures (e.g.: de Koker et al., EPSL 2013) can have very important impacts on the classical views of the solidification of magma oceans (Labrosse et al., Nature 2007; Labrosse et al., The Early Earth 2015). The goal of our study is to understand and characterize the influence of melting on the long-term thermo-chemical evolution of rocky planet interiors, starting from an initial molten state (magma ocean). Our approach is to model viscous creep of the solid mantle, while parameterizing processes that involve melt as previously done in 1-D models, including melt-solid separation at all melt fractions, the use of an effective diffusivity to parameterize turbulent mixing, coupling to a parameterized core heat balance and a radiative surface boundary condition. These enhancements have been made to the numerical code StagYY (Tackley, PEPI 2008). We present results for the evolution of an Earth-like planet from a molten initial state to present day, while testing the effect of uncertainties in parameters such as melt-solid density differences, surface heat loss and efficiency of turbulent mixing. Our results show rapid cooling and crystallization until the

  9. Recommendations for a restart of Molten Salt Reactor development

    Moir, R. W.

    2007-01-01

    The concept of the molten salt reactor (MSR) refuses to go away. The Generation-IV process lists the MSR as one of the six concepts to be considered for extending fuel resources. Good fuel utilization and good economics are required to meet the often cited goal of 10 TWe globally and 1 TWe for the US by non-carbon energy sources in this century by nuclear fission. A strong incentive for the molten salt reactor design is its good fuel utilization, good economics, amazing flexibility and promised large benefits. It can: - use thorium or uranium; o be designed with lots of graphite to have a fairly thermal neutron spectrum or without graphite moderator to have a fast neutron spectrum reactor; - fission uranium isotopes and plutonium isotopes; - operate with non-weapon grade fissile fuel, or in suitable sites it can operate with enrichment between reactor-grade and weapon-grade fissile fuel; - be a breeder or near breeder; - operate at temperature >1100 degree C if carbon composites are successfully employed. Enhancing 2 32U content in the uranium to over 500 pm makes the fuel undesirable for weapons, but it should not detract from its economic use in liquid fuel reactors: a big advantage in nonproliferation. Economics of the MSR is enhanced by operating at low pressure and high temperature and may even lead to the preferred route to hydrogen production. The cost of the electricity produced from low enriched fuel averaged over the life of the entire process, has been predicted to be about 10% lower than that from LWRs, and 20% lower for high enriched fuel, with uncertainties of about 10%. The development cost has been estimated at about 1 B$ (e.g., a 100 M$/y base program for ten years) not including construction of a series of reactors leading up to the deployment of multiple commercial units at an assumed cost of 9 B$ (450 M$/y over 20 years). A benefit of liquid fuel is that smaller power reactors can faithfully test features of larger reactors, thereby reducing the

  10. Production of Oxygen from Lunar Regolith by Molten Oxide Electrolysis

    Curreri, Peter A.

    2009-01-01

    This paper describes the use of the molten oxide electrolysis (MOE) process for the extraction of oxygen for life support and propellant, and silicon and metallic elements for use in fabrication on the Moon. The Moon is rich in mineral resources, but it is almost devoid of chemical reducing agents, therefore, molten oxide electrolysis is ideal for extraction, since the electron is the only practical reducing agent. MOE has several advantages over other extraction methods. First, electrolytic processing offers uncommon versatility in its insensitivity to feedstock composition. Secondly, oxide melts boast the twin key attributes of highest solubilizing capacity for regolith and lowest volatility of any candidate electrolytes. The former is critical in ensuring high productivity since cell current is limited by reactant solubility, while the latter simplifies cell design by obviating the need for a gas-tight reactor to contain evaporation losses as would be the case with a gas or liquid phase fluoride reagent operating at such high temperatures. Alternatively, MOE requires no import of consumable reagents (e.g. fluorine and carbon) as other processes do, and does not rely on interfacing multiple processes to obtain refined products. Electrolytic processing has the advantage of selectivity of reaction in the presence of a multi-component feed. Products from lunar regolith can be extracted in sequence according to the stabilities of their oxides as expressed by the values of the free energy of oxide formation (e.g. chromium, manganese, Fe, Si, Ti, Al, magnesium, and calcium). Previous work has demonstrated the viability of producing Fe and oxygen from oxide mixtures similar in composition to lunar regolith by molten oxide electrolysis (electrowinning), also called magma electrolysis having shown electrolytic extraction of Si from regolith simulant. This paper describes recent advances in demonstrating the MOE process by a joint project with participation by NASA KSC and

  11. Visualization study of molten metal-water interaction by using neutron radiography

    Mishima, K.; Hibiki, T.; Saito, Y.

    1999-01-01

    The purpose of this study is to visualize the behavior of molten metal dropped into water during the premixing process by means of neutron radiography which makes use of the difference in the attenuation characteristics of materials. For this purpose, a high-sensitive, high-frame-rate imaging system using neutron radiography was constructed and was applied to visualization of the behavior of molten metal dropped into water. The test rig consisted of a furnace and a test section. The furnace could heat the molten metal up to 650 C. The test section was a rectangular tank made of aluminum alloy. The tank was filled with heavy water and molten Wood's metal was dropped into heavy water. Visualization study was carried out with use of the high-frame-rate neutron radiography to see the breakup of molten metal jet or lump dropped into heavy water pool. In the images obtained, water, steam or air bubbles, molten metal jets or droplets, cloud of small particles of molten metal after atomization could be distinguished. The debris of Wood's metal was collected after the experiment, and the relation between the break-up behavior and the size and the shape of the debris particles was investigated. (orig.)

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

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

    2009-01-01

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

  13. Molten salt reactors and possible scenarios for future nuclear power deployment

    Merle-Lucotte, E.; Mathieu, L.; Heuer, D.; Loiseaux, J. M.; Billebaud, A.; Brissot, R.; David, S.; Garzenne, C.; Laulan, O.; Le Brun, C.; Lecarpentier, D.; Liatard, E.; Meplan, O.; Michel-Sendis, F.; Nuttin, A.; Perdu, F.

    2004-01-01

    An important fraction of the nature energy demand may be satisfied by nuclear power. In this context, the possibilities of worldwide nuclear deployment are studied. We are convinced that the Molten Salt Reactors may play a central role in this deployment. The Molten Salt Reactor needs to be coupled to a reprocessing unit in order to extract the Fission Products which poison the core. The efficiency of this reprocessing has a crucial influence on reactor behavior especially for the breeding ratio. The Molten Salt Breeder Reactor project was based on an intensive reprocessing for high breeding purposes. A new concept of Thorium Molten Salt Reactor is presented here. Including this new concept in the worldwide nuclear deployment, to satisfy these power needs, we consider three typical scenarios, based on three reactor types: Pressurized Water Reactor, Fast Neutron Reactor and Thorium Molten Salt Reactor. The aim of this paper is to demonstrate, in a first hand that a Thorium Molten Salt Reactor can be realistic, with correct temperature coefficients and at least iso-breeder with slow reprocessing and new geometry; on the other hand that such Molten Salt Reactors enable a successful nuclear deployment, while minimizing fuel and waste management problems. (authors)

  14. Recovery of metal chlorides from their complexes by molten salt displacement

    McLaughlin, D.F.; Stoltz, R.A.

    1989-01-01

    This patent describes a process for recovering zirconium or hafnium chloride from a complex of zirconium or hafnium tetrachloride and phosphorus oxychloride. The process comprising: introducing liquid complex of zirconium or hafnium tetrachloride and phosphorus oxychloride into an upper portion of a feed column containing zirconium or hafnium tetrachloride vapor and phosphorus oxychloride vapor. The liquid complex absorbing zirconium or hafnium tetrachloride vapor and producing a bottoms liquid and also producing a phosphorus oxychloride vapor stripped of zirconium or hafnium tetrachloride; introducing the bottoms liquid into a molten salt containing displacement reactor, the reactor containing molten salt comprising at least 30 mole percent lithium chloride and at least 30 mole percent of at least one other alkali metal chloride, the reactor being heated to 30-450 0 C to displace phosphorus oxychloride from the complex and product zirconium or hafnium tetrachloride vapor and phosphorus oxychloride vapor and zirconium or hafnium tetrachloride-containing molten salt; introducing the zirconium or hafnium tetrachloride vapor and the phosphorus oxychloride vapor into the feed column below the point of introduction of the liquid stream; introducing the zirconium or hafnium tetrachloride containing-molten salt into a recovery vessel where zirconium or hafnium tetrachloride is removed from the molten salt to produce zirconium or hafnium tetrachloride product and zirconium or hafnium chloride-depleted molten salt; and recycling the zirconium or hafnium tetachloride-depleted molten salt to the displacement reactor

  15. A study on the corrosion test of equipment material handling hot molten salt

    Ro, Seung Gy; Jeong, M.S.; Hong, S.S.; Cho, S.H.; Shin, Y.J.; Park, H.S.; Zhang, J.S.

    1999-02-01

    On this technical report, corrosion behavior of austenitic stainless steels of SUS 316L and SUS 304L in molten salt of LiCl-Li 2 O has been investigated in the temperature range of 650 - 850 dg C. Corrosion products of SUS 316L in molten salt consisted of two layers, an outer layer of LiCrO 2 and inner layer of Cr 2 O 3 .The corrosion layer was uniform in molten salt of LiCl, but the intergranular corrosion occurred in addition to the uniform corrosion in mixed molten salt of LiCl-Li 2 O. The corrosion rate increased slowly with the increase of temperature up to 750 dg C, but above 750 dg C rapid increase in corrosion rate observed. SUS 316L stainless steel showed slower corrosion rate and higher activation energy for corrosion than SUS 304L, exhibiting higher corrosion resistance in the molten salt. In heat-resistant alloy, dense protective oxide scale of LiCrO 2 was formed in molten salt of LiCl. Whereas in mixed molten salt of LiCl-Li 2 O, porous non-protective scale of Li(Cr, Ni, Fe)O 2 was formed. (Author). 44 refs., 4 tabs., 16 figs

  16. Natural convection heat transfer characteristics of the molten metal pool with solidification by boiling coolant

    Cho, Jae Seon; Suh, Kune Yull; Chung, Chang Hyun; Park, Rae Joon; Kim, Sang Baik

    1997-01-01

    This paper presents results of experimental studies on the heat transfer and solidifcation of the molten metal pool with overlying coolant with boiling. The metal pool is heated from the bottom surface and coolant is injected onto the molten metal pool. As a result, the crust, which is a solidified layer, may form at the top of the molten metal pool. Heat transfer is accomplished by a conjugate mechanism, which consists of the natural convection of the molten metal pool, the conduction in the crust layer and the convective boiling heat transfer in the coolant. This work examines the crust formation and the heat transfer rate on the molten metal pool with boiling coolant. The simulant molten pool material is tin (Sn) with the melting temperature of 232 .deg. C. Demineralized water is used as the working coolant. The crust layer thickness was ostensibly varied by the heated bottom surface temperature of the test section, but not much affected by the coolant injection rate. The correlation between the Nusselt number and the Rayleight number in the molten metal pool region of this study is compared against the crust formation experiment without coolant boiling and the literature correlations. The present experimental results are higher than those from the experiment without coolant boiling, but show general agreement with the Eckert correlation, with some deviations in the high and low ends of the Rayleigh number. This discrepancy is currently attributed to concurrent rapid boiling of the coolant on top of the metal layer

  17. Effect of crust increase on natural convection heat transfer in the molten metal pool

    Park, Rae Joon; Kim, Sang Baik; Kim, Hee Dong; Choi, Sang Min

    1999-01-01

    An experimental study has been performed on natural convection heat transfer with a rapid crust formation in the molten metal pool of a low Prandtl number fluid. Two types of steady state tests, a low and high geometric aspect ratio cases in the molten metal pool, were performed. The crust thickness by solidification was measured as a function of boundary surface temperatures. The experimental results on the relationship between the Nusselt number and Rayleigh number in the molten metal pool with a crust formation were compared with existing correlations. The experimental study has shown that the bottom surface temperature of the molten metal layer, in all experiments, is the major influential parameter in the crust formation, due to the natural convection flow. The Nusselt number of the case without a crust formation in the molten metal pool is greater than that of the case with the crust formation at the same Rayleigh number. The present experimental results on the relationship between the Nusselt number and Rayleigh number in the molten metal pool match well with Globe and Dropkin's correlation. From the experimental results, a new correlation between the Nusselt number and Rayleigh number in the molten metal pool with the crust formation was developed as Nu=0.0923 (Ra) 0.0923 (2 X 10 4 7 ). (author)

  18. Redox reactions in rare earth chloride molten electrolytes

    Khokhlov, V.A.; Novoselova, A.V.; Nikolaeva, E.V.; Tkacheva, O.Yu.; Salyulev, A.B.

    2007-01-01

    Rare earth (REM, Ln) solutions in chloride melts including MCI+LnCl 3 mixtures, where M - alkali metals, were investigated by potentiometry, voltammetry, conductometry in wide concentration and temperature intervals. Findings present complete and trusty information on the valent state of rare earths, structure and composition of complex ions affecting essentially on properties of electrolytes. It is demonstrated that the coexistence of rare earth ions with different oxidation level formed as a result of possible redox reactions: 2Ln 3+ + Ln ↔3Ln 2+ , Ln 2+ + Ln↔2Ln + and nM + + Ln↔nM + Ln n+ appears sharply in thermodynamic and transport properties of molten Ln-LnCl 3 and Ln-LnCl 3 -MCl systems [ru

  19. Molten salt destruction of rubber and chlorinated solvents

    Upadhye, R.S.; Wilder, J.G.

    1994-09-01

    Acceptable methods for the treatment of mixed wastes are not currently available. The authors have investigated Molten Salt Destruction (MSD) as an alternative to incineration of mixed wastes. MSD differs from incineration in several ways: there is no evidence of open flames in MSD, the containment of actinides is accomplished by chemical means (wetting and dissolution), the operating temperature of MSD is much lower (700--590 C vs 1,000--1,200 C) thus lowering the volatility of actinides. Furthermore, no acid gases are released from MSD. These advantages provide the main incentive for developing MSD as an alternative to incineration. The authors have demonstrated the viability of the MSD process to cleanly destroy rubber and chlorinated solvents

  20. Experimental Compressibility of Molten Hedenbergite at High Pressure

    Agee, C. B.; Barnett, R. G.; Guo, X.; Lange, R. A.; Waller, C.; Asimow, P. D.

    2010-12-01

    Experiments using the sink/float method have bracketed the density of molten hedenbergite (CaFeSi2O6) at high pressures and temperatures. The experiments are the first of their kind to determine the compressibility of molten hedenbergite at high pressure and are part of a collaborative effort to establish a new database for an array of silicate melt compositions, which will contribute to the development of an empirically based predictive model that will allow calculation of silicate liquid density and compressibility over a wide range of P-T-X conditions where melting could occur in the Earth. Each melt composition will be measured using: (i) double-bob Archimedean method for melt density and thermal expansion at ambient pressure, (ii) sound speed measurements on liquids to constrain melt compressibility at ambient pressure, (iii) sink/float technique to measure melt density to 15 GPa, and (iv) shock wave measurements of P-V-E equation of state and temperature between 10 and 150 GPa. Companion abstracts on molten fayalite (Waller et al., 2010) and liquid mixes of hedenbergite-diopside and anorthite-hedenbergite-diopside (Guo and Lange, 2010) are also presented at this meeting. In the present study, the hedenbergite starting material was synthesized at the Experimental Petrology Lab, University of Michigan, where melt density, thermal expansion, and sound speed measurements were also carried out. The starting material has also been loaded into targets at the Caltech Shockwave Lab, and experiments there are currently underway. We report here preliminary results from static compression measurement performed at the Department of Petrology, Vrije Universiteit, Amsterdam, and the High Pressure Lab, Institute of Meteoritics, University of New Mexico. Experiments were carried out in Quick Press piston-cylinder devices and a Walker-style multi-anvil device. Sink/float marker spheres implemented were gem quality synthetic forsterite (Fo100), San Carlos olivine (Fo90), and

  1. Melt migration modeling in partially molten upper mantle

    Ghods, Abdolreza

    The objective of this thesis is to investigate the importance of melt migration in shaping major characteristics of geological features associated with the partial melting of the upper mantle, such as sea-floor spreading, continental flood basalts and rifting. The partial melting produces permeable partially molten rocks and a buoyant low viscosity melt. Melt migrates through the partially molten rocks, and transfers mass and heat. Due to its much faster velocity and appreciable buoyancy, melt migration has the potential to modify dynamics of the upwelling partially molten plumes. I develop a 2-D, two-phase flow model and apply it to investigate effects of melt migration on the dynamics and melt generation of upwelling mantle plumes and focusing of melt migration beneath mid-ocean ridges. Melt migration changes distribution of the melt-retention buoyancy force and therefore affects the dynamics of the upwelling plume. This is investigated by modeling a plume with a constant initial melt of 10% where no further melting is considered. Melt migration polarizes melt-retention buoyancy force into high and low melt fraction regions at the top and bottom portions of the plume and therefore results in formation of a more slender and faster upwelling plume. Allowing the plume to melt as it ascends through the upper mantle also produces a slender and faster plume. It is shown that melt produced by decompressional melting of the plume migrates to the upper horizons of the plume, increases the upwelling velocity and thus, the volume of melt generated by the plume. Melt migration produces a plume which lacks the mushroom shape observed for the plume models without melt migration. Melt migration forms a high melt fraction layer beneath the sloping base of the impermeable oceanic lithosphere. Using realistic conditions of melting, freezing and melt extraction, I examine whether the high melt fraction layer is able to focus melt from a wide partial melting zone to a narrow region

  2. Open problems in reprocessing of a molten salt reactor fuel

    Lelek, Vladimir; Vocka, Radim

    2000-01-01

    The study of fuel cycle in a molten salt reactor (MSR) needs deeper understanding of chemical methods used for reprocessing of spent nuclear fuel and preparation of MSR fuel, as well as of the methods employed for reprocessing of MSR fuel itself. Assuming that all the reprocessing is done on the basis of electrorefining, we formulate some open questions that should be answered before a flow sheet diagram of the reactor is designed. Most of the questions concern phenomena taking place in the vicinity of an electrode, which influence the efficiency of the reprocessing and sensibility of element separation. Answer to these questions would be an important step forward in reactor set out. (Authors)

  3. Definition of breeding gain for molten salt reactors - 147

    Nagy, K.; Kloosterman, J.L.; Lathouwers, D.; Van der Hagen, T.H.J.J.

    2010-01-01

    The graphite-moderated Molten Salt Reactor (MSR) is a potential breeder reactor using the thorium fuel cycle. The MSR has unique properties due to the possibility of making changes to the salt composition during operation. Most important is the extraction of protactinium, which separates the fissile uranium production into two volumes: the reactor core and the external stockpile. The paper focuses on the definition of breeding gain in such a system. The prospects of using breeding gain expressions defined for solid fuel reactors are investigated and new definitions are given which incorporate the processes occurring in the reactor core and the external stockpile. The difference of the growth rate of the mass of fissile material and breeding gain is pointed out. The new definitions are applied to an optimization study of the graphite-salt lattice of a breeder MSR. (authors)

  4. Graphite and carbonaceous materials in a molten salt nuclear reactor

    Rousseau, Ginette; Lecocq, Alfred; Hery, Michel.

    1982-09-01

    A project for a molten salt 1000 MWe reactor is studied by EDF-CEA teams. The design provides for a chromesco 3 vessel housing graphite structures in which the salt circulates. The salt (Th, U, Be and Li fluorides) is cooled by direct contact with lead. The graphites and carbonated materials, inert with respect to lead and the fuel salt, are being considered not only as moderators, but as reflectors and in the construction of the sections where the heat exchange takes place. On the basis of the problems raised in the operation of the reactor, a study programme on French experimental materials (Le Carbone Lorraine, SERS, SEP) has been defined. Hence, depending on the function or functions that the material is to ensure in the structure, the criteria of choice which follow will have to be examined: behaviour under irradiation, insertion of a fluid in the material, thermal properties required, mechanical properties required, utilization [fr

  5. Diffusion, electrical mobility and ionic interactions in molten Salts

    Lantelme, F.

    1965-05-01

    The diffusion and the electrical migration of ions in the molten alkali nitrates LiNO 3 , NaNO 3 and KNO 3 and in their mixtures have been examined using stable or radio-active isotope indicators. This experimental works shows that there are large differences in the diffusion coefficients and the electric mobilities when they are compared using the Nernst-Einstein formula. An interpretive model has been put forward which shows the role played by poly-ionic displacements: in a salt AC the particles moving are not only the free ions A - and C + but also the groups [A n C m ] (m-n)+ ... These results confirm the importance of electrostatic attraction and of the polarizability of the ions. This mechanisms, furthermore, explains the inversions of electrical mobilities often observed in liquid ionic media. (author) [fr

  6. The jet impingement phase of molten core-concrete interactions

    Sienicki, J.J.; Spencer, B.W.

    1986-01-01

    Scoping calculations have been carried out demonstrating that a significant and abrupt reduction in the corium temperature may be realized when molten corium drains as a jet from a localized breach in the RPV lower head to impinge upon the concrete basemat. The temperature decrease may range from a value of ∼170 K (∼140 K) for limestone (basaltic) aggregate concrete to a value approaching the initial corium superheat depending upon whether the forced convection impingement heat flux is assumed to be controlled by either thermal conduction across a slag film layer or the temperature boundary condition represented by a corium crust. The magnitude of the temperature reduction remains significant as the initial corium temperature, impinging corium mass, and initial localized breach size are varied over their range of potential values

  7. Filbe molten salt research for tritium breeder applications

    Anderl, R.A.; Petti, D.A.; Smolik, G.R.

    2004-01-01

    This paper presents an overview of Flibe (2Lif·BeF 2 ) molten salt research activities conducted at the INEEL as part of the Japan-US JUPITER-II joint research program. The research focuses on tritium/chemistry issues for self-cooled Flibe tritium breeder applications and includes the following activities: (1) Flibe preparation, purification, characterization and handling, (2) development and testing of REDOX strategies for containment material corrosion control, (3) tritium behavior and management in Flibe breeder systems, and (4) safety testing (e.g., mobilization of Flibe during accident scenarios). This paper describes the laboratory systems developed to support these research activities and summarizes key results of this work to date. (author)

  8. Titanium electroplating of copper in molten salt media

    Renaud, Denis

    1985-01-01

    After a bibliographical survey on electroplating in molten salt media and on the electrolytic production of titanium, the author explains the reasons for the choice of the LiF-NaF-KF eutectic mix as solvent. He recalls the main properties which are used, and describes the conventional and convolutional processing of data obtained by linear volt-amperometry. He presents the electrolyte preparation mode which takes into account the existence of titanium ions with intermediate oxidation degree, and the reactivity of titanium with oxygenated species. Experimental results are discussed. Then, after the study of the mechanism of reduction of trivalent titanium into titanium on molybdenum (intermetallic diffusion is here negligible), he reports the study of this mechanism on copper (it is a more complicated situation, due to combinations between titanium and copper). The effect of different parameters (electrolyte purity, current density, electrode potential and temperature) is interpreted in order to identify optimal conditions for titanium electroplating of copper [fr

  9. Operating method of molten carbonate type fuel cell

    Nakanishi, Tsuneo

    1988-12-06

    Molten carbonate type fuel cell involves a problem of oxidation of anode while the unit is stopped. Although there is a method proposed wherein an inactive gas is supplied to anode during the stoppage, the market-available inactive gas contains a slight amount of oxygen which makes it difficult to prevent the deterioration of the anode. In this invention, at the start and the stop other than the normal operation, a protective gas mixture of an inactive gas with a small amount of hydrogen is supplied to the anode. The inactive gas is a commercial type nitrogen, argon or helium; hydrogen is mixed in amount 0.5 - 2.0% of the inactive gas. By this method, oxygen in air which comes in from the gas-sealed portion of the cell is reduced by hydrogen in the protective gas and is discharged in the form of water. 2 figs.

  10. Countercurrent Flow of Molten Glass and Air during Siphon Tests

    Guerrero, H.N.

    2001-01-01

    Siphon tests of molten glass were performed to simulate potential drainage of a radioactive waste melter, the Defense Waste Processing Facility (DWPF) at the Savannah River Site. Glass is poured from the melter through a vertical downspout that is connected to the bottom of the melter through a riser. Large flow surges have the potential of completely filling the downspout and creating a siphon effect that has the potential for complete draining of the melter. Visual observations show the exiting glass stream starts as a single-phase pipe flow, constricting into a narrow glass stream. Then a half-spherical bubble forms at the exit of the downspout. The bubble grows, extending upwards into the downspout, while the liquid flows counter-currently to one side of the spout. Tests were performed to determine what are the spout geometry and glass properties that would be conducive to siphoning, conditions for terminating the siphon, and the total amount of glass drained

  11. Simulations of rapid pressure-induced solidification in molten metals

    Patel, Mehul V.; Streitz, Frederick H.

    2004-01-01

    The process of interest in this study is the solidification of a molten metal subjected to rapid pressurization. Most details about solidification occurring when the liquid-solid coexistence line is suddenly transversed along the pressure axis remain unknown. We present preliminary results from an ongoing study of this process for both simple models of metals (Cu) and more sophisticated material models (MGPT potentials for Ta). Atomistic (molecular dynamics) simulations are used to extract details such as the time and length scales that govern these processes. Starting with relatively simple potential models, we demonstrate how molecular dynamics can be used to study solidification. Local and global order parameters that aid in characterizing the phase have been identified, and the dependence of the solidification time on the phase space distance between the final (P,T) state and the coexistence line has been characterized

  12. Molten salt reactor as asymptotic safety nuclear system

    Novikov, V.M.; Ignatyev, V.V.

    1989-01-01

    Safety is becoming the main and priority problem of the nuclear power development. An increase of the active safety measures could hardly be considered as the proper way to achieve the asymptotically high level of nuclear safety. It seem that the more realistic way to achieve such a goal is to minimize risk factors and to maximize the use of inherent and passive safety properties. The passive inherent safety features of the liquid fuel molten salt reactor (MSR) technology are making it attractive for future energy generation. The achievement of the asymptotic safety in MSR is being connected with the minimization of such risk factors as a reactivity excess, radioactivity stored, decay heat, non nuclear energy stored in core. In this paper safety peculiarities of the different MSR concepts are discussed

  13. Electrochemical study in molten sodium fluoroborate at 4200C

    Wagner, J.F.

    1983-06-01

    By analysing the behavior of the electrochemical system Cu (I)/Cu it was possible to study the acid-base properties of molten sodium fluoroborate. The anion of the solvent BF 4 - is shown to undergo a strong dissociation according to the equilibrium BF 4 - BF 3 (g) + F - , the Ki constant at 420 0 C being evaluated at 1.58 x 10 -2 mol kg -1 atm. The acidity variations of sodium fluoroborate at this temperature are limited to about two pF units (pKi=1.8). A potentiometric study of the copper, silver and nickel systems showed that the corresponding metallic cations are little complexed by fluoride ions in spite of the strong dissociation of the solvent [fr

  14. Measurements of Thermophysical Properties of Molten Silicon and Geranium

    Rhim, Won-Kyu

    2001-01-01

    The objective of this ground base program is to measure thermophysical properties of molten/ undercooled silicon, germanium, and Si-Ge alloys using a high temperature electrostatic levitator and in clearly assessing the need of the microgravity environment to achieve the objective with higher degrees of accuracy. Silicon and germanium are two of the most important semiconductors for industrial applications: silicon is unsurpassed as a microelectronics material, occupying more than 95% of the electronics market. Si-Ge alloy is attracting keen interest for advanced electronic and optoelectronic applications in view of its variable band gap and lattice parameter depending upon its composition. Accurate thermophysical properties of these materials are very much needed in the semiconductor industry for the growth of large high quality crystals.

  15. Molten Salt Fuel Cycle Requirements for ADTT Applications

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

    1999-01-01

    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 ORNLs 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

  16. Coulometric thermometric titration of halides in molten calcium nitrate tetrahydrate.

    Zsigrai, I J; Bartusz, D B

    1983-01-01

    A method for coulometric thermometric precipitation titrations of chloride, bromide and iodide in molten calcium nitrate tetrahydrate at 55 degrees with coulometrically generated silver ions has been developed. The change in temperature during the titration is followed with the aid of a thermistor bridge coupled to a recorder. To minimize the temperature effect of the passage of current through the melt, two thermistors are connected in opposition in the bridge, with one in the anodic and the other in the cathodic cell compartment. Amounts of 62-80 mumole of halide have been determined with relative error below 0.4% and relative standard deviation less than 2.7%. The relative error in determination of 40 mumole of iodide was + 2%.

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

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

    1993-01-01

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

  18. Modelization of the SECM in molten salts environment

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

    2013-01-01

    We develop a cellular automata simulation of SECM (Scanning Electrochemical Microscopy)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 also the results for other, more complicated substrate surface geometries e. g. regular saw modulated surface, or surface obtained by an Eden model process. We show that with a simple cellular automata model we can reasonably well simulate the results of SECM setup. The stochastic resolution of the diffusion equations is made possible by the parallel code implemented on GPU

  19. Fuel cycle cost analysis on molten-salt reactors

    Shimazu, Yoichiro

    1976-01-01

    An evaluation is made of the fuel cycle costs for molten-salt reactors (MSR's), developed at Oak Ridge National Laboratory. Eight combinations of conditions affecting fuel cycle costs are compared, covering 233 U-Th, 235 U-Th and 239 Pu-Th fuels, with and without on-site continuous fuel reprocessing. The resulting fuel cycle costs range from 0.61 to 1.18 mill/kWh. A discussion is also given on the practicability of these fuel cycles. The calculations indicate that somewhat lower fuel cycle costs can be expected from reactor operation in converter mode on 235 U make-up with fuel reprocessed in batches every 10 years to avoid fission product precipitation, than from operation as 233 U-Th breeder with continuous reprocessing. (auth.)

  20. Experimental evaluation of mercury release from molten lead

    Tutu, N.K.; Greene, G.A.; Van Tuyle, G.J.

    1994-01-01

    In order to assess the worst impact of an extremely improbable accident in an accelerator target for producing tritium, an event scenario was developed and analyzed, and an experiment was Performed to resolve an important question raised by the analysis. The target, known as SILC for ''Spallation Induced Lithium Conversion,'' contains approximately 22 metric tons of Pb, with small inventories of potentially hazardous radionuclides which continue to accumulate as the production cycle continues. Analysis of a scenario involving several failures in the normal, backup, and emergency cooling systems is presented, including event simulation by BNL indicating when and how long the Pb continues to melt, and a summary of SNL estimates of the releases of potentially hazardous spallation products is given. Finally, a recent experiment is described in which it was shown that virtually no mercury is likely to escape from the molten Pb, a result having significant impact on the potential risk of such worst-case scenarios

  1. Co-ordination of heterovalent cation impurities in molten salts

    Andreoni, W.; Rovere, M.; Tosi, M.P.

    1982-01-01

    The local liquid structure around heterovalent cation impurities in molten chlorides is discussed in relation to spectroscopic data on solutions of transition metal ions. A tightly packed, low co-ordination shell is shown to be favoured by Coulomb ionic interactions for physically reasonable values of the size of the impurity. A competition between these forces and ''crystal field'' interactions favouring octahedral co-ordination is thus to be expected for many transition metal ions, as suggested by Gruen and McBeth. The transition observed for some transition metal ions from higher to lower co-ordination with increasing temperature is attributed primarily to entropy differences, that are roughly estimated in a solid-like model. (author)

  2. Heat transfer from internally-heated molten UO2 pools

    Stein, R.P.; Baker, L. Jr.; Gunther, W.H.; Cook, C.

    1978-01-01

    Experimental measurements of heat transfer from internally heated pools of molten UO 2 have been obtained for two cell sizes: 10 cm x 10 cm and 20 cm x 20 cm. The experiments with the large cell have supported a previous conclusion from early small data that the measured downward heat fluxes are higher than would be expected on the basis of considerations of thermal convection. A convective model underpredicts the downward heat fluxes by a factor of 2.5 to 4.5 for all but one early experiment. Arbitrary assumptions of increased thermal conductivity do not account for the discrepancy. A single model based on internal thermal radiation heat transfer is able to account for the high values. The model uses the optically thick Rosseland approximation. Because of this, it is tentatively concluded that thermal radiation plays a dominant role in controlling the heat transfer from internally heated molted fuel

  3. Natural gas anodes for aluminium electrolysis in molten fluorides.

    Haarberg, Geir Martin; Khalaghi, Babak; Mokkelbost, Tommy

    2016-08-15

    Industrial primary production of aluminium has been developed and improved over more than 100 years. The molten salt electrolysis process is still suffering from low energy efficiency and considerable emissions of greenhouse gases (CO2 and PFC). A new concept has been suggested where methane is supplied through the anode so that the CO2 emissions may be reduced significantly, the PFC emissions may be eliminated and the energy consumption may decrease significantly. Porous carbon anodes made from different graphite grades were studied in controlled laboratory experiments. The anode potential, the anode carbon consumption and the level of HF gas above the electrolyte were measured during electrolysis. In some cases it was found that the methane oxidation was effectively participating in the anode process.

  4. Characteristics of fission product release from a molten pool

    Yun, J.I.; Suh, K.Y.; Kang, C.S.

    2001-01-01

    The volatile fission products are released from the debris pool, while the less volatile fission products tend to remain as condensed phases because of their low vapor pressure. The release of noble gases and the volatile fission products is dominated by bubble dynamics. The release of the less volatile fission products from the pool can be analyzed based on mass transport through a liquid with the convection flow. The physico-numerical models were orchestrated from existing submodels in various disciplines of engineering to estimate the released fraction of fission products from a molten pool. It was assumed that the pool has partially filled hemispherical geometry. For the high pool pressure, the diameter of the bubbles at detachment was calculated utilizing the Cole and Shulman correlation with the effect of system pressure. Sensitivity analyses were performed and results of the numerical calculations were compared with analysis results for the TMI-2 accident. (author)

  5. The solvent extraction of ytterbium from a molten eutectic

    Lengyel, T.

    1977-01-01

    The paper summarizes the results which were obtained in measurements performed with different binary mixtures of solvents being capable of effectively extracting ytterbium from the molten eutectic lithium nitrate--ammonium nitrate. In the course of elaborating the possible ways of extractive separation of rare earths systematic investigations regarding the individual members of the group are required. The binary solvent mixtures consisted of thenoyl-trifluoracetone (TTA), β-isopropil-tropolone (IPT), tributyl phosphate (TBP), di-2-ethylhexyl phosphoric acid (HDEHP), 2,2'-bipyridyl (bipy), dibutyl phtalate (DBP) and Amberlite LA-2 (LA-2). The concentration of the central ion was kept at 5x10 -6 M by using Yb-169 of high specific activity as a tracer for the radiometric assay. (T.I.)

  6. Development of flexible support for molten salt reactor

    Xie, Mingqiang

    2014-01-01

    Supporting member design for equipment and pipes is the requisite factor to realize the concept. It's a challenge to design a reliable supporting structure in molten salt reactor (MSR) due to the extraordinary working temperature (max 750 deg. C). High temperature may cause large expansion and reduce the mechanical strength of material, The support is required both enough strength and flexibility. In this paper, an all-dimensional support was designed, the validation work was carried out on a high temperature test loop. The results indicate that the support has a good performance, it reduce the thermal stress effectively and support the equipment and pipes stably for one year. The support design has a significance referential meaning for MSR construction (authors)

  7. Development of molten carbonate fuel cells for power generation

    1980-04-01

    The broad and comprehensive program included elements of system definition, cell and system modeling, cell component development, cell testing in pure and contaminated environments, and the first stages of technology scale up. Single cells, with active areas of 45 sq cm and 582 sq cm, were operated at 650 C and improved to state of the art levels through the development of cell design concepts and improved electrolyte and electrode components. Performance was shown to degrade by the presence of fuel contaminants, such as sulfur and chlorine, and due to changes in electrode structure. Using conventional hot press fabrication techniques, electrolyte structures up to 20" x 20" were fabricated. Promising approaches were developed for nonhot pressed electrolyte structure fabrication and a promising electrolyte matrix material was identified. This program formed the basis for a long range effort to realize the benefits of molten carbonate fuel cell power plants.

  8. Behaviour of metals and alloys in molten fluoride media

    Fabre, St.

    2009-01-01

    Fluoride salts are contemplated for Generation IV nuclear systems which structural materials need to resist corrosion at high temperatures. Corrosion of metals in molten fluorides has been investigated in support of the Molten Salt Reactor's development and led to an optimized alloy, Hastelloy-N, but it lacked fundamentals data for the comprehension of materials' degradation mechanisms. The main objective of this work is then to help with the understanding of the corrosion behaviour of nickel and its alloys in fluoride salts. An experimental method was built up using electrochemical techniques and enabled to investigate the thermochemical conditions of the media and the influence of different parameters (media, temperature and quantity of impurities) on the behaviour of the materials. Most tests were performed in LiF-NaF mixtures between 800 and 1000 C. Pure metals can be classified as follows: Cr ≤ Fe ≤ Ni ≤ Mo ≤ W in increasing stability order and two specific behaviours were evidenced: Cr and Fe corrode in the melt, whereas Ni, Mo and W are stable, underlining the significance level of the redox couple controlling the reactions in the mixture. Moreover, corrosion current densities increase with temperature, fluoro-acidity and the quantity of dissolved oxide in the melt. Binary Ni-Cr alloys were also tested; selective attack of Cr is first observed before both elements are oxidized. Combining thermochemical calculations and experimental results enables to propose an approach to establish an optimized composition for a stable alloy. Immersion tests were finally achieved in addition to the electrochemical tests: interpretations of both methods were compared and completed. (author)

  9. Thermal behaviour of a spherical addition to molten metals

    Roehmen, E.

    1995-05-01

    This thesis presents a numerical model for describing the thermal behaviour of a spherical alloy addition when added to a melt. It is assumed that: no significant heat of solution between the alloy addition and the melt is involved, the dissolution rate is dominated by heat transfer from the melt, the heat flow into the addition is spherically symmetric, the additions have a well defined melting point, there are no solid phase transformations, heat conduction can be represented by Fourier`s law, and the heat transfer from the melt can be described by an average heat transfer coefficient. The model is validated by comparison with experimental data obtained from immersion experiments on: (1) a 4.88 cm diameter Al sphere chilled in liquid nitrogen to -196 {sup o}C and then immersed in water of 3.8 {sup o}C and 18.1 {sup o}C, (2) 4.90 cm diameter Al spheres at room temperatures immersed in molten Al of 720 {sup o}C, and (3) 3.72 cm diameter 75 wt% FeSi spheres at 150 {sup o}C immersed in molten steel of 1600 {sup o}C. The shell thickness and temperatures at the sphere centre and surface were recorded as functions of time. For model and experiment to agree, it was found that the density, specific heat and thermal conductivity of the alloy addition must depend on temperature, and an inner heat transfer resistance across the sphere-shell interphase must be included. The sensible heat of the melt that solidifies should be included in the heat balance only when the shell is expanding. The inner heat transfer resistance is shown to be very important in determining the melting/dissolution time for alloy additions that react strongly with the melt. 70 refs., 60 figs., 36 tabs.

  10. On purpose simulation model for molten salt CSP parabolic trough

    Caranese, Carlo; Matino, Francesca; Maccari, Augusto

    2017-06-01

    The utilization of computer codes and simulation software is one of the fundamental aspects for the development of any kind of technology and, in particular, in CSP sector for researchers, energy institutions, EPC and others stakeholders. In that extent, several models for the simulation of CSP plant have been developed with different main objectives (dynamic simulation, productivity analysis, techno economic optimization, etc.), each of which has shown its own validity and suitability. Some of those models have been designed to study several plant configurations taking into account different CSP plant technologies (Parabolic trough, Linear Fresnel, Solar Tower or Dish) and different settings for the heat transfer fluid, the thermal storage systems and for the overall plant operating logic. Due to a lack of direct experience of Molten Salt Parabolic Trough (MSPT) commercial plant operation, most of the simulation tools do not foresee a suitable management of the thermal energy storage logic and of the solar field freeze protection system, but follow standard schemes. ASSALT, Ase Software for SALT csp plants, has been developed to improve MSPT plant's simulations, by exploiting the most correct operational strategies in order to provide more accurate technical and economical results. In particular, ASSALT applies MSPT specific control logics for the electric energy production and delivery strategy as well as the operation modes of the Solar Field in off-normal sunshine condition. With this approach, the estimated plant efficiency is increased and the electricity consumptions required for the plant operation and management is drastically reduced. Here we present a first comparative study on a real case 55 MWe Molten Salt Parabolic Trough CSP plant placed in the Tibetan highlands, using ASSALT and SAM (System Advisor Model), which is a commercially available simulation tool.

  11. Transformation and fragmentation behavior of molten aluminum in sodium pool

    Nishimura, S.; Kinoshita, I.; Ueda, N.; Sugiyama, K. I.

    2003-01-01

    In order to investigate the possibility of fragmentation of the metallic alloy fuel on liquid phase formed by metallurgical reactions, which is important in evaluating the sequence of core disruptive accidents for metallic fuel fast reactors, a series of experiments was carried out using molten aluminum and sodium under the condition that the boiling of sodium on the surface of the melt does not occur. The melting point of aluminum (933K) is roughly equivalent to the liquefaction temperature between the U-Pu-Zr alloy fuel and the SUS cladding (about 923K). The thermal fragmentation of a molten aluminum with a solid crust in the sodium pool is caused by the transient pressurization within the melt confined by the solid crust even under the condition that the instantaneous contact interface temperature between the melt and the sodium is below the boiling point of sodium. This indicates the possibility that the metallic alloy fuel on liquid phase formed by metallurgical reactions can be fragmented without occurring the boiling of sodium on the surface of the melt. The transient pressurization within the melt is considered to be caused by following two mechanisms. i) the overheating of the coolant entrapped hydrodynamically inside the aluminum melt confined by solid crust ii) the progression of solid crust inward and the squeeze of inner liquid part of the aluminum melt confined by solid crust It is found that the degree of fragmentation defined by mass median diameter has the same tendency for different dropping modes (drop or jet) with different mass and ambient Weber number of the melt in the present experimental conditions

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

    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.

  13. Anodic and cathodic reactions in molten calcium chloride

    Fray, D.J.

    2002-01-01

    Calcium chloride is a very interesting electrolyte in that it is available, virtually free, in high purity form as a waste product from the chemical industry. It has a very large solubility for oxide ions, far greater than many alkali halides and other divalent halides and has the same toxicity as sodium chloride and also a very high solubility in water. Intuitively, on the passage of current, it is expected that calcium would be deposited at the cathode and chlorine would evolve at the anode. However, if calcium oxide is added to the melt, it is possible to deposit calcium and evolve oxygen containing gases at the anode, making the process far less polluting than when chlorine is evolved. This process is discussed in terms of the addition of calcium to molten lead. Furthermore, these reactions can be altered dramatically depending upon the electrode materials and the other ions dissolved in the calcium chloride. As calcium is only deposited at very negative cathodic potentials, there are several interesting cathodic reactions that can occur and these include the decomposition of the carbonate ion and the ionization of oxygen, sulphur, selenium and tellurium. For example, if an oxide is used as the cathode in molten calcium chloride, the favoured reaction is shown to be the ionization of oxygen O + 2e - → O 2- rather than Ca 2+ + 2 e- → Ca. The oxygen ions dissolve in the salt leaving the metal behind, and this leads to the interesting hypothesis that metal oxides can be reduced directly to the metal purely by the use of electrons. Examples are given for the reduction of titanium dioxide, zirconium dioxide, chromium oxide and niobium oxide and by mixing oxide powders together and reducing the mixed compact, alloys and intermetallic compounds are formed. Preliminary calculations indicate that this new process should be much cheaper than conventional metallothermic reduction for these elements. (author)

  14. Molten salt reactor technology for long-range and wide-scale nuclear energy system

    Ignatiev, V.; Alexseev, P.; Menshikov, L.; Prusakov, V.; Subbotine, S.

    1997-01-01

    A possibility of creation of multi-component nuclear power system in which alongside with thermal and fast reactors, molten salt burner reactors, for incineration of weapon grade plutonium, some minor actinides and transmutation of some fission products will be presented. The purposes of this work are to review the present status of the molten salt reactor technology and innovative non-aqueous chemical processing methods, to indicate the importance of the uncertainties remaining, to identify the additional work needed, and to evaluate the probability of success in obtaining improved safety characteristics for new concept of molten salt - burner reactor with external neutron source. 8 refs., 3 figs., 2 tabs

  15. Parametric studies on the fuel salt composition in thermal molten salt breeder reactors

    Nagy, K.; Kloosterman, J.L.; Lathouwers, D.; Van der Hagen, T.H.J.J.

    2008-01-01

    In this paper the salt composition and the fuel cycle of a graphite moderated molten salt self-breeder reactor operating on the thorium cycle is investigated. A breeder molten salt reactor is always coupled to a fuel processing plant which removes the fission products and actinides from the core. The efficiency of the removal process(es) has a large influence on the breeding capacity of the reactor. The aim is to investigate the effect on the breeding ratio of several parameters such as the composition of the molten salt, moderation ratio, power density and chemical processing. Several fuel processing strategies are studied. (authors)

  16. Concept of the demonstration molten salt unit for the transuranium elements transmutations

    Alekseev, P.; Dudnikov, A.; Prusakov, V.; Subbotin, S.; Zakirov, R.; Lelek, V.; Peka, I.

    1999-01-01

    Fluorine reprocessing is discussed of spent fuel and of fluoride molten salt reactor in critical and subcritical modes for plutonium and minor actinides burning. International collaboration for creation of such system is proposed. Additional neutron source in the core will have positive influence on the transmutation processes in the reactor. Demonstration critical molten salt reactor of small power capacity will permit to decide the most part of problems inherent to large critical reactors and subcritical drivers. It could be expected that fluoride molten salt transmuter can work without accelerator as a critical reactor. (author)

  17. Measurement and Analysis of Density of Molten Ni-W Alloys

    FANG Liang; XIAO Feng; TAO Zainan; MuKai Kusuhiro

    2005-01-01

    The density of molten Ni-W alloys was measured with a modified pycnometric method. It is found that the density of the molten Ni- W alloys decreases with temperature rising, but increases with the increase of tungsten concentration in the alloys. The molar volume of molten Ni- W binary alloys increases with the increase of temperature and tungsten concentration. The partial molar volume of tungsten in liquid Ni- W binary alloy has been calculated approximately as ( - 1.59+ 5.64 × 10-3 T) × 10-6m3 ·mol-1.

  18. Structural Analysis of Molten NaNO3 by Molecular Dynamics Simulation

    Tahara, Shuta; Toyama, Hiroshi; Shimakura, Hironori; Fukami, Takanori

    2017-08-01

    MD simulation for molten NaNO3 has been performed by using the Born-Mayer-Huggins-type potentials. The new structural features of molten NaNO3 are investigated by several analytical methods. The coordination-number and bond-angle distributions are similar to those of simple molten salts such as NaCl except for the variation caused by the different size of the anion and cation. Na+ ions are attracted toward O- ions, and get separated from N+ ions by Coulomb interactions. The distribution of the dihedral angle between NO3 - plannar ionic molecules has also been investigated.

  19. Molten salt reactors. Synthesis of studies realized between 1973 and 1983. Experimental loop file

    1983-03-01

    Four test loops were developed for the experimental study of a molten salt reactor with lead salt direct contact. A molten salt loop, completely in graphite, including the pump, showed that this material is convenient for salt containment and circulation. Reactor components like flowmeters, electromagnetic pumps, pressure gauge, valves developed for liquid sodium, were tested with liquid lead. A water-mercury loop was built for lead-molten salt simulation studies. Finally a lead-salt loop (COMPARSE) was built to study the behaviour of salt particles carried by lead in the heat exchanger. [fr

  20. Actinide removal from molten salts by chemical oxidation and salt distillation

    McNeese, J.A.; Garcia, E.; Dole, V.R. [Los Alamos National Laboratory, NM (United States)] [and others

    1995-10-01

    Actinide removal from molten salts can be accomplished by a two step process where the actinide is first oxidized to the oxide using a chemical oxidant such as calcium carbonate or sodium carbonate. After the actinide is precipitated as an oxide the molten salt is distilled away from the actinide oxides leaving a oxide powder heel and an actinide free distilled salt that can be recycled back into the processing stream. This paper discusses the chemistry of the oxidation process and the physical conditions required to accomplish a salt distillation. Possible application of an analogous process sequence for a proposed accelerator driven transmutation molten salt process is also discussed.

  1. Numerical analysis of partially molten splat during thermal spray process using the finite element method

    Zirari, M.; Abdellah El-Hadj, A.; Bacha, N.

    2010-03-01

    A finite element method is used to simulate the deposition of the thermal spray coating process. A set of governing equations is solving by a volume of fluid method. For the solidification phenomenon, we use the specific heat method (SHM). We begin by comparing the present model with experimental and numerical model available in the literature. In this study, completely molten or semi-molten aluminum particle impacts a H13 tool steel substrate is considered. Next we investigate the effect of inclination of impact of a partially molten particle on flat substrate. It was found that the melting state of the particle has great effects on the morphologies of the splat.

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

    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

  3. Actinide removal from molten salts by chemical oxidation and salt distillation

    McNeese, James A.; Garcia, Eduardo; Dole, Vonda R.; Griego, Walter J.

    1995-01-01

    Actinide removal from molten salts can be accomplished by a two step process where the actinide is first oxidized to the oxide using a chemical oxidant such as calcium carbonate or sodium carbonate. After the actinide is precipitated as an oxide the molten salt is distilled away from the actinide oxides leaving a oxide powder heel and an actinide free distilled salt that can be recycled back into the processing stream. This paper discusses the chemistry of the oxidation process and the physical conditions required to accomplish a salt distillation. Possible application of an analogous process sequence for a proposed accelerator driven transmutation molten salt process is also discussed

  4. Accuracy analysis of the thermal diffusivity measurement of molten salts by stepwise heating method

    Kato, Yoshio; Furukawa, Kazuo

    1976-11-01

    The stepwise heating method for measuring thermal diffusivity of molten salts is based on the electrical heating of a thin metal plate as a plane heat source in the molten salt. In this method, the following estimations on error are of importance: (1) thickness effect of the metal plate, (2) effective length between the plate and a temperature measuring point and (3) effect of the noise on the temperature rise signal. In this report, a measuring apparatus is proposed and measuring conditions are suggested on the basis of error estimations. The measurements for distilled water and glycerine were made first to test the performance; the results agreed well with standard values. The thermal diffusivities of molten NaNO 3 at 320-380 0 C and of molten Li 2 BeF 4 at 470-700 0 C were measured. (auth.)

  5. Molten-salt reactor strategies viewed from fuel conservation effect, (1)

    Furuhashi, Akira

    1976-01-01

    Saving of material requirements in the long-term fuel cycle is studied by introducing molten-salt reactors with good neutron economy into a projection of nuclear generating capacity in Japan. In this first report an examination is made on the effects brought by the introduction of molten-salt converter reactors starting with Pu which are followed by 233 U breeders of the same type. It is shown that the sharing of some Pu in the light water- and fast breeder-reactor system with molten-salt reactors provides a more rapid transition to the self-supporting, breeding cycle than the simple fast breeding system, thus leading to an appreciable fuel conservation. Considerations are presented on the strategic repartition of generating capacity among reactor types and it is shown that all of the converted 233 U should be promptly invested to molten-salt breeders to quickly establish the dual breeding system, instead of recycling to converters themselves. (auth.)

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

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

    2006-01-01

    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)

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

    Bennett, M.R.; Bamberge, C.E.; Kelmers, A.D.

    1980-01-01

    The subject relates to fuel preparation for molten salt breeder reactors, and more particularly to the reconstitution of spent molten fuel salt after fission product removal. During the course of reactor operation, fission products including rare earths and bred-in protactinium build up in the fuel salt and adversely affect the nuclear properties of the fuel. In order to more efficiently operate the reactor, the level of neutron poison fission products must be kept at a minimum. This is accomplished by continuously removing spent fuel from the primary circuit, processing it to remove fission products, and returning the reprocessed molten salt to the primary circuit. It is desirable for safety and economy that the fuel processing plant be a component of the reactor itself and that the salt be kept in the molten state throughout the processing system. (auth)

  8. A radioactive tracer dilution method to determine the mass of molten salt

    Lei Cao; Jarrell, Josh; Hardtmayer, D.E.; White, Susan; Herminghuysen, Kevin; Kauffman, Andrew; Sanders, Jeff; Li, Shelly

    2017-01-01

    A new technique for molten salt mass determination, termed radioactive tracer dilution, that uses 22 Na as a tracer was validated at bench scale. It has been a challenging problem to determine the mass of molten salt in irregularly shaped containers, where a highly radioactive, high-temperature molten salt was used to process nuclear spent/used fuel during electrochemical recycling (pyro-processing) or for coolant/fuel salt from molten salt reactors. A radioactive source with known activity is dissolved into the salt. After a complete mixture, a small amount of the salt is sampled and measured in terms of its mass and radioactivity. By finding the ratio of the mass to radioactivity, the unknown salt mass in the original container can be precisely determined. (author)

  9. System Requirements Document for the Molten Salt Reactor Experiment 233U conversion system

    Aigner, R.D.

    2000-01-01

    The purpose of the conversion process is to convert the 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

  10. Molten fuel/coolant interaction studies: some results obtained with the Windscale small shock tube rig

    Higham, E.J.; Vaughan, G.J.

    1978-02-01

    Experiments are described in which water has been brought into contact with various molten metals in a shock tube, thus simulating the fall of coolant into molten uranium dioxide in a postulated reactor accident. Impact velocities of the water on to the molten material were in the range 5 to 7 m/s. Shock-pulse pressures in the water column after impact and particle size distributions of the dispersed resolidified material that was recovered were measured. The proportion of dispersed material and the size of the shock pulse (by comparison with that expected from water hammer alone) have been used as criteria for the occurrence of a molten fuel/coolant interaction and such interactions of varying degrees of violence have been found for water/aluminium, water/bismuth, water/tin, over a range of temperatures from 350 0 C to 950 0 C, for water/boric oxide, but not for water/magnesium. (author)

  11. High Surface Area Iridium Anodes and Melt Containers for Molten Oxide Electrolysis, Phase II

    National Aeronautics and Space Administration — Direct electrochemical reduction of molten regolith is the most attractive method of oxygen production on the lunar surface, because no additional chemical reagents...

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

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

    2016-04-01

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

  13. Evaluation of a molten salt electrolyte for direct reduction of actinides

    Alangi, Nagaraj; Anupama, P.; Mukherjee, Jaya; Gantayet, L.M.

    2011-01-01

    Use of molten fluoride salt towards direct reduction of actinides and lanthanides by molten salt electrolysis is of interest for problems related to metallic nuclear fuels. The performance of the molten salt bath is dependent on the pre-conditioning of the molten salt. A procedure for conditioning of LiF-BaF 2 salt mixtures has been developed based on systematic electrochemical experimental investigations using voltammetry with graphite and platinum as electrode materials. We utilize the linear sweep voltammetry (LSV) as a diagnostic tool for assessment of the electrolyte condition. This technique is fast and offers the advantage of in-situ/online measurement eliminating the need for sampling. The conditioning procedure that was developed was tried on LiF-CaF 2

  14. Proceedings of the workshop on molten salts technology and computer simulation

    Hayashi, Hirokazu; Minato, Kazuo [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2001-12-01

    Applications of molten salts technology to separation and synthesis of materials have been studied eagerly, which would develop new fields of materials science. Research Group for Actinides Science, Department of Materials Science, Japan Atomic Energy Research Institute (JAERI), together with Reprocessing and Recycle Technology Division, Atomic Energy Society of Japan, organized the Workshop on Molten Salts Technology and Computer Simulation at Tokai Research Establishment, JAERI on July 18, 2001. In the workshop eleven lectures were made and lively discussions were there on the fundamentals and applications of the molten salts technology that covered the structure and basic properties of molten salts, the pyrochemical reprocessing technology and the relevant computer simulation. The 10 of the presented papers are indexed individually. (J.P.N.)

  15. Visualization of direct contact heat transfer between water and molten alloy by neutron radiography. 1

    Nishi, Yoshihisa; Furuya, Masahiro; Kinoshita, Izumi; Takenaka, Nobuyuki; Matsubayashi, Masahito.

    1997-01-01

    Design of an innovative Steam Generator (SG) for Liquid Metal Fast Reactors (LMFRs) using liquid-liquid direct contact heat transfer has been developing. In this concept, the SG shell is filled with a molten alloy, which is heated by primary sodium. Water is fed into the high-temperature, molten alloy, and evaporates by direct contact heating. In order to obtain the fundamental information needed to discuss the heat transfer mechanisms of direct contact between the water and molten alloy, this phenomenon was observed by neutron radiography. JRR-3M thermal neutron radiography at the Japan Atomic Energy Research Institute was used. This paper deals with the results of visualization of direct contact heat exchange in the molten alloy. (author)

  16. Process technology for the molten-salt reactor 233U--Th cycle

    Hightower, J.R. Jr.

    1975-01-01

    After a brief description of the design features of the molten-salt breeder reactor, fuel processing for removal of 233 Pa and fission products is examined. Some recent developments in processing technology are discussed

  17. Investigation of Inner Vacuum Sucking method for degassing of molten aluminum

    Zeng, Jianmin; Gu, Ping; Wang, Youbing

    2012-01-01

    Hydrogen is a harmful gas element that is appreciably soluble in aluminum and its alloys. Removal of hydrogen from molten aluminum has been one of the most important tasks in aluminum melt processing. In this paper, a patented degassing process, which is based on principle of vacuum metallurgy, is proposed. A porous head that connects a vacuum system is immersed in the molten aluminum. The vacuum is created within the porous head and the dissolved hydrogen will diffuse unidirectionally towards the porous head according to Sievert's law. In this way, the hydrogen in the molten aluminum can be removed. The Fick's diffusion equation is used to explain hydrogen transfer in the molten aluminum. RPT experiments are carried out to evaluate the effectiveness of the new degassing process. The experiments indicate that the hydrogen content can be dramatically reduced by use of this process.

  18. Numerical investigation on natural convection and solidification of molten pool with OpenFOAM

    Wang Xi; Meng Zhaocan; Cheng Xu

    2015-01-01

    The in-vessel retention is adopted by the third generation nuclear power technology as an important severe accident mitigation strategy. The integrity of reactor pressure vessel depends on the heat flux distribution of molten pool. In present study, the solidification model in open source CFD software OpenFOAM was applied to simulate solidification and natural convection which was driven by internal heat source or temperature difference. The stratified molten pool heat transfer experiment carried out by Royal Institute of Technology was analyzed in the paper, and the solidified crust, temperature and heat flux distributions were obtained. The simulation results were compared with experimental data. It is shown that this numerical method can be used in the simulation of natural convection and solidification of molten pool, and it will probably be used in the analysis of molten corium behavior in reactor lower head. (authors)

  19. Thermophysical Properties of Molten Silicon Measured by JPL High Temperature Electrostatic Levitator

    Rhim, W. K.; Ohsaka, K.

    1999-01-01

    Five thermophysical properties of molten silicon measured by the High Temperature Electrostatic Levitator (HTESL) at JPL are presented. The properties measured are the density, the constant pressure specific heat capacity, the hemispherical total emissivity, the surface tension and the viscosity.

  20. Molten salt hazardous waste disposal process utilizing gas/liquid contact for salt recovery

    Grantham, L.F.; McKenzie, D.E.

    1984-01-01

    The products of a molten salt combustion of hazardous wastes are converted into a cooled gas, which can be filtered to remove hazardous particulate material, and a dry flowable mixture of salts, which can be recycled for use in the molten salt combustion, by means of gas/liquid contact between the gaseous products of combustion of the hazardous waste and a solution produced by quenching the spent melt from such molten salt combustion. The process results in maximizing the proportion of useful materials recovered from the molten salt combustion and minimizing the volume of material which must be discarded. In a preferred embodiment a spray dryer treatment is used to achieve the desired gas/liquid contact

  1. Yttria-stabilized zirconia as membrane material for electrolytic deoxidation of CaO-CaCl{sub 2} melts

    Martin, A.; Poignet, J. C.; Fouletier, J. [Univ Grenoble, LEPMI, CNRS, INPG, UJF, F-38402 St Martin Dheres (France); Allibert, M. [LPSC, F-38026 Grenoble 1 (France); Lambertin, D. [SPDE, CEA Marcoule, F-30207 Bagnols Sur Ceze (France); Bourges, G. [SRPU, CEA Valduc, F-21120 Is Sur Tille (France)

    2010-07-01

    This article is devoted to the study of the stability of an yttria-stabilized zirconia membrane used in the electrolysis of molten CaCl{sub 2}-CaO mixtures at 850 degrees C. Intentiostatic and potentiostatic electrolysis were carried for periods ranging from 10 to 20 h. Post-mortem composition profiles across the zirconia membrane were determined using Raman spectroscopy and microprobe analysis. The membrane degradation was analyzed in terms of synergetic parameters, i. e., chemical, electrochemical, and thermomechanical effects. (authors)

  2. Robotic membranes

    Ramsgaard Thomsen, Mette

    2008-01-01

    The relationship between digital and analogue is often constructed as one of opposition. The perception that the world is permeated with underlying patterns of data, describing events and matter alike, suggests that information can be understood apart from the substance to which it is associated......, and that its encoded logic can be constructed and reconfigured as an isolated entity. This disembodiment of information from materiality implies that an event like a thunderstorm, or a material like a body, can be described equally by data, in other words it can be read or written. The following prototypes......, Vivisection and Strange Metabolisms, were developed at the Centre for Information Technology and Architecture (CITA) at the Royal Danish Academy of Fine Arts in Copenhagen as a means of engaging intangible digital data with tactile physical material. As robotic membranes, they are a dual examination...

  3. Impact on breeding rate of different Molten Salt reactor core structures

    Wang Haiwei; Mei Longwei; Cai Xiangzhou; Chen Jingen; Guo Wei; Jiang Dazhen

    2013-01-01

    Background: Molten Salt Reactor (MSR) has several advantages over the other Generation IV reactor. Referred to the French CNRS research and compared to the fast reactor, super epithermal neutron spectrum reactor type is slightly lower and beading rate reaches 1.002. Purpose: The aim is to explore the best conversion zone layout scheme in the super epithermal neutron spectrum reactor. This study can make nuclear fuel as one way to solve the energy problems of mankind in future. Methods: Firstly, SCALE program is used for molten salt reactor graphite channel, molten salt core structure, control rods, graphite reflector and layer cladding structure. And the SMART modules are used to record the important actinides isotopes and their related reaction values of each reaction channel. Secondly, the thorium-uranium conversion rate is calculated. Finally, the better molten salt reactor core optimum layout scheme is studied comparing with various beading rates. Results: Breading zone layout scheme has an important influence on the breading rate of MSR. Central graphite channels in the core can get higher neutron flux irradiation. And more 233 Th can convert to 233 Pa, which then undergoes beta decay to become 233 U. The graphite in the breading zone gets much lower neutron flux irradiation, so the life span of this graphite can be much longer than that of others. Because neutron flux irradiation in the uranium molten salt graphite has nearly 10 times higher than the graphite in the breading zone, it has great impact on the thorium-uranium conversion rates. For the super epithermal neutron spectrum molten salt reactors, double salt design cannot get higher thorium-uranium conversion rates. The single molten salt can get the same thorium-uranium conversion rate, meanwhile it can greatly extend the life of graphite in the core. Conclusions: From the analysis of calculation results, Blanket breeding area in different locations in the core can change the breeding rates of thorium

  4. Development of High-Temperature Transport System for Molten Salt in Pyroprocessing

    Lee, Sung Ho; Kim, In Tae; Park, Sung Bin

    2014-01-01

    The electrorefining process, which is a key process in pyroprocessing, is composed of two parts, electrorefining to deposit a uranium with a solid cathode and electrowinning to co-deposit TRU and RE with a liquid cadmium cathode (LCC). As the electrorefining operation proceedes, TRU and RE are accumulated in electrolyte LiCl-KCl salt, and after the electrorefining process, the molten salt used in an electrorefining reactor should by transported to the next process, the electrowinning process, to recover U/TRU/RE; Thus, a molten salt transfer system by suction is now being developed. An apparatus for suction transport experiments was designed and constructed for the development of high- temperature molten salt transport technology. Suction transport experiments were performed using LiC-KCl eutectic salt. The feasibility of pyro-reprocessing has been demonstrated through many laboratory-scale experiments. In pyroprocessing, a eutectic LiCl-KCl salt was used as a liquid elextrolyte for a recovery of actinides. However, reliable transport technologies for these high temperature liquids have not yet been developed. A preliminary study on high-temperature transport technology for molten salt by suction is now being carried out. In this study, three different salt transport technologies (gravity, suction pump, and centrifugal pump) were investigated to select the most suitable method for molten salt transport. An apparatus for suction transport experiments was designed and installed for the development of high-temperature molten salt transport technology. Basic preliminary suction transport experiments were carried out using the prepared LiC-KCl eutectic salt at 500 .deg. C to observe the transport behavior of LiCl-KCl molten salt. In addition, a PRIDE salt transport system was designed and installed for an engineering-scale salt transport demonstration. Several types of suction transport experiments using molten salt (LiCl-KCl eutectics) for the development of a high

  5. Development of High-Temperature Transport System for Molten Salt in Pyroprocessing

    Lee, Sung Ho; Kim, In Tae; Park, Sung Bin [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-05-15

    The electrorefining process, which is a key process in pyroprocessing, is composed of two parts, electrorefining to deposit a uranium with a solid cathode and electrowinning to co-deposit TRU and RE with a liquid cadmium cathode (LCC). As the electrorefining operation proceedes, TRU and RE are accumulated in electrolyte LiCl-KCl salt, and after the electrorefining process, the molten salt used in an electrorefining reactor should by transported to the next process, the electrowinning process, to recover U/TRU/RE; Thus, a molten salt transfer system by suction is now being developed. An apparatus for suction transport experiments was designed and constructed for the development of high- temperature molten salt transport technology. Suction transport experiments were performed using LiC-KCl eutectic salt. The feasibility of pyro-reprocessing has been demonstrated through many laboratory-scale experiments. In pyroprocessing, a eutectic LiCl-KCl salt was used as a liquid elextrolyte for a recovery of actinides. However, reliable transport technologies for these high temperature liquids have not yet been developed. A preliminary study on high-temperature transport technology for molten salt by suction is now being carried out. In this study, three different salt transport technologies (gravity, suction pump, and centrifugal pump) were investigated to select the most suitable method for molten salt transport. An apparatus for suction transport experiments was designed and installed for the development of high-temperature molten salt transport technology. Basic preliminary suction transport experiments were carried out using the prepared LiC-KCl eutectic salt at 500 .deg. C to observe the transport behavior of LiCl-KCl molten salt. In addition, a PRIDE salt transport system was designed and installed for an engineering-scale salt transport demonstration. Several types of suction transport experiments using molten salt (LiCl-KCl eutectics) for the development of a high

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

    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

  7. Status of the French research in the field of molten salt nuclear reactors

    Hery, M.; Israel, M.; Fauger, P.; Lecocq, A.

    1977-01-01

    The research program of the CEA in the field of molten salt nuclear reactors has been concerned with MSBR type reactors (Molten Salt Breeder Reactor). The papers written after having performed the theoretical analysis are entitled: core, circuits, chemistry and economy; they include some criticisms and suggestions. The experimental studies consisted in: graphite studies, chemical studies of the salt, metallic materials, the salt loop and the lead loop [fr

  8. Deposition of niobium plate on niobium-titanium from molten salts

    Matychenko, Eh.S.; Shevyrev, A.A.; Stolyarova, L.A.; Sukhorzhevskaya, S.L.

    1993-01-01

    A possibility of using Nb-Ti alloys (50 and 34 mas.% of Ti) as substrates for deposition of niobium coating of chloride-fluoride and fluoride molten salts is studied. Corrosion behaviour of alloys indicates in the electrolytic bath within 970-1070 K interval, coating structure and state of coating-substrate boundary are investigated. Chloride-fluoride molten salt usefullness for making products with niobium coatings is shown

  9. Study of tritium removal from fusion reactor blankets of molten salt and lithium--aluminum

    Talbot, J.B.

    1976-03-01

    The sorption of tritium by molten lithium--bismuth (Li--Bi, approx. 15 at. % lithium) and solid equiatomic lithium--aluminum (Li--Al) was investigated experimentally to evaluate the potential applications of both materials in a controlled thermonuclear reactor. The Li--Bi alloy was proposed to countercurrently extract tritium from a molten salt (Li 2 BeF 4 ) blanket. However, because of the low solubility ( 0 C, the extraction process is not attractive

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

    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.

  11. Contribution to the study of the vertical molten zone process (1963)

    Lenzin, M.

    1963-01-01

    Construction and use of several molten zone apparatuses operating either vertically or horizontally. Efficient purification of uranyl nitrate hexahydrate but less successful in the case of other hydrated double salts and of zirconyl chloride in the hydrochloric gel form. Demonstration and study of the dissymmetry in the direction of the transport of the impurity during, the purification by a vertical molten zone process. (author) [fr

  12. Study on the quench behavior of molten fuel material jet into coolant

    Abe, Yutaka; Kizu, Tetsuya; Arai, Takahiro; Nariai, Hideki; Chitose, Keiko; Koyama, Kazuya

    2004-01-01

    In a core disruptive accident (CDA) of a Fast Breeder Reactor, the post accident heat removal (PAHR) is crucial for the accident mitigation. The molten core material should be solidified in the sodium coolant in the reactor vessel. In the present experiment, molten material jet is injected into water to experimentally obtain fragments and the visualized information of the fragmentation. The distributed particle behavior of the molten material jet is observed with high-speed video camera. The distributions of the fragmented droplet diameter from the molten material jet are evaluated by correcting the solidified particles. The experimental results of the mean fragmented droplet diameter are compared with the existing theories. Consequently, the fragmented droplet diameter is close to the value estimated based on the Kelvin-Helmholtz instability. Once the particle diameter of the fragmented molten material could be known from a hydrodynamic model, it becomes possible to estimate the mass ratio of the molten particle to the total injected mass by combining an appropriate heat transfer model. The heat transfer model used in the present study is composed of the fragmentation model based on the Kelvin-Helmholtz instability. The mass ratio of the molten fragment to total mass of the melted mixed oxide fuel in sodium coolant estimated in the present study is very small. The result means that most of the molten mixed oxide fuel material injected into the sodium coolant can be cooled down under the solidified temperature, that is so called quenched, if the amount of the coolant is sufficient. (author)

  13. Mutual inductance appliance for measuring the level of a molten metal

    Zbinden, Marc.

    1982-01-01

    The invention concerns an appliance for measuring the level of a molten metal of the kind using the variation of the mutual inductance between two imbricated windings depending on the level of the free area of the molten metal in the range of levels taken up by the windings. It has a particularly significant use in measuring the level of liquid sodium, especially in nuclear facilities where sodium is used as coolant [fr

  14. Recommendations for a restart of molten salt reactor development

    Moir, R.W.

    2008-01-01

    The concept of the molten salt reactor (MSR) refuses to go away. The Generation-IV process lists the MSR as one of the six concepts to be considered for extending fuel resources. Good fuel utilization and good economics are required to meet the often-cited goal of 10 TWe globally and 1 TWe for the US by non-carbon energy sources in this century by nuclear fission. Strong incentives for the molten salt reactor design are its good fuel utilization, good economics, amazing fuel flexibility and promised large benefits. It can: - use thorium or uranium; - be designed with lots of graphite to have a fairly thermal neutron spectrum or without graphite moderator to have an epithermal neutron spectrum; - fission uranium isotopes and plutonium isotopes; - produces less long-lived wastes than today's reactors by a factor of 10-100; - operate with non-weapon grade fissile fuel, or in suitable sites it can operate with enrichment between reactor-grade and weapon grade fissile fuel; - be a breeder or near breeder; - operate at temperature >1100 deg. C if carbon composites are successfully developed. Enhancing 232 U content in the uranium to over 500 ppm makes the fuel undesirable for weapons, but it should not detract from its economic use in liquid fuel reactors: a big advantage in nonproliferation. Economics of the MSR are enhanced by operating at low pressure and high temperature and may even lead to the preferred route to hydrogen production. The cost of the electricity produced from low enriched fuel averaged over the life of the entire process, has been predicted to be about 10% lower than that from LWRs, and 20% lower for high-enriched fuel, with uncertainties of about 10%. The development cost has been estimated at about 1 B$ (e.g., a 100 M$/year base program for 10 years) not including construction of a series of reactors leading up to the deployment of multiple commercial units at an assumed cost of 9 B$ (450 M$/year over 20 years). A benefit of liquid fuel is that

  15. Studies on the molten salt reactor. Code development and neutronics analysis of MSRE-type design

    Zhuang Kun; Cao Liangzhi; Zheng Youqi; Wu Hongchun

    2015-01-01

    The molten salt reactor is characterized by its use of the fluid-fuel, which serves both as a fuel and as a coolant simultaneously. The position of delayed neutron precursors continuously changes both in the core and in the external loop due to the fuel circulation, and the fission products are extracted by an online fuel reprocessing unit, which all lead to the modeling methods for the conventional reactors using solid fuel not applicable. This study establishes suitable calculation models for the neutronics analysis of the molten salt reactor and develops a new code named MOREL based on the three-dimensional diffusion steady and transient calculations. Some numerical tests are chosen to verify the code and the numerical results indicate that MOREL can be used for the analysis of the molten salt reactor. After verification, it is applied to analyze the characteristics of a typical molten salt reactor, including the steady characteristics, the influence of fuel circulation on the kinetic behaviors. Besides, the influence of online fuel reprocessing simulation is also examined. The results show that inherent safety is the character of the molten salt reactor from the aspect of reactivity feedback and the fuel circulation has great influence on the kinetic characteristics of molten salt reactor. (author)

  16. Assessment of the Capability of Molten Salt Reactors as a Next Generation High Temperature Reactors

    Elsheikh, B.M.

    2017-01-01

    Molten Salt Reactor according to Aircraft Reactor Experiment (ARE) and the Molten Salt Reactor Experiment (MSRE) programs, was designed to be the first full-scale, commercial nuclear power plant utilizing molten salt liquid fuels that can be used for producing electricity, and producing fissile fuels (breeding)burning actinides. The high temperature in the primary cycle enables the realization of efficient thermal conversion cycles with net thermal efficiencies reach in some of the designs of nuclear reactors greater than 45%. Molten salts and liquid salt because of their low vapor pressure are excellent candidates for meeting most of the requirements of these high temperature reactors. There is renewed interest in MSRs because of changing goals and new technologies in the use of high-temperature reactors. Molten Salt Reactors for high temperature create substantial technical challenges to have high effectiveness intermediate heat transfer loop components. This paper will discuss and investigate the capability and compatibility of molten salt reactors, toward next generation high temperature energy system and its technical challenges

  17. Convective heat transfer characteristics in the turbulent region of molten salt in concentric tube

    Chen, Y.S.; Wang, Y.; Zhang, J.H.; Yuan, X.F.; Tian, J.; Tang, Z.F.; Zhu, H.H.; Fu, Y.; Wang, N.X.

    2016-01-01

    In order to better understand the heat transfer behavior and characteristics of molten salt in heat exchanger, the convective heat transfer characteristics of molten salt in salt-to-oil concentric tube are studied. Overall heat transfer coefficients of the heat exchanger are calculated using Wilson plots. Heat transfer coefficients of tube side molten salt with the range of Reynolds number from 10,000 to 50,000 and the Prandtl number from 11 to 27 are evaluated invoking the calculated overall heat transfer coefficients. The effects of velocity and temperature on the convective heat transfer in the turbulent region of molten salt are studied by comparing with the traditional correlations. The results show that the heat transfer characteristics of molten salt are in line with the empirical heat transfer correlation; however, Dittus–Boelter, Gnielinski, Sieder–Tate and Hausen correlations all give a larger deviation for the experimental data. Finally, based on the experimental data and Sieder–Tate correlation, a modified heat transfer correlation is proposed and good agreement is observed between the experimental data and the modified correlation. The results will also provide an important reference for the design of the heat exchangers in the Thorium-based Molten Salt Reactor.

  18. Fragmentation of a single molten copper and silver droplets penetrating a sodium pool with solid crust

    Wataru Itagaki; Ken-ichiro Sugiyama; Satoshi Nishimura; Izumi Kinoshita

    2005-01-01

    As a basic study of molten fuel-coolant interaction in liquid metal fast cooled reactors, we carried out a series of experiments for the fragmentation of molten copper droplet penetrating sodium pool at instantaneous contact interface temperatures below its freezing point. A single molten copper droplet with 5g in weight and with superheating varied from 0 degree C to 131 degree C was dropped into a sodium pool in a wide range of ambient Weber numbers 24 to 228. In addition to the experiment of molten copper droplet, molten silver droplet with 5gs in weight and with superheating varied from 3 degree C to 174 degree C was dropped into the sodium pool at an ambient Weber number of about 80. From the observation of the cross section of solidified silver droplet without fragmentation, it was clearly confirmed that sodium micro jet is driven into the inside from the upper surface of molten droplet keeping liquid phase, which is clear evidence for the thermal fragmentation mechanism proposed in the previous paper. Large scattering in the values of dimensionless mass median diameter observed in the present experimental study is recognized to be dependent on whether latent heat instantaneously released due to the injection of sodium micro jet can be effectively utilized for fragmentation. (authors)

  19. Comparison of molten chloride and fluoride salts potentialities for An/Ln separation by electrodeposition

    Laplace, A.; Peron, F.; Marrot, F.; Lacquement, J. [DRCP/SCPS/LPP - CEA/CEN Valrho - BP 17171 - 30207 Bagnols/Ceze (France)

    2008-07-01

    The objective of this paper is the comparison of molten fluoride and chloride salts potentialities for Am/Nd separation by electrodeposition on inert cathode, on a purely thermodynamic point of view. The molten LiF-CaF{sub 2} eutectic (77-23 mol.%, at 780 deg. C) was considered for this study. Cyclic voltammetry showed a one step Am(III)/Am reduction at a potential of {approx_equal}+0.5 V vs. Li{sup +}/Li. A potential difference of 290 mV between Am and Nd metallic deposition was estimated by square-wave voltammetry. This Am/Nd potential difference is more important than in molten chlorides (220 mV in the LiCl-KCl eutectic at 500 deg. C). Moreover in molten fluoride salt, the americium and neodymium (+II) oxidation state is not stable contrary to the molten chloride one where corrosion of deposited Am would be potential. However this larger potential difference in molten fluorides is quite balanced by the higher working temperature. (authors)

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

    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.

  1. Break-up and quench behavior of molten material in coolant

    Abe, Y.; Kizu, T.; Arai, T.; Nariai, H.; Chitose, K.; Koyama, K.

    2003-01-01

    In a Core Disruptive Accident (CDA) of a Fast Breeder Reactor, the Post Accident Heat Removal(PAHR) is crucial for the accident mitigation. The molten core material should be solidified in the sodium coolant in the reactor vessel. The material, being fragmented while solidification and forming debris bed, will be cooled in the coolant. In the experiment, molten material jet is injected into water to experimentally obtain fragments and the visualized information of the fragmentation and boiling phenomena during PAHR in CDA. The distributed particle behavior of the molten material jet is observed with high-speed video camera. The experimental results are compared with the existing theories. Consequently, the marginal wavelength on the surface of a water jet is close to the value estimated based on the Rayleigh-Taylor instability. Moreover, the fragmented droplet diameter obtained from the interaction of molten material and water is close to the value estimated based on the Kelvin-Helmholtz instability. Once the particle diameter of the fragmented molten material could be known from a hydrodynamic model, it becomes possible to estimate the mass of the molten particle with some appropriate heat transfer model

  2. Experimental study on forced convection boiling heat transfer on molten alloy

    Nishimura, Satoshi; Ueda, Nobuyuki; Nishi, Yoshihisa; Furuya, Masahiro; Kinoshita, Izumi

    1999-01-01

    In order to clarify the characteristics of forced convection boiling heat transfer on molten metal, basic experiments have been carried out with subcooled water flowing on molten Wood's alloy pool surface. In these experiments, water flows horizontally in a rectangular duct. A cavity filled with Wood's alloy is present in a portion of the bottom of the duct. Wood's alloy is heated by a copper conductor at the bottom of the cavity. The experiments have been carried out with various velocities and subcoolings of water, and temperature of Wood's alloy. Boiling curves on the molten alloy surface were obtained and compared with that on a solid heat transfer surface. It is observed that the boiling curve on molten alloy is in a lower superheat region than the boiling curve on a solid surface. This indicates that the heat transfer performance of forced convection boiling on molten alloy is enhanced by increase of the heat transfer area, due to oscillation of the surface and fragmentation of molten alloy

  3. Amorphous tantala and its relationship with the molten state

    Alderman, O. L. G.; Benmore, C. J.; Neuefeind, J.; Coillet, E.; Mermet, A.; Martinez, V.; Tamalonis, A.; Weber, R.

    2018-04-01

    The structure factors of molten T a2O5 and N b2O5 have been measured by high-energy x-ray and pulsed neutron diffraction. These are compared to transmission-mode x-ray diffraction through a self-supported 15-μm ion-beam sputtered amorphous tantala film. Atomistic models derived from the diffraction data by means of empirical potential structure refinement reveal that tantala and niobia liquids are very close to isomorphous, as confirmed by measurement of a molten mixture, T a0.8N b1.2O5 . Nonetheless, peak Nb-O bond lengths are about 1 % shorter than those for Ta-O, at temperatures, T*=T /Tmelt , scaled to the melting points. Mean coordination numbers are nM O≃5.6 (1 ) ,nO M≃2.23 (4 ) in the liquid state, and nTaO≃6.6 (2 ) ,nOTa≃2.63 (8 ) in the solid. The liquids are built from five- and six-fold M -O polyhedra which connect principally by corner sharing, with a minority of edge sharing; a-T a2O5 on the other hand has a local structure more akin to the crystalline polymorphs, built primarily from six- and seven-fold polyhedra, with a larger degree of edge sharing. The structural differences between liquid and amorphous T a2O5 , coupled with observations of increasing peak bond lengths upon cooling, are consistent with the interpretation that the amorphous film reaches a supercooled liquidlike metastable equilibrium during deposition. In other words, the amorphous film shares a common progenitor state with a hypothetical glass quenched from a fragile melt. In addition, we show that recent classical interatomic potentials do not fully reproduce the diffraction data, and infer that inclusion of attractive (non-Coulombic) Ta-Ta interactions is important, particularly for obtaining the correct degree of edge sharing, coordination numbers, and densities. Nanoscale inhomogeneity of the amorphous film is confirmed by the observation of small-angle x-ray scattering.

  4. Molten Salt: Concept Definition and Capital Cost Estimate

    Stoddard, Larry [Black & Veatch, Kansas City, MO (United States); Andrew, Daniel [Black & Veatch, Kansas City, MO (United States); Adams, Shannon [Black & Veatch, Kansas City, MO (United States); Galluzzo, Geoff [Black & Veatch, Kansas City, MO (United States)

    2016-06-30

    The Department of Energy’s (DOE’s) Office of Renewable Power (ORP) has been tasked to provide effective program management and strategic direction for all of the DOE’s Energy Efficiency & Renewable Energy’s (EERE’s) renewable power programs. The ORP’s efforts to accomplish this mission are aligned with national energy policies, DOE strategic planning, EERE’s strategic planning, Congressional appropriation, and stakeholder advice. ORP is supported by three renewable energy offices, of which one is the Solar Energy Technology Office (SETO) whose SunShot Initiative has a mission to accelerate research, development and large scale deployment of solar technologies in the United States. SETO has a goal of reducing the cost of Concentrating Solar Power (CSP) by 75 percent of 2010 costs by 2020 to reach parity with base-load energy rates, and to reduce costs 30 percent further by 2030. The SunShot Initiative is promoting the implementation of high temperature CSP with thermal energy storage allowing generation during high demand hours. The SunShot Initiative has funded significant research and development work on component testing, with attention to high temperature molten salts, heliostats, receiver designs, and high efficiency high temperature supercritical CO2 (sCO2) cycles. DOE retained Black & Veatch to support SETO’s SunShot Initiative for CSP solar power tower technology in the following areas: 1. Concept definition, including costs and schedule, of a flexible test facility to be used to test and prove components in part to support financing. 2. Concept definition, including costs and schedule, of an integrated high temperature molten salt (MS) facility with thermal energy storage and with a supercritical CO2 cycle generating approximately 10MWe. 3. Concept definition, including costs and schedule, of an integrated high temperature falling particle facility with thermal energy storage and with a supercritical CO2

  5. Deep-Earth Equilibration between Molten Iron and Solid Silicates

    Brennan, M.; Zurkowski, C. C.; Chidester, B.; Campbell, A.

    2017-12-01

    Elemental partitioning between iron-rich metals and silicate minerals influences the properties of Earth's deep interior, and is ultimately responsible for the nature of the core-mantle boundary. These interactions between molten iron and solid silicates were influential during planetary accretion, and persist today between the mantle and liquid outer core. Here we report the results of diamond anvil cell experiments at lower mantle conditions (40 GPa, >2500 K) aimed at examining systems containing a mixture of metals (iron or Fe-16Si alloy) and silicates (peridotite). The experiments were conducted at pressure-temperature conditions above the metallic liquidus but below the silicate solidus, and the recovered samples were analyzed by FIB/SEM with EDS to record the compositions of the coexisting phases. Each sample formed a three-phase equilibrium between bridgmanite, Fe-rich metallic melt, and an oxide. In one experiment, using pure Fe, the quenched metal contained 6 weight percent O, and the coexisting oxide was ferropericlase. The second experiment, using Fe-Si alloy, was highly reducing; its metal contained 10 wt% Si, and the coexisting mineral was stishovite. The distinct mineralogies of the two experiments derived from their different starting metals. These results imply that metallic composition is an important factor in determining the products of mixed phase iron-silicate reactions. The properties of deep-Earth interfaces such as the core-mantle boundary could be strongly affected by their metallic components.

  6. Electrochemical reduction of cerium oxides in molten salts

    Claux, B.; Serp, J.; Fouletier, J.

    2011-01-01

    This brief article describes a pyrochemical process that is used by CEA to turn actinide oxides into metal actinides. This process is applied to Cerium oxides (CeO 2 ) that simulate actinide oxides well chemically as cerium belongs to the lanthanide family. The process is in fact an electrolysis of cerium oxide in a bath of molten calcium chloride salt whose temperature is between 800 and 900 Celsius degrees. At those temperatures calcium chloride becomes a ionic liquid (Ca 2+ and Cl - ) that is a good electrical conductor and is particularly well-adapted as solvent to an electrolytic process. The electrolysis current allows the transformation of solvent Ca 2+ ions into metal calcium which, in turn, can reduce cerium oxide into metal cerium through chromatically. Experimental data shows the reduction of up to 90% of 10 g samples of CeO 2 in a 6 hour long electrolysis while the best reduction rate ever known was 80% so far. This result is all the more promising that cerium oxides are more difficult to reduce than actinide oxides from the thermodynamical perspective

  7. Molybdenum carbide coating electrodeposited from molten fluoride bath

    Topor, D.C.; Selman, J.R.

    1987-01-01

    Molybdenum carbide has been recently considered as a candidate material for the protection of common steel-based substrates in high-temperature high-sulfur activity applications. Methods to produce coatings of materials such as Mo/sub 2/C are scarce and only the electrodeposition from molten salts can yield dense, pore-free layers on various metallic profiles. Recently Stern reported the deposition of a Mo/sub 2/C coating on nickel substrate form, FLINAK + K/sub 2/MoCl/sub 6/ + Na/sub 2/CO/sub 3/ mixture at 850 0 C. Electrodeposition of Mo/sub 2/C on a cathode surface proceeds according to a rather complicated mechanism which may involve simultaneous reduction of carbonate to C, of molybdate to Mo and a subsequent chemical reaction between both species. The deposit grows further as a coherent coating. Reduction of CO/sub 2/ or carbonate to carbon in a fused salt medium could follow different paths but Li/sup +/ ions or other highly polarizing ions must be present. A similar situation in which a polyatomic anion discharges at the cathode is encountered when molybdates are used as source of molybdenum. In fluoride melts the chemistry of Mo(VI) species is considered to be much simpler due to the hard fluoride ions. These ions form strong complexes with molybdenum and the resulting solution is more stable

  8. Experimental investigation of the MSFR molten salt reactor concept

    Yamaji, Bogdan; Aszodi, Attila [Budapest University of Technology and Economics (Hungary). Inst. of Nuclear Techniques

    2014-11-15

    In the paper experimental modelling and investigation of the MSFR concept will be presented. MSFR is a homogeneous, single region liquid fuelled fast reactor concept. In case of molten salt reactors the core neutron flux and fission distribution is determined by the flow field through distribution and transport of fissile material and delayed neutron precursors. Since the MSFR core is a single region homogeneous volume without internal structures, it is a difficult task to ensure stable flow field, which is strongly coupled to the volumetric heat generation. These considerations suggest that experimental modelling would greatly help to understand the flow phenomena in such geometry. A scaled and segmented experimental mock-up of MSFR was designed and built in order to carry out particle image velocimetry measurements. Basic flow behaviour inside the core region can be investigated and the measurement data can also provide resource for the validation of computational fluid dynamics models. Measurement results of steady state conditions will be presented and discussed.

  9. Neutron scattering lengths of molten metals determined by gravity refractometry

    Reiner, G.; Waschkowski, W.; Koester, L.

    1990-01-01

    Very accurate values of the coherent neutron scattering lengths of the heavy elements Bi and Pb are important quantities for the investigation of the electric interactions of neutrons with atoms. We performed, therefore, a series of experiments to determine accurate scattering lengths by means of neutron gravity refractometry on liquid mirrors of molten metals. The possible perturbations of the necessary reflection measurements have been discussed in details. After taking into account the uncertainties and corrections associated with observable perturbations we obtained the following values for bound atoms: b(Bi)=8.532±0.002 fm, b(Pb)=9.405±0.003 fm, b(Tl)=8.776±0.005 fm, b(Sn)=6.225±0.002 fm and b(Ga)=7.288±0.002 fm. These data are corrected for the local field effect occuring in the reflection on liquids. The recently reported results for the neutron's electric polarizability and the neutron-electron scattering length are supported by the Bi- and Pb-scattering length of this work. (orig.)

  10. Neutron scattering lengths of molten metals determined by gravity refractometry

    Reiner, G; Waschkowski, W; Koester, L [Technische Univ. Muenchen, Garching (Germany, F.R.). Fakultaet fuer Physik

    1990-10-01

    Very accurate values of the coherent neutron scattering lengths of the heavy elements Bi and Pb are important quantities for the investigation of the electric interactions of neutrons with atoms. We performed, therefore, a series of experiments to determine accurate scattering lengths by means of neutron gravity refractometry on liquid mirrors of molten metals. The possible perturbations of the necessary reflection measurements have been discussed in details. After taking into account the uncertainties and corrections associated with observable perturbations we obtained the following values for bound atoms: b(Bi)=8.532{plus minus}0.002 fm, b(Pb)=9.405{plus minus}0.003 fm, b(Tl)=8.776{plus minus}0.005 fm, b(Sn)=6.225{plus minus}0.002 fm and b(Ga)=7.288{plus minus}0.002 fm. These data are corrected for the local field effect occuring in the reflection on liquids. The recently reported results for the neutron's electric polarizability and the neutron-electron scattering length are supported by the Bi- and Pb-scattering length of this work. (orig.).

  11. Neutron scattering lengths of molten metals determined by gravity refractometry

    Reiner, G.; Waschkowski, W.; Koester, L. (Technische Univ. Muenchen, Garching (Germany, F.R.). Fakultaet fuer Physik)

    1990-10-01

    Very accurate values of the coherent neutron scattering lengths of the heavy elements Bi and Pb are important quantities for the investigation of the electric interactions of neutrons with atoms. We performed, therefore, a series of experiments to determine accurate scattering lengths by means of neutron gravity refractometry on liquid mirrors of molten metals. The possible perturbations of the necessary reflection measurements have been discussed in details. After taking into account the uncertainties and corrections associated with observable perturbations we obtained the following values for bound atoms: b(Bi)=8.532{plus minus}0.002 fm, b(Pb)=9.405{plus minus}0.003 fm, b(Tl)=8.776{plus minus}0.005 fm, b(Sn)=6.225{plus minus}0.002 fm and b(Ga)=7.288{plus minus}0.002 fm. These data are corrected for the local field effect occuring in the reflection on liquids. The recently reported results for the neutron's electric polarizability and the neutron-electron scattering length are supported by the Bi- and Pb-scattering length of this work. (orig.).

  12. Optimized molten salt receivers for ultimate trough solar fields

    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.

  13. Desulfurization kinetics of molten copper by gas bubbling

    Fukunaka, Y.; Nishikawa, K.; Sohn, H. S.; Asaki, Z.

    1991-02-01

    Molten copper with 0.74 wt pct sulfur content was desulfurized at 1523 K by bubbling Ar-O2 gas through a submerged nozzle. The reaction rate was significantly influenced not only by the oxygen partial pressure but also by the gas flow rate. Little evolution of SO2 gas was observed in the initial 10 seconds of the oxidation; however, this was followed by a period of high evolution rate of SO2 gas. The partial pressure of SO2 gas decreased with further progress of the desulfurization. The effect of the immersion depth of the submerged nozzle was negligible. The overall reaction is decomposed to two elementary reactions: the desulfurization and the dissolution rate of oxygen. The assumptions were made that these reactions are at equilibrium and that the reaction rates are controlled by mass transfer rates within and around the gas bubble. The time variations of sulfur and oxygen contents in the melt and the SO2 partial pressure in the off-gas under various bubbling conditions were well explained by the mathematical model combined with the reported thermodynamic data of these reactions. Based on the present model, it was anticipated that the oxidation rate around a single gas bubble was mainly determined by the rate of gas-phase mass transfer, but all oxygen gas blown into the melt was virtually consumed to the desulfurization and dissolution reactions before it escaped from the melt surface.

  14. Steelmaking-Casting of Molten Steel by Decarburization Ladle Matching

    Wei Liu

    2018-01-01

    Full Text Available Steelmaking–continuous casting is a complex process. The method of selecting a ladle, which also functions as a storage device, follows a specific process of the production plan. In ladle matching, several ladle attributes are considered. However, matching objectives are difficult to achieve simultaneously. Different molten steel properties have contributed to the complexity of matching constraints, and, thus, matching optimization is regarded a multiconflict goal problem. In the process of optimization, the first-order rule learning method is first used to extract key ladle attributes (performance indicators, including highest temperature, usage frequency, lowest-level material, and outlet. On the basis of a number of indicators, such as ladle temperature, quantity, material, and usage frequency, as well as skateboard quantity, the ladle matching model is established. Second, the rule of ladle selection is determined by the method of least-generalization rule learning. Third, a simulation experiment is carried out according to various scheduling order strategies and matching priority combinations. Finally, the heuristic ladle matching method based on the rule priority (RP is determined for possible industrial applications. Results show that the accuracy of ladle selection can be improved. In particular, the numbers of ladles and maintenance times are reduced. Consequently, furnace production efficiency is also enhanced.

  15. Thermal hydraulic study of a corium molten pool

    Pigny, S.; Grand, D.; Seiler, J.M.; Durin, M.

    1993-01-01

    The thermohydraulic behaviour of a mass of molten core is investigated, in the frame of PWR severe accidents studies. The corium may be located in the vessel lower head or in an external core-catcher. It is assumed to be present in the container instantaneously. Its motion is described by one velocity field. It may be homogeneous or made of two stratified fluids. The residual power is assumed to be constant and uniform in the UO 2 phase. The radiative losses and the external water-cooling are taken into account. The thermal resistance of a peripheral crust is considered. The influence of the crust on the pool geometry may be studied. The wall behaviour is analysed by a conduction calculation. The interest of a sacrificial layer is underlined, so as the necessity of a multicomponent multiphase model to study the behaviour of a core catcher. It is also concluded that some experiments are needed for code validation about volume heated natural convection and multiphase flows. (author). 14 figs., 3 refs

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

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

    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

  17. Wetting of molybdenum with molten Cu-O alloys

    Yupko, V.L.; Garbuz, V.V.; Kryuchkova, N.I.

    1992-01-01

    The Cu-O alloys were prepared from type MOb copper (GOST 859-78) with an oxygen content of 0.001 wt.% and type ChDA cuprous oxide (MRTU 6-09-1451-64), the powder of which was first pressed into briquettes. The weighted portions of Cu 2 O were weighed on an Elektrobalans scale having an absolute error of ±5 · 10 -7 g. The relative error in weighing an approximately 1 · 10 -4 g weighed portion of Cu 2 O for preparation of the alloy with the minimum oxygen content of 0.002% was, therefore, ± 0.5% and consequently for the alloys with a higher oxygen content the accuracy was higher. The alloys were prepared on a ZrO 2 + 5% Y 2 O 3 ceramic at 1,420 K in a vacuum of 6.7 · 10 -3 Pa,d their weight was 1.0-1.5 g, and the melting time 30 sec. The pure type MOb copper was remelted in the same manner. The time relationships of the angle of wetting of molybdenum by molten Cu-O alloys under conditions of combined heating are given. With an increase in oxygen content from 0.004 to 0.005%, wetting drops sharply

  18. Electrochemical reduction of actinides oxides in molten salts

    Claux, B.

    2011-01-01

    Reactive metals are currently produced from their oxide by multiple steps reduction techniques. A one step route from the oxide to the metal has been suggested for metallic titanium production by electrolysis in high temperature molten chloride salts. In the so-called FFC process, titanium oxide is electrochemically reduced at the cathode, generating O 2- ions, which are converted on a graphite anode into carbon oxide or dioxide. After this process, the spent salt can in principle be reused for several batches which is particularly attractive for a nuclear application in terms of waste minimization. In this work, the electrochemical reduction process of cerium oxide (IV) is studied in CaCl 2 and CaCl 2 -KCl melts to understand the oxide reduction mechanism. Cerium is used as a chemical analogue of actinides. Electrolysis on 10 grams of cerium oxide are made to find optimal conditions for the conversion of actinides oxides into metals. The scale-up to hundred grams of oxide is also discussed. (author) [fr

  19. Molten pool characterization of laser lap welded copper and aluminum

    Xue, Zhiqing; Hu, Shengsun; Zuo, Di; Cai, Wayne; Lee, Dongkyun; Elijah, Kannatey-Asibu, Jr.

    2013-12-01

    A 3D finite volume simulation model for laser welding of a Cu-Al lap joint was developed using ANSYS FLUENT to predict the weld pool temperature distribution, velocity field, geometry, alloying element distribution and transition layer thickness—all key attributes and performance characteristics for a laser-welded joint. Melting and solidification of the weld pool was simulated with an enthalpy-porosity formulation. Laser welding experiments and metallographic examination by SEM and EDX were performed to investigate the weld pool features and validate the simulated results. A bowl-shaped temperature field and molten pool, and a unique maximum fusion zone width were observed near the Cu-Al interface. Both the numerical simulation and experimental results indicate an arch-shaped intermediate layer of Cu and Al, and a gradual transition of Cu concentration from the aluminum plate to the copper plate with high composition gradient. For the conditions used, welding with Cu on top was found to result in a better weld joint.

  20. Molten pool characterization of laser lap welded copper and aluminum

    Xue, Zhiqing; Hu, Shengsun; Zuo, Di; Cai, Wayne; Lee, Dongkyun; Elijah, Kannatey-Asibu Jr

    2013-01-01

    A 3D finite volume simulation model for laser welding of a Cu–Al lap joint was developed using ANSYS FLUENT to predict the weld pool temperature distribution, velocity field, geometry, alloying element distribution and transition layer thickness—all key attributes and performance characteristics for a laser-welded joint. Melting and solidification of the weld pool was simulated with an enthalpy-porosity formulation. Laser welding experiments and metallographic examination by SEM and EDX were performed to investigate the weld pool features and validate the simulated results. A bowl-shaped temperature field and molten pool, and a unique maximum fusion zone width were observed near the Cu–Al interface. Both the numerical simulation and experimental results indicate an arch-shaped intermediate layer of Cu and Al, and a gradual transition of Cu concentration from the aluminum plate to the copper plate with high composition gradient. For the conditions used, welding with Cu on top was found to result in a better weld joint. (paper)

  1. Electrochemical behavior of molten fluoride-water system

    Takenaka, Toshihide; Ito, Yasuhiko; Ishikawa, Takayasu; Oishi, Jun

    1984-11-01

    The cathodic behavior of a molten fluoride-water system was investigated by the potential sweep method. LiF-KF-NaF eutectic melt was used as an electrolyte and HF-H/sub 2/O gas mixture with Ar as a carrier was bubbled into it. Gold wire was used as a working electrode. The peak currents due to the reduction of HF and H/sub 2/O were clearly observed. The relations between peak currents and the square roots of the scanning rates were linear, strongly suggesting that the reduction reactions of the HF and H/sub 2/O dissolved in the melt were diffusion controlled. From the linearity of the relations between peak currents and partial pressures of HF and H/sub 2/O in the low partial pressure region, it was concluded that the concentrations of HF and H/sub 2/O in a fluoride melt are proportional to the partial pressure of each gas. The peak current due to the reduction of OH/sup -/ ion could not be observed, though a clear peak current was observed when OH/sup -/ ion was added to the melt and a cathodic scan was applied immediately. This indicates that OH/sup -/ ion is unstable in a fluoride melt under HF-H/sub 2/O atmosphere.

  2. Oxidation mechanism and passive behaviour of nickel in molten carbonate

    Vossen, J.P.T. (ECN Fossil Fuels, Petten (Netherlands)); Ament, P.C.H.; De Wit, J.H.W. (Div. of Corrosion, Lab. for Maaterials Sceince, Delft Univ. of Technology, Delft (Netherlands))

    1994-07-01

    The oxidation and passivation mechanism and the passive behaviour of nickel in molten carbonate have been investigated with impedance measurements. The oxidation of nickel proceeds according to a dissolution and reprecipitation process. The slowest steps in the reaction sequence are the dissociation reaction of the carbonate and the diffusion of the formed NiO to the metal surface. In the passive range, dissolution of Ni[sup 2+] proceeds after diffusion of Ni[sup 2+] through the oxide layer. The Ni[sup 2+] is formed at the metal/oxide interface. The slowest process is the diffusion of bivalent nickel ions through the passive scale. The formation of trivalent nickel ions probably takes place at the oxide/melt interface. This reaction is accompanied by the incorporation of an oxygen ion and a nickel vacancy in the NiO lattice. The trivalent nickel ions and the nickel vacancy diffuse to the bulk of the oxide scale. The slowest step in this sequence is the dissociation of the carbonate ions and the incorporation of the oxygen ion in the NiO lattice. 9 figs., 2 tabs., 11 refs.

  3. Recent advances on polymeric membranes for membrane reactors

    Buonomenna, M. G.; Choi, Seung Hak

    2012-01-01

    . The successful use of membranes in membrane reactors is primary the result of two developments concerning: (i) membrane materials and (ii) membrane structures. The selection of a suited material and preparation technique depends on the application the membrane

  4. Natural convection heat transfer characteristics of the molten metal pool with solidification by boiling coolant

    Cho, Jae Seon; Suh, Kune Yull; Chung, Chang Hyun [Seoul National University, Seoul (Korea, Republic of); Paark, Rae Joon; Kim, Sang Baik [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1997-12-31

    This paper presents results of experimental studies on the heat transfer and solidification of the molten metal pool with overlying coolant with boiling. The metal pool is heated from the bottom surface and coolant is injected onto the molten metal pool. Ad a result, the crust, which is a solidified layer, may form at the top of the molten metal pool. Heat transfer is accomplished by a conjugate mechanism, which consists of the natural convection of the molten metal pool, the conduction in the crust layer and the convective boiling heat transfer in the coolant. This work examines the crust formation and the heat transfer rate on the molten metal pool with boiling coolant. The simulant molten pool material is tin (Sn) with the melting temperature of 232 deg C. Demineralized water is used as the working coolant. The crust layer thickness was ostensibly varied by the heated bottom surface temperature of the test section, but not much affected by the coolant injection rate. The correlation between the Nusselt number and the Rayleigh number in the molten metal pool region of this study is compared against the crust formation experiment without coolant boiling and the literature correlations. The present experimental results are higher than those from the experiment without coolant boiling, but show general agreement with the Eckert correlation, with some deviations in the high and low ends of the Rayleigh number. This discrepancy is currently attributed to concurrent rapid boiling of the coolant on top of the metal layer. 10 refs., 4 figs., 1 tab. (Author)

  5. Natural convection heat transfer characteristics of the molten metal pool with solidification by boiling coolant

    Cho, Jae Seon; Suh, Kune Yull; Chung, Chang Hyun [Seoul National University, Seoul (Korea, Republic of); Paark, Rae Joon; Kim, Sang Baik [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1998-12-31

    This paper presents results of experimental studies on the heat transfer and solidification of the molten metal pool with overlying coolant with boiling. The metal pool is heated from the bottom surface and coolant is injected onto the molten metal pool. Ad a result, the crust, which is a solidified layer, may form at the top of the molten metal pool. Heat transfer is accomplished by a conjugate mechanism, which consists of the natural convection of the molten metal pool, the conduction in the crust layer and the convective boiling heat transfer in the coolant. This work examines the crust formation and the heat transfer rate on the molten metal pool with boiling coolant. The simulant molten pool material is tin (Sn) with the melting temperature of 232 deg C. Demineralized water is used as the working coolant. The crust layer thickness was ostensibly varied by the heated bottom surface temperature of the test section, but not much affected by the coolant injection rate. The correlation between the Nusselt number and the Rayleigh number in the molten metal pool region of this study is compared against the crust formation experiment without coolant boiling and the literature correlations. The present experimental results are higher than those from the experiment without coolant boiling, but show general agreement with the Eckert correlation, with some deviations in the high and low ends of the Rayleigh number. This discrepancy is currently attributed to concurrent rapid boiling of the coolant on top of the metal layer. 10 refs., 4 figs., 1 tab. (Author)

  6. Experimental studies of thermal and chemical interactions between molten aluminum and nuclear dispersion fuels with water

    Farahani, A.A.

    1997-01-01

    Because of the possibility of rapid physical and chemical molten fuel-water interactions during a core melt accident in noncommercial or experimental reactors, it is important to understand the interactions that might occur if these materials were to contact water. An existing vertical 1-D shock tube facility was improved and a gas sampling device to measure the gaseous hydrogen in the upper chamber of the shock tube was designed and built to study the impact of a water column driven downward by a pressurized gas onto both molten aluminum (6061 alloy) and oxide and silicide depleted nuclear dispersion fuels in aluminum matrices. The experiments were carried out with melt temperatures initially at 750 to 1,000 C and water at room temperature and driving pressures of 0.5 and 1 MPa. Very high transient pressures, in many cases even larger than the thermodynamic critical pressure of the water (∼ 20 MPa), were generated due to the interactions between the water and the crucible and its contents. The molten aluminum always reacted chemically with the water but the reaction did not increase consistently with increasing melt temperature. An aluminum ignition occurred when water at room temperature impacted 28.48 grams of molten aluminum at 980.3 C causing transient pressures greater than 69 MPa. No signs of aluminum ignition were observed in any of the experiments with the depleted nuclear dispersion fuels, U 3 O 8 -Al and U 3 Si 2 -Al. The greater was the molten aluminum-water chemical reaction, the finer was the debris recovered for a given set of initial conditions. Larger coolant velocities (larger driving pressures) resulted in more melt fragmentation but did not result in more molten aluminum-water chemical reaction. Decreasing the water temperature also resulted in more melt fragmentation and did not suppress the molten aluminum-water chemical reaction

  7. Magnetically controlled permeability membranes

    Kosel, Jurgen

    2013-10-31

    A bioactive material delivery system can include a thermoresponsive polymer membrane and nanowires distributed within the thermoresponsive polymer membrane. Magnetic activation of a thermoresponsive polymer membrane can take place via altering the magnetization or dimensions of nanowires dispersed or ordered within the membrane matrix.

  8. Magnetically controlled permeability membranes

    Kosel, Jü rgen; Khashab, Niveen M.; Zaher, Amir

    2013-01-01

    A bioactive material delivery system can include a thermoresponsive polymer membrane and nanowires distributed within the thermoresponsive polymer membrane. Magnetic activation of a thermoresponsive polymer membrane can take place via altering the magnetization or dimensions of nanowires dispersed or ordered within the membrane matrix.

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

    Hathaway, Brandon Jay

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

  10. Electrochemical extraction of samarium from molten chlorides in pyrochemical processes

    Castrillejo, Y.; Fernandez, P.; Medina, J.; Hernandez, P.; Barrado, E.

    2011-01-01

    This work concerns the electrochemical extraction of samarium from molten chlorides. In this way, the electrochemical behaviour of samarium ions has been investigated in the eutectic LiCl-KCl at the surface of tungsten, aluminium and aluminium coated tungsten electrodes. On a W inert electrode the electro-reduction of Sm(III) takes place in only one soluble-soluble electrochemical step Sm(III)/Sm(II). The electrochemical system Sm(II)/Sm(0) has not been observed within the electrochemical window, because of the prior reduction of Li(I) ions from the solvent, which inhibits the electro-extraction of Sm species from the salt on such a substrate. Sm metal in contact with the melt react to give Li(0) according to the reaction: Sm(0) + 2Li(I) ↔ Sm(II) + 2Li(0). On the contrary, on reactive Al electrodes the electrochemical system Sm(II)/Sm(0) was observed within the electroactive range. The potential shift of the redox couple is caused by the decrease of Sm activity in the metal phase due to the formation of Sm-Al alloys at the interface. The formation mechanism of the intermetallic compounds was studied in a melt containing: (i) both Sm(III) and Al(III) ions, using W and Al coated tungsten electrodes, and (ii) Sm(III) ions using an Al electrode. Analysis of the samples after potentiostatic electrolysis by X-ray diffraction and scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDS), allowed the identification of Al 3 Sm and Al 2 Sm.

  11. Electrochemical extraction of samarium from molten chlorides in pyrochemical processes

    Castrillejo, Y., E-mail: ycastril@qa.uva.es [QUIANE/Dept Quimica Analitica, F. de Ciencias, Universidad de Valladolid, Prado de la Magdalena s/n, 47005 Valladolid (Spain); Fernandez, P. [QUIANE/Dept Quimica Analitica, F. de Ciencias, Universidad de Valladolid, Prado de la Magdalena s/n, 47005 Valladolid (Spain); Medina, J. [Dept Fisica Materia Condensada Cristalografia y Mineralogia, F. de Ciencias, Universidad de Valladolid, Prado de la Magdalena s/n, 47005 Valladolid (Spain); Hernandez, P. [Centro de Investigaciones Quimicas, Universidad Autonoma del Estado de Hidalgo, Carr. Pachuca-Tulancingo Km. 4.5, C.P. 42076 Pachuca, Hidalgo (Mexico); Barrado, E. [QUIANE/Dept Quimica Analitica, F. de Ciencias, Universidad de Valladolid, Prado de la Magdalena s/n, 47005 Valladolid (Spain)

    2011-10-01

    This work concerns the electrochemical extraction of samarium from molten chlorides. In this way, the electrochemical behaviour of samarium ions has been investigated in the eutectic LiCl-KCl at the surface of tungsten, aluminium and aluminium coated tungsten electrodes. On a W inert electrode the electro-reduction of Sm(III) takes place in only one soluble-soluble electrochemical step Sm(III)/Sm(II). The electrochemical system Sm(II)/Sm(0) has not been observed within the electrochemical window, because of the prior reduction of Li(I) ions from the solvent, which inhibits the electro-extraction of Sm species from the salt on such a substrate. Sm metal in contact with the melt react to give Li(0) according to the reaction: Sm(0) + 2Li(I) {r_reversible} Sm(II) + 2Li(0). On the contrary, on reactive Al electrodes the electrochemical system Sm(II)/Sm(0) was observed within the electroactive range. The potential shift of the redox couple is caused by the decrease of Sm activity in the metal phase due to the formation of Sm-Al alloys at the interface. The formation mechanism of the intermetallic compounds was studied in a melt containing: (i) both Sm(III) and Al(III) ions, using W and Al coated tungsten electrodes, and (ii) Sm(III) ions using an Al electrode. Analysis of the samples after potentiostatic electrolysis by X-ray diffraction and scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDS), allowed the identification of Al{sub 3}Sm and Al{sub 2}Sm.

  12. Modelling of the Molten Core Concrete Interaction (MCCI)

    Guillaume, M.

    2008-01-01

    Severe accidents of nuclear power plants are very unlikely to occur, yet it is necessary to be able to predict the evolution of the accident. In some situations, heat generation due to the disintegration of fission products could lead to the melting of the core. If the molten core falls on the floor of the building, it would provoke the melting of the concrete floor. The objective of the studies is to calculate the melting rate of the concrete floor. The work presented in this report is in the continuity of the segregation phase model of Seiler and Froment. It is based on the results of the ARTEMIS experiments. Firstly, we have developed a new model to simulate the transfers within the interfacial area. The new model explains how heat is transmitted to concrete: by conduction, convection and latent heat generation. Secondly, we have modified the coupled modelling of the pool and the interfacial area. We have developed two new models: the first one is the 'liquidus model', whose main hypothesis is that there is no resistance to solute transfer between the pool and the interfacial area. The second one is 'the thermal resistance model', whose main hypothesis is that there is no solute transfer and no dissolution of the interfacial area. The second model is able to predict the evolution of the pool temperature and the melting rate in the tests 3 and 4, with the condition that the obstruction time of the interfacial area is about 10 5 s. The model is not able to explain precisely the origin of this value. The liquidus model is able to predict correctly the evolution of the pool temperature and the melting rate in the tests 2 and 6. (author) [fr

  13. An experimental study of pressure shadows in partially molten rocks

    Qi, Chao; Zhao, Yong-Hong; Kohlstedt, David L.

    2013-11-01

    As a two-phase, solid-melt material flows around rigid particles, melt-depleted and melt-enriched regions (i.e., pressure shadows) develop due to the coupled fluxes of melt and solid driven by pressure gradients around the particles. To study this compaction-decompaction process, samples composed of fine-grained San Carlos olivine plus mid-ocean ridge basalt containing dispersed sub-millimeter-sized, single crystal beads of olivine were deformed in torsion at a temperature of 1473 K and a confining pressure of 300 MPa. Indicated by melt distribution maps obtained from reflected-light optical and backscattered electron microscopy, melt-enriched and melt-depleted regions around the beads became observable at a local shear strain of γ≈1 in samples with an initially homogeneously distributed melt fraction of ϕ≈0.05. The melt-enriched regions (ϕbarhigh≈0.06 to 0.10) and the melt-depleted regions (ϕbarlow≈0.02 to 0.04), extending as far as one radius of the bead, were symmetrically distributed around the bead. The flow field of the olivine matrix determined from crystallographic preferred orientations agrees with theoretical predictions based on two-phase flow analysis. These experiments are the first to produce pressure shadows in partially molten rocks. One implication of this study is that it will be possible to constrain the ratio of bulk to shear viscosity, which is inferred from the distribution of melt using a combination of experimental observations and numerical simulations.

  14. Development of galvanic high energy cells with molten salt electrolytes

    Borger, W.; Ely, G.; Kunze, D.; Laig-Hoerstebrock, H.; Panesar, H.; Sterr, G.; Wunderlich, A.

    1985-01-01

    The development work during the period 1980-1983 was mainly directed towards the development of technical LiAl/FeS cells, the development of separators, tests of cells and modules, and more basic work. An important objective was the improvement of cycle life at constant specific energy. Technical cells with 140 Ah nominal capacity at the five hour rate and 100 Wh.kg/sup -1/ specific energy performed up to 400 full cycles (30 A discharge), while in 10 Ah test cells more than 2000 full cycles have been demonstrated. The improvement of cycle life of technical cells was achieved by the use of improved separators fabricated from MgO-powder and by a vacuum-tight electrical feedthrough. A design concept of a 10 cell module has been developed based upon 200 Ah cell with two positive and three negative plates. A detailed investigation of safety aspects showed that there is no specific risk related to the LiAl/molten salt/FeS system. Thermal management of a 24 kWh battery was investigated and the Ohmic heat generated in the leads seems to be the critical factor. A range of total materials cost between 60 and 130 DM/kWh has been estimated. The price of LiAl/FeS batteries will most probably also be in the range of conventional secondary batteries. The cost/benefit analysis shows a considerable potential of energy conservation by the use of light-weight high energy batteries. Compared with a expected technical life of 7 years a pay-back period between 2 and 6 years seems attractive. However, the economy of the electric vehicle is strongly influenced by the higher purchase price of an electric vehicle and the present energy level.

  15. Dry molten globule intermediates and the mechanism of protein unfolding.

    Baldwin, Robert L; Frieden, Carl; Rose, George D

    2010-10-01

    New experimental results show that either gain or loss of close packing can be observed as a discrete step in protein folding or unfolding reactions. This finding poses a significant challenge to the conventional two-state model of protein folding. Results of interest involve dry molten globule (DMG) intermediates, an expanded form of the protein that lacks appreciable solvent. When an unfolding protein expands to the DMG state, side chains unlock and gain conformational entropy, while liquid-like van der Waals interactions persist. Four unrelated proteins are now known to form DMGs as the first step of unfolding, suggesting that such an intermediate may well be commonplace in both folding and unfolding. Data from the literature show that peptide amide protons are protected in the DMG, indicating that backbone structure is intact despite loss of side-chain close packing. Other complementary evidence shows that secondary structure formation provides a major source of compaction during folding. In our model, the major free-energy barrier separating unfolded from native states usually occurs during the transition between the unfolded state and the DMG. The absence of close packing at this barrier provides an explanation for why phi-values, derived from a Brønsted-Leffler plot, depend primarily on structure at the mutational site and not on specific side-chain interactions. The conventional two-state folding model breaks down when there are DMG intermediates, a realization that has major implications for future experimental work on the mechanism of protein folding. 2010 Wiley-Liss, Inc.

  16. Hot corrosion behavior of plasma-sprayed partially stabilized zirconia coatings in a lithium molten salt

    Cho, Soo Haeng; Hong, Sun Seok; Kang, Dae Seong; Park, Byung Heong; Hur, Jin Mok; Lee, Han Soo

    2008-01-01

    The electrolytic reduction of spent oxide fuel involves the liberation of oxygen in a molten LiCl electrolyte, which results in a chemically aggressive environment that is too corrosive for typical structural materials. It is essential to choose the optimum material for the process equipment handling molten salt. IN713LC is one of the candidate materials proposed for application in electrolytic reduction process. In this study, Yttria-Stabilized Zirconia (YSZ) top coat was applied to a surface of IN713LC with an aluminized metallic bond coat by an optimized plasma spray process, and were investigated the corrosion behavior at 675 .deg. C for 216 hours in the molten salt LiCl-Li 2 O under an oxidizing atmosphere. The as-coated and tested specimens were examined by OM, SEM/EDS and XRD, respectively. The bare superalloy reveals obvious weight loss, and the corrosion layer formed on the surface of the bare superalloy was spalled due to the rapid scale growth and thermal stress. The top coatings showed a much better hot-corrosion resistance in the presence of LiCl-Li 2 O molten salt when compared to those of the uncoated superalloy and the aluminized bond coatings. These coatings have been found to be beneficial for increasing to the hot-corrosion resistance of the structural materials for handling high temperature lithium molten salts

  17. Low-temperature synthesis of nanocrystalline ZrC coatings on flake graphite by molten salts

    Ding, Jun, E-mail: dingjun@wust.edu.cn; Guo, Ding; Deng, Chengji; Zhu, Hongxi; Yu, Chao

    2017-06-15

    Highlights: • Uniform ZrC coatings are prepared on flake graphite at 900 °C. • ZrC coatings are composed of nanosized (30–50 nm) particles. • The template growth mechanism is believed to be dominant in the molten salt synthesis process. - Abstract: A novel molten salt synthetic route has been developed to prepare nanocrystalline zirconium carbide (ZrC) coatings on flake graphite at 900 °C, using Zr powder and flake graphite as the source materials in a static argon atmosphere, along with molten salts as the media. The effects of different molten salt media, the sintered temperature, and the heat preservation time on the phase and microstructure of the synthetic materials were investigated. The ZrC coatings formed on the flake graphite were uniform and composed of nanosized particles (30–50 nm). With an increase in the reaction temperature, the ZrC nanosized particles were more denser, and the heat preservation time and thickness of the ZrC coating also increased accordingly. Electron microscopy was used to observe the ZrC coatings on the flake graphite, indicating that a “template mechanism” played an important role during the molten salt synthesis.

  18. Deployment of quasi-digital sensor for high temperature molten salt level measurement in pyroprocessing plants

    Sanga, Ramesh; Agarwal, Sourabh; Sivaramakrishna, M.; Rao, G. Prabhakara

    2018-04-01

    Development of a liquid molten salt level sensor device that can detect the level of liquid molten salt in the process vessels of pyrochemical reprocessing of spent metallic fuels is detailed. It is proposed to apply a resistive-type pulsating sensor-based level measurement approach. There are no commercially available sensors due to limitations of high temperature, radiation, and physical dimensions. A compact, simple, rugged, low power, and high precise pulsating sensor-based level probe and simple instrumentation for the molten salt liquid level sensor to work in the extreme conditions has been indigenously developed, with high precision and accuracy. The working principle, design concept, and results have been discussed. This level probe is mainly composed of the variable resistor made up of ceramic rods. This resistor constitutes the part of resistance-capacitance-type Logic Gate Oscillator (LGO). A change in the molten salt level inside the tank causes a small change in the resistance which in turn changes the pulse frequency of the LGO. Thus the frequency, the output of the instrument that is displayed on the LCD of an embedded system, is a function of molten salt level. In the present design, the range of level measurement is about 10 mm. The sensitivity in position measurement up to 10 mm is ˜2.5 kHz/mm.

  19. Carbon particle induced foaming of molten sucrose for the preparation of carbon foams

    Narasimman, R.; Vijayan, Sujith; Prabhakaran, K.

    2014-01-01

    Graphical abstract: - Highlights: • An easy method for the preparation of carbon foam from sucrose is presented. • Wood derived activated carbon particles are used to stabilize the molten sucrose foam. • The carbon foams show relatively good mechanical strength. • The carbon foams show excellent CO 2 adsorption and oil absorption properties. • The process could be scaled up for the preparation of large foam bodies. - Abstract: Activated carbon powder was used as a foaming and foam setting agent for the preparation of carbon foams with a hierarchical pore structure from molten sucrose. The rheological measurements revealed the interruption of intermolecular hydrogen bonding in molten sucrose by the carbon particles. The carbon particles stabilized the bubbles in molten sucrose by adsorbing on the molten sucrose–gas interface. The carbon foams obtained at the activated carbon powder to sucrose weight ratios in the range of 0–0.25 had a compressive strength in the range of 1.35–0.31 MPa. The produced carbon foams adsorb 2.59–3.04 mmol/g of CO 2 at 760 mmHg at 273 K and absorb oil from oil–water mixtures and surfactant stabilized oil-in-water emulsions with very good selectivity and recyclability

  20. Removal of alkaline-earth elements by a carbonate precipitation in a chloride molten salt

    Yung-Zun Cho; In-Tae Kim; Hee-Chui Yang; Hee-Chui Eun; Hwan-Seo Park; Eung-Ho Kim

    2007-01-01

    Separation of some alkaline-earth chlorides (Sr, Ba) was investigated by using carbonate injection method in LiCl-KCl eutectic and LiCl molten salts. The effects of the injected molar ratio of carbonate([K 2 (or Li 2 )CO 3 /Sr(or Ba)Cl 2 ]) and the temperature(450-750 deg.) on the conversion ratio of the Sr or Ba carbonate were determined. In addition, the form of the Sr and Ba carbonate resulting from the carbonation reaction with carbonates was identified via XRD and SEM-EDS analysis. In these experiments, the carbonate injection method can remove Sr and Ba chlorides effectively over 99% in both LiCl-KCl eutectic and LiCl molten salt conditions. When Sr and Ba were co-presented in the eutectic molten salt, they were carbonated in a form of Ba 0.5 Sr 0.3 CO 3 . And when Sr was present in LiCl molten salt, it was carbonated in the form of SrCO 3 . Carbonation ratio increased with a decreasing temperature and it was more favorable in the case of a K 2 CO 3 injection than that of Li 2 CO 3 . Based on this experiment, it is postulated that carbonate precipitation method has the potential for removing alkali-earth chlorides from LiCl-KCl eutectic and LiCl molten salts. (authors)