WorldWideScience

Sample records for oxide fuel prepared

  1. Oxidation stability of biodiesel fuel as prepared by supercritical methanol

    Energy Technology Data Exchange (ETDEWEB)

    Jiayu Xin; Hiroaki Imahara; Shiro Saka [Kyoto University, Kyoto (Japan). Department of Socio-Environmental Energy Science, Graduate School of Energy Science

    2008-08-15

    A non-catalytic supercritical methanol method is an attractive process to convert various oils/fats efficiently into biodiesel. To evaluate oxidation stability of biodiesel, biodiesel produced by alkali-catalyzed method was exposed to supercritical methanol at several temperatures for 30 min. As a result, it was found that the tocopherol in biodiesel is not stable at a temperature higher than 300{sup o}C. After the supercritical methanol treatment, hydroperoxides were greatly reduced for biodiesel with initially high in peroxide value, while the tocopherol slightly decreased in its content. As a result, the biodiesel prepared by the supercritical methanol method was enhanced for oxidation stability when compared with that prepared by alkali-catalyzed method from waste oil. Therefore, supercritical methanol method is useful especially for oils/fats having higher peroxide values. 32 refs., 8 figs., 3 tabs.

  2. Model for solid oxide fuel cell cathodes prepared by infiltration

    DEFF Research Database (Denmark)

    Samson, Alfred Junio; Søgaard, Martin; Hendriksen, Peter Vang

    2017-01-01

    A 1-dimensional model of a cathode has been developed in order to understand and predict the performance of cathodes prepared by infiltration of La0.6Sr0.4Co1.05O3-δ (LSC) into porous backbones of Ce0.9Gd0.1O1.95 (CGO). The model accounts for the mixed ionic and electronic conductivity of LSC......, ionic conductivity of CGO, gas transport in the porous cathode, and the oxygen reduction reaction at the surface of percolated LSC. Geometrical variations are applied to reflect a changing microstructure of LSC under varying firing temperatures. Using microstructural parameters obtained from detailed...... scanning electron microscopy and simulations of the measured polarization resistances, an expression for the area specific resistance (rp) associated with the oxygen exchange on the surface of the infiltrated LSC particles was extracted and compared with literature values. A series of microstructural...

  3. New methodology of preparation support for solid oxide fuel cells using different pore forming agent

    Energy Technology Data Exchange (ETDEWEB)

    Fiuza, Raigenis da P.; Guedes, Bruna C.F.; Silva, Marcos A. da; Carvalho, Luiz F.V. de; Boaventura, Jaime S. [Universidade Federal da Bahia (IQ/UFBA), Salvador, BA (Brazil). Inst. de Quimica; Pontes, Luiz A.M. [Universidade Federal da Bahia (EP/UFBA), Salvador, BA (Brazil). Escola Politecnica. Programa de Pos-Graduacao em Engenharia Quimica

    2008-07-01

    The development of environment-friendly energy sources has been of the most important scientific and technological area. Solid oxide fuel cells (SOFC) are very promising alternative for their ability to handle renewable fuels with low emissions and high efficiency. However, this device requires massive improvement before commercial application. This work studies the pore formation in the cell anode and cathode with NaHCO{sub 3} or citric acid, comparing to graphite. The three agents make pore with similar features, but the use of NaHCO{sub 3} and citric acid considerably improves the adhesion of the electrode-electrolyte interface, critical characteristic for good cell efficiency. The prepared anode-electrolyte-cathode structure was studied by SEM technique. The SOFC prepared using citric acid was tested with gaseous ethanol, natural gas and hydrogen. For all these three fuels the SOFC shows virtually no overpotential, indicating the good ionic conductance of the electrodes-electrolyte interface.. (author)

  4. Preparation of cathode materials for solid oxide solid fuel (SOFC) using gelatin

    International Nuclear Information System (INIS)

    Silva, R.M.; Aquino, F. de M.; Macedo, D.A. de; Sa, A.M.; Galvao, G.O.

    2016-01-01

    Fuel cells are electrochemical devices that convert chemical energy into electrical energy. These devices are basically divided into interconnectors, electrolyte, anode, and cathode. Recently, studies of improvements in microstructural and morphological properties of calcium cobaltate (Ca_3Co_4O_9, C349) has been made regarding its potential use as SOFC cathode for intermediate temperature. Gelatin has proven to be effective as a polymerizing agent in the synthesis of nanocrystalline materials. This work reports the synthesis and characterization of the C349 cathode using commercial gelatin. The structural properties of the material were determined by X-ray diffraction (XRD). Morphological characterization was performed by scanning electron microscopy (SEM). The results showed the formation of the crystalline phase at 900 °C, indicating the effectiveness of the gelatin in the preparation of cathodes for SOFC. (author)

  5. Some characterisation profiles of uranium oxides pertaining to-ceramic fuel preparation

    International Nuclear Information System (INIS)

    El-Fekey, S.A.; Bishay, A.F.; Farah, M.Y.; Hammad, F.H.

    1978-01-01

    The effect of several variables during various stages of preparation of UO 2 powder such as precipitation, calcination and reduction on some physico-chemical properties of intermediate oxides and UO 2 powders were investigated. The methods used for characterisation were powder density, specific surface area by permeability, X-ray analysis and O/U ratio by T.G.A. The powder density of uranates was found to increase with the decrease of uranium content in uranyl nitrate solution, the increase of pH and duration of precipitation. The surface area of uranates was found to increase with the increase of pH, temperature of precipitation and the decrease of duration of precipitation. The effect of calcination for 18 hours showed that as the calcination temperature was increased for 100-800 0 C, the powder density increses and the surface area decreases. The variaton in powder density of uranates were eliminated when calcination was carried out at 700 0 C for 18 hours. The progress of the formation of intermediate oxide was followed by X-rays analysis. Two steps reduction methods, two hours at 400 0 C followed by two hours at 700 0 C, eliminated the effect of preparatory history on the 0/U ratio and produced powders having more or less the same 0/U ratio

  6. Internal fuel pin oxidizer

    International Nuclear Information System (INIS)

    Andrews, M.G.

    1978-01-01

    A nuclear fuel pin has positioned within it material which will decompose to release an oxidizing agent which will react with the cladding of the pin and form a protective oxide film on the internal surface of the cladding

  7. Uranium plutonium oxide fuels

    International Nuclear Information System (INIS)

    Cox, C.M.; Leggett, R.D.; Weber, E.T.

    1981-01-01

    Uranium plutonium oxide is the principal fuel material for liquid metal fast breeder reactors (LMFBR's) throughout the world. Development of this material has been a reasonably straightforward evolution from the UO 2 used routinely in the light water reactor (LWR's); but, because of the lower neutron capture cross sections and much lower coolant pressures in the sodium cooled LMFBR's, the fuel is operated to much higher discharge exposures than that of a LWR. A typical LMFBR fuel assembly is shown. Depending on the required power output and the configuration of the reactor, some 70 to 400 such fuel assemblies are clustered to form the core. There is a wide variation in cross section and length of the assemblies where the increasing size reflects a chronological increase in plant size and power output as well as considerations of decreasing the net fuel cycle cost. Design and performance characteristics are described

  8. Solid Oxide Fuel Cell

    DEFF Research Database (Denmark)

    2010-01-01

    The solid oxide fuel cell comprising a metallic support material, an active anode layer consisting of a good hydrocarbon cracking catalyst, an electrolyte layer, an active cathode layer, and a transition layer consisting of preferably a mixture of LSM and a ferrite to the cathode current collector...

  9. Pilot-scale demonstration of the modified direct denitration process to prepare uranium oxide for fuel fabrication evaluation

    International Nuclear Information System (INIS)

    Kitts, F.G.

    1994-04-01

    The Uranium-Atomic Vapor Laser Isotope Separation (U-AVLIS) Program has the objective of developing a cost-competitive enrichment process that will ultimately replace the gaseous diffusion process used in the United States. Current nuclear fuel fabricators are set up to process only the UF 6 product from gaseous diffusion enrichment. Enriched uranium-iron alloy from the U-AVLIS separator system must be chemically converted into an oxide form acceptable to these fabricators to make fuel pellets that meet American Society for Testing and Materials (ASTM) and utility company specifications. A critical step in this conversion is the modified direct denitration (MDD) that has been selected and presented in the AVLIS Conceptual Design for converting purified uranyl nitrate to UO 3 to be shipped to fabricators for making UO 2 pellets for power reactor fuel. This report describes the MDD process, the equipment used, and the experimental work done to demonstrate the conversion of AVLIS product to ceramic-grade UO 3 suitable for making reactor-grade fuel pellets

  10. Electrometallurgical treatment of oxide spent fuels

    International Nuclear Information System (INIS)

    Karell, E. J.

    1999-01-01

    The Department of Energy (DOE) inventory of spent nuclear fuel contains a wide variety of oxide fuel types that may be unsuitable for direct repository disposal in their current form. The molten-salt electrometallurgical treatment technique developed by Argonne National Laboratory (ANL) has the potential to simplify preparing and qualifying these fuels for disposal by converting them into three uniform product streams: uranium metal, a metal waste form, and a ceramic waste form. This paper describes the major steps in the electrometallurgical treatment process for oxide fuels and provides the results of recent experiments performed to develop and scale up the process

  11. Single-step Preparation of Nano-homogeneous NiO/YSZ Comp osite Ano de for Solid Oxide Fuel Cells

    Institute of Scientific and Technical Information of China (English)

    Jung-Hoon Song; Mi Young Park; Hye Won Park; Hyung-Tae Lim

    2013-01-01

    Homogeneous co-precipitation and hydrothermal treatment were used to prepare nano-and highly dispersed NiO/YSZ (yttria-stabilized zirconia) composite powders. Composite powders of size less than 100 nm were successfully prepared. This process did not require separate sintering of the YSZ and NiO to be used as the raw materials for solid oxide fuel cells. The performance of a cell fabricated using the new powders (max. power density∼0.87 W/cm2) was higher than that of a cell fabricated using conventional powders (max. power density∼0.73 W/cm2). Co-precipitation and hydrothermal treatment proved to be very effective processes for reducing cell production costs as well as improving cell performance.

  12. Preparation of Sr2(MgMo)1-xRuxO6 ceramics for use in a solid oxide fuel cell anode

    International Nuclear Information System (INIS)

    Bezerra, Matheus Eiji Ohno; Florio, Daniel Zanetti de; Fonseca, Fabio Coral

    2016-01-01

    Full text: Solid Oxide Fuel Cells are the most efficient devices known for the direct conversion of fuels into electric energy. Such devices have advanced steadily and are already available for specific applications such as portable power and residential stationary generation. The main objective of this work is the development of anodes for SOFC operating directly with renewable fuels, without the addition of water and using strategic fuels such as ethanol and natural gas. Specifically, a family of mixed ionic-electronic compounds has been investigated: the double perovskites with compositions Sr 2 (MgMo) 1-x Ru x O 6 with x = 0; 1; 2; 5; 10 e 20 at.%. This material has been synthesized by polymeric precursor method. The resins were prepared by combining stoichiometric amounts of the starting solutions. The resulting solution was heated treated under magnetic stirring. The thermal decomposition of the polymeric resin was studied by means of simultaneous thermogravimetric and differential scanning calorimetry up to 1500 °C with heating and cooling rates of 10 °/min in Ar. The thermal decomposition result shows mass loss up to, approximately, 900 °C. However X-ray diffraction analyses of the powder heat treated at 900 °C and 1200 °C presents a considerable content of an undesiderate phase (SrMoO 4 ). According to the literature for similar compounds a thermal treatment under reduction conditions could be necessary to obtain the double perovskites single phase. After this treatment the material will be characterized regarding its electrical properties. The expected results will contribute to advance both the understanding of the mixed ionic electronic ceramics and the SOFC technology using renewable fuels. (author)

  13. Preparation of functional layers for anode-supported solid oxide fuel cells by the reverse roll coating process

    Science.gov (United States)

    Mücke, R.; Büchler, O.; Bram, M.; Leonide, A.; Ivers-Tiffée, E.; Buchkremer, H. P.

    The roll coating technique represents a novel method for applying functional layers to solid oxide fuel cells (SOFCs). This fast process is already used for mass production in other branches of industry and offers a high degree of automation. It was utilized for coating specially developed anode (NiO + 8YSZ, 8YSZ: 8 mol% yttria-stabilized zirconia) and electrolyte (8YSZ) suspensions on green and pre-sintered tape-cast anode supports (NiO + 8YSZ). The layers formed were co-fired in a single step at 1400 °C for 5 h. As a result, the electrolyte exhibited a thickness of 14-18 μm and sufficient gas tightness. Complete cells with a screen-printed and sintered La 0.65Sr 0.3MnO 3- δ (LSM)/8YSZ cathode yielded a current density of 0.9-1.1 A cm -2 at 800 °C and 0.7 V, which is lower than the performance of non-co-fired slip-cast or screen-printed Jülich standard cells with thinner anode and electrolyte layers. The contribution of the cell components to the total area-specific resistance (ASR) was calculated by analyzing the distribution function of the relaxation times (DRTs) of measured electrochemical impedance spectra (EIS) and indicates the potential improvement in the cell performance achievable by reducing the thickness of the roll-coated layers. The results show that the anode-supported planar half-cells can be fabricated cost-effectively by combining roll coating with subsequent co-firing.

  14. Preparation method of Ni@Pt/C nanocatalyst affects the performance of direct borohydride-hydrogen peroxide fuel cell: Improved power density and increased catalytic oxidation of borohydride.

    Science.gov (United States)

    Hosseini, Mir Ghasem; Mahmoodi, Raana

    2017-08-15

    The Ni@Pt/C electrocatalysts were synthesized using two different methods: with sodium dodecyl sulfate (SDS) and without SDS. The metal loading in synthesized nanocatalysts was 20wt% and the molar ratio of Ni: Pt was 1:1. The structural characterizations of Ni@Pt/C electrocatalysts were investigated by field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HR-TEM). The electrocatalytic activity of Ni@Pt/C electrocatalysts toward BH 4 - oxidation in alkaline medium was studied by means of cyclic voltammetry (CV), chronopotentiometry (CP), chronoamperometry (CA) and electrochemical impedance spectroscopy (EIS). The results showed that Ni@Pt/C electrocatalyst synthesized without SDS has superior catalytic activity toward borohydride oxidation (22016.92Ag Pt -1 ) in comparison with a catalyst prepared in the presence of SDS (17766.15Ag Pt -1 ) in NaBH 4 0.1M at 25°C. The Membrane Electrode Assembly (MEA) used in fuel cell set-up was fabricated with catalyst-coated membrane (CCM) technique. The effect of Ni@Pt/C catalysts prepared with two methods as anode catalyst on the performance of direct borohydride-hydrogen peroxide fuel cell was studied. The maximum power density was obtained using Ni@Pt/C catalyst synthesized without SDS at 60°C, 1M NaBH 4 and 2M H 2 O 2 (133.38mWcm -2 ). Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Solid oxide fuel cells fueled with reducible oxides

    Science.gov (United States)

    Chuang, Steven S.; Fan, Liang Shih

    2018-01-09

    A direct-electrochemical-oxidation fuel cell for generating electrical energy includes a cathode provided with an electrochemical-reduction catalyst that promotes formation of oxygen ions from an oxygen-containing source at the cathode, a solid-state reduced metal, a solid-state anode provided with an electrochemical-oxidation catalyst that promotes direct electrochemical oxidation of the solid-state reduced metal in the presence of the oxygen ions to produce electrical energy, and an electrolyte disposed to transmit the oxygen ions from the cathode to the solid-state anode. A method of operating a solid oxide fuel cell includes providing a direct-electrochemical-oxidation fuel cell comprising a solid-state reduced metal, oxidizing the solid-state reduced metal in the presence of oxygen ions through direct-electrochemical-oxidation to obtain a solid-state reducible metal oxide, and reducing the solid-state reducible metal oxide to obtain the solid-state reduced metal.

  16. Preparation of plutonium oxide

    International Nuclear Information System (INIS)

    Roberts, W.G.; Sutcliffe, P.W.

    1982-01-01

    A 238 Pu 16 O 2 fuel for a heart pacemaker battery is produced on an essentially two-stage process wherein, in the first stage, 238 Pusup(nat)O 2 is reduced with graphite to form the sesquicarbide 238 Pu 2 C 3 and, in the second stage, the carbide is converted to 238 Pu 16 O 2 by using water depleted in 17 O and 18 O. The product, which can be made reproducibly, has radiation characteristics well within those recommended for bio-medical use. (author)

  17. Fuels Preparation Department monthly report, May 1958

    Energy Technology Data Exchange (ETDEWEB)

    1958-06-17

    This report describes the operation of the fuels preparation department for the month of May, 1958. Manufacturing employee relations, process development, plant improvements, and financial operations are discussed.

  18. Heating subsurface formations by oxidizing fuel on a fuel carrier

    Science.gov (United States)

    Costello, Michael; Vinegar, Harold J.

    2012-10-02

    A method of heating a portion of a subsurface formation includes drawing fuel on a fuel carrier through an opening formed in the formation. Oxidant is supplied to the fuel at one or more locations in the opening. The fuel is combusted with the oxidant to provide heat to the formation.

  19. Solid Oxide Fuel Cell Experimental Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — NETL’s Solid Oxide Fuel Cell Experimental Laboratory in Morgantown, WV, gives researchers access to models and simulations that predict how solid oxide fuel cells...

  20. Sol-gel preparation of uranium oxide spheres

    International Nuclear Information System (INIS)

    Dolezal, J.; Urbanek, V.

    1978-01-01

    Information is presented on problems of preparing nuclear fuel by the sol-gel method. Basic data on different process types are given. A more detailed description of the method of preparation of spherical particles of uranium oxide gel developed and used at the Nuclear Research Institute at Rez is given. Advantages and disadvantages of sol-gel materials are discussed in comparison with fuel materials prepared by classical precipitation methods. The feasibility of the sol-gel methods for preparing other materials is shortly mentioned and their application outlined. (author)

  1. Dissolving method for nuclear fuel oxide

    International Nuclear Information System (INIS)

    Tomiyasu, Hiroshi; Kataoka, Makoto; Asano, Yuichiro; Hasegawa, Shin-ichi; Takashima, Yoichi; Ikeda, Yasuhisa.

    1996-01-01

    In a method of dissolving oxides of nuclear fuels in an aqueous acid solution, the oxides of the nuclear fuels are dissolved in a state where an oxidizing agent other than the acid is present together in the aqueous acid solution. If chlorate ions (ClO 3 - ) are present together in the aqueous acid solution, the chlorate ions act as a strong oxidizing agent and dissolve nuclear fuels such as UO 2 by oxidation. In addition, a Ce compound which generates Ce(IV) by oxidation is added to the aqueous acid solution, and an ozone (O 3 ) gas is blown thereto to dissolve the oxides of nuclear fuels. Further, the oxides of nuclear fuels are oxidized in a state where ClO 2 is present together in the aqueous acid solution to dissolve the oxides of nuclear fuels. Since oxides of the nuclear fuels are dissolved in a state where the oxidizing agent is present together as described above, the oxides of nuclear fuels can be dissolved even at a room temperature, thereby enabling to use a material such as polytetrafluoroethylene and to dissolve the oxides of nuclear fuels at a reduced cost for dissolution. (T.M.)

  2. Spent fuel. Dissolution and oxidation

    International Nuclear Information System (INIS)

    Grambow, B.

    1989-03-01

    Data from studies of the low temperature air oxidation of spent fuel were retrieved in order to provide a basis for comparison between the mechanism of oxidation in air and corrosion in water. U 3 O 7 is formed by diffusion of oxygen into the UO 2 lattice. A diffusion coefficient of oxygen in the fuel matric was calculated for 25 degree C to be in the range of 10 -23 to 10 -25 m 2 /s. The initial rates of U release from spent fuel and from UO 2 appear to be similar. The lowest rates (at 25 degree c >10 -4 g/(m 2 d)) were observed under reducing conditions. Under oxidizing conditions the rates depend mainly of the nature and concentraion of the oxidant and/or on corbonate. In contact with air, typical initial rates at room temperature were in the range between 0.001 and 0.1 g/(m 2 d). A study of apparent U solubility under oxidizing conditions was performed and it was suggested that the controlling factor is the redox potential at the UO 2 surface rather than the E h of the bulk solution. Electrochemical arguments were used to predict that at saturation, the surface potential will eventually reach a value given by the boundaries at either the U 3 O 7 /U 3 O 8 or the U 3 O 7 /schoepite stability field, and a comparison with spent fuel leach data showed that the solution concentration of uranium is close to the calculated U solubility at the U 3 O 7 /U 3 O 8 boundary. The difference in the cumulative Sr and U release was calculated from data from Studsvik laboratory. The results reveal that the rate of Sr release decreases with the square root of time under U-saturated conditions. This time dependence may be rationalized either by grain boundary diffusion or by diffusion into the fuel matrix. Hence, there seems to be a possibility of an agreement between the Sr release data, structural information and data for oxygen diffusion in UO 2 . (G.B.)

  3. Fuel-cycle cost comparisons with oxide and silicide fuels

    International Nuclear Information System (INIS)

    Matos, J.E.; Freese, K.E.

    1982-01-01

    This paper addresses fuel cycle cost comparisons for a generic 10 MW reactor with HEU aluminide fuel and with LEU oxide and silicide fuels in several fuel element geometries. The intention of this study is to provide a consistent assessment of various design options from a cost point of view. Fuel cycle cost benefits could result if a number of reactors were to utilize fuel elements with the same number or different numbers of the same standard fuel plate. Data are presented to quantify these potential cost benefits. This analysis shows that there are a number of fuel element designs using LEU oxide or silicide fuels that have either the same or lower total fuel cycle costs than the HEU design. Use of these fuels with the uranium densities considered requires that they are successfully demonstrated and licensed

  4. Highly-dispersed Ta-oxide catalysts prepared by electrodeposition in a non-aqueous plating bath for polymer electrolyte fuel cell cathodes

    KAUST Repository

    Seo, Jeongsuk; Cha, Dong Kyu; Takanabe, Kazuhiro; Kubota, Jun; Domen, Kazunari

    2012-01-01

    The Ta-oxide cathode catalysts were prepared by electrodeposition in a non-aqueous solution. These catalysts showed excellent catalytic activity and have an onset potential of 0.92 V RHE for the oxygen reduction reaction (ORR). The highly-dispersed Ta species at the nanometer scale on the carbon black was an important contributor to the high activity. © 2012 The Royal Society of Chemistry.

  5. Preparation and characterization of La0,60Sr0,40Co0,20Fe0,80O3-δ powders for intermediate temperature solid oxide fuel cells (ITSOFC) cathode

    International Nuclear Information System (INIS)

    Vargas, R.A.; Chiba, R.; Bonturim, E.; Andreoli, M.; Seo, E.S.M.

    2009-01-01

    Nowadays a material that is studied as cathode in intermediate temperature solid oxide fuel cells (ITSOFC) is the mixing oxide La 0,60S r 0 , 40 Co 0 , 20 Fe 0 , 80 O 3-δ (LSCF), that possess pseudo-perovskite structure. The objective of this work is to present the physical, chemical and microstructural of LSCF powders characteristics, prepared by the citrate technique. The main analyses utilized were: X-ray diffraction, X-ray fluorescence spectroscopy, laser scattering granulometry, and scanning electron microscopy. The results show that the elimination of organic precursors is important for desired structure formation and that amount of this phase depends on cobalt content. Moreover, the chemical composition is next to stoichiometric calculated (x=0.40 and y=0.80) and the average sizes of particles are adjusted for ceramic suspensions preparation, contributing for the wet powder spraying step conformation. (author)

  6. Transient survivability of LMR oxide fuel pins

    International Nuclear Information System (INIS)

    Weber, E.T.; Pitner, A.L.; Bard, F.E.; Culley, G.E.; Hunter, C.W.

    1986-01-01

    Fuel pin integrity during transient events must be assessed for both the core design and safety analysis phases of a reactor project. A significant increase in the experience related to limits of integrity for oxide fuel pins in transient overpower events has been realized from testing of fuel pins irradiated in FFTF and PFR. Fourteen FFTF irradiated fuel pins were tested in TREAT, representing a range of burnups, overpower ramp rates and maximum overpower conditions. Results of these tests along with similar testing in the PFR/TREAT program, provide a demonstration of significant safety margins for oxide fuel pins. Useful information applied in analytical extrapolation of fuel pin test data have been developed from laboratory transient tests on irradiated fuel cladding (FCTT) and on unirradiated fuel pellet deformation. These refinements in oxide fuel transient performance are being applied in assessment of transient capabilities of long lifetime fuel designs using ferritic cladding

  7. Gas transport in solid oxide fuel cells

    CERN Document Server

    He, Weidong; Dickerson, James

    2014-01-01

    This book provides a comprehensive overview of contemporary research and emerging measurement technologies associated with gas transport in solid oxide fuel cells. Within these pages, an introduction to the concept of gas diffusion in solid oxide fuel cells is presented. This book also discusses the history and underlying fundamental mechanisms of gas diffusion in solid oxide fuel cells, general theoretical mathematical models for gas diffusion, and traditional and advanced techniques for gas diffusivity measurement.

  8. Preparation of anode-electrolyte structures using graphite, sodium bicarbonate or citric acid as pore forming agents for application in solid oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Paz Fiuza, Raigenis da; Silva, Marcos Aurelio da; Guedes, Bruna C.; Pontes, Luiz A.; Boaventura, Jaime Soares [UFBA, Salvador, Bahia (Brazil). Energy and Materials Science Group

    2010-07-01

    Cermets based on Ni supported on YSZ or GDC were prepared for use as anode in direct reform SOFCs. NaHCO3 (Na-Ni-YSZ and Na-Ni-GDC) or citric acid (Ac-Ni-YSZ and Ac-Ni-GDC) were used as pore forming agents (PFAs). The SOFC anode was also prepared using graphite (G-Ni-YSZ and G-Ni-GDC) as PFA for the purposes of comparison. The testing unitary SOFC, planar type, was made by pressing the anode-electrolyte assembly, followed by sintering at 1500 C. After this, LSM (lanthanum and strontium manganite) paint was used for the cathode deposition. The powdered cermets were evaluated in ethanol steam reforming at 650 C. The ethanol conversion was 84% and 32% for cermets Na-Ni-YSZ and G-Ni-YSZ, respectively and the selectivity to H{sub 2} was 32 and 20% for the two cermets, respectively. The Na-Ni-YSZ cermet was ten times more resistant to carbon deposition than the G-Ni-YSZ cermet. SEM micrographs of the anode-electrolyte assembly showed that the use of NaHCO{sub 3} as PFA created a well formed interface between layers with homogeneously distributed pores. In contrast, graphite as PFA formed a loose interface between anode and electrolyte. The performance of the unitary SOFC was evaluated using ethanol, hydrogen or methane as fuel. The cell operated well using any of these fuels; however, they exhibited different electrochemical behavior. (orig.)

  9. Serving the fuel cycle: preparing tomorrow's packagings

    International Nuclear Information System (INIS)

    Roland, V.

    2001-01-01

    The main fleet of transport packagings serving today the fuel cycle was born more than 20 years ago. Or was it they? The present paper will show that serving the fuel cycle by preparing tomorrow's logistics is actually an on-going process, rather than a rupture. We shall review the great packagings of the fuel cycle: In the front end, the major actors are the UF 4 , UF 6 , enriched UF 6 , UO 2 powders, fresh fuel packagings. In the back end of the fuel cycle, we find the dry transport casks of the TN-12, TN-17, TN-13, family and also the Excellox wet flasks. In the waste management, a whole fleet of containers, culminating in the TN Gemini, are available or being created. (author)

  10. Application of gel microsphere processes to preparation of Sphere-Pac nuclear fuel

    International Nuclear Information System (INIS)

    Haas, P.A.; Notz, K.J.; Spence, R.D.

    1978-01-01

    Sphere-Pac fabrication of nuclear fuels using two or more sizes of oxide or carbide spheres is ideally suited to nonproliferation-fuel cycles and remote refabrication. The sizes and compositions of spheres necessary for such fuel cycles have not been commonly prepared; therefore, modifications of sol-gel processes to meet these requirements are being developed and demonstrated

  11. Relationship Between Particle and Plasma Properties and Coating Characteristics of Samaria-Doped Ceria Prepared by Atmospheric Plasma Spraying for Use in Solid Oxide Fuel Cells

    Science.gov (United States)

    Cuglietta, Mark; Kesler, Olivera

    2012-06-01

    Samaria-doped ceria (SDC) has become a promising material for the fabrication of high-performance, intermediate-temperature solid oxide fuel cells (SOFCs). In this study, the in-flight characteristics, such as particle velocity and surface temperature, of spray-dried SDC agglomerates were measured and correlated to the resulting microstructures of SDC coatings fabricated using atmospheric plasma spraying, a manufacturing technique with the capability of producing full cells in minutes. Plasmas containing argon, nitrogen and hydrogen led to particle surface temperatures higher than those in plasmas containing only argon and nitrogen. A threshold temperature for the successful deposition of SDC on porous stainless steel substrates was calculated to be 2570 °C. Coating porosity was found to be linked to average particle temperature, suggesting that plasma conditions leading to lower particle temperatures may be most suitable for fabricating porous SOFC electrode layers.

  12. Preparation of Ni-Fe bimetallic porous anode support for solid oxide fuel cells using LaGaO{sub 3} based electrolyte film with high power density

    Energy Technology Data Exchange (ETDEWEB)

    Ju, Young-Wan; Ida, Shintaro; Ishihara, Tatsumi [Department of Applied Chemistry, Faculty of Engineering, Kyushu University, Motooka 744, Nishi-Ku, Fukuoka 819-0395 (Japan); Eto, Hiroyuki [Mitsubishi Materials Corporation, Central Research Institute, 1002-14 Mukohyama, Naka-Shi, Ibaraki 311-0102 (Japan); Inagaki, Toru [The Kansai Electric Power Co., Inc., 11-20 Nakoji 3-Chome, Amagasaki, Hyogo 661-0974 (Japan)

    2010-10-01

    Optimization of sintering temperature for NiO-Fe{sub 2}O{sub 3} composite oxide substrate was studied in order to obtain a dense substrate with smooth surface. By in situ reduction, the substrate was changed to a porous Ni-Fe alloy metal. The volumetric shrinkage and porosity of the substrate were also studied systematically with the Ni-Fe substrate reduced at different temperatures. A Sr and Mg-doped LaGaO{sub 3} (LSGM) thin film was prepared on dense substrate by the pulsed laser deposition (PLD) method. The LSGM film with stoichiometric composition was successfully prepared under optimal deposition parameters and a target composition. Sm{sub 0.5}Sr{sub 0.5}CoO{sub 3} (SSC55) cathode was prepared by the slurry coating method on the deposited film. Prepared SOFC single cell shows high power density and the maximum power density (MPD) achieved was 1.79, 0.82 and 0.29 W cm{sup -2} at 973, 873 and 773 K, respectively. After thermal cycle from 973 to 298 K, the cell shows almost theoretical open circuit potential (1.1 V) and the power density of 1.62 W cm{sup -2}, which is almost the same as that at first cycles. Therefore, the Ni-Fe porous metal support made by the selective reduction is highly promising as a metal anode substrate for SOFC using LaGaO{sub 3} thin film. (author)

  13. Experience with oxide fuel for advanced reactors

    International Nuclear Information System (INIS)

    Leggett, R.D.

    1984-01-01

    This paper focuses on the use and potential of oxide fuel systems for the LMFBR. The flawless performance of mixed oxide (UO 2 -PuO 2 ) fuel in FFTF to 100,000 MWd/MTM is reviewed and means for achieving 200,000 MWd/MTM are presented. This includes using non-swelling alloys for cladding and ducts to overcome the limitations caused by swelling of the current alloys. Examples are provided of the inherently safe characteristics of oxide fuel including a large negative Doppler coefficient, its dispersive nature under hypothetical accident scenarios, and the low energy molten fuel-coolant interaction. Developments in fuel fabrication and reprocessing that stress safety and reduced personnel exposure are presented. Lastly, the flexibility to design for maximum fuel supply (high breeding gain) or minimum fuel cost (long lifetime) is shown

  14. Electrolytes for solid oxide fuel cells

    Science.gov (United States)

    Fergus, Jeffrey W.

    The high operating temperature of solid oxide fuel cells (SOFCs), as compared to polymer electrolyte membrane fuel cells (PEMFCs), improves tolerance to impurities in the fuel, but also creates challenges in the development of suitable materials for the various fuel cell components. In response to these challenges, intermediate temperature solid oxide fuel cells (IT-SOFCs) are being developed to reduce high-temperature material requirements, which will extend useful lifetime, improve durability and reduce cost, while maintaining good fuel flexibility. A major challenge in reducing the operating temperature of SOFCs is the development of solid electrolyte materials with sufficient conductivity to maintain acceptably low ohmic losses during operation. In this paper, solid electrolytes being developed for solid oxide fuel cells, including zirconia-, ceria- and lanthanum gallate-based materials, are reviewed and compared. The focus is on the conductivity, but other issues, such as compatibility with electrode materials, are also discussed.

  15. Electrolytes for solid oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Fergus, Jeffrey W. [Auburn University, Materials Research and Education Center, 275 Wilmore Laboratories, Auburn, AL 36849 (United States)

    2006-11-08

    The high operating temperature of solid oxide fuel cells (SOFCs), as compared to polymer electrolyte membrane fuel cells (PEMFCs), improves tolerance to impurities in the fuel, but also creates challenges in the development of suitable materials for the various fuel cell components. In response to these challenges, intermediate temperature solid oxide fuel cells (IT-SOFCs) are being developed to reduce high-temperature material requirements, which will extend useful lifetime, improve durability and reduce cost, while maintaining good fuel flexibility. A major challenge in reducing the operating temperature of SOFCs is the development of solid electrolyte materials with sufficient conductivity to maintain acceptably low ohmic losses during operation. In this paper, solid electrolytes being developed for solid oxide fuel cells, including zirconia-, ceria- and lanthanum gallate-based materials, are reviewed and compared. The focus is on the conductivity, but other issues, such as compatibility with electrode materials, are also discussed. (author)

  16. Experience with oxide fuel for advanced reactors

    International Nuclear Information System (INIS)

    Leggett, R.D.

    1984-04-01

    This paper focuses on the use and potential of oxide fuel system for the LMFBR. The flawless performance of mixed oxide (UO 2 -PuO 2 ) fuel in FFTF to 100,000 MWd/MTM is reviewed and means for achieving 200,000 MWd/MTM are presented. This includes using non-swelling alloys for cladding and ducts to overcome the limitations caused by swelling of the current alloys. Exampled are provided of the inherently safe characteristics of oxide fuel including a large negative Doppler coefficient, its dispersive nature under hypothetical accident scenarios, and the low energy molten fuel-coolant interaction. Developments in fuel fabrication and reprocessing that stress safety and reduced personnel exposure are presented. Lastly, the flexibility to design for maximum fuel supply (high breeding gain) or minimum fuel cost (long lifetime) is shown

  17. UK experience on fuel and cladding interaction in oxide fuels

    Energy Technology Data Exchange (ETDEWEB)

    Batey, W [Dounreay Experimental Reactor Establishment, Thurso, Caithness (United Kingdom); Findlay, J R [AERE, Harwell, Didcot, Oxon (United Kingdom)

    1977-04-01

    The occurrence of fuel cladding interactions in fast reactor fuels has been observed in UK irradiations over a period of years. Chemical incompatibility between fuel and clad represents a potential source of failure and has, on this account, been studied using a variety of techniques. The principal fuel of interest to the UK for fast reactor application is mixed uranium plutonium oxide clad in stainless steel and it is in this field that the majority of work has been concentrated. Some consideration has been given to carbide fuels, because of their application as an advanced fuel. This experience is described in the accompanying paper. Several complementary initiatives have been followed to investigate the interactions in oxide fuel. The principal source of experimental information is from the experimental fuel irradiation programme in the Dounreay Fast Reactor (DFR). Supporting information has been obtained from irradiation programmes in Materials Testing Reactors (MTR). Conditions approaching those in a fast reactor are obtained and the effects of specific variables have been examined in specifically designed experiments. Out-of-reactor experiments have been used to determine the limits of fuel and cladding compatibility and also to give indications of corrosion The observations from all experiments have been examined in the light of thermo-dynamic predictions of fuel behaviour to assess the relative significance of various observations and operating conditions. An experimental programme to control and limit the interactions in oxide fuel is being followed.

  18. UK experience on fuel and cladding interaction in oxide fuels

    International Nuclear Information System (INIS)

    Batey, W.; Findlay, J.R.

    1977-01-01

    The occurrence of fuel cladding interactions in fast reactor fuels has been observed in UK irradiations over a period of years. Chemical incompatibility between fuel and clad represents a potential source of failure and has, on this account, been studied using a variety of techniques. The principal fuel of interest to the UK for fast reactor application is mixed uranium plutonium oxide clad in stainless steel and it is in this field that the majority of work has been concentrated. Some consideration has been given to carbide fuels, because of their application as an advanced fuel. This experience is described in the accompanying paper. Several complementary initiatives have been followed to investigate the interactions in oxide fuel. The principal source of experimental information is from the experimental fuel irradiation programme in the Dounreay Fast Reactor (DFR). Supporting information has been obtained from irradiation programmes in Materials Testing Reactors (MTR). Conditions approaching those in a fast reactor are obtained and the effects of specific variables have been examined in specifically designed experiments. Out-of-reactor experiments have been used to determine the limits of fuel and cladding compatibility and also to give indications of corrosion The observations from all experiments have been examined in the light of thermo-dynamic predictions of fuel behaviour to assess the relative significance of various observations and operating conditions. An experimental programme to control and limit the interactions in oxide fuel is being followed

  19. Direct Coal Oxidation in Modified Solid Oxide Fuel Cells

    DEFF Research Database (Denmark)

    Deleebeeck, Lisa; Gil, Vanesa; Ippolito, Davide

    2015-01-01

    Hybrid direct carbon fuel cells employ a classical solid oxide fuel cell together with carbon dispersed in a carbonate melt on the anode side. In a European project, the utilization of various coals has been investigated with and without addition of an oxidation catalyst to the carbon-carbonate s......Hybrid direct carbon fuel cells employ a classical solid oxide fuel cell together with carbon dispersed in a carbonate melt on the anode side. In a European project, the utilization of various coals has been investigated with and without addition of an oxidation catalyst to the carbon......-carbonate slurry or anode layer. The nature of the coal affects both open circuit voltage and power output. Highest OCV and power densities were observed for bituminous coal and by adding manganese oxide or praseodymium-doped ceria to the carbon/carbonate mixture. Comparing the carbon black fueled performance...... bituminous coal (73 mW/cm2). © 2015 ECS - The Electrochemical Society...

  20. Direct Coal Oxidation in Modified Solid Oxide Fuel Cells

    DEFF Research Database (Denmark)

    Deleebeeck, Lisa; Gil, Vanesa; Ippolito, Davide

    2017-01-01

    Hybrid direct carbon fuel cells employ a classical solid oxide fuel cell together with carbon dispersed in a carbonate melt on the anode side. In a European project, the utilization of various coals has been investigated with and without addition of an oxidation catalyst to the carbon-carbonate s......Hybrid direct carbon fuel cells employ a classical solid oxide fuel cell together with carbon dispersed in a carbonate melt on the anode side. In a European project, the utilization of various coals has been investigated with and without addition of an oxidation catalyst to the carbon......-carbonate slurry or anode layer. The nature of the coal affects both open circuit voltage and power output. Highest OCV and power densities were observed for bituminous coal and by adding manganese oxide or praseodymium-doped ceria to the carbon/carbonate mixture. Comparing the carbon black fueled performance...... bituminous coal (73 mW/cm2)....

  1. Preparation of ternary Pt/Rh/SnO2 anode catalysts for use in direct ethanol fuel cells and their electrocatalytic activity for ethanol oxidation reaction

    Science.gov (United States)

    Higuchi, Eiji; Takase, Tomonori; Chiku, Masanobu; Inoue, Hiroshi

    2014-10-01

    Pt, Rh and SnO2 nanoparticle-loaded carbon black (Pt/Rh/SnO2/CB) catalysts with different contents of Pt and Rh were prepared by the modified Bönnemann method. The mean size and size distribution of Pt, Rh and SnO2 for Pt-71/Rh-4/SnO2/CB (Pt : Rh : Sn = 71 at.%: 4 at.%: 25 at.%) were 3.8 ± 0.7, 3.2 ± 0.7 and 2.6 ± 0.5 nm, respectively, indicating that Pt, Rh and SnO2 were all nanoparticles. The onset potential of ethanol oxidation current for the Pt-65/Rh-10/SnO2/CB and Pt-56/Rh-19/SnO2/CB electrodes was ca. 0.2 V vs. RHE which was ca. 0.2 V less positive than that for the Pt/CB electrode. The oxidation current at 0.6 V for the Pt/Rh/SnO2/CB electrode (ca. 2% h-1) decayed more slowly than that at the Pt/SnO2/CB electrode (ca. 5% h-1), indicating that the former was superior in durability to the latter. The main product of EOR in potentiostatic electrolysis at 0.6 V for the Pt-71/Rh-4/SnO2/CB electrode was acetic acid.

  2. Jet Fuel Based High Pressure Solid Oxide Fuel Cell System

    Science.gov (United States)

    Gummalla, Mallika (Inventor); Yamanis, Jean (Inventor); Olsommer, Benoit (Inventor); Dardas, Zissis (Inventor); Bayt, Robert (Inventor); Srinivasan, Hari (Inventor); Dasgupta, Arindam (Inventor); Hardin, Larry (Inventor)

    2015-01-01

    A power system for an aircraft includes a solid oxide fuel cell system which generates electric power for the aircraft and an exhaust stream; and a heat exchanger for transferring heat from the exhaust stream of the solid oxide fuel cell to a heat requiring system or component of the aircraft. The heat can be transferred to fuel for the primary engine of the aircraft. Further, the same fuel can be used to power both the primary engine and the SOFC. A heat exchanger is positioned to cool reformate before feeding to the fuel cell. SOFC exhaust is treated and used as inerting gas. Finally, oxidant to the SOFC can be obtained from the aircraft cabin, or exterior, or both.

  3. Synthesis and characterization of scandia ceria stabilized zirconia powders prepared by polymeric precursor method for integration into anode-supported solid oxide fuel cells

    Science.gov (United States)

    Tu, Hengyong; Liu, Xin; Yu, Qingchun

    2011-03-01

    Scandia ceria stabilized zirconia (10Sc1CeSZ) powders are synthesized by polymeric precursor method for use as the electrolyte of anode-supported solid oxide fuel cell (SOFC). The synthesized powders are characterized in terms of crystalline structure, particle shape and size distribution by X-ray diffraction (XRD), transmission electron microscopy (TEM) and photon correlation spectroscopy (PCS). 10Sc1CeSZ electrolyte films are deposited on green anode substrate by screen-printing method. Effects of 10Sc1CeSZ powder characteristics on sintered films are investigated regarding the integration process for application as the electrolytes in anode-supported SOFCs. It is found that the 10Sc1CeSZ films made from nano-sized powders with average size of 655 nm are very porous with many open pores. In comparison, the 10Sc1CeSZ films made from micron-sized powders with average size of 2.5 μm, which are obtained by calcination of nano-sized powders at higher temperatures, are much denser with a few closed pinholes. The cell performances are 911 mW cm-2 at the current density of 1.25 A cm-2 and 800 °C by application of Ce0.8Gd0.2O2 (CGO) barrier layer and La0.6Sr0.4CoO3 (LSC) cathode.

  4. A conceptual model for the fuel oxidation of defective fuel

    International Nuclear Information System (INIS)

    Higgs, J.D.; Lewis, B.J.; Thompson, W.T.; He, Z.

    2007-01-01

    A mechanistic conceptual model has been developed to predict the fuel oxidation behaviour in operating defective fuel elements for water-cooled nuclear reactors. This theoretical work accounts for gas-phase transport and sheath reactions in the fuel-to-sheath gap to determine the local oxygen potential. An improved thermodynamic analysis has also been incorporated into the model to describe the equilibrium state of the oxidized fuel. The fuel oxidation kinetics treatment accounts for multi-phase transport including normal diffusion and thermodiffusion for interstitial oxygen migration in the solid, as well as gas-phase transport in the fuel pellet cracks. The fuel oxidation treatment is further coupled to a heat conduction equation. A numerical solution of the coupled transport equations is obtained by a finite-element technique with the FEMLAB 3.1 software package. The model is able to provide radial-axial profiles of the oxygen-to-uranium ratio and the fuel temperatures as a function of time in the defective element for a wide range of element powers and defect sizes. The model results are assessed against coulometric titration measurements of the oxygen-to-metal profile for pellet samples taken from ten spent defective elements discharged from the National Research Universal Reactor at the Chalk River Laboratories and commercial reactors

  5. Preparation of Sr{sub 2}(MgMo){sub 1-x}Ru{sub x}O{sub 6} ceramics for use in a solid oxide fuel cell anode

    Energy Technology Data Exchange (ETDEWEB)

    Bezerra, Matheus Eiji Ohno; Florio, Daniel Zanetti de [Universidade Federal do ABC (UFABC), SP (Brazil); Fonseca, Fabio Coral, E-mail: matheus.eiji@aluno.ufabc.edu.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2016-07-01

    Full text: Solid Oxide Fuel Cells are the most efficient devices known for the direct conversion of fuels into electric energy. Such devices have advanced steadily and are already available for specific applications such as portable power and residential stationary generation. The main objective of this work is the development of anodes for SOFC operating directly with renewable fuels, without the addition of water and using strategic fuels such as ethanol and natural gas. Specifically, a family of mixed ionic-electronic compounds has been investigated: the double perovskites with compositions Sr{sub 2}(MgMo){sub 1-x}Ru{sub x}O{sub 6} with x = 0; 1; 2; 5; 10 e 20 at.%. This material has been synthesized by polymeric precursor method. The resins were prepared by combining stoichiometric amounts of the starting solutions. The resulting solution was heated treated under magnetic stirring. The thermal decomposition of the polymeric resin was studied by means of simultaneous thermogravimetric and differential scanning calorimetry up to 1500 °C with heating and cooling rates of 10 °/min in Ar. The thermal decomposition result shows mass loss up to, approximately, 900 °C. However X-ray diffraction analyses of the powder heat treated at 900 °C and 1200 °C presents a considerable content of an undesiderate phase (SrMoO{sub 4}). According to the literature for similar compounds a thermal treatment under reduction conditions could be necessary to obtain the double perovskites single phase. After this treatment the material will be characterized regarding its electrical properties. The expected results will contribute to advance both the understanding of the mixed ionic electronic ceramics and the SOFC technology using renewable fuels. (author)

  6. The TMI regenerable solid oxide fuel cell

    Science.gov (United States)

    Cable, Thomas L.

    1995-04-01

    Energy storage and production in space requires rugged, reliable hardware which minimizes weight, volume, and maintenance while maximizing power output and usable energy storage. These systems generally consist of photovoltaic solar arrays which operate during sunlight cycles to provide system power and regenerate fuel (hydrogen) via water electrolysis; during dark cycles, hydrogen is converted by the fuel cell into system. The currently preferred configuration uses two separate systems (fuel cell and electrolyzer) in conjunction with photovoltaic cells. Fuel cell/electrolyzer system simplicity, reliability, and power-to-weight and power-to-volume ratios could be greatly improved if both power production (fuel cell) and power storage (electrolysis) functions can be integrated into a single unit. The Technology Management, Inc. (TMI), solid oxide fuel cell-based system offers the opportunity to both integrate fuel cell and electrolyzer functions into one unit and potentially simplify system requirements. Based an the TMI solid oxide fuel cell (SOPC) technology, the TMI integrated fuel cell/electrolyzer utilizes innovative gas storage and operational concepts and operates like a rechargeable 'hydrogen-oxygen battery'. Preliminary research has been completed on improved H2/H2O electrode (SOFC anode/electrolyzer cathode) materials for solid oxide, regenerative fuel cells. Improved H2/H2O electrode materials showed improved cell performance in both fuel cell and electrolysis modes in reversible cell tests. ln reversible fuel cell/electrolyzer mode, regenerative fuel cell efficiencies (ratio of power out (fuel cell mode) to power in (electrolyzer model)) improved from 50 percent (using conventional electrode materials) to over 80 percent. The new materials will allow the TMI SOFC system to operate as both the electrolyzer and fuel cell in a single unit. Preliminary system designs have also been developed which indicate the technical feasibility of using the TMI SOFC

  7. Fuel cycle cost comparisons with oxide and silicide fuels

    Energy Technology Data Exchange (ETDEWEB)

    Matos, J E; Freese, K E [RERTR Program, Argonne National Laboratory (United States)

    1983-09-01

    This paper addresses fuel cycle cost comparisons for a generic 10 MW reactor with HEU aluminide fuel and with LEU oxide and silicide fuels in several fuel element geometries. The intention of this study is to provide a consistent assessment of various design options from a cost point of view. The status of the development and demonstration of the oxide and silicide fuels are presented in several papers in these proceedings. Routine utilization of these fuels with the uranium densities considered here requires that they are successfully demonstrated and licensed. Thermal-hydraulic safety margins, shutdown margins, mixed cores, and transient analyses are not addressed here, but analyses of these safety issues are in progress for a limited number of the most promising design options. Fuel cycle cost benefits could result if a number of reactors were to utilize fuel elements with the same number or different numbers of the same standard fuel plate. Data is presented to quantify these potential cost benefits. This analysis shows that there are a number of fuel element designs using LEU oxide or silicide fuels that have either the same or lower total fuel cycle costs than the HEU design. Use of these fuels with the uranium densities considered requires that they are successfully demonstrated and licensed. All safety criteria for the reactor with these fuel element designs need to be satisfied as well. With LEU oxide fuel, 31 g U/cm{sup 3} 1 and 0.76 mm--thick fuel meat, elements with 18-22 plates 320-391 g {sup 235}U) result in the same or lower total costs than with the HEU element 23 plates, 280 g {sup 235}U). Higher LEU loadings (more plates per element) are needed for larger excess reactivity requirements. However, there is little cost advantage to using more than 20 of these plates per element. Increasing the fuel meat thickness from 0.76 mm to 1.0 mm with 3.1 g U/cm{sup 3} in the design with 20 plates per element could result in significant cost reductions if the

  8. Interconnection of bundled solid oxide fuel cells

    Science.gov (United States)

    Brown, Michael; Bessette, II, Norman F; Litka, Anthony F; Schmidt, Douglas S

    2014-01-14

    A system and method for electrically interconnecting a plurality of fuel cells to provide dense packing of the fuel cells. Each one of the plurality of fuel cells has a plurality of discrete electrical connection points along an outer surface. Electrical connections are made directly between the discrete electrical connection points of adjacent fuel cells so that the fuel cells can be packed more densely. Fuel cells have at least one outer electrode and at least one discrete interconnection to an inner electrode, wherein the outer electrode is one of a cathode and and anode and wherein the inner electrode is the other of the cathode and the anode. In tubular solid oxide fuel cells the discrete electrical connection points are spaced along the length of the fuel cell.

  9. Durability of solid oxide fuel cells using sulfur containing fuels

    DEFF Research Database (Denmark)

    Hagen, Anke; Rasmussen, Jens Foldager Bregnballe; Thydén, Karl Tor Sune

    2011-01-01

    The usability of hydrogen and also carbon containing fuels is one of the important advantages of solid oxide fuel cells (SOFCs), which opens the possibility to use fuels derived from conventional sources such as natural gas and from renewable sources such as biogas. Impurities like sulfur compounds...... are critical in this respect. State-of-the-art Ni/YSZ SOFC anodes suffer from being rather sensitive towards sulfur impurities. In the current study, anode supported SOFCs with Ni/YSZ or Ni/ScYSZ anodes were exposed to H2S in the ppm range both for short periods of 24h and for a few hundred hours. In a fuel...

  10. Process for the fabrication of nuclear fuel oxide pellets

    International Nuclear Information System (INIS)

    Francois, Bernard; Paradis, Yves.

    1977-01-01

    Process for the fabrication of nuclear fuel oxide pellets of the type for which particles charged with an organic binder -selected from the group that includes polyvinyl alcohol, carboxymethyl cellulose, polyvinyl compounds and methyl cellulose- are prepared from a powder of such an oxide, for instance uranium dioxide. These particles are then compressed into pellets which are then sintered. Under this process the binder charged particles are prepared by stirring the powder with a gas, spraying on to the stirred powder a solution or a suspension in a liquid of this organic binder in order to obtain these particles and then drying the particles so obtained with this gas [fr

  11. Preparation and characterization of polyindole - iron oxide nanocomposite electrolyte

    International Nuclear Information System (INIS)

    Rajasudha, G.; Stephen, A.; Narayanan, V.

    2009-01-01

    Full text: A novel polyindole-iron oxide containing LiClO 4 solid polymer electrolyte has been prepared. The diverse property of magnetic nanoparticle has elicited wide interest from the point of view of technological applications. Their properties are known to be strongly dependent on size, anisotropy and inter particle interactions. The proton conducting materials has received considerable attention as electrolyte materials in technological applications such as fuel cells, sensors and electrochromic display. In this work, polyindole-iron oxide nanocomposite containing LiClO 4 was prepared by in situ polymerization. The indole was polymerized in the presence of iron oxide, using ammonium peroxy disulphate as an oxidizing agent. The polyindole-iron oxide nanocomposite was characterized by XRD, IR, SEM, TGA and TEM. The iron oxide nano particles was incorporated into polyindole and was confirmed by XRD and Fourier transform infrared (FTIR) spectroscopy. The surface Morphology and thermal stability were studied by thermogravimetric analysis (TGA) and SEM respectively. The ionic conductivity of polyindole electrolyte was analyzed from impedance spectrum. The prepared polyindole-iron oxide nanocomposite could be used as solid electrolyte in lithium ion batteries

  12. Solid Oxide Fuel Cells Operating on Alternative and Renewable Fuels

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xiaoxing; Quan, Wenying; Xiao, Jing; Peduzzi, Emanuela; Fujii, Mamoru; Sun, Funxia; Shalaby, Cigdem; Li, Yan; Xie, Chao; Ma, Xiaoliang; Johnson, David; Lee, Jeong; Fedkin, Mark; LaBarbera, Mark; Das, Debanjan; Thompson, David; Lvov, Serguei; Song, Chunshan

    2014-09-30

    This DOE project at the Pennsylvania State University (Penn State) initially involved Siemens Energy, Inc. to (1) develop new fuel processing approaches for using selected alternative and renewable fuels – anaerobic digester gas (ADG) and commercial diesel fuel (with 15 ppm sulfur) – in solid oxide fuel cell (SOFC) power generation systems; and (2) conduct integrated fuel processor – SOFC system tests to evaluate the performance of the fuel processors and overall systems. Siemens Energy Inc. was to provide SOFC system to Penn State for testing. The Siemens work was carried out at Siemens Energy Inc. in Pittsburgh, PA. The unexpected restructuring in Siemens organization, however, led to the elimination of the Siemens Stationary Fuel Cell Division within the company. Unfortunately, this led to the Siemens subcontract with Penn State ending on September 23rd, 2010. SOFC system was never delivered to Penn State. With the assistance of NETL project manager, the Penn State team has since developed a collaborative research with Delphi as the new subcontractor and this work involved the testing of a stack of planar solid oxide fuel cells from Delphi.

  13. Preparation and characterization of Pt-Sn/C and Pt-Ir/C catalysts for the electrochemical oxidation of ethanol in polymer electrolyte membrane fuel cell

    CSIR Research Space (South Africa)

    Masombuka, T

    2007-11-01

    Full Text Available oxidation is still low. Development of new active catalysts able to break C-C bond and complete oxidation of ethanol into CO 2 is of fundamental importance. Generally, a third metal is added to the best binary Pt-Sn catalyst to improve CO tolerance...

  14. Preparation of oxide materials from metal alkoxides

    International Nuclear Information System (INIS)

    Turevskaya, E.P.; Turova, N.Ya.; Yanovskaya, M.I.

    2000-01-01

    The results of studies on the sol-gel technologies on the basis of alkoxides are presented. The synthesis and properties of titanates zirconates, niobates, tantalates, vanadates and solid solutions on the basis of Mo, W and Bi oxides, iron oxides and high-temperature superconductors are presented. The most important aspects, determining the choice of optimal conditions for preparation of oxides of concrete compositions with required properties are pointed out. Accomplishment of the whole chain of studies made it possible to synthesize a broad range of metal alkoxides and study their properties and also carry out large-scale studies on preparation of various oxides and materials on the basis thereof, using the source base of the sol-gel method [ru

  15. High Performance Cathodes for Solid Oxide Fuel Cells Prepared by Infiltration of La0.6Sr0.4CoO32d into Gd-Doped Ceria

    DEFF Research Database (Denmark)

    Samson, Alfred Junio; Søgaard, Martin; Knibbe, Ruth

    2011-01-01

    Cathodes prepared by infiltration of La0.6Sr0.4CoO3d (LSC40) into a porous Ce0.9Gd0.1O1.95 (CGO10) backbone have been developed for low temperature solid oxide fuel cells. The CGO10 backbone has been prepared by screen printing a CGO10 ink on both sides of a 180 m dense CGO10 electrolyte......-tape followed by firing. LSC40 was introduced into the CGO10 porous backbone by multiple infiltrations of aqueous nitrate solutions followed by firing at 350C. A systematic study of the performance of the cathodes was performed by varying the CGO10 backbone firing temperature, the LSC40 firing temperature...... and the number of infiltrations. The cathode polarization resistance was measured using electrochemical impedance spectroscopy on symmetrical cells in ambient air, while the resulting structures were characterized by scanning electron microscopy (SEM) and high temperature X-ray diffraction (HT-XRD). The firing...

  16. The TMI Regenerative Solid Oxide Fuel Cell

    Science.gov (United States)

    Cable, Thomas L.; Ruhl, Robert C.; Petrik, Michael

    1996-01-01

    Energy storage and production in space requires rugged, reliable hardware which minimizes weight, volume, and maintenance while maximizing power output and usable energy storage. Systems generally consist of photovoltaic solar arrays which operate (during sunlight cycles) to provide system power and regenerate fuel (hydrogen) via water electrolysis and (during dark cycles) fuel cells convert hydrogen into electricity. Common configurations use two separate systems (fuel cell and electrolyzer) in conjunction with photovoltaic cells. Reliability, power to weight and power to volume ratios could be greatly improved if both power production (fuel cells) and power storage (electrolysis) functions can be integrated into a single unit. The solid oxide fuel cell (SOFC) based design integrates fuel cell and electrolyzer functions and potentially simplifies system requirements. The integrated fuel cell/electrolyzer design also utilizes innovative gas storage concepts and operates like a rechargeable 'hydrogen-oxygen battery'. Preliminary research has been completed on improved H2/H20 electrode (SOFC anode/electrolyzer cathode) materials for regenerative fuel cells. Tests have shown improved cell performance in both fuel and electrolysis modes in reversible fuel cell tests. Regenerative fuel cell efficiencies, ratio of power out (fuel cell mode) to power in (electrolyzer mode), improved from 50 percent using conventional electrode materials to over 80 percent. The new materials will allow a single SOFC system to operate as both the electolyzer and fuel cell. Preliminary system designs have also been developed to show the technical feasibility of using the design for space applications requiring high energy storage efficiencies and high specific energy. Small space systems also have potential for dual-use, terrestrial applications.

  17. Mathematical modeling of solid oxide fuel cells

    Science.gov (United States)

    Lu, Cheng-Yi; Maloney, Thomas M.

    1988-01-01

    Development of predictive techniques, with regard to cell behavior, under various operating conditions is needed to improve cell performance, increase energy density, reduce manufacturing cost, and to broaden utilization of various fuels. Such technology would be especially beneficial for the solid oxide fuel cells (SOFC) at it early demonstration stage. The development of computer models to calculate the temperature, CD, reactant distributions in the tubular and monolithic SOFCs. Results indicate that problems of nonuniform heat generation and fuel gas depletion in the tubular cell module, and of size limitions in the monolithic (MOD 0) design may be encountered during FC operation.

  18. Critical experiments with mixed oxide fuel

    International Nuclear Information System (INIS)

    Harris, D.R.

    1997-01-01

    This paper very briefly outlines technical considerations in performing critical experiments on weapons-grade plutonium mixed oxide fuel assemblies. The experiments proposed would use weapons-grade plutonium and Er 2 O 3 at various dissolved boron levels, and for specific fuel assemblies such as the ABBCE fuel assembly with five large water holes. Technical considerations described include the core, the measurements, safety, security, radiological matters, and licensing. It is concluded that the experiments are feasible at the Rensselaer Polytechnic Institute Reactor Critical Facility. 9 refs

  19. Stability of solid oxide fuel cell materials

    Energy Technology Data Exchange (ETDEWEB)

    Armstrong, T.R.; Bates, J.L.; Chick, L.A. [Pacific Northwest Lab., Richland, WA (United States)

    1996-04-01

    Interconnection materials in a solid oxide fuel cell are exposed to both highly oxidizing conditions at the cathode and to highly reducing conditions at the anode. The thermal expansion characteristics of substituted lanthanum and yttrium chromite interconnect materials were evaluated by dilatometry as a function of oxygen partial pressures from 1 atm to 10{sup -18} atm, controlled using a carbon dioxide/hydrogen buffer.

  20. Microstructure characterizaton of advanced oxide fuel

    International Nuclear Information System (INIS)

    Rasmussen, D.E.; Gerber, E.W.; McCord, R.B.

    1977-01-01

    Preirradiation porosity, grain size, and microcomposition characteristics are presented for selected advanced oxide (PuO 2 -UO 2 ) LMFBR developmental fuels fabricated for irradiation testing in EBR-II. Quantitative microscopy, electron microprobe analysis, and a recently developed quantitative autoradiographic technique are utilized to relate microstructure characteristics to fabrication parameters

  1. Trends for Methane Oxidation at Solid Oxide Fuel Cell Conditions

    DEFF Research Database (Denmark)

    Kleis, Jesper; Jones, Glenn; Abild-Pedersen, Frank

    2009-01-01

    First-principles calculations are used to predict a plausible reaction pathway for the methane oxidation reaction. In turn, this pathway is used to obtain trends in methane oxidation activity at solid oxide fuel cell (SOFC) anode materials. Reaction energetics and barriers for the elementary...... the Ni surfaces to other metals of interest. This allows the reactivity over the different metals to be understood in terms of two reactivity descriptors, namely, the carbon and oxygen adsorption energies. By combining a simple free-energy analysis with microkinetic modeling, activity landscapes of anode...

  2. Thermochemical aspects of fuel-cladding and fuel-coolant interactions in LMFBR oxide fuel pins

    International Nuclear Information System (INIS)

    Adamson, M.G.; Aitken, E.A.; Caputi, R.W.; Potter, P.E.; Mignanelli, M.A.

    1979-01-01

    This paper examines several thermochemical aspects of the fuel-cladding, fuel-coolant and fuel-fission product interactions that occur in LMFBR austenitic stainless steel-clad mixed (U,Pu)-oxide fuel pins during irradiation under normal operating conditions. Results are reported from a variety of high temperature EMF cell experiments in which continuous oxygen activity measurements on reacting and equilibrium mixtures of metal oxides and (excess) liquid alkali metal (Na, K, Cs) were performed. Oxygen potential and 0:M thresholds for Na-fuel reactions are re-evaluated in the light of new measurements and newly-assessed thermochemical data, and the influence on oxygen potential of possible U-Pu segregation between oxide and urano-plutonate (equilibrium) phases has been analyzed. (orig./RW) [de

  3. MARMOT update for oxide fuel modeling

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yongfeng [Idaho National Lab. (INL), Idaho Falls, ID (United States); Schwen, Daniel [Idaho National Lab. (INL), Idaho Falls, ID (United States); Chakraborty, Pritam [Idaho National Lab. (INL), Idaho Falls, ID (United States); Jiang, Chao [Idaho National Lab. (INL), Idaho Falls, ID (United States); Aagesen, Larry [Idaho National Lab. (INL), Idaho Falls, ID (United States); Ahmed, Karim [Idaho National Lab. (INL), Idaho Falls, ID (United States); Jiang, Wen [Idaho National Lab. (INL), Idaho Falls, ID (United States); Biner, Bulent [Idaho National Lab. (INL), Idaho Falls, ID (United States); Bai, Xianming [Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States); Tonks, Michael [Pennsylvania State Univ., University Park, PA (United States); Millett, Paul [Univ. of Arkansas, Fayetteville, AR (United States)

    2016-09-01

    This report summarizes the lower-length-scale research and development progresses in FY16 at Idaho National Laboratory in developing mechanistic materials models for oxide fuels, in parallel to the development of the MARMOT code which will be summarized in a separate report. This effort is a critical component of the microstructure based fuel performance modeling approach, supported by the Fuels Product Line in the Nuclear Energy Advanced Modeling and Simulation (NEAMS) program. The progresses can be classified into three categories: 1) development of materials models to be used in engineering scale fuel performance modeling regarding the effect of lattice defects on thermal conductivity, 2) development of modeling capabilities for mesoscale fuel behaviors including stage-3 gas release, grain growth, high burn-up structure, fracture and creep, and 3) improved understanding in material science by calculating the anisotropic grain boundary energies in UO$_2$ and obtaining thermodynamic data for solid fission products. Many of these topics are still under active development. They are updated in the report with proper amount of details. For some topics, separate reports are generated in parallel and so stated in the text. The accomplishments have led to better understanding of fuel behaviors and enhance capability of the MOOSE-BISON-MARMOT toolkit.

  4. Preparation and characterization of perovskite structure lanthanum gallate and lanthanum aluminate based oxides

    OpenAIRE

    Li, Shuai

    2009-01-01

    The present work was initiated to study the synthesis and properties of lanthanum gallate based oxides as intermediate temperature electrolyte for solid oxide fuel cells. The wet chemical method, polymer complexing route, was used to prepare the precursor powders. To further investigate the polymer complexing method, it was also applied to the preparation of lanthanum aluminate based oxides.   Single perovskite phase La0.8Sr0.2Ga0.83Mg0.17O2.815 can be prepared by the polymer complexing meth...

  5. Behaviour of defective CANDU fuel: fuel oxidation kinetic and thermodynamic modelling

    International Nuclear Information System (INIS)

    Higgs, J.

    2005-01-01

    The thermal performance of operating CANDU fuel under defect conditions is affected by the ingress of heavy water into the fuel element. A mechanistic model has been developed to predict the extent of fuel oxidation in defective fuel and its affect on fuel thermal performance. A thermodynamic treatment of such oxidized fuel has been performed as a basis for the boundary conditions in the kinetic model. Both the kinetic and thermodynamic models have been benchmarked against recent experimental work. (author)

  6. Preparations for the Integral Fast Reactor fuel cycle demonstration

    International Nuclear Information System (INIS)

    Lineberry, M.J.; Phipps, R.D.

    1989-01-01

    Modifications to the Hot Fuel Examination Facility-South (HFEF/S) have been in progress since mid-1988 to ready the facility for demonstration of the unique Integral Fast Reactor (IFR) pyroprocess fuel cycle. This paper updates the last report on this subject to the American Nuclear Society and describes the progress made in the modifications to the facility and in fabrication of the new process equipment. The IFR is a breeder reactor, which is central to the capability of any reactor concept to contribute to mitigation of environmental impacts of fossil fuel combustion. As a fast breeder, fuel of course must be recycled in order to have any chance of an economical fuel cycle. The pyroprocess fuel cycle, relying on a metal alloy reactor fuel rather than oxide, has the potential to be economical even at small-scale deployment. Establishing this quantitatively is one important goal of the IFR fuel cycle demonstration

  7. PREPARATION OF NICKEL - COBALT SPINEL OXIDES NixCO3 ...

    African Journals Online (AJOL)

    degree of crystallinity give rise to reversible nickel incorporation. Pellets ... are of interest in solid oxide fuel cell and this is one of the features which make them attractive ... oxide system can only be obtained in a limited composition extent.

  8. Mixed oxide fuel pellet and manufacturing method thereof

    International Nuclear Information System (INIS)

    Yuda, Ryoichi; Ito, Ken-ichi; Masuda, Hiroshi.

    1993-01-01

    In a method of manufacturing nuclear fuel pellets which comprises compression molding a mixed oxide powder containing UO 2 and PuO 2 followed by sintering, a sintering agent having a composition comprising about 40 to 80 wt% of SiO 2 and the balance of Al 2 O 3 is mixed to a mixed oxide at a ratio of about 40ppm to about 0.5 wt% based on the total amount of the mixed oxide and the sintering agent, to prepare a mixture. The mixture is molded into a compression product and then sintered at a weakly acidic atmosphere at a temperature of about 1500degC to 1800degC. With such procedures, the sintering agent forms an eutectic product of a single liquid phase, PuO 2 is dispersed over the entire region of the pellet by way of the liquid phase, formation of a solid solution phase is promoted to annihilate a free PuO 2 phase. Further, growth of crystal grains is promoted. Accordingly, since the MOX fuel pellets prepared according to the present invention have a uniform solid solution state, and no free PuO 2 phase remains, increase of FP gas emission due to local nuclear fission of Pu can be avoided. (T.M.)

  9. Influence of the fuel in the nanostructure catalyzer oxides synthesis

    International Nuclear Information System (INIS)

    Zampiva, R.Y.S.; Panta, P.C.; Carlos, R.B.; Alves, A.K.; Bergmann, C.P.

    2012-01-01

    Among the techniques used in catalysts production, the solution combustion synthesis (SCS) has been increasingly applied due the possibility of producing, at low cost, highly pure and homogeneous nanostructured powders. The smaller the particle diameter, the greater the activity of the catalyst. In SCS, the size of the particles produced depends on the process variables. In order to formulate the optimal methodology for the preparation of nanostructured oxides for catalysis, it was studied the fuel-oxidant concentration ratio, and the use of glycine and polyethylene glycol with molecular weight 200 (PEG 200) as fuel in the SCS of Iron, Magnesium and Molybdenum based catalysts. The phase identification of the products was performed by x-ray diffraction (XRD). Particle size and surface area analysis were done to characterize the particles size and the samples morphology was obtained by scanning electron microscopy. Results indicated the formation of high purity nanomaterials obtained for low concentrations of fuel, and a wide variation in the nanostructure sizes depending on the concentration and type of fuel used. (author)

  10. Solid oxide fuel cells and hydrogen production

    International Nuclear Information System (INIS)

    Dogan, F.

    2009-01-01

    'Full text': A single-chamber solid oxide fuel cell (SC-SOFC), operating in a mixture of fuel and oxidant gases, provides several advantages over the conventional SOFC such as simplified cell structure (no sealing required). SC-SOFC allows using a variety of fuels without carbon deposition by selecting appropriate electrode materials and cell operating conditions. The operating conditions of single chamber SOFC was studied using hydrocarbon-air gas mixtures for a cell composed of NiO-YSZ / YSZ / LSCF-Ag. The cell performance and catalytic activity of the anode was measured at various gas flow rates. The results showed that the open-circuit voltage and the power density increased as the gas flow rate increased. Relatively high power densities up to 660 mW/cm 2 were obtained in a SC-SOFC using porous YSZ electrolytes instead of dense electrolytes required for operation of a double chamber SOFC. In addition to propane- or methane-air mixtures as a fuel source, the cells were also tested in a double chamber configuration using hydrogen-air mixtures by controlling the hydrogen/air ratio at the cathode and the anode. Simulation of single chamber conditions in double chamber configurations allows distinguishing and better understanding of the electrode reactions in the presence of mixed gases. Recent research efforts; the effect of hydrogen-air mixtures as a fuel source on the performance of anode and cathode materials in single-chamber and double-chamber SOFC configurations,will be presented. The presentation will address a review on hydrogen production by utilizing of reversible SOFC systems. (author)

  11. High density UO2 powder preparation for HWR fuel

    International Nuclear Information System (INIS)

    Hwang, S. T.; Chang, I. S.; Choi, Y. D.; Cho, B. R.; Kwon, S. W.; Kim, B. H.; Moon, B. H.; Kim, S. D.; Phyu, K. M.; Lee, K. A.

    1992-01-01

    The objective of this project is to study on the preparation of method high density UO 2 powder for HWR Fuel. Accordingly, it is necessary to character ize the AUC processed UO 2 powder and to search method for the preparation of high density UO 2 powder for HWR Fuel. Therefore, it is expected that the results of this study can effect the producing of AUC processed UO 2 powder having sinterability. (Author)

  12. Durable and Robust Solid Oxide Fuel Cells

    DEFF Research Database (Denmark)

    Hjalmarsson, Per; Knibbe, Ruth; Hauch, Anne

    project had as one of its’ overarching goals to improve durability and robustness of the Danish solid oxide fuel cells. The project focus was on cells and cell components suitable for SOFC operation in the temperature range 600 – 750 °C. The cells developed and/or studied in this project are intended......The solid oxide fuel cell (SOFC) is an attractive technology for the generation of electricity with high efficiency and low emissions. Risø DTU (now DTU Energy Conversion) works closely together with Topsoe Fuel Cell A/S in their effort to bring competitive SOFC systems to the market. This 2-year...... for use within the CHP (Combined Heat and Power) market segment with stationary power plants in the range 1 – 250 kWe in mind. Lowered operation temperature is considered a good way to improve the stack durability since corrosion of the interconnect plates in a stack is lifetime limiting at T > 750 °C...

  13. New Catalysts for Direct Methanol Oxidation Fuel Cells

    Energy Technology Data Exchange (ETDEWEB)

    Adzic, Radoslav

    1998-08-01

    A new class of efficient electrocatalytic materials based on platinum - metal oxide systems has been synthetized and characterized by several techniques. Best activity was found with NiWO{sub 4}-, CoWO{sub 4}-, and RuO{sub 2}- sr¡pported platinum catalysts. A very similar activity at room temperature was observed with the electrodes prepared with the catalyst obtained from International Fuel Cells Inc. for the same Pt loading. Surprisingly, the two tungstates per se show a small activity for methanol oxidation without any Pt loading. Synthesis of NiWO{sub 4} and CoWO{sub 4} were carried out by solid-state reactions. FTIR spectroscopy shows that the tungstates contain a certain amount of physically adsorbed water even after heating samples at 200{degrees}C. A direct relationship between the activity for methanol oxidation and the amount of adsorbed water on those oxides has been found. The Ru(0001) single crystal shows a very small activity for CO adsorption and oxidation, in contrast to the behavior of polycrystalline Ru. In situ extended x-ray absorption fine structure spectroscopy (EXAFS) and x-ray absorption near edge spectroscopy (XANES) showed that the OH adsorption on Ru in the Pt-Ru alloy appears to be the limiting step in methanol oxidation. This does not occur for Pt-RuO{SUB 2} electrocatalyst, which explains its advantages over the Pt-Ru alloys. The IFCC electrocatalyst has the properties of the Pt-Ru alloy.

  14. Solid Oxide Fuel Cell Systems PVL Line

    International Nuclear Information System (INIS)

    Shearer, Susan; Rush, Gregory

    2012-01-01

    In July 2010, Stark State College (SSC), received Grant DE-EE0003229 from the U.S. Department of Energy (DOE), Golden Field Office, for the development of the electrical and control systems, and mechanical commissioning of a unique 20kW scale high-pressure, high temperature, natural gas fueled Stack Block Test System (SBTS). SSC worked closely with subcontractor, Rolls-Royce Fuel Cell Systems (US) Inc. (RRFCS) over a 13 month period to successfully complete the project activities. This system will be utilized by RRFCS for pre-commercial technology development and training of SSC student interns. In the longer term, when RRFCS is producing commercial products, SSC will utilize the equipment for workforce training. In addition to DOE Hydrogen, Fuel Cells, and Infrastructure Technologies program funding, RRFCS internal funds, funds from the state of Ohio, and funding from the DOE Solid State Energy Conversion Alliance (SECA) program have been utilized to design, develop and commission this equipment. Construction of the SBTS (mechanical components) was performed under a Grant from the State of Ohio through Ohio's Third Frontier program (Grant TECH 08-053). This Ohio program supported development of a system that uses natural gas as a fuel. Funding was provided under the Department of Energy (DOE) Solid-state Energy Conversion Alliance (SECA) program for modifications required to test on coal synthesis gas. The subject DOE program provided funding for the electrical build, control system development and mechanical commissioning. Performance testing, which includes electrical commissioning, was subsequently performed under the DOE SECA program. Rolls-Royce Fuel Cell Systems is developing a megawatt-scale solid oxide fuel cell (SOFC) stationary power generation system. This system, based on RRFCS proprietary technology, is fueled with natural gas, and operates at elevated pressure. A critical success factor for development of the full scale system is the capability to

  15. Tubular solid oxide fuel cell development program

    Energy Technology Data Exchange (ETDEWEB)

    Ray, E.R.; Cracraft, C.

    1995-12-31

    This paper presents an overview of the Westinghouse Solid Oxide Fuel Cell (SOFC) development activities and current program status. The Westinghouse goal is to develop a cost effective cell that can operate for 50,000 to 100,000 hours. Progress toward this goal will be discussed and test results presented for multiple single cell tests which have now successfully exceeded 56,000 hours of continuous power operation at temperature. Results of development efforts to reduce cost and increase power output of tubular SOFCs are described.

  16. Solid oxide fuel cell field trial evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Wilcox, C.P.; Winstanley, R.; Nietsch, T.; Smith, C.; Knight, R.; Seymore, C.

    2000-07-01

    This report focuses on issues relating to a field trial of a solid oxide fuel cell (SOFC). Aspects examined include markets for SOFC systems, the choice of systems for demonstration in year 2002, the assessment of industrial interest, and evaluation and ranking of candidate systems. The identification and evaluation of interest in field trials, the estimation of the capital and running costs of a field trial, and identification of the benefits to the UK and barriers to implementation of SOFC systems are discussed. (UK)

  17. Spent oxide fuel regeneration by crystallization in molybdate melts

    International Nuclear Information System (INIS)

    Ustinov, O.A.; Sukhanov, L.P.; Yakunin, S.A.

    2006-01-01

    Paper describes a procedure to regenerate spent oxide fuel by its crystallization in molybdate melts. Paper presents the process procedures to regenerate spent fuel of both fast and thermal neutron reactors. One analyzes the advantages of the elaborated procedure [ru

  18. Copper based anodes for bio-ethanol fueled low-temperature solid oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Kondakindi, R.R.; Karan, K. [Queen' s Univ., Kingston, ON (Canada)

    2003-07-01

    Laboratory studies have been conducted to develop a low-temperature solid oxide fuel cell (SOFC) fueled by bio-ethanol. SOFCs are considered to be a potential source for clean and efficient electricity. The use of bio-ethanol to power the SOFC contributes even further to reducing CO{sub 2} emissions. The main barrier towards the development of the proposed SOFC is the identification of a suitable anode catalyst that prevents coking during electro-oxidation of ethanol while yielding good electrical performance. Copper was selected as the catalyst for this study. Composite anodes consisting of copper catalysts and gadolinium-doped ceria (GDC) electrolytes were prepared using screen printing of GDC and copper oxide on dense GDC electrolytes and by wet impregnation of copper nitrate in porous GDC electrolytes followed by calcination and sintering. The electrical conductivity of the prepared anodes was characterized to determine the percolation threshold. Temperature-programmed reduction and the Brunner Emmett Teller (BET) methods were used to quantify the catalyst dispersion and surface area. Electrochemical performance of the single-cell SOFC with a hydrogen-air system was used to assess the catalytic activities. Electrochemical Impedance Spectroscopy was used to probe the electrode kinetics.

  19. Stability of solid oxide fuel cell materials

    Energy Technology Data Exchange (ETDEWEB)

    Armstrong, T.R.; Bates, J.L.; Coffey, G.W.; Pederson, L.R. [Pacific Northwest National Lab., Richland, WA (United States)] [and others

    1996-08-01

    Chromite interconnection materials in an SOFC are exposed to both highly oxidizing conditions at the cathode and to highly reducing conditions at the anode. Because such conditions could lead to component failure, the authors have evaluated thermal, electrical, chemical, and structural stabilities of these materials as a function of temperature and oxygen partial pressure. The crystal lattice of the chromites was shown to expand for oxygen partial pressures smaller than 10{sup {minus}10} atm, which could lead to cracking and debonding in an SOFC. Highly substituted lanthanum chromite compositions were the most susceptible to lattice expansion; yttrium chromites showed better dimensional stability by more than a factor of two. New chromite compositions were developed that showed little tendency for lattice expansion under strongly reducing conditions, yet provided a good thermal expansion match to other fuel cell components. Use of these new chromite interconnect compositions should improve long-term SOFC performance, particularly for planar cell configurations. Thermodynamic properties of substituted lanthanum manganite cathode compositions have been determined through measurement of electromotive force as a function of temperature. Critical oxygen decomposition pressures for Sr and Ca-substituted lanthanum manganites were established using cells based on a zirconia electrolyte. Strontium oxide and calcium oxide activities in a lanthanum manganite matrix were determined using cells based on strontium fluoride and calcium fluoride electrolytes, respectively. The compositional range of single-phase behavior of these ABO{sub 3}-type perovskites was established as a function of A/B cation ratios and the extent of acceptor doping. Before this work, very little thermodynamic information was in existence for substituted manganite compositions. Such information is needed to predict the long-term stability of solid oxide fuel cell assemblies.

  20. Multi-metallic anodes for solid oxide fuel cell applications

    International Nuclear Information System (INIS)

    Restivo, T.A. Guisard; Mello-Castanho, S.R.H.; Leite, D. Will

    2009-01-01

    A new method for direct preparation of materials for solid oxide fuel cell anode - Ni- YSZ cermets - based on mechanical alloying (MA) of the original powders is developed, allowing to admix homogeneously any component. Additive metals are selected from thermodynamic criteria, leading to compacts consolidation through sintering by activated surface (SAS). The combined process MA-SSA can reduce the sintering temperature by 300 deg C, yielding porous anodes. Densification mechanisms are discussed from quasi-isothermal sintering kinetics results. Doping with Ag, W, Cu, Mo, Nb, Ta, in descending order, promotes the densification of pellets through liquid phase sintering and evaporation of metals and oxides, which allow reducing the sintering temperature. Powders and pellets characterization by electronic microscopy and X-ray diffraction completes the result analyses. (author)

  1. Development of solid oxide fuel cell technology

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Dae Kab; Kim, Sun Jae; Jung, Choong Hwan; Kim, Kyung Hoh; Park, Ji Yun; Oh, Suk Jin [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1995-01-01

    Solid Oxide Fuel Cell (SOFC) technologies that use zirconium oxide as the electrolyte material were studied in this present report. SOFC exhibits a very high power generation efficiency of over 50 %, and does not discharge pollution materials such as dusts, sulfur dioxide, and nitrogen oxide. Zirconia, Ni/YSZ (yttria stabilized zirconia), and La-Sr-Mn-Oxide materials were developed for the electrolyte material, for the anode, and for the cathode, respectively. After making thin zirconia plate using tape casting process, anode and cathode powders were screen printed on the zirconia plate for fabricating unit cells. A test system composed of a vertical tube furnace, digital multimeter, DC current supplier, and measuring circuit was constructed for testing the unit cell performance. This system was controlled by a home-made computer program. Founded on this unit cell technology and system, a multi-stack SOFC system was studied. This system was composed of 10 unit cells each of them had an electrode area of 40 x 40 mm. Based on this system design, large and thin zirconia plates of 70 x 70 mm in area was fabricated for the electrolyte. Different from in the unit cell system, interconnectors are needed in the multi-stack system for connecting unit cells electrically. For this interconnectors, Inconel 750 alloy was selected, sliced into wafers, machined, surface finished, and then Pt-plated. 55 figs, 8 tabs, 51 refs. (Author).

  2. Development of solid oxide fuel cell technology

    International Nuclear Information System (INIS)

    Kang, Dae Kab; Kim, Sun Jae; Jung, Choong Hwan; Kim, Kyung Hoh; Park, Ji Yun; Oh, Suk Jin

    1995-01-01

    Solid Oxide Fuel Cell (SOFC) technologies that use zirconium oxide as the electrolyte material were studied in this present report. SOFC exhibits a very high power generation efficiency of over 50 %, and does not discharge pollution materials such as dusts, sulfur dioxide, and nitrogen oxide. Zirconia, Ni/YSZ (yttria stabilized zirconia), and La-Sr-Mn-Oxide materials were developed for the electrolyte material, for the anode, and for the cathode, respectively. After making thin zirconia plate using tape casting process, anode and cathode powders were screen printed on the zirconia plate for fabricating unit cells. A test system composed of a vertical tube furnace, digital multimeter, DC current supplier, and measuring circuit was constructed for testing the unit cell performance. This system was controlled by a home-made computer program. Founded on this unit cell technology and system, a multi-stack SOFC system was studied. This system was composed of 10 unit cells each of them had an electrode area of 40 x 40 mm. Based on this system design, large and thin zirconia plates of 70 x 70 mm in area was fabricated for the electrolyte. Different from in the unit cell system, interconnectors are needed in the multi-stack system for connecting unit cells electrically. For this interconnectors, Inconel 750 alloy was selected, sliced into wafers, machined, surface finished, and then Pt-plated. 55 figs, 8 tabs, 51 refs. (Author)

  3. Medium-temperature solid oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Maffei, N.; Kuriakose, A.K. [Natural Resources Canada, Ottawa, ON (Canada). Materials Technology Lab

    2000-07-01

    The Materials Technology Laboratory (MTL) of Natural Resources Canada has been conducting research on the development of a solid oxide fuel cell (SOFC) for the past decade. Fuel cells convert chemical energy directly into electric energy in an efficient and environmentally friendly manner. SOFCs are considered to be good stationary power sources for commercial and residential applications and will likely be commercialized in the near future. The research at MTL has focused on the development of new electrolytes for use in SOFCs. In the course of this research, monolithic planar single cell SOFCs based on doubly doped ceria and lanthanum gallate have been fabricated and tested at 700 degrees C. This paper compared the performance characteristics of both these systems. The data suggested the presence of a significant electronic conductivity in the SOFC incorporating doubly doped ceria, resulting in lower than expected voltage output. The stability of the SOFC, however, did not appear to be negatively affected. The lanthanum gallate based SOFC performed well. It was concluded that reducing the operating temperature of SOFCs would improve their reliability and enhance their operating life. First generation commercial SOFCs will use a zirconium oxide-based electrolytes while second generation units might possibly use ceria-based and/or lanthanum gallate electrolytes. 24 refs., 6 figs.

  4. Chemical Characterization and Reactivity of Fuel-Oxidizer Reaction Product

    Science.gov (United States)

    David, Dennis D.; Dee, Louis A.; Beeson, Harold D.

    1997-01-01

    Fuel-oxidizer reaction product (FORP), the product of incomplete reaction of monomethylhydrazine and nitrogen tetroxide propellants prepared under laboratory conditions and from firings of Shuttle Reaction Control System thrusters, has been characterized by chemical and thermal analysis. The composition of FORP is variable but falls within a limited range of compositions that depend on three factors: the fuel-oxidizer ratio at the time of formation; whether the composition of the post-formation atmosphere is reducing or oxidizing; and the reaction or post-reaction temperature. A typical composition contains methylhydrazinium nitrate, ammonium nitrate, methylammonium nitrate, and trace amounts of hydrazinium nitrate and 1,1-dimethylhydrazinium nitrate. Thermal decomposition reactions of the FORP compositions used in this study were unremarkable. Neither the various compositions of FORP, the pure major components of FORP, nor mixtures of FORP with propellant system corrosion products showed any unusual thermal activity when decomposed under laboratory conditions. Off-limit thruster operations were simulated by rapid mixing of liquid monomethylhydrazine and liquid nitrogen tetroxide in a confined space. These tests demonstrated that monomethylhydrazine, methylhydrazinium nitrate, ammonium nitrate, or Inconel corrosion products can induce a mixture of monomethylhydrazine and nitrogen tetroxide to produce component-damaging energies. Damaging events required FORP or metal salts to be present at the initial mixing of monomethylhydrazine and nitrogen tetroxide.

  5. Addressing fuel recycling in solid oxide fuel cell systems fed by alternative fuels

    DEFF Research Database (Denmark)

    Rokni, Masoud

    2017-01-01

    An innovative study on anode recirculation in solid oxide fuel cell systems with alternative fuels is carried out and investigated. Alternative fuels under study are ammonia, pure hydrogen, methanol, ethanol, DME and biogas from biomass gasification. It is shown that the amount of anode off......%. Furthermore, it is founded that for the case with methanol, ethanol and DME then at high utilization factors, low anode recirculation is recommended while at low utilization factors, high anode recirculation is recommended. If the plant is fed by biogas from biomass gasification then for each utilization...

  6. Modeling of thermal expansion coefficient of perovskite oxide for solid oxide fuel cell cathode

    Science.gov (United States)

    Heydari, F.; Maghsoudipour, A.; Alizadeh, M.; Khakpour, Z.; Javaheri, M.

    2015-09-01

    Artificial intelligence models have the capacity to eliminate the need for expensive experimental investigation in various areas of manufacturing processes, including the material science. This study investigates the applicability of adaptive neuro-fuzzy inference system (ANFIS) approach for modeling the performance parameters of thermal expansion coefficient (TEC) of perovskite oxide for solid oxide fuel cell cathode. Oxides (Ln = La, Nd, Sm and M = Fe, Ni, Mn) have been prepared and characterized to study the influence of the different cations on TEC. Experimental results have shown TEC decreases favorably with substitution of Nd3+ and Mn3+ ions in the lattice. Structural parameters of compounds have been determined by X-ray diffraction, and field emission scanning electron microscopy has been used for the morphological study. Comparison results indicated that the ANFIS technique could be employed successfully in modeling thermal expansion coefficient of perovskite oxide for solid oxide fuel cell cathode, and considerable savings in terms of cost and time could be obtained by using ANFIS technique.

  7. Integrated analysis of oxide nuclear fuel sintering

    International Nuclear Information System (INIS)

    Baranov, V.; Kuzmin, R.; Tenishev, A.; Timoshin, I.; Khlunov, A.; Ivanov, A.; Petrov, I.

    2011-01-01

    Dilatometric and thermal-gravimetric investigations have been carried out for the sintering process of oxide nuclear fuel in gaseous Ar - 8% H 2 atmosphere at temperatures up to 1600 0 C. The pressed compacts were fabricated under real production conditions of the OAO MSZ with application of two different technologies, so called 'dry' and 'wet' technologies. Effects of the grain size growth after the heating to different temperatures were observed. In order to investigate the effects produced by rate of heating on properties of sintered fuel pellets, the heating rates were varied from 1 to 8 0 C per minute. Time of isothermal overexposure at maximal temperature (1600 0 C) was about 8 hours. Real production conditions were imitated. The results showed that the sintering process of the fuel pellets produced by two technologies differs. The samples sintered under different heating rates were studied with application of scanning electronic microscopy analysis for determination of mean grain size. A simulation of heating profile for industrial furnaces was performed to reduce the beam cycles and estimate the effects of variation of the isothermal overexposure temperatures. Based on this data, an optimization of the sintering conditions was performed in operations terms of OAO MSZ. (authors)

  8. Preparation of Reduced Graphene Oxides as Electrode Materials for Supercapacitors

    KAUST Repository

    Bai, Yaocai

    2012-01-01

    Reduced graphene oxide as outstanding candidate electrode material for supercapacitor has been investigated. This thesis includes two topics. One is that three kinds of reduced graphene oxides were prepared by hydrothermal reduction under different

  9. Modeling the Thermal Rocket Fuel Preparation Processes in the Launch Complex Fueling System

    Directory of Open Access Journals (Sweden)

    A. V. Zolin

    2015-01-01

    Full Text Available It is necessary to carry out fuel temperature preparation for space launch vehicles using hydrocarbon propellant components. A required temperature is reached with cooling or heating hydrocarbon fuel in ground facilities fuel storages. Fuel temperature preparing processes are among the most energy-intensive and lengthy processes that require the optimal technologies and regimes of cooling (heating fuel, which can be defined using the simulation of heat exchange processes for preparing the rocket fuel.The issues of research of different technologies and simulation of cooling processes of rocket fuel with liquid nitrogen are given in [1-10]. Diagrams of temperature preparation of hydrocarbon fuel, mathematical models and characteristics of cooling fuel with its direct contact with liquid nitrogen dispersed are considered, using the numerical solution of a system of heat transfer equations, in publications [3,9].Analytical models, allowing to determine the necessary flow rate and the mass of liquid nitrogen and the cooling (heating time fuel in specific conditions and requirements, are preferred for determining design and operational characteristics of the hydrocarbon fuel cooling system.A mathematical model of the temperature preparation processes is developed. Considered characteristics of these processes are based on the analytical solutions of the equations of heat transfer and allow to define operating parameters of temperature preparation of hydrocarbon fuel in the design and operation of the filling system of launch vehicles.The paper considers a technological system to fill the launch vehicles providing the temperature preparation of hydrocarbon gases at the launch site. In this system cooling the fuel in the storage tank before filling the launch vehicle is provided by hydrocarbon fuel bubbling with liquid nitrogen. Hydrocarbon fuel is heated with a pumping station, which provides fuel circulation through the heat exchanger-heater, with

  10. Simulation study of a PEM fuel cell system fed by hydrogen produced by partial oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Ozdogan, S [Marmara University, Faculty of Engineering, Istanbul (Turkey); Ersoz, A; Olgun, H [TUBITAK Marmara Research Center, Energy Systems and Environmental Research Institute, Kocaeli (Turkey)

    2003-09-01

    Within the frame of sustainable development, efficient and clean, if possible zero emission energy production technologies are of utmost importance in various sectors such as utilities, industry, households and transportation. Low-temperature fuel cell systems are suitable for powering transportation systems such as automobiles and trucks in an efficient and low-emitting manner. Proton exchange membrane (PEM) fuel cell systems constitute the most promising low temperature fuel cell option being developed globally. PEM fuel cells generate electric power from air and hydrogen or from a hydrogen rich gas via electrochemical reactions. Water and waste heat are the only by-products of PEM fuel cells. There is great interest in converting current hydrocarbon based common transportation fuels such as gasoline and diesel into hydrogen rich gases acceptable by PEM fuel cells. Hydrogen rich gases can be produced from conventional transportation fuels via various reforming technologies. Steam reforming, partial oxidation and auto-thermal reforming are the three major reforming technologies. In this paper, we discuss the results of a simulation study for a PEM fuel cell with partial oxidation. The Aspen HYSYS 3.1 code has been used for simulation purposes. Two liquid hydrocarbon fuels have been selected to investigate the effect of average molecular weights of hydrocarbons, on the fuel processing efficiency. The overall system efficiency depends on the fuel preparation and fuel cell efficiencies as well as on the heat integration within the system. It is desired to investigate the overall system efficiencies for net electrical power production at 100 kW considering bigger scale transport applications. Results indicate that fuel properties, fuel preparation system operating parameters and PEM fuel cell polarization curve characteristics all affect the overall system efficiency. (authors)

  11. An improved method of preparation of nanoparticular metal oxide catalysts

    DEFF Research Database (Denmark)

    2014-01-01

    The present invention concerns an improved method of preparation of nanoparticular vanadium oxide/anatase titania catalysts having a narrow particle size distribution. In particular, the invention concerns preparation of nanoparticular vanadium oxide/anatase titania catalyst precursors comprising...... combustible crystallization seeds upon which the catalyst metal oxide is coprecipitated with the carrier metal oxide, which crystallization seeds are removed by combustion in a final calcining step....

  12. Mesoporous metal oxides and processes for preparation thereof

    Energy Technology Data Exchange (ETDEWEB)

    Suib, Steven L.; Poyraz, Altug Suleyman

    2018-03-06

    A process for preparing a mesoporous metal oxide, i.e., transition metal oxide. Lanthanide metal oxide, a post-transition metal oxide and metalloid oxide. The process comprises providing an acidic mixture comprising a metal precursor, an interface modifier, a hydrotropic ion precursor, and a surfactant; and heating the acidic mixture at a temperature and for a period of time sufficient to form the mesoporous metal oxide. A mesoporous metal oxide prepared by the above process. A method of controlling nano-sized wall crystallinity and mesoporosity in mesoporous metal oxides. The method comprises providing an acidic mixture comprising a metal precursor, an interface modifier, a hydrotropic ion precursor, and a surfactant; and heating the acidic mixture at a temperature and for a period of time sufficient to control nano-sized wall crystallinity and mesoporosity in the mesoporous metal oxides. Mesoporous metal oxides and a method of tuning structural properties of mesoporous metal oxides.

  13. Fuel cracking in relation to fuel oxidation in support of an out-reactor instrumented defected fuel experiment

    Energy Technology Data Exchange (ETDEWEB)

    Quastel, A.; Thiriet, C. [Atomic Energy of Canada Limited, Chalk River, ON (Canada); Lewis, B., E-mail: brent.lewis@uoit.ca [Univ. of Ontario Inst. of Tech., Oshawa, ON (Canada); Corcoran, E., E-mail: emily.corcoran@rmc.ca [Royal Military College of Canada, Kingston, ON (Canada)

    2014-07-01

    An experimental program funded by the CANDU Owners Group (COG) is studying an out-reactor instrumented defected fuel experiment in Stern Laboratories (Hamilton, Ontario) with guidance from Atomic Energy of Canada Limited (AECL). The objective of this test is to provide experimental data for validation of a mechanistic fuel oxidation model. In this experiment a defected fuel element with UO{sub 2} pellets will be internally heated with an electrical heater element, causing the fuel to crack. By defecting the sheath in-situ the fuel will be exposed to light water coolant near normal reactor operating conditions (pressure 10 MPa and temperature 265-310{sup o}C) causing fuel oxidation, especially near the hotter regions of the fuel in the cracks. The fuel thermal conductivity will change, resulting in a change in the temperature distribution of the fuel element. This paper provides 2D r-θ plane strain solid mechanics models to simulate fuel thermal expansion, where conditions for fuel crack propagation are investigated with the thermal J integral to predict fuel crack stress intensity factors. Finally since fuel crack geometry can affect fuel oxidation this paper shows that the solid mechanics model with pre-set radial cracks can be coupled to a 2D r-θ fuel oxidation model. (author)

  14. Performance Evaluation of Solid Oxide Fuel Cell by Computer ...

    African Journals Online (AJOL)

    The search for sustainable energy source that can compete with the existing one led to the discovery and acceptance of fuel cell technologies as a perfect replacement for fossil fuel. The ability of Solid Oxide Fuel Cells (SOFC) to capture the heat generation during the process of energy generation from electrochemical ...

  15. Reviews on Solid Oxide Fuel Cell Technology

    Directory of Open Access Journals (Sweden)

    Apinan Soottitantawat

    2009-02-01

    Full Text Available Solid Oxide Fuel Cell (SOFC is one type of high temperature fuel cell that appears to be one of the most promising technology to provide the efficient and clean energy production for wide range of applications (from small units to large scale power plants. This paper reviews the current status and related researches on SOFC technologies. In details, the research trend for the development of SOFC components(i.e. anode, electrolyte, cathode, and interconnect are presented. Later, the current important designs of SOFC (i.e. Seal-less Tubular Design, Segmented Cell in Series Design, Monolithic Design and Flat Plate Design are exampled. In addition, the possible operations of SOFC (i.e. external reforming, indirect internal reforming, and direct internal reforming are discussed. Lastly, the research studies on applications of SOFCs with co-generation (i.e. SOFC with Combined Heat and Power (SOFC-CHP, SOFC with Gas Turbine (SOFC-GT and SOFC with chemical production are given.

  16. Plutonium spot of mixed oxide fuel, 2

    International Nuclear Information System (INIS)

    Suzuki, Yukio; Maruishi, Yoshihiro; Satoh, Masaichi; Aoki, Toshimasa; Muto, Tadashi

    1974-01-01

    In a fast reactor, the specification for the homogeneity of plutonium in plutonium-uranium mixed-oxide fuel is mainly dependent on the nuclear characteristics, whereas in a thermal reactor, on thermal characteristics. This homogeneity is measured by autoradiography as the plutonium spot size of the specimens which are arbitrarily chosen fuel pellets from a lot. Although this is a kind of random sampling, it is difficult to apply this method to conventional digital standards including JIS standards. So a special sampling inspection method was studied. First, it is assumed that the shape of plutonium spots is spherical, the size distribution is logarithmic normal, and the standard deviation is constant. Then, if standard deviation and mean spot size are given, the logarithmic normal distribution is decided unitarily, and further if the total weight of plutonium spots for a lot of pellets is known, the number of the spots (No) which does not conform to the specification can be obtained. Then, the fraction defective is defined as No devided by the number of pellets per lot. As to the lot with such fraction defective, the acceptance coefficient of the lot was obtained through calculation, in which the number of sampling, acceptable diameter limit observed and acceptable conditions were used as parameters. (Tai, I.)

  17. Learning curves for solid oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Rivera-Tinoco, R.; Schoots, K. [Energy research Centre of the Netherlands (Netherlands). Policy Studies; Zwaan, B.C.C. van der [Energy research Centre of the Netherlands (Netherlands). Policy Studies; Columbia Univ., New York City, NY (United States). Lenfest Center for Sustainable Energy

    2010-07-01

    We present learning curves for solid oxide fuel cells (SOFCs) and combined heat and power (CHP) SOFC systems with an electric capacity between 1 and 250 kW. On the basis of the cost breakdown of production cost data from fuel cell manufacturers, we developed a bottom-up model that allows for determining overall manufacturing costs from their respective cost components, among which material, energy, labor, and capital charges. The results obtained from our model prove to deviate by at most 13% from total cost figures quoted in the literature. For the early pilot stage of development, we find for SOFC manufacturing a learning rate between 14% and 17%, and for total SOFC system fabrication between 16% and 19%. We argue that the corresponding cost reductions result largely from learning-by-searching effects (R and D) rather than learning-by-doing. When considering a longer time frame that includes the early commercial production stage, we find learning rates between 14% and 39%, which represent a mix of phenomena such as learning-by-doing, learning-by-searching, economies-of-scale and automation. (orig.)

  18. Nanostructured Solid Oxide Fuel Cell Electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Sholklapper, Tal Zvi [Univ. of California, Berkeley, CA (United States)

    2007-01-01

    The ability of Solid Oxide Fuel Cells (SOFC) to directly and efficiently convert the chemical energy in hydrocarbon fuels to electricity places the technology in a unique and exciting position to play a significant role in the clean energy revolution. In order to make SOFC technology cost competitive with existing technologies, the operating temperatures have been decreased to the range where costly ceramic components may be substituted with inexpensive metal components within the cell and stack design. However, a number of issues have arisen due to this decrease in temperature: decreased electrolyte ionic conductivity, cathode reaction rate limitations, and a decrease in anode contaminant tolerance. While the decrease in electrolyte ionic conductivities has been countered by decreasing the electrolyte thickness, the electrode limitations have remained a more difficult problem. Nanostructuring SOFC electrodes addresses the major electrode issues. The infiltration method used in this dissertation to produce nanostructure SOFC electrodes creates a connected network of nanoparticles; since the method allows for the incorporation of the nanoparticles after electrode backbone formation, previously incompatible advanced electrocatalysts can be infiltrated providing electronic conductivity and electrocatalysis within well-formed electrolyte backbones. Furthermore, the method is used to significantly enhance the conventional electrode design by adding secondary electrocatalysts. Performance enhancement and improved anode contamination tolerance are demonstrated in each of the electrodes. Additionally, cell processing and the infiltration method developed in conjunction with this dissertation are reviewed.

  19. Solid Oxide Fuel Cells Canada (SOFCC)

    International Nuclear Information System (INIS)

    Birss, V.; Borglum, B.

    2006-01-01

    Vision: To enhance co-ordination and to ensure sustainable funding of research, development, and commercialization of solid oxide fuel cells and related technologies in Canada in order to create products that serve the world. Current Research Areas of Investigation: Mission: To provide cleaner air, reduce CO 2 emissions, better utilize fuel resources, increase economic prosperity, and enhance the quality of life in Canada and the world by enabling and accelerating development of the Canadian SOFC industry. To achieve this, we will: 1. Establish national priorities for the research, development, design, demonstration, and the innovation process; commercialization of SOFC and related technologies; 2. Develop a strategy to produce commercial products within 5 years; 3. Co-ordinate activities as one integrated Canada-wide initiative; 4. Facilitate effective access to funding by providing a venue for funders to directly participate in; 5. Provide an integrating and interdisciplinary function to maximize the collective knowledge, expertise, and capacity of the alliance partners; 6. Maintain strategic relevance within an ever changing global context by providing high-quality intelligence. (author)

  20. Advanced methods of solid oxide fuel cell modeling

    CERN Document Server

    Milewski, Jaroslaw; Santarelli, Massimo; Leone, Pierluigi

    2011-01-01

    Fuel cells are widely regarded as the future of the power and transportation industries. Intensive research in this area now requires new methods of fuel cell operation modeling and cell design. Typical mathematical models are based on the physical process description of fuel cells and require a detailed knowledge of the microscopic properties that govern both chemical and electrochemical reactions. ""Advanced Methods of Solid Oxide Fuel Cell Modeling"" proposes the alternative methodology of generalized artificial neural networks (ANN) solid oxide fuel cell (SOFC) modeling. ""Advanced Methods

  1. Learning curves for solid oxide fuel cells

    International Nuclear Information System (INIS)

    Rivera-Tinoco, Rodrigo; Schoots, Koen; Zwaan, Bob van der

    2012-01-01

    Highlights: ► We present learning curves for fuel cells based on empirical data. ► We disentangle different cost reduction mechanisms for SOFCs. ► We distinguish between learning-by-doing, R and D, economies-of-scale and automation. - Abstract: In this article we present learning curves for solid oxide fuel cells (SOFCs). With data from fuel cell manufacturers we derive a detailed breakdown of their production costs. We develop a bottom-up model that allows for determining overall SOFC manufacturing costs with their respective cost components, among which material, energy, labor and capital charges. The results obtained from our model prove to deviate by at most 13% from total cost figures quoted in the literature. For the R and D stage of development and diffusion, we find local learning rates between 13% and 17% and we demonstrate that the corresponding cost reductions result essentially from learning-by-searching effects. When considering periods in time that focus on the pilot and early commercial production stages, we find regional learning rates of 27% and 1%, respectively, which we assume derive mainly from genuine learning phenomena. These figures turnout significantly higher, approximately 44% and 12% respectively, if also effects of economies-of-scale and automation are included. When combining all production stages we obtain lr = 35%, which represents a mix of cost reduction phenomena. This high learning rate value and the potential to scale up production suggest that continued efforts in the development of SOFC manufacturing processes, as well as deployment and use of SOFCs, may lead to substantial further cost reductions.

  2. Sintered nuclear fuel and method of preparing same

    International Nuclear Information System (INIS)

    Abate-Daga, G.; Amato, I.

    1975-01-01

    A description is given of a method of preparing a nuclear fuel containing a consumable nuclear poison uniformly distributed therein in the form of coated micro-spheres of between 10 and 2,000 microns diameter, consisting in preparing sintered micro-spheres of the consumable poison, covering those micro-spheres with a protective coating and incorporating the coated micro-spheres into uranium dioxide powder, followed by sintering

  3. Formulation and method for preparing gels comprising hydrous aluminum oxide

    Science.gov (United States)

    Collins, Jack L.

    2014-06-17

    Formulations useful for preparing hydrous aluminum oxide gels contain a metal salt including aluminum, an organic base, and a complexing agent. Methods for preparing gels containing hydrous aluminum oxide include heating a formulation to a temperature sufficient to induce gel formation, where the formulation contains a metal salt including aluminum, an organic base, and a complexing agent.

  4. The burnup dependence of light water reactor spent fuel oxidation

    International Nuclear Information System (INIS)

    Hanson, B.D.

    1998-07-01

    Over the temperature range of interest for dry storage or for placement of spent fuel in a permanent repository under the conditions now being considered, UO 2 is thermodynamically unstable with respect to oxidation to higher oxides. The multiple valence states of uranium allow for the accommodation of interstitial oxygen atoms in the fuel matrix. A variety of stoichiometric and nonstoichiometric phases is therefore possible as the fuel oxidizers from UO 2 to higher oxides. The oxidation of UO 2 has been studied extensively for over 40 years. It has been shown that spent fuel and unirradiated UO 2 oxidize via different mechanisms and at different rates. The oxidation of LWR spent fuel from UO 2 to UO 2.4 was studied previously and is reasonably well understood. The study presented here was initiated to determine the mechanism and rate of oxidation from UO 2.4 to higher oxides. During the early stages of this work, a large variability in the oxidation behavior of samples oxidized under nearly identical conditions was found. Based on previous work on the effect of dopants on UO 2 oxidation and this initial variability, it was hypothesized that the substitution of fission product and actinide impurities for uranium atoms in the spent fuel matrix was the cause of the variable oxidation behavior. Since the impurity concentration is roughly proportional to the burnup of a specimen, the oxidation behavior of spent fuel was expected to be a function of both temperature and burnup. This report (1) summarizes the previous oxidation work for both unirradiated UO 2 and spent fuel (Section 2.2) and presents the theoretical basis for the burnup (i.e., impurity concentration) dependence of the rate of oxidation (Sections 2.3, 2.4, and 2.5), (2) describes the experimental approach (Section 3) and results (Section 4) for the current oxidation tests on spent fuel, and (3) establishes a simple model to determine the activation energies associated with spent fuel oxidation (Section 5)

  5. Oxidation catalysts and process for preparing same

    International Nuclear Information System (INIS)

    1980-01-01

    Compounds particularly suitable as oxidation catalysis are described, comprising specified amounts of uranium, antimony and tin as oxides. Processes for making and using the catalysts are described. (U.K.)

  6. Plasmon-enhanced Solar Fuel Production with Gold-metal Oxide Hybrid Nanomaterials

    DEFF Research Database (Denmark)

    Engelbrekt, Christian; Law, Matt; Zhang, Jingdong

    , provide new catalytic routes and expands the scope of solar photocatalysis. We prepare metal oxide SNPs, gold PNPs and their hybrids through mild aqueous syntheses to develop efficient photocatalyst for solar fuel production. Focus is placed on the synergetic interplay between SNPs and PNPs, understanding...

  7. Improvements in or relating to refractory oxide protective coatings for fuel can

    International Nuclear Information System (INIS)

    Cairns, J.A.; Bennett, M.J.; Linacre, J.K.

    1981-01-01

    An improved coating for Advanced Gas Cooled Nuclear Reactor austenitic stainless steel fuel cans is described which, tests have shown, inhibits the deposition of carbon on the cans in carbon-containing ionising radiation environments. The coating comprises a refractory oxide which has been prepared by a vapour phase condensation method, in combination with a noble metal. (U.K.)

  8. Non-traditional Oxidants in Preparative Coordination Chemistry

    Science.gov (United States)

    Kukushkin, Vadim Yu; Kukushkin, Yurii N.

    1986-10-01

    The application of nitrosonium and arenediazonium salts, carbenium, silver(I), and mercury(II) ions, protic acids, and amine oxides as oxidants in preparative coordination chemistry is examined. Specific examples illustrate which problems in the field of the synthesis and reactions of coordination compounds can be solved with the aid of these oxidants. The bibliography includes 158 references.

  9. Fuel handling alternatives to prepare for large scale fuel channel replacement

    International Nuclear Information System (INIS)

    Martire, S.; Sandu, I.

    2007-01-01

    It is desirable to reduce the duration of defuelling the reactor in preparation for retube, as the cost of replacement power is $750K/day. Three fast defuelling concepts are presented. With the Through Flow Defuelling method, the fuel string is hydraulically pushed into the downstream Fuelling Machine (FM) by flow passing through the fuel channel. The Long Stroke C Ram method replaces the FM C Ram with a longer one capable of pushing all fuel bundles into the receiving FM. Defuelling Hardware uses enhanced design of ram extensions that interconnect mechanically to extend the Ram stroke to push fuel bundles into the receiving FM. This paper will present descriptions of each defuelling concept to prepare for Large Scale Fuel Channel Replacement. Advantages and disadvantages of each concept will be discussed and a recommendation will be made for future implementation. (author)

  10. Synthesis of jet fuel range branched cycloalkanes with mesityl oxide and 2-methylfuran from lignocellulose

    Science.gov (United States)

    Li, Shanshan; Li, Ning; Wang, Wentao; Li, Lin; Wang, Aiqin; Wang, Xiaodong; Zhang, Tao

    2016-09-01

    Jet fuel range branched cycloalkanes with high density (0.82 g mL-1) and low freezing point (217-219 K) was first prepared by the solvent-free intramolecular aldol condensation of the trione from the hydrolysis of the alkylation product of mesityl oxide and 2-methylfuran (or the one-pot reaction of mesityl oxide, 2-methylfuran and water), followed by hydrodeoxygenation (HDO).

  11. Aluminum cladding oxidation of prefilmed in-pile fueled experiments

    Energy Technology Data Exchange (ETDEWEB)

    Marcum, W.R., E-mail: marcumw@engr.orst.edu [Oregon State University, School of Nuclear Science and Engineering, 116 Radiation Center, Corvallis, OR 97331 (United States); Wachs, D.M.; Robinson, A.B.; Lillo, M.A. [Idaho National Laboratory, Nuclear Fuels & Materials Department, 2525 Fremont Ave., Idaho Falls, ID 83415 (United States)

    2016-04-01

    A series of fueled irradiation experiments were recently completed within the Advanced Test Reactor Full size plate In center flux trap Position (AFIP) and Gas Test Loop (GTL) campaigns. The conduct of the AFIP experiments supports ongoing efforts within the global threat reduction initiative (GTRI) to qualify a new ultra-high loading density low enriched uranium-molybdenum fuel. This study details the characterization of oxide growth on the fueled AFIP experiments and cross-correlates the empirically measured oxide thickness values to existing oxide growth correlations and convective heat transfer correlations that have traditionally been utilized for such an application. This study adds new and valuable empirical data to the scientific community with respect to oxide growth measurements of highly irradiated experiments, of which there is presently very limited data. Additionally, the predicted oxide thickness values are reconstructed to produce an oxide thickness distribution across the length of each fueled experiment (a new application and presentation of information that has not previously been obtainable in open literature); the predicted distributions are compared against experimental data and in general agree well with the exception of select outliers. - Highlights: • New experimental data is presented on oxide layer thickness of irradiated aluminum fuel. • Five oxide growth correlations and four convective heat transfer correlations are used to compute the oxide layer thickness. • The oxide layer thickness distribution is predicted via correlation for each respective experiment. • The measured experiment and predicted distributions correlate well, with few outliers.

  12. Preparations for the shipment of RA-3 reactor irradiated fuel

    International Nuclear Information System (INIS)

    Goldschmidt, Adrian; Novara, Oscar; Lafuente, Jose

    2002-01-01

    During the last quarter of 2000, in the Radioactive Waste Management Area of the Argentine National Commission of Atomic Energy (CNEA), located at Ezeiza Atomic Center (CAE), activities associated to the shipment of 207 MTR spent fuels containing high enrichment uranium were carried out within the Foreign Research Reactor/Domestic Research Reactor Receipt Program launched by the US Department of Energy (DOE). The MTR spent fuel shipped to Savannah River Site (SRS) was fabricated in Argentina with 90% enriched uranium of US origin and it was utilized in the operation of the research and radioisotope production reactor RA-3 from 1968 until 1987. After a cooling period at the reactor, the spent fuel was transferred to the Central Storage Facility (CSF) located in the waste management area of CAE for interim storage. The spent fuel (SF) inventory consisted of 166 standard assemblies (SA) and 41 control assemblies (CA). Basically, the activities performed were the fuel conditioning operations inside the storage facility (remote transference of the assemblies to the operation pool, fuel cropping, fuel re-identification, loading in transport baskets, etc.) conducted by CNEA. The loading of the filled baskets in the transport casks (NAC-LWT) by means of intermediate transfer systems and loaded casks final preparations were conducted by NAC personnel (DOE's contractor) with the support of CNEA personnel. (author)

  13. Interim results from UO2 fuel oxidation tests in air

    International Nuclear Information System (INIS)

    Campbell, T.K.; Gilbert, E.R.; Thornhill, C.K.; White, G.D.; Piepel, G.F.; Griffin, C.W.j.

    1987-08-01

    An experimental program is being conducted at Pacific Northwest Laboratory (PNL) to extend the characterization of spent fuel oxidation in air. To characterize oxidation behavior of irradiated UO 2 , fuel oxidation tests were performed on declad light-water reactor spent fuel and nonirradited UO 2 pellets in the temperature range of 135 to 250 0 C. These tests were designed to determine the important independent variables that might affect spent fuel oxidation behavior. The data from this program, when combined with the test results from other programs, will be used to develop recommended spent fuel dry-storage temperature limits in air. This report describes interim test results. The initial PNL investigations of nonirradiated and spent fuels identified the important testing variables as temperature, fuel burnup, radiolysis of the air, fuel microstructure, and moisture in the air. Based on these initial results, a more extensive statistically designed test matrix was developed to study the effects of temperature, burnup, and moisture on the oxidation behavior of spent fuel. Oxidation tests were initiated using both boiling-water reactor and pressurized-water reactor fuels from several different reactors with burnups from 8 to 34 GWd/MTU. A 10 5 R/h gamma field was applied to the test ovens to simulate dry storage cask conditions. Nonirradiated fuel was included as a control. This report describes experimental results from the initial tests on both the spent and nonirradiated fuels and results to date on the tests in a 10 5 R/h gamma field. 33 refs., 51 figs., 6 tabs

  14. Development of advanced mixed oxide fuels for plutonium management

    International Nuclear Information System (INIS)

    Eaton, S.; Beard, C.; Buksa, J.; Butt, D.; Chidester, K.; Havrilla, G.; Ramsey, K.

    1997-06-01

    A number of advanced Mixed Oxide (MOX) fuel forms are currently being investigated at Los Alamos National Laboratory that have the potential to be effective plutonium management tools. Evolutionary Mixed Oxide (EMOX) fuel is a slight perturbation on standard MOX fuel, but achieves greater plutonium destruction rates by employing a fractional nonfertile component. A pure nonfertile fuel is also being studied. Initial calculations show that the fuel can be utilized in existing light water reactors and tailored to address different plutonium management goals (i.e., stabilization or reduction of plutonium inventories residing in spent nuclear fuel). In parallel, experiments are being performed to determine the feasibility of fabrication of such fuels. Initial EMOX pellets have successfully been fabricated using weapons-grade plutonium

  15. Development of advanced mixed oxide fuels for plutonium management

    International Nuclear Information System (INIS)

    Eaton, S.; Beard, C.; Buksa, J.; Butt, D.; Chidester, K.; Havrilla, G.; Ramsey, K.

    1997-01-01

    A number of advanced Mixed Oxide (MOX) fuel forms are currently being investigated at Los Alamos National Laboratory that have the potential to be effective plutonium management tools. Evolutionary Mixed Oxide (EMOX) fuel is a slight perturbation on standard MOX fuel, but achieves greater plutonium destruction rates by employing a fractional nonfertile component. A pure nonfertile fuel is also being studied. Initial calculations show that the fuel can be utilized in existing light water reactors and tailored to address different plutonium management goals (i.e., stabilization or reduction of plutonium inventories residing in spent nuclear fuel). In parallel, experiments are being performed to determine the feasibility of fabrication of such fuels. Initial EMOX pellets have successfully been fabricated using weapons-grade plutonium. (author)

  16. Physicochemical analysis of interaction of oxide fuel with pyrocarbon coatings of fuel particles

    International Nuclear Information System (INIS)

    Lyutikov, R.A.; Khromov, Yu.F.; Chernikov, A.S.

    1990-01-01

    Equilibrium pressure of (CO+Kr,Xe) gases inside fuel particle with oxide kern depending on design features of fuel particle, on temperature. on (O/U) initial composition and fuel burnup is calculated using the suggested model. Analysis of possibility for gas pressure reduction by means of uranium carbide alloying of kern and degree increase of solid fission product retention (Cs for example) during alumosilicate alloying of uranium oxide is conducted

  17. Preparation and characterization of PtRu/C, PtBi/C, PtRuBi/C electrocatalysts for direct electro-oxidation of ethanol in PEM fuels cells using the method of reduction by sodium borohydride

    International Nuclear Information System (INIS)

    Brandalise, Michele

    2010-01-01

    Pt/C, PtBi/C, PtRu/C and PtRuBi/C electrocatalysts were prepared by a borohydride reduction methodology and tested for ethanol oxidation. This methodology consists in mix a solution with sodium hydroxide and sodium borohydride to a mixture containing water/isopropyl alcohol, metallic precursors and the Vulcan XC 72 carbon support. It was studied the addition method of borohydride (drop by drop addition or rapid addition). The obtained electrocatalysts were characterized by energy dispersive X ray spectroscopy (EDX), thermogravimetric analysis (TGA), X ray diffraction (XRD), transmission electron microscope (TEM) and cyclic voltammetry. The ethanol electro-oxidation was studied by cyclic voltammetry and chronoamperometry using the thin porous coating technique. The electrocatalysts were tested in real conditions of operation by unit cell tests. The stability of PtRuBi/C electrocatalysts was evaluated by cyclic voltammetry, chronoamperometry using the ultra-thin porous coating technique and ring-disk electrode. The PtRuBi/C electro catalyst apparently presented a good performance for ethanol electro-oxidation but experimental evidences showed accentuated bismuth dissolution. (author)

  18. Preparation of cathode materials for solid oxide solid fuel (SOFC) using gelatin; Preparacao de materiais catodicos para celulas a combustivel de oxido solido (SOFC) atraves do uso de gelatina

    Energy Technology Data Exchange (ETDEWEB)

    Silva, R.M.; Aquino, F. de M.; Macedo, D.A. de; Sa, A.M.; Galvao, G.O., E-mail: rinaldo_mendesa@hotmail.com [Universidade Federal da Paraiba (UFPB), Joao Pessoa, PB (Brazil)

    2016-07-01

    Fuel cells are electrochemical devices that convert chemical energy into electrical energy. These devices are basically divided into interconnectors, electrolyte, anode, and cathode. Recently, studies of improvements in microstructural and morphological properties of calcium cobaltate (Ca{sub 3}Co{sub 4}O{sub 9}, C349) has been made regarding its potential use as SOFC cathode for intermediate temperature. Gelatin has proven to be effective as a polymerizing agent in the synthesis of nanocrystalline materials. This work reports the synthesis and characterization of the C349 cathode using commercial gelatin. The structural properties of the material were determined by X-ray diffraction (XRD). Morphological characterization was performed by scanning electron microscopy (SEM). The results showed the formation of the crystalline phase at 900 °C, indicating the effectiveness of the gelatin in the preparation of cathodes for SOFC. (author)

  19. Sealing materials for solid oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Larsen, P.H.

    1999-02-01

    A major obstacle in the achievement of high electrical efficiency for planar solid oxide fuel cell stacks (SOFC) is the need for long term stable seals at the operational temperature between 850 and 1000 deg. C. In the present work the formation and properties of sealing materials for SOFC stacks that fulfil the necessary requirements were investigated. The work comprises analysis of sealing material properties independently, in simple systems as well as tests in real SOFC stacks. The analysed sealing materials were based on pure glasses or glass-ceramic composites having B{sub 2}O{sub 3}, P{sub 2}O{sub 5} or siO{sub 2} as glass formers, and the following four glass systems were investigated: MgO/caO/Cr{sub 2}O{sub 3}-Al{sub 2}O{sub 3}B{sub 2}O{sub 3}-P{sub 2}O{sub 5}, MgO-Al{sub 2}O{sub 3}-P{sub 2}O{sub 5}, MgO-Al{sub 2}O{sub 3}-P{sub 2}O{sub 5}-SiO{sub 2} and BaO/Na{sub 2}O-Al{sub 2}O{sub 3}-SiO{sub 2}. (au) 32 tabs., 106 ills., 107 refs.

  20. Preparation of nuclear fuel spheres by flotation-internal gelation

    Science.gov (United States)

    Haas, P.A.; Fowler, V.L.; Lloyd, M.H.

    1984-12-21

    A simplified internal gelation process is claimed for the preparation of gel spheres of nuclear fuels. The process utilizes perchloroethylene as a gelation medium. Gelation is accomplished by directing droplets of a nuclear fuel broth into a moving volume of hot perchloroethylene (about 85/sup 0/C) in a trough. Gelation takes place as the droplets float on the surface of the perchloroethylene and the resultant gel spheres are carried directly into an ager column which is attached to the trough. The aged spheres are disengaged from the perchloroethylene on a moving screen and are deposited in an aqueous wash column. 3 figs.

  1. As-Deposited (La1-xSrx)(Ga1-y-zMgyCoz)O3-(x+y+z)/2 Crystallized Thin Films Prepared by Pulsed Laser Deposition for Application to Solid Oxide Fuel Cell Electrolyte

    Science.gov (United States)

    Mitsugi, Fumiaki; Kanazawa, Seiji; Ohkubo, Toshikazu; Nomoto, Yukiharu; Ishihara, Tatsumi; Takita, Yusaku

    2004-01-01

    Doped lanthanum gallate (La1-xSrx)(Ga1-y-zMgyCoz)O3-(x+y+z)/2 (LSGMCO) perovskite oxide films were deposited on a quartz glass, LaAlO3 single-crystal substrate and porous anode electrode of a solid oxide fuel cell (SOFC) by pulsed laser deposition. It was necessary to increase the substrate temperature up to 800°C for a crystallization of the LSGMCO films. The film deposited on the LaAlO3 single-crystal substrate grew along the c-axis. The as-deposited LSGMCO thick film fabricated on the porous substrate at 800°C and at an oxygen pressure of 20Pa was formed from polycrystal columns and showed a high conductivity of 0.7S/cm at a measurement temperature of 800°C. The activation energies were 0.72 eV at 600-800°C and 1.05 eV at 400-600°C.

  2. Structural analysis of nickel doped cerium oxide catalysts for fuel reforming in solid oxide fuel cells

    Science.gov (United States)

    Cavendish, Rio

    As world energy demands increase, research into more efficient energy production methods has become imperative. Heterogeneous catalysis and nanoscience are used to promote chemical transformations important for energy production. These concepts are important in solid oxide fuel cells (SOFCs) which have attracted attention because of their potential to provide an efficient and environmentally favorable power generation system. The SOFC is also fuel-flexible with the ability to run directly on many fuels other than hydrogen. Internal fuel reforming directly in the anode of the SOFC would greatly reduce the cost and complexity of the device. Methane is the simplest hydrocarbon and a main component in natural gas, making it useful when testing catalysts on the laboratory scale. Nickel (Ni) and gadolinium (Gd) doped ceria (CeO 2) catalysts for potential use in the SOFC anode were synthesized with a spray drying method and tested for catalytic performance using partial oxidation of methane and steam reforming. The relationships between catalytic performance and structure were then investigated using X-ray diffraction, transmission electron microscopy, and environmental transmission electron microscopy. The possibility of solid solutions, segregated phases, and surface layers of Ni were explored. Results for a 10 at.% Ni in CeO2 catalyst reveal a poor catalytic behavior while a 20 at.% Ni in CeO2 catalyst is shown to have superior activity. The inclusion of both 10 at.% Gd and 10 at.% Ni in CeO2 enhances the catalytic performance. Analysis of the presence of Ni in all 3 samples reveals Ni heterogeneity and little evidence for extensive solid solution doping. Ni is found in small domains throughout CeO2 particles. In the 20 at.% Ni sample a segregated, catalytically active NiO phase is observed. Overall, it is found that significant interaction between Ni and CeO2 occurs that could affect the synthesis and functionality of the SOFC anode.

  3. Desulfurization of Diesel Fuel by Oxidation and Solvent Extraction

    Directory of Open Access Journals (Sweden)

    Wadood Taher Mohammed

    2015-02-01

    Full Text Available This research presents a study in ultra-desulfurization of diesel fuel produced from conventional hydro desulfurization process, using oxidation and solvent extraction techniques. Dibenzothiophene (DBT was the organosulfur compound that had been detected in sulfur removal. The oxidation process used hydrogen peroxide as an oxidant and acetic acid as homogeneous catalyst . The solvent extraction process used acetonitrile (ACN and N-methyl – 2 - pyrrolidone (NMP as extractants . Also the effect of five parameters (stirring speed :150 , 250 , 350 , and 450 rpm, temperature (30 , 40 , 45 , and 50 oC, oxidant/simulated diesel fuel ratio (0.5 , 0.75 , 1 , and 1.5 , catalyst/oxidant ratio(0.125,0.25,0.5,and0.75 , and solvent/simulated diesel fuel ratio(0.5,0.6,0.75,and1 were examined as well as solvent type. The results exhibit that the highest removal of sulfur is 98.5% using NMP solvent while it is 95.8% for ACN solvent. The set of conditions that show the highest sulfur removal is: stirring speed of 350 rpm , temperature 50oC , oxidant/simulated diesel fuel ratio 1 , catalyst/oxidant ratio 0.5 , solvent/simulated diesel fuel ratio 1. These best conditions were applied upon real diesel fuel (produced from Al-Dora refinerywith 1000 ppm sulfur content . It was found that sulfur removal was 64.4% using ACN solvent and 75% using NMP solvent.

  4. Electrochemical preparation of new uranium oxide phases

    International Nuclear Information System (INIS)

    Smolenskij, V.V.; Lyalyushkin, N.V.; Bove, A.L.; Komarov, V.K.; Kapshukov, I.I.

    1992-01-01

    Behaviour of uranium ions in oxidation states 3+ and 4+ in molten chlorides of alkali metals in the temperature range of 700-900 degC in the atmosphere of an inert gas was studied by the method of cyclic voltametry. It is shown that as a result of introduction of crystal uranium dioxide into the salt melt formation of uranium oxide ions of the composition UO + and UO 2+ occurs, the ions participating in electrode reactions and bringing about formation of the following uranium oxides on the cathode: UO and, presumably, U 3 O 4 . Oxides UO and U 3 O 4 are thermodynamically unstable at low temperatures and decompose into uranium oxide of the composition UO 2-x , where x varies from 0 to 0.05, and metal uranium

  5. Novel synthesis strategy for the preparation of individual phytosterol oxides.

    Science.gov (United States)

    Gao, Junlan; Yue, Qiulin; Ji, Yishun; Cheng, Beijiu; Zhang, Xin

    2013-01-30

    Sterols (cholesterol and phytosterols) are important structural components of cell membranes and major constituents of lipid metabolism. Research on their oxides, such as the factors affecting oxidation, oxides' structures, and qualitative and quantitative analysis, aroused more attention in this decade. However, the biological roles of individual phytosterol oxides are still unclear because no commercial individual phytosterol oxide standards are available. Different from the traditional chemical synthesis, in the present study, chemical synthesis from a starting phytosterol mixture followed with a semipreparative HPLC separation produced individual oxides. TLC and analytical HPLC were used here to not only monitor the reaction process but also specifically analyze the synthetic intermediates and oxides. The chromatographic results exhibited strict rules and similar characteristics. Finally, for the first time, four individual phytosterol oxides were successfully separated and collected by a semipreparative HPLC system, thus providing a novel strategy for the preparation of individual phytosterol oxides.

  6. Oxide thickness measurement for monitoring fuel performance at high burnup

    International Nuclear Information System (INIS)

    Jaeger, M.A.; Van Swam, L.F.P.; Brueck-Neufeld, K.

    1991-01-01

    For on-site monitoring of the fuel performance at high burnup, Advanced Nuclear Fuels uses the linear scan eddy current method to determine the oxide thickness of irradiated Zircaloy fuel cans. Direct digital data acquisition methods are employed to collect the data on magnetic storage media. This field-proven methodology allows oxide thickness measurements and rapid interpretation of the data during the reactor outages and makes it possible to immediately reinsert the assemblies for the next operating cycle. The accuracy of the poolside measurements and data acquisition/interpretation techniques have been verified through hot cell metallographic measurements of rods previously measured in the fuel pool. The accumulated data provide a valuable database against which oxide growth models have been benchmarked and allow for effective monitoring of fuel performance. (orig.) [de

  7. performance calculations of gadolinium oxide and boron nitride coated fuel

    International Nuclear Information System (INIS)

    Tanker, E.; Uslu, I.; Disbudak, H.; Guenduez, G.

    1997-01-01

    A comparative study was performed on the behaviour of natural uranium dioxide-gadolinium oxide mixture fuel and boron nitride coated low enriched fuel in a pressurized water reactor. A fuel element containing one burnable poison fuel pins was modeled with the computer code WIMS, and burn-up dependent critically, fissile isotope inventory and two dimensional power distribution were obtained. Calculations were performed for burnable poison fuels containing 5% and 10% gadolinium oxide and for those coated with 1μ,5μ and 10μ of boron nitride. Boron nitride coating was found superior to gadolinium oxide on account of its smoother criticality curve, lower power peaks and insignificant change in fissile isotope content

  8. Glass/Ceramic Composites for Sealing Solid Oxide Fuel Cells

    Science.gov (United States)

    Bansal, Narottam P.; Choi, Sung R.

    2007-01-01

    A family of glass/ceramic composite materials has been investigated for use as sealants in planar solid oxide fuel cells. These materials are modified versions of a barium calcium aluminosilicate glass developed previously for the same purpose. The composition of the glass in mole percentages is 35BaO + 15CaO + 5Al2O3 + 10B2O3 + 35SiO2. The glass seal was found to be susceptible to cracking during thermal cycling of the fuel cells. The goal in formulating the glass/ ceramic composite materials was to (1) retain the physical and chemical advantages that led to the prior selection of the barium calcium aluminosilicate glass as the sealant while (2) increasing strength and fracture toughness so as to reduce the tendency toward cracking. Each of the composite formulations consists of the glass plus either of two ceramic reinforcements in a proportion between 0 and 30 mole percent. One of the ceramic reinforcements consists of alumina platelets; the other one consists of particles of yttria-stabilized zirconia wherein the yttria content is 3 mole percent (3YSZ). In preparation for experiments, panels of the glass/ceramic composites were hot-pressed and machined into test bars.

  9. Redox Stable Anodes for Solid Oxide Fuel Cells

    Directory of Open Access Journals (Sweden)

    Guoliang eXiao

    2014-06-01

    Full Text Available Solid oxide fuel cells (SOFCs can convert chemical energy from the fuel directly to electrical energy with high efficiency and fuel flexibility. Ni-based cermets have been the most widely adopted anode for SOFCs. However, the conventional Ni-based anode has low tolerance to sulfur-contamination, is vulnerable to deactivation by carbon build-up (coking from direct oxidation of hydrocarbon fuels, and suffers volume instability upon redox cycling. Among these limitations, the redox instability of the anode is particularly important and has been intensively studied since the SOFC anode may experience redox cycling during fuel cell operations even with the ideal pure hydrogen as the fuel. This review aims to highlight recent progresses on improving redox stability of the conventional Ni-based anode through microstructure optimization and exploration of alternative ceramic-based anode materials.

  10. Review of oxidation rates of DOE spent nuclear fuel : Part 1 : nuclear fuel

    International Nuclear Information System (INIS)

    Hilton, B.A.

    2000-01-01

    The long-term performance of Department of Energy (DOE) spent nuclear fuel (SNF) in a mined geologic disposal system depends highly on fuel oxidation and subsequent radionuclide release. The oxidation rates of nuclear fuels are reviewed in this two-volume report to provide a baseline for comparison with release rate data and technical rationale for predicting general corrosion behavior of DOE SNF. The oxidation rates of nuclear fuels in the DOE SNF inventory were organized according to metallic, Part 1, and non-metallic, Part 2, spent nuclear fuels. This Part 1 of the report reviews the oxidation behavior of three fuel types prototypic of metallic fuel in the DOE SNF inventory: uranium metal, uranium alloys and aluminum-based dispersion fuels. The oxidation rates of these fuels were evaluated in oxygen, water vapor, and water. The water data were limited to pure water corrosion as this represents baseline corrosion kinetics. Since the oxidation processes and kinetics discussed in this report are limited to pure water, they are not directly applicable to corrosion rates of SNF in water chemistry that is significantly different (such as may occur in the repository). Linear kinetics adequately described the oxidation rates of metallic fuels in long-term corrosion. Temperature dependent oxidation rates were determined by linear regression analysis of the literature data. As expected the reaction rates of metallic fuels dramatically increase with temperature. The uranium metal and metal alloys have stronger temperature dependence than the aluminum dispersion fuels. The uranium metal/water reaction exhibited the highest oxidation rate of the metallic fuel types and environments that were reviewed. Consequently, the corrosion properties of all DOE SNF may be conservatively modeled as uranium metal, which is representative of spent N-Reactor fuel. The reaction rate in anoxic, saturated water vapor was essentially the same as the water reaction rate. The long-term intrinsic

  11. Process for preparing sintered uranium dioxide nuclear fuel

    International Nuclear Information System (INIS)

    Carter, R.E.

    1975-01-01

    Uranium dioxide is prepared for use as fuel in nuclear reactors by sintering it to the desired density at a temperature less than 1300 0 C in a chemically controlled gas atmosphere comprised of at least two gases which in equilibrium provide an oxygen partial pressure sufficient to maintain the uranium dioxide composition at an oxygen/uranium ratio of at least 2.005 at the sintering temperature. 7 Claims, No Drawings

  12. Fission product release by fuel oxidation after water ingress

    International Nuclear Information System (INIS)

    Schreiber.

    1990-01-01

    On the basis of data obtained by a literature search, a computer code has been established for the calculation of the degree of oxidation of the fuel in the damaged fuel particles, and hence of the fission product release as a function of the time period of steam ingress. (orig.) [de

  13. A strategic approach for preparation of oxide nanomaterials

    Indian Academy of Sciences (India)

    A microwave assisted solvothermal method is described for rapid preparation of nano-oxides. This method is based on exploiting differential dielectric constants to induce preferred heating and decomposition of the oxide precursors in the presence of suitable capping agents. This strategic approach has been used to ...

  14. Synthesis and characterization of zinc oxide thin films prepared by ...

    African Journals Online (AJOL)

    Zinc oxide thin films were prepared with ammonia/ammonium chloride buffer as the reaction moderating agent in the chemical bath deposition technique. An observable color change during the reaction due to variations in the reactants concentration indicated the existence of the cupric (CuO) and cuprous (Cu2O) oxides ...

  15. Initiation of depleted uranium oxide and spent fuel testing for the spent fuel sabotage aerosol ratio program

    Energy Technology Data Exchange (ETDEWEB)

    Molecke, M.A.; Gregson, M.W.; Sorenson, K.B. [Sandia National Labs. (United States); Billone, M.C.; Tsai, H. [Argonne National Lab. (United States); Koch, W.; Nolte, O. [Fraunhofer Inst. fuer Toxikologie und Experimentelle Medizin (Germany); Pretzsch, G.; Lange, F. [Gesellschaft fuer Anlagen- und Reaktorsicherheit (Germany); Autrusson, B.; Loiseau, O. [Inst. de Radioprotection et de Surete Nucleaire (France); Thompson, N.S.; Hibbs, R.S. [U.S. Dept. of Energy (United States); Young, F.I.; Mo, T. [U.S. Nuclear Regulatory Commission (United States)

    2004-07-01

    We provide a detailed overview of an ongoing, multinational test program that is developing aerosol data for some spent fuel sabotage scenarios on spent fuel transport and storage casks. Experiments are being performed to quantify the aerosolized materials plus volatilized fission products generated from actual spent fuel and surrogate material test rods, due to impact by a high energy density device, HEDD. The program participants in the U.S. plus Germany, France, and the U.K., part of the international Working Group for Sabotage Concerns of Transport and Storage Casks, WGSTSC have strongly supported and coordinated this research program. Sandia National Laboratories, SNL, has the lead role for conducting this research program; test program support is provided by both the U.S. Department of Energy and Nuclear Regulatory Commission. WGSTSC partners need this research to better understand potential radiological impacts from sabotage of nuclear material shipments and storage casks, and to support subsequent risk assessments, modeling, and preventative measures. We provide a summary of the overall, multi-phase test design and a description of all explosive containment and aerosol collection test components used. We focus on the recently initiated tests on ''surrogate'' spent fuel, unirradiated depleted uranium oxide, and forthcoming actual spent fuel tests. The depleted uranium oxide test rodlets were prepared by the Institut de Radioprotection et de Surete Nucleaire, in France. These surrogate test rodlets closely match the diameter of the test rodlets of actual spent fuel from the H.B. Robinson reactor (high burnup PWR fuel) and the Surry reactor (lower, medium burnup PWR fuel), generated from U.S. reactors. The characterization of the spent fuels and fabrication into short, pressurized rodlets has been performed by Argonne National Laboratory, for testing at SNL. The ratio of the aerosol and respirable particles released from HEDD-impacted spent

  16. Introduction of mixed oxide fuel elements in the belgian cores

    International Nuclear Information System (INIS)

    Charlier, A.F.; Hollasky, N.A.

    1994-01-01

    The important amount of plutonium recovered from the reprocessing of spent fuel on the one hand, the national and international experience of the use of mixed oxide UO 2 -PuO 2 fuel in power reactors on the other hand, have led Belgian utilities to decide the introduction of Mixed-Oxide fuel in Doel unit 3 and Tihange unit 2 cores. The 'MOX' project has shown that it was possible without reducing safety or requiring modifications of the plant equipment. It has been approved by the Belgian 'Nuclear Safety Commission'. (authors). 1 tab., 2 figs

  17. Conversion of hydrocarbons in solid oxide fuel cells

    DEFF Research Database (Denmark)

    Mogensen, Mogens Bjerg; Kammer Hansen, K.

    2003-01-01

    Recently, a number of papers about direct oxidation of methane and hydrocarbon in solid oxide fuel cells (SOFC) at relatively low temperatures (about 700degreesC) have been published. Even though the conversion of almost dry CH4 at 1000degreesC on ceramic anodes was demonstrated more than 10 years...

  18. Irradiation behavior of uranium oxide - Aluminum dispersion fuel

    International Nuclear Information System (INIS)

    Hofman, Gerard L.; Rest, Jeffrey; Snelgrove, James L.

    1996-01-01

    An oxide version of the DART code has been generated in order to assess the irradiation behavior of UO 2 -Al dispersion fuel. The aluminum-fuel interaction models were developed based on U 3 O 8 -Al irradiation data. Deformation of the fuel element occurs due to fuel particle swelling driven by both solid and gaseous fission products and as a consequence of the interaction between the fuel particles and the aluminum matrix. The calculations show that, with the assumption that the correlations derived from U 3 O 8 are valid for UO 2 , the LEU UO 2 -Al with a 42% fuel volume loading (4 g U/cm 3 ) irradiated at fuel temperatures greater than 413 K should undergo breakaway swelling at core burnups greater than about 1.12 x 10 27 fissions m -3 (∼63% 235 U burnup). (author)

  19. Irradiation behavior of uranium oxide-aluminum dispersion fuel

    International Nuclear Information System (INIS)

    Hofman, G.L.; Rest, J.; Snelgrove, J.L.

    1996-01-01

    An oxide version of the DART code has been generated in order to assess the irradiation behavior of UO 2 -Al dispersion fuel. The aluminum-fuel interaction models were developed based on U 3 O 8 -Al irradiation data. Deformation of the fuel element occurs due to fuel particle swelling driven by both solid and gaseous fission products, as well as a consequence of the interaction between the fuel particles and the aluminum matrix. The calculations show, that with the assumption that the correlations derived from U 3 O 8 are valid for UO 2 , the LEU UO 2 -Al with a 42% fuel volume loading (4 gm/cc) irradiated at fuel temperatures greater than 413 K should undergo breakaway swelling at core burnups greater than about 1.12 x 10 27 fissions m -3 (∼ 63% 235 U burnup)

  20. Transmutation of minor actinide using BWR fueled mixed oxide

    International Nuclear Information System (INIS)

    Susilo, Jati

    2000-01-01

    Nuclear spent fuel recycle has a strategic importance in the aspect of nuclear fuel economy and prevention of its spread-out. One among other application of recycle is to produce mixed oxide fuel (Mo) namely mixed Plutonium and uranium oxide. As for decreasing the burden of nuclear high level waste (HLW) treatment, transmutation of minor actinide (MA) that has very long half life will be carried out by conversion technique in nuclear reactor. The purpose of this study was to know influence of transition fuel cell regarding the percent weight of transmutation MA in the BWR fueled MOX. Calculation of cell BWR was used SRAC computer code, with assume that the reactor in equilibrium. The percent weight of transmutation MA to be optimum by increasing the discharge burn-up of nuclear fuel, raising ratio of moderator to fuel volume (Vm/Vf), and loading MA with percent weight about 3%-6% and also reducing amount of percent weight Pu in MOX fuel. For mixed fuel standard reactor, reactivity value were obtained between about -50pcm ∼ -230pcm for void coefficient and -1.8pcm ∼ -2.6pcm for fuel temperature coefficient

  1. Assessment of bio-fuel options for solid oxide fuel cell applications

    Science.gov (United States)

    Lin, Jiefeng

    Rising concerns of inadequate petroleum supply, volatile crude oil price, and adverse environmental impacts from using fossil fuels have spurred the United States to promote bio-fuel domestic production and develop advanced energy systems such as fuel cells. The present dissertation analyzed the bio-fuel applications in a solid oxide fuel cell-based auxiliary power unit from environmental, economic, and technological perspectives. Life cycle assessment integrated with thermodynamics was applied to evaluate the environmental impacts (e.g., greenhouse gas emission, fossil energy consumption) of producing bio-fuels from waste biomass. Landfill gas from municipal solid wastes and biodiesel from waste cooking oil are both suggested as the promising bio-fuel options. A nonlinear optimization model was developed with a multi-objective optimization technique to analyze the economic aspect of biodiesel-ethanol-diesel ternary blends used in transportation sectors and capture the dynamic variables affecting bio-fuel productions and applications (e.g., market disturbances, bio-fuel tax credit, policy changes, fuel specification, and technological innovation). A single-tube catalytic reformer with rhodium/ceria-zirconia catalyst was used for autothermal reformation of various heavy hydrocarbon fuels (e.g., diesel, biodiesel, biodiesel-diesel, and biodiesel-ethanol-diesel) to produce a hydrogen-rich stream reformates suitable for use in solid oxide fuel cell systems. A customized mixing chamber was designed and integrated with the reformer to overcome the technical challenges of heavy hydrocarbon reformation. A thermodynamic analysis, based on total Gibbs free energy minimization, was implemented to optimize the operating environment for the reformations of various fuels. This was complimented by experimental investigations of fuel autothermal reformation. 25% biodiesel blended with 10% ethanol and 65% diesel was determined to be viable fuel for use on a truck travelling with

  2. Oxidative dissolution of ADOPT compared to standard UO2 fuel

    International Nuclear Information System (INIS)

    Nilsson, Kristina; Roth, Olivia; Jonsson, Mats

    2017-01-01

    In this work we have studied oxidative dissolution of pure UO 2 and ADOPT (UO 2 doped with Al and Cr) pellets using H 2 O 2 and gammaradiolysis to induce the process. There is a small but significant difference in the oxidative dissolution rate of UO 2 and ADOPT pellets, respectively. However, the difference in oxidative dissolution yield is insignificant. Leaching experiments were also performed on in-reactor irradiated ADOPT and UO 2 pellets under oxidizing conditions. The results indicate that the U(VI) release is slightly slower from the ADOPT pellet compared to the UO 2. This could be attributed to differences in exposed surface area. However, fission products with low UO 2 solubility display a higher relative release from ADOPT fuel compared to standard UO 2 -fuel. This is attributed to a lower matrix solubility imposed by the dopants in ADOPT fuel. The release of Cs is higher from UO 2 which is attributed to the larger grain size of ADOPT. - Highlights: •Oxidative dissolution of ADOPT fuel is compared to standard UO 2 fuel. •Only marginal differences are observed. •The main difference observed is in the relative release rate of fission products. •Differences are claimed to be attributed to a lower matrix solubility imposed by the dopants in ADOPT fuel.

  3. Process for recovery of plutonium from fabrication residues of mixed fuels consisting of uranium oxide and plutonium oxide

    International Nuclear Information System (INIS)

    Heremanns, R.H.; Vandersteene, J.J.

    1983-01-01

    The invention concerns a process for recovery of plutonium from fabrication residues of mixed fuels consisting of uranium oxide and plutonium oxide in the form of PuO 2 . Mixed fuels consisting of uranium oxide and plutonium oxide are being used more and more. The plants which prepare these mixed fuels have around 5% of the total mass of fuels as fabrication residue, either as waste or scrap. In view of the high cost of plutonium, it has been attempted to recover this plutonium from the fabrication residues by a process having a purchase price lower than the price of plutonium. The problem is essentially to separate the plutonium, the uranium and the impurities. The residues are fluorinated, the UF 6 and PuF 6 obtained are separated by selective absorption of the PuF 6 on NaF at a temperature of at least 400 0 C, the complex obtained by this absorption is dissolved in nitric acid solution, the plutonium is precipitated in the form of plutonium oxalate by adding oxalic acid, and the precipitated plutonium oxalate is calcined

  4. Desulfurization of Diesel Fuel by Oxidation and Solvent Extraction

    OpenAIRE

    Wadood Taher Mohammed; Raghad Fareed Kassim Almilly; Sheam Bahjat Abdulkareem Al-Ali

    2015-01-01

    This research presents a study in ultra-desulfurization of diesel fuel produced from conventional hydro desulfurization process, using oxidation and solvent extraction techniques. Dibenzothiophene (DBT) was the organosulfur compound that had been detected in sulfur removal. The oxidation process used hydrogen peroxide as an oxidant and acetic acid as homogeneous catalyst . The solvent extraction process used acetonitrile (ACN) and N-methyl – 2 - pyrrolidone (NMP) as extractants . Also the ef...

  5. Analysis of fuel cladding chemical interaction in mixed oxide fuel pins

    International Nuclear Information System (INIS)

    Weber, J.W.; Dutt, D.S.

    1976-01-01

    An analysis is presented of the observed interaction between mixed oxide 75 wt percent UO 2 --25 wt percent PuO 2 fuel and 316--20 percent CW stainless steel cladding in LMFBR type fuel pins irradiated in EBR-II. A description is given of the test pins and their operating conditions together with, metallographic observations and measurements of the fuel/cladding reaction, and a correlation equation is developed relating depth of cladding attack to temperature and burnup. Some recent data on cladding reaction in fuel pins with low initial O/M in the fuel are given and compared with the correlation equation curves

  6. Universal electrode interface for electrocatalytic oxidation of liquid fuels.

    Science.gov (United States)

    Liao, Hualing; Qiu, Zhipeng; Wan, Qijin; Wang, Zhijie; Liu, Yi; Yang, Nianjun

    2014-10-22

    Electrocatalytic oxidations of liquid fuels from alcohols, carboxylic acids, and aldehydes were realized on a universal electrode interface. Such an interface was fabricated using carbon nanotubes (CNTs) as the catalyst support and palladium nanoparticles (Pd NPs) as the electrocatalysts. The Pd NPs/CNTs nanocomposite was synthesized using the ethylene glycol reduction method. It was characterized using transmission electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction, voltammetry, and impedance. On the Pd NPs/CNTs nanocomposite coated electrode, the oxidations of those liquid fuels occur similarly in two steps: the oxidations of freshly chemisorbed species in the forward (positive-potential) scan and then, in the reverse scan (negative-potential), the oxidations of the incompletely oxidized carbonaceous species formed during the forward scan. The oxidation charges were adopted to study their oxidation mechanisms and oxidation efficiencies. The oxidation efficiency follows the order of aldehyde (formaldehyde) > carboxylic acid (formic acid) > alcohols (ethanol > methanol > glycol > propanol). Such a Pd NPs/CNTs nanocomposite coated electrode is thus promising to be applied as the anode for the facilitation of direct fuel cells.

  7. Behavior of molybdenum in mixed-oxide fuel

    International Nuclear Information System (INIS)

    Giacchetti, G.; Sari, C.

    1976-01-01

    Metallic molybdenum, Mo--Ru--Rh--Pd alloys, barium, zirconium, and tungsten were added to uranium and uranium--plutonium oxides by coprecipitation and mechanical mixture techniques. This material was treated in a thermal gradient similar to that existing in fuel during irradiation to study the behavior of molybdenum in an oxide matrix as a function of the O/(U + Pu) ratio and some added elements. Result of ceramographic and microprobe analysis shows that when the overall O/(U + Pu) ratio is less than 2, molybdenum and Mo--Ru--Rh--Pd alloy inclusions are present in the uranium--plutonium oxide matrix. If the O/(U + Pu) ratio is greater than 2, molybdenum oxidizes to MoO 2 , which is gaseous at a temperature approximately 1000 0 C. Molybdenum oxide vapor reacts with barium oxide and forms a compound that exists as a liquid phase in the columnar grain region. Molybdenum oxide also reacts with tungsten oxide (tungsten is often present as an impurity in the fuel) and forms a compound that contains approximately 40 wt percent of actinide metals. The apparent solubility of molybdenum in uranium and uranium--plutonium oxides, determined by electron microprobe, was found to be less than 250 ppM both for hypo- and hyperstoichiometric fuels

  8. EBSD and TEM Characterization of High Burn-up Mixed Oxide Fuel

    International Nuclear Information System (INIS)

    Teague, Melissa C; Gorman, Brian P.; Miller, Brandon D; King, Jeffrey

    2014-01-01

    Understanding and studying the irradiation behavior of high burn-up oxide fuel is critical to licensing of future fast breeder reactors. Advancements in experimental techniques and equipment are allowing for new insights into previously irradiated samples. In this work dual column focused ion beam (FIB)/scanning electron microscope (SEM) was utilized to prepared transmission electron microscope samples from mixed oxide fuel with a burn-up of 6.7% FIMA. Utilizing the FIB/SEM for preparation resulted in samples with a dose rate of <0.5 mRem/h compared to approximately 1.1 R/h for a traditionally prepared TEM sample. The TEM analysis showed that the sample taken from the cooler rim region of the fuel pellet had approximately 2.5x higher dislocation density than that of the sample taken from the mid-radius due to the lower irradiation temperature of the rim. The dual column FIB/SEM was additionally used to prepared and serially slice approximately 25 um cubes. High quality electron back scatter diffraction (EBSD) were collected from the face at each step, showing, for the first time, the ability to obtain EBSD data from high activity irradiated fuel

  9. Emission of nitrous oxide during combustion of organic fuels

    Energy Technology Data Exchange (ETDEWEB)

    Kotler, V.R.; Gol' dberg, A.S.

    1990-11-01

    Analyzes formation of nitrogen oxides during combustion of coal, natural gas and mazout: chemical reactions that lead to formation of nitrous oxide during coal combustion, reaction kinetics and reaction yields, factors that influence emission of nitrogen oxides from a furnace, factors that influence formation of nitrous oxide (temperature effects, air excess ratio, coal burnout degree, etc.), effects of fuel type and its chemical composition, effects of flue gas desulfurization and denitrification methods on nitrous oxide yield. Analyses show that yield of nitrous oxide is low and does not exceed 5 cm{sup 3}/m{sup 3} flue gas (0.0005%). However chemical reactions of nitrogen oxides, sulfur dioxide and water vapor in the atmosphere are said to form additional quantities of nitrous oxide which negatively influence the ozone layer. 4 refs.

  10. Effectiveness of paper-structured catalyst for the operation of biodiesel-fueled solid oxide fuel cell

    Science.gov (United States)

    Quang-Tuyen, Tran; Kaida, Taku; Sakamoto, Mio; Sasaki, Kazunari; Shiratori, Yusuke

    2015-06-01

    Mg/Al-hydrotalcite (HDT)-dispersed paper-structured catalyst (PSC) was prepared by a simple paper-making process. The PSC exhibited excellent catalytic activity for the steam reforming of model biodiesel fuel (BDF), pure oleic acid methyl ester (oleic-FAME, C19H36O2) which is a mono-unsaturated component of practical BDFs. The PSC exhibited fuel conversion comparable to a pelletized catalyst material, here, conventional Ni-zirconia cermet anode for solid oxide fuel cell (SOFC) with less than one-hundredth Ni weight. Performance of electrolyte-supported cell connected with the PSC was evaluated in the feed of oleic-FAME, and stable operation was achieved. After 60 h test, coking was not observed in both SOFC anode and PSC.

  11. Oxidation behavior of fuel cladding tube in spent fuel pool accident condition

    International Nuclear Information System (INIS)

    Nemoto, Yoshiyuki; Kaji, Yoshiyuki; Ogawa, Chihiro; Nakashima, Kazuo; Tojo, Masayuki

    2017-01-01

    In spent fuel pool (SFP) under loss-of-cooling or loss-of-coolant severe accident condition, the spent fuels will be exposed to air and heated by their own residual decay heat. Integrity of fuel cladding is crucial for SFP safety therefore study on cladding oxidation in air at high temperature is important. Zircaloy-2 (Zry2) and zircaloy-4 (Zry4) were applied for thermogravimetric analyses (TGA) in different temperatures in air at different flow rates to evaluate oxidation behavior. Oxidation rate increased with testing temperature. In a range of flow rate of air which is predictable in spent fuel lack during a hypothetical SFP accident, influence of flow rate was not clearly observed below 950degC for the Zry2, or below 1050degC for Zry4. In higher temperature, oxidation rate was higher in high rate condition, and this trend was seen clearer when temperature increased. Oxide layers were carefully examined after the TGA analyses and compared with mass gain data to investigate detail of oxidation process in air. It was revealed that the mass gain data in pre-breakaway regime reflects growth of dense oxide film on specimen surface, meanwhile in post-breakaway regime, it reflects growth of porous oxide layer beneath fracture of the dense oxide film. (author)

  12. Advances in direct oxidation methanol fuel cells

    Science.gov (United States)

    Surampudi, S.; Narayanan, S. R.; Vamos, E.; Frank, H.; Halpert, G.; Laconti, Anthony B.; Kosek, J.; Prakash, G. K. Surya; Olah, G. A.

    1993-01-01

    Fuel cells that can operate directly on fuels such as methanol are attractive for low to medium power applications in view of their low weight and volume relative to other power sources. A liquid feed direct methanol fuel cell has been developed based on a proton exchange membrane electrolyte and Pt/Ru and Pt catalyzed fuel and air/O2 electrodes, respectively. The cell has been shown to deliver significant power outputs at temperatures of 60 to 90 C. The cell voltage is near 0.5 V at 300 mA/cm(exp 2) current density and an operating temperature of 90 C. A deterrent to performance appears to be methanol crossover through the membrane to the oxygen electrode. Further improvements in performance appear possible by minimizing the methanol crossover rate.

  13. Breaking up of pure and simulated 'burnt' mixed oxide fuel by chemical interaction with oxidized sodium

    International Nuclear Information System (INIS)

    Besnard, R.; Chaudat, J.P.

    1983-01-01

    A large experimental program have permitted to investigate the behaviour of mixed oxide fuel coming in contact with hot oxidized sodium. The kinetic of the reaction, the size and the chemical nature of the particules after interaction have been studied. The main part of experiments have been performed using mixed oxide fuel non irradiated at first and with simulated fission products afterwards. Complementary informations have been obtained with UO 2 fuel pellets. After description of the experimental devices, the results are discussed and the importance of the main parameters, like temperature and fission products effect, are pointed out. (orig.)

  14. Preparation and utilization of metal oxide fine powder

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Joon Soo; Jang, Hee Dong; Lim, Young Woong; Kim, Sung Don; Lee, Hi Sun; Lee, Hoo In; Kim, Chul Joo; Shim, Gun Joo; Jang, Dae Kyu [Korea Inst. of Geology Mining and Materials, Taejon (Korea, Republic of)

    1995-12-01

    Metal oxide fine powders finds many applications in industry as new materials. It is very much necessary for the development of such powders to improve the domestic industry. The purpose of present research is to develop a process for the preparation and utilization of metal oxide fine powder. This project is consisted of two main subjects. (1) Production of ultrafine metal oxide powder: Ultrafine metal oxide powder is defined as a metal oxide powder of less than 100 nanometer in particle size. Experiments for the control of particle size and distributions in the various reaction system and compared with results of (2 nd year research). Various reaction systems were adopted for the development of feasible process. Ultrafine particles could be prepared even higher concentration of TiCl{sub 4} and lower gas flowrate compared to TiCl{sub 4}-O{sub 2} system in the TiCl{sub 4}-Air-H{sub 2}O system. Ultrafine Al{sub 2}O{sub 3} powders also prepared with the change of concentration and gas flowrate. Experiments on the treatment of surface characteristics of ultrafine TiO{sub 2} powders were investigated using esterification and surface treating agents. A mathematical model that can predict the particle size and distribution was also developed. (2) Preparation of cerium oxide for high-grade polishing powder: Used cerium polishing powder was recycled for preparation of high grade cerium oxide polishing powder. Also, cerium hydroxide which was generated as by-product in processing of monazite ore was used as another material. These two materials were leached respectively by using acid, and the precipitate was gained in each leached solution by adjusting pH of the solution, and by selective crystallization. These precipitates were calcined to make high grade cerium oxide polishing powder. The effect of several experimental variables were investigated, and the optimum conditions were obtained through the experiments. (author). 81 refs., 49 figs., 27 tabs.

  15. Alternative anode materials for solid oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Goodenough, John B.; Huang, Yun-Hui [Texas Materials Institute, ETC 9.102, 1 University Station, C2200, The University of Texas at Austin, Austin, TX 78712 (United States)

    2007-11-08

    The electrolyte of a solid oxide fuel cell (SOFC) is an O{sup 2-}-ion conductor. The anode must oxidize the fuel with O{sup 2-} ions received from the electrolyte and it must deliver electrons of the fuel chemisorption reaction to a current collector. Cells operating on H{sub 2} and CO generally use a porous Ni/electrolyte cermet that supports a thin, dense electrolyte. Ni acts as both the electronic conductor and the catalyst for splitting the H{sub 2} bond; the oxidation of H{sub 2} to H{sub 2}O occurs at the Ni/electrolyte/H{sub 2} triple-phase boundary (TPB). The CO is oxidized at the oxide component of the cermet, which may be the electrolyte, yttria-stabilized zirconia, or a mixed oxide-ion/electron conductor (MIEC). The MIEC is commonly a Gd-doped ceria. The design and fabrication of these anodes are evaluated. Use of natural gas as the fuel requires another strategy, and MIECs are being explored for this application. The several constraints on these MIECs are outlined, and preliminary results of this on-going investigation are reviewed. (author)

  16. Fuel-cladding chemical interaction in mixed-oxide fuels

    International Nuclear Information System (INIS)

    Lawrence, L.A.; Weber, J.W.; Devary, J.L.

    1978-10-01

    The character and extent of fuel-cladding chemical interaction (FCCI) was established for UO 2 -25 wt% PuO 2 clad with 20% cold worked Type 316 stainless steel irradiated at high cladding temperatures to peak burnups greater than 8 atom %. The data base consists of 153 data sets from fuel pins irradiated in EBR-II with peak burnups to 9.5 atom %, local cladding inner surface temperatures to 725 0 C, and exposure times to 415 equivalent full power days. As-fabricated oxygen-to-metal ratios (O/M) ranged from 1.938 to 1.984 with the bulk of the data in the range 1.96 to 1.98. HEDL P-15 pins provided data at low heat rates, approx. 200 W/cm, and P-23 series pins provided data at higher heat rates, approx. 400 W/cm. A design practice for breeder reactors is to consider an initial reduction of 50 microns in cladding thickness to compensate for possible FCCI. This approach was considered to be a conservative approximation in the absence of a comprehensive design correlation for extent of interaction. This work provides to the designer a statistically based correlation for depth of FCCI which reflects the influences of the major fuel and operating parameters on FCCI

  17. In-pile irradiation of rock-like oxide fuels

    International Nuclear Information System (INIS)

    Nitani, N.; Kuramoto, K.; Yamashita, T.; Nakano, Y.; Akie, H.

    2001-01-01

    Five kinds of ROX fuels were prepared and irradiated using 20% enriched U instead of Pu. Non-destructive and destructive post-irradiation examinations were carried out. FP gas release rates of the particle-dispersed type fuels and homogeneously-blended type fuels were larger than that of the Yttria-stabilized zirconia containing UO 2 single phase fuel. From results of SEM and EPMA, decomposition of the spinel was observed. The decomposition of the spinel is probably avoided by lowering the irradiation temperature, less than 1700 K. The regions suffering the irradiation damage of the particle dispersed type fuels were less than those of the homogeneously-blended type fuels. (author)

  18. In-pile irradiation of rock-like oxide fuels

    Energy Technology Data Exchange (ETDEWEB)

    Nitani, N.; Kuramoto, K.; Yamashita, T.; Nakano, Y.; Akie, H. [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan)

    2001-07-01

    Five kinds of ROX fuels were prepared and irradiated using 20% enriched U instead of Pu. Non-destructive and destructive post-irradiation examinations were carried out. FP gas release rates of the particle-dispersed type fuels and homogeneously-blended type fuels were larger than that of the Yttria-stabilized zirconia containing UO{sub 2} single phase fuel. From results of SEM and EPMA, decomposition of the spinel was observed. The decomposition of the spinel is probably avoided by lowering the irradiation temperature, less than 1700 K. The regions suffering the irradiation damage of the particle dispersed type fuels were less than those of the homogeneously-blended type fuels. (author)

  19. Development of examination technique for oxide layer thickness measurement of irradiated fuel rods

    International Nuclear Information System (INIS)

    Koo, D. S.; Park, S. W.; Kim, J. H.; Seo, H. S.; Min, D. K.; Kim, E. K.; Chun, Y. B.; Bang, K. S.

    1999-06-01

    Technique for oxide layer thickness measurement of irradiated fuel rods was developed to measure oxide layer thickness and study characteristic of fuel rods. Oxide layer thickness of irradiated fuels were measured, analyzed. Outer oxide layer thickness of 3 cycle-irradiated fuel rods were 20 - 30 μm, inner oxide layer thickness 0 - 10 μm and inner oxide layer thickness on cracked cladding about 30 μm. Oxide layer thickness of 4 cycle-irradiated fuel rods were about 2 times as thick as those of 1 cycle-irradiated fuel rods. Oxide layer on lower region of irradiated fuel rods was thin and oxide layer from lower region to upper region indicated gradual increase in thickness. Oxide layer thickness from 2500 to 3000 mm showed maximum and oxide layer thickness from 3000 to top region of irradiated fuel rods showed decreasing trend. Inner oxide layer thicknesses of 4 cycle-irradiated fuel rod were about 8 μm at 750 - 3500 mm from the bottom end of fuel rod. Outer oxide layer thickness were about 8 μm at 750 - 1000 mm from the bottom end of fuel rod. These indicated gradual increase up to upper region from the bottom end of fuel rod. These indicated gradual increase up to upper region from the bottom end of fuel. Oxide layer thickness technique will apply safety evaluation and study of reactor fuels. (author). 6 refs., 14 figs

  20. Case study application of the IAEA safeguards assessment methodology to a mixed oxide fuel fabrication facility

    International Nuclear Information System (INIS)

    Swartz, J.; McDaniel, T.

    1981-01-01

    Science Applications, Inc. has prepared a case study illustrating the application of an assessment methodology to an international system for safeguarding mixed oxide (MOX) fuel fabrication facilities. This study is the second in a series of case studies which support an effort by the International Atomic Energy Agency (IAEA) and an international Consultant Group to develop a methodology for assessing the effectiveness of IAEA safeguards. 3 refs

  1. High temperature transient deformation of mixed oxide fuels

    International Nuclear Information System (INIS)

    Slagle, O.D.

    1986-01-01

    The purpose of this paper is to present recent experimental results on fuel creep under transient conditions at high temperatures. The effect of temperature, stress, heating rate, density and grain size were considered. An empirical formulation is derived for the relationship between strain, stress, temperature and heating rate. This relationship provides a means for incorporating stress relief into the analysis of fuel-cladding interaction during an overpower transient. The effect of sample density and initial grain size is considered by varying the sample parameters. Previously derived steady-state creep relationships for the high temperature creep of mixed oxide fuel were combined with the time dependency of creep found for UO 2 to calculate a transient creep relationship for mixed oxide fuel. These calculated results were found to be in good agreement with the measured high temperature transient creep results

  2. Preparation and Characterization of Tin Oxide Nanowires

    Directory of Open Access Journals (Sweden)

    A. Kabiri

    2013-12-01

    Full Text Available The aim of this research is preparation of SnO2 nanowires by means of Thermal chemical reaction vapor transport deposition (TCRVTD method from SnO powders. The morphology, chemical composition and microstructure properties of the nanowires are characterized using field emission scanning electron microscope (FE-SEM, EDS, and XRD. The XRD diffraction patterns reveal that the SnO2 nanowires have been grown in the form of tetragonal crystal structures with the lattice parameter of a=b=0.440 nm, and c=0.370 nm. The SEM images reveal that SnO2 nanowires have successfully been grown on the Si substrate. The EDS patterns show that only elements of Sn, O and Au are detected. Prior to the VLS process the substrate is coated by a thin layer of Au. The diameter of nanowires is measured to be something between 20-100 nm.

  3. Reirradiation of mixed-oxide fuel pins at increased temperatures

    International Nuclear Information System (INIS)

    Lawrence, L.A.; Weber, E.T.

    1976-05-01

    Mixed-oxide fuel pins from EBR-II irradiations were reirradiated in the General Electric Test Reactor (GETR) at higher temperatures than experienced in EBR-II to study effects of the increased operating temperatures on thermal/mechanical and chemical behavior. The response of a mixed-oxide fuel pin to a power increase after having operated at a lower power for a significant portion of its life-time is an area of performance evaluation where little information currently exists. Results show that the cladding diameter changes resulting from the reirradiation are strongly dependent upon both prior burnup level and the magnitude of the temperature increase. Results provide the initial rough outlines of boundaries within which mixed-oxide fuel pins can or cannot tolerate power increases after substantial prior burnup at lower powers

  4. A novel direct carbon fuel cell by approach of tubular solid oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Renzhu; Zhao, Chunhua; Li, Junliang; Zeng, Fanrong; Wang, Shaorong; Wen, Tinglian; Wen, Zhaoyin [CAS Key Laboratory of Materials for Energy Conversion, Shanghai Inorganic Energy Materials and Power Source Engineering Center, Shanghai Institute of Ceramics, Chinese Academy of Sciences (SICCAS), 1295 Dingxi Road, Shanghai 200050 (China)

    2010-01-15

    A direct carbon fuel cell based on a conventional anode-supported tubular solid oxide fuel cell, which consisted of a NiO-YSZ anode support tube, a NiO-ScSZ anode functional layer, a ScSZ electrolyte film, and a LSM-ScSZ cathode, has been successfully achieved. It used the carbon black as fuel and oxygen as the oxidant, and a preliminary examination of the DCFC has been carried out. The cell generated an acceptable performance with the maximum power densities of 104, 75, and 47 mW cm{sup -2} at 850, 800, and 750 C, respectively. These results demonstrate the feasibility for carbon directly converting to electricity in tubular solid oxide fuel cells. (author)

  5. Preparation and study of properties of dispersed graphene oxide

    Directory of Open Access Journals (Sweden)

    Evgeniya Seliverstova

    2015-09-01

    Full Text Available Ability of graphene oxide to form stable dispersion in organic solvents was studied in this work. As it was shown, sonication of graphene leads to the decreas of the particle size. Stability of prepared graphene dispersions was studied upon measurements of distribution of number of the particles via size and change of optical density of the solutions with time. It was found that graphene oxide forms a more stable dispersion in tetrahydrofuran and dimethylformamide than in chloroform and acetone.

  6. Thulium oxide fuel characterization study: Part 3, Procedures

    International Nuclear Information System (INIS)

    Nelson, C.A.; Anderson, R.W.; Talbot, M.; Bierds, W.

    1970-06-01

    Procedures are presented for the following: Tm 2 O 3 -Yb 2 O 3 pseudo - binary phase diagram tests; compatibility tests; thulium-170 oxide dose rate measurements; preparation of Tm 2 O 3 wafers; SRL thulium and/or ytterbium oxide powder reprocessing for sintering; cold pressing and sintering thulium oxide wafers; preparation of thulium and/or ytterbium oxide powder via precipitation with oxalic acid, ammonium oxalate, urea and methyl oxalate; determination of the total surface area of rare earth oxide powders; determining oxygen in thulia - thulia/ytterbia for the purpose of determining metal-to-oxygen ratios; and determination of the impact resistance to fines generation of sintered rare earth oxide

  7. Improving the performance of solid oxide fuel cell systems

    OpenAIRE

    Halinen, Matias

    2015-01-01

    Solid oxide fuel cell (SOFC) systems can provide power production at a high electrical efficiency and with very low emissions. Furthermore, they retain their high electrical efficiency over a wide range of output power and offer good fuel flexibility, which makes them well suited for a range of applications. Currently SOFC systems are under investigation by researchers as well as being developed by industrial manufacturers. The first commercial SOFC systems have been on the market for some...

  8. Preparation and characterization of antimony barium composite oxide photocatalysts

    Science.gov (United States)

    Han, X. P.; Yao, B. H.; Pan, Q. H.; Pen, C.; Zhang, C. L.

    2018-01-01

    In this paper, two kinds of antimony barium composite oxide photocatalysts have been prepared by two methods and characterized by XRD and SEM. The photocatalytic activity was evaluated by a photocatalytic reactor and an ultraviolet spectrophotometer. The results showed that-BaSb2O5•4H2O, BaSb2O6 two kinds of antimony barium composite oxide photocatalysts were successfully prepared in this experiment and they showed good photocatalytic properties. In addition, BaSb2O6 morphology showed more regular, microstructure and better catalytic performance.

  9. Innovative Seals for Solid Oxide Fuel Cells (SOFC)

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Raj

    2008-06-30

    A functioning SOFC requires different type of seals such as metal-metal, metal-ceramic, and ceramic-ceramic. These seals must function at high temperatures between 600--900{sup o}C and in oxidizing and reducing environments of the fuels and air. Among the different type of seals, the metal-metal seals can be readily fabricated using metal joining, soldering, and brazing techniques. However, the metal-ceramic and ceramic-ceramic seals require significant research and development because the brittle nature of ceramics/glasses can lead to fracture and loss of seal integrity and functionality. Consequently, any seals involving ceramics/glasses require a significant attention and technology development for reliable SOFC operation. This final report is prepared to describe the progress made in the program on the needs, approaches, and performance of high temperature seals for SOFC. In particular, a new concept of self-healing glass seals is pursued for making seals between metal-ceramic material combinations, including some with a significant expansion mismatch.

  10. A method for the preparation of a fuel, by the addition of one or more components to a base fuel

    NARCIS (Netherlands)

    2013-01-01

    The present invention relates to a method for the preparation of a fuel, by the addition of one or more components to a base fuel, wherein the method comprises the following steps: i) providing a base fuel; ii) withdrawing aromatic components from a styrene / propylene ox ide production plant; iii)

  11. The neutronic and fuel cycle performance of interchangeable 3500 MWth metal and oxide fueled LMRs

    International Nuclear Information System (INIS)

    Fujita, E.K.; Wade, D.C.

    1990-01-01

    This study summarizes the neutronic and fuel cycle analysis performed at Argonne National Laboratory for an oxide and a metal fueled 3500 MWth LMR. These reactor designs formed the basis for a joint US/European study of LMR ATWS events. The oxide and metal core designs were developed to meet reactor performance specifications that are constrained by requirements for core loading interchangeability and for a small burnup reactivity swing. Differences in the computed performance parameters of the oxide and metal cores, arising from basic differences in their neutronic characteristics, are identified and discussed. It is shown that metal and oxide cores designed to the same ground rules exhibit many similar performance characteristics; however, they differ substantially in reactivity coefficients, control strategies, and fuel cycle options. 12 refs., 2 figs., 12 tabs

  12. Preparation of Reduced Graphene Oxides as Electrode Materials for Supercapacitors

    KAUST Repository

    Bai, Yaocai

    2012-06-01

    Reduced graphene oxide as outstanding candidate electrode material for supercapacitor has been investigated. This thesis includes two topics. One is that three kinds of reduced graphene oxides were prepared by hydrothermal reduction under different pH conditions. The pH values were found to have great influence on the reduction of graphene oxides. Acidic and neutral media yielded reduced graphene oxides with more oxygen-functional groups, lower specific surface areas but broader pore size distributions than those in basic medium. Variations induced by the pH changes resulted in great differences in the supercapacitor performance. The graphene produced in the basic solution presented mainly electric double layer behavior with specific capacitance of 185 F/g, while the other two showed additional pseudocapacitance behavior with specific capacitance of 225 F/g (acidic) and 230 F/g (neutral), all at a constant current density of 1A/g. The other one is that different reduced graphene oxides were prepared via solution based hydrazine reduction, low temperature thermal reduction, and hydrothermal reduction. The as- prepared samples were then investigated by UV-vis spectroscopy, X-ray diffraction, Raman spectroscopy, and Scanning electron microscope. The supercapacitor performances were also studied and the hydrothermally reduced graphene oxide exhibited the highest specific capacitance.

  13. Methods of preparing deposits containing iron oxides for recycling

    Directory of Open Access Journals (Sweden)

    T. Lis

    2013-04-01

    Full Text Available The metallurgical industry is one of the largest sources of wastes. Some of them, however, owing to their content of metals such as zinc or iron, may become valuable secondary raw materials. In order to achieve that purpose, they require appropriate preparation. This article provides a discussion on the methods of preparation of scrap from steelworks, namely deposits containing iron oxides, enabling their recycling.

  14. Description of a reference mixed oxide fuel fabrication plant (MOFFP)

    International Nuclear Information System (INIS)

    1978-01-01

    In order to evaluate the environment impact, due to the Mixed Oxide Fuel Fabrication Plants, work has been initiated to describe the general design and operating conditions of a reference Mixed Oxide Fuel Fabrication Plant (MOFFP) for the 1990 time frame. The various reference data and basic assumptions for the reference MOFFP plant have been defined after discussion with experts. The data reported in this document are only made available to allow an evaluation of the environmental impact due to a reference MOFFP plant. These data have therefore not to be used as recommandation, standards, regulatory guides or requirements

  15. Process for producing nuclear reactor fuel oxides

    International Nuclear Information System (INIS)

    Goenrich, H.; Druckenbrodt, W.G.

    1981-01-01

    The waste gases of the calcination process furnace in the AVC or AV/PuC process (manufacture of nuclear reactor fuel dioxides) are returned to the furnace in a closed circuit. The NH 3 produced replaces the hydrogen which would otherwise be required for reduction in this process. (orig.) [de

  16. Oxidation Characteristics and Electrical Properties of Doped Mn-Co Spinel Reaction Layer for Solid Oxide Fuel Cell Metal Interconnects

    Directory of Open Access Journals (Sweden)

    Pingyi Guo

    2018-01-01

    Full Text Available To prevent Cr poisoning of the cathode and to retain high conductivity during solid oxide fuel cell (SOFC operation, Cu or La doped Co-Mn coatings on a metallic interconnect is deposited and followed by oxidation at 750 °C. Microstructure and composition of coatings after preparation and oxidation is analyzed by X-ray diffraction (XRD and scanning electron microscopy (SEM. High energy micro arc alloying process, a low cost technique, is used to prepare Cu or La doped Co-Mn coatings with the metallurgical bond. When coatings oxidized at 750 °C in air for 20 h and 100 h, Co3O4 is the main oxide on the surface of Co-38Mn-2La and Co-40Mn coatings, and (Co,Mn3O4 spinel continues to grow with extended oxidation time. The outmost scales of Co-33Mn-17Cu are mainly composed of cubic MnCo2O4 spinel with Mn2O3 after oxidation for 20 h and 100 h. The average thickness of oxide coatings is about 60–70 μm after oxidation for 100 h, except that Co-40Mn oxide coatings are a little thicker. Area-specific resistance of Cu/La doped Co-Mn coatings are lower than that of Co-40Mn coating. (Mn,Co3O4/MnCo2O4 spinel layer is efficient at blocking the outward diffusion of chromium and iron.

  17. Fabrication of oxide dispersion strengthened ferritic clad fuel pins

    International Nuclear Information System (INIS)

    Zirker, L.R.; Bottcher, J.H.; Shikakura, S.; Tsai, C.L.

    1991-01-01

    A resistance butt welding procedure was developed and qualified for joining ferritic fuel pin cladding to end caps. The cladding are INCO MA957 and PNC ODS lots 63DSA and 1DK1, ferritic stainless steels strengthened by oxide dispersion, while the end caps are HT9 a martensitic stainless steel. With adequate parameter control the weld is formed without a residual melt phase and its strength approaches that of the cladding. This welding process required a new design for fuel pin end cap and weld joint. Summaries of the development, characterization, and fabrication processes are given for these fuel pins. 13 refs., 6 figs., 1 tab

  18. Steam and partial oxidation reforming options for hydrogen production from fossil fuels for PEM fuel cells

    Directory of Open Access Journals (Sweden)

    Yousri M.A. Welaya

    2012-06-01

    Full Text Available Proton exchange membrane fuel cell (PEM generates electrical power from air and from hydrogen or hydrogen rich gas mixtures. Therefore, there is an increasing interest in converting current hydrocarbon based marine fuels such as natural gas, gasoline, and diesel into hydrogen rich gases acceptable to the PEM fuel cells on board ships. Using chemical flow sheeting software, the total system efficiency has been calculated. Natural gas appears to be the best fuel for hydrogen rich gas production due to its favorable composition of lower molecular weight compounds. This paper presents a study for a 250 kW net electrical power PEM fuel cell system utilizing a partial oxidation in one case study and steam reformers in the second. This study has shown that steam-reforming process is the most competitive fuel processing option in terms of fuel processing efficiency. Partial oxidation process has proved to posses the lowest fuel processing efficiency. Among the options studied, the highest fuel processing efficiency is achieved with natural gas steam reforming system.

  19. Melting temperature of uranium - plutonium mixed oxide fuel

    Energy Technology Data Exchange (ETDEWEB)

    Ishii, Tetsuya; Hirosawa, Takashi [Power Reactor and Nuclear Fuel Development Corp., Oarai, Ibaraki (Japan). Oarai Engineering Center

    1997-08-01

    Fuel melting temperature is one of the major thermodynamical properties that is used for determining the design criteria on fuel temperature during irradiation in FBR. In general, it is necessary to evaluate the correlation of fuel melting temperature to confirm that the fuel temperature must be kept below the fuel melting temperature during irradiation at any conditions. The correlations of the melting temperature of uranium-plutonium mixed oxide (MOX) fuel, typical FBR fuel, used to be estimated and formulized based on the measured values reported in 1960`s and has been applied to the design. At present, some experiments have been accumulated with improved experimental techniques. And it reveals that the recent measured melting temperatures does not agree well to the data reported in 1960`s and that some of the 1960`s data should be modified by taking into account of the recent measurements. In this study, the experience of melting temperature up to now are summarized and evaluated in order to make the fuel pin design more reliable. The effect of plutonium content, oxygen to metal ratio and burnup on MOX fuel melting was examined based on the recent data under the UO{sub 2} - PuO{sub 2} - PuO{sub 1.61} ideal solution model, and then formulized. (J.P.N.)

  20. Melting temperature of uranium - plutonium mixed oxide fuel

    International Nuclear Information System (INIS)

    Ishii, Tetsuya; Hirosawa, Takashi

    1997-08-01

    Fuel melting temperature is one of the major thermodynamical properties that is used for determining the design criteria on fuel temperature during irradiation in FBR. In general, it is necessary to evaluate the correlation of fuel melting temperature to confirm that the fuel temperature must be kept below the fuel melting temperature during irradiation at any conditions. The correlations of the melting temperature of uranium-plutonium mixed oxide (MOX) fuel, typical FBR fuel, used to be estimated and formulized based on the measured values reported in 1960's and has been applied to the design. At present, some experiments have been accumulated with improved experimental techniques. And it reveals that the recent measured melting temperatures does not agree well to the data reported in 1960's and that some of the 1960's data should be modified by taking into account of the recent measurements. In this study, the experience of melting temperature up to now are summarized and evaluated in order to make the fuel pin design more reliable. The effect of plutonium content, oxygen to metal ratio and burnup on MOX fuel melting was examined based on the recent data under the UO 2 - PuO 2 - PuO 1.61 ideal solution model, and then formulized. (J.P.N.)

  1. LG Solid Oxide Fuel Cell (SOFC) Model Development

    Energy Technology Data Exchange (ETDEWEB)

    Haberman, Ben [LG Fuel Cell Systems Inc., North Canton, OH (United States); Martinez-Baca, Carlos [LG Fuel Cell Systems Inc., North Canton, OH (United States); Rush, Greg [LG Fuel Cell Systems Inc., North Canton, OH (United States)

    2013-05-31

    This report presents a summary of the work performed by LG Fuel Cell Systems Inc. during the project LG Solid Oxide Fuel Cell (SOFC) Model Development (DOE Award Number: DE-FE0000773) which commenced on October 1, 2009 and was completed on March 31, 2013. The aim of this project is for LG Fuel Cell Systems Inc. (formerly known as Rolls-Royce Fuel Cell Systems (US) Inc.) (LGFCS) to develop a multi-physics solid oxide fuel cell (SOFC) computer code (MPC) for performance calculations of the LGFCS fuel cell structure to support fuel cell product design and development. A summary of the initial stages of the project is provided which describes the MPC requirements that were developed and the selection of a candidate code, STAR-CCM+ (CD-adapco). This is followed by a detailed description of the subsequent work program including code enhancement and model verification and validation activities. Details of the code enhancements that were implemented to facilitate MPC SOFC simulations are provided along with a description of the models that were built using the MPC and validated against experimental data. The modeling work described in this report represents a level of calculation detail that has not been previously available within LGFCS.

  2. Strength of Anode‐Supported Solid Oxide Fuel Cells

    DEFF Research Database (Denmark)

    Faes, A.; Frandsen, Henrik Lund; Kaiser, Andreas

    2011-01-01

    Nickel oxide and yttria doped zirconia composite strength is crucial for anode‐supported solid oxide fuel cells, especially during transient operation, but also for the initial stacking process, where cell curvature after sintering can cause problems. This work first compares tensile and ball....... Even though the electrolyte is to the tensile side, it is found that the anode support fails due to the thermo‐mechanical residual stresses....

  3. Platinum redispersion on metal oxides in low temperature fuel cells

    DEFF Research Database (Denmark)

    Tripkovic, Vladimir; Cerri, Isotta; Nagami, Tetsuo

    2013-01-01

    We have analyzed the aptitude of several metal oxide supports (TiO2, SnO2, NbO2, ZrO2, SiO2, Ta2O5 and Nb2O5) to redisperse platinum under electrochemical conditions pertinent to the Proton Exchange Membrane Fuel Cell (PEMFC) cathode. The redispersion on oxide supports in air has been studied in ...

  4. Fuel cells: spectroscopic studies in the electrocatalysis of alcohol oxidation

    OpenAIRE

    Iwasita Teresa

    2002-01-01

    Modern spectroscopic methods are useful for elucidating complex electrochemical mechanisms as those occurring during the oxidation of small organic molecules (CH3OH, HCOH, HCOOH). In the present paper it is shown the use of spectroscopic methods to study the oxidation of alcohols on platinum or Pt-based binary electrodes. These reactions are of importance in conexion with the development of anode systems for use in fuel cells. Mass spectrometry and FT infrared spectroscopy allow to establishi...

  5. Fuel cycle industrialization program prepared by N-Fuel Research Committee, ANRE

    Energy Technology Data Exchange (ETDEWEB)

    1978-09-01

    To meet the new situation resulting from the scaling down of nuclear power development plan in Japan, and the changes due to the new U.S. nuclear non-proliferation policy, the Nuclear Fuel Research Committee of the Agency of Natural Resources and Energy of MITI has prepared the ''Interim Report on the Nuclear Fuel Cycle''. It sets out in precise terms the methods that should be followed for establishing the nuclear fuel cycle in Japan. Major items treated in this report are; uranium ore development, promotion of uranium stockpiling, construction of domestic uranium enrichment plant, promotion of the construction of a nuclear fuel park, Pu utilization and cooperation in international movement for nuclear non-proliferation, and the establishment of measures for radioactive waste management. Discussions are made from technological, economical, and political view points. Also attached are a table of the comprehensive industrialization plan up to the year 2000 and a table of estimated nuclear fuel demand and supply in Japan.

  6. Preparation, characterization and antibacterial activity of oxidized κ-carrageenan.

    Science.gov (United States)

    Zhu, Mingjin; Ge, Liming; Lyu, Yongbo; Zi, Yaxin; Li, Xinying; Li, Defu; Mu, Changdao

    2017-10-15

    The oxidized κ-carrageenans with different oxidation levels were prepared through the hydrogen peroxide and copper sulfate redox system. The oxidation level of oxidized κ-carrageenan was successfully controlled by adjusting the dosage of hydrogen peroxide. The results showed that the microtopography of oxidized κ-carrageenan changed from rough granules to smooth flakes, mainly resulting from the easily melting property of oxidized κ-carrageenan induced by introduced carboxyl and aldehyde groups. Especially, the antibacterial activity of oxidized κ-carrageenans against Gram-positive bacteria (Staphylococcus aureus and Listeria monocytogenes) and Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa) was systematically investigated. The results showed that the oxidized κ-carrageenan could damage the bacterial cell wall and cytoplasmic membrane and suppress the growth of both Gram-positive and Gram-negative bacteria. The oxidized κ-carrageenan possessed broad-spectrum antibacterial activity, which may be used as a new antibacterial agent. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Application of green chemistry techniques to prepare electrocatalysts for direct methanol fuel cells.

    Science.gov (United States)

    Shimizu, Kenichi; Wang, Joanna S; Wai, Chien M

    2010-03-25

    A series of green techniques for synthesizing carbon nanotube-supported platinum nanoparticles and their high electrocatalytic activity toward methanol fuel cell applications are reported. The techniques utilize either the supercritical fluid carbon dioxide or water as a medium for depositing platinum nanoparticles on surfaces of multiwalled or single-walled carbon nanotubes. The catalytic properties of the carbon nanotubes-supported Pt nanoparticle catalysts prepared by four different techniques are compared for anodic oxidation of methanol and cathodic reduction of oxygen using cyclic voltammetry. One technique using galvanic exchange of Pt(2+) in water with zerovalent iron present on the surfaces of as-grown single-walled carbon nanotubes produces a Pt catalyst that shows an unusually high catalytic activity for reduction of oxygen but a negligible activity for oxidation of methanol. This fuel-selective catalyst may have a unique application as a cathode catalyst in methanol fuel cells to alleviate the problems caused by crossover of methanol through the polymer electrolyte membrane.

  8. Low temperature spent fuel oxidation under tuff repository conditions

    International Nuclear Information System (INIS)

    Einziger, R.E.; Woodley, R.E.

    1985-01-01

    The Nevada Nuclear Waste Storage Investigations Project is studying the suitability of tuffaceous rocks at Yucca Mountain, Nye County, Nevada, for high level waste disposal. The oxidation state of LWR spent fuel in a tuff repository may be a significant factor in determining its ability to inhibit radionuclide migration. Long term exposure at low temperatures to the moist air expected in a tuff repository is expected to increase the oxidation state of the fuel. A program is underway to determine the spent fuel oxidation mechanisms which might be active in a tuff repository. Initial work involves a series of TGA experiments to determine the effectiveness of the technique and to obtain preliminary oxidation data. Tests were run at 200 0 C and 225 0 C for as long as 720 hours. Grain boundary diffusion appears to open up a greater surface area for oxidation prior to onset of bulk diffusion. Temperature strongly influences the oxidation rates. The effect of moisture is small but readily measurable. 25 refs., 7 figs., 4 tabs

  9. Monitoring the oxidation of nuclear fuel cladding using Raman spectroscopy

    International Nuclear Information System (INIS)

    Mi, Hongyi; Mikael, Solomon; Allen, Todd; Sridharan, Kumar; Butt, Darryl; Blanchard, James P.; Ma, Zhenqiang

    2014-01-01

    In order to observe Zircaloy-4 (Zr-4) cladding oxidation within a spent fuel canister, cladding oxidized in air at 500 °C was investigated by micro-Raman spectroscopy to measure the oxide layer thickness. Systematic Raman scans were performed to study the relationship between typical Raman spectra and various oxide layer thicknesses. The thicknesses of the oxide layers developed for various exposure times were measured by cross-sectional Scanning Electron Microscopy (SEM). The results of this work reveal that each oxide layer thickness has a corresponding typical Raman spectrum. Detailed analysis suggests that the Raman scattering peaks around wave numbers of 180 cm −1 and 630 cm −1 are the best choices for accurately determining the oxide layer thickness. After Gaussian–Lorentzian deconvolution, these two peaks can be quantitatively represented by four peaks. The intensities of the deconvoluted peaks increase consistently as the oxide layer becomes thicker and sufficiently strong signals are produced, allowing one to distinguish the bare and oxidized cladding samples, as well as samples with different oxide layer thicknesses. Hence, a process that converts sample oxide layer thickness to optical signals can be achieved

  10. Fuel-sodium reaction product formation in breached mixed-oxide fuel

    International Nuclear Information System (INIS)

    Bottcher, J.H.; Lambert, J.D.B.; Strain, R.V.; Ukai, S.; Shibahara, S.

    1988-01-01

    The run-beyond-cladding-breach (RBCB) operation of mixed-oxide LMR fuel pins has been studied for six years in the Experimental Breeder Reactor-II (EBR-II) as part of a joint program between the US Department of Energy and the Power Reactor and Nuclear Fuel Development Corporation of Japan. The formation of fuel-sodium reaction product (FSRP), Na 3 MO 4 , where M = U/sub 1-y/Pu/sub y/, in the outer fuel regions is the major phenomenon governing RBCB behavior. It increases fuel volume, decreases fuel stoichiometry, modifies fission-product distributions, and alters thermal performance of a pin. This paper describes the morphology of Na 3 MO 4 observed in 5.84-mm diameter pins covering a variety of conditions and RBCB times up to 150 EFPD's. 8 refs., 1 fig

  11. Solid Oxide Fuel Cell Stack Diagnostics

    DEFF Research Database (Denmark)

    Mosbæk, Rasmus Rode; Barfod, Rasmus Gottrup

    As SOFC technology is moving closer to a commercial break through, methods to measure the “state-of-health” of operating stacks are becoming of increasing interest. This requires application of advanced methods for detailed electrical and electrochemical characterization during operation....... An operating stack is subject to compositional gradients in the gaseous reactant streams, and temperature gradients across each cell and across the stack, which complicates detailed analysis. Several experimental stacks from Topsoe Fuel Cell A/S were characterized using Electrochemical Impedance Spectroscopy...... in the hydrogen fuel gas supplied to the stack. EIS was used to examine the long-term behavior and monitor the evolution of the impedance of each of the repeating units and the whole stack. The observed impedance was analyzed in detail for one of the repeating units and the whole stack and the losses reported...

  12. Preparation of Dispersion-Hardened Copper by Internal Oxidation

    DEFF Research Database (Denmark)

    Brøndsted, Povl; Sørensen, Ole Toft

    1978-01-01

    Internal oxidation experiments in CO2/CO atmospheres on Cu-Al alloys for preparation of dispersion-hardened Cu are described. The oxygen pressures of the atmospheres used in the experiments were controlled with a solid electrolyte oxygen cell based on ZrO2 (CaO). The particle size distributions o...

  13. Oxide fuels and targets for transmutation

    International Nuclear Information System (INIS)

    Sudreau, F.; Bonnerot, J.M.; Warin, D.; Gaillard-Groleas, G.; Ferroud-Plattet, M.P.

    2007-01-01

    Full text of publication follows. Direction 1 of the French Act dated 30 December 1991 on the management of high-level, long-lived radioactive waste involves exploring solutions designed to separate long-lived radionuclides from the spent fuel and to transmute them under neutron flux into shorter half-lives or stable elements. In the French research programme conducted by CEA, these radionuclides are mainly minor actinides (americium, neptunium and curium) and fission products (particularly caesium, iodine and technetium). Within this context, this paper aims at illustrating the vast programme that CEA has performed in order to demonstrate the scientific and technical feasibility of minor actinide transmutation. An important part of the research was carried out in collaboration with French research (CNRS) and industrial (EDF, AREVA) organisations, and also in the framework of international co-operation programmes with the European Institute for Transuranium Elements in Karlsruhe (ITU), the US Department of Energy (DOE), the Japanese Atomic Energy Research Institute (now JAEA) and Central Research Institute of Electric Power Industry (CRIEPI) and the Russian Ministry for Atomic Energy (ROSATOM). Such research made it possible to evaluate the capacity of MOX fuels to be used as a support for minor actinide transmutation (homogeneous method). Simulations of pressurised water reactor (PWR) fuels have revealed the limits of this transmutation method, which are mainly related to the pressurization of the fuel rods and the formation of high active californium. On the contrary, for sodium-cooled fast reactor fuels possibly designed with large expansion plenums a first experimental demonstration of the transmutation of americium and neptunium has been successful in the Phenix reactor. Various studies designed to demonstrate the theoretical and experimental feasibility of transmutation using an inert support (heterogeneous method) have been carried out in HFR (EFTTRA

  14. NITROUS OXIDE EMISSIONS FROM FOSSIL FUEL COMBUSTION

    Science.gov (United States)

    The role of coal combustion as a significant global source of nitrous oxide (N2O) emissions was reexamined through on-line emission measurements from six pulverized-coal-fired utility boilers and from laboratory and pilot-scale combustors. The full-scale utility boilers yielded d...

  15. Studies on Y{sub 2}SiO{sub 5}:Ce phosphors prepared by gel combustion using new fuels

    Energy Technology Data Exchange (ETDEWEB)

    Muresan, L.E., E-mail: laura_muresan2003@yahoo.com [“Raluca Ripan” Institute for Research in Chemistry, Babeş Bolyai University, Fântânele 30, 400294 Cluj-Napoca (Romania); Oprea, B.F.; Cadis, A.I.; Perhaita, I. [“Raluca Ripan” Institute for Research in Chemistry, Babeş Bolyai University, Fântânele 30, 400294 Cluj-Napoca (Romania); Ponta, O. [Faculty of Physics, Babeş Bolyai University, 400084 Cluj-Napoca (Romania)

    2014-12-05

    Highlights: • Y{sub 2}SiO{sub 5}:Ce was prepared by combustion using aspartic or glutamic acid as fuels. • Combustion process occurs differently depending on the fuels amount. • Single phase X2-Y{sub 2}SiO{sub 5} phosphors were obtained in fuel rich conditions. • PL measurements indicate that aspartic acid is a better fuel than glutamic. • Optimal preparative conditions were established for synthesis of Y{sub 2}SiO{sub 5}:Ce. - Abstract: Cerium activated yttrium silicate (Y{sub 2}SiO{sub 5}:Ce) phosphors were prepared by combustion, using yttrium–cerium nitrate as oxidizer, aspartic or glutamic acid as fuel and TEOS as source of silicon. In this study, aspartic and glutamic acid are used for the first time for the synthesis of Y{sub 2}SiO{sub 5}:Ce phosphors. The fuels molar amount was varied from 0.5 mol to 1.5 mol in order to reveal the thermal behavior of intermediary products (gels and ashes) same as the structural and luminescent characteristics of final products (phosphors). According to thermal analysis correlated with FTIR and XPS investigations, the combustion process occurs differently depending on the fuel amount; unreacted nitrate compounds have been identified in fuel lean conditions and carbonate based compounds along with organic residue in rich fuel conditions. The conversion to well crystallized silicates was revealed by changes of FTIR vibration bands and confirmed by XRD measurements. Based on luminescent spectra, aspartic acid is a better fuel than glutamic acid. A positive effect on the luminescence have been observed for samples fired in air due to complete remove of organic residue. The best luminescence was obtained for combustions with 0.75 mol aspartic acid and 1.25 mol glutamic respectively, fired at 1400 °C for 4 h in air atmosphere.

  16. Micro-Solid Oxide Fuel Cell: A multi-fuel approach for portable applications

    International Nuclear Information System (INIS)

    Patil, Tarkeshwar C.; Duttagupta, Siddhartha P.

    2016-01-01

    Highlights: • We report the oxygen ion transport properties at the electrode–electrolyte interface (EEI) of the SOFC for the first time. • This ion transport plays a key role in the overall performance of SOFCs with different fuels. • The GIIB mechanism is also studied for the first time. • GIIB is assumed to be the prime reason for low power density and ion conductivity at the EEI when using hydrocarbon fuels. • Due to its scalability, a fuel cell can serve as a power source for on-chip applications and all portable equipment. - Abstract: The impact of oxygen ion transport at the electrolyte–electrode interface of a micro-solid oxide fuel cell using different fuels is investigated. Model validation is performed to verify the results versus the reported values. Furthermore, as the hydrogen-to-carbon ratio decreases, the diffusivity of the oxygen ion increases. This increase in diffusivity is observed because the number of hydrogen atoms available as the reacting species increases in fuels with lower hydrogen-to-carbon ratios. The oxygen ion conductivity and output power density decrease as the hydrogen-to-carbon ratio of the fuels decreases. The reason behind this impact is the formation of a gas-induced ion barrier at the electrode–electrolyte interface by the CO_2 molecules formed during the reaction at the interface, thus blocking the flow of oxygen ions. As the oxygen ions become blocked, the output current contribution from the reaction also decreases and thereby affects the overall performance of the micro-solid oxide fuel cell. The experimental verification confirms this because of a significant decrease in the output power density. Furthermore, as per the application in portable devices, the appropriate choice of fuel can be chosen so that the micro-solid oxide fuel cell operates at the maximum power density.

  17. Performance of advanced oxide fuel pins in EBR-II

    International Nuclear Information System (INIS)

    Lawrence, L.A.; Jensen, S.M.; Hales, J.W.; Karnesky, R.A.; Makenas, B.J.

    1986-05-01

    The effects of design and operating parameters on mixed-oxide fuel pin irradiation performance were established for the Hanford Engineering Development Laboratory (HEDL) advanced oxide EBR-II test series. Fourteen fuel pins breached in-reactor with reference 316 SS cladding. Seven of the breaches are attributed to FCMI. Of the remaining seven breached pins, three are attributed to local cladding over-temperatures similar to the breach mechanism for the reference oxide pins irradiated in EBR-II. FCCI was found to be a contributing factor in two high burnup, i.e., 11.7 at. % breaches. The remaining two breaches were attributed to mechanical interaction of UO 2 fuel and fission products accumulated in the lower cladding insulator gap, and a loss of cladding ductility possibly due to liquid metal embrittlement. Fuel smear density appears to have the most significant impact on lifetime. Quantitative evaluations of cladding diameter increases attributed to FCMI, established fuel smear density, burnup, and cladding thickness-to-diameter ratio as the major parameters influencing the extent of cladding strain

  18. Preparation and characterization of several transition metal oxides

    International Nuclear Information System (INIS)

    Wold, A.; Dwight, K.

    1989-01-01

    The structure-property relationships of several conducting transition metal oxides, as well as their preparative methods, are presented in this paper. The importance of preparing homogeneous phases with precisely known stoichiometry is emphasized. A comparison is also made of the various techniques used to prepare both polycrystalline and single crystal samples. For transition metal oxides, the metallic properties are discussed either in terms of metal-metal distances which are short enough to result in metallic behavior, or in terms of the formation of a π* conduction band resulting from covalent metal-oxygen interactions. Metallic behavior is observed when the conduction bands are populated with either electrons or holes. The concentration of these carriers can be affected by either cation or anion substitutions. The discussion in this presentation will be limited to the elements Re, Ti, V, Cr, Mo, and Cu

  19. Technoeconomy of different solid oxide fuel cell based hybrid cycle

    DEFF Research Database (Denmark)

    Rokni, Masoud

    2014-01-01

    Gas turbine, steam turbine and heat engine (Stirling engine) is used as bottoming cycle for a solid oxide fuel cell plant to compare different plants efficiencies, CO2 emissionsand plants cost in terms of $/kW. Each plant is then integrated with biomass gasification and finally six plants...

  20. Kinetic and geometric aspects of solid oxide fuel cell electrodes

    DEFF Research Database (Denmark)

    Mogensen, Mogens Bjerg; Skaarup, Steen

    1996-01-01

    The paper gives an overview of the main factors controlling the performance of the solid oxide fuel cell (SOFC) electrodes, emphasizing the most widely chosen anodes and cathodes, Ni-YSZ and LSM-YSZ. They are often applied as composites (mixtures) of the electron conducting electrode material...

  1. Safety criteria related to microheterogeneities in LWR mixed oxide fuels

    International Nuclear Information System (INIS)

    Renard, A.; Mostin, N.

    1978-01-01

    The main safety aspets of PuO 2 microheterogeneities in the pellets of LWR mixed oxide fuels are reviewed. Points of interest are studied, especially the transient behaviour in accidental conditions and criteria are deduced for use in the specification and quality control of the fabricated product. (author)

  2. POST CRITICAL HEAT TRANSFER AND FUEL CLADDING OXIDATION

    Directory of Open Access Journals (Sweden)

    Vojtěch Caha

    2016-12-01

    Full Text Available The knowledge of heat transfer coefficient in the post critical heat flux region in nuclear reactor safety is very important. Although the nuclear reactors normally operate at conditions where critical heat flux (CHF is not reached, accidents where dryout occur are possible. Most serious postulated accidents are a loss of coolant accident or reactivity initiated accident which can lead to CHF or post CHF conditions and possible disruption of core integrity. Moreover, this is also influenced by an oxide layer on the cladding surface. The paper deals with the study of mathematical models and correlations used for heat transfer calculation, especially in post dryout region, and fuel cladding oxidation kinetics of currently operated nuclear reactors. The study is focused on increasing of accuracy and reliability of safety limit calculations (e.g. DNBR or fuel cladding temperature. The paper presents coupled code which was developed for the solution of forced convection flow in heated channel and oxidation of fuel cladding. The code is capable of calculating temperature distribution in the coolant, cladding and fuel and also the thickness of an oxide layer.

  3. Simulation with GOTHIC of experiments Oxidation of fuel in Air

    International Nuclear Information System (INIS)

    Martinez-Murillo Mendez, J. C.

    2012-01-01

    In the present work has been addressed for the first time la simulation with the GOTHIC code, experiments oxidation and ignition of SFP in phase 1. This work represents a solid starting point for analysis of specific degradation of fuel in the pools of our facilities.

  4. Safety problems related to microheterogeneities in physically mixed oxide fuels

    International Nuclear Information System (INIS)

    Renard, A.; Evrard, G.; Vanhellemont, G.

    1976-01-01

    The safety aspects of microheterogeneities in LMFBR mixed oxide fuel are reviewed from the point of view of the pin behaviour dynamic study, the fabrication and the quality control. The paper emphasizes some significant parameters in transient conditions, the prevention means in the fabrication process and the analysis methods for the control

  5. Thermodynamic and kinetic modelling of fuel oxidation behaviour in operating defective fuel

    International Nuclear Information System (INIS)

    Lewis, B.J.; Thompson, W.T.; Akbari, F.; Thompson, D.M.; Thurgood, C.; Higgs, J.

    2004-01-01

    A theoretical treatment has been developed to predict the fuel oxidation behaviour in operating defective nuclear fuel elements. The equilibrium stoichiometry deviation in the hyper-stoichiometric fuel has been derived from thermodynamic considerations using a self-consistent set of thermodynamic properties for the U-O system, which emphasizes replication of solubilities and three-phase invariant conditions displayed in the U-O binary phase diagram. The kinetics model accounts for multi-phase transport including interstitial oxygen diffusion in the solid and gas-phase transport of hydrogen and steam in the fuel cracks. The fuel oxidation model is further coupled to a heat conduction model to account for the feedback effect of a reduced thermal conductivity in the hyper-stoichiometric fuel. A numerical solution has been developed using a finite-element technique with the FEMLAB software package. The model has been compared to available data from several in-reactor X-2 loop experiments with defective fuel conducted at the Chalk River Laboratories. The model has also been benchmarked against an O/U profile measurement for a spent defective fuel element discharged from a commercial reactor

  6. Fuel removal from plasma-facing components by oxidation-based techniques. An overview of surface conditions after oxidation

    International Nuclear Information System (INIS)

    Rubel, M.J.; De Temmerman, G.; Sergienko, G.; Sundelin, P.; Emmoth, B.; Philipps, V.

    2007-01-01

    Oxygen-assisted fuel removal is reported for laboratory-prepared a-C:D films and for layers obtained by boronisation in a tokamak and then exposed to a helium-oxygen glow discharge in TEXTOR. Oxidation of thick mixed-material co-deposits under laboratory conditions is also presented. The essential results are following: (i) laboratory-prepared amorphous deuterated carbon (a-C:D) layers are decomposed efficiently by the He-O 2 glow: D and C contents are decreased by a factor of 45-220 and 25-60, respectively; (ii) the same treatment of the boronised films leads to the release of D but no removal of carbon is observed; (iii) the thermal oxidation (at 300 deg. C in air under laboratory conditions) of co-deposits on PFC and probes exposed to the SOL reduces the D content by a factor of 4-5 after 2 h, whereas nearly complete fuel removal (98%) occurs after 10 h at 300 deg. C. The study shows that the fuel removal efficiency is dependent on the overall composition of the mixed layer. It is high from pure a-C:D films but distinctly less efficient from real co-deposits

  7. Preparation of UO2 fragments for fuel-debris experiments

    International Nuclear Information System (INIS)

    Tinkle, M.C.; Kircher, J.A.; Zinn, R.M.; Eash, D.T.

    1982-01-01

    A unique process was developed for preparing multi-kilogram quantities of > 90% dense fragments of enriched and depleted UO 2 sized 20 mm to 0.038 mm for fuel debris experiments. Precipitates of UO 4 . xH 2 O were treated to obtain UO 2 powders that would yield large cohesive green pieces when isostatically pressed to 206 MPa. The pressed pieces were crushed into fragments that were about 30% oversized, and heated to 1800 0 C for 24 h in H 2 . Oversizing compensates for shrinkage during densification. Effort was dramatically reduced by working on a large scale and by presizing the green UO 2 instead of directly crushing densified pellets

  8. Corrosion mechanisms of spent fuel under oxidizing conditions

    International Nuclear Information System (INIS)

    Finn, P.A.; Finch, R.; Buck, E.; Bates, J.

    1997-01-01

    The release of 99 Tc can be used as a reliable marker for the extent of spent oxide fuel reaction under unsaturated high-drip-rate conditions at 90 degrees C. Evidence from leachate data and from scanning and transmission electron microscopy (SEM and TEM) examination of reacted fuel samples is presented for radionuclide release, potential reaction pathways, and the formation of alteration products. In the ATM-103 fuel, 0.03 of the total inventory of 99 Tc is released in 3.7 years under unsaturated and oxidizing conditions. Two reaction pathways that have been identified from SEM are (1) through-grain dissolution with subsequent formation of uranyl alteration products, and (2) grain-boundary dissolution. The major alteration product identified by x-ray diffraction (XRD) and SEM, is Na-boltwoodite, Na[(UO 2 )(SiO 3 OH)]lg-bullet H 2 O, which is formed from sodium and silicon in the water leachant

  9. Solid Oxide Fuel Cell Hybrid System for Distributed Power Generation

    Energy Technology Data Exchange (ETDEWEB)

    Faress Rahman; Nguyen Minh

    2004-01-04

    This report summarizes the work performed by Hybrid Power Generation Systems, LLC (HPGS) during the July 2003 to December 2003 reporting period under Cooperative Agreement DE-FC26-01NT40779 for the U. S. Department of Energy, National Energy Technology Laboratory (DOE/NETL) entitled ''Solid Oxide Fuel Cell Hybrid System for Distributed Power Generation''. The main objective of this project is to develop and demonstrate the feasibility of a highly efficient hybrid system integrating a planar Solid Oxide Fuel Cell (SOFC) and a micro-turbine. In addition, an activity included in this program focuses on the development of an integrated coal gasification fuel cell system concept based on planar SOFC technology. Also, another activity included in this program focuses on the development of SOFC scale up strategies.

  10. Development of a solid oxide fuel cell (SOFC) automotive auxiliary power unit (APU) fueled by gasoline

    International Nuclear Information System (INIS)

    DeMinco, C.; Mukerjee, S.; Grieve, J.; Faville, M.; Noetzel, J.; Perry, M.; Horvath, A.; Prediger, D.; Pastula, M.; Boersma, R.; Ghosh, D.

    2000-01-01

    This paper describes the design and the development progress of a 3 to 5 auxiliary power unit (APU) based on a gasoline fueled solid oxide fuel cell (SOFC). This fuel cell was supplied reformate gas (reactant) by a partial oxidation (POx) catalytic reformer utilizing liquid gasoline and designed by Delphi Automotive Systems. This reformate gas consists mainly of hydrogen, carbon monoxide and nitrogen and was fed directly in to the SOFC stack without any additional fuel reformer processing. The SOFC stack was developed by Global Thermoelectric and operates around 700 o C. This automotive APU produces power to support future 42 volt vehicle electrical architectures and loads. The balance of the APU, designed by Delphi Automotive Systems, employs a packaging and insulation design to facilitate installation and operation on-board automobiles. (author)

  11. PREPARATION AND CHARACTERIZATION OF SOLID ELECTROLYTES: FUEL CELL APPLICATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Rambabu Bobba; Josef Hormes; T. Wang; Jaymes A. Baker; Donald G. Prier; Tommy Rockwood; Dinesha Hawkins; Saleem Hasan; V. Rayanki

    1997-12-31

    The intent of this project with Federal Energy Technology Center (FETC)/Morgantown Energy Technology Center (METC) is to develop research infrastructure conductive to Fuel Cell research at Southern University and A and M College, Baton Route. A state of the art research laboratory (James Hall No.123 and No.114) for energy conversion and storage devices was developed during this project duration. The Solid State Ionics laboratory is now fully equipped with materials research instruments: Arbin Battery Cycling and testing (8 channel) unit, Electrochemical Analyzer (EG and G PAR Model 273 and Solartron AC impedance analyzer), Fuel Cell test station (Globe Tech), Differential Scanning Calorimeter (DSC-10), Thermogravimetric Analyzer (TGA), Scanning Tunneling Microscope (STM), UV-VIS-NIR Absorption Spectrometer, Fluorescence Spectrometer, FT-IR Spectrometer, Extended X-ray Absorption Fine Structure (EXAFS) measurement capability at Center for Advanced Microstructure and Devices (CAMD- a multimillion dollar DOE facility), Glove Box, gas hood chamber, high temperature furnaces, hydraulic press and several high performance computers. IN particular, a high temperature furnace (Thermodyne 6000 furnace) and a high temperature oven were acquired through this project funds. The PI Dr. R Bobba has acquired additional funds from federal agencies include NSF-Academic Research Infrastructure program and other DOE sites. They have extensively used the multimillion dollar DOE facility ''Center'' for Advanced Microstructures and Devices (CAMD) for electrochemical research. The students were heavily involved in the experimental EXAFS measurements and made use of their DCM beamline for EXAFS research. The primary objective was to provide hands on experience to the selected African American undergraduate and graduate students in experimental energy research.The goal was to develop research skills and involve them in the Preparation and Characterization of Solid

  12. Confinement of ruthenium oxides volatilized during nuclear fuels reprocessing

    International Nuclear Information System (INIS)

    Maas, E.T. Jr.; Longo, J.M.

    1980-01-01

    While many materials have been suggested and employed as trapping agents for gaseous oxides of fission product ruthenium volatilized during nuclear fuels reprocessing, none that is known to form thermodynamically stable compounds with rutheniunm has been utilized. We have employed alkaline earth metal compounds for this purpose because of their ability to form stable mixed metal oxide phases with ruthenium. Results of experiments in which RuO 4 was volatilized from either a solid source (RuO 2 .xH 2 O) or from solution [Ru(NO)(NO 3 ) 3 ] in HNO 3 and passed through beds of alkaline earth metal carbonates and calcium oxide held at 600 to 750 0 C have demonstrated that compounds of formulation MRuO 3 (M = calcium, strontium, barium) are formed. Under oxidizing conditions, these materials exist as stable ceramic phases, whereas under reducing conditions, they are transformed into intimate mixtures of the alkaline earth metal oxide and nonvolatile ruthenium metal

  13. A development of solid oxide fuel cell technology

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Hee Chun; Lee, Chang Woo [Korea Electric Power Corp. (KEPCO), Taejon (Korea, Republic of). Research Center; Kim, Kwy Youl; Yoon, Moon Soo; Kim, Ho Ki; Kim, Young Sik; Mun, Sung In; Eom, Sung Wuk [Korea Electrotechnology Research Inst., Changwon (Korea, Republic of)

    1995-12-31

    Solid oxide fuel cell which was consisted of ceramics has high power density and is very simple in shape. The project named A development of SOFC(Solid Oxide Fuel Cell) technology is to develop the unit cell fabrication processing and to evaluate the unit cell of solid oxide full cell. In this project, a manufacturing process of cathode by citrate method and polymeric precursor methods were established. By using tape casting method, high density thin electrolyte was manufactured and has high performance. Unit cell composed with La{sub 17}Sr{sub 13}Mn{sub 3} as cathode, 8YSZ electrolyte and 50% NiYSZ anode had a performance of O.85 W/cm{sup 2} and recorded 510 hours operation time. On the basis of these results. 100 cm{sup 2} class unit cell will be fabricated and tests in next program (author). 59 refs., 120 figs.

  14. A development of solid oxide fuel cell technology

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Hee Chun; Lee, Chang Woo [Korea Electric Power Corp. (KEPCO), Taejon (Korea, Republic of). Research Center; Kim, Kwy Youl; Yoon, Moon Soo; Kim, Ho Ki; Kim, Young Sik; Mun, Sung In; Eom, Sung Wuk [Korea Electrotechnology Research Inst., Changwon (Korea, Republic of)

    1996-12-31

    Solid oxide fuel cell which was consisted of ceramics has high power density and is very simple in shape. The project named A development of SOFC(Solid Oxide Fuel Cell) technology is to develop the unit cell fabrication processing and to evaluate the unit cell of solid oxide full cell. In this project, a manufacturing process of cathode by citrate method and polymeric precursor methods were established. By using tape casting method, high density thin electrolyte was manufactured and has high performance. Unit cell composed with La{sub 17}Sr{sub 13}Mn{sub 3} as cathode, 8YSZ electrolyte and 50% NiYSZ anode had a performance of O.85 W/cm{sup 2} and recorded 510 hours operation time. On the basis of these results. 100 cm{sup 2} class unit cell will be fabricated and tests in next program (author). 59 refs., 120 figs.

  15. Preparation of La{sub 0.75}Sr{sub 0.25}Cr{sub 0.5}Mn{sub 0.5}O{sub 3-{delta}} fine powders by carbonate coprecipitation for solid oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Ha, Sang Bu; Cho, Pyeong-Seok; Cho, Yoon Ho; Lee, Dokyol; Lee, Jong-Heun [Department of Materials Science and Engineering, Korea University, Anam-dong, Sungbuk-ku, Seoul 136-713 (Korea)

    2010-01-01

    A range of La{sub 0.75}Sr{sub 0.25}Cr{sub 0.5}Mn{sub 0.5}O{sub 3-{delta}} (LSCM) powders is prepared by the carbonate coprecipitation method for use as anodes in solid oxide fuel cells. The supersaturation ratio (R = [(NH{sub 4}){sub 2}CO{sub 3}]/([La{sup 3+}] + [Sr{sup 2+}] + [Cr{sup 3+}] + [Mn{sup 2+}])) during the coprecipitation determines the relative compositions of La, Sr, Cr, and Mn. The composition of the precursor approaches the stoichiometric one at the supersaturation range of 4 {<=} R {<=} 12.5, whereas Sr and Mn components are deficient at R < 4 and excessive at R = 25. The fine and phase-pure LSCM powders are prepared by heat treatment at very low temperature (1000 C) at R = 7.5 and 12.5. By contrast, the solid-state reaction requires a higher heat-treatment temperature (1400 C). The catalytic activity of the LSCM electrodes is enhanced by using carbonate-derived powders to manipulate the electrode microstructures. (author)

  16. Caramel, uranium oxide fuel plates for water cooled reactors

    International Nuclear Information System (INIS)

    Bussy, Pierre; Delafosse, Jacques; Lestiboudois, Guy; Cerles, J.-M.; Schwartz, J.-P.

    1979-01-01

    The fuel is composed of thin plates assembled parallel to each other to form bundles or assemblies. Each plate is composed of a pavement of uranium oxide pellets, insulated from each other by a zircaloy cladding. The 235 U enrichment does not exceed 8%. The range of uses for this fuel extends from electric power generating reactors to irradiation reactors for research work. A parametric study in test loops has made it possible to determine the operating limits of this thick fuel, without bursting. The resulting diagram gives the permissible power densities, with and without cycling for specific burn-ups beyond 50,000 MWd/t. The thinnest plates were also irradiated in total in the form of advance assemblies irradiated in the core of the OSIRIS pile prior to its transformation. This transformation and the operation of this reactor with a core of 'Caramel' elements is the main trial experiment of this fuel [fr

  17. General considerations on the oxide fuel-cladding chemical interaction

    International Nuclear Information System (INIS)

    Pascard, R.

    1977-01-01

    Since the very first experimental irradiations in thermal reactors, performed in view of the future Rapsodie fuel general study, corrosion cladding anomalies were observed. After 10 years of Rapsodie and more than two years of Phenix, performance brought definite confirmation of the chemical reactions between the irradiated fuel and cladding. That is the reason for which the fuel designers express an urgent need for determining the corrosion rates. Semi-empirical laws and mechanisms describing corrosion processes are proposed. Erratic conditions for appearance of the oxide-cladding corrosion are stressed upon. Obviously such a problem can be fully appreciated only by a statistical approach based on a large number of observations on the true LMFBR fuel pins

  18. Emission computer tomography on a Dodewaard mixed oxide fuel pin

    International Nuclear Information System (INIS)

    Buurveld, H.A.; Dassel, G.

    1993-12-01

    A nondestructive technique as well as a destructive PIE technique have been used to verify the results obtained with a newly 8-e computer tomography (GECT) system. Multi isotope Scanning (MIS), electron probe micro analysis (EPMA) and GECT were used on a mixed oxide (MOX) fuel rod from the Dodewaard reactor with an average burnup of 24 MWd/kg fuel. GECT shows migration of Cs to the periphery of fuel pellets and to radial cracks and pores in the fuel, whereas MIS shows Cs migration to pellet interfaces. The EPMA technique appeared not to be useful to show migration of Cs but, it shows the distribution of fission products from Pu. EPMA clearly shows the distribution of fission products from Pu, but did not reveal the Cs-migration. (orig./HP)

  19. Thermal radiation modelling in a tubular solid oxide fuel cell

    International Nuclear Information System (INIS)

    Austin, M.E.; Pharoah, J.G.; Vandersteen, J.D.J.

    2004-01-01

    Solid Oxide Fuel Cells (SOFCs) are becoming the fuel cell of choice among companies and research groups interested in small power generation units. Questions still exist, however, about the operating characteristics of these devices; in particular the temperature distribution in the fuel cell. Using computational fluid dynamics (CFD) a model is proposed that incorporates conduction, convection and radiation. Both surface-to-surface and participating media are considered. It is hoped that a more accurate account of the temperature field in the various flow channels and cell components will be made to assist work on design of fuel cell components and reaction mechanisms. The model, when incorporating radiative heat transfer with participating media, predicts substantially lower operating temperatures and smaller temperature gradients than it does without these equations. It also shows the importance of the cathode air channel in cell cooling. (author)

  20. An economic route to mass production of graphene oxide solution for preparing graphene oxide papers

    Energy Technology Data Exchange (ETDEWEB)

    Liou, Yan-Jia; Tsai, Bo-Da; Huang, Wu-Jang, E-mail: wjhuang@mail.npust.edu.tw

    2015-03-15

    Highlights: • Graphene oxide paper can be prepared from synthesized graphene sheet containing carbon materials. • Graphene oxide paper can be used as a phase change materials for thermal storage. • To prepare graphene oxide paper from synthesized graphene sheet containing carbon materials could highly reduce the cost. - Abstract: Graphene oxide paper (GOP) is a composite material fabricated from graphene oxide (GO) solution. In addition, it can be a novel and potential material for application on the separation of water vapor from gaseous steam or larger alkali ions from aqueous solution. GOP could be used as electricity and thermal storage materials. The preparation of GO commonly uses high purity natural or artificial graphite. It is difficult to prepare GOP from artificial graphite powder due to the cost of $1,450 US/ton. In this study, we tried to prepare GOPs from homemade graphene sheets containing carbon materials (GSCCMs) and evaluate the thermal properties of GSCCM derived GOPs. Results show that GSCCM derived GOPs have a higher phase transition temperature, and the average mesophase phase change enthalpy is 9.41 J/g, which is 2.87 times higher than graphite derived GOP. Therefore, to prepare GOP from GSCCMs could highly reduce the cost.

  1. Preparation for commissioning of nuclear plant with reference to British Nuclear Fuels Plc fuel handling plant project

    International Nuclear Information System (INIS)

    Bamber, D.R.

    1987-01-01

    The new Fuel Handling Plant at British Nuclear Fuels Sellafield is part of a Pound 550M complex which provides facilities for the receipt, storage and mechanical preparation of both Magnox and A.G.R. fuel. The plant is very large and complex with considerable use of computer based process control systems, providing for physical and nuclear safety. The preparation of such plant for active commissioning necessitates a great many physical checks and technical evaluations in support of its safety case. This paper describes arrangements for plant commissioning checks, against the regulatory framework and explains the physical preparations necessary for their timely accomplishment. (author)

  2. Preparation for commissioning of nuclear plant with reference to British Nuclear Fuels Plc fuel handling plant project

    International Nuclear Information System (INIS)

    Bamber, D.

    1987-01-01

    The new Fuel Handing Plant at British Nuclear Fuels Sellafield is part of a Pound 550M complex which provides facilities for the receipt, storage and mechanical preparation of both magnox and A.G.R. fuel. The plant is very large and complex with considerable use of computer based process control systems, providing for physical and nuclear safety. The preparation of such plant for ''active'' commissioning necessitates a great many physical checks and technical evaluations in support of its safety case. This paper describes arrangements for plant commissioning checks, against the regulatory framework and explains the physical preparations necessary for their timely accomplishment. (author)

  3. The development of latent fingerprints by zinc oxide and tin oxide nanoparticles prepared by precipitation technique

    Science.gov (United States)

    Luthra, Deepali; Kumar, Sacheen

    2018-05-01

    Fingerprints are the very important evidence at the crime scene which must be developed clearly with shortest duration of time to solve the case. Metal oxide nanoparticles could be the mean to develop the latent fingerprints. Zinc oxide and Tin Oxide Nanoparticles were prepared by using chemical precipitation technique which were dried and characterized by X-ray diffraction, UV-Visible spectroscopy and FTIR. The size of zinc oxide crystallite was found to be 14.75 nm with minimum reflectance at 360 nm whereas tin oxide have the size of 90 nm and reflectance at minimum level 321 nm. By using these powdered samples on glass, plastic and glossy cardboard, latent fingerprints were developed. Zinc oxide was found to be better candidate than tin oxide for the fingerprint development on all the three types of substrates.

  4. Oxidation behaviour and electrical properties of cobalt/cerium oxide composite coatings for solid oxide fuel cell interconnects

    DEFF Research Database (Denmark)

    Harthøj, Anders; Holt, Tobias; Møller, Per

    2015-01-01

    This work evaluates the performance of cobalt/cerium oxide (Co/CeO2) composite coatings and pure Co coatings to be used for solid oxide fuel cell (SOFC) interconnects. The coatings are electroplated on the ferritic stainless steels Crofer 22 APU and Crofer 22H. Coated and uncoated samples...

  5. Fuel-cladding mechanical interaction effects in fast reactor mixed oxide fuel

    Energy Technology Data Exchange (ETDEWEB)

    Boltax, A [Westinghouse Electric Corporation, Advanced Reactor Division, Madison, PA (United States); Biancheria, A

    1977-04-01

    Thermal and fast reactor irradiation experiments on mixed oxide fuel pins under steady-state and power change conditions reveal evidence for significant fuel-cladding mechanical interaction (FCMI) effects. Analytical studies with the LIFE-III fuel performance code indicate that high cladding stresses can be produced by general and local FCMI effects. Also, evidence is presented to show that local cladding strains can be caused by the accumulation of cesium at the fuel-cladding interface. Although it is apparent that steady-state FCMI effects have not given rise to cladding breaches in current fast reactors, it is anticipated that FCMI may become more important in the future because of interest in: higher fuel burnups; increased power ramp rates; load follow operation; and low swelling cladding alloys. (author)

  6. Fuel-cladding mechanical interaction effects in fast reactor mixed oxide fuel

    International Nuclear Information System (INIS)

    Boltax, A.; Biancheria, A.

    1977-01-01

    Thermal and fast reactor irradiation experiments on mixed oxide fuel pins under steady-state and power change conditions reveal evidence for significant fuel-cladding mechanical interaction (FCMI) effects. Analytical studies with the LIFE-III fuel performance code indicate that high cladding stresses can be produced by general and local FCMI effects. Also, evidence is presented to show that local cladding strains can be caused by the accumulation of cesium at the fuel-cladding interface. Although it is apparent that steady-state FCMI effects have not given rise to cladding breaches in current fast reactors, it is anticipated that FCMI may become more important in the future because of interest in: higher fuel burnups; increased power ramp rates; load follow operation; and low swelling cladding alloys. (author)

  7. Degradation of solid oxide fuel cell metallic interconnects in fuels containing sulfur

    Energy Technology Data Exchange (ETDEWEB)

    Ziomek-Moroz, M.; Hawk, Jeffrey A.

    2005-01-01

    Hydrogen is the main fuel for all types of fuel cells except direct methanol fuel cells. Hydrogen can be generated from all manner of fossil fuels, including coal, natural gas, diesel, gasoline, other hydrocarbons, and oxygenates (e.g., methanol, ethanol, butanol, etc.). Impurities in the fuel can cause significant performance problems and sulfur, in particular, can decrease the cell performance of fuel cells, including solid oxide fuel cells (SOFC). In the SOFC, the high (800-1000°C) operating temperature yields advantages (e.g., internal fuel reforming) and disadvantages (e.g., material selection and degradation problems). Significant progress in reducing the operating temperature of the SOFC from ~1000 ºC to ~750 ºC may allow less expensive metallic materials to be used for interconnects and as balance of plant (BOP) materials. This paper provides insight on the material performance of nickel, ferritic steels, and nickel-based alloys in fuels containing sulfur, primarily in the form of H2S, and seeks to quantify the extent of possible degradation due to sulfur in the gas stream.

  8. Nanostructured Gd-CeO2 electrolyte for solid oxide fuel cell by aqueous tape casting

    Science.gov (United States)

    Akbari-Fakhrabadi, A.; Mangalaraja, R. V.; Sanhueza, Felipe A.; Avila, Ricardo E.; Ananthakumar, S.; Chan, S. H.

    2012-11-01

    Gadolinia-doped ceria (Ce0.9Gd0.1O1.95, GDC) electrolyte was fabricated by aqueous-based tape casting method for solid oxide fuel cells (SOFCs). The ceramic powder prepared by combustion synthesis was used with poly acrylic acid (PAA), poly vinyl alcohol (PVA), poly ethylene glycol (PEG), Octanol, 2,4,7,9-tetramethyl-5-decyne-4,7-diol ethoxylate and double distilled water as dispersant, binder, plasticizer, defoamer, surfactant and solvent respectively, to prepare stable GDC slurry. The conditions for preparing stable GDC slurries were studied and optimized by sedimentation, zeta potential and viscosity measurements. Green tapes with smooth surface, flexibility, thickness in the range of 0.35-0.4 mm and 45% relative green density were prepared. Conventional and flash sintering techniques were used and compared for densification which demonstrated the possibility of surpassing sintering at high temperatures and retarding related grain growth.

  9. Thermodynamic analysis of SOFC (solid oxide fuel cell)–Stirling hybrid plants using alternative fuels

    International Nuclear Information System (INIS)

    Rokni, Masoud

    2013-01-01

    A novel hybrid power system (∼10 kW) for an average family home is proposed. The system investigated contains a solid oxide fuel cell (SOFC) on top of a Stirling engine. The off-gases produced in the SOFC cycle are fed to a bottoming Stirling engine, at which additional power is generated. Simulations of the proposed system were conducted using different fuels, which should facilitate the use of a variety of fuels depending on availability. Here, the results for natural gas (NG), ammonia, di-methyl ether (DME), methanol and ethanol are presented and analyzed. The system behavior is further investigated by comparing the effects of key factors, such as the utilization factor and the operating conditions under which these fuels are used. Moreover, the effect of using a methanator on the plant efficiency is also studied. The combined system improves the overall electrical efficiency relative to that of a stand-alone Stirling engine or SOFC plant. For the combined SOFC and Stirling configuration, the overall power production was increased by approximately 10% compared to that of a stand-alone SOFC plant. System efficiencies of approximately 60% are achieved, which is remarkable for such small plant sizes. Additionally, heat is also produced to heat the family home when necessary. - Highlights: • Integrating a solid oxide fuel with a Stirling engine • Design of multi-fuel hybrid plants • Plants running on alternative fuels; natural gas, methanol, ethanol, DME and ammonia • Thermodynamic analysis of hybrid SOFC–Stirling engine plants

  10. Solid Oxide Fuel Cells coupled with a biomass gasification unit

    Directory of Open Access Journals (Sweden)

    Skrzypkiewicz Marek

    2016-01-01

    Full Text Available A possibility of fuelling a solid oxide fuel cell stack (SOFC with biomass fuels can be realized by coupling a SOFC system with a self-standing gasification unit. Such a solution enables multi-fuel operation, elasticity of the system as well as the increase of the efficiency of small-scale biomass-to-electricity conversion units. A system of this type, consisting of biomass gasification unit, gas purification unit, SOFC stack, anode off-gas afterburner and peripherals was constructed and operated successfully. During the process, biomass fuel (wood chips was gasified with air as gasification agent. The gasifier was capable of converting up to 30 kW of fuel to syngas with efficiencies up to 75%. Syngas leaving the gasification unit is delivered to a medium temperature adsorber for sulphur compounds removal. Steam is added to the purified fuel to maintain steam to carbon ratio higher than 2. The syngas then is passed to a SOFC stack through a fuel preheater. In such a configuration it was possible to operate a commercial 1.3 kW stack within its working regime. Conducted tests confirmed successful operation of a SOFC stack fuelled by biomass-sourced syngas.

  11. Catalytic oxidative desulfurization of liquid hydrocarbon fuels using air

    Science.gov (United States)

    Sundararaman, Ramanathan

    Conventional approaches to oxidative desulfurization of liquid hydrocarbons involve use of high-purity, expensive water soluble peroxide for oxidation of sulfur compounds followed by post-treatment for removal of oxidized sulfones by extraction. Both are associated with higher cost due to handling, storage of oxidants and yield loss with extraction and water separation, making the whole process more expensive. This thesis explores an oxidative desulfurization process using air as an oxidant followed by catalytic decomposition of sulfones thereby eliminating the aforementioned issues. Oxidation of sulfur compounds was realized by a two step process in which peroxides were first generated in-situ by catalytic air oxidation, followed by catalytic oxidation of S compounds using the peroxides generated in-situ completing the two step approach. By this technique it was feasible to oxidize over 90% of sulfur compounds present in real jet (520 ppmw S) and diesel (41 ppmw S) fuels. Screening of bulk and supported CuO based catalysts for peroxide generation using model aromatic compound representing diesel fuel showed that bulk CuO catalyst was more effective in producing peroxides with high yield and selectivity. Testing of three real diesel fuels obtained from different sources for air oxidation over bulk CuO catalyst showed different level of effectiveness for generating peroxides in-situ which was consistent with air oxidation of representative model aromatic compounds. Peroxides generated in-situ was then used as an oxidant to oxidize sulfur compounds present in the fuel over MoO3/SiO2 catalyst. 81% selectivity of peroxides for oxidation of sulfur compounds was observed on MoO3/SiO2 catalyst at 40 °C and under similar conditions MoO3/Al2O3 gave only 41% selectivity. This difference in selectivity might be related to the difference in the nature of active sites of MoO3 on SiO2 and Al2O 3 supports as suggested by H2-TPR and XRD analyses. Testing of supported and bulk Mg

  12. Preparation and charaterization of Pt/functionalized graphene and its electrocatalysis for methanol oxidation

    International Nuclear Information System (INIS)

    Liang, Qingsheng; Zhang, Li; Cai, Maolin; Li, Yong; Jiang, Kun; Zhang, Xin; Shen, Pei Kang

    2013-01-01

    Water-dispersible 8-hydroxy-1,3,6-pyrene trisulfonic acid trisodium salt (PyS)-functionalized graphene (PyS-graphene) sheets were prepared by a π–π interaction method, in which the aromatic organic molecules of PyS were reacted with graphene. The PyS-graphene sheets were used as Pt nanoparticle support to prepare a Pt/PyS-graphene catalyst for direct methanol fuel cells. The prepared materials were characterized by ultraviolet spectrometry (UV–vis), Fourier transform infrared spectrometry (FT-IR), atomic force microscopy (AFM), X-ray diffraction (XRD), Raman spectroscopy (SERS), and transmission electron microscopy (TEM). The electrocatalytic properties of the catalysts for methanol oxidation were evaluated by cyclic voltammetry (CV). The Pt/PyS-graphene catalysts were found to have higher electrocatalytic activity for methanol oxidation than Pt/graphene catalyst. This finding can be attributed to the introduction of negative sulfonic (SO 3 − ) groups to the graphene sheet surface, which makes the graphene sheets dispersible in water. Consequently, the Pt nanoparticles were uniformly and securely deposited onto the graphene sheet surface. These results suggested that the sulfonic group-modified water-dispersible graphene sheets can be used to improve the electrocatalytic activity of catalysts for fuel cells

  13. Synthesis and Characterization of Oxide Feedstock Powders for the Fuel Cycle R and D Program

    International Nuclear Information System (INIS)

    Voit, Stewart L.; Vedder, Raymond James; Johnson, Jared A.

    2010-01-01

    Nuclear fuel feedstock properties, such as physical, chemical, and isotopic characteristics, have a significant impact on the fuel fabrication process and, by extension, the in-reactor fuel performance. This has been demonstrated through studies with UO 2 spanning greater than 50 years. The Fuel Cycle R and D Program with The Department of Energy Office of Nuclear Energy has initiated an effort to develop a better understanding of the relationships between oxide feedstock, fresh fuel properties, and in-reactor fuel performance for advanced mixed oxide compositions. Powder conditioning studies to enable the use of less than ideal powders for ceramic fuel pellet processing are ongoing at Los Alamos National Laboratory (LANL) and an understanding of methods to increase the green density and homogeneity of pressed pellets has been gained for certain powders. Furthermore, Oak Ridge National Laboratory (ORNL) is developing methods for the co-conversion of mixed oxides along with techniques to analyze the degree of mixing. Experience with the fabrication of fuel pellets using co-synthesized multi-constituent materials is limited. In instances where atomically mixed solid solutions of two or more species are needed, traditional ceramic processing methods have been employed. Solution-based processes may be considered viable synthesis options, including co-precipitation (AUPuC), direct precipitation, direct-conversion (Modified Direct Denitration or MDD) and internal/external gelation (sol-gel). Each of these techniques has various advantages and disadvantages. The Fiscal Year 2010 feedstock development work at ORNL focused on the synthesis and characterization of one batch of UO x and one batch of U 80 Ce 20 O x . Oxide material synthesized at ORNL is being shipped to LANL for fuel fabrication process development studies. The feedstock preparation was performed using the MDD process which utilizes a rotary kiln to continuously thermally denitrate double salts of ammonium

  14. Iron oxide redox chemistry and nuclear fuel disposal

    International Nuclear Information System (INIS)

    Jobe, D.J.; Lemire, R.J.; Taylor, P.

    1997-04-01

    Solubility and stability data for iron (III) oxides and aqueous Fe(II) and Fe(III) species are reviewed, and selected values are used to calculate potential-pH diagrams for the iron system at temperatures of 25 and 100 deg C, chloride activities {C1 - } = 10 -2 and 1 mol/kg, total carbonate activity {C T } = 10 -3 mol/kg, and iron(III) oxide/oxyhydroxide solubility products (25 deg C values) K sp = {Fe 3+ }{OH - } 3 = 10 -38.5 , 10 -40 and 10 -42 . The temperatures and anion concentrations bracket the range of conditions expected in a Canadian nuclear fuel waste disposal vault. The three solubility products represent a conservative upper limit, a most probable value, and a minimum credible value, respectively, for the iron oxides likely to be important in controlling redox conditions in a disposal vault for CANDU nuclear reactor fuel. Only in the first of these three cases do the calculated redox potentials significantly exceed values under which oxidative dissolution of the fuel may occur. (author)

  15. Electroreduction of carbon monoxide to liquid fuel on oxide-derived nanocrystalline copper

    Science.gov (United States)

    Li, Christina W.; Ciston, Jim; Kanan, Matthew W.

    2014-04-01

    The electrochemical conversion of CO2 and H2O into liquid fuel is ideal for high-density renewable energy storage and could provide an incentive for CO2 capture. However, efficient electrocatalysts for reducing CO2 and its derivatives into a desirable fuel are not available at present. Although many catalysts can reduce CO2 to carbon monoxide (CO), liquid fuel synthesis requires that CO is reduced further, using H2O as a H+ source. Copper (Cu) is the only known material with an appreciable CO electroreduction activity, but in bulk form its efficiency and selectivity for liquid fuel are far too low for practical use. In particular, H2O reduction to H2 outcompetes CO reduction on Cu electrodes unless extreme overpotentials are applied, at which point gaseous hydrocarbons are the major CO reduction products. Here we show that nanocrystalline Cu prepared from Cu2O (`oxide-derived Cu') produces multi-carbon oxygenates (ethanol, acetate and n-propanol) with up to 57% Faraday efficiency at modest potentials (-0.25 volts to -0.5 volts versus the reversible hydrogen electrode) in CO-saturated alkaline H2O. By comparison, when prepared by traditional vapour condensation, Cu nanoparticles with an average crystallite size similar to that of oxide-derived copper produce nearly exclusive H2 (96% Faraday efficiency) under identical conditions. Our results demonstrate the ability to change the intrinsic catalytic properties of Cu for this notoriously difficult reaction by growing interconnected nanocrystallites from the constrained environment of an oxide lattice. The selectivity for oxygenates, with ethanol as the major product, demonstrates the feasibility of a two-step conversion of CO2 to liquid fuel that could be powered by renewable electricity.

  16. Synthesis and characterization of brannerite wasteforms for the immobilization of mixed oxide fuel residues

    Energy Technology Data Exchange (ETDEWEB)

    Bailey, D.J.; Stennett, M.C.; Hyatt, N.C. [Immobilisation Science Laboratory, Department of Materials Science and Engineering, University of Sheffield, Sheffield, S1 3JD (United Kingdom)

    2016-07-01

    A possible method for the reduction of civil Pu stockpiles is the reuse of Pu in mixed oxide fuel (MOX). During MOX fuel production, residues unsuitable for further recycle will be produced. Due to their high actinide content MOX residues require immobilization within a robust host matrix. Although it is possible to immobilize actinides in vitreous wasteforms; ceramic phases, such as brannerite (UTi{sub 2}O{sub 6}), are attractive due to their high waste loading capacity and relative insolubility. A range of uranium brannerite, formulated Gd{sub x}U{sub 1-x}Ti{sub 2}O{sub 6}, were prepared using a mixed oxide route. Charge compensation of divalent and trivalent cations was expected to occur via the oxidation of U{sup 4+} to higher valence states (U{sup 5+} or U{sup 6+}). Gd{sup 3+} was added to act as a neutron absorber in the final Pu bearing wasteform. X-ray powder diffraction of synthesised specimens found that phase distribution was strongly affected by processing atmosphere (air or Ar). In all cases prototypical brannerite was formed accompanied by different secondary phases dependent on processing atmosphere. Microstructural analysis (SEM) of the sintered samples confirmed the results of the X-ray powder diffraction. The preliminary results presented here indicate that brannerite is a promising host matrix for mixed oxide fuel residues. (authors)

  17. Non-destructive delamination detection in solid oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Gazzarri, J.I.; Kesler, O. [Department of Mechanical Engineering, University of British Columbia, 2054-6250 Applied Science Lane, Vancouver, BC V6T 1Z4 (Canada)

    2007-05-15

    A finite element model has been developed to simulate the steady state and impedance behaviour of a single operating solid oxide fuel cell (SOFC). The model results suggest that electrode delamination can be detected minimally-invasively by using electrochemical impedance spectroscopy. The presence of cathode delamination causes changes in the cell impedance spectrum that are characteristic of this type of degradation mechanism. These changes include the simultaneous increase in both the series and polarization resistances, in proportion to the delaminated area. Parametric studies show the dependence of these changes on the extent of delamination, on the operating point, and on the kinetic characteristics of the fuel cell under study. (author)

  18. Light water reactor mixed-oxide fuel irradiation experiment

    International Nuclear Information System (INIS)

    Hodge, S.A.; Cowell, B.S.; Chang, G.S.; Ryskamp, J.M.

    1998-01-01

    The United States Department of Energy Office of Fissile Materials Disposition is sponsoring and Oak Ridge National Laboratory (ORNL) is leading an irradiation experiment to test mixed uranium-plutonium oxide (MOX) fuel made from weapons-grade (WG) plutonium. In this multiyear program, sealed capsules containing MOX fuel pellets fabricated at Los Alamos National Laboratory (LANL) are being irradiated in the Advanced Test Reactor (ATR) at the Idaho National Engineering and Environmental Laboratory (INEEL). The planned experiments will investigate the utilization of dry-processed plutonium, the effects of WG plutonium isotopics on MOX performance, and any material interactions of gallium with Zircaloy cladding

  19. Operation of real landfill gas fueled solid oxide fuel cell (SOFC) using internal dry reforming

    DEFF Research Database (Denmark)

    Langnickel, Hendrik; Hagen, Anke

    2017-01-01

    Biomass is one renewable energy source, which is independent from solar radiation and wind effect. Solid oxide fuel cells (SOFC’s) are able to convert landfill gas derived from landfill directly into electricity and heat with a high efficiency. In the present work a planar 16cm2 SOFC cell...... was necessary to prevent poisoning and thereby to decrease the degradation rate....

  20. Catalyst development and systems analysis of methanol partial oxidation for the fuel processor - fuel cell integration

    Energy Technology Data Exchange (ETDEWEB)

    Newson, E; Mizsey, P; Hottinger, P; Truong, T B; Roth, F von; Schucan, Th H [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1999-08-01

    Methanol partial oxidation (pox) to produce hydrogen for mobile fuel cell applications has proved initially more successful than hydrocarbon pox. Recent results of catalyst screening and kinetic studies with methanol show that hydrogen production rates have reached 7000 litres/hour/(litre reactor volume) for the dry pox route and 12,000 litres/hour/(litre reactor volume) for wet pox. These rates are equivalent to 21 and 35 kW{sub th}/(litre reactor volume) respectively. The reaction engineering problems remain to be solved for dry pox due to the significant exotherm of the reaction (hot spots of 100-200{sup o}C), but wet pox is essentially isothermal in operation. Analyses of the integrated fuel processor - fuel cell systems show that two routes are available to satisfy the sensitivity of the fuel cell catalysts to carbon monoxide, i.e. a preferential oxidation reactor or a membrane separator. Targets for individual system components are evaluated for the base and best case systems for both routes to reach the combined 40% efficiency required for the integrated fuel processor - fuel cell system. (author) 2 figs., 1 tab., 3 refs.

  1. Purification and preparation of graphite oxide from natural graphite

    Energy Technology Data Exchange (ETDEWEB)

    Panatarani, C., E-mail: c.panatarani@phys.unpad.ac.id; Muthahhari, N.; Joni, I. Made [Instrumentation Systems and Functional Material Processing Laboratory, Department of Physics, Faculty of Mathematics and Natural Sciences, Universitas Padjadjaran, Padjadjaran University, Jl. Raya Bandung-Sumedang KM 21, Jatinangor, 45363, Jawa Barat (Indonesia); Rianto, Anton [Grafindo Nusantara Ltd., Belagio Mall Lantai 2, Unit 0 L3-19, Kawasan Mega Kuningan, Kav. B4 No.3, Jakarta Selatan (Indonesia)

    2016-03-11

    Graphite oxide has attracted much interest as a possible route for preparation of natural graphite in the large-scale production and manipulation of graphene as a material with extraordinary electronic properties. Graphite oxide was prepared by modified Hummers method from purified natural graphite sample from West Kalimantan. We demonstrated that natural graphite is well-purified by acid leaching method. The purified graphite was proceed for intercalating process by modifying Hummers method. The modification is on the reaction time and temperature of the intercalation process. The materials used in the intercalating process are H{sub 2}SO{sub 4} and KMNO{sub 4}. The purified natural graphite is analyzed by carbon content based on Loss on Ignition test. The thermo gravimetricanalysis and the Fouriertransform infrared spectroscopy are performed to investigate the oxidation results of the obtained GO which is indicated by the existence of functional groups. In addition, the X-ray diffraction and energy dispersive X-ray spectroscopy are also applied to characterize respectively for the crystal structure and elemental analysis. The results confirmed that natural graphite samples with 68% carbon content was purified into 97.68 % carbon content. While the intercalation process formed a formation of functional groups in the obtained GO. The results show that the temperature and reaction times have improved the efficiency of the oxidation process. It is concluded that these method could be considered as an important route for large-scale production of graphene.

  2. Performance analysis of hybrid solid oxide fuel cell and gas turbine cycle: Application of alternative fuels

    International Nuclear Information System (INIS)

    Zabihian, Farshid; Fung, Alan S.

    2013-01-01

    Highlights: • Variation of the stream properties in the syngas-fueled hybrid SOFC–GT cycle. • Detailed analysis of the operation of the methane-fueled SOFC–GT cycle. • Investigate effects of inlet fuel type and composition on performance of cycle. • Comparison of system operation when operated with and without anode recirculation. - Abstract: In this paper, the hybrid solid oxide fuel cell (SOFC) and gas turbine (GT) model was applied to investigate the effects of the inlet fuel type and composition on the performance of the cycle. This type of analysis is vital for the real world utilization of manufactured fuels in the hybrid SOFC–GT system due to the fact that these fuel compositions depends on the type of material that is processed, the fuel production process, and process control parameters. In the first part of this paper, it is shown that the results of a limited number of studies on the utilization of non-conventional fuels have been published in the open literature. However, further studies are required in this area to investigate all aspects of the issue for different configurations and assumptions. Then, the results of the simulation of the syngas-fueled hybrid SOFC–GT cycle are employed to explain the variation of the stream properties throughout the cycle. This analysis can be very helpful in understanding cycle internal working and can provide some interesting insights to the system operation. Then, the detailed information of the operation of the methane-fueled SOFC–GT cycle is presented. For both syngas- and methane-fueled cycles, the operating conditions of the equipment are presented and compared. Moreover, the comparison of the characteristics of the system when it is operated with two different schemes to provide the required steam for the cycle, with anode recirculation and with an external source of water, provides some interesting insights to the system operation. For instance, it was shown that although the physical

  3. Safety aspects of LWR fuel reprocessing and mixed oxide fuel fabrication plants

    International Nuclear Information System (INIS)

    Fischer, M.; Leichsenring, C.H.; Herrmann, G.W.; Schueller, W.; Hagenberg, W.; Stoll, W.

    1977-01-01

    The paper is focused on the safety and the control of the consequences of credible accidents in LWR fuel reprocessing plants and in mixed oxide fuel fabrication plants. Each of these plants serve for many power reactor (about 50.000 Mwel) thus the contribution to the overall risk of nuclear energy is correspondingly low. Because of basic functional differences between reprocessing plants, fuel fabrication plants and nuclear power reactors, the structure and safety systems of these plants are different in many respects. The most important differences that influence safety systems are: (1) Both fuel reprocessing and fabrication plants do not have the high system pressure that is associated with power reactors. (2) A considerable amount of the radioactivity of the fuel, which is in the form of short-lived radionuclides has decayed. Therefore, fuel reprocessing plants and mixed oxide fuel fabrication plants are designed with multiple confinement barriers for control of radioactive materials, but do not require the high-pressure containment systems that are used in LWR plants. The consequences of accidents which may lead to the dispersion of radioactive materials such as chemical explosions, nuclear excursions, fires and failure of cooling systems are considered. A reasonable high reliability of the multiple confinement approach can be assured by design. In fuel reprocessing plants, forced cooling is necessary only in systems where fission products are accumulated. However, the control of radioactive materials can be maintained during normal operation and during the above mentioned accidents, if the dissolver off-gas and vessel off-gas treatment systems provide for effective removal of radioactive iodine, radioactive particulates, nitrogen oxides, tritium and krypton 85. In addition, the following incidents in the dissolver off-gas system itself must be controlled: failures of iodine filters, hydrogen explosion in O 2 - and NOsub(x)-reduction component, decomposition of

  4. Lanthanum Manganate Based Cathodes for Solid Oxide Fuel Cells

    DEFF Research Database (Denmark)

    Jørgensen, Mette Juhl

    Composite cathodes for solid oxide fuel cells were investigated using electrochemical impedance spectroscopy and scanning electron microscopy. The aim was to study the oxygen reduction process in the electrode in order to minimise the voltage drop in the cathode. The electrodes contained...... five processes were found to affect the impedance of LSM/YSZ composite electrodes. Two high frequency processes were ascribed to transport of oxide ions/oxygen intermediates across LSM/YSZ interfaces and through YSZ in the composite. Several competitive elementary reaction steps, which appear as one...

  5. Fabrication experience with mixed-oxide LWR fuels at the BELGONUCLEAIRE plant

    International Nuclear Information System (INIS)

    Vanhellemont, G.

    1979-01-01

    For nearly 20 years BELGONUCLEAIRE has been involved in a steadily growing effort to increase its production of mixed oxides. This programme has ranged from basic research and process development through a pilot-scale unit to today's mixed-oxide fuel fabrication plant at Dessel, which has been in operation for just over 5 years. The reference fabrication flow sheet includes UO 2 , PuO 2 and a scraped powder preparation, sintered ground pellets as well as rod fabrication and assembling. With regard to quality, attention is especially paid to the process monitoring and quality controls at the qualification step and during the routine production. Entirely different types of thermal UO 2 -PuO 2 fuel pellets, rods and assemblies have been manufactured for PWR and BWR operation. For these fabrications, some diagrams of the results with regard to the required technical specifications are presented. Special emphasis is placed on the occasional deviations of some finished products from the specifications and on the solutions applied to avoid such problems. Concerning the actual capacity of the mixed-oxide fuel fabrication plant, several limiting factors due to the nature of plutonium itself are discussed. Taking into account all these ambient limitations, a reference PWR mixed-oxide fuel output of nominally 18 t/a is obtained. The industrial feasibility of UO 2 -PuO 2 fuel fabrication has been thoroughly demonstrated by the present BELGONUCLEAIRE plant. The experience obtained has led to progressive improvements of the fabrication process and adaptation of the product controls in order to ensure the requested quality levels. (author)

  6. Materials for high temperature solid oxide fuel cells

    International Nuclear Information System (INIS)

    Singhal, S.C.

    1987-01-01

    High temperature solid oxide fuel cells show great promise for economical production of electricity. These cells are based upon the ability of stabilized zirconia to operate as an oxygen ion conductor at elevated temperatures. The design of the tubular solid oxide fuel cell being pursued at Westinghouse is illustrated. The cell uses a calcia-stabilized zironcia porous support tube, which acts both as a structural member onto which the other cell components are fabricated in the form of thin layers, and as a functional member to allow the passage, via its porosity, of air (or oxygen) to the air electrode. This paper summarizes the materials and fabrication processes for the various cell components

  7. Passive measurements of mixed-oxide fuel for nuclear nonproliferation

    International Nuclear Information System (INIS)

    Dolan, Jennifer L.; Flaska, Marek; Pozzi, Sara A.; Chichester, David L.

    2013-01-01

    We present new results on passive measurements and simulations of mixed-oxide fuel-pin assemblies. Potential tools for mixed-oxide fuel pin characterization are discussed for future nuclear-nonproliferation applications. Four EJ-309 liquid scintillation detectors coupled with an accurate pulse timing and digital, offline and optimized pulse-shape discrimination method were used. Measurement analysis included pulse-height distributions to distinguish between purely fission neutron sources and alpha-n plus fission neutrons sources. Time-dependent cross-correlation functions were analyzed to measure the fission neutron contribution to the measured sample's neutron source. The use of Monte Carlo particle transport code MCNPX-PoliMi is discussed in conjunction with the measurements

  8. Method to fabricate high performance tubular solid oxide fuel cells

    Science.gov (United States)

    Chen, Fanglin; Yang, Chenghao; Jin, Chao

    2013-06-18

    In accordance with the present disclosure, a method for fabricating a solid oxide fuel cell is described. The method includes forming an asymmetric porous ceramic tube by using a phase inversion process. The method further includes forming an asymmetric porous ceramic layer on a surface of the asymmetric porous ceramic tube by using a phase inversion process. The tube is co-sintered to form a structure having a first porous layer, a second porous layer, and a dense layer positioned therebetween.

  9. Current status of Westinghouse tubular solid oxide fuel cell program

    Energy Technology Data Exchange (ETDEWEB)

    Parker, W.G. [Westinghouse Science and Technology Center, Pittsburgh, PA (United States)

    1996-04-01

    In the last ten years the solid oxide fuel cell (SOFC) development program at Westinghouse has evolved from a focus on basic material science to the engineering of fully integrated electric power systems. Our endurance for this cell is 5 to 10 years. To date we have successfully operated at power for over six years. For power plants it is our goal to have operated before the end of this decade a MW class power plant. Progress toward these goals is described.

  10. Structural design considerations for micromachined solid-oxide fuel cells

    Science.gov (United States)

    Srikar, V. T.; Turner, Kevin T.; Andrew Ie, Tze Yung; Spearing, S. Mark

    Micromachined solid-oxide fuel cells (μSOFCs) are among a class of devices being investigated for portable power generation. Optimization of the performance and reliability of such devices requires robust, scale-dependent, design methodologies. In this first analysis, we consider the structural design of planar, electrolyte-supported, μSOFCs from the viewpoints of electrochemical performance, mechanical stability and reliability, and thermal behavior. The effect of electrolyte thickness on fuel cell performance is evaluated using a simple analytical model. Design diagrams that account explicitly for thermal and intrinsic residual stresses are presented to identify geometries that are resistant to fracture and buckling. Analysis of energy loss due to in-plane heat conduction highlights the importance of efficient thermal isolation in microscale fuel cell design.

  11. Some alternatives to the mixed oxide fuel cycle

    International Nuclear Information System (INIS)

    Deonigi, D.E.; Eschbach, E.A.; Goldsmith, S.; Pankaskie, P.J.; Rohrmann, C.A.; Widrig, R.D.

    1977-02-01

    While on initial examination each of the six fuel cycle concepts (tandem cycle, extended burnup, fuel rejuvenation, coprocessing, partial reprocessing, and thorium) described in the report may have some potential for improving safeguards, none of the six appears to have any other major or compelling advantages over the mixed oxide (MOX) fuel cycle. Compared to the MOX cycle, all but coprocessing appear to have major disadvantages, including severe cost penalties. Three of the concepts-tandem, extended burnup, and rejuvenation--share the basic problems of the throwaway cycle (GESMO Alternative 6): without reprocessing, high-level waste volumes and costs are substantially increased, and overall uranium utilization decreases for three reasons. First, the parasitic fission products left in the fuel absorb neutrons in later irradiation steps reducing the overall neutronic efficiencies of these cycles. Second, discarded fuel still has sufficient fissile values to warrant recycle. Third, perhaps most important, the plutonium needed for breeder start-up will not be available; without the breeder, uranium utilization would drop by about a factor of sixty. Two of the concepts--coprocessing and partial reprocessing--involve variations of the basic MOX fuel cycle's chemical reprocessing step to make plutonium diversion potentially more difficult. These concepts could be used with the MOX fuel cycle or in conjunction with the tandem, extended burnup and rejuvenation concepts to eliminate some of the problems with those cycles. But in so doing, the basic impetus for those cycles--elimination of reprocessing for safeguards purposes--no longer exists. Of all the concepts considered, only coprocessing--and particularly the ''master blend'' version--appears to have sufficient promise to warrant a more detailed study. The master blend concept could possibly make plutonium diversion more difficult with minimal impact on the reprocessing and MOX fuel fabrication operations

  12. SOLID OXIDE FUEL CELL HYBRID SYSTEM FOR DISTRIBUTED POWER GENERATION

    Energy Technology Data Exchange (ETDEWEB)

    Faress Rahman; Nguyen Minh

    2003-07-01

    This report summarizes the work performed by Hybrid Power Generation Systems, LLC during the January 2003 to June 2003 reporting period under Cooperative Agreement DE-FC26-01NT40779 for the U. S. Department of Energy, National Energy Technology Laboratory (DOE/NETL) entitled ''Solid Oxide Fuel Cell Hybrid System for Distributed Power Generation''. The main objective of this project is to develop and demonstrate the feasibility of a highly efficient hybrid system integrating a planar Solid Oxide Fuel Cell (SOFC) and a micro-turbine. In addition, an activity included in this program focuses on the development of an integrated coal gasification fuel cell system concept based on planar SOFC technology. This report summarizes the results obtained to date on: System performance analysis and model optimization; Reliability and cost model development; System control including dynamic model development; Heat exchanger material tests and life analysis; Pressurized SOFC evaluation; and Pre-baseline system definition for coal gasification fuel cell system concept.

  13. Solid oxide fuel cell having a monolithic core

    International Nuclear Information System (INIS)

    Ackerman, J.P.; Young, J.E.

    1984-01-01

    A solid oxide fuel cell for electrochemically combining fuel and oxidant for generating galvanic output, wherein the cell core has an array of electrolyte and interconnect walls that are substantially devoid of any composite inert materials for support. Instead, the core is monolithic, where each electrolyte wall consists of thin layers of cathode and anode materials sandwiching a thin layer of electrolyte material therebetween, and each interconnect wall consists of thin layers of the cathode and anode materials sandwiching a thin layer of interconnect material therebetween. The electrolyte walls are arranged and backfolded between adjacent interconnect walls operable to define a plurality of core passageways alternately arranged where the inside faces thereof have only the anode material or only the cathode material exposed. Means direct the fuel to the anode-exposed core passageways and means direct the oxidant to the cathode-exposed core passageway; and means also direct the galvanic output to an exterior circuit. Each layer of the electrolyte and interconnect materials is of the order of 0.002-0.01 cm thick; and each layer of the cathode and anode materials is of the order of 0.002-0.05 cm thick

  14. Predicting spent fuel oxidation states in a tuff repository

    International Nuclear Information System (INIS)

    Einziger, R.E.; Woodley, R.E.

    1987-01-01

    Nevada Nuclear Waste Storage Investigations Project (NNWSI) is studying the suitability of the tuffaceous rocks at Yucca Mountain as a waste repository for spent fuel disposal. The oxidation state of the LWR spent fuel in the moist air environment of a tuff repository could be a significant factor in determining its leaching and dissolution characteristics. Predictions as to which oxidation states would be present are important in analyzing such a repository and thus the present study was undertaken. A set of TGA (thermogravimetric analysis) tests were conducted on well-controlled samples of irradiated PWR fuel with time and temperature as the only variables. The tests were conducted between 140 and 225 0 C for a duration up to 2200 hours. The weight gain curves were analyzed in terms of diffusion through a layer of U 3 O 7 , diffusion into the grains to form a solid solution, a simplified empirical representation of a combination of grain boundary diffusion and bulk grain oxidation. Reaction rate constants were determined in each case, but analysis of these data could not establish a definitive mechanism. 21 refs., 10 figs., 3 tabs

  15. Strategies for Lowering Solid Oxide Fuel Cells Operating Temperature

    Directory of Open Access Journals (Sweden)

    Albert Tarancón

    2009-11-01

    Full Text Available Lowering the operating temperature of solid oxide fuel cells (SOFCs to the intermediate range (500–700 ºC has become one of the main SOFC research goals. High operating temperatures put numerous requirements on materials selection and on secondary units, limiting the commercial development of SOFCs. The present review first focuses on the main effects of reducing the operating temperature in terms of materials stability, thermo-mechanical mismatch, thermal management and efficiency. After a brief survey of the state-of-the-art materials for SOFCs, attention is focused on emerging oxide-ionic conductors with high conductivity in the intermediate range of temperatures with an introductory section on materials technology for reducing the electrolyte thickness. Finally, recent advances in cathode materials based on layered mixed ionic-electronic conductors are highlighted because the decreasing temperature converts the cathode into the major source of electrical losses for the whole SOFC system. It is concluded that the introduction of alternative materials that would enable solid oxide fuel cells to operate in the intermediate range of temperatures would have a major impact on the commercialization of fuel cell technology.

  16. SOLID STATE ENERGY CONVERSION ALLIANCE DELPHI SOLID OXIDE FUEL CELL

    Energy Technology Data Exchange (ETDEWEB)

    Steven Shaffer; Sean Kelly; Subhasish Mukerjee; David Schumann; Gail Geiger; Kevin Keegan; John Noetzel; Larry Chick

    2003-12-08

    The objective of Phase I under this project is to develop a 5 kW Solid Oxide Fuel Cell power system for a range of fuels and applications. During Phase I, the following will be accomplished: Develop and demonstrate technology transfer efforts on a 5 kW stationary distributed power generation system that incorporates steam reforming of natural gas with the option of piped-in water (Demonstration System A). Initiate development of a 5 kW system for later mass-market automotive auxiliary power unit application, which will incorporate Catalytic Partial Oxidation (CPO) reforming of gasoline, with anode exhaust gas injected into an ultra-lean burn internal combustion engine. This technical progress report covers work performed by Delphi from January 1, 2003 to June 30, 2003, under Department of Energy Cooperative Agreement DE-FC-02NT41246. This report highlights technical results of the work performed under the following tasks: Task 1 System Design and Integration; Task 2 Solid Oxide Fuel Cell Stack Developments; Task 3 Reformer Developments; Task 4 Development of Balance of Plant (BOP) Components; Task 5 Manufacturing Development (Privately Funded); Task 6 System Fabrication; Task 7 System Testing; Task 8 Program Management; and Task 9 Stack Testing with Coal-Based Reformate.

  17. Burnup performance of rock-like oxide (ROX) fuel in small pebble bed reactor with accumulative fuel loading scheme

    International Nuclear Information System (INIS)

    Simanullang, Irwan Liapto; Obara, Toru

    2017-01-01

    Highlights: • Burnup performance using ROX fuel in PBR with accumulative fuel loading scheme was analyzed. • Initial excess reactivity was suppressed by reducing 235 U enrichment in the startup condition. • Negative temperature coefficient was achieved in all condition of PBR with accumulative fuel loading scheme using ROX fuel. • Core lifetime of PBR with accumulative fuel loading scheme using ROX fuel was shorter than with UO 2 fuel. • In PBR with accumulative fuel loading scheme using ROX fuel, achieved discharged burnup can be as high as that for UO 2 fuel. - Abstract: The Japan Atomic Energy Agency (JAEA) has proposed rock-like oxide (ROX) fuel as a new, once-through type fuel concept. Here, burnup performance using ROX fuel was simulated in a pebble bed reactor with an accumulative fuel loading scheme. The MVP-BURN code was used to simulate the burnup calculation. Fuel of 5 g-HM/pebble with 20% 235 U enrichment was selected as the optimum composition. Discharged burnup could reach up to 218 GWd/t, with a core lifetime of about 8.4 years. However, high excess reactivity occurred in the initial condition. Initial fuel enrichment was therefore reduced from 20% to 4.65% to counter the initial excess reactivity. The operation period was reduced by the decrease of initial fuel enrichment, but the maximum discharged burnup was 198 GWd/t. Burnup performance of ROX fuel in this reactor concept was compared with that of UO 2 fuel obtained previously. Discharged burnup for ROX fuel in the PBR with an accumulative fuel loading scheme was as high as UO 2 fuel. Maximum power density could be lowered by introducing ROX fuel compared to UO 2 fuel. However, PBR core lifetime was shorter with ROX fuel than with UO 2 fuel. A negative temperature coefficient was achieved for both UO 2 and ROX fuels throughout the operation period.

  18. Electrocatalyst advances for hydrogen oxidation in phosphoric acid fuel cells

    Science.gov (United States)

    Stonehart, P.

    1984-01-01

    The important considerations that presently exist for achieving commercial acceptance of fuel cells are centered on cost (which translates to efficiency) and lifetime. This paper addresses the questions of electrocatalyst utilization within porous electrode structures and the preparation of low-cost noble metal electrocatalyst combinations with extreme dispersions of the metal. Now that electrocatalyst particles can be prepared with dimensions of 10 A, either singly or in alloy combinations, a very large percentage of the noble metal atoms in a crystallite are available for reaction. The cost savings for such electrocatalysts in the present commercially driven environment are considerable.

  19. New Cathode Materials for Intermediate Temperature Solid Oxide Fuel Cells

    Energy Technology Data Exchange (ETDEWEB)

    Allan J. Jacobson

    2006-09-30

    the perovskite compositions that were being investigated at PNNL, in order to assess the relative importance of the intrinsic properties such as oxygen ion diffusion and surface exchange rates as predictors of performance in cell tests. We then used these measurements to select new materials for scaled up synthesis and performance evaluation in single cell tests. The results of the single cell tests than provided feedback to the materials synthesis and selection steps. In this summary, the following studies are reported: (1) Synthesis, characterization, and DC conductivity measurements of the P1 compositions La{sub 0.8}Sr{sub 0.2}FeO{sub 3-x} and La{sub 0.7}Sr{sub 0.3}FeO{sub 3-x} were completed. A combinational approach for preparing a range P1 (La,Sr)FeO{sub 3} compositions as thin films was investigated. Synthesis and heat treatment of amorphous SrFeO{sub 3-x} and LaFeO{sub 3-x} films prepared by pulsed laser deposition are described. (2) Oxygen transport properties of K1 compositions La{sub x}Pr{sub 2-x}NiO{sub 4+d} (x =2.0, 1.9, 1.2, 1.0 and 0) measured by electrical conductivity relaxation are presented in this report. Area specific resistances determined by ac impedance measurements for La{sub 2}NiO{sub 4+{delta}} and Pr{sub 2}NiO{sub 4+{delta}} on CGO are encouraging and suggest that further optimization of the electrode microstructure will enable the target to be reached. (3) The oxygen exchange kinetics of the oxygen deficient double perovskite LnBaCo{sub 2}O{sub 5.5+{delta}} (Ln=Pr and Nd) were determined by electrical conductivity relaxation. The high electronic conductivity and rapid diffusion and surface exchange kinetics of PBCO suggest its application as cathode material in intermediate temperature solid oxide fuel cells. The first complete cell measurements were performed on Ni/CGO/CGO/PBCO/CGO cells. (4) The oxygen exchange kinetics of highly epitaxial thin films of PrBaCo{sub 2}O{sub 5.5+{delta}} (PBCO) has been determined by electrical conductivity

  20. Electrode Design for Low Temperature Direct-Hydrocarbon Solid Oxide Fuel Cells

    Science.gov (United States)

    Chen, Fanglin (Inventor); Zhao, Fei (Inventor); Liu, Qiang (Inventor)

    2015-01-01

    In certain embodiments of the present disclosure, a solid oxide fuel cell is described. The solid oxide fuel cell includes a hierarchically porous cathode support having an impregnated cobaltite cathode deposited thereon, an electrolyte, and an anode support. The anode support includes hydrocarbon oxidation catalyst deposited thereon, wherein the cathode support, electrolyte, and anode support are joined together and wherein the solid oxide fuel cell operates a temperature of 600.degree. C. or less.

  1. Electrode design for low temperature direct-hydrocarbon solid oxide fuel cells

    Science.gov (United States)

    Chen, Fanglin; Zhao, Fei; Liu, Qiang

    2015-10-06

    In certain embodiments of the present disclosure, a solid oxide fuel cell is described. The solid oxide fuel cell includes a hierarchically porous cathode support having an impregnated cobaltite cathode deposited thereon, an electrolyte, and an anode support. The anode support includes hydrocarbon oxidation catalyst deposited thereon, wherein the cathode support, electrolyte, and anode support are joined together and wherein the solid oxide fuel cell operates a temperature of 600.degree. C. or less.

  2. Thermal performance of fresh mixed-oxide fuel in a fast flux LMR [liquid metal reactor

    International Nuclear Information System (INIS)

    Ethridge, J.L.; Baker, R.B.

    1985-01-01

    A test was designed and irradiated to provide power-to-melt (heat generation rate necessary to initiate centerline fuel melting) data for fresh mixed-oxide UO 2 -PuO 2 fuel irradiated in a fast neutron flux under prototypic liquid metal reactor (LMR) conditions. The fuel pin parameters were selected to envelope allowable fabrication ranges and address mass production of LMR fuel using sintered-to-size techniques. The test included fuel pins with variations in fabrication technique, pellet density, fuel-to-cladding gap, Pu concentration, and fuel oxygen-to-metal ratios. The resulting data base has reestablished the expected power-to-melt in mixed-oxide fuels during initial reactor startup when the fuel temperatures are expected to be the highest. Calibration of heat transfer models of fuel pin performance codes with these data are providing more accurate capability for predicting steady-state thermal behavior of current and future mixed-oxide LMR fuels

  3. Development of solid oxide fuel cells; Desenvolvimento de celulas a combustivel do tipo oxido solido (SOFC)

    Energy Technology Data Exchange (ETDEWEB)

    Boaventura, Jaime S.; Alencar, Marcelo Goncalves F. de; Amaral, Alexandre Alves do; Benedicto, Joao Paulo Santos; Silva, Marcos A. [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil). Inst. de Quimica. Dept. de Fisico-Quimica

    2006-07-01

    Fuel cells allow the energy production without the thermodynamic restriction of the conversion of heat into work. Among their various types, the solid oxide fuel cells (SOFC), operating at high temperatures, allow the methane conversion into electricity directly on the anode. The main element of the SOFC is the structure A/E/C: anode/electrolyte/cathode, all sintered at high temperature as resistant ceramic materials. Dense electrolyte (YSZ: zirconia stabilized for Yttria) separates the anode (Ni+Co/YSZ: cobalt promoted nickel, supported on YSZ) and cathode (LSM: strontium-doped lanthanum manganite), both with porosity obtained by graphite addition. To obtain suitable A/E/C pellets, the layer sintering with appropriate mechanical and textural characteristics is essential, requiring excellent electric junctions between them. The cell performance has been evaluated between 850 and 950 degree C, using hydrogen or methane fuel; the tension and current for different resistance values in the electrical circuit have been measured. The cobalt addition to the cell anode significantly increased its activity for the reform reaction. The beneficial effect was probably due to the easier nickel reduction in cobalt presence. This work had the objectives of developing and evaluating electro-catalysts, as well as the solid oxide fuel cells using these catalysts as anode. Five SOFC models (SOFC 1 to SOFC 5) are described; all of them were developed aiming at improving the preparation of the anode/electrolyte/cathode structure (A/E/C). (author)

  4. Preparation and characterization of Ce/Zr mixed oxides and their use as catalysts for the direct oxidation of dry CH{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Larrondo, Susana; Vidal, Maria Adelina; Irigoyen, Beatriz; Amadeo, Norma [Lab. de Procesos Cataliticos, Depto. de Ing. Quimica, Facultad de Ingenieria, University de Buenos Aires, Pab. de Industrias, Ciudad Universitaria, 1428 Buenos Aires (Argentina); Craievich, Aldo F. [Instituto de Fisica, USP, Travessa R da Rua do Matao, no.187, Cidade Universitaria, 05508-900, Sao Paulo, SP (Brazil); Lamas, Diego G.; Fabregas, Ismael O.; Lascalea, Gustavo E.; Reca, Noemi E. Walsoee de [Centro de Investigaciones en Solidos CINSO, CITEFA-CONICET, J.B. de La Salle 4397, 1603 Villa Martelli, Buenos Aires (Argentina)

    2005-10-30

    Solid oxide fuel cells have a promissory future in the direct combustion of fuels but, their main drawbacks are the high operation temperature and the rapid performance degradation due to carbon deposition in the anode. The development of ceria-based anodes with good electronic conductivity at lower temperatures seems to be a promising way to solve those problems. In this work, preparation of compositionally homogeneous Ce/Zr oxides by a gel-combustion process and their characterization are reported. A detailed crystallographic study performed by synchrotron radiation X-ray diffraction has been carried out, in order to analyze the correlation between crystal structure and catalytic properties. The oxides presented specific area values, porous size distribution and carbon content values desirable for solid catalysts. Likewise, increasing the content of ZrO{sub 2} facilitates the reducibility of both surface and bulk sites in the solid. The oxides have been active in the combustion of methane. Their performances were stable during a typical work period of 8h, with no evidence of formation of carbonaceous deposits. The experiments that were carried out confirm the promising features of these oxides as anodic materials in solid oxide fuel cells.

  5. Fuel cells: spectroscopic studies in the electrocatalysis of alcohol oxidation

    Directory of Open Access Journals (Sweden)

    Iwasita Teresa

    2002-01-01

    Full Text Available Modern spectroscopic methods are useful for elucidating complex electrochemical mechanisms as those occurring during the oxidation of small organic molecules (CH3OH, HCOH, HCOOH. In the present paper it is shown the use of spectroscopic methods to study the oxidation of alcohols on platinum or Pt-based binary electrodes. These reactions are of importance in conexion with the development of anode systems for use in fuel cells. Mass spectrometry and FT infrared spectroscopy allow to establishing the reaction intermediates and products and the dependence of the amount of species on the applied potential. FTIR and scanning tunneling microscopy contribute to understand the effects of the surface structure on the rate of reaction. Examples are presented for methanol and ethanol oxidation at pure and modified Pt catalysts.

  6. Solid oxide fuel cell having a glass composite seal

    Science.gov (United States)

    De Rose, Anthony J.; Mukerjee, Subhasish; Haltiner, Jr., Karl Jacob

    2013-04-16

    A solid oxide fuel cell stack having a plurality of cassettes and a glass composite seal disposed between the sealing surfaces of adjacent cassettes, thereby joining the cassettes and providing a hermetic seal therebetween. The glass composite seal includes an alkaline earth aluminosilicate (AEAS) glass disposed about a viscous glass such that the AEAS glass retains the viscous glass in a predetermined position between the first and second sealing surfaces. The AEAS glass provides geometric stability to the glass composite seal to maintain the proper distance between the adjacent cassettes while the viscous glass provides for a compliant and self-healing seal. The glass composite seal may include fibers, powders, and/or beads of zirconium oxide, aluminum oxide, yttria-stabilized zirconia (YSZ), or mixtures thereof, to enhance the desirable properties of the glass composite seal.

  7. Thermal imaging of solid oxide fuel cell anode processes

    Energy Technology Data Exchange (ETDEWEB)

    Pomfret, Michael B.; Kidwell, David A.; Owrutsky, Jeffrey C. [Chemistry Division, U.S. Naval Research Laboratory, Washington, DC 20375 (United States); Steinhurst, Daniel A. [Nova Research Inc., Alexandria, VA 22308 (United States)

    2010-01-01

    A Si-charge-coupled device (CCD), camera-based, near-infrared imaging system is demonstrated on Ni/yttria-stabilized zirconia (YSZ) fragments and the anodes of working solid oxide fuel cells (SOFCs). NiO reduction to Ni by H{sub 2} and carbon deposition lead to the fragment cooling by 5 {+-} 2 C and 16 {+-} 1 C, respectively. When air is flowed over the fragments, the temperature rises 24 {+-} 1 C as carbon and Ni are oxidized. In an operational SOFC, the decrease in temperature with carbon deposition is only 4.0 {+-} 0.1 C as the process is moderated by the presence of oxides and water. Electrochemical oxidation of carbon deposits results in a {delta}T of +2.2 {+-} 0.2 C, demonstrating that electrochemical oxidation is less vigorous than atmospheric oxidation. While the high temperatures of SOFCs are challenging in many respects, they facilitate thermal imaging because their emission overlaps the spectral response of inexpensive Si-CCD cameras. Using Si-CCD cameras has advantages in terms of cost, resolution, and convenience compared to mid-infrared thermal cameras. High spatial ({proportional_to}0.1 mm) and temperature ({proportional_to}0.1 C) resolutions are achieved in this system. This approach provides a convenient and effective analytical technique for investigating the effects of anode chemistry in operating SOFCs. (author)

  8. Thermal imaging of solid oxide fuel cell anode processes

    Science.gov (United States)

    Pomfret, Michael B.; Steinhurst, Daniel A.; Kidwell, David A.; Owrutsky, Jeffrey C.

    A Si-charge-coupled device (CCD), camera-based, near-infrared imaging system is demonstrated on Ni/yttria-stabilized zirconia (YSZ) fragments and the anodes of working solid oxide fuel cells (SOFCs). NiO reduction to Ni by H 2 and carbon deposition lead to the fragment cooling by 5 ± 2 °C and 16 ± 1 °C, respectively. When air is flowed over the fragments, the temperature rises 24 ± 1 °C as carbon and Ni are oxidized. In an operational SOFC, the decrease in temperature with carbon deposition is only 4.0 ± 0.1 °C as the process is moderated by the presence of oxides and water. Electrochemical oxidation of carbon deposits results in a Δ T of +2.2 ± 0.2 °C, demonstrating that electrochemical oxidation is less vigorous than atmospheric oxidation. While the high temperatures of SOFCs are challenging in many respects, they facilitate thermal imaging because their emission overlaps the spectral response of inexpensive Si-CCD cameras. Using Si-CCD cameras has advantages in terms of cost, resolution, and convenience compared to mid-infrared thermal cameras. High spatial (∼0.1 mm) and temperature (∼0.1 °C) resolutions are achieved in this system. This approach provides a convenient and effective analytical technique for investigating the effects of anode chemistry in operating SOFCs.

  9. Thermal gradient effects on the oxidation of Zircaloy fuel cladding

    International Nuclear Information System (INIS)

    Klein, A.C.; Reyes, J.N. Jr.; Maguire, M.A.

    1990-01-01

    A Thermal Gradient Test Facility (TGTF) has been designed and constructed to measure the thermal gradient effect on pressurized water reactor (PWR) fuel rod cladding. The TGTF includes a heat flux simulator assembly capable of producing a wide range of PWR operating conditions including water flow velocities and temperatures, water chemistry conditions, cladding temperatures, and heat fluxes ranging to 160 W/cm 2 . It is fully instrumented including a large number of thermocouples both inside the water flow channel and inside the cladding. Two test programs are in progress. First, cladding specimens are pre-oxidized in air at 500 deg. C and in 400 deg. C steam for various lengths of time to develop a range of uniform oxide thicknesses from 1 to 60 micrometers. The pre-oxidized specimens are placed in the TGTF to characterize the oxide thermal conductivity under a variety of water flow and heat flux conditions. Second, to overcome the long exposure times required under typical PWR conditions a series of tests with the addition of high concentrations of lithium hydroxide to the water are being considered. Static autoclave tests have been conducted with lithium hydroxide concentrations ranging from 0 to 2 moles per liter at 300, 330, and 360 deg. C for up to 36 hours. Results for zircaloy-4 show a considerable increase in the weight gain for the exposed samples with oxidation rate enhancement factors as high as 70 times that of pure water. Operation of the TGTF with elevated lithium hydroxide levels will yield real-time information concerning the effects of a heat flux on the oxidation kinetics of zircaloy fuel rod cladding. (author). 5 refs, 5 figs, 2 tabs

  10. Gas phase deposition of oxide and metal-oxide coatings on fuel particles

    International Nuclear Information System (INIS)

    Patokin, A.P.; Khrebtov, V.L.; Shirokov, B.M.

    2008-01-01

    Production processes and properties of oxide (Al 2 O 3 , ZrO 2 ) and metal-oxide (Mo-Al 2 O 3 , Mo-ZrO 2 , W-Al 2 O 3 , W-ZrO 2 ) coatings on molybdenum substrates and uranium dioxide fuel particles were investigated. It is shown that the main factors that have an effect on the deposition rate, density, microstructure and other properties of coatings are the deposition temperature, the ratio of H 2 and CO 2 flow rates, the total reactor pressure and the ratio of partial pressures of corresponding metal chlorides during formation of metal-oxide coatings

  11. Performance of planar single cell lanthanum gallate based solid oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Maffei, N.; Kuriakose, A.K. [Materials Technology Labs., CANMET, Natural Resources Canada, Ottawa, ON (Canada)

    1998-09-01

    A novel synthesis of high purity, single phase strontium-magnesium doped lanthanum gallate through a nitrate route is described. The prepared powder is formed into planar monolithic elements by uniaxial pressing followed by isostatic pressing and sintering. XRD analysis of the sintered elements reveal no detectable secondary phases. The performance of the electrolyte in solid oxide fuel cells (SOFC) with three different anode/cathode combinations tested at 700 C with respect to the J-V and power density is reported. The data show that the characteristics of this SOFC are strongly dependent on the particular anode/cathode system chosen. (orig.)

  12. Performance of planar single cell lanthanum gallate based solid oxide fuel cells

    Science.gov (United States)

    Maffei, N.; Kuriakose, A. K.

    A novel synthesis of high purity, single phase strontium-magnesium doped lanthanum gallate through a nitrate route is described. The prepared powder is formed into planar monolithic elements by uniaxial pressing followed by isostatic pressing and sintering. XRD analysis of the sintered elements reveal no detectable secondary phases. The performance of the electrolyte in solid oxide fuel cells (SOFC) with three different anode/cathode combinations tested at 700°C with respect to the J- V and power density is reported. The data show that the characteristics of this SOFC are strongly dependent on the particular anode/cathode system chosen.

  13. Microwave assisted sintering of gadolinium doped barium cerate electrolyte for intermediate temperature solid oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Arumugam Senthil, E-mail: senthu.ramp@gmail.com [Department of Physics, PSG College of Technology, Coimbatore, 641 004, Tamilnadu (India); Balaji, Ramamoorthy [Department of Physics, PSG College of Technology, Coimbatore, 641 004, Tamilnadu (India); Jayakumar, Srinivasalu [Department of Physics, PSG Institute of Technology and Applied Research, Coimbatore, 641 062, Tamilnadu (India); Pradeep, Chandran [Department of Physics, Indian Institute of Technology, Madras, 600 036, Tamilnadu (India)

    2016-10-01

    In Solid Oxide Fuel Cell (SOFC), electrolyte plays a vital role to increase the energy conversion efficiency. The main hurdle of such electrolyte in fuel cell is its higher operating temperature (1000 °C) which results in design limitation and higher fabrication cost. In order to reduce the operating temperature of SOFC, a suitable electrolyte has been prepared through co-precipitation method followed by microwave sintering of solid ceramic. The calcination temperature for the as-prepared powder was identified using Differential Scanning Calorimetry. The crystal structure of the sample was found to exhibit its orthorhombic perovskite structure. The particle size was determined using High-Resolution Transmission Electron Microscope with uniform in shape and size, match with XRD results and confirmed from structural analysis. Thus, the sample prepared via co-precipitation method and the solid ceramic sintered through microwave can be a promising electrolyte for fuel cells operated at intermediate temperature. - Highlights: • To synthesis the composite electrolyte by chemical method and sinter using microwave. • To reduce the operating temperature of electrolyte for high ionic conductivity in SOFC's. • To study the phase purity and to develop nanocomposite at reduced temperature.

  14. Reversible solid oxide fuel cells (R-SOFCs) with chemically stable proton-conducting oxides

    KAUST Repository

    Bi, Lei

    2015-07-01

    Proton-conducting oxides offer a promising way of lowering the working temperature of solid oxide cells to the intermediate temperate range (500 to 700. °C) due to their better ionic conductivity. In addition, the application of proton-conducting oxides in both solid oxide fuel cells (SOFCs) and sold oxide electrolysis cells (SOECs) provides unique advantages compared with the use of conventional oxygen-ion conducting conductors, including the formation of water at the air electrode site. Since the discovery of proton conduction in some oxides about 30. years ago, the development of proton-conducting oxides in SOFCs and SOECs (the reverse mode of SOFCs) has gained increased attention. This paper briefly summarizes the development in the recent years of R-SOFCs with proton-conducting electrolytes, focusing on discussing the importance of adopting chemically stable materials in both fuel cell and electrolysis modes. The development of electrode materials for proton-conducting R-SOFCs is also discussed. © 2015 Elsevier B.V.

  15. Preparation of molybdenum oxide thin films by MOCVD

    International Nuclear Information System (INIS)

    Guerrero, R. Martinez; Garcia, J.R. Vargas; Santes, V.; Gomez, E.

    2007-01-01

    In this study, molybdenum oxide films were prepared in a horizontal hot-wall MOCVD apparatus using molybdenum dioxide acetylacetonate as precursor. The molybdenum precursor was synthesized from acetylacetone and molybdenum oxide powder. Thermal gravimetric (TG) and differential thermal analyses (DTA) of the precursor suggested the formation of molybdenum oxides around 430 o C (703 K). Thus, a range of deposition temperatures varying from 350 to 630 o C (623-903 K) was explored to investigate the effects on the nature of the molybdenum oxide films. X-ray diffraction (XRD) results showed that the films consisted of α-MoO 3 phase at deposition temperatures ranging from 400 to 560 o C (673-833 K). Crystalline α-MoO 3 films can be obtained from molybdenum dioxide acetylacetonate precursor, without need of a post-annealing treatment. The best crystalline quality was found in films having needle-like crystallites grown at deposition temperature of about 560 o C (833 K), which exhibit a strong (0 1 0) preferred orientation and a transparent visual appearance

  16. Preparation of molybdenum oxide thin films by MOCVD

    Energy Technology Data Exchange (ETDEWEB)

    Guerrero, R. Martinez [Depto. de Ingenieria Metalurgica, ESIQIE-IPN, Mexico 07300, D.F. (Mexico); Garcia, J.R. Vargas [Depto. de Ingenieria Metalurgica, ESIQIE-IPN, Mexico 07300, D.F. (Mexico)]. E-mail: rvargasga@ipn.mx; Santes, V. [CIIEMAD-IPN, Miguel Othon de Mendizabal 485, Mexico 07700, D.F. (Mexico); Gomez, E. [Instituto de Quimica-UNAM, Circuito Exterior-Ciudad Universitaria, Mexico 04510, D.F. (Mexico)

    2007-05-31

    In this study, molybdenum oxide films were prepared in a horizontal hot-wall MOCVD apparatus using molybdenum dioxide acetylacetonate as precursor. The molybdenum precursor was synthesized from acetylacetone and molybdenum oxide powder. Thermal gravimetric (TG) and differential thermal analyses (DTA) of the precursor suggested the formation of molybdenum oxides around 430 {sup o}C (703 K). Thus, a range of deposition temperatures varying from 350 to 630 {sup o}C (623-903 K) was explored to investigate the effects on the nature of the molybdenum oxide films. X-ray diffraction (XRD) results showed that the films consisted of {alpha}-MoO{sub 3} phase at deposition temperatures ranging from 400 to 560 {sup o}C (673-833 K). Crystalline {alpha}-MoO{sub 3} films can be obtained from molybdenum dioxide acetylacetonate precursor, without need of a post-annealing treatment. The best crystalline quality was found in films having needle-like crystallites grown at deposition temperature of about 560 {sup o}C (833 K), which exhibit a strong (0 1 0) preferred orientation and a transparent visual appearance.

  17. Preparation and characterization of vanadium oxide thin films

    Energy Technology Data Exchange (ETDEWEB)

    Monfort, O.; Plesch, G. [Comenius University of Bratislava, Faculty of Natural Sciences, Department of Inorganic Chemistry, 84215 Bratislava (Slovakia); Roch, T. [Comenius University of Bratislava, Faculty of Mathematics Physics and Informatics, Department of Experimental Physics, 84248 Bratislava (Slovakia)

    2013-04-16

    The thermotropic VO{sub 2} films have many applications, since they exhibit semiconductor-conductor switching properties at temperature around 70 grad C. Vanadium oxide thin films were prepared via sol-gel method. Spin coater was used to depose these films on Si/SiO{sub 2} and lime glass substrates. Thin films of V{sub 2}O{sub 5} can be reduced to metastable VO{sub 2} thin films at the temperature of 450 grad C under the pressure of 10{sup -2} Pa. These films are then converted to thermotropic VO{sub 2} at 700 grad C in argon under normal pressure. (authors)

  18. Equipment to weld fuel rods of mixed oxides

    International Nuclear Information System (INIS)

    Aparicio, G.; Orlando, O.S.; Olano, V.R.; Toubes, B.; Munoz, C.A.

    1987-01-01

    Two welding outfits system T1G were designed and constructed to weld fuel rods with mixed oxides pellets (uranium and plutonium). One of them is connected to a glove box where the loading of sheaths takes place. The sheaths are driven to the welder through a removable plug pusher in the welding chamber. This equipment was designed to perform welding tests changing the parameters (gas composition and pressure, welding current, electrode position, etc.). The components of the welder, such as plug holder, chamber closure and peripheral accessories, were designed and constructed taking into account the working pressures in the machine, which is placed in a controlled area and connected to a glove box, where special safety conditions are necessary. The equipment to weld fuel bars is complemented by another machine, located in cold area, of the type presently used in the fuel elements factory. This equipment has been designed to perform some welding operations in sheaths and mixed oxide rods of the type Atucha I and II. Both machines have a programmed power supply of wide range and a vacuum, and pressurizing system that allows the change of parameters. Both systems have special features of handling and operation. (Author)

  19. Oxide fuel pin transient performance analysis and design with the TEMECH code

    International Nuclear Information System (INIS)

    Bard, F.E.; Dutt, S.P.; Hinman, C.A.; Hunter, C.W.; Pitner, A.L.

    1986-01-01

    The TEMECH code is a fast-running, thermal-mechanical-hydraulic, analytical program used to evaluate the transient performance of LMR oxide fuel pins. The code calculates pin deformation and failure probability due to fuel-cladding differential thermal expansion, expansion of fuel upon melting, and fission gas pressurization. The mechanistic fuel model in the code accounts for fuel cracking, crack closure, porosity decrease, and the temperature dependence of fuel creep through the course of the transient. Modeling emphasis has been placed on results obtained from Fuel Cladding Transient Test (FCTT) testing, Transient Fuel Deformation (TFD) tests and TREAT integral fuel pin experiments

  20. A preparation method of thorium nitrides and their oxidation behavior

    International Nuclear Information System (INIS)

    Miyake, M.; Katsura, M.; Uno, M.

    1991-01-01

    In the preparation of ThN, thermal decomposition of Th 3 N 4 has been performed under various conditions and the kind of products has been examined as a function of temperature and time. In the Th-N-O system there exist ThN, Th 3 N 4 , ThO 2 , and Th 2 N 2 O as solid phases. The thermodynamic stability of these solid compounds has been evaluated as a function of P(O 2 ) and P(N 2 ) and compared with the experimental results. One of the main aims in this work is to explore the oxidation behaviour of thorium nitrides. Preliminary oxidation experiments of ThN and Th 3 N 4 gave the same result. From the study of the air oxidation of Th 3 N 4 , it was found that the oxidation product obtained close to room temperature exhibited only one or more diffuse reflections in its diffraction pattern, suggesting that the product may be of a poor crystalline nature. In order to reveal the dependence of the crystallinity of the product on the oxidation temperature, powdered Th 3 N 4 was exposed to air for one week at 0, 50, and 100degC and the product was examined by X-ray diffraction. In order to prepare ThO 2 with a wide variety of degrees of crystallinity, poorly-crystallized ThO 2 , which is produced by the air oxidation of Th 3 N 4 at 50degC, was heat-treated at temperatures ranging from 200 to 1,400degC in air and vacuum. The degree of crystallinity of ThO 2 heat-treated at and below 1000degC is discussed in terms of the number of detected peaks in the X-ray diffraction patterns, and above 1100degC in terms of the Kα doublet resolution of detected peaks. (author). 11 refs., 7 figs., 6 tabs

  1. Platinum redispersion on metal oxides in low temperature fuel cells.

    Science.gov (United States)

    Tripković, Vladimir; Cerri, Isotta; Nagami, Tetsuo; Bligaard, Thomas; Rossmeisl, Jan

    2013-03-07

    We have analyzed the aptitude of several metal oxide supports (TiO(2), SnO(2), NbO(2), ZrO(2), SiO(2), Ta(2)O(5) and Nb(2)O(5)) to redisperse platinum under electrochemical conditions pertinent to the Proton Exchange Membrane Fuel Cell (PEMFC) cathode. The redispersion on oxide supports in air has been studied in detail; however, due to different operating conditions it is not straightforward to link the chemical and the electrochemical environment. The largest differences reflect in (1) the oxidation state of the surface (the oxygen species coverage), (2) temperature and (3) the possibility of platinum dissolution at high potentials and the interference of redispersion with normal working potential of the PEMFC cathode. We have calculated the PtO(x) (x = 0, 1, 2) adsorption energies on different metal oxides' surface terminations as well as inside the metal oxides' bulk, and we have concluded that NbO(2) might be a good support for platinum redispersion at PEMFC cathodes.

  2. Thermal stress analysis of sulfur deactivated solid oxide fuel cells

    Science.gov (United States)

    Zeng, Shumao; Parbey, Joseph; Yu, Guangsen; Xu, Min; Li, Tingshuai; Andersson, Martin

    2018-03-01

    Hydrogen sulfide in fuels can deactivate catalyst for solid oxide fuel cells, which has become one of the most critical challenges to stability. The reactions between sulfur and catalyst will cause phase changes, leading to increase in cell polarization and mechanical mismatch. A three-dimensional computational fluid dynamics (CFD) approach based on the finite element method (FEM) is thus used to investigate the polarization, temperature and thermal stress in a sulfur deactivated SOFC by coupling equations for gas-phase species, heat, momentum, ion and electron transport. The results indicate that sulfur in fuels can strongly affect the cell polarization and thermal stresses, which shows a sharp decrease in the vicinity of electrolyte when 10% nickel in the functional layer is poisoned, but they remain almost unchanged even when the poisoned Ni content was increased to 90%. This investigation is helpful to deeply understand the sulfur poisoning effects and also benefit the material design and optimization of electrode structure to enhance cell performance and lifetimes in various hydrocarbon fuels containing impurities.

  3. Dissolution of mixed oxide spent fuel from FBR

    International Nuclear Information System (INIS)

    Sanyoshi, H.; Nishina, H.; Toyota, O.; Yamamoto, R.; Nemoto, S.; Okamoto, F.; Togashi, A.; Kawata, T.; Hayashi, S.

    1991-01-01

    At the Tokai Works of the Power Reactor and Nuclear Fuel Development Corporation (PNC), the Chemical Processing Facility (CPF) has been continuing operation since 1982 for laboratory scale hot experiments on reprocessing of FBR mixed oxide fuel. As a part of these experiments, dissolution experiments have been performed to define the key parameters affecting dissolution rates such as concentration of nitric acid, temperature and burnup and also to confirm the amount of insoluble residue. The dissolution rate of the irradiated fuel was determined to be in proportion to the 1.7 power of the nitric acid concentration. The activation energy determined from the experiments varied from 6 to 11 kcal/mol depending on the method of dissolution. The dissolution rate decreased as the fuel burnup increased in low nitric acid media below 5 mol/l. However, it was found that the effect of the burnup became negligible in a high concentration of nitric acid media. The amount of insoluble residue and its constituents were evaluated by changing the dissolution condition. (author)

  4. AlliedSignal solid oxide fuel cell technology

    Energy Technology Data Exchange (ETDEWEB)

    Minh, N.; Barr, K.; Kelly, P.; Montgomery, K. [AlliedSignal Aerospace Equipment Systems, Torrance, CA (United States)

    1996-12-31

    AlliedSignal has been developing high-performance, lightweight solid oxide fuel cell (SOFC) technology for a broad spectrum of electric power generation applications. This technology is well suited for use in a variety of power systems, ranging from commercial cogeneration to military mobile power sources. The AlliedSignal SOFC is based on stacking high-performance thin-electrolyte cells with lightweight metallic interconnect assemblies to form a compact structure. The fuel cell can be operated at reduced temperatures (600{degrees} to 800{degrees}C). SOFC stacks based on this design has the potential of producing 1 kW/kg and 1 ML. This paper summarizes the technical status of the design, manufacture, and operation of AlliedSignal SOFCs.

  5. Planar solid oxide fuel cells: the Australian experience and outlook

    Science.gov (United States)

    Godfrey, Bruce; Föger, Karl; Gillespie, Rohan; Bolden, Roger; Badwal, S. P. S.

    Since 1992, Ceramic Fuel Cells (CFCL) has grown to what is now the largest focussed program globally for development of planar ceramic (solid oxide) fuel cell, SOFC, technology. A significant intellectual property position in know-how and patents has been developed, with over 80 people involved in the venture. Over $A60 million in funding for the activities of the company has been raised from private companies, government-owned corporations and government business-support programs, including from energy — particularly electricity — industry shareholders that can facilitate access to local markets for our products. CFCL has established state-of-the-art facilities for planar SOFC R&D, with their expansion and scaling-up to pilot manufacturing capability underway. We expect to achieve commercial introduction of our market-entry products in 2002, with prototype systems expected to be available from early 2001.

  6. Paper-based membraneless hydrogen peroxide fuel cell prepared by micro-fabrication

    Science.gov (United States)

    Mousavi Ehteshami, Seyyed Mohsen; Asadnia, Mohsen; Tan, Swee Ngin; Chan, Siew Hwa

    2016-01-01

    A paper-based membraneless single-compartment hydrogen peroxide power source prepared by micro-electromechanical systems (MEMS) technology is reported. The cell utilizes hydrogen peroxide as both fuel and oxidant in a low volume cell fabricated on paper. The fabrication method used is a simple method where precise, small-sized patterns are produced which include the hydrophilic paper bounded by hydrophobic resin. Open circuit potentials of 0.61 V and 0.32 V are achieved for the cells fabricated with Prussian Blue as the cathode and aluminium/nickel as the anode materials, respectively. The power produced by the cells is 0.81 mW cm-2 at 0.26 V and 0.38 mW cm-2 at 0.14 V, respectively, even after the cell is bent or distorted. Such a fuel cell provides an easily fabricated, environmentally friendly, flexible and cost saving power source. The cell may be integrated within a self-sustained diagnostic system to provide the on-demand power for future bio-sensing applications.

  7. Catalytic Oxidation of Toluene on Hydrothermally Prepared Ceria Nanocrystals

    Directory of Open Access Journals (Sweden)

    M. Duplančić

    2018-01-01

    Full Text Available Ceria nanocrystals were prepared hydrothermally and tested as potential catalysts for oxidation of volatile organic compounds using toluene as a model compound. Pure ceria with a crystallite size of 4 nm, determined by the Scherrer method from XRD pattern has been obtained. The specific surface area of the prepared nanoparticles determined by BET analysis yielded 201 m2 g–1, while the band gap of 3.2 eV was estimated from DRS spectrum via Tauc’s plot. Catalytic tests were performed on calcined ceria (500 °C with increased crystallite size (9 nm caused by thermal treatment. The tests showed good activities for the toluene oxidation with T50 temperatures, corresponding to 50 % toluene conversion, observed at 250 °C and even lower temperatures depending on the total flow rate of the gas mixture. The one-dimensional pseudo-homogeneous model of the fixed bed reactor was proposed to describe the reactor performance and the appropriate kinetic parameters were estimated. Good agreement between experimental data and the proposed model was observed.

  8. Nanotubes of rare earth cobalt oxides for cathodes of intermediate-temperature solid oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Sacanell, Joaquin [Departamento de Fisica, Centro Atomico Constituyentes, CNEA, Av. Gral. Paz 1499, 1650 San Martin, Buenos Aires (Argentina); CINSO (Centro de Investigaciones en Solidos), CITEFA-CONICET, J.B. de La Salle 4397, 1603 Villa Martelli, Buenos Aires (Argentina); Leyva, A. Gabriela [Departamento de Fisica, Centro Atomico Constituyentes, CNEA, Av. Gral. Paz 1499, 1650 San Martin, Buenos Aires (Argentina); Escuela de Ciencia y Tecnologia, UNSAM. Av. Gral. Paz 1499, 1650 San Martin, Buenos Aires (Argentina); Bellino, Martin G.; Lamas, Diego G. [CINSO (Centro de Investigaciones en Solidos), CITEFA-CONICET, J.B. de La Salle 4397, 1603 Villa Martelli, Buenos Aires (Argentina)

    2010-04-02

    In this work we studied the electrochemical properties of cathodes for intermediate-temperature solid oxide fuel cells (IT-SOFCs) prepared with nanotubes of La{sub 0.6}Sr{sub 0.4}CoO{sub 3} (LSCO). Their nanostructures consist of agglomerated nanoparticles in tubular structures of sub-micrometric diameter. The resulting cathodes are highly porous both at the micro- and the nanoscale. This fact increases significantly the access to active sites for the oxygen reduction. We investigated the influence of the diameter of the precursor nanotubes on the polarization resistance of the LSCO cathodes on CeO{sub 2}-10 mol.% Sm{sub 2}O{sub 3} (SDC) electrolytes under air atmosphere, evaluated in symmetrical [LSCO/SDC/LSCO] cells. Our results indicate an optimized performance when the diameter of precursor nanotubes is sufficiently small to become dense nanorods after cathode sintering. We present a phenomenological model that successfully explains the behavior observed and considers that a small starting diameter acts as a barrier that prevents grains growth. This is directly related with the lack of contact points between nanotubes in the precursor, which are the only path for the growth of ceramic grains. We also observed that a conventional sintering process (of 1 h at 1000 C with heating and cooling rates of 10 C min{sup -1}) has to be preferred against a fast firing one (1 or 2 min at 1100 C with heating and cooling rates of 100 C min{sup -1}) in order to reach a higher performance. However, a good adhesion of the cathode can be achieved with both methods. Our results suggest that oxygen vacancy diffusion is enhanced while decreasing LSCO particle size. This indicates that the high performance of our nanostructured cathodes is not only related with the increase of the number of active sites for oxygen reduction but also to the fact that the nanotubes are formed by nanoparticles. (author)

  9. SOLID STATE ENERGY CONVERSION ALLIANCE DELPHI SOLID OXIDE FUEL CELL

    Energy Technology Data Exchange (ETDEWEB)

    Steven Shaffer; Sean Kelly; Subhasish Mukerjee; David Schumann; Gail Geiger; Kevin Keegan; Larry Chick

    2004-05-07

    The objective of this project is to develop a 5 kW Solid Oxide Fuel Cell power system for a range of fuels and applications. During Phase I, the following will be accomplished: Develop and demonstrate technology transfer efforts on a 5 kW stationary distributed power generation system that incorporates steam reforming of natural gas with the option of piped-in water (Demonstration System A). Initiate development of a 5 kW system for later mass-market automotive auxiliary power unit application, which will incorporate Catalytic Partial Oxidation (CPO) reforming of gasoline, with anode exhaust gas injected into an ultra-lean burn internal combustion engine. This technical progress report covers work performed by Delphi from July 1, 2003 to December 31, 2003, under Department of Energy Cooperative Agreement DE-FC-02NT41246. This report highlights technical results of the work performed under the following tasks: Task 1 System Design and Integration; Task 2 Solid Oxide Fuel Cell Stack Developments; Task 3 Reformer Developments; Task 4 Development of Balance of Plant (BOP) Components; Task 5 Manufacturing Development (Privately Funded); Task 6 System Fabrication; Task 7 System Testing; Task 8 Program Management; Task 9 Stack Testing with Coal-Based Reformate; and Task 10 Technology Transfer from SECA CORE Technology Program. In this reporting period, unless otherwise noted Task 6--System Fabrication and Task 7--System Testing will be reported within Task 1 System Design and Integration. Task 8--Program Management, Task 9--Stack Testing with Coal Based Reformate, and Task 10--Technology Transfer from SECA CORE Technology Program will be reported on in the Executive Summary section of this report.

  10. Identification of a Methane Oxidation Intermediate on Solid Oxide Fuel Cell Anode Surfaces with Fourier Transform Infrared Emission.

    Science.gov (United States)

    Pomfret, Michael B; Steinhurst, Daniel A; Owrutsky, Jeffrey C

    2013-04-18

    Fuel interactions on solid oxide fuel cell (SOFC) anodes are studied with in situ Fourier transform infrared emission spectroscopy (FTIRES). SOFCs are operated at 800 °C with CH4 as a representative hydrocarbon fuel. IR signatures of gas-phase oxidation products, CO2(g) and CO(g), are observed while cells are under load. A broad feature at 2295 cm(-1) is assigned to CO2 adsorbed on Ni as a CH4 oxidation intermediate during cell operation and while carbon deposits are electrochemically oxidized after CH4 operation. Electrochemical control provides confirmation of the assignment of adsorbed CO2. FTIRES has been demonstrated as a viable technique for the identification of fuel oxidation intermediates and products in working SOFCs, allowing for the elucidation of the mechanisms of fuel chemistry.

  11. Preparation, characterisation, engine performance and emission characteristics of coconut oil based hybrid fuels

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Pranil J.; Singh, Anirudh [Division of Physics, School of Engineering and Physics, Faculty of Science, Technology and Environment, University of the South Pacific, 325 Fletcher Road, Suva (Fiji); Khurma, Jagjit [Division of Chemistry, School of Biological, Chemical and Environmental Sciences, Faculty of Science, Technology and Environment, University of the South Pacific, Suva (Fiji)

    2010-09-15

    In this study, hybrid fuels consisting of coconut oil, aqueous ethanol and a surfactant (butan-1-ol) were prepared and tested as a fuel in a direct injection diesel engine. After determining fuel properties such as the density, viscosity and gross calorific values of these fuels, they were used to run a diesel engine. The engine performance and exhaust emissions were investigated and compared with that of diesel. The experimental results show that the efficiency of the hybrid fuels is comparable to that of diesel. As the viscosity of the hybrid fuels decreased and approached that of diesel, the efficiency increased progressively towards that of diesel. The exhaust emissions were lower than those for diesel, except carbon monoxide emissions, which increased. Hence, it is concluded that these hybrid fuels can be used successfully as an alternative fuel in diesel engines without any modifications. Their completely renewable nature ensures that they are environmentally friendly with regard to their emissions characteristics. (author)

  12. Synthesis and electrochemical performances of LiNiCuZn oxides as anode and cathode catalyst for low temperature solid oxide fuel cell.

    Science.gov (United States)

    Jing, Y; Qin, H; Liu, Q; Singh, M; Zhu, B

    2012-06-01

    Low temperature solid oxide fuel cell (LTSOFC, 300-600 degrees C) is developed with advantages compared to conventional SOFC (800-1000 degrees C). The electrodes with good catalytic activity, high electronic and ionic conductivity are required to achieve high power output. In this work, a LiNiCuZn oxides as anode and cathode catalyst is prepared by slurry method. The structure and morphology of the prepared LiNiCuZn oxides are characterized by X-ray diffraction and field emission scanning electron microscopy. The LiNiCuZn oxides prepared by slurry method are nano Li0.28Ni0.72O, ZnO and CuO compound. The nano-crystallites are congregated to form ball-shape particles with diameter of 800-1000 nm. The LiNiCuZn oxides electrodes exhibits high ion conductivity and low polarization resistance to hydrogen oxidation reaction and oxygen reduction reaction at low temperature. The LTSOFC using the LiNiCuZn oxides electrodes demonstrates good cell performance of 1000 mW cm(-2) when it operates at 470 degrees C. It is considered that nano-composite would be an effective way to develop catalyst for LTSOFC.

  13. Impedance Modeling of Solid Oxide Fuel Cell Cathodes

    DEFF Research Database (Denmark)

    Mortensen, Jakob Egeberg; Søgaard, Martin; Jacobsen, Torben

    2010-01-01

    A 1-dimensional impedance model for a solid oxide fuel cell cathode is formulated and applied to a cathode consisting of 50/50 wt% strontium doped lanthanum cobaltite and gadolinia doped ceria. A total of 42 impedance spectra were recorded in the temperature range: 555-852°C and in the oxygen...... partial pressure range 0.028-1.00 atm. The recorded impedance spectra were successfully analyzed using the developed impedance model in the investigated temperature and oxygen partial pressure range. It is also demonstrated that the model can be used to predict how impedance spectra evolve with different...

  14. Fabrication of mixed oxide fuel using plutonium from dismantled weapons

    International Nuclear Information System (INIS)

    Blair, H.T.; Chidester, K.; Ramsey, K.B.

    1996-01-01

    A very brief summary is presented of experimental studies performed to support the use of plutonium from dismantled weapons in fabricating mixed oxide (MOX) fuel for commercial power reactors. Thermal treatment tests were performed on plutonium dioxide powder to determine if an effective dry gallium removal process could be devised. Fabrication tests were performed to determine the effects of various processing parameters on pellet quality. Thermal tests results showed that the final gallium content is highly dependent on the treatment temperature. Fabrication tests showed that the milling process, sintering parameters, and uranium feed did effect pellet properties. 1 ref., 1 tab

  15. Hydrogen peroxide oxidant fuel cell systems for ultra-portable applications

    Science.gov (United States)

    Valdez, T. I.; Narayanan, S. R.

    2001-01-01

    This paper will address the issues of using hydrogen peroxide as an oxidant fuel in a miniature DMFC system. Cell performance for DMFC based fuel cells operating on hydrogen peroxide will be presented and discussed.

  16. Novel metal oxides prepared by ingenious synthetic routes

    International Nuclear Information System (INIS)

    Rao, C.N.R.; Gopalakrishnan, J.; Vidyasagar, K.; Ganguli, A.K.; Ramanan, A.; Ganapathi, L.

    1986-01-01

    Several novel oxides have been prepared by the decomposition of carbonate precursors of calcite structure of the general formulas Mn/sub 1-x/M/sub x/CO 3 (M = Mg,Co,Cd), Ca/sub 1-x/M/sup prime//sub x/CO 3 , and Ca/sub 1-x/-yM/sup //sub x/M/sup double-prime//sub y/CO 3 (M',M'' = Mn,Fe,Co). Typical of the oxides synthesized are a variety of monoxides, Mn/sub 1-x/M/sub x/O, of rocksalt structure and perovskite-related oxides such as Ca 2 FeCoO 5 , Ca 2 Co 2 O 5 , and Ca 3 Fe 2 MnO 8 , many of them exhibiting novel anion-vacancy-ordered superstructures. An interesting series of oxides prepared by the topotactic reduction of Ca 2 Fe/sub 2-x/Mn/sub x/O/sub 6-y/ (synthesized by the decomposition of the corresponding carbonate precursors) is Ca 2 Fe/sub 2-x/Mn/sub x/O 5 where three different coordination polyhedra (octahedra, tetrahedra, and square pyramids) of the transition metals coexist. Topotactic reduction of LaCoO 3 and LaNiO 3 yields new oxides, La 2 Co 2 O 5 and La 2 Ni 2 O 5 , possessing anion-vacancy-ordered superstructures. While La 2 Co 2 O 5 adopts the brownmillerite structure, La 2 Ni 2 O 5 exhibits a new type of vacancy ordering with octahedral and square-planar coordination of Ni 2+ . Slightly reduced LaNiO 3 seem to exhibit crystallographic shear (CS) planes similar to WO/sub 3-x/. Topotactic dehydration of isostructural Mo/sub 1-x/W/sub x/O 3 x H 2 O provides a convenient route for the synthesis of Mo/sub 1-x/W/sub x/O 3 (0 3 -related structure

  17. Facile preparation of superhydrophobic surfaces based on metal oxide nanoparticles

    Science.gov (United States)

    Bao, Xue-Mei; Cui, Jin-Feng; Sun, Han-Xue; Liang, Wei-Dong; Zhu, Zhao-Qi; An, Jin; Yang, Bao-Ping; La, Pei-Qing; Li, An

    2014-06-01

    A novel method for fabrication of superhydrophobic surfaces was developed by facile coating various metal oxide nanoparticles, including ZnO, Al2O3 and Fe3O4, on various substrates followed by treatment with polydimethylsiloxane (PDMS) via chemical vapor deposition (CVD) method. Using ZnO nanoparticles as a model, the changes in the surface chemical composition and crystalline structures of the metal oxide nanoparticles by PDMS treatment were investigated by X-ray photoelectron spectroscopy (XPS), X-ray powder diffraction (XRD) and Fourier transform infrared (FTIR) analysis. The results show that the combination of the improved surface roughness generated from of the nanoparticles aggregation with the low surface-energy of silicon-coating originated from the thermal pyrolysis of PDMS would be responsible for the surface superhydrophobicity. By a simple dip-coating method, we show that the metal oxide nanoparticles can be easily coated onto the surfaces of various textural and dimensional substrates, including glass slide, paper, fabric or sponge, for preparation of superhydrophobic surfaces for different purpose. The present strategy may provide an inexpensive and new route to surperhydrophobic surfaces, which would be of technological significance for various practical applications especially for separation of oils or organic contaminates from water.

  18. Facile preparation of superhydrophobic surfaces based on metal oxide nanoparticles

    International Nuclear Information System (INIS)

    Bao, Xue-Mei; Cui, Jin-Feng; Sun, Han-Xue; Liang, Wei-Dong; Zhu, Zhao-Qi; An, Jin; Yang, Bao-Ping; La, Pei-Qing; Li, An

    2014-01-01

    A novel method for fabrication of superhydrophobic surfaces was developed by facile coating various metal oxide nanoparticles, including ZnO, Al 2 O 3 and Fe 3 O 4 , on various substrates followed by treatment with polydimethylsiloxane (PDMS) via chemical vapor deposition (CVD) method. Using ZnO nanoparticles as a model, the changes in the surface chemical composition and crystalline structures of the metal oxide nanoparticles by PDMS treatment were investigated by X-ray photoelectron spectroscopy (XPS), X-ray powder diffraction (XRD) and Fourier transform infrared (FTIR) analysis. The results show that the combination of the improved surface roughness generated from of the nanoparticles aggregation with the low surface-energy of silicon-coating originated from the thermal pyrolysis of PDMS would be responsible for the surface superhydrophobicity. By a simple dip-coating method, we show that the metal oxide nanoparticles can be easily coated onto the surfaces of various textural and dimensional substrates, including glass slide, paper, fabric or sponge, for preparation of superhydrophobic surfaces for different purpose. The present strategy may provide an inexpensive and new route to surperhydrophobic surfaces, which would be of technological significance for various practical applications especially for separation of oils or organic contaminates from water.

  19. Facile preparation of superhydrophobic surfaces based on metal oxide nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Bao, Xue-Mei; Cui, Jin-Feng; Sun, Han-Xue; Liang, Wei-Dong; Zhu, Zhao-Qi; An, Jin; Yang, Bao-Ping; La, Pei-Qing; Li, An, E-mail: lian2010@lut.cn

    2014-06-01

    A novel method for fabrication of superhydrophobic surfaces was developed by facile coating various metal oxide nanoparticles, including ZnO, Al{sub 2}O{sub 3} and Fe{sub 3}O{sub 4}, on various substrates followed by treatment with polydimethylsiloxane (PDMS) via chemical vapor deposition (CVD) method. Using ZnO nanoparticles as a model, the changes in the surface chemical composition and crystalline structures of the metal oxide nanoparticles by PDMS treatment were investigated by X-ray photoelectron spectroscopy (XPS), X-ray powder diffraction (XRD) and Fourier transform infrared (FTIR) analysis. The results show that the combination of the improved surface roughness generated from of the nanoparticles aggregation with the low surface-energy of silicon-coating originated from the thermal pyrolysis of PDMS would be responsible for the surface superhydrophobicity. By a simple dip-coating method, we show that the metal oxide nanoparticles can be easily coated onto the surfaces of various textural and dimensional substrates, including glass slide, paper, fabric or sponge, for preparation of superhydrophobic surfaces for different purpose. The present strategy may provide an inexpensive and new route to surperhydrophobic surfaces, which would be of technological significance for various practical applications especially for separation of oils or organic contaminates from water.

  20. Preparation of cerium oxide for lens polishing powder

    International Nuclear Information System (INIS)

    Injarean, Uthaiwan; Rodthongkom, Chouvana; Pichestapong, Pipat; Changkrurng, Kalaya

    2003-10-01

    Cerium is an element of rare earth group which is called lanthanide series. It is found in the ores like monazite and xenotime which are the tailings of tin mines in the south of Thailand. Cerium is used mostly as lens polishing powder besides the applications in other industries. In this study, cerium extracted from monazite ore breakdown by alkaline process was used for the preparation of lens polishing powder. Cerium hydroxide cake from the process was dissolved by hydrochloric acid and precipitated with oxalic acid. The oxalate precipitate then was calcined to oxide powder and its particle size was measured. Precipitation conditions being studied are concentration of feed cerium chloride solution, concentration of oxalic acid used for the precipitation, concentration of sulfuric acid used as precipitation control reagent and the precipitation temperature. It was found that the appropriate precipitation conditions yielded the fine oxide powder with particle size about 12μm. The oxide powder can be ground to the size of 1-3 μm which is suitable for making lens polishing powder

  1. Mixed fuel strategy for carbon deposition mitigation in solid oxide fuel cells at intermediate temperatures.

    Science.gov (United States)

    Su, Chao; Chen, Yubo; Wang, Wei; Ran, Ran; Shao, Zongping; Diniz da Costa, João C; Liu, Shaomin

    2014-06-17

    In this study, we propose and experimentally verified that methane and formic acid mixed fuel can be employed to sustain solid oxide fuel cells (SOFCs) to deliver high power outputs at intermediate temperatures and simultaneously reduce the coke formation over the anode catalyst. In this SOFC system, methane itself was one part of the fuel, but it also played as the carrier gas to deliver the formic acid to reach the anode chamber. On the other hand, the products from the thermal decomposition of formic acid helped to reduce the carbon deposition from methane cracking. In order to clarify the reaction pathways for carbon formation and elimination occurring in the anode chamber during the SOFC operation, O2-TPO and SEM analysis were carried out together with the theoretical calculation. Electrochemical tests demonstrated that stable and high power output at an intermediate temperature range was well-maintained with a peak power density of 1061 mW cm(-2) at 750 °C. With the synergic functions provided by the mixed fuel, the SOFC was running for 3 days without any sign of cell performance decay. In sharp contrast, fuelled by pure methane and tested at similar conditions, the SOFC immediately failed after running for only 30 min due to significant carbon deposition. This work opens a new way for SOFC to conquer the annoying problem of carbon deposition just by properly selecting the fuel components to realize their synergic effects.

  2. Failure mechanisms for compacted uranium oxide fuel cores

    International Nuclear Information System (INIS)

    Berghaus, D.G.; Peacock, H.B.

    1980-01-01

    Tension, compression, and shear tests were performed on test specimens of aluminum-clad, compacted powder fuel cores to determine failure mechanisms of the core material. The core, which consists of 70% uranium oxide in an aluminum matrix, frequently fails during post-extrusion drawing. Tests were conducted to various strain levels up to failure of the core. Sections were made of tested specimens to microscopically study initiation of failure. Two failure modes wee observed. Tensile failure mode is initiated by prior tensile failure of uranium oxide particles with the separation path strongly influenced by the arrangement of particles. Delamination mode consists of the separation of laminae formed during extrusion of tubes. Separation proceeds from fine cracks formed parallel to the laminae. Tensile failure mode was experienced in tension and shear tests. Delamination mode was produced in compression tests

  3. Anodes for Solid Oxide Fuel Cells Operating at Low Temperatures

    DEFF Research Database (Denmark)

    Abdul Jabbar, Mohammed Hussain

    An important issue that has limited the potential of Solid Oxide Fuel Cells (SOFCs) for portable applications is its high operating temperatures (800-1000 ºC). Lowering the operating temperature of SOFCs to 400-600 ºC enable a wider material selection, reduced degradation and increased lifetime....... On the other hand, low-temperature operation poses serious challenges to the electrode performance. Effective catalysts, redox stable electrodes with improved microstructures are the prime requisite for the development of efficient SOFC anodes. The performance of Nb-doped SrT iO3 (STN) ceramic anodes...... at 400ºC. The potential of using WO3 ceramic as an alternative anode materials has been explored. The relatively high electrode polarization resistance obtained, 11 Ohm cm2 at 600 ºC, proved the inadequate catalytic activity of this system for hydrogen oxidation. At the end of this thesis...

  4. Fuel rod quenching with oxidation and precursory cooling

    International Nuclear Information System (INIS)

    Davidi, A.; Elias, E.; Olek, S.

    1999-01-01

    During a loss-of-coolant-accident in LWR fuel rods may be temporarily exposed thus reaching high temperature levels. The injection of cold water into the core, while providing the necessary cooling to prevent melting may also generate steam inducing exothermal oxidation of the cladding. A number of high temperature quenching experiments [I] have demonstrated that during the early phase of the quenching process, the rate of hydrogen generation increased markedly and the surface temperatures rose rapidly. These effects are believed to result from thermal stresses breaking up the oxide layer on the zircalloy cladding, thus exposing the inner surface to oxidizing atmosphere. Steam reacts exothermally with the metallic components of the newly formed surface causing temporarily local temperature escalation. The main objective of this study is to develop and assess a one-dimensional time-dependent rewetting model to address the problem of quenching of hot surfaces undergoing exothermic oxidation reactions. Addressing a time-dependent problem is an important aspect of the work since it is believed that the progression of a quench-front along a hot oxidizing surface is an unsteady process. Several studies dealing with time-dependent rewetting problems have been published, e.g. [2]-[5], but none considers oxidation reactions downstream of the quench-front. The main difficulty in solving time-dependent rewetting problems stems from the fact that either the quench-front velocity or the quench-front positions constitute a time-dependent eigenvalue of the problem. The model is applied to describe the interrelated processes of cooling and exothermic steam-metal reactions at the vapor zirconium-cladding interface during quenching of degraded fuel rods. A constant heat transfer coefficient is assumed upstream of the quenching front whereas the combined effect of oxidation and post dry-out cooling is described by prescribing a heat flux distribution of general form downstream. The

  5. Comparison of Core Performance with Various Oxide fuels on Sodium Cooled Fast Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Jin Ha; Kim, Myung Hyun [Kyung Hee University, Yongin (Korea, Republic of)

    2016-05-15

    The system is called Prototype GenIV Sodium-cooled Fast Reactor (PGSFR). Ultimate goal of PGSFR is test for capability of TRU transmutation. Purpose of this study is test for evaluation of in-core performance and TRU transmutation performance by applying various oxide fuel loaded TRU. Fuel type of reference core is changed to uranium-based oxide fuel. Oxide fuel has a lot of experience through fuel fabrication and reactor operation. This study performed by compared and analyzed a core performance of various oxide fuels. (U,Pu)O{sub 2} and (U,TRU)O{sub 2} which various oxide fuel types are selected as extreme case for comparison with core performance and transmutation capability of TRU isotopes. Thorium-based fuel is known that it has good performance for burner reactor due to low proliferation characteristic. To check the performance of TRU incineration for comparison with uranium-based fuel on prototype SFR, Thorium-based fuel, (Th,U)O{sub 2}, (Th,Pu)O{sub 2} and (Th,TRU)O{sub 2}, is selected. Calculations of core performance for various oxide fuel are performed using the fast calculation tool, TRANSX / DANTSTS / REBUS-3. In this study, comparison of core performance and transmutation performance is conducted with various fuel types in a sodium-cooled fast reactor. Mixed oxide fuel with TRU can produce the energy with small amount of fissile material. However, the TRU fuel is confirmed to bring a potential decline of the safety parameters. In case of (Th,U)O2 fuel, the flux level in thermal neutron region becomes lower because of higher capture cross-section of Th-232 than U-238. However, Th-232 has difficulty in converting to TRU isotopes. Therefore, the TRU consumption mass is relatively high in mixed oxide fuel with thorium and TRU.

  6. Comparison of Core Performance with Various Oxide fuels on Sodium Cooled Fast Reactor

    International Nuclear Information System (INIS)

    Choi, Jin Ha; Kim, Myung Hyun

    2016-01-01

    The system is called Prototype GenIV Sodium-cooled Fast Reactor (PGSFR). Ultimate goal of PGSFR is test for capability of TRU transmutation. Purpose of this study is test for evaluation of in-core performance and TRU transmutation performance by applying various oxide fuel loaded TRU. Fuel type of reference core is changed to uranium-based oxide fuel. Oxide fuel has a lot of experience through fuel fabrication and reactor operation. This study performed by compared and analyzed a core performance of various oxide fuels. (U,Pu)O_2 and (U,TRU)O_2 which various oxide fuel types are selected as extreme case for comparison with core performance and transmutation capability of TRU isotopes. Thorium-based fuel is known that it has good performance for burner reactor due to low proliferation characteristic. To check the performance of TRU incineration for comparison with uranium-based fuel on prototype SFR, Thorium-based fuel, (Th,U)O_2, (Th,Pu)O_2 and (Th,TRU)O_2, is selected. Calculations of core performance for various oxide fuel are performed using the fast calculation tool, TRANSX / DANTSTS / REBUS-3. In this study, comparison of core performance and transmutation performance is conducted with various fuel types in a sodium-cooled fast reactor. Mixed oxide fuel with TRU can produce the energy with small amount of fissile material. However, the TRU fuel is confirmed to bring a potential decline of the safety parameters. In case of (Th,U)O2 fuel, the flux level in thermal neutron region becomes lower because of higher capture cross-section of Th-232 than U-238. However, Th-232 has difficulty in converting to TRU isotopes. Therefore, the TRU consumption mass is relatively high in mixed oxide fuel with thorium and TRU.

  7. On the intrinsic transient capability and limitations of solid oxide fuel cell systems

    OpenAIRE

    Mueller, F; Jabbari, F; Brouwer, J

    2009-01-01

    The intrinsic transient performance capability and limitation of integrated solid oxide fuel cell (SOFC) systems is evaluated based on the system balance-of-plant response and fuel cell operating requirements (i.e., allowable deviation from nominal operation). Specifically, non-dimensional relations are derived from conservation principles that quantify the maximum instantaneous current increase that a solid oxide fuel cell system can safely manage based on (1) the desired fuel cell operating...

  8. Preparation and characterization of polymeric membranes for fuel cells

    KAUST Repository

    Nunes, Suzana Pereira

    2012-01-01

    This paper summarized part of the material development for fuel cell conducted in my group in the last 10 years, based on new functionalized polymers with phosphonic, sulfonic as well as oxadiazole and triazole sites. © 2012 Bentham Science

  9. Cobalt oxide-based catalysts deposited by cold plasma for proton exchange membrane fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Kazimierski, P.; Jozwiak, L.; Sielski, J.; Tyczkowski, J., E-mail: jacek.tyczkowski@p.lodz.pl

    2015-11-02

    In proton exchange membrane fuel cells (PEMFC), both the anodic hydrogen oxidation reaction and the cathodic oxygen reduction reaction (ORR) require appropriate catalysts. So far, platinum-based catalysts are still the best option for this purpose. However, because these catalysts are too expensive for making commercially viable fuel cells, extensive research over the past decade has focused on developing noble metal-free alternative catalysts. In this paper, an approach based on cobalt oxide films fabricated by plasma-enhanced metal-organic chemical vapor deposition is presented. Such a material can be used to prepare catalysts for ORR in PEMFC. The films containing CoO{sub X} were deposited on a carbon paper thereby forming the electrode. Morphology and atomic composition of the films were investigated by scanning electron microscopy and energy-dispersive X-ray spectroscopy, respectively. The possibility of their application as the electro-catalyst for ORR in PEMFC was investigated and the electro-catalytic activities were evaluated by the electrochemical measurements and single cell tests. It was found that the fuel cell with Pt as the anode catalyst and CoO{sub X} deposit as the cathode catalyst was characterized by the open circuit voltage of 635 mV, Tafel slope of approx. 130 mV/dec and the maximum power density of 5.3 W/m{sup 2}. - Highlights: • Cobalt oxide catalyst for proton exchange membrane fuel cells was plasma deposited. • The catalyst exhibits activity for the oxygen reduction reaction. • Morphology and atomic composition of the catalyst were determined.

  10. Preparation of supported PtRu/C electrocatalyst for direct methanol fuel cells

    International Nuclear Information System (INIS)

    Jiang Luhua; Sun Gongquan; Zhao Xinsheng; Zhou Zhenhua; Yan Shiyou; Tang Shuihua; Wang Guoxiong; Zhou Bing; Xin Qin

    2005-01-01

    In this work, high-surface supported PtRu/C were prepared with Ru(NO)(NO 3 ) 3 and [Pt(H 2 NCH 2 CH 2 NH 2 ) 2 ]Cl 2 as the precursors and hydrogen as a reducing agent. XRD and TEM analyses showed that the PtRu/C catalysts with different loadings possessed small and homogeneous metal particles. Even at high metal loading (40 wt.% Pt, 20 wt.% Ru) the mean metal particle size is less than 4 nm. Meanwhile, the calculated Pt crystalline lattice parameter and Pt (2 2 0) peak position indicated that the geometric structure of Pt was modified by Ru atoms. Among the prepared catalysts, the lattice parameter of 40-20 wt.% PtRu/C contract most. Cyclic voltammetry (CV), chronoamperometry (CA), CO stripping and single direct methanol fuel cell tests jointly suggested that the 40-20 wt.% PtRu/C catalyst has the highest electrochemical activity for methanol oxidation

  11. Mastication: A fuel reduction and site preparation alternative

    Science.gov (United States)

    Jeff Halbrook; Han-Sup Han; Russell T. Graham; Theresa B. Jain; Robert Denner

    2006-01-01

    During the fall of 2005, a study was conducted at Priest River Experimental Forest (PREF) in northern Idaho to investigate the economics of mastication used to treat activity and standing live fuels. In this study, a rotary head masticator was used to crush and chop activity fuels within harvest units on 37.07 acres. Production averaged 0.57 acres/hour (range 0.21-0.89...

  12. Preparation results for lifetime test of conversion LEU fuel in plutonium production reactors

    International Nuclear Information System (INIS)

    Vatulin, A.; Stetskiy, Yu.; Kukharkin, N.; Kalougin, A.; Gavrilov, P.; Ivanov, A.

    1999-01-01

    The program of converting Russian production reactors for the purpose to stop their plutonium fabrication is currently in progress. The program also provides for operation of these reactors under the conversion mode with using of low-enriched fuel (LEU). LEU fuel elements were developed and activities related to their preparation for reactor tests were carried out. (author)

  13. Ceria-thoria pellet manufacturing in preparation for plutonia-thoria LWR fuel production

    Energy Technology Data Exchange (ETDEWEB)

    Drera, Saleem S., E-mail: saleem.drera@scatec.no [Thor Energy AS, Karenslyst allé 9C, 0278 Oslo (Norway); Björk, Klara Insulander [Thor Energy AS, Karenslyst allé 9C, 0278 Oslo (Norway); Sobieska, Matylda [Institute for Energy Technology (IFE), Nuclear Materials, Os allé 5, NO-1777, Halden (Norway)

    2016-10-15

    Thorium dioxide (thoria) has potential to assist in niche roles as fuel for light water reactors (LWRs). One such application for thoria is its use as the fertile component to burn plutonium in a mixed oxide fuel (MOX). Thor Energy and an international consortium are currently irradiating plutonia-thoria (Th-MOX) fuel in an effort to produce data for its licensing basis. During fuel-manufacturing research and development (R&D), surrogate materials were utilized to highlight procedures and build experience. Cerium dioxide (ceria) provides a good surrogate platform to replicate the chemical nature of plutonium dioxide. The project’s fuel manufacturing R&D focused on powder metallurgical techniques to ensure manufacturability with the current commercial MOX fuel production infrastructure. The following paper highlights basics of the ceria-thoria fuel production including powder milling, pellet pressing and pellet sintering. Green pellets and sintered pellets were manufactured with average densities of 67.0% and 95.5% that of theoretical density respectively. - Highlights: • High quality Ce−Th fuel production can be accomplished by utilizing powder metallurgical procedures. • Powder morphology is key to obtaining high density fuels. • Optimal pellet pressing is obtained when 3.5–4 tons of force is applied by the pellet press for powder compaction. • Pellet sintering is accomplished effectively in an Air oxidizing atmosphere. • Based on this surrogate work, expected (Th,Pu)O{sub 2} fuel density is 95.5% of theoretical density.

  14. Composite cathode based on yttria stabilized bismuth oxide for low-temperature solid oxide fuel cells

    International Nuclear Information System (INIS)

    Xia Changrong; Zhang Yuelan; Liu Meilin

    2003-01-01

    Composites consisting of silver and yttria stabilized bismuth oxide (YSB) have been investigated as cathodes for low-temperature honeycomb solid oxide fuel cells with stabilized zirconia as electrolytes. At 600 deg. C, the interfacial polarization resistances of a porous YSB-Ag cathode is about 0.3 Ω cm 2 , more than one order of magnitude smaller than those of other reported cathodes on stabilized zirconia. For example, the interfacial resistances of a traditional YSZ-lanthanum maganites composite cathode is about 11.4 Ω cm 2 at 600 deg. C. Impedance analysis indicated that the performance of an YSB-Ag composite cathode fired at 850 deg. C for 2 h is severely limited by gas transport due to insufficient porosity. The high performance of the YSB-Ag cathodes is very encouraging for developing honeycomb fuel cells to be operated at temperatures below 600 deg. C

  15. High temperature steam oxidation of Al3Ti-based alloys for the oxidation-resistant surface layer on Zr fuel claddings

    International Nuclear Information System (INIS)

    Park, Jeong-Yong; Kim, Il-Hyun; Jung, Yang-Il; Kim, Hyun-Gil; Park, Dong-Jun; Choi, Byung-Kwon

    2013-01-01

    We investigated the feasibility to apply Al 3 Ti-based alloys as the surface layer for improving the oxidation resistance of Zr fuel claddings under accident conditions. Two types of Al 3 Ti-based alloys with the compositions of Al–25Ti–10Cr and Al–21Ti–23Cr in atomic percent were prepared by arc-melting followed by homogenization annealing at 1423 K for 48 h. Al–25Ti–10Cr alloy showed an L1 2 quasi-single phase microstructure with a lot of needle-shaped minor phase and pores. Al–21Ti–23Cr alloy consisted of an L1 2 matrix and Cr 2 Al as the second phase. Al 3 Ti-based alloys showed an extremely low oxidation rate in a 1473 K steam for up to 7200 s when compared to Zircaloy-4. Both alloys exhibited almost the same oxidation rate in the early stage of oxidation, but Al–25Ti–10Cr showed a little lower oxidation rate after 4000 s than Al–21Ti–23Cr. The difference in the oxidation rate between two types of Al 3 Ti-based alloys was too marginal to distinguish the oxidation behavior of each alloy. The resultant oxide exhibited almost the same characteristics in both alloys even though the microstructure was explicitly distinguished from each other. The crystal structure of the oxide formed up to 2000 s was identified as Al 2 O 3 in both alloys. The oxide morphology consisted of columnar grains whose length was almost identical to the average oxide thickness. On the basis of the results obtained, it is considered that Al 3 Ti-based alloy is one of the promising candidates for the oxidation-resistant surface layer on Zr fuel claddings

  16. A solid oxide fuel cell system for buildings

    International Nuclear Information System (INIS)

    Zink, Florian; Lu, Yixin; Schaefer, Laura

    2007-01-01

    This paper examines an integrated solid oxide fuel cell (SOFC) absorption heating and cooling system used for buildings. The integrated system can provide heating/cooling and/or hot water for buildings while consuming natural gas. The aim of this study is to give an overall description of the system. The possibility of such an integrated system is discussed and the configuration of the system is described. A system model is presented, and a specific case study of the system, which consists of a pre-commercial SOFC system and a commercial LiBr absorption system, is performed. In the case study, the detailed configuration of an integrated system is given, and the heat and mass balance and system performance are obtained through numerical calculation. Based on the case study, some considerations with respect to system component selection, system configuration and design are discussed. Additionally, the economic and environmental issues of this specific system are evaluated briefly. The results show that the combined system demonstrates great advantages in both technical and environmental aspects. With the present development trends in solid oxide fuel cells and the commercial status of absorption heating and cooling systems, it is very likely that such a combined system will become increasingly feasible within the following decade

  17. Nuclear fuel cycle under progressing preparation of its systemisation

    International Nuclear Information System (INIS)

    Anon.

    2001-01-01

    Trends of nuclear development in Japan show more remarkable advancements in 2000, such as new addition of nuclear power plant, nuclear fuel cycling business, and so on. Based on an instruction of the criticality accident in JCO formed on September, 1999, government made efforts on revision of the law on regulation of nuclear reactor and so forth and establishment of a law on protection of nuclear accident as sooner, to enforce nuclear safety management and nuclear accident protective countermeasure. On the other hand, the nuclear industry field develops some new actions such as establishment of Nuclear Safety Network (NSnet)', mutual evaluation of nuclear-relative works (pier review), and so forth. And, on the high level radioactive wastes disposal of the most important subject remained in nuclear development, the Nuclear Waste Management Organization of Japan' of its main business body was established on October, 1999 together with establishment of the new law, to begin a business for embodiment of the last disposal aiming at 2030s to 2040s. On the same October, the Japan Nuclear Fuel Limited. concluded a safety agreement on premise of full-dress transportation of the used fuels to the Rokkasho Reprocessing Plant in Aomori prefecture with local government, to begin their transportation from every electric company since its year end. Here were described on development of the nuclear fuel cycling business in Japan, establishment of nuclear fuel cycling, disposal on the high level radioactive wastes, R and D on geological disposal of the high level radioactive wastes, establishment on cycle back-end of nuclear fuels, and full-dressing of nuclear fuel cycling. (G.K.)

  18. The conceptual flowsheet of effluent treatment during preparing spherical fuel elements of HTR

    Energy Technology Data Exchange (ETDEWEB)

    Ying, Quan, E-mail: quanying@tsinghua.edu.cn; Xiao-tong, Chen; Bing, Liu; Gen-na, Fu; Yang, Wang; You-lin, Shao; Zhen-ming, Lu; Ya-ping, Tang; Chun-he, Tang

    2014-05-01

    High temperature gas-cooled reactor (HTR) is one of the advanced nuclear reactors owing to its inherent safety and broad applications. For HTR, one of the key components is the ceramic fuel element. During the preparation of spherical fuel elements, the radioactive effluent treatment is necessary. Referring to the current treatment technologies and methods, the conceptual flowsheet of low-level radioactive effluent treatment during preparing spherical fuel elements was established. According to the above treatment process, the uranium concentration was decreased from 200 mg/l to the level of discharged standard.

  19. Hydrocarbon fuel processing of micro solid oxide fuel cell systems[Dissertation 17455

    Energy Technology Data Exchange (ETDEWEB)

    Stutz, M. J.

    2007-07-01

    The scope of this thesis is the numerical and experimental investigation of the fuel processing of a micro solid oxide fuel cell (SOFC) running on hydrocarbon fuel. The goal is to enhance the overall system efficiency by optimization of the reforming process in the steady state and the improvement of the start-up process. Micro SOFC are a potential alternative to the currently used batteries in portable devices. Liquid butane in a cartridge could be the energy source. This dissertation is focused on the fuel processing of the system, namely the reforming and post-combusting processes. The reformer converts the hydrocarbon fuel to a hydrogen rich gas that can be utilized by the SOFC. The post-combustor depletes the toxic and/or explosive gases before leaving the exhaust. Chapter One presents a short introduction to the field of hydrocarbon fuel processing in micro solid oxide fuel cell systems, the next three chapters deal with computational modeling of the transport phenomena inside a micro-reformer, which leads to a better understanding of the chemistry and the physics therein, hence progress in the design and operation parameters. The experimental part (i.e. Chapter Five) of this thesis focuses on the feasibility of a novel hybrid start-up method of a fuel cell system that employs existing components as an additional heat source. In Chapter Two the effect of wall heat conduction on the syngas (hydrogen and carbon monoxide) production of a micro-reformer, representing micro-fabricated channels or monoliths, is investigated. Methane is used as a model hydrocarbon fuel since its heterogeneous reaction path on rhodium is known and validated. The simulations demonstrate that the axial wall conduction strongly influences the performance of the micro-reformer and should not be neglected without a careful a priori investigation of its impact. Methane conversion and hydrogen yield are strongly dependent of the wall inner surface temperature, which is influenced by the

  20. Evaluation of apatite silicates as solid oxide fuel cell electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Marrero-Lopez, D. [Dpto. de Fisica Aplicada I, Laboratorio de Materiales y Superficies (Unidad Asociada al C.S.I.C.), Universidad de Malaga, 29071 Malaga (Spain); Dpto. de Quimica Inorganica, Universidad de La Laguna, 38200 La Laguna, Tenerife (Spain); Martin-Sedeno, M.C.; Aranda, M.A.G. [Dpto. de Quimica Inorganica, Universidad Malaga, 29071 Malaga (Spain); Pena-Martinez, J. [Dpto. de Quimica Inorganica, Universidad de La Laguna, 38200 La Laguna, Tenerife (Spain); Instituto de Energias Renovables, Parque Tecnologico, Universidad de Castilla La Mancha, 02006 Albacete (Spain); Ruiz-Morales, J.C.; Nunez, P. [Dpto. de Quimica Inorganica, Universidad de La Laguna, 38200 La Laguna, Tenerife (Spain); Ramos-Barrado, J.R. [Dpto. de Fisica Aplicada I, Laboratorio de Materiales y Superficies (Unidad Asociada al C.S.I.C.), Universidad de Malaga, 29071 Malaga (Spain)

    2010-05-01

    Apatite-type silicates have been considered as promising electrolytes for Solid Oxide Fuel Cells (SOFC); however studies on the potential use of these materials in SOFC devices have received relatively little attention. The lanthanum silicate with composition La{sub 10}Si{sub 5.5}Al{sub 0.5}O{sub 26.75} has been evaluated as electrolyte with the electrode materials commonly used in SOFC, i.e. manganite, ferrite and cobaltite as cathode materials and NiO-CGO composite, chromium-manganite and Sr{sub 2}MgMoO{sub 6} as anode materials. Chemical compatibility, area-specific resistance and fuel cell studies have been performed. X-ray powder diffraction (XRPD) analysis did not reveal any trace of reaction products between the apatite electrolyte and most of the aforementioned electrode materials. However, the area-specific polarisation resistance (ASR) of these electrodes in contact with apatite electrolyte increased significantly with the sintering temperature, indicating reactivity at the electrolyte/electrode interface. On the other hand, the ASR values are significantly improved using a ceria buffer layer between the electrolyte and electrode materials to prevent reactivity. Maximum power densities of 195 and 65 mWcm{sup -2} were obtained at 850 and 700 C, respectively in H{sub 2} fuel, using an 1 mm-thick electrolyte, a NiO-Ce{sub 0.8}Gd{sub 0.2}O{sub 1.9} composite as anode and La{sub 0.6}Sr{sub 0.4}Co{sub 0.8}Fe{sub 0.2}O{sub 3-{delta}} as cathode materials. This fuel cell was tested for 100 h in 5%H{sub 2}-Ar atmosphere showing stable performance. (author)

  1. Conversion of highly enriched uranium in thorium-232 based oxide fuel for light water reactors: MOX-T fuel

    Energy Technology Data Exchange (ETDEWEB)

    Vapirev, E; Jordanov, T; Khristoskov, I [Sofia Univ. (Bulgaria). Fizicheski Fakultet

    1996-12-31

    The possibility of using highly enriched uranium available from military inventories for production of mixed oxide fuel (MOX) has been proposed. The fuel is based on U-235 dioxide as fissile isotope and Th-232 dioxide as a non-fissile isotope. It is shown that although the fuel conversion coefficient to U-233 is expected to be less than 1, the proposed fuel has several important advantages resulting in cost reduction of the nuclear fuel cycle. The expected properties of MOX fuel (cross-sections, generated chains, delayed neutrons) are estimated. Due to fuel generation the initial enrichment is expected to be 1% less for production of the same energy. In contrast to traditional fuel no long living actinides are generated which reduces the disposal and reprocessing cost. 7 refs.

  2. Concept for a small, colocated fuel cycle facility for oxide breeder fuels

    International Nuclear Information System (INIS)

    Burch, W.D.; Stradley, J.G.; Lerch, R.E.

    1987-01-01

    As part of a United States Department of Energy (USDOE) program to examine innovative liquid-metal reactor (LMR) system designs over the past three years, the Oak Ridge National Laboratory (ORNL) and the Westinghouse Hanford Company (WHC) collaborated on studies of mixed oxide fuel cycle options. A principal effort was an advanced concept for a small integrated fuel cycle colocated with a 1300-MW(e) reactor station. The study provided a scoping design and a basis on which to proceed with implementation of such a facility if future plans so dictate. The facility integrated reprocessing, waste management, and refabrication functions in a single facility of nominal 35-t/year capacity utilizing the latest technology developed in fabrication programs at WHC and in reprocessing at ORNL. The concept was based on many years of work at both sites and extensive design studies of prior years

  3. Concept for a small, colocated fuel cycle facility for oxide breeder fuels

    International Nuclear Information System (INIS)

    Burch, W.D.; Lerch, R.E.; Stradley, J.G.

    1987-01-01

    As part of a United States Department of Energy (USDOE) program to examine innovative liquid-metal reactor (LMR) system designs over the past three years, the Oak Ridge National Laboratory (ORNL) and the Westinghouse Hanford Company (WHC) collaborated on studies of mixed oxide fuel cycle options. A principal effort was an advanced concept for a small integrated fuel cycle colocated with a 1300-MW(e) reactor station. The study provided a scoping design, capital and operating cost estimates, and a basis on which to proceed with implementation of such a facility if future plans so dictate. The facility integrated reprocessing, waste management, and refabrication functions in a single facility of nominal 35-t/year capacity utilizing the latest technology developed in fabrication programs at WHC and in reprocessing at ORNL. The concept was based on many years of work at both sites and extensive design studies of prior years

  4. Investigations of fuel cladding chemical interaction in irradiated LMFBR type oxide fuel pins

    International Nuclear Information System (INIS)

    Roake, W.E.; Adamson, M.G.; Hilbert, R.F.; Langer, S.

    1977-01-01

    Understanding and controlling the chemical attack of fuel pin cladding by fuel and fission products are major objectives of the U.S. LMFBR Mixed Oxide Irradiation Testing Program. Fuel-cladding chemical interaction (FCCI) has been recognized as an important factor in the ability to achieve goal peak burnups of 8% (80.MWd/kg) in FFTF and in excess of 10% (100.MWd/kg) in the LMFBR demonstration reactors while maintaining coolant bulk outlet temperatures up to ∼60 deg. C (1100 deg. F). In this paper we review pertinent parts of the irradiation program and describe recent observation of FCCI in the fuel pins of this program. One goal of the FCCI investigations is to obtain a sufficiently quantitative understanding of FCCI such that correlations can be developed relating loss of effective cladding thickness to irradiation and fuel pin fabrication parameters. Wastage correlations being developed using different approaches are discussed. Much of the early data on FCCI obtained in the U.S. Mixed Oxide Fuel Program came from capsule tests irradiated in both fast and thermal flux facilities. The fast flux irradiated encapsulated fuel pins continue to provide valuable data and insight into FCCI. Currently, however, bare pins with prototypic fuels and cladding irradiated in the fast flux Experimental Breeder Reactor-II (EBR-II) as multiple pin assemblies under prototypic powers, temperatures and thermal gradients are providing growing quantities of data on FCCI characteristics and cladding thickness losses from FCCI. A few special encapsulated fuel pin tests are being conducted in the General Electric Test Reactor (GETR) and EBR-II, but these are aimed at providing specific information under irradiation conditions not achievable in the fast flux bare pin assemblies or because EBR-II Operation or Safety requirements dictate that the pins be encapsulated. The discussion in this paper is limited to fast flux irradiation test results from encapsulated pins and multiple pin

  5. Investigations of fuel cladding chemical interaction in irradiated LMFBR type oxide fuel pins

    Energy Technology Data Exchange (ETDEWEB)

    Roake, W E [Westinghouse-Hanford Co., Richland, WA (United States); Adamson, M G [General Electric Company, Vallecitos Nuclear Center, Pleasanton, CA (United States); Hilbert, R F; Langer, S

    1977-04-01

    Understanding and controlling the chemical attack of fuel pin cladding by fuel and fission products are major objectives of the U.S. LMFBR Mixed Oxide Irradiation Testing Program. Fuel-cladding chemical interaction (FCCI) has been recognized as an important factor in the ability to achieve goal peak burnups of 8% (80.MWd/kg) in FFTF and in excess of 10% (100.MWd/kg) in the LMFBR demonstration reactors while maintaining coolant bulk outlet temperatures up to {approx}60 deg. C (1100 deg. F). In this paper we review pertinent parts of the irradiation program and describe recent observation of FCCI in the fuel pins of this program. One goal of the FCCI investigations is to obtain a sufficiently quantitative understanding of FCCI such that correlations can be developed relating loss of effective cladding thickness to irradiation and fuel pin fabrication parameters. Wastage correlations being developed using different approaches are discussed. Much of the early data on FCCI obtained in the U.S. Mixed Oxide Fuel Program came from capsule tests irradiated in both fast and thermal flux facilities. The fast flux irradiated encapsulated fuel pins continue to provide valuable data and insight into FCCI. Currently, however, bare pins with prototypic fuels and cladding irradiated in the fast flux Experimental Breeder Reactor-II (EBR-II) as multiple pin assemblies under prototypic powers, temperatures and thermal gradients are providing growing quantities of data on FCCI characteristics and cladding thickness losses from FCCI. A few special encapsulated fuel pin tests are being conducted in the General Electric Test Reactor (GETR) and EBR-II, but these are aimed at providing specific information under irradiation conditions not achievable in the fast flux bare pin assemblies or because EBR-II Operation or Safety requirements dictate that the pins be encapsulated. The discussion in this paper is limited to fast flux irradiation test results from encapsulated pins and multiple pin

  6. Status report on preparation of IAEA guidelines for qualification of research reactor fuels

    International Nuclear Information System (INIS)

    Snelgrove, J.L.

    2007-01-01

    The International Atomic Energy Agency, through a consultancy, is preparing a document describing good practices for the qualification of research reactor fuel. The rationale for the preparation of the document and the document's organization and content are discussed. It is anticipated that the consultants will present a final draft to the IAEA by mid-December for editing and publication in 2008.

  7. Powder of a copper oxide superconductor precursor, fabrication process and use for the preparation of superconducting oxide

    International Nuclear Information System (INIS)

    Dehaudt, P.

    1990-01-01

    The precursor powder comprises at least a copper compound (hydroxide, oxide and hydroxynitrates), at least a rare earth and/or yttrium compound (nitrates, hydroxides and hydroxynitrates) or bismuth oxide and at least an alkaline earth nitrate. It can be prepared by atomization drying of a suspension a copper precipitate or coprecipitate and other elements of the superconducting oxide in solution [fr

  8. Preparation and characterization of polymeric membranes for fuel cells

    KAUST Repository

    Nunes, Suzana Pereira

    2012-06-24

    This paper summarized part of the material development for fuel cell conducted in my group in the last 10 years, based on new functionalized polymers with phosphonic, sulfonic as well as oxadiazole and triazole sites. © 2012 Bentham Science Publishers. All rights reserved.

  9. Thermodynamic analysis of SOFC (solid oxide fuel cell) - Stirling hybrid plants using alternative fuels

    DEFF Research Database (Denmark)

    Rokni, Masoud

    2013-01-01

    A novel hybrid power system (∼10 kW) for an average family home is proposed. The system investigated contains a solid oxide fuel cell (SOFC) on top of a Stirling engine. The off-gases produced in the SOFC cycle are fed to a bottoming Stirling engine, at which additional power is generated...... to that of a stand-alone Stirling engine or SOFC plant. For the combined SOFC and Stirling configuration, the overall power production was increased by approximately 10% compared to that of a stand-alone SOFC plant. System efficiencies of approximately 60% are achieved, which is remarkable for such small plant sizes...

  10. Effect of coating density on oxidation resistance and Cr vaporization from solid oxide fuel cell interconnects

    Science.gov (United States)

    Talic, Belma; Falk-Windisch, Hannes; Venkatachalam, Vinothini; Hendriksen, Peter Vang; Wiik, Kjell; Lein, Hilde Lea

    2017-06-01

    Manganese cobalt spinel oxides are promising materials for protective coatings for solid oxide fuel cell (SOFC) interconnects. To achieve high density such coatings are often sintered in a two-step procedure, involving heat treatment first in reducing and then in oxidizing atmospheres. Sintering the coating inside the SOFC stack during heating would reduce production costs, but may result in a lower coating density. The importance of coating density is here assessed by characterization of the oxidation kinetics and Cr evaporation of Crofer 22 APU with MnCo1.7Fe0.3O4 spinel coatings of different density. The coating density is shown to have minor influence on the long-term oxidation behavior in air at 800 °C, evaluated over 5000 h. Sintering the spinel coating in air at 900 °C, equivalent to an in-situ heat treatment, leads to an 88% reduction of the Cr evaporation rate of Crofer 22 APU in air-3% H2O at 800 °C. The air sintered spinel coating is initially highly porous, however, densifies with time in interaction with the alloy. A two-step reduction and re-oxidation heat treatment results in a denser coating, which reduces Cr evaporation by 97%.

  11. Development of advanced spent fuel management process. The fabrication and oxidation behavior of simulated metallized spent fuel

    Energy Technology Data Exchange (ETDEWEB)

    Ro, Seung Gy; Shin, Y.J.; You, G.S.; Joo, J.S.; Min, D.K.; Chun, Y.B.; Lee, E.P.; Seo, H.S.; Ahn, S.B

    1999-03-01

    The simulated metallized spent fuel ingots were fabricated and evaluated the oxidation rates and the activation energies under several temperature conditions to develop an advanced spent fuel management process. It was also checked the alloying characteristics of the some elements with metal uranium. (Author). 3 refs., 1 tab., 36 figs.

  12. Designing and optimization of a micro CHP system based on Solid Oxide Fuel Cell with different fuel processing technologies

    DEFF Research Database (Denmark)

    Liso, Vincenzo; Nielsen, Mads Pagh; Kær, Søren Knudsen

    2009-01-01

    are the possibility to partially reform hydrocarbon in the fuel cell anode compartment and the possibility to use high quality heat for cogeneration. In this work, different configurations of solid oxide fuel cell system for decentralized electricity production are examined. The Balance of Plant (BoP) components...

  13. Hydrogen sulfide-powered solid oxide fuel cells

    Science.gov (United States)

    Liu, Man

    2004-12-01

    The potential utilization of hydrogen sulfide as fuel in solid oxide fuel cells has been investigated using an oxide-ion conducting YSZ electrolyte and different kinds of anode catalysts at operating temperatures in the range of 700--900°C and at atmospheric pressure. This technology offers an economically attractive alternative to present methods for removing toxic and corrosive H2S gas from sour gas streams and a promising approach for cogenerating electrical energy and useful chemicals. The primary objective of the present research was to find active and stable anode materials. Fuel cell experimental results showed that platinum was a good electrocatalyst for the conversion of H2S, but the Pt/YSZ interface was physically unstable due to the reversible formation and decomposition of PtS in H 2S streams at elevated temperatures. Moreover, instability of the Pt/YSZ interface was accelerated significantly by electrochemical reactions, and ultimately led to the detachment of the Pt anode from the electrolyte. It has been shown that an interlayer of TiO2 stabilized the Pt anode on YSZ electrolyte, thereby prolonging cell lifetime. However, the current output for a fuel cell using Pt/TiO2 as anode was not improved compared to using Pt alone. It was therefore necessary to investigate novel anode systems for H 2S-air SOFCs. New anode catalysts comprising composite metal sulfides were developed. These catalysts exhibited good electrical conductivity and better catalytic activity than Pt. In contrast to MoS2 alone, composite catalysts (M-Mo-S, M = Fe, Co, Ni) were not volatile and had superior stability. However, when used for extended periods of time, detachment of Pt current collecting film from anodes comprising metal sulfides alone resulted in a large increase in contact resistance and reduction in cell performance. Consequently, a systematic investigation was conducted to identify alternative electronic conductors for use with M-Mo-S catalysts. Anode catalysts

  14. Preparation of uranium-based oxide catalysts; Preparation de catalyseurs oxydes a base d'uranium

    Energy Technology Data Exchange (ETDEWEB)

    Bressat, R [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1965-07-01

    We have studied the thermal decomposition of uranyl and uranium IV oxalates as a mean of producing uranium dioxide. We have isolated the main intermediate phases of the decompositions and have indexed the lines of their X-ray diffraction patterns. The oxides produced by the decomposition are ill-defined and unstable: they strongly absorb atmospheric oxygen with modification of the composition and, in certain cases, of the structure (pyrophoric oxide). With a view to obtaining stable oxides, we have prepared mixed uranium-thorium oxalates. In order to prepare an oxalate having a homogeneous composition, it is necessary to adopt a well-defined preparation method: the addition of solutions of thorium and uranium IV nitrates to a continually saturated oxalic acid solution. The mixed oxide obtained from the thermal decomposition of an oxalate U{sub x}Th{sub 1-x}(C{sub 2}O{sub 4}){sub 2}, 2 H{sub 2}O at 500 C for 24 hours in a current of oxygen leads to a cubic structure which is well-defined both in the bulk and superficially when x is less than 0.35. Above this atomic concentration of uranium, some uranium moves out of the lattice in the form of UO{sub 3} or U{sub 3}O{sub 8} according to the temperature. The mixed oxide is not stoichiometric,(U{sub x}Th{sub 1-x}O{sub 2+y}) and the average degree of oxidation of the uranium varies with the temperature and partial oxygen pressure. The oxides thus formed have a high surface area. By dissolving the mixed oxalates in a concentrated solution of ammonium oxalate, it is possible to deposit the catalyst on a support, but the differences in the solubilities of the thorium and uranium IV oxalates in the ammonium oxalate make it impossible to prepare double salts formed either of thorium and uranium and of ammonium. (author) [French] Nous avons etudie la decomposition thermique des oxalates d'uranyle et d'uranium IV en vue d'aboutir au dioxide d'uranium. Nous avons pu isoler les principales phases intermediaires des decompositions

  15. Improvements in the preparation of nuclear fuel elements with addition of a molding mixture to fuel particles

    International Nuclear Information System (INIS)

    Miertschin, G.N.; Leary, D.F.

    1975-01-01

    An improved molting mixture to be added to nuclear fuel particles for the preparation of nuclear fuel elements is presented. It consists of carbon and pitch particles and contains an additive reducing the final coke yield of the fuel mass formed. This additive is chosen from: polystyrene and copolymers of styrene and butadiene of molecular weight between 500 and 1000000; aromatic compounds of molecular weight between 75 and 300; saturated hydrocarbon polymers of molecular weight between 500 and 1000000. The additive may be camphor, naphthalene, anthracene, phenanthrene, dimethyl terephthalate or their mixtures and is present at a concentration of 5 to 50% by weight. The carbon particles used consist of powdered graphite. These fuel elements are intended for gas-cooled high-temperature reactors [fr

  16. Graphene oxide powders with different oxidation degree, prepared by synthesis variations of the Hummers method

    International Nuclear Information System (INIS)

    Guerrero-Contreras, Jesus; Caballero-Briones, F.

    2015-01-01

    Graphene oxide (GO) powders with different oxidation degree estimated through the relative intensity of the infrared absorption bands related to oxygen containing groups were prepared through variations of the Hummers method. The GO powders were analyzed by Transmission Electron Microscopy, Energy dispersive spectroscopy, X-ray Photoelectron Spectroscopy, Fourier Transform Infrared Spectroscopy, Raman spectroscopy, X-ray Diffraction, UV–VIS spectroscopy and Electrical Resistance measurements. Several square micron GO sheets with low wrinkling were obtained. Oxygen to carbon ratio is around 0.2 in all the samples although a strong variance in the relative intensity of the oxygen related infrared bands is evident. Thus, the oxidation degree was estimated from the FTIR measurements using the quotient between the C–O related bands area to the total area under the spectra. FTIR shows presence of hydroxyl (–OH), epoxy (C–O–C), carboxyl (–COOH) and carbonyl (C=O) moieties and evidence of intermolecular interactions between adjacent groups. These interactions influence the exfoliation degree, the absorbance of the GO suspensions, as well as the electrical resistance, while the crystalline domain sizes, estimated from XRD and Raman do not show a noticeable behavior related with the composition and molecular structure. The results indicate that the electrical resistance is influenced mainly by the surface chemistry of the GO powders and not only by the O/C ratio. The control of the surface chemistry of GO powders would allow their use as additives in organic bulk heterojunction solar cells with enhanced photoconversion efficiency. - Highlights: • Powders of graphene oxide with different oxidation degree were prepared through variations of the Hummers method. • Raman spectroscopy and XRD demonstrated similar crystallite domain size in the samples. • Electrical resistance, exfoliation degree and optical absorption depend on the molecular structure.

  17. Graphene oxide powders with different oxidation degree, prepared by synthesis variations of the Hummers method

    Energy Technology Data Exchange (ETDEWEB)

    Guerrero-Contreras, Jesus; Caballero-Briones, F., E-mail: fcaballero@ipn.mx

    2015-03-01

    Graphene oxide (GO) powders with different oxidation degree estimated through the relative intensity of the infrared absorption bands related to oxygen containing groups were prepared through variations of the Hummers method. The GO powders were analyzed by Transmission Electron Microscopy, Energy dispersive spectroscopy, X-ray Photoelectron Spectroscopy, Fourier Transform Infrared Spectroscopy, Raman spectroscopy, X-ray Diffraction, UV–VIS spectroscopy and Electrical Resistance measurements. Several square micron GO sheets with low wrinkling were obtained. Oxygen to carbon ratio is around 0.2 in all the samples although a strong variance in the relative intensity of the oxygen related infrared bands is evident. Thus, the oxidation degree was estimated from the FTIR measurements using the quotient between the C–O related bands area to the total area under the spectra. FTIR shows presence of hydroxyl (–OH), epoxy (C–O–C), carboxyl (–COOH) and carbonyl (C=O) moieties and evidence of intermolecular interactions between adjacent groups. These interactions influence the exfoliation degree, the absorbance of the GO suspensions, as well as the electrical resistance, while the crystalline domain sizes, estimated from XRD and Raman do not show a noticeable behavior related with the composition and molecular structure. The results indicate that the electrical resistance is influenced mainly by the surface chemistry of the GO powders and not only by the O/C ratio. The control of the surface chemistry of GO powders would allow their use as additives in organic bulk heterojunction solar cells with enhanced photoconversion efficiency. - Highlights: • Powders of graphene oxide with different oxidation degree were prepared through variations of the Hummers method. • Raman spectroscopy and XRD demonstrated similar crystallite domain size in the samples. • Electrical resistance, exfoliation degree and optical absorption depend on the molecular structure.

  18. Biobutanol as Fuel for Direct Alcohol Fuel Cells-Investigation of Sn-Modified Pt Catalyst for Butanol Electro-oxidation.

    Science.gov (United States)

    Puthiyapura, Vinod Kumar; Brett, Dan J L; Russell, Andrea E; Lin, Wen-Feng; Hardacre, Christopher

    2016-05-25

    Direct alcohol fuel cells (DAFCs) mostly use low molecular weight alcohols such as methanol and ethanol as fuels. However, short-chain alcohol molecules have a relative high membrane crossover rate in DAFCs and a low energy density. Long chain alcohols such as butanol have a higher energy density, as well as a lower membrane crossover rate compared to methanol and ethanol. Although a significant number of studies have been dedicated to low molecular weight alcohols in DAFCs, very few studies are available for longer chain alcohols such as butanol. A significant development in the production of biobutanol and its proposed application as an alternative fuel to gasoline in the past decade makes butanol an interesting candidate fuel for fuel cells. Different butanol isomers were compared in this study on various Pt and PtSn bimetallic catalysts for their electro-oxidation activities in acidic media. Clear distinctive behaviors were observed for each of the different butanol isomers using cyclic voltammetry (CV), indicating a difference in activity and the mechanism of oxidation. The voltammograms of both n-butanol and iso-butanol showed similar characteristic features, indicating a similar reaction mechanism, whereas 2-butanol showed completely different features; for example, it did not show any indication of poisoning. Ter-butanol was found to be inactive for oxidation on Pt. In situ FTIR and CV analysis showed that OHads was essential for the oxidation of primary butanol isomers which only forms at high potentials on Pt. In order to enhance the water oxidation and produce OHads at lower potentials, Pt was modified by the oxophilic metal Sn and the bimetallic PtSn was studied for the oxidation of butanol isomers. A significant enhancement in the oxidation of the 1° butanol isomers was observed on addition of Sn to the Pt, resulting in an oxidation peak at a potential ∼520 mV lower than that found on pure Pt. The higher activity of PtSn was attributed to the

  19. Storage of LWR spent fuel in air: Volume 1: Design and operation of a spent fuel oxidation test facility

    International Nuclear Information System (INIS)

    Thornhill, C.K.; Campbell, T.K.; Thornhill, R.E.

    1988-12-01

    This report describes the design and operation and technical accomplishments of a spent-fuel oxidation test facility at the Pacific Northwest Laboratory. The objective of the experiments conducted in this facility was to develop a data base for determining spent-fuel dry storage temperature limits by characterizing the oxidation behavior of light-water reactor (LWR) spent fuels in air. These data are needed to support licensing of dry storage in air as an alternative to spent-fuel storage in water pools. They are to be used to develop and validate predictive models of spent-fuel behavior during dry air storage in an Independent Spent Fuel Storage Installation (ISFSI). The present licensed alternative to pool storage of spent fuel is dry storage in an inert gas environment, which is called inerted dry storage (IDS). Licensed air storage, however, would not require monitoring for maintenance of an inert-gas environment (which IDS requires) but does require the development of allowable temperature limits below which UO 2 oxidation in breached fuel rods would not become a problem. Scoping tests at PNL with nonirradiated UO 2 pellets and spent-fuel fragment specimens identified the need for a statistically designed test matrix with test temperatures bounding anticipated maximum acceptable air-storage temperatures. This facility was designed and operated to satisfy that need. 7 refs

  20. Behavior of strontium- and magnesium-doped gallate electrolyte in direct carbon solid oxide fuel cells

    International Nuclear Information System (INIS)

    Zhang, Li; Xiao, Jie; Xie, Yongmin; Tang, Yubao; Liu, Jiang; Liu, Meilin

    2014-01-01

    Highlights: • La 0.9 Sr 0.1 Ga 0.8 Mg 0.2 O 3−δ (LSGM) can be used as electrolyte of direct carbon SOFCs. • DC-SOFC with LSGM electrolyte gives higher performance than that with YSZ. • LSGM-electrolyte DC-SOFC gives maximum power density of 383 mW cm −2 at 850 °C. • Operation of LSGM-DC-SOFC at 210 mA cm −2 lasts 72 min, with fuel utilization of 60%. - Abstract: Perovskite-type La 0.9 Sr 0.1 Ga 0.8 Mg 0.2 O 3−δ (LSGM) is synthesized by conventional solid state reaction. Its phase composition, microstructure, relative density, and oxygen-ionic conductivity are investigated. Tubular electrolyte-supported solid oxide fuel cells (SOFCs) are prepared with the LSGM as electrolyte and gadolinia doped ceria (GDC) mixed with silver as anode. The SOFCs are operated with Fe-loaded activated carbon as fuel and ambient air as oxidant. A typical single cell gives a maximum power density of 383 mW cm −2 at 850 °C, which is nearly 1.3 times higher than that of the similar cell with YSZ as electrolyte. A stability test of 72 min is carried out at a constant current density of 210 mA cm −2 , with a fuel utilization of 60%, indicating that LaGaO 3 -based electrolyte is promising to be applied in direct carbon SOFCs (DC-SOFCs)

  1. Behavior of strontium- and magnesium-doped gallate electrolyte in direct carbon solid oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Li; Xiao, Jie; Xie, Yongmin [The Key Laboratory of Fuel Cell Technology of Guangdong Province, School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou 510641 (China); Tang, Yubao [Key Laboratory of Sensor Analysis of Tumor Marker Ministry of Education, College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao o 266042 (China); Liu, Jiang, E-mail: jiangliu@scut.edu.cn [The Key Laboratory of Fuel Cell Technology of Guangdong Province, School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou 510641 (China); New Energy Research Institute, College of Environment and Energy, South China University of Technology, Guangzhou 510006 (China); Liu, Meilin [New Energy Research Institute, College of Environment and Energy, South China University of Technology, Guangzhou 510006 (China); School of Materials Science and Engineering, Georgia Institute of Technology, 771 Ferst Drive, Atlanta, GA 30332-0245 (United States)

    2014-09-01

    Highlights: • La{sub 0.9}Sr{sub 0.1}Ga{sub 0.8}Mg{sub 0.2}O{sub 3−δ} (LSGM) can be used as electrolyte of direct carbon SOFCs. • DC-SOFC with LSGM electrolyte gives higher performance than that with YSZ. • LSGM-electrolyte DC-SOFC gives maximum power density of 383 mW cm{sup −2} at 850 °C. • Operation of LSGM-DC-SOFC at 210 mA cm{sup −2} lasts 72 min, with fuel utilization of 60%. - Abstract: Perovskite-type La{sub 0.9}Sr{sub 0.1}Ga{sub 0.8}Mg{sub 0.2}O{sub 3−δ} (LSGM) is synthesized by conventional solid state reaction. Its phase composition, microstructure, relative density, and oxygen-ionic conductivity are investigated. Tubular electrolyte-supported solid oxide fuel cells (SOFCs) are prepared with the LSGM as electrolyte and gadolinia doped ceria (GDC) mixed with silver as anode. The SOFCs are operated with Fe-loaded activated carbon as fuel and ambient air as oxidant. A typical single cell gives a maximum power density of 383 mW cm{sup −2} at 850 °C, which is nearly 1.3 times higher than that of the similar cell with YSZ as electrolyte. A stability test of 72 min is carried out at a constant current density of 210 mA cm{sup −2}, with a fuel utilization of 60%, indicating that LaGaO{sub 3}-based electrolyte is promising to be applied in direct carbon SOFCs (DC-SOFCs)

  2. Synthesis and characterization of magnesium doped cerium oxide for the fuel cell application

    International Nuclear Information System (INIS)

    Kumar, Amit; Kumari, Monika; Kumar, Mintu; Kumar, Sacheen; Kumar, Dinesh

    2016-01-01

    Cerium oxide has attained much attentions in global nanotechnology market due to valuable application for catalytic, fuel additive, and widely as electrolyte in solid oxide fuel cell. Doped cerium oxide has large oxygen vacancies that allow for greater reactivity and faster ion transport. These properties make cerium oxide suitable material for SOFCs application. Cerium oxide electrolyte requires lower operation temperature which shows improvement in processing and the fabrication technique. In our work, we synthesized magnesium doped cerium oxide by the co-precipitation method. With the magnesium doping catalytic reactivity of CeO_2 was increased. Synthesized nanoparticle were characterized by the XRD and UV absorption techniques.

  3. Neutronic study using oxide and nitride fuels for the Super Phenix 2 reactor

    International Nuclear Information System (INIS)

    Batista, J.L.; Renke, C.A.C.

    1991-11-01

    This report presents a neutronic analysis and a description of the Super Phenix 2 reactor, taken as reference. We present the methodology and results for cell and global reactor calculations for oxide (U O 2 - Pu O 2 ) and nitride (U N - Pu N) fuels. To conclude we compare the performance of oxide and nitride fuels for the reference reactor. (author)

  4. Modern methods of material accounting for mixed oxide fuel fabrication facility

    International Nuclear Information System (INIS)

    Eggers, R.F.; Pindak, J.L.; Brouns, R.J.; Williams, R.C.; Brite, D.W.; Kinnison, R.R.; Fager, J.E.

    1981-01-01

    The generic requirements loss detection, and response to alarms of a contemporary material control and accounting (MCandA) philosophy have been applied to a mixed oxide fuel fabrication plant to produce a detailed preliminary MCandA system design that is generally applicable to facilities of this type. This paper summarizes and discusses detailed results of the mixed oxide fuel fabrication plant study

  5. Statistical model for grain boundary and grain volume oxidation kinetics in UO2 spent fuel

    International Nuclear Information System (INIS)

    Stout, R.B.; Shaw, H.F.; Einziger, R.E.

    1989-09-01

    This paper addresses statistical characteristics for the simplest case of grain boundary/grain volume oxidation kinetics of UO 2 to U 3 O 7 for a fragment of a spent fuel pellet. It also presents a limited discussion of future extensions to this simple case to represent the more complex cases of oxidation kinetics in spent fuels. 17 refs., 1 fig

  6. Hydrogen Oxidation Reaction at the Ni/YSZ Anode of Solid Oxide Fuel Cells from First Principles

    Science.gov (United States)

    Cucinotta, Clotilde S.; Bernasconi, Marco; Parrinello, Michele

    2011-11-01

    By means of ab initio simulations we here provide a comprehensive scenario for hydrogen oxidation reactions at the Ni/zirconia anode of solid oxide fuel cells. The simulations have also revealed that in the presence of water chemisorbed at the oxide surface, the active region for H oxidation actually extends beyond the metal/zirconia interface unraveling the role of water partial pressure in the decrease of the polarization resistance observed experimentally.

  7. Cathodes for Solid Oxide Fuel Cells Operating at Low Temperatures

    DEFF Research Database (Denmark)

    Samson, Alfred Junio

    . High performance cathodes were obtained from strontium-doped lanthanum cobaltite (LSC) infiltrated - Ce0.9Gd0.1O1.95 (CGO) ionic conducting backbone. Systematic tuning of the CGO and LSC firing temperatures and LSC loading resulted in a cathode with low polarization resistance, Rp = 0.044 cm2 at 600......This dissertation focuses on the development of nanostructured cathodes for solid oxide fuel cells (SOFCs) and their performance at low operating temperatures. Cathodes were mainly fabricated by the infiltration method, whereby electrocatalysts are introduced onto porous, ionic conducting backbones...... with increasing LSC firing temperature, highlighting the importance of materials compability over higher ionic conductivity. The potential of Ca3Co4O9+delta as an electrocatalyst for SOFCs has also been explored and encouraging results were found i.e., Rp = 0.64 cm2 for a Ca3Co4O9+delta/CGO 50 vol % composite...

  8. Decommissioning of a mixed oxide fuel fabrication facility

    International Nuclear Information System (INIS)

    Buck, S.; Colquhoun, A.

    1990-01-01

    Decommissioning of the coprecipitation plant, which made plutonium/uranium oxide fuel, is a lead project in the BNFL Sellafield decommissioning programme. The overall programme has the objectives of gaining data and experience in a wide range of decommissioning operations and hence in this specific project to pilot the decommissioning of plant heavily contaminated with plutonium and other actinides. Consequently the operations have been used to test improvements in temporary containment, contamination control and decontamination methods and also to develop in situ plutonium assay, plutonium recovery and size-reduction methods. Finally the project is also yielding data on manpower requirements, personnel radiation uptake and waste arisings to help in the planning of future decommissioning projects

  9. Role of thermal analysis in uranium oxide fuel fabrication process

    International Nuclear Information System (INIS)

    Balaji Rao, Y.; Yadav, R.B.

    2006-01-01

    The present paper discusses the application of thermal analysis, particularly, differential thermal analysis (Dta) at various stages of fuel fabrication process. The useful role of Dta in knowing the decomposition pattern and calcination temperature of Adu along with de-nitration temperature is explained. The decomposition pattern depends upon the type of drying process adopted for wet ADU cake (ADU C). Also, the paper highlights the utility of DTA in determining the APS and SSA of UO 2+x and U 3 O 8 powders as an alternate technique. Further, the temperature difference (ΔT max ) between the two exothermic peaks obtained in UO 2+x powder oxidation is related to sintered density of UO 2 pellets. (author)

  10. Measurement and analysis of transient vaporization in oxide fuel materials

    International Nuclear Information System (INIS)

    Benson, D.A.; Bergeron, E.G.

    1979-01-01

    This paper describes a series of experiments in which samples are heated to produce high vapor pressure states in times of 10 -6 to 10 -3 seconds. Experimental measurements of vapor pressures over fresh UO 2 from the pulsed electron beam and pulsed reactor heating tests are presented and compared with other high temperature data. The interpretation of the vapor pressure measured in the tests is discussed in detail. Effects of original sample stoichiometry, chemical interactions with the container and non-equilibrium evaporation due to induced temperature gradients are discussed. Special attention is given to dynamic behavior in rapid heating and vaporization of the oxide due to chemical non-equilibrium. Finally, similar projected reactor experiments on irradiated fuel are described and vapor pressure predictions made using available equilibrium models. A discussion of information accessible from such future tests and its importance is presented. (orig.) [de

  11. Failure analysis of electrolyte-supported solid oxide fuel cells

    Science.gov (United States)

    Fleischhauer, Felix; Tiefenauer, Andreas; Graule, Thomas; Danzer, Robert; Mai, Andreas; Kuebler, Jakob

    2014-07-01

    For solid oxide fuel cells (SOFCs) one key aspect is the structural integrity of the cell and hence its thermo mechanical long term behaviour. The present study investigates the failure mechanisms and the actual causes for fracture of electrolyte supported SOFCs which were run using the current μ-CHP system of Hexis AG, Winterthur - Switzerland under lab conditions or at customer sites for up to 40,000 h. In a first step several operated stacks were demounted for post-mortem inspection, followed by a fractographic evaluation of the failed cells. The respective findings are then set into a larger picture including an analysis of the present stresses acting on the cell like thermal and residual stresses and the measurements regarding the temperature dependent electrolyte strength. For all investigated stacks, the mechanical failure of individual cells can be attributed to locally acting bending loads, which rise due to an inhomogeneous and uneven contact between the metallic interconnect and the cell.

  12. Measurement and analysis of transient vaporization in oxide fuel materials

    International Nuclear Information System (INIS)

    Gorham-Bergeron, E.; Benson, D.A.

    1978-01-01

    A series of experiments is described in which samples are heated to produce high vapor pressure states in times of 10 -6 to 10 -3 seconds. Experimental measurements of vapor pressures over fresh UO 2 from the pulsed electron beam and pulsed reactor heating tests are presented and compared with other high temperature data. The interpretation of the vapor pressures measured in the tests is discussed in detail. Effects of original sample stoichiometry, chemical interactions with the container and non-equilibrium evaporation due to induced temperature gradients are discussed. Special attention is given to dynamic behavior in rapid heating and vaporization of the oxide due to chemical nonequilibrium. Finally, similar projected reactor experiments on irradiated fuel are described and vapor pressure predictions made using available equilibrium models. A discussion of information accessible from such future tests and its importance is presented

  13. Study of catalysis for solid oxide fuel cells and direct methanol fuel cells

    Science.gov (United States)

    Jiang, Xirong

    Fuel cells offer the enticing promise of cleaner electricity with lower environmental impact than traditional energy conversion technologies. Driven by the interest in power sources for portable electronics, and distributed generation and automotive propulsion markets, active development efforts in the technologies of both solid oxide fuel cell (SOFC) and direct methanol fuel cell (DMFC) devices have achieved significant progress. However, current catalysts for fuel cells are either of low catalytic activity or extremely expensive, presenting a key barrier toward the widespread commercialization of fuel cell devices. In this thesis work, atomic layer deposition (ALD), a novel thin film deposition technique, was employed to apply catalytic Pt to SOFC, and investigate both Pt skin catalysts and Pt-Ru catalysts for methanol oxidation, a very important reaction for DMFC, to increase the activity and utilization levels of the catalysts while simultaneously reducing the catalyst loading. For SOFCs, we explored the use of ALD for the fabrication of electrode components, including an ultra-thin Pt film for use as the electrocatalyst, and a Pt mesh structure for a current collector for SOFCs, aiming for precise control over the catalyst loading and catalyst geometry, and enhancement in the current collect efficiency. We choose Pt since it has high chemical stability and excellent catalytic activity for the O2 reduction reaction and the H2 oxidation reaction even at low operating temperatures. Working SOFC fuel cells were fabricated with ALD-deposited Pt thin films as an electrode/catalyst layer. The measured fuel cell performance reveals that comparable peak power densities were achieved for ALD-deposited Pt anodes with only one-fifth of the Pt loading relative to a DC-sputtered counterpart. In addition to the continuous electrocatalyst layer, a micro-patterned Pt structure was developed via the technique of area selective ALD. By coating yttria-stabilized zirconia, a

  14. Electrode Reaction Pathway in Oxide Anode for Solid Oxide Fuel Cells

    Science.gov (United States)

    Li, Wenyuan

    Oxide anodes for solid oxide fuel cells (SOFC) with the advantage of fuel flexibility, resistance to coarsening, small chemical expansion and etc. have been attracting increasing interest. Good performance has been reported with a few of perovskite structure anodes, such as (LaSr)(CrMn)O3. However, more improvements need to be made before meeting the application requirement. Understanding the oxidation mechanism is crucial for a directed optimization, but it is still on the early stage of investigation. In this study, reaction mechanism of oxide anodes is investigated on doped YCrO 3 with H2 fuel, in terms of the origin of electrochemical activity, rate-determining steps (RDS), extension of reactive zone, and the impact from overpotential under service condition to those properties. H2 oxidation on the YCs anodes is found to be limited by charge transfer and H surface diffusion. A model is presented to describe the elementary steps in H2 oxidation. From the reaction order results, it is suggested that any models without taking H into the charge transfer step are invalid. The nature of B site element determines the H2 oxidation kinetics primarily. Ni displays better adsorption ability than Co. However, H adsorption ability of such oxide anode is inferior to that of Ni metal anode. In addition, the charge transfer step is directly associated with the activity of electrons in the anode; therefore it can be significantly promoted by enhancement of the electron activity. It is found that A site Ca doping improves the polarization resistance about 10 times, by increasing the activity of electrons to promote the charge transfer process. For the active area in the oxide anode, besides the traditional three-phase boundary (3PB), the internal anode surface as two-phase boundary (2PB) is proven to be capable of catalytically oxidizing the H2 fuel also when the bulk lattice is activated depending on the B site elements. The contribution from each part is estimated by switching

  15. Fission gas behavior in mixed-oxide fuel during transient overpower

    International Nuclear Information System (INIS)

    Randklev, E.H.; Treibs, H.A.; Mastel, B.; Baldwin, D.L.

    1979-01-01

    Fission gas behavior can be important in determining fuel pin and core performance during a reactor transient. The results are presented of examinations characterizing the changes in microstructural distribution and retention of fission gas in fuel for a series of transient overpower (50 cents/s) tested mixed-oxide fuel pins and their steady state siblings

  16. Evaluation of the oxide and silicide fuels reactivity in the RSG-GAS core

    International Nuclear Information System (INIS)

    S, Tukiran; M S, Tagor; S, Lily; Pinem, S.

    2000-01-01

    Fuel exchange of The RSG-GAS reactor core from uranium oxide to uranium silicide in the same loading, density, and enrichment, that is, 250 gr, 2.98 gr/cm 3 , and 19.75 % respectively, will be performed in-step wise. In every cycle of exchange with 5/l mode, it is needed to evaluate the parameter of reactor core operation. One of the important operation parameters is fuel reactivity that gives effect to the core reactivity. The experiment was performed at core no. 36, BOC, low power which exist 2 silicide fuels. The evaluation was done based on the RSG-GAS control rod calibration consisting of 40 fuels and 8 control rod.s. From 40 fuels in the core, there are 2 silicide fuels, RI-225/A-9 and RI-224/C-3. For inserting 2 silicide fuels, the reactivity effect to the core must be know. To know this effect , it was performed fuels reactivity experiment, which based on control rod calibration. But in this case the RSG-GAS has no other fresh oxide fuel so that configuration of the RSG-GAS core was rearranged by taking out the both silicide fuels and this configuration is used as reference core. Then silicide fuel RI-224 was inserted to position F-3 replacing the fresh oxide fuel RI-260 so the different reactivity of the fuels is obtained. The experiment result showed that the fuel reactivity change is in amount of 12.85 cent (0.098 % ) The experiment result was compared to the calculation result, using IAFUEL code which amount to 13.49 cent (0.103 %) The result showed that the reactivity change of oxide to silicide fuel is small so that the fuel exchange from uranium oxide to uranium silicide in the first step can be done without any significant change of the operation parameter

  17. Novel Mg-Doped SrMoO3 Perovskites Designed as Anode Materials for Solid Oxide Fuel Cells

    Directory of Open Access Journals (Sweden)

    Vanessa Cascos

    2016-07-01

    Full Text Available SrMo1−xMxO3−δ (M = Fe and Cr, x = 0.1 and 0.2 oxides have been recently described as excellent anode materials for solid oxide fuel cells at intermediate temperatures (IT-SOFC with LSGM as the electrolyte. In this work, we have improved their properties by doping with aliovalent Mg ions at the B-site of the parent SrMoO3 perovskite. SrMo1−xMgxO3−δ (x = 0.1, 0.2 oxides have been prepared, characterized and tested as anode materials in single solid-oxide fuel cells, yielding output powers near 900 mW/cm−2 at 850 °C using pure H2 as fuel. We have studied its crystal structure with an “in situ” neutron power diffraction (NPD experiment at temperatures as high as 800 °C, emulating the working conditions of an SOFC. Adequately high oxygen deficiencies, observed by NPD, together with elevated disk-shaped anisotropic displacement factors suggest a high ionic conductivity at the working temperatures. Furthermore, thermal expansion measurements, chemical compatibility with the LSGM electrolyte, electronic conductivity and reversibility upon cycling in oxidizing-reducing atmospheres have been carried out to find out the correlation between the excellent performance as an anode and the structural features.

  18. Preparation of spherical fuel elements for HTR-PM in INET

    International Nuclear Information System (INIS)

    Xiangwen, Zhou; Zhenming, Lu; Jie, Zhang; Bing, Liu; Yanwen, Zou; Chunhe, Tang; Yaping, Tang

    2013-01-01

    Highlights: • Modifications and optimizations in the manufacture of spherical fuel elements (SFE) for HTR-PM are presented. • A newly developed overcoater exhibits good stability and high efficiency in the preparation of overcoated particles. • The optimized carbonization process reduces the process time from 70 h in the period of HTR-10 to 20 h. • Properties of the prepared SFE and matrix graphite balls meet the design specifications for HTR-PM. • In particular the mean free uranium fraction of 5 consecutive batches is only 8.7 × 10 −6 . -- Abstract: The spherical fuel elements were successfully manufactured in the period of HTR-10. In order to satisfy the mass production of fuel elements for HTR-PM, several measures have been taken in modifying and optimizing the manufacture process of fuel elements. The newly developed overcoater system and its corresponding parameters exhibited good stability and high efficiency in the preparation of overcoated particles. The optimized carbonization process could reduce the carbonization time from more than 70 h to 20 h and improve the manufacturing efficiency. Properties of the manufactured spherical fuel elements and matrix graphite balls met the design specifications for HTR-PM. The mean free uranium fraction of 5 consecutive batches was 8.7 × 10 −6 . The optimized fuel elements manufacturing process could meet the requirements of design specifications of spherical fuel elements for HTR-PM

  19. Integrated Solid Oxide Fuel Cell Power System Characteristics Prediction

    Directory of Open Access Journals (Sweden)

    Marian GAICEANU

    2009-07-01

    Full Text Available The main objective of this paper is to deduce the specific characteristics of the CHP 100kWe Solid Oxide Fuel Cell (SOFC Power System from the steady state experimental data. From the experimental data, the authors have been developed and validated the steady state mathematical model. From the control room the steady state experimental data of the SOFC power conditioning are available and using the developed steady state mathematical model, the authors have been obtained the characteristic curves of the system performed by Siemens-Westinghouse Power Corporation. As a methodology the backward and forward power flow analysis has been employed. The backward power flow makes possible to obtain the SOFC power system operating point at different load levels, resulting as the load characteristic. By knowing the fuel cell output characteristic, the forward power flow analysis is used to predict the power system efficiency in different operating points, to choose the adequate control decision in order to obtain the high efficiency operation of the SOFC power system at different load levels. The CHP 100kWe power system is located at Gas Turbine Technologies Company (a Siemens Subsidiary, TurboCare brand in Turin, Italy. The work was carried out through the Energia da Ossidi Solidi (EOS Project. The SOFC stack delivers constant power permanently in order to supply the electric and thermal power both to the TurboCare Company and to the national grid.

  20. Performance Analysis and Development Strategies for Solid Oxide Fuel Cells

    International Nuclear Information System (INIS)

    Ivers-Tiffee, E; Leonide, A; Weber, A

    2011-01-01

    Solid oxide fuel cells (SOFC) are of great interest for a diverse range of applications. Within the past 10 years, an increase in power density by one order of magnitude, a lowering of the operating temperature by 200 K, and degradation rates lowered by a factor of 10 have been achieved on the cell and stack level. However, there is still room for further enhancement of the overall performance by suitably tailoring the cell components on a micro- and nanostructural level. The efficiency of the electrochemically active single cell is characterized by the linear ohmic losses within the electrolyte and by nonlinear polarization losses at the electrode-electrolyte interfaces. Both depend on material composition and operation conditions (temperature and time, fuel utilisation and gas composition). The area-specific resistance (ASR) is considered as the figure of merit for overall performance. ASR values of anode supported cells (ASC) were determined by means of impedance spectroscopy and subsequently separated into ohmic losses (mainly electrolyte) and nonlinear polarisation losses resulting from gas diffusion and activation polarization in the cathode and anode. The efficiencies of ASCs will be discussed for various material combinations in the temperature range of technological interest (between 550 deg. C and 850 deg. C).

  1. Investigation of aluminosilicate refractory for solid oxide fuel cell applications

    Science.gov (United States)

    Gentile, Paul Steven

    Stationary solid oxide fuel cells (SOFCs) have been demonstrated to provide clean and reliable electricity through electro-chemical conversion of various fuel sources (CH4 and other light hydrocarbons). To become a competitive conversion technology the costs of SOFCs must be reduced to less than $400/kW. Aluminosilicate represents a potential low cost alternative to high purity alumina for SOFC refractory applications. The objectives of this investigation are to: (1) study changes of aluminosilicate chemistry and morphology under SOFC conditions, (2) identify volatile silicon species released by aluminosilicates, (3) identify the mechanisms of aluminosilicate vapor deposition on SOFC materials, and (4) determine the effects of aluminosilicate vapors on SOFC electrochemical performance. It is shown thermodynamically and empirically that low cost aluminosilicate refractory remains chemically and thermally unstable under SOFC operating conditions between 800°C and 1000°C. Energy dispersive spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS) of the aluminosilicate bulk and surface identified increased concentrations of silicon at the surface after exposure to SOFC gases at 1000°C for 100 hours. The presence of water vapor accelerated surface diffusion of silicon, creating a more uniform distribution. Thermodynamic equilibrium modeling showed aluminosilicate remains stable in dry air, but the introduction of water vapor indicative of actual SOFC gas streams creates low temperature (active anode interface.

  2. Solid oxide fuel cell performance under severe operating conditions

    DEFF Research Database (Denmark)

    Koch, Søren; Hendriksen, P.V.; Mogensen, Mogens Bjerg

    2006-01-01

    The performance and degradation of Solid Oxide Fuel Cells (SOFC) were studied under severe operating conditions. The cells studied were manufactured in a small series by ECN, in the framework of the EU funded CORE-SOFC project. The cells were of the anode-supported type with a double layer LSM...... cathode. They were operated at 750 °C or 850 °C in hydrogen with 5% or 50% water at current densities ranging from 0.25 A cm–2 to 1 A cm–2 for periods of 300 hours or more. The area specific cell resistance, corrected for fuel utilisation, ranged between 0.20 Ω cm2 and 0.34 Ω cm2 at 850 °C and 520 m......V, and between 0.51 Ω cm2 and 0.92 Ω cm2 at 750 °C and 520 mV. The degradation of cell performance was found to be low (ranging from 0 to 8%/1,000 hours) at regular operating conditions. Voltage degradation rates of 20 to 40%/1,000 hours were observed under severe operating conditions, depending on the test...

  3. Challenge for lowering concentration polarization in solid oxide fuel cells

    Science.gov (United States)

    Shimada, Hiroyuki; Suzuki, Toshio; Yamaguchi, Toshiaki; Sumi, Hirofumi; Hamamoto, Koichi; Fujishiro, Yoshinobu

    2016-01-01

    In the scope of electrochemical phenomena, concentration polarization at electrodes is theoretically inevitable, and lowering the concentration overpotential to improve the performance of electrochemical cells has been a continuing challenge. Electrodes with highly controlled microstructure, i.e., high porosity and uniform large pores are therefore essential to achieve high performance electrochemical cells. In this study, state-of-the-art technology for controlling the microstructure of electrodes has been developed for realizing high performance support electrodes of solid oxide fuel cells (SOFCs). The key is controlling the porosity and pore size distribution to improve gas diffusion, while maintaining the integrity of the electrolyte and the structural strength of actual sized electrode supports needed for the target application. Planar anode-supported SOFCs developed in this study realize 5 μm thick dense electrolyte (yttria-stabilized zirconia: YSZ) and the anode substrate (Ni-YSZ) of 53.6 vol.% porosity with a large median pore diameter of 0.911 μm. Electrochemical measurements reveal that the performance of the anode-supported SOFCs improves with increasing anode porosity. This Ni-YSZ anode minimizes the concentration polarization, resulting in a maximum power density of 3.09 W cm-2 at 800 °C using humidified hydrogen fuel without any electrode functional layers.

  4. A review of the breeding potentials of carbide, nitride and oxide fueled LMFBRs and GCFRs

    International Nuclear Information System (INIS)

    Handa, Muneo

    1977-11-01

    The effects of design parameters in large variation on compound system doubling time of large advanced-fueled LMFBR are described on the base of recent U.S. results. The fuel element design by Combustion Engineering Inc. in step-by-step substitution of the initial oxide fuel subassemblies with carbide ones is explained. Breeding characteristics of the oxide-fueled LMFBR and its potential design modifications are expounded. The gas cooled fast breeder program in West Germany and in the United States are briefed. Definitions of the breeding ratio and doubling time in overall fuel cycle are given. (auth.)

  5. Solid oxide fuel cells towards real life applications. Final report

    Energy Technology Data Exchange (ETDEWEB)

    2010-07-01

    Solid Oxide Fuel Cells offer a clean and efficient way of producing electricity and heat from a wide selection of fuels. The project addressed three major challenges to be overcome by the technology to make commercialisation possible. (1) At the cell level, increased efficiency combined with production cost reduction has been achieved through an optimization of the manufacturing processes, b) by using alternative raw materials with a lower purchase price and c) by introducing a new generation of fuel cells with reduced loss and higher efficiency. (2) At the stack level, production cost reduction is reduced and manufacturing capacity is increased through an optimization of the stack production. (3) At the system level, development of integrated hotbox concepts for the market segments distributed generation (DG), micro combined heat and power (mCHP), and auxiliary power units (APU) have been developed. In the mCHP segment, two concepts have been developed and validated with regards to market requirements and scalability. In the APU-segment, different types of reformers have been tested and it has been proven that diesel can be reformed through appropriate reformers. Finally, operation experience and feedback has been gained by deployment of stacks in the test facility at the H.C. OErsted Power Plant (HCV). This demonstration has been carried out in collaboration between TOFC and DONG Energy Power A/S (DONG), who has participated as a subcontractor to TOFC. The demonstration has given valuable knowledge and experience with design, start-up and operation of small power units connected to the grid and future development within especially the mCHP segment will benefit from this. In this report, the project results are described for each of the work packages in the project. (Author)

  6. Method of manufacturing gadolinium oxide-incorporated nuclear fuel sintering products

    International Nuclear Information System (INIS)

    Komono, Akira; Seki, Makoto; Omori, Sadayuki.

    1987-01-01

    Purpose: To manufacture nuclear fuel sintering products excellent in burning property and mechanical property. Constitution: In the manufacturing step for nuclear fuel sintering products, specific metal oxides are added for promoting the growth of crystal grains in the sintering. Those metal oxides melted at a temperature lower than the sintering temperature of a mixture of nuclear fuel oxide powder and oxide power, or those metal oxides causing eutectic reaction are used as the metal oxide. Particularly, those compounds having oxygen atom - metal atom ratio (O/M) of not less than 2 are preferably used. As such metal oxides usable herein transition metal oxides, e.g., Nb 2 O 5 , TiO 2 , MoO 3 and WO 3 are preferred, with Nb 2 O 3 and TiO 2 being preferred particularly. (Seki, T.)

  7. Electrochemical processing of spent nuclear fuels: An overview of oxide reduction in pyroprocessing technology

    Directory of Open Access Journals (Sweden)

    Eun-Young Choi

    2015-12-01

    Full Text Available The electrochemical reduction process has been used to reduce spent oxide fuel to a metallic form using pyroprocessing technology for a closed fuel cycle in combination with a metal-fuel fast reactor. In the electrochemical reduction process, oxides fuels are loaded at the cathode basket in molten Li2O–LiCl salt and electrochemically reduced to the metal form. Various approaches based on thermodynamic calculations and experimental studies have been used to understand the electrode reaction and efficiently treat spent fuels. The factors that affect the speed of the electrochemical reduction have been determined to optimize the process and scale-up the electrolysis cell. In addition, demonstrations of the integrated series of processes (electrorefining and salt distillation with the electrochemical reduction have been conducted to realize the oxide fuel cycle. This overview provides insight into the current status of and issues related to the electrochemical processing of spent nuclear fuels.

  8. Thin copper oxide films prepared by ion beam sputtering with subsequent thermal oxidation: Application in chemiresistors

    Energy Technology Data Exchange (ETDEWEB)

    Horak, P., E-mail: phorak@ujf.cas.cz [Nuclear Physics Institute, Academy of Sciences of the Czech Republic, 250 68 Řež (Czech Republic); Bejsovec, V.; Vacik, J.; Lavrentiev, V. [Nuclear Physics Institute, Academy of Sciences of the Czech Republic, 250 68 Řež (Czech Republic); Vrnata, M. [Department of Physics and Measurements, The University of Chemistry and Technology, Prague, Technická 5, 166 28 Prague 6 (Czech Republic); Kormunda, M. [Department of Physics, Jan Evangelista Purkyně University in Ústí nad Labem, České mládeže 8, 400 96 Ústí nad Labem (Czech Republic); Danis, S. [Department of Condensed Matter Physics, Faculty of Mathematics and Physics, Charles University in Prague, Ke Karlovu 5, 121 16 Prague 2 (Czech Republic)

    2016-12-15

    Highlights: • A rapid oxidation process of thin copper films. • Sheet resistance up to 10{sup 9} Ω/◊. • Mixed oxide phase at 200 °C with significant hydroxide presence. • Gas sensing response to 1000 ppm of hydrogen and methanol vapours. • Increased sensitivity with Pd and Au catalyst to hydrogen and methanol, respectively. - Abstract: Copper oxide films were prepared by thermal oxidation of thin Cu films deposited on substrates by ion beam sputtering. The subsequent oxidation was achieved in the temperature range of 200 °C–600 °C with time of treatment from 1 to 7 h (with a 1-h step) in a furnace open to air. At temperatures 250 °C–600 °C, the dominant phase formed was CuO, while at 200 °C mainly the Cu{sub 2}O phase was identified. However, the oxidation at 200 °C led to a more complicated composition − in the depth Cu{sub 2}O phase was observed, though in the near-surface layer the CuO dominant phase was found with a significant presence of Cu(OH){sub 2}. A limited amount of Cu{sub 2}O was also found in samples annealed at 600 °C. The sheet resistance R{sub S} of the as-deposited Cu sample was 2.22 Ω/□, after gradual annealing R{sub S} was measured in the range 2.64 MΩ/□–2.45 GΩ/□. The highest R{sub S} values were obtained after annealing at 300 °C and 350 °C, respectively. Oxygen depth distribution was studied using the {sup 16}O(α,α) nuclear reaction with the resonance at energy 3032 keV. It was confirmed that the higher oxidation degree of copper is located in the near-surface region. Preliminary tests of the copper oxide films as an active layer of a chemiresistor were also performed. Hydrogen and methanol vapours, with a concentration of 1000 ppm, were detected by the sensor at an operating temperature of 300 °C and 350 °C, respectively. The response of the sensors, pointed at the p-type conductivity, was improved by the addition of thin Pd or Au catalytic films to the oxidic film surface. Pd-covered films showed

  9. Advanced manufacturing of intermediate temperature, direct methane oxidation membrane electrode assemblies for durable solid oxide fuel cell, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — ITN proposes to create an innovative anode supported membrane electrode assembly (MEA) for solid oxide fuel cells (SOFCs) that is capable of long-term operation at...

  10. Transport of oxide spent fuel. Industrial experience of COGEMA

    International Nuclear Information System (INIS)

    Lenail, B.

    1985-01-01

    COGEMA, the world leading Company in the reprocessing industry who is also involved in the transport activity, is ruling all transports of spent fuel to La Hague reprocessing plant. The paper summarizes some aspects of the experience gained in this field (road, rail and sea transports) and describes the standards defined by COGEMA as regards transport casks. These standards are as follows: - casks of dry type, - casks of the maximum size compatible with rail transports, - capability to be unloaded with standardized equipment and following standard procedures. Considering: 1) the extremely large experience of COGEMA for all transport modes and, 2) the fact that all these transports are performed in full compliance with the IAEA recommendations, COGEMA is convinced that its experience could serve to help countries or utilities willing to undertake to establish a transport system within their own country COGEMA is prepared to contribute to this task on terms to be agreed [fr

  11. Effect of the thickness of a fluoropolymer film on the radiotically prepared fuel cell membranes

    International Nuclear Information System (INIS)

    Ko, Beom Seok; Sohn, Joon Yong; Nho, Young Chang; Shin, Jun Hwa; Kim, Jong Il

    2010-01-01

    To observe the effect of the thickness of a fluoropolymer film on the radiotically prepared fuel cell membranes, fuel cell membranes with various thickness were prepared by simultaneous radiation grafting of styrene into polyethylene-co-tetrafluoroethylene (ETFE) with various thicknesses (25, 50 and 100 μm) and subsequent sulfonation. The physico-chemical properties of the prepared membranes such as ion exchange capacity, water uptake, distribution of sulfonic acid group were evaluated in the correlation with the thickness of ETFE film. In additions, proton conductivity and methanol permeability of the prepared membranes were also evaluated. The results revealed that the proton conductivity and methanol permeability of the prepared membranes were largely affected by the thickness of ETFE film utilized as a base film

  12. Effect of the thickness of a fluoropolymer film on the radiotically prepared fuel cell membranes

    Energy Technology Data Exchange (ETDEWEB)

    Ko, Beom Seok; Sohn, Joon Yong; Nho, Young Chang; Shin, Jun Hwa [Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of); Kim, Jong Il [Chonbuk National University, Jeonju (Korea, Republic of)

    2010-06-15

    To observe the effect of the thickness of a fluoropolymer film on the radiotically prepared fuel cell membranes, fuel cell membranes with various thickness were prepared by simultaneous radiation grafting of styrene into polyethylene-co-tetrafluoroethylene (ETFE) with various thicknesses (25, 50 and 100 {mu}m) and subsequent sulfonation. The physico-chemical properties of the prepared membranes such as ion exchange capacity, water uptake, distribution of sulfonic acid group were evaluated in the correlation with the thickness of ETFE film. In additions, proton conductivity and methanol permeability of the prepared membranes were also evaluated. The results revealed that the proton conductivity and methanol permeability of the prepared membranes were largely affected by the thickness of ETFE film utilized as a base film.

  13. Jojoba methyl ester as a diesel fuel substitute: Preparation and characterization

    Energy Technology Data Exchange (ETDEWEB)

    Radwan, M.S.; Ismail, M.A.; Elfeky, S.M.S.; Abu-Elyazeed, O.S.M. [Mechanical Power Engineering Department, Faculty of Engineering at Mattaria, University of Helwan, Masakin Elhelmia, Mattaria, Cairo 11718 (Egypt)

    2007-02-15

    The aim of the present work is to prepare jojoba methyl ester (JME) as a diesel fuel substitute. This was carried out experimentally and its chemical and physical properties were determined. Esterification method is used to produce methyl ester from raw jojoba oil. This method is optimized to produce the highest amount of fuel using a minimum amount of methyl alcohol. To achieve the above aim, a test rig for fuel production was developed. To measure the JME burning velocity a constant volume bomb was developed. The bomb was fully instrumented with a piezoelectric pressure transducer, charge amplifier, digital storage oscilloscope, A/D converter and a personal computer. Several grades of fuel were produced but, two grades only were selected and tested as an economical alternative fuel. The chemical and physical properties of these grades of fuel are measured as well as the laminar burning velocity. It is found that JME liquid fuel exhibited lower burning velocities than iso-octane. The new fuel is found to be suitable for compression ignition engine particularly in the indirect-injection ones, while for direct-injection, and high-speed engines fuel modifications are required. The new fuel is safe, has no sulphur content and reduces the engine wear as well as lengthens the lifetime of lubricating oil. (author)

  14. The spectrographic analysis of plutonium oxide or mixed plutonium oxide/uranium oxide fuel pellets by the dried residue technique

    International Nuclear Information System (INIS)

    Jarbo, G.J.; Faught, P.; Hildebrandt, B.

    1980-05-01

    An emission spectrographic method for the quantitative determination of metallic impurities in plutonium oxide and mixed plutonium oxide/uranium oxide is described. The fuel is dissolved in nitric acid and the plutonium and/or uranium extracted with tributyl phosphate. A small aliquot of the aqueous residue is dried on a 'mini' pyrolitic graphite plate and excited by high voltage AC spark in an oxygen atmosphere. Spectra are recorded in a region which has been specially selected to record simultaneously lines of boron and cadmium in the 2nd order and all the other elements of interest in the 1st order. Indium is used as an internal standard. The excitation of very small quantities of the uraniumm/plutonium free residue by high voltage spark, together with three separate levels of containment reduce the hazards to personnel and the environment to a minimum with limited effect on sensitivity and accuracy of the results. (auth)

  15. High-resolution characterization of oxidation mechanism of zirconium nuclear fuel cladding alloys

    International Nuclear Information System (INIS)

    Hu, J.; Lozano-Perez, S.; Grovenor, C.

    2015-01-01

    Full text of publication follows. Zirconium alloys are used extensively as cladding materials in modern light water reactors to separate the uranium dioxide (UO 2 ) fuel rods and the coolant water in order to prevent the escape of radioactive fission products whilst maintaining heat transfer to the coolant. With increasing demand for high burn-up in modern nuclear reactors, environmental degradation of these alloys is now the life limiting factor for fuel assemblies. As part of the MUZIC-2 collaboration studying oxidation and hydrogen pickup in Zr alloys, several high resolution analysis techniques have been used to study the microstructure of a range of commercial and developmental Zr alloys. The sample used for this investigation was prepared from a Westinghouse TM developmental alloy with composition of Zr-0.9Nb-0.01Sn-0.08Fe (wt %) in the recrystallized condition. The sample was oxidised in an autoclave at EDF Energy under simulated PWR water conditions at 360 C. degrees for 360 days. Using Transmission Electron Microscope (TEM), we have studied the development of the equiaxed-columnar-equiaxed grain structure, and observe that the columnar grains are both longer and show a stronger preferred texture in more corrosion-resistant alloys. Fresnel imaging revealed the existence of both parallel interconnected pores and some vertically interconnected pores along the columnar oxide grain boundaries, which become more disconnected near the metal-oxide interface. Electron Energy Loss Spectroscopy (EELS) provided accurate quantitative analysis of the oxygen concentration across the interface, identifying the existence of local regions of stoichiometric ZrO and Zr 3 O 2 with varying thickness. These observations will be discussed in the context of current models for oxidation in zirconium alloys. (authors)

  16. Photocatalysis of zinc oxide nanotip array/titanium oxide film heterojunction prepared by aqueous solution deposition

    Science.gov (United States)

    Lee, Ming-Kwei; Lee, Bo-Wei; Kao, Chen-Yu

    2017-05-01

    A TiO2 film was prepared on indium tin oxide (ITO)/glass by aqueous solution deposition (ASD) with precursors of ammonium hexafluoro-titanate and boric acid at 40 °C. The photocatalysis of annealed TiO2 film increases with increasing growth time and decreases with increasing growth times longer than 60 min. A ZnO nanotip array was prepared on ZnO seed layer/TiO2 film/glass by aqueous solution deposition with precursors of zinc nitrate and ammonium hydroxide at 70 °C. The photocatalysis of ASD-ZnO/ASD-TiO2 film/ITO glass can be better than that of P25.

  17. Preparation of porous titanium oxide films onto indium tin oxide for application in organic photovoltaic devices

    Energy Technology Data Exchange (ETDEWEB)

    Macedo, Andreia G. [Laboratorio de Dispositivos Nanoestruturados, Departamento de Fisica, Universidade Federal do Parana, Curitiba, Parana (Brazil); Mattos, Luana L.; Spada, Edna R.; Serpa, Rafael B.; Campos, Cristiani S. [Laboratorio de Sistemas Nanoestruturados, Departamento de Fisica, Universidade Federal de Santa Catarina, Florianopolis, Santa Catarina (Brazil); Grova, Isabel R.; Ackcelrud, Leni [Laboratorio de Polimeros Paulo Scarpa, Departamento de Quimica, Universidade Federal do Parana, Curitiba, Parana (Brazil); Reis, Francoise T.; Sartorelli, Maria L. [Laboratorio de Sistemas Nanoestruturados, Departamento de Fisica, Universidade Federal de Santa Catarina, Florianopolis, Santa Catarina (Brazil); Roman, Lucimara S., E-mail: lsroman@fisica.ufpr.br [Laboratorio de Dispositivos Nanoestruturados, Departamento de Fisica, Universidade Federal do Parana, Curitiba, Parana (Brazil)

    2012-05-01

    In this work, porous ordered TiO{sub 2} films were prepared through sol gel route by using a monolayer of polystyrene spheres as template on indium-tin oxide/glass substrate. These films were characterized by SEM, AFM, Raman spectroscopy, UV-vis absorbance and XRD. The UV-vis absorbance spectrum show a pseudo band gap (PBG) with maxima at 460 nm arising from the light scattering and partial or total suppression of the photon density of states, this PBG can be controlled by the size of the pore. We also propose the use of this porous film as electron acceptor electrode in organic photovoltaic cells; we show that devices prepared with porous titania displayed higher efficiencies than devices using compact titania films as electrode. Such behaviour was observed in both bilayer and bulk heterojunction devices.

  18. Preparation of porous titanium oxide films onto indium tin oxide for application in organic photovoltaic devices

    International Nuclear Information System (INIS)

    Macedo, Andreia G.; Mattos, Luana L.; Spada, Edna R.; Serpa, Rafael B.; Campos, Cristiani S.; Grova, Isabel R.; Ackcelrud, Leni; Reis, Françoise T.; Sartorelli, Maria L.; Roman, Lucimara S.

    2012-01-01

    In this work, porous ordered TiO 2 films were prepared through sol gel route by using a monolayer of polystyrene spheres as template on indium-tin oxide/glass substrate. These films were characterized by SEM, AFM, Raman spectroscopy, UV-vis absorbance and XRD. The UV-vis absorbance spectrum show a pseudo band gap (PBG) with maxima at 460 nm arising from the light scattering and partial or total suppression of the photon density of states, this PBG can be controlled by the size of the pore. We also propose the use of this porous film as electron acceptor electrode in organic photovoltaic cells; we show that devices prepared with porous titania displayed higher efficiencies than devices using compact titania films as electrode. Such behaviour was observed in both bilayer and bulk heterojunction devices.

  19. Highly durable anode supported solid oxide fuel cell with an infiltrated cathode

    DEFF Research Database (Denmark)

    Samson, Alfred Junio; Hjalmarsson, Per; Søgaard, Martin

    2012-01-01

    An anode supported solid oxide fuel cell with an La0.6Sr0.4Co1.05O3_δ (LSC) infiltrated-Ce0.9Gd0.1O1.95 (CGO) cathode that shows a stable performance has been developed. The cathode was prepared by screen printing a porous CGO backbone on top of a laminated and co-fired anode supported half cell...... was tested at 700 deg. C under a current density of 0.5 A cm-2 for 1500 h using air as oxidant and humidified hydrogen as fuel. The electrochemical performance of the cell was analyzed by impedance spectroscopy and current evoltage relationships. No measurable degradation in the cell voltage or increase...... in the resistance from the recorded impedance was observed during long term testing. The power density reached 0.79Wcm-2 at a cell voltage of 0.6 V at 750 deg. C. Post test analysis of the LSC infiltrated-CGO cathode by scanning electron microscopy revealed no significant micro-structural difference...

  20. Nanostructured Carbon Materials as Supports in the Preparation of Direct Methanol Fuel Cell Electrocatalysts

    Directory of Open Access Journals (Sweden)

    María Jesús Lázaro

    2013-08-01

    Full Text Available Different advanced nanostructured carbon materials, such as carbon nanocoils, carbon nanofibers, graphitized ordered mesoporous carbons and carbon xerogels, presenting interesting features such as high electrical conductivity and extensively developed porous structure were synthesized and used as supports in the preparation of electrocatalysts for direct methanol fuel cells (DMFCs. The main advantage of these supports is that their physical properties and surface chemistry can be tailored to adapt the carbonaceous material to the catalytic requirements. Moreover, all of them present a highly mesoporous structure, diminishing diffusion problems, and both graphitic character and surface area can be conveniently modified. In the present work, the influence of the particular features of each material on the catalytic activity and stability was analyzed. Results have been compared with those obtained for commercial catalysts supported on Vulcan XC-72R, Pt/C and PtRu/C (ETEK. Both a highly ordered graphitic and mesopore-enriched structure of these advanced nanostructured materials resulted in an improved electrochemical performance in comparison to the commercial catalysts assayed, both towards CO and alcohol oxidation.

  1. Selection of optimal conditions for preparation of emulsified fuel fluids

    Science.gov (United States)

    Ivanov, V. A.; Berg, V. I.; Frolov, M. D.

    2018-05-01

    The aim of the article is to derive the optimal concept of physical and chemical effects, and its application to the production of water-fuel emulsions. The authors set a research task to attempt to estimate the influence of the surfactant concentration on such indicator as the time before the beginning of emulsion breaking. The analysis, based on experimental data, showed that an increase in the concentration of sodium lauryl sulfate is expedient to a certain point, corresponding to 0.05% of the total mass fraction. The main advantage of the model is a rational combination of methods of physical and chemical treatment used in the production of emulsions.

  2. Carbon and Redox Tolerant Infiltrated Oxide Fuel-Electrodes for Solid Oxide Cells

    DEFF Research Database (Denmark)

    Skafte, Theis Løye; Sudireddy, Bhaskar Reddy; Blennow, P.

    2016-01-01

    To solve issues of coking and redox instability related to the presence of nickel in typical fuel electrodes in solid oxide cells,Gd-doped CeO2 (CGO) electrodes were studied using symmetriccells. These electrodes showed high electro-catalytic activity, butlow electronic conductivity. When...... infiltrated with Sr0.99Fe0.75Mo0.25O3-δ (SFM), the electronic conductivity wasenhanced. However, polarization resistance of the cells increased,suggesting that the infiltrated material is less electro-catalyticallyactive and was partly blocking the CGO surface reaction sites. Theactivity could be regained...... by infiltrating nano-sized CGO orNiCGO on top of SFM, while still sustaining the high electronicconductivity. Ohmic resistance of the electrodes was thuspractically eliminated and performance comparable to, or betterthan, state-of-the-art fuel electrodes was achieved. The Nicontaining cells were damaged by carbon...

  3. Tin-oxide-coated single-walled carbon nanotube bundles supporting platinum electrocatalysts for direct ethanol fuel cells

    International Nuclear Information System (INIS)

    Hsu, Ryan S; Higgins, Drew; Chen Zhongwei

    2010-01-01

    Novel tin-oxide (SnO 2 )-coated single-walled carbon nanotube (SWNT) bundles supporting platinum (Pt) electrocatalysts for ethanol oxidation were developed for direct ethanol fuel cells. SnO 2 -coated SWNT (SnO 2 -SWNT) bundles were synthesized by a simple chemical-solution route. SnO 2 -SWNT bundles supporting Pt (Pt/SnO 2 -SWNTs) electrocatalysts and SWNT-supported Pt (Pt/SWNT) electrocatalysts were prepared by an ethylene glycol reduction method. The catalysts were physically characterized using TGA, XRD and TEM and electrochemically evaluated through cyclic voltammetry experiments. The Pt/SnO 2 -SWNTs showed greatly enhanced electrocatalytic activity for ethanol oxidation in acid medium, compared to the Pt/SWNT. The optimal SnO 2 loading of Pt/SnO 2 -SWNT catalysts with respect to specific catalytic activity for ethanol oxidation was also investigated.

  4. Tin-oxide-coated single-walled carbon nanotube bundles supporting platinum electrocatalysts for direct ethanol fuel cells.

    Science.gov (United States)

    Hsu, Ryan S; Higgins, Drew; Chen, Zhongwei

    2010-04-23

    Novel tin-oxide (SnO(2))-coated single-walled carbon nanotube (SWNT) bundles supporting platinum (Pt) electrocatalysts for ethanol oxidation were developed for direct ethanol fuel cells. SnO(2)-coated SWNT (SnO(2)-SWNT) bundles were synthesized by a simple chemical-solution route. SnO(2)-SWNT bundles supporting Pt (Pt/SnO(2)-SWNTs) electrocatalysts and SWNT-supported Pt (Pt/SWNT) electrocatalysts were prepared by an ethylene glycol reduction method. The catalysts were physically characterized using TGA, XRD and TEM and electrochemically evaluated through cyclic voltammetry experiments. The Pt/SnO(2)-SWNTs showed greatly enhanced electrocatalytic activity for ethanol oxidation in acid medium, compared to the Pt/SWNT. The optimal SnO(2) loading of Pt/SnO(2)-SWNT catalysts with respect to specific catalytic activity for ethanol oxidation was also investigated.

  5. Indium tin oxide films prepared via wet chemical route

    International Nuclear Information System (INIS)

    Legnani, C.; Lima, S.A.M.; Oliveira, H.H.S.; Quirino, W.G.; Machado, R.; Santos, R.M.B.; Davolos, M.R.; Achete, C.A.; Cremona, M.

    2007-01-01

    In this work, indium tin oxide (ITO) films were prepared using a wet chemical route, the Pechini method. This consists of a polyesterification reaction between an α-hydroxicarboxylate complex (indium citrate and tin citrate) with a polyalcohol (ethylene glycol) followed by a post annealing at 500 deg. C. A 10 at.% of doping of Sn 4+ ions into an In 2 O 3 matrix was successfully achieved through this method. In order to characterize the structure, the morphology as well as the optical and electrical properties of the produced ITO films, they were analyzed using different experimental techniques. The obtained films are highly transparent, exhibiting transmittance of about 85% at 550 nm. They are crystalline with a preferred orientation of [222]. Microscopy discloses that the films are composed of grains of 30 nm average size and 0.63 nm RMS roughness. The films' measured resistivity, mobility and charge carrier concentration were 5.8 x 10 -3 Ω cm, 2.9 cm 2 /V s and - 3.5 x 10 20 /cm 3 , respectively. While the low mobility value can be related to the small grain size, the charge carrier concentration value can be explained in terms of the high oxygen concentration level resulting from the thermal treatment process performed in air. The experimental conditions are being refined to improve the electrical characteristics of the films while good optical, chemical, structural and morphological qualities already achieved are maintained

  6. Methanol oxidation at platinized copper particles prepared by galvanic replacement

    Directory of Open Access Journals (Sweden)

    Ioanna Mintsouli

    2016-04-01

    Full Text Available Bimetallic Pt-Cu particles have been prepared by galvanic replacement of Cu precursor nanoparticles, upon the treatment of the latter with a chloro-platinate acidic solution. The resulting particles, typically a few tens of nm large, were supported on high surface area carbon (Vulcan® XC–72R, Cabot and tested as electrodes. Surface electrochemistry in deaerated acid solutions was similar to that of pure Pt, indicating the existence of a Pt shell (hence the particles are denoted as Pt(Cu. Pt(Cu/C supported catalysts exhibit superior carbon monoxide and methanol oxidation activity with respect to their Pt/C analogues when compared on a per electroactive surface area basis, due to the modification of Pt activity by Cu residing in the particle core. However, as a result of large particle size and agglomeration phenomena, Pt(Cu/C are still inferior to Pt/C when compared on a mass specific activity basis.

  7. Fuel cell membrane preparation: effects of base polymer

    Energy Technology Data Exchange (ETDEWEB)

    Brack, H P; Scherer, G G [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-06-01

    Radiation grafted films and membranes prepared from the partially fluorinated base copolymer poly(ethylene-alt-tetrafluoroethylene) or ETFE have better mechanical properties than those prepared from poly(tetrafluoroethylene-co-hexafluoropropylene) or FEP. The influence of the base copolymer film type on the grafting rate and yields is reported in the present investigation. An understanding of the effects of these parameters is important so that the grafting process can be carried out reproducibly in as short a time as possible. The grafting rate and yield as a function of the irradiation dose has been found to be much higher for the partially fluorinated base copolymer ETFE. (author) 2 figs., 1 tab., 5 refs.

  8. TEMPO-oxidized Konjac glucomannan as appliance for the preparation of hard capsules

    NARCIS (Netherlands)

    Chen, Yuying; Zhao, Huiying; Liu, Xianwu; Li, Zusen; Liu, Bin; Wu, Jiande; Shi, Mengxuan; Norde, Willem; Li, Yuan

    2016-01-01

    TEMPO-oxidized Konjac glucomannan (OKGM) was developed as new material for preparing vegetarian hard capsules. OKGM of different degrees of oxidation: DO30%, DO50%, and DO80% were prepared to select optimum DO for capsule formation. FT-IR results proved that the primary alcohol groups on KGM were

  9. Preparation and research on properties of castor oil as a diesel fuel additive

    OpenAIRE

    Nurbakhit Imankulov

    2012-01-01

    The research shows an opportunity of preparing biodiesel fuel on the basis of local diesel fuel and the bioadditive - castor oil. Limiting optimum concentration of introduction of the bioadditive equal was established as 5% mass ratio. The castor oil released from seeds of Palma Christi grown on experimental field. All physical and chemical characteristics of the oil including IR-spectra were determined. Operating conditions of castor oil introduction (temperature, solubility, concentra-tion,...

  10. Determination of oxygen potentials and O/M ratios of oxide nuclear reactor fuels by means of an automated solid state galvanic cell

    International Nuclear Information System (INIS)

    Toci, F.; Cambini, M.

    1987-01-01

    An automated version of the electromotive force (emf) cell for the determination of oxygen activities and oxygen to metal ratios of oxide nuclear reactor fuel, irradiated or not, is reported together with some measurements. 9 figs., 17 refs. In appendix a method is described for preparing suitable electrolyte crucibles

  11. The thermomechanical stability of micro-solid oxide fuel cells fabricated on anodized aluminum oxide membranes

    Science.gov (United States)

    Kwon, Chang-Woo; Lee, Jae-Il; Kim, Ki-Bum; Lee, Hae-Weon; Lee, Jong-Ho; Son, Ji-Won

    2012-07-01

    The thermomechanical stability of micro-solid oxide fuel cells (micro-SOFCs) fabricated on an anodized aluminum oxide (AAO) membrane template is investigated. The full structure consists of the following layers: AAO membrane (600 nm)/Pt anode/YSZ electrolyte (900 nm)/porous Pt cathode. The utilization of a 600-nm-thick AAO membrane significantly improves the thermomechanical stability due to its well-known honeycomb-shaped nanopore structure. Moreover, the Pt anode layer deposited in between the AAO membrane and the YSZ electrolyte preserves its integrity in terms of maintaining the triple-phase boundary (TPB) and electrical conductivity during high-temperature operation. Both of these results guarantee thermomechanical stability of the micro-SOFC and extend the cell lifetime, which is one of the most critical issues in the fabrication of freestanding membrane-type micro-SOFCs.

  12. Synthesis and characterization of novel electrolyte materials for intermediate temperature solid oxide fuel cells

    International Nuclear Information System (INIS)

    Chaubey, Nityanand; Chattopadhyaya, M.C.; Wani, B.N.; Bharadwaj, S.R.

    2008-01-01

    The high operating temperature of SOFCs using zirconia based electrolyte have several restrictions on materials used as interconnect and sealing and also requires use of expensive ceramics. Lowering the operating temperature of SOFCs to 600-800 deg C will enable to use cheaper materials and reduce the cost of fabrication while keeping the high power density. Lanthanide gallates are considered to be very promising solid electrolytes for intermediate temperature (600-800 deg C) solid oxide fuel cells (IT-SOFCs) due to their high ionic conductivity at lower temperatures. Phase purity of this material is a concern for the researchers for a long time. These materials are prepared at very high temperature (∼1400 deg C), since it is known that at around 1100 deg C, solubilities of Sr and Mg in LaGaO 3 were close to zero. Hence in the present work perovskite oxides of Ln 1-x Sr x Ga 1-y Mg y O 3-δ (Ln= Sm, Gd and x = 0.10, y=0.20) have been prepared by different methods i.e. solid state reaction, gel combustion and co-precipitation methods

  13. Behavior of mixed-oxide fuel elements during the TOPI-1E transient overpower test

    International Nuclear Information System (INIS)

    Tsai, H.; Neimark, L.A.; Yamamoto, K.; Hirai, K.; Shikakura, S.

    1993-12-01

    A slow-ramp, extended overpower transient test was conducted on a group of nineteen preirradiated mixed-oxide fuel elements in EBR-II. During the transient two of the test elements with high-density fuel and tempered martensitic cladding (PNC-FMS) breached at an overpower of ∼75%. Fuel elements with austenitic claddings (D9, PNC316, and PNC150), many with aggressive design features and high burnups, survived the overpower transient and incurred little or no cladding strain. Fuel elements with annual fuel or heterogeneous fuel columns also behaved well

  14. Reprocessing fuel from the Southwest Experimental Fast Oxide Reactor at the Savannah River Plant

    International Nuclear Information System (INIS)

    Gray, L.W.; Campbell, T.G.

    1985-11-01

    The irradiated fuel, reject fuel tubes, and fuel fabrication scrap from the Southwest Experimental Fast Oxide Reactor (SEFOR) were transferred to the Savannah River Plant (SRP) for uranium and plutonium recovery. The unirradiated material was declad and dissolved at SRP; dissolution was accomplished in concentrated nitric acid without the addition of fluoride. The irradiated fuel was declad at Atomics International and repacked in aluminum. The fuel and aluminum cans were dissolved at SRP using nitric acid catalyzed by mercuric nitrate. As this fuel was dissolved in nongeometrically favorable tanks, boron was used as a soluble neutron poison

  15. Dissolution of mixed oxide fuel as a function of fabrication variables

    International Nuclear Information System (INIS)

    Lerch, R.E.

    1979-08-01

    Dissolution properties of mechanically blended mixed oxide fuel were very dependent on the six fuel fabrication variables studied. Fuel sintering temperature, source of PuO 2 and PuO 2 content of the fuel had major effects: (1) as the sintering temperature was increased from 1400 to 1700 0 C, pellet dissolution was more complete; (2) pellets made from burned metal derived PuO 2 were more completely dissolved than pellets made from calcined nitrate derived PuO 2 which in turn were more completely dissolved than pellets made from calcined nitrate derived PuO 2 ; (3) as the PuO 2 content decreased from 25 to 15 wt % PuO 2 , pellet dissolution was more complete. Preferential dissolution of uranium occurred in all the mechanically blended mixed oxide. Unirradiated mixed oxide fuel pellets made by the Sol Gel process were generally quite soluble in nitric acid. Unirradiated mixed oxide fuel pellets made by the coprecipitation process dissolved completely and rapidly in nitric acid. Fuel made by the coprecipitation process was more completely dissolved than fuel made by the Sol Gel process which, in turn, was more completely dissolved than fuel made by mechanically blending UO 2 and PuO 2 as shown below. Addition of uncomplexed fluoride to nitric acid during fuel dissolution generally rendered all fuel samples completely dissolvable. In boiling 12M nitric acid, 95 to 99% of the plutonium which was going to dissolve did so in the first hour. Irradiated mechanically blended mixed oxide fuel with known fuel fabrication conditions was also subjected to fuel dissolution tests. While irradiation was shown to increase completeness of plutonium dissolution, poor dissolubility due to adverse fabrication conditions (e.g., low sintering temperature) remained after irradiation

  16. Photoelectrochemical and electrocatalytic properties of thermally oxidized copper oxide for efficient solar fuel production

    KAUST Repository

    Garcia Esparza, Angel T.; Limkrailassiri, Kevin; Leroy, Fré dé ric; Rasul, Shahid; Yu, Weili; Lin, Liwei; Takanabe, Kazuhiro

    2014-01-01

    We report the use of a facile and highly scalable synthesis process to control growth products of earth-abundant Cu-based oxides and their application in relevant photoelectrochemical and electrochemical solar fuel generation systems. Characterization of the synthesized Cu(I)/Cu(II) oxides indicates that their surface morphology and chemical composition can be simply tuned by varying two synthesis parameters (time and temperature). UV-Vis spectroscopy and impedance spectroscopy studies are performed to estimate the band structures and electronic properties of these p-type semiconductor materials. Photoelectrodes made of Cu oxides possess favorable energy band structures for production of hydrogen from water; the position of their conduction band is ≈1 V more negative than the water-reduction potential. High acceptor concentrations on the order of 1018-1019 cm-3 are obtained, producing large electric fields at the semiconductor-electrolyte interface and thereby enhancing charge separation. The highly crystalline pristine samples used as photocathodes in photoelectrochemical cells exhibit high photocurrents under AM 1.5G simulated illumination. When the samples are electrochemically reduced under galvanostatic conditions, the co-existence of the oxide with metallic Cu on the surface seems to function as an effective catalyst for the selective electrochemical reduction of CO2. © the Partner Organisations 2014.

  17. Pt nanoparticle-reduced graphene oxide nanohybrid for proton exchange membrane fuel cells.

    Science.gov (United States)

    Park, Dae-Hwan; Jeon, Yukwon; Ok, Jinhee; Park, Jooil; Yoon, Seong-Ho; Choy, Jin-Ho; Shul, Yong-Gun

    2012-07-01

    A platinum nanoparticle-reduced graphene oxide (Pt-RGO) nanohybrid for proton exchange membrane fuel cell (PEMFC) application was successfully prepared. The Pt nanoparticles (Pt NPs) were deposited onto chemically converted graphene nanosheets via ethylene glycol (EG) reduction. According to the powder X-ray diffraction (XRD) pattern and transmission electron microscopy (TEM) analysis, the face-centered cubic Pt NPs (3-5 nm in diameter) were homogeneously dispersed on the RGO nanosheets. The electrochemically active surface area and PEMFC power density of the Pt-RGO nanohybrid were determined to be 33.26 m2/g and 480 mW/cm2 (maximum values), respectively, at 75 degrees C and at a relative humidity (RH) of 100% in a single-cell test experiment.

  18. Trace and surface analysis of ceramic layers of solid oxide fuel cells by mass spectrometry.

    Science.gov (United States)

    Becker, J S; Breuer, U; Westheide, J; Saprykin, A I; Holzbrecher, H; Nickel, H; Dietze, H J

    1996-06-01

    For the trace analysis of impurities in thick ceramic layers of a solid oxide fuel cell (SOFC) sensitive solid-state mass spectrometric methods, such as laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) and radiofrequency glow discharge mass spectrometry (rf-GDMS) have been developed and used. In order to quantify the analytical results of LA-ICP-MS, the relative sensitivity coefficients of elements in a La(0.6)Sr(0.35)MnO(3) matrix have been determined using synthetic standards. Secondary ion mass spectrometry (SIMS) - as a surface analytical method - has been used to characterize the element distribution and diffusion profiles of matrix elements on the interface of a perovskite/Y-stabilized ZrO(2) layer. The application of different mass spectrometric methods for process control in the preparation of ceramic layers for the SOFC is described.

  19. A combined SEM and CV Study of Solid Oxide Fuel Cell Interconnect Steels

    DEFF Research Database (Denmark)

    Kammer Hansen, Kent; Ofoegbu, Stanley; Mikkelsen, Lars

    2012-01-01

    Scanning electron microscopy and cyclic voltammetry were used to investigate the high temperature oxidation behavior of two solid oxide fuel cell interconnect steels. One alloy had a low content of manganese; the other alloy had a high content of manganese. Four reduction and four oxidation peaks...

  20. Thin copper oxide films prepared by ion beam sputtering with subsequent thermal oxidation: Application in chemiresistors

    Science.gov (United States)

    Horak, P.; Bejsovec, V.; Vacik, J.; Lavrentiev, V.; Vrnata, M.; Kormunda, M.; Danis, S.

    2016-12-01

    Copper oxide films were prepared by thermal oxidation of thin Cu films deposited on substrates by ion beam sputtering. The subsequent oxidation was achieved in the temperature range of 200 °C-600 °C with time of treatment from 1 to 7 h (with a 1-h step) in a furnace open to air. At temperatures 250 °C-600 °C, the dominant phase formed was CuO, while at 200 °C mainly the Cu2O phase was identified. However, the oxidation at 200 °C led to a more complicated composition - in the depth Cu2O phase was observed, though in the near-surface layer the CuO dominant phase was found with a significant presence of Cu(OH)2. A limited amount of Cu2O was also found in samples annealed at 600 °C. The sheet resistance RS of the as-deposited Cu sample was 2.22 Ω/□, after gradual annealing RS was measured in the range 2.64 MΩ/□-2.45 GΩ/□. The highest RS values were obtained after annealing at 300 °C and 350 °C, respectively. Oxygen depth distribution was studied using the 16O(α,α) nuclear reaction with the resonance at energy 3032 keV. It was confirmed that the higher oxidation degree of copper is located in the near-surface region. Preliminary tests of the copper oxide films as an active layer of a chemiresistor were also performed. Hydrogen and methanol vapours, with a concentration of 1000 ppm, were detected by the sensor at an operating temperature of 300 °C and 350 °C, respectively. The response of the sensors, pointed at the p-type conductivity, was improved by the addition of thin Pd or Au catalytic films to the oxidic film surface. Pd-covered films showed an increased response to hydrogen at 300 °C, while Au-covered films were more sensitive to methanol vapours at 350 °C.

  1. In situ Reduction and Oxidation of Nickel from Solid Oxide Fuel Cells in a Transmission Electron Microscope

    DEFF Research Database (Denmark)

    Faes, Antonin; Jeangros, Quentin; Wagner, Jakob Birkedal

    2009-01-01

    Environmental transmission electron microscopy was used to characterize in situ the reduction and oxidation of nickel from a Ni/YSZ solid oxide fuel cell anode support between 300-500{degree sign}C. The reduction is done under low hydrogen pressure. The reduction initiates at the NiO/YSZ interface...

  2. Pilot-scale equipment development for pyrochemical treatment of spent oxide fuel

    International Nuclear Information System (INIS)

    Herrmann, S. D.

    1999-01-01

    Fundamental objectives regarding spent nuclear fuel treatment technologies include, first, the effective distribution of spent fuel constituents among product and stable waste forms and, second, the minimization and standardization of waste form types and volumes. Argonne National Laboratory (ANL) has developed and is presently demonstrating the electrometallurgical treatment of sodium-bonded metal fuel from Experimental Breeder Reactor II, resulting in an uranium product and two stable waste forms, i.e. ceramic and metallic. Engineering efforts are underway at ANL to develop pilot-scale equipment which would precondition irradiated oxide fuel via pyrochemical processing and subsequently allow for electrometallurgical treatment of such non-metallic fuels into standard product and waste forms. This paper highlights the integration of proposed spent oxide fuel treatment with existing electrometallurgical processes. System designs and technical bases for development of pilot-scale oxide reduction equipment are also described

  3. Partial Oxidation of n-Butane over a Sol-Gel Prepared Vanadium Phosphorous Oxide

    Directory of Open Access Journals (Sweden)

    Juan M. Salazar

    2013-01-01

    Full Text Available Vanadium phosphorous oxide (VPO is traditionally manufactured from solid vanadium oxides by synthesizing VOHPO4∙0.5H2O (the precursor followed by in situ activation to produce (VO2P2O7 (the active phase. This paper discusses an alternative synthesis method based on sol-gel techniques. Vanadium (V triisopropoxide oxide was reacted with ortho-phosphoric acid in an aprotic solvent. The products were dried at high pressure in an autoclave with a controlled excess of solvent. This procedure produced a gel of VOPO4 with interlayer entrapped molecules. The surface area of the obtained materials was between 50 and 120 m2/g. Alcohol produced by the alkoxide hydrolysis reduced the vanadium during the drying step, thus VOPO4 was converted to the precursor. This procedure yielded non-agglomerated platelets, which were dehydrated and evaluated in a butane-air mixture. Catalysts were significantly more selective than the traditionally prepared materials with similar intrinsic activity. It is suggested that the small crystallite size obtained increased their selectivity towards maleic anhydride.

  4. Preparation and investigations of thermal properties of copper oxide ...

    Indian Academy of Sciences (India)

    The effects of copper oxide, aluminium oxide and graphite on the thermal and structural properties of the organic ... solar energy, and heat regulation of electronics, biomedical ..... We gratefully acknowledge the financial support provided by.

  5. Novel strategy for the preparation of graphene-encapsulated mesoporous metal oxides with enhanced lithium storage

    International Nuclear Information System (INIS)

    Lin, Rong; Yue, Wenbo; Niu, Fangzhou; Ma, Jie

    2016-01-01

    As potential anode materials for lithium-ion batteries, mesoporous metal oxides show high reversible capacities but relatively poor cycle stability due to the structural collapse during cycles. Graphene-encapsulated mesoporous metal oxides may increase the electronic conductivity of the composite as well as stabilize the mesostructure of metal oxides, thereby enhancing the electrochemical performance of mesoporous metal oxides. Herein we describe a novel strategy for the preparation of graphene-encapsulated mesoporous metal oxides (SnO_2, Mn_3O_4), which exhibit superior electrochemical performance compared to pure mesoporous metal oxides. Moreover, some mesoporous metal oxides may be further reduced to low-valence metal oxides when calcined in presence of graphene. Mesoporous metal oxides with high isoelectric points are not essential for this synthesis method since metal oxides are connected with graphene through mesoporous silica template, thus expanding the types of graphene-encapsulated mesoporous metal oxides.

  6. Coriander seed oil methyl esters as biodiesel fuel: Unique fatty acid composition and excellent oxidative stability

    International Nuclear Information System (INIS)

    Moser, Bryan R.; Vaughn, Steven F.

    2010-01-01

    Coriander (Coriandrum sativum L.) seed oil methyl esters were prepared and evaluated as an alternative biodiesel fuel and contained an unusual fatty acid hitherto unreported as the principle component in biodiesel fuels: petroselinic (6Z-octadecenoic; 68.5 wt%) acid. Most of the remaining fatty acid profile consisted of common 18 carbon constituents such as linoleic (9Z,12Z-octadeca-dienoic; 13.0 wt%), oleic (9Z-octadecenoic; 7.6 wt%) and stearic (octadecanoic; 3.1 wt%) acids. A standard transesterification procedure with methanol and sodium methoxide catalyst was used to provide C. sativum oil methyl esters (CSME). Acid-catalyzed pretreatment was necessary beforehand to reduce the acid value of the oil from 2.66 to 0.47 mg g -1 . The derived cetane number, kinematic viscosity, and oxidative stability (Rancimat method) of CSME was 53.3, 4.21 mm 2 s -1 (40 o C), and 14.6 h (110 o C). The cold filter plugging and pour points were -15 o C and -19 o C, respectively. Other properties such as acid value, free and total glycerol content, iodine value, as well as sulfur and phosphorous contents were acceptable according to the biodiesel standards ASTM D6751 and EN 14214. Also reported are lubricity, heat of combustion, and Gardner color, along with a comparison of CSME to soybean oil methyl esters (SME). CSME exhibited higher oxidative stability, superior low temperature properties, and lower iodine value than SME. In summary, CSME has excellent fuel properties as a result of its unique fatty acid composition.

  7. Synthesis and characterization of cobaltite nanotubes for solid-oxide fuel cell cathodes

    Energy Technology Data Exchange (ETDEWEB)

    Napolitano, F; Baque, L; Troiani, H; Granada, M; Serquis, A, E-mail: aserquis@cab.cnea.gov.a [Instituto Balseiro-Centro Atomico Bariloche and CONICET, San Carlos de Bariloche (Argentina)

    2009-05-01

    La{sub 1-x}Sr{sub x}Co{sub 1-y}FeyO{sub 3-d}elta oxides are good candidates for solid oxide fuel cell (SOFC) cathodes because these materials present high ionic and electronic conductivity, and compatibility with Cerium Gadolinium Oxide (CGO) electrolytes allowing a lower operation temperature. In this work, we report the synthesis of La{sub 0.4}Sr{sub 0.6}Co{sub 0.8}Fe{sub 0.2}O{sub 3-d}elta (LSCF) nanotubes prepared by a porous polycarbonate membrane approach, obtaining different microstructures depending on sintering conditions. The structure and morphology of the nanotubes and deposited films were characterized by X-ray diffraction, transmission and scanning microscopy. Finally, we obtained nanostructured films of vertically aligned LSCF tubes deposited over the whole surface of CGO pellets with diameter up to 2.5cm in a direct and single step process.

  8. High-performance micro-solid oxide fuel cells fabricated on nanoporous anodic aluminum oxide templates

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Chang-Woo; Kim, Hyun-Mi; Kim, Ki-Bum [WCUHybrid Materials Program, Department of Materials Science and Engineering, Seoul National University, 599 Gwanak-ro, Gwanak-gu, Seoul, 151-742 (Korea, Republic of); Son, Ji-Won; Lee, Jong-Ho; Lee, Hae-Weon [High Temperature Energy Materials Center, Korea Institute of Science and Technology, 39-1, Hawolgok-dong, Seongbuk-gu, Seoul, 136-791 (Korea, Republic of)

    2011-03-22

    Micro-solid oxide fuel cells ({mu}-SOFCs) are fabricated on nanoporous anodic aluminum oxide (AAO) templates with a cell structure composed of a 600-nm-thick AAO free-standing membrane embedded on a Si substrate, sputter-deposited Pt electrodes (cathode and anode) and an yttria-stabilized zirconia (YSZ) electrolyte deposited by pulsed laser deposition (PLD). Initially, the open circuit voltages (OCVs) of the AAO-supported {mu}-SOFCs are in the range of 0.05 V to 0.78 V, which is much lower than the ideal value, depending on the average pore size of the AAO template and the thickness of the YSZ electrolyte. Transmission electron microscopy (TEM) analysis reveals the formation of pinholes in the electrolyte layer that originate from the porous nature of the underlying AAO membrane. In order to clog these pinholes, a 20-nm thick Al{sub 2}O{sub 3} layer is deposited by atomic layer deposition (ALD) on top of the 300-nm thick YSZ layer and another 600-nm thick YSZ layer is deposited after removing the top intermittent Al{sub 2}O{sub 3} layer. Fuel cell devices fabricated in this way manifest OCVs of 1.02 V, and a maximum power density of 350 mW cm{sup -2} at 500 C. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  9. Method and device for the dry preparation of ceramic uranium dioxide nuclear fuel wastes

    International Nuclear Information System (INIS)

    Pirk, H.; Roepenack, H.; Goeldner, U.

    1977-01-01

    Reprocessing of waste, resulting from the production of ceramic sintered bodies from uranium dioxide for use as nuclear fuel, in a dry process into very finely dispersed pure U 3 O 8 powder may be improved by applying vibrating screening during oxidation. An appropriate device is described. (UWI) [de

  10. Preparation of the electrochemically formed spinel-lithium manganese oxides

    Energy Technology Data Exchange (ETDEWEB)

    Katakura, Katsumi; Wada, Kohei; Kajiki, Yoshiyuki; Yamamoto, Akiko [Department of Chemical Engineering, Nara National College of Technology, 22 Yata-cho Yamotokoriyama, Nara 639-1080 (Japan); Ogumi, Zempachi [Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8510 (Japan)

    2009-04-01

    Electrochemically formed spinel-lithium manganese oxides were synthesized from manganese hydroxides prepared by a cathodic electrochemical precipitation from various concentrations of manganese nitrate solutions. Two types of manganese hydroxides were formed from diluted and concentrated Mn(NO{sub 3}){sub 2} aqueous solutions. Uniform and equi-sized disk shaped Mn(OH){sub 2} crystals of 0.2-5 {mu}m in diameter were obtained on a Pt substrate after the electrochemical precipitation from lower concentration of ranging from 2 mmol dm{sup -3} to 2 mol dm{sup -3} Mn(NO{sub 3}){sub 2} aq., while the grass blade-like precipitate which is ascribed to manganese hydroxide with 20-80 {mu}m long and 1-5 {mu}m wide were formed from concentrated Mn(NO{sub 3}){sub 2} aq. Both manganese hydroxides gave the electrochemically formed spinel-LiMn{sub 2}O{sub 4} onto a Pt sheet, which is ready for electrochemical measurement, after calcination of the Li incorporated precipitate at 750 C without any additives. While the shape and size of the secondary particle frameworks (aggregates) of the electrochemically formed spinel-LiMn{sub 2}O{sub 4} can be controlled by the electrolysis conditions, the nanostructured primary crystals of 200 nm in diameter were obtained in all cases except that the fiber-like nanostructured spinel-LiMn{sub 2}O{sub 4} crystals with 200 nm in diameter were obtained from concentrated Mn(NO{sub 3}){sub 2} aq. Though these two types of electrochemically formed spinel-LiMn{sub 2}O{sub 4} showed well-shaped CVs even in higher scan rates, it would be suitable for high power density battery applications. These behaviors are assumed to be ascribed to the crystal size and shape of the processed spinel-LiMn{sub 2}O{sub 4}. (author)

  11. [Preparation of polyelectrolyte microcapsules containing ferrosoferric oxide nanoparticles].

    Science.gov (United States)

    Liu, Xiao-Qing; Zheng, Chun-Li; Zhu, Jia-Bi

    2011-01-01

    In this study, polyelectrolyte microcapsules have been fabricated by biocompatible ferrosoferric oxide nanoparticles (Fe3O4 NPs) and poly allyamine hydrochloride (PAH) using layer by layer assembly technique. The Fe3O4 NPs were prepared by chemical co-precipitation, and characterized by transmission electron microscopy (TEM) and infrared spectrum (IR). Quartz cell also was used as a substrate for building multilayer films to evaluate the capability of forming planar film. The result showed that Fe3O4 NPs were selectively deposited on the surface of quartz cell. Microcapsules containing Fe3O4 NPs were fabricated by Fe3O4 NPs and PAH alternately self-assembly on calcium carbonate microparticles firstly, then 0.2 molL(-1) EDTA was used to remove the calcium carbonate. Scanning electron microscopy (SEM), Zetasizer and vibrating sample magnetometer (VSM) were used to characterize the microcapsule's morphology, size and magnetic properties. The result revealed that Fe3O4 NPs and PAH were successfully deposited on the surface of CaCO3 microparticles, the microcapsule manifested superparamagnetism, size and saturation magnetization were 4.9 +/- 1.2 microm and 8.94 emu x g(-1), respectively. As a model drug, Rhodamin B isothiocyanate labeled bovine serum albumin (RBITC-BSA) was encapsulated in microcapsule depended on pH sensitive of the microcapsule film. When pH 5.0, drug add in was 2 mg, the encapsulation efficiency was (86.08 +/- 3.36) % and the drug loading was 8.01 +/- 0.30 mg x m(L-1).

  12. Fundamental Studies of Irradiation-Induced Defect Formation and Fission Product Dynamics in Oxide Fuels

    Energy Technology Data Exchange (ETDEWEB)

    Stubbins, James

    2012-12-19

    The objective of this research program is to address major nuclear fuels performance issues for the design and use of oxide-type fuels in the current and advanced nuclear reactor applications. Fuel performance is a major issue for extending fuel burn-up which has the added advantage of reducing the used fuel waste stream. It will also be a significant issue with respect to developing advanced fuel cycle processes where it may be possible to incorporate minor actinides in various fuel forms so that they can be 'burned' rather than join the used fuel waste stream. The potential to fission or transmute minor actinides and certain long-lived fission product isotopes would transform the high level waste storage strategy by removing the need to consider fuel storage on the millennium time scale.

  13. Lanthanum manganate based cathodes for solid oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Juhl Joergensen, M.

    2001-07-01

    Composite cathodes for solid oxide fuel cells were investigated using electrochemical impedance spectroscopy and scanning electron microscopy. The aim was to study the oxygen reduction process in the electrode in order to minimise the voltage drop in the cathode. The electrodes contained a composite layer made from lanthanum strontium manganate (LSM) and yttria stabilised zirconia (YSZ) and a layer of pure LSM aimed for current collection. The performance of the composite electrodes was sensitive to microstructure and thickness. Further, the interface between the composite and the current collecting layer proved to affect the performance. In a durability study severe deg-radation of the composite electrodes was found when passing current through the electrode for 2000 hours at 1000 deg. C. This was ascribed to pore formation along the composite interfaces and densification of the composite and current collector microstructure. An evaluation of the measurement approach indicated that impedance spectroscopy is a very sensitive method. This affects the reproducibility, as small undesirable variations in for instance the microstructure from electrode to electrode may change the impedance. At least five processes were found to affect the impedance of LSM/YSZ composite electrodes. Two high frequency processes were ascribed to transport of oxide ions/oxygen intermediates across LSM/YSZ interfaces and through YSZ in the composite. Several competitive elementary reaction steps, which appear as one medium frequency process in the impedance spectra, were observed. A low frequency arc related to gas diffusion limitation in a stagnant gas layer above the composite structure was detected. Finally, an inductive process, assumed to be connected to an activation process involving segregates at the triple phase boundary between electrode, electrolyte and gas phase, was found. (au)

  14. Carbon deposition thresholds on nickel-based solid oxide fuel cell anodes I. Fuel utilization

    Science.gov (United States)

    Kuhn, J.; Kesler, O.

    2015-03-01

    In the first of a two part publication, the effect of fuel utilization (Uf) on carbon deposition rates in solid oxide fuel cell nickel-based anodes was studied. Representative 5-component CH4 reformate compositions (CH4, H2, CO, H2O, & CO2) were selected graphically by plotting the solutions to a system of mass-balance constraint equations. The centroid of the solution space was chosen to represent a typical anode gas mixture for each nominal Uf value. Selected 5-component and 3-component gas mixtures were then delivered to anode-supported cells for 10 h, followed by determination of the resulting deposited carbon mass. The empirical carbon deposition thresholds were affected by atomic carbon (C), hydrogen (H), and oxygen (O) fractions of the delivered gas mixtures and temperature. It was also found that CH4-rich gas mixtures caused irreversible damage, whereas atomically equivalent CO-rich compositions did not. The coking threshold predicted by thermodynamic equilibrium calculations employing graphite for the solid carbon phase agreed well with empirical thresholds at 700 °C (Uf ≈ 32%); however, at 600 °C, poor agreement was observed with the empirical threshold of ∼36%. Finally, cell operating temperatures correlated well with the difference in enthalpy between the supplied anode gas mixtures and their resulting thermodynamic equilibrium gas mixtures.

  15. Internal shorting and fuel loss of a low temperature solid oxide fuel cell with SDC electrolyte

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Xinge; Robertson, Mark; Deces-Petit, Cyrille; Qu, Wei; Kesler, Olivera; Maric, Radenka; Ghosh, Dave [Institute for Fuel Cell Innovation, National Research Council Canada, 4250 Wesbrook Mall, Vancouver, BC V6T 1W5 (Canada)

    2007-02-10

    A solid oxide fuel cell with Sm{sub 0.2}Ce{sub 0.8}O{sub 1.9} (SDC) electrolyte of 10 {mu}m in thickness and Ni-SDC anode of 15 {mu}m in thickness on a 0.8 mm thick Ni-YSZ cermet substrate was fabricated by tape casting, screen printing and co-firing. A composite cathode, 75 wt.% Sm{sub 0.5}Sr{sub 0.5}CoO{sub 3} (SSCo) + 25 wt.% SDC, approximately 50 {mu}m in thickness, was printed on the co-fired half-cell, and sintered at 950 C. The cell showed a high electrochemical performance at temperatures ranging from 500 to 650 C. Peak power density of 545 mW cm{sup -2} at 600 C was obtained. However, the cell exhibited severe internal shorting due to the mixed conductivity of the SDC electrolyte. Both the amount of water collected from the anode outlet and the open circuit voltage (OCV) indicated that the internal shorting current could reach 0.85 A cm{sup -2} or more at 600 C. Zr content inclusions were found at the surface and in the cross-section of the SDC electrolyte, which could be one of the reasons for reduced OCV and oxygen ionic conductivity. Fuel loss due to internal shorting of the thin SDC electrolyte cell becomes a significant concern when it is used in applications requiring high fuel utilization and electrical efficiency. (author)

  16. Novel quasi-symmetric solid oxide fuel cells with enhanced electrochemical performance

    KAUST Repository

    Chen, Yonghong

    2016-02-16

    Symmetrical solid oxide fuel cell (SSOFC) using same materials as both anode and cathode simultaneously has gained extensively attentions, which can simplify fabrication process, minimize inter-diffusion between components, enhance sulfur and coking tolerance by operating the anode as the cathode in turn. With keeping the SSOFC\\'s advantages, a novel quasi-symmetrical solid oxide fuel cell (Q-SSOFC) is proposed to further improve the performance, which optimally combines two different SSOFC electrode materials as both anode and cathode simultaneously. PrBaFe2O5+δ (PBFO) and PrBaFe1.6Ni0.4O5+δ (PBFNO, Fe is partially substituted by Ni.) are prepared and applied as both cathode and anode for SSOFC, which exhibit desirable chemical and thermal compatibility with Sm0.8Ce0.2O1.9 (SDC) electrolyte. PBFO cathode exhibits higher oxygen reduction reaction (ORR) activity than PBFNO cathode in air, whereas PBFNO anode exhibits higher hydrogen oxidation reaction (HOR) activity than PBFO anode in H2. The as-designed Q-SSOFC of PBFNO/SDC/PBFO exhibits higher electrochemical performance than the conventional SSOFCs of both PBFO/SDC/PBFO and PBFNO/SDC/PBFNO. The superior performance of Q-SSOFC is attributed to the lowest polarization resistance (Rp). The newly developed Q-SSOFCs open doors for further improvement of electrochemical performance in SSOFC, which hold more promise for various potential applications. © 2016 Elsevier B.V. All rights reserved.

  17. Thermodynamic Analysis of an Integrated Solid Oxide Fuel Cell Cycle with a Rankine Cycle

    DEFF Research Database (Denmark)

    Rokni, Masoud

    2010-01-01

    Hybrid systems consisting of Solid Oxide Fuel Cells (SOFC) on the top of a Steam Turbine (ST) are investigated. The plants are fired by natural gas (NG). A desulfurization reactor removes the sulfur content in the fuel while a pre-reformer breaks down the heavier hydrocarbons. The pre-treated fuel......% are achieved which is considerably higher than the conventional Combined Cycles (CC). Both ASR (Adiabatic Steam Reformer) and CPO (Catalytic Partial Oxidation) fuel pre-reformer reactors are considered in this investigation....

  18. Preparing microspheres of actinide nitrides from carbon containing oxide sols

    International Nuclear Information System (INIS)

    Triggiani, L.V.

    1975-01-01

    A process is given for preparing uranium nitride, uranium oxynitride, and uranium carboxynitride microspheres and the microspheres as compositions of matter. The microspheres are prepared from carbide sols by reduction and nitriding steps. (Official Gazette)

  19. Solid oxide fuel cells with bi-layered electrolyte structure

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Xinge; Robertson, Mark; Deces-Petit, Cyrille; Xie, Yongsong; Hui, Rob; Qu, Wei; Kesler, Olivera; Maric, Radenka; Ghosh, Dave [Institute for Fuel Cell Innovation, National Research Council Canada, 4250 Wesbrook Mall, Vancouver, B.C. V6T 1W5 (Canada)

    2008-01-10

    In this work, we have developed solid oxide fuel cells with a bi-layered electrolyte of 2 {mu}m SSZ and 4 {mu}m SDC using tape casting, screen printing, and co-firing processes. The cell reached power densities of 0.54 W cm{sup -2} at 650 C and 0.85 W cm{sup -2} at 700 C, with open circuit voltage (OCV) values larger than 1.02 V. The electrical leaking between anode and cathode through an SDC electrolyte has been blocked in the bi-layered electrolyte structure. However, both the electrolyte resistance (R{sub el}) and electrode polarization resistance (R{sub p,a+c}) increased in comparison to cells with single-layered SDC electrolytes. The formation of a solid solution of (Ce, Zr)O{sub 2-x} during sintering process and the flaws in the bi-layered electrolyte structure seem to be the main causes for the increase in the R{sub el} value (0.32 {omega} cm{sup 2}) at 650 C, which is almost one order of magnitude higher than the calculated value. (author)

  20. Sensitivity analysis of characteristics of spent mixed oxide fuel

    International Nuclear Information System (INIS)

    Hagura, Naoto; Yoshida, Tadashi

    2008-01-01

    Prediction error was evaluated for decay heat and nuclide generation in spent mixed oxide (MOX) fuels on the basis of error files in JENDL-3.3. This computational analysis was performed using SWAT code system, ORIGEN2 code, and ERRORJ code. The results of nuclide generation error evaluation were compared with some discrepancies in the calculated values to experimental values (C/E ratio) which were already published and were obtained by analysis of post irradiated experiments (PIE) data. Though the discrepancies of some C/E values, especially those of americium and curium isotopes, ranged from a half to twice, the present error evaluation based on the error file of nuclide generation became 10% or less. We conclude that the discrepancy between calculation and the PIE data is almost factor 5 larger than that evaluated from the covariance data in JENDL-3.3. Therefore the practical error value of total decay heat should be 20% or more on 1 σ basis. (authors)

  1. Internal reforming of methane in solid oxide fuel cell systems

    Science.gov (United States)

    Peters, R.; Dahl, R.; Klüttgen, U.; Palm, C.; Stolten, D.

    Internal reforming is an attractive option offering a significant cost reduction, higher efficiencies and faster load response of a solid oxide fuel cell (SOFC) power plant. However, complete internal reforming may lead to several problems which can be avoided with partial pre-reforming of natural gas. In order to achieve high total plant efficiency associated with low energy consumption and low investment costs, a process concept has been developed based on all the components of the SOFC system. In the case of anode gas recycling an internal steam circuit exists. This has the advantage that there is no need for an external steam generator and the steam concentration in the anode gas is reduced. However, anode gas recycling has to be proven by experiments in a pre-reformer and for internal reforming. The addition of carbon dioxide clearly shows a decrease in catalyst activity, while for temperatures higher than 1000 K hydrogen leads to an increase of the measured methane conversion rates.

  2. Constrained Sintering in Fabrication of Solid Oxide Fuel Cells.

    Science.gov (United States)

    Lee, Hae-Weon; Park, Mansoo; Hong, Jongsup; Kim, Hyoungchul; Yoon, Kyung Joong; Son, Ji-Won; Lee, Jong-Ho; Kim, Byung-Kook

    2016-08-09

    Solid oxide fuel cells (SOFCs) are inevitably affected by the tensile stress field imposed by the rigid substrate during constrained sintering, which strongly affects microstructural evolution and flaw generation in the fabrication process and subsequent operation. In the case of sintering a composite cathode, one component acts as a continuous matrix phase while the other acts as a dispersed phase depending upon the initial composition and packing structure. The clustering of dispersed particles in the matrix has significant effects on the final microstructure, and strong rigidity of the clusters covering the entire cathode volume is desirable to obtain stable pore structure. The local constraints developed around the dispersed particles and their clusters effectively suppress generation of major process flaws, and microstructural features such as triple phase boundary and porosity could be readily controlled by adjusting the content and size of the dispersed particles. However, in the fabrication of the dense electrolyte layer via the chemical solution deposition route using slow-sintering nanoparticles dispersed in a sol matrix, the rigidity of the cluster should be minimized for the fine matrix to continuously densify, and special care should be taken in selecting the size of the dispersed particles to optimize the thermodynamic stability criteria of the grain size and film thickness. The principles of constrained sintering presented in this paper could be used as basic guidelines for realizing the ideal microstructure of SOFCs.

  3. Sensitivity analysis of characteristics of spent mixed oxide fuel

    Energy Technology Data Exchange (ETDEWEB)

    Hagura, Naoto; Yoshida, Tadashi [Musashi Institute of Technology, 1-28-1 Tamazutsumi, Setagaya, Tokyo 158-8557 (Japan)

    2008-07-01

    Prediction error was evaluated for decay heat and nuclide generation in spent mixed oxide (MOX) fuels on the basis of error files in JENDL-3.3. This computational analysis was performed using SWAT code system, ORIGEN2 code, and ERRORJ code. The results of nuclide generation error evaluation were compared with some discrepancies in the calculated values to experimental values (C/E ratio) which were already published and were obtained by analysis of post irradiated experiments (PIE) data. Though the discrepancies of some C/E values, especially those of americium and curium isotopes, ranged from a half to twice, the present error evaluation based on the error file of nuclide generation became 10% or less. We conclude that the discrepancy between calculation and the PIE data is almost factor 5 larger than that evaluated from the covariance data in JENDL-3.3. Therefore the practical error value of total decay heat should be 20% or more on 1 sigma basis. (authors)

  4. Constrained Sintering in Fabrication of Solid Oxide Fuel Cells

    Science.gov (United States)

    Lee, Hae-Weon; Park, Mansoo; Hong, Jongsup; Kim, Hyoungchul; Yoon, Kyung Joong; Son, Ji-Won; Lee, Jong-Ho; Kim, Byung-Kook

    2016-01-01

    Solid oxide fuel cells (SOFCs) are inevitably affected by the tensile stress field imposed by the rigid substrate during constrained sintering, which strongly affects microstructural evolution and flaw generation in the fabrication process and subsequent operation. In the case of sintering a composite cathode, one component acts as a continuous matrix phase while the other acts as a dispersed phase depending upon the initial composition and packing structure. The clustering of dispersed particles in the matrix has significant effects on the final microstructure, and strong rigidity of the clusters covering the entire cathode volume is desirable to obtain stable pore structure. The local constraints developed around the dispersed particles and their clusters effectively suppress generation of major process flaws, and microstructural features such as triple phase boundary and porosity could be readily controlled by adjusting the content and size of the dispersed particles. However, in the fabrication of the dense electrolyte layer via the chemical solution deposition route using slow-sintering nanoparticles dispersed in a sol matrix, the rigidity of the cluster should be minimized for the fine matrix to continuously densify, and special care should be taken in selecting the size of the dispersed particles to optimize the thermodynamic stability criteria of the grain size and film thickness. The principles of constrained sintering presented in this paper could be used as basic guidelines for realizing the ideal microstructure of SOFCs. PMID:28773795

  5. HIGH-TEMPERATURE TUBULAR SOLID OXIDE FUEL CELL GENERATOR DEVELOPMENT

    Energy Technology Data Exchange (ETDEWEB)

    S.E. Veyo

    1998-09-01

    During the Westinghouse/USDOE Cooperative Agreement period of November 1, 1990 through November 30, 1997, the Westinghouse solid oxide fuel cell has evolved from a 16 mm diameter, 50 cm length cell with a peak power of 1.27 watts/cm to the 22 mm diameter, 150 cm length dimensions of today's commercial prototype cell with a peak power of 1.40 watts/cm. Accompanying the increase in size and power density was the elimination of an expensive EVD step in the manufacturing process. Demonstrated performance of Westinghouse's tubular SOFC includes a lifetime cell test which ran for a period in excess of 69,000 hours, and a fully integrated 25 kWe-class system field test which operated for over 13,000 hours at 90% availability with less than 2% performance degradation over the entire period. Concluding the agreement period, a 100 kW SOFC system successfully passed its factory acceptance test in October 1997 and was delivered in November to its demonstration site in Westervoort, The Netherlands.

  6. Mathematical modeling of synthesis gas fueled electrochemistry and transport including H2/CO co-oxidation and surface diffusion in solid oxide fuel cell

    Science.gov (United States)

    Bao, Cheng; Jiang, Zeyi; Zhang, Xinxin

    2015-10-01

    Fuel flexibility is a significant advantage of solid oxide fuel cell (SOFC). A comprehensive macroscopic framework is proposed for synthesis gas (syngas) fueled electrochemistry and transport in SOFC anode with two main novelties, i.e. analytical H2/CO electrochemical co-oxidation, and correction of gas species concentration at triple phase boundary considering competitive absorption and surface diffusion. Staring from analytical approximation of the decoupled charge and mass transfer, we present analytical solutions of two defined variables, i.e. hydrogen current fraction and enhancement factor. Giving explicit answer (rather than case-by-case numerical calculation) on how many percent of the current output contributed by H2 or CO and on how great the water gas shift reaction plays role on, this approach establishes at the first time an adaptive superposition mechanism of H2-fuel and CO-fuel electrochemistry for syngas fuel. Based on the diffusion equivalent circuit model, assuming series-connected resistances of surface diffusion and bulk diffusion, the model predicts well at high fuel utilization by keeping fixed porosity/tortuosity ratio. The model has been validated by experimental polarization behaviors in a wide range of operation on a button cell for H2-H2O-CO-CO2-N2 fuel systems. The framework could be helpful to narrow the gap between macro-scale and meso-scale SOFC modeling.

  7. Effects of an oxidizing atmosphere in a spent fuel packaging facility

    International Nuclear Information System (INIS)

    Einziger, R.E.

    1991-09-01

    Sufficient oxidation of spent fuel can cause a cladding breach to propagate, resulting in dispersion of fuel particulates and gaseous radionuclides. The literature for spent fuel oxidation in storage and disposal programs was reviewed to evaluate the effect of an oxidizing atmosphere in a preclosure packaging facility on (1) physical condition of the fuel and (2) operations in the facility. Effects such as cladding breach propagation, cladding oxidation, rod dilation, fuel dispersal, 14 C and 85 Kr release, and crud release were evaluated. The impact of these effects, due to oxidation, upon a spent fuel handling facility is generally predicted to be less than the impact of similar effects due to fuel rod breached during handling in an inert-atmosphere facility. Preliminary temperature limits of 240 degree C and 227 degree C for a 2-week or 4-week handling period and 175 degree C for 2-year lag storage would prevent breach propagation and fuel dispersal. Additional data that are needed to support the assumptions in this analysis or complete the database were identified

  8. Effect of increased fuel temperature on emissions of oxides of nitrogen from a gas turbine combustor burning ASTM jet-A fuel

    Science.gov (United States)

    Marchionna, N. R.

    1974-01-01

    An annular gas turbine combustor was tested with heated ASTM Jet-A fuel to determine the effect of increased fuel temperature on the formation of oxides of nitrogen. Fuel temperature ranged from ambient to 700 K. The NOx emission index increased at a rate of 6 percent per 100 K increase in fuel temperature.

  9. Modeling of thermo-mechanical and irradiation behavior of mixed oxide fuel for sodium fast reactors

    International Nuclear Information System (INIS)

    Karahan, Aydin; Buongiorno, Jacopo

    2010-01-01

    An engineering code to model the irradiation behavior of UO 2 -PuO 2 mixed oxide fuel pins in sodium-cooled fast reactors was developed. The code was named fuel engineering and structural analysis tool (FEAST-OXIDE). FEAST-OXIDE has several modules working in coupled form with an explicit numerical algorithm. These modules describe: (1) fission gas release and swelling, (2) fuel chemistry and restructuring, (3) temperature distribution, (4) fuel-clad chemical interaction and (5) fuel-clad mechanical analysis. Given the fuel pin geometry, composition and irradiation history, FEAST-OXIDE can analyze fuel and cladding thermo-mechanical behavior at both steady-state and design-basis transient scenarios. The code was written in FORTRAN-90 program language. The mechanical analysis module implements the LIFE algorithm. Fission gas release and swelling behavior is described by the OGRES and NEFIG models. However, the original OGRES model has been extended to include the effects of joint oxide gain (JOG) formation on fission gas release and swelling. A detailed fuel chemistry model has been included to describe the cesium radial migration and JOG formation, oxygen and plutonium radial distribution and the axial migration of cesium. The fuel restructuring model includes the effects of as-fabricated porosity migration, irradiation-induced fuel densification, grain growth, hot pressing and fuel cracking and relocation. Finally, a kinetics model is included to predict the clad wastage formation. FEAST-OXIDE predictions have been compared to the available FFTF, EBR-II and JOYO databases, as well as the LIFE-4 code predictions. The agreement was found to be satisfactory for steady-state and slow-ramp over-power accidents.

  10. Modeling of thermo-mechanical and irradiation behavior of mixed oxide fuel for sodium fast reactors

    Energy Technology Data Exchange (ETDEWEB)

    Karahan, Aydin, E-mail: karahan@mit.ed [Center for Advanced Nuclear Energy Systems, Nuclear Science and Engineering Department, Massachusetts Institute of Technology, MA (United States); Buongiorno, Jacopo [Center for Advanced Nuclear Energy Systems, Nuclear Science and Engineering Department, Massachusetts Institute of Technology, MA (United States)

    2010-01-31

    An engineering code to model the irradiation behavior of UO{sub 2}-PuO{sub 2} mixed oxide fuel pins in sodium-cooled fast reactors was developed. The code was named fuel engineering and structural analysis tool (FEAST-OXIDE). FEAST-OXIDE has several modules working in coupled form with an explicit numerical algorithm. These modules describe: (1) fission gas release and swelling, (2) fuel chemistry and restructuring, (3) temperature distribution, (4) fuel-clad chemical interaction and (5) fuel-clad mechanical analysis. Given the fuel pin geometry, composition and irradiation history, FEAST-OXIDE can analyze fuel and cladding thermo-mechanical behavior at both steady-state and design-basis transient scenarios. The code was written in FORTRAN-90 program language. The mechanical analysis module implements the LIFE algorithm. Fission gas release and swelling behavior is described by the OGRES and NEFIG models. However, the original OGRES model has been extended to include the effects of joint oxide gain (JOG) formation on fission gas release and swelling. A detailed fuel chemistry model has been included to describe the cesium radial migration and JOG formation, oxygen and plutonium radial distribution and the axial migration of cesium. The fuel restructuring model includes the effects of as-fabricated porosity migration, irradiation-induced fuel densification, grain growth, hot pressing and fuel cracking and relocation. Finally, a kinetics model is included to predict the clad wastage formation. FEAST-OXIDE predictions have been compared to the available FFTF, EBR-II and JOYO databases, as well as the LIFE-4 code predictions. The agreement was found to be satisfactory for steady-state and slow-ramp over-power accidents.

  11. Preparation of Fluidization Feed of UO2 Pellets by Oxidation

    International Nuclear Information System (INIS)

    Rachmat-Pratomo; H, Didiek; Suwondo, B; Sigit

    2000-01-01

    The investigation of oxidation of uranium dioxide (UO 2 ) pellets to thetri uranium octoxide (U 3 O 8 ) powder had been carried. Several factor suchtemperature, time of oxidation and the concentration of air are important.The oxidation of UO 2 pellet are carried out on electric furnace atatmosphere as media. The oxidation temperature started at 300 o C, 400 o C,500 o C, and 600 o C along 1 hour. The time oxidation removed to 2 hours and3 hours. The efficiency of oxidation are the ratio of the weight of thepowder product are the uranium content, true density, and specific surfacearea. Result the optimum temperature are 500 o C along 3 hours, uraniumcontent : 84.78%, true density: 8.8293 g/cm 3 and specific surface area :0.389071 m 2 /g. (author)

  12. Preparation, characterization and catalytic activity of uranium-antimony oxide for selective oxidation of propene

    Energy Technology Data Exchange (ETDEWEB)

    Baussart, H.; Delobel, R.; Le Bras, M.; Le Maguer, D.; Leroy, J.M. (Ecole Nationale Superieure de Chimie de Lille, 59 (France). Lab. de Catalyse et Physico-Chimie des Solides)

    1982-02-01

    The selective oxidation of propene to acrolein over USb/sub 3/O/sub 10/ was studied in a continuous flow reactor. The experimental results show that the preparation of a well-defined catalyst of uniform composition depends on the temperature and time of calcination. The kinetic data indicate that acrolein is formed via a redox mechanism in which the surface of the catalyst is partially reduced. Moessbauer spectroscopy reveals the presence of Sb/sup 5 +/ and Sb/sup 3 +/ in the used catalyst. I.r. spectroscopy shows a structural modification. On the basis of these results it is concluded that each steady-state condition is characterized by a vacancy concentration leading to the observed modifications of the catalyst.

  13. Rational Design of a Water-Storable Hierarchical Architecture Decorated with Amorphous Barium Oxide and Nickel Nanoparticles as a Solid Oxide Fuel Cell Anode with Excellent Sulfur Tolerance.

    Science.gov (United States)

    Song, Yufei; Wang, Wei; Ge, Lei; Xu, Xiaomin; Zhang, Zhenbao; Julião, Paulo Sérgio Barros; Zhou, Wei; Shao, Zongping

    2017-11-01

    Solid oxide fuel cells (SOFCs), which can directly convert chemical energy stored in fuels into electric power, represent a useful technology for a more sustainable future. They are particularly attractive given that they can be easily integrated into the currently available fossil fuel infrastructure to realize an ideal clean energy system. However, the widespread use of the SOFC technology is hindered by sulfur poisoning at the anode caused by the sulfur impurities in fossil fuels. Therefore, improving the sulfur tolerance of the anode is critical for developing SOFCs for use with fossil fuels. Herein, a novel, highly active, sulfur-tolerant anode for intermediate-temperature SOFCs is prepared via a facile impregnation and limited reaction protocol. During synthesis, Ni nanoparticles, water-storable BaZr 0.4 Ce 0.4 Y 0.2 O 3- δ (BZCY) perovskite, and amorphous BaO are formed in situ and deposited on the surface of a Sm 0.2 Ce 0.8 O 1.9 (SDC) scaffold. More specifically, a porous SDC scaffold is impregnated with a well-designed proton-conducting perovskite oxide liquid precursor with the nominal composition of Ba(Zr 0.4 Ce 0.4 Y 0.2 ) 0.8 Ni 0.2 O 3- δ (BZCYN), calcined and reduced in hydrogen. The as-synthesized hierarchical architecture exhibits high H 2 electro-oxidation activity, excellent operational stability, superior sulfur tolerance, and good thermal cyclability. This work demonstrates the potential of combining nanocatalysts and water-storable materials in advanced electrocatalysts for SOFCs.

  14. Fuel Cell Power Plant Initiative. Volume 1; Solid Oxide Fuel Cell/Logistics Fuel Processor 27 kWe Power System Demonstration for ARPA

    Science.gov (United States)

    Veyo, S.E.

    1997-01-01

    This report describes the successful testing of a 27 kWe Solid Oxide Fuel Cell (SOFC) generator fueled by natural gas and/or a fuel gas produced by a brassboard logistics fuel preprocessor (LFP). The test period began on May 24, 1995 and ended on February 26, 1996 with the successful completion of all program requirements and objectives. During this time period, this power system produced 118.2 MWh of electric power. No degradation of the generator's performance was measured after 5582 accumulated hours of operation on these fuels: local natural gas - 3261 hours, jet fuel reformate gas - 766 hours, and diesel fuel reformate gas - 1555 hours. This SOFC generator was thermally cycled from full operating temperature to room temperature and back to operating temperature six times, because of failures of support system components and the occasional loss of test site power, without measurable cell degradation. Numerous outages of the LFP did not interrupt the generator's operation because the fuel control system quickly switched to local natural gas when an alarm indicated that the LFP reformate fuel supply had been interrupted. The report presents the measured electrical performance of the generator on all three fuel types and notes the small differences due to fuel type. Operational difficulties due to component failures are well documented even though they did not affect the overall excellent performance of this SOFC power generator. The final two appendices describe in detail the LFP design and the operating history of the tested brassboard LFP.

  15. Dry air oxidation kinetics of K-Basin spent nuclear fuel

    International Nuclear Information System (INIS)

    Abrefah, J.; Buchanan, H.C.; Gerry, W.M.; Gray, W.J.; Marschman, S.C.

    1998-06-01

    The safety and process analyses of the proposed Integrated Process Strategy (IPS) to move the N-Reactor spent nuclear fuel (SNF) stored at K-Basin to an interim storage facility require information about the oxidation behavior of the metallic uranium. Limited experiments have been performed on the oxidation reaction of SNF samples taken from an N-Reactor outer fuel element in various atmospheres. This report discusses studies on the oxidation behavior of SNF using two independent experimental systems: (1) a tube furnace with a flowing gas mixture of 2% oxygen/98% argon; and (2) a thermogravimetric system for dry air oxidation

  16. Tritium distribution between the fuel can and the oxide of fuel elements of light-water reactors

    International Nuclear Information System (INIS)

    Masson, M.

    1986-12-01

    The study on the measurement of tritium and other radionuclide contained in zircaloy fuel cans of the water cooled reactor fuel elements had two aims: the first was to estimate with accuracy the distribution of tritium in a fuel element (can + oxide). The measurement of tritium in the zircaloy fuel cans of the BORSSELE fuel elements associated with the measurement of tritium in the oxide allowed the establishment of a complete tritium balance on an industrial spent fuel element. This result has been compared to the values calculated by the code CEA/SEN and will allow to validate or adjust this calculation. The second aim delt with the characterization of the other radionuclides gaseous (Kr85) or not (Cs 134 and 137) contained in the solid zircaloy wastes (hulls) coming from the industrial reprocessing of ''water cooled'' fuel elements. These activity measurements in the hulls allowed to estimate the residual content of tritium, Kr 85 and other radionuclides which may be found in these solid wastes (high-level βγ radioactive wastes). Original experimental methods have been developed to reach these aims (dissolution in ammonium bifluoride medium and quantitative recovery of gases produced, radiochromatography, and liquid scintillation after double distillation). One tries to explain the presence of Kr 85 in the irradiated can [fr

  17. Solid oxide fuel cells for transportation: A clean, efficient alternative for propulsion

    International Nuclear Information System (INIS)

    Kumar, R.; Krumpelt, M.; Myles, K.M.

    1993-01-01

    Fuel cells show great promise for providing clean and efficient transportation power. Of the fuel cell propulsion systems under investigation, the solid oxide fuel cell (SOFC) is particularly attractive for heavy duty transportation applications that have a relatively long duty cycle, such as locomotives, trucks, and barges. Advantages of the SOFC include a simple, compact system configuration; inherent fuel flexibility for hydrocarbon and alternative fuels; and minimal water management. The specific advantages of the SOFC for powering a railroad locomotive are examined. Feasibility, practicality, and safety concerns regarding SOFCs in transportation applications are discussed, as am the major R ampersand D issues

  18. Neutronic feasibility of PWR core with mixed oxide fuels in the Republic of Korea

    International Nuclear Information System (INIS)

    Kim, Y.J.; Joo, H.K.; Jung, H.G.; Sohn, D.S.

    1997-01-01

    Neutronic feasibility of a PWR core with mixed oxide (MOX) fuels has been investigated as part of the feasibility study for recycling spent fuels in Korea. A typical 3-loop PWR with 900 MWe capacity is selected as reference plant to develop equilibrium core designs with low-leakage fuel management scheme, while incorporating various MOX loading. The fuel management analyses and limited safety analyses show that, safely stated, MOX recycling with 1/3 reload fraction can be accommodated for both annual and 18 month fuel cycle schemes in Korean PWRs, without major design modifications on the reactor systems. (author). 12 refs, 4 figs, 3 tabs

  19. Fuzzy Logic Based Controller for a Grid-Connected Solid Oxide Fuel Cell Power Plant.

    Science.gov (United States)

    Chatterjee, Kalyan; Shankar, Ravi; Kumar, Amit

    2014-10-01

    This paper describes a mathematical model of a solid oxide fuel cell (SOFC) power plant integrated in a multimachine power system. The utilization factor of a fuel stack maintains steady state by tuning the fuel valve in the fuel processor at a rate proportional to a current drawn from the fuel stack. A suitable fuzzy logic control is used for the overall system, its objective being controlling the current drawn by the power conditioning unit and meet a desirable output power demand. The proposed control scheme is verified through computer simulations.

  20. Pilot-scale equipment development for lithium-based reduction of spent oxide fuel

    International Nuclear Information System (INIS)

    Herrmann, S. D.

    1998-01-01

    An integral function of the electrometallurgical conditioning of DOE spent nuclear fuel is the standardization of waste forms. Argonne National Laboratory (ANL) has developed and is presently demonstrating the electrometallurgical conditioning of sodium-bonded metal fuel from Experimental Breeder Reactor II, resulting in uranium, ceramic waste, and metal waste forms. Engineering studies are underway at ANL in support of pilot-scale equipment development, which would precondition irradiated oxide fuel and likewise demonstrate the application of electrometallurgical conditioning to such non-metallic fuels. This paper highlights the integration of proposed spent oxide fuel conditioning with existing electrometallurgical processes. Additionally, technical bases for engineering activities to support a scale up of an oxide reduction process are described

  1. Application of the monolithic solid oxide fuel cell to space power systems

    International Nuclear Information System (INIS)

    Myles, K.M.; Bhattacharyya, S.K.

    1991-01-01

    The monolithic solid-oxide fuel cell (MSOFC) is a promising electrochemical power generation device that is currently under development at Argonne National Laboratory. The extremely high power density of the MSOFC leads to MSOFC systems that have sufficiently high energy densities that they are excellent candidates for a number of space missions. The fuel cell can also be operated in reverse, if it can be coupled to an external power source, to regenerate the fuel and oxidant from the water product. This feature further enhances the potential mission applications of the MSOFC. In this paper, the current status of the fuel cell development is presented---the focus being on fabrication and currently achievable performance. In addition, a specific example of a space power system, featuring a liquid metal cooled fast spectrum nuclear reactor and a monolithic solid oxide fuel cell, is presented to demonstrate the features of an integrated system

  2. Thermodynamic analysis of Direct Urea Solid Oxide Fuel Cell in combined heat and power applications

    Science.gov (United States)

    Abraham, F.; Dincer, I.

    2015-12-01

    This paper presents a comprehensive steady state modelling and thermodynamic analysis of Direct Urea Solid Oxide Fuel Cell integrated with Gas Turbine power cycle (DU-SOFC/GT). The use of urea as direct fuel mitigates public health and safety risks associated with the use of hydrogen and ammonia. The integration scheme in this study covers both oxygen ion-conducting solid oxide fuel cells (SOFC-O) and hydrogen proton-conducting solid oxide fuel cells (SOFC-H). Parametric case studies are carried out to investigate the effects of design and operating parameters on the overall performance of the system. The results reveal that the fuel cell exhibited the highest level of exergy destruction among other system components. Furthermore, the SOFC-O based system offers better overall performance than that with the SOFC-H option mainly due to the detrimental reverse water-gas shift reaction at the SOFC anode as well as the unique configuration of the system.

  3. Application of the monolithic solid oxide fuel cell to space power systems

    Science.gov (United States)

    Myles, Kevin M.; Bhattacharyya, Samit K.

    1991-01-01

    The monolithic solid-oxide fuel cell (MSOFC) is a promising electrochemical power generation device that is currently under development at Argonne National Laboratory. The extremely high power density of the MSOFC leads to MSOFC systems that have sufficiently high energy densities that they are excellent candidates for a number of space missions. The fuel cell can also be operated in reverse, if it can be coupled to an external power source, to regenerate the fuel and oxidant from the water product. This feature further enhances the potential mission applications of the MSOFC. In this paper, the current status of the fuel cell development is presented—the focus being on fabrication and currently achievable performance. In addition, a specific example of a space power system, featuring a liquid metal cooled fast spectrum nuclear reactor and a monolithic solid oxide fuel cell, is presented to demonstrate the features of an integrated system.

  4. Efficient and Scalable Fabrication of Solid Oxide Fuel Cells via 3D-Printing

    Data.gov (United States)

    National Aeronautics and Space Administration — Although solid oxide fuel cells (SOFCs) are a source of both efficient and clean electricity, the brittle ceramic materials which comprise them are difficult to form...

  5. Novel quasi-symmetric solid oxide fuel cells with enhanced electrochemical performance

    KAUST Repository

    Chen, Yonghong; Cheng, Zhuanxia; Yang, Yang; Gu, Qingwen; Tian, Dong; Lu, Xiaoyong; Yu, Weili; Lin, Bin

    2016-01-01

    Symmetrical solid oxide fuel cell (SSOFC) using same materials as both anode and cathode simultaneously has gained extensively attentions, which can simplify fabrication process, minimize inter-diffusion between components, enhance sulfur and coking

  6. Solid Oxide Fuel Cell Based Upon Colloidal Deposition of Thin Films for Lower Temperature Operation (Preprint)

    National Research Council Canada - National Science Library

    Reitz, T. L; Xiao, H

    2006-01-01

    In order to reduce the operating temperature of solid oxide fuel cells (SOFCs), anode-supported cells incorporating thin film electrolytes in conjunction with anode/electrolyte and cathode/electrolyte interlayers were studied...

  7. Microstructural evolution of nanograin nickel-zirconia cermet anode materials for solid oxide fuel cell applications

    International Nuclear Information System (INIS)

    Nayak, Bibhuti Bhusan

    2012-01-01

    The aim of the study is to study the structure, microstructure, porosity, thermal expansion, electrical conductivity and electrochemical behavior of the anode material thus synthesized in order to find its suitability for solid oxide fuel cell (SOFC) anode application

  8. Development of an engineered safeguards system concept for a mixed-oxide fuel fabrication facility

    International Nuclear Information System (INIS)

    Chapman, L.D.; de Montmollin, J.M.; Deveney, J.E.; Fienning, W.C.; Hickman, J.W.; Watkins, L.D.; Winblad, A.E.

    1976-08-01

    An initial concept of an Engineered Safeguards System for a representative commercial mixed-oxide fuel fabrication facility is presented. Computer simulation techniques for evaluation and further development of the concept are described. An outline of future activity is included

  9. Electroplating of Protective Coatings on Interconnects Used for Solid Oxide Fuel Cell Stacks

    DEFF Research Database (Denmark)

    Harthøj, Anders

    Solid oxide fuel Cell (SOFC) technology can with a high efficiency produce environmentally clean electricity by converting the chemical energy in a fuel to electrical energy. SOFC systems have a high operation temperature, approx. 600-850 °C. Advantages compared to other types of fuel cells......, are they can utilize a wide range of fuels, e.g. hydrogen, natural gas and methanol, do not contain noble metals and have a high efficiency. A major obstacle to the commercialization of SOFC technology is the high degradation rates and costs of the systems. A significant source of degradation is high...... on the side facing its anode. Two high temperature corrosion issues, which both affect the air side of the interconnect, are especially significant, both of: Formation of thick oxide scales on its surface and evaporation of chromium species from the oxide. The oxide scales increases the electrical resistance...

  10. A green preparation method of battery grade α-PbO based on Pb-O2 fuel cell

    Science.gov (United States)

    Wang, Pingyuan; Pan, Junqing; Gong, Shumin; Sun, Yanzhi

    2017-08-01

    In order to solve the problem of high pollution and high energy consumption of the current lead oxide (PbO) preparation processes, a new clean and energy saving preparation method for high purity α-PbO via discharge of a Pb-O2 fuel cell is reported. The fuel cell with metallic lead anode, oxygen cathode, and 30% NaOH electrolyte can provide a discharge voltage of 0.66-0.38 V corresponding to discharge current range of 5-50 mA cm-2. PbO is precipitated from the NaHPbO2-containing electrolyte through a cooling crystallization process after discharge process, and the XRD patterns indicate the structure is pure α-PbO. The mother liquid after crystallization can be recycled for the next batch. The obtained PbO mixed with 60% Shimadzu PbO is superior to the pure Shimadzu PbO in discharge capacity and cycle ability.

  11. Uranium dioxide and beryllium oxide enhanced thermal conductivity nuclear fuel development

    International Nuclear Information System (INIS)

    Andrade, Antonio Santos; Ferreira, Ricardo Alberto Neto

    2007-01-01

    The uranium dioxide is the most used substance as nuclear reactor fuel for presenting many advantages such as: high stability even when it is in contact with water in high temperatures, high fusion point, and high capacity to retain fission products. The conventional fuel is made with ceramic sintered pellets of uranium dioxide stacked inside fuel rods, and presents disadvantages because its low thermal conductivity causes large and dangerous temperature gradients. Besides, the thermal conductivity decreases further as the fuel burns, what limits a pellet operational lifetime. This research developed a new kind of fuel pellets fabricated with uranium dioxide kernels and beryllium oxide filling the empty spaces between them. This fuel has a great advantage because of its higher thermal conductivity in relation to the conventional fuel. Pellets of this kind were produced, and had their thermophysical properties measured by the flash laser method, to compare with the thermal conductivity of the conventional uranium dioxide nuclear fuel. (author) (author)

  12. An oxidation-resistant indium tin oxide catalyst support for proton exchange membrane fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Chhina, H.; Campbell, S. [Ballard Power Systems Inc., 9000 Glenlyon Parkway, Burnaby, BC V5J 5J8 (Canada); Kesler, O. [Department of Mechanical Engineering, University of British Columbia, Vancouver, BC, V6T 1Z4 (Canada)

    2006-10-27

    The oxidation of carbon catalyst supports causes degradation in catalyst performance in proton exchange membrane fuel cells (PEMFCs). Indium tin oxide (ITO) is considered as a candidate for an alternative catalyst support. The electrochemical stability of ITO was studied by use of a rotating disk electrode (RDE). Oxidation cycles between +0.6 and +1.8V were applied to ITO supporting a Pt catalyst. Cyclic voltammograms (CVs) both before and after the oxidation cycles were obtained for Pt on ITO, Hispec 4000 (a commercially available catalyst), and 40wt.% Pt dispersed in-house on Vulcan XC-72R. Pt on ITO showed significantly better electrochemical stability, as determined by the relative change in electrochemically active surface area after cycling. Hydrogen desorption peaks in the CVs existed even after 100 cycles from 0.6 to 1.8V for Pt on ITO. On the other hand, most of the active surface area was lost after 100 cycles of the Hispec 4000 catalyst. The 40wt.% Pt on Vulcan made in-house also lost most of its active area after only 50 cycles. Pt on ITO was significantly more electrochemically stable than both Hispec 4000 and Pt on Vulcan XC-72R. In this study, it was found that the Pt on ITO had average crystallite sizes of 13nm for Pt and 38nm for ITO. Pt on ITO showed extremely high thermal stability, with only {approx}1wt.% loss of material for ITO versus {approx}57wt.% for Hispec 4000 on heating to 1000{sup o}C. The TEM data show Pt clusters dispersed on small crystalline ITO particles. The SEM data show octahedral shaped ITO particles supporting Pt. (author)

  13. Gamma-radiolytic preparation of multi-component oxides

    Czech Academy of Sciences Publication Activity Database

    Procházková, L.; Bárta, J.; Čuba, V.; Ekberg, C.; Tietze, S.; Jakubec, Ivo

    2016-01-01

    Roč. 124, JUL (2016), s. 68-74 ISSN 0969-806X. [Tihany Symposium on Radiation Chemistry /13./. Balatonalmadi, 29.08.2015-03.09.2015] Institutional support: RVO:61388980 Keywords : Radiation synthesis * Inorganic oxide * Zinc oxide * Synthetic garnet * X-ray diffraction Subject RIV: CA - Inorganic Chemistry Impact factor: 1.315, year: 2016

  14. An afterburner-powered methane/steam reformer for a solid oxide fuel cells application

    Science.gov (United States)

    Mozdzierz, Marcin; Chalusiak, Maciej; Kimijima, Shinji; Szmyd, Janusz S.; Brus, Grzegorz

    2018-04-01

    Solid oxide fuel cell (SOFC) systems can be fueled by natural gas when the reforming reaction is conducted in a stack. Due to its maturity and safety, indirect internal reforming is usually used. A strong endothermic methane/steam reforming process needs a large amount of heat, and it is convenient to provide thermal energy by burning the remainders of fuel from a cell. In this work, the mathematical model of afterburner-powered methane/steam reformer is proposed. To analyze the effect of a fuel composition on SOFC performance, the zero-dimensional model of a fuel cell connected with a reformer is formulated. It is shown that the highest efficiency of a solid oxide fuel cell is achieved when the steam-to-methane ratio at the reforming reactor inlet is high.

  15. System modeling of an air-independent solid oxide fuel cell system for unmanned undersea vehicles

    Science.gov (United States)

    Burke, A. Alan; Carreiro, Louis G.

    To examine the feasibility of a solid oxide fuel cell (SOFC)-powered unmanned undersea vehicle (UUV), a system level analysis is presented that projects a possible integration of the SOFC stack, fuel steam reformer, fuel/oxidant storage and balance of plant components into a 21-in. diameter UUV platform. Heavy hydrocarbon fuel (dodecane) and liquid oxygen (LOX) are chosen as the preferred reactants. A maximum efficiency of 45% based on the lower heating value of dodecane was calculated for a system that provides 2.5 kW for 40 h. Heat sources and sinks have been coupled to show viable means of thermal management. The critical design issues involve proper recycling of exhaust steam from the fuel cell back into the reformer and effective use of the SOFC stack radiant heat for steam reformation of the hydrocarbon fuel.

  16. Fuel component of electricity generation cost for the BN-800 reactor with 800 MOX fuel and uranium oxide fuel, increased fuel burnup, and removal of radial breeding blanket

    International Nuclear Information System (INIS)

    Raskach, A.

    2000-01-01

    There are two completed design concepts of NPP with BN-800 type reactors developed with due regard for enhanced safety requirements. They have been created for the 3 rd unit of Beloyarsk NPP and for three units of South Ural NPP. Both concepts are proposed to use mixed oxide fuel (MOX) based on civil plutonium. At this moment economical estimations carried out for these projects need to be revised in connection with the changes of economical situation in Russia and the world nuclear market structure. It is also essential to take into account the existing problem of the excess ex-weapons plutonium utilization and the possibility of using this plutonium to fabricate MOX fuel for the BN-800 reactors. (authors)

  17. Power generation using spinel manganese-cobalt oxide as a cathode catalyst for microbial fuel cell applications.

    Science.gov (United States)

    Mahmoud, Mohamed; Gad-Allah, Tarek A; El-Khatib, K M; El-Gohary, Fatma

    2011-11-01

    This study focused on the use of spinel manganese-cobalt (Mn-Co) oxide, prepared by a solid state reaction, as a cathode catalyst to replace platinum in microbial fuel cells (MFCs) applications. Spinel Mn-Co oxides, with an Mn/Co atomic ratios of 0.5, 1, and 2, were prepared and examined in an air cathode MFCs which was fed with a molasses-laden synthetic wastewater and operated in batch mode. Among the three Mn-Co oxide cathodes and after 300 h of operation, the Mn-Co oxide catalyst with Mn/Co atomic ratio of 2 (MnCo-2) exhibited the highest power generation 113 mW/m2 at cell potential of 279 mV, which were lower than those for the Pt catalyst (148 mW/m2 and 325 mV, respectively). This study indicated that using spinel Mn-Co oxide to replace platinum as a cathodic catalyst enhances power generation, increases contaminant removal, and substantially reduces the cost of MFCs. Copyright © 2011 Elsevier Ltd. All rights reserved.

  18. Characteristics of SME biodiesel-fueled diesel particle emissions and the kinetics of oxidation.

    Science.gov (United States)

    Jung, Heejung; Kittelson, David B; Zachariah, Michael R

    2006-08-15

    Biodiesel is one of the most promising alternative diesel fuels. As diesel emission regulations have become more stringent, the diesel particulate filter (DPF) has become an essential part of the aftertreatment system. Knowledge of kinetics of exhaust particle oxidation for alternative diesel fuels is useful in estimating the change in regeneration behavior of a DPF with such fuels. This study examines the characteristics of diesel particulate emissions as well as kinetics of particle oxidation using a 1996 John Deere T04045TF250 off-highway engine and 100% soy methyl ester (SME) biodiesel (B100) as fuel. Compared to standard D2 fuel, this B100 reduced particle size, number, and volume in the accumulation mode where most of the particle mass is found. At 75% load, number decreased by 38%, DGN decreased from 80 to 62 nm, and volume decreased by 82%. Part of this decrease is likely associated with the fact that the particles were more easily oxidized. Arrhenius parameters for the biodiesel fuel showed a 2-3times greater frequency factor and approximately 6 times higher oxidation rate compared to regular diesel fuel in the range of 700-825 degrees C. The faster oxidation kinetics should facilitate regeneration when used with a DPF.

  19. Experimental and thermodynamic evaluation of the melting behavior of irradiated oxide fuels

    International Nuclear Information System (INIS)

    Adamson, M.G.; Aitken, E.A.; Caputi, R.W.

    1985-01-01

    Onset of melting is an important performance limit for irradiated UO 2 and UO 2 -based nuclear reactor fuels. Melting (solidus) temperatures are reasonably well known for starting fuel materials such as UO 2 and (U,PU)O 2 , however the influence of burnup on oxide fuel melting behavior continues to represent an area of considerable uncertainty. In this paper we report the results of a variety of melting temperature measurements on pseudo-binary fuel-fissia mixtures such as UO 2 -PUO 2 , UO 2 -CeO 2 , UO 2 -BaO, UO 2 -SrO, UO 2 -BaZrO 3 and UO 2 -SrZrO 3 . These measurements were performed using the thermal arrest technique on tungsten-encapsulated specimens. Several low melting eutectics, the existence of which had previously been inferred from post-irradiation examinations of high burnup mixed oxide fuels, were characterized in the course of the investigation. Also, an assessment of melting temperature changes in irradiated oxide fuels due to the production and incorporation of soluble oxidic fission products was performed by application of solution theory to the available pseudo-binary phase diagram data. The results of this assessment suggest that depression of oxide fuel solidus temperatures by dissolved fission products is substantially less than that indicated by earlier experimental studies. (orig.)

  20. Strontium Titanate-based Composite Anodes for Solid Oxide Fuel Cells

    DEFF Research Database (Denmark)

    Blennow Tullmar, Peter; Kammer Hansen, Kent; Wallenberg, L.R.

    2008-01-01

    Surfactant-assisted infiltration of Gd-doped ceria (CGO) in Nb-doped SrTiO3 (STN) was investigated as a potential fuel electrode for solid oxide fuel cells (SOFC). An electronically conductive backbone structure of STN was first fabricated at high temperatures and then combined with the mixed con...

  1. EVALUATION OF TIRE-DERIVED FUEL FOR USE IN NITROGEN OXIDE REDUCTION BY REBURNING

    Science.gov (United States)

    Tire-derived fuel (TDF) was tested in a small-scale (44 kW or 150,000 Btu/hr) combustor to determine its feasibility as a fuel for use in reburning for control of nitrogen oxide (NO). TDF was gravity-fed into upward flowing combustion gases from a primary natural gas flame doped ...

  2. Biomass-powered Solid Oxide Fuel Cells : Experimental and Modeling Studies for System Integrations

    NARCIS (Netherlands)

    Liu, M.

    2013-01-01

    Biomass is a sustainable energy source which, through thermo-chemical processes of biomass gasification, is able to be converted from a solid biomass fuel into a gas mixture, known as syngas or biosyngas. A solid oxide fuel cell (SOFC) is a power generation device that directly converts the chemical

  3. Behavior of mixed-oxide fuel subjected to multiple thermal transients

    International Nuclear Information System (INIS)

    Fenske, G.R.; Neimark, L.A.; Poeppel, R.B.; Hofman, G.L.

    1985-01-01

    The microstructural behavior of irradiated mixed-oxide fuel subjected to multiple, mild thermal transients was investigated using direct electrical heating. The results demonstrate that significant intergranular porosity, accompanied by large-scale (>90%) release of the retained fission gas, developed as a result of the cyclic heating. Microstructural examination of the fuel indicated that thermal-shock-induced cracking of the fuel contributed significantly to the increased swelling and gas release. 29 refs., 12 figs

  4. Behavior of mixed-oxide fuel subjected to multiple thermal transients

    International Nuclear Information System (INIS)

    Fenske, G.R.; Hofman, G.L.; Neimark, L.A.; Poeppel, R.B.

    1983-11-01

    The microstructural behavior of irradiated mixed-oxide fuel subjected to multiple, mild thermal transients was investigated using direct electrical heating. The results demonstrate that significant intergranular porosity, accompanied by large-scale (>90%) release of the retained fission gas, developed as a result of the cyclic heating. Microstructural examination of the fuel indicated that thermal-shock-induced cracking of the fuel contributed significantly to the increased swelling and gas release

  5. Carbon-Nickel oxide nanocomposites: Preparation and charecterisation

    CSIR Research Space (South Africa)

    Tile, N

    2011-07-01

    Full Text Available Nanocomposite materials have wide range of applications in solar energy conversion. In this work, C-NiO nanocomposite coatings are prepared using sol-gel synthesis and deposited on aluminium substrates using a spin coater. The coatings are prepared...

  6. Mathematical modeling of oxygen transport in solid oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Svensson, Ann Mari

    1997-12-31

    This thesis develops mathematical models to describe the electrochemical performance of a solid oxide fuel cell cathode based on electrochemical kinetics and mass transfer. The individual effects of various coupled processes are investigated. A one-dimensional model is developed based on porous electrode theory. Two different mechanisms are investigated for the charge transfer reaction. One of these assumes that intermediately adsorbed oxygen atoms are reduced at the electrode/electrolyte interface, similar to the models proposed for metal electrodes. Simulated polarization curves exhibit limited currents due to depletion of oxygen adsorbates at high cathodic overvoltages. An empirical correlation is confirmed to exist between the limiting current an the oxygen partial pressure, however, a similar correlation often assumed to exist between the measured polarization resistance and the oxygen partial pressure could not be justified. For the other model, oxygen vacancies are assumed to be exchanged directly at the electrode/electrolyte interface. The electrochemical behaviour is improved by reducing the oxygen partial pressure, due to increased vacancy concentration of the electrode material. Simulated polarization curves exhibit Tafel-like slopes in the cathodic direction, which are due to polarization concentration, and not activation polarization in the conventional sense. Anodic limiting currents are predicted due to lack of available free sites for vacancy exchange at the cathode side. The thesis also presents a theoretical treatment of current and potential distributions in simple two-dimensional cell geometries, and a two-dimensional model for a porous electrode-electrolyte system for investigation of the effect of interfacial diffusion of adsorbates along the electrode/electrolyte interface. 172 refs., 60 figs., 11 tabs.

  7. Radiolytic Preparation of Electrocatalysts with Pt-Co and Pt-Sn Nanoparticles for a Proton Exchange Membrane Fuel Cell

    Directory of Open Access Journals (Sweden)

    Sang Kyum Kim

    2014-01-01

    Full Text Available Nanosized Pt-Sn/VC and Pt-Co/VC electrocatalysts were prepared by a one-step radiation-induced reduction (30 kGy process using distilled water as the solvent and Vulcan XC72 as the supporting material. While the Pt-Co/VC electrodes were compared with Pt/VC (40 wt%, HiSpec 4000, in terms of their electrocatalytic activity towards the oxidation of H2, the Pt-Co/VC electrodes were evaluated in terms of their activity towards the hydrogen oxidation reaction (HOR and compared with Pt/VC (40 wt%, HiSpec 4000, Pt-Co/VC, and Pt-Sn/VC in a single cell. Additionally, the prepared electrocatalyst samples (Pt-Co/VC and Pt-Sn/VC were characterized by transmission electron microscopy (TEM, scanning electron microscope (SEM, thermogravimetric analysis (TGA, X-ray diffraction (XRD, X-ray photoelectron spectroscopy (XPS, electrochemical surface area (ECSA, and fuel cell polarization performance.

  8. Laser induced densification of cerium gadolinium oxide: Application to single-chamber solid oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Mariño, Mariana [École Nationale Supérieure des Mines, SPIN-EMSE, CNRS: UMR 5307, LGF, F-42023 Saint-Étienne (France); Rieu, Mathilde, E-mail: rieu@emse.fr [École Nationale Supérieure des Mines, SPIN-EMSE, CNRS: UMR 5307, LGF, F-42023 Saint-Étienne (France); Viricelle, Jean-Paul [École Nationale Supérieure des Mines, SPIN-EMSE, CNRS: UMR 5307, LGF, F-42023 Saint-Étienne (France); Garrelie, Florence [Université Jean Monnet, Laboratoire Hubert Curien, CNRS: UMR 5516, 42000 Saint-Etienne (France)

    2016-06-30

    Graphical abstract: - Highlights: • CGO surface densifications were induced by UV and IR laser irradiations. • Grain growth or densified cracked surfaces were observed by SEM. • UV laser treatments allow a decrease of gas permeation through electrolyte layer. • Electrical conductivity of the electrolyte was modified by laser treatments. • Grain growth of electrolyte induced by UV laser improved cell performances. - Abstract: In single-chamber solid oxide fuel cells (SC-SOFC), anode and cathode are placed in a gas chamber where they are exposed to a fuel/air mixture. Similarly to conventional dual-chamber SOFC, the anode and the cathode are separated by an electrolyte. However, as in the SC-SOFC configuration the electrolyte does not play tightness role between compartments, this one can be a porous layer. Nevertheless, it is necessary to have a diffusion barrier to prevent the transportation of hydrogen produced locally at the anode to the cathode that reduces fuel cell performances. This study aims to obtain directly a diffusion barrier through the surface densification of the electrolyte Ce{sub 0.9}Gd{sub 0.1}O{sub 1.95} (CGO) by a laser treatment. KrF excimer laser and Yb fiber laser irradiations were used at different fluences and number of pulses to modify the density of the electrolyte coating. Microstructural characterizations confirmed the modifications on the surface of the electrolyte for appropriate experimental conditions showing either grain growth or densified but cracked surfaces. Gas permeation and electrical conductivities of the modified electrolyte were evaluated. Finally SC-SOFC performances were improved for the cells presenting grain growth at the electrolyte surface.

  9. Preparation of oxide glasses from metal alkoxides by sol-gel method

    Science.gov (United States)

    Kamiya, K.; Yoko, T.; Sakka, S.

    1987-01-01

    An investigation is carried out on the types of siloxane polymers produced in the course of the hydrolysis of silicon tetraethoxide, as well as the preparation of oxide glasses from metal alkoxides by the sol-gel method.

  10. Evaluation of the Optimum Composition of Low-Temperature Fuel Cell Electrocatalysts for Methanol Oxidation by Combinatorial Screening.

    Science.gov (United States)

    Antolini, Ermete

    2017-02-13

    Combinatorial chemistry and high-throughput screening represent an innovative and rapid tool to prepare and evaluate a large number of new materials, saving time and expense for research and development. Considering that the activity and selectivity of catalysts depend on complex kinetic phenomena, making their development largely empirical in practice, they are prime candidates for combinatorial discovery and optimization. This review presents an overview of recent results of combinatorial screening of low-temperature fuel cell electrocatalysts for methanol oxidation. Optimum catalyst compositions obtained by combinatorial screening were compared with those of bulk catalysts, and the effect of the library geometry on the screening of catalyst composition is highlighted.

  11. Behaviour of rock-like oxide fuels under reactivity-initiated accident conditions

    International Nuclear Information System (INIS)

    Kazuyuki, Kusagaya; Takehiko, Nakamura; Makio, Yoshinaga; Hiroshi, Akie; Toshiyuki, Yamashita; Hiroshi, Uetsuka

    2002-01-01

    Pulse irradiation tests of three types of un-irradiated rock-like oxide (ROX) fuel - yttria-stabilised zirconia (YSZ) single phase, YSZ and spinel (MgAl 2 O 4 ) homogeneous mixture and particle-dispersed YSZ/spinel - were conducted in the Nuclear Safety Research Reactor to investigate the fuel behaviour under reactivity-initiated accident conditions. The ROX fuels failed at fuel volumetric enthalpies above 10 GJ/m 3 , which was comparable to that of un-irradiated UO 2 fuel. The failure mode of the ROX fuels, however, was quite different from that of the UO 2 fuel. The ROX fuels failed with fuel pellet melting and a part of the molten fuel was released out to the surrounding coolant water. In spite of the release, no significant mechanical energy generation due to fuel/coolant thermal interaction was observed in the tested enthalpy range below∼12 GJ/m 3 . The YSZ type and homogenous YSZ/spinel type ROX fuels failed by cladding burst when their temperatures peaked, while the particle-dispersed YSZ/spinel type ROX fuel seemed to have failed by cladding local melting. (author)

  12. Shippingport LWBR (Th/U Oxide) Fuel Characteristics for Disposal Criticality Analysis

    International Nuclear Information System (INIS)

    Taylor, L. L.; Loo, H. H.

    1999-01-01

    Department of Energy (DOE)-owned spent nuclear fuels encompass many fuel types. In an effort to facilitate criticality analysis for these various fuel types, they were categorized into eight characteristic fuel groups with emphasis on fuel matrix composition. Out of each fuel group, a representative fuel type was chosen for analysis as a bounding case within that fuel group. Generally, burnup data, fissile enrichments, and total fuel and fissile mass govern the selection of the representative or candidate fuel within that group. The Shippingport Light Water Breeder Reactor (LWBR) fuels incorporate more of the conventional materials (zirconium cladding/heavy metal oxides) and fabrication details (rods and spacers) that make them comparable to a typical commercial fuel assembly. The LWBR seed/blanket configuration tested a light-water breeder concept with Th-232/U-233 binary fuel matrix. Reactor design used several assembly configurations at different locations within the same core . The seed assemblies contain the greatest fissile mass per (displaced) unit volume, but the blanket assemblies actually contain more fissile mass in a larger volume; the atom-densities are comparable

  13. Lipid oxidation in omega-3 emulsions prepared with milk proteins

    DEFF Research Database (Denmark)

    Horn, Anna Frisenfeldt; Nielsen, Nina Skall; Andersen, Ulf

    An increasing body of evidence supports the health beneficial effects of omega-3 polyunsaturated fatty acids. Therefore, incorporation of marine oils into foods has also gained an increasing interest. However, the highly unsaturated lipids present in marine oils are prone to lipid oxidation......, and their addition to foods is therefore limited by the development of unpleasant off-flavors. Hence, efficient strategies are necessary to protect the lipids and thereby make fish oil-enriched food products successful in the marketplace. In an attempt to increase the oxidative stability of fish oil-enriched food...... stable product. Thus, a better understanding of factors influencing lipid oxidation in delivery emulsions themselves is therefore needed to understand the differences observed between food systems. In oil-in-water emulsions, lipid oxidation is expected to be initiated at the oil-water interface...

  14. Development, preparation and characterization of uranium molybdenum alloys for dispersion fuel application

    International Nuclear Information System (INIS)

    Sinha, V.P.; Prasad, G.J.; Hegde, P.V.; Keswani, R.; Basak, C.B.; Pal, S.; Mishra, G.P.

    2009-01-01

    Most of the research and test reactors worldwide have undergone core conversion from high enriched uranium base fuel to low enriched uranium base fuel under the Reduced Enrichment for Research and Test Reactor (RERTR) program, which was launched in the late 1970s to reduce the risk of nuclear proliferation. To realize this goal, high density uranium compounds and γ-stabilized uranium alloy powder were identified. In Metallic Fuels Division of BARC, R and D efforts are on to develop these high density uranium base alloys. This paper describes the preparation flow sheet for different compositions of Uranium and molybdenum alloys by an innovative powder processing route with uranium and molybdenum metal powders as starting materials. The same composition of U-Mo alloys were also fabricated by conventional method i.e. ingot metallurgy route. The U-Mo alloys prepared by both the methods were then characterized by XRD for phase analysis. The photomicrographs of alloys with different compositions prepared by powder metallurgy and ingot metallurgy routes are also included in the paper. The paper also covers the comparison of properties of the alloys prepared by powder metallurgy and ingot metallurgy routes

  15. Development, preparation and characterization of uranium molybdenum alloys for dispersion fuel application

    Energy Technology Data Exchange (ETDEWEB)

    Sinha, V.P. [Metallic Fuels Division, Bhabha Atomic Research Centre, Mumbai 400085 (India)], E-mail: vedsinha@barc.gov.in; Prasad, G.J.; Hegde, P.V.; Keswani, R.; Basak, C.B.; Pal, S.; Mishra, G.P. [Metallic Fuels Division, Bhabha Atomic Research Centre, Mumbai 400085 (India)

    2009-04-03

    Most of the research and test reactors worldwide have undergone core conversion from high enriched uranium base fuel to low enriched uranium base fuel under the Reduced Enrichment for Research and Test Reactor (RERTR) program, which was launched in the late 1970s to reduce the risk of nuclear proliferation. To realize this goal, high density uranium compounds and {gamma}-stabilized uranium alloy powder were identified. In Metallic Fuels Division of BARC, R and D efforts are on to develop these high density uranium base alloys. This paper describes the preparation flow sheet for different compositions of Uranium and molybdenum alloys by an innovative powder processing route with uranium and molybdenum metal powders as starting materials. The same composition of U-Mo alloys were also fabricated by conventional method i.e. ingot metallurgy route. The U-Mo alloys prepared by both the methods were then characterized by XRD for phase analysis. The photomicrographs of alloys with different compositions prepared by powder metallurgy and ingot metallurgy routes are also included in the paper. The paper also covers the comparison of properties of the alloys prepared by powder metallurgy and ingot metallurgy routes.

  16. Properties of Copper Doped Neodymium Nickelate Oxide as Cathode Material for Solid Oxide Fuel Cells

    Directory of Open Access Journals (Sweden)

    Lee Kyoung-Jin

    2016-06-01

    Full Text Available Mixed ionic and electronic conducting K2NiF4-type oxide, Nd2Ni1-xCuxO4+δ (x=0~1 powders were synthesized by solid state reaction technique and solid oxide fuel cells consisting of a Nd2Ni1-xCuxO4+δ cathode, a Ni-YSZ anode and ScSZ as an electrolyte were fabricated. The effect of copper substitution for nickel on the electrical and electrochemical properties was examined. Small amount of copper doping (x=0.2 resulted in the increased electrical conductivity and decreased polarization resistance. It appears that this phenomenon was associated with the high mean valence of nickel and copper and the resulting excess oxygen (δ. It was found that power densities of the cell with the Nd2Ni1-xCuxO4+δ (x=0.1 and 0.2 cathode were higher than that of the cell with the Nd2NiO4+δ cathode.

  17. NiO-YSZ cermets supported low temperature solid oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Xinge; Robertson, Mark; Deces-Petit, Cyrille; Xie, Yongsong; Hui, Rob; Yick, Sing; Styles, Edward; Roller, Justin; Kesler, Olivera; Maric, Radenka; Ghosh, Dave [Institute for Fuel Cell Innovation, National Research Council Canada, 3250 East Mall, Vancouver, BC (Canada V6T 1W5)

    2006-10-20

    Solid oxide fuel cells with thin electrolyte of two types, Sm{sub 0.2}Ce{sub 0.8}O{sub 1.9} (SDC) (15{mu}m) single-layer and 8mol% Yttria stabilized zirconia (YSZ) (5{mu}m)+SDC (15{mu}m) bi-layer on NiO-YSZ cermet substrates were fabricated by screen printing and co-firing. A Sm{sub 0.5}Sr{sub 0.5}CoO{sub 3} cathode was printed, and in situ sintered during a cell performance test. The SDC single-layer electrolyte cell showed high electrochemical performance at low temperature, with a 1180mWcm{sup -2} peak power density at 650{sup o}C. The YSZ+SDC bi-layer electrolyte cell generated 340mWcm{sup -2} peak power density at 650{sup o}C, and showed good performance at 700-800{sup o}C, with an open circuit voltage close to theoretical value. Many high Zr-content micro-islands were found on the SDC electrolyte surface prior to the cathode preparation. The influence of co-firing temperature and thin film preparation methods on the Zr-islands' appearance was investigated. (author)

  18. Models for the Configuration and Integrity of Partially Oxidized Fuel Rod Cladding at High Temperatures

    International Nuclear Information System (INIS)

    Siefken, L.J.

    1999-01-01

    Models were designed to resolve deficiencies in the SCDAP/RELAP5/MOD3.2 calculations of the configuration and integrity of hot, partially oxidized cladding. These models are expected to improve the calculations of several important aspects of fuel rod behavior. First, an improved mapping was established from a compilation of PIE results from severe fuel damage tests of the configuration of melted metallic cladding that is retained by an oxide layer. The improved mapping accounts for the relocation of melted cladding in the circumferential direction. Then, rules based on PIE results were established for calculating the effect of cladding that has relocated from above on the oxidation and integrity of the lower intact cladding upon which it solidifies. Next, three different methods were identified for calculating the extent of dissolution of the oxidic part of the cladding due to its contact with the metallic part. The extent of dissolution effects the stress and thus the integrity of the oxidic part of the cladding. Then, an empirical equation was presented for calculating the stress in the oxidic part of the cladding and evaluating its integrity based on this calculated stress. This empirical equation replaces the current criterion for loss of integrity which is based on temperature and extent of oxidation. Finally, a new rule based on theoretical and experimental results was established for identifying the regions of a fuel rod with oxidation of both the inside and outside surfaces of the cladding. The implementation of these models is expected to eliminate the tendency of the SCDAP/RELAP5 code to overpredict the extent of oxidation of the upper part of fuel rods and to underpredict the extent of oxidation of the lower part of fuel rods and the part with a high concentration of relocated material. This report is a revision and reissue of the report entitled, Improvements in Modeling of Cladding Oxidation and Meltdown

  19. Pressurized solid oxide fuel cell integral air accumular containment

    Science.gov (United States)

    Gillett, James E.; Zafred, Paolo R.; Basel, Richard A.

    2004-02-10

    A fuel cell generator apparatus contains at least one fuel cell subassembly module in a module housing, where the housing is surrounded by a pressure vessel such that there is an air accumulator space, where the apparatus is associated with an air compressor of a turbine/generator/air compressor system, where pressurized air from the compressor passes into the space and occupies the space and then flows to the fuel cells in the subassembly module, where the air accumulation space provides an accumulator to control any unreacted fuel gas that might flow from the module.

  20. Safety aspects related to burnup increase and mixed oxide fuel

    International Nuclear Information System (INIS)

    Thomas, W.

    1992-01-01

    The dominant factor presently limiting the fuel burnup is the response of the cladding hulls. To maintain the excellent record of very low fuel failure rates for increased burnups further technical development is underway and necessary. In the nuclear fuel cycle increased burnups lead to a remarkable reduction of spent fuel arisings and corresponding economic savings. Thermal recycling of plutonium presently provides an opportunity to reduce the rising accumulation of plutunium in a situation where there is no demand for this fissile material in Fast Breeder Reactors. (orig.) [de

  1. Development status of metallic, dispersion and non-oxide advanced and alternative fuels for power and research reactors

    International Nuclear Information System (INIS)

    2003-09-01

    eighties until the present days. The aspects of HTGR fuels, as well as partitioning and transmutation (P and T) of minor actinides and relative specific fuels have not been addressed. The International Atomic Energy Agency's (IAEA) Division of Nuclear Fuel Cycle and Waste Technology has been closely involved for many years in the above mentioned activities in the framework of the Advisory Group on Advanced Fuel Technology and Performance (fast reactor fuels) and Technical Working Group on Water Reactor Fuel Performance and Technology (thermal power reactor fuels). Apart from the progress made during the last decade, this report summarizes technological approaches, out-of-pile and in-pile properties of many types of advanced non-oxide fuels. It is expected that the report will provide IAEA Member States and their nuclear engineers with useful information and will preserve knowledge in the area for future developments. The review was prepared by a group of experts in the field from Germany, India and the Russian Federation and supported by information from specialists in Japan, Switzerland and the IAEA engaged in non-oxide fuel developments and related subjects

  2. Cathode and electrolyte materials for solid oxide fuel cells and ion transport membranes

    Science.gov (United States)

    Jacobson, Allan J; Wang, Shuangyan; Kim, Gun Tae

    2014-01-28

    Novel cathode, electrolyte and oxygen separation materials are disclosed that operate at intermediate temperatures for use in solid oxide fuel cells and ion transport membranes based on oxides with perovskite related structures and an ordered arrangement of A site cations. The materials have significantly faster oxygen kinetics than in corresponding disordered perovskites.

  3. Use of a Burkholderia cenocepacia ABTS Oxidizer in a Microbial Fuel Cell

    Science.gov (United States)

    Microbial fuel cells (MFCs) often use biological processes to generate electrons from organic material contained in the anode chamber and abiotic processes employing atmospheric oxygen as the oxidant in the cathode chamber. This study investigated the accumulation of an oxidant in bacterial cultures...

  4. Uranium oxide fuel cycle analysis in VVER-1000 with VISTA simulation code

    Science.gov (United States)

    Mirekhtiary, Seyedeh Fatemeh; Abbasi, Akbar

    2018-02-01

    The VVER-1000 Nuclear power plant generates about 20-25 tons of spent fuel per year. In this research, the fuel transmutation of Uranium Oxide (UOX) fuel was calculated by using of nuclear fuel cycle simulation system (VISTA) code. In this simulation, we evaluated the back end components fuel cycle. The back end component calculations are Spent Fuel (SF), Actinide Inventory (AI) and Fission Product (FP) radioisotopes. The SF, AI and FP values were obtained 23.792178 ton/y, 22.811139 ton/y, 0.981039 ton/y, respectively. The obtained value of spent fuel, major actinide, and minor actinide and fission products were 23.8 ton/year, 22.795 ton/year, 0.024 ton/year and 0.981 ton/year, respectively.

  5. Potential electrode materials for symmetrical Solid Oxide Fuel Cells

    Directory of Open Access Journals (Sweden)

    Ruiz Morales, J. C.

    2008-08-01

    Full Text Available Chromites, titanates and Pt-YSZ-CeO2 cermets have been investigated as potential electrode materials for an alternative concept of Solid Oxide Fuel Cell (SOFC, the symmetrical SOFCs (SFC. In this configuration, the same electrode material is used simultaneously as anode and cathode. Interconnector materials, such as chromites, could be considered as potential SFC electrodes, at least under pure hydrogen-fed at relatively high temperatures, as they do not exhibit significant catalytic activity towards hydrocarbon oxidation. This may be overcome by partially substituting Cr in the perovskite B-sites by other transition metal cations such as Mn. La0.75Sr0.25Cr0.5Mn0.5O3-δ (LSCM is a good candidate for such SFCs, rendering fuel cell performances in excess of 500 and 300mW/cm2 using pure H2 and CH4 as fuel, at 950 oC. Similarly, typical n-type electronic conductors traditionally regarded as anode materials, such as strontium titanates, may also operate under oxidising conditions as cathodes by substituting some Ti content for Fe to introduce p-type conductivity. Preliminary electrochemical experiments on La4Sr8Ti12-xFexO38-δ-based SFCs show that they perform reasonably well under humidified H2, at high temperatures. A third group of materials is the support material of any typical cermet anode, i.e. YSZ, CeO2 plus a current collector. It has been found that this combination could be optimised to operate as SFC electrodes, rendering performances of 400mW/cm2 under humidified pure H2 at 950oC.

    Cromitas, titanatos y cermets de Pt-YSZ-CeO2 han sido investigados como potenciales materiales de electrodo para un concepto alternativo de Pilas de Combustible de Óxidos Sólidos (SOFC, las pilas SOFC simétricas (SFC. En

  6. Study of tape casting of Yttria stabilized zirconia for apply in solid oxide fuel cell

    International Nuclear Information System (INIS)

    Santana, Leonardo de Paulo

    2008-01-01

    The hydrogen economy has been risen as new option for supply the growing global demand for energy. A fuel cell is an electrochemical device able to use hydrogen as a energy source. Carbon dioxide (CO 2 ) emission is very low so it is ecologically friendly, once energy is produced by a reaction of hydrogen and oxygen. The production of energy from hydrogen fuelled devices can be done even in small unities and in a distributed way. It can bring energy for isolated communities, where traditional energy distribution systems can not be reached. A fuel cell is composed essentially of 3 components: anode, cathode and the electrolyte. In present days, there are many materials proposed for use as electrolyte in fuel cells. Among then, Yttria stabilized zirconia (YSZ) is the most studied and effectively used in solid oxide fuel cell. Tape casting technology is a cheap, simple and efficient way to cast ceramics slurries in laminates thick enough to be used as components for fuel cells. Considering theses aspects, in this work, ceramic thin film forming was studied using tape casting technology with raw materials prepared from Brazilian zircon ores. It is described in literature that ceramic slurries are generally made from powders with low surface area (often between 0,5 to 10m 2 /g), and the powders used in this study had larger surface area (often between 40 to 80m 2 /g). The use of zeta potential is indicated to study the stability of a suspension of ceramic powders. However, for suspensions with large concentration of solid, it is also necessary to determine the flow curve, because in these conditions, the double electric layer formed during the stabilization of suspensions can be compressed. In the rheological properties study, calcined ceramic powders were classified using a set of ABNT series screens and separated and retained by the de mesh 60 screen. Flow curve of suspension was determined in aqueous suspensions of these powders. For tape casting processing, a binder

  7. Preparation and proton conductivity of composite membranes based on sulfonated poly(phenylene oxide) and benzimidazole

    International Nuclear Information System (INIS)

    Liu Yifeng; Yu Qinchun; Wu Yihua

    2007-01-01

    The Bronsted acid-base composite membrane was prepared by entrapping benzimidazole in sulfonated poly(phenylene oxide) by tuning the doping ratios. Their thermal stability, dynamic mechanical properties and proton conductivity were investigated under the conditions for intermediate temperature proton exchange membrane (PEM) fuel cell operation. In addition, investigation of activation energies of the SPPO-xBnIm at different relative humidity was also performed. TG-DTA curves reveal these SPPO-xBnIm composite materials had the high thermal stability. The proton conductivity of SPPO-xBnIm composite material increased with the temperature, and the highest proton conductivity of SPPO-xBnIm composite materials was found to be 8.93 x 10 -4 S/cm at 200 deg. C under 35% relative humidity (RH) with a 'doping rate' where x = 2. The SPPO-2BnIm composite membrane show higher storage moduli and loss moduli than SPPO. Tests in a hydrogen-air laboratory cell demonstrate the applicability of SPPO-2BnIm in PEMFCs at intermediate temperature under non-humidified conditions

  8. Oxidative dissolution of ADOPT compared to standard UO{sub 2} fuel

    Energy Technology Data Exchange (ETDEWEB)

    Nilsson, Kristina [School of Chemical Science and Engineering, Applied Physical Chemistry, KTH Royal Institute of Technology, SE-100 44 Stockholm (Sweden); Roth, Olivia [Studsvik Nuclear AB, SE-611 82 Nyköping (Sweden); Jonsson, Mats, E-mail: matsj@kth.se [School of Chemical Science and Engineering, Applied Physical Chemistry, KTH Royal Institute of Technology, SE-100 44 Stockholm (Sweden)

    2017-05-15

    In this work we have studied oxidative dissolution of pure UO{sub 2} and ADOPT (UO{sub 2} doped with Al and Cr) pellets using H{sub 2}O{sub 2} and gammaradiolysis to induce the process. There is a small but significant difference in the oxidative dissolution rate of UO{sub 2} and ADOPT pellets, respectively. However, the difference in oxidative dissolution yield is insignificant. Leaching experiments were also performed on in-reactor irradiated ADOPT and UO{sub 2} pellets under oxidizing conditions. The results indicate that the U(VI) release is slightly slower from the ADOPT pellet compared to the UO{sub 2.} This could be attributed to differences in exposed surface area. However, fission products with low UO{sub 2} solubility display a higher relative release from ADOPT fuel compared to standard UO{sub 2}-fuel. This is attributed to a lower matrix solubility imposed by the dopants in ADOPT fuel. The release of Cs is higher from UO{sub 2} which is attributed to the larger grain size of ADOPT. - Highlights: •Oxidative dissolution of ADOPT fuel is compared to standard UO{sub 2} fuel. •Only marginal differences are observed. •The main difference observed is in the relative release rate of fission products. •Differences are claimed to be attributed to a lower matrix solubility imposed by the dopants in ADOPT fuel.

  9. Controlling of morphology and electrocatalytic properties of cobalt oxide nanostructures prepared by potentiodynamic deposition method

    Energy Technology Data Exchange (ETDEWEB)

    Hallaj, Rahman [Department of Chemistry, University of Kurdistan, P.O. Box 416, Sanandaj (Iran, Islamic Republic of); Akhtari, Keivan [Department of Chemistry, University of Kurdistan, P.O. Box 416, Sanandaj (Iran, Islamic Republic of); Research Center for Nanotechnology, University of Kurdistan, P.O.Box 416, Sanandaj (Iran, Islamic Republic of); Salimi, Abdollah, E-mail: absalimi@uok.ac.ir [Department of Chemistry, University of Kurdistan, P.O. Box 416, Sanandaj (Iran, Islamic Republic of); Research Center for Nanotechnology, University of Kurdistan, P.O.Box 416, Sanandaj (Iran, Islamic Republic of); Soltanian, Saied [Department of Physics, University of Kurdistan, P.O. Box 416, Sanandaj (Iran, Islamic Republic of)

    2013-07-01

    Electrodeposited cobalt oxide nanostructures were prepared by Repetitive Triangular Potential Scans (RTPS) as a simple, remarkably fast and scalable potentiodynamic method. Electrochemical deposition of cobalt oxide nanostructures onto GC electrode was performed from aqueous Co(NO{sub 3}){sub 2}, (pH 6) solution using cyclic voltammetry method. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) were used to characterize the morphology of fabricated nanostructures. The evaluation of electrochemical properties of deposited films was performed using cyclic voltametry (CV) and impedance spectroscopy (IS) techniques. The analysis of the experimental data clearly showed that the variations of potential scanning ranges during deposition process have drastic effects on the geometry, chemical structure and particle size of cobalt oxide nanoparticles. In addition, the electrochemical and electrocatalytic properties of prepared nanostructures can be controlled through applying different potential windows in electrodeposition process. The imaging and voltammetric studies suggested to the existence of at least three different shapes of cobalt-oxide nanostructures in various potential windows applied for electrodeposition. With enlarging the applied potential window, the spherical-like cobalt oxide nanoparticles with particles sizes about 30–50 nm changed to the grain-like structures (30 nm × 80 nm) and then to the worm-like cobalt oxide nanostructures with 30 nm diameter and 200–400 nm in length. Furthermore, the roughness of the prepared nanostructures increased with increasing positive potential window. The GC electrodes modified with cobalt oxide nanostructures shows excellent electrocatalytic activity toward H{sub 2}O{sub 2} and As (III) oxidation. The electrocatalytic activity of cobalt oxide nanostructures prepared at more positive potential window toward hydrogen peroxide oxidation was increased, while for As(III) oxidation the electrocatalytic

  10. Controlling of morphology and electrocatalytic properties of cobalt oxide nanostructures prepared by potentiodynamic deposition method

    International Nuclear Information System (INIS)

    Hallaj, Rahman; Akhtari, Keivan; Salimi, Abdollah; Soltanian, Saied

    2013-01-01

    Electrodeposited cobalt oxide nanostructures were prepared by Repetitive Triangular Potential Scans (RTPS) as a simple, remarkably fast and scalable potentiodynamic method. Electrochemical deposition of cobalt oxide nanostructures onto GC electrode was performed from aqueous Co(NO 3 ) 2 , (pH 6) solution using cyclic voltammetry method. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) were used to characterize the morphology of fabricated nanostructures. The evaluation of electrochemical properties of deposited films was performed using cyclic voltametry (CV) and impedance spectroscopy (IS) techniques. The analysis of the experimental data clearly showed that the variations of potential scanning ranges during deposition process have drastic effects on the geometry, chemical structure and particle size of cobalt oxide nanoparticles. In addition, the electrochemical and electrocatalytic properties of prepared nanostructures can be controlled through applying different potential windows in electrodeposition process. The imaging and voltammetric studies suggested to the existence of at least three different shapes of cobalt-oxide nanostructures in various potential windows applied for electrodeposition. With enlarging the applied potential window, the spherical-like cobalt oxide nanoparticles with particles sizes about 30–50 nm changed to the grain-like structures (30 nm × 80 nm) and then to the worm-like cobalt oxide nanostructures with 30 nm diameter and 200–400 nm in length. Furthermore, the roughness of the prepared nanostructures increased with increasing positive potential window. The GC electrodes modified with cobalt oxide nanostructures shows excellent electrocatalytic activity toward H 2 O 2 and As (III) oxidation. The electrocatalytic activity of cobalt oxide nanostructures prepared at more positive potential window toward hydrogen peroxide oxidation was increased, while for As(III) oxidation the electrocatalytic activity decreased

  11. Error Analysis of Ceramographic Sample Preparation for Coating Thickness Measurement of Coated Fuel Particles

    International Nuclear Information System (INIS)

    Liu Xiaoxue; Li Ziqiang; Zhao Hongsheng; Zhang Kaihong; Tang Chunhe

    2014-01-01

    The thicknesses of four coatings of HTR coated fuel particle are very important parameters. It is indispensable to control the thickness of four coatings of coated fuel particles for the safety of HTR. A measurement method, ceramographic sample-microanalysis method, to analyze the thickness of coatings was developed. During the process of ceramographic sample-microanalysis, there are two main errors, including ceramographic sample preparation error and thickness measurement error. With the development of microscopic techniques, thickness measurement error can be easily controlled to meet the design requirements. While, due to the coated particles are spherical particles of different diameters ranged from 850 to 1000μm, the sample preparation process will introduce an error. And this error is different from one sample to another. It’s also different from one particle to another in the same sample. In this article, the error of the ceramographic sample preparation was calculated and analyzed. Results show that the error introduced by sample preparation is minor. The minor error of sample preparation guarantees the high accuracy of the mentioned method, which indicates this method is a proper method to measure the thickness of four coatings of coated particles. (author)

  12. Export control guide: Spent nuclear fuel reprocessing and preparation of plutonium metal

    International Nuclear Information System (INIS)

    1993-10-01

    The international Treaty on the Non-Proliferation of Nuclear Weapons, also referred to as the Non-Proliferation Treaty (NPT), states in Article III, paragraph 2(b) that open-quotes Each State Party to the Treaty undertakes not to provide . . . equipment or material especially designed or prepared for the processing, use or production of special fissionable material to any non-nuclear-weapon State for peaceful purposes, unless the source or special fissionable material shall be subject to the safeguards required by this Article.close quotes This guide was prepared to assist export control officials in the interpretation, understanding, and implementation of export laws and controls relating to the international Trigger List for irradiated nuclear fuel reprocessing equipment, components, and materials. The guide also contains information related to the production of plutonium metal. Reprocessing and its place in the nuclear fuel cycle are described briefly; the standard procedure to prepare metallic plutonium is discussed; steps used to prepare Trigger List controls are cited; descriptions of controlled items are given; and special materials of construction are noted. This is followed by a comprehensive description of especially designed or prepared equipment, materials, and components of reprocessing and plutonium metal processes and includes photographs and/or pictorial representations. The nomenclature of the Trigger List has been retained in the numbered sections of this document for clarity

  13. A recommendation for the thermal conductivity of oxide fuels

    International Nuclear Information System (INIS)

    Kang, K. H.; Ryu, H. J.; Song, K. C.; Yang, M. S.; Na, S. H.; Lee, Y. W.; Moon, H. S.; Kim, H. S.

    2004-01-01

    The thermal conductivity of nuclear fuel is one of the most important properties because it affects the fuel operating temperature. Therefore, it influences almost all the important processes occurred in nuclear fuel during irradiation, such as gas release, swelling and grain growth. The model of the thermal conductivity of nuclear fuel should be used in the codes to evaluate the performance of it analytically and be required in the nuclear fuel research and development. The thermal conductivity, k, of UO 2 depends on the deviation from stoichiometry, x, the burnup, b, and the fractional porosity, p, as well as the temperature, T: k = k(x, b, p, T), (1) Changes in thermal conductivity occur during irradiation because of fission-gas bubble formation, pores, cracks, fission product build-up and possible changes in the oxygen to uranium ratio (O/U). The dependence on temperature and porosity has been well studied and incorporated in computer codes used for the in-pile fuel behavior analysis. There are several studies on the effect of impurity on the thermal conductivity of UO 2 . In this paper, the variables affected on the thermal conductivity were studied. The available data of the thermal conductivity of UO 2 , UO 2+x , (U, Pu)O 2 , (U, Pu)O 2 and simulated fuel for irradiation fuel were reviewed and analyzed. The best models were recommended

  14. Waste management analysis for the nuclear fuel cycle. II. Recycle preparation for wastewater streams

    International Nuclear Information System (INIS)

    Smith, C.M.; Navratil, J.D.; Plock, C.E.

    1979-01-01

    Recycle preparation methods were evaluated for secondary aqueous waste streams likely to be produced during reactor fuel fabrication and reprocessing. Adsorption, reverse osmosis, and ozonization methods were evaluated on a laboratory scale for their application to the treatment of wastewater. Activated carbon, macroreticular resins, and polyurethanes were tested to determine their relative capabilities for removing detergents and corrosive anions from wastewater. Conceptual flow sheets were constructed for purifying wastewater by reverse osmosis. In addition, the application of ozonization techniques for water recycle preparation was examined briefly

  15. Steam and partial oxidation reforming options for hydrogen production from fossil fuels for PEM fuel cells

    OpenAIRE

    Yousri M.A. Welaya; Mohamed M. El Gohary; Nader R. Ammar

    2012-01-01

    Proton exchange membrane fuel cell (PEM) generates electrical power from air and from hydrogen or hydrogen rich gas mixtures. Therefore, there is an increasing interest in converting current hydrocarbon based marine fuels such as natural gas, gasoline, and diesel into hydrogen rich gases acceptable to the PEM fuel cells on board ships. Using chemical flow sheeting software, the total system efficiency has been calculated. Natural gas appears to be the best fuel for hydrogen rich gas productio...

  16. A Phase Transfer Catalyzed Permanganate Oxidation: Preparation of Vanillin from Isoeugenol Acetate.

    Science.gov (United States)

    Lampman, Gary M.; Sharpe, Steven D.

    1983-01-01

    Background information, laboratory procedures, and results are provided for the preparation of vanillin from isoeugenol acetate. Reaction scheme used to prepare the vanillin and a table indicating the different oxidation experiments carried out on isoeugenol or isoeugenol acetate are also provided. (JN)

  17. Local charge transport properties of hydrazine reduced monolayer graphene oxide sheets prepared under pressure condition

    DEFF Research Database (Denmark)

    Ryuzaki, Sou; Meyer, Jakob Abild Stengaard; Petersen, Søren Vermehren

    2014-01-01

    Charge transport properties of chemically reduced graphene oxide (RGO) sheets prepared by treatment with hydrazine were examined using conductive atomic force microscopy. The current-voltage (I-V) characteristics of monolayer RGO sheets prepared under atmospheric pressure followed an exponentially...

  18. Preparation and analysis of new proton conducting membranes for fuel cells

    DEFF Research Database (Denmark)

    Søgaard, Susanne Roslev; Huan, Qian; Lund, Peter Brilner

    2007-01-01

    A range of potential new fuel cell membranes were prepared by inserting zirconium phosphate (ZrP) into divinylbenzene (DVB) crosslinked, sulfonated, polystyrene grafted poly(ethylene-alt-tetrafluoroethylene) and poly(vinyl difluoride) membranes using an ion exchange procedure. In short, the prefo......A range of potential new fuel cell membranes were prepared by inserting zirconium phosphate (ZrP) into divinylbenzene (DVB) crosslinked, sulfonated, polystyrene grafted poly(ethylene-alt-tetrafluoroethylene) and poly(vinyl difluoride) membranes using an ion exchange procedure. In short....... Additional zirconium phosphate treatment resulted in composite ETFE samples containing up to 15 wt.% ZrP and composite PVdF samples containing up to 27 wt.%. TG analyses of the ETFE-g-PSSA and PVdF-g-PSSA composite membranes indicated no significant changes of the thermal stability in comparison...

  19. Assessment of the Dry Processed Oxide Fuel in Liquid Metal Fast Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Roh, Gyu Hong; Choi, Hang Bok

    2005-09-15

    The neutronic feasibility of the dry process oxide fuel was assessed for the sodium-cooled and lead-cooled fast reactors (SFR and LFR, respectively), which were recommended as Generation-IV (Gen-IV) reactor systems by the Gen-IV international forum. The reactor analysis was performed for the equilibrium fuel cycle of two core configurations: Hybrid BN-600 benchmark core with an enlarged lattice pitch and a modified BN-600 core. The dry process technology assumed in this study is the molten-salt process, which was developed by Russian scientists for recycling oxide fuels. The core calculation was performed by the REBUS-3 code and the reactor characteristics such as the transuranic (TRU) enrichment, breeding ratio, peak linear power, burnup reactivity swing, etc. were calculated for the equilibrium core under a fixed fuel management scheme. The results showed that a fissile self-sustainable breakeven core was achievable without blanket fuels when the fuel volume fraction was {approx}50% and most of the fission products were removed. If the design criteria used in this study is proved to be acceptable through a detailed physics design and thermal hydraulic analysis in the future, it is practically possible to construct an equilibrium fuel cycle of the SFR and LFR systems based on the oxide fuel by utilizing the dry process technology.

  20. Assessment of the Dry Processed Oxide Fuel in Liquid Metal Fast Reactors

    International Nuclear Information System (INIS)

    Roh, Gyu Hong; Choi, Hang Bok

    2005-09-01

    The neutronic feasibility of the dry process oxide fuel was assessed for the sodium-cooled and lead-cooled fast reactors (SFR and LFR, respectively), which were recommended as Generation-IV (Gen-IV) reactor systems by the Gen-IV international forum. The reactor analysis was performed for the equilibrium fuel cycle of two core configurations: Hybrid BN-600 benchmark core with an enlarged lattice pitch and a modified BN-600 core. The dry process technology assumed in this study is the molten-salt process, which was developed by Russian scientists for recycling oxide fuels. The core calculation was performed by the REBUS-3 code and the reactor characteristics such as the transuranic (TRU) enrichment, breeding ratio, peak linear power, burnup reactivity swing, etc. were calculated for the equilibrium core under a fixed fuel management scheme. The results showed that a fissile self-sustainable breakeven core was achievable without blanket fuels when the fuel volume fraction was ∼50% and most of the fission products were removed. If the design criteria used in this study is proved to be acceptable through a detailed physics design and thermal hydraulic analysis in the future, it is practically possible to construct an equilibrium fuel cycle of the SFR and LFR systems based on the oxide fuel by utilizing the dry process technology